JP2018087603A - Chain guide and chain transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rotation of a roller shaft when a roller rotates by the traveling of a chain.SOLUTION: Shaft insertion grooves 25 are formed at a pair of opposing side plate parts 23 of a guide base 20 which is arranged at one side of a chain 5, and a roller 22 for rollingly guiding the chain 5 is rotatably supported by a roller shaft 21 whose end part is supported by the shaft insertion grooves 25. The shaft insertion grooves 25 support the shaft end part of the roller shaft 21 at their groove end edges, the shaft insertion grooves 25 have fixed members 26 which are fixed in a state of being fit into the grooves, and the fixed members 26 press the shaft end part of the roller shaft 21.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a chain guide used for adjusting the tension of a chain or for guiding movement of a chain, and a chain transmission using the chain guide.

  The automobile engine transmits the rotation of the crankshaft to a camshaft via a timing chain (hereinafter simply referred to as “chain”), and opens and closes the valve of the combustion chamber by the rotation of the camshaft.

  Such a camshaft drive chain transmission device includes a drive sprocket attached to the crankshaft, a driven sprocket attached to the camshaft, a chain spanned between the drive sprocket and the driven sprocket, and the chain. A swingable chain guide disposed on the slack side, a chain tensioner that presses the chain guide toward the chain, and a fixed chain guide disposed on the tension side of the chain are often used.

  Here, the chain guide on the swing side keeps the chain tension constant by pressing the chain with the urging force of the chain tensioner, and the chain guide on the fixed side keeps the ideal chain travel line while maintaining the chain's tension. Suppresses vibration.

  As a swing-side chain guide and a fixed-side chain guide used in such a chain transmission device, a type in which a guide surface extending along the chain traveling direction is brought into sliding contact with the chain is known. This sliding type chain guide has a problem that since the contact with the chain is a sliding contact, the running resistance of the chain is large and the torque transmission loss is large.

  In order to solve the problems of the chain guide, those described in Patent Document 1 or Patent Document 2 are known. The chain guide described in these documents includes a guide base extending in the traveling direction of the chain, a plurality of roller shafts attached to the guide base at intervals along the traveling direction of the chain, and each roller shaft. The roller is rotatably supported by the roller, and the chain is guided by a cylindrical outer peripheral surface of the roller.

  This chain guide is characterized in that since the contact with the chain is a rolling contact, the running resistance of the chain is small and the torque transmission loss is small.

International Publication 2010/090139 JP 2012-189200 A

  Incidentally, the chain guide described in Patent Document 1 is assembled by inserting the roller shaft from the side of the guide base, and there is a problem that the workability of the assembly is poor.

  Therefore, in the chain guide described in Patent Document 2, an insertion recess and an arc-shaped fixed recess are formed on the opposing wall surfaces of the pair of side plates constituting the guide base, and both ends of the roller shaft are inserted. The problem with the chain guide described in Patent Document 1 is solved by inserting and assembling from the recess to the fixed recess from the chain side.

  In such a chain guide described in Patent Document 2, the width of the insertion port of the fixed recess is formed smaller than the inner diameter of the fixed recess, and the roller shaft is prevented from coming off by the edge of the insertion port. However, with such a retaining against the roller shaft, it is difficult to prevent the rotation of the roller shaft against the rotation of the roller due to the running of the chain.

  When the roller shaft rotates, there is a problem in that the opposing wall surface of the side plate portion where the fixed recess is formed wears, and the roller shaft vibrates and abnormal noise is generated due to the vibration.

  An object of the present invention is to prevent the rotation of the roller shaft when the roller is rotated by running of the chain.

  In order to solve the above-described problems, in the chain guide according to the present invention, a guide base having a pair of opposed side plate portions extending along the running direction of the chain, and a shaft end portion are supported by the opposed pair of side plate portions. In the chain guide comprising a plurality of roller shafts attached at intervals in the length direction of the side plate portion, and a plurality of rollers rotatably supported on each of the roller shafts, the pair of opposed side plates The portion has a shaft insertion groove portion into which the shaft end portion of the roller shaft is fitted on the opposite surface, and the shaft insertion groove portion extends in the width direction of the side plate portion from the side surface of the side plate portion on the chain side. The shaft insertion groove may be configured such that a fixing member is fixed in a state of being fitted therein, and the fixing member presses the shaft end of the roller shaft.

  According to this configuration, since the shaft end portion of the roller shaft supported by the shaft insertion groove is pressed by the fixing member in the shaft insertion groove, the rotation of the roller shaft accompanying the rotation of the roller during the chain travels. Is prevented.

  The fixing member has a connecting projection protruding outward in the axial direction of the roller shaft, and a locking piece extending in the length direction of the side plate connected to the connecting projection, and the side plate is An engagement hole that is located on the outer side in the axial direction of the roller shaft with respect to the shaft insertion groove and extends in the width direction of the side plate from the side surface on the chain side of the side plate, and the engagement hole and the shaft insertion groove The guide plate has a guide groove extending in the width direction of the side plate from the side surface on the chain side of the side plate, and the locking piece of the fixing member is fitted in the engagement hole. The connection protrusion can adopt a configuration in which the guide groove can be moved in the width direction of the side plate.

  According to this configuration, the fixing member can be prevented from falling inward in the axial direction of the roller shaft from the shaft insertion groove by fitting the engaging piece portion of the fixing member into the engaging hole of the side plate portion.

  A configuration in which the fixing member is fitted to the shaft insertion groove with a margin in a length direction of the side plate portion, or an adhesive layer made of an adhesive between the fixing member and a groove inner wall of the shaft insertion groove. The structure which has can be employ | adopted. In this case, it is possible to prevent the fixing member from falling out of the shaft insertion groove.

  Further, the fixing member has a stopper piece portion on the outer side in the length direction of the side plate portion, the shaft insertion groove portion has an engagement hole portion on a groove side surface facing the inner side in the length direction of the side plate portion, The fixing member may employ a configuration in which the stopper piece is engaged with an interference in the engagement hole of the shaft insertion groove.

  The stopper piece of the fixing member is engaged with the fastening hole in the engaging hole of the shaft insertion groove, so that the fixing member is securely fixed to the shaft insertion groove.

  In the chain transmission device according to the present invention, a swingable chain guide for guiding the movement of the timing chain is provided on one side of the slack side chain of the timing chain, with the timing chain being spanned between the driving sprocket and the driven sprocket. A chain transmission device in which an adjustment force of a chain tensioner is applied to the swing side end portion of the chain guide and the swing side end portion is pressed against the timing chain. The above chain guide can be employed.

  According to the present invention, since the rotation of the roller shaft is prevented, the roller shaft does not wear against the opposing wall surface of the side plate portion, and the vibration of the roller shaft and the generation of noise due to the vibration can be prevented.

Schematic which shows the chain transmission apparatus incorporating the chain guide of 1st embodiment which concerns on this invention 1 is a partially cutaway longitudinal sectional view of the chain guide shown in FIG. Partial cutaway longitudinal section of the main part of the chain guide Sectional drawing along the IV-IV line of FIG. Sectional view along line VV in FIG. Sectional drawing which shows fitting to shaft insertion groove part of fixing member Perspective view showing attachment of roller and roller shaft to chain guide The perspective view which shows fitting to the shaft insertion groove part of the other form of a fixing member The perspective view which shows other embodiment of the chain guide which concerns on this invention Sectional drawing which shows the fitting state to the shaft insertion groove part of a fixing member same as the above The perspective view which shows other embodiment of the chain guide which concerns on this invention Sectional drawing which shows the fitting state to the shaft insertion groove part of a fixing member same as the above

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a chain transmission 50 incorporating a chain guide according to a first embodiment of the present invention. The chain transmission 50 is hung between the drive sprocket 2 fixedly attached to the crankshaft 1 of the engine, the driven sprocket 4 fixedly attached to the camshaft 3, and the drive sprocket 2 and the driven sprocket 4. The chain 5 is passed, and the rotation of the crankshaft 1 is transmitted to the camshaft 3 through the chain 5, and the valve (not shown) of the combustion chamber is opened and closed by the rotation of the camshaft 3.

  When the engine is operating, the rotation direction of the crankshaft 1 is constant (right rotation in the figure). At this time, the chain 5 is stretched on the side that is pulled into the drive sprocket 2 as the crankshaft 1 rotates. The portion on the side that is fed from the drive sprocket 2 is the slack side.

  On the slack side of the chain 5, there are provided a chain guide 7 supported so as to be swingable about the fulcrum shaft 6 and a chain tensioner 8 for pressing the chain guide 7 toward the chain 5. On the other hand, a fixed chain guide 9 is provided on the tension side of the chain 5.

  The chain guide 7 extends vertically along the chain 5, and a fulcrum shaft 6 is inserted into an insertion hole 10 provided at an upper end portion of the chain guide 7, and is supported to be swingable about the fulcrum shaft 6. A chain tensioner 8 is in contact with the swing end portion of the chain guide 7, and the chain guide 7 is biased toward the chain 5 by the chain tensioner 8.

  Similarly to the chain guide 7, the chain guide 9 also has a shape extending vertically up and down along the chain 5. The chain guide 9 is fixed by tightening the bolts 12 by inserting bolts 12 into insertion holes 11 provided at both upper and lower ends.

  Here, when the swinging side chain guide 7 and the fixed side chain guide 9 are compared, the swinging side chain guide 7 has an insertion hole 10 for inserting the swinging fulcrum shaft 6 at one end. The chain guide 9 on the fixed side is different from that formed in that the insertion holes 11 for inserting the bolts 12 for fixing are formed at both ends. It is.

  Therefore, the swing-side chain guide 7 will be described below, and the fixed-side chain guide 9 will be denoted by the same reference numerals and the description thereof will be omitted.

  As shown in FIGS. 2 to 4, the chain guide 7 includes a guide base 20 extending in the traveling direction of the chain 5, and a plurality of roller shafts 21 attached to the guide base 20 side by side along the traveling direction of the chain 5. And rollers 22 rotatably supported on the respective roller shafts 21.

  The guide base 20 extends along the traveling direction of the chain 5 and is disposed between a pair of opposed side plate portions 23, 23 that support both ends of each roller shaft 21 and the adjacent roller shaft 21. And a plate-like connecting portion 24 that connects the 23 to each other. The side plate portion 23 is a plate that is long in the traveling direction of the chain 5. Both ends of the connecting portion 24 are fixed to the side plate portion 23 along the width direction (short direction) of the side plate portion 23, and the facing interval of the side plate portion 23 is maintained.

  As shown in FIG. 2, the pair of opposed side plate portions 23 are curved along the traveling direction of the chain 5, and the shaft end portions of the roller shafts 21 are fitted on the opposed surfaces of the respective side plate portions 23. A mating shaft insertion groove 25 is provided. As shown in FIG. 3, the shaft insertion groove portion 25 is formed to extend from the side surface 23 a on the chain 5 side of the side plate portion 23 to one side in the width direction of the side plate portion 23 (direction opposite to the biasing direction of the chain tensioner 8). .

  The shaft insertion groove portion 25 supports the shaft end portion of the roller shaft 21 at the groove end edge portion 25 a on one side in the width direction of the side plate portion 23. A fixing member 26 is fixed to the shaft insertion groove 25 while being fitted therein.

  As shown in FIG. 5, the shaft insertion groove 25 has an opening width W <b> 1 slightly larger than the diameter dimension of the roller shaft 21 from the side surface 23 a of the side plate portion 23 toward one side in the width direction of the side plate portion 23. Further, the shaft insertion groove portion 25 introduces the shaft end portion of the roller shaft 21 from the side surface 23a of the side plate portion 23 to the groove end edge portion 25a. The groove end edge portion 25 a of the shaft insertion groove portion 25 has an arc shape along the outer peripheral surface of the shaft end portion of the roller shaft 21.

  As shown in FIGS. 6 and 7, the fixing member 26 is formed of a rectangular flat plate, and an edge portion 26 a on one side in the width direction of the side plate portion 23 has an arc shape along the outer peripheral portion of the roller shaft 21. In the fixing member 26, as shown in FIG. 6, the width W2 in the direction orthogonal to the width direction of the side plate portion 23 (the same direction as the urging direction of the chain tensioner 8) (the length direction of the side plate portion 23) is the shaft insertion groove portion 25. The opening width W1 is slightly larger.

  For this reason, the fixing member 26 is fitted and fixed to the shaft insertion groove portion 25 with a tightening margin in the length direction of the side plate portion 23. As shown in FIG. 4, the thickness of the fixing member 26 is the same as the groove depth of the shaft insertion groove portion 25.

  Then, the fixing member 26 presses the shaft end portion of the roller shaft 21 supported by the groove end edge portion 25a of the shaft insertion groove portion 25 in one width direction of the side plate portion 23 in a state of being fitted to the shaft insertion groove portion 25. It has become.

  As shown in FIG. 8, the fixing member 26 has an adhesive on the surface facing the groove inner wall of the shaft insertion groove portion 25 without setting a tightening margin in the length direction of the side plate portion 23 with respect to the shaft insertion groove portion 25. The adhesive layer 26b formed by the above may be formed. Thereby, the fixing member 26 is fitted and fixed to the shaft insertion groove portion 25 by the adhesive layer 26b interposed between the groove inner walls of the shaft insertion groove portion 25.

  The guide base 20 can be formed by injection molding of a synthetic resin containing a fiber reinforcement. As the synthetic resin, for example, polyamide (PA) such as PA66 or PA46 can be used. Glass fiber, carbon fiber, aramid fiber, etc. can be used as the fiber reinforcing material to be blended in the synthetic resin. The guide base 20 may be formed of a light metal such as an aluminum alloy or a magnesium alloy.

  The roller shaft 21 is a solid cylindrical body formed of a steel material such as SUJ2 or SC material, and is subjected to heat treatment in order to improve the surface wear resistance. Examples of the heat treatment include bright quenching and induction quenching.

  As shown in FIG. 4, the roller 22 is rotatably mounted on the outer periphery of the roller shaft 21, and the cylindrical outer peripheral surface 22 a of the roller 22 contacts the chain 5 for guidance. The roller 22 is a roller bearing including an outer ring 27, a plurality of rollers 28 incorporated inside the outer ring 27, and a cage 29 that holds these rollers 28.

  The outer ring 27 is a shell-shaped outer ring formed into a cup shape by drawing a steel plate such as SPC or SCM. At both ends of the outer ring 27, radially inward flanges 27a are formed. The outer diameter of the outer ring 27 is set, for example, in a range of 10 mm to 25 mm, and the outer diameters of all the outer rings 27 are the same.

  The outer ring 27 is a heat-treated product cured by heat treatment, and the wear resistance of the outer peripheral surface 22a is ensured by the heat treatment. Examples of the heat treatment of the outer ring 27 include induction hardening, carburizing treatment, and carbonitriding treatment.

  In this embodiment, in order to reduce the weight of the roller 22 and minimize the running resistance of the chain 5, the roller bearing is used alone as the roller 22, but a cylindrical resin is provided on the outer periphery of the outer ring 27 of the roller bearing. A member attached with a member or an iron member may be used as the roller 22, and other types of bearings may be used instead of the roller bearings. Here, the roller bearing refers to a cylindrical roller bearing and a needle roller bearing.

  Further, as shown in FIG. 1, the side plate portion 23 in the swingable chain guide 7 is curved, the side plate portion 23 in the fixed chain guide 9 is not curved, and the length direction is linear. Although the shapes are different, the chain guide 9 may be curved similarly to the chain guide 7.

  The chain transmission device 50 of this embodiment has the above structure, and in the torque transmission state in which the rotation of the crankshaft 1 is transmitted to the camshaft 3 by the movement of the chain 5 spanned between the drive sprocket 2 and the driven sprocket 4. When the tension of the chain 5 changes due to the fluctuation of the load, the chain tensioner 8 operates to absorb the tension change. For this reason, the chain 5 is always held in a predetermined tension state.

  At the time of torque transmission for transmitting the rotation of the crankshaft 1 to the camshaft 3, the roller 22 comprising the roller bearings of the swingable chain guide 7 and the fixed chain guide 9 is rotated by contact with the chain 5, and the chain 5 Is guided to roll.

  Since each of the plurality of rollers 22 of the swingable chain guide 7 and the fixed chain guide 9 is rotated by contact with the chain 5 as described above, a rotating torque is generated from the roller 22 to the roller shaft 21. Will be loaded.

  At this time, the shaft end portion of the roller shaft 21 fitted in the shaft insertion groove portion 25 is pressed to one side in the width direction of the side plate portion 23 by the fixing member 26 fitted in the shaft insertion groove portion 25. For this reason, torque applied to the shaft end portion of the roller shaft 21 is received by the groove end edge portion 25a of the shaft insertion groove portion 25 and the edge portion 26a of the fixing member 26, and the rotation of the roller shaft 21 is prevented.

  When the rotation of the roller shaft 21 is prevented, the roller shaft 21 does not wear against the groove edge 25a of the shaft insertion groove 25, and the vibration of the roller shaft 21 and the generation of noise due to the vibration can be prevented. .

  A chain guide according to another embodiment of the present invention will be described with reference to FIGS. As the chain guide of this embodiment, the fixing member 26 has a connecting projection 26c that protrudes outward in the axial direction of the roller shaft 21, and a locking piece 30 that is connected to the connecting projection 26c. The first embodiment described above in that it has an engagement hole 31 into which the locking piece portion 30 of the fixing member 26 is fitted, and a guide groove portion 31a in which the connecting projection portion 26c moves along the width direction of the side plate portion 23. The chain guide is different. The other structure is considered to be the same as that of the chain guide of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  In the chain guide of this embodiment, the side plate portion 23 is positioned on the outer side in the axial direction of the roller shaft 21 with respect to the shaft insertion groove portion 25, and one side in the width direction of the side plate portion 23 from the side surface 23 a on the chain 5 side of the side plate portion 23. An engagement hole 31 is formed extending in the direction.

  The side plate portion 23 has a guide groove portion 31 a that communicates with the engagement hole 31 and the shaft insertion groove portion 25 and extends from the side surface 23 a on the chain 5 side of the side plate portion 23 to one side in the width direction of the side plate portion 23. In the engagement hole 31 of the side plate portion 23, a guide groove portion 31 a communicates with a central portion in the length direction of the side plate portion 23. The engagement hole 31 is formed so that the opening width in the length direction of the side plate portion 23 is larger than the guide groove portion 31a.

  The fixing member 26 includes a connecting projection 26 c that protrudes outward in the axial direction of the roller shaft 21, and a locking piece 30 that is connected to the connecting projection 26 c and extends in the length direction of the side plate 23.

  The locking piece portion 30 is a rectangular flat plate member, and a connecting projection portion 26 c is connected to a central portion in the length direction of the side plate portion 23 in a state of being parallel to the fixing member 26. Further, the locking piece 30 is fitted into the engagement hole 31 by a clearance fit from the side surface 23 a on the chain 5 side of the side plate portion 23 to one side in the width direction of the side plate portion 23. The connecting projection part 26 c is inserted into the guide groove part 31 a and is movable in the width direction of the side plate part 23.

  For this reason, in a state where the engaging piece portion 30 is fitted in the engaging hole 31 of the side plate portion 23 and the connecting projection portion 26c is fitted in the guide groove portion 31a, the fixing member 26 is connected to the side plate portion 23 on the chain 5 side. The side plate 23 can be moved in one width direction from the side surface 23a.

  The fixing member 26 moved to one side in the width direction of the side plate portion 23 presses the shaft end portion of the roller shaft 21 supported by the groove end edge portion 25 a of the shaft insertion groove portion 25. The fixed member 26 in the pressed state is prevented from dropping from the inside of the shaft insertion groove 25 inward in the axial direction of the roller shaft 21. This is because the fixing member 26 is engaged with the engaging hole 31 of the side plate portion 23 of the locking piece portion 30.

  A chain guide according to still another embodiment of the present invention will be described with reference to FIGS. As the chain guide of this embodiment, the fixing member 26 has stopper pieces 32 on both sides of the side plate portion 23 in the length direction, and the shaft insertion groove portion 25 is on the groove side surface facing the length plate inner side of the side plate portion 23. The chain guide is different from the chain guide of the first embodiment described above in that it has an engagement hole 33 with which the stopper piece 32 of the fixing member 26 is engaged. The other structure is considered to be the same as that of the chain guide of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  In the chain guide of this embodiment, the shaft insertion groove portion 25 of the side plate portion 23 is formed on the groove side surface facing the inner side in the length direction of the side plate portion 23 and is an engagement hole portion that is recessed outward in the length direction of the side plate portion 23. 33.

  The fixing member 26 is formed with stopper pieces 32 protruding outward in the length direction of the side plate portion 23 on both sides of the side surface of the side plate portion 23 facing outward in the length direction. The stopper piece 32 is elastically deformable in the length direction of the side plate portion 23 and is engaged with the engagement hole portion 33 of the shaft insertion groove portion 25 with a tightening margin in the length direction of the side plate portion 23. Yes.

  The fixing member 26 presses the shaft end portion of the roller shaft 21 against the groove end edge portion 25a of the shaft insertion groove portion 25 in a state where the stopper piece portion 32 is engaged with the engagement hole portion 33 of the side plate portion with tightening allowance. It has become. The fixed member 26 in the pressed state can prevent the roller shaft 21 from falling inward in the axial direction and to the chain 5 side by the stopper piece portion 32 engaged with the engagement hole portion 33 of the side plate portion 23.

1 Crankshaft 2 Drive sprocket 3 Camshaft 4 Driven sprocket 5 Timing chain (chain)
6 fulcrum shafts 7 and 9 chain guide 8 chain tensioners 10 and 11 insertion hole 12 bolt 20 guide base 21 roller shaft 22 roller 22a outer peripheral surface 23 side plate portion 23a side surface 24 connecting portion 25 shaft insertion groove portion 25a groove end edge portion 26 fixing member 26a edge Portion 26b adhesive layer 26c connecting projection 27 outer ring 27a collar 28 roller 29 retainer 30 locking piece 31 engaging hole 31a guide groove 32 stopper piece 33 engaging hole 50 chain transmission device W1 opening width W2 width

Claims (6)

A guide base having a pair of opposed side plate portions extending along the running direction of the chain, and a plurality of shaft end portions supported by the pair of opposed side plate portions and attached at intervals in the length direction of the side plate portions. In a chain guide comprising a roller shaft and a plurality of rollers rotatably supported on each of the roller shafts,
The pair of opposed side plate portions has a shaft insertion groove portion into which the shaft end portion of the roller shaft is fitted on the opposite surface, and the shaft insertion groove portion is spaced from the side surface of the side plate portion on the chain side by the width of the side plate portion. A fixing member is fixed to the shaft insertion groove portion so as to be fitted therein, and the fixing member presses the shaft end portion of the roller shaft. Chain guide. The fixing member has a connecting protrusion that protrudes outward in the axial direction of the roller shaft, and a locking piece that extends in the length direction of the side plate connected to the connecting protrusion.
The side plate portion is positioned on the outer side in the axial direction of the roller shaft with respect to the shaft insertion groove portion, and extends from the side surface on the chain side of the side plate portion in the width direction of the side plate portion; A guide groove that communicates with the shaft insertion groove and extends in the width direction of the side plate from the side surface of the side plate on the chain side;
The coupling protrusion of the fixing member is movable in the width direction of the side plate in a state where the locking piece of the fixing member is fitted in the engagement hole. The chain guide according to claim 1.   3. The chain guide according to claim 1, wherein the fixing member is fitted into the shaft insertion groove with a tightening margin in a length direction of the side plate.   The chain guide according to claim 1, further comprising an adhesive layer made of an adhesive between the fixing member and a groove inner wall of the shaft insertion groove. The fixing member has a stopper piece on the outside in the length direction of the side plate portion,
The shaft insertion groove portion has an engagement hole portion on a groove side surface facing the inner side in the length direction of the side plate portion,
2. The chain guide according to claim 1, wherein the fixing member is configured such that the stopper piece is engaged with an engagement hole of the shaft insertion groove with a tightening margin. A timing chain is placed between the drive sprocket and the driven sprocket, and a swingable chain guide is provided on one side of the slack side chain of the timing chain to guide the movement of the timing chain. In the chain transmission device, the adjustment force of the chain tensioner is applied to the part, and the swing side end is pressed against the timing chain.
The chain transmission device according to any one of claims 1 to 5, wherein the chain guide is the chain guide according to any one of claims 1 to 5.

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