JP2011094697A - Wear-resistant chain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wear-resistant chain capable of restricting outbreaks of peeling under the environment wherein the chain is used, and improved in wear resistance. <P>SOLUTION: In this chain, both ends of a bush are fixed by respectively fitting them in bush holes of a pair of inner plates, and both ends of a connecting pin loosely passing through the bush are fixed by fitting them in pin holes of a pair of outer plates arranged both outside of the pair of inner plates. At least one of a surface of the connecting pin and an inner surface of the bush is formed with irregular surface, and an intermediate layer formed from a metal or a carbide including at least one of Si, Cr, W and Ti is formed on the irregular surface, and a DLC film is formed on the intermediate layer to improve tightness of the film and to solve the described problems. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chain in which a plurality of link plates such as a roller chain, a bush chain, a silent chain, and a general industrial chain, which are mainly used as a timing chain of an automobile, are connected to each other so as to be alternately bent by pins. The present invention relates to a wear-resistant chain whose wear resistance is improved by surface treatment of pins and members that are in sliding contact with the pins.

  Conventionally, the surface of the pin is known as a material with very high hardness, low friction coefficient and good corrosion resistance in order to suppress wear due to sliding between the pin and bushing or the pin and link plate, which causes chain elongation of automobile timing chains. So-called DLC treatment has been attempted (see Patent Document 1, for example).

JP 2006-29462 A

  However, in general, DLC treatment has a film thickness as small as 0.5 to 2 μm, and when the film thickness is increased, peeling occurs in the use environment of the chain, and satisfactory wear resistance cannot be obtained.

  Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to solve the problem of the conventional DLC treatment, and it is difficult to cause peeling even under the use environment of the chain, and the wear resistance is improved. It is to provide a wear resistant chain.

  As a result of intensive research conducted by the inventor to solve the above-mentioned problems, the DLC film formed by the conventional DLC treatment has a large residual compressive stress and a large difference in hardness with the base material is the cause of peeling. Based on this knowledge, the present invention has been completed.

  First, according to the first aspect of the present invention, both ends of the bushing are fitted and fixed in the bushing holes of the pair of inner plates, and both ends of the connecting pin that is loosely penetrated in the bushing are both outer sides of the pair of inner plates. In the chain that is fitted and fixed to the pin holes of the pair of outer plates arranged on the concave and convex surface is formed on at least one of the surface of the connecting pin and the inner surface of the bush. An intermediate layer made of a metal or carbide containing at least one of Cr, W, and Ti is formed, and a DLC film is formed on the intermediate layer, thereby solving the above-mentioned problem.

  The invention according to claim 2 further solves the above problem by forming the uneven surface by blasting in the chain according to claim 1.

  In the invention according to claim 3, the inner link plates having a pair of teeth, a pair of pin holes and a back surface are alternately arranged in the longitudinal direction of the chain and are arranged in the guide row and the non-guide row, respectively. A guide plate having a pair of pin holes is disposed on both outermost sides of the guide row, a connecting pin is inserted into each pin hole of the inner link plate, and both ends of the connecting pin are fitted in the pin holes of the guide plate In the silent chain that is fixed, an uneven surface is formed on at least one of the surface of the connecting pin and the inner peripheral surface of the pin hole of the inner link plate, and on the uneven surface, at least Si, Cr, W, Ti An intermediate layer made of a metal or carbide containing one is formed, and a DLC film is formed on the intermediate layer, thereby solving the above problem.

  The invention according to claim 4 further solves the above problem by forming the uneven surface by blasting in the chain according to claim 3.

  Here, DLC in the present invention means a diamond-like carbon, that is, a carbon film having characteristics similar to diamond known as diamond-like carbon, and is one of new materials for hard thin films.

  According to the first aspect of the present invention, both ends of the bush are respectively fitted and fixed in the bush holes of the pair of inner plates, and both ends of the connecting pin that is loosely passed through the bush are on both outer sides of the pair of inner plates. In the chain that is fitted and fixed to the pin holes of the pair of outer plates, an uneven surface is formed on at least one of the surface of the connecting pin and the inner surface of the bush, and Si, Cr, W are formed on the uneven surface. An intermediate layer made of a metal or carbide containing at least one Ti is formed, and a DLC film is formed on the intermediate layer, whereby the uneven surface exhibits an anchor effect and the presence of the intermediate layer makes the base material As a result of alleviating the hardness difference between the DLC film and the DLC film, the adhesion between the base material and the DLC film is improved, so that the wear resistance of the chain can be improved.

  Further, according to the invention according to claim 2, in the chain according to claim 1, since the uneven surface is formed by blasting, an anchor effect is obtained, so that the adhesion of the coating can be further increased. it can.

  According to the third aspect of the present invention, the inner link plates having a pair of teeth, a pair of pin holes, and a back surface are alternately arranged in the longitudinal direction of the chain and arranged in the guide row and the non-guide row, respectively. In addition, a guide plate having a pair of pin holes is disposed on both outermost sides of the guide row, a connecting pin is inserted into each pin hole of the inner link plate, and both ends of the connecting pin are fitted and fixed to the pin holes of the guide plate. In the silent chain, an uneven surface is formed on at least one of the surface of the connecting pin and the inner peripheral surface of the pin hole of the inner link plate, and includes at least one of Si, Cr, W, Ti on the uneven surface. An intermediate layer made of metal or carbide is formed, and a DLC film is formed on the intermediate layer, so that the uneven surface has an anchor effect and the presence of the intermediate layer. More results hardness difference between the base material and the DLC coating is reduced, because the adhesiveness between the base material and DLC film, improvement of the wear resistance of the chain can be realized.

  In addition, according to the invention of claim 4, in the silent chain according to claim 3, since the uneven surface is formed by blasting, an anchor effect is obtained, so that the adhesion of the coating is further increased. Can do.

1 is a perspective view of a roller chain that is Embodiment 1 of the present invention. FIG. Sectional drawing of the pin surface of the roller chain of Example 1. FIG. The figure which shows the elongation curve by the acceleration test of the roller chain of Example 1. FIG. The perspective view of the silent chain which is Example 2 of this invention.

  In one embodiment of the present invention, both ends of the bush are respectively fitted and fixed in the bush holes of the pair of inner plates, and both ends of the connecting pin loosely penetrated in the bush are disposed on both outer sides of the pair of inner plates. In the chain that is fitted and fixed to the pin holes of the pair of outer plates, an uneven surface is formed on at least one of the surface of the connecting pin and the inner surface of the bush, and Si, Cr, W, Ti are formed on the uneven surface. An intermediate layer made of a metal or carbide containing at least one is formed, and a DLC film is formed on the intermediate layer, so that peeling hardly occurs even in the use environment of the chain, and wear resistance is improved. As long as the wear-resistant chain is provided, any specific embodiment may be used.

  In another embodiment of the present invention, the inner link plates having a pair of teeth, a pair of pin holes, and a back surface are alternately arranged in the longitudinal direction of the chain and arranged in the guide row and the non-guide row, respectively. A guide plate having a pair of pin holes is disposed on both outermost sides of the guide row, a connecting pin is inserted into each pin hole of the inner link plate, and both ends of the connecting pin are fitted and fixed to the pin holes of the guide plate. In the silent chain, an uneven surface is formed on at least one of the surface of the connecting pin and the inner peripheral surface of the pin hole of the inner link plate, and the metal including at least one of Si, Cr, W, Ti on the uneven surface, The intermediate layer made of carbide is formed, and the DLC film is formed on the intermediate layer. As long as they provide a wear resistant chain in which improved, specific embodiments thereof may any be any one.

  That is, the wear-resistant chain of the present invention may be, for example, a bush chain, a roller chain, or a silent chain.

  An example in which the present invention is applied to a roller chain will be described with reference to FIGS. Here, FIG. 1 is a perspective view of the roller chain of the first embodiment, FIG. 2 is a cross-sectional view of the pin surface of the roller chain of the first embodiment, and FIG. 3 is an acceleration of the roller chain of the first embodiment. It is a figure which shows the elongation curve by a test.

  In the roller chain 10 according to the first embodiment, as shown in FIG. 1, both ends of the bush 12 are press-fitted into the bush holes 11 a of the pair of inner plates 11, and both ends of the pin 16 loosely passed through the bush 12 are paired. The inner plate 11 is press-fitted into pin holes 14 a of a pair of outer plates 14 arranged on both outer sides. And the roller 13 is extrapolated to the bush 12 rotatably.

  An uneven surface is formed on at least one of the surface of the pin 16 and the inner surface of the bush 12 by a shot blast method. The roughness of the uneven surface was such that the arithmetic average roughness Ra based on JIS B0601-1994 was 0.03 to 0.10 μm.

  Furthermore, an intermediate layer made of a metal or carbide containing at least one of Si, Cr, W, and Ti is formed on the uneven surface by a CVD method, a PVD method, a sputtering method, or the like. The thickness of the intermediate layer was 1 to 5 μm.

A DLC film was formed on the intermediate layer by the PVD method. The thickness of the DLC film was 1 to 2 μm.
Here, in order to confirm the effect exhibited by the wear-resistant chain of Example 1, an acceleration test was performed using a motoring tester under the following conditions, and the chain elongation (%) was measured. Inventive product 1 is a Cr metal film as an intermediate layer on the concavo-convex surface and a DLC film is formed on the intermediate layer. Inventive product 2 is a Cr carbide film as an intermediate layer on the concavo-convex surface and DLC on the intermediate layer. The film is formed. As a comparative example, the comparative product 1 has no concavo-convex surface, an intermediate layer, and a DLC film, and the comparative product 2 has no concavo-convex surface and an intermediate layer and only the DLC film exists. The result is shown in FIG.

<Test conditions>
B) Chain: Roller chain with a pitch of 8 mm b) Number of sprocket teeth: 23 x 46 c) Chain load: 1.5 kN
D) Rotational speed: 6500 revolutions / minute e) Test time: 200 hours

As can be seen from FIG. 3, it can be seen that the wear resistance of the coating layer of Example 1 is improved twice or more compared to the case where the DLC film is simply applied.
In the above example, Cr is exemplified as the metal contained in the intermediate layer, but similar results were obtained with Si, W, and Ti.

  As described above, according to the roller chain of the present embodiment, it is possible to use a hard DLC film, which has been considered unsuitable as a coating material in terms of adhesion, as a pin coating material. As a result, the wear resistance of the roller chain can be dramatically improved.

  Next, an example in which the present invention is applied to a silent chain will be described with reference to FIG. Here, FIG. 4 is a perspective view of the silent chain of the second embodiment.

  Below, the chain comprised as a silent chain which is Example 2 of this invention is demonstrated based on FIG.

  As shown in FIG. 4, the silent chain 20 includes guide links A and inner link plates 22 having a pair of pin holes 22a, a pair of teeth 22b, and a back surface 22c that are alternately displaced in the longitudinal direction of the silent chain 20. The guide plates 24 having the pin holes 24a are arranged in the non-guide rows B, respectively, are arranged on the outermost sides of the guide rows, and the pins 26 are inserted into the respective pin holes 22a of the inner link plate 22. Both ends are fitted and fixed in pin holes 24 a of the guide plate 24.

  And the unevenness | corrugation similar to Example 1 was formed in the base material of the pin 26, and DLC coating was performed. In order to confirm the effect of the silent chain of Example 2, an acceleration test was performed using a motoring tester under the same conditions as in Example 1, and the chain elongation (%) was measured. Results were obtained.

  As described above, according to the wear-resistant chain of the present invention, the DLC coating, which has been considered to be unsuitable for the chain pin covering material due to the problem of adhesion, although having high hardness is applied to the surface of the base material. And an intermediate layer made of a metal or carbide containing at least one of Si, Cr, W and Ti can be used as a covering material for the chain. This is a remarkable improvement in the wear resistance of the steel.

DESCRIPTION OF SYMBOLS 10 ... Roller chain 11 ... Inner plate 12 ... Bush 13 ... Roller 14 ... Outer plate 14a ... Pin hole 16 ... Pin 20 ... Silent chain 22 ... Inside Link plate 22a ... Pin hole 22b ... Teeth 22c ... Back surface 24 ... Guide plate 24a ... Pin hole 26 ... Pin A ... Guide row B ... Non-guide row

Claims (4)

A pair of outer plate pin holes in which both ends of the bushing are respectively fitted and fixed in the bushing holes of the pair of inner plates, and both ends of the connecting pin loosely penetrated in the bushing are arranged on both outer sides of the pair of inner plates. In the chain fitted and fixed to
An uneven surface is formed on at least one of the surface of the connecting pin and the inner surface of the bush, and an intermediate layer made of a metal or carbide containing at least one of Si, Cr, W, Ti is formed on the uneven surface. A chain, wherein a DLC film is formed on the intermediate layer.   The chain according to claim 1, wherein the uneven surface is formed by blasting. The inner link plates having a pair of teeth, a pair of pin holes and a back surface are alternately arranged in the longitudinal direction of the chain and arranged in the guide row and the non-guide row, respectively, and the guide plate having a pair of pin holes is In the silent chain that is disposed on both outermost sides of the guide row, a connecting pin is inserted into each pin hole of the inner link plate, and both ends of the connecting pin are fitted and fixed to the pin holes of the guide plate,
An uneven surface is formed on at least one of the surface of the connecting pin and the inner peripheral surface of the pin hole of the inner link plate, and the metal or carbide containing at least one of Si, Cr, W, Ti is formed on the uneven surface. The silent chain is characterized in that an intermediate layer is formed, and a DLC film is formed on the intermediate layer.   The silent chain according to claim 3, wherein the uneven surface is formed by blasting.

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