JP2018161762A - Bead apex rubber formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means by which a length of a rubber passage in a molding head and an inner pressure of the passage can be reduced, the molding head can be down-sized, and a rubber flow can be easily controlled.SOLUTION: A bead apex rubber formation apparatus of this invention comprises: a rubber extruder 4 including a gear pump 6 at a front end part thereof and a molding head 5 attached to a front end of the rubber extruder. The molding head 5 includes: a molding room 11 encircled by an outer peripheral surface As, a first lateral surface S1, and a second lateral surface S2 of a bead core A and extending in a peripheral direction; and a rubber inflow port 15 communicating to a rubber outflow port 6H via a rubber passage 10 and opening at the first lateral surface S1. In the gear pump 6, a pair of gears 8 are disposed so that axis centers j thereof face in a vertical direction and opening shapes of the rubber outflow port 6H and the rubber inflow port 15 are made a vertically lengthy flat shape in the vertical direction respectively.SELECTED DRAWING: Figure 11

Description

  The present invention relates to 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 apparatus that integrally forms a bead apex rubber on an outer peripheral surface of a bead core that rotates around an axis. This apparatus comprises a molding head at the front end of a rubber extruder provided with a gear pump at the front end. The molding head has a molding chamber which is surrounded by the outer peripheral surface of the bead core and inner wall surfaces on both sides in the axial direction and extends in the circumferential direction. Then, the bead apex rubber is formed by allowing the rubber from the rubber extruder to flow into the molding chamber through a rubber inlet opening at one inner wall surface through the rubber flow path.

  In the device, as conceptually shown in FIG. 12, the gear b of the gear pump a is arranged with its axis bi facing horizontally. Therefore, the shape of the rubber outlet c provided in the gear pump a is also a horizontally long flat shape that is long in the horizontal direction due to its structure. However, when the rubber flows into the molding chamber d, in order to sufficiently fill the rubber up to the tip (radial outer end) of the bead apex rubber e, the shape of the rubber inflow port f is set in the vertical direction (radial direction). It is preferable to use a long and flat shape.

  Therefore, in the apparatus, it is necessary to guide the rubber from the rubber discharge port c to the rubber inflow port f while changing from the horizontally flat shape to the vertically long shape. However, in this case, since the change in the cross-sectional shape is large, it is necessary to set the rubber flow path g long and the internal pressure high. And the rubber flow path g becomes long, which leads to an increase in the size of the molding head. Further, since the volume of the flow path increases with the length of the rubber flow path g, the responsiveness is deteriorated and the rubber flow is difficult to control. Also, when removing the bead core, the gear pump is stopped and the rubber inlet f is closed with a shutter or the like. At this time, the residual pressure in the flow path is high, so that the rubber tends to leak from the rubber inlet f.

JP2013-237224A

  Therefore, the present invention can reduce the length of the rubber flow path and the pressure in the flow path, reduce the size of the molding head, facilitate the control of the rubber flow, and the rubber from the rubber inlet caused by the residual pressure in the flow path. It is an object of the present invention to provide a bead apex rubber forming apparatus that can contribute to the suppression of leakage of water.

The present invention is a bead apex rubber forming device that continuously forms 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 i;
A rubber extruder that includes a gear pump having a pair of gears meshing with each other at the front end, and extrudes unvulcanized rubber from a rubber discharge port in accordance with on / off of the gear pump;
A molding head attached to the front end of the rubber extruder,
The molding head is
A bead apex rubber molding chamber which is surrounded by the outer peripheral surface of the bead core, the first side surface on one side in the axial direction and the second side surface on the other side and extends in the circumferential direction, and a rubber flow path through the rubber discharge port. A rubber inflow opening that is continuous and open at the first side surface,
In the gear pump, the pair of gears is arranged with its axis j oriented in the vertical direction,
The opening shape of the rubber discharge port and the rubber inflow port is a vertically long flat shape that is long in the vertical direction.

  In the bead apex rubber forming apparatus according to the present invention, it is preferable that the molding head includes a shutter wall portion after the molding chamber is closed on the rear side in the rotation direction of the bead core with respect to the rubber inlet.

In the bead apex rubber forming apparatus according to the present invention, the molding head includes:
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 the rear shutter wall at the rear end of the second side surface;
When the first cover wall body is in an open state without providing a rear shutter wall portion, the first cover wall body is formed of a second cover wall body that closes only the second side surface instead of the first cover wall body. Is preferred.

  In the present invention, as described above, the gear of the gear pump is arranged with its axis j oriented in the vertical direction. Thereby, the rubber discharge port of a gear pump can be made into the vertically long flat shape long in the perpendicular direction similar to a rubber inflow port.

  That is, the change in the cross-sectional shape of the rubber from the rubber discharge port to the rubber inlet becomes small. Therefore, it is possible to set the rubber flow path short and the internal pressure low while stabilizing the rubber flow.

  As a result, the rubber flow path is shortened, so that the molding head can be reduced in size. Further, since the volume of the flow path is reduced as the rubber flow path is shortened, the rubber flow can be easily controlled. Further, since the residual pressure in the flow path is reduced, it is possible to suppress the leakage of rubber from the rubber inlet when the rubber inlet is closed with a shutter or the like.

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. It is a perspective view which shows a rubber discharge port, a rubber inflow port, and a rubber flow path conceptually. It is a perspective view explaining the problem in the conventional bead apex rubber forming apparatus.

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, the rubber extruder 4, and the molding head 5 attached to the front end of the rubber extruder 4 are provided, and the bead apex rubber B is continuously formed over the entire circumference on the outer peripheral surface As of the bead core A.

  The rubber extruder 4 includes a gear pump 6 at the front end, and pushes unvulcanized rubber G from a rubber discharge port 6H of the gear pump 6 and supplies it to the molding head 5 in response to turning on and off of the gear pump 6. In this example, the one where the gear pump 6 is connected to the tip of the extruder body 7 is employed.

  As the extruder body 7, a screw-type well-known structure can be suitably employed. The gear pump 6 is a constant volume extruder equipped with a pair of gears 8 meshing with each other in a casing 6A. The gear pump 6 rotates the gears 8 by an electric motor (not shown) to remove the rubber G from the outer periphery of each gear 8. It pushes out from the rubber discharge port 6H through between the surface and the inner peripheral surface of the casing 6A. In the forming apparatus 1 of the present invention, the gear pump 6 is mounted in a vertically placed posture in which the axis j of each gear 8 is oriented in the vertical direction.

  As shown in FIGS. 1 and 2, the bead core holding means 2 includes a plurality of (in this example, four) rollers 2 a that receive the inner peripheral surface of the bead core A in this example. 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 this example supports a horizontal moving table 25 that supports the roller holding table 3 so as to be movable in a horizontal horizontal direction, and supports the roller holding table 3 so as to be 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 molding head 5 includes a molding chamber 11 for molding bead apex rubber, a rubber inlet 15 through which rubber G flows into the molding chamber 11, and the rubber inlet 15 and the rubber discharge port. The rubber flow path 10 which conduct | electrically_connects 6H is provided.

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

  In this example, the molding head 5 includes a head main body 12 fixed to the distal end portion of the rubber extruder 4 and a covering wall body 14 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. A rubber inflow port 15 through which the rubber G from the rubber extruder 4 flows into the molding chamber 11 is formed on the first side surface S1.

  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 has the second side surface S2 constituting the molding chamber 11 and the rear side of the rubber inlet 15 (in the rotational direction F of the bead core A). And a shutter wall 9 after the molding chamber 11 is closed on the rear side. In this example, the rear shutter wall portion 9 is disposed at the rear end portion (the rear end portion in the rotation direction F) of the second side surface S2. 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 in this example. 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.

  As conceptually shown in FIG. 11, the gear pump 6 is mounted in a vertically installed posture in which the axis j of each gear 8 faces in the vertical direction. In the gear pump 6, the rubber G is sent to the rubber discharge port 6H through the space between the outer periphery of each gear 8 and the inner periphery of the casing 6A while being stretched in the axis j direction. Therefore, the opening shape of the rubber discharge port 6H is formed in a vertically long flat shape that is long in the vertical direction that is the direction of the axis j.

  On the other hand, when the rubber G is caused to flow into the molding chamber 11, if the height of the rubber inlet 15 is low, it becomes difficult to sufficiently fill the rubber to the tip (radially outer end) of the bead apex rubber B. Incurs the risk of defects. Therefore, the opening shape of the rubber inlet 15 is formed in a vertically long flat shape that is long in the vertical direction, which is the radial direction of the bead apex rubber B.

  As described above, the opening shape of the rubber discharge port 6H and the rubber inlet 15 is a vertically long flat shape that is long in the vertical direction, so that the cross-sectional shape of the rubber G from the rubber discharge port 6H to the rubber inlet 15 is reduced. Change can be reduced. Therefore, the length L of the rubber flow path 10 can be shortened and the internal pressure can be set low.

  And since the length L of the rubber flow path 10 becomes short, it becomes possible to miniaturize the shaping head 5, in this example, the head body 12. Further, as the length L becomes shorter, the volume of the entire rubber flow path 10 becomes smaller, so that the rubber flow can be easily controlled. Further, when the rubber inlet 15 is closed by the shutter 30 after the gear pump 6 is stopped, the residual pressure in the rubber flow path 10 is low, so that leakage of the rubber G from the rubber inlet 15 can be surely prevented. become.

  The rubber flow path 10 of this example includes a constant flow path portion 10A having a constant cross-sectional shape connected to the rubber discharge port 6H, a constant flow path portion 10B having a constant cross-sectional shape continuous to the rubber inlet 15, and the constant flow path portion 10A. A case is shown in which a joint flow path portion 10C is provided that joins 10B while smoothly changing the cross-sectional shape. However, the constant flow path portions 10 </ b> A and 10 </ b> B can be deleted as the rubber flow path 10.

  In this way, the gear pump 6 is mounted in a vertically installed posture with the axis j of the gear 8 oriented in the vertical direction, and the opening shapes of the rubber discharge port 6H and the rubber inflow port 15 are vertically long and flat in the vertical direction. Such a structure can also be employed in a forming apparatus 1 as described in Patent Document 1. Specifically, the rear shutter wall portion 9 is provided in the head main body 12 so as to be able to protrude and retract in the axial direction from the first side surface S1, and the covering wall body 14 is configured only by the second covering wall body 14B. The Such a forming apparatus 1 can also exhibit the same effect.

  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.

  In the forming method of the present embodiment, as schematically shown in FIG. 2, a molding step of integrally forming the bead apex rubber B on the outer peripheral surface As of the rotating bead core A by allowing the rubber G to flow into the molding chamber 11. With

  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 rubber G flows 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 6 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 6 is operated, and the rubber inlet 15 is opened by the shutter 30 as shown in FIGS. 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 rubber G from the rubber inlet 15 can easily flow into the joint space J.

  After the connection step P5, the gear pump 6 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 formation apparatus 2 Bead core holding means 4 Rubber extruder 5 Molding head 6 Gear pump 6H Rubber discharge port 8 Gear 9 Rear shutter wall part 10 Rubber flow path 11 Molding chamber 12 Head main body 14 Cover wall body 14A First cover Wall body 14B Second covering wall body 15 Rubber inflow port As Outer peripheral surface B Bead apex rubber G Rubber S1 First side surface S2 Second side surface Y1 Open state Y2 Closed state

Claims (3)

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 i;
A rubber extruder that includes a gear pump having a pair of gears meshing with each other at the front end, and extrudes unvulcanized rubber from a rubber discharge port in accordance with on / off of the gear pump;
A molding head attached to the front end of the rubber extruder,
The molding head is
A bead apex rubber molding chamber which is surrounded by the outer peripheral surface of the bead core, the first side surface on one side in the axial direction and the second side surface on the other side and extends in the circumferential direction, and a rubber flow path through the rubber discharge port. A rubber inflow opening that is continuous and open at the first side surface,
In the gear pump, the pair of gears is arranged with its axis j oriented in the vertical direction,
A bead apex rubber forming apparatus in which the opening shape of the rubber discharge port and the rubber inflow port is a vertically flat shape that is long in the vertical direction.   The bead apex rubber forming apparatus, wherein the molding head includes a shutter wall portion after the molding chamber is closed on the rear side in the rotational direction of the bead core with respect to the rubber inlet. 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 the rear shutter wall at the rear end of the second side surface;
When the first cover wall body is in an open state without providing a rear shutter wall portion, the first cover wall body is formed of a second cover wall body that closes only the second side surface instead of the first cover wall body. The bead apex rubber forming apparatus according to claim 2.

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