CONCRETE SURFACE NEUTRALIZED LAYER AND PAINTED

LAYER REMOVING DEVICE

Technical Field

[1] The present invention relates to a dry remover for removing a neutralization layer and a coating layer on a surface of a concrete structure. When a reinforcing member such as a fiberboard is attached to a surface of a concrete structure by means of an adhesive, the dry remover grinds a surface, on which an adhesive is applied, of a concrete structure in order to remove a paint layer or a neutralization layer coated on the surface of the concrete structure and to allow the surface of the concrete structure to have proper surface roughness. Background Art

[2] A conventional grinder 1 is shown in FIG. 11. The conventional grinder has been used to grind a surface, on which an adhesive is applied, of a concrete structure in order to remove a paint layer and a neutralization layer coated on the surface of the concrete structure and to allow the surface of the concrete structure to have proper surface roughness.

[3] A grinding wheel 2 used in the conventional grinder 1 is shown in FIG. 1 IB, and the grinding wheel 2 includes a disk 4 and cutting blades 3 fixed on the surface of the disk 4.

[4] As shown in FIG. 1 IA, the grinding wheel 2 is combined with the conventional grinder 1. After that, the grinding wheel 2 is rotated while being horizontal with respect to the surface of the concrete structure 6 so that the cutting blades 3 come in contact with the surface of the concrete structure 6. Accordingly, the cutting blades 3 grind the surface of the concrete structure 6 so as to remove paint 5 on the surface of the concrete structure 6.

[5] When the surface of the concrete structure 6 is grinded as described above, the paint layer 5 is gradually removed by the rotation of the grinding wheel 2.

[6] That is, the grinding wheel 2 should be rotated many times to remove the paint 5 at a predetermined position on the surface of the concrete structure.

[7] However, since the paint has viscosity, it is difficult to remove the paint 5. For this reason, the surface treatment of the concrete structure 6 becomes one of difficult processes, which increases the term of work. Further, since the paint layer 5 is not completely removed, construction failure may easily occur.

[8] In general, when the concrete is grinded (or cut), a lot of dust occurs. As a result, works are hindered, and environmental pollutions occur. In addition, a large amount of

frictional heat is generated in the grinding wheel (or cutting blades), thus, it is not possible to continuously use a grinding machine (cutting machine) for a long time. In the grinding wheel, blades (for example, diamond tips) are attached to a shank. Meanwhile, when the much frictional heat is transmitted to the grinding wheel (or cutting blades), the blades (for example, diamond tips) detach from the shank. Accordingly, the grinding wheel (or cutting blades) is no longer operable.

[9] A coolant is generally supplied to the grinding wheel (or cutting blades) to prevent the above-mentioned problems, that is, dust occurrence, blade detachment caused by frictional heat, and the like. In this case, the above-mentioned problems are partially solved, but the concrete structure becomes wet by the coolant. Accordingly, it is not possible to immediately perform the succeeding processes for applying an adhesive on the surface of the concrete structure and for attaching a reinforcing member on the surface of the concrete structure. Furthermore, construction failure, such as an attachment failure, may be easily caused by humidity at a construction site. Disclosure of Invention Technical Problem

[10] The present invention is made to solve the above-mentioned problems, and has the following objects.

[11] A first object of the invention is to provide a device that can rapidly remove a paint layer or neutralization layer on the surface of the concrete structure in a dry condition.

[12] A second object of the invention is to provide a device that can completely remove a paint layer or neutralization layer on the surface of the concrete structure in a dry condition.

[13] A third object of the invention is to provide a device that can completely remove a paint layer or a neutralization layer to allow a surface of a concrete structure to have proper surface roughness. Technical Solution

[14] The invention provides the following dry remover to achieve the above-mentioned objects.

[15] A dry remover for removing a neutralization layer and a coating layer on a surface of a concrete structure includes a housing, a motor provided in the housing, a transmission unit that transmits a driving force of the motor, and a cutting blade assembly that is provided in the housing and is driven by power transmitted from the transmission unit. The cutting blade assembly is formed in a cylinder shape, and is horizontally mounted in an opening formed at the lower side of the housing so that a peripheral portion of the cutting blade assembly comes in contact with the ground. Further, a plurality of cutting blades is provided on the peripheral portion of the cutting

blade assembly so as to form a predetermined shape. Brief Description of the Drawings

[16] FIG. 1 is a lower perspective view of a dry remover for removing a neutralization layer and a coating layer on a surface of a concrete structure.

[17] FIG. 2 is an upper perspective view of the dry remover for removing a neutralization layer and a coating layer on a surface of a concrete structure. [18] FIG. 3 is a view illustrating a combined state of a motor, a transmission unit, and a cutting blade assembly. [19] FIG. 4A is a cross-sectional view taken along line the A-A' of FIG. 1, and FIG. 4B is a view illustrating an arrangement state of a cutting blade and a drive wheel. [20] FIG. 5A is a perspective view showing a particular embodiment of the cutting blade assembly, FIG. 5B is a perspective view of the cutting blade, FIG. 5C is a view of the cutting blades, and FIG. 5D is a cross-sectional view of the cutting blade assembly. [21] FIGS. 6 A, 6B, and 6C are views of other particular embodiments of the cutting blades in the cutting blade assembly shown in FIG. 5, respectively. [22] FIG. 7A is a perspective view of another particular embodiment of the cutting blade assembly, FIG. 7B is a view of the cutting blades, FIG. 7C and 7D are cross-sectional views of the cutting blade assembly. [23] FIGS. 8A, 8B, 8C, 8D and 8E are views of still other particular embodiments of the cutting blades in the cutting blade assembly shown in FIG. 7, respectively. [24] FIG. 9A is a perspective view of still another particular embodiment of a cutting blade assembly, FIG. 9B is an upper perspective view showing each disk forming the cutting blade assembly, FIG. 9C is a lower perspective view showing each disk forming the cutting blade assembly, FIG. 9D is an upper perspective view showing another particular embodiment of each disk forming the cutting blade assembly, and

FIG. 9E is a lower perspective view showing another particular embodiment of each disk forming the cutting blade assembly. [25] FIG. 1OA is a plan view showing each of the cutting blades not having cutting blade cooling holes, and FIG. 1OB is a plan view showing each of the cutting blades having cutting blade cooling holes. [26] FIG. 1 IA is a view showing a conventional grinder, and FIG. 1 IB is a perspective view showing a grinding wheel used in the conventional grinder.

Best Mode for Carrying Out the Invention [27] Hereinafter, a preferred embodiment of the invention will be described in detail with reference to the accompanying drawings. [28] FIG. 1 is a lower perspective view of a dry remover for removing a neutralization layer and a coating layer on a surface of a concrete structure, FIG. 2 is an upper

perspective view of the dry remover for removing a neutralization layer and the coating layer on the surface of the concrete structure, FIG. 3 is a view illustrating that a motor 200, a transmission unit 300, and a cutting blade assembly 400 are combined to one another.

[29] A housing 100 serves as an entire body, and has an opening 110 at the lower side thereof so that the cutting blade assembly 400 to be provided in the housing comes in contact with the concrete surface, as shown in FIG. 1.

[30] The motor 200 and the transmission unit 300 are provided in the housing 100.

[31] As shown in FIG. 3, the transmission unit 300, which transmits a driving force of the motor 200 provided in the housing 100 to the cutting blade assembly 400, is connected to an output shaft of the motor 200. Accordingly, the cutting blade assembly 400 is rotated by power transmitted from the transmission unit 300.

[32] The transmission unit 300 adjusts the torque and rotational speed of the motor, and transmits the torque and rotational speed of the motor to the cutting blade assembly 400. In addition, when are used as the transmission unit 300, power generated by the motor can be transmitted at a right angle as shown in FIG. 3.

[33] As shown in FIGS. 1 and 2, the housing 100 is provided with a plurality of drive wheels 120 at the lower side thereof.

[34] The housing 100 further includes slots 140 to mount the drive wheels 120, and the slots 140 are inclined at a predetermined angle with respect to a horizontal plane. A rotary shaft of each drive wheel 120 is fixed at a predetermined position in each slot 140.

[35] Since the slots 140 are inclined at a predetermined angle with respect to a horizontal plane, the height of the lower surface of the housing 100 is determined depending on the fixed position of the rotary shaft of each drive wheel 120 in each slot 140 when the drive wheels 120 come in contact with a surface of a concrete structure.

[36] That is, since the fixed position of each drive wheel 120 determines the height of the lower surface of the housing 100, it is possible to properly adjust a depth of concrete cut by the cutting blade assembly 400, which is provided in the opening 110 at the lower side of the housing, on the surface of the concrete structure.

[37] FIG. 4A is a cross-sectional view taken along the line A-A' of FIG. 1, and shows that the cutting blade assembly 400 is mounted in the housing 100. FIG. 4B shows that a cutting blade 410 protrudes further out of the housing than the drive wheel 120 by a predetermined distance. If the cutting blade 410 does not protrude further out of the housing than the drive wheel 120 by a predetermined distance s, even though the drive wheels 120 are in contact with the surface of the concrete structure and the cutting blade assembly 400 is driven, it is not possible to cut the surface of the concrete structure.

[38] As shown in FIG. 2, the housing 100 is provided with handles 130 at predetermined positions on the upper side thereof.

[39] By means of the handles 130, a user can effectively control the dry remover for removing a neutralization layer and a coating layer on a surface of the concrete structure.

[40] That is, when using the handles 130, a user can easily move the dry remover for removing a neutralization layer and a coating layer on a surface of a concrete structure and perform an operation using the dry remover.

[41] Furthermore, the housing 100 is provided with a dust collecting hose joint opening

150. The dust collecting hose joint opening 150 communicates a portion, at which the cutting blade assembly 400 is provided, with the outside of the housing. Accordingly, it is possible to discharge dust, which is generated while the cutting blade assembly 400 is rotated to cut the surface of the concrete structure, to the outside of the housing through the dust collecting hose joint opening 150.

[42] The cutting blade assembly 400 is formed in a cylinder shape, and is horizontally mounted in the opening 110 formed at the lower side of the housing 100 so that the peripheral portion of the cutting blade assembly can come in contact with the ground. A plurality of cutting blades 410 is provided on the peripheral portion of the cutting blade assembly 400 so as to form a predetermined shape. A particular embodiment of the cutting blade assembly 400 and a particular array structure of the cutting blades 410 are shown in FIGS. 5 to 11.

[43] According to the particular embodiment of the cutting blade assembly 400 shown in

FIG. 5, the cutting blade assembly 400 is formed in a hollow cylinder shape, and includes a plurality of ventilation openings 420, a shaft insertion hole 430, a plurality of cutting blade cooling holes 415, and a plurality of peripheral portion cooling holes 440. The ventilation openings 420 are provided on the upper and lower surfaces of the cutting blade assembly 400, and the shaft insertion hole 430 passes through centers of the upper and lower surfaces of the cutting blade assembly. The cutting blade cooling holes 415 are provided to the cutting blades 410, respectively, and the peripheral portion cooling holes 440 are provided on the peripheral portion of the cutting blade assembly so as to correspond to the cutting blade cooling holes 415, respectively.

[44] In other words, the cutting blade assembly 400 includes a plurality of cutting blades

410 on the peripheral portion thereof. Further, the cutting blade assembly 400 can be ventilated through the cutting blade cooling holes 415 that are provided to the cutting blades 410, respectively, and the peripheral portion cooling holes 440 that are provided on the peripheral portion of the cutting blade assembly so as to correspond to the cutting blade cooling holes 415, respectively. Furthermore, since the ventilation openings 420 are provided on the upper and lower surfaces of the cutting blade

assembly 400, it is possible to ventilate the cutting blade assembly 400.

[45] That is, the cutting blade assembly 400 includes the cutting blade cooling holes 415, the peripheral portion cooling holes 440, and the ventilation openings 420. Accordingly, it is possible to effectively reduce frictional heat generated while the cutting blade assembly 400 is rotated to cut the surface of the concrete structure.

[46] FIG. 5A is a schematic perspective view of the cutting blade assembly. FIG. 5B is a perspective view of the cutting blade 410 provided on the peripheral portion of the cutting blade assembly 400, and shows that the cutting blade cooling hole 415 is formed at the center of the cutting blade 410.

[47] FIG. 5C is a view showing the array structure of the cutting blades 410 provided on the peripheral portion of the cutting blade assembly 400, and shows a particular embodiment in which the plurality of cutting blades 410 is arrayed on the peripheral portion of the cutting blade assembly in a matrix shape.

[48] FIG. 5D is a cross-sectional view taken along the line A-A' of FIG. 5A, and shows that the inside of the cutting blade assembly 400 communicates with the outside thereof through the cutting blade cooling holes 415 and the peripheral portion cooling holes 440.

[49] In the cutting blade assembly, the cutting blades (for example, diamond tips) are generally attached to a shank made of a steel material. In this configuration, when the cutting blade assembly performs the dry cutting of concrete, a large amount of frictional heat is generated. Attachment portions between the shank and the cutting blades are damaged due to the frictional heat, and the cutting blades detach from the shank. Accordingly, the cutting blade assembly is no longer operable, and the cutting operation frequently should be stopped. The invention provides the following structure in order to solve the above-mentioned problem. In the structure, the cutting blade cooling holes are formed at the center of the cutting blades, respectively, and the peripheral portion cooling holes are provided to the hollow cylindrical shank having the cutting blades attached thereon so as to correspond to the cutting blade cooling holes, respectively. For this reason, when the cutting blade assembly rotates, air freely passes through the cooling holes so as to reduce the frictional heat that is transmitted to the attachment portions between the cutting blades and the shank having the cutting blades attached thereon. As a result, it is possible to prevent the cutting blades from being detached from the shank.

[50] FIG. 6 also shows array structures of the cutting blades 410 provided on the peripheral portion of the cutting blade assembly 400. FIG. 6A shows an array structure in which the cutting blades 410 are arrayed in a zigzag pattern in an axial direction of the cutting blade assembly 400, and FIGS. 6B and 6C show array structures in which the cutting blades 410 are arrayed in a line in the axial direction of the cutting blade

assembly 400 and arrayed in a zigzag pattern in a circumferential direction of the cutting blade assembly 400.

[51] A particular array structure of the cutting blades 410 is not limited to the array structures shown in FIG. 6 but can be variously modified without departing from the scope of the invention.

[52] According to a particular embodiment of a cutting blade assembly 400 shown in

FIG. 7, peripheral portion cooling holes 440 are provided at positions, which do not have the cutting blades 410, on the peripheral portion of the cutting blade assembly.

[53] In a case of the cutting blade assembly shown in FIG. 7, the cutting blade cooling hole 415 is not provided to each of the cutting blades 410. Accordingly, the peripheral portion cooling holes 440 should be provided at positions, which do not have the cutting blades 410, on the peripheral portion of the cutting blade assembly in order to ventilate the cutting blade assembly 400.

[54] As a result, in the case of the cutting blade assembly shown in FIG. 7, when the cutting blade assembly is ventilated through the peripheral portion cooling holes 440 and the ventilation openings 420, it is possible to reduce frictional heat generated while the cutting blade assembly cuts the surface of the concrete structure.

[55] FIG. 7A is a perspective view of the cutting blade assembly 400. FIG. 7B is a view showing the array structure of the cutting blades 410 provided on the peripheral portion of the cutting blade assembly 400, and shows a particular embodiment in which the plurality of cutting blades 410 is vertically or horizontally arrayed on the peripheral portion of the cutting blade assembly in a matrix shape and the peripheral portion cooling holes 440 are vertically or horizontally provided at positions not having the cutting blades 410 on the peripheral portion thereof.

[56] FIG. 7C is a cross-sectional view taken along the line A-A' of FIG. 7A, and shows the cross-section of the cutting blade, which does not have the cutting blade cooling hole 415.

[57] FIG. 7D is a cross-sectional view taken along the line B-B' of FIG. 7B, and shows that the inside of the cutting blade assembly 400 communicates with the outside thereof.

[58] FIG. 8 also shows array structures of the cutting blades 410 provided on the peripheral portion of the cutting blade assembly 400. FIG. 8A shows an array structure in which the cutting blades 410 are arrayed in a zigzag pattern in the axial direction of the cutting blade assembly 400, and FIGS. 8B, 8C, 8D and 8E show array structures in which the cutting blades 410 are arrayed in a line in the axial direction of the cutting blade assembly 400 and arrayed in a zigzag pattern in the circumferential direction of the cutting blade assembly 400. In particular, FIG. 8E shows an array structures in which two types of cutting blades 410 having different shapes are alternately arrayed

in the circumferential direction of the cutting blade assembly 400.

[59] In FIG. 8, the cutting blade cooling hole 415 is not provided to each of the cutting blades, and the peripheral portion cooling holes 440 are provided at positions, which do not have the cutting blades 410, on the peripheral portion of the cutting blade assembly at predetermined intervals.

[60] A particular array structure of the cutting blades 410 is not limited to the array structures shown in FIG. 8 but can be variously modified without departing from the scope of the invention.

[61] According to another particular embodiment of a cutting blade assembly 400 shown in FIG. 9, the cutting blade assembly 400 is configured such that a plurality of disks 450 having a predetermined thickness is combined to each other. Each of the disks 450 includes cutting blades 451, cooling grooves 452, a plurality of disk cooling holes 453, a spacer 454 and a shaft insertion hole 455. The cutting blades 451 are formed on the peripheral portion of each disk at predetermined intervals, and the cooling grooves 452 are formed between the cutting blades 451 by incising the peripheral portion of each disk. The plurality of disk cooling holes 453 passes through the upper and lower surfaces of the disk, and the spacer 454 protrudes from the lower surface of the disk at the center of the disk. The shaft insertion hole 455 passes through the center of the spacer 454.

[62] The cutting blade assembly 400 shown in FIG. 9 is formed in a solid cylinder shape, not a hollow cylinder shape, consisting of a plurality of disks 450.

[63] Each of the disks 450 forming the cutting blade assembly 400 includes the plurality of cutting blades 451 on the peripheral portion thereof, and each of the cooling grooves 452 that is formed between the cutting blades 451 by incising the peripheral portion of the disk.

[64] In addition, each of the disks includes the disk cooling holes 453 passing through the upper and lower surfaces of the disk.

[65] Accordingly, the frictional heat of the cutting blade assembly 400 is reduced by means of the disk cooling holes 453 and the cooling grooves 452.

[66] Further, each of the disks includes the spacer 454 that protrudes from the lower surface of the disk at the center of the disk so as to be perpendicular to the lower surface thereof. Therefore, when the plurality of disks 450 is combined by inserting a shaft into the shaft insertion holes 455 of the disks, the disks 450 are spaced from each other at predetermined intervals.

[67] Since the disks 450 are spaced from each other at predetermined intervals, the cutting blades 451 can be spaced from each other and the cutting blade assembly can be ventilated between the disks 450. As a result, it is possible to reduce the frictional heat generated by the cutting blade assembly 400.

[68] FIG. 9A is a perspective view showing that the disks 450 forming the cutting blade assembly 400 are combined. FIG. 9B is an upper perspective view showing each of the disks 450 forming the cutting blade assembly 400, and FIG. 9C is a lower perspective view showing each of the disks 450 forming the cutting blade assembly 400. FIG. 9D is an upper perspective view showing another particular embodiment of the disks 450 forming the cutting blade assembly, and FIG. 9E is a lower perspective view showing another particular embodiment of the disks 450 forming the cutting blade assembly.

[69] As shown in FIGS. 9B and 9C, the cutting blades 451 and the cooling grooves 452 are alternately formed on the peripheral portion of the disk 450, and the spacer 454 is formed on the lower surface of the disk as shown in FIG. 9C.

[70] As shown in FIGS. 9D and 9E, the cooling grooves 452 and the cutting blades 451 are alternately formed on the peripheral portion of the disk 450 at predetermined intervals, and the spacer 454 is formed on the lower surface of the disk as shown in FIG. 9E.

[71] In other words, portions not having the cutting blades 451 are formed on the peripheral portion of the disk. That is, since the cutting blades are sparsely formed on the peripheral portion of the disk, it is possible to improve the cooling efficiency.

[72] FIG. 10 is a plan view showing various embodiments of the cutting blades 410 and

451. FIG. 1OA shows each of cutting blades not having cutting blade cooling holes 415, and FIG. 1OB shows each of cutting blades having cutting blade cooling holes 415. However, particular shapes of the cutting blades 410 and 451 are not limited to the shapes shown in FIG. 10, and can be modified in various shapes.

[73] The above-mentioned dry remover according to the invention can be used for various purposes depending on the size thereof. That is, when having a small size, the dry remover can be used to cut a ceiling or wall. When having a middle or large size, the dry remover can be used to cut a floor. Industrial Applicability

[74] The dry remover according to the invention has the following advantages.

[75] First, it is possible to rapidly remove a paint layer on the surface of the concrete structure.

[76] In other words, the invention has a technical principle in which the cutting blades

410 provided on the peripheral portion of the cutting blade assembly 400 cut the surface of the concrete structure while the cutting blade assembly 400 is rotated. Accordingly, according to the invention, it is possible to rapidly remove the paint layer that is painted on the surface of the concrete structure.

[77] Second, it is possible to completely remove the paint layer on the surface of the concrete structure.

[78] In other words, the dry remover according to the invention has an improved effect for cutting the surface of the concrete structure unlike a conventional grinder. Accordingly, it is possible to completely remove the paint layer on the surface of the concrete structure.

[79] That is, since the function of the dry remover according to the invention does not deteriorate by the viscosity of the paint, it is possible to rapidly and completely remove the paint layer on the surface of the concrete structure.

[80] Third, it is possible to remove the paint layer and to allow the surface of the concrete structure to have proper surface roughness.

[81] That is, according to the dry remover of the invention, the cutting blades 410 do not continuously come in contact with the surface of the concrete structure to grind the surface of the concrete structure, but are rotated and apply impacts on the surface of the concrete structure to gradually cut the surface of the concrete structure. Accordingly, it is possible to remove the paint layer and to allow the surface of the concrete structure to have proper surface roughness.

[82] When the surface of the concrete structure is allowed to have proper surface roughness, it is possible to remarkably improve adhesive strength caused by an adhesive.

[83] In addition, since all of the processes are performed in a dry condition, the processed surface of the concrete structure is kept in a dry condition. Therefore, as soon as the cutting has been completed, it is possible to perform the succeeding processes for applying an adhesive on the surface of the concrete structure and for attaching a reinforcing member such as a fiberboard on the surface of the concrete structure. As a result, it is possible to reduce the term of works and to prevent construction failure such as an attachment failure caused by humidity from occurring.