JPH0842649A - Tensioner - Google Patents

Abstract

PURPOSE:To improve size stability and wear resistance of a damping member by forming the damping member by using a resin composition consisting mainly of polyethersulfon resin. CONSTITUTION:A tensioner T exerts a given tension by pressing a belt against a pulley 8 by the energizing force of an energizing means 3. Meanwhile, when a moving member 2 is moved in a direction reverse to an energizing direction during the fluctuation of a belt tension, movement thereof is damped by damping members 15 and 16. A spring support 15 and an insert bearing 16 are formed of a resin composition consisting mainly of polyethersulfon resin and added with 2-8wt.% polytetrafuloroethylene resin and 2-20wt.% aramide fibers. This constitution prevents the decrease of a life and the generation of noise owing to a torque fluctuation caused by a size change during high temperature operation or internal heat generation occasioned by the increase of wear of a slide part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to apply a predetermined tension to a V-belt or the like for driving an auxiliary machine by an automobile engine, and change the damping force for the tension adjusting operation according to the tension variation. The present invention relates to an improved tensioner, and more particularly to an improved composition of a damping member.

[0002]

2. Description of the Related Art As this type of tensioner, for example, the one disclosed in Japanese Patent Publication No. 62-2182 is generally known, and a tensioner for a belt wound between a driving pulley and a plurality of driven pulleys is known. It is used to press the span between pulleys and to stably transmit the rotational force of the drive pulley to all driven pulleys.

Specifically, as illustrated in FIG. 1, a fixing member 1 having a shaft portion 4 and fixed to a fixed body such as an automobile engine, and a shaft member 4 of the fixing member 1 are rotatable. Has a boss portion 7 which is fitted to the outside, and an arm portion 9 which rotatably supports the pulley 8 around an axis Q parallel to the rotation axis P of the boss portion 7 at the tip is provided in a protruding manner. The rotating member 2 is rotatably supported by the fixed member 1 in the portion 7. A torsion coil spring 3 is arranged on the outer peripheral side of the boss portion 7 of the rotating member 2 to urge the rotating member 2 to rotate with respect to the fixed member 1 in a predetermined direction.

Further, a cylindrical spring support 15 with a flange is provided between the inner circumference of the torsion coil spring 3 and the outer circumference of the boss portion 7 of the rotating member 2, and is fixed to the inner circumference of the boss portion 7 of the rotating member 2. Cylindrical insert bearings 16 are provided between the outer periphery of the shaft portion 4 of the member 1 and damping members made of synthetic resin for damping the rotation of the rotating member 2. Then, when the rotating member 2 is rotated in the direction opposite to the rotating biasing direction due to the fluctuation of the belt tension, the rotating member 2 is rotated in the rotating biasing direction more than when the rotating member 2 is rotated in the rotating biasing direction. The rotation of the belt is damped with a large force, which effectively suppresses the vibration of the belt.

Further, in the one disclosed in the above publication, a large damping force is not necessary, but Zytel (registered trademark) is used as the resin material of the damping member when damping a belt vibration having a large amplitude. Is proposed. This Seitel is made of Polyamide 6
-6 resin as a main component, and has relatively high wear resistance and low friction.

[0006]

However, since the polyamide resin such as the polyamide 6-6 resin is a crystalline resin having a low glass transition point, there is a drawback that the dimensional change due to heat generation during sliding is large. is there.

That is, when it is used as a damping member of a tensioner, the clearance at the sliding portion may actually become smaller than necessary due to dimensional changes.
At that time, the torque fluctuation becomes large. On the contrary, if the clearance in the sliding part becomes unnecessarily large, the vibration of the belt cannot be suppressed effectively this time, and the wear of the sliding surface increases remarkably, which shortens the life due to internal heat generation. , The noise becomes loud. It may be possible to apply grease to the sliding surface in order to improve wear resistance, but in this case, the grease will scatter as the usage period becomes longer, so It is not an effective measure.

The present invention has been made in view of the above points, and its main purpose is to apply a predetermined tension to the belt as described above and suppress the belt vibration by the operation of the damping member. In order to improve the dimensional stability and wear resistance of the damping member, the composition of the damping member is improved.

[0009]

In order to achieve the above object, in the invention of claim 1, as a main component of the damping member, an amorphous material having a higher glass transition point than a polyamide resin which is a crystalline resin is used. Polyether sulfone resin (hereinafter,
(Referred to as PES).

Specifically, in the present invention, there is provided a fixing member which can be fixed to a fixed body and a pulley for pressing the belt, and the pulley is supported by the fixing member so as to be movable in the direction of pressing the belt. Movable member, a biasing means interposed between the fixed member and the movable member for biasing the movable member in a predetermined direction with respect to the fixed member, and a biasing means interposed between the fixed member and the movable member, the movable member And a damping member for damping the movement of the movable member, and presses the belt against the pulley by the urging force of the urging means to apply a predetermined tension, while the movable member reverses the urging direction when the belt tension changes. In contrast to the tensioner which is designed to dampen its movement when moved in the direction of, the damping member is made of a resin composition containing PES as a main component. And the.

According to a second aspect of the present invention, in the above-mentioned first aspect of the invention, the damping member is 2 to 8 wt% of polytetrafluoroethylene resin (hereinafter referred to as PTFE),
The resin composition is composed of 2 to 20 wt% of aramid fiber and the balance of PES.

According to a third aspect of the present invention, in the second aspect of the present invention, the fixed member has a shaft portion, and the movable member is externally fitted to the shaft portion of the fixed member so as to be rotatable from its tip end side. It has a boss part that is The biasing means is a torsion coil spring which is arranged on the outer peripheral side of the boss of the movable member and biases the movable member in a predetermined direction with respect to the fixed member. The damping member is interposed between the torsion coil spring and the boss portion of the movable member, and the inner peripheral surface of which is slidably contacted with the outer peripheral surface of the boss portion in a state of being fixed to the fixed member side. And

According to the invention of claim 4, in the invention of claim 2, when the fixing member, the movable member and the urging means of the tensioner are the same as those of the invention of claim 5, the damping member is the movable member. The insert bearing is interposed between the boss portion and the shaft portion of the fixing member, and the outer peripheral surface of which can be slidably contacted with the inner peripheral surface of the boss portion in a state of being fixed to the fixing member side.

In the invention of claim 5, the above-mentioned claim 3 or 4
In the invention, at least the boss portion of the movable member is made of an aluminum alloy.

[0015]

With the above construction, in the invention of claim 1, P which is used as a main component of the resin composition of the damping member.
Since ES is one of the amorphous resins and has a higher glass transition point than that of polyamide resin, it has excellent dimensional stability at high temperatures and excellent abrasion resistance at high temperatures. Therefore, the dimensional stability and wear resistance of the damping member at high temperature are improved, which causes torque fluctuation due to dimensional change at high temperature and internal wear due to increased wear at sliding parts, resulting in a shorter life. It becomes difficult to cause a situation such as noise or noise.

According to the second aspect of the present invention, the damping member is made of the resin composition in which PTFE is added to the PES. Therefore, by adding PTFE, the friction coefficient of the damping member can be adjusted. At this time,
If the amount of PTFE added is less than 2 wt%, the friction coefficient becomes too large and wear resistance deteriorates, while the amount added is 8 w.
If it exceeds t%, the friction coefficient becomes too small, so PT
By adding FE in the range of 2 to 8 wt%, a friction coefficient in an appropriate range can be obtained. The addition of PTFE also has the effect of reducing the change with time of the friction coefficient.

By adding aramid fiber to the PES, impact resistance and abrasion resistance are improved as compared with the case of PES alone. At this time, if the addition amount of the aramid fiber is less than 2 wt%, the abrasion resistance becomes insufficient, while if the addition amount exceeds 20 wt%, the friction coefficient becomes too small, so that the aramid fiber is in the range of 2 to 20 wt%. When added in, the appropriate impact resistance and wear resistance can be obtained without reducing the friction coefficient. Furthermore, with aramid fibers, unlike the case where glass fibers or carbon fibers are added, it is unlikely that a metal such as an aluminum alloy will be damaged or worn.

According to a third aspect of the present invention, the damping member is interposed between the torsion coil spring and the boss portion of the movable member, and the inner peripheral surface is the outer peripheral surface of the boss portion while being fixed to the fixed member side. In the invention of claim 4, the damping member is interposed between the boss portion of the movable member and the shaft portion of the fixed member, and the outer peripheral surface thereof slides on the inner peripheral surface of the boss portion. Since it is an insert bearing that can contact,
In these inventions, the action of the invention of claim 2 is specifically carried out.

In the invention of claim 5, since at least the boss portion of the movable member is made of an aluminum alloy,
The action of the invention of claim 2 is sufficiently exhibited.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the entire structure of a tensioner T according to an embodiment. The basic structure of the tensioner T is a fixing member 1 made of an aluminum alloy that can be fixed to a fixed body such as an automobile engine, and the tensioner T is assembled to the fixing member 1. And a rotating member 2 as a movable member made of an aluminum alloy that is rotatably supported about a rotating axis P, and is fixed between the fixing member 1 and the rotating member 2 to fix the rotating member 2. The member 1 is provided with a torsion coil spring 3 as an urging means for urging the member 1 to rotate counterclockwise in FIG.

The fixing member 1 has a bottomed cylindrical rear cup portion 1a whose front end side (lower left side in FIG. 1) is open, and a front end side in the rotation axis P from the center of the bottom wall of the rear cup portion 1a. Has a shaft portion 4 that extends toward the front and two mounting portions 5 that extend radially outward on the outer circumference of the rear cup portion 1a, and three bolt insertion holes provided in these mounting portions 5 In FIG. 6, a fixing bolt (not shown) is used to fix the fixed body. Although not shown, a rear end portion of the rear cup portion 1a is formed with a base end side locking hole penetrating the peripheral wall in the radial direction.

The rotating member 2 is open at the base end side (upper right side in FIG. 1) and the opening is at the rear cup portion 1a.
Of the front cup portion 2a facing the opening portion of the front cup portion 2a, extending from the center of the bottom wall of the front cup portion 2a toward the base end side in the direction of the rotation axis P, and extending from the tip end side to the shaft portion 4 of the fixing member 1. The boss portion 7 to be fitted is provided on the outer periphery of the front cup portion 2a so as to project outward in the radial direction, and at the projecting end thereof, a pulley 8 is provided around an axis Q parallel to the rotation axis P of the boss portion 7. Has an arm portion 9 rotatably supported. The rotating member 2 is rotatably supported by the fixed member 1 at the boss portion 7 and is made of synthetic resin by a front plate 10 made of a substantially circular metal plate attached to the tip of the shaft portion 4 of the fixed member 1. It is prevented from coming off via the thrust washer 11. Further, the front plate 10 has a restriction piece 10a.
Are projected outward in the radial direction, and are rotated by engaging the restriction piece 10a with a notch 12 provided by notching a part of the peripheral wall on the outer surface of the bottom wall of the front cup 2a. The rotation range of the member 2 is restricted. on the other hand,
A shaft portion 9a that extends in the direction of the axis Q and axially supports the pulley 8 is provided in a protruding manner at the protruding end of the arm portion 9, and the pulley 8 is retained by a pulley bolt 14 via a dust shield 13. . In addition, the front cup portion 2a
The peripheral wall has a front end locking hole (not shown) penetrating the peripheral wall in the radial direction.

The main body of the torsion coil spring 3 is left-handed, and both the base end 3a and the front end 3b are formed to project radially outward from the main body. Further, the base end 3a radially penetrates into the base end side locking hole in the rear cup portion 1a peripheral wall of the fixing member 1, and the tip end 3b radially penetrates into the front end side locking hole in the front cup portion 2a peripheral wall of the rotating member 2. And is locked by this, so that each of the end portions 3a, 3
The movement of b is restricted in the circumferential direction. Then, by operating the main body in a direction in which the diameter of the main body expands with the both ends 3a and 3b locked, the rotating member 2 is rotationally biased in a predetermined direction (counterclockwise direction in FIG. 1). Has been done.

A spring support 15 as a damping member is provided on the outer peripheral side of the boss portion 7 of the rotating member 2.
Is interposed. The spring support 15 has a flanged cylindrical shape as a whole, and an inner peripheral surface of the cylindrical main body portion 15a is slidably contactable with an outer peripheral surface of the boss portion 7. Further, an outward flange-shaped flange portion 15 that contacts the inner surface of the bottom wall of the rear cup portion 1a is provided at the opening edge of the body portion 15a on the base end side.
b is circumferentially provided, and the flange portion 15a is pressed against the inner surface of the bottom wall by the compression biasing force of the torsion coil spring 3, whereby the spring support 15 is fixed to the fixing member 1 side. .

An insert bearing 16 as a damping member is interposed between the inner circumference of the boss portion 7 of the rotating member 2 and the outer circumference of the shaft portion 4 of the fixed member 1. The insert bearing 16 has a cylindrical shape with both ends open. The outer peripheral surface of the insert bearing 16 and the inner peripheral surface of the boss portion 7 of the rotating member 2 are each formed in a tapered shape in cross section in which the tip side is slightly smaller in diameter than the base side. Further, the inner peripheral surface of the insert bearing 16 and the outer peripheral surface of the shaft portion 4 of the fixing member 1 are also formed in a tapered cross-section whose diameter is slightly smaller on the tip side than on the base side. Although not shown, a key groove extending in the direction of the rotation axis P is provided on the outer periphery of the shaft portion 4, and a key portion engaging with the key groove is provided on the inner periphery of the insert bearing 16. As a result, the rotation of the insert bearing 16 on the side of the fixed member 1 is stopped.

Thus, the tensioner T configured as described above is used for an auxiliary machine drive mechanism of an automobile engine as shown in FIG. 2, for example. Here, a drive pulley 22 is connected to the crankshaft 21 of the engine so as to rotate integrally therewith.
And a plurality of driven pulleys 23 for driving auxiliary devices such as a power steering device, an alternator, and an air conditioner, respectively, and a predetermined V-ribbed belt t running in a direction shown by an arrow in FIG. It is used to give the tension of. In the tensioner T, as the tension of the belt t wound around the pulley 8 of the rotating member 2 fluctuates, the body portion 15a of the spring support 15 is rotated by the pressing force of the torsion coil spring 3 inward in the radial direction. The boss portion 7 of the rotating member 2 is pressed against the boss portion 7 of the second main body 15a and a portion of the outer peripheral surface of the boss portion 7, and the boss portion 7 of the rotating member 2 is pressed by the above-mentioned pressing force. By being pressed against, a frictional force is generated between a part of the inner peripheral surface of the boss portion 7 and a part of the outer peripheral surface of the insert bearing 16, and the frictional force damps the rotation of the rotating member 2. When the rotating member 2 rotates in the direction opposite to the rotating biasing direction (clockwise direction in FIG. 1 and counterclockwise direction in FIG. 2), the frictional force that damps the rotation is generated. Since it is made larger than the frictional force at the time of rotating in the urging direction, the rotation of the rotating member 2 is suppressed when the belt tension sharply increases, which prevents the fluttering of the belt t. become.

As a feature of the present invention, the resin composition of the spring support 15 and the insert bearing 16 is mainly composed of PES (polyether sulfone resin) represented by the following structural formula and contains 2 to 8 wt%. Of P
2 to 2 with TFE (polytetrafluoroethylene resin)
0% by weight of aramid fiber was added.

[0028]

(Equation 1)

Therefore, according to this embodiment, since PES, which is an amorphous resin having a high glass transition point, is used as the main component of the resin composition of the spring support 15 and the insert bearing 16, it is a crystalline resin. It is possible to improve the dimensional stability at high temperatures, as compared with the conventional spring support and insert bearing containing polyamide 6-6 resin as a main component.

As a result, it is possible to suppress a change in the clearance of the sliding portion due to a dimensional change at a high temperature, so that the torque fluctuation due to the above-mentioned clearance becoming unnecessarily small and the clearance more than necessary. However, there is a problem caused by the fact that the belt vibration is insufficiently controlled and the wear at the sliding parts becomes significantly large, which shortens the life due to internal heat generation and causes noise. It will be difficult. Further, it is possible to improve wear resistance at high temperature.

As an example of the above PES, for example, US IC
In the 4100G and 4800G grades of "VICTREX (trade name)" manufactured by Company I, while the glass transition point Tg of the polyamide 6-6 resin is about Tg = 65 ° C, Tg = 225 ° C, which is high. Dimensional stability at high temperature is superior to that of polyamide 6-6 resin. It also has excellent wear resistance at high temperatures. In addition, an ether group (-
Since O-) is present, the mobility of the polymer chain in the melt phase, that is, the processability is good. Further, since the p-phenylene unit is alternately linked with a sulfone group (—SO ₂ —) and an ether group, it is stable to chemicals. Further, it has an advantage of excellent cost performance.

Further, by adding PTFE to the PES, the friction coefficients of the spring support 15 and the insert bearing 16 can be adjusted to appropriate values. At this time, when the amount of PTFE added is less than 2 wt%, the friction coefficient becomes too large and wear resistance deteriorates, while when the amount added exceeds 8 wt%, the friction coefficient becomes too small, so that PTFE is 2 to 8 wt%. By adding in the range of%, the friction coefficient in the proper range can be obtained. In addition, the addition of PTFE has the advantage that the change with time of the friction coefficient can be reduced.

Further, by adding aramid fiber to the above PES, impact resistance and abrasion resistance can be improved as compared with the case of PES alone. At this time, if the addition amount of the aramid fiber is less than 2 wt%, the abrasion resistance becomes insufficient, while if the addition amount exceeds 20 wt%, the friction coefficient becomes too small.
By adding in the range of wt%, proper impact resistance and wear resistance can be obtained without lowering the friction coefficient. Further, the aramid fiber has an advantage that unlike the case of adding the glass fiber or the carbon fiber, the boss portion 7 of the rotating member 2 made of an aluminum alloy is less likely to be damaged or worn.

In the above embodiment, only the spring support 15 and the insert bearing 16 were made of the resin composition containing PES as the main component, but the thrust washer 1
1 may be composed of the same resin composition.

In the above embodiment, the torsion coil spring 3 is used.
Has spring support 15 and insert bearing 1
Although 6 is pressed against the boss portion 7 of the rotating member 2 to generate the damping force, the concrete damping generation mechanism may be different from this.

In the above embodiment, the torsion coil spring 3 is used as the biasing means, but a leaf spring or the like may be used.

Further, in the above embodiment, the rotating member 2 as a movable member is rotatably supported by the fixed member 1. However, the movement mode of the movable member is not limited to the rotating movement. For example, it may reciprocate linearly.

Here, a concrete example of the damping member will be described. Seven types of invention examples 1 to 7 as damping members were prepared with the formulations shown in Table 1 below, and the dynamic friction coefficient and wear rate of these were tested. The material is P
The ES manufactured by Mitsui Toatsu Chemical Co., Inc. and the aramid fiber manufactured by Toray Co., Ltd. Kevlar (registered trademark) were used.

[0039]

[Table 1]

As shown in Table 1 above, in Invention Example 1, P
The least addition amount of TFE and aramid fiber, 2.
5 wt% PTFE and 2.0 wt% aramid fiber were respectively added to the remaining 95.5 wt% PES. In Invention Examples 2 to 7, the addition amounts of PTFE and aramid fiber were gradually increased, and in Invention Example 7 in which the addition amount was the largest, 7.5 wt% of PTFE and 20.
0 wt% aramid fiber, the rest is 72.5 wt%
Of PES, respectively.

For comparison, Comparative Examples 1 to 5 were prepared, and the dynamic friction coefficient and the wear rate of these were also tested. That is, as shown in Table 1 above, Comparative Example 1 is PE
S was 100 wt%, and neither PTFE nor aramid fiber was added. 97.0 wt% in Comparative Example 2
% PES, only 3.0 wt% PTFE was added, and in Comparative Example 3, 98.0 wt% PES, only 2.0 wt% aramid fiber was added. Further, in Comparative Example 4, 70.0 wt% PES was added to 10.0 wt% PTFE.
And 20.0 wt% aramid fiber were added. Also,
As Comparative Example 5, polyamide 6- which is a conventional main component
PTFE and aramid fiber were added to 6 resins. That is, 5.0 wt% of PTFE and 5.0 wt% of aramid fiber, the balance of 90.0 wt% of polyamide 6-
6 resin.

The specific procedure of the test is as follows. First, each of the above resin compositions is injection-molded to obtain a disk-shaped molded product having a diameter of 40 mm and a height of 5 mm, and then a cylindrical product having a diameter of 6 mm and a height of 5 mm is obtained from each molded product. A test piece was prepared by cutting. Then, with the high cycle type reciprocating friction tester shown in FIG.
While overlapping with a predetermined load, the mating member 32 was reciprocally moved in the vertical direction in the figure with a predetermined amplitude, and the dynamic friction coefficient and the wear rate were examined. As a test condition, a mating material 32 was a tensile test dumbbell made of aluminum die cast made of the same aluminum alloy as the tensioner T, and a test load was 57.
kgf (pressure: 20MPa), reciprocating amplitude ± 1.8m
m, the test frequency is 13.888 Hz (sine wave),
Further, assuming the state in the engine room while the vehicle was running, the test was carried out for 24 hours at an ambient temperature of 110 ° C.
In the figure, 33 is a surface pressure detection load cell for detecting the load with which the test piece 31 is pressed against the mating member 32.
Reference numeral 4 denotes a frictional force detection load cell that detects the frictional force between the test piece 31 and the mating member 32.

Then, the dynamic friction coefficient is calculated based on the pressing load and the frictional force 24 hours after the start of the test, and the wear rate is calculated based on the height and weight of the test piece 31 before and after the test. did. In this case, as an evaluation standard, a large damping force can be expected when the dynamic friction coefficient is 0.1 or more, and the wear rate [unit: m
m ³ / h], the lower the better, but 1.0 mm ³
If it is less than or equal to / h, it can be used sufficiently.
In the following description, the unit of the wear rate is omitted for simplicity.

The above results are also shown in Table 1 above. First, comparing invention example 3 and comparative example 5 in which both PTFE and aramid fiber were added by 5.0 wt%, the dynamic friction coefficient increased from 0.067 to 0.146 by about 2.2 times, and the abrasion The speed is reduced from 1.320 to 0.415 to less than 1/3. That is, by changing the main component from the conventional polyamide 6-6 resin to PES, a large sliding friction can be obtained, the damping can be increased correspondingly, and the wear resistance can be significantly improved. I understand.

Next, the ranges of the respective addition amounts of PTFE and aramid fiber that achieve the above effects will be considered. First, from Invention Examples 1 to 7, the amount of PTFE added is 2.5 to
7.5 wt% and the amount of aramid fiber added is 2.0 to 2
It can be seen that if it is 0.0 wt%, the dynamic friction coefficient is 0.1 or more and the wear rate is 1.0 or less, which satisfies the evaluation criteria.

Here, the suitable range of the amount of PTFE added will be further examined. Inventive Example 1 and Comparative Example 3
The amount of PTFE added was 2.5 wt% to 0
As the wear rate decreases from 0.862 to 2.62.
It turns out that it changes to 876 and exceeds 1.0. At the same time, the coefficient of dynamic friction also increased from 0.153 to 0.265. That is, when the amount of PTFE added is less than 2.0 wt%, the wear rate may exceed 1.0. Therefore, the lower limit of the amount of PTFE added is 2.0 w
It turns out that t% is sufficient. When the amount of PTFE added is less than 2.0 wt%, the dynamic friction coefficient also becomes too large at 0.2 or more and wear resistance deteriorates.

On the other hand, by comparing Invention Example 7 and Comparative Example 4, the amount of PTFE added was 7.5 wt% to 10.0 wt.
%, The coefficient of dynamic friction increases from 0.104 to 0.
It changes to 070 and becomes smaller than 0.1. That is, the dynamic friction coefficient is about 1.0 when the amount of PTFE added is 8.0 wt%. Therefore, it is understood that the upper limit of the amount of PTFE added is preferably 8.0 wt%.
If the amount of PTFE added exceeds 8.0 wt%, the dynamic friction coefficient will be too small, less than 0.1, and it will be difficult to obtain a sufficient damping force. From these things, P
When the amount of TFE added is 2.0 to 8.0 wt% and the amount of aramid fiber added is 3.0 to 20.0 wt%, it is possible to clear the evaluation criteria of the tensioner T as a damping member. I understand.

A case where the amount of the aramid fiber added deviates from the range of 2.0 to 20.0 wt% is also considered. First, when the lower limit value of 2.0 wt% is not reached, it can be seen from the comparison between Invention Examples 1 and 2 that the wear rate exceeds 1.0. Next, 2 which is the upper limit
When it exceeds 0.0 wt%, it can be seen from the comparison of Invention Examples 6 and 7 that the dynamic friction coefficient is smaller than 0.1.

[0049]

As described above, according to the first aspect of the invention, the fixing member which can be fixed to the fixed body and the pulley for pressing the belt are provided, and the pulley is arranged in the direction of pressing the belt. A movable member movably supported by the fixed member, and an urging means interposed between the fixed member and the movable member for urging the movable member in a predetermined direction with respect to the fixed member,
In the tensioner which is interposed between the fixed member and the movable member and includes a damping member for damping the movement of the movable member, since the damping member is made of a resin composition containing PES as a main component, polyamide 6-6 Compared to the conventional resin-based products, it is possible to improve dimensional stability and wear resistance at high temperatures, and to improve torque stability due to dimensional changes at high temperatures or increased wear at sliding parts. It is possible to prevent a situation in which the life is shortened or noise is generated due to heat generation.

According to the invention of claim 2, the damping member is made of a resin composition comprising 2 to 8 wt% of PTFE, 2 to 20 wt% of aramid fiber, and the balance of PES. The dynamic friction coefficient and wear resistance of can be adjusted to an appropriate range, and
It is possible to improve impact resistance, and it is possible to prevent the sliding member from being scratched or abraded when the sliding member is a metal such as an aluminum alloy.

According to the third aspect of the present invention, the movable member is rotatably fitted to the shaft portion of the fixed member at the boss portion while the torsion coil is disposed on the outer peripheral side of the boss portion of the movable member. The damping member is interposed between the torsion coil spring and the boss portion of the movable member and fixed to the fixed member side with respect to the tensioner which is urged to rotate in a predetermined direction by the spring. In this state, the inner peripheral surface is composed of a spring support that can slide on the outer peripheral surface of the boss. Further, according to the invention of claim 4, in the same tensioner, the damping member is interposed between the boss portion of the movable member and the shaft portion of the fixed member and is prevented from rotating to the fixed member side. The outer peripheral surface is an insert bearing that can slide on the inner peripheral surface of the boss. Therefore, according to these inventions, it is possible to specifically obtain the effect of the invention of claim 2 above.

According to the invention of claim 5, since at least the boss portion of the movable member is made of an aluminum alloy, the effect of the invention of claim 2 can be sufficiently exerted.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a tensioner according to an embodiment of the present invention.

FIG. 2 is a front view showing a usage example of the tensioner.

FIG. 3 is a front view partially showing a main part of a reciprocating wear tester.

[Explanation of symbols]

 1 Fixed member 2 Rotating member (movable member) 3 Torsional coil spring (biasing means) 4 Shaft part 7 Boss part 8 Pulley 15 Spring support (damping member) 16 Insert bearing (damping member) P Rotating shaft center Q Shaft center T tensioner t V ribbed belt (belt)

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Claims (5)

[Claims] 1. A fixed member that can be fixed to a fixed body, a movable member that has a pulley for pressing a belt, and the pulley is movably supported in the direction of pressing the belt by the fixed member. An urging means interposed between the fixed member and the movable member for urging the movable member in a predetermined direction with respect to the fixed member, and a damping member interposed between the fixed member and the movable member for damping the movement of the movable member. When the belt is pressed against the pulley by the urging force of the urging means to give a predetermined tension, the movable member is moved in a direction opposite to the urging direction when the belt tension changes. In the tensioner adapted to dampen its movement by a damping member, the damping member is composed of a resin composition containing a polyether sulfone resin as a main component. Tensioner, wherein the door. 2. The tensioner according to claim 1, wherein the damping member is composed of 2 to 8 wt% of polytetrafluoroethylene resin, 2 to 20 wt% of aramid fiber, and the balance of polyether sulfone resin. A tensioner characterized by being composed of objects. 3. The tensioner according to claim 2, wherein the fixed member has a shaft portion, and the movable member is a boss portion rotatably fitted to the shaft portion of the fixed member from its tip end side. The biasing means is a torsion coil spring which is arranged on the outer peripheral side of the boss portion of the movable member and biases the movable member in a predetermined direction with respect to the fixed member, and the damping member is A tensioner, which is a spring support which is interposed between a torsion coil spring and a boss portion of a movable member, and whose inner peripheral surface is slidably contactable with an outer peripheral surface of the boss portion while being fixed to the fixed member side. . 4. The tensioner according to claim 2, wherein the fixed member has a shaft portion, and the movable member is a boss portion rotatably fitted to the shaft portion of the fixed member from the tip side thereof. The biasing means is a torsion coil spring which is arranged on the outer peripheral side of the boss portion of the movable member and biases the movable member in a predetermined direction with respect to the fixed member, and the damping member is An insert bearing which is interposed between the boss portion of the movable member and the shaft portion of the fixed member, and is an insert bearing whose outer peripheral surface is capable of sliding contact with the inner peripheral surface of the boss portion while being fixed to the fixed member side. Tensioner. 5. The tensioner according to claim 3, wherein at least the boss portion of the movable member is made of an aluminum alloy.