JP2006159622A - Rubber member molding equipment and rubber material molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rubber member molding equipment capable of properly performing the cutting of a strip at the time of completion of molding, in molding a rubber member by winding a rubber strip around a molding drum. <P>SOLUTION: The rubber member molding equipment is equipped with an extruder 2 for kneading a rubber material to feed it out, a gear pump 3 for feeding out the rubber material supplied from the extruder 2 to a molding cap 4, the molding drum 7 around which the rubber strip extruded through the cap 4 is wound, a first servomotor 6 for driving the gear pump 3, a second servomotor 9 for driving the drum 7 and a control unit 8 for controlling the servomotors 6 and 9. The gear pump 3 is stopped immediately before the drum 7 is stopped at the time of completion of the bonding of the rubber strip and reversely rotated by predetermined quantity immediately after the stop of the gear pump 3, the cap 4 is moved in the direction of the drum after the drum 7 is stopped, the drum 7 is again rotated in connection with the movement of the cap 4 and the drum 7 is stopped simultaneously with the contact of the cap 4 with the surface of the wound rubber strip to separate the cap 4 from the surface of the rubber strip. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rubber member molding facility and a rubber material molding method for molding a rubber member having a desired cross-sectional shape by winding a rubber strip around a rotary support.

  Conventionally, a so-called strip build method is known in which a rubber member is formed by winding a ribbon-shaped rubber strip in the circumferential direction (see, for example, Patent Documents 1 to 3 below). According to such a strip build method, a rubber member having a desired cross-sectional shape can be formed by winding a rubber strip around a rotating support such as a forming drum and sequentially laminating it. Such a rubber member is used, for example, as a rubber member constituting a sidewall portion of a pneumatic tire.

  The rubber strip is continuously formed by extruding a rubber material kneaded by an extruder screw through a molding die having a predetermined cross-sectional shape. In this regard, there is known an extrusion device configured to supply a rubber material to a molding die using a gear pump for the purpose of suppressing variation in the discharge amount of the rubber strip (see Patent Document 4 below).

  After the rubber strip is wound around a molding drum by a predetermined amount to form the rubber member, it is necessary to cut the rubber strip. For example, in Patent Document 1, a swinging cutter is provided between a rubber extruder and a forming drum, and unnecessary rubber at a winding start portion and a winding end portion is cut by this cutter. By using the cutter, the rubber strip can be surely cut, but it is necessary to control the cutter and its control, resulting in problems of cost increase and equipment enlargement.

  Moreover, as a method of cutting the rubber strip at the end of winding without using a cutter, there is a method as shown in the figure, which will be briefly described. In the figure, an extrusion apparatus 1 includes an extruder 2, a gear pump 3, and a molding die 4, and a rubber strip S having a predetermined cross-sectional shape is extruded from the molding die 4. The forming drum 7 is rotationally driven in the counterclockwise direction R, and a rubber strip S is wound around it (see FIG. 1A). When the winding of the predetermined amount of the rubber strip S is completed, the driving of the molding drum 7 and the extrusion device 1 (the gear pump 3 and the extruder 2) is stopped. Next, only the molding drum 7 is rotated again in the counterclockwise direction R. Thereby, the rubber strip S is pulled and cut so as to be torn off.

According to such a method of cutting the rubber strip S, it is not necessary to provide a cutter, but it is not guaranteed where the rubber strip S is cut. There is no problem if the rubber strip S is cut at the tip of the molding die 4, but if the rubber strip S is cut between the molding drum 7 and the molding die 4, rubber remains at the tip of the molding die 4. In the molding of the next process, it affects the sticking of rubber. Further, since the last part of the rubber strip S to be attached is pulled, the part becomes thin, and there is a problem that the uniformity is affected.
JP-A-9-29858 JP 2002-178415 A JP 2002-205512 A JP 2003-266523 A

  The present invention has been made in view of the above circumstances, and the problem is that when a rubber member is formed by winding a rubber strip around a rotating support, the rubber strip can be appropriately cut at the end of molding. It is to provide a member molding facility and a rubber material molding method.

In order to solve the above problems, the rubber member molding equipment according to the present invention is:
An extruder for kneading and feeding the rubber material, a gear pump for feeding the rubber material supplied from the extruder to the molding die, and a rotating support body around which the rubber strip extruded through the molding die is wound, A rubber member molding facility comprising: a first drive device that drives the gear pump; a second drive device that rotationally drives the rotary support; and a control device that controls the first drive device and the second drive device. In
The controller is
Means for stopping the gear pump at the same time or immediately before stopping the rotation support at the end of the attachment of the rubber strip to the rotation support, and causing a predetermined amount of reverse rotation immediately after the stop;
Means for moving the molding die in the direction of the rotation support after the rotation support has stopped;
Means for rotating and driving the rotary support again in conjunction with the movement of the molding die;
Means for stopping the rotating support again at the same time or almost simultaneously with the surface of the rubber strip around which the molding die is wound;
And a means for moving the molding die in a direction away from the surface of the rubber strip after the contact.

  The operation and effect of the rubber member molding equipment having this configuration will be described. The extruder kneads and extrudes the rubber material, and the extruded rubber material is supplied to the gear pump. Further, the rubber material is fed from the gear pump to the molding die, and the rubber strip is pushed out from the molding die. The extruded rubber strip is wound around the rotating support to form a rubber member having a predetermined shape. The gear pump is driven by the first driving device, and the rotary support is driven by the second driving device. Moreover, the control apparatus which controls a 1st drive device and a 2nd drive device is provided, and the drive of a gear pump or a rotation support body can be controlled. The control by the control device at the end of the rubber strip application is performed as follows.

  First, the rotary support is stopped and the gear pump is also stopped. Thereby, the pushing-out operation of the rubber strip is also stopped. The gear pump is stopped at the same time or immediately before the rotation support is stopped. Thereafter, the gear pump is reversely rotated. That is, the rubber strip is rotated in a direction opposite to the direction in which the rubber strip is extruded. Thereby, the residual pressure in the gear pump can be eliminated, and the rubber strip can be easily cut. This reverse rotation is performed by a predetermined amount. After the rotation support stops, the molding die is moved in the direction of the rotation support. In conjunction with this operation, the rotary support is rotated again. This is to prevent sagging of the rubber strip existing between the rotating support and the molding die. When the molding die comes into contact with the surface of the rubber strip wound around the rotary support, the rotary support is stopped again. Next, the molding die is moved in a direction away from the surface of the rubber strip. At this time, the residual pressure is eliminated by performing reverse rotation of the gear pump, and the rubber strip can be reliably cut at the tip of the molding die. As a result, it is possible to provide a rubber member molding facility that appropriately cuts the rubber strip at the end of molding when the rubber member is wound around the rotating support to mold the rubber member.

  In the present invention, it is preferable that a pressure sensor for detecting an outlet side pressure in the gear pump is provided, and the reverse rotation of the gear pump is performed until the pressure value is lowered to a predetermined level.

  The predetermined amount when the gear pump is reversely rotated may be a preset fixed value, but it is more preferable to perform control using a pressure sensor. That is, the outlet side pressure in the gear pump can be detected by the pressure sensor, and it can be detected that the residual pressure has been lowered to a predetermined level based on this pressure value. Thereby, reverse rotation of a gear pump can be performed more accurately and a rubber strip can be cut | disconnected reliably.

In order to solve the above problems, a rubber material molding method according to the present invention includes:
By kneading and feeding the rubber material with an extruder, feeding the rubber material supplied from the extruder to a molding die with a gear pump, and winding a rubber strip extruded through the molding die around a rotating support In a rubber material molding method for molding a rubber member,
A step of stopping the gear pump at the same time or immediately before stopping the rotation support at the end of attaching the rubber strip to the rotation support, and reversely rotating immediately after the stop;
A step of moving the molding die in the direction of the rotation support after the rotation support is stopped;
A step of rotationally driving the rotary support again in conjunction with the movement of the molding die;
A step of stopping the rotating support again at the same time or almost simultaneously with contact with the surface of the rubber strip around which the molding die is wound;
And a step of moving the molding die in a direction away from the surface of the rubber strip.

  Furthermore, in the present invention, it is preferable to further include a step of detecting the outlet side pressure in the gear pump by a pressure sensor, and the reverse rotation step of the gear pump is preferably performed until the pressure value is lowered to a predetermined level.

  The operations and effects of this configuration are as described above.

  A preferred embodiment of a rubber member molding facility according to the present invention will be described with reference to the drawings.

<Configuration of rubber member molding equipment>
FIG. 1 is a schematic view showing an example of the configuration of a rubber member molding facility according to the present invention. The rubber member molding facility shown in FIG. 1 includes an extrusion device 1, a molding drum 7 (corresponding to the rotary support), and a control device 8.

  The extrusion apparatus 1 includes an extruder 2, a gear pump 3 connected to the front end side in the extrusion direction of the extruder 2, and a molding base 4 connected to the front end side thereof. The extruder 2 includes a cylindrical barrel 2a, a hopper 2b connected to the supply port of the barrel 2a, a screw 2c for kneading a rubber material and feeding it to the tip side, and a first drive device as a drive device for rotationally driving the screw 2c. 3 servo motors 2d. The rotation speed of the third servo motor 2d is controlled by third servo motor control means 15 included in the control device 8.

  The gear pump 3 has a pair of gears 5 and has a function of feeding a rubber material toward the outlet toward the molding die 4. Each of the gears 5 is rotationally driven by a first servo motor 6 (corresponding to the first driving device), and the number of rotations thereof is controlled by a first servo motor control means 13 included in the control device 8. For convenience of illustration, the pair of gears 5 are arranged in the vertical direction in FIG. 1, but are actually arranged in the plane direction (the direction in which the rotation axis of the gear 5 is up and down in FIG. 1).

  A pressure sensor 11 is provided on the outlet side of the gear pump 3, and detects the outlet side pressure in the gear pump 3, that is, the pressure when the gear pump 3 sends out the rubber material. Further, the residual pressure on the outlet side in the gear pump 3 when the gear pump 3 is stopped is detected. Further, a pressure sensor 12 is provided on the inlet side of the gear pump 3, and detects an inlet side pressure in the gear pump 3, that is, a pressure when a rubber material is supplied from the extruder 2 to the gear pump 3.

  In the present embodiment, the detection result by the pressure sensor 12 is sent to the pressure adjusting means 16 of the control device 8. The pressure adjusting means 16 gives a command to the third servo motor control means 15 so that the pressure value detected by the pressure sensor 12 matches a preset pressure value (first set value). The first set value can be appropriately set via an input unit (not shown). The pressure adjusting means 16 has, for example, a pressure support controller that outputs an analog voltage value in response to a signal received from the pressure sensor 12, and sends a speed command corresponding to the voltage value to the third servo motor control means 15. It may be configured to send to the third servo motor 2d via That is, the third servo motor control means 15 controls the rotational speed of the third servo motor 2d that drives the screw 2c in accordance with the inlet side pressure in the gear pump 3. Thereby, the inlet side pressure in the gear pump 3 is kept constant, and the supply amount of the rubber material by the extruder 2 is stabilized.

  The molding die 4 has a predetermined cross-sectional shape, and the rubber material supplied from the gear pump 3 to the molding die 4 is continuously extruded in the form of a rubber strip S having a predetermined cross-sectional shape. The rubber strip S has a small ribbon width and a small thickness, and various sizes can be adopted depending on the type of tire. Further, the cross-sectional shape of the rubber strip S is not limited to a specific one, and various and preferable shapes can be adopted according to the finished cross-sectional shape such as a triangle, a crescent shape, a circle, and a rectangle.

  The forming drum 7 is configured to be rotatable in the R direction by a second servomotor 9 (corresponding to a second driving device). The rotation speed of the second servo motor 9 is controlled by the second servo motor control means 14 included in the control device 8. The rubber strip S extruded through the molding die 4 is directly supplied to the molding drum 7, and the rubber strip S is rotated by rotating the molding drum 7 in the R direction with the rubber strip S adhered. Can be wound along the circumferential direction. The pressure roller 10 has a function of pressure bonding the rubber strip S supplied to the molding drum 7.

  The detection result by the pressure sensor 11 provided in the gear pump 3 is sent to the pressure comparison means 17 of the control device 8. The pressure comparison means 17 compares the pressure value detected by the pressure sensor 11 with the preset pressure value (second set value) after the gear pump 3 starts to drive, and the detected pressure value is the first value. A command for starting the rotation of the forming drum 7 is given to the second servo motor control means 14 after a predetermined time has elapsed with reference to the time when the value becomes equal to or greater than 2 set values. That is, the molding drum 7 starts rotating after the gear pump 3 is driven for a predetermined time with reference to the time when the outlet side pressure in the gear pump 3 becomes equal to or higher than the predetermined pressure. The predetermined pressure (second set value) and the predetermined time can be appropriately set via an input unit (not shown).

  Further, the pressure comparison means 17 uses a pressure value detected by the pressure sensor 11 when the gear pump 3 is rotated in reverse at the end of winding of the rubber strip S as a preset pressure value (third set value). It is determined whether the residual pressure on the outlet side in the gear pump 3 has decreased to a predetermined level. When the residual pressure falls below a predetermined level, a command signal for stopping the reverse rotation of the gear pump 3 is sent from the first servo motor control means 13 to the first servo motor 6.

  The forming drum 7 is configured to reciprocate in an axial direction (a direction perpendicular to the paper surface in FIG. 1) by a driving device (not shown), and the reciprocating movement is controlled by the control device 8. By moving the rotating forming drum 7 relative to the extrusion device 1 in the axial direction, the rubber strip S can be spirally wound along the circumferential direction to form a rubber member having a desired cross-sectional shape. . On the other hand, the extrusion device 1 is configured to be movable forward and backward in the extrusion direction by the front / rear drive device 18, and such movement is also controlled by the front / rear drive device control means 19 of the control device 8.

  Instead of the configuration in which the forming drum 7 is reciprocated in the direction perpendicular to the paper surface, the extrusion apparatus 1 may be configured to reciprocate in the direction perpendicular to the paper surface.

<Rubber member molding method (at the start of application)>
Next, a method for molding a rubber member using the above rubber member molding equipment (particularly at the start of application) will be described. FIG. 2 is a flowchart showing an example of a procedure when starting molding of a rubber member.

  First, the extrusion device 1 moves forward (# 1) and is brought close to the forming drum 7 as shown in FIG. At this time, a predetermined interval is provided between the molding die 4 and the outer peripheral surface of the molding drum 7. The timing at which the extrusion device 1 is brought close to the molding drum 7 is not particularly limited as long as the predetermined interval is provided before the rubber strip S is discharged.

  Next, the rubber material adjusted in the previous step is put into the hopper 2b of the extruder 2. Here, the rubber material is not particularly limited. For example, the rubber material is a general-purpose rubber raw material such as natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), etc. And prepared by kneading and heat crosslinking. Moreover, there is no restriction | limiting in particular as a shape of the rubber material thrown in, For example, shapes, such as a ribbon shape, a sheet form, a pellet form, are mentioned. The charged rubber material is kneaded by the screw 2c of the extruder 2, sent to the front end side in the extrusion direction, and supplied to the gear pump 3 (# 2, 3). Then, the rubber material supplied to the gear pump 3 is sent to the outlet side toward the molding die 4 by a pair of rotating gears 5 (# 4).

  When the rubber material is fed to the outlet side of the gear pump 3, the pressure sensor 11 detects the outlet side pressure in the gear pump 3 (# 5). The detection result is sent to the control device 8 and compared with a preset pressure value (second set value) by the pressure comparison means 17. When the detected pressure value is equal to or greater than the second set value, a command is given to the second servo motor control means 14 after a predetermined time has elapsed from that point, and the rotation of the molding drum 7 is started. (# 6, 7).

  That is, the rotation of the forming drum 7 is started after the gear pump 3 is driven for a predetermined time with reference to the time point when the detected pressure value becomes equal to or higher than the predetermined pressure value. By driving the gear pump 3 for a predetermined time, a predetermined amount of the rubber strip S is discharged to the molding drum 7 as shown in FIG. Further, the rotation of the molding drum 7 is started thereafter, and as shown in FIG. 3C, the rubber strip S at the start of the discharge is not agglomerated but is secured to the molding drum 7. Is done.

  The extrusion apparatus 1 moves backward (# 8) after the molding drum 7 is rotated several times or before it is rotated once (# 8), and a predetermined interval is provided between the molding drum 7 and the extrusion apparatus 1. The molding drum 7 is reciprocated in the axial direction in accordance with the desired cross-sectional shape of the rubber member while being rotationally driven in the R direction (# 9). Thereby, the rubber strip S is wound spirally along the circumferential direction. The driving of the molding drum 7 and the extrusion device 1 is controlled by the control device 8, and a control program for that purpose is input to the control device 8 in advance.

  While the rubber strip S is continuously extruded, the pressure sensor 12 detects the inlet side pressure in the gear pump 3. The detection result is sent to the control device 8, and the pressure adjusting means 16 instructs the third servo motor control means 15 so that the detected pressure value matches the preset pressure value (first set value). And the number of rotations of the third servo motor is controlled.

<Rubber member molding method (at the end of pasting)>
Next, a process at the end of molding of the rubber member will be described with reference to a flowchart of FIG. 4 and a schematic diagram of FIG. In step # 9 of the flowchart of FIG. 2, the rubber strip S is gradually wound around the forming drum 7. When the winding process is to be terminated, a termination process start command is issued (# 10 in FIG. 4). Thereby, the gear pump 3 stops first (# 11). The gear pump 3 is stopped immediately before the rotation of the molding drum 7 is stopped (see FIG. 5A). Immediately after the gear pump 3 is stopped, the gear pump 3 is reversely rotated (# 12). Immediately after this, the forming drum 7 is also stopped (# 13, FIG. 5B). The direction in which the gear pump 3 is rotated in the reverse direction is opposite to the direction in which the rubber strip S is extruded. By rotating the gear pump 3 in the reverse direction, the residual pressure on the outlet side in the gear pump 3 can be eliminated. Although the rotation of the molding drum 7 is stopped immediately after the rotation of the gear pump 3 is stopped, the rotation is not limited to this and may be performed simultaneously.

  After the reverse rotation of the gear pump 3 is started, the pressure on the outlet side in the gear pump 3 is detected by the pressure sensor 11. Then, a comparison is made as to whether or not the pressure value has decreased to a preset third set value (predetermined level) (# 14). When it is detected that the gear pump 3 has decreased to a predetermined level, the reverse rotation of the gear pump 3 is stopped (# 15). Next, as shown in FIG.5 (c), the extrusion apparatus 1 is advanced (approached) in the direction of the forming drum 7 (# 16).

  When the extrusion device 1 is brought closer to the molding drum 7, sagging occurs in the rubber strip S located between the molding drum 7 and the molding die 4. In order to prevent this sagging phenomenon, the molding drum 7 is Again, it is rotated in the counterclockwise direction R (# 17). Thereby, the extrusion apparatus 1 can be brought close to the forming drum 7 so as not to cause sagging. Next, the molding die 4 comes into contact with the rubber surface wound around the molding drum 7 (# 18, FIG. 5D). The forward drive of the extrusion device 1 is stopped at the position just touched (# 19). It is possible to calculate in advance how far the extrusion device 1 is advanced to determine whether the molding die 4 contacts the rubber surface. Based on this calculated value, the amount by which the extrusion apparatus 1 is advanced can be controlled. Simultaneously or substantially simultaneously with the contact of the molding die 4 with the rubber surface, the rotational driving of the molding drum 7 is stopped (# 20). The degree of contact with the rubber surface may be lightly touched, or may be contacted so as to push the surface slightly. Thereby, the rubber strip S can be cut more reliably. Next, the extrusion apparatus 1 is retracted in a direction away from the forming drum 7 (# 21). During this backward movement, the rubber strip S is cut at the tip of the molding die 4. Since there is no residual pressure, the rubber strip S can be cut reliably. Further, the rubber strip S can be cut without forcibly pulling, and the uniformity is not adversely affected.

  When the next rubber member is continuously molded, the process returns to # 1, the extrusion device 1 is brought close to the molding drum 7, and the rubber member is molded according to the above-described procedure. In such a case, the exit side of the gear pump 3 is filled with a rubber material to some extent, but even in such a state, according to the rubber member molding method according to the present invention, at the start of molding of the rubber member. The rubber strip S can be discharged without excess or deficiency.

<Another embodiment>
Examples of the rubber member molded according to the present invention include, but are not limited to, a rubber member constituting a tread portion and a sidewall portion of a pneumatic tire, a solid tire, a pneumatic rubber roller, and the like.

  In the present embodiment, the time during which the gear pump 3 is reversely rotated is controlled by the pressure sensor 11, but the pressure sensor 11 may be used so as to reversely rotate for a predetermined fixed time without using the pressure sensor 11.

The schematic diagram which shows an example of a structure of the rubber member molding equipment which concerns on this invention Flow chart showing an example of the procedure at the start of rubber member molding Schematic showing the state at the start of molding of a rubber member by the strip build method Flow chart showing an example of the procedure at the end of molding of a rubber member Schematic showing the state at the end of molding of rubber member by strip build method The figure explaining the malfunction which arises when using the conventional rubber member molding equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 2 Extruder 2c Screw 2d 3rd servo motor 3 Gear pump 4 Molding die 5 Gear 6 1st servo motor (1st drive device)
7 Forming drum 8 Control device 9 Second servo motor (second drive device)
DESCRIPTION OF SYMBOLS 11 Pressure sensor 12 Pressure sensor 16 Pressure adjustment means 17 Pressure comparison means 18 Front-rear drive device 19 Front-rear drive device control means

Claims (4)

An extruder for kneading and feeding the rubber material, a gear pump for feeding the rubber material supplied from the extruder to the molding die, and a rotating support body around which the rubber strip extruded through the molding die is wound, A rubber member molding facility comprising: a first drive device that drives the gear pump; a second drive device that rotationally drives the rotary support; and a control device that controls the first drive device and the second drive device. In
The controller is
Means for stopping the gear pump at the same time or immediately before stopping the rotation support at the end of the attachment of the rubber strip to the rotation support, and causing a predetermined amount of reverse rotation immediately after the stop;
Means for moving the molding die in the direction of the rotation support after the rotation support has stopped;
Means for rotating and driving the rotary support again in conjunction with the movement of the molding die;
Means for stopping the rotating support again at the same time or almost simultaneously with the surface of the rubber strip around which the molding die is wound;
And a means for moving the molding die in a direction away from the surface of the rubber strip after the contact.   The rubber member molding equipment according to claim 1, further comprising a pressure sensor that detects an outlet side pressure in the gear pump, wherein the reverse rotation of the gear pump is performed until the pressure value is lowered to a predetermined level. By kneading and feeding the rubber material with an extruder, feeding the rubber material supplied from the extruder to a molding die with a gear pump, and winding a rubber strip extruded through the molding die around a rotating support In a rubber material molding method for molding a rubber member,
A step of stopping the gear pump at the same time or immediately before stopping the rotation support at the end of attaching the rubber strip to the rotation support, and reversely rotating immediately after the stop;
A step of moving the molding die in the direction of the rotation support after the rotation support is stopped;
A step of rotationally driving the rotary support again in conjunction with the movement of the molding die;
A step of stopping the rotating support again at the same time or almost simultaneously with contact with the surface of the rubber strip around which the molding die is wound;
And a step of moving the molding die in a direction away from the surface of the rubber strip.   The rubber material according to claim 3, further comprising a step of detecting an outlet side pressure in the gear pump by a pressure sensor, wherein the reverse rotation step of the gear pump is performed until the pressure value is lowered to a predetermined level. Molding method.

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