JP7283066B2 - Rubber sheet cutting device - Google Patents

Description

The present invention relates to a rubber sheet cutting device.

Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2016-101729) discloses a cutting device as a cutting device for cutting a rubber material. This cutting device forms edge strips narrower than the rubber material from the rubber material as a rubber sheet. In this cutting device, the chopping board and the cutter face each other across the rubber material. On the cutting board, the cutter cuts the conveyed rubber material. This cutting forms edge strips from the rubber material.

Japanese Patent Application Laid-Open No. 2016-101729

In this cutting device, the rubber material is cut by a cutter while being conveyed. A tension acts on the rubber material in the conveying direction. The rubber material is cut while this tension is applied. Depending on the state of transportation of the rubber material, etc., the tension caused by this transportation may vary. This tension variation reduces the cutting accuracy of the rubber material.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cutting apparatus capable of improving the cutting accuracy of a rubber sheet.

A rubber sheet cutting apparatus according to the present invention cuts a rubber sheet along the conveying direction while conveying the rubber sheet to form a strip.
This cutting device
a cutter for cutting the rubber sheet;
A carry-in roller for sending the rubber sheet toward the cutter and a carry-out roller for carrying out the strip obtained by being cut by the cutter, wherein the peripheral speed Vo of the carry-out roller is faster than the peripheral speed Vi of the carry-in roller, and a tension generator.

Preferably, the cutting device comprises a support base.
This support is
a front support surface that supports the rubber sheet between the carry-in roller and the cutter;
a rear support surface that supports the strip between the cutter and the carry-out roller;
A recess is provided between the front and rear support surfaces and is recessed from the front and rear support surfaces and in which the cutter is positioned.

Preferably, the rake angle of said cutter is greater than 0°.

Preferably, the ratio Vi/Vo of the peripheral speed Vi to the peripheral speed Vo is 0.98 or more.

Preferably, the peripheral speed Vo is 10 m/min or more and 20 m/min or less.

Preferably, the carry-in roller includes a pair of carry-in roller bodies that rotate with the rubber sheet therebetween. The carry-out roller includes a pair of carry-out roller main bodies that rotate with the band sandwiched therebetween.

A method for manufacturing a band according to the present invention is a method of forming a band by cutting a rubber sheet along a conveying direction with a cutter while conveying the rubber sheet.
This manufacturing method
(A) a step of preparing the rubber sheet; and (B) feeding the rubber sheet toward the cutter with a carry-in roller having a peripheral speed of Vi, and cutting the rubber sheet with the cutter to obtain the band, It includes a step of sending out by a carry-out roller having a peripheral speed Vo higher than the peripheral speed Vi.

Preferably, the thickness of the rubber sheet is more than 1 mm and 3 mm or less.

A rubber sheet cutting device according to the present invention includes a tension generator. This tension generator applies proper tension to the rubber sheet to be cut. The occurrence of poor cutting of the rubber sheet is suppressed. This cutting device contributes to improving the quality of the obtained band.

FIG. 1 is a conceptual diagram showing a part of a belt manufacturing facility including a rubber sheet cutting device according to one embodiment of the present invention. 2 is a side view of the cutting device of FIG. 1; FIG. FIG. 3 is an explanatory view showing the state of use of the cutting device of FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

FIG. 1 shows part of a strip production facility 2 . This strip manufacturing facility 2 includes a rubber sheet cutting device 4 (hereinafter also referred to as a cutting device 4) according to the present invention. This strip production facility 2 further comprises a plurality of guide rollers 6 and two winding rollers 8 . In FIG. 1, a rubber sheet 10 and two strips 12 are indicated by two-dot chain lines together with the strip manufacturing facility 2. As shown in FIG. In FIG. 1, the arrow X represents the front-rear direction of the cutting device 4, the arrow Y represents the left-right direction, and the arrow Z represents the up-down direction.

Although not shown, the strip production facility 2 further includes an extruder and a calender. The extruder has a function of kneading and extruding the rubber composition. A rubber material is obtained from the rubber composition by this extruder. A calendering device has a function of roll-molding this rubber material. A rubber sheet 10 is obtained from the rubber material by this calendering device.

Each guide roller 6 has a function of guiding the conveyed rubber sheet 10 to the next process. In this strip manufacturing facility 2, the guide roller 6 is positioned between a calendering device and a cutting device 4 (not shown). A guide roller 6 guides the rubber sheet 10 from the calendar device to the cutting device 4 .

The cutting device 4 of FIG. 1 has a function of cutting the rubber sheet 10 along the conveying direction while conveying the rubber sheet 10 . A strip 12 is formed from the rubber sheet 10 by the cutting device 4 . The width of the strip 12 is narrower than the width of the rubber sheet 10.例文帳に追加The cutting device 4 cuts the rubber sheet 10 to form two strips 12 .

Each winding roller 8 has a function of winding the strip 12 into a roll. The winding roller 8 includes a winding roller body 8a. The winding roller main body 8a is rotationally driven by a motor (not shown). The strip 12 wound into a roll is sent to the next process (not shown).

The cutting device 4 includes a tension generator 14 , a support base 16 and a cutter 18 . The tension generating device 14 includes a carry-in roller 20 and two carry-out rollers 22 . The carry-in roller 20 is positioned between the support base 16 and the guide roller 6 that guides the rubber sheet 10 to the support base 16 . The carry-in roller 20 is arranged at a position closer to the support base 16 than the guide roller 6 is. Each carry-out roller 22 is positioned between the support base 16 and the take-up roller 8 . The carry-out roller 22 is arranged at a position closer to the support base 16 than the take-up roller 8 is.

The carry-in roller 20 includes an upper carry-in roller body 20a and a lower carry-in roller body 20b as a pair of carry-in roller bodies. Each of the upper carry-in roller body 20a and the lower carry-in roller body 20b is rotatable. The upper carry-in roller main body 20a and the lower carry-in roller main body 20b are rotationally driven by a motor (not shown) of the carry-in roller 20. As shown in FIG. This motor has a function of rotating the upper carry-in roller body 20a and the lower carry-in roller body 20b in the direction to feed the rubber sheet 10 toward the support table 16. As shown in FIG. Either one of the upper carry-in roller main body 20a and the lower carry-in roller main body 20b may be rotationally driven by this motor, or both may be used.

Each carry-out roller 22 includes an upper carry-out roller body 22a and a lower carry-out roller body 22b as a pair of carry-out roller bodies. Each of the upper carry-out roller body 22a and the lower carry-out roller body 22b is rotatable. The upper carry-out roller main body 22a and the lower carry-out roller main body 22b are rotationally driven by a motor (not shown) provided in the carry-out roller 22. As shown in FIG. This motor has a function of rotating the upper carry-out roller main body 22a and the lower carry-out roller main body 22b in the direction in which the strip 12 is sent out from the support table 16. As shown in FIG. Either one of the upper carry-out roller main body 22a and the lower carry-out roller main body 22b may be driven to rotate, or both may be used.

The support table 16 is positioned between the carry-in roller 20 and the two carry-out rollers 22 . The support base 16 has a front support surface 16a, a rear support surface 16b and a recess 16c. The front support surface 16a is positioned between the carry-in roller 20 and the recess 16c. The rear support surface 16b is positioned between the carry-out roller 22 and the recess 16c. The recess 16c is located between the front support surface 16a and the rear support surface 16b. The recess 16c is recessed downward from the front support surface 16a and the rear support surface 16b. The depth of this concave portion 16c is the deepest in the front-rear direction center between the front support surface 16a and the rear support surface 16b. The depth of this recess 16c gradually decreases from the center toward the front support surface 16a. The depth of the recess 16c gradually decreases from the center toward the rear support surface 16b.

The cutter 18 is arranged above the support base 16 . The cutter 18 has a cutter body 18a and a holder 18b. The holder 18b holds the cutter body 18a. The holder 18b positions the cutter main body 18a with respect to the support base 16. As shown in FIG. The cutter body 18a is positioned between the front support surface 16a and the rear support surface 16b. The blade 18c of the cutter body 18a faces the front support surface 16a. The blade 18c extends along the longitudinal direction of the cutter body 18a.

A side view of the cutting device 4 is shown in FIG. The arrow R represents the contour of the bottom surface 16d of the recess 16c. The contour of the bottom surface 16d is formed by an arc with a radius of curvature R. As shown in FIG. 2, the tip 18d of the cutter body 18a is located in the recess 16c. The tip portion 18d is inserted into the concave portion 16c. A tip 18e of the blade 18c is positioned at the deepest center of the recess 16c in the front-rear direction. The blade 18c extends obliquely upward in the direction in which the rubber sheet 10 is conveyed.

A two-dot chain line L1 in FIG. 2 represents a straight line extending in contact with the front support surface 16a and the rear support surface 16b of the support base 16. As shown in FIG. A two-dot chain line L2 represents a straight line extending in the vertical direction perpendicular to the straight line L1. A double arrow θ represents the rake angle of the blade 18c. This rake angle θ is measured as the angle between the straight line L2 and the blade 18c. The rake angle θ is expressed as 0° on the straight line L2, positive when counterclockwise from the straight line L2, and negative when clockwise from the straight line L2. In FIG. 2, the rake angle .theta. of this blade 18c is a positive angle larger than 0.degree.

FIG. 3 shows how the cutting device 4 cuts the rubber sheet 10 while being conveyed to form the band 12 . A double-headed arrow t1 in FIG. 3 represents the thickness of the rubber sheet 10 . A double-headed arrow t2 represents the thickness of the strip 12 .

In FIG. 3, the upper carry-in roller body 20a and the lower carry-in roller body 20b sandwich the rubber sheet 10 in the thickness t1 direction. The upper carry-in roller main body 20a and the lower carry-in roller main body 20b rotate at a peripheral speed Vi in the direction of sending the rubber sheet 10 toward the cutter 18. As shown in FIG. This peripheral speed Vi is measured on the outer peripheral surfaces of the upper carry-in roller main body 20a and the lower carry-in roller main body 20b. When either one of the upper carry-in roller main body 20a and the lower carry-in roller main body 20b is driven, the peripheral speed Vi is measured on the outer peripheral surface of the driven one.

Similarly, the upper carry-out roller body 22a and the lower carry-out roller body 22b sandwich the strip 12 in the thickness t2 direction. The upper carry-out roller main body 22a and the lower carry-out roller main body 22b rotate at a peripheral speed Vo in the direction of sending the band 12 away from the cutter 18 . This peripheral speed Vo is measured on the outer peripheral surfaces of the upper carry-out roller main body 22a and the lower carry-out roller main body 22b. When either one of the upper carry-out roller body 22a and the lower carry-out roller body 22b is driven, the peripheral speed Vo is measured on the outer peripheral surface of the driven one.

In this cutting device 4 , the peripheral speed Vo of the carry-out roller 22 is faster than the peripheral speed Vi of the carry-in roller 20 . As a result, a tension acts on the rubber sheet 10 and the strip 12 between the carry-in roller 20 and the carry-out roller 22 in the conveying direction. Due to this tension, the rubber sheet 10 and the strip 12 are stretched between the carry-in roller 20 and the carry-out roller 22 . The rubber sheet 10 is in contact with the front support surface 16a. The strip 12 abuts the rear support surface 16b. In this state, the rubber sheet 10 is cut by the cutter 18 while being conveyed.

Here, a method for manufacturing the strip 12 will be described using the strip manufacturing equipment 2 of FIG. In this production method, a rubber composition is kneaded and extruded by an extruder (not shown) (STEP 1). A rubber material is obtained from the rubber composition by this extruder. A rubber material is rolled by a calendering device (not shown) (STEP 2). A rubber sheet 10 is obtained from the rubber material by this calendering device. Thus, the rubber sheet 10 is prepared. The rubber sheet 10 is guided by guide rollers 6 and sent to the cutting device 4 .

In the cutting device 4 , the rubber sheet 10 is cut by the cutter 18 while the rubber sheet 10 is fed by the carry-in rollers 20 . By this cutting, a strip 12 narrower than the rubber sheet 10 is formed from the rubber sheet 10 . The strip 12 is delivered from the cutting device 4 by the delivery rollers 22 . In this manner, the rubber sheet 10 is cut by the cutter 18 while being sent to the cutter 18 by the carry-in rollers 20, and the band 12 obtained from the rubber sheet 10 is sent out by the carry-out rollers 22 (STEP 3).

In this cutting device 4, two strips 12 are formed. Each strip 12 is wound by the winding roller 8 (STEP 4). In this manner, the strip 12 wound into a roll is obtained.

Although two strips 12 are formed in this cutting device 4, the number of strips 12 may be one, or three or more. In this cutting device 4, the number of winding rollers 8 is changed according to the number of belts 12 to be formed. Also, the number of cutters 18 is changed in accordance with the number of cut portions of the rubber sheet 10 .

An example of a tire manufacturing method using this strip 12 will be described. A method of manufacture in which the band 12 is used as an edge strip will now be described as an example. Here, the strip 12 is used as part of a belt member that forms a tire belt. In this belt member, the belt member 12 is adhered to the width direction end portion of the belt member main body. The strip 12 covers the widthwise end of the belt member main body. A belt member is thus obtained. The band 12 protects the widthwise end of the belt member main body.

In addition to this belt member, rubber members forming various parts of the tire, such as a tread member forming a tread, a sidewall member forming a sidewall, and a bead member forming a bead, are prepared. These rubber members are combined to form a low cover. This raw cover is vulcanized in a mold. A tire is obtained from the raw cover by this vulcanization. In this way, strip 12 forms an edge strip as part of the belt.

In the tension generating device 14 of the cutting device 4 , the peripheral speed Vo of the carry-out roller 22 is faster than the peripheral speed Vi of the carry-in roller 20 . The tension generating device 14 applies tension to the rubber sheet 10 and the strip 12 between the carry-out roller 22 and the carry-in roller 20 . This tension is stable with suppressed variation. This tension prevents the rubber sheet 10 and the strip 12 from loosening. This rubber sheet 10 is stably cut by a cutter 18 . In this cutting device 4, occurrence of poor cutting of the rubber sheet 10 is suppressed.

Due to this tension, the rubber sheet 10 and the strip 12 are restrained from rising from the front support surface 16a and the rear support surface 16b. The rubber sheet 10 and band 12 are stably supported by the front support surface 16a and the rear support surface 16b. In this cutting device 4, the rubber sheet 10 is cut more stably in the concave portion 16c by the support between the front support surface 16a and the rear support surface 16b.

By making the peripheral speed Vo higher than the peripheral speed Vi, tension can be generated in the rubber sheet 10 and the strip 12 . From this point of view, this ratio Vi/Vo is less than one. On the other hand, the rubber sheet 10 and the strip 12 are deformed in the tension generating device 14 in which the ratio Vi/Vo is too small and the tension is too large. This deformation impairs the forming accuracy of the strip 12 obtained. From this point of view, the ratio Vi/Vo is preferably 0.98 or more.

In the cutting device 4, the peripheral speed Vi and the peripheral speed Vo may be individually adjustable. By adjusting the peripheral speed Vi and the peripheral speed Vo, the tension acting on the rubber sheet 10 and the strip 12 can be adjusted.

A cutting device 4 having a high peripheral speed Vo and a high peripheral speed Vi contributes to an improvement in the productivity of the strip 12 . From this point of view, the peripheral speed Vo is preferably 10 m/min or more. On the other hand, the cutting device 4 with too high peripheral speed Vo and peripheral speed Vi is likely to cause poor cutting of the band 12, and is likely to impair the shape accuracy of the band 12. FIG. From these points of view, this peripheral speed Vo is preferably 20 m/min or less.

In the cutting device 4, the upper carry-in roller main body 20a and the lower carry-in roller main body 20b rotate with the rubber sheet 10 interposed therebetween. This suppresses the occurrence of slippage between the rubber sheet 10 and the upper carry-in roller body 20a and the lower carry-in roller body 20b. Further, the upper carry-out roller main body 22a and the lower carry-out roller main body 22b rotate with the strip 12 interposed therebetween. As a result, slippage between the belt member 12 and the upper carry-out roller main body 22a and the lower carry-out roller main body 22b is suppressed. As a result, tension is stably applied to the rubber sheet 10 and the strip 12 in the cutting device 4 . The rubber sheet 10 is cut while being stably tensioned. This cutting device 4 contributes to improving the cutting accuracy of the rubber sheet 10 .

A rubber sheet 10 having a large thickness t1 is difficult to cut. By applying tension, the cutting device 4 can stably cut the rubber sheet 10 thicker than before. This cutting device 4 is suitable for cutting a rubber sheet 10 having a thickness t1 exceeding 1 mm. On the other hand, from the viewpoint of stable cutting by the cutting device 4, the thickness t1 is preferably 3 mm or less.

In this cutting device 4, the rubber sheet 10 is cut while the rubber sheet 10 is supported by the front support surface 16a and the strip 12 is supported by the rear support surface 16b. However, in the cutting according to the present invention, tension is stably acting on the rubber sheet 10 and the strip 12, so the support by the front support surface 16a and the rear support surface 16b is not essential. In this cutting, the rubber sheet 10 may be cut while being supported by either the front support surface 16a or the rear support surface 16b, or by being supported by neither.

In the conventional cutting method, the rubber sheet 10 and the strip 12 sometimes float upward due to the cutter 18 having a positive rake angle θ. This floating hinders stable cutting of the rubber sheet. For this reason, although not shown, in the conventional cutting method, the rake angle θ of the cutter 18 is set to a negative angle in order to suppress this lifting. As a result, lifting of the rubber sheet 10 and the band 12 is suppressed.

On the other hand, the cutting device 4 applies tension to the rubber sheet 10 stably. By applying tension, the rubber sheet 10 and the strip 12 are prevented from rising regardless of the rake angle θ of the cutter 18 . Therefore, in this cutting device 4, as shown in FIG. 2, even if the rake angle .theta. is set to a positive angle larger than 0.degree.

Furthermore, in the cutter 18 shown in FIG. 2, since the rake angle θ is greater than 0°, even if the cutter 18 is lowered, the blade 18c is prevented from coming into direct contact with the bottom surface 16d of the recess 16c. . In this cutting device 4, abrasion and breakage of the blade 18c are suppressed. This cutting device 4 can contribute to improving the durability of the cutter 18 .

Here, the strip 12 used for the tire belt has been described as an example. A tire mounted on a vehicle rotates at high speed. The molding accuracy of a tire greatly affects the performance of a tire that rotates at high speed. The molding accuracy of the rubber members forming each part of the tire affects the molding accuracy of the tire. This cutting device 4 is excellent in forming accuracy of the strip 12 . From this point of view, the cutting device 4 is suitable for manufacturing the band 12 used for tires.

This tire manufacturing method is an example of a manufacturing method using the cutting device 4, and the use of the strip 12 is not limited to this. This method of manufacturing the strip 12 can be widely applied to a method of manufacturing a strip-shaped rubber member that is obtained by cutting into a predetermined width.

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

[Example 1]
A strip was obtained using the strip manufacturing facility of FIG. The thickness t1 of the rubber sheet used was 1.5 mm. The peripheral speed Vi of the carry-in roller of the tension generator was 9.8 m/min, and the peripheral speed Vo of the carry-out roller was 10.0 m/min.

[Comparative Example 1]
A strip manufacturing facility was prepared in the same manner as in Example 1, except that the cutting device did not have a tension generator. In this cutting device, the rake angle θ of the cutter is set to a negative angle from the viewpoint of preventing the rubber sheet from floating and from the viewpoint of preventing wear due to contact of the tip of the tooth. Otherwise, in the same manner as in Example 1, a strip was obtained.

[Comparative Example 2-6]
A strip was obtained in the same manner as in Comparative Example 1 except that the thickness of the rubber sheet was as shown in Table 1.

[Example 2-8]
A strip was obtained in the same manner as in Example 1, except that the thickness of the rubber sheet and the peripheral speed Vi of the carry-in roller were as shown in Table 2.

[Example 9]
The peripheral speed Vi of the carry-in roller of the tension generator was 14.7 m/min, and the peripheral speed Vo of the carry-out roller was 15.0 m/min. Others were carried out in the same manner as in Example 1 to obtain a strip.

[Comparative Example 7]
A strip manufacturing facility was prepared in the same manner as in Example 9, except that the cutting device did not have a tension generator. In this cutting device, the rake angle θ of the cutter is set to a negative angle from the viewpoint of preventing the rubber sheet from floating. Otherwise, in the same manner as in Example 9, a strip was obtained.

[Comparative Example 8-12]
A strip was obtained in the same manner as in Comparative Example 7 except that the thickness of the rubber sheet was as shown in Table 3.

[Examples 10-20]
A strip was obtained in the same manner as in Example 9 except that the thickness of the rubber sheet and the peripheral speed Vi of the carry-in roller were as shown in Table 2.

[Cutting evaluation]
Cutting of the rubber sheet by the cutting device was evaluated. The results are shown in Tables 1-5. This evaluation result is evaluated with a three-level index. A larger number is more preferable for this index. At this index of 3, the rubber sheet was stably cut to obtain a strip. With an index of 2, the rubber sheet was cut to obtain a strip, but the rubber sheet was confirmed to be bent during cutting. With an index of 1, poor cutting of the rubber sheet was confirmed.

As shown in Tables 1 to 5, the production methods of Examples are evaluated higher than the production methods of Comparative Examples. From this evaluation result, the superiority of the present invention is clear.

The method described above can be widely applied to the cutting of rubber sheets that are cut in the conveying direction while being conveyed.

2 Belt manufacturing equipment 4 Cutting device 10 Rubber sheet 12 Belt 14 Tension generator 16 Support base 16a Front support surface 16b Rear supporting surface 16c... Recess 18... Cutter 20... Carry-in roller 20a... Upper carry-in roller body 20b... Lower carry-in roller body 22... Carry-out roller 22a... Upper carry-out roller body 22b・・・Lower carry-out roller body

Claims (6)

A cutting device that cuts along the conveying direction while conveying a rubber sheet to form a strip,
a cutter for cutting the rubber sheet;
A carry-in roller for sending the rubber sheet toward the cutter and a carry-out roller for carrying out the strip obtained by cutting with the cutter, wherein the peripheral speed Vo of the carry-out roller is faster than the peripheral speed Vi of the carry-in roller. and a tension generator,
The carrying-in roller comprises a pair of carrying-in roller bodies that rotate with the rubber sheet sandwiched therebetween,
The carry-out roller comprises a pair of carry-out roller bodies that rotate with the belt sandwiched therebetween,
A rubber sheet cutting device, wherein the ratio Vi/Vo of the peripheral speed Vi to the peripheral speed Vo is 0.98 or more. a front support surface that supports the rubber sheet between the carry-in roller and the cutter;
a rear support surface that supports the strip between the cutter and the carry-out roller;
2. The rubber sheet according to claim 1, further comprising a support platform recessed from said front support surface and said rear support surface between said front support surface and said rear support surface and comprising a recess in which said cutter is arranged. cutting equipment. 3. The rubber sheet cutting device according to claim 1, wherein the rake angle of said cutter is greater than 0[deg.]. The rubber sheet cutting device according to any one of claims 1 to 3, wherein said peripheral speed Vo is 10 m/min or more and 20 m/min or less. A method in which a rubber sheet is conveyed and cut with a cutter along the conveying direction to form a strip,
(A) a step of preparing the rubber sheet; and (B) feeding the rubber sheet toward the cutter with a carry-in roller having a peripheral speed of Vi, and cutting the rubber sheet with the cutter to obtain the band, including a step of sending out with a carry-out roller having a peripheral speed Vo higher than the peripheral speed Vi,
In the step (B),
A pair of carrying-in roller bodies included in the carrying-in roller rotates while sandwiching the rubber sheet to feed the rubber sheet,
A pair of carry-out roller bodies included in the carry-out roller rotates with the belt sandwiched therebetween to feed out the belt,
A method for manufacturing a strip, wherein the ratio Vi/Vo of the peripheral speed Vi to the peripheral speed Vo is 0.98 or more. 6. The method for manufacturing a strip according to claim 5, wherein the rubber sheet has a thickness of more than 1 mm and 3 mm or less.

Images