Title of the Invention:

Apparatus for Recovering Abrasives, Apparatus for Blasting process Comprising the Apparatus for Recovering Abrasives and Method of Blasting process

Field of Technology

[0001]

This invention is directed to an apparatus for recovering abrasives, an apparatus for blasting process comprising the apparatus for recovering abrasives and also to a method of blasting process to efficiently recover the abrasives that are sprayed against the workpiece in the blasting process.

Background Technology

[0002]

Conventionally the technology of blasting process has been used in surface treatment such as the process removing burrs, roughening the surfaces of works, the process moving of flow marks of casting, refining in etching, etc. For the apparatus for blasting process that is generally used, the abrasives that are used in blasting process of the workpiece are recovered. Then the abrasives are separated from the abrasives that are non-reusable and the dust that is produced from the workpiece in blasting process and are reused. For example, Patent Document 1 discloses an apparatus for blasting process that comprises a section for recovery in the shape of a funnel formed under a chamber for blasting process where the workpiece is treated by blasting process, such that it can recover by suctioning the abrasives that fall into the section for recovery and then separates them by a cyclone.

Patent Document

[0003]

Patent Document 1 : Publication of the Japanese patent application. Publication No. H09-323263 Summary of the Invention

Problem to be solved by the invention

[0004]

However, the apparatus for blasting process of Patent Document 1 could not efficiently recover the abrasives, because they were sprayed all over a chamber of a vast capacity and adhered to the walls of the chamber and a transporting path. Particularly if the abrasives were fine particles that had diameters less than a few micrometers, it was more difficult to recover them because they were more likely to adhere to the walls of the chamber and the transporting path. Also, the separating apparatus and recovery path were to have larger sizes because the separating apparatus that produced a suctioning force was required to have a higher level of suctioning force (negative suctioning pressure and suctioning volume) so as to have the abrasives in the chamber of a vast capacity suctioned by the negative suctioning pressure of the separating apparatus.

[0005]

In view of these problems, the purpose of the present invention is to provide

an apparatus for recovering abrasives, an apparatus for blasting process comprising the apparatus for recovering abrasives and a method of blasting process, wherein the abrasives can be efficiently recovered and wherein the size of the apparatus for blasting process can be made smaller by minimizing the apparatus such as a separating apparatus that produces a suctioning force so as to recover the abrasives.

Means to Solve Problem

[0006]

To achieve the above purpose, as stated in claim 1, the present invention uses technological means wherein an apparatus for recovering abrasives attached to the spray nozzle for the blasting process suctions and recovers the abrasives that are sprayed from the spray nozzle for the blasting process against the workpiece, and also the dust that is produced from the blasting process. The apparatus for recovering abrasives comprises a covering for preventing scattering formed in the shape of a box that covers the mouth of the spray nozzle and that has an opening, the covering for preventing the scattering that prevents scattering of the abrasives and the dust, and that is formed to have a gap between the end part of the opening and the surface for treatment of the workpiece so as to allow the outside air that is suctioned to enter, and also comprising a suctioning apparatus that suctions and exhausts, using the air suctioned through the gap as a transport means, through a suctioning member attached to the covering for preventing scattering, the abrasives and the dust that are within the covering for preventing the scattering.

[0007]

According to the invention of claim 1, the apparatus for recovering abrasives can efficiently recover the abrasives and the dust because while it prevents the scattering of the abrasives and the dust by means of the covering for preventing scattering, it needs to suction, by means of the suctioning apparatus, only a small volume inside the covering for preventing scattering, wherein the suctioning apparatus for recovering abrasives, by a suctioning member attached to the covering for preventing scattering, suctions and exhausts at the position close to the workpiece, the abrasives and the dust, using as a transport means the outside air that is suctioned through the gap disposed between the end part of the opening of the covering for preventing scattering and the surface of the workpiece. Also, the apparatus for recovering abrasives of the present invention can prevent the abrasives and the dust from adhering to the transport mechanism of the workpiece. So, the workpiece is not damaged during transport. Further, the workpiece is not damaged during transport if the nozzle or the workpiece is moved during the blasting process. This is because the gap through which the outside air is suctioned is provided between the end part of the opening and the surface for treatment of the workpiece.

[0008]

According to the invention of claim 2, the present invention uses technological means wherein the apparatus for recovering abrasives comprises the suctioning member attached to the upper end part of the covering for preventing scattering and also it comprises a supplementary suctioning member attached to the side of the covering for preventing scattering, on which side the suctioning member is attached.

[0009]

According to the invention of claim 2, the abrasives are efficiently recovered because the air stream flowing toward the suctioning member within the covering for preventing scattering is produced by the supplementary suctioning member attached to the side of the covering for preventing scattering. The upper end part means the portion of the upper part (ceiling-part) of the covering for preventing scattering, which portion is closer to the outer end (toward the periphery) relative to the center.

[0010]

According to the invention of claim 3, the present invention uses technological means wherein the apparatus for recovering abrasives has a guide member that is disposed close to the end part of the opening of and at the inner side of the covering for preventing scattering so as to introduce the outside air through the gap and that is formed as a surface extending toward the end part of the opening from the inner side of the covering for preventing scattering toward its outer side.

[0011]

According to the invention of claim 3, because the apparatus for recovering abrasives has a guide member that is disposed close to the end part of the opening of and at the inner side of the covering for preventing scattering, and that leads the outside air through the gap, the outside air can be smoothly introduced into the inside of the covering for preventing scattering through the gap formed between the end part of the opening and the surface for treatment of the workpiece. In this way no area where a peeling-off vortex flow is likely to occur at the position close to the end part of the opening of the covering for preventing scattering is produced. So, the increase of the resistance (loss of pressure) due to the flow of the outside air that is suctioned through the gap and the retention of the abrasives and the dust are prevented. Thus the abrasives and the dust can be efficiently suctioned and removed.

[0012]

According to the invention of claim 4, the present invention uses technological means wherein the apparatus for recovering abrasives has a spray nozzle that has a mouth for blasting process formed in the shape of a rectangle.

[0013]

As stated in claim 4, because the spray nozzle for blasting process, of which the mouth is formed in the shape of a rectangle, can have a greater width for treatment, it can treat a greater area with improved efficiency. However, as this kind of spray nozzle used a larger amount of abrasives, there was a problem in that not enough abrasives could be recovered. But the apparatus for recovering abrasives of the present invention can efficiently suction and recover the abrasives and the dust. So, it can be suitably used even if this kind of spray nozzle for the blasting process is used.

[0014]

According to the invention of claim 5, the present invention uses technological means wherein the apparatus for recovering abrasives has a spray nozzle for blasting process wherein the gravitational spraying method is applied.

[0015]

According to the invention of claim 5, because the apparatus for recovering abrasives uses a spray nozzle of the gravitational spraying method, wherein the particles are supplied by means of a negative pressure generated by the pressurized air that is provided inside the nozzle, it does not require a large auxiliary apparatus, such as a pressurizing tank that is used in the method of direct spraying where the abrasives are first supplied to the pressurized tank and then supplied to the spray nozzle for blasting process by pressurizing the pressurized tank and sprayed. Thus the size of an apparatus for blasting process can be minimized.

[0016]

According to the invention of claim 6, the present invention uses technological means wherein the apparatus for recovering abrasives has a spray nozzle for the blasting process disposed in an inclined position against the surface for treatment of the workpiece, wherein the suctioning member is installed toward the position of the surface for treatment of the workpiece and in the direction opposite to the inclined position of the nozzle.

[0017] As stated in claim 6, because the apparatus for recovering abrasives has a spray nozzle inclined against the surface for treatment of the workpiece, the abrasives and the dust are apt to scatter in the direction opposite to the inclined direction of the spray nozzle. As the suctioning member is installed in the position where the abrasives and the dust are scattered, the abrasives and the dust are efficiently suctioned and removed. As described in claim 7, the suctioning member can be disposed toward the positions to which the abrasives are directed and which are on the surface for treatment of the workpiece and in a direction that is opposite the inclined direction of the spray nozzle for blasting process.

[0018]

According to the invention of claim 8, the present invention uses technological means wherein the apparatus for recovering abrasives has the spray nozzle for the blasting process inclined against the surface for treatment of the workpiece by an angle of 30-75 degrees.

[0019]

According to the invention of claim 8, the apparatus for recovering abrasives can efficiently suction and remove the abrasives and the dust by having the spray nozzle for blasting process inclined against the surface for treatment of the workpiece by an angle of 30-75 degrees.

[0020]

According to the invention of claim 9, the present invention uses technological means wherein the apparatus for recovering abrasives has the suctioning member disposed in such a way that the direction of the suctioning is to form a tangential line along the circumference of an imaginary circle drawn around the center of the positions of the sprayed particles that are sprayed and which positions are on the surface for treatment of the workpiece.

[0021]

By the suctioning member being disposed as described in claim 9, the apparatus for recovering abrasives can generate a vortex-shaped flow of air within the covering for preventing scattering. In this way the apparatus for recovering abrasives can efficiently suction and remove the abrasives and the dust by having the abrasives and the dust be less likely to leak out through the gap.

[0022]

According to the invention of claim 10, the present invention uses technological means wherein the apparatus for recovering abrasives has a cleaning apparatus installed close to the outer side of the covering for preventing scattering. The cleaning apparatus removes the abrasives and the dust that remains on the surface for treatment of the workpiece after the blasting process, comprising a second covering for preventing scattering being formed in the shape of a box, the second covering for preventing scattering being formed to have a second gap between the end part of the opening and the surface for treatment of the workpiece so as to allow the outside air that is suctioned to enter, an air-blowing nozzle that blows the pressurized air against the surface for treatment of the workpiece within the second covering for preventing scattering and that separates and removes the abrasives and the dust from the surface for treatment of the workpiece, and a second suctioning member that is attached to the second covering for preventing scattering, and that suctions and exhausts, using the air suctioned through the second gap as a transport means, the abrasives and the dust within the second covering for preventing scattering.

[0023]

According to the invention of claim 10, after the blasting process the abrasives and the dust attached to the surface of the workpiece can be separated and removed by the pressurized air being blown from the air-blowing nozzle that is disposed within the second covering for preventing scattering against the surface for treatment of the workpiece. The second covering for preventing scattering prevents the separated abrasives and the dust from scattering. The second covering for preventing scattering suctions and exhausts via the second suctioning member attached to the second covering for preventing scattering, at the position close to the workpiece, the abrasives and the dust, using as a transport means the outside air that is suctioned through the second gap disposed between the end part of the opening of the second covering for preventing scattering and the surface of the workpiece. Thus the surface of the workpiece can be cleaned. In this way the abrasives and the dust that are attached by blasting to the workpiece are prevented from leaking out and scattering out of the apparatus for blasting process. The wording "after the blasting process" used herein means not only the completion of the entire treatment of the workpiece, but also when a part of the surface for treatment of the workpiece moves relative to the outside surface of the second covering for preventing scattering during the treatment.

[0024]

According to the invention of claim 11 , the present invention uses technological means wherein the apparatus for recovering abrasives has a guide member that is disposed close to the end part of the opening of and at the inner side of the second covering for preventing scattering and that is formed as a surface extending toward the end part of the opening from the inner side of the covering for preventing scattering toward its outer side so as to lead the outside air through the gap.

[0025]

According to the invention of claim 11, because the apparatus for recovering abrasives has a guide member (second guide member) that is disposed close to the end part (the second end part) of the opening of and at the inner side of the second covering for preventing scattering, and that leads the outside air through the gap, the outside air can be smoothly introduced into the inside of the covering for preventing scattering through the gap formed between the end part of the opening and the surface for treatment of the workpiece. In this way no area where a peeling-off vortex flow is likely to occur at the position close to the second end part of the opening of the covering for preventing scattering is produced. So, the increase of the resistance (loss of pressure) due to the flow of the outside air that is suctioned through the gap and the retention of the abrasives and the dust are prevented. Thus the abrasives and the dust can be efficiently suctioned and removed.

[0026]

According to the invention of claim 12, the present invention uses technological means wherein the apparatus for blasting process comprises the apparatus for recovering abrasives. Further, according to the invention of claim 13, the apparatus for blasting process comprises a suctioning apparatus that suctions and recovers the abrasives, and a separating apparatus that separates and takes out the reusable abrasives from the abrasives that are recovered.

[0027]

As stated in claims 12 and 13, in the apparatus for blasting process that comprises the apparatus for recovering abrasives, the abrasives and the dust are suctioned and recovered by the apparatus for recovering abrasives, and reusable abrasives are supplied to the apparatus for blasting process. So, the separating apparatus that generates the suctioning force necessary to transport the abrasives and a dust collector, etc., can be made smaller. This in turn can make the overall size of the apparatus for blasting process smaller.

[0028]

According to the invention of claim 14, the present invention uses technological means wherein a method of blasting process uses the apparatus for blasting process where the abrasives are sprayed against the surface for treatment of the workpiece, and at the same time the suctioning apparatus suctions the abrasives within the covering for preventing scattering, or within the covering for preventing scattering and the second covering for preventing scattering, and recovers the abrasives. Then the reusable abrasives are separated and taken out from the recovered abrasives.

[0029]

According to the invention of claim 14, by the method of the blasting process wherein the method uses the apparatus for blasting process comprising the suctioning apparatus that recovers the abrasives that are sprayed from the spray nozzle and that are within the covering for preventing scattering, or within the covering for preventing scattering and the second covering for preventing scattering, and then the reusable abrasives are separated and taken out from the recovered abrasives, the separating apparatus can be made smaller and thus the overall size of the apparatus for blasting process can be made smaller. The conventional apparatus for blasting process had a structure where all the air inside the chamber for treatment should be suctioned, such that a large suctioning force was required. Also, immediately after the separation the abrasives were put into a separator (to separate and take out the reusable abrasives. Generally as a separator, a wind power device, such as a cyclone, was used). So, the separators, which had a corresponding suctioning force, were large. The apparatus for blasting process of the present invention needs only smaller suctioning capacity, and the reusable abrasives are first recovered by the suctioning apparatus and then the reusable abrasives are separated and recovered. So, the separator needs only be capable of separating the abrasives. Thus the separator can be made smaller.

Brief Description of the Drawings

[0030]

Fig. 1 is a structural chart of the apparatus for blasting process comprising the apparatus for recovering the abrasives.

Fig. 2 is an illustration of the covering for preventing scattering and the suctioning member.

Fig. 2(A) is an illustration of the cross section, Fig. 2(B) is an illustration of the plan view, and Fig. 2(C) is an illustration of the enlarged cross section of the end part of the opening of the covering for preventing scattering. Fig. 3 is an illustration of the second covering for preventing scattering and the second suctioning member of the cleaning apparatus. Fig. 3(A) is a cross-sectional view, Fig. 3(B) is an illustration of the plan view, and Fig. 3(C) is an illustration of the enlarged cross section of the end part of the opening of the second covering for preventing scattering.

Fig. 4 is an illustration of the enlarged cross section of an alternative guide member that is formed at the end part of the opening of the covering for preventing scattering, and that leads the outside air into the covering for preventing scattering. Fig. 5 is an illustration of the plan view of an alternative covering for preventing scattering.

Fig. 6 is an illustration of the cross section of an alternative second guide member that is formed at the end part of the opening of the second covering for preventing scattering, and that leads the outside air into the second covering for preventing scattering.

Fig. 7 is an illustration of the cross section of an alternative cleaning apparatus.

Fig. 8 is an illustration of the plan view of an alternative second covering for preventing scattering.

Fig. 9 is an illustration of the example and a comparative example. Fig. 9 (A) is an illustration of the example and Fig. 9 (B) is an illustration of the comparative example. Fig. 10 is an illustration of the apparatus for recovering the abrasives comprising the supplementary suctioning member.

Embodiment for Carrying Out the Invention

[0031]

Below the apparatus for recovering abrasives and the apparatus for blasting process comprising the apparatus for recovering abrasives in one embodiment of the present invention are explained based on the drawings. In the present embodiment the apparatus for blasting process using the gravitational spraying (suctioning) method is selected as a representative example. As shown in Fig. 1, the apparatus for blasting process 1 comprises the following:

a spraying apparatus 10 that treats the workpiece by spraying the abrasives, an apparatus for recovering 20 that recovers the abrasives sprayed from the spraying apparatus 10 and the dust generated from the blasting process of the workpiece W,

a feeding apparatus 30 that separates the abrasives recovered by the apparatus for recovering 20 and supplies the abrasives to the spraying apparatus 10, and a blasting process section 40 that performs the blasting process of the workpiece by the spraying apparatus 10.

[0032]

The spraying apparatus 10 comprises a spray nozzle 11 that sprays the abrasives against the workpiece, equipment for supplying pressurized air 12, such as a compressor that supplies the pressurized air to the spray nozzle 11 through a pipe for air 13, and a transfer mechanism for the spray nozzle (not shown). The spray nozzle 11 is connected to a hopper 32, which will be referred to below, via a tube for supplying abrasives.

[0033]

The apparatus for recovering 20 comprises the covering for preventing scattering 21 that prevents the abrasives that are sprayed from the spray nozzle from scattering, a suctioning apparatus 22 that suctions and recovers via a duct for suctioning 52 the abrasives inside the covering for preventing scattering 21 and the dust generated from workpiece W by the blasting process, and a cleaning apparatus 23 that removes the abrasives and the dust attached to the workpiece W that passes through the covering for preventing scattering 21. The cleaning apparatus 23 is connected to the suctioning apparatus 22 via a second duct for suctioning.

[0034]

The structures of the covering for preventing scattering 21 and the cleaning apparatus 23 will later be explained in detail. The suctioning apparatus 22 of the present embodiment comprises a capturing unit 22a that suctions and captures the abrasives (that also include the abrasives that are unusable, for example, because they were smashed) and the dust generated from workpiece W by the blasting process, and a storage tank 22b that stores the abrasives and the dust. The abrasives and the dust are suctioned by the capturing unit 22a and captured by a filter in the capturing unit 22a. The abrasives and the dust that are captured can be separated from the filter by a publicly-known method such as a pulse-jet, mechanical means, etc., and stored in the storage tank 22b.

[0035]

The feeding apparatus 30 comprises a separating apparatus 31 that recovers the abrasives and the dust of the treated workpiece from the suctioning apparatus 22 via a duct for recovering 54, and that separates the reusable abrasives from the non-reusable abrasives and the dust; a storage tank that stores the abrasives supplied by the separating apparatus 31; a hopper 32 comprising an apparatus for supplying a fixed quantity of the abrasives to the spray nozzle 11 via a tube for feeding the abrasives 51 ; and a dust collector 33 that exhausts and recovers via a duct 55 the non-reusable abrasives and the dust that are separated by the separating apparatus 31.

[0036]

In this embodiment, a separator of a cyclone-type is used as the separating apparatus 31. The separator of the cyclotron-type carries out the separation by blowing fine particles together with air into the upper part of the cyclone-tower 31a. The reusable abrasives of the abrasives and dust in the air stream generated by the negative pressure produced by the dust-collector 33 are separated from the air stream by the centrifugal force of the whirling air stream and reach the surrounding walls. Then they are captured in a buffer-tank 31b that is at the lower part of the cyclone-tower 31a. The non-reusable abrasives and the dust are suctioned by the duct 55 and recovered by the dust-collector 33.

[0037]

The blasting process section 40 comprises a chamber for blasting 41 that performs the blasting process and the transport mechanism 42 that transports the workpiece. The transport mechanism 42 consists of rollers for transport 42a that transport the workpiece and a stage 42b that suctions and holds the workpiece and positions it.

[0038]

Next, the structure of the covering for preventing scattering is explained. In this embodiment, a spray nozzle 11, having a mouth in the shape of a rectangle, is used. As shown in Figs. 2(A) and 2(B), the long side of the rectangle of the mouth of the spray nozzle is disposed in an inclined position against the surface for treatment of the workpiece so that the long side of the rectangle is placed vertically against the direction that the workpiece or the nozzle runs. If the spray nozzle 11 of this type is used, the width for the treatment can be made greater. Thus an area of a greater width can be efficiently treated with blasting. But a larger amount of abrasives are used. So, the conventional recovering method cannot recover enough abrasives. The covering for preventing scattering 21 is formed in the shape of a box having an opening such that it covers the spray nozzle 11. The covering for preventing scattering 21, which is attached to the spray nozzle 11 , and the spray nozzle 11 , together form one body.

[0039]

The covering for preventing scattering 21 is disposed in such a way that its distance to the surface for treatment S of the workpiece W is to allow a gap T between the end part of the opening 21a and the surface for treatment S of the workpiece W, through which gap T the outside air can be suctioned.

[0040]

On the upper part of the covering for preventing scattering 21 is installed a suctioning member 21b, which is connected to the duct for suctioning 52, the suctioning member 21b suctioning and exhausting to the outside the abrasives and the dust within the covering for preventing scattering 21 by means of the outside air introduced through the gap T. The suctioning member 21b is disposed toward the positions P of the abrasives that are sprayed by the spray nozzle 11 , and is inclined in the direction opposite to the inclined direction of the spray nozzle 11.

[0041]

The angle of the gradient of the spray nozzle 11 against the surface for treatment of the workpiece is preferably 30-75 degrees. If the angle is too small the speed of the abrasives that are sprayed overcome the suctioning force, and then the abrasives leak outside the covering for preventing scattering. If the angle is too large the effects from the spray nozzle 11 that is disposed in the inclined position will be insufficient. In the present embodiment the covering for preventing scattering 21 having the shape of a box, of which the lateral side has the shape of a rectangle, and is used. But a covering for preventing scattering 21 having a shape of a box with its lateral side having a certain inclined surface of a trapezoid can be used, thereby the spray nozzle 11 and the suctioning member 21b are placed on the inclined surface and thus the spray nozzle 11 that is inclined can be easily installed. [0042]

The width of the gap T, distance between the end part of the opening and the surface for treatment of the workpiece, is adjusted in such a way that sufficient outside air can be suctioned and also that the abrasives and the dust do not leak outside. The gap T is a few mm wide. It preferably is 1.0-4.0 mm wide. If the gap T is less than 1.0 mm wide, the pressure loss in suctioning the outside air becomes larger, and the covering for preventing scattering 21 may contact the workpiece. That is, the workpiece W could be damaged if the covering for preventing scattering 21 were to contact the workpiece. If the gap T is more than 4 mm wide, the speed of the outside air that is suctioned through the gap T is reduced, making it lower than the speed of the abrasives that are sprayed from the spray nozzle 11, whereby the abrasives and the dust will leak outside the covering for preventing scattering.

[0043]

As shown in Fig. 2 (C), the guide member 21c, which is formed as the surface that extends from the inside of the covering for preventing scattering 21 to its outside toward the end part of the opening 21a, and which is disposed at the inner side of the covering for preventing scattering 21 and formed at the end part of the opening 21a, so as to lead the outside air through the gap T.

In this embodiment, the guide member 21c is formed as a curved surface of a convex shape, the convex shape being formed by the lower end part of the opening of the covering for preventing scattering 21 c being rounded and protruding in the outer direction. The guide member 21c can prevent the area from being formed where a peeling-off vortex flow is likely to occur. So, it is possible to minimize the increase of the resistance of the air (loss of pressure) when the outside air is suctioned through the gap T, and also to prevent the retention of the abrasives and the dust. Thus the abrasives and the dust can be efficiently suctioned and removed.

[0044]

Also, as shown in Fig. 10, the suctioning member 21h can be placed closer to the end part that is away from the center line of the covering for preventing scattering 21 and on the upper part of the covering for preventing scattering 21. Further, the spray nozzle 11 can be placed closer to the end part opposite the side where the suctioning member 21h is placed. Also, the supplementary suctioning member 21i can be placed on the side surface where the suctioning member is placed. By the suctioning force of the supplementary suctioning member the air stream that flows toward the part where the suctioning member is placed is generated. So, the abrasives are efficiently suctioned by the suctioning member 21h. The supplementary suctioning member 21 i is to facilitate the generation of the air stream so as to efficiently suction the abrasives by the suctioning member 21h. So, the suctioning force at the supplementary suctioning member 21i need not be greater than that at suctioning member 21h. In the present embodiment, five supplementary suctioning members are placed. They have diameters that are sufficiently smaller than the diameter of the suctioning member.

[0045]

The spray nozzle can be installed in a position that is either vertical or inclined against the surface for treatment of the workpiece, but preferably in a position that is inclined, but most preferably in a position that is inclined at an angle of 30-75 degrees against the surface for treatment of the workpiece. If the angle of the gradient is too small, the speed of the abrasives that are sprayed overcomes the suctioning force and the abrasives will leak outside the covering for preventing scattering. If the angle is too large the effects from the air stream generated by the suctioning force of the supplementary suctioning members are not insufficient.

[0046]

Also, in the present embodiment, the guide member 21g, which is formed as a surface that extends from the inside of the covering for preventing scattering 21 to its outside toward the end part of the opening 2 If, is placed at the inner side of the covering for preventing scattering 21 and formed at the end part of the opening 2 If, so as to lead the outside air through the gap T.

[0047]

Next, the cleaning apparatus is explained. In the present embodiment, a spray nozzle having a mouth that has the shape of a rectangle is used as an air-blowing nozzle 23b. As shown in Figs. 3 (A) and 3 (B), the long side of the rectangle is placed vertically against the direction that the workpiece or the nozzle runs. If such an air-blowing nozzle 23b is used, the width that is to be treated can be made greater, and that area of the greater width can be efficiently treated. The second covering for preventing scattering 23 a is formed in the shape of a box having an opening such that it covers an air-blowing nozzle 23b. The second covering for preventing scattering 23a, which is attached to the air-blowing nozzle 23b, and the air-blowing nozzle 23b, together form one body.

[0048]

The second covering for preventing scattering 23a is placed in such a way that its distance to the surface treatment S of the workpiece W allows a gap t between the second end part of the opening 23d and the surface for treatment S of the workpiece W, through which gap t the outside air can be suctioned.

[0049]

On the upper part of the second covering for preventing scattering 23a is installed a second suctioning member 23c that is connected to a second duct for suctioning 53, the second suctioning member 23c suctioning and exhausting to the outside the abrasives and the dust within the second covering for preventing scattering 23a by means of the outside air introduced through the gap t. The suctioning member 23c is disposed in a way that it is nearly vertical against the workpiece.

[0050]

The width of the gap t , distance between the second end part of the opening and the surface for treatment of the workpiece, is adjusted in such a way that sufficient outside air can be suctioned and also that the abrasives and the dust do not leak outside. The gap t is a few mm wide. It preferably is 1.0-4.0 mm wide. If the gap t is less than 1.0 mm wide, the pressure loss in suctioning the outside air becomes larger and the second covering for preventing scattering 23a may contact the workpiece. That is, the workpiece W could be damaged if the second covering for preventing scattering 23a were to contact the workpiece. If the gap t exceeds 4 mm in width, the speed of the outside air that is suctioned through the gap t is reduced, making it lower than the speed of the abrasives that are sprayed from the air-blowing nozzle 23 b, whereby the abrasives and the dust will leak outside the second covering for preventing scattering 23 a. [0051]

As shown in Fig. 3 (C), the second guide member 23e, which is formed as the surface that extends from the inside of the second covering for preventing scattering 23 a to its outside toward the second end part of the opening 23 d, and that is at the inner side of the second covering for preventing scattering 23 a and formed at the second end part of the opening 23d, is to lead the outside air through the gap t. In this embodiment, the second guide member 23 e is formed as a curved surface of a convex shape, the convex shape being formed by the lower end part of the opening of the second covering for preventing scattering 23 a being rounded and protruding in the outer direction. The second guide member 23e can prevent the area from being formed where a peeling-off vortex flow is likely to occur. So, it is possible to minimize the increase of the resistance of the air (loss of pressure) when the outside air is suctioned through the gap t, and also to prevent the retention of the abrasives and the dust. Thus the abrasives and the dust can be efficiently suctioned and removed.

[0052]

Next, the movement of the apparatus for blasting process 1 thus constituted is explained. First, the transport mechanism 42 delivers the workpiece W just below the spray nozzle 11. The spray nozzle 11 is fixed in a predetermined position.

[0053]

Next, the workpiece W is treated by blasting process while it is moved relative to the spray nozzle 11. When the pressurized air is introduced into the inside of the spray nozzle 11 by equipment for supplying pressurized air 12 by a predetermined operation, negative pressure is produced in the spray nozzle 11, whereby the abrasives supplied from the hopper 32 in a fixed quantity are suctioned into the spray nozzle 11 via the tube for supplying abrasives 51. The pressurized air causes the speed of the abrasives that are suctioned into the spray nozzle 11 to increase and they are then sprayed against the surface for treatment S of the workpiece W. Thus the blasting process is carried out. In this operation, the workpiece W can be moved relative to the spray nozzle 11 by the transport mechanism 42, or the spray nozzle 11 can be moved by the transfer mechanism for the spray nozzle (not shown). [0054]

The abrasives that are sprayed from the spray nozzle 11 and are scattered after they hit the workpiece W, and the dust generated during the blasting process, are suctioned and removed from the inside of the covering for preventing scattering 21 by the suctioning member 21b, and then transported by means of the outside air that works as a transporting medium and that is suctioned through the gap T disposed between the covering for preventing scattering 21 and the surface for treatment S of the workpiece. The abrasives and the dust that are suctioned by the suctioning member 21b are suctioned and recovered by the suctioning apparatus 22 through the duct for suctioning 52.

[0055]

The apparatus for blasting process of the present invention, while preventing the abrasives and the dust from scattering by the covering for preventing scattering 21, suctions and exhausts them near the workpiece W by means of the outside air that is introduced through the gap T as a transporting medium. So, the apparatus for blasting process of the present invention needs to suction only the small volume within the covering for preventing scattering 21. So, it can efficiently recover the abrasives and the dust. Especially the fine abrasives with a particle size of a few μ m or less, which can be easily recovered, can be efficiently recovered. Even if the spray nozzle 11 that has a mouth in the shape of a rectangle is used, whereby many abrasives are sprayed, the abrasives and the dust can be sufficiently recovered. Further, the apparatus for blasting process of the present invention can prevent the abrasives and the dust from adhering to the transport mechanism 42 for the workpiece. So, the workpiece W is not damaged during transport.

[0056]

By the spray nozzle 11 being placed in a position inclined against the surface for treatment S of the workpiece W, the abrasives and the dust are likely to scatter in the direction that is opposite the inclined direction of the spray nozzle 11. Further, the suctioning member 21b is placed in the direction where the abrasives and the dust are supposed to scatter, so they are efficiently suctioned and removed.

[0057]

Moreover, because the guide member 21 c is formed at the end part of the opening 21a and leads the outside air through the gap T, the guide member 21c can prevent the area from being formed where a peeling-off vortex flow is likely to occur. So, it is possible to minimize the increase of the resistance of the air stream when the outside air is suctioned through the gap T, and to prevent the retention of the abrasives and the dust. Thus the abrasives and the dust can be efficiently suctioned and removed.

[0058]

The workpiece W that has been treated with blasting is transported outside the covering for preventing scattering 21 by the transport mechanism 42. The cleaning apparatus 23 is installed on a location along the path of the transportation. Under the apparatus passes the workpiece W that has been treated by blasting process.

[0059]

The pressurized air that is supplied from the equipment for supplying pressurized air 12 is sprayed by the air-blowing nozzle 23b against the workpiece W that was transported. Thus the abrasives and the dust that are attached to the surface of the workpiece W are removed from the surface of the workpiece W. The abrasives and the dust that are removed from the surface are suctioned and removed by the second suctioning member 23c from inside the second covering for preventing scattering 23a, with the outside air acting as a transporting medium, which air is suctioned through the gap t that is positioned between the second covering for preventing scattering 23 a and the surface for treatment S of the workpiece. The abrasives and the dust that are suctioned and removed by the second suctioning member 23c are suctioned and recovered by the suctioning apparatus 22 through the second duct for suctioning 53 that is connected to the duct for suctioning 52 that forms a passage between the covering for preventing scattering 21 and the suctioning apparatus 22.

[0060]

The abrasives and the dust that are suctioned and recovered are stored in a storage tank 22b that is within the suctioning apparatus 22. The suctioning apparatus 22 needs only to have a capacity to suction the insides of the covering for preventing scattering 21 and the second covering for preventing scattering 23a. Both need only contain a small volume. So, the size of the suctioning apparatus 22 can be minimized.

[0061]

The abrasives that are recovered by the apparatus for recovering 20 comprising the covering for preventing scattering 21, the suctioning apparatus 22, and the cleaning apparatus 23, are transported to the separating apparatus 31, wherein as the abrasives have already been suctioned and recovered by the apparatus for recovering 20, the volume of the air that is to be generated by the dust collector 33 and that is supplied to the separating apparatus 31 for transporting the abrasives can be smaller. Thus the separating apparatus 31, the dust collector 33, etc., that should generate the suctioning force can, in turn, be made smaller.

[0062]

The abrasives and the dust that are transported to the separating apparatus 31 are separated into reusable abrasives, and non-reusable abrasives and dust. The non-reusable abrasives and the dust are recovered by the dust collector 33 through the duct 55.

[0063]

The reusable abrasives are stored in a buffer-tank 31b, and supplied to the hopper 32, based on the need. Thus by recycling the reusable abrasives, continuous blasting process can be advantageously maintained.

[0064]

Alternative embodiment

The spraying apparatus 10, feeding apparatus 30, and blasting process section 40, of the apparatus for blasting process 1, are not limited to those described in the above embodiments, but publicly known apparatuses, etc., can also be used. For example, an apparatus for pressurized blasting process can be used as the apparatus for blasting process 1. Also, the spray nozzle 11 can have a mouth of a circular shape. The spray nozzle 11 can be disposed in a position such that the particles can be sprayed vertically against the surface for treatment S of the workpiece. [0065]

The covering for preventing scattering 21 shown in Fig. 2, and the second covering for preventing scattering 23a shown in Fig. 3, both have a shape of a box. But the shape of the coverings is not limited to this shape and it can be selected from various shapes, such as a cylinder, cone, pyramid, etc.

[0066]

The guide member 21c is formed on the inner side of the covering for preventing scattering 21, close to its end part of the opening 21a, as a surface that extends from the inside of the covering for preventing scattering 21 toward the end part of the opening 21a. The guide member 21c can be formed in any one of the various shapes as long as the outside air can be smoothly introduced through the gap T. For example, as shown in Figs. 4 (A) and 4 (B), the guide member 21c can be formed as a surface having a round curvature at least at the inner side of the end part of the opening 21a.

[0067]

The number of suctioning members 21b and their positions can be suitably selected based on the need. For example, in the above embodiment, a suctioning member 21b can be added in the direction of the long side of the rectangle of the spray nozzle 11. In this way the abrasives and the dust that are scattered in the direction of the long side of the rectangle of the spray nozzle 11 can be efficiently suctioned and removed.

[0068]

Also, as shown in Fig. 5, the suctioning members 21b can be positioned in such a way that their direction of suction forms a tangential line along the circumference of a circle, of which the center is the center of the positions P of the sprayed particles that are sprayed on the surface for treatment S of the workpiece W. By having the suctioning member 21b be positioned in this way, a vortex-shaped flow of air can be generated within the covering for preventing scattering 21. The suctioning member 21b can efficiently suction and remove the abrasives and the dust because it makes the abrasives and the dust less likely to leak out through the gap T. Particularly, if the spray nozzle 11 is placed vertically against the surface for treatment S of the workpiece, the abrasives and the dust are more likely to scatter in radial directions within the covering for preventing scattering 21. So, the present combination can be suitably used.

[0069]

The air-blowing nozzle 23 b is not limited to the one described in the above embodiment. For example, the mouth of the air-blowing nozzle 23b can be in a circular shape, more than one air-blowing nozzles 23b can be used, or the air-blowing nozzle 23b can be placed in such a position that the direction of spraying can be inclined against the surface for treatment S of the workpiece.

[0070]

The second guide member 23e is formed at the inner side of and close to the end part of the opening 23d as a surface that extends from the inside of the second covering for preventing scattering 23a to its outside toward the end part of the opening 23d. The shape of the second guide member 23e can be selected from various shapes so long as it can smoothly introduce the outside air through the gap t. For example, as shown in Figs.

6 (A) and 6 (B), the second guide member 23e can be produced by having at least the inner side of the end part of the second opening 23d formed as a surface having a round curvature.

[0071]

The number of second suctioning members 23 c and their positions are appropriately selected based on the need. For example, as shown in Fig. 7, a second suctioning member 23c can be added at the front and the rear of the air-blowing nozzle 23b in the direction of the movement of the workpiece. In this way the abrasives and the dust that are scattered within the second covering for preventing scattering 23a can be efficiently suctioned and removed.

[0072]

Also, as shown in Fig. 8, the second suctioning members 23c can be positioned in such a way that their direction of suction forms a tangential line along the circumference of a circle, of which the center is the center of the positions P where the pressurized air is sprayed on the workpiece W. By having the second suctioning member 23c be positioned in this way, it can generate a vortex-shaped flow of air within the second covering for preventing scattering 23a. The second suctioning member 23c can efficiently suction and remove the abrasives and the dust because it makes the abrasives and the dust less likely to leak out through the gap t. Particularly, when the air-blowing nozzle 23b is placed vertically against the surface for treatment S of the workpiece, the abrasives and the dust are more likely to scatter in radial directions within the second covering for preventing scattering 23 a. So, the present combination can be suitably used.

[0073]

The air-blowing nozzle 23b not only sprays the pressurized air, but it also can comprise a means for discharging the static electricity of the abrasives and the dust and the workpiece. For example, a small amount of water or a substance for discharging the static electricity may be included, or ions or radicals that are generated by a corona discharge, etc., can be included in the pressurized air, or an ultra-sonic sound (ultrasonic air-blow) can be used.

[0074]

The cleaning apparatus 23 of the present embodiment need not be provided, if the abrasives and the dust are not attached to the surface of the workpiece W after it is treated with blasting process, or if the quantity of the abrasives and the dust that are attached are so little that they can be neglected.

[0075]

The suctioning apparatus 22 of the present embodiment need not be provided if a feeding apparatus 30 of a large size need not be considered.

[0076]

If the feeding apparatus 30 has a sufficient capacity for suctioning, it also can be used as the apparatus for recovering 20. For example, if the workpiece W is small, and if the volume of the chamber for blasting 41 is small, and if the dust-collector 33 can have a sufficient suctioning capacity, then an independent apparatus for recovering need not be provided. In this case, the separating apparatus 31 and the dust-collector 33 can work as the apparatus for recovering 20. Example 1 [0077]

In this example, the shape of the guide member 21c of the covering for preventing scattering 21 is discussed. It is to be understood that the present invention is not limited to the example given below.

[0078]

The covering for preventing scattering 21, having a shape of a cylinder with a diameter of 150 mm and height of 45 mm, and comprising a guide member 21c that is formed as a surface having a round curvature and that extends from the inside of the covering for preventing scattering 21 toward the outside and comprising the suctioning member 21b, was used. The suction static pressure of a blower that was connected to the suctioning member 21b via the duct for suctioning 52 and the static pressure at the end part of the opening 21a, when the blower suctioned the air, were measured. Also, in the comparative example, as shown in Fig. 9 (B), the covering for preventing scattering 21 that has no guide member 21c was used. All other conditions in the comparative example were the same as those in the example.

[0079]

The results are shown in Table 1. The suction static pressure of the blower when the covering for preventing scattering 21 had the guide member 21c was -8.3 kPa, and the volume of the suctioned air was 5.2 m ³ , while, for the covering for preventing scattering 21 that had no guide member 21c, the suction static pressure of the blower was -11.2 kPa, and the volume of the suctioned air was 4.1 m ³ .

[0080]

From the results, it is observed that when the covering for preventing scattering 21 had the guide member 21c, the static pressure of the blower became lower and the volume of the suctioned air was larger, compared with the static pressure and the volume of the suctioned air, respectively, when the covering for preventing scattering 21 had no guide member 21c.

[0081]

Table 1 b lower

stat i c pressure at

the end part of suct i on stat ic

gu i de member 21 c the open i ng 21 a vo l ume suct i oned pressure

(kPa) (kPa) (m /mm)

Yes - 3. 4 -8. 3 5. 2

No - 7. 3 - 1 1 . 2 4. 1

Example 2

[0082]

In this example, the effects of the supplementary suctioning member 21i and the effects of the gradient of the angle of the spray nozzle 11 are investigated. The present inventions are not limited to the example given below.

[0083]

The covering for preventing scattering 21, being 160 mm wide, 200 mm long, and 45 mm high, and having a guide member 21 g that is formed as a surface having, at the end part of the opening 2 If, a round curvature and that extends from the inside of the covering for preventing scattering 21 toward the outside, was used. The suctioning member 21h, having a diameter of 13 mm, was installed on the ceiling of the covering for preventing scattering 21. The suctioning member 21h was installed at such a position where the center of the ellipse (including a circle) formed by the cross section of the covering for preventing scattering 21 and the suctioning member 21 h is moved to the end part away from the center line by 90 mm in the direction of the length of the long side of the rectangle of the covering for preventing scattering 21. Further, a supplementary suctioning member 21 i was installed on the side of the covering for preventing scattering 21 and was detached from the end part of the opening by 10 mm. In this example, five pipes, each having a diameter of 8 mm, were disposed in positions whereby the pipes were separated from each other at equal distances. Also, the spray nozzles were each inclined at angles of 25, 30, 45, 75, and 80 degrees.

[0084] The suctioning member 21h and the supplementary suctioning member 21 i were connected to the suctioning apparatus (not shown) by the duct for suctioning 52 and the supplementary duct for suctioning 56, respectively. The abrasives (WA # 600) were sprayed from the spray nozzle at 0.6 MPa and the suctioning apparatus was operated at the same time. Any leak of the abrasives to the outside of the covering for preventing scattering 21 or any amount of the abrasives remaining on the surface for treatment of the workpiece after the completion of the spraying were investigated.

[0085]

No leak of the abrasives was observed when the spray nozzles were inclined at the angles of 30, 45, 75, and 80 degrees. But a leak was observed when the spray nozzle was inclined at the angle of 25 degrees. When the spray nozzle was at the angle of 80 degrees, it was observed that the abrasives remained on the surface for treatment of the workpiece. Thus, it was found that the optimal angle of inclination of the spray nozzle was 30-75 degrees.

[0086]

Effect of the embodiments

(1) According to the apparatus for recovering 20 of the present invention, the apparatus for recovering abrasives can recover the abrasives and the dust efficiently. This is because while it prevents the scattering of the abrasives and the dust by means of the covering for preventing scattering 21, it has to suction only a small volume within the covering for preventing scattering 21, and because the suctioning apparatus for recovering abrasives suctions and exhausts, at the position close to the workpiece, the abrasives and the dust, using as a transport medium the outside air that is suctioned through the gap T. Particularly, the apparatus for recovering abrasives of the present invention can efficiently recover the fine abrasives that have been difficult to recover before. Also, the apparatus for recovering abrasives of the present invention can sufficiently recover the abrasives and the dust, even if a spray nozzle that has a mouth formed in the shape of a rectangle and that usually sprays a larger amount of abrasives is used. Further, the apparatus for recovering abrasives of the present invention can prevent the abrasives and the dust from adhering to the transport mechanism 42 of the workpiece W. So, the workpiece W is not damaged during transport.

[0087]

(2) The apparatus for recovering abrasives has a guide member 21c that is formed at the end part of the opening 21a. The guide member 21c introduces the outside air through the gap T. So, it can prevent the area from being formed where a peeling-off vortex flow is likely to occur at the position close to the end part of the opening 21a when the outside air is introduced. So, the increase of the resistance (loss of pressure) due to the flow of the outside air that is suctioned through the gap

T and the retention of the abrasives and the dust are prevented. Thus the abrasives and the dust can be efficiently removed by suctioning.

[0088]

(3) By having the spray nozzle 11 being in the inclined position against the surface for treatment S of the workpiece W, the abrasives and the dust are likely to scatter in the direction that is opposite to the direction of inclination of the spray nozzle 11. Because the suctioning member 21b is disposed in the direction where the abrasives and the dust are supposed to scatter, they are efficiently suctioned and removed.

[0089]

(4) After the blasting process, the pressurized air that is blown from the air-blowing nozzle 23b against the workpiece W can separate the abrasives and the dust that are attached to the workpiece W. Thus the abrasives and the dust that are separated are prevented from scattering by the second covering for preventing scattering 23 a and they are suctioned and exhausted near the workpiece W, with the outside air as a transporting medium, which air is suctioned through the gap t. So, no abrasives or dust leaks out and the cleaning of the workpiece W can be carried out.

[0090]

(5) The apparatus for recovering abrasives has the second guide member 23e that is disposed at the end part of the second opening 23d. So, it can prevent the area from being formed where a peeling-off vortex flow is likely to occur at the position close to the end part of the second opening 23 d when the outside air is introduced through the gap t. So, the increase of the resistance of the air (loss of pressure) due to the flow of the outside air that is suctioned through the gap t and the retention of the abrasives and the dust are prevented. Thus the abrasives and the dust can be efficiently removed by suctioning.

[0091]

(6) According to the apparatus for blasting process 1 of the present invention having the apparatus for recovering 20, because the abrasives have already been suctioned and recovered by the apparatus for recovering 20, the volume of the air that is to be generated by the duct collector 33 and that is to be supplied to the separating apparatus 31 for transporting the abrasives can be smaller. Thus the separating apparatus 31, the dust collector 33, etc., that should generate the suctioning force necessary to transport the abrasives, can be made smaller.

[0092]

Other embodiments:

If the problem of a leak of the abrasives and the dust need not be considered because the quantity of the abrasives that are used is small, a chamber for blasting 41 need not be provided. Also, if the materials or products that do not like dust are treated with blasting process, the blasting process section 40, such as the chamber for blasting 41, can be formed as a clean booth.

[0093]

The basic Japanese patent applications, No. 2009-210309, filed September 11, 2009, and No. 2010-106095, filed May 6, 2010, are hereby incorporated in their entirety by reference in the present application.

The present invention will become more fully understood from the detailed description of this specification. However, the detailed description and the specific embodiment illustrate desired embodiments of the present invention and are described only for the purpose of explanation. Various possible changes and modifications will be apparent to those of ordinary skill in the art on the basis of the detailed description. The applicant has no intention to dedicate to the public any disclosed embodiments. Among the disclosed changes and modifications, those that may not literally fall within the scope of the present claims constitute, therefore, a part of the present invention in the sense of the doctrine of equivalents.

The articles "a," "an," and "the," and similar referents in the specification and claims, are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not limit the scope of the invention unless otherwise noted

Denotations of Numbers

[0094]

I apparatus for blasting process

10 spraying apparatus

I I spray nozzle

12 equipment for supplying pressurized air

13 pipe for air

20 apparatus for recovering

21 covering for preventing scattering

21 a, 21 f end part of the opening

21 b, 21 h suctioning member

21c, 21g guide member

21 i supplementary suctioning member

22 suctioning apparatus

22a capturing unit

22b storage tank

23 cleaning apparatus 23a second covering for preventing scattering

23b air-blowing nozzle

23c second suctioning member

23 d second end part of the opening

23e second guide member

30 feeding apparatus

31 separating apparatus

31a cyclone tower

31b buffer-tank

32 hopper

33 dust collector

40 blasting process section

41 chamber for blasting

42 transport mechanism

42a roller for transport

42b stage

51 tube for supplying abrasives

52 duct for suctioning

53 second duct for suctioning

54 duct for recovering

55 duct

56 supplementary duct for suctioning

S surface for treatment

T gap

t gap (second gap)

W workpiece

P positions P of the abrasives that are sprayed p positions p where the pressurized air is sprayed