chain

Abstract

To provide a chain that can reduce friction loss, alleviate the developing wear on sliding surfaces of a chain guide member, and reduce vibration and noise of the chain during running.SOLUTION: A chain is made up of a multiplicity of inner link plates 110 and outer link plates 120 alternately coupled together with connecting pins along a longitudinal direction of the chain. The height from a pitch line PL to a highest point on a backside 112 of the plurality of inner link plates 110 (backside height HI of the inner link plates) is different from the height from a pitch line PL to a highest point on a backside 122 of the plurality of outer link plates 120 (backside height HO of the outer link plates) by more than 0 and not greater than 0.5 mm.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to chains such as roller chains and bushing chains used in power transmission mechanisms of automobiles, industrial machines, etc. [Background technology]

[0002] A known conventional power transmission chain is one that consists of a pair of left and right inner link plates, a pair of left and right outer link plates positioned on either side of the pair of left and right inner link plates, and multiple inner link plates connected alternately in the longitudinal direction of the chain with connecting pins.

[0003] In such chains, the outer link plates and inner link plates are each oval in shape, and when the back surface height of these outer link plates and inner link plates is defined as the distance from the pitch line of the chain to the outermost end face of each link plate, the back surface height of the outer link plates and the back surface height of the inner link plates are the same height.When the outer link plates and the inner link plates are at the same back surface height, when they come into sliding contact with the chain guide, the contact area between them is large and frictional resistance is large, resulting in friction loss, which is a problem. In particular, when a roller chain is incorporated into an automobile engine and used as a timing chain, large friction losses can cause problems such as poor fuel economy.

[0004] To solve this problem, a roller chain is known that reduces friction loss by alternately connecting a large number of outer link plates that do not slide against the guide member and elliptical inner link plates with convex edges that abut the sliding guide surfaces of the guide member using connecting pins, thereby reducing the contact area of ​​the entire chain with the chain guide (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-255523 Summary of the Invention [Problem to be solved by the invention]

[0006] With known chains, the contact area of ​​the entire chain with the chain guide is small, allowing lubricating oil to seep in through the gap between the outer link plate and the chain guide, reducing friction loss. However, because only the convex parts of the inner link plates slide against the chain guide member, the increased surface pressure causes greater wear on the sliding surface of the chain guide member. As the wear progresses, deep grooves form in the sliding parts of the inner link plates, which can cause pitching when the chain is running (when the inner link plates enter the sliding surface of the chain guide or run on the sliding surface of the chain guide, the chain falls into the groove, or moves vertically from within the groove to try to go over the side wall), which can result in vibration and noise.

[0007] The present invention solves these problems, and its purpose is to provide a chain that reduces friction loss, slows the progression of wear on the sliding surfaces of the chain guide members, and reduces vibration and noise when the chain is running. [Means for solving the problem]

[0008] The present invention relates to a chain comprising a pair of left and right inner link plates, a pair of left and right outer link plates respectively disposed on both outsides of the pair of left and right inner link plates, and a large number of the inner link plates and outer link plates connected alternately in the chain longitudinal direction with connecting pins, wherein the difference between the height from the pitch line of the highest part of the back surface of the inner link plates relative to the pitch line (the back surface height of the inner link plates) and the height from the pitch line of the highest part of the back surface of the outer link plates relative to the pitch line (the back surface height of the outer link plates) is greater than 0 and 0.5 mm or less. When the sliding surface of the chain guide member is worn to a certain extent, both the back surfaces of the inner link plates and the back surfaces of the outer link plates are in sliding contact with the sliding surface of the chain guide member.This solves the above problem. [Effects of the Invention]

[0010] According to the chain of claim 1, the difference in back height between the multiple inner link plates and the multiple outer link plates is greater than 0, so when the sliding surface of the chain guide member is not worn, only one link plate slides against the chain guide member, thereby reducing the contact area of ​​the entire chain with the chain guide and reducing friction loss. Furthermore, by keeping the difference in back height between the multiple inner link plates and the multiple outer link plates to 0.5 mm or less, when the sliding surface of the chain guide member wears to a certain extent, the other link plate begins to slightly slide against the chain guide member, and by dispersing the surface pressure, it is possible to prevent deep grooves from forming only in the sliding portion of one link plate due to wear on the sliding surface of the chain guide member, thereby preventing pitching and resulting in vibration and noise when the chain is running. According to the configurations of claims 2 to 4, it is possible to further reduce friction loss and reduce vibration and noise when the chain is running. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an explanatory diagram of a chain according to an embodiment of the present invention; [Figure 2] 1 is a side view of an outer link plate and an inner link plate of a chain according to an embodiment of the present invention. FIG. [Figure 3] A schematic diagram of the back height of the outer link plates and inner link plates of a chain. [Figure 4] FIG. 1 is a schematic diagram illustrating the relationship between the chain and the chain guide. DETAILED DESCRIPTION OF THE INVENTION

[0013] A chain according to one embodiment of the present invention will be described below with reference to the drawings. As shown in Figures 1 and 2, the chain 100 comprises a pair of left and right inner link plates 110, bushings 130 whose bushing ends are press-fitted into bushing holes 111 of the inner link plates 110, a pair of left and right outer link plates 120 arranged on either side of the pair of left and right inner link plates 110, and connecting pins 140 that are rotatably inserted into the bushings 130 and whose pin ends are press-fitted into pin holes 121 of the outer link plates 120, and is formed by connecting a large number of inner link plates 110 and outer link plates 120 alternately in the longitudinal direction of the chain with the connecting pins 140.

[0014] In this embodiment, the back surface 112 of the inner link plate 110 is formed in a curved shape that is highest at the center part in the longitudinal direction of the chain, and has a back surface height HI from the pitch line PL of the chain 100 (the line connecting the centers of the connecting pins 140) to the highest part, as shown in Figure 3. In addition, the back surface 122 of the outer link plate 120 is formed in a flat shape with the highest part continuing in a straight line in the longitudinal direction of the chain, and as shown in Figure 3, it has a back surface height HO from the pitch line PL of the chain 100 (the line connecting the centers of the connecting pins 140) to the highest part.

[0015] In this embodiment, the relationship between the back height HI of the inner link plate 110 and the back height HO of the outer link plate 120 is as follows: HO+0.5mm≧HI>HO is set to. By making HI>HO, as shown in Figure 4(A), when the sliding surface GS of the chain guide G is not worn, only the back surface 112 of the inner link plate 110 comes into contact with the sliding surface GS, and the back surface 122 of the outer link plate 120 does not come into contact with the sliding surface GS, thereby reducing frictional resistance. Furthermore, by making HO+0.5mm≧HI, the depth of the groove GG caused by wear due to the back surface 112 of the inner link plate 110 does not exceed 0.5mm, as shown in Figure 4(B), and the effect of pitting can be reduced.

[0016] Furthermore, when the amount of elastic deformation of the sliding surface GS of the chain guide G under high tension and the clearance between the connecting pin 140 and the bushing 130 are taken into consideration, HI≧HO+0.1mm This makes it possible to reliably prevent both the back surface 112 of the inner link plate 110 and the back surface 122 of the outer link plate 120 from sliding against each other when the sliding surface GS of the chain guide G is not worn. Furthermore, by making HO+0.3 mm≧HI, the effects of pitching can be avoided more effectively.

[0017] In this embodiment, by making the back surface 112 of the inner link plate 110 a curved back surface, it is possible to reduce frictional resistance in a manner similar to the above-mentioned known technology when the sliding surface GS of the chain guide G is not worn, but the back surface 112 of the inner link plate 110 may also be a flat back surface. Furthermore, by making the back surface 122 of the outer link plate 120 a flat back surface, it is possible to minimize the progression of wear after the sliding surface GS of the chain guide G wears and the back surface 122 of the outer link plate 120 comes into contact with the sliding surface GS of the chain guide G, but the back surface 122 of the outer link plate 120 may also be a curved back surface.

[0018] Furthermore, the back height HO of the outer link plate 120 is increased, HI+0.5mm≧HO>HI In this case, the back surface 112 of the inner link plate 110 and the back surface 122 of the outer link plate 120 may each be either a curved back surface or a flat back surface. Furthermore, if either the back surface 112 of the inner link plate 110 or the back surface 122 of the outer link plate 120 has a curved back surface and the other has a flat back surface, then HO may be equal to HI.

[0019] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the present invention as set forth in the claims. For example, in the above-described embodiment, a bushing chain was used in which the bushing abutted against the sprocket, but it could also be a roller chain in which rollers were loosely fitted around the outer periphery of the bushing, or a chain in which the bushing was omitted and the inner link plate was loosely fitted onto the connecting pin. [Explanation of symbols]

[0020] 100 ··· Chain 110 Inner link plate 111 Bush hole 112... Back 120 Outer link plate 121 Pinhole 122... Back 130 Bush 140 ··· Connecting pin PL: Pitch line HI: Height of the back of the inner link plate HO: Back height of outer link plate G··· Chain guide GS... Sliding surface GG...Groove

Claims

1. A chain comprising a pair of left and right inner link plates, a pair of left and right outer link plates respectively disposed on both outer sides of the pair of left and right inner link plates, and a number of the inner link plates and the outer link plates connected alternately in the chain longitudinal direction with connecting pins, a difference in height from the pitch line of the highest portion of the back surfaces of the inner link plates relative to the pitch line and a difference in height from the pitch line of the highest portion of the back surfaces of the outer link plates relative to the pitch line is greater than 0 mm and not greater than 0.5 mm, A chain described in which the back surfaces of both the inner link plates and the outer link plates are configured to slide against the sliding surface of the chain guide member when the sliding surface of the chain guide member wears to a certain extent.

2. 2. The chain according to claim 1, wherein the difference in height from the pitch line of the highest part of the back surfaces of the inner link plates relative to the pitch line and the height from the pitch line of the highest part of the back surfaces of the outer link plates relative to the pitch line is 0.1 mm to 0.3 mm.

3. one of the inner link plates or the outer link plates has a curved back surface at the center in the chain longitudinal direction that is convex in the chain height direction, 3. The chain according to claim 1, wherein the other of the plurality of inner link plates or the plurality of outer link plates has a flat back surface that keeps the chain height constant in the longitudinal direction of the chain.

4. 4. The chain according to claim 3, wherein the height of said flat back surface from the pitch line is lower than the height of said curved back surface from the pitch line at its highest point relative to the pitch line.

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