JP7095396B2 - Rubber sheet cutting device - Google Patents

Description

The present invention relates to a rubber sheet cutting device.

Japanese Unexamined Patent Publication No. 2000-141510 discloses a rubber sheet cutting device. In this cutting device, the rubber sheet is conveyed to a predetermined cutting position. The rubber sheet to be conveyed slides on the sliding surface of the traveling plate. This rubber sheet is cut at a predetermined cutting position. By this cutting, a sheet piece is formed from the rubber sheet. Similarly, JP-A-2017-132143 also discloses a rubber sheet cutting device.

Japanese Unexamined Patent Publication No. 2000-141510 JP-A-2017-132143

Rubber sheets for tires have high adhesive strength. This rubber sheet causes a large sliding resistance when sliding on the sliding surface of the traveling plate. This sliding resistance causes variation in the cutting width of the sheet piece. In addition, this rubber sheet easily adheres to the sliding surface. The occurrence of this adhesion causes the cutting device to stop.

An object of the present invention is to provide a cutting device provided with a sliding surface on which a rubber sheet for a tire can easily slide.

The cutting device according to the present invention includes a cutting tool for cutting a rubber sheet for a tire, and a traveling plate for supporting the rubber sheet cut by the cutting tool. The traveling plate has an upper surface. A sliding surface on which the rubber sheet slides and a non-sliding groove are formed on the upper surface.

Preferably, the non-sliding groove extends so as to be inclined outward from the center in the width direction of the sliding surface toward the direction in which the rubber sheet slides on the sliding surface.

Preferably, the absolute value of the inclination angle θt formed by the sliding direction of the rubber sheet and the extending direction of the non-sliding groove is 10 ° or less.

The non-sliding groove includes a front wall surface in front of the rubber sheet in the feed direction. Preferably, the wall surface angle θw formed by the front wall surface and the sliding surface is an obtuse angle.

A plurality of the non-sliding grooves are formed on the upper surface. Preferably, the pitch of the non-sliding groove is 10 mm or more and 100 mm or less.

Preferably, the width of the non-sliding groove is 0.5 mm or more and 1.5 mm or less.

Preferably, the cutting device is used for cutting the rubber sheet including the cord and the topping rubber covering the cord.

The method for cutting a rubber sheet according to the present invention includes a transport step of sliding a rubber sheet for a tire on an upper surface on which a non-sliding groove and a sliding surface are formed and transporting the rubber sheet to a cutting position, and a method of cutting the rubber sheet. It is provided with a molding process of cutting at a position.

Preferably, in this cutting method, the rubber sheet comprises a cord and a topping rubber covering the cord.

In the cutting device according to the present invention, a sliding surface and a non-sliding groove are formed on the upper surface of the traveling plate. On this upper surface (sliding surface), the contact area with the rubber sheet is reduced. The sliding surface of this cutting device makes it easy for the rubber sheet to slide.

FIG. 1 is a conceptual diagram showing a cutting device according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a part of a rubber sheet cut by the cutting device of FIG. 1. FIG. 3 is a partially enlarged view of the cutting device as viewed in the direction of arrow III in FIG. FIG. 4 is a partially enlarged view seen in the direction of arrow IV in FIG. FIG. 5 is an enlarged cross-sectional view taken along the line segment VV of FIG. FIG. 6 is an explanatory diagram showing a usage state of the cutting device of FIG.

Hereinafter, the present invention will be described in detail based on a preferred embodiment with reference to the drawings as appropriate.

The cutting device 2 shown in FIG. 1 includes a cutting tool 4, a traveling plate 6, and a conveyor 8 as a transport device. FIG. 1 shows a rubber sheet 10 to be cut by the cutting device 2 and a sheet piece 12 formed from the rubber sheet 10. The arrow X in FIG. 1 indicates the front-back direction and the front direction of the cutting device 2, the arrow Y indicates the left-right direction and the left direction, and the arrow Z indicates the vertical direction and the upward direction.

The cutting tool 4 includes a guide 14, a holder 16, and a cutter 18. The guide 14 is arranged above the traveling plate 6. The guide 14 extends in the left-right direction. The guide 14 supports the holder 16. The guide 14 has a function of moving the holder 16 in the left-right direction. The holder 16 has a function of holding the cutter 18. The cutter 18 is movable in the left-right direction together with the holder 16.

The traveling plate 6 includes a front traveling plate 20 and a rear traveling plate 22. The front traveling plate 20 and the rear traveling plate 22 are arranged in the front-rear direction with the cutting groove 24 through which the moving cutter 18 is passed. The front traveling plate 20 is arranged in front of the cutting groove 24. The rear traveling plate 22 is arranged behind the cutting groove 24.

The front traveling plate 20 includes a front upper surface 20f as an upper surface that is an upward facing surface. A front sliding surface 20a as a sliding surface is formed on the front upper surface 20f. The rear traveling plate 22 is provided with a rear upper surface 22f as an upper surface. A rear sliding surface 22a as a sliding surface is formed on the rear upper surface 22f. The front sliding surface 20a and the rear sliding surface 22a are arranged in the front-rear direction with the cutting groove 24 in between. The front sliding surface 20a is located in front of the cutting groove 24. The rear sliding surface 22a is located behind the cutting groove 24.

The conveyor 8 includes a front conveyor 26 and a rear conveyor 28. The front conveyor 26 is arranged in front of the rear conveyor 28. The front conveyor 26 and the rear conveyor 28 extend in the front-rear direction, respectively. The conveyor 8 is composed of a front conveyor 26 and a rear conveyor 28. The conveyor 8 may have a function of transporting the rubber sheet 10 and the sheet piece 12 in the front-rear direction, and even one conveyor may have three or more conveyors. It may be composed of. In this cutting device 2, the front conveyor 26 and the rear conveyor 28 are belt conveyors, respectively. Other conveyors such as a roller conveyor may be used as the front conveyor 26 and the rear conveyor 28.

The rubber sheet 10 is cut by the cutting tool 4. By this cutting, the sheet piece 12 is formed from the rubber sheet 10. The double-headed arrow Ws in FIG. 1 represents the cutting width of the sheet piece 12.

FIG. 2 shows a partially enlarged view of the rubber sheet 10. As shown in FIG. 2, the rubber sheet 10 is composed of a large number of cords 30 arranged in parallel and an unvulcanized topping rubber 32 covering these cords 30. The rubber sheet 10 has a long strip shape. Each cord 30 extends in the longitudinal direction of the rubber sheet 10. The rubber sheet 10 is a material that forms each part of the tire such as a belt, a carcass, and a reinforcing layer. The alternate long and short dash line CL represents a center line extending in the longitudinal direction of the rubber sheet 10. The alternate long and short dash line La represents the center line of the code 30. This center line La extends parallel to the center line CL.

FIG. 3 shows an enlarged view of a part of the traveling plate 6 and the conveyor 8 as seen in the direction of arrow III in FIG. The left-right direction in FIG. 3 represents the front-back direction forward direction. The traveling plate 6 is arranged on the conveyor 8 (conveyor 26 and conveyor 28). In the vertical direction, a gap 34 is formed between the conveyor 8 (conveyor 28) and the traveling plate 6. A cutting groove 24 is located between the rear upper surface 22f of the rear traveling plate 22 and the front upper surface 20f of the front traveling plate 20. A cutting groove 24 is located between the front end 22b of the rear sliding surface 22a of the rear traveling plate 22 and the rear end 20c of the front sliding surface 20a of the front traveling plate 20. The rear end 22c of the rear sliding surface 22a is located near the surface of the conveyor 8 (conveyor 28). The rear sliding surface 22a is inclined from the lower side to the upper side from the rear end 22c toward the front end 22b. The front sliding surface 20a is inclined from the upper side to the lower side from the rear end 20c toward the front end 20b. The front end 20b of the front sliding surface 20a is located near the surface of the conveyor 8 (conveyor 26).

FIG. 4 shows the rear sliding surface 22a as viewed in the direction of arrow IV in FIG. The alternate long and short dash line Lb represents a center line extending in the front-rear direction of the rear sliding surface 22a. The rear traveling plate 22 is provided with a plurality of non-sliding grooves 36. Each non-sliding groove 36 is formed between the rear sliding surfaces 22a. If the non-sliding groove 36 is not formed, the non-sliding groove 36 is formed in a portion forming a part of the rear sliding surface 22a.

The double-headed arrow θt in FIG. 4 represents the angle formed by the center line Lb and the center line of the non-sliding groove 36. This angle θt represents the inclination angle of the non-sliding groove 36. The inclination angle θt is measured along the rear sliding surface 22a. The inclination angle θt is expressed with respect to the center line Lb, with clockwise as positive and counterclockwise as negative. The double-headed arrow Pg represents the pitch of the non-sliding groove 36. This pitch Pg is measured as the distance between the center line of the non-sliding groove 36 and the center line of another non-sliding groove 36 adjacent to the non-sliding groove 36. This pitch Pg is measured along the rear sliding surface 22a.

Each non-sliding groove 36 extends inclined with respect to the center line Lb. The non-sliding groove 36 extends from the rear to the front with an outward inclination in the left-right direction from the center line Lb. On the rear sliding surface 22a on the right side of the center line Lb, the non-sliding groove 36 is inclined at an inclination angle θt. On the rear sliding surface 22a on the left side of the center line Lb, the non-sliding groove 36 is inclined at an inclination angle −θt. These non-sliding grooves 36 are inclined symmetrically with respect to the center line Lb.

FIG. 5 shows a cross section along the line segment VV of FIG. The non-sliding groove 36 includes a front wall surface 38 and a rear wall surface 40. The front wall surface 38 is continuous with the rear sliding surface 22a. The front wall surface 38 extends from the rear sliding surface 22a toward the bottom 42. The point P1 represents a boundary point between the rear sliding surface 22a and the front wall surface 38 in this cross section. The rear wall surface 40 is continuous with the rear sliding surface 22a. The rear wall surface 40 extends from the rear sliding surface 22a toward the bottom 42. The point P2 represents a boundary point between the rear sliding surface 22a and the rear wall surface 40 in this cross section. In the front-back direction, the boundary point P1 is located before the boundary point P2.

The double-headed arrow Wg in FIG. 5 represents the groove width of the non-sliding groove 36. This groove width Wg is measured as the distance between the boundary point P1 and the boundary point P2 in this cross section. The double-headed arrow Hg represents the depth of the non-sliding groove 36. This depth Hg is measured as the distance from the rear sliding surface 22a to the bottom 42. This depth Hg is measured in a direction perpendicular to the rear sliding surface 22a. In this non-sliding groove 36, the front wall surface 38 and the rear wall surface 40 are continuously formed to form a bottom 42, but the present invention is not limited to this. The bottom 42 may be formed as a surface between the front wall surface 38 and the rear wall surface 40. If the bottom 42 is a surface, the depth Hg is measured at the deepest position of the bottom 42. The double-headed arrow θw represents the wall surface angle formed by the rear sliding surface 22a and the front wall surface 38. This wall surface angle θw is an obtuse angle.

Although not shown, the front traveling plate 20 also has a plurality of non-sliding grooves 36 like the rear traveling plate 22. Each non-sliding groove 36 is formed between the front sliding surfaces 20a. In the front traveling plate 20, the inclination angle θt, the pitch Pg, the groove width Wg, the depth Hg, the wall surface angle θw, and the like are the same as those of the rear traveling plate 22. Those of the front traveling plate 20 are obtained with reference to the front sliding surface 20a instead of the rear sliding surface 22a. In the front traveling plate 20, the same non-sliding groove 36 as the rear traveling plate 22 is formed, but different non-sliding grooves may be formed at different inclination angles, pitches, and the like. Further, the front traveling plate 20 does not have to form a non-sliding groove.

FIG. 6 shows a state of the rubber sheet 10 conveyed by the cutting device 2. FIG. 6 is viewed in the same orientation as FIG. The arrow F indicates the transport direction of the rubber sheet 10. The rubber sheet 10 is conveyed by the belt conveyor 26 and the belt conveyor 28. The rubber sheet 10 slides between the rear sliding surface 22a and the front sliding surface 20a of the traveling plate 6.

A method of cutting the rubber sheet 10 will be described using the cutting device 2. This cutting method includes a transfer process, a positioning process, a sheet piece forming process, and a carrying-out process.

In the transfer step, the rubber sheet 10 is conveyed by the belt conveyor 28. The tip of the rubber sheet 10 slides on the rear sliding surface 22a and the front sliding surface 20a of the traveling plate 6 to reach the belt conveyor 26. After that, as shown in FIG. 6, the rubber sheet 10 is conveyed by the belt conveyor 26 and the belt conveyor 28.

In the positioning step, the belt conveyor 28 stops the rubber sheet 10 at a predetermined cutting position. This predetermined cutting position is a position where the rubber sheet 10 is cut by the cutting tool 4. In this positioning step, the cut portion of the rubber sheet 10 is positioned in the cutting groove 24. The front sliding surface 20a supports the front portion of the cut portion of the rubber sheet 10. The rear sliding surface 22a supports the rear portion of the cut portion of the rubber sheet 10.

In the sheet piece forming step, the holder 16 and the cutter 18 move along the guide 14. The cutter 18 moves along the cutting groove 24. The rubber sheet 10 is cut by the cutter 18. By this cutting, the sheet piece 12 is formed.

In the carry-out process, the sheet piece 12 is conveyed by the belt conveyor 26. In this cutting method, the rubber sheet 10 is conveyed while the sheet piece 12 is conveyed. The sheet piece 12 is conveyed to a predetermined carry-out position. In this way, the sheet piece 12 is obtained from the rubber sheet 10.

Although not shown, a plurality of sheet pieces 12 are joined to form a strip-shaped member. In this strip-shaped member, the sheet pieces 12 are joined together with the cut surface as the end face in the width direction. In this strip-shaped member, the cord piece formed from the cord 30 extends orthogonally to the longitudinal direction of the strip-shaped member. Further, the rubber sheet 10 may be cut at a predetermined angle inclined in the longitudinal direction of the rubber sheet 10 to form the sheet piece 12. By joining the sheet pieces 12 with the cut surface as the end face in the width direction, a strip-shaped member in which the cord pieces are inclined and extended in the longitudinal direction can be formed.

The outer surface of the rubber sheet 10 is made of unvulcanized rubber, and is easily deformed and easily adhered. In this cutting device 2, a rear sliding surface 22a and a non-sliding groove 36 are formed on the rear upper surface 22f. As a result, the contact area between the rubber sheet 10 and the rear sliding surface 22a is reduced. After this, the rubber sheet 10 is slippery on the sliding surface 36. This prevents the rubber sheet 10 from coming into close contact with the rear sliding surface 22a. By suppressing this close contact, the rubber sheet 34 is suppressed from entering the gap 34 between the traveling plate 6 and the belt conveyor 28. Further, in this cutting device 2, it is suppressed that the positioning of the rubber sheet 10 varies. As a result, it is suppressed that the cutting width Ws of the sheet piece 12 varies.

On the rear upper surface 22f, the non-sliding groove 36 is inclined and extends. The non-sliding groove 36 is inclined from the center in the width direction to the outside in the left-right direction from the rear to the front where the rubber sheet 10 slides. The rubber sheet 10 is conveyed while being expanded outward in the width direction by the non-sliding groove 36. As a result, wrinkles are suppressed from being generated on the rubber sheet 10. It is suppressed that the rubber sheet 10 is pushed toward the center side.

On the rear sliding surface 22a where the inclination angle θt of the non-sliding groove 36 is too large, the sliding resistance of the rubber sheet 10 is increased. From the viewpoint of reducing the sliding resistance, the absolute value of the inclination angle θt is preferably 10 ° or less, more preferably 5 ° or less.

The wall surface angle θw formed by the front wall surface 38 and the rear sliding surface 22a is an obtuse angle. As a result, the non-sliding groove 36 suppresses the increase in the sliding resistance of the rubber sheet 10.

The rear sliding surface 22a having a small pitch P of the non-sliding groove 36 has a small sliding resistance of the rubber sheet 10. From this viewpoint, the pitch P is preferably 100 mm or less, more preferably 70 mm or less, and particularly preferably 50 mm or less. On the other hand, if the pitch P of the non-sliding grooves 36 is too small, the number of non-sliding grooves 36 becomes too large. Too many non-sliding grooves 36 increase the sliding resistance of the rubber sheet 10. From the viewpoint of reducing the sliding resistance, the pitch P is preferably 10 mm or more, more preferably 20 mm or more, and particularly preferably 30 mm or more.

The rear sliding surface 22a having a large groove width Wg of the non-sliding groove 36 has a small sliding resistance of the rubber sheet 10. From this point of view, the groove width Wg is preferably 0.5 mm or more. On the other hand, if the groove width Wg of the non-sliding groove 36 is too large, the sliding resistance of the rubber sheet 10 is rather increased. From the viewpoint of reducing the sliding resistance, the groove width Wg is preferably 1.5 mm or less.

The rubber sheet 10 includes a cord 30. In the rubber sheet 10 provided with the cord 30, by inclining the non-sliding groove 36, the portion where the cord 30 extends is suppressed from engaging with the non-sliding groove 36. On the other hand, by reducing the absolute value of the inclination angle θt of the non-sliding groove 36, it is suppressed that the sliding resistance is increased by the non-sliding groove 36. The cutting device 2 is particularly suitable for cutting a rubber sheet 10 including a cord 30 and a topping rubber 32 for the cord 30. Further, in the non-sliding groove 36 having a small groove width Wg, the portion where the cord 30 extends is further suppressed from engaging. From this point of view, the groove width Wg is preferably 1.5 mm or less.

In this cutting device 2, the front traveling plate 20 and the rear traveling plate 22 are separate bodies, but the present invention is not limited to this. The front traveling plate 20 and the rear traveling plate 22 may be integrally formed. A cutting groove 24 may be formed between the front sliding surface 20a of the integrally formed front traveling plate 20 and the rear traveling surface 22a of the rear traveling plate 22.

Hereinafter, the effects of the present invention will be clarified by Examples, but the present invention should not be construed in a limited manner based on the description of these Examples.

[Example 1]
The cutting device shown in FIG. 1 was prepared. The pitch of the non-sliding groove was 50 mm. The inclination angle θt of the non-sliding groove was 5 °. The groove width of the non-sliding groove was 1 mm, and the depth was 1 mm.

[Comparative Example 1]
A conventional cutting device was prepared. No non-sliding groove was formed on this running plate. Other configurations were the same as in Example 1.

[Example 2-4]
A cutting device was formed in the same manner as in Example 1 except that the pitch of the non-sliding groove was set as shown in Table 1.

[Adhesion evaluation]
The rubber sheet was cut using each cutting device. Using each cutting device for one month, the number of occurrences of adhesion trouble between the rear sliding surface and the rubber sheet was investigated. The results are shown in Table 1 as an index. In this index, the number of occurrences of the contact trouble in Comparative Example 1 is 1.0, and the number of occurrences is expressed as an index. The smaller this index is, the less frequently it occurs. The smaller this index is, the more preferable it is.

[Evaluation of variation in cutting width]
Variations in cutting width Ws were investigated for the sheet pieces obtained by each cutting device. The results are shown in Table 1 as an index. This index is expressed in three stages with the variation of Comparative Example 1 as the reference value “2”. The larger this index is, the more preferable it is. "2" of this index means the same as that of Comparative Example 1, and "3" means that the variation is smaller than that of Comparative Example 1.

As shown in Table 1, the cutting device of the embodiment has a higher evaluation than the cutting device of the comparative example. From this evaluation result, the superiority of the present invention is clear.

The method described above can be widely applied to the production of rubber materials for tires.

2 ... Cutting device 4 ... Cutting tool 6 ... Running plate 8 ... Conveyor 10 ... Rubber sheet 12 ... Sheet piece 18 ... Cutter 20 ... Front running plate 20f ...・ Front upper surface 20a ・ ・ ・ Front sliding surface 22 ・ ・ ・ Rear running plate 22f ・ ・ ・ Rear upper surface 22a ・ ・ ・ Rear sliding surface 24 ・ ・ ・ Cutting groove 26 ・ ・ ・ Front conveyor 28 ・ ・ ・ Rear conveyor 30 ... Cord 32 ... Topping rubber 36 ... Non-sliding groove 38 ... Front wall surface 42 ... Bottom

Claims (8)

A cutting device including a cutting tool for cutting a rubber sheet for a tire and a traveling plate for supporting the rubber sheet cut by the cutting tool.
The traveling plate has an upper surface, and the traveling plate has an upper surface.
A sliding surface on which the rubber sheet slides and a non-sliding groove are formed on the upper surface.
A cutting device in which the non-sliding groove extends from the center toward the outside in the width direction of the sliding surface toward the direction in which the rubber sheet slides on the sliding surface . The cutting device according to claim 1, wherein the absolute value of the inclination angle θt formed by the sliding direction of the rubber sheet and the extending direction of the non-sliding groove is 10 ° or less. The non-sliding groove comprises a front wall surface in front of the rubber sheet in the feed direction.
The cutting device according to claim 1 or 2, wherein the wall surface angle θw formed by the front wall surface and the sliding surface is an obtuse angle. A plurality of the non-sliding grooves are formed on the upper surface.
The cutting device according to any one of claims 1 to 3, wherein the pitch of the non-sliding groove is 10 mm or more and 100 mm or less. The cutting device according to any one of claims 1 to 4, wherein the width of the non-sliding groove is 0.5 mm or more and 1.5 mm or less. The cutting device according to any one of claims 1 to 5, which is used for cutting the rubber sheet including the cord and the topping rubber covering the cord. A transport process in which the rubber sheet for tires is slid on the upper surface where the non-sliding groove and the sliding surface are formed and transported to the cutting position.
The rubber sheet is provided with a molding process for cutting at the cutting position.
A method for cutting a rubber sheet , wherein the non-sliding groove extends from the center toward the outside in the width direction of the sliding surface toward the direction in which the rubber sheet slides on the sliding surface . The cutting method according to claim 7, wherein the rubber sheet includes a cord and a topping rubber covering the cord.

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