JP2019048408A - Rubber extrusion apparatus and method for producing rubber extrusion - Google Patents

Abstract

To provide a rubber extrusion device and a method for producing a rubber extrusion, capable of reducing the number of operation steps required for replacing parts and stably producing rubber extrusions of various desired shapes with high accuracy.SOLUTION: A die 5 attached to a head 4 of a rubber extrusion device 1 is provided with a bending member 6 disposed at a front-end position of an extrusion flow path 4a and bendingly deformable in a direction of changing an area of an extrusion port 7. The bending member 6 has two split pieces 6a and a split portion 6b that splits the split pieces 6a from each other along an extending direction of the extrusion flow path 4a. In a state in which a gap between the split pieces 6a generated by the split portion 6b is closed by a distal end 8b of a pressing portion 8, the bending member 6 is deformed as desired and an unvulcanized rubber R1 obtained by mixing and kneading while pushing a rubber material R forward by a screw 3 installed in a cylinder 2 is fed into the extrusion flow path 4a and extruded from the extrusion port 7, so that a rubber extruded product R 2 of a desired shape is manufactured.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a rubber extrusion apparatus and a method for producing a rubber extrusion, and more specifically, even if variations occur due to rubber physical properties, extrusion conditions, etc., the number of steps required for part correction work is reduced while the desired shape is obtained. The present invention relates to a rubber extrusion device capable of stably and stably producing a rubber extrudate and a method of producing a rubber extrudate.

  In producing a rubber product such as a tire, there is an extrusion step of extruding unvulcanized rubber by a rubber extrusion device. In the rubber extrusion device, the unvulcanized rubber is plasticized by the screw installed therein and is fed into the extrusion channel formed in the die at the front end. A die having an extrusion port of a desired shape is installed at the front end of the die, and an unvulcanized rubber passes through the extrusion port to produce a rubber extrusion molded into a desired shape.

  If the rubber type is different, the rubber physical properties are also different, and the rubber type is the same rubber, and the rubber physical properties vary somewhat from lot to lot. In addition, there are variations in extrusion conditions and the like from lot to lot. Therefore, even if the unvulcanized rubber is extruded using the same die, it may not be possible to obtain a rubber extrusion having a desired shape due to these variations. In such a case, an extra operation time is required to correct the shape of the die or adjust extrusion conditions and the like each time.

  For example, various structures for changing the shape of the extrusion port by sliding a slide member installed in a die have been proposed (see, for example, Patent Documents 1 and 2). In the structure proposed by these documents, although the shape of the extrusion port can be largely changed, it is difficult to finely change the shape of the extrusion port or to change locally. Therefore, there is room for improvement in order to stably and stably produce a rubber extruded product having a desired shape in accordance with variations due to rubber physical properties, extrusion conditions and the like.

Unexamined-Japanese-Patent No. 2004-243732 JP 2012-187712 A

  It is an object of the present invention to accurately and stably manufacture a rubber extrusion of a desired shape while reducing the number of steps required for the correction work of parts even if variations occur due to rubber physical properties, extrusion conditions, etc. A rubber extrusion device and a method for producing a rubber extrudate.

  In order to achieve the above object, the rubber extruding apparatus of the present invention comprises an accommodating portion for accommodating a rubber material, an extruding mechanism for extruding the rubber material from the accommodating portion as unvulcanized rubber, and an extrusion flow communicating with the accommodating portion. A rubber extrusion apparatus comprising: a head having a path; and a die attached to the head and forming an extrusion port at a front end position of the extrusion flow path, wherein the die is disposed at a front end position of the extrusion flow path The bending member includes a bending member that bends and deforms in a direction to change the area of the extrusion port, and a pressing portion that bends and deforms the bending member, and the bending member divides the bending member along the extending direction of the extrusion flow path. It is characterized in that the bending member is bent and deformed in a state in which the pressing portion closes a gap of the bending member generated by the dividing portion.

  In the method for producing a rubber extruded product according to the present invention, a rubber material is put into the housing portion, and the rubber material is used as an unvulcanized rubber, and the extrusion channel formed in the head installed in the housing portion by the extrusion mechanism. In a method for producing a rubber extrusion that is fed and extruded as a rubber extrusion from an extrusion port formed by a die attached to the head, the die is disposed at the front end position of the extrusion channel to change the area of the extrusion port And a dividing portion for dividing the bending member along the extending direction of the extrusion flow passage, and a clearance of the bending member caused by the dividing portion. Is maintained in a desired state of bending deformation in a state where it is closed by a pressing portion, and the unvulcanized rubber is passed through the extrusion channel and pushed out from the extrusion port, thereby obtaining a desired shape Characterized in that to produce a beam extrudate.

  According to the present invention, since the die is provided with the bending member that is bent and deformed in the direction to change the area of the extrusion port, the extrusion port is finely or locally maintained by maintaining the bending member in the desired bending deformation state. Can be changed. Therefore, according to the dispersion | variation by rubber | gum physical properties, extrusion conditions, etc., it becomes possible to manufacture the rubber extrusion of a desired shape stably with sufficient accuracy. In addition, since the bending member has a dividing portion that divides the bending member along the extending direction of the extrusion flow path, it is advantageous for increasing the amount of bending deformation without causing plastic deformation. And since the bending member is bent and deformed in a state in which the gap of the bending member generated by the dividing portion is closed by the pressing portion, the extruded unvulcanized rubber does not leak from the dividing portion. In addition, it is possible to obtain a rubber extrusion having a desired shape without performing the extra work for adjusting the extruding conditions, etc. or the correction work of the die as in the prior art, or minimizing the extra work. it can.

It is an explanatory view which illustrates the outline of the rubber extrusion device of the present invention by side view. It is explanatory drawing which illustrates the periphery of the head of FIG. 1 by a plain view. It is explanatory drawing which illustrates the inside of a head periphery by the AA cross-sectional view of FIG. It is explanatory drawing which illustrates the bending member arrange | positioned above the extrusion port of FIG. 2 by planar view. It is explanatory drawing which illustrates the state which is maintaining the bending member of FIG. 2 in a desired bending deformation state by a plain view. It is explanatory drawing which shows the modification of a bending member by a plain view. It is an explanatory view showing another modification of a bending member by plain view. It is explanatory drawing which illustrates another modification of a bending member by a plain view.

  Hereinafter, the rubber extrusion apparatus and the method for producing a rubber extrudate according to the present invention will be described based on the embodiments shown in the drawings.

  The rubber extruding device 1 of the present invention illustrated in FIGS. 1 to 4 includes a cylindrical cylinder 2 functioning as a housing portion for housing a rubber material R, a screw 3 disposed inside the cylinder 2, and the cylinder 2. A head 4 disposed at the front end and a die 5 attached to the head 4 are provided. The screw 3 is an extrusion mechanism that extrudes the rubber material R accommodated in the cylinder 2 from the cylinder 2 as the unvulcanized rubber R1. In this embodiment, the rubber extrusion device 1 further includes a sensor 10 and a control unit 11 to which detection data from the sensor 10 is input. At the front of the die 5, a conveyor device 12 is disposed for transporting the extruded rubber extruded material R2 to the next process.

  As illustrated in FIG. 3, at the front end of the cylinder 2, the internal space narrows toward the front. The head 4 has an extrusion channel 4 a penetrating in the front-rear direction, and the extrusion channel 4 a communicates with the internal space of the cylinder 2.

  The front end opening area of the extrusion channel 4 a of the head 4 is the extrusion port 7. The die 5 includes a bending member 6 disposed at a front end position of the extrusion flow passage 4a, and a pressing portion 8 which bends and deforms the bending member 6.

  The bending member 6 has a dividing portion 6b for dividing the bending member 6 along the extending direction of the extrusion flow passage 4a (left and right direction in FIG. 3, and vertical direction in FIG. 4). In this embodiment, the bending member 6 has two divided pieces 6a disposed adjacent to each other across the dividing portion 6b. The dividing portion 6 b is a gap (for example, a minute gap of about 0.1 mm to several mm) existing between the adjacently arranged divided pieces 6 a. Each divided piece 6a is fixed to the front of the head 4 by a fixing bolt 6d.

  In the rubber extrusion device 1 of this embodiment, two bending members 6 having the same specifications are disposed to face each other above and below the extrusion port 7. A dividing portion 6b is formed at the center position in the left-right direction of each bending member 6, and an arc-shaped stress relieving portion 6c is formed at a position between the dividing portion 6b and each fixing bolt 6d. Between the parting part 6b and each stress relaxation part 6c, it is an inclined surface which inclines toward the parting part 6b.

  In this embodiment, the respective fragments 6a are symmetrical with respect to the dividing portion 6b, but may be asymmetric. For example, the divided portions 6b can be unevenly distributed from the center position in the width direction of the extrusion port 7 to one side in the width direction, and the lengths of the respective divided pieces 6a can be made different.

  In this embodiment, an actuator (a hydraulic cylinder or the like) having a rod 8a moving in a direction (vertical direction in FIGS. 2 and 3) orthogonal to the extending direction of the extrusion flow passage 4a is employed as the pressing portion 8. The respective pressing parts 8 are controlled independently of one another. Fixing plates 9 are attached to the upper and lower side surfaces of the head 4 so as to protrude outward, and pressing portions 8 are provided on the respective fixing plates 9.

  The tip 8b of the rod 8a is in contact with the inclined surface at the central portion in the left-right direction of the bending member 6 to close the dividing portion 6b. The contact portion of the distal end portion 8 b with the bending member 6 may have a shape corresponding to the contact portion with the front end portion 8 b of the bending member 6. In this embodiment, the contact portion of the bending member 6 with the distal end portion 8b has a V groove shape starting from the dividing portion 6b in a front view. The contact portion of the distal end portion 8b with the bending member 6 has an arrowhead shape that fits in the V groove shape described above in a front view. For example, if the contact portion with the distal end portion 8b of the bending member 6 is a circular arc groove shape in the front view point, the contact portion with the bending member 6 of the front end portion 8b fits in the circular arc groove shape described above in front view It is good to make it an arc shape.

  Each bending member 6 is pressed by the tip end portion 8 b of the pressing portion 8 and can bend and deform within the range of elastic deformation, thereby covering a part of the extrusion port 7. That is, the bending member 6 is bent and deformed in the direction of changing the area of the extrusion port 7.

  Examples of the material of the bending member 6 include stainless steel and spring steel. The thickness of the thinnest portion of the stress relieving portion 6c in plan view of the bending member 6 is, for example, about 0.1 mm to 10 mm, though depending on the material.

  The pressing portion 8 can also be configured to have, for example, a servomotor and a ball screw that is rotated by the servomotor and moved in the axial direction. In this case, the bending member 6 is pressed and deformed by the tip of the ball screw.

  As illustrated in FIG. 5, when the bending member 6 is pressed by the distal end portion 8 b of the rod 8 a by the operation of the pressing portion 8, the bending member 6 deforms with the fixing bolt 6 d as a fulcrum. By this bending deformation of the bending member 6, the area of the front end opening of the extrusion channel 4a covered by the bending member 6 changes, so that the shape of the extrusion port 7 changes.

  The bending member 6 is configured to be able to be maintained in a desired bending deformation state. The operation of the pressing unit 8 is controlled by the control unit 11 based on data detected by the sensor 10. Therefore, under the control of the control unit 11, the bending member 6 is maintained in a desired bending deformation state in a state in which the gap between the divided pieces 6a generated by the dividing portion 6b is closed by the tip 8b.

  Hereinafter, the procedure of the method for producing a rubber extrudate of the present invention will be described.

  When producing the rubber extruded product R2 by the rubber extrusion device 1, a predetermined amount of rubber material R such as a raw material rubber and a compounding agent is introduced into the internal space of the cylinder 2. The rubber material R is mixed and kneaded by the rotating screw 3. In the die 5, the bending member 6 is bent and maintained to be in a desired bending deformation state. The unvulcanized rubber R1 pushed forward by the screw 3 is softened (plasticized) to a certain extent and is fed into the extrusion channel 4a to pass through the extrusion channel 4a.

  The front end opening area of the extrusion channel 4 a is partially covered by the bending member 6, and the die 5 forms an extrusion port 7 of a desired shape. By extruding the unvulcanized rubber R1 from the extrusion port 7 formed into the desired shape, the unvulcanized rubber R1 is stamped to produce the rubber extruded product R2 of the desired shape. For example, a rubber extrusion R2 such as a strip-like tire member formed in a predetermined shape is manufactured using the present invention. The rubber extrudate R2 is conveyed by the conveyance conveyor device 12 to the next process while being extruded.

  If there is a variation in the physical properties of the unvulcanized rubber R1 or variations due to extrusion conditions etc., then the shape of the extruded rubber R2 produced by the extrusion of the same shape also varies. The amount of bending deformation of the bending member 6 of the present invention is, for example, about 0.1 mm to 20 mm although it depends on the distance (span) between the contact position of the tip 8 b with the bending member 6 and the fixing bolt 6 d The amount of bending deformation can be maintained. Therefore, the shape of the extrusion port 7 can be finely changed or locally changed.

  Therefore, according to the present invention, even if variations occur due to rubber physical properties, extrusion conditions, etc., the bending deformation of each bending member 6 is controlled using each pressing portion 8, and the bending of the bending member 6 is performed as desired. By maintaining the deformed state, the extrusion port 7 can be set to a desired shape. By extruding the unvulcanized rubber R1 from the extrusion port 7 in this state, it is possible to accurately and stably produce a rubber extruded product R2 of a desired shape.

  In each case, according to the variation due to the physical properties of the rubber, extrusion conditions, etc., the extra work conventionally performed for adjusting the shape of the die or adjusting the extrusion conditions is unnecessary, or the extra work is minimized. become. Therefore, it is advantageous to improve the productivity of the rubber extrudate R2.

  Since the bending member 6 has the dividing portions 6b described above, each of the divided pieces 6a is supported by the head 4 like a cantilever. When the dividing portion 6b does not exist, the bending member 6 is supported by the head 4 like a double-supported beam, and when pressed by the pressing portion 8, the amount of bending deformation is increased without plastic deformation. Is difficult. However, in the present invention, since the bending members 6 have the dividing portions 6 b, it is advantageous to increase the amount of bending deformation without plastic deformation of the bending members 6 (each of the divided pieces 6 a). Along with this, it becomes easy to stably and stably manufacture the rubber extruded product R2 having a desired shape. In addition, it is also advantageous to prolong the service life (life) of the bending member 6.

  Then, since the flexible member 6 is bent and deformed in a state where the gap between the flexible members 6 (portions 6a) formed by the dividing portion 6b is closed by the end 8b of the pressing portion 8, the extruded unvulcanized rubber R1 is a divided portion There is no leakage from 6b. Therefore, it is possible to prevent an adverse effect due to the dividing portion 6b on the shape of the rubber extruded product R2 to be manufactured.

  Further, according to the present invention, by providing the bending member 6 at the front end position of the extrusion flow channel 4a, only the shape of the extrusion port 7 is changed without changing the shape of the extrusion flow channel 4a. Therefore, the present invention can be easily applied to existing rubber extruders.

  In this embodiment, the sensor 10 detects the shape (width dimension and thickness dimension) of the rubber extruded material R2 immediately after the extrusion. The target value of the shape (width dimension and thickness dimension) of the rubber extruded material R2 is input to the control unit 11, and the deflection member is made so that the difference between the detection data and the target value becomes small. Control the deflection deformation state of 6 (feedback control).

  The correlation data of the fluctuation parameters such as rubber physical properties and extrusion conditions, the bending deformation state of the bending member 6, and the shape of the rubber extrusion R2 when the bending member 6 is extruded in the bending deformation state is accumulated to some extent In this case, the correlation data is input to the control unit 11. And when starting extrusion of rubber | gum extrudate R2, the actual variation parameter and the target value of the shape of rubber | gum extrusion R2 are input into the control part 11, These data, and the above-mentioned are input beforehand Based on the correlation data, the bending member 6 is preset in a desired bending deformation state, and the unvulcanized rubber R1 is extruded so that the rubber extrusion R2 has a desired shape. Thereafter, the bending deformation state of the bending member 6 is controlled by the above-described feedback control.

  By using the present invention, for example, when a rubber extrusion R2 to be a tire constituent member is manufactured, it is possible to obtain a desired shape with high accuracy. Therefore, manufacturing a tire using this rubber extruded product R2 is advantageous for improving the uniformity of the tire.

  As in this embodiment, when the stress relaxation portion 6 c is provided in the bending member 6, bending deformation can be performed more finely and locally, so the extrusion port 7 is finely changed or locally changed. Become more advantageous to In addition, since the response (deformation speed) in bending and deforming the bending member 6 is also improved, it is advantageous to quickly change the shape of the extrusion port 7.

  When the extrusion port 7 is rectangular as illustrated in FIG. 2, in the extruded rubber extruded product R2, the central portion of the long side tends to expand. Therefore, as illustrated in FIG. 5, the bending members 6 are disposed at positions corresponding to the upper and lower long sides of the extrusion port 7, and bending deformation of the bending members 6 is performed so that central portions of the long sides approach each other. When extrusion is carried out, it becomes easy to obtain a rubber extruded product R2 of rectangular cross section.

  The bending member 6 can be installed at any position around the extrusion port 7 as well as above and below the extrusion port 7 at one or more than one. Further, the direction in which the pressing portion 8 moves is not limited to the vertical direction, but may be the horizontal direction or an oblique direction. In FIG. 6, the bending members 6 are respectively set at four places in the upper, lower, left, and right of the extrusion port 7. Each bending member 6 is bent and deformed by the independently controlled pressing portion 8. According to the rubber extrusion device 1 of FIG. 6, the shape of the extrusion port 7 can be changed over the entire circumference.

  The bending member 6 is not limited to a configuration having a plurality of independent divided pieces 6a divided by the dividing portion 6b, and may be configured not to include the divided pieces 6a as illustrated in FIG. In FIG. 7, the dividing portion 6 b is formed at one place of one annular bending member 6.

  The dividing portion 6 b is not limited to a minute gap, but may be a relatively large gap (for example, 10 mm or more) as illustrated in FIG. 8. In FIG. 8, not only the divided pieces 6 a but also the leading end 8 b of the pressing portion 8 can be positively used as a member for partitioning the extrusion port 7. Then, the extrusion port 7 is formed into a desired shape by the distal end portion 8b moved to the predetermined position and the bending members 6 (each of the divided pieces 6a) flexed and deformed by the distal end portion 8b, and the unvulcanized rubber R1 The rubber is extruded to produce a rubber extrudate R2.

  Although the structure which extrudes unvulcanized rubber R1 using the screw 3 arrange | positioned to the inside of the cylinder 2 was illustrated as rubber extrusion apparatus 1 in embodiment mentioned above, this invention is not limited to this structure. For example, the present invention can be applied to a structure in which the unvulcanized rubber R1 is extruded and a structure in which the unvulcanized rubber R1 is extruded using a gear pump.

1 rubber extrusion device 2 cylinder (housing part)
3 Screw (extrusion mechanism)
4 head 4a extrusion flow path 5 die 6 deflection member 6a division fragment 6b division portion 6c stress relaxation portion 6d fixing bolt 7 extrusion port 8 pressing portion (actuator)
8a Rod 8b Tip 9 Fixing plate 10 Sensor 11 Controller 12 Conveyor unit R Rubber material R1 Unvulcanized rubber R2 Rubber extruded material

Claims (5)

A storage portion in which a rubber material is stored, an extrusion mechanism for extruding the rubber material as the unvulcanized rubber from the storage portion, a head having an extrusion flow path communicating with the storage portion, and the head attached to the head A rubber extrusion device comprising a die for forming an extrusion port at a front end position of the flow path,
The bending member includes a bending member disposed at a front end position of the extrusion flow path and bendingly deforming in a direction to change the area of the extrusion port, and a pressing portion bending and deforming the bending member, the bending member A dividing portion for dividing the bending member along the extending direction of the extrusion flow path, and the pressing member bends and deforms the bending member in a state of closing the gap of the bending member generated by the dividing portion A rubber extrusion device characterized by   The rubber extrusion device according to claim 1, wherein the pressing portion is an actuator having a rod moving in a direction perpendicular to the extending direction of the extrusion flow path.   The rubber extrusion device according to claim 1, wherein a plurality of the bending members are provided, and each of the bending members is configured to be independently bent and deformed.   The sensor according to any one of claims 1 to 3, further comprising: a sensor for detecting the shape of the rubber extrusion extruded from the extrusion port; and a control unit for controlling a bending deformation state of the bending member based on detection data of the sensor. Rubber extrusion device as described. A rubber material is introduced into the housing portion, and the rubber material is fed as an unvulcanized rubber into an extrusion flow path formed in a head installed in the housing portion by an extrusion mechanism, and formed by a die attached to the head In a method of producing a rubber extrusion that is extruded as a rubber extrusion from the extrusion port,
The die is disposed at the front end position of the extrusion channel, and includes a bending member that is bent and deformed in a direction to change the area of the extrusion port, and the bending member bends along the extension direction of the extrusion channel. The unvulcanized rubber is maintained in a desired state of bending deformation in a state of having a dividing portion for dividing the member and closing the gap of the flexible member generated by the dividing portion by the pressing portion. A method for producing a rubber extrudate characterized in that a rubber extrudate having a desired shape is produced by passing through an extrusion channel and extruding from the extrusion port.

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