JP2012177391A - Chain guide and chain tensioner device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chain guide 5 which can effectively prevent the fall-down of a chain 1 without forming steps at external peripheral faces of rollers 12, and a chain tensioner using the same.SOLUTION: In the chain guide 5 composed of a plurality of the rollers 12 contacting with the chain 1, and a guide base 9 in which the plurality of rollers 12 are arranged along the chain 1 which is endlessly bridged, the guide base 9 has an opposing side plate member 9a arranged along the traveling direction of the chain 1 which supports both ends of support shafts 13 of the rollers 12, and the height of the side plate member 9a is set higher than outside diameter faces of the rollers 12 which are supported to the side plate member 9a.

Description

  The present invention relates to a chain guide and a chain tensioner device that apply tension to a chain that is stretched endlessly so that the chain is not slackened.

  In the chain tensioner device, a chain guide that contacts the chain is installed in the middle of the chain spanned endlessly between the drive sprocket and the driven sprocket, and at least one of the chain guides is set substantially perpendicular to the traveling direction of the chain. By applying pressure, tension is applied so that slack does not occur in a chain that travels at high speed, and it is used in a timing chain of an engine valve drive device.

  Since the chain guide is guided while being in contact with the chain, there arises a problem that sliding resistance due to friction is generated between the chain guide and noise and mechanical loss increase.

  As a technique for suppressing the noise and mechanical loss of the chain guide, those described in Patent Document 1 or Patent Document 2 are known. The chain guides described in these documents are formed in a curved shape along the running direction of the chain, and a roller is disposed on the sliding surface portion that comes into contact with the chain, and the roller is pressed against the chain running at high speed while rolling. Thus, sliding resistance is reduced.

JP-A-9-236157 JP 2010-180900 A

  By the way, in the chain guides described in these documents, since the chain travels at a high speed, there is a concern that the chain flutters while traveling and the chain falls off the chain guide.

  For this reason, a method for preventing the chain from falling off by providing a step on the outer peripheral surface of the roller in contact with the chain is also conceivable. is there.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a chain guide that can effectively prevent the chain from dropping off without making a step on the outer peripheral surface of the roller, and a chain tensioner device using the same.

  In order to solve the above-mentioned problems, the present invention provides a chain guide comprising a plurality of rollers in contact with a chain and a guide base in which the plurality of rollers are arranged along an endlessly spanned chain. The guide base includes opposing side plate members provided along the running direction of the chain that supports both ends of the support shaft of the roller, and the height of the side plate member is the outer diameter surface of the roller supported by the side plate member. It is characterized by being formed higher than.

  By setting the height of the side plate member to be lower than the position of the connecting pin of the chain that runs in contact with the roller, the connecting pin of the chain does not hit the side plate member, thereby preventing the side plate member from being worn. it can.

  The roller includes a support shaft supported by the side plate member and a needle roller bearing provided on an outer peripheral surface of the support shaft, and an outer ring of the needle roller bearing contacts the chain. Moreover, you may make it cover the iron outer ring which contacts a chain on the outer periphery of the said outer ring | wheel.

  As the needle roller bearing, there can be used a roller comprising a steel outer ring having inward flanges at both ends and a roller with a cage incorporated in the outer ring.

  The steel outer ring is formed by press molding, but may be formed by cut-out molding.

  It is preferable that the steel outer ring or the iron outer ring has a hardness higher than that of the chain so that the steel outer ring or the iron outer ring is less likely to be worn even when a chain running at high speed comes into contact.

  As a material of the steel outer ring or the iron outer ring, for example, a material capable of performing a hardening process such as SUJ2, SCM or the like is preferable.

  From the viewpoint of durability, the curing treatment preferably has a curing depth of 0.05 μm or more.

  The thickness of the steel outer ring or iron outer ring is preferably 1 mm or more in order to prevent deformation and improve strength.

  The bus bar shape of the steel outer ring or iron outer ring is preferably a drum shape or a straight shape in order to avoid local high surface pressure due to point contact with the chain.

  It is preferable to form minute irregularities on the surface of the steel outer ring or iron outer ring in order to improve the lubricating oil retention performance.

  Further, the surface of the steel outer ring or the iron outer ring may be subjected to nitriding treatment to improve the strength.

  The roundness of the steel outer ring or iron outer ring is preferably 20 μm or less in order to reduce vibration and achieve quietness.

  At least two chain guides according to the present invention are arranged in the middle of an endlessly spanned chain, and one chain guide is supported at one end by a rotating shaft and the other end is swung by a pressing device. By constructing so that tension is applied to the chain and one other chain guide is configured so that both ends are fixed and pressed against the chain, an excellent chain tensioner device with less mechanical loss can be obtained. .

In the chain guide according to the present invention, the height of the opposing side plate members provided on both sides of the chain is formed higher than the outer diameter surface of the roller with which the chain contacts. be able to.
In addition, by setting the height of the side plate member lower than the position of the connecting pin of the chain that runs in contact with the roller, the chain connecting pin does not hit the side plate member, thereby preventing the side plate member from being worn. can do.

It is a perspective view showing one embodiment of a chain guide concerning this invention. It is the top view which looked at the chain guide of FIG. 1 from the chain side. It is a front view of the chain guide of FIG. It is a front view which shows embodiment of the top view which shows the state which removed the roller from the chain guide of FIG. It is sectional drawing of the AA line of FIG. It is the elements on larger scale of FIG. It is a transverse cross section showing one embodiment of a chain guide concerning this invention. It is a transverse cross section showing one embodiment of a chain guide concerning this invention. It is a cross-sectional view showing another embodiment of the chain guide according to the present invention. It is a front view which shows an example of the chain tensioner apparatus which uses the chain guide which concerns on this invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated in order to avoid duplication of description.

  The chain guide according to the embodiment of the present invention is used, for example, to apply tension to a timing chain of an engine valve drive system.

  As shown in FIG. 9, the timing chain 1 includes a crank sprocket 2 attached to the crankshaft, a first cam sprocket 3 attached to the first camshaft of the valve operating mechanism, and a second cam sprocket attached to the second camshaft. 4 is wound endlessly.

  The timing chain 1 between the crank sprocket 2 and the first cam sprocket 3 and between the crank sprocket 2 and the second cam sprocket 4 has a first chain guide 5a and a second chain guide 5b so that the timing chain 1 does not loosen. Is arranged.

  The first chain guide 5a is configured such that one end side in the longitudinal direction is rotatably supported by the engine by the rotating shaft 6 and the other end side is swung by the pressing device 7 to apply tension to the timing chain 1. .

  The second chain guide 5b is fixed so that both ends in the longitudinal direction are fixed to the engine by the mounting shaft 8 so that the tensioned timing chain 1 is not loosened.

  The first chain guide 5a and the second chain guide 5b are different in that the first chain guide 5a is swung by the pressing device 7 whereas the second chain guide 5b is fixed to the engine without swinging. Since the basic structure for guiding the timing chain 1 is the same, only the chain guide 5 will be described hereinafter. The chain guide 5 is also referred to as a chain lever.

  The chain guide 5 includes a plurality of rollers 12 that come into contact with the timing chain 1 and a guide base 9 that arranges the plurality of rollers 12 along the timing chain 1 spanned in an endless manner.

  The guide base 9 includes a pair of side plate members 9 a formed in a curved shape along the timing chain 1 and a column member 10 that connects the side plate members 9 a.

  Further, through holes 11 are provided at both longitudinal ends of the side plate member 9a. A shaft (not shown) is inserted into the through hole 11 and attached to the inner wall of the engine cover, for example.

  Like the first chain guide 5a, one end side in the longitudinal direction is rotatably supported by the engine by a rotating shaft, and the other end side is swung by the pressing device 7 to apply tension to the timing chain 1. In this case, the through hole 11 of the side plate member 9a may be provided only on one end side in the longitudinal direction.

  The pressing device 7 that presses the first chain guide 5a may be a mechanical type that presses with a spring or a screw, or a hydraulic type that presses with a hydraulic pressure.

  The pair of side plate members 9a have a predetermined interval in the width direction, and a plurality of rollers 12 that contact the timing chain 1 are arranged between the side plate members 9a. The arrangement of the rollers 12 may be uniform with respect to the curved side plate member 9a, or may be different so that many rollers 12 are arranged on the entrance side of the timing chain 1 in the running direction. Good.

  Support recesses 14 that support both ends of the support shaft 13 of the roller 12 are provided on the opposing wall surface of the side plate member 9a.

  As shown in FIGS. 4, 5, and 6, the support recess 14 includes an insertion recess 14 a that opens to the end surface on the timing chain 1 side, and an end of the support shaft 13 that is continuous with the insertion recess 14 a The both ends of the support shaft 13 of the roller 12 are inserted into the fixed recess 14b from the insertion recess 14a, and the both ends of the side plate member 9a are inserted into the fixed recess 14b. I support it.

  As shown in FIG. 5, a plurality of the support recesses 14 are arranged along the curved shape of the side plate member 9 a, and the column member 10 is disposed between the support recess 14 and the support recess 14.

  As shown in the enlarged view of FIG. 6, the insertion recess 14a is formed in a tapered shape having a wide opening a and gradually narrowing to a position reaching the fixed recess 14b. The width dimension of the insertion port b at a position where it is connected to the location 14b is smaller than the diameter φ of the arc-shaped fixed recess 14b.

  A diameter φ of the arc-shaped fixed recess 14b is formed to be smaller than the diameter of the support shaft 13, and the support shaft 13 is press-fitted and fixed to the fixed recess 14b.

  Further, as shown in FIGS. 1 and 2, the support recess 14 is formed in a non-penetrating state in the side plate member 9a. Thereby, the movement of the inserted support shaft 13 in the axial direction is restricted.

  In this embodiment, the side plate member 9a and the column member 10 are integrally formed by resin molding using, for example, polyamide (PA) 46 or polyamide (PA) 66, which is a polymer obtained by polycondensation of diaminobutane and adipic acid. Is done. Moreover, in order to increase mechanical strength, the thing which compounded glass fiber and carbon fiber in PA46 and PA66 can also be used.

  Weight reduction can be achieved by forming the side plate member 9a and the column member 10 with resin. Moreover, the resin which forms with the side plate member 9a and the column member 10 can use a highly heat conductive thing in order to thermally radiate frictional heat.

  The side plate member 9a and the column member 10 can be formed by casting or die casting using a light metal such as aluminum or magnesium, for example, other than the resin.

  As shown in FIG. 7, the roller 12 includes the support shaft 13 and a needle roller bearing having a steel outer ring 12 a, and the steel outer ring 12 a contacts the timing chain 1. Moreover, as shown in FIG. 8, you may make it cover the iron outer ring 12d which contacts the timing chain 1 on the outer peripheral surface of the steel outer ring 12a.

  The needle roller bearing is a radial needle roller bearing including a steel outer ring 12a having inward flanges at both ends and a roller 12c with a cage 12b incorporated in the outer ring 12a.

  The outer ring 12a can be formed by press molding or scraping molding.

  When the outer ring 12a is formed by press molding, it is preferable that the inward flanges at both ends are subjected to edge bending after the cage 12b and 12c are assembled, and heat-treated after assembly.

  Further, the hardness of the outer ring 12a or the iron outer ring 12d is higher than the hardness of the timing chain 1, so that wear can be prevented.

  As the material of the outer ring 12a or the iron outer ring 12d, a material that can be hardened by heat treatment, such as SUJ2 or SCM, is used.

  When the outer ring 12a or the iron outer ring 12d is cured by heat treatment, the curing depth is preferably 0.05 μm or more.

  Minute irregularities may be formed on the surface of the outer ring 12a or the iron outer ring 12d in order to improve the lubricating oil retention performance.

  The surface of the outer ring 12a or the iron outer ring 12d may be subjected to nitriding treatment.

  The generatrix shape on the surface of the outer ring 12a or the iron outer ring 12d is preferably a drum shape or a straight shape in order to avoid local high surface pressure due to point contact with the timing chain 1.

  The roundness of the outer ring 12a or the outer ring 12d made of iron is desirably 20 μm or less in order to reduce vibration and achieve quietness.

  The thickness of the outer ring 12a or the iron outer ring 12d is preferably 1 mm or more in terms of strength.

  The rollers 12c are held at a predetermined interval in the circumferential direction by a cage 12b. As the cage 12b, a V-type cage having a V-shaped column part is used. By using the cage 12b, skew of the roller 12c can be prevented, the end surface of the roller 12c can be prevented from directly touching the collar portion of the outer ring 12a, and wear of the side plate member 9a can be prevented. In addition, you may comprise with the rolling bearing of the full roller structure which does not use the holder | retainer 12b.

  Next, in order to assemble the roller 12 to the opposing side plate member 9a, first, as shown in FIG. 5, the roller 12 fitted with the support shaft 13 is prepared. Then, both ends of the support shaft 13 of the roller 12 face the insertion recess 14a of the support recess formed on the opposing wall surface of the side plate member 9a, and are fixed into the insertion recess 14a by dropping into the insertion recess 14a. Insert into the recess 14b. In this embodiment, since the opening a is wide and the insertion recess 14a is formed in a taper shape, when the support shaft 13 is inserted, the support shaft 13 can be easily moved from the opening a through the insertion port b. It can be guided to the arcuate fixed recess 14b.

  According to the above embodiment, since the diameter φ of the arc-shaped fixed recess 14b is smaller than the diameter of the support shaft 13, the support shaft 13 is press-fitted and attached to the fixed recess 14b. As a result, the rotation of the support shaft 13 can be suppressed. Moreover, since the width of the insertion port b connected to the fixed recess 14b is smaller than the diameter φ of the arc-shaped fixed recess 14b, the insertion port b functions to prevent the support shaft 13 from coming off. Furthermore, since the support recess 14 is formed so as not to penetrate the side plate member 9a, the axial movement of the support shaft 13 to be inserted can be restricted.

  Next, with the support shaft 13 of the roller 12 fitted in the support recess 14 of the opposing side plate member 9a, as shown in FIGS. 1, 3, 4 and 7, the outer peripheral surface of the roller 12 is It is lower than the end face of the side plate member 9a.

  That is, the height of the side plate member 9a is formed so as to be higher than the outer diameter surface of the roller 12, whereby the timing chain 1 is guided between the opposing wall surfaces of the side plate member 9a and travels. The chain 1 is prevented from falling off the opposing wall surface of the side plate member 9a.

  Moreover, as shown in FIG. 7, it is desirable that the height to the end surface of the side plate member 9a is lower than the position of the connecting pin 1b that connects the plates 1a constituting the timing chain 1. If the height to the end face of the side plate member 9a is higher than the position of the connecting pin 1b that connects the plates 1a constituting the timing chain 1, the connecting pin 1b hits the opposing wall surface of the side plate member 9a, which is not preferable. .

  Next, FIG. 9 is a cross-sectional view showing a chain guide 5 according to another embodiment of the present invention. About this embodiment, about the structure which is common in embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted and a different structure is demonstrated below. In this embodiment, as shown in FIG. 8, an oil hole 15 is provided at the center of the support shaft 13, and a discharge hole 15 a through which oil is discharged is provided at a position opposite to the timing chain 1. The side plate member 9 a is provided with a hole 16 that is continuous with the oil hole 15. Thus, by providing the oil hole 15, oil can be supplied into the bearing. In addition, heat can be released. As described above, the direction of the discharge hole 15a of the oil hole 15 is preferably opposite to that of the timing chain 1, so that the oil is smoothly supplied into the bearing. Further, the support shaft 13 is hollowed by the oil hole 15a, so that the weight can be reduced.

  Further, the chain guide 5 of each embodiment of the present invention can apply tension to various drive chains in addition to the engine timing chain, and can reduce mechanical loss.

  As shown in FIG. 10, the chain tensioner device using the chain guide 5 of the present invention has a first chain in which the rotating shaft 6 is inserted into the through hole 11 at one end and the other end is swung by the pressing device 7. The guide 5a and the second chain guide 5b, both ends of which are fixed to the engine by the mounting shaft 8, are configured. According to this chain tensioner device, the mechanical loss of the engine timing chain can be reduced and the weight thereof can be reduced, and the fuel consumption rate can be improved.

  The timing chain 1 can be either a roller chain or a silent chain.

  Moreover, in the above embodiment, although the example which formed the side-plate member 9a and the column member 10 integrally was shown, you may divide | segment both and form them separately.

  The chain guide according to the present invention is effectively used in a mechanism for applying tension to a drive chain such as an engine.

DESCRIPTION OF SYMBOLS 1 Timing chain 2 Crank sprocket 3 1st cam sprocket 4 2nd cam sprocket 5 Chain guide 5a 1st chain guide 5b 2nd chain guide 6 Rotating shaft 7 Pressing device 8 Mounting shaft 9 Guide base 9a Side plate member 10 Column member 11 Through-hole 12 Roller 12a Outer ring 12b Cage 12c Roller 12d Iron outer ring 13 Support shaft 14 Support recess 14a Insertion recess 14b Fixed recess 15 Oil hole 15a Discharge hole 16 Hole

Claims (16)

  In a chain guide comprising a plurality of rollers in contact with the chain and a guide base arranged along the endlessly spanned chain, the guide base has both ends of the support shaft of the roller. A chain comprising opposing side plate members provided along a running direction of a chain to be supported, wherein the side plate member has a height higher than an outer diameter surface of a roller supported by the side plate member. guide.   The chain guide according to claim 1, wherein a height of the side plate member is set to be lower than a position of a connecting pin of a chain that runs in contact with the roller.   The chain guide according to claim 1 or 2, wherein the roller is constituted by the support shaft and a needle roller bearing including an outer ring provided on an outer peripheral surface of the support shaft.   The chain guide according to claim 3, wherein an outer ring of the needle roller is covered with an iron outer ring that contacts the chain.   The chain guide according to claim 3 or 4, wherein the needle roller bearing includes a steel outer ring having inward flanges at both ends and a roller with a cage incorporated in the outer ring.   The chain guide according to any one of claims 3 to 5, wherein the steel outer ring is formed by press molding.   The chain guide according to any one of claims 3 to 6, wherein the steel outer ring is formed by machining.   The chain guide according to any one of claims 3 to 7, wherein the hardness of the steel outer ring or the iron outer ring is higher than the hardness of the chain.   The chain guide according to any one of claims 3 to 7, wherein a bus bar shape of the steel outer ring or the iron outer ring is a drum shape or a straight shape.   The chain guide according to any one of claims 3 to 9, wherein minute irregularities for improving the retention performance of the lubricating oil are formed on a surface of the steel outer ring or the iron outer ring.   The chain guide according to any one of claims 3 to 10, wherein a thickness of the steel outer ring or the iron outer ring is 1 mm or more.   The chain guide according to any one of claims 3 to 11, wherein a surface of the steel outer ring or the iron outer ring is subjected to a hardening treatment having a depth of 0.05 µm or more.   The chain guide according to claim 12, wherein a surface of the steel outer ring or the iron outer ring is subjected to nitriding treatment.   The chain guide according to any one of claims 3 to 13, wherein the roundness of the steel outer ring or the iron outer ring is 20 µm or less.   The chain tensioner apparatus by which the chain guide in any one of Claims 1-14 is arrange | positioned in the middle part of the chain spanned endlessly.   At least two chain guides according to any one of claims 1 to 14 are arranged in the middle of the endlessly spanned chain, and one chain guide is supported at one end side by a rotating shaft and at the other end side. A chain tensioner device configured to swing by a pressing device and apply tension to the chain, and the other one chain guide is configured such that both ends are fixed and pressed against the chain.

Images