JP2003329093A - Auto-tensioner and damping member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auto-tensioner provided with a damping member which is less to liable crack or damage and to produce noise. <P>SOLUTION: Two setting holes 112 are formed in a damping member 70, and the damping member 70 is integrally set in a swinging arm by respectively engaging with two projections 348 formed at the swinging arm. The damping member 70 is integrally set in a fixing member. The damping member 70 is pressed and energized into a fixing member at outside in the axial direction. A clearance is provided between the setting hole 112 and the projection 348 in the pressing and energizing direction, and the both are placed in contact with in the frictional sliding direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tensioner used in, for example, a belt drive mechanism of an automobile engine, and more particularly to improvement of a damping member thereof.

[0002]

2. Description of the Related Art An automatic tensioner is used in a belt drive mechanism that transmits a driving force of an engine to a plurality of devices by a single endless belt, and applies an appropriate tension to the belt, and at the same time, the engine speed and load are Attenuates vibration of the belt caused by fluctuations. This ensures that the driving force of the engine is transmitted to each device.

Generally, an autotensioner has a fixing member fixed to an engine block or the like, a swinging arm pivotally supported by the fixing member, and a tip end of the swinging arm attached to contact with a belt. Equipped with a pulley. The oscillating arm is rotationally biased in the direction in which the belt is tensioned by the torsional torque of the torsion coil spring that is provided substantially coaxially with the oscillating axis and that tries to elastically return in the direction in which the coil diameter increases. Appropriate tension is applied to the belt.

Further, the autotensioner is provided with a damping mechanism for damping the belt, for example, a damping member is provided between the swing arm and the fixed member, and when the swing arm swings following the belt tension fluctuation. A friction damping mechanism is provided to generate a frictional resistance, that is, a damping force to brake the swing. An example of such a friction damping mechanism is Japanese Patent No. 2981433.
In this configuration, the damping member is integrally attached to the swing arm, and is pressed against the fixed member by an urging member that is separate from the torsion coil spring to generate stable high frictional resistance. In this case, the magnitude of the frictional resistance depends on the urging force of the urging member and is not related to the torsion torque, so a large damping force can be obtained simply by changing the urging force of the urging member without increasing the torsion torque. It has the advantage of being able to.

However, there is a problem that stress is likely to be concentrated on the engaging portion of the damping member with the rocking arm and is easily broken. In particular, in the structure in which the damping member is integrally attached to the swing arm by the engagement of the protrusion formed on the swing arm and the mounting hole formed in the damping member as in Japanese Patent No. 2891433, the protrusion and the mounting hole are If you do not make a close contact without a gap, a peculiar noise called a tapping noise will be generated when the arm swings, but if the damping member wears and displaces in the direction in which it is biased, a relatively large stress acts on the mounting hole. There is a problem of causing early damage.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a damping member that is less likely to cause crack damage and generates less noise, and an auto tensioner including the damping member. That is the purpose.

[0007]

SUMMARY OF THE INVENTION An autotensioner according to the present invention includes a fixing member, a swing arm rotatably supported by the fixing member, and one of the fixing member and the swing arm and the other. And a damping member that brakes the swing arm by frictionally sliding between the fixed member and the swing arm, the damping member being a protrusion formed on one of the fixed member and the swing arm. The most main feature is that it has a mounting hole that engages with, and that this mounting hole has a gap in the pressing force direction with respect to the projection and is in close contact in the friction sliding direction.

In the above automatic tensioner, the protrusion formed on one of the fixed member and the swing arm has a cylindrical shape parallel to the swing axis, and the mounting hole formed in the damping member is substantially the radius of the protrusion. It may be an elongated hole having the same width. In this case, it is preferable that the longitudinal direction of the mounting hole coincides with the pressing biasing direction of the damping member and the width direction substantially coincides with the friction sliding direction of the damping member. .

Further, the autotensioner of the present invention includes a bottomed cylindrical fixing member, a swing arm having a flat plate portion arranged in an opening of the fixing member, and rotatably supported by the fixing member. A damping member that is integrally attached to the flat plate portion of the moving arm and is pressed and biased toward the fixed member, and relatively rotates when the swing arm swings to frictionally slide with the fixed member to brake the swing arm. The damping member has a cylindrical portion that frictionally slides on the cylindrical side surface of the fixing member, and a mounting hole that engages with a protrusion formed on the swing arm, and the mounting hole is provided with respect to the protrusion. It is characterized in that there is a gap in the radial direction for pressing and pressing, and they are in close contact with each other in the circumferential direction for frictional sliding.

Further, the autotensioner of the present invention comprises a flat plate-shaped fixing member, a swinging arm having a bottomed tubular portion opening toward the fixing member and rotatably supported by the fixing member, and the fixing member. And a damping member that brakes the swing arm by frictionally sliding with a bottomed tubular portion that rotates relative to the swing arm when the swing arm swings. The damping member has a cylindrical portion that frictionally slides on the cylindrical side surface of the bottomed cylindrical portion of the swing arm, and a mounting hole that engages with a protrusion formed on the fixing member. It is characterized in that it has a gap in the radial direction that presses and urges against the projection, and that it is in close contact in the circumferential direction where it frictionally slides.

In the above auto tensioner, the gap between the mounting hole and the protrusion is preferably more than 0.3 mm and 2 mm or less, and most preferably 0.4 mm.
The dimensional difference between the mounting hole and the protrusion in the frictional sliding direction is preferably 0.3 mm or less.

The autotensioner of the present invention has a fixed member, a swing arm rotatably supported by the fixed member, one of the fixed member and the swing arm, and is biased by the other. A mounting member that includes a damping member that brakes the swing arm by frictionally sliding between the fixed member and the swing arm, the damping member engaging with a protrusion formed on one of the fixed member and the swing arm. There is a hole, and this mounting hole is 0.3m in the direction of pressing force against the protrusion.
It is characterized in that it has a gap of more than m and 2 mm or less and is closely adhered with a dimensional difference of 0.3 mm or less in the friction sliding direction.

Further, the damping member of the present invention is engaged with one of the fixing member or the swing arm of the auto tensioner and is urged by the other and is frictionally slid between the fixing member and the swing arm. A damping member for braking the swing arm, which has a mounting hole formed on one of the fixed member or the swing arm and engaged with a protrusion extending along the swing axis. It is characterized in that it has a gap in the pressing direction and is in close contact in the friction sliding direction.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an autotensioner and a damping member according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing a belt drive mechanism to which an auto tensioner according to a first embodiment of the present invention is applied. The belt drive mechanism includes a single endless belt 10, which includes a drive pulley 12 mounted on the output shaft of an engine (not shown) and a driven pulley mounted on a plurality of devices, such as an air conditioner. It is wound around a pulley 14 for a conditioner, a pulley 16 for a power steering device, a pulley 18 for an alternator, and idler pulleys 20 and 22. When the drive pulley 12 rotates, the belt 10
Rotates in the clockwise direction in the figure, and the pulleys 14 and 1 of each device
The rotational driving force is transmitted to 6 and 18.

The automatic tensioner 30 includes a drive pulley 12
In particular, the belt 10 is disposed behind the drive pulley 12 where the belt 10 is most slack in the belt rotation direction, and the pulley 32 of the auto tensioner 30 rotates relative to the back surface of the belt 10, that is, the outer peripheral side while contacting the belt 10. The swing arm 34 rotationally urges the pulley 32 in the counterclockwise direction in which the belt 10 is tensioned, so that the belt 10 is always given an appropriate tension.

When the belt 10 vibrates due to fluctuations in engine speed and load, this vibration is transmitted to the swing arm 34 via the pulley 32, and the swing arm 34 swings the swing axis L1.
Is swung around, and the pulley 32 is relatively moved between the position shown by the solid line and the position shown by the broken line. Swing arm 34
When swinging, the damping member (reference numeral 70; see FIG. 2)
The frictional resistance caused by acts as a damping force for braking the swing arm 34, and the relative movement of the pulley 32 is suppressed, and the vibration of the belt 10 is damped.

FIG. 2 is a sectional view showing the internal structure of the auto tensioner 30. The auto tensioner 30 includes a fixing member 40 integrally formed in a bottomed tubular shape from a metal material such as an aluminum alloy, and the fixing member 40 is fixed to an engine block (not shown). Opening 4 of fixing member 40
A swing arm 34 is arranged at 02.

The swing arm 34 is integrally formed from a metal material such as aluminum alloy. The swing arm 34 has an opening 4
Disk-shaped arm bottom part 3 having a diameter slightly smaller than 02
42 (flat plate portion), and the rocking bearing portion 34 for inserting the stepped bolt 44 in the center of the arm bottom surface portion 342.
4 is formed. The stepped bolt 44 inserted through the rocking bearing portion 344 is screwed and fixed to the cylindrical bearing portion 406 formed in the center of the bottom surface portion 404 of the fixing member 40. As a result, the swing arm 34 is rotatably supported by the stepped bolt 44, that is, the swing arm 34 is attached to the fixed member 40 so as to swing around the swing axis L1. A thrust bearing 48 is provided between the swing arm 34 and the head of the stepped bolt 44 to smoothly rotate the both.

The swing arm 34 has a pulley bearing portion 346 which projects from the arm bottom portion 342 to the opposite side of the fixed member 40.
The pulley 32 is rotatably attached to the outside of the pulley bearing portion 346 in the radial direction via the ball bearing 50. The rotation axis of the pulley 32 is parallel to the swing axis L1. The ball bearing 50 includes a pulley bearing portion 346, which includes a mounting bolt 52 screwed and fixed in the pulley bearing portion 346 and a washer 54 interposed between the head portion of the mounting bolt 52 and the upper end surface of the ball bearing 50. Fixed to.

A torsion coil spring 60 is arranged inside the fixing member 40. Torsion coil spring 60
Is a winding spring wound around the bearing portion 406, and one end portion 62 thereof is locked to the bottom surface portion 404 and the other end portion (not shown) thereof is locked to the arm bottom surface portion 342. The torsion coil spring 60 is twisted by a predetermined angle in the clockwise direction of FIG. 1 where the coil diameter is reduced, and is inserted in a state of being compressed in the swing axis L1 direction. The torsional torque of the torsion coil spring 60, which tends to elastically return in the direction in which the coil diameter increases, urges the oscillating arm 34 around the oscillating axis L1 in the counterclockwise direction in FIG. A predetermined tension is applied to the belt 10 thus obtained.

A cylindrical damping member 70 is provided between the opening 402 and the arm bottom 342. The damping member 70 is formed of an elastic member such as resin or rubber. For example, polyacetal, a polymer material such as nylon containing molybdenum for self-lubricating property, glass fiber reinforced nylon having excellent strength, and carbon fiber reinforced plastic, etc. Is used. The damping member 70 is integrally attached to the arm bottom surface portion 342, and outwardly in the radial direction, that is, by the C-shaped ring springs 72 that are provided in a state of being contracted inward in the radial direction and are stacked in the axial direction. It is pressed and urged toward the inner peripheral surface 408 (cylindrical side surface) of the opening 402.

When the swing arm 34 relatively rotates about the swing axis L1, the damping member 70 rotates integrally with the swing arm 34, and the outer peripheral surface 102a frictionally slides on the inner peripheral surface 408. . Therefore, the frictional resistance generated by the swinging (relative rotation) of the swinging arm 34 acts on the swinging arm 34 as a damping force, and the swinging arm 34 is strongly braked, so that the pulley 32 slowly follows the belt 10, Ten vibrations are dampened.

By urging the damping member 70 by the C-shaped ring spring 72 which is separate from the torsion coil spring 60, the damping member 70 is urged toward the fixing member 40 side in the circumferential direction substantially uniformly and with a constant pressure. Therefore, a stable damping force can be obtained. Moreover, since the magnitude of the damping force is proportional to the biasing force of the C-shaped ring spring 72, it is extremely easy to set a desired damping force.

The damping member 7 will be described with reference to FIGS. 3 to 8.
The configuration of 0 will be described in detail. 3 is a plan view of the damping member 70 as seen from the swing arm 34 side, and FIG. 4 is a partially enlarged view thereof. 5 is a perspective view of a cross section taken along the line I-I of FIG. 3 as seen from the direction of the arrow, and FIG. 6 is a cross sectional view thereof. 7 and 8 are a perspective view and a cross-sectional view showing a state in which the C-shaped ring spring 72 is attached to the damping member 70. 5 to 8, the damping member 70 is shown with the surface facing the fixing member 40 set to the upper side.

The damping member 70 is a cylindrical member having a diameter of about 9 cm separated at the cut portion 106, and is formed symmetrically with respect to the diameter including the cut portion 106 (line I-I in FIG. 3). Specifically, the damping member 70 has a cylindrical portion 102 that is partially separated, and the outer peripheral surface 102 of the cylindrical portion 102.
a has substantially the same diameter as the inner peripheral surface 408 of the fixing member 40, and abuts on the inner peripheral surface 408 near the opening of the fixing member 40. On the end surface of the cylindrical portion 102 on the swing arm 34 side, the cylindrical portion 10
A crown head 104 larger than a diameter of 2 is formed. The damping member 70 is attached to the fixing member 40 such that its axis coincides with the swing axis L1. At this time, the lower surface 104a of the crown 104 contacts the opening end surface of the fixing member 40. The cutting portion 106 not only absorbs thermal deformation of the damping member 70 and allows a minute displacement such that the damping member 70 expands in the radial direction due to wear, but also drains water that has penetrated into the fixing member 40. It functions as a drainage part.

On the inner peripheral surface 102b of the cylindrical portion 102, the arm engaging portion 110 is formed so as to face the cutting portion 106. The arm engaging portion 110 is bulged toward the center in the radial direction of the cylindrical portion 102. A mounting hole 112 is formed in each of the two arm engaging portions 110 so as to penetrate therethrough in the axial direction. The axis of each mounting hole 112 is parallel to the axis of the cylindrical portion 120, that is, the swing axis L1. The two mounting holes 112 are eccentric with respect to the swing shaft member 44 and are formed at the same position in the radial direction. Two mounting holes 11
The corresponding protrusions 348 are respectively inserted into the two (see FIG. 2).
reference). By the engagement of the mounting hole 112 and the protrusion 348, the relative movement of the damping member 70 in the rotation direction with respect to the swing arm 34 is restricted.

As shown in FIG. 4, the mounting hole 112 is an elongated hole, and its longitudinal direction (shown by a chain double-dashed line in FIG. 4) coincides with the pressing biasing direction A of the damping member 70 which is the radial direction. The width direction perpendicular to the longitudinal direction substantially corresponds to the frictional sliding direction B of the damping member 70, which is the circumferential direction.

The longitudinal length D1 of the mounting hole 112 is larger than the outer diameter D2 of the protrusion 348 (shown by the one-dot chain line in FIG. 4) formed on the swing arm 34, and the dimensional difference between them (D1-D).
2), that is, the gap between the mounting hole 112 and the protrusion 348 in the pressing and urging direction is preferably more than 0.3 mm and not more than 2 mm, and most preferably 0.4 mm. By providing this gap, the protrusion 348 can relatively move in the mounting hole 112 along the radial direction A by a very small amount. Therefore, the outer peripheral surface 1 that frictionally slides with the fixing member 40
02a is worn and the thickness of the cylindrical portion 102 is reduced, and when the damping member 70 is slightly displaced so as to be expanded in the radial direction by the urging of the C-shaped ring spring 72, the protrusion 34
8 relatively moves inward in the mounting hole 112 in the radial direction, and this minute displacement is allowed. Thereby, the engaging portion 11
It is possible to avoid stress concentration at 0 or the boundary portion between the engaging portion 110 and the cylindrical portion 102, and prevent early crack damage of the damping member 70.

In order to fully exhibit the friction performance of the automatic tensioner 10, the fixing member 40, the stepped bolt 44,
It is necessary that the axis of each of the arm bottom surface portion 342, the damping member 70, and the C-shaped ring spring 72 be aligned with the swing axis L1. However, auto tensioner 1
When 0 is mass-produced, the axes of all the components are not necessarily aligned with the swing axis L1.
When 2 is attached to be tilted with respect to the swing axis L1 or displaced in the radial direction, the position of the protrusion 348 from the swing axis L1 deviates from the original position, and thus is formed from a relatively soft material. A large load is likely to be applied to the damping member 70, which causes early damage and noise generation. Strictly, there are slight individual differences in each auto tensioner 10 manufactured through various processes such as molding, processing, or assembly of each part, and each part of each auto tensioner has an axial deviation. It is very time-consuming and time-consuming to inspect whether or not there is any misalignment.

However, the damping member 70 of this embodiment is used.
Is the projection 348 and the mounting hole 112 in the pressing biasing direction A.
Since it can be displaced by a very small amount due to the gap between and, even if the position of the protrusion 348 is displaced in the radial direction as described above, if the C-shaped ring spring 72 is attached, its position is automatically adjusted by its urging force. A slight displacement is performed to eliminate the displacement, and the entire outer peripheral surface 102a can be surely brought into close contact with the inner peripheral surface 408 of the fixing member 40, and a load due to the positional displacement does not occur. Therefore, regarding the radial displacement, the individual difference in the friction performance is eliminated, and the strict quality control as described above becomes unnecessary.

As for the friction sliding direction B, the mounting hole 11
The width D3 of 2 is substantially equal to the outer diameter D2 of the protrusion 348,
The dimensional difference (D3-D2) between them is 0.3 mm or less. Therefore, even if the protrusion 348 relatively moves in the mounting hole 112, the protrusion 348 is always in close contact with the mounting hole 112 in the frictional sliding direction without a gap, and a knocking sound may be generated when the swing arm 34 swings. Absent.

The corner portion 110c of the arm engaging portion 110 on the side of the fixing member 40 is rounded with a predetermined diameter. Further, on the supporting surface 110a of the arm engaging portion 110 on the side of the fixing member 40, two disk-shaped supporting protrusions 116 are provided on both sides of the mounting hole 112. Corner 110
The diameter of the roundness of c and the height of the support protrusion 116 may be formed to be the same length, and the length is not particularly limited.
Further, a strip-shaped projection 120 extending in the circumferential direction from the cutting portion 106 is provided on the inner peripheral surface 102b. As shown in FIG. 6, the band-shaped projection 120 is provided on the end surface 120a on the fixing member 40 side.
Are formed on the same plane P as the end surface 116a of the support protrusion 116 (indicated by a chain double-dashed line in FIG. 6).

The ring receiver 122 is a belt-shaped protrusion extending in the circumferential direction on the inner peripheral surface 102b of the cylindrical portion 102, and is formed between the protrusion 120 and the arm engaging portion 110. The ring receiver 122 is located closer to the fixing member 40 than the plane P (upper side in FIG. 6) in the axial direction of the inner peripheral surface 102b. Corner portion 1 of the ring receiver 122 on the side of the fixing member 40
22c is rounded. C-shaped ring spring 72
The plate width (diameter in the radial direction) of the engaging portion 1 is from the opening 106 side.
The thickness is gradually increased toward the 10 side. The C-shaped ring spring 72 has an inner peripheral surface 102 of the damping member 70.
a in close contact with a, and as shown in FIG.
The upper surface 116a of the support protrusion 116 and the upper surface 12 of the protrusion 120
It is sandwiched between 0a and 0a in the axial direction.

The auto tensioner 30 of the first embodiment is
The mounting hole 112 is formed as an elongated hole having a width equal to the outer diameter of the protrusion 348 and having a gap between the protrusion 348 and the longitudinal direction, and the longitudinal direction is the pressing biasing direction A of the damping member 70. It is provided with a structure in which the widthwise direction and the frictional sliding direction B of the damping member 70 are substantially matched. As a result, it is possible to prevent early damage to the damping member 70, and at the same time, to prevent generation of a knocking sound at the time of rocking.

In the first embodiment, the damping member 70 is fixed to the swinging arm 34 and frictionally slides on the fixing member 40. However, as in the second embodiment shown in FIG. The protrusion 348 may be formed on the side to fix the damping member 70 and frictionally slide with the opening-side inner peripheral surface 252 (cylindrical side surface) of the bottomed tubular portion 350 of the swing arm 34. In FIG. 9, the same components as those in the first embodiment are designated by the same reference numerals.

Further, in the first embodiment, the shape of the protrusion 348 is a cylinder and the shape of the mounting hole 112 is a long hole.
The shapes of both are not limited to those in the first embodiment, and the condition that there is a gap between the protrusion 348 and the mounting hole 112 in the pressing bias direction and the two are in close contact in the friction sliding direction is satisfied. It should have been done.

[0038]

According to the present invention, it is possible to obtain an auto tensioner having a damping member which is less likely to be damaged by cracks and has less noise.

[Brief description of drawings]

FIG. 1 is a layout view schematically showing a belt system of an automobile engine to which an auto tensioner according to a first embodiment of the first invention is applied.

FIG. 2 is a cross-sectional view of the auto tensioner shown in FIG.

FIG. 3 is a plan view of the damping member shown in FIG. 2 viewed from a swing arm side.

FIG. 4 is a partially enlarged view of FIG.

5 is a perspective view of the damping member shown in FIG. 3 taken along the line I-I of FIG.

6 is a sectional view of the damping member shown in FIG. 3 taken along the line I-I of FIG.

7 is a perspective view showing a state in which a C-shaped ring spring is engaged with the damping member shown in FIG. 3, taken along line I-I of FIG.

8 is a sectional view showing the damping member shown in FIG. 3 together with a C-shaped ring spring, taken along line I-I of FIG. 3;

FIG. 9 is a sectional view showing an auto tensioner according to a second embodiment of the present invention.

[Explanation of symbols]

30 auto tensioner 34 Swing arm 342 Arm bottom part (flat part) 348 protrusion 40 fixing member 402 opening 408 Inner peripheral surface (cylindrical side surface) 70 Damping member 102 cylindrical part 102a outer peripheral surface 112 mounting holes 350 Bottomed cylindrical part 252 Inner peripheral surface on opening side (cylindrical side surface)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Teru Takahashi             172 Gates Yu, Ikezawa Town, Yamatokoriyama City, Nara Prefecture             Nitta Asia Co., Ltd. Nara factory (72) Inventor Akira Kubota             172 Gates Yu, Ikezawa Town, Yamatokoriyama City, Nara Prefecture             Nitta Asia Co., Ltd. Nara factory F-term (reference) 3J049 AA01 BB05 BB10 BB15 BB16                       BB23 BB25 BH02 CA03

Claims (9)

[Claims] 1. A fixing member, a swinging arm rotatably supported by the fixing member, and one of the fixing member and the swinging arm, which is urged and pressed by the other, and is fixed to the fixing member. A damping member that brakes the swing arm by frictionally sliding with the swing arm, wherein the damping member engages with a protrusion formed on one of the fixing member and the swing arm. Has a mounting hole for
The autotensioner is characterized in that the mounting hole has a gap in the pressing force direction with respect to the protrusion and is in close contact with the protrusion in the friction sliding direction. 2. A protrusion formed on one of the fixing member and the swing arm has a cylindrical shape parallel to the swing axis, and a mounting hole formed on the damping member is substantially the same as the diameter of the protrusion. And a longitudinal direction thereof coincides with a pressing biasing direction of the damping member and a width direction thereof substantially coincides with a friction sliding direction of the damping member. The automatic tensioner according to claim 1. 3. A bottomed tubular fixing member, a swing arm having a flat plate portion arranged in an opening of the fixing member and rotatably supported by the fixing member, and a flat plate of the swing arm. And a damping member that is integrally attached to the portion and is pressed and biased toward the fixed member, and relatively rotates when the swing arm swings to frictionally slide with the fixed member to brake the swing arm. The damping member has a cylindrical portion that frictionally slides on the cylindrical side surface of the fixing member, and a mounting hole that engages with a protrusion formed on the swing arm, and the mounting hole is An auto tensioner characterized in that it has a clearance in the radial direction for pressing and biasing against the projection and is in close contact in the circumferential direction for frictional sliding. 4. A flat plate-shaped fixing member, a swing arm having a bottomed tubular portion opening toward the fixing member, and rotatably supported by the fixing member, and integrally with the fixing member. A damping member that is attached and is pressed and biased toward the swing arm, and frictionally slides on the bottomed tubular portion that rotates relative to the swing arm when swinging the swing arm to brake the swing arm. The damping member has a cylindrical portion that frictionally slides on the cylindrical side surface of the bottomed cylindrical portion of the swing arm, and a mounting hole that engages with a protrusion formed on the fixing member. An auto tensioner characterized in that a mounting hole has a clearance in a radial direction for pressing and biasing against the protrusion and is in close contact with a frictionally sliding circumferential direction. 5. The gap is greater than 0.3 mm and 2 mm
The automatic tensioner according to any one of claims 1 to 4, wherein: 6. The auto tensioner according to claim 5, wherein the gap is 0.4 mm. 7. The automatic tensioner according to claim 1, wherein a dimensional difference between the mounting hole and the protrusion in a frictional sliding direction is 0.3 mm or less. 8. A fixing member, a swinging arm rotatably supported by the fixing member, and one of the fixing member and the swinging arm and being biased by the other to press the biasing arm. A damping member that brakes the swing arm by frictionally sliding with the swing arm, wherein the damping member engages with a protrusion formed on one of the fixing member and the swing arm. Has a mounting hole for
This mounting hole is 0.3m in the direction of pressing force against the protrusion.
An autotensioner having a gap of more than 2 m and not more than m and closely adhering with a dimensional difference of not more than 0.3 mm in the friction sliding direction. 9. The swing arm by engaging with one of a fixing member or a swing arm of an autotensioner and being biased by the other to frictionally slide between the fixing member and the swing arm. A damping member for braking the vehicle, the mounting member having a mounting hole formed on one of the fixing member or the swing arm and extending along the swing axis, and the mounting hole is provided with respect to the protrusion. A damping member having a gap in a pressing force direction and being closely attached in a friction sliding direction.