JP2008173828A - Mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold capable of surely molding a leg part for a support member. <P>SOLUTION: The pressure in a cavity is measured with a pressure sensor 58 when the mold is closed, and it is determined whether or not the pressure of a rubber material G filling the cavity arrives at the predetermined pressure (the pressure required for the rubber material G to be surely vulcanized and bonded to leg parts 20A, 20B). When it is determined that the pressure in the cavity becomes as predetermined or more when the mold is closed, vulcanization molding is performed for a predetermined time and at a predetermined temperature. The respective leg parts 20A, 20B can be surely vulcanized and bonded to both edge parts 18A, 18B of a support member 16 thereby. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mold for manufacturing a support body that is disposed inside a pneumatic tire and enables traveling when the internal pressure is reduced.

Providing the support body assembled to the rim on the inside of the pneumatic tire is useful for run-flat traveling during emergency traveling such as puncture.
As this support, there is one having a ring-shaped support member (a metallic annular body) and ring-shaped rubber legs joined to both edges in the width direction of the support member by vulcanization. . When manufacturing such a support, a support member is manufactured in advance, and an adhesive is applied to the support member to vulcanize and bond the rubber.

As a manufacturing method in the case of forming the leg portion on the support member, there are injection, transfer, compression and the like.
Injection vulcanization is performed by injecting rubber into a cavity from an extruder or the like directly connected to a mold.
In transfer vulcanization and compression vulcanization, a predetermined amount of rubber is added in consideration of the cavity and overflow portion, and vulcanization and molding are performed simultaneously.

Examples of those that vulcanize rubber by injection include those described in Patent Document 1, for example, and those that compression vulcanize rubber include those described in Patent Document 2, for example. Moreover, as what vulcanizes | transfer vulcanizes rubber | gum, there exist some which are described in patent document 3, for example.
JP-A-48-021765 JP 62-032038 A JP-A-62-240519 JP 04-267117 A

  For the vulcanization adhesion between the support member and the rubber, a certain pressure or more is required. Even if the appearance of the product after the vulcanization molding is not abnormal, peeling may occur at the interface between the rubber and the adhesive. In addition, it is difficult to judge whether or not the rubber and the support member are adhered to each other with a product after vulcanization molding.

  In view of the above fact, an object of the present invention is to provide a mold capable of reliably molding a leg portion with respect to a support member.

  The invention according to claim 1 is a ring-shaped device that is arranged inside a pneumatic tire and supports the inner side of the tread portion of the pneumatic tire by contacting the outer peripheral surface when the pneumatic tire is crushed due to a decrease in internal pressure. The support member and the leg member made of an elastic material joined to both edges of the support member in the width direction are used for manufacturing a support body, and the leg member is integrally formed with the support member. A mold for molding, wherein the mold includes a cavity for molding the leg portion, and a pressure sensor for detecting a pressure in the cavity.

Next, the operation of the mold according to claim 1 will be described.
In the mold according to claim 1, when the leg is molded by filling the cavity with an elastic material, the pressure in the cavity can be detected by a pressure sensor, and thus the pressure during vulcanization is detected. By doing so, it can be determined whether or not the elastic material can be securely vulcanized and bonded to the support member, and it is possible to prevent the production of a support body having insufficient adhesive force between the support member and the leg portion.

  The invention described in claim 2 is characterized in that in the mold according to claim 1, the mold is a mold for compression vulcanization molding.

Next, the operation of the mold according to claim 2 will be described.
By using the mold of claim 2, compression vulcanization molding of the leg portion can be performed.

  According to a third aspect of the present invention, in the mold according to the first aspect, the mold is a mold for transfer vulcanization molding.

Next, the operation of the mold according to claim 3 will be described.
By using the metal mold according to claim 3, transfer vulcanization molding of the legs can be performed.

  According to a fourth aspect of the present invention, in the mold according to the first aspect, the mold is a mold for injection vulcanization molding.

Next, the operation of the mold according to claim 4 will be described.
By using the mold according to claim 4, it is possible to perform injection vulcanization molding of the legs.

  According to a fifth aspect of the present invention, in the mold according to the fourth aspect, the extrusion amount of an extruder that injects an elastic material into the cavity according to the pressure in the cavity detected by the sensor. It is characterized in that a control device for controlling is connected.

Next, the operation of the mold according to claim 5 will be described.
In the mold according to the fifth aspect, the control device controls the extrusion amount of the extruder that injects the elastic material into the cavity according to the pressure in the cavity. That is, by setting in advance a pressure at which the elastic material can surely be vulcanized and bonded to the support member, and by feedback controlling the extruder so that the pressure in the cavity is equal to or higher than the preset pressure, the leg portion The injection vulcanization molding can be reliably performed.

  Since the metal mold | die of this invention was set as the said structure, the support body to which the supporting member and the leg part were adhere | attached reliably can be manufactured reliably.

Hereinafter, embodiments will be described and embodiments of the present invention will be described.
[First Embodiment]
First, the first embodiment will be described. In 1st Embodiment, the support body 14 arrange | positioned inside the pneumatic tire 10 (refer FIG. 2) is manufactured using the vulcanization molding apparatus 12 (refer FIG. 3) which can be vulcanized.

  The support 14 of the present embodiment is a ring-shaped support member 16 formed of a plate-like member, and a ring-shaped member made of rubber joined to both edges 18A and 18B in the width direction of the support member 16 by vulcanization. Leg portions 20A and 20B.

As shown in FIG. 3, the vulcanization molding apparatus 12 includes a ring-shaped core mold 26 that supports the support member 16 from the inside in a state of non-contact with both edge portions 18A and 18B. Further, the vulcanization molding apparatus 12 includes an upper intermediate mold 28 and a lower intermediate mold 30 that are movable up and down and are provided so as to form a pair of molds with the core mold 26 sandwiched from the axial direction. Further, the vulcanization molding device 12 is provided on the upper side of the upper intermediate mold 28 and is provided on the lower side of the lower mold 30 and the upper mold 32 for transferring the rubber material, and the lower mold for transferring the rubber material. And a mold 34.
The core mold 26, the upper intermediate mold 28, the lower intermediate mold 30, the upper mold 32, and the lower mold 34 constitute a transfer mold.

  The upper intermediate mold 28 is disposed above the core mold 26, and the lower intermediate mold 30 is disposed below the core mold 26. The lower intermediate mold 30 can be moved up and down by a push-up cylinder 36. Further, the upper mold 32, the upper intermediate mold 28, the lower intermediate mold 30, and the lower mold 34 are in a state of being aligned by shafts 40A1, 40A2, 40B1, and 40B2. The lower intermediate mold 30 is configured to open and close with the core mold 26 sandwiched from above and below.

  The upper intermediate mold 28 has a wall surface portion 29 </ b> A that forms a cavity 42 </ b> A for forming the leg portion 20 </ b> A with the core mold 26, and the lower intermediate mold 30 is connected to the core mold 26. There is a wall surface portion 29B forming a cavity 42B for forming the leg portion 20B therebetween.

  The upper intermediate mold 28 is formed with runners 44A1 and 44A2 communicating with the cavity 42A. Similarly, the lower intermediate mold 30 is formed with runners 44B1 and 44B2 communicating with the cavity 42B. The upper intermediate mold 28 is formed with pod portions 46A1 and 46A2 that communicate with the runners 44A1 and 44A2 and accommodate the rubber material G to be transferred into the cavity.

  The upper mold 32 and the lower mold 34 are fixed to an upper surface board 50 and a lower surface board 52 constituting the vulcanization molding apparatus 12, respectively. The shafts 40A1 and 40A2 are both held on the upper surface board 50 so as to be movable back and forth, and the shafts 40B1 and 40B2 are both held on the lower surface board 52 so as to be able to move forward and backward.

  Convex portions 54A1 and A2 corresponding to the dimensions of the pod portions 46A1 and 46A2 are formed on the upper die 32. When the upper die 32 is overlaid on the upper intermediate die 28, the convex portions 54A1 and 54A2 are formed. The rubber material G is inserted into the pod portions 46A1 and 46A2, and the rubber material G in the pod portions 46A1 and 46A2 is pushed out to the runners 44A1 and 44A2 and transferred into the cavities.

The lower mold 34 is formed with pod portions 46B1 and 46B2 having the same dimensions as the pod portion 46A1.
The lower intermediate mold 30 is formed with convex portions 54B1 and B2 corresponding to the dimensions of the pod portions 46B1 and 46B2, and the runners 44B1 and 44B2 penetrate the convex portions 54B1 and 54B2, respectively. When the lower intermediate mold 30 is overlaid on the lower mold 34, the convex portions 54B1 and 54B2 are inserted into the pod portions 46B1 and 46B2, respectively, and the rubber material G in the pod portions 46B1 and 46B2 is runners 44B1 and 44B2, respectively. It is pushed out to transfer into the cavity.

The lower intermediate mold 30 is formed with a mounting table portion 56 on which each member constituting the core mold 26 is slidably mounted and can be fixed at a predetermined position. Further, the lower intermediate mold 30 is provided with a ring-shaped outer abutment portion 57 that abuts the support member 16 from the radially outer side and supports the support member 16. The contact surface of the outer contact portion 57 has a short cylindrical inner surface so that the support member 16 can be set and the support 14 can be taken out. The support member 16 can be held between the outer contact portion 57 and the core mold 26.
The upper intermediate mold 28 and the lower intermediate mold 30 are provided with steam chambers 59 and 60, respectively.

As shown in FIG. 1, a pressure sensor 58 for detecting the pressure in the cavity is attached to the wall surface 29 </ b> A in the upper intermediate mold 28. Although not shown, the lower intermediate mold 30 is also provided with a pressure sensor 58 for detecting the pressure in the cavity on the wall surface 29B.
These pressure sensors 58 are connected to a pressure gauge 60.

(Function)
Hereinafter, the process of manufacturing the support body 14 by joining the leg portions 20A and 20B to the support member 16 by vulcanization molding using the vulcanization molding apparatus 12 will be described.
First, the upper mold 32, the upper intermediate mold 28, the lower intermediate mold 30, and the lower mold 34 are separated from each other, and rubber materials (rubber fabric) G are put into the pod portions 46A1 and 46A2, respectively. The amount of the rubber material G is determined in consideration of the volumes of the runners 44A1 and 44A2 so that the rubber material is injected into the cavity by an amount necessary for forming the leg portion 20A. Similarly, the rubber material G is put in each of the pod portions 46B1 and 46B2.

  In this state, the diameter of the core mold 26 is enlarged and brought into contact with the support member 16 from the inside, thereby fixing the position of the core mold 26. As a result, the support member 16 is sandwiched between the lower intermediate mold 30 and the core mold 26, and a cavity 42B is formed around the edge 18B of the support member 16.

Thereafter, the upper intermediate plate 28 is lowered by lowering the upper surface board 50, and is closed with respect to the core die 26. As a result, a cavity 42 </ b> A is formed around the edge 18 </ b> A of the support member 16.
Further, the upper cylinder 50 and the lower intermediate mold 30 are lowered by the same distance by lowering the push-up cylinder 36, and the lowering is stopped at a predetermined height position. The stop height position is the height position immediately before the rubber material G accommodated in the pod portions 46A1, 46A2 is pushed out by the convex portions 54A1, 54A2, respectively, and the rubber material G accommodated in the pod portions 46B1, 46B2 is the convex portion 54B1, It is set to the height position just before pushing out by 54B2.

  Then, by simultaneously lowering the upper mold 32, the upper intermediate mold 28, and the lower intermediate mold 30 from this state, the rubber material G is simultaneously pressed by the convex portions 54A1, 54A2, 54B1, and 54B2, and each runner is pressed. Are transferred simultaneously into the cavity via

Here, after the pressure in the cavity is measured by the pressure sensor 58 and vulcanization molding is performed at a predetermined temperature for a predetermined time, the pressure of the rubber material G filled in the cavity is set to a predetermined pressure (leg portion). It is determined whether or not the pressure required for reliably vulcanizing and bonding the rubber material G to 20A and 20B has been reached.
And after predetermined time progress, the support body 14 by which leg part 20A, 20B is joined to both edge part 18A, 18B of the supporting member 16, respectively is taken out.

  When the pressure in the cavity is less than the predetermined pressure, it is considered that the rubber material G is insufficient, so that the amount of the rubber material G may be adjusted thereafter.

  As described above, in this embodiment, the legs 20A and 20B are securely vulcanized and bonded to the both edges 18A and 18B of the support member 16 by measuring the pressure in the cavity when the mold is closed. become able to.

[Second Embodiment]
Next, a second embodiment will be described.
In the second embodiment, leg portions 20A are provided on both edges 18A and 18B of the support member 16 by a compression molding die comprising a core die 62, an upper die 64, and a lower die 66 as shown in FIG. 20B is vulcanized and bonded.

  In this compression molding mold, the upper mold 64 and the core mold 62 compress the rubber material G to form the leg portion 20A, and the lower mold 66 and the core mold 62 compress the rubber material G. Thus, the leg portion 20B is formed. The upper mold 64 and the lower mold 66 are provided with a jacket (heater) (not shown) for vulcanization.

In the present embodiment, a pressure sensor 58 for detecting the pressure in the cavity is attached to the upper mold 64 and the core mold 62.
Also in this embodiment, after performing vulcanization molding at a predetermined temperature for a predetermined time, the pressure of the rubber material G filled in the cavity is set to a predetermined pressure (the rubber material G is surely attached to the legs 20A and 20B). It is determined whether or not the pressure required to be vulcanized and bonded is reached.

As a result, the leg portions 20A and 20B can be reliably vulcanized and bonded to both edge portions 18A and 18B of the support member 16, respectively.
When the pressure in the cavity is less than the predetermined pressure, it is considered that the rubber material G is insufficient, so that the amount of the rubber material G may be adjusted thereafter.

[Third Embodiment]
Next, a third embodiment will be described.
In the third embodiment, both edge portions 18A and 18B (not shown) of the support member 16 are formed by an injection molding die including a core die 68, an upper die 70, and a lower die (not shown) as shown in FIG. ) Are vulcanized and bonded to leg portions 20A and 20B (not shown).

An extruder 72 for filling the rubber material G in the cavity is connected to the upper mold 70.
The pressure sensor 58 is attached to each of the upper mold 70 and the lower mold as in the above-described embodiment.

  The extruder 72 and the pressure sensor 58 are connected to a control device 74, and the control device 74 controls the amount of extrusion of the extruder 72 according to the pressure in the cavity. More specifically, a pressure at which the rubber material G can be reliably vulcanized and bonded to the support member 16 is set in advance, and the extruder 72 is fed back so that the pressure in the cavity becomes equal to or higher than the preset pressure. By controlling, the injection vulcanization molding of the legs 20A and 20B can be performed reliably.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

In the above embodiment, a rubber material is used as the elastic material, but an elastomer other than rubber may be used as long as it is a moldable material.
In the above embodiment, the pressure sensor 58 is provided in the upper mold and the lower mold. However, the pressure sensor 58 may be located at other parts (for example, the core) as long as the pressure of the cavity for molding the leg can be directly measured. It may be provided in the mold.

It is sectional drawing which shows the principal part of the metal mold | die which concerns on 1st Embodiment. It is sectional drawing of the pneumatic tire and rim | limb with which the support body was mounted | worn. (A) And (B) is sectional drawing which shows the state before transferring a rubber material with the metal mold | die of 1st Embodiment, respectively, and after making it transfer. (A) is sectional drawing which shows the state before compression molding with the metal mold | die which concerns on 2nd Embodiment, (B) is sectional drawing which shows the state which closed the lower metal mold | die. It is a block diagram of the vulcanization molding system containing the metal mold | die which performs injection molding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Vulcanization molding apparatus 14 Support body 16 Support member 20A Leg part 20B Leg part 26 Core mold 28 Upper intermediate mold 30 Lower intermediate mold 32 Upper mold 34 Lower mold 42A Cavity 42B Cavity 62 Core mold Mold 64 Upper mold 66 Lower mold 68 Core mold 70 Upper mold 72 Extruder 74 Controller G Rubber material (elastic material)

Claims (5)

A ring-shaped support member that is disposed inside the pneumatic tire and supports the inner side of the tread portion of the pneumatic tire in contact with the outer peripheral surface when the pneumatic tire is crushed due to a decrease in internal pressure; and the width of the support member A mold for integrally molding the leg portion on the support member, used when manufacturing a support body having a leg portion made of an elastic material bonded to both edges in a direction. ,
The mold has a cavity for molding the leg and a pressure sensor for detecting a pressure in the cavity.   The mold according to claim 1, wherein the mold is a mold for compression vulcanization molding.   The mold according to claim 1, wherein the mold is a mold for transfer vulcanization molding.   The mold according to claim 1, wherein the mold is a mold for injection vulcanization molding.   5. A control device for controlling an extrusion amount of an extruder that injects an elastic material into the cavity according to a pressure in the cavity detected by the sensor is connected to the sensor. The mold as described in.

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