JP2006170435A - Auto tensioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auto tensioner for turnably energizing a turning member 30 in a belt thrusting direction with the torsional torque of a torsional coil spring 50 while using the reaction of the torsional torque for generating damping force on the turn of the turning member 30, thus sufficiently suppressing the resonance of the torsional coil spring 50 due to the rotational fluctuation and vibration of an engine without omitting an outer periphery side damping member 17 which holds a boss portion 31 of the turning member 30 between an inside damping member 14 externally fitted onto a shaft portion 11 of a fixing member 10 and itself. <P>SOLUTION: To a coil portion 51 of the torsional coil spring 50, an elastically deformable vibration absorbing member 70 in an approximately circular cross section is elastically fitted into the state of embracing the coil portion 51 at its outer periphery side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an auto tensioner that presses an accessory drive belt of an automobile engine by a twisting torque of a torsion coil spring, and generates a damping force for a belt pressing operation using a reaction force of the twisting torque. The present invention relates to a measure for reducing stress due to resonance of a torsion coil spring.

  Generally, as an auto tensioner used for a belt type auxiliary machine drive device for an automobile engine, it is rotatably supported by a boss part fitted on a shaft part of a fixed member via an inner peripheral side damping member. The rotating member is urged to rotate in the belt pressing direction by the torsional torque of the torsion coil spring disposed on the boss portion of the rotating member via the outer peripheral damping member, while the reaction force of the torsional torque causes the outer peripheral side to rotate. A part of the damping member in the circumferential direction is pressed inward in the radial direction, and the boss portion is clamped between the outer periphery side damping member and the inner periphery side damping member, so that the damping force with respect to the rotation of the rotation member is increased. What is generated is known.

  By the way, in the above-described auto tensioner, when the torsion coil spring is vibrated due to rotational fluctuation or vibration of the engine, if the excitation frequency matches the natural frequency of the torsion coil spring, a resonance phenomenon occurs in the torsion coil spring. Due to the resonance phenomenon, a large stress is generated in the torsion coil spring and the torsion coil spring may be broken.

  On the other hand, the natural frequency of the torsion oil spring is determined by the shape and characteristics designed according to the belt tension to be applied, and therefore the natural frequency itself of the torsion coil spring cannot be changed.

Therefore, in the conventional case, as described in Patent Document 1, a cylindrical vibration isolation member is provided on the outer periphery of the boss portion of the rotating member, and a part of the vibration isolation member in the circumferential direction is twisted by a coil. The coil portion of the spring is brought into contact with the inner peripheral side, thereby preventing resonance of the torsion coil spring without changing the natural frequency of the torsion coil spring.
Japanese Unexamined Patent Publication No. 2003-120768 (page 4, FIGS. 3 to 5)

  However, in the above conventional case, since the vibration isolating member is located on the outer peripheral surface of the boss part, the outer side damping member has to be omitted, and the damping force is reduced accordingly. is there.

  In addition, since the vibration-proof member is in contact with the coil portion of the torsion coil spring only in a narrow range in the circumferential direction, there is a drawback that resonance cannot be sufficiently suppressed.

  The present invention has been made in view of these points, and its main object is to urge the rotating member in the belt pressing direction by the torsion torque of the torsion coil spring, while the reaction force of the torsion torque. In an auto tensioner that generates a damping force with respect to the rotation of the rotating member by using the rotation member, the resonance of the torsion coil spring can be sufficiently suppressed without omitting the outer peripheral damping member. .

  In order to achieve the above object, in the present invention, the vibration isolation member is arranged on the outer peripheral surface of the boss portion, that is, on the outer peripheral side of the coil portion of the torsion coil spring, not on the inner peripheral side of the coil portion of the torsion coil spring. I did it.

  Specifically, in the present invention, a fixing member that has a shaft portion and is fixed to the fixed side, and a boss that is externally fitted on the shaft portion so as to be rotatable around the shaft center of the shaft portion. And a rotation member that has a belt pressing portion for pressing the belt, and is supported by the fixing member so as to be rotatable around the axis by the fixing member, and the fixing member and the rotating member. And a torsion coil spring provided with a torsion coil spring that biases the rotating member in a direction in which the belt pressing portion presses the belt.

  The coil portion of the torsion coil spring is provided with a vibration-damping member having a substantially arc-shaped cross section that is elastically deformable and is fitted in a state of holding the coil portion from the outer peripheral side.

  In addition, in said structure, it can form so that the circumferential direction both ends of a vibration isolating member may each warp in the radial direction outer side.

  In addition, the vibration isolating member can include a conductive metal plate having a substantially arc-shaped cross section and an electrodeposition coating layer formed on the surface of the metal plate. In that case, the metal plate of the vibration isolating member can be provided with a locking portion for suspending the metal plate when the electrodeposition coating layer is formed.

  By the way, since the coil portion of the torsion coil spring and the vibration isolating member are in sliding contact with each other, for example, due to a reduction in stick-slip caused by a large difference between the static friction coefficient and the dynamic friction coefficient between them. , Sliding noise as noise may occur. In response to this, any one of the contact portion of the coil portion with the vibration isolating member and the contact portion of the vibration isolating member with the coil portion is caused to have a sliding sound caused by relative sliding of the coil portion and the vibration isolating member. It can be set as the sliding sound reduction part which suppresses generation | occurrence | production of this.

  When the above-mentioned sliding noise reduction part is a contact part with the coil part in the vibration isolating member, the vibration isolating member is detachably held on the vibration isolating member main body and the inner peripheral side of the vibration isolating member main body. It is possible to have a sliding sound reducing body that forms the sliding noise reducing portion. As a specific example thereof, the circumferential length of the sliding noise reducing body is made larger than the circumferential length of the vibration isolator body, and the sliding noise reducing body is connected to both ends of the sliding noise reducing body in the circumferential direction. For example, it is possible to bend outward in the radial direction so as to be held by the vibration-proof member body.

  According to the present invention, the rotating member is urged to rotate in the belt pressing direction by the torsion torque of the torsion coil spring, while the damping force for the rotation of the rotating member is generated by the reaction force of the torsion torque. In the auto tensioner, since the vibration isolating member is elastically fitted to the coil portion of the torsion coil spring so as to be held from the outside in the radial direction, the torsion coil spring can be provided without omitting the outer peripheral damping member. Can be sufficiently suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows the overall configuration of an auto tensioner according to Embodiment 1 of the present invention. This auto tensioner uses a plurality of auxiliary machines to transfer a part of the output torque of an automobile engine through a single transmission belt B. It is used to apply a predetermined tension to the transmission belt B in a belt transmission device having a serpentine layout.

  The auto tensioner includes a fixing member 10 fixed to the engine, and a rotating member 30 that is rotatably supported by the fixing member 10.

  The fixing member 10 includes a shaft portion 11 disposed so as to extend in a direction perpendicular to the tensioner mounting surface of the engine (left-right direction in FIG. 1), and one of the shaft portions 11 (right side in the drawing). A flange portion 12 provided so as to project radially in the outer periphery of an end portion (hereinafter referred to as a base end portion), and a side wall portion 13 provided so as to surround the shaft portion 11 on the flange portion 12. Have Although not shown in the drawing, a plurality of mounting pieces are provided on the outer periphery of the flange portion 12 so as to protrude outward in the radial direction, and the mounting pieces extend from the shaft portion 11. Bolt holes penetrating in the direction (hereinafter referred to as the axial direction) are provided. These bolt holes are used for passing bolts when the auto tensioner is attached to the engine. Further, in the vicinity of the flange portion 12 in the side wall portion 13, a fixed side locking hole (not shown) penetrating the side wall portion 13 in the radial direction is provided.

  The outer periphery of the shaft portion 11 is formed in a tapered shape having a cross section that gradually decreases in outer diameter toward the other end portion (left side in FIG. 1) of the shaft portion 11 (hereinafter referred to as a tip portion). A key groove 11a extending substantially in the axial direction is provided on the tapered outer periphery. An insert bearing 14 as a substantially cylindrical inner circumferential damping member made of a resin material is fitted on the shaft portion 11. The inner circumference of the insert bearing 14 is formed in a tapered cross section having a taper angle substantially the same as that of the outer circumference of the shaft portion 11. A key portion 14 a extending in the axial direction is provided on the inner periphery, and the rotation of the insert bearing 14 with respect to the shaft portion 11 is prevented by engaging the key portion 14 a with the key groove 11 a of the shaft portion 11. Has been made. Further, the outer periphery of the insert bearing 14 has a portion on the key portion 14a side in the circumferential direction (a lower portion in FIG. 1) formed in the thick portion 14b, while a portion on the opposite side to the key portion 14a (the same portion) The upper portion of the figure is formed in the thin portion 14c.

  On the other hand, the rotating member 30 includes a substantially cylindrical boss portion 31 externally fitted on the shaft portion 11 of the fixed member 10 via the insert bearing 14, and a tip portion of the shaft portion 11 in the boss portion 31. The flange portion 32 is provided so as to protrude outward in the radial direction on the outer periphery of the portion corresponding to the outer peripheral portion, and on the periphery of the flange portion 32, the peripheral portion is opposed to the side wall portion 13 of the fixing member 10. A side wall 33 is provided, and an arm 34 is provided so as to extend radially outward from the outer periphery of the flange 32. Further, in the vicinity of the flange portion 32 in the side wall portion 33, a rotation side locking hole (not shown) penetrating the side wall portion 33 in the radial direction is provided.

  The boss portion 31 of the rotating member 30 is externally fitted onto the shaft portion 11 of the fixing member 10 via the insert bearing 14, whereby the outer peripheral surface of the thick portion 14 b of the insert bearing 14 is The inner peripheral surface of the boss part 31 is in sliding contact with the shaft center so as to be rotatable. The shaft portion 11 of the fixing member 10 passes through the boss portion 31 of the rotating member 30, and a disc-shaped front plate 15 is attached to the tip thereof so as not to rotate.

  A circular recess 35 concentric with the rotation axis is formed on the upper surface of the flange portion 32 of the rotation member 30. A thrust washer 16 made of a resin flat plate that can slide on the bottom surface of the circular recess 35 is disposed in the circular recess 35, and the thrust washer 16 includes a rotating member 30, a front plate 15, and the like. It is sandwiched between.

  A bolt mounting hole 36 extending in parallel with the rotation axis is provided at the tip of the arm portion 34 of the rotation member 30. A female screw is screwed into the bolt mounting hole 36 and a bolt 37 is screwed. Between the head of the bolt 37 and the arm portion 34, two bearings 38, 38, which are overlapped in the axial direction of the bolt 37, are clamped and fixed in the inner ring, and the outer ring of the bearings 38, 38 is fixed to the outer ring. The tension pulley 39 as a belt pressing portion that presses the transmission belt B is externally fitted and is coupled together in a rotating manner. In addition, a disc-shaped dust seal 40 for preventing dust from entering the bearing 38 is disposed between the bearing 38 on the head side of the bolt 37 and the head.

  Between the boss part 31 and the side wall part 33 in the rotating member 30, a spring support 17 is disposed as an outer peripheral damping member made of a resin material. The spring support 17 includes a cylindrical portion 17a as a substantially cylindrical sliding portion arranged so as to be fitted onto the boss portion 31 of the rotating member 30, and the cylindrical portion 17a. The outer peripheral portion of the portion corresponding to the base end portion is circumferentially provided so as to protrude outward in the radial direction, and includes a flange portion 17 b disposed on the flange portion 12 of the fixing member 10. The inner periphery of the cylindrical portion 17 a is formed in a tapered cross section having substantially the same taper angle as the outer periphery of the boss portion 31, and can be slidably contacted with the outer peripheral surface of the boss portion 31.

  A torsion coil spring 50 that constantly urges the rotating member 30 in the direction in which the tension pulley 39 presses the transmission belt B against the fixed member 10 is disposed on the flange portion 17 b of the spring support 17. The coil portion 51 of the torsion coil spring 50 is left-handed and is arranged on the cylindrical portion 17 a of the spring support 17 in a loosely fitted state. The two tongues 52 and 53 on the fixed side and the rotation side of the torsion coil spring 50 are provided so as to protrude outward from the coil portion 51 in the radial direction. The fixed side tongue 52 is locked in the fixed side locking hole of the fixed member 10, and the rotating side tongue 53 is locked in the rotating side locking hole of the rotating member 30.

  The torsion coil spring 50 is twisted in the direction in which the coil portion 51 is reduced in diameter and is interposed between the fixed member 10 and the rotating member 30, whereby the torsion torque in the direction in which the coil portion 51 is increased in diameter. Accordingly, the rotating member 30 is urged in the belt pressing direction, and the portion of the cylindrical portion 17a of the spring support 17 corresponding to the thick portion 14b of the insert bearing 14 is moved in the coil portion 51 by the reaction force of the twisting torque. It is configured to press radially inward by part of the circumferential direction. When the cylindrical portion 17 a of the spring support 17 is pressed, the inner peripheral surface of the cylindrical portion 17 a is on the outer peripheral surface of the boss portion 31 of the rotating member 30 and the outer periphery of the thick portion 14 b of the insert bearing 14. The surfaces are in pressure contact with the inner peripheral surface of the boss portion 31 of the rotating member 30. Further, the torsion coil spring 50 is compressed in the axial direction, so that the thrust washer 16 comes into pressure contact with the bottom surface of the circular recess 35 of the rotating member 30.

  In this embodiment, the torsion coil spring 50 is elastically fitted in a state in which a vibration-proof collar 70 as a vibration-proof member having a substantially arc-shaped cross section that can be elastically deformed holds the coil portion 51 from the outer peripheral side. It is worn.

  Specifically, the anti-vibration collar 70 is formed by bending a metal plate (for example, carbon tool steel, etc.) having a high self-damping action, and the surface thereof is electrodeposited for the purpose of rust prevention. A layer is formed. As shown in FIGS. 2 to 5, the anti-vibration collar 70 has a circumferential length exceeding half of the outer circumferential length of the coil portion 51, a center angle of 180 ° or more, and an inner diameter of the coil. It is made smaller than the outer diameter of the part 51, and, thereby, is elastically contacted with the coil part 51 in the range exceeding half of the circumferential direction.

  Further, the width dimension of the anti-vibration collar 70 (the dimensions in the left and right directions in FIGS. 3 and 5) is the length dimension of the portion excluding approximately one turn from each of the tongues 52 and 53 in the coil portion 51 of the torsion coil spring 50. In this way, the anti-vibration collar 70 does not come into contact with the tongues 52 and 53 of the torsion coil spring 50.

  Further, as shown in FIGS. 2 and 4, both end portions in the circumferential direction of the vibration isolating collar 70 are slightly bent outwardly in the radial direction, whereby the anti-vibration collar 70 is twisted by the torsion coil spring 50. When the coil portion 51 is mounted, the edge portions at both ends in the circumferential direction of the vibration isolation collar 70 do not damage the coating film applied to the surface of the wire of the torsion coil spring 50. In addition, the mounting work itself performed by elastically deforming the vibration-proof collar 70 in the diameter expansion direction is facilitated.

  Further, the metal plate of the vibration-proof collar 70 is provided with a suspension hole 71 in order to facilitate the electrodeposition coating work.

  The operation of the anti-vibration collar 70 in the auto tensioner configured as described above and attached to the automobile engine will be described. The torsion coil spring 50 of the auto tensioner is inherent to the torsion coil spring 50 due to rotational fluctuation and vibration of the engine. When vibration is applied with a period that matches the frequency, resonance occurs in the torsion coil spring 50. At this time, along with the resonance, sliding friction is generated between the vibration-proof collar 70 and the coil portion 51 of the torsion coil spring 50. Therefore, the resonance is attenuated by the frictional force.

  Here, a test performed for confirming the effect of the anti-vibration collar 70 will be described. The test procedure is to attach an auto tensioner to the engine and operate the engine between the idle rotation speed (approximately 550 rpm) and the allowable maximum rotation speed (approximately 6600 rpm) before and after the vibration isolation collar 70 is mounted. The stress (unit: MPa) generated in the torsion coil spring 50 was measured. In addition, carbon tool steel (SK5 of “JIS G 4401”) was adopted as the material of the vibration isolating collar 70, and the metal plate (plate thickness was 0.5 mm) was bent to form the vibration isolating collar 70. . With respect to the dimensions of each part of the anti-vibration collar 70, the inner diameter is 22 m, the width dimension is 45 mm, and the central angle corresponding to the circumferential length is 260 ° (the center corresponding to the circumferential length on the opening side). The angle is 100 °). The above results are also shown in FIG. In addition, the same figure (a) is before mounting | wearing, and the same figure (b) is after mounting | wearing.

  As can be seen from FIG. 6A, before the vibration-proof collar 70 is mounted, the stress is large (approximately ± 200 MPa) in the high engine speed range (per 5800 rpm), and the torsion coil spring 50 is broken as it is. Is concerned. In such a case, it is generally necessary to change the spring specifications so that resonance does not occur in the normal rotation range (for example, the spring constant is increased). Since the tension of the spring becomes high, the occurrence of spring breakage can be avoided, but it has an adverse effect on the engine such as a deterioration in fuel consumption.

  On the other hand, after mounting the anti-vibration collar 70, as can be seen from FIG. 6B, the stress generated in the torsion coil spring 50 was within ± 100 MPa over the entire engine speed. That is, it can be seen that the stress generated by resonance can be suppressed to half or less by mounting the vibration-proof collar 70 of the present embodiment. Therefore, in this case, it is not necessary to change the spring specifications, and the engine is not adversely affected.

  As typical forms of vibration of the coil portion 51 of the torsion coil spring 50, there are radial vibration (particularly the axial central portion of the coil portion 51) and axial vibration. It is inferred that multiple forms are combined. As the vibration damping action of the vibration isolation collar 70 against the vibration of the coil portion 51, the vibration of the coil portion 51 is caused by the force that the vibration isolation collar 70 grips the coil portion 51 in the radial direction. It is thought that the movement is restrained. Further, regarding the vibration in the axial direction, it is considered that the movement of the coil portion 51 is constrained by the frictional force caused by the relative sliding in the axial direction between the vibration-proof collar 70 and the coil portion 51.

  Therefore, according to the present embodiment, the rotating member 30 is urged to rotate in the belt pressing direction by the torsional torque of the torsion coil spring 50, and between the insert bearing 14 and the spring support 17 by the reaction force of the torsional torque. In the auto tensioner in which the boss portion 31 of the rotating member 30 is clamped to generate a damping force for the rotation of the rotating member 30, the section of the torsion coil spring 50 has a substantially arc shape. Since the elastically deformable anti-vibration collar 70 is elastically fitted in a state of being held from the outside in the radial direction, the damping force generated when the spring support is omitted is not reduced. The resonance of the torsion coil spring 50 can be sufficiently suppressed.

  Further, since the anti-vibration collar 70 is elastically fitted to the outer periphery of the coil portion 51 of the torsion coil spring 50, the anti-vibration collar 70 is previously attached to the torsion coil spring 50 when the auto tensioner is assembled. The torsion coil spring 50 can be assembled, and the auto tensioner can be easily assembled.

  Further, since the vibration-proof collar 70 is mounted in a state of being in close contact with the outer periphery of the coil portion 51 of the torsion coil spring 50, the coil portion 51 of the torsion coil spring 50, the fixing member 10 and the rotating member are provided as a storage space. Only a slight gap space between each of the 30 side wall portions 13 and 33 is required, and it is not necessary to change the structure of the auto tensioner itself. As a result, additional setting to the existing auto tensioner is easy.

  In the above-described embodiment, the width dimension of the vibration-proof collar 70 is set to the length dimension of the portion excluding substantially one turn from each of the tongues 52 and 53 in the coil portion 51 of the torsion coil spring 50. However, the vibration isolator according to the present invention includes conditions such as the natural frequency of the torsion coil spring and the frequency distribution of the excitation frequency for the torsion coil spring, including the contact state, material, and shape of the color coil portion 51. It can be arbitrarily designed according to.

  In the above embodiment, carbon tool steel is used as the material of the vibration-proof collar 70. However, the type of material is not particularly limited, and self-damping property and manufacturing cost (processing) Can be appropriately employed depending on the conditions such as the property. Incidentally, in the case of an iron-based metal material, generally, the more carbon is contained, the higher the self-damping action, but the worse the workability.

(Embodiment 2)
FIG. 7 shows the overall configuration of the auto tensioner according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected and shown to the same part as the case of Embodiment 1. FIG.

  In the present embodiment, as shown in FIG. 8, the contact portion of the torsion coil spring 50 in the vibration isolating collar 70 with the coil portion 51 is free of sliding sound accompanying relative sliding of the vibration isolating collar 70 and the coil portion 51. It is a sliding noise reduction unit that suppresses generation.

  Specifically, the anti-vibration collar 70 includes a collar main body 71 and a sliding sound reducing body 72 that is detachably held on the inner peripheral side of the collar main body 71 and forms the above-described sliding noise reducing portion. Have The sliding noise reduction body 72 is made of a resin sliding material in which the difference between the static friction coefficient and the dynamic friction coefficient with the coil portion 51 is smaller than that in the case of the collar body 71. In addition, the sliding sound reducing body 72 is formed in a circular arc shape in the same manner as the collar body 71. However, the arc length dimension is slightly longer than the arc length dimension of the collar body 71, and both ends in the arc length direction are bent outward in the radial direction. This bent portion is an engaging portion 72 a that engages with the collar main body 71 so that the sliding sound reducing body 72 is held by the collar main body 71. The configuration of the color main body 71 is the same as that of the anti-vibration collar 70 in the first embodiment, and the other configuration is the same as that in the first embodiment, and thus the description thereof is omitted.

  In the auto tensioner configured as described above, when the collar body 71 and the coil portion 51 of the torsion coil spring 50 are in direct contact, the collar body 71 is made of metal and is in contact with each other. The sliding sound is likely to be generated, and the sliding sound may become noise. On the other hand, in this embodiment, since the contact part with the coil part 51 in the vibration-proof collar 70 is made of a resin-made sliding sound reducing body 72 and is in contact with resin and metal, such sliding The generation of sound is suppressed compared to the case of metals.

  Therefore, according to the present embodiment, the contact portion of the anti-vibration collar 70 with the coil portion 51 of the torsion coil spring 50 is a sliding sound reduction portion made of the sliding noise reduction body 72. Generation of sliding sound due to relative sliding with the coil portion 51 of the torsion coil spring 50 can be suppressed. Therefore, in addition to the effects of the first embodiment, noise caused by the addition of the vibration-proof collar 70 Can be suppressed.

  In the above-described embodiment, the sliding sound reduction unit is configured by the sliding noise reduction body 72 formed separately from the color main body 71. For example, at least the coil part 51 of the color main body 71 These contact surfaces may be integrally formed by coating the same resin material as that of the sliding sound reducing body 72.

  In the above-described embodiment, the sliding sound reduction unit is provided on the vibration isolation collar 70 side. However, the sliding sound reduction unit may be provided on the coil unit 51 side of the torsion coil spring 50. The moving sound reduction unit may be integral with or separate from the coil unit 51.

  Furthermore, in the above embodiment, the sliding sound reduction part is made of a resin material, but a sliding sound between the coil part 51 of the torsion coil spring 50 and the vibration isolation collar 70 is required. The material of the sliding sound reduction part is not particularly limited as long as it can be reduced to the noise level.

It is a longitudinal section showing the whole auto tensioner composition concerning Embodiment 1 of the present invention. It is a top view which shows a vibration proof collar. FIG. 3 is a right side view showing a vibration-proof collar when FIG. 2 is a front view. It is a top view which shows the state by which the vibration proof collar was fitted by the torsion coil spring. It is the VV sectional view taken on the line of FIG. Characteristic diagram (a) showing the relationship between engine rotation speed and torsion coil spring generated stress in auto tensioner before vibration isolation collar and relationship between engine rotation speed and torsion coil spring generated stress in auto tensioner after vibration isolation collar It is a characteristic view (b) which shows. FIG. 3 is a view corresponding to FIG. 1 illustrating an overall configuration of an auto tensioner according to a second embodiment of the present invention. FIG. 5 is a view corresponding to FIG. 4 showing a state in which a vibration-proof collar composed of a color main body and a sliding sound reducing body is fitted to a torsion coil spring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fixing member 11 Shaft part 30 Rotating member 31 Boss part 39 Tension pulley (belt press part)
50 Torsion coil spring 51 Coil part 70 Anti-vibration collar (anti-vibration member)
70a Suspension hole (locking part)
71 Color body (anti-vibration member body)
72 Sliding noise reduction body (sliding noise reduction part)

Claims (7)

A fixing member having a shaft portion and fixed to the fixed side;
A boss part that is fitted on the shaft part so as to be rotatable around the axis of the shaft part, and a belt pressing part for pressing a belt. The shaft is supported by the fixing member in the boss part. A rotating member supported so as to be rotatable around the center;
An autotensioner provided with a torsion coil spring interposed between the fixing member and the rotating member and biasing the rotating member in a direction in which the belt pressing portion presses the belt, An auto-tensioner comprising: a vibration isolating member having a substantially arc-shaped cross section that is elastically deformable and is fitted to a coil portion of the torsion coil spring so as to hold the coil portion from the outer peripheral side. The auto tensioner according to claim 1,
The auto-tensioner characterized in that both ends in the circumferential direction of the vibration-proof member are warped radially outward. The auto tensioner according to claim 2,
An anti-vibration member has a conductive metal plate having a substantially arc-shaped cross section, and an electrodeposition coating layer formed on the surface of the metal plate. The auto tensioner according to claim 3,
An auto-tensioner characterized in that the metal plate of the vibration isolating member has a locking portion for suspending the metal plate when the electrodeposition coating layer is formed. The auto tensioner according to claim 1,
Either the contact portion of the coil portion of the torsion coil spring with the vibration isolation member or the contact portion of the vibration isolation member with the coil portion of the torsion coil spring is slid along with the relative sliding of the coil portion and the vibration isolation member. An auto tensioner characterized by being a sliding noise reduction unit that suppresses the generation of dynamic noise. The auto tensioner according to claim 5,
The sliding noise reduction part is a contact part with the coil part of the torsion coil spring in the vibration isolating member,
The vibration isolating member has a vibration isolating member main body and a sliding sound reducing body that is detachably held on the inner peripheral side of the vibration isolating member main body and forms the sliding sound reducing portion. Auto tensioner. The auto tensioner according to claim 6, wherein
The circumferential length of the sliding noise reduction body is larger than the circumferential length of the vibration isolator body,
An auto tensioner, wherein both ends in the circumferential direction of the sliding noise reducing body are bent outward in the radial direction so that the sliding noise reducing body is held by the vibration isolator body.

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