JP2018154013A - Method for forming bead apex rubber, and apparatus for forming bead apex rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the tip of a bead apex rubber from being caught up, shorten the processing time, and restrain the protrusion of the rubber, thus to reduce the deterioration of forming quality of the bead apex rubber.SOLUTION: A method for forming bead apex rubber includes a formation step P1, an inflow port closing step P2, a connection space opening step P3, a connection space closing step P4, and a connection step P5. In the formation step P1, an unvulcanized rubber G is flowed into a forming chamber 11 in a rear side closed state and a bead apex rubber B having a front end portion Bf is formed. In the inflow port closing step P2, a rubber inflow port 15 is closed by a shutter 30 when the front end portion Bf approaches a shutter wall portion 9 in the rear side. In the connection space opening step P3, a second side surface S2 is removed together with the shutter wall portion 9 in the rear side and a connection space J whose the second side surface S2 is open between a rear end portion Br and a front end portion Bf. In the connection space closing step P4, the connection space J is closed by disposing a third side surface S3. In the connection step P5, the unvulcanized rubber G is flowed into the closed connection space J and the rear end portion Br and the front end portion Bf are integrally connected.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a bead apex rubber forming method and a bead apex rubber forming apparatus capable of accurately forming a bead apex rubber on an outer peripheral surface of a bead core.

  Patent Document 1 below proposes a bead apex rubber forming method including a forming step of integrally forming a bead apex rubber on the outer peripheral surface of a bead core that rotates around an axis.

  However, in the molding process, when the tip of the bead apex is formed, the entire space of the molding chamber closed by the front and rear shutters is filled with unvulcanized rubber, which requires time and increases the process time. . Further, when the bead core makes a round and the tip of the bead apex rubber returns to the molding chamber, the tip is caught on one inner wall surface of the molding chamber, and it is easy to cause malfunction such as failure to return. .

  Accordingly, the present inventor has eliminated the front shutter and has a first cover wall body having a rear shutter as a cover wall body forming one inner wall surface, and a second cover wall having no rear shutter. A device composed of body and body was proposed. In this apparatus, a molding chamber is formed by the first covering wall body and the head main body, and bead apex rubber is formed until the bead core makes a substantially round. Then, when the bead core makes a substantially round, the first covering wall body is removed, and instead of the first covering wall body, the second covering wall body is disposed between the front end portion and the rear end portion of the bead apex rubber. Install to straddle.

  As a result, it is possible to prevent the tip from being caught when returning. In addition, since the previous shutter is eliminated, the time required for forming the tip portion can be eliminated and the process time can be shortened.

  However, in the proposed apparatus, a problem occurs when the first covering wall body is replaced with the second covering wall body. Specifically, when removing the first cover wall, the rubber extruder is temporarily stopped, but even after the stop, unnecessary rubber leaks from the rubber inlet due to the residual pressure in the rubber flow path. . Therefore, the shape of the rubber in the molding chamber becomes distorted. Therefore, when attaching the second covering wall body, a new problem that the deformed rubber protrudes from, for example, between the second covering wall body and the head main body and causes a reduction in the molding quality of the bead apex rubber. Will occur.

JP2013-237224A

  Therefore, the present invention can prevent the tip of the bead apex rubber from being caught, eliminates the time required for forming the tip, shortens the process time, and prevents the rubber from protruding when the second covering wall body is attached. It is an object of the present invention to provide a bead apex rubber forming method and a bead apex rubber forming apparatus that can suppress a reduction in molding quality of the bead apex rubber.

1st invention of this application is a bead apex rubber formation method which forms bead apex rubber continuously over the circumference on the outer peripheral surface of a bead core,
Forming on the outer peripheral surface of the bead core a molding chamber for forming a bead apex rubber extending in the circumferential direction surrounded by the first side surface on one side in the axial direction of the molding head and the second side surface on the other side. The chamber includes a molding step in which bead apex rubber is integrally formed on the outer peripheral surface of the bead core that rotates around the axis by allowing unvulcanized rubber to flow from the rubber inlet provided in the first side surface into the room.
The molding process is as follows:
The unvulcanized rubber is removed while rotating the bead core in the closed state of the rear of the molding chamber closed by the shutter wall portion provided at the rear end portion of the second side surface with the front side in the bead core rotating direction open. A forming step of forming a bead apex rubber having a tip by inflowing;
An inlet closing step of stopping the bead core and closing the rubber inlet with a shutter provided on the first side surface when the bead core makes a round and the tip approaches a rear shutter wall;
In the closed state of the rubber inflow port, the second side surface is removed together with the rear shutter wall portion, and a joint space where the second side surface side is opened is formed between the rear end portion and the front end portion of the bead apex rubber. Joint space release step,
In place of the second side surface, a joint space closing step for closing the joint space by arranging at least a third side surface straddling between the rear end portion and the tip end portion,
And a connecting step of integrally connecting the rear end portion and the front end portion by opening the rubber inlet by the shutter and allowing unvulcanized rubber to flow into the closed joint space.

The second invention of the present application is a bead apex rubber forming device for continuously forming a bead apex rubber over the circumference on the outer peripheral surface of the bead core,
A bead core holding means for holding the bead core rotatably about its axis;
And a molding chamber for forming a bead apex rubber that extends in the circumferential direction surrounded by the first side surface on the one axial side and the second side surface on the other side on the outer peripheral surface of the bead core. With a molding head
The molding head is
A head body having the first side surface and provided with a rubber inlet on the first side surface;
And a cover wall that is movably supported between an open state in which the second side surface of the molding chamber is opened and a closed state in which the second side surface is closed to form the molding chamber. Including the body,
The covering wall body is
A first covering wall body provided with a shutter wall portion after closing a rear side of the molding chamber at a rear end portion of the second side surface;
When the first cover wall body is in an open state without the rear shutter wall portion, it is formed from a second cover wall body that closes only the second side surface instead of the first cover wall body,
The head body extends from the front side toward the rear side along the first side surface,
In addition, a shutter is provided that can open and close the rubber inlet by sliding back and forth on the front side of the rear shutter wall.

  In the bead apex rubber forming method of the first invention, in a state where the front side of the molding chamber is opened and only the rear side is closed, unvulcanized rubber is allowed to flow in while rotating the bead core, thereby having a bead apex rubber having a tip portion. Is forming. That is, the tip portion forming step in the forming method of Patent Document 1 is eliminated, and the tip portion is also formed together by the intermediate portion forming step.

  Therefore, the time required for the tip portion forming step can be eliminated, and the process time can be shortened. When forming the bead apex rubber with the front side of the molding chamber open, the front end surface of the front end portion becomes uneven due to the absence of the front shutter. However, since the rubber is filled between the front end surface and the rear end portion by the connection step, the unevenness is eliminated after the connection. Rather, since the protrusion of the rubber in the tip portion forming step is prevented, the accuracy of forming the bead apex rubber can be improved.

  Further, when the bead core makes a round and the tip of the bead apex rubber approaches the rear shutter wall, the second side is removed together with the rear shutter wall, and the third side is replaced by the rear side. It is arranged across the end and the tip.

  Accordingly, it is possible to prevent malfunction such as the tip of the bead apex rubber being caught when returning. Further, since the joint space can be reliably closed by the third side surface, the rubber connection between the rear end portion and the front end portion can be performed with high accuracy.

  In the present invention, a shutter is provided on the first side surface. Therefore, when the second side surface is removed together with the rear shutter wall (joint space opening step), the rubber inlet can be closed by the shutter. Therefore, the rubber can be prevented from flowing out from the rubber inlet, and the deformation of the rubber in the molding chamber from which the second side surface has been removed can be prevented. Further, when the third side surface is disposed, it is possible to prevent the deformed rubber from protruding and causing a decrease in the molding quality of the bead apex rubber.

  In particular, by arranging the shutter so that it can slide back and forth in front of the rear shutter wall, the shutter does not get caught between the rear shutter wall and the first side surface, and the shutter operation is smooth. Can be done.

  The bead apex rubber forming apparatus according to the second aspect of the invention can also exhibit the same effects as the bead apex rubber forming method.

It is the partial side view to which the principal part of the bead apex rubber forming apparatus of this invention was expanded. It is a perspective view of the principal part of a bead apex rubber forming apparatus. It is sectional drawing along the axial direction which shows a shaping | molding chamber. (A) is sectional drawing seen from the top which shows a molding chamber, (B) is sectional drawing of the direction orthogonal to an axial center direction. (A), (B) is sectional drawing seen from the top explaining a formation step. (A) is an inlet closing step, (B) is a cross section viewed from above explaining a joint space opening step. (A) is a splicing space closing step, and (B) to (C) are cross sections seen from above for explaining the connection step. (A), (B) is the side view and front view which show an example of the holding means of a covering wall body. (A), (B) is the side view and front view which show the other example of the holding means of a covering wall body. (A), (B) is the side view and front view which show the further another example of the holding means of a covering wall body.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIGS. 1 and 2, a bead apex rubber forming apparatus 1 (sometimes simply referred to as a forming apparatus 1) of the present embodiment is a bead core that holds a bead core A for a tire so as to be rotatable around its axis i. The holding means 2 and the molding head 5 attached to the tip of the rubber extruder 4 are provided, and the bead apex rubber B is continuously formed on the outer peripheral surface As of the bead core A over the entire circumference.

  The rubber extruder 4 is not particularly limited, and a known structure can be appropriately employed. In this example, a screw type extruder main body 4A having a gear pump 4B connected to the tip thereof is employed. The rubber extruder 4 can supply the unvulcanized rubber G to the molding head 5 according to whether the gear pump 4B is turned on or off.

  In this example, the bead core holding means 2 includes a plurality of (four in this example) rollers 2a that receive the inner peripheral surface of the bead core A and are parallel to each other. Each roller 2a is pivotally supported by the roller holding base 3. Each roller 2a is supported so as to be movable inward and outward in the radial direction about the axis i through an expansion / contraction diameter means (not shown). Thereby, the bead cores A of various sizes having different diameters can be detachably supported. As the expansion / contraction diameter means, various known structures can be employed. In this example, one of the rollers 2a is connected to a motor and can rotate the held bead core A.

  As shown in FIG. 1, the bead core holding means 2 of the present example includes a horizontal moving table 25 that supports the roller holding table 3 so as to be movable in a horizontal direction, and a roller holding table 3 that is movable in the vertical direction. And a lifting platform 26. In this example, the case where the elevator 26 is guided through the rails attached to the frame 27 and the lateral movement table 25 is guided through the rails attached to the elevator 26 is shown. The horizontal moving table 25 and the lifting table 26 are driven in the horizontal direction and the vertical direction by known driving means using, for example, a ball screw mechanism. Thereby, the bead core holding means 2 of this example can move the axial center i to a free position.

  As shown in FIGS. 2 and 3, the rotating bead core A partially passes through the molding head 5 in the circumferential direction. The molding head 5 is surrounded by a first side surface S1 on one side in the axial direction of the molding head 5 and a second side surface S2 on the other side on the outer peripheral surface As of the passing bead core A in the circumferential direction. A forming chamber 11 having a triangular cross section is provided.

  Specifically, the molding head 5 includes a head main body 12 that is fixed to the distal end portion of the rubber extruder 4 and a covering wall body 14 that is supported by the head main body 12 via a holding means 13. The head body 12 forms the first side surface S1 by the outward surface so. The first side surface S1 is formed with a rubber inlet 15 through which the unvulcanized rubber G from the rubber extruder 4 flows into the molding chamber 11.

  As shown in FIGS. 8A and 8B, the covering wall body 14 is formed of a first covering wall body 14A and a second covering wall body 14B.

  As shown in FIGS. 3 and 4A, the first covering wall body 14A includes the second side surface S2 constituting the molding chamber 11, and the rear side of the molding chamber 11 (the rear side in the rotation direction F of the bead core). And the shutter wall 9 after closing. The rear shutter wall 9 is disposed at the rear end of the second side surface S2 (the rear end of the bead core rotation direction F). The rear shutter wall 9 is preferably arranged in the vicinity of the rubber inlet 15, and the circumferential distance L between the rear shutter wall 9 and the rubber inlet 15 (FIG. 4B). Is preferably 1 mm or less.

  As shown in FIG. 3, in this example, the first covering wall body 14A has a block shape, and the inward surface si is connected to the inclined surface portion si1 inclined downward and the upper edge of the inclined surface portion si1. An upper contact surface portion si2 that can contact the outward surface so, and a contact surface portion si3 that is continuous with the rear edge of the inclined surface portion si1 and can contact the outward surface so. The inclined surface part si1 forms the second side surface S2. Further, the upper contact surface portion si2 closes the upper side of the molding chamber 11 and functions as a stopper for the first covering wall body 14A in the closed state Y2. Further, the contact surface portion si3 on the side forms the rear shutter wall portion 9.

  As shown in FIGS. 8A and 8B, the first covering wall body 14A has an open state Y1 in which the second side surface S2 side of the molding chamber 11 is opened via the first holding means 13A, The two side surfaces S2 are closed and supported so as to be movable between a closed state Y2 in which the molding chamber 11 is formed.

  In this example, the first holding means 13A includes an arm 16 having one end fixed to the first covering wall body 14A, and a driving tool 17 that tilts the arm 16 up and down around a fulcrum Q1 provided on the head body 12. The case with Although not particularly defined as the arm 16, in this example, an L-shaped main portion 16 </ b> A having one end fixed to the first covering wall body 14 </ b> A and the other end pivotally supported by a fulcrum Q <b> 1 is provided. The driving tool 17 is a cylinder in this example, and is pivotally supported by the head main body 12 so as to be able to tilt up and down around the fulcrum Q2. And pivotally supported at a position Q3 different from the fulcrum Q1. The first covering wall body 14A can be moved between the open state Y1 and the closed state Y2 by expansion and contraction of the rod.

  Further, as shown in FIG. 7, the second covering wall body 14B does not include the rear shutter wall portion 9, and when the first covering wall body 14A is in the open state Y1, the first covering wall body 14A Instead, only the second side surface of the molding chamber 11 is closed.

The second covering wall body 14B has substantially the same configuration as the first covering wall body 14A, and is different in the following points.
a) The second covering wall body 14B does not include the rear shutter wall portion 9.
b) The second side surface S2 of the second covering wall body 14B is located on the rear side (rear side in the rotation direction F) beyond the rear shutter wall portion 9 with respect to the second side surface S2 of the first covering wall body 14A. The extended surface portion 18 extends. In the present invention, in order to distinguish from the second side surface S2 of the first covering wall body 14A, the second side surface S2 of the second covering wall body 14B may be referred to as a third side surface S3. Since the third side surface S3 has the extended surface portion 18 in this way, in the joint space closing step P4, which will be described later, the rear end portion Br and the front end portion Bf of the bead apex rubber B can be straddled. Can be closed.

  As shown in FIGS. 8A and 8B, the second covering wall body 14B is also supported so as to be movable between the open state Y1 and the closed state Y2 via the second holding means 13B. . Then, when the first covering wall body 14A is in the closed state Y2, the second covering wall body 14B stands by in the open state Y1. When the first covering wall body 14A is in the open state Y1, the second covering wall body 14B is in the closed state Y2, and only the second side surface of the molding chamber 11 is closed instead of the first covering wall body 14A. . That is, the joint space J is closed.

  The second holding means 13B has the same configuration as the first holding means 13A, and the second side surface side of the molding chamber 11 can be alternately opened and closed by changing the direction of tilting.

  As shown in FIGS. 4A and 4B, the head main body 12 includes a shutter 30 extending from the front side toward the rear side along the first side surface S1. The shutter 30 can open and close the rubber inlet 15 by sliding back and forth on the front side of the rear shutter wall portion 9.

  Specifically, a guide groove 31 for guiding the shutter 30 is provided in the first side surface S1. The rear end 31E of the guide groove 31 terminates on the front side with respect to the position of the rear shutter wall portion 9. The rubber inflow port 15 opens at the groove bottom of the guide groove 31. The shutter 30 has a plate shape and is held in the guide groove 31 so as to be slidable back and forth. The surface of the shutter 30 is substantially flush with the first side surface S1. The shutter 30 is actuated by moving means 32. In this example, the moving means 32 is a cylinder 32A supported on the side surface of the head main body 12 via the mounting plate 33, and the front end portion of the shutter 30 is attached to the rod end thereof.

  9A and 9B show another example of the forming head 5. In this example, a movable table 20 that can move in the circumferential direction is provided on the head body 12, and first and second holding means 13 </ b> A and 13 </ b> B are attached side by side on the movable table 20. Accordingly, the first and second holding means 13A and 13B can alternately open and close the second side surface of the molding chamber 11 by moving the moving base 20 in the circumferential direction while keeping the same tilting direction.

  FIGS. 10A and 10B show other examples of the first and second holding means 13A and 13B. In this example, each of the first and second holding means 13A and 13B does not include the arm 16 pivotably supported, and the first and second cover wall bodies 14A and 14B are connected to the head main body 12. It is slidably supported along the outward surface so. Specifically, each of the first and second holding means 13A, 13B includes, for example, a cylinder 23 that is fixed to the head body 12 via, for example, a mounting bracket 22, and a The first and second cover wall bodies 14A and 14B are provided so as to be slidable along the outward surface so. In this example, a cylinder with a guide is adopted as the cylinder 23, but a guide (not shown) for guiding the first and second cover wall bodies 14A and 14B can be appropriately provided in the head body 12.

  Next, a bead apex rubber forming method (sometimes simply referred to as a forming method) will be described using the forming apparatus 1.

  2, the bead apex rubber B is integrally formed on the outer peripheral surface As of the rotating bead core A by allowing the unvulcanized rubber G to flow into the molding chamber 11, as schematically shown in FIG. It has a molding process.

  This forming step includes a forming step P1, an inlet closing step P2, a joint space opening step P3, a joint space closing step P4, and a connecting step P5.

  5-7 is sectional drawing which looked at the molding chamber 11 from the top, Comprising: The bead core A is drawn with the dashed-dotted line for convenience. As shown in FIG. 5 (A), the forming step P1 uses the first covering wall body 14A, the front side of the molding chamber 11 is opened, and the rear side is closed by the rear shutter wall portion 9. This is performed in the rear closed state R (closed state Y2). In the rear closed state R, the unvulcanized rubber G is caused to flow from the rubber inlet 15 while rotating the bead core A. Thereby, the bead apex rubber B which has the front-end | tip part Bf is formed gradually.

  Next, in the inlet closing step P2, as shown in FIG. 5 (B), when the bead core A makes a substantially round and the front end Bf approaches the rear shutter wall 9, the bead core A is held by the bead core holding means 2. Stop rotating.

  In synchronization with this rotation stop, the gear pump 4B is temporarily stopped. However, even after the stop, the rubber leaks from the rubber inlet 15 due to the residual pressure in the rubber flow path. Therefore, as shown in FIG. 6A, the rubber inlet 15 is closed by the shutter 30 to prevent rubber leakage from the rubber inlet 15. Since the shutter 30 slides in front of the rear shutter wall 9, the shutter 30 does not interfere with the rear shutter wall 9 and can be smoothly opened and closed.

  Next, in the joint space opening step P3, as shown in FIG. 6B, in the closed state of the rubber inflow port 15 by the shutter 30, the first covering wall body 14A is set to the open state Y1. That is, the second side surface S2 is removed together with the rear shutter wall portion 9. As a result, a joint space J is formed between the rear end portion Br and the front end portion Bf of the bead apex rubber B and the second side surface S2 side is open.

  Next, in the joint space closing step P4, as shown in FIG. 7A, the molding chamber 11 is closed by using the second covering wall body 14B instead of the first covering wall body 14A. That is, instead of the second side surface S2 of the first covering wall body 14A, the third side surface S3 of the second covering wall body 14B straddling at least between the rear end portion Br and the front end portion Bf is disposed, and the joint Space J is closed.

  Next, in the connection step P5, the gear pump 4B is operated, and the rubber inlet 15 is opened by the shutter 30, as shown in FIGS. 7B and 7C. Vulcanized rubber G is introduced. The rear end portion Br and the front end portion Bf are integrally connected by the inflowing rubber. Here, since the rubber inlet 15 is close to the rear shutter wall 9, the unvulcanized rubber G from the rubber inlet 15 can easily flow into the joint space J.

  Note that after the connection step P5, the gear pump 4B is stopped and the rubber inlet 15 is closed by the shutter 30, and then the second covering wall body 14B is in the open state Y1, and the bead apex rubber B extends over the entire circumference. The bead core A thus formed is taken out.

  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.

DESCRIPTION OF SYMBOLS 1 Bead apex rubber forming apparatus 2 Bead core holding means 4 Rubber extruder 5 Molding head 9 Rear shutter wall part 11 Molding chamber 12 Head main body 13 Holding means 14 Cover wall body 14A 1st cover wall body 14B 2nd cover wall body 15 Rubber inlet 30 Shutter As Outer surface A Bead core Bf Tip end Br Rear end B Bead apex rubber G Unvulcanized rubber J Joint space P1 Formation step P2 Inlet closing step P3 Joint space opening step P4 Joint space closing step P5 Connection Step R Rear closed state S1 First side surface S2 Second side surface S3 Third side surface Y1 Open state Y2 Closed state

Claims (2)

A bead apex rubber forming method in which a bead apex rubber is continuously formed on the outer peripheral surface of a bead core over a circumference,
Forming on the outer peripheral surface of the bead core a molding chamber for forming a bead apex rubber extending in the circumferential direction surrounded by the first side surface on one side in the axial direction of the molding head and the second side surface on the other side. The chamber includes a molding step in which bead apex rubber is integrally formed on the outer peripheral surface of the bead core that rotates around the axis by allowing unvulcanized rubber to flow from the rubber inlet provided in the first side surface into the room.
The molding process is as follows:
The unvulcanized rubber is removed while rotating the bead core in the closed state of the rear of the molding chamber closed by the shutter wall portion provided at the rear end portion of the second side surface with the front side in the bead core rotating direction open. A forming step of forming a bead apex rubber having a tip by inflowing;
An inlet closing step of stopping the bead core and closing the rubber inlet with a shutter provided on the first side surface when the bead core makes a round and the tip approaches a rear shutter wall;
In the closed state of the rubber inlet, the second side surface is removed together with the rear shutter wall portion, and a joint space is formed between the rear end portion and the tip end portion of the bead apex rubber and the second side surface is open. Space opening step,
In place of the second side surface, a joint space closing step for closing the joint space by arranging at least a third side surface straddling between the rear end portion and the tip end portion,
And a bead apex rubber including a connecting step of integrally connecting the rear end portion and the front end portion by opening the rubber inlet by the shutter and allowing unvulcanized rubber to flow into the closed joint space. Forming method. A bead apex rubber forming device that continuously forms a bead apex rubber over the entire circumference of the bead core,
A bead core holding means for holding the bead core rotatably about its axis;
And a molding chamber for forming a bead apex rubber that extends in the circumferential direction surrounded by the first side surface on the one axial side and the second side surface on the other side on the outer peripheral surface of the bead core. With a molding head
The molding head is
A head body having the first side surface and provided with a rubber inlet on the first side surface;
And a cover wall that is movably supported between an open state in which the second side surface of the molding chamber is opened and a closed state in which the second side surface is closed to form the molding chamber. Including the body,
The covering wall body is
A first covering wall body provided with a shutter wall portion after closing a rear side of the molding chamber at a rear end portion of the second side surface;
When the first cover wall body is in an open state without the rear shutter wall portion, it is formed from a second cover wall body that closes only the second side surface instead of the first cover wall body,
The head main body extends from the front side to the rear side along the first side surface, and slides back and forth on the front side of the rear shutter wall portion to open and close the rubber inlet. A bead apex rubber forming device.

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