JPH0324347A - Autotensioner - Google Patents

Abstract

PURPOSE:To facilitate to accurately finish the elasticity of a torsion coil spring so as to conform to the design value by forming first and second straight parts extending in the tangential direction on both ends of the torsion coil spring. CONSTITUTION:First and second straight parts 39a, 39b formed on both ends of a wire material 38 for constituting a torsion coil spring 29 are elastically abutted on a first plane part 28a on a fixing member 24 side and on a second plane part 36b on an oscillating member 30 side respectively. Thereby both ends of the spring 29 are lockedly engaged with a first circumferential wall 27 fixed to the member 24, and with a second circumferential wall 34 fixed to the member 30 respectively. Consequently, the necessity to bend the wire material 38 constituting the spring 29 in a small curvature can be dispensed with. When the spring 29 is manufactured, only cold coiling of a heat-treated wire material 38 will do, and reheating of the heat-treated wire material 38 can be dispensed with. As a result, repeated heat treatment of quenching and tempering for the wire material 38 can be also dispensed with, and the finishing of the spring 29 in a dimensional accuracy as specified in the design can be relatively facilitated.

Description

Detailed Description of the Invention (Field of Application in Industry A) The auto tensioner according to the present invention includes a belt for driving engine auxiliary equipment such as an alternator and a compressor;
Alternatively, it is used to apply appropriate tension to the tie belt of an automobile engine.

(Prior Art) When driving auxiliary equipment of an automobile engine such as an alternator, a compressor, or an oil cylinder for power steering, a belt drive mechanism as shown in FIG. 10 is used.

In this Fig. 10, 2 is a drive pulley that is rotationally driven by the engine crankshaft, 3, 3 are driven pulleys fixed to the ends of the manual shafts of various auxiliary machines, and 4, 4 are the belt 1 drive pulleys. A guide pulley 5 that guides a portion of the belt 1 is a tension pulley for applying appropriate tension to the belt 1.

This tension pulley 5 is pivotally supported, for example, at the tip of a swinging member 7 that swings about a pivot shaft 6. By connecting one end of a spring 8 to this swinging member 7 and elastically pressing the tension pulley 5 toward the belt 1, it is possible to ), the tension of this belt 1 is always kept constant. Incidentally, as an autotensioner for always applying appropriate tension to the belt 1, autotensioners such as those described in U.S. Pat. Nos. 4,698,049 and 4,473,362 have been known. It is being

Among these conventional autotensioners, the one described in the above-mentioned US Pat. No. 4,473,362, for example, is constructed as shown in FIG.

In this FIG.
A fixed shaft fixed to the fixed shaft 10 has a
A rubber buffer cylinder 12 is fixed by press fitting.

On the other hand, a swinging member 7 with a tension pulley 5 pivotally supported at its tip
A metal sleeve 14 is fixed to the inner circumferential surface of a holding cylinder 13 made of resin, which is fixed to the base end of the cylinder, and this sleeve 14 is slidably attached to the cylinder 12. It is fitted externally.

A torsion coil spring 16 having elasticity in the torsional direction is provided between the housing 15 fixed to the substrate 11 and the swinging member 7, and this I return coil spring 16 allows
The tension pulley 5 is given elasticity to press the belt.

That is, both ends of the torsion coil spring 16 are bent at right angles in an appropriate direction (outward in the case of the example shown in FIG. 11) to form locking portions 51, 51, and each locking portion 51, 51 is engaged with a slot 52 formed on the housing 15 or a locking step 53 formed on the swinging member 7, thereby causing the swinging member 7 to swing about the fixed shaft 10. Provides directional elasticity.

In the auto tensioner configured in this way, when the belt that the tension pulley 5 is in elastic contact with vibrates slightly, the rubber buffer cylinder 12 absorbs this vibration, and when the belt is displaced significantly, The inner circumferential surface of the sleeve 14 and the outer circumferential surface of the buffer cylinder 12 slide against each other based on the elasticity of the torsion coil spring 16, causing the swinging member 7 to swing, and the tension pulley 5 to follow the movement of the belt. let

(Problems to be Solved by the Invention) However, in the case of the conventional autotensioner configured and operated as described above, the following disadvantages occur.

That is, the housing 15 and the board 11 that have locked one of the locking portions 51 of the torsion coil spring 16 engage with each other by engaging the locking protrusion 54 formed on the housing 15 and the locking hole 55 formed in the board 11. By doing so, the housing 15 is assembled so as not to rotate with respect to the substrate l1, and since the elasticity of the torsion coil spring 16 is interposed between the housing 15 and the swinging member 7, the tension pulley 5 comes into elastic contact. Belt 1 (
10), a torsion coil spring 1 is provided between the housing 15 and the swinging member 7.
It is necessary that the elasticity of No. 6 is an accurate value as designed.

However, in the case of the torsion coil spring 16 incorporated in the conventional auto tensioner, the locking portions 51, 51 are provided at both ends.
It was difficult to set the elasticity to an accurate value as designed. That is, since the locking parts 51, 51 at both ends of the torsion coil spring 16 are formed by bending the wire that constitutes the torsion coil spring 16 at right angles with a small curvature, cracks do not occur in the wire when bending. In order to prevent this from occurring, it is necessary to heat and temper the ends of the wire before bending. After forming the locking portions 51, 51 on both ends of the wire, both ends of the wire are hardened, but as the hardening and tempering are repeated, the wire deforms and becomes a torsion coil spring. The twist angle of 16 tends to be different from the design value.

If the torsion angle of the torsion coil spring 16 differs from the design value, the auto tensioner incorporating this torsion coil spring 16 may not be able to apply the desired tension to the timing belt, etc. .

In order to eliminate such inconvenience, the present inventor first developed the 12th to
Invented an auto tensioner as shown in Figure 14 (1999).
Utility Model Registration Application No. 53939).

In the case of the auto tensioner according to the present invention, the fixed shaft 10
A torsion coil spring 18 is provided between the fixed member 17 provided with the tension pulley 5 and the swinging member 7 supporting the tension pulley 5.
The configuration shown in FIGS. 13 and 14 is used in which first and second straight portions 19 and 20 extending in the tangential direction are formed at both ends.

A hole 21 is formed at the tip of each straight portion 19, 20.
, 21, locking pins 22, 22 formed on the fixed member 17 and the swinging member 7 are inserted, and both ends of the torsion coil spring 18 are locked to the fixed member 17 and the swinging member 7, respectively.

In the case of the autotensioner of the previous invention configured as described above, there is no need to bend the wire that makes up the torsion coil spring 18 for applying tension with a small curvature, and as a result, there is no need to heat this wire, and the wire Since there is no need to repeat hardening and tempering, it becomes easy to accurately finish the elasticity of the torsion coil spring 18 according to the designed value, and the tension applied to the belt by the auto-tensioner becomes relatively accurate.

In the case of the previous invention which is constructed and operates as described above, the elasticity of the torsion coil spring 18 for applying tension can be adjusted relatively accurately, but it is impossible to completely regulate the elasticity to the designed value. It's still difficult. For this reason, the allowable tension limit is narrow.
In the case of autotensioners used for special purposes, further improvements are desired.

The autotensioner of the present invention was conceived in view of the above-mentioned circumstances.

(Means for Solving the Problems) The autotensioner of the present invention, like conventional autotensioners, has a fixed shaft of a fixed member, and is fitted onto the fixed shaft and swings around the fixed shaft. a swinging member; a tension pulley pivotally supported on the swinging member by a pivot parallel to the fixed shaft provided at the end of an arm extending in the radial direction of the swinging member; and a return coil spring that is respectively engaged with the swinging member and imparting elasticity to the swinging member in the direction of pressing the tension pulley against the belt.

Furthermore, in the auto tensioner of the present invention, first and second straight portions extending in a tangential direction are formed at both ends of the torsion coil spring, and a first locking portion is formed on the fixing member. a wall portion facing the outer edge of the first linear portion, a second locking wall portion formed on the swinging member facing the outer edge of the second straight portion, and a first locking wall; The tip of an adjustment screw screwed from the outside into a screw hole formed in at least one of the torsion coil spring and the second locking wall is brought into contact with the outer edge of the straight portion of the torsion coil spring end. (Function) The function of applying tension to the belt using the autotensioner of the present invention configured as described above is the same as that of the conventional autotensioner described above. However, in the case of the auto-tensioner of the present invention, by rotating the threaded adjustment screw formed in one of the locking walls, a torsion coil for applying tension is brought into contact with the tip of the adjustment screw. The elasticity of this torsion coil spring can be adjusted by displacing the end of the spring.For this reason, even if the elasticity of the torsion coil spring is not exactly as designed, this elasticity can be adjusted later. Based on the elasticity of the torsion coil spring, the auto tensioner can more accurately apply tension to the belt.

(Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

1 to 9 show embodiments of the present invention. FIG. 1 is a sectional view showing the overall structure, FIG. 2 is a view from above of FIG. 1 with only the swinging member taken out, and FIG. Figure 3 is a sectional view taken along the line A-A in Figure 2, Figure 4 is a view from below in Figure 3, Figure 5 is a view from above in Figure 1 with only the fixing member taken out, and Figure 6. is a sectional view taken along line B-B in Fig. 5, Fig. 7 is a view seen from the right side of Fig. 6, Fig. 8 is a side view of the torsion coil spring, and Fig. 9 is a sectional view of the torsion coil spring.
It is a view seen from the right side of the figure.

Reference numeral 23 denotes a fixed shaft of the fixed member 24, which is formed into a circular tube shape as a whole, and one end (the upper end in FIG. 1) is connected to the fixed member 24.
A base plate portion 25 of a short cylindrical housing piece 25 with a bottom, which is a part of the housing piece 25 and comes into contact with the surface on which the auto tensioner is attached.
It is continuous with a. This housing piece 25 is constructed by forming a first peripheral wall 27 having a shape as shown in FIG. 5 on the peripheral edge of a base plate portion 25a continuous from one end of the fixed shaft 23.

That is, this first peripheral wall 27 is formed in a three-quarter arc shape concentrically with the fixed shaft 23, and extends along both sides of the circumferential direction e of the first curved surface portion 26.
A pair of first plane parts 28a orthogonal to each other
, 28b are connected to each other, and inside the first circumferential wall 27, there is an axial half portion of a torsion coil spring 29 having a shape as shown in FIGS. 8 and 9 in a free state. It can be stored freely.

On the other hand, the fixed shaft 23C formed at the center of the fixed member 24 having the above-described shape allows the swinging cylinder 31 formed at the base end of the swinging member 30 to be externally moved through the sliding bearings 32, 32. It's fitted.

At the inner peripheral edge of the rocking plate part 33 and at the outer peripheral edge of the rocking member 30, which has the shape of the rocking cylinder 31, at a position surrounding the rocking cylinder 31, there is a second peripheral wall in the shape of a short cylinder with a bottom. 34 is formed to be continuous with the swing cylinder 31, thereby forming a housing piece 42. That is, as shown in FIG. 2, the second peripheral wall 34 connects both circumferential edges of the second curved surface portion 35 shaped like a three-quarter circular arc with a pair of second peripheral walls perpendicular to each other. Plane part 3
6a and 36b are connected to each other and have a mirror-symmetrical shape with the first peripheral wall 27, and this second peripheral wall
The remaining axial half of a torsion coil spring 29, which has a shape as shown in FIGS. 8 and 9 in a free state, can be freely stored inside the spring.

The housing piece 42 including the 20th circumferential wall 34 and the housing piece 25 including the first circumferential wall 27 are
When the swing tubes 31 are fitted onto the fixed glaze 23 of the fixed member 24, they are combined with each other in the middle, and function as a housing 41 that covers a torsion coil spring 29 and a rubber tube 49, which will be described below.

The torsion coil spring 29 is made by coiling a wire 38 having a rectangular cross section with the long side in the radial direction (the left-right direction in FIG. 1) so that the long side is arranged at right angles to the fixed shaft 23. The wire rod 38 has first and second straight portions 39a, 3 formed at both ends thereof.
9b extend in the tangential direction of the coil portion 40, and protrude outward beyond the outer periphery of the coil portion 40.

When the torsion coil spring 29 having the above-described shape is housed inside the first circumferential wall 27 and the second circumferential wall 34 as described above, the first A first linear portion 39a is provided on the inner surface of the first flat portion 28a, which is a locking wall portion.
The outer edge of the second linear portion 39b is made to face the second plane portion 36b, which is a second locking wall portion and forms a part of the second peripheral wall 34, and the outer edge of the second straight portion 39b is made to face the second plane portion 36b, which is a second locking wall portion and forms a part of the second peripheral wall 34, respectively. In the free state of the torsion coil spring 29, the first
The second straight parts 39a and 39b are located on a straight line with each other, but when assembling the autotensioner of the present invention, one half of the torsion coil spring 29 is placed inside the first peripheral wall 27, and the other half is placed inside the second peripheral wall 27. After storing the fixed member 24 and the swinging member 30 in the peripheral wall 34 of
By elastically deforming the torsion coil spring 29 as shown by the chain line in FIG. 2, a preload is applied to the swinging member 30.

That is, in the state where the torsion coil spring 29 is elastically deformed in this way, the first straight part of the first and second straight parts 39a and 39b formed at both ends of the torsion coil spring 29 The outer edge of 39a is elastically attached to the inner surface of the first plane portion 28a, and the outer edge of the second straight portion 39b is elastically attached to the inner surface of the second plane portion 36b, either directly or via an adjustment screw 46, which will be described later. Pressed.

As a result, the swinging member 30 has the fixed shaft 23 as the center.
In Figure 2, an elastic force is applied that tends to swing clockwise. As described above, the pair of housing pieces 25 and 42 are combined in a middle position, and the fixed member 24 provided with both housing pieces 25 and 42 and the swinging member 30 are rotated 90 degrees relative to each other. In this case, since the opening edge of the first peripheral wall 27 and the opening edge of the second peripheral wall 34 are substantially aligned with each other, a large gap is formed at the joint between the two housing pieces 25 and 42. There isn't.

Further, the base end portion of an arm piece 43 is coupled to the outer circumferential surface of the second peripheral wall 34 that guards the housing piece 42 on the swinging member 30 side, and a pivot provided at the tip of this arm piece 43 44&: The tension pulley 5 is supported by the externally supported rolling bearing 45.
is rotatably supported. The center of rotation of the tension pulley 5 (which coincides with the center of the pivot shaft 44 and the rolling bearing 45) is parallel to the fixed shaft 23, and the elasticity of the torsion coil spring 29 causes the swinging member 30 to rotate around the fixed shaft 23. As the tension pulley 5 swings, the outer peripheral surface of the tension pulley 5 is pressed against the belt 1 (FIG. 10).

On the other hand, a first plane part forming the first circumferential wall 27 constituting the housing piece 25 on the fixed member 24 side and facing the outer edge of the first straight part 39a formed at one end of the torsion coil spring 29 A screw hole 47 is formed in a part of 28a at a position facing the outer edge of the tip of the first straight portion 39a. Then, the adjustment screw 46 is screwed into this screw hole 47 from the outside of the first plane portion 28a, and the adjustment screw 46
The distal end portion of the first linear portion 39a is brought into contact with the outer edge of the distal end portion of the first linear portion 39a. Reference numeral 48 denotes a lock nut screwed onto the intermediate portion of the adjustment screw 46 in order to prevent the adjustment screw 46 from loosening.

Furthermore, among the pair of housing pieces 25 and 42 constituting the housing 41, the inner surface of the base plate portion 25a of one housing piece 25 having the fixed shaft 23 is provided with an axial direction ( (vertical direction in Figure 1) one end surface (first
The other end surface in the axial direction of the rubber tube 49 is attached to the inner surface of the bottom portion 42a of the housing piece 42, which has a swing tube 31 that connects the upper end surface of are combined. Therefore, in the assembled state of the autotensioner of the present invention, stress in the torsional direction is applied to the rubber cylinder 49 as the fixed shaft 23 and the swinging member 30 are displaced.

Further, a protrusion 50 is formed on the outer surface of the base plate 25a of the housing piece 25 on the fixed shaft 23 side, and when assembling the auto tensioner, the protrusion 50 is attached to the side surface of the engine, etc.
The housing piece 25 is fitted into a recess (not shown) formed in the board 11 (FIG. 11) on which the auto tensioner is mounted, thereby preventing the housing piece 25 from being displaced relative to the board 11.

The amount of movement between the pair of housing pieces 25 and 42 is determined by the small diameter portion provided on the outer periphery of the locking ring 56 fixed to the end of the fixed shaft 23 provided on the housing piece 25 side, and the small diameter portion provided on the housing piece 42 side. The protrusion 57 formed on the inner periphery of the opening of the provided swinging cylinder 31 is limited by engagement with both housing pieces 25, 4.
2 is combined, it is possible to continue applying preload to the torsion coil spring 29 provided between both housing pieces 25 and 42. In addition, in this way, the torsion coil spring 2
9 is preloaded (in this state, the rubber cylinder 49 is subjected to stress in the torsional direction between the pair of housing pieces 25 and 42, but the preload applied to the torsion coil spring 29 and the rubber cylinder 49 are The stress applied to the torsion coil spring 29 is determined to be independent of the applied stress.In other words, the preload applied to the torsion coil spring 29 &: is determined from the viewpoint of applying appropriate tension to the timing belt, and the stress applied to the rubber cylinder 49 is , its size is determined from the point of view of effective vibration damping.

The auto tensioner of the present invention constructed as described above fixes the cylindrical fixed shaft 23 to a substrate such as the side surface of the engine block with the bolt 9 inserted from below in FIG. When performing this mounting operation, the protrusion 50 formed on the outer surface of the base plate portion 25a of the housing piece 25 is inserted into the recess formed on the base plate.

In this way, once the auto tensioner is installed at a predetermined location on the front surface of the circuit board, the tension pulley 5, which pivots on the tip end of the swinging member 30, resists the elasticity of the torsion coil spring 29. It is swung in a direction away from the traveling position shown in Figure 10). Then, with the swinging member 30 swinging in this manner, the timing belt 1 is hooked onto the tension pulley 5. In this state, the swinging member 30 swings due to the elasticity of the torsion coil spring 29, and the outer peripheral surface of the tension pulley 5, which is rotatably supported by a rolling bearing 45 at the tip of the swinging member 30, is attached to the timing belt. 1, and depending on the elasticity of the torsion coil spring 29, the tying belt 1
Appropriate tension is applied.

By the way, the auto tensioner of the present invention incorporates ↑
In the case of return coil spring 29, this t return coil spring 2
The first and second straight portions 3 9 a and 3 9 b formed at both ends of the wire 38 constituting the wire rod 9 are connected to the first flat portion 28 a on the fixed member 24 side and the second flat portion 28 a on the swinging member 30 side, respectively. By elastically contacting the flat portion 36b, both ends of the torsion coil spring 29 are connected to the first peripheral wall 27 fixed to the fixed member 24 and the second peripheral wall 34 fixed to the swinging member 30. It is locked in. Therefore, unlike the torsion coil spring 16 incorporated in the conventional auto tensioner shown in FIG. There is no need to bend according to the curvature.

Therefore, when manufacturing the torsion coil spring 29, the torsion coil spring 29 can be made by simply winding the heat-treated wire 38 in a cold state, and there is no need to heat the heat-treated wire 38 again. As a result, there is no need for repeated heat treatment of hardening and tempering the wire rod 38, making it relatively easy to finish the dimensional accuracy of the torsion coil spring 29 exactly as designed. The tension applied will be relatively accurate.

Furthermore, in the case of the auto tensioner of the present invention, even if the elasticity of the torsion coil spring 29 does not match the designed value, the elasticity of the torsion coil spring 29 can be adjusted after the resetting recoil spring 29 is assembled into the auto tensioner. Elasticity can be adjusted.

That is, the adjusting screw 46 screwed into the screw hole 47 formed in the first flat part 28a of the first peripheral wall 27 is rotated, and the tip of the adjusting screw 46 protrudes from the inner surface of the first flat part 28a. By adjusting the amount, the amount of twist of the torsion coil spring 29 can be adjusted, and the magnitude of the elasticity imparted to the swinging member 30 can be adjusted. After adjustment, tighten adjustment screw 4
The lock nut 48 screwed into the middle part of the first flat part 2
Tighten it toward the outer surface of the adjustment screw 8a to prevent the adjustment screw 46 from loosening.

When the timing belt 1 becomes slack and the tension pulley 5 displaces, the torsion coil spring 29 also displaces accordingly. Since the spring constant of this torsion coil spring 29 can be set small, even if the timing belt 1 becomes slack, the force with which the tension pulley 5 presses the timing belt 1 due to the elasticity of the torsion coil spring 29 will hardly change. Therefore, stable tension can be continuously applied to the tying belt 1. Moreover, by reducing the spring constant of the torsion coil spring 29 in this way,
The torque capacity of this torsion coil spring 29 does not become small. Furthermore, if the timing belt 1 that is pressed by the tension pulley 5 causes slight vibrations (timing belt 1
), this vibration is transmitted to the swing member 30 via the rolling bearing 45, and the swing member 30 resists the elasticity of the torsion coil spring 29. There is a tendency to sway.

In this case, when the swinging member 30 tries to swing, the housing piece 42 on the swinging member 30 side and the fixed shaft 23
Stress in the torsional direction is applied to the rubber tube 49 provided so as to span between the housing piece 25 on the side. Rubber tube 4
When deforming the rubber cylinder 49, hysteresis loss occurs internally, so even if stress in the torsional direction is applied to the rubber tube 49 as described above, a large portion of this stress is consumed as hysteresis loss, resulting in no vibration. Vibrations applied to the moving member 30 are damped.

In the case of the autotensioner of this embodiment, the amount of torsional deformation applied to the rubber cylinder 49 in advance is such that the maximum hysteresis loss is produced independently of the preload applied to the torsion coil spring 29, as described above. Because it is stipulated in
The vibration damping effect is sufficient.

Furthermore, if the tension of the timing belt 1 changes greatly (if the tension decreases) due to elongation of the timing belt 1 due to long-term use, etc., the swinging member 30 will rotate around the fixed shaft 23. The tension pulley 5, which swings based on the elasticity of the torsion coil spring 29 and is pivotally supported at the tip of the swinging member 30 via a rolling bearing 45, follows the movement of the timing belt 1. Continue to apply appropriate tension to 1. Even in this case, as mentioned above, there is no large variation in the tension of the timing belt 1. In the case of the above embodiment, the torsion coil spring 29 is made of a wire rod 38 with a rectangular cross section, and the adjustment screw 46 is provided only between the torsion coil spring 29 and the fixing member 24. Although the structure is shown, the torsion coil spring 29 to be incorporated into the autotensioner of the present invention is not limited to such a shape, and may be made of a wire rod with a circular cross section as shown in FIG. But it's okay.

Furthermore, the part where the adjustment screw 46 is provided is also the same as that of the torsion coil spring 2.
9 and the swinging member 30, or between the torsion coil spring 29 and the fixed member 24, and between the torsion coil spring 29 and the swinging member 33.

(Effects of the Invention) Since the autotensioner of the present invention is configured and operates as described above, it is easy to adjust the elasticity of the torsion coil spring to obtain the tension applied to the belt accurately according to the designed value. Moreover, even if the elasticity deviates from the designed value, this elasticity can be adjusted later, making it possible to apply accurate tension to various belts such as the timing belt as desired.

In other words, the precision required when manufacturing torsion coil springs is no longer as strict, making it easier to manufacture torsion coil springs, and improving the yield of torsion coil springs, making it possible to reduce manufacturing costs. becomes.

[Brief explanation of drawings]

1 to 9 show embodiments of the present invention, FIG. 1 is a sectional view showing the overall configuration, FIG. 2 is a view from above of FIG. 1 with only the swinging member taken out, and FIG. The figure is a sectional view taken along the line A-A in Figure 2, Figure 4 is a view from below in Figure 3, Figure 5 is a view from above in Figure 1 with only the fixing member taken out, and Figure 6 is a view from above in Figure 1. Fig. 5 is a B-B sectional view, Fig. 7 is a view seen from the right side of Fig. 6, Fig. 8 is a side view of the torsion coil spring, and Fig. 9 is a sectional view of the torsion coil spring.
FIG. 10 is a schematic front view showing an example of an auto tensioner in use, FIG. 11 is a diagram similar to FIG. 1, and FIG. 12 is a diagram showing an example of a conventional auto tensioner. ~1
Fig. 4 shows an autotensioner according to the previous invention, Fig. 12 is a schematic front view showing the overall configuration, Fig. 13 is a front view of the torsion coil spring, and Fig. 14 is a side view of the same. 1: Belt, 2: Drive pulley, 3: Driven pulley, 4: Guide pulley, 5 = Tension pulley, 6: Pivot, 7: Swing member, 8: Spring, 9: Bolt, 10: Fixed shaft, 11:
Substrate, 12: Buffer tube, 13: Holding tube, 14: Sleeve,
l5: housing, 16: torsion coil spring, 17: fixing member, 18: torsion coil spring, 19: first straight section, 2
0: Second straight part, 21: Hole, 22: Locking pin, 23:
Fixed shaft, 24: Fixed member, 25: Housing piece, 25a
: Substrate part, 26: First curved surface part, 27: First peripheral wall, 28
a, 28b: first plane part, 29: torsion coil spring, 30
: Rocking member, 31: Rocking cylinder, 32: Sliding bearing, 33: Rocking plate, 34: Second peripheral wall, 35: Second curved surface part, 36a
, 36b: second plane part, 37: rubber cylinder, 38: wire rod, 3
9a: first straight part, 39b: second straight part, 40: coil part, 41: housing, 42: housing piece, 42
a: bottom, 43; arm piece, 44: pivot, 45: rolling bearing, 46: adjustment screw, 47: screw hole, 48: lock nut, 49: rubber cylinder, 50: protrusion, 51: locking part, 52 : slot, 53: locking step, 54: locking protrusion, 55: locking hole, 56: locking ring, 57: protrusion.

Claims (5)

[Claims] (1) A fixed shaft of a fixed member, a swinging member that swings around this fixed shaft, and a part of the swinging member provided with a
A tension pulley pivotally supported on a pivot parallel to the fixed shaft, and both ends of the tension pulley are respectively locked to the fixed member and the swinging member, and an elastic force in the direction of pressing the tension pulley against the belt is applied to the swinging member. In an auto tensioner having a torsion coil spring, first and second straight portions extending in a tangential direction are formed at both ends of the torsion coil spring, and a first straight portion formed on the fixing member is provided. A locking wall portion is arranged to face the outer edge of the first linear portion, and a second locking wall portion formed on the swinging member is opposed to the outer edge of the second linear portion, respectively. The tip of an adjustment screw screwed from the outside into a screw hole formed in at least one of the stop wall portion and the second locking wall portion is brought into contact with the outer edge of the straight portion of the end portion of the torsion coil spring. An auto tensioner featuring: (2) Attach a cylindrical fixed shaft to the inner circumferential edge of the base plate that contacts the surface on which the auto tensioner is to be attached, and place a circular fixed shaft on the outer circumferential edge of the base plate between the three-quarter circular arc-shaped first curved surfaces that are perpendicular to each other. A short cylindrical first peripheral wall provided with a pair of first flat parts,
one of the pair of first plane parts is used as a first locking wall part, and the inner peripheral edge of the rocking plate part is connected to the fixed shaft via a sliding bearing. The externally fitted rocking cylinder has a short cylindrical shape with a pair of second plane parts orthogonal to each other provided between a three-quarter arcuate second curved part on the outer peripheral edge of the rocking plate part. , a second peripheral wall mirror-symmetrical to the first peripheral wall is formed to form a swinging member, and one of the pair of second flat parts is used as a second locking wall part. , The auto tensioner according to claim 1. (3) A solid damping device is provided between the opposing peripheral surfaces of the swinging member and the fixed member, with one axial end coupled to the swinging member and the other axial end coupled to the fixed member,
3. The autotensioner according to claim 1, wherein the amount of deformation of the spring and the amount of deformation of the solid damping device are set independently of each other so that the amount of deformation of the spring and the amount of deformation of the solid damping device are different during use. (4) The solid damping device is a cylindrical rubber tube, and includes a small diameter fixed shaft, a medium diameter rubber tube, and a large diameter torsion coil spring.
4. The autotensioners of claim 3, wherein the autotensioners are arranged concentrically with respect to each other. (5) The autotensioner according to any one of claims 1 to 4, wherein the torsion coil spring is a wire rod having a rectangular cross section that is closely wound with the long side of the cross section aligned with the radial direction of the torsion coil spring. .