Chain guide

Abstract

To provide a simple-structured chain guide with improved durability and capable of preventing detachment or breakage of a supplementary member and of reliably reducing vibration and noise. The chain guide includes a supplementary member made of a different material from a guide body. The supplementary member is configured to have an engaging hole, which allows attachment of the supplementary member to a side face of a support wall part provided between a guide part and a base part of the guide body.

Claims

1. A chain guide comprising a guide body having a guide shoe that slidably guides a running chain, and a supplementary member made of a different material from the guide body, the guide body including a guide part on a side facing the guide shoe, a base part located away from the guide part, and a support wall part provided between the guide part and the base part, the supplementary member being configured to include an engaging hole that allows attachment of the supplementary member to at least one side face of the support wall part, and the supplementary member being made of rubber.

2. The chain guide according to claim 1, wherein the support wall part has at least one projection insertable to the engaging hole of the supplementary member.

3. The chain guide according to claim 2, wherein the engaging hole of the supplementary member is formed in a shape that allows the supplementary member to move relative to the projections along a longitudinal direction of the guide body.

4. The chain guide according to claim 2, wherein the projections are disposed at each of two points in a longitudinal direction of the guide body, and at least one of the projections has a locking piece extending to the opposite direction from the other projection.

5. The chain guide according to claim 1, further comprising an engaging pin having an insertion head insertable to the engaging hole of the supplementary member, the support wall part having a pin insertion hole in which the engaging pin can be inserted.

6. The chain guide according to claim 5, wherein the pin insertion hole of the support wall part is formed in a shape that allows the engaging pin to move along a longitudinal direction of the guide body relative to the support wall part.

7. The chain guide according to claim 5, wherein the engaging hole of the supplementary member is formed in a shape that allows the engaging pin to move along a longitudinal direction of the guide body relative to the supplementary member.

8. A chain guide comprising a guide body having a guide shoe that slidably guides a running chain, and a supplementary member made of a different material from the guide body, wherein the guide body includes a guide part on a side facing the guide shoe, a base part located away from the guide part, and a support wall part provided between the guide part and the base part, the supplementary member is configured to include an engaging hole that allows attachment of the supplementary member to at least one side face of the support wall part, and the guide body has a concave section at least on one side face of the support wall part, the support wall part being a bottom face and the guide part and the base part being a side face of the concave section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a chain guide (pivoting guide) according to a first embodiment of the present invention;

(2) FIG. 2 is an exploded illustrative view of the chain guide of FIG. 1;

(3) FIG. 3 is a cross-sectional view of the chain guide of FIG. 1;

(4) FIG. 4 is an enlarged view of the vicinity of a projection on a support wall part of the chain guide of FIG. 1;

(5) FIG. 5 is a perspective view of a chain guide (fixed guide) according to a second embodiment of the present invention;

(6) FIG. 6 is an exploded illustrative view of the chain guide of FIG. 5;

(7) FIG. 7 is a perspective view of a chain guide (pivoting guide) according to a third embodiment of the present invention;

(8) FIG. 8 is an exploded illustrative view of the chain guide of FIG. 7;

(9) FIG. 9 is a cross-sectional view of the chain guide of FIG. 7;

(10) FIG. 10 is an enlarged view of the vicinity of a projection on a support wall part of the chain guide of FIG. 7;

(11) FIG. 11 is a perspective view of a chain guide (pivoting guide) according to a fourth embodiment of the present invention;

(12) FIG. 12 is an exploded illustrative view of the chain guide of FIG. 11;

(13) FIG. 13 is an enlarged view of an engaging pin of the chain guide of FIG. 11; and

(14) FIG. 14 is a cross-sectional view of the chain guide of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(15) A chain guide (pivoting guide) 100 according to a first embodiment of the present invention will be hereinafter described with reference to the drawings.

(16) The chain guide 100 includes a guide body 101 having a sliding guide surface 111, which is a guide shoe that slidably guides a running chain, and a supplementary member 140 made of a different material from the guide body 101, as shown in FIG. 1 to FIG. 4.

(17) The guide body 101 includes a guide part 110 on the side facing the sliding guide surface 111, a base part 130 located away from the guide part 110, a support wall part 120 provided between the guide part 110 and the base part 130, and a boss part 160 for attaching the chain guide pivotably in an engine room or the like.

(18) Concave sections for accommodating supplementary members 140 are formed on both sides of the support wall part 120 of the guide body 101, with the support wall part 120 being bottom faces, and the guide part 110 and base part 130 being side faces.

(19) The supplementary member 140 has two engaging holes 141 in a front part and a rear part of the longitudinal direction, while the support wall part 120 has projections 121 that can fit into the engaging holes 141 of the supplementary member 140, i.e., the supplementary member 140 is configured to be attachable to a side face of the support wall part 120.

(20) The projection 121 has an insertion head 122 having a larger diameter than the engaging hole 141 of the supplementary member 140 and provided with an elastic slit 127, as shown in FIG. 4.

(21) Since the supplementary member 140 is never removed both during use and when not in use once it is attached to the support wall part 120 in an assembly process, the insertion head 122 should preferably have a shape that allows easy insertion but prevents detachment, as shown in the drawing.

(22) In this embodiment, there are through holes 128, which allow ejection from the molds of the injection molding or the like, in the support wall part 120 at the foot of the projections 121.

(23) Due to the meld design of the injection molding or the like, the projections 121 are located at different positions on one side and the other side of the support wall part 120.

(24) While the guide part 110 has the sliding guide surface 111 on the upper face thereof in this embodiment, a guide shoe formed by a different component may be fixed to the top of the guide body 101.

(25) The supplementary member 140 should preferably be made of rubber for reducing vibration and noise.

(26) The amount of deformation rubber undergoes with temperature changes is different from that of the guide body 101 made of resin or the like, and the rubber shrinks as time passes by the long-term use under a high-temperature or an oil-present environment. Even so, since the supplementary member is engaged with the projections 121 in the engaging holes 141, the surrounding parts of the engaging holes 141 entirely expand and contract so that stress is dispersed, which minimizes breakage caused by stress concentration and repeated deformation.

(27) It is also possible to design the supplementary member 140 to be larger than the concave section in the guide body 101 to prevent any gaps from being formed when the supplementary member shrinks, or conversely, smaller than the concave section to ensure there is and will always be a clearance that does not generate vibration or noise even under temperature changes or aging degradation.

(28) A chain guide 200 (fixed guide) according to a second embodiment of the present invention has boss parts 260 for fixing the chain guide in an engine room or the like at two points in the longitudinal direction, as shown in FIG. 5 and FIG. 6. Concave sections for accommodating supplementary members 240 are formed between the two boss parts 260 and between the boss parts and both outer ends in the longitudinal direction on both sides, with the support wall part 220 being bottom faces, and the guide part 210 and base part 230 being side faces, i.e., the guide body has six concave sections on both sides in total.

(29) In this embodiment, supplementary members 240 are attached to four of these concave sections.

(30) Other configurations are similar to those of the first embodiment.

(31) A chain guide 300 (pivoting guide) according to a third embodiment of the present invention has projections 321 that can fit into engaging holes 341 of the supplementary member 340 at two points in the longitudinal direction of the support wall part 320 as shown in FIG. 8 to FIG. 10. Each projection 321 includes a locking piece 323 at the tip extending to the opposite direction from the other projection 321.

(32) As the locking piece 323 prevents detachment, the projections 321 need not be forced into the engaging holes, so that assembling is made even easier.

(33) Other configurations are similar to those of the first embodiment.

(34) A chain guide 400 (pivoting guide) according to a fourth embodiment of the present invention further includes engaging pins 450, which have an insertion head 452 that can fit into engaging holes 441 of the supplementary member 440, while the support wall part 420 has pin insertion holes 424 in which the engaging pins 450 are inserted, as shown in FIG. 11 to FIG. 14.

(35) The engaging pin 450 has a retention flange 451 on the opposite side from the insertion head 452, as shown in FIG. 13.

(36) The pin insertion hole 424 of the support wall part 420 includes an attachment part 425 where the engaging pin 450 can pass through, and continuously therewith, a sliding part 426 where the retention flange 451 of the engaging pin 450 cannot pass through and the engaging pin 450 can slide along the longitudinal direction.

(37) The supplementary member 440 is provided with clearance holes 442 for avoiding interference with the retention flanges 451 of the engaging pins 450 inserted into the supplementary member 440 on the opposite side.

(38) Other configurations are similar to those of the first embodiment.

(39) In this embodiment, the engaging pins 450 can slide inside the pin insertion holes 424 in accordance with deformation of the supplementary member 440, and therefore no stress is generated even when the supplementary member 440 undergoes shrinkage due to temperature changes or aging degradation.

(40) While specific examples of the chain guide according to the present invention have been described in various embodiments above, the chain guide according to the present invention is not limited to these examples, and the shapes, positions, sizes, and positional relationships with each other of various constituent parts may be modified in various manners.

(41) For example, while the guide part, base part, and support wall part together have an H-shaped cross section to accommodate the supplementary members in the concave sections formed on both side faces of the support wall part, in the embodiments described above, the supplementary member may be provided only on one side face.

(42) Alternatively, the guide part, base part, and support wall part together may have a U-shaped cross section, and the supplementary member may be provided to the concave side face, or to the opposite side face, of the support wall part, or, the guide part, base part, and support wall part may have the same width, and the supplementary member may be provided to a side face of the guide body without a concave section.

(43) While the chain guides of various embodiments described above are provided inside an engine having a timing system, the purpose of use is not limited to this and the chain guide can be applied to various instruments.

(44) The chain guide may not necessarily be applied to a transmission mechanism that uses a chain but can also be used for similar transmission mechanisms that use belts, ropes and the like, and can be applied in a variety of industrial fields.