[Document Type] Specification [Title of the Invention] Chip Discharge Conveyor System Provided With a Separation Function [Detailed Description of the Invention] [0001] [Technical Field of the Invention] During a metal working or a resin finishing process such as cutting or grinding performed by a machine tool, a machine tool discharges coolant and chips of assorted sizes, including cutting or grinding chips of iron-, aluminum-, or copper-based metal or resin that are discharged from the machine tool. The present invention relates to a chip discharge conveyor system provided with a separation function, whereby dirty coolant containing chips of assorted sizes is charged into a treatment tank comprising a hinged belt type conveyor provided in the treatment tank such that the hinged belt conveyor runs and circulates; and whereby chips separated from coolant are transported by a discharge belt, which is a portion of a hinged belt of the conveyor, the hinged belt serving to transport and discharge chips and running at the top, to a chip discharge portion to discharge them out from the treatment tank, and whereby coolant separated from chips by a separating screen box provided between the discharge belt and a return belt, the return belt being a portion of the hinged belt and functioning as a return portion of the conveyor while running at the bottom, is drained in the lateral outward direction of the treatment tank.

[00023 [Prior Art) When a machine tool cuts or grinds metal or resin material, a coolant such as cutting oil or lubricant dissolved in water is used to cool the cutting or grinding tool, or workpiece. A conventional hinged belt type chip discharge conveyor system wherein a hinged belt conveyor removes chips from dirty coolant discharged from a machine tool and discharges such chips out from a treatment tank while coolant is drained out from the treatment tank through a drain hole provided in the treatment tank is publicly known.

It should also be noted that a scraper type chip discharge conveyor system wherein a scraper type conveyor removes chips from dirty coolant discharged from a machine tool and discharges such chips from a treatment tank while coolant is drained from a treatment tanlc through a drain hole provided in a treatment tank or from a separating screen box provided between a return chain which runs at the top and a transport chain which runs at the bottom is known.

[0003] [Problems to be Solved by the Invention] In a conventional chip discharge conveyor system as mentioned above, when a drain hole is provided in the treatment tank, coolant and a massive amount of small chips are discharged into a coolant storage tank through the drain hole because no mechanism to discharge small chips is specially provided. Consequently, the coolant storage tank requires bothersome frequent cleaning.

[0004] In the above-mentioned conventional hinged belt type chip discharge conveyor system, when dirty coolant is charged into the treatment tank, relatively large chips are caught by a discharge belt and carried to a chip discharge portion to be discharged outside. However, small chips precipitate, passing through a clearance between two adjacent hinged plates of the hinged belt or a clearance of a side chain, while a part of the small chips are caught on a return belt and transported to a conveyor tail portion.

[0005] However, a cavity is created between tail disks whereby the side chains on both sides of the hinged belt forming the conveyor are wound. Consequently, when the return belt makes an upward turn at the conveyor tail portion, chips which are carried on the return belt continuously drop onto the return belt inside the upturn belt section and remain in the cavity inside the upturn belt section, where the chips gradually aggregate to become a sausage-like mass.

[0006] The mass of chips grown inside the upturn belt section then vertically pushes the discharge belt and the return belt, which consequently stops the conveyor in due course. Whenever the conveyor shuts down due to a mass of chips like this, the conveyor must be detached from the inside of the machine tool and the hinged belt must be detached from the conveyor for cleaning.

[0007] In the past, according to the size of chips charged with coolant, a hinged type conveyor was selected when the majority of the chips were relatively large-sized, while a scraper type conveyor was selected when the majority of the chips were relatively small-sized. However, due to enhanced performance achieved by recent machine tools or due to more complicated machining procedures, the forms of chips to be discharged are becoming more complicated, making it difficult to categorize chips in a simple manner, as mentioned before. Under such circumstances, a hinged type chip discharge conveyor system can carry relatively large chips but not relatively small chips, which causes the problem as described above. A scraper type chip discharge conveyor can carry relatively small chips, however, it cannot discharge relatively large chips which are tangled in the cleats. Consequently, problems arise, wherein chips accumulated between a separating screen box and the cleats cause clogging, chips tangled around a driving shaft aggregate into a tube-like mass, pressing cleats out and causing deterioration of the mesh between the chain and a driving chain wheel, which consequently shuts down the conveyor. Whenever the conveyor shuts down, the conveyor must be detached from the inside of the machine tool to detach the hinged belt from the conveyor for cleaning.

[0008] It is accordingly a general object of the present invention to overcome the foregoing drawbacks of the prior art.

A more specific object of the invention is to provide a chip discharge conveyor system provided with a separation function which can prevent chips from remaining inside the upturn belt section at the conveyor tail portion and causing a mass of chips to aggregate when dirty coolant containing chips of assorted sizes is treated, can prevent a massive amount of relatively small-sized chips from running out into the coolant storage tank, can remove chips adhering to a perforated plate provided as either the top surface or bottom surface plate of the separating screen box while preventing clogging, and, moreover, can serve as a chip discharge conveyor system that uses only one conveyor to handle dirty coolant, regardless of the conditions of chips to be charged.

[0009] [Means for Solving the Problem] To achieve the foregoing object, the invention according to claim 1 is a chip discharge conveyor system provided with a separation function, comprising a treatment tarllc wherein a hinged belt type conveyor is provided such that the hinged belt conveyor runs and circulates while making a turn at a conveyor tail portion and at a chip discharge portion, and the hinged belt type conveyor is also provided with a separating screen box disposed between a discharge belt and a return belt of the conveyor, whereby dirty coolant containing chips of assorted sizes is charged into the treatment tank and the chips of assorted sizes are removed and transported by the discharge belt to a chip discharge portion to be discharged outside of the treatment tank while filtered coolant which is filtered by a separating screen box is discharged to the exterior of the treatment tank, wherein a cylindrical member is provided inside the conveyor tail portion where the return belt makes an upward turn in the width direction thereof, a partition plate is provided below the discharge belt of the conveyor in confronted relation to the discharge belt along the length thereof, the separating screen box is provided at an opening of the partition plate such that a top surface of the separating screen box approximately aligns with the partition plate surface; and an outer cleat attached to an outer circumferential surface of a belt of the conveyor while a chip scraping device is attached to an inner circumferential surface of the belt.

The invention according to claim 2 is a chip discharge conveyor system provided with a separation function according to claim 1, wherein the separating screen box comprises a top surface plate and a bottom surface plate, and wherein at least one of either the top surface plate or the bottom surface plate is a perforated plate with a plurality of holes.

[0010] In the invention mentioned above, for the hinged belt conveyor, the term "discharge belt"is used to refer to the hinged belt which runs at the top, while the term "return belt"is used to refer to the hinged belt which runs at the bottom. It should also be noted that the term"longitudinal direction"is used herein to refer to the direction parallel to the direction that an endless hinged belt runs, while the term"width direction"is used herein to refer to the direction perpendicular to the direction that the hinged belt runs. For chips of assorted sizes, the term 'large chips"is used to refer to those chips such as long chips, curled chips and a mass of chips whose sizes are big enough not pass through a clearance of a hinged belt but are caught by the discharge belt, while the term"small chips"is used to refer to those chips whose sizes are small enough to precipitate, passing through a clearance between two adjacent hinged plates of the hinged belt, or a clearance of the side chain. One separating screen box is mounted or a plurality of separating screen boxes are mounted, at appropriate intervals.

[OQ11] [Operation of the Invention] In the previously described chip discharge conveyor system, when dirty coolant containing chips of assorted sizes is charged into the treatment tank, large chips are caught on the discharge belt to be transported and discharged. Small chips which are not caught by the discharge belt are accumulated onto the partition plate, are caught on the return belt (on an inner circumferential surface of the hinged belt), or precipitate and accumulate onto the bottom plate of the treatment tank. The small chips accumulated onto the bottom plate of the treatment tank are scraped by the outer cleats of the return belt which runs at the bottom, and scooped up by the return belt when it makes an upward turn at the conveyor tail portion, then, the scooped chips are transported and discharged along with large chips by the discharge belt which runs at the top.

[0012] It should also be noted that the small chips caught on the return belt stay on the return belt to be transported to the conveyor tail portion, and, when the conveyor makes an upward turn at the conveyor tail portion, the small chips are transported in a partial circumferential path along the length of the cylindrical member provided at the upturn belt portion and then transferred onto the partition plate via a chip scraping device mounted on the inner circumferential surface of the hinged belt. Consequently, such small chips as well as chips caught on the partition plate are transported on and along the partition plate, using the chip scraping device, to discharge the chips at the chip discharge portion.

[0013] Meanwhile, coolant separated from chips by the separating screen box is drained in the lateral outward direction of the treatment tank. It should also be noted that chips adhering to the perforated plate at the top of the separating screen box are scraped by the chip scraping device mounted on the inner circumferential surface of the conveyor belt and transferred onto the partition plate, while chips adhering to the perforated plate at the bottom of the separating screen box are scraped by the chip scraping device onto the return belt.

[0014] [Embodiments of the Invention] One embodiment of the invention is described in reference to Figures 1 to 9.

As shown in Figure 1, a chip discharge conveyor system 1 provided with a separation function whereby chips are separated from coolant generally comprises a treatment tank 2 for dirty coolant K, a hinged belt type conveyor 4 comprising an endless hinged belt 3 provided inside the treatment tank 2, a cylindrical member 5 provided inside an upturn belt section where a return belt 4b rnakes an upward turn at a conveyor tail portion A, a longitudinally extending partition plate 6 provided below a discharge belt 4a in a confronted relation to the discharge belt 4a, and a separating screen box 8 provided between the partition plate 6 and an opening 6a.

[0015] In the chip discharge conveyor system 1, when dirty coolant K containing chips of assorted sizes is charged into the treatment tank 2, only chips of assorted sizes kl and k2 are transported to a chip discharge portion B and discharged to a chip collection box D, while coolant C separated by the separating screen box 8 outflows to a coolant storage tank E located below or by the side of the treatment tank 2. F in each Figure denotes the direction for the conveyor to advance.

[0016] The chip discharge conveyor system provided with a separation function is specifically described as follows. As shown in Figures 1 to 3, the treatment tank 2 comprises a horizontal bottom plate 2b extending from a cover 2a of the conveyor tail A, an inclined wall surface plate 2c extending from the bottom plate 2b toward a chip discharge portion B located diagonally upward, and a curved plate 2d.

[0017] The hinged belt type conveyor 4 comprises the hinged belt 3 whose side chain 3b is wound around a tail disk 4c at the conveyor tail portion A, and around a driving sprocket 4d at the chip discharge portion B, so that the conveyor 4 can circulate.

[0018] As shown in Figures 4 and 5, the hinged belt 3 comprises a plurality of hinged plates 3a connected with one another by belt pins 3c inserted through hinge sleeves 3a'.

The hinged plates 3a are longitudinally arranged between a pair of side chains 3b each consisting of a roller chain. The hinge sleeves 3a'each form together with one belt pin 3c a joint portion of the hinged plate 3a. The side chain 3b comprises a link plate 3d and a roller 3e, and the belt pin 3c is inserted through the roller 3e.

[0019] Each of the hinged plates 3a has a pair of side wings 3f attached to opposite ends thereof in the width direction of the hinged belt 3. As shown in Figure 3, each of the side wings 3f is composed of a wing plate 3fl and a mounting plate 3f2 and is attached to the hinged plate 3a via the mounting plate 3f2. Adjacent wing plates 3fl of one side wing 3f overlap with each other in the width direction of the hinged belt 3 so that there is no space formed between adjacent wing plates 3fl even when the hinged belt 3 makes an upward turn at the conveyor tail portion A.

[0020] An outer circumferential surface of the hinged belt 3 has outer cleats 3g which are mounted at intervals of several units of hinged plates 3a, while an inner circumferential surface of the hinged belt 3 has brushes 3h which are chip scraping devices to be mounted, keeping a certain interval. The brush 3h is mounted, having its brush base plate 3hl attached to the outer cleat 3g while making the brush 3h project from a long hole formed on the hinged plate 3a toward the belt inner circumferential surface (see Figures 3,7, 8, and others).

[0021] As shown in Figures 3 and 6, the conveyor 4 circulates while making an upward turn at the conveyor tail portion A, wherein a pair of tail disks 4c are provided to wind the side chain 3b of the hinged belt 3, and a cylindrical member 5 composed of a pipe or a tube is provided between the pair of tail disks 4c, namely, along the width direction.

[0022] The cylindrical member 5 functions, as an assistant member, to guide and support the small chips k2 caught on the return belt 4b by means of brushes 3h to carry small chips k2 in a partial circumferential path along the length of the cylindrical member 5 to the partition plate 6 when the hinged belt 3 makes an upward turn.

Therefore, the cylindrical member 5 doesn't need to rotate. In Figure 6,2f denotes a return belt truck which guides and supports the return belt 4b, while 2g denotes a hold-down truck which guides, supports, and holds down the discharge belt 4a.

[0023] The flat surface plate partition plate 6 whose width is approximately the same as that of the hinged belt 3 is provided below the discharge belt 4a of the conveyor 4 in a confronted relation to the discharge belt 4a extending over the longitudinal direction.

A chip discharge mechanism 7 is provided to the partition plate 5 at the chip discharge portion B to discharge the small chips k2 carried onto the partition plate 6.

[0024] As shown in Figures 1 and 9, this charge mechanism 7 comprises an opening in the top'portion of the chip discharge mechanism 7a formed by the chip discharge portion B and the partition plate 6, a trough provided at the opening in the top portion of the chip discharge mechanism 7a, and a screw conveyor 7c disposed inside the trough 7bi The screw conveyor 7c is driven by a sprocket 7d which engages with the side chain 3b. Chips transported on and along the partition plate 6 by the brush 3 drop at the opening in the top portion of the chip discharge mechanism 7a into the trough 7b, and are discharged by the screw conveyor 7c in the outward direction of the treatment tank 2.

[0025] As shown in Figures 2,3, 8, and others, the separating screen box comprising a separation function to separate clean coolant from dirty coolant is an approximately rectangular body which consists of a top surface plate 8a and a bottom surface plate 8b.

The top surface plate comprises a plane plate with no holes or a perforated plate with a plurality of holes, while the bottom surface plate 8b may comprise either a plane plate with no holes or a perforated plate with a plurality of holes. An outflow opening 8c for coolant is provided in one or both lateral sides of the separating screen box.

[0026] It should also be noted that 8d in Figure 2 denotes a mounting flange for the separating screen box 8. The mounting flange 8d makes the separating screen box 8 demountable, whereby the separating screen box 8 can be bolted onto a side wall of the treatment tank 2.2g in Figure 8 denotes a mounting structure for the separating screen box 8.

[0027] The separating screen box 8 is provided between the discharge belt 4a and the return belt of 4b of the conveyor 4 and mounted at an opening 6a of the partition plate 6, approximately aligning the top surface plate 8a of the separating screen box 8 with the surface of the partition plate 6. The opening 6a of the partition plate 6 is formed by a space created between partition plates separated from each other. It should also be noted that separating screen box 8 is provided or a plurality of separating screen boxes 8 are provided, keeping appropriate intervals.

[0028] The following is a description of the operation of the chip discharge conveyor system as described above. When dirty coolant K containing chips of assorted sizes is charged into the treatment tank 2 from above, large chips kl are caught on the discharge belt 4a, and transported to and discharged at the chip discharge portion B located diagonally above the treatment tank 2 for chip collection by the chip collection box D.

In this case, the chip discharge belt 4a runs diagonally upward receiving chips by the action of outer cleats 3g, while draining coolant off from chips to be discharged.

[0029] if Small chips k2 which are not caught on the discharge belt 4a accumulate and are-caught onto the partition plate 6, or are caught on the return belt 4b, or precipitate and accumulate onto the horizontal bottom plate 2b which serves as a bottom plate of the treatment tank 2.

[0030] Small chips k2 accumulated onto the bottom plate 2b are scraped out by the outer cleat 3g of the return belt 4b running along the bottom plate 2b and transported to the conveyor tail portion A, wherein such chips are scooped up by the return belt 4b when the return belt 4b makes an upward turn, and then, the scooped chips are transported and discharged along with large chips by the discharge belt which runs at the top. At this time, some of small chips k2 drop down from the discharge belt 4a and precipitate, and are then scraped again to be transported.

[0031] It should also be noted that the small chips k2 caught on the return belt 4b stay on the return belt 4b to be transported to the conveyor tail portion A, and when the hinged belt 3 of the conveyor 4 makes an upward turn, the small chips are transported in a partial circumferential path along the length of the cylindrical member 5 provided at the upturn belt portion via the brush 3h attached to the inner circumferential surface of the hinged belt 3, and then transferred onto the partition plate 6 via the brush 3h.

Consequently, such small chips as well as the chips k2 caught on the partition plate 6 are transported on and along the partition plate 6 to the discharge portion B, using the brush 3h of the discharge belt 4a and the partition plate 6, ensuring that the chip discharge mechanism 7 discharges chips which are collected by the chip collection box.

[0032] In this case, chips k2 adhering to the top surface perforated plate 8a of the separating screen box 8 are scraped off by the brush 3h and are transferred onto the adjacent partition plate 2 to be transported to the chip discharge portion B. Chips adhering to the bottom surface perforated plate 8b are scraped onto the return belt 4b and are transferred onto the partition plate 6 when the return belt 4b makes an upward turn as described above. In this case, scraping performed by the brush 3 prevents the perforated plate 8a from clogging.

[0033] Meanwhile, coolant is separated by the separating screen box 8, while running out through either the top perforated plate 8a, or the bottom surface perforated plate 8b, or through both top surface and bottom surface perforated plates, 8a and 8b, is drained through a coolant discharge opening 8c in the lateral outward direction of the treatment tatk 2 to be collected in a coolant storage tank E.

[0034] One embodiment has been explained, however a metal inner plate can be used as a chip scraping device instead of the brush 3h. It also should be noted that the hinged plate 3a may be a plane plate with no holes as in the explained embodiment, a plate having a plurality of small holes or perforations, a dimpled plate having a plurality of small hollows or dimples in one surface, or any combination of these.

[0035] Instead of using the screw conveyor as the chip discharge mechanism 7 provided at the chip discharge portion of the partition plate, the trough can be provided at an opening in the top portion of the chip discharge mechanism 7, inclining diagonally downward toward the lateral side of the treatment tank to make chips slide into the treatment tank. In this case, a supply of clean coolant with the trough facilitates the discharge of chips.

[0036] [Effects of the Invention] As described above, in the chip discharge conveyor system provided with a separation function according to the invention, large chips can be caught, transported, and discharged by a discharge belt, while small chips precipitated and accumulated onto a horizontal bottom plate are scraped off by an outer cleat on a return belt, and scooped up by the return belt when the return belt makes an upward turn at a conveyor tail, and then, the scooped chips can be transported by the discharge belt running at the top to discharge the chips at a chip discharge portion.

[0037] Since a partition plate is provided below the discharge belt of the conveyor in confronted relation to the discharge belt along the length thereof while a cylindrical member is provided inside the conveyor tail portion where the return belt of the conveyor makes an upward turn, in the width direction thereof, small chips caught on the return belt can be transferred onto the partition plate along the cylindrical member, using a chip scraping device mounted on an inner circumferential surface of the conveyor belt and the cylindrical member when the return belt makes an upward turn at the conveyor tail portion. As a result, development of a mass of chips inside an upturn belt section can be prevented, which consequently prevents the conveyor from shutting down due to an aggregated mass of chips.

[0038] It should also be noted that the chip scraping device mounted on the inner circumferential surface of the conveyor hinged belt helps chips to be transported along the cylindrical member, the partition plate and a top surface plate of a separating screen box. Additionally, the chip scraping device makes it possible to remove chips adhering to the top surface plate and/or to a bottom surface plate of the separating screen box, which consequently prevents a perforated plate of the separating screen box from clogging. As a result, both coolant recovery rate and coolant treatment efficiency are enhanced, thereby frequency of maintenance can be reduced.

[0039] As described above, since the cylindrical member and the partition plate are provided with a treatment tank while a chip scraping device is mounted on an inner circumferential surface of a belt according to the invention, chips can be discharged, using a discharge belt, whereby chips of assorted sizes and coolant, both of which are separated from dirty coolant, can be separately collected at the same time, and dirty coolant containing chips of assorted sizes can be handled by one chip discharge conveyor system that uses only one conveyor.

[Brief Descriptions of the Drawings] [Figure 1] Schematic side view of a chip discharge conveyor system according to one embodiment of the present invention [Figure 23 Perspective view of the essential features of Figure 1 [Figure 3] Enlarged side view of a conveyor tail portion from above [Figure 4] Fragmentary plan view of a hinged belt of the chip discharge conveyor system of figure 1 [Figure 5] Perspective view of a side wing of the discharge conveyor system of figure 1 [Figure 6] Cross-sectional view taken along line X-X'of Figure 4 [Figure 7] Cross-sectional view taken along line Y-Y'of Figure 4 [Figure 8] Cross-sectional view taken along line Z-Z'of Figure 4 [Figure 9] Plan view of the vicinity of a chip discharge mechanism of the discharge conveyor system of figure 1 [Brief Description of the Reference Symbols] 1 chip discharge conveyor system 2 treatment tank 2a cover 2b horizontal bottom plate 2c inclined wall surface plate 2d curved plate 2g separating screen box mounting structure 3 hinged belt 3a hinged plate 3b side chain 3c belt pin 3f side wing 3g outer cleat 3h brush 4 conveyor 4a top discharge belt 4b bottom return belt 4c tail disk 4d driving sprocket 5 cylindrical member 6 partition plate 6a opening 7 chip discharge mechanism 7a opening at the top portion of chip discharge mechanism 7b trough 7c screw conveyor 7d sprocket 8 separating screen box 8a top surface plate 8b bottom surface plate 8c coolant discharge opening 8d mounting flange A conveyor tail portion B chip discharge portion D chip collection box K dirty coolant kl, k2 chips of assorted sizes