JPWO2006064538A1 - Method for producing metal-rubber composite product - Google Patents

Abstract

Prevents rubber burrs when molding metal-rubber composites such as vibration-proof bushings. Therefore, by using the molding die 10 provided with the rubber reservoir recesses 54 and 56 along the edge of the cavity 16, the rubber material R is injected into the cavity at the time of the first molding, so that the inner and outer cylinders 2 and 3 and the rubber The elastic body 4 is integrally molded, and the rubber reservoir recesses 54 and 56 are filled with a rubber material to form the sealing rubbers 62 and 64. Then, the sealing rubbers 62 and 64 are left in the rubber reservoir recesses 54 and 56 at the time of demolding, and the inner cylinder 2 and the outer cylinder 3 are set in the molding die 10 in that state, and the second and subsequent moldings are performed. The rubber rubber R for sealing prevents the rubber material R from flowing out of the cavity 16.

Description

  The present invention relates to a method for manufacturing a metal-rubber composite product in which a metal part and a rubber elastic body are integrally molded, and a mold used therefor, and more particularly to a manufacturing method and a mold suitable for manufacturing a vibration isolator. It is.

  When manufacturing a bush type vibration isolator comprising an inner cylinder, an outer cylinder that concentrically surrounds the inner cylinder, and a rubber elastic body interposed between the two cylinders, the following method is generally used. . That is, an inner cylinder and an outer cylinder are set in a mold, and a rubber material is injected into a cavity formed between the inner and outer cylinders and an inner surface of the mold, and the rubber material is filled into the cavity. Thus, a rubber elastic body is integrally vulcanized and molded between the inner and outer cylinders.

  In the manufacture of such a vibration isolator, it is required from the viewpoint of ensuring the performance as a vibration isolator and preventing the appearance of rubber burrs on the end surface of the inner cylinder and the outer peripheral surface of the outer cylinder. For this reason, measures for preventing rubber burrs have been taken.

  As a conventional general measure, for example, to prevent rubber burrs on the inner cylinder end face, adjust the dimensions of the outer diameter of the inner cylinder end and the inner diameter of the recess of the mold that holds the inner cylinder. There is a method of fitting with no gap (for example, Japanese Patent Laid-Open No. 7-276382). However, when the sealing property is to be secured by fitting the metal between the mold and the inner cylinder in this way, it is necessary to tighten the degree of fitting. Impairs the durability. There is also a problem that it is difficult to come off during demolding.

  Further, as described in the above publication, an elastic material or a soft material made of a material different from the rubber elastic body is disposed on the mold portion that contacts the end surface of the inner cylinder, and these inner cylinders are disposed when the mold is closed. There is a measure to ensure sealing performance by pressing against an elastic material or soft material. However, such a method of separately disposing a sealing material such as an elastic material or a soft material requires a disposition cost, and since the shape and dimensions of the sealing material are different for each product, various types of sealing materials are prepared. From this point of view, the cost is high.

Japanese Patent Application Laid-Open No. 2000-43062 discloses an inner cylinder end by providing a large-diameter portion and a small-diameter portion at an end portion of the inner cylinder, and press-contacting the edge of the mold to the step portion between the two A method for preventing rubber burr in the part is described. However, in this case, processing for providing the above-described stepped portion at the end of the inner cylinder is separately required, leading to high costs. In addition, since the edges of the mold are brought into pressure contact, there is a concern about the problem of wear in this portion.
: Japanese Unexamined Patent Publication No. 7-276382 : Japanese Unexamined Patent Publication No. 2000-43062

  The present invention has been made in view of the above, and manufacture of a metal-rubber composite product capable of preventing rubber burrs at low cost while avoiding the problem of product demolding failure and mold wear. It is an object to provide a method and a mold.

  In the manufacturing method according to the present invention, a metal part is set in a mold, a rubber material is injected into a cavity formed between the metal part and the mold, and a rubber elastic body is formed on the surface of the metal part. A metal-rubber composite product manufacturing method in which a rubber reservoir recess is provided along an edge of the surface of the metal part facing the cavity. By setting a metal part and injecting a rubber material into the cavity, the rubber material is filled into the cavity to integrally form the metal part and a rubber elastic body, and the rubber material is formed in the rubber reservoir recess. The sealing rubber is molded by molding the sealing rubber, removing the integrally molded metal part and rubber elastic body from the molding die, and molding the rubber reservoir recess. The metal part is set in the mold while the rubber for sealing is left, the rubber for sealing is left, the rubber material is injected into the cavity, and the metal part and the rubber elastic body are It is an integral molding.

  A molding die according to the present invention is a molding die for molding a metal-rubber composite product formed by integrally molding a rubber elastic body on the surface of a metal part, and for molding the rubber elastic body. A rubber reservoir recess is provided along an edge of the surface of the metal part facing the cavity, and the rubber pool recess is provided in a mold part facing the metal part surface and has a minute gap. A rubber for sealing that prevents the rubber material from flowing out of the cavity is molded by being filled with the rubber material through the minute gap.

  According to the present invention, the molding die is provided with the rubber reservoir recess at a location corresponding to the seal portion of the cavity, and at the time of the first molding, the rubber elastic body of the product is molded and the rubber material is stored in the rubber reservoir. Sealing rubber is provided by filling the recess. Next, by leaving the sealing rubber in the mold during the mold removal, it can function as a seal material for preventing the rubber material from flowing out of the cavity in the subsequent molding.

  In the present invention, the sealing rubber contacts the surface of the metal part along the edge of the metal part surface facing the cavity, thereby preventing the rubber material from flowing out of the cavity. It is preferred that

  In the present invention, it is preferable that the rubber reservoir recess communicates with the cavity through a minute gap. In this case, when a rubber material is injected into the cavity at the time of the first molding, the rubber material passes through the minute gap and is filled into the rubber reservoir recess.

  In the present invention, the rubber reservoir recess is preferably formed in a cross-sectional shape with a narrow opening side. With such a cross-sectional shape, the sealing rubber molded in the rubber reservoir recess does not come off during product demolding and can be used repeatedly as a sealing material.

  In the present invention, the mold may be provided with an open air vent that opens to the cavity. By providing such an air release vent, the gas in the cavity can be extracted to the outside air, and the moldability can be improved. Further, in a multi-cavity mold that can mold a plurality of products at a time, cavity balance can be achieved by discharging excess rubber material from the open vent.

  The present invention is particularly used for manufacturing a vibration isolator comprising an inner cylinder that is a metal part, an outer cylinder that surrounds the inner cylinder, and a rubber elastic body interposed between the inner cylinder and the outer cylinder. It is effective. In this case, the rubber reservoir recess is provided in the mold portion facing the outer peripheral surface of the end portion of the inner cylinder, and the cavity and the cavity between the outer peripheral surface of the inner cylinder end portion and the mold portion facing the same. It is preferable that a minute gap that communicates with the rubber reservoir recess is formed, and thereby, generation of rubber burrs on the inner cylinder end surface can be effectively suppressed.

  Also, in this case, the rubber reservoir recess is provided in the mold portion facing the axial end surface of the outer cylinder, and a part of the opening surface of the rubber reservoir recess is covered by the outer cylinder end surface, and the cavity and the It is preferable that a minute gap that communicates with the rubber reservoir recess is formed, whereby the generation of rubber burrs on the outer peripheral surface at the outer cylinder end can be effectively suppressed.

  According to the present invention, since the rubber material for molding the rubber elastic body of the product is used as it is as the sealing material, rubber burrs can be prevented at low cost. Also, even if different types of products are provided, if a rubber reservoir recess is provided in the mold, a seal material corresponding to the mold will be formed at the time of the first molding. There is a clear advantage over the arrangement.

  In addition, since a rubber material is used to prevent rubber burrs, there is no need to ensure sealing performance by tightly fitting the metal between the mold and metal parts. Wear problems can be avoided.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a cross-sectional view of a molding die 10 according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part thereof, and FIGS. The mold 10 is an injection mold for vulcanizing the vibration isolating bush (vibration isolator) 1 shown in FIG.

  The anti-vibration bush 1 includes a metal inner cylinder 2, a metal outer cylinder 3 concentrically surrounding the metal inner cylinder 2, and a rubber elastic body that is interposed between the inner cylinder 2 and the outer cylinder 3 to couple them together. 4 and. The rubber elastic body 4 is provided with a straight portion 5 which is a through hole in the axial direction, and the straight portion 5 is provided at two locations opposed to each other in the radial direction across the inner cylinder 2. Further, on one end surface of the rubber elastic body 4, convex portions 6 are provided at two locations facing each other in the radial direction across the inner cylinder 2, and the convex portions 6 do not overlap with the straight portions 5. Is provided. The convex portion 6 is formed to connect the gate 24 of the injection path to be described later and the air release vent 28.

  As shown in FIG. 1, the molding die 10 includes an upper die 12 and a lower die 14 that can be closed and opened by moving up and down relative to the upper die 12. A cavity 16 for molding the rubber elastic body 4 is formed by closing the mold 14. The molding die 10 includes a plurality of, for example, eight cavities 16 so that a plurality of vibration-proof bushings can be molded at a time.

  A runner block 18 is provided on the upper surface of the upper mold 12, a sprue 20 penetrating the runner block 18 in the vertical direction, a horizontal runner 22 formed on a joint surface between the runner block 18 and the upper mold 12, a cavity An injection path for injecting a rubber material R, which is a molding material, into the cavity 16 by a gate 24 to 16 and a runner hole 26 that penetrates the upper mold 12 vertically and connects the horizontal runner 22 and the gate 24. Is formed.

  The molding die 10 is provided with an air release vent 28 that opens to the upper end surface of the cavity 16. The air release vent 28 is provided on the opposite side of the gate 24 in the radial direction, extends upward from the cavity 16, and is drawn out of the mold along the joint surface between the runner block 18 and the upper mold 12. Yes.

  The inner cylinder 2 and the outer cylinder 3 are set in the mold 10. Specifically, the upper mold 12 and the lower mold 14 are provided with core pins 30 and 32 for holding the inner cylinder 2 in a posture in which the axial direction thereof is directed in the vertical direction. By being inserted inside the inner cylinder 2, the inner cylinder 2 is held so as to be sandwiched from above and below. The core pin 30 of the upper mold 12 is urged downward by a spring 34 in order to improve the demoldability. The core pin 32 of the lower die 14 is provided so as to be movable up and down by an ejector 36, and a product is taken out by pushing up the inner cylinder 2 upward when removing the die. On the other hand, the outer cylinder 3 is held by the upper and lower molds 12 and 14 so as to surround the inner cylinder 2, and the hollow cylinder-shaped above-mentioned is formed between the inner and outer cylinders 2 and 3 and the upper and lower molds 12 and 14 thus held. A cavity 16 is formed.

  The upper mold 12 is configured to be disassembled into a plurality of mold parts. Specifically, as shown in FIG. 2, the upper mold 12 is fitted to the upper surface molding part 38 for molding the upper surface of the rubber elastic body 4 and the inner peripheral surface thereof. A ring-shaped inner tube support portion 40 that is joined to and supports the end surface 2a of the inner tube 2 and a ring-shaped member that is externally fitted to the outer peripheral surface of the upper surface molding portion 38 and contacts and supports the end surface 3a of the outer tube 3. And an outer cylinder support portion 42. The upper surface forming portion 38 is provided with a core portion 44 for forming the straight portion 5.

  Similarly, the lower mold 14 is configured to be disassembled into a plurality of mold parts. Specifically, the lower mold 14 is fitted into the lower surface molding part 46 that molds the lower surface of the rubber elastic body 4 and the inner peripheral surface thereof, and the inner cylinder. A cylindrical inner cylinder support portion 48 that abuts and supports the two end surfaces 2a, and a ring-shaped outer cylinder support portion 50 that is fitted on the outer peripheral surface of the lower surface molding portion 46 and abuts and supports the end surface 3a of the outer cylinder 3. And comprising. The lower surface molding portion 46 is provided with a core portion 52 for molding the straight portion 5.

  As shown in FIG. 2, the molding die 10 is provided with rubber reservoir recesses 54 and 56 along the edge portions of the surfaces of the inner cylinder 2 and the outer cylinder 3 facing the cavity 16. In other words, the rubber mold recesses 54 and 56 are provided in the mold 10 along the boundary between the portion covered with the rubber elastic body 4 and the portion not covered in the inner cylinder 2 and the outer cylinder 3.

  As shown in FIGS. 2 and 3, the rubber reservoir recess 54 on the side of the inner cylinder 2 opens inward toward the outer peripheral surface of the inner cylinder 2 in the mold portion facing the outer peripheral surface of the end of the inner cylinder 2. And is formed between the upper surface molding portion 38 or the lower surface molding portion 46 described above and the inner cylinder support portions 40 and 48 disposed on the inner side thereof. The rubber reservoir recess 54 is provided over the entire circumference of the outer peripheral surface of the inner cylinder 2. Further, the rubber reservoir recess 54 is formed in a cross-sectional shape narrowed on the opening side so that the cross-sectional area of the opening side is smaller than the back side, and in this embodiment, it is formed in a dovetail shape as shown in FIG. Has been. A minute gap (slit) 58 that allows the cavity 16 and the rubber reservoir recess 54 to communicate with each other is formed on the outer peripheral surface of the end portion of the inner cylinder 2 and the inner peripheral surface of the upper surface molding portion 38 or the lower surface molding portion 46 facing this. ing. The minute gap 58 is not particularly limited as long as it is a size that allows the rubber material R to flow out of the cavity 16 into the rubber reservoir recess 54 and fill the recess 54 with the rubber material R during the first molding described later. 0.5 mm or less, more preferably 0.05 to 0.4 mm, and in this embodiment, it is set to about 0.1 mm.

  As shown in FIGS. 2 and 4, the rubber reservoir recess 56 on the outer cylinder 3 side is opened toward the end surface 3 a of the outer cylinder 3 in the molding die portion facing the axial end surface 3 a of the outer cylinder 3. It is provided, and is formed between the above-described upper surface molding portion 38 or the lower surface molding portion 46 and the outer cylinder support portions 42 and 50 disposed on the outside thereof. The rubber reservoir recess 56 is provided over the entire circumference of the end surface 3 a of the outer cylinder 3. Further, the rubber reservoir recess 56 is formed in a cross-sectional shape narrowed to the opening side so that the opening side has a smaller cross-sectional area than the back side. The opening surface of the rubber reservoir recess 56 is covered with the end surface 3 a of the outer cylinder 3 on the outer peripheral side, and the inner peripheral side portion not covered with the end surface 3 a is a minute that allows the cavity 16 and the rubber reservoir recess 56 to communicate with each other. It is secured as a gap (slit) 60. The minute gap 60 is not particularly limited as long as it is a size that allows the rubber material R to flow out of the cavity 16 into the rubber reservoir recess 56 and fill the recess 56 with the rubber material R during the first molding described later. 0.5 mm or less, more preferably 0.05 to 0.4 mm, and in this embodiment, it is set to about 0.3 mm.

  In the present embodiment, the anti-vibration bush 1 is manufactured as follows using the molding die 10 as described above.

(1) First, as shown in FIG. 2, the first vibration isolating bush 1 is molded in a state where the rubber reservoir recesses 54 and 56 are not filled with rubber. Specifically, the inner cylinder 2 and the outer cylinder 3 are set in a state where the lower mold 14 is lowered and the mold is opened, the lower mold 14 is raised and the mold is closed, and then the rubber material R is removed from the sprue 20 into the cavity 16. Inject into. As a result, as shown in FIG. 5, the rubber material R is filled into the cavity 16, and the rubber elastic body 4 is integrally vulcanized and molded into the inner and outer cylinders 2 and 3. At the same time, the rubber material R injected into the cavity 16 is filled into the rubber reservoir recesses 54 and 56 through the minute gaps 58 and 60, and the sealing rubbers 62 and 64 are vulcanized. At this time, the surplus rubber material R is discharged out of the cavity 16 from the atmosphere opening vent 28.

(2) Next, the vibration isolating bush 1 molded in the above (1) is removed from the mold 10. Demolding is performed by lowering the lower mold 14 and opening the mold as shown in FIG. 6 and pushing the core pin 32 of the lower mold 14 upward by the ejector 36. During this demolding, the sealing rubbers 62 and 64 formed in the rubber reservoir recesses 54 and 56 have a cross-sectional shape in which the rubber reservoir recesses 54 and 56 are narrowed on the opening side. It is cut without being molded and left in the rubber reservoir recesses 54 and 56. At the time of mold removal, the rubber solidified by the sprue 20 and the runners 22 and 26 can be taken out by contacting and separating the upper mold 12 from the runner block 18.

(3) With the sealing rubbers 62 and 64 left as described above, the inner cylinder 2 and the outer cylinder 3 are set in the mold 10 as shown in FIG. R is injected to form the vibration isolating bush 1 for the second and subsequent times.

  In the second and subsequent moldings, the sealing rubbers 62 and 64 abut against the outer peripheral surface of the end of the inner cylinder 2 and the end surface 3 a of the outer cylinder 3 along the edge of the cavity 16. The outflow of the material R is prevented, and there is no rubber burr. Strictly speaking, the sealing rubbers 62 and 64 may not be in contact with the outer peripheral surface of the inner cylinder 2 or the end surface 3a of the outer cylinder 3, and a rubber material R is secured by ensuring a gap of about several μm. It is also possible to vent the gas from this part while preventing the outflow. Further, in the second and subsequent moldings, most of the gas in the cavity 16 is exhausted from the atmosphere opening vent 28, and moldability can be ensured.

  The sealing rubbers 62 and 64 molded in this way deteriorate due to repeated use. In this case, the molding die 10 is disassembled and the sealing rubbers 62 and 64 are removed by cleaning. Then, the sealing rubbers 62 and 64 may be molded again as described above.

  In the present embodiment configured as described above, the rubber material R for forming the rubber elastic body 4 of the vibration isolating bush 1 is also used as the sealing rubbers 62 and 64 as it is, so that rubber burrs can be prevented at low cost. it can.

  In addition, for various types of vibration isolators, if the above-described rubber reservoir recesses 54 and 56 are provided in the mold 10, the sealing rubber 62 corresponding to the mold 10 is formed at the time of the first molding. 64 are formed, it is not necessary to prepare seal materials of various shapes separately, and it is suitable for high-mix low-volume production.

  Further, since the sealing rubbers 62 and 64 made of the rubber material R prevent rubber burrs, it is not necessary to ensure sealing performance by tightly fitting the metal between the mold and the inner and outer cylinders. In addition, it is possible to avoid the problem of demolding of the vibration isolating bush and the wear of the mold.

  In the above-described embodiment, the mold and the manufacturing method of the vibration isolating bush have been described. However, the present invention is not limited to this, and can be similarly applied to other vibration isolating apparatuses. The present invention can be similarly applied to various metal-rubber composite products composed of a metal part and a rubber elastic body formed integrally on the surface of the metal part.

FIG. 1 is a longitudinal sectional view of a mold according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view of a part of the mold.
FIG. 3 is an enlarged cross-sectional view showing an inner cylinder end portion in the same mold.
FIG. 4 is an enlarged cross-sectional view showing an outer cylinder end portion in the same mold.
FIG. 5 is a cross-sectional view showing a state after injection of a rubber material of the same mold.
FIG. 6 is a cross-sectional view showing a state when the mold is removed.
FIG. 7 is a cross-sectional view of the molding die after molding a rubber for sealing.
FIG. 8 is a cross-sectional view of a vibration isolating bush.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Anti-vibration bush, 2 ... Inner cylinder, 3 ... Outer cylinder, 3a ... End surface of an outer cylinder, 4 ... Rubber elastic body, 10 ... Mold, 16 ... Cavity, 28 ... Air release vent, 54, 56 ... Rubber reservoir Recess, 58, 60 ... minute gap, 62, 64 ... rubber for sealing

The present invention, metal parts and metal rubber elastic body and is formed integrally - relates to the method of manufacturing a rubber composite article, and in particular relates to a preferred production method for the manufacture of anti-vibration device.

The present invention has been made in view of the above, and manufacture of a metal-rubber composite product capable of preventing rubber burrs at low cost while avoiding the problem of product demolding failure and mold wear. It aims to provide a method.

Oite to the present invention, as the mold, the metal formed by molding integrally the rubber elastic body on the surface of metal parts - a mold for molding a rubber composite articles, molding the rubber elastic body And a rubber reservoir recess is provided along an edge of the surface of the metal part facing the cavity. The rubber reservoir recess is provided in a mold part facing the surface of the metal part and is minute. A rubber that communicates with the cavity through a gap and is filled with a rubber material through the minute gap to form a rubber for sealing that prevents the rubber material from flowing out of the cavity can be used. The

Claims (9)

Metal-rubber in which a metal part is set in a mold, a rubber material is injected into a cavity formed between the metal part and the mold, and a rubber elastic body is integrally formed on the surface of the metal part A method of manufacturing a composite product,
Using a molding die provided with a rubber reservoir recess along the edge of the metal part surface facing the cavity,
By setting a metal part in the mold and injecting a rubber material into the cavity, the rubber material is filled into the cavity to integrally form the metal part and a rubber elastic body, and the rubber reservoir Filling the recess with the rubber material to form a sealing rubber,
The molded part of the metal part and the rubber elastic body molded as described above is removed from the molding die, and the sealing rubber molded in the rubber reservoir recess is left in the rubber reservoir recess,
A metal part is set in the mold with the sealing rubber remaining, and a rubber material is injected into the cavity to integrally form the metal part and the rubber elastic body. -Manufacturing method of rubber composite products. The sealing rubber abuts against the surface of the metal part along the edge of the metal part surface facing the cavity, thereby preventing the rubber material from flowing out of the cavity. The method for producing a metal-rubber composite product according to claim 1. The method for producing a metal-rubber composite product according to claim 1, wherein the rubber reservoir recess communicates with the cavity through a minute gap. 2. The method for producing a metal-rubber composite product according to claim 1, wherein the rubber reservoir recess is formed in a cross-sectional shape with a narrow opening side. 2. The method for producing a metal-rubber composite product according to claim 1, wherein the molding die is provided with an open air vent that opens to the cavity. The metal-rubber composite product is a vibration isolator comprising an inner cylinder that is a metal part, an outer cylinder that surrounds the inner cylinder, and a rubber elastic body interposed between the inner cylinder and the outer cylinder. The method for producing a metal-rubber composite product according to claim 1. The rubber reservoir recess is provided in a mold part facing the outer peripheral surface of the end portion of the inner cylinder, and the cavity and the rubber reservoir are provided between the outer peripheral surface of the inner cylinder end part and the mold part facing the outer peripheral surface. 7. The method for producing a metal-rubber composite product according to claim 6, wherein a minute gap is formed to communicate with the recess. The rubber reservoir recess is provided in a mold portion facing the axial end surface of the outer cylinder, and a part of the opening surface of the rubber reservoir recess is covered with the outer cylinder end surface to form the cavity and the rubber reservoir recess. 7. The method for producing a metal-rubber composite product according to claim 6, wherein a minute gap to be communicated is formed. A molding die for molding a metal-rubber composite product formed by integrally molding a rubber elastic body on the surface of a metal part,
A cavity for molding the rubber elastic body;
A rubber reservoir recess is provided along the edge of the metal part surface facing the cavity,
The rubber reservoir recess is provided in a mold part facing the surface of the metal part and communicates with the cavity through a minute gap, and the cavity is filled with a rubber material through the minute gap. A molding die for a metal-rubber composite product for molding a sealing rubber for preventing the rubber material from flowing out of the rubber.

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