JP2008093949A - Molding mold of vibration isolation device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding mold of a vibration isolation device and its manufacturing method smoothly demolding a molded vibration isolation device. <P>SOLUTION: The molding mold of a vibration isolation device allows a molding material of a rubber-like elastic body to be injected and filled into a cavity 8 formed between an inner cylinder 2 and an outer cylinder 3. The molding mold is equipped with a molding surface part 31 for molding the axial side surface of the rubber-like elastic body, a support pin 34 which is disposed at the center of the molding surface part 31, supports the lower end surface of the inner cylinder 2 by being inserted from the lower end opening of the inner cylinder 2, and is thrustably constituted toward the upper side, and a stripper die part 7b which is disposed at the outer peripheral side of the molding surface part 31 and has an opposed surface 76 opposing an outer peripheral side part of the lower end surface of the outer cylinder 3. The molding mold is constituted so that the stripper mold part 7b is separated from the lower mold 6 to displace to the upper side approximately simultaneously with thrusting of the support pin 34 when the mold is opened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a molding die and a manufacturing method of a vibration isolator mainly used for a vibration isolating bush or a vibration isolating mount for a vehicle.

  As such an anti-vibration device, a device in which a rubber-like elastic body is interposed between an inner cylinder and an outer cylinder surrounding the inner cylinder is known. Further, as a mold for molding the vibration isolator, as illustrated in FIG. 6, the mold includes an upper mold 55 and a lower mold 56 that can be clamped with middle molds 57 a and 57 b interposed therebetween, A cavity 58 formed between the outer cylinder 53 and the outer cylinder 53 is generally configured so that a molding material of a rubber-like elastic body can be injected and filled through an injection hole 59 (for example, Patent Document 1 below).

  In the illustrated mold, a nested mold 60 having a molding surface portion 63 for molding the axial side surface of the rubber-like elastic body is provided on both upper and lower sides of the cavity 58, and inserted into the inner cylinder 52 at the center thereof. Support pins 51 and 54 are projected. The support pin 51 is configured to be able to be pushed up by an ejector continuously provided below. The lower end portion of the outer cylinder 53 is fitted between the middle die 57 b and the nested die 60, and the lower end surface thereof is supported by the support surface 62 of the nested die 60. Further, the lower end portion of the inner cylinder 52 is fitted between the support pin 51 and the insert mold 60.

  In this mold, the molding material is injected and filled in the cavity 58, and after the rubber-like elastic body is integrally formed in the inner cylinder 52 and the outer cylinder 53, the upper mold 55 is separated from the lower mold 56, and the middle mold A plurality of mold parts constituting 57a are displaced to the outer peripheral side. Thereby, the molded vibration isolator is in a state where the upper body is exposed. Then, the support pin 51 is pushed up by the ejector to push up the vibration isolator so that it can be taken out of the mold. Such a mechanism is also described in Patent Documents 2 and 3 below.

However, when it is difficult to remove the lower end portion of the outer cylinder 53, such as when the dimensions of the outer cylinder 53 vary or when the adhesive applied to the inner peripheral surface of the outer cylinder 53 is dripped and fixed, as described above. Further, there is a problem that the mold removal cannot be smoothly performed only by supporting the inner cylinder 52 and pushing up the vibration isolator, and the mold removal operation is not stable.
Japanese Utility Model Publication No. 2-15315 JP 2002-79551 A Japanese Patent No. 3438315

  This invention is made | formed in view of the said situation, The objective is to provide the shaping | molding die of a vibration isolator and a manufacturing method which can demold the molded vibration isolator smoothly.

  The above object can be achieved by the present invention having the following configuration. That is, in the mold for the vibration isolator according to the present invention, when the upper mold and the lower mold are clamped, a cavity is formed between the inner cylinder and the outer cylinder that surrounds the inner cylinder in an axially parallel manner, In the mold of the vibration isolator configured to be able to inject and fill the molding material of the rubber-like elastic body into the cavity, the mold is disposed between the inner cylinder and the outer cylinder, and the axial side surface of the rubber-like elastic body is arranged It is arranged at the center of the molding surface part to be molded and the molding surface part on the lower mold side, is inserted from the lower end opening of the inner cylinder, supports the lower end surface of the inner cylinder, and is configured to be able to push upward. A support pin; and a stripper mold part disposed on the outer peripheral side of the molding surface part on the lower mold side and having an opposing surface facing the outer peripheral side part of the lower end surface of the outer cylinder. The stripper mold part is separated from the lower mold at almost the same time as it pushes up. Te are those configured so as to be displaced upward.

  The effect when the vibration isolator is molded using the mold according to the present invention will be described. In forming the vibration isolator, first, the inner cylinder and the outer cylinder are set in the mold, and then the upper mold and the lower mold are clamped to form a cavity between the two cylinders. In such a mold clamping state, a support pin is fitted into the lower end opening of the inner cylinder, and the lower end surface of the inner cylinder is supported by the support pin. Moreover, the opposing surface of a stripper type | mold part opposes the outer peripheral side part of the lower end surface of an outer cylinder.

  Next, the rubber-like elastic body molding material is injected and filled into the cavity, and after the rubber-like elastic body is integrally formed in the inner cylinder and the outer cylinder, the upper mold and the lower mold are opened, and the molded vibration isolation Demold the device. In the present invention, when the mold is opened, the stripper mold part is separated from the lower mold and displaced upward at substantially the same time as the support pins are pushed up. Thereby, the vibration isolator can be pushed up in a state where the lower end surfaces of the inner cylinder and the outer cylinder are supported, and the demolding can be performed smoothly.

  In the above, the stripper mold is provided with a nesting mold having a support surface for placing and supporting the inner peripheral portion of the lower end surface of the outer cylinder and the molding surface portion on the lower mold side, and the stripper mold on the outer periphery of the nesting mold It is preferable that the inner peripheral side end of the facing surface is disposed between the flat end portions of the lower end surface of the outer cylinder.

  In the above configuration, the inner peripheral side portion of the lower end surface of the outer cylinder is supported by the nested support surface, and the opposing surface of the stripper mold portion is opposed to the outer peripheral side portion. The space between the molds can be sealed with a support surface, and end surface burrs on the lower end surface of the outer cylinder can be prevented. Further, the inner peripheral side end of the opposing surface is arranged between the flat end portions of the lower end surface of the outer cylinder, so that when the stripper mold portion is separated from the lower die and displaced upward, the flat end portion is mounted on the opposing surface. The lower end surface of the outer cylinder can be appropriately supported.

  In the above, it is preferable that the facing surface is disposed at a lower position than the support surface in the mold clamping state. When the mold is clamped, if the opposing surface of the stripper mold part is positioned slightly above the support surface of the nested mold, a gap is formed between the inner peripheral side portion of the lower end surface of the outer cylinder and the support surface. As a result, the molding material may enter and end face burrs may be generated. Therefore, according to the above configuration, the opposing surface is arranged at a position lower than the support surface, so that the lower end portion of the outer cylinder and the mold are reliably sealed with the support surface of the nested mold, and the end surface variability is ensured. Can be prevented appropriately.

  The vibration isolator manufacturing method according to the present invention includes a support pin fitted into the lower end opening of the inner cylinder to support the lower end surface of the inner cylinder, and the upper mold and the lower mold are clamped, A first step of forming a cavity between a cylinder and an outer cylinder surrounding the inner cylinder in parallel with the axis; and a molding material of a rubber-like elastic body is injected and filled into the cavity, and the inner cylinder and the outer cylinder are filled. A second step of integrally molding the rubber-like elastic body, a third step of opening the mold and separating the upper die from the lower die, and substantially simultaneously with pushing up the support pin upward, A stripper mold portion having a facing surface facing the outer peripheral side portion of the lower end surface is separated from the lower mold and displaced upward, and is pushed up while supporting the lower end surfaces of the inner cylinder and the outer cylinder to dampen the vibration. And a fourth step of demolding the device.

  According to the above method, the effects of the present invention as described above are expressed. That is, the vibration isolator can be pushed up in a state where the lower end surfaces of the inner cylinder and the outer cylinder are supported, and demolding can be performed smoothly.

  In the above, in the first to third steps, the facing surface in which the inner peripheral side end is disposed between the flat end portions of the lower end surface of the outer cylinder is spaced downward from the lower end surface of the outer cylinder. It is preferable that the inner peripheral side portion of the lower end surface of the outer cylinder is placed and supported on a support surface of a nested mold disposed on the inner periphery of the stripper mold portion.

  According to the above method, the effects of the present invention as described above are expressed. That is, it is possible to appropriately prevent the end surface burr on the lower end surface of the outer cylinder by appropriately sealing the lower end portion of the outer cylinder and the mold with the support surface of the nested mold.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an anti-vibration bush (an example of an anti-vibration device). FIG. 2 is a cross-sectional view of an essential part showing an example of a mold for the vibration isolator according to the present invention. FIG. 3 is an enlarged cross-sectional view of the lower end portion of the outer cylinder set in the same mold. FIG. 4 is a cross-sectional view of the main part when a molding material for rubber-like elastic material is injected and filled in the mold. FIG. 5 is a cross-sectional view of the main part showing a state when the mold is removed.

  First, the anti-vibration bush 1 shown in FIG. 1 will be briefly described. The vibration isolating bush 1 includes an inner cylinder 2, an outer cylinder 3 concentrically surrounding the inner cylinder 2, and a rubber-like elastic body 4 interposed between the inner cylinder 2 and the outer cylinder 3 to couple them together. Is provided. The inner cylinder 2 and the outer cylinder 3 can be formed of a known high-rigidity material, and for example, a steel material or a high-rigidity resin material can be used. Moreover, as the rubber-like elastic body 4, a known rubber material in the technical field of automobile vibration-proof rubber can be used without limitation.

  The inner cylinder 2 is longer in the axial direction than the outer cylinder 3, and both end portions 21 and 23 protrude from the axial side surface 4 a of the rubber-like elastic body 4. The rubber-like elastic body 4 extends from the outer peripheral surface of the inner cylinder 2 to the outer peripheral side while reducing the axial length, and has an axial length equal to or less than that of the outer cylinder 3 on the inner peripheral surface of the outer cylinder 3. Has reached. In the present embodiment, two straight portions 25 penetrating the rubber-like elastic body 4 in the axial direction are provided at two locations facing in the radial direction across the inner cylinder 2, and the outer periphery of the central portion in the axial direction of the inner cylinder 2 is provided. A stopper 26 is fixed to the surface.

  Next, the mold shown in FIG. 2 will be described. The upper die 5 and the lower die 6 provided in this forming die are configured so as to be clamped with an intermediate die 7a and an intermediate die 7b (corresponding to the stripper die part) sandwiched between them, and an upper surface of the upper die 5 has a runner plate. 20 is laid. The middle mold 7a is composed of a combination of a plurality of mold parts divided in the circumferential direction, and each is configured to be displaceable in the radial direction. The middle mold 7b is fixedly attached to an eject plate (not shown) disposed below the lower mold 6, and is configured to be separated from the lower mold 6 and displaced upward.

  The inner cylinder 2 and the outer cylinder 3 are each supported in an upright posture, and are configured so that a molding material for the rubber-like elastic body 4 can be injected and filled into a cavity 8 formed between the inner cylinder 2 and the outer cylinder 3 through an injection hole. The injection hole is not shown because it is provided at a position shifted by 90 ° from the cross section shown in FIG. 2, but extends in the vertical direction (axial direction) from the runner groove provided on the lower surface of the runner plate 20 to form the cavity 8. (See FIG. 6).

  In this mold, the nested molds 10 and 30 are arranged so as to face each other. The insert mold 30 has a molding surface portion 31 that molds the axial side surface 4 a of the rubber-like elastic body 4, and is fixed in a state of being fitted to the recessed portion 32 of the lower mold 6. The shape of the molding surface portion 31 corresponds to the axial side surface 4 a and bulges upward from the lower end surface of the outer cylinder 3. Similarly, the insert mold 10 also has a molding surface portion 11 and is fixed to the recessed portion 12 of the upper mold 5. The projecting portions 17 and 37 project from the molding surface portions 11 and 31 toward the cavity 8, thereby forming a straight portion 25.

  At the center of the molding surface portion 11 on the upper mold 5 side, an annular hole portion 13 into which the upper end portion 21 of the inner cylinder 2 is inserted, and a support pin 14 to be inserted from the upper end opening of the inner cylinder 2 are provided. The support pin 14 is urged downward by a spring 16 disposed on the base portion 15 in order to improve the demoldability of the molded product. The base portion 15 is formed with a step for supporting the upper end surface of the inner cylinder 2, and a seal ring 18 is disposed on the outer periphery thereof.

  At the center of the molding surface portion 31 on the lower mold 6 side, an annular hole portion 33 into which the lower end portion 23 of the inner cylinder 2 is inserted and a support pin 34 into which the lower end opening of the inner cylinder 2 is inserted are provided. The support pin 34 is configured to be pushed upward by an ejector plate connected to the base portion 35 in order to improve the demoldability of the molded product. The base portion 35 is formed with a step for supporting the lower end surface of the inner cylinder 2, and a seal ring 38 is disposed on the outer periphery thereof.

  The middle mold 7a is formed so as to project from the upper part to the inner peripheral side, and has an inner peripheral flange portion 71 located above the outer cylinder 3 in a clamped state. The inner peripheral flange portion 71 is formed with a tapered surface 74 whose inner diameter gradually decreases downward. The burr groove 72 is formed in an annular shape inscribed in the taper surface 74 and communicates with the cavity 8 through a minute gap.

  The middle mold 7b is formed so as to project from the lower part to the inner peripheral side, and has an annular inner peripheral flange portion 75 located below the outer cylinder 3 in a clamped state. The inner peripheral flange portion 75 is formed with a tapered surface 77 whose inner diameter gradually decreases upward. As shown in an enlarged view in FIG. 3, an opposing surface 76 facing the outer peripheral side portion of the lower end surface of the outer cylinder 3 is provided in an annular shape on the upper portion of the inner peripheral flange portion 71. In addition, a support surface 39 that supports the inner peripheral portion of the lower end surface of the outer cylinder 3 is provided on the nested die 30 disposed on the inner periphery of the middle die 7b.

  The space between the lower end portion of the outer cylinder 3 and the mold is sealed by the support surface 39, thereby preventing end burr at the lower end surface of the outer cylinder 3. In the present embodiment, the opposed surface 76 is arranged below the support surface 39 in the mold clamping state, and even when a slight positional deviation occurs between the mold parts, the opposed surface 76 is arranged. Is not arranged above the support surface 39. Therefore, it can be surely sealed with the support surface 39, and end surface burrs can be prevented appropriately.

  The middle dies 7 a and 7 b are configured to be movable up and down together with the lower die 6. When the die is opened, the middle dies 7 a and 7 b are displaced downward from the clamping state shown in FIG. Then, after the mold part constituting the middle mold 7a is displaced to the outer peripheral side and the upper body of the vibration isolating bushing 1 is exposed, the middle mold 7b is separated from the lower mold 6 and at the same time as the support pin 34 is pushed up. It is comprised so that it may displace. The operation of each mold part is controlled by a control device (not shown). The middle die 7b only needs to be relatively displaced upward with respect to the lower die 6, and only the lower die 6 may be lowered while the middle die 7b is stationary.

  The inner peripheral side end of the facing surface 76 is disposed between the flat end portions 3a on the lower end surface of the outer cylinder 3, and is preferably disposed in the center of the flat end portion 3a. Thereby, when the middle mold 7b is separated from the lower mold 6 and displaced upward, the flat end 3a can be placed on the facing surface 76 and the lower end surface of the outer cylinder 3 can be appropriately supported. If this is arranged on the inclined portion 3b that is chamfered at the lower end surface, the lower end surface of the outer cylinder 3 may not be supported and may be damaged. In addition, when arranged on the inclined portion 3c, sealing by the support surface 39 cannot be performed, and end surface burrs are likely to occur. The tapered surface 77 circumscribes the nesting die 30. In order to avoid interference with the nesting die 30, the angle formed between the facing surface 76 and the tapered surface 77 is set to 90 ° or less.

  Hereinafter, a method of manufacturing the vibration isolating bush 1 using the above-described mold will be described. First, after setting the inner cylinder 2 and the outer cylinder 3 in the mold, the upper mold 5 and the lower mold 6 are clamped with the middle molds 7a and 7b interposed therebetween, and the inner cylinder 2 and the outer cylinder as shown in FIG. 3 is formed between the first and second cavities 3 (corresponding to the first step). In the clamped state, the support pin 34 is inserted into the lower end opening of the inner cylinder 2, and the lower end surface of the inner cylinder 2 is supported by the step of the base portion 35. Further, as shown in FIG. 3, the inner peripheral side portion of the lower end surface of the outer cylinder 3 is placed on the support surface 39 of the nested die 30, and the facing surface of the middle die 7b is spaced downward from the lower end surface. 76 is arranged.

  Next, the molding material of the rubber-like elastic body 4 is injected and filled into the cavity 8, and the rubber-like elastic body 4 is integrally formed in the inner cylinder 2 and the outer cylinder 3 (corresponding to the second step). At this time, since the space between the lower end portion of the outer cylinder 3 and the mold is reliably sealed by the support surface 39 of the insert mold 30, the generation of end surface burrs is appropriately prevented.

  In the present embodiment, the surplus molding material is fed into the burr groove 72 through the minute gap, and the annular burr 73 is formed. When a molding material is injected into multiple cavities from a single injection device, the time until the molding material is filled differs between cavities, and therefore the molding material overflows easily in cavities filled with molding material first. However, since the overflow portion can be received by the burr groove portion 72, the cavity balance of the entire mold can be achieved, and end surface burr can be effectively prevented.

  In addition, as a molding material of the rubber-like elastic body 4, a general-purpose rubber such as natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR) or the like alone or Two or more types can be used as a mixture, and these include compounding materials such as fillers such as carbon black and silica, vulcanizing agents (sulfurs), vulcanization accelerators, plasticizers, anti-aging agents, and the like. What was mixed suitably and prepared so that heat-crosslinking is possible is used.

  Thereafter, the upper mold 5 and the lower mold 6 are opened to take out the vibration isolating bush 1. In the mold opening, first, the middle molds 7a and 7b are displaced downward together with the lower mold 6, and the upper mold 5 is separated from the lower mold 6 (corresponding to the third step). At this time, since the outer cylinder 3 is pressed from above by the inner peripheral flange portion 71 of the middle mold 7a, the vibration isolating bush 1 is held to the lower mold 6 side, and the end 21 of the inner cylinder 2 is connected to the annular hole. 13 can be easily and reliably removed.

  Next, the middle die 7a is displaced to the outer peripheral side to be separated from the outer cylinder 3, and the upper body of the vibration isolating bush 1 is exposed. An annular burr 73 is attached to the vibration isolating bush 1 but can be easily removed because it is connected to the rubber-like elastic body 4 at the thin wall portion.

  Subsequently, as shown in FIG. 5, the support pin 34 is pushed upward to remove the lower end portion of the inner cylinder 2 from the annular hole portion 33. At the same time as the support pin 34 is pushed up, the middle die 7b is separated from the lower die 6 and displaced upward, and is pushed up while supporting the lower end surfaces of the inner cylinder 2 and the outer cylinder 3 (the fourth Equivalent to the process). As a result, the demolding operation is stabilized, and the anti-vibration bush 1 can be smoothly demolded.

  The present invention is not limited to the embodiment described above, and various improvements and modifications can be made without departing from the spirit of the present invention. Therefore, in the above-described embodiment, an example in which the stripper mold portion (medium mold) is attached and fixed to the eject plate is shown, but instead, the stripper mold portion is placed on the upper surface of the lower mold, and between them. The stripper mold part may be displaced upward by the biasing force of the arranged spring. The structure of the vibration isolator is not limited to that described above, but when the rubber elastic body is provided with a curled portion as in the above-described embodiment, the protrusion that forms the curled portion is a rubber. The present invention is particularly useful because it can be smoothly removed from the elastic body.

Cross section of anti-vibration bush Sectional drawing of the principal part showing an example of a mold of the vibration isolator according to the present invention Sectional drawing which expands and shows the lower end part of the outer cylinder set to the same mold Cross-sectional view of the main part when the molding material of rubber-like elastic material is injected and filled in the same mold Cross-sectional view of the main part showing how the mold is removed Cross-sectional view of the main part showing an example of a molding die of a conventional vibration isolator

Explanation of symbols

1 Anti-vibration bush (vibration isolator)
2 Inner cylinder 3 Outer cylinder 3a Flat end 4 Rubber elastic body 4a Axial side surface 5 Upper mold 6 Lower mold 7a Middle mold 7b Middle mold (stripper mold section)
8 Cavity 30 Nesting mold 31 Molding surface portion 34 Support pin 39 Support surface 75 Inner peripheral flange portion 76 Opposing surface 77 Tapered surface

Claims (5)

When the upper mold and the lower mold are clamped, a cavity is formed between the inner cylinder and the outer cylinder that surrounds the inner cylinder in an axially parallel manner, and a molding material of a rubber-like elastic body can be injected and filled into the cavity. In the mold of the vibration isolator configured in
A molding surface portion that is disposed between the inner cylinder and the outer cylinder, and that molds an axial side surface of the rubber-like elastic body;
A support pin that is arranged in the center of the molding surface portion on the lower mold side, is inserted from the lower end opening of the inner cylinder, supports the lower end surface of the inner cylinder, and is configured to be able to push upward.
A stripper mold part disposed on the outer peripheral side of the molding surface part on the lower mold side and having an opposing surface facing the outer peripheral side part of the lower end surface of the outer cylinder;
A mold for an anti-vibration device, wherein the stripper mold part is separated from the lower mold and displaced upward substantially at the same time as the support pins are pushed up when the mold is opened. A support surface that supports the inner peripheral side portion of the lower end surface of the outer cylinder by placing thereon and a nesting die having the molding surface portion on the lower mold side,
The anti-vibration device molding according to claim 1, wherein the stripper mold portion is disposed on an outer periphery of the nested mold, and an inner peripheral side end of the facing surface is disposed between flat end portions of a lower end surface of the outer cylinder. Type.   The mold for an anti-vibration device according to claim 2, wherein the opposing surface is disposed at a position lower than the support surface in a clamped state. A support pin is inserted into the lower end opening of the inner cylinder to support the lower end surface of the inner cylinder, the upper mold and the lower mold are clamped, and the inner cylinder and the outer cylinder surrounding the inner cylinder in parallel with each other A first step of forming a cavity therebetween;
A second step of injecting and filling a molding material of a rubber-like elastic body into the cavity and integrally molding the rubber-like elastic body into the inner cylinder and the outer cylinder;
A third step of opening the mold to separate the upper mold from the lower mold;
At substantially the same time as the support pin is pushed upward, a stripper mold portion having a facing surface facing the outer peripheral side portion of the lower end surface of the outer cylinder is separated from the lower mold and displaced upward, and the inner cylinder and And a fourth step of releasing the vibration isolator by pushing it up while supporting the lower end surface of the outer cylinder.   In the first to third steps, the facing surface in which the inner peripheral end is disposed between the flat end portions of the lower end surface of the outer cylinder is disposed at a position spaced downward from the lower end surface of the outer cylinder. A method for manufacturing a vibration isolator according to claim 4, wherein an inner peripheral side portion of a lower end surface of the outer cylinder is placed and supported on a support surface of a nested mold disposed on an inner periphery of the stripper mold part. .

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