JPH085093B2 - Manufacturing method of inner link assembly having resin sleeve on bush peripheral surface of bushed chain - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a method for manufacturing a highly accurate wear resistant bushed chain (including a roller bushed chain) .

[0002]

2. Description of the Related Art A highly wear-resistant chain with little elongation and no play is made up of an inner link assembly in which engineering plastic resin sleeves are fitted around the bushes whose both ends are compressed into the connecting pin insertion holes of the inner link. Although it has a three-dimensional shape, as a conventional method of fitting the engineering plastic resin sleeve to the bush peripheral surface of the inner link assembly, first, after fitting the engineering plastic resin sleeve to the bush peripheral surface, A method of press-fitting both ends into the connecting pin insertion holes of the inner link, or, as shown in FIG. 4, first, the connecting pin insertion holes 1 ′, 1 ′ of the pair of inner links 1, 1 are first.
After both ends of the cylindrical bushes 2, 2 are press-fitted as shown in the steps (A) to (B), the cylindrical engineering plastic resin sleeves 3 are molded in the step (B).
The method of inserting into the cylindrical bushes 2, 2 as shown in FIG.

[0003]

In any of the above-mentioned conventional methods for manufacturing the inner link assembly, the resin sleeve formed on the bush is press-fitted. Therefore, when the press-fitting is performed, the resin sleeve is excessively large. A compressive stress is generated, which causes the sleeve to break, and when the both ends of the bush are press-fitted into the connecting pin insertion holes of the inner link, an axial compressive force acts on the bush. As shown in (B), it is transformed into a barrel shape, and the resin sleeve fitted on the peripheral surface of the bush is also transformed into a barrel shape or a drum shape, so that
It has the drawback of significantly reducing the wear life of the sleeve.

[0004]

Therefore, according to the present invention, after both ends of the bush are press-fitted into the connecting pin insertion holes of the inner link,
Heated molten resin is injected and injected into the cylindrical void formed on the peripheral surface of the bush, cooled, and then demolded to form a cylindrical inner peripheral surface or outer peripheral surface on the resin sleeve that does not follow the deformation of the peripheral surface of the bush. It is a method of manufacturing an inner link assembly.

[0005]

[Function] Since the molding die surface of the resin injection space formed between the bush peripheral surface and the molding die has a cylindrical shape, the sleeve surface which is in contact with the molding die surface even if the bush peripheral surface is deformed into a barrel shape Will be molded into a cylindrical shape.

[0006]

The manufacturing method of the first embodiment of the inner link assembly is as follows.
As shown in FIG. 1, a resin sleeve 4 having a cylindrical inner peripheral surface is integrally formed on the inner peripheral surface of the cylindrical bush 2 by the steps from (A) to (D). )
In the step shown in FIG. 6 and the step shown in (B), both ends of the cylindrical bush 2 are press-fitted into the connecting pin insertion hole 1'of the inner link 1 as in the conventional example described above. In the step shown in FIG. 3, the inner link assembly having the bush fitted therein is loaded into the injection molding die, and the outer diameter of the core M ′ having a circular cross section, which is erected on the lower die M1, is made smaller than the inner diameter of the bush 2. Bush 2
A cylindrical clearance is held and inserted into the inside, and a heated molten resin is injected into the clearance by a known injection molding means to form a resin sleeve 4 having a circular inner peripheral surface on the inner circumference of the bush 2. Molded,
After cooling, the mold is demolded to manufacture an inner link assembly of a bushed chain having a resin sleeve 4 having an inner circular shape integrally formed on the inner peripheral surface of the bush 2 shown in FIG.

In the method of the second embodiment shown in FIG. 2, a resin sleeve 5 is integrally molded on the outer peripheral surface of a cylindrical bush 2, and steps (A) and (B) are the same as those of the first embodiment. Similarly, in the step (C), the lower die M1 and the upper die M of the molding die that surround the bush 2 by holding a small amount of circular voids on the outer peripheral surface thereof.
2, the molds are clamped together, and the heated molten resin is injected and injected into the circular void by a known means from the resin injection port of the upper mold M2,
This is a method of manufacturing an inner link assembly in which the resin sleeve 5 is integrally molded on the outer peripheral surface of the bush 2 after cooling and demolding as shown in step (D).

FIG. 3 shows the method of the third embodiment, in which the bush 2
A method for manufacturing an inner link in the case of a bushed chain with a roller in which a roller is rotatably supported, wherein a resin sleeve formed by injection molding is integrally formed on the outer peripheral surface of the bush.

First, as shown in (A), a cylindrical roller R
Is immersed in an electroless nickel bath B1 to form a thick plating layer N on the entire surface of the cylindrical roller, and then the cylindrical roller R of the thick plating layer is fitted onto the cylindrical bush 2 as shown in FIG. Then, both ends of the bush 2 are press-fitted into the connecting pin insertion holes 1'of the inner link 1, and both end surfaces of the cylindrical roller R are pressed against the inner side surface of the inner link 1 without a gap as shown in (C). At the same time, a cylindrical gap δ is formed between the inner peripheral surface of the cylindrical roller R and the outer peripheral surface of the bush 2, and an injection port P for pressurizing the resin into the gap δ is provided through one inner link. Then
Next, as shown in (D), the inner link assembly assembled in (C) is loaded into the molding die M, and the heated molten resin is injected from the injection port P into the cylindrical space δ by a known injection molding means. Inject and fill.

At this time, since both end surfaces of the cylindrical roller R are in pressure contact with the inner side surface of the inner link, there is no possibility that the molten resin injected into the cylindrical space δ leaks out of the space δ.

After cooling, the inner link assembly is removed from the mold, and the inner link assembly is immersed in an electrolytic bath B2 of a nitric acid solution shown in (E) to energize it, and a thick plating layer formed on the entire surface of the cylindrical roller R. Are dissolved and removed.

Therefore, it is taken out from the electrolytic bath B2,
In the inner link assembly that has been washed with water, as shown in (F), gaps caused by removal of the thick plating layer are present between the end surfaces of the roller R and the inner surface of the inner link, and between the inner peripheral surface of the roller R and the bush 2. It is possible to obtain a structure in which the roller is rotatably supported by the sleeve 6, which is formed between the outer surface and the outer surface of the resin sleeve 6 integrally formed on the outer surface.

[0013]

Industrial Applicability According to the present invention, the bush is press-fitted into the connecting pin insertion hole of the inner link to form an inner link assembly, and then a molten resin is injection-molded into the bush to integrally mold the resin. Since it is a sleeve, even if the bush body is deformed into a barrel shape, the surface of the resin sleeve formed by injection molding can be molded into a cylindrical surface, so there is no uneven wear and the wear life of the sleeve And the sleeve is formed by injection molding of molten resin, and since the sleeve is not inserted and press-fitted into the bush, compression internal stress does not occur in the sleeve. Therefore, one of the causes of the destruction of the sleeve could be eliminated, and the durability could be greatly increased.

Further, since the sleeve is formed by injection molding, rigidity at the time of fitting and press-fitting is unnecessary, so that it is possible to obtain a thin sleeve.

[Brief description of drawings]

FIG. 1 is a process explanatory view showing a first embodiment of the method of the present invention, in which (A) to (D) show the order of processes.

FIG. 2 is a process explanatory view showing a second embodiment of the method of the present invention, wherein (A) to (D) show the order of processes.

FIG. 3 is a process explanatory view of the third embodiment of the method of the present invention, in which (A) to (F) represent the order of processes.

FIG. 4 is a process explanatory view of a conventional method, in which (A) to
(C) represents the order of steps.

[Explanation of symbols]

 1 Inner link 1'Connecting pin insertion hole 2 Bushing 3, 4, 5, 6 Resin sleeve M1, M2 Molding mold B1, B2 Immersion bath

Claims (2)

[Claims] 1. After press-fitting both ends of a cylindrical bush into a connecting pin insertion hole of an inner link, the bush is loaded into a molding die that holds a small inner cylindrical void with respect to the peripheral surface of the bush. Next, a method for producing an inner link assembly of a bushed chain, comprising injecting heated molten resin into the cylindrical void, injecting the molten resin into the hollow, and releasing the die to integrally form a resin sleeve having a cylindrical surface on the peripheral surface of the bush. 2. Both ends of a cylindrical bush loosely inserted in a cylindrical roller having an electroless thick plating layer formed on the entire surface are press-fitted into inner link connecting pin insertion holes so that both end surfaces of the cylindrical roller are inner side surfaces of the inner link. Then, the molten resin is injected into the cylindrical clearance space of the roller and bush through the resin injection port penetrating the inner link, and after cooling, the electroless thick plating layer on the entire surface of the roller is electrolytically removed. A gap is formed by removing the thick plating layer between the both end surfaces of the roller and the inner surface of the inner link and between the inner peripheral surface of the roller and the outer peripheral surface of the injection press-fit resin integrally formed on the outer peripheral surface of the bush. Bushed chain inner link assembly manufacturing method.