JP2018130895A - Rubber extruder and manufacturing method of rubber extrusion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber extruder and a manufacturing method of a rubber extrusion, capable of stably manufacturing a rubber extrusion of various desired shapes with high precision while reducing an operation man-hour required for a component change.SOLUTION: A die 5 to be mounted on a head 4 of a rubber extruder 1 includes a deflection member 5a arranged at a front end position of an extrusion flow channel 4a and configured to deflect in a direction to change an area of an extrusion port 6. While maintaining the deflection member 5a in a desired deflection state, a screw 3 arranged inside a cylinder 2 extrudes a rubber material R frontward, as well as mixes and kneads the rubber material to obtain unvulcanized rubber R1, and the unvulcanized rubber is sent to an extrusion flow channel 4a and extruded from the extrusion port 6, so that a rubber extrusion R2 of a desired shape can be manufactured.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rubber extrusion apparatus and a method for producing a rubber extrudate, and more specifically, even if variations occur due to rubber physical properties, extrusion conditions, etc., while reducing the man-hours required for component correction operations, etc. The present invention relates to a rubber extruding apparatus and a method for producing a rubber extrudate capable of accurately and stably producing a rubber extrudate.

  When manufacturing rubber products such as tires, there is an extrusion process in which unvulcanized rubber is extruded by a rubber extrusion device. In the rubber extrusion device, unvulcanized rubber is plasticized by an internal screw and is sent to an extrusion flow path formed in a front end die. A die having an extrusion port of a desired shape is installed at the front end of the die, and a rubber extrudate molded into a desired shape is produced by passing unvulcanized rubber through the extrusion port.

  Different rubber types have different rubber properties, and there are some variations in rubber properties from lot to lot for the same rubber type. In addition, there are variations in extrusion conditions and the like for each lot. For this reason, even if unvulcanized rubber is extruded using the same die, there may be a case where a rubber extrudate having a desired shape cannot be obtained due to these variations. In such a case, extra work steps are required to correct the shape of the die or adjust the 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 on a die have been proposed (see, for example, Patent Documents 1 and 2). In the structures proposed by these documents, the shape of the extrusion port can be changed greatly, but it is difficult to change the shape of the extrusion port finely or locally. Therefore, there is room for improvement in order to accurately and stably produce a rubber extrudate having a desired shape according to variations due to rubber physical properties, extrusion conditions, and the like.

JP 2004-243732 A JP 2012-187712 A

  An object of the present invention is to accurately and stably produce a rubber extrudate having a desired shape while reducing the number of man-hours required for correcting parts and the like even if variations occur due to rubber physical properties, extrusion conditions, and the like. An object of the present invention is to provide a rubber extrusion apparatus and a method for producing a rubber extrudate.

  In order to achieve the above object, a rubber extrusion device according to the present invention comprises a cylindrical cylinder, a screw disposed in the internal space of the cylinder, and an extrusion flow channel installed at the front end of the cylinder and communicating with the internal space. And a die that is attached to the head and that forms an extrusion port at the front end position of the extrusion flow path, wherein the die is disposed at the front end position of the extrusion flow path and the extrusion port It has the structure which has the bending member which bends and deforms in the direction which changes the area of this, and can maintain the said bending member in a desired bending deformation state.

  The method for producing a rubber extrudate according to the present invention is an unvulcanized product in which a rubber material is put into an internal space of a cylindrical cylinder, and the rubber material is mixed and kneaded while being pushed forward by a screw disposed in the internal space. In a method for producing a rubber extrudate, the rubber is fed into an extrusion passage formed in a head installed at the front end of the cylinder, and extruded as a rubber extrudate from an extrusion port formed by a die attached to the head. The die is disposed at a front end position of the extrusion flow path, and has a bending member that bends and deforms in a direction that changes the area of the extrusion port, and maintains the bending member in a desired bending deformation state, and A rubber extrudate having a desired shape is produced by passing the vulcanized rubber through the extrusion flow path and extruding it from the extrusion port.

  According to the present invention, since the die has the bending member that bends and deforms in the direction in which the area of the extrusion port is changed, the extrusion port is made finer by maintaining the bending member in a desired bending deformation state, or Can be changed locally. Therefore, a rubber extrudate having a desired shape can be accurately and stably manufactured according to variations due to rubber physical properties, extrusion conditions, and the like. Further, it is possible to obtain a rubber extrudate having a desired shape without performing an extra work for adjusting a die or the like as in the past or an extra work for adjusting an extrusion condition or the like, or minimizing an extra work. it can.

It is explanatory drawing which illustrates the outline | summary of the rubber extrusion apparatus of this invention by a side view. It is explanatory drawing which illustrates the periphery of the head of FIG. 1 by a front view. FIG. 3 is an explanatory view illustrating the inside of the periphery of the head in a cross-sectional view taken along the line AA of FIG. It is explanatory drawing which illustrates the state which is maintaining the bending member of FIG. 2 in the desired bending deformation state. It is explanatory drawing which illustrates the modification of a bending member by a front view. It is explanatory drawing which illustrates another modification of a bending member by a front view. It is explanatory drawing which illustrates another modification of a bending member by a front view.

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

  The rubber extrusion device 1 of the present invention illustrated in FIGS. 1 to 3 includes a cylindrical cylinder 2, a screw 3 disposed inside the cylinder 2, and a head 4 disposed at the front end of the cylinder 2. Yes. A die 5 is attached to the head 4. In this embodiment, the rubber extrusion device 1 further includes a sensor 9 and a control unit 10 to which detection data from the sensor 9 is input. A conveyor device 11 that conveys the extruded rubber extrudate R2 to the next process is disposed in front of the die 5.

  At the front end of the cylinder 2, the internal space is narrowed toward the front. The head 4 has an extrusion channel 4 a that penetrates in the front-rear direction, and the extrusion channel 4 a communicates with the internal space of the cylinder 2.

  At the front end position of the extrusion flow path 4 a of the head 4, an extrusion port 6 is formed by the die 5. The die 5 has a bending member 5 a disposed at the front end position of the extrusion channel 4 a and a fixing bolt 5 c that fixes the bending member 5 a to the front surface of the head 4. The rubber extruding apparatus 1 of this embodiment has two flexible members 5a that are opposed to each other in the vertical direction on the front surface of the die 5. Each bending member 5a is fixed to the die 5 by a fixing bolt 5c that passes through both front and rear ends. Two arc-shaped stress relaxation portions 5b are formed at the center in the left-right direction of the bending member 5a with a space in the left-right direction, and a flat surface is formed between the stress relaxation portions 5b.

  Each bending member 5a is disposed adjacent to the front end opening of the extrusion flow path 4a, and can be partially deformed within the range of elastic deformation to cover a part of the front end opening. Examples of the material of the bending member 5a include stainless steel and spring steel. The thickness of the thinnest part (stress relaxation part 5b) in plan view of the bending member 5a is, for example, about 0.1 mm to 10 mm, although it depends on the material.

  Fixed plates 8 are attached to both the upper and lower side surfaces of the head 4 so as to protrude outward, and actuators 7 are installed on the respective fixed plates 8. The actuator 7 has a pressing portion 7a that moves in a direction (vertical direction in FIGS. 2 and 3) perpendicular to the extending direction of the extrusion flow path 4a. The tip of the pressing part 7a is in contact with the flat part at the center in the left-right direction of the bending member 5a.

  In this embodiment, a hydraulic cylinder is employed as the actuator 7. In addition, the actuator 7 can be configured to include, for example, a servo motor and a ball screw that rotates by the servo motor and moves in the axial direction. In this case, the ball screw is used as the pressing portion 7a, or the pressing portion 7a is provided at the tip of the ball screw.

  As illustrated in FIG. 4, when the bending member 5 a is pressed by the pressing portion 7 a by the operation of the actuator 7, it is bent and deformed with the fixing bolt 5 c as a fulcrum. Due to this bending deformation of the bending member 5a, the area of the extrusion port 6 changes because the opening area of the front end of the extrusion flow path 4a covered by the bending member 5a changes.

  The bending member 5a can be maintained in a desired bending deformation state. The operation of the actuator 7 is controlled by the control unit 10 based on detection data from the sensor 9. Therefore, the bending member 5a is maintained in a desired bending deformation state by the control of the control unit 10.

  Hereafter, the procedure of the manufacturing method of the rubber extrudate of this invention is demonstrated.

  When the rubber extrudate R2 is produced by the rubber extruding device 1, a predetermined amount of the rubber material R such as raw rubber and compounding agent is put 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 5a is bent and deformed and maintained in a desired bending deformation state. The unvulcanized rubber R1 pushed forward by the screw 3 is softened to some extent (plasticized), is sent to the extrusion flow path 4a, and passes through the extrusion flow path 4a.

  The opening area of the front end of the extrusion channel 4 a is partially covered by the bending member 5 a, and the extrusion port 6 having a desired shape is formed by the die 5. The unvulcanized rubber R1 is extruded from the extrusion port 6 formed in this desired shape, and is molded by molding to produce a rubber extrudate R2 having a desired shape. For example, a rubber extrudate R such as a strip-shaped tire member formed in a predetermined shape is manufactured from the present invention. The rubber extrudate R2 is conveyed to the next step by the conveyor device 11 while being extruded.

  If there is a variation in the rubber physical properties of the unvulcanized rubber R1 or a variation due to the extrusion conditions, the shape of the rubber extrudate R2 produced even if it is extruded through the extrusion port 6 having the same shape also varies. The amount of bending deformation of the bending member 5a of the present invention depends on the interval (span) between the fixing bolts 5c, but is about 0.1 mm to 10 mm, for example, and is pressed against the bending member 5a by the pressing portion 7a. By changing the position, the shape of the extrusion port 6 can be changed finely or locally.

  Therefore, according to the present invention, the rubber extrudate R2 having a desired shape can be accurately and stably manufactured by controlling the degree of deformation of the bending member 5a even if variations due to rubber physical properties, extrusion conditions, and the like occur. Can do. Also, according to variations due to rubber physical properties, extrusion conditions, etc., each time the shape of the die is corrected, or the extra work conventionally done to adjust the extrusion conditions, etc. is unnecessary or unnecessary work Minimize. Therefore, it is advantageous to improve the productivity of the rubber extrudate R2.

  Moreover, in the present invention, by providing the bending member 5a at the front end position of the extrusion channel 4a, only the shape of the extrusion port 6 is changed without changing the shape of the extrusion channel 4a. Therefore, the present invention can be easily applied to existing rubber extruders.

  In this embodiment, the sensor 9 detects the shape (width dimension or thickness dimension) of the rubber extrudate R2 immediately after extrusion. The control unit 10 is input with a target value of the shape (width dimension or thickness dimension) of the rubber extrudate R2, and compares the detection data with the target value so that the difference between the two becomes small. The bending deformation state of 5a is controlled (feedback control is performed).

  Correlation data of fluctuation parameters such as rubber physical properties and extrusion conditions, the bending deformation state of the bending member 5a, and the shape of the rubber extrudate R2 when the bending member 5a is extruded in the bending deformation state are accumulated to some extent. In this case, the correlation data is input to the control unit 10 in advance. Then, when starting the extrusion of the rubber extrudate R2, the actual variation parameters and the target value of the shape of the rubber extrudate R2 are input to the control unit 10, and these data and the above-described pre-input are input. Based on the correlation data, the bending member 5a is preset in a desired bending deformation state, and the rubber extrudate R2 is extruded so as to have a desired shape. Thereafter, the bending deformation state of the bending member 5a is controlled by the feedback control described above.

  For example, when the rubber extrudate R2 to be a tire constituent member is manufactured using the present invention, it can be accurately formed into a desired shape. Therefore, manufacturing a tire using this rubber extrudate R2 is advantageous for improving the uniformity of the tire.

  If the stress relieving part 5b is provided in the bending member 5a as in this embodiment, it can be bent and deformed more finely and locally, so the extrusion port 6 can be changed finely or locally. It becomes more and more advantageous. Moreover, since the response (deformation speed) at the time of bending and deforming the bending member 5a is also improved, it is advantageous to quickly change the shape of the extrusion port 6.

  In the case where the extrusion port 6 is rectangular as illustrated in FIG. 2, the center part of the long side tends to expand in the extruded rubber extrudate R2. Therefore, as illustrated in FIG. 4, the bending member 5 a is disposed at a position corresponding to the upper and lower long sides of the extrusion port 6, and the bending member 5 a is bent and deformed so that the central portions of the long sides are close to each other. Extrusion makes it easy to obtain a rubber extrudate R2 having a rectangular cross section.

  Not only the configuration in which one pressing portion 7a (actuator 7) is provided for one bending member 5a, but also a plurality of pressing portions 7a (actuators 7) may be provided as illustrated in FIGS. it can. Further, the direction in which the pressing portion 7a moves is not limited to the vertical direction, and can be a horizontal direction or an oblique direction. The number of fixing bolts 5c for fixing one bending member 5a to the head 4 can be singular or plural.

  For one extrusion port 6 (front end opening of the extrusion flow path 4a), a plurality of bending members 5a may be provided as illustrated in FIGS. 2 and 3, as illustrated in FIGS. It can also be set as the structure which provides the one bending member 5a. In FIG. 7, an annular bending member 5a surrounding the entire circumference of the front end opening of the extrusion channel 4a is provided.

DESCRIPTION OF SYMBOLS 1 Rubber extrusion apparatus 2 Cylinder 3 Screw 4 Head 4a Extrusion flow path 5 Die 5a Deflection member 5b Stress relaxation part 5c Fixing bolt 6 Extrusion port 7 Actuator 7a Press part 8 Fixing plate 9 Sensor 10 Control part 11 Conveyor apparatus R Rubber material R1 Not yet Vulcanized rubber R2 rubber extrudate

Claims (5)

A cylindrical cylinder, a screw arranged in the internal space of the cylinder, a head having an extrusion flow path installed at the front end of the cylinder and communicating with the internal space, and the extrusion flow path attached to the head In a rubber extrusion apparatus provided with a die that forms an extrusion port at the front end position of
The die is disposed at the front end position of the extrusion flow path, and has a bending member that bends and deforms in a direction that changes the area of the extrusion port, and is configured to be able to maintain the bending member in a desired bending deformation state. A rubber extrusion device.   2. The actuator according to claim 1, further comprising an actuator having a pressing portion that moves in a direction orthogonal to the extending direction of the extrusion flow path, wherein the bending member is bent and deformed by pressing the bending member by the pressing portion. The rubber extrusion apparatus as described.   The rubber extrusion device according to claim 1 or 2, wherein a plurality of the bending members are provided, and each of the bending members bends and deforms independently.   The sensor according to any one of claims 1 to 3, further comprising: a sensor that detects a shape of the rubber extrudate extruded from the extrusion port; and a control unit that controls a bending deformation state of the bending member based on detection data of the sensor. The rubber extrusion apparatus as described. A rubber material was put into an internal space of a cylindrical cylinder, and unvulcanized rubber mixed and kneaded while pushing the rubber material forward by a screw disposed in the internal space was installed at the front end of the cylinder. In a method for producing a rubber extrudate that is fed into an extrusion flow path formed in a head and extruded as a rubber extrudate from an extrusion port formed by a die attached to the head.
The die is disposed at a front end position of the extrusion flow path, and has a bending member that bends and deforms in a direction that changes the area of the extrusion port, and maintains the bending member in a desired bending deformation state, and A method for producing a rubber extrudate, comprising producing a rubber extrudate having a desired shape by passing vulcanized rubber through the extrusion flow path and extruding from the extrusion port.

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