chain guide

Abstract

The present application provides a chain guide, even in the case of different chains used, by a common design, the most appropriate performance of the position, trajectory, length of the chain contact can be obtained. Specifically, it is provided with a guide surface (110) for sliding guide of the moving chain and at least one mounting portion (123) of the chain guide (100), the guide surface (110) has: the first guide surface (111) extending in the length direction; And the second guide surface (112) is arranged to protrude side by side with the first guide surface (111), the height of the second guide surface (112) protruding from the first guide surface (111) is different in the length direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a chain guide provided with a guide surface that guides a moving chain and at least one mounting portion. BACKGROUND

[0002] Conventionally, in order to stabilize and appropriately maintain tension of a chain that moves between sprockets, a chain guide provided with a guide surface that guides a moving chain and a body portion that supports the guide surface in a direction in which the chain moves is generally used.

[0003] For example, as shown in Figure 8 , a timing system is known, which is a timing system of an engine that moves a transmission chain CH, such as a roller chain, a bush chain, a silent chain, or the like, that is looped and rotated without a joint between sprockets S1, S2 provided respectively to a crankshaft and a camshaft in an engine room E, the timing chain CH being looped and rotated without a joint between a drive sprocket S1 mounted to the crankshaft in the engine room E and a pair of driven sprockets S2 mounted to the camshaft, a chain guide (swing guide) 500 that swings and a chain guide (fixed guide) 600 that guides the timing chain CH.

[0004] The chain guide (fixed guide) 600 is fixed in the engine room E by two mounting shafts Q using two mounting portions 623.

[0005] The chain guide (swing guide) 500 is mounted in the engine room E and is capable of swinging in a looped and rotated plane of the timing chain CH with a swing axis P of the mounting portion 523 as a center.

[0006] The chain tensioner T suppresses vibration while appropriately maintaining tension of the timing chain CH by pressing a pressing portion 524 of the chain guide (swing guide) 500.

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent Application Laid-Open No. 2001-041299 SUMMARY

[0009] In such a known chain guide, when mounted in the engine room E as in the example of Figure 8 , a position, a locus, a length, and the like at which the chain guide comes into contact with the chain are determined according to the specifications of the engine, a layout of the chain, specifications of the chain used, and the like, and a dedicated chain guide is used individually in order to obtain the most appropriate performance.

[0010] Therefore, when the specifications of the engine, the layout of the chain, and the like are different, chain guides of different specifications are also required to be designed and manufactured.

[0011] As for the mounting portion of the engine, as is known from Patent Document 1 and the like, a plurality of mounting portions are provided in advance, so that a common chain guide can be used.

[0012] However, when the chain layout is different, it is difficult to obtain the most appropriate performance.

[0013] In addition, when the specifications of the chain used are different, even if the chain layout and the mounting portion of the chain guide are the same, the contact position, trajectory, length, and the like of the chain guide and the chain for obtaining the most appropriate performance are different, and different chain guides need to be designed and manufactured.

[0014] The present application is made to solve the above problems, and the technical problem to be solved is to provide a chain guide that can provide the contact position, trajectory, and length of the chain guide and the chain for obtaining the most appropriate performance by the same chain guide even when the chain used is different.

[0015] The present application is a chain guide having a guide surface that slidably guides a moving chain and at least one mounting portion, the guide surface having a first guide surface extending in the length direction and a second guide surface provided to protrude side by side with the first guide surface, and having a portion in which the height of the second guide surface protruding from the first guide surface differs in the length direction, thereby solving the above problems.

[0016] According to the chain guide of the present technical solution 1, since the guide surface has a first guide surface extending in the length direction and a second guide surface provided to protrude side by side with the first guide surface, and has a portion in which the height of the second guide surface protruding from the first guide surface differs in the length direction, different contact positions, trajectories, and lengths can be obtained by the chain slidably guided by the first guide surface and the chain slidably guided by the second guide surface, and the contact position, trajectory, and length of the chain guide and the chain for obtaining the most appropriate performance can be provided by the same chain guide.

[0017] According to the structure described in the present technical solution 2, since the trajectories in the length direction of the first guide surface and the second guide surface are formed in arc shapes having different centers, respectively, different trajectories can be easily achieved.

[0018] According to the structure described in the present technical solution 3, since the first guide surface is formed on both sides in the width direction of the second guide surface, in the case of a roller chain or a bush chain, sliding occurs between the chain plate and the first guide surface on both sides in the width direction, and in the case of a silent chain, sliding occurs between the back surface and the second guide surface in the center in the width direction, so the center position in the width direction can be made the same even in the case of any one chain.

[0019] According to the structure described in the present technical solution 4, since the guide flange is provided on both sides of the guide surface in the width direction, the portion of the guide flange adjacent to the guide surface is formed to have a protrusion height higher than that of the second guide surface, and thus the displacement of the chain in the width direction can be limited to be small when the silent chain is guided by sliding on the second guide surface.

[0020] According to the structure described in the present technical solution 5, since the inclined surface that smoothly continues to at least one of the first guide surface and the second guide surface is formed at at least one end of the guide surface in the length direction, the most appropriate contact position and contact length can be provided for both types of chains. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a perspective view of a chain guide (fixed guide) according to an embodiment of the present application.

[0022] Figure 2 is a cross-sectional view of Figure 1

[0023] Figure 3 is a schematic view of a chain used.

[0024] Figure 4 is a schematic view of the abutment of the chain and the guide surface.

[0025] Figure 5 is a mode diagram of an embodiment of the first guide surface and the second guide surface.

[0026] Figure 6 is a mode diagram of another embodiment of the first guide surface and the second guide surface.

[0027] Figure 7 is a mode diagram of still another embodiment of the first guide surface and the second guide surface.

[0028] Figure 8 is a schematic view of a timing system of a conventional engine.

[0029] SYMBOL DESCRIPTION

[0030] ​500 - chain guide (swing guide); 100, 600 - chain guide (fixed guide); 110 - guide surface; 111 - 1st guide surface; 112 - 2nd guide surface; 113 - 1st front end inclined surface; 114 - 2nd front end inclined surface; 115 - 1st rear end inclined surface; 116 - 2nd rear end inclined surface; 120 - guide flange; 123, 523, 623 - mounting portion; 524 - pressing portion; E - engine room; S1 - driving sprocket; S2 - driven sprocket; CH - timing chain; Q - mounting shaft; P - swing shaft; T - chain tensioner; RC - roller chain; SC - silent chain; RH - back height (roller chain); SH - back height (silent chain); RP - chain pitch (roller chain); SP - chain pitch (silent chain); PL - pitch line; C1 - 1st guide surface arc center; C2 - 2nd guide surface arc center. DETAILED DESCRIPTION

[0031] One embodiment of the present application relates to a chain guide (fixed guide) 100 which is fixed in an engine having a timing system, guides and stabilizes the movement of a timing chain, as shown in Figure 1 , Figure 2 , has a guide surface 110 on the upper side, and is fixed in an engine room by two mounting portions 123.

[0032] The guide surface 110 has a 1st guide surface 111 which extends in the length direction, and a 2nd guide surface 112 which is provided to protrude side by side with the 1st guide surface.

[0033] The 1st guide surface 111 is formed on both sides in the width direction of the 2nd guide surface 112, and a guide flange 120 which restricts the lateral movement of the timing chain is provided on the outside in the width direction of the two 1st guide surfaces 111.

[0034] This embodiment is configured to be usable for either one of a roller chain RC and a silent chain SC as shown in Figure 3 , as shown in Figure 4 , the inner link plate IP of the roller chain RC is slidingly guided by the 1st guide surface 111, and the back of the link plate LP of the silent chain SC is slidingly guided by the 2nd guide surface 112.

[0035] Further, as shown in Figure 4 , since the guide flange 120 restricts the outside of the outer link plate OP of the roller chain RC, and the portion of the guide flange 120 which is adjacent to the 1st guide surface 111 is formed to have a protruding height which is higher than the 2nd guide surface 112, it is configured to restrict the outside of the guide plate GP of the silent chain SC.

[0036] Even when the chain layout is the same and the mounting portions of the chain guides are the same, the most appropriate chain pitches RP, SP are different when using the roller chain RC and when using the silent chain SC, respectively.

[0037] In addition, as shown in Figure 4 the back surface height RH (distance from pitch line to sliding surface) of the inner link plate IP of the roller chain RC and the back surface height SH of the link plate LP of the silent chain SC are also different, respectively.

[0038] Thus, the most appropriate values of the position in the height direction and the locus where the chain guide comes into contact with the chain are different, respectively, and the most appropriate length of the free span from the sprocket to the chain guide is also different.

[0039] In the present application, since the portion where the second guide surface 112 protrudes from the first guide surface 111 has different heights in the length direction, i.e., does not protrude at a uniform height, the position in the height direction and the locus where the chain guide comes into contact with the chain can be optimally set.

[0040] In addition, a first front end inclined surface 113 that smoothly continues the first guide surface 111 is formed at one end portion in the length direction of the first guide surface 111, a first rear end inclined surface 115 is formed at the other end portion, a second front end inclined surface 114 that smoothly continues the second guide surface 112 is formed at one end portion in the length direction of the second guide surface 112, and a second rear end inclined surface 116 is formed at the other end portion.

[0041] The first front end inclined surface 113, the first rear end inclined surface 115, the second front end inclined surface 114, and the second rear end inclined surface 116 do not slide with the chain under normal circumstances, but when the chain is subjected to up-and-down vibration, they alleviate the impact when the chain comes into contact with the first guide surface 111 and the second guide surface 112, and by making the lengths of these portions different, respectively, the position in the length direction where the chain guide comes into contact with the chain can be optimally set, and the free span can be made the most appropriate length on different chains.

[0042] It is preferable that the locus in the length direction of the first guide surface 111 and the second guide surface 112 be formed in an arc shape having different centers, respectively.

[0043] For example, as described in Figure 5 the same circular arc radius can be made, and the center CI of the first guide surface 111 and the center C2 of the second guide surface 112 can be made to be offset in the direction close to the chain, as described in Figure 6 the same circular arc radius can be made, and the center CI of the first guide surface 111 and the center C2 of the second guide surface 112 can be made to be offset in the direction close to the chain and in the length direction, as described in Figure 7As described above, the first guide surface 111 and the second guide surface 112 can be formed in different radii of curvature, and the center C1 of the first guide surface 111 and the center C2 of the second guide surface 112 can be offset in the direction of the chain.

[0044] Further, Figures 5 to 7 The drawing is exaggerated for the purpose of explanation, and the amount of offset of the tracks of the first guide surface 111 and the second guide surface 112 is small, and in fact, the design is made so that the rollers of the roller chain RC do not contact the second guide surface 112.

[0045] Although the above-described embodiments are specific examples of the chain guide according to the present application, the chain guide according to the present application is not limited to these, and the shape, position, size, arrangement relationship, and the like of each component can be variously modified.

[0046] For example, although the above-described embodiments show a mode in which the chain guide is used as a fixed guide, one of the two support portions can be formed as a pressing portion that is pressed by a tensioning device, and thus the chain guide can be used as a swing guide.

[0047] Further, although each of the embodiments is a chain guide having two support portions, the chain guide can have three or more support portions.

[0048] Further, in the above-described embodiments, although the second guide surface 112 is present only at the center, when the width of the silent chain SC is larger than that of the roller chain RC, the second guide surface 112 can be provided at both outer sides of the first guide surface 111.

[0049] Further, for a chain having a different sliding position in the width direction, any number of the first guide surface 111 and the second guide surface 112 can be provided at any position in the width direction, and a plurality of guide surfaces having different tracks can be provided.

[0050] Further, the shape of the guide flange 120, the position of the chain, and the like can be appropriately designed according to the chain used.

[0051] Further, although the above-described embodiments are embodiments provided in an engine having a timing system, the present application is not limited to this, and can be applied to various kinds of machines.

[0052] Further, the present application is not limited to a transmission mechanism using a chain, but can be applied to a similar transmission mechanism using a belt, a rope, or the like, and can be used in various industrial fields.

Claims

1. A chain guide having a guide surface that slidably guides a moving chain and at least one mounting portion, characterized in that the guide surface has a first guide surface that slidably guides an inner link plate of a roller chain extending in a length direction, and a second guide surface that slidably guides a link plate of a silent chain provided so as to project in parallel with the first guide surface, and in that a portion where the second guide surface projects from the first guide surface differs in height in the length direction. The trajectories of the first guide surface and the second guide surface in the length direction are respectively formed in an arc shape having different centers. The first guide surface is formed on both sides in a width direction of the second guide surface.

2. A chain guide according to claim 1, characterised in that 4. The chain guide according to claim 3, characterized in that guide flanges are provided on both sides in a width direction of the guide surface, a portion of the guide flange that is adjacent to the guide surface is formed so as to be higher than the projection height of the second guide surface, and at least one end portion in the length direction of the guide surface is formed with an inclined surface that smoothly continues to at least one of the first guide surface and the second guide surface.

3. A chain guide according to claim 1 or claim 2, characterised in that The trajectories of the first guide surface and the second guide surface in the length direction are respectively formed in an arc shape having different centers. The first guide surface is formed on both sides in a width direction of the second guide surface.

4. The chain guide according to claim 3, characterized in that guide flanges are provided on both sides in a width direction of the guide surface, a portion of the guide flange that is adjacent to the guide surface is formed so as to be higher than the projection height of the second guide surface, and at least one end portion in the length direction of the guide surface is formed with an inclined surface that smoothly continues to at least one of the first guide surface and the second guide surface. ​ 5. A chain guide according to claim 1 or claim 2, characterised in that the chain guide is formed as a chain guide according to any one of claims 3 to 6. ​

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