JPH0414613B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a shock absorber for a torsional damper that is attached to a rotating shaft such as a crankshaft of an internal combustion engine and absorbs torsional vibrations of the rotating shaft, and a method for forming the same. Regarding types.

(Prior Art) Conventionally, a buffer body bonded between a damper hub and a damper mass of the torsional damper is manufactured as follows. That is, as shown in FIG. 4, the first fixed mold 3 is assembled into a predetermined shape.
1. Inside the second fixed mold 32 and the movable mold 33, a damper hub 34 and an annular damper mass 35 are arranged coaxially so as to face each other, and these damper hubs 34
A rubber material 39 is injected into the cavity 36 formed between the damper mass 35 and the damper mass 35 by applying pressure to the plunger 38 inserted into the chamber 37 of the movable mold 33, and the rubber material 39 is heated and cured. In order to press fit the rubber material 39 into the cavity 36, the movable mold 33 is equipped with a runner 4 that communicates with the material supply chamber 37.
0 and the cavity 36 connected to the runner 40.
A gate 41 opening inward is bored.

As shown in FIG. 5, the gate 41 may be formed into a narrow cylindrical shape continuous with the runner 40, or as shown in FIG.
There is one in which the tip of the gate 41 is tapered and expanded in diameter.

After molding is completed, when the movable mold 33 and the first fixed mold 31 and second fixed mold 32 are opened, the rubber material 39 that has hardened within the chamber 37, runner 40, and gate 41 is removed from the runt 40 and the gate 41. break at the boundary. The rubber material 39 hardened within the gate 41 is further cut to a predetermined length and remains as a protrusion at the end of the molded buffer.

(Problems to be Solved by the Invention) However, in the case of such a conventional example, as shown in FIG. 5 or FIG.
Although the gate 41 and the cavity 36 are smoothly continuous without any steps, there is a corner between the gate 41 and the cavity 36. Therefore, when the movable mold 33, the first fixed mold 31, and the second fixed mold 32 are opened after molding is completed, the rubber material 39 that has hardened within the chamber 37, the runner 40, and the gate 41 is removed between the runner 40 and the gate 41. gate 41 and cavity 3 without being broken at the boundary.
It is easy to break at the boundary with 6. Therefore, if the cured rubber material 39 is broken at the boundary between the gate 41 and the cavity 36, a recessed hole will be formed at the end of the molded buffer body. This torsional damper in which a recessed hole is formed in the buffer body has a problem in that during use, cracks occur from the recessed hole, the function of the buffer body is quickly impaired, and durability is reduced. In addition, in order to avoid this, great care must be taken when releasing the molded product, resulting in a problem of poor workability.

The present invention has been made in order to solve the problems of the prior art, and its purpose is to prevent the edges of the buffer from being removed during mold release when molding a buffer for a torsional damper. A method for manufacturing a buffer body for a torsional damper, which can reliably prevent the formation of recessed holes in the torsional damper, improve the quality of the torsional damper, and facilitate manufacturing and improve workability. Our objective is to provide molds for this purpose.

(Means for Solving the Problems) Therefore, in order to achieve the above object, the present invention provides a manufacturing method according to the first invention, in which the fixed mold and the movable mold are closed, and then, In a method for manufacturing a shock absorber for a torsional damper by injecting an elastic material into a cavity of a fixed mold through a supply path of a movable mold, then curing the elastic material by heating, and then separating the fixed mold and the movable mold. , the supply channel and the cavity are continuously filled with the hardened buffer, and the part of the supply channel that enters the cavity is a constriction port with a small cross-sectional area and a release port with a large cross-sectional area. It is configured to cut near the boundary. Further, the mold according to the second invention is a mold consisting of a fixed mold having a cavity and a movable mold having a supply path for injecting an elastic material into the cavity of the fixed mold. , the part of the movable supply path that enters the fixed cavity is divided into a narrow cross-sectional area considerably smaller than the non-entering part and located on the side opposite to the cavity, and a large cross-sectional area close to the cavity side. It is configured to be divided into a release port and a release port.

(Example) The present invention will be explained below based on the illustrated example. FIG. 1 shows a mold 1 used in the manufacturing method of the present invention. , a second fixed mold 5 and a movable mold 6. As shown in FIG. 3, the torsional damper 2 is constructed by bonding the annular buffer body 3 between a damper hub 7 and an annular damper mass 8, which are coaxially arranged to face each other. A mounting hole 9 is provided at the center of the damper hub 7 for fixing a crankshaft or the like to a rotating shaft (not shown).

The first fixing mold 4 is provided with a projection 10 that fits into the mounting hole 9 of the damper hub 7 and fixes the damper hub 7 therein. A second fixed mold 5 joined to the first fixed mold 4 is formed into an annular shape and has an inner diameter equal to the outer diameter of the damper hub 7, and a damper mass is provided on the inner periphery of the upper end of the second fixed mold 5. An annular stepped portion 11 is provided for fitting and fixing 8.
Furthermore, the movable mold 6 forms an annular cavity 12 between the damper hub 7 and the damper mass 8 when fitted to the second fixed mold 5, and the movable mold 6 is coated with rubber or the like. A chamber 13 is provided for supplying elastic material, into which a plunger 14 is fitted.

The movable mold 6 is provided with a supply path for injecting the elastic material 15 supplied into the chamber 13 into the cavity 12, and the portion of the supply path that enters the cavity 12 is non-contact. Approach part 1
The aperture opening 17 has a small cross-sectional area, which is considerably smaller than the cross-sectional area of the opening 6, and is located on the side opposite to the cavity, and the release opening 18 has a large cross-sectional area, which is closer to the cavity side. The non-entering portion 16 of the supply path is composed of a runner formed in a tapered tubular shape, and the throttle opening 17 located between the non-entering portion 16 and the release port 18 is an extremely short tubular passage with a small diameter. It is made up of The release port 18 following the throttle port 17 has a cross-sectional area larger than the cross-sectional area of the throttle port 17, and is formed of a tapered tubular gate with a slightly enlarged diameter at the tip end.

In the above configuration, the torsional damper buffer body is molded using the mold according to the present invention as follows. That is, as shown in FIG. 1, a damper hub 7 and a damper mass 8 are arranged in the mold 1, and a cavity 12 is formed between the damper hub 7 and the damper mass 8. Next, the elastic material 15 mixed with sulfuric acid is supplied into the chamber 13 of the movable mold 6, and the plunger 14 is inserted into the chamber 13.
The elastic material 15 is pressurized into the movable mold 6 through the supply channels 16, 17, and 18 of the movable mold 6. By heating the mold 1, the elastic material 15 in the cavity 12 is hardened, forming the buffer body 3 and adhering between the damper hub 7 and the damper mass 8. At that time, an adhesive is applied in advance to the bonding surfaces of the damper hub 7 and the damper mass 8, if necessary.

After the molding is completed as described above, the movable mold 6 and the first
The fixed mold 4 and the second fixed mold 5 are released to release the molded product. At this time, the elastic material 15 that has hardened in the supply channel passes through the aperture 17 with a small cross-sectional area and the release port 18 with a large cross-sectional area. Stress is concentrated near the boundary 19 between the two parts and the part is cut. If the aperture opening 17 is cut in the middle, the aperture opening 17 and the release opening 18 will be removed after the mold is released.
Cut by appropriate means at the boundary. Therefore, in the end, the elastic material 15 hardened within the release port 18 remains at the injection end of the molded cushioning body 3 of the torsional damper 2 as a residual protrusion 20, and when the mold is released, the elastic material 15 hardened in the release port 18 remains in the form of a residual protrusion 20. 15, a recessed hole is formed in the remaining protrusion 20, so that no recessed hole is formed in the buffer body 3 itself.

(Effect of the invention) The present invention consists of the above configuration and operation,
In the method for manufacturing a torsional damper buffer according to the first aspect of the present invention, the supply path and the cavity are continuously filled with a hardened buffer,
Since the supply channel is cut at the part where it enters the cavity and near the boundary between the aperture port with a small cross-sectional area and the release port with a large cross-sectional area, the inside of the supply channel is cut when the mold is released after molding is completed. The elastic material cured with
The cut is made at least near the boundary, and no recessed hole is formed in the buffer by cutting on the side of the molded buffer. Therefore, it is possible to reliably prevent the formation of recessed holes in the buffer body, improving the quality of the torsional damper, and there is no need to take special precautions when demolding, making the work easier. It has various advantages such as improved productivity. Moreover, in the case of a mold for a cushioning body for a torsional damper according to the second aspect of the present invention, a mold used in the above manufacturing method can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a molding die for a torsional damper buffer according to the present invention, FIG. 2 is an enlarged sectional view showing main parts, and FIG. 3 is a sectional view showing a torsional damper. Fig. 4 is a sectional view showing a conventional mold, Fig. 5 is an enlarged sectional view showing the main parts of the same mold, and Fig. 6 is an enlarged sectional view showing another embodiment of the main part of the same mold. be. Explanation of symbols, 1... Molding mold, 4, 5... Fixed mold, 6... Movable mold, 12... Cavity, 16...
...Non-entering portion (supply path), 17... Throttle port (supply path), 18... Release port (supply path), 19... Boundary.

Claims (1)

[Claims] 1. After the fixed mold and the movable mold are closed, an elastic material is injected into the cavity of the fixed mold through the supply path of the movable mold, and after the elastic material is heated and hardened, the fixed mold is closed. In a method for manufacturing a torsional damper buffer by releasing a mold and a movable mold, the supply path and the cavity are continuously filled with the hardened buffer, and the hardened buffer is introduced into the cavity of the supply path. 1. A method for producing a torsional damper shock absorber, characterized in that cutting is performed near the boundary between an aperture opening with a small cross-sectional area and a release opening with a large cross-sectional area. 2 A mold consisting of a fixed mold having a cavity and a movable mold having a supply path for injecting an elastic material into the cavity of the fixed mold, wherein the cavity of the fixed mold is one of the supply paths of the movable mold. The toshiba is characterized in that the part that enters the inside is divided into a narrowing opening with a small cross-sectional area that is considerably smaller than the cross-sectional area of the non-entering part and located on the cavity side, and an opening opening with a large cross-sectional area that is close to the cavity side. Molding mold for buffer body for lateral damper.