JPH0528020Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a molding device for a vibration-proof rubber bushing, and more specifically to a technical means for preventing the occurrence of rubber burrs on the end face of an inner cylindrical metal fitting.

(Problems to be solved by conventional techniques and inventions) One type of vibration-proof rubber is a rubber bushing, which has an inner cylindrical metal fitting and a rubber elastic body fixed to the surrounding state, and has a cylindrical shape as a whole. Generally, this molding device for vibration-proof rubber bushings has a pin set upright on the lower mold to fit the inner cylindrical metal fitting of the vibration-proof rubber bushing, and the lower mold and the upper mold are connected directly or by using an intermediate mold. After the molds are sandwiched and matched, a rubber material is injected into the cylindrical cavity of the mold and vulcanized.

However, in conventional molding apparatuses, when the molds are clamped, it is inevitable that some gaps will be created between the upper and lower end surfaces of the inner cylinder fitting and the mold. If such a gap is created, when a rubber material is injected into the cavity of the mold, the rubber material wraps around the gap and remains as a rubber burr on the end face of the inner cylinder fitting. For this reason, conventionally, after the anti-vibration rubber bushing has been molded and vulcanized, the end face of the inner cylindrical metal fitting is buffed to remove the rubber burrs attached to the end face of the inner cylindrical metal fitting.

However, if such finishing work is performed, the total number of steps for manufacturing the anti-vibration rubber bushing will increase.
As a result, production efficiency decreases.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and the gist thereof is to provide an outside of the inner cylindrical fitting with a diameter larger than that of the pins on the lower side of the pins. An inner cylinder support part with the same diameter as the diameter is provided, and the support part is fitted into the fitting hole of the lower mold so as to be slidable in the axial direction without any gaps, and the support part is attached to the side of the upper mold by a spring member. When the mold is clamped, the inner cylinder pressing surface on the upper mold side is brought into contact with the upper end surface of the inner cylinder, and the inner cylinder is pushed into the lower mold side against the urging force of the spring member. The rubber material is injected into the molded cavity in a state where the presser surface and the upper surface of the support part are pressed against the upper and lower end surfaces of the inner cylinder to form a closed state. be.

(Operation and effect of the invention) In the device of the present invention, when the mold is clamped, the presser surface on the upper mold side comes into contact with the upper end surface of the inner cylinder metal fitting, and the inner cylinder metal fitting, together with the pin and the inner cylinder support part, is moved to the lower mold side. Push it in. In other words, the presser surface and the upper surface of the inner cylinder support part on the lower mold side are
The inner cylindrical metal fitting is in a state in which it is strongly pressed against the upper and lower end surfaces by the force of the spring member (in a closed state). Therefore, when rubber material is injected into the molding cavity, the rubber material will not enter between the end face of the inner cylinder fitting and the mold (because the gap is zero).
This prevents rubber burrs from adhering to the end face of the inner cylindrical metal fitting, and there is no need for finishing work to remove burrs from the end face of the inner cylindrical metal fitting after vulcanization.

This reduces the number of manufacturing steps for the anti-vibration rubber bushing and improves mass productivity.

The device of the present invention uses a spring member to reduce the gap between the end face of the inner cylindrical fitting and the mold to zero. Therefore, even if there is variation in the dimensions of the inner cylindrical fitting, the variation is due to the elastic deformation of the spring. This ensures that the gap between the end face of the inner cylinder fitting and the mold is zero. In other words, in the past, due to variations in the dimensions of the inner cylinder metal fitting, or in relation to the dimensional tolerances of the outer cylinder metal fitting when it has an outer cylinder metal fitting, it has not been practical to make the gap between the end face of the inner cylinder metal fitting and the mold zero. However, in the present invention, this problem has been solved and it has become possible to reliably prevent rubber burrs from adhering to the end face of the inner cylinder fitting.

(Example) Next, an example of the present invention will be described in detail based on the drawings.

In FIG. 2, 10 is a vibration-isolating rubber bushing having a cylindrical shape as a whole, and includes an inner cylindrical metal fitting 12,
It is composed of an outer cylindrical metal fitting 14 and a rubber elastic body 16. The rubber elastic body 16 is formed with holes 18 for making the spring characteristics in the radial direction different in two axial directions perpendicular to each other.

As shown in FIG. 2, when this anti-vibration rubber bushing 10 was molded using a conventional molding device, it was inevitable that rubber burrs would form on the end surface 20 of the inner cylindrical metal fitting 12.

FIG. 1 shows a schematic configuration of a molding apparatus of this example for preventing the occurrence of rubber burrs. As shown in the figure, this molding apparatus has an upper mold 22, a middle mold 24, and a lower mold 26, and a molding cavity 28 is formed when these molds are closed.

The upper mold 22 is provided with a separation mold 30 for molding the hole 18, and the lower mold 26 is provided with a corresponding separation mold 32, which are brought together at a mating surface 34. It's becoming like that. Note that the separation mold 30 on the upper mold 22 side is formed with a pressing surface 36 for pressing the upper end surface of the inner cylindrical metal fitting 12.

The lower mold 26 is divided into upper and lower halves by divided bodies 38 and 40, each having a small diameter recess 42 and a large diameter recess 44 formed therein. And these recesses 4
2 and 44 accommodate approximately the lower half of a pressing body 46 for pressing the inner cylinder fitting 12. This pressing body 46 has a large diameter shaft portion 48 at the base end and a flange 50.
and an intermediate shaft portion 52. A disc spring 54 is fitted into the base end shaft portion 48, and its biasing force is exerted on the pressing body 46 via the flange 50. In addition, the flange 50 is moved into the recess 4 by the biasing force of the disc spring 54 in the normal state, that is, in the mold opening state.
4, and is slightly spaced apart from the top surface 56 when the mold is closed.

The pressing body 46 has a pin 58 on its upper portion into which the inner cylindrical metal fitting 12 is inserted, and a support portion 60 for supporting the inner cylindrical metal fitting 12 is formed below the pin 58 . The upper end portion of the pin 58 and the support portion 60 are fitted into fitting holes 62 and 64 formed in the upper mold side separation mold 30 and the lower mold side separation mold 32, respectively, without any gap and slidably in the axial direction. are combined. still,
The outer diameter of the support portion 60 is the same as the outer diameter of the inner cylinder fitting 12.

Next, the operation of this device will be explained.

With the upper mold 22 separated above the middle mold 24, the outer cylindrical metal fitting 14 and the inner cylindrical metal fitting 12 are first set at corresponding positions in the molding cavity 28. That is, the outer cylindrical metal fitting 14 is set so as to fit on the inner peripheral surface of the cavity 28, and the inner cylindrical metal fitting 12 is fitted onto the pin 58 and set. Note that in the open state where the upper mold 22 is separated from the middle mold 24, the upper end of the outer cylindrical metal fitting 14 protrudes slightly above the upper surface of the middle mold 24, and the pressing body 46 The flange 50 is brought into contact with the upper surface of the recess 44 due to the biasing force.

When the upper mold 22 and the lower mold 26 are closed together with the middle mold 24 in between in this state, the holding surface 36 of the separation mold 30 on the upper mold 22 side is first pressed against the inner cylindrical metal fitting held by the pin 58. 12, and as the mold is closed, the inner cylindrical metal fitting 12 is slightly pushed into the lower mold 26 side together with the pin 58 (that is, the pressing body 46). That is, the entire pressing body 46 is pushed down against the biasing force of the disk spring 54 while the upper and lower end surfaces of the inner cylinder fitting 12 are sandwiched between the pressing surface 36 and the upper surface of the support portion 60. At this time, the flange 50 of the pressing body 46 is slightly separated from the upper surface 56 of the recess 44, resulting in the state shown in FIG.

Incidentally, when the mold is closed, the outer cylindrical metal fitting 14, which is slightly protruding upward from the upper surface of the middle mold 24, also
It is sandwiched between the upper mold 22 and the lower mold 26 and pressurized in the axial direction, thereby deforming it into a curved state as shown in FIG.

In this way, the upper mold 22, the middle mold 24, the lower mold 26
With the mold closed, a rubber material is then injected into the molding cavity 28, but at this time the separated mold 30
and 32 are in a state of engagement with the upper and lower end surfaces of the inner cylindrical metal fitting 12, and no gap is created between them, so that the rubber material injected into the cavity 28 is injected into the separated molds 30 and 32. and the upper and lower end surfaces of the inner cylindrical fitting 12. Therefore, after vulcanization molding, the inner cylinder fitting 12
No rubber burrs remain on the end surface of the inner cylindrical metal fitting 12, and therefore there is no need to perform a finishing operation to remove burrs from the end surface of the inner cylinder metal fitting 12. Incidentally, when the molding apparatus of this example was used, the deburring work that was previously required was completely unnecessary, and production capacity was improved by 30 to 40%.

Although the embodiments of the present invention have been described in detail above, the present invention can also be configured in other forms.

For example, the present invention can be applied to a vibration-proof rubber bushing in which the axial cross-sectional shape of the hole in the rubber elastic body is different from the above example, and in some cases, it can be applied to a vibration-proof rubber bushing that does not have such a hole. It is also applicable.

Further, in the above example, the disc spring is embedded in the recess of the lower mold, but it is also possible to arrange the disc spring in other forms, and furthermore, such a disc spring is the most suitable as a spring member. However, it is possible to use other spring members, and the present invention can be constructed with various modifications based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a schematic configuration of a molding device that is an embodiment of the present invention, and FIGS. 2 and 3 are a perspective view and a cross-sectional view of a vibration-proof rubber bushing to which the molding device is applied. be. 10... Anti-vibration rubber bushing, 12... Inner cylindrical metal fitting, 14... Outer cylindrical fitting, 16... Rubber elastic body, 2
2... Upper mold, 24... Middle mold, 26... Lower mold, 28
... Molding cavity, 30, 32 ... Separate mold, 3
6... Pressing surface, 54... Belleville spring, 60... Inner cylinder support portion, 62, 64... Fitting hole.

Claims (1)

[Scope of Claim for Utility Model Registration] A pin is set upright on the lower mold to fit the inner cylindrical metal fitting of the anti-vibration rubber bushing, and the lower mold and the upper mold are matched directly or with an intermediate mold in between. In a device for forming a vibration-proof rubber bushing by injecting a rubber material into a cylindrical cavity of a mold, a groove having a diameter larger than that of the pin and the same diameter as the outer diameter of the metal fitting of the inner cylinder is provided on the underside of the pin. An inner cylinder support part is provided, and the support part is fitted into the fitting hole of the lower mold so as to be slidable in the axial direction without a gap, and the support part is biased toward the upper mold side by a spring member. When clamping the mold, the inner cylinder holding surface on the upper mold side is brought into contact with the upper end surface of the inner cylinder to push the inner cylinder into the lower mold side against the biasing force of the spring member, and the inner cylinder is pushed into the lower mold side against the urging force of the spring member. The rubber material is injected into the molded cavity in a state in which the presser surface and the upper surface of the support part are pressed against the upper and lower end surfaces of the inner cylinder to form a closed state. A molding device for swinging rubber bushings.