JP2018020416A - Method for cutting unvulcanized rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cutting an unvulcanized rubber which is reduced in a replacement frequency of a knife while improving a quality.SOLUTION: A method for cutting a belt-like member includes a cutting step of cutting and dividing a belt-like body 34 containing a cord and an unvulcanized rubber covering the cord into a plurality of belt-like members 36 having widths narrower than the belt-like body 34. The cutting step includes hitting a cutting edge 32 of a knife 14 against the belt-like body 34 fed in a longitudinal direction, and cutting and dividing the belt-like body 34 into the belt-like members 36. When the belt-like body is cut and divided into the belt-like members 36, a direction to which the cutting edge 32 extends and a longitudinal direction of the belt-like body 34 cross each other. The knife 14 is slid in a direction crossing the longitudinal direction of the belt-like body 34.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of cutting unvulcanized rubber with a knife.

  Japanese Unexamined Patent Application Publication No. 2012-131111 describes a method for manufacturing a jointless band. This jointless band is composed of a cord and unvulcanized rubber covering the cord. In this jointless band manufacturing method, a TOP strip of a wide strip is cut into a cameron of a strip narrower than the TOP strip with a knife. This cameron is further cut into a narrow jointless band with a knife.

JP 2012-131111 A

  In this manufacturing method, the TOP reaction sent in the longitudinal direction is applied to the cutting edge of the stopped knife. The TOP surface is cut by the cutting edge of this knife. The cutting edge of this knife is worn by use. The sharpness of a knife with worn blades is reduced. This reduction in sharpness reduces the quality of the Cameron and jointless bands. For this reason, the knife with reduced sharpness is replaced. Changing the knife impedes productivity. An object of the present invention is to provide a method for cutting unvulcanized rubber that improves the quality and reduces the replacement frequency of the knife.

The method for cutting unvulcanized rubber according to the present invention includes a cutting step in which a belt-like body including a cord and unvulcanized rubber covering the cord is cut into a plurality of belt-like members having a narrower width than the belt-like body.
In the cutting step, a blade edge of a knife is applied to the strip that is sent in the longitudinal direction, and the strip is cut into strip members. When the band-shaped member is cut, the direction in which the blade edge of the knife extends and the longitudinal direction of the band-shaped body intersect. At this time, the knife is slid in a direction intersecting the longitudinal direction of the strip.

  Preferably, in the cutting step, the knife is slid in the extending direction of the blade edge.

  Preferably, the sliding speed of the knife is 3 (cm / s) or less.

  A strip-shaped member cutting device according to the present invention includes a transport device that transports a strip including a cord and unvulcanized rubber that covers the cord in the longitudinal direction, and a strip that is fed in the longitudinal direction by the transport device. A frame for holding the knife, a frame guide for slidably supporting the frame, and a drive device for sliding the frame. The slidable direction of the frame is a direction that intersects the longitudinal direction of the strip.

  Preferably, the direction in which the frame slides is parallel to the direction in which the blade edge of the knife held by the frame extends.

  Preferably, the frame guide can change a direction in which the frame is slid.

  Preferably, the driving device includes a driving unit that rotates and a mechanism that converts the rotating motion into a reciprocating motion.

  In the cutting process according to the present invention, the knife slides crossing the direction in which the belt-like body is fed. This knife cuts the strip while sliding. In this cutting step, the band-shaped body is cut using a wide range of knife edges. This knife can maintain the sharpness of the knife for a long period of time compared to conventional cutting. In this cutting process, a clean cut surface is maintained for a long time. The cord damage accompanying the cutting of the strip is suppressed for a long time. In this cutting process, the service life of the knife is long. The frequency of knife replacement is reduced.

FIG. 1 is a conceptual diagram illustrating a part of a cutting apparatus for a manufacturing method according to an embodiment of the present invention. FIG. 2 is a view in the direction of arrow II in FIG. FIG. 3 is an enlarged view of the holder and knife of the cutting apparatus of FIG. FIG. 4 is a conceptual diagram of the cutting device of FIG.

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

  A part of the cutting device 2 is shown in FIG. The cutting device 2 includes a gantry 4, a driving device 6, a frame guide 8, a frame 10, a number of holders 12, and a number of knives 14. The arrow X in FIG. 1 represents forward in the front-rear direction, the arrow Y represents leftward in the left-right direction, and the arrow Z represents upward in the vertical direction. As will be described later, the cutting device 2 further includes a transport device 15 (see FIG. 4).

  The drive device 6 includes a motor 16 as a drive unit, a first link 18, and a second link 20. One end 18a of the first link 18 is fixed to the rotating shaft 16a of the motor 16, and the other end 18b of the first link 18 is rotatable about the rotating shaft 16a. One end 20 a of the second link 20 is pivotally attached to the other end 18 b of the first link 18. The rotation axes of the end 18b and the end 20a are parallel to the rotation axis 16a of the motor 16.

  The frame 10 includes a frame main body 22, a slide bar 24, and a connecting body 26. The slide bar 24 supports the frame body 22. The slide bar 24 extends in the left-right direction. One end 26 a of the coupling body 26 is pivotally attached to the end 20 b of the second link 20. The other end 26 b of the connecting body 26 is connected to one end 24 a of the slide bar 24. One end 26 a of the connection body 26 is pivotally attached to the other end 20 b of the second link 20. The rotation axis of the end 26 a and the end 20 b is parallel to the rotation axis 16 a of the motor 16.

  As shown in FIG. 2, the cutting device 2 includes a pair of left and right frame guides 8. Each frame guide 8 includes a guide plate 8a and a guide plate 8b. The one guide plates 8a and 8b extend parallel to each other with the one end 24a of the slide bar 24 therebetween. The other guide plates 8a and 8b extend parallel to each other with the other end 24b of the slide bar 24 in between. In this cutting device 2, the frame guide 8 supports the slide bar 24 so as to be slidable in the vertical direction.

  The holder 12 is attached to the frame body 22 (see FIG. 1). A number of holders 12 are attached to the frame body 22. As shown in FIG. 2, in the cutting device 2, seven holders 12 are attached to the frame body 22. Each holder 12 has a knife 14 detachably attached thereto. A double-headed arrow P in FIG. 2 represents an interval between adjacent holders 12 in the left-right direction. The holders 12 are mounted side by side at a predetermined interval P in the left-right direction. Although not shown, the predetermined interval P can be changed.

  FIG. 3 shows the holder 12 and the knife 14 as viewed in the left-right direction. The knife 14 includes a core 28 and a blade 30 that extends downward from the core 28. The blade 30 includes a blade tip 32 and a peak 33 that extend along the longitudinal direction of the blade 30 at the end of the blade 30. The core 14 is sandwiched between the holders 12. This knife 14 is fixed to the holder 12. The blade 30 extends downward from the holder 12. The double arrow L represents the length of the blade edge 32. This length L is measured as a linear distance in the vertical direction. A double-headed arrow θ represents the angle of intersection between the blade edge 32 and the strip 34.

  As shown in FIG. 1 and FIG. 2, the cutting device 2 cuts the strip 34 into a plurality of strip members 36 with the knife 14. In the cutting device 2, the belt-like body 34 is cut into a plurality of belt-like members 36 having a uniform width at the interval P. By changing the interval P, the belt-like members 36 having different widths can be manufactured. The strip 34 is composed of a cord and an unvulcanized topping rubber that covers the cord. The cord of the strip 34 extends in the longitudinal direction of the strip 34. Similarly to the belt-like body 34, the belt-like member 36 is also made of a cord and unvulcanized rubber that covers the cord.

  As shown in FIG. 4, the conveying device 15 is located between a roller 38 around which the belt-like body 34 is wound and a plurality of rollers 40 around which the belt-like member 36 is wound. The transport device 15 includes guide rollers 42, 43, and 44, a number of tension rollers 46, and a motor as a drive unit (not shown). The guide rollers 42, 43 and 44 guide the belt-like body 34 and the belt-like member 36 from the roller 38 to the roller 40. The tension roller 46 applies a longitudinal tension to the belt-like body 34 and the belt-like member 36. The transport device 15 has a function of transporting the belt-like body 34 and the belt-like member 36 between the roller 38 and the plurality of rollers 40.

  A tire manufacturing method will be described using the cutting device 2. This manufacturing method includes a band-shaped member manufacturing process in which the band-shaped member 36 is obtained, a preforming process in which a large number of members including the band-shaped member 36 are bonded to form a raw cover, and the raw cover is vulcanized in a mold. It has a vulcanization process. A tire is obtained from the raw cover through this vulcanization step.

  The band-shaped member manufacturing process includes a band-shaped body feeding process, a cutting process, and a band-shaped member winding process.

  In the step of stripping, a roller 38 around which the strip 34 is wound is prepared. The belt-like body 34 is fed out from the roller 38 by a motor (not shown) of the transport device 15. The fed belt-like body 34 is guided by the guide rollers 42, 43 and 44 and sent toward the roller 40.

  In the cutting process, the band-shaped body 34 is cut into a large number of band-shaped members 36 by the knife 14. As shown in FIG. 4, the belt-like body 34 and the many belt-like members 36 are stretched with a tension applied in the longitudinal direction between the guide roller 42 and the guide roller 43. Between the guide roller 42 and the guide roller 43, the knife 14 is applied to the stretched strip 34.

  As the motor 16 shown in FIG. 1 rotates, the slide bar 24 slides up and down via the first link 20, the second link 22, and the coupling body 26. Together with the slide bar 24, the holder 12 and the knife 14 slide up and down to reciprocate. The knife 14 cuts the strip 34 while sliding in the vertical direction in which the cutting edge 32 extends.

  As shown in FIG. 2, in this example, the band 34 is cut into eight band members 36 by the knife 14. Although not shown, a plurality of cords are arranged in the width direction of the belt-like body 34 and extend along the longitudinal direction. The knife 14 cuts unvulcanized rubber between a cord and a cord adjacent to the cord.

  A double arrow S in FIG. 4 represents the sliding direction of the knife 14. This knife 14 represents a reciprocating motion in the vertical direction. The strip 34 is fed toward the roller 40. The band-shaped body 34 is pressed toward the blade edge 32 while being fed forward, and is cut into a large number of band-shaped members 36.

  The strip-shaped member 36 thus cut is guided by the guide rollers 43 and 44 and sent toward the roller 40. Each belt-like member 36 is tensioned by a tension roller 46. The belt-like members 36 are wound around the rollers 40, respectively. The wound belt-like member 36 is sent to a preforming process.

  In the preforming step, the belt-like member 36 is fed out from the roller 40. The fed strip-shaped member 36 is cut into a predetermined length. The belt-like member 36 having a predetermined length is bonded to another member to form a raw cover. The raw cover is vulcanized in a mold in a vulcanization process to obtain a tire. Prior to the preforming step, the strip-shaped member 36 may be cut into a predetermined length, and then the plurality of cut strip-shaped members 36 may be bonded together. In the preforming step, the plurality of bonded strip members 36 may be bonded to other members to form a raw cover.

  In this manufacturing method, when cutting into the strip-shaped member 36, the cutting edge 32 of the knife 14 is slid on the plane including the up-down direction and the front-rear direction. The blade edge 32 is slid in the vertical direction so as to intersect the forward direction in which the strip 34 is fed. The cutting edge 32 in a range where it slides and contacts the belt-like body 34 cuts the belt-like body 34 into the belt-like member 36. The cutting edge 32 is not locally worn unlike the conventional cutting method. This manufacturing method can reduce wear of the cutting edge 32 as compared with the conventional method. In this manufacturing method, the replacement frequency of the knife 14 is reduced. In this manufacturing method, the blade edge 32 is slid on a plane including the vertical direction and the front-rear direction, but the sliding direction of the blade edge 32 of the present invention is not limited to this. The cutting edge 32 may be slid in a direction that intersects the direction in which the band-shaped body 34 is sent (longitudinal direction of the band-shaped body 34) and is cut by the cutting edge 32. For example, the cutting edge 32 may be slid on the plane including the longitudinal direction and the thickness direction of the strip 34 and intersecting the longitudinal direction of the strip 34.

  In this manufacturing method, the direction in which the frame 10 is slid and the direction in which the cutting edge 32 of the knife 14 extends are made parallel. By sliding in parallel with the blade edge 32, fluctuations in the load on the blade edge 32 due to the slide are reduced. Thereby, breakage of the blade edge 32 and the like are suppressed. From this viewpoint, it is preferable that the direction in which the knife 14 is slid and the direction in which the cutting edge 32 of the knife 14 extends are parallel.

  In this manufacturing method, the belt-like body 34 is cut by the knife 14 between the roller 42 and the roller 43. The band-shaped body 34 and the band-shaped member 36 are swung in the thickness direction between the roller 42 and the roller 43 by being cut by the knife 14. If the sliding speed of the knife 14 is too fast, the belt-like body 34 and the belt-like member 36 swing greatly as the knife 14 slides. This large runout roughens the cut surface of the belt-like member 36. This large runout can cause cord damage. From these viewpoints, the slide speed of the knife 14 is preferably 3 (cm / s) or less, more preferably 2 (cm / s) or less, and particularly preferably 1 (cm / s) or less. This speed is measured as the maximum speed of the reciprocating knife 14.

  In this manufacturing method, by reducing the crossing angle θ between the blade edge 32 and the belt-like body 34, the thickness-direction deflection of the belt-like body 34 and the belt-like member 36 to be fed can be reduced. From this viewpoint, the crossing angle θ is preferably less than 90 °, and more preferably 80 ° or less. On the other hand, the replacement frequency of the knife 14 can be reduced by moving the position in contact with the strip 34 along the cutting edge 32. From this viewpoint, the crossing angle θ is preferably 45 ° or more, and more preferably 55 ° or more.

  In this cutting device 2, this intersection angle θ may be changeable. For example, the frame guide 8 extending in the vertical direction may be tiltable with respect to the vertical direction. By tilting the frame guide 8, the direction in which the frame 10 is slid can be changed. Thereby, the crossing angle θ can be easily changed.

  Further, the drive device 6 includes a crank mechanism. This crank mechanism is a mechanism that converts rotational motion into reciprocating motion. By providing this crank mechanism, even if the inclination angle of the frame guide 8 is changed, the rotational movement of the motor 16 can be converted into a reciprocating movement corresponding to the inclination angle. This crank mechanism facilitates changing and adjusting the crossing angle θ.

  Further, since the driving device 6 converts the rotational motion into a reciprocating motion, a continuous and smooth reciprocating motion is easily achieved as compared with a reciprocating motion using a cylinder or the like. This smooth reciprocation can reduce damage to the cutting edge 32. From this viewpoint, it is preferable that the cutting device 2 includes a mechanism that converts the rotational motion into a reciprocating motion.

  The method described above can be widely applied to a method of cutting a sheet-like member containing unvulcanized rubber that covers a cord and the cord with a knife.

DESCRIPTION OF SYMBOLS 2 ... Cutting device 4 ... Stand 6 ... Drive device 8 ... Frame guide 10 ... Frame 12 ... Holder 14 ... Knife 16 ... Motor 18 ... First link 20 ... second link 22 ... frame main body 24 ... slide bar 26 ... connector 28 ... core 30 ... blade 32 ... blade tip 33 ... peak 34 ...・ Strip-like body 36 ... Strip-like member 38,40 ... Roller 42,43,44 ... Guide roller 46 ... Tension roller

Claims (7)

A strip including a cord and an unvulcanized rubber covering the cord includes a cutting step in which the strip is cut into a plurality of strip members having a narrower width than the strip.
In the cutting step, a blade edge of a knife is applied to the strip that is sent in the longitudinal direction, and the strip is cut into strip members,
When cutting into the strip-shaped member, the direction in which the blade edge of the knife extends and the longitudinal direction of the strip-shaped body intersect, and the knife is slid in the direction intersecting the longitudinal direction of the strip-shaped body. Cutting method of vulcanized rubber. In the cutting step,
The cutting method according to claim 1, wherein the knife is slid in a direction in which the blade edge extends.   The cutting method according to claim 1 or 2, wherein a sliding speed of the knife is 3 (cm / s) or less. A transport device for transporting a belt-like body including a cord and unvulcanized rubber covering the cord in a longitudinal direction;
A knife that cuts a belt-like body sent in the longitudinal direction by the transport device into a plurality of belt-like members;
A frame for holding the knife;
A frame guide for slidably supporting the frame;
A drive device for sliding the frame,
A strip-shaped member cutting device in which a slidable direction of the frame is set to a direction intersecting with a longitudinal direction of the strip-shaped body. The direction in which the frame slides;
The strip | belt-shaped member cutting device of Claim 4 with which the direction where the blade edge | tip of the said knife hold | maintained at the said frame is extended is parallel.   The belt-shaped member cutting device according to claim 4 or 5, wherein the frame guide can change a direction in which the frame is slid.   The strip | belt-shaped member cutting device in any one of Claim 4 to 6 provided with the drive part which the said drive device rotates, and the mechanism which converts this rotary motion into a reciprocating motion.

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