JP2014217999A - Device and method for cutting rubber strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress bending of a rubber strip at a cut-off part when cutting the rubber strip while conveying the rubber strip on a conveyor belt.SOLUTION: A device for cutting a rubber strip includes: a cutter holder supported so as to be rotatable about a shaft center extending in a width direction and perpendicular to a conveying direction; and a flat plate-like cutter whose back surface is fixed to a cutter fitting surface of the cutter holder. In the device for cutting a rubber strip, an air-blowout flow passage extending vertically from an upper end to a lower end and blowing air out toward a blade tip edge from the lower end in a reference state where a cutter is directed to the rubber strip at right angle and the blade tip edge is directed downward, is provided between the cutter fitting surface and the back surface.

Description

  The present invention relates to a rubber strip cutting device and a cutting method capable of cutting a rubber strip conveyed on a conveying belt with high accuracy while being conveyed.

  In recent years, from the viewpoint of improving productivity, a so-called strip wind type tire forming method has been proposed in which a rubber member such as a tread rubber or a sidewall rubber is formed using a long strip-like unvulcanized rubber strip (for example, (See Patent Document 1).

  In this strip wind system, as shown in FIG. 7, an unvulcanized rubber strip G extruded from a rubber extruder is transported using a transport belt a and continuously wound spirally on a rotating drum b. Thus, a rubber member having a desired cross-sectional shape is formed. Therefore, the strip wind method requires a cutting device c that can cut the rubber strip G while transporting it on the transport belt a at the end of winding.

  The conventional cutting device c includes a cutter holder c1 that is rotatably supported around an axis J, and a flat cutter c2 that is attached to the cutter holder c1 so as to be integrally rotatable. Then, as shown in FIG. 8, the rubber strip G is cut while being conveyed by rotating the cutter c2 once at a rotational speed equal to the conveying speed of the rubber strip G.

  However, in the apparatus c, since the surface of the cutter c2 is smooth, the rubber strip G after cutting sticks to the cutter c2, and problems such as the bending d of the rubber strip G occurring at the cut portion are caused.

JP 2006-159443 A

  Therefore, the present invention is based on the provision of an air blowing channel for blowing air toward the edge of the blade between the cutter holder and the cutter, and the rubber strip that adheres to the cutter is forcibly separated by blowing the air. It is an object of the present invention to provide a rubber strip cutting device and a cutting method that can suppress the occurrence of bending or the like of the rubber strip at the cutting portion.

In order to solve the above-mentioned problem, the invention of claim 1 of the present application is a rubber strip cutting device having a cutter for cutting a long strip-shaped rubber strip while transporting it on a transport belt,
A cutter holder that is supported so as to be rotatable about an axis extending at right angles to the conveying direction and extending in the width direction of the rubber strip, and having a cutter mounting surface parallel to the axis;
A flat plate with a back surface fixed to the cutter mounting surface, and a cutter having a blade edge parallel to the axis on the outer edge on the side away from the axis;
Between the cutter mounting surface and the back surface,
In a reference state in which the cutter is perpendicular to the rubber strip and the edge of the blade is directed downward, an air blowing passage that extends vertically from the upper end of the passage to the lower end of the passage and blows air from the lower end of the passage toward the edge of the blade. It is characterized by providing.

In claim 2, the plurality of air blowing channels are arranged in parallel in the width direction,
The cutter mounting surface has a collective recess extending in the width direction in the reference state and intersecting the upper end of each air blowing channel, and the collective recess is connected to an air supply source. .

  According to a third aspect of the present invention, the cutter holder includes a holder vertical groove extending vertically in the reference state on the cutter mounting surface, and the air blowing channel is formed by a gap between the holder vertical groove and the back surface. It is characterized by being formed.

  According to a fourth aspect of the present invention, the cutter includes, on the back surface, a cutter vertical groove or a cutter vertical rib extending vertically in the reference state, and a gap between the cutter vertical groove or the cutter vertical rib and the cutter mounting surface. The air blowing channel is formed.

  According to a fifth aspect of the present invention, the cutter includes a V-shaped notch at the center in the width direction and at the edge of the blade.

Moreover, Claim 6 is a rubber strip cutting method using the rubber strip cutting device according to any one of Claims 1 to 5,
From the position where the cutter is perpendicular to the rubber strip until the cutter stops rotating, air is blown out from the air blowing channel.

  As described above, the present invention includes an air blowing channel for blowing air toward the blade edge of the cutter between the cutter mounting surface of the cutter holder and the back surface of the cutter. Accordingly, the rubber strip that adheres to the back surface of the cutter after cutting can be forcibly separated by the air from the air blowing flow path, and the occurrence of bending of the rubber strip at the cutting portion can be suppressed.

It is a perspective view which shows an example of the strip wind apparatus using the rubber strip cutting device of this invention. It is a transverse cross section perpendicular to an axis showing a rubber strip cutting device in a standard state. It is the bottom view which looked at the rubber strip cutting device in a standard state from the lower part. It is a disassembled perspective view of the rubber strip cutting device in a reference state. (A), (B) is the disassembled perspective view which shows the other Example of the rubber strip cutting device, and a front view. (A), (B) is the perspective view and front view which show other Example of the rubber strip cutting device. It is a perspective view which shows the conventional rubber strip cutting device. It is an effect | action figure explaining the problem.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a perspective view showing an example of a strip wind device 2 using a rubber strip cutting device 1 of the present invention (hereinafter sometimes simply referred to as “cutting device 1”). A conveyor unit 2A having a conveyor belt 3 and a support unit 2B for supporting the conveyor unit 2A are provided.

The support portion 2B of this example is
A lateral movement table 2Ba that is movable in the lateral direction parallel to the drum axis 4i of the drum 4;
A vertical movement table 2Bb supported on the horizontal movement table 2Ba so as to be movable in a vertical direction perpendicular to the drum axis 4i;
The vertical moving base 2Bb includes a swivel base 2Bc supported so as to be turnable around a vertical swivel axis 2i.

  Further, the conveyor portion 2A of this example includes a frame 5 supported by the swivel base 2Bc. The transport belt 3 is guided by a plurality of guide rollers 6 supported by the frame 5 so as to be able to go around in the transport direction Fx.

  The cutting device 1 is attached to the frame 5 and cuts the rubber strip G conveyed on the conveying belt 3.

  As shown in FIGS. 2 and 3, the cutting device 1 includes a cutter holder 8 that is supported so as to be rotatable around an axis J perpendicular to the conveying direction Fx and extending in the width direction Fy of the rubber strip G, and the cutter holder 8. And a flat plate-like cutter 9 fixed to be integrally rotatable. FIG. 2 shows a reference state Y in which the cutter 9 is perpendicular to the rubber strip G and the cutting edge 9T is directed downward.

  As shown in FIG. 4, the cutter holder 8 has a rectangular block-shaped base body 10, and support shafts 11 forming the axis J protrude from both side surfaces 10 </ b> S <b> 1 of the base body 10 in the width direction Fy. Yes. A cutter mounting surface 12 parallel to the axis J is formed on the front surface 10S2 of the base body 10 facing forward in the rotational direction. The support shafts 11 and 11 are pivotally supported by, for example, a portal frame 7 (shown in FIG. 1) attached to the frame 5 via bearings and the like, and a motor M is connected to one support shaft 11. The

  Further, in this example, a positioning step surface 13 is formed on the front surface 10S2 so as to rise along the width direction both side edges 12E1 and the upper end edge 12E2 of the cutter mounting surface 12 in the reference state Y. Thereby, the position shift of the cutter 9 is prevented. In this example, the step surface 13 is formed by an inward surface of a rib-like protrusion 14 protruding from the front surface 10S2.

  Next, the cutter 9 has a flat plate shape in which the back surface 9 </ b> A is fixed to the cutter mounting surface 12. In this example, the case where the said cutter 9 is fixed to the cutter attachment surface 12 with the volt | bolt 16 is shown.

  The cutter 9 includes a sharp cutting edge 9T that is parallel to the axis J at the outer edge on the side away from the axis J, that is, the lower edge in the reference state Y. In this example, a V-shaped notch 17 is provided at the center of the blade edge 9T in the width direction. The notch depth of the notch portion 17 is larger than the thickness t (shown in FIG. 2) of the rubber strip G, and the notch portion 17 is used to prevent meandering of the pasted portion of the rubber strip G. Useful. Further, the blade edge 9T projects a distance L (shown in FIG. 2) below the lower end edge 12E3 of the cutter mounting surface 12, and a difference L− from the thickness t of the rubber strip G of the distance L. t is preferably about 5.0 to 10.0 mm.

  At least one, in this example, four air blowing channels 15 are formed between the cutter mounting surface 12 and the back surface 9A. In the reference state Y, the air blowing channel 15 extends vertically from the channel upper end 15a to the channel lower end 15b.

  The cutter mounting surface 12 includes a collective recess 18 that extends in the width direction Fy in the reference state Y and intersects the flow path upper end 15a of each air blowing flow path 15. The collective recess 18 extends upward from the collective recess 18 and is connected to an air supply source (not shown) such as a pump through an air intake hole 19 opened at the upper surface 10S3 of the base body 10. Accordingly, each air blowing channel 15 can blow air from the opening of the channel lower end 15b toward the cutting edge 9T, and the wind pressure causes the rubber strip G to adhere at the time of cutting from the back surface 9A. Can be peeled off.

  A plurality of air blowing channels 15 are preferably formed as the air blowing channels 15. In this case, the plurality of air blowing channels 15 are preferably arranged in parallel in the width direction Fy at regular intervals, for example, and are particularly arranged at symmetrical positions around the width center line Co (shown in FIG. 4). Is more preferable. The number of the air blowing channels 15 is preferably 4 to 8, and particularly preferably an even number. If the number is less than four, it is difficult to exert a peeling effect over the entire width of the rubber strip G. For example, the rubber strip G may be bent at both ends in the width direction. Further, if the number exceeds eight, further improvement of the peeling effect cannot be expected, and conversely, the number of processing steps for forming the air blowing channel 15 increases, resulting in a disadvantage in manufacturing cost and manufacturing efficiency. In the case of an odd number, one of them is formed on the width center line Co, but the V-shaped notch 17 is formed on the width center line Co. The peeling effect is small.

  In this example, the cutter mounting surface 12 is provided with a holder vertical groove 20 extending vertically in the reference state Y. The lower end 20b of the holder vertical groove 20 opens at the lower surface 10S4 of the base body 10, and the upper end 20a of the holder vertical groove 20 intersects the collective recess 18. Therefore, in the case of this example, the air blowing flow path 15 is formed by the gap between the holder vertical groove 20 and the back surface 9A.

  The depth 15h (shown in FIG. 2) of the air blowing channel 15 is not particularly limited, but is preferably in the range of 0.3 to 1.0 mm, and the depth 18h of the collective recess 18 is the air blowing channel. The depth of 15 is preferably 15h or more.

5 and 6 show another example of the cutting device 1.
In the case of FIG. 5, instead of the holder vertical groove 20, a cutter vertical rib 25 having a small height extending vertically in the reference state Y is provided on the back surface 9 </ b> A of the cutter 9. In the present embodiment, the cutter mounting surface 12 is provided with a recess 26 into which the cutter vertical rib 25 is fitted. The recess 26 extends downward from the collective recess 18 and opens at the lower surface 10S4 of the base 10. Therefore, in the case of this example, as shown in FIG. 5B, the air blowing is caused by the gaps between the cutter vertical rib 25, the back surface 9A, and the bottom surface of the recessed portion 26 of the cutter mounting surface 12. A flow path 15 is formed. The cutter vertical rib 25 may be brought into contact with the cutter mounting surface 12 without forming the recess 26.

  In the case of FIG. 6, instead of the holder vertical groove 20, a cutter vertical groove 28 having a small depth extending vertically in the reference state Y is provided in the back surface 9 </ b> A of the cutter 9. In this case, as shown in FIG. 6B, the air blowing channel 15 is formed by the gap between the cutter longitudinal groove 28 and the cutter mounting surface 12.

Next, when cutting the rubber strip G using the cutting device 1,
The cutter 9 is rotated once at a rotational speed at which the peripheral speed at the cutting edge 9T of the cutter 9 is equal to the conveying speed of the rubber strip G. Thereby, the rubber strip G can be cut while being conveyed.

  At this time, air is blown out from the air blowing channel 15 from the reference state Y until the cutter 9 stops rotating. Thereby, the rubber strip G sticking to the back surface 9A of the cutter 9 can be peeled from the back surface 9A at the time of cutting. If the air blowing is earlier than the reference state Y, the rubber strip G may be displaced due to air. The amount of air blown out from the air blowout channel 15 is preferably 36 liters / second or more.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  In order to confirm the effect of the present invention, a cutting device having the structure shown in FIGS. 2 to 4 was made as a prototype, and the occurrence of bending of the rubber strip at the cutting portion was confirmed. Evaluation displayed the incidence rate (%) of bending when cut | disconnected 100 times. A lower value is preferred.

The common specifications are as follows.
・ Air blowout channel: rectangular cross section (depth 0.5mm, width 0.5mm)
・ Rubber strip: Width 23mm, thickness 1.0mm
・ Cutter: Width 35mm

  The air blowing channel is formed at a symmetrical position around the width center line Co. Each air blowing channel was arranged at equal intervals over the entire width of the cutter.

  As shown in the table, it can be confirmed that the example products are effective in suppressing the bending of the rubber strip, and in particular, it is confirmed that the excellent effect is exhibited with 4 to 8 pieces. In addition, even if it exceeded eight, the further improvement of the said effect was not recognized. Moreover, although the same test was done also about the cutting device of the structure of FIG. 5, 6, the same result was able to be obtained.

DESCRIPTION OF SYMBOLS 1 Rubber strip cutting device 3 Conveyor belt 8 Cutter holder 9 Cutter 9A Back surface 9T Blade edge 12 Cutter attachment surface 15 Air blowing flow path 15a Flow path upper end 15b Flow path lower end 15
17 Notch 18 Collective recess 20 Holder vertical groove 28 Cutter vertical groove 25 Cutter vertical rib Fx Conveying direction Fy Width direction G Rubber strip J Axis center Y Reference state

Claims (6)

A rubber strip cutting device having a cutter for cutting a long strip-shaped rubber strip while being conveyed on a conveying belt,
A cutter holder that is supported so as to be rotatable about an axis extending at right angles to the conveying direction and extending in the width direction of the rubber strip, and having a cutter mounting surface parallel to the axis;
A flat plate with a back surface fixed to the cutter mounting surface, and a cutter having a blade edge parallel to the axis on the outer edge on the side away from the axis;
Between the cutter mounting surface and the back surface,
In a reference state in which the cutter is perpendicular to the rubber strip and the edge of the blade is directed downward, an air blowing passage that extends vertically from the upper end of the passage to the lower end of the passage and blows air from the lower end of the passage toward the edge of the blade. A rubber strip cutting device characterized by comprising: While a plurality of air blowing channels are arranged in parallel in the width direction,
The cutter mounting surface includes a collective recess extending in the width direction in the reference state and intersecting with the upper end of each of the air blowing channels, and the collective recess is connected to an air supply source. The rubber strip cutting device according to claim 1.   The cutter holder has a holder vertical groove extending vertically in the reference state on the cutter mounting surface, and the air blowing channel is formed by a gap between the holder vertical groove and the back surface. The rubber strip cutting device according to claim 1 or 2.   The cutter includes a cutter vertical groove or a cutter vertical rib extending vertically in the reference state on the back surface, and the air blowing channel is formed by a gap between the cutter vertical groove or the cutter vertical rib and the cutter mounting surface. The rubber strip cutting device according to claim 1, wherein the rubber strip cutting device is formed.   5. The rubber strip cutting device according to claim 1, wherein the cutter includes a V-shaped notch at the center in the width direction and at the edge of the blade. A rubber strip cutting method using the rubber strip cutting device according to any one of claims 1 to 5,
A method of cutting a rubber strip, characterized in that air is blown out from the air blowing flow path from the reference state until the cutter stops rotating.

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