JP2018146101A - Tensioner integrated chain guide and chain tensile force adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tensioner integrated chain guide which needs a small number of work hours for attachment to an engine block and eliminates the need of processing of an oil supply passage to the engine block.SOLUTION: A tensioner integrated chain guide includes: a chain guide 10 which is supported so as to swing in response to a tensile force of a chain 7; a cylinder 11 which is fixedly provided at the chain guide 10; a cylindrical plunger 12 which is inserted into the cylinder 11 so as to slide in an axial direction; a screw rod 13 inserted into the plunger 12; a male screw 17 formed at an outer periphery of the screw rod 13; a female screw 18 which is formed at an inner periphery of the plunger 12 so as to threadedly engage with the male screw 17; and a return spring 15 which is assembled into a space between the screw rod 13 and the plunger 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tensioner-integrated chain guide used for a chain transmission device of an internal combustion engine, and a chain tension adjusting device using the tensioner-integrated chain guide.

  As a chain transmission device used in an internal combustion engine such as an automobile engine, for example, the transmission of crankshaft rotation to a camshaft, or transmission of crankshaft rotation to an auxiliary device such as an oil pump, a water pump or a supercharger There are those that transmit the rotation of the crankshaft to the balancer shaft, and those that connect the intake cam and the exhaust cam of the twin cam engine. A chain tensioner is used to keep the chain tension of these chain transmission devices within an appropriate range.

  As this chain tensioner, for example, the one described in Patent Document 1 is known. The chain tensioner of Patent Document 1 includes a cylinder fixed to an engine block, a cylindrical plunger that is slidably inserted in the cylinder in the axial direction, and a return that urges the plunger in a direction in which the plunger protrudes from the cylinder. An oil supply passage for supplying hydraulic oil to a pressure chamber surrounded by the spring, the cylinder and the plunger, and a check valve provided at an end portion of the oil supply passage on the pressure chamber side.

  This chain tensioner is used with the protruding end of the plunger from the cylinder in contact with the chain guide. The chain guide is a member that is supported so as to swing according to the tension of the chain. The chain tensioner contacts the surface of the chain guide opposite to the side in contact with the chain, and presses the chain guide toward the chain.

  When the chain tension increases during engine operation, the chain tension is transmitted to the chain tensioner via the chain guide, and the chain tensioner plunger moves into the cylinder to absorb the chain tension. . At this time, a damper force is generated by the hydraulic oil filled in the pressure chamber surrounded by the cylinder and the plunger. On the other hand, when the tension of the chain is reduced during the operation of the engine, the plunger of the chain tensioner moves in a direction protruding from the cylinder, and the plunger presses the chain via the chain guide to absorb the slack of the chain. At this time, since the volume of the pressure chamber surrounded by the cylinder and the plunger is increased, the check valve of the oil supply passage is opened, and the hydraulic oil supplied from the oil pump is introduced into the pressure chamber through the oil supply passage.

JP 2011-21646 A

  By the way, the chain tensioner of Patent Document 1 requires supply of hydraulic pressure by an oil pump. Therefore, it is necessary to process an oil supply passage for the chain tensioner in the engine block, which is expensive. In addition to the work of attaching the chain guide to the engine block, it is necessary to perform the work of attaching the cylinder of the chain tensioner to the engine block with a plurality of bolts.

  The problem to be solved by the present invention is to provide a tensioner-integrated chain guide that requires less man-hours for attachment to the engine block and that does not require processing of an oil supply passage to the engine block.

In order to solve the above problems, the present invention provides a tensioner-integrated chain guide having the following configuration.
A chain guide that contacts the chain and is supported to swing according to the tension of the chain;
A cylinder that is fixed to the chain guide so as to move integrally with the chain guide when the chain guide swings, and that opens to the opposite side of the chain guide that contacts the chain;
A cylindrical plunger that is slidably inserted in the cylinder in the axial direction, an insertion end into the cylinder is open, and a protruding end from the cylinder is closed;
A screw rod inserted into the plunger in a state where one end is accommodated in the plunger and the other end protrudes from an insertion end of the plunger into the cylinder;
A male screw formed on the outer periphery of the screw rod;
A female screw formed on the inner periphery of the plunger so as to be screw-engaged with the male screw;
A tensioner-integrated chain guide comprising: a return spring that is incorporated between the screw rod and the plunger and biases the plunger in a direction in which the plunger protrudes from the cylinder.

  In this way, the tensioner function is integrated with the chain guide, so there is no need to install the chain tensioner on the engine block separately from the operation of installing the chain guide on the engine block. There are few mounting man-hours. Further, when the chain tension increases during engine operation, the plunger moves in the direction in which the plunger is pushed into the cylinder by the chain tension, and absorbs the chain tension. At this time, the plunger and the screw rod rotate relative to each other while the female screw on the inner periphery of the plunger and the male screw on the outer periphery of the screw rod slide with each other, so that a damper action occurs due to the frictional resistance between the male screw and the female screw. Thus, since the damper action is obtained by the frictional resistance between the male screw and the female screw, it is not necessary to supply hydraulic pressure to the tensioner-integrated chain guide, and processing of the oil supply passage to the engine block is unnecessary.

  A rod sheet that supports an end surface of the screw rod that protrudes from the plunger can be provided in the cylinder.

  It is preferable to provide an oil introduction hole for introducing splashed oil outside the cylinder into the cylinder on the outer periphery of the cylinder.

  In this way, the oil introduced into the cylinder through the oil introduction hole smoothly slides between the male screw on the outer periphery of the screw rod and the female screw on the inner periphery of the plunger, thereby preventing wear of the male screw and the female screw. Can do.

  The female screw and the male screw have a flank angle of the pushing-side flank that receives pressure when a load is applied in a direction in which the plunger is pushed into the cylinder, and a load in a direction in which the plunger protrudes from the cylinder is applied. A sawtooth shape larger than the flank angle of the protruding flank receiving pressure can be formed.

  If it does in this way, since the sliding resistance between the pushing side flank of a male screw and a female screw becomes large, it becomes possible to exhibit a high damper effect | action.

  At this time, the flank angle of the pushing side flank can be set in a range of 72 ° to 78 °, and the flank angle of the protruding side flank can be set in a range of 12 ° to 18 °.

  The surface of at least one of the female screw and the male screw can be a satin finish.

  In this case, the satin finish prevents the oil film from being formed by the squeeze effect between the male screw and the female screw, so that a stable damper action can be obtained.

  Further, in the present invention, as the chain tension adjusting device using the above-described tensioner-integrated chain guide, the above-described tensioner-integrated chain guide, a fulcrum shaft that supports the tensioner-integrated chain guide in a swingable manner, and the tensioner There is provided a chain tension adjusting device comprising: an abutment pin fixed at a position facing the protruding end of the plunger from the cylinder so as to receive the protruding end of the plunger of the integral chain guide from the cylinder.

  This chain tension adjusting device can be installed on the engine block simply by attaching a single abutment pin to the engine block as a member other than the chain guide attached to the engine block. Few.

  By the way, when the chain guide swings around the fulcrum shaft, sliding in the direction perpendicular to the fulcrum shaft occurs between the protruding end of the plunger from the cylinder and the contact surface of the contact pin. If this sliding is not performed smoothly, the swing of the chain guide may become unstable. Therefore, it is preferable that the contact pin has a contact surface with respect to the protruding end of the plunger from the cylinder in a cylindrical shape parallel to the fulcrum shaft.

  In this way, when sliding in the direction perpendicular to the fulcrum shaft occurs between the protruding end of the plunger from the cylinder and the contact surface of the contact pin, the sliding is smooth and the chain guide swings. It will be stable.

  The plunger center line and the cylindrical shape generated when the protruding length of the plunger from the cylinder is changed while keeping the protruding end of the plunger from the cylinder in contact with the contact pin. It is preferable that the maximum deviation of the contact surface from the center of the cylinder is 3 mm or less.

  In this way, the abutment pin contacts the plunger at a position on the plunger center line or close to within 3 mm from the center line, so that it is possible to prevent the moment from falling and acting on the plunger. The sliding of the female screw on the periphery and the male screw on the outer periphery of the screw rod can be made smooth.

  The contact pin can be fixed by press-fitting the end of the contact pin into a pin insertion hole formed in the engine block.

  If it does in this way, attachment work of a contact pin will become very easy.

  A screw shaft portion may be provided on the contact pin, and the screw pin portion may be screwed into a screw hole formed in the engine block to fix the contact pin.

  If it does in this way, attachment work of a contact pin will become very easy.

  The tensioner-integrated chain guide of the present invention integrates the function of the tensioner with the chain guide, so it is necessary to perform the work of attaching the chain tensioner to the engine block separately from the work of attaching the chain guide to the engine block. There is little, and the man-hour for mounting to the engine block is small. Further, when the chain tension increases during engine operation, the plunger moves in the direction in which the plunger is pushed into the cylinder by the chain tension, and absorbs the chain tension. At this time, the plunger and the screw rod rotate relative to each other while the female screw on the inner periphery of the plunger and the male screw on the outer periphery of the screw rod slide with each other, so that a damper action occurs due to the frictional resistance between the male screw and the female screw. Thus, since the damper action is obtained by the frictional resistance between the male screw and the female screw, it is not necessary to supply hydraulic pressure to the tensioner-integrated chain guide, and processing of the oil supply passage to the engine block is unnecessary.

The fragmentary sectional view which shows the chain transmission device which employ | adopted the chain tension adjustment apparatus containing the tensioner integrated chain guide of embodiment of this invention FIG. 1 is an enlarged sectional view in the vicinity of the plunger of FIG. Enlarged cross-sectional view of male and female threads shown in FIG. Fig. 2 is a top view of the contact pin and plunger shown in Fig. 2. The figure which shows the other example of the contact pin of FIG. The figure which shows the state which the protrusion length from the cylinder of the plunger of FIG. 2 became the minimum. The figure which shows the state which the protrusion length from the cylinder of the plunger of FIG. 2 became the maximum. The figure which shows the modification which provided the oil introduction hole and the oil discharge hole in the cylinder of FIG. FIG. 3 is an enlarged cross-sectional view showing a modification in which the surface of the male screw shown in FIG. FIG. 3 is an enlarged cross-sectional view showing a modified example in which an oil film exclusion groove is provided on the pushing side flank of the male screw shown in FIG. Sectional drawing which shows the modification which added the assist spring to the chain tensioner of FIG. The figure which shows the modification which made the part which slidably contacts the chain of the chain guide shown in FIG. 1, and other parts into a different body.

  FIG. 1 shows a chain transmission device employing a chain tension adjusting device 2 including a tensioner-integrated chain guide 1 according to an embodiment of the present invention. In this chain transmission device, a sprocket 4 fixed to an engine crankshaft 3 and a sprocket 6 fixed to a camshaft 5 are connected via a chain 7, and the chain 7 rotates the crankshaft 3. This is transmitted to the camshaft 5, and the valve (not shown) of the combustion chamber is opened and closed by the rotation of the camshaft 5.

  When the engine is operating, the rotation direction of the crankshaft 3 is constant (right rotation in the figure). At this time, the chain 7 is pulled into the sprocket 4 as the crankshaft 3 rotates (right side in the figure). The portion on the side is the tension side, and the portion (left side in the figure) sent out from the sprocket 4 is the slack side. A chain tension adjusting device 2 is provided on the slack side portion of the chain 7. The chain tension adjusting device 2 includes a tensioner integrated chain guide 1, a fulcrum shaft 8 that supports the tensioner integrated chain guide 1 in a swingable manner, and a contact pin 9.

  As shown in FIGS. 1 and 2, the tensioner-integrated chain guide 1 includes a chain guide 10 that contacts the chain 7, a cylinder 11 that opens on the opposite side of the chain guide 10 from the side that contacts the chain 7, and a cylinder 11 is a cylindrical plunger 12 that is slidably inserted in the axial direction in 11, one end is accommodated in the plunger 12, and the other end protrudes from the insertion end of the plunger 12 into the cylinder 11. A screw rod 13 inserted into the plunger 12, a rod sheet 14 incorporated in the cylinder 11 so as to support an end surface of the screw rod 13 projecting from the plunger 12, and between the screw rod 13 and the plunger 12. And a return spring 15 incorporated in the housing.

  As shown in FIG. 1, the chain guide 10 has an elongated shape extending along the chain 7. A fulcrum hole 16 is formed at the end of the chain guide 10, and the chain guide 10 is swingably supported around a fulcrum shaft 8 inserted into the fulcrum hole 16. The fulcrum shaft 8 is fixed to the engine block 24 (see FIG. 4). The chain guide 10 is in contact with the chain 7 from the outer peripheral side of the travel path of the chain 7 so as to swing according to the tension of the chain 7.

  The cylinder 11 is formed integrally with the chain guide 10 so as to move together with the chain guide 10 when the chain guide 10 swings. As a material of the cylinder 11 and the chain guide 10, a synthetic resin mixed with a fiber reinforcing material can be used. As the synthetic resin, for example, polyamide (PA) such as nylon 66 or nylon 46 can be used. Moreover, as a fiber reinforcing material mix | blended with a synthetic resin, glass fiber, carbon fiber, an aramid fiber, etc. can be used.

  As shown in FIG. 2, the plunger 12 is formed in a cylindrical shape in which an insertion end into the cylinder 11 is opened and a protruding end from the cylinder 11 is closed. The material of the plunger 12 is an iron-based material (for example, a steel material such as SCM or SCr). The outer periphery of the plunger 12 is a cylindrical surface, and the inner periphery of the cylinder 11 is also a cylindrical surface. The size of the gap between the outer periphery of the plunger 12 and the inner periphery of the cylinder 11 is very small, and is set in a range of 0.015 to 0.080 mm in radius difference.

  A male screw 17 is formed on the outer periphery of the screw rod 13. The male screw 17 is screw-engaged with a female screw 18 formed on the inner periphery of the plunger 12. The material of the screw rod 13 is an iron-based material (for example, a steel material such as SCM or SCr). The male screw 17 can be formed by forming a blank (bottomed cylindrical material) of the screw rod 13 by cold forging and then rolling the outer periphery of the blank.

  The male screw 17 on the outer periphery of the screw rod 13 and the female screw 18 on the inner periphery of the plunger 12 have a flank angle θ1 (see FIG. 3) of the pushing-side flank 19 that receives pressure when a load in the direction of pushing the plunger 12 into the cylinder 11 is applied. Is formed in a sawtooth shape larger than the flank angle θ2 (see FIG. 3) of the protruding flank 20 that receives pressure when a load in a direction in which the plunger 12 protrudes from the cylinder 11 is applied.

  A return spring 15 is incorporated between the protruding end of the plunger 12 from the cylinder 11 and the screw rod 13. One end of the return spring 15 is accommodated in a spring accommodating hole 21 formed in the end surface of the screw rod 13 on the side accommodated in the plunger 12 and supported by the bottom surface of the spring accommodating hole 21. . The other end of the return spring 15 presses the end of the plunger 12 that protrudes from the cylinder 11 via the spring seat 22. By this pressing, the return spring 15 urges the plunger 12 in a direction in which the plunger 12 protrudes from the cylinder 11.

  As shown in FIG. 3, the flank angle θ1 of the push-in flank 19 of the male screw 17 and the female screw 18 is set in a range of 72 ° to 78 °. By setting the flank angle θ1 of the pushing side flank 19 to 72 ° or more, when an axial load in the direction of pushing the plunger 12 into the cylinder 11 is statically applied between the screw rod 13 and the plunger 12, the male screw It is possible to reliably prevent slippage between the push-in side flank 19 of the female screw 17 and the female screw 18. Further, by setting the flank angle θ1 of the push-side flank 19 to 78 ° or less, when an axial load in a direction of pushing the plunger 12 into the cylinder 11 is applied between the screw rod 13 and the plunger 12, the male screw 17 It is possible to prevent the female screw 18 from being locked like a wedge.

  The flank angle θ2 of the protruding flank 20 of the male screw 17 and the female screw 18 is set in a range of 12 ° to 18 °. By setting the flank angle θ2 of the protruding flank 20 to 18 ° or less, when an axial load in a direction in which the plunger 12 protrudes from the cylinder 11 is statically applied between the screw rod 13 and the plunger 12, a male screw The screw rod 13 and the plunger 12 can be smoothly moved relative to each other in the direction in which the plunger 12 protrudes from the cylinder 11 by causing slippage between the protrusion 17 of the female screw 18 and the protruding flank 20 of the female screw 18.

  As shown in FIG. 4, the contact pin 9 is fixed at a position facing the protruding end of the plunger 12 from the cylinder 11 so as to receive the protruding end of the plunger 12 from the cylinder 11. In the contact pin 9, a contact surface 23 with respect to a protruding end of the plunger 12 from the cylinder 11 is formed in a cylindrical shape parallel to the fulcrum shaft 8. The abutment pin 9 may be formed in a cylindrical shape only on the surface facing the protruding end of the plunger 12 from the cylinder 11, but as shown in the figure, the protruding end of the plunger 12 from the cylinder 11 If the opposing portions are made cylindrical over the entire circumference, the cost is low.

  The surface of the contact pin 9 (particularly the contact surface 23 with the plunger 12) is preferably subjected to a chromization process or a diamond-like carbon (DLC) film coating process. If it does in this way, wear of contact pin 9 can be prevented effectively.

  The contact pin 9 is fixed by press-fitting the end of the contact pin 9 into a pin insertion hole 25 formed in the engine block 24. The pin insertion hole 25 is a hole parallel to the fulcrum shaft 8. Here, an example in which the end portion of the contact pin 9 is press-fitted into the pin insertion hole 25 in order to facilitate the mounting operation of the contact pin 9 has been described. However, as shown in FIG. The contact pin 9 may be fixed by providing the screw shaft portion 9 a and screwing the screw shaft portion 9 a into the screw hole 26 formed in the engine block 24. If it does in this way, attachment work of contact pin 9 will become very easy. In this case, it is preferable to form a tool engaging portion 27 (for example, a two-surface width portion) on the contact pin 9 with which a tool for rotating the contact pin 9 is engaged.

  As shown in FIG. 6, when the protruding length of the plunger 12 from the cylinder 11 is minimized while keeping the protruding end of the plunger 12 from the cylinder 11 in contact with the contact pin 9, The contact pin 9 is arranged so that the center line L substantially coincides with the cylindrical center O of the contact pin 9. As shown in FIG. 7, when the protrusion length of the plunger 12 from the cylinder 11 is maximized, the center line L of the plunger 12 is larger than when the protrusion length of the plunger 12 from the cylinder 11 is minimized. Is shifted closer to the fulcrum shaft 8 than the cylindrical center O of the contact pin 9. At this time, the fixed position of the cylinder 11 with respect to the chain guide 10 is set so that the deviation g between the center line L of the plunger 12 and the cylindrical center O of the contact pin 9 is 3 mm or less.

  Next, an operation example of the tensioner-integrated chain guide 1 will be described.

  When the tension of the chain 7 is increased during the operation of the engine, the chain guide 10 moves in the direction approaching the contact pin 9 and the plunger 12 moves in the direction in which the plunger 12 is pushed into the cylinder 11 due to the tension of the chain 7. Absorb the tension of 7. At this time, the plunger 12 and the screw rod 13 rotate relative to each other while the pushing-side flank 19 of the female screw 18 on the inner periphery of the plunger 12 and the pushing-side flank 19 of the male screw 17 on the outer periphery of the screw rod 13 slide with each other. A damper action is generated by the frictional resistance between the pushing side flank 19 of the male screw 17 and the female screw 18.

  On the other hand, when the tension of the chain 7 becomes smaller during the operation of the engine, the chain guide 10 moves away from the contact pin 9 and the plunger 12 protrudes from the cylinder 11 to absorb the slack of the chain 7. At this time, due to the urging force of the return spring 15, the protruding flank 20 of the female screw 18 on the inner periphery of the plunger 12 abuts on the protruding flank 20 of the male screw 17 on the outer periphery of the screw rod 13. The screw rod 13 is rotated by the slip between the projecting side flank 20, and the plunger 12 moves in a direction projecting from the cylinder 11.

  Further, when the engine is stopped, the tension of the chain 7 may increase depending on the stop position of the camshaft 5. In this case, since the chain 7 does not vibrate, no slip occurs between the push-side flank 19 of the female screw 18 on the inner periphery of the plunger 12 and the push-side flank 19 of the male screw 17 on the outer periphery of the screw rod 13. The position is fixed, and the movement of the chain guide 10 toward the contact pin 9 is locked. Therefore, when the engine is restarted, the chain 7 is hardly slackened, and the engine can be started smoothly.

  In this tensioner-integrated chain guide 1, the function of the tensioner is integrated with the chain guide 10, so that the operation of attaching the chain tensioner to the engine block 24 is separate from the operation of attaching the chain guide 10 to the engine block 24. There is no need to perform the operation, and the number of mounting steps to the engine block 24 is small. Further, since the damper action is obtained by the frictional resistance between the male screw 17 and the female screw 18, it is not necessary to supply hydraulic pressure to the tensioner-integrated chain guide 1, and processing of the oil supply passage to the engine block 24 is unnecessary.

  Further, the tensioner-integrated chain guide 1 employs the sawtooth male screw 17 and the female screw 18 in which the flank angle θ1 of the pushing-side flank 19 is larger than the flank angle θ2 of the protruding flank 20, and therefore the male screw 17 and the female screw are used. The sliding resistance between the 18 pushing side flank 19 is large, and a high damper action can be exhibited.

  Further, the chain tension adjusting device 2 can be attached to the engine block 24 only by attaching the single contact pin 9 to the engine block 24 as a member other than the chain guide 10 to be attached to the engine block 24. The number of mounting steps for the engine block 24 is small.

  By the way, when the chain guide 10 swings around the fulcrum shaft 8, sliding in the direction perpendicular to the fulcrum shaft 8 occurs between the protruding end of the plunger 12 from the cylinder 11 and the contact surface of the contact pin 9. . If this sliding is not performed smoothly, the swing of the chain guide 10 may become unstable.

  On the other hand, the chain tension adjusting device 2 employs the contact pin 9 in which the contact surface 23 with respect to the protruding end of the plunger 12 from the cylinder 11 is formed in a cylindrical shape parallel to the fulcrum shaft 8. When sliding in the direction orthogonal to the fulcrum shaft 8 occurs between the projecting end of the plunger 12 from the cylinder 11 and the contact surface of the contact pin 9, the sliding is smooth and the chain guide 10 swings. Is stable.

  In addition, as shown in FIGS. 6 and 7, the chain tension adjusting device 2 is configured so that the protruding end of the plunger 12 from the cylinder 11 is kept in contact with the contact pin 9, while the plunger 11 is moved from the cylinder 11. The maximum shift amount g between the center line L of the plunger 12 and the cylindrical center O of the cylindrical contact surface 23 of the contact pin 9 generated when the protrusion length is changed is 3 mm or less. That is, since the contact pin 9 contacts the plunger 12 at a position on the center line L of the plunger 12 or within 3 mm from the center line L, it is possible to prevent a falling moment from acting on the plunger 12, and as a result. The sliding of the internal thread 18 on the inner periphery of the plunger 12 and the external thread 17 on the outer periphery of the screw rod 13 is smooth.

  As shown in FIG. 8, splash oil outside the cylinder 11 (for example, splash oil scattered by a chain 7 rotating inside the engine) is placed inside the cylinder 11 on the upper part of the outer periphery of the cylinder 11. You may provide the oil introduction hole 30 to introduce. In this way, the oil introduced into the cylinder 11 from the oil introduction hole 30 smoothly slides between the external thread 17 on the outer periphery of the screw rod 13 and the internal thread 18 on the inner periphery of the plunger 12, Wear of the internal thread 18 can be prevented. Furthermore, an oil discharge hole 31 that discharges oil inside the cylinder 11 to the outside of the cylinder 11 may be provided in a portion of the outer periphery of the cylinder 11 facing downward. In this way, the wear powder generated inside the cylinder 11 can be discharged to the outside of the cylinder 11 together with the oil, and the wear powder is caught between the male screw 17 of the screw rod 13 and the female screw 18 of the plunger 12. Can be prevented.

  As shown in FIG. 9, the surface of the male screw 17 (preferably the portion of the pushing side flank 19) can be made into a satin finish. By doing so, the satin finish prevents an oil film due to the squeeze effect from being formed between the male screw 17 and the female screw 18, so that a stable damper action can be obtained. In the figure, an example in which the surface of the male screw 17 is a satin finish is shown, but the surface of the female screw 18 may be a satin finish, and the surfaces of both the male screw 17 and the female screw 18 may be a satin finish. The satin can be processed by shot peening.

  As shown in FIG. 10, an oil film exclusion groove 32 may be formed in the pushing side flank 19 of the male screw 17. Even in this case, since the oil film exclusion groove 32 prevents the oil film due to the squeeze effect from being formed between the male screw 17 and the female screw 18, a stable damper action can be obtained. As the oil film removal groove 32, when a spiral groove extending along the lead of the screw is employed in the central portion of the pushing side flank 19, the oil film removal groove 32 can be formed simultaneously with the rolling of the male screw 17. Cost.

  As shown in FIG. 11, an assist spring 33 may be added. In FIG. 11, the assist spring 33 is a compression coil spring incorporated between the insertion end of the plunger 12 into the cylinder 11 and the rod seat 14. When the assist spring 33 is provided, the biasing force in the direction in which the plunger 12 protrudes from the cylinder 11 is increased, and the followability of the chain guide 10 to the chain 7 can be improved.

  In the above-described embodiment, the cylinder 11 fixed to the chain guide 10 has been described as an example in which the chain guide 10 and the chain guide 10 are integrally formed. However, the cylinder 11 is formed separately from the chain guide 10. Then, the cylinder 11 may be attached to the chain guide 10 and fixed. In this case, the cylinder 11 can be formed of an aluminum alloy, and the chain guide 10 can be formed of a synthetic resin containing a fiber reinforcement. Further, as shown in FIG. 12, only a portion 10a of the chain guide 10 that is in sliding contact with the chain 7 is formed of a synthetic resin containing a fiber reinforcing material, and the portion 10b other than the portion of the chain guide 10 that is in sliding contact with the chain 7 The cylinder 11 may be integrally formed with an aluminum alloy.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Tensioner-integrated chain guide 2 Chain tension adjusting device 7 Chain 8 Support shaft 9 Contact pin 9a Screw shaft portion 10 Chain guide 11 Cylinder 12 Plunger 13 Screw rod 14 Rod seat 15 Return spring 17 Male screw 18 Female screw 19 Push side flank 20 Projection Side flank 23 Contact surface 24 Engine block 25 Pin insertion hole 26 Screw hole 30 Oil introduction hole θ1, θ2 Flank angle L Center line O Cylindrical center g Deviation

Claims (11)

A chain guide (10) that contacts the chain (7) and is supported so as to swing according to the tension of the chain (7);
The chain guide (10) is fixed to the chain guide (10) so as to move integrally with the chain guide (10) when the chain guide (10) swings, and the chain (7) of the chain guide (10) A cylinder (11) that opens to the opposite side to the side that contacts
A cylindrical plunger (12) which is inserted into the cylinder (11) so as to be slidable in the axial direction, an insertion end into the cylinder (11) is opened, and a protruding end from the cylinder (11) is closed. When,
A screw inserted into the plunger (12) with one end housed in the plunger (12) and the other end protruding from the insertion end of the plunger (12) into the cylinder (11). A rod (13);
A male screw (17) formed on the outer periphery of the screw rod (13);
A female screw (18) formed on the inner periphery of the plunger (12) so as to be screw-engaged with the male screw (17);
A tensioner-integrated chain that includes a return spring (15) that is incorporated between the screw rod (13) and the plunger (12) and biases the plunger (12) in a direction in which the plunger (12) protrudes from the cylinder (11). guide.   The tensioner-integrated chain guide according to claim 1, wherein a rod sheet (14) for supporting an end surface of the screw rod (13) protruding from the plunger is provided in the cylinder (11).   The tensioner integrated type according to claim 1 or 2, wherein an oil introduction hole (30) for introducing splashed oil outside the cylinder (11) into the inside of the cylinder (11) is provided on an outer periphery of the cylinder (11). Chain guide.   The female screw (18) and the male screw (17) have a flank angle (θ1) of the pushing side flank (19) that receives pressure when a load in a direction of pushing the plunger (12) into the cylinder (11) is applied. Is a sawtooth shape larger than the flank angle (θ2) of the protruding flank (20) that receives pressure when a load is applied in a direction in which the plunger (12) protrudes from the cylinder (11). The tensioner-integrated chain guide according to any one of claims 1 to 3.   The flank angle (θ1) of the push-in flank (19) is set in the range of 72 ° to 78 °, and the flank angle (θ2) of the protruding flank (20) is set in the range of 12 ° to 18 °. The tensioner-integrated chain guide according to claim 4.   6. The tensioner-integrated chain guide according to claim 1, wherein at least one surface of the female screw (18) and the male screw (17) is textured.   7. The tensioner-integrated chain guide (1) according to any one of claims 1 to 6, a fulcrum shaft (8) for swingably supporting the tensioner-integrated chain guide (1), and the tensioner-integrated chain guide A contact pin fixed at a position facing the projecting end of the plunger (12) from the cylinder (11) so as to receive the projecting end of the plunger (12) from the cylinder (11). (9) and a chain tension adjusting device.   A contact surface (23) of the contact pin (9) with respect to a protruding end of the plunger (12) from the cylinder (11) is formed in a cylindrical shape parallel to the fulcrum shaft (8). 8. The chain tension adjusting device according to 7.   The protruding length of the plunger (12) from the cylinder (11) is maintained while keeping the protruding end of the plunger (12) from the cylinder (11) in contact with the contact pin (9). The maximum deviation amount (g) between the center line (L) of the plunger (12) and the cylindrical center (O) of the cylindrical contact surface (23) generated when changed is 3 mm or less. Chain tension adjuster as described in 1.   The contact pin (9) is fixed by press-fitting an end of the contact pin (9) into a pin insertion hole (25) formed in the engine block (24). The chain tension adjusting device according to any one of the above.   The contact pin (9) has a screw shaft portion (9a), and the screw shaft portion (9a) is screwed into a screw hole (26) formed in the engine block (24). The chain tension adjusting device according to any one of claims 7 to 9, wherein 9) is fixed.

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