JP2013213566A - Autotensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely design damping characteristics of a vibration attenuation means in an autotensioner A, to enable variable adjustment of damping force and to apply stable and high damping force.SOLUTION: An autotensioner A includes a fixing member 1 having a shaft 3, and an oscillating member 10 having a boss 12 externally fitted into the shaft 3 in a swingable manner. The oscillating member 10 includes a torsion coil spring 18 in which a pulley 17 in contact with a belt B is rotatably supported on an arm tip 16a offset from the oscillating center of the boss 12, and which pivotably biases the oscillating member 10 in a direction where the pulley 17 presses the belt B. As a means for attenuating the oscillation of the oscillating member 10, a plurality of Belleville springs 30, 31 compressed and stacked between a front plate 26 fixed to the shaft 3 and the end face of the boss 12, to generate a damping force at least by mutual sliding resistance between the Belleville springs 30, 31.

Description

  The present invention relates to an auto tensioner, and more particularly, to a damping force obtained by sliding resistance between a plurality of disc springs.

  Conventionally, for example, in a belt transmission system such as a belt-type auxiliary machine drive device of an automobile engine, a tension is applied to the belt, and the damping operation is damped to suppress the vibration (flapping) of the belt and to provide a stable torque transmission. Autotensioners that let you do this are known.

  Specifically, the auto tensioner is, for example, a fixing member that is attached and fixed to an engine, and a shaft portion (spindle) of the fixing member that is externally fitted to the boss portion and rotatably supported, and has a tension at the tip portion. A movable part such as an arm, etc., on which the pulley is rotatably supported, and a boss part of this movable part are arranged, one end is locked to the fixed member and the other end is locked to the movable part, and fixed by torsion torque. A torsion coil spring that urges the movable portion in a direction in which the tension pulley presses the belt against the member, and a damping means that attenuates the swing of the movable portion.

  As the damping means, for example, a cylindrical resin-made insert bearing is interposed between the outer peripheral surface of the shaft portion of the fixed member and the inner peripheral surface of the boss portion of the movable portion. A structure that dampens the swing of the movable part, and a structure that attenuates the swing of the movable part by placing a resin spring support around the boss part of the movable part and pressing the spring support against the outer peripheral surface of the boss part by a torsion coil spring Etc. are used.

  By the way, in the above damping means, the insert bearing made of resin and the spring support are slidably contacted with the metal to generate the damping force, so the damping characteristics are the bore diameter of the boss portion of the movable part and the torque of the torsion coil spring. The product is designed to be uniform for each product, and it is difficult to design the damping characteristics by adjusting the same.

  In other words, when the belt contact angle with respect to the pulley is small, the amplitude of the auto tensioner becomes excessive, causing problems such as belt slip and fluttering abnormal noise, which may result in failure of the belt transmission system. Becomes scarce. In order to establish this belt transmission system stably, it is necessary to add a device or the like separately, and there is a difficulty in becoming an expensive belt transmission system.

  Therefore, if the damping characteristics of the auto tensioner can be designed, the versatility of the belt transmission system will increase, and the optimum damping characteristics will be designed for each belt transmission system to construct an efficient belt transmission system. Can do. As a result, the belt-type accessory drive device for an automobile engine can be expected to reduce the fuel consumption of the engine, and it is not necessary to add a device or the like and is inexpensive.

  Conventionally, the damping force can be adjusted, for example, as disclosed in Patent Document 1, for example, the tip of the shaft portion of the fixing member is protruded to the outer surface side of the boss portion, and a disk-shaped plate is formed on the protruding portion. The member is fixed and fixed by caulking or the like so that the member cannot rotate, and a resin sliding plate material is disposed between the plate member and the end surface of the boss portion in a state of being sandwiched between the receiving member and the pressing member, It has been proposed to adjust the damping force by urging the pressing member toward the receiving member with a disc spring.

  Further, in Patent Document 2, a friction member is interposed between the lower end surface of the boss of the arm and the upper end surface of the base, and a damping force is obtained by pressing the friction member against the upper end surface of the base with a disc spring. At the same time, it has been proposed to variably adjust the damping force by changing the biasing force of the disc spring.

  As shown in Patent Documents 3 to 5, it is proposed that a plurality of disc springs are stacked as a spring for generating an urging force that presses against a friction member.

JP-A-7-113449 (particularly paragraphs 0026 to 0036, FIG. 1 and FIG. 3) Japanese Utility Model Publication No. 6-14601 (particularly paragraph 0020) Japanese Utility Model Laid-Open No. 5-14711 (especially FIGS. 1 to 3) Japanese Utility Model Publication No. 5-83516 (particularly paragraph 0022, FIG. 4) Japanese Unexamined Patent Publication No. 7-12188 (particularly paragraph 0026, FIG. 2)

  However, in Patent Documents 1 and 2, although the damping force can be adjusted by changing the spring force of the disc spring itself, the pressing force on the friction member is only changed by the biasing force of the disc spring. The generation of the damping force utilizes sliding resistance between the resin and a metal such as aluminum, and it is difficult to provide a stable high damping force.

  Further, Patent Documents 3 to 5 only show that a plurality of disc springs are stacked to increase the biasing force, and these disc springs have only a function of a biasing unit that presses the friction material.

  The present invention has been made in view of these points, and its purpose is to variably adjust the damping force by improving the configuration of the damping means in the auto tensioner so that the damping characteristics can be designed accurately. And to provide a stable and high damping force.

  In order to achieve the above object, in the present invention, the damping force is generated by the sliding resistance between the plurality of disc springs themselves.

  Specifically, the first invention includes a first member having a shaft portion, and a second member having a boss portion that is swingably fitted to the shaft portion. One of the members is fixed to the fixed body, and on the other side, a pulley contacting the belt is rotatably supported at a portion offset from the swing center of the boss portion, and the first and second members are rotatably supported. It is premised on an auto tensioner provided with a torsion coil spring that relatively urges the pulley in the direction in which the pulley presses the belt, and a damping means that attenuates the swing between the first and second members.

  The damping means includes a plurality of disc springs that are interposed between the first and second members in a compressed and overlapping state and generate a damping force at least by mutual sliding resistance. Features.

  In the first aspect of the invention, when one of the first and second members swings (vibrates) around the shaft portion of the first member together with the pulley due to a change in belt tension, the swing is braked and attenuated by the damping means. The tension of is automatically adjusted. The damping means includes a plurality of disc springs interposed between the first and second members in a compressed and overlapped state, and a damping force is generated by at least sliding resistance between the disc springs. To do.

  In this way, by generating a damping force by at least the sliding resistance between the disc springs, a stable high damping force can be applied, and it is optimal for each belt transmission system at low cost without the addition of devices etc. Therefore, it is possible to design an accurate damping characteristic and to construct an efficient belt transmission system.

  According to a second invention, in the first invention, the tip portion of the shaft portion protrudes from the end surface of the boss portion, and a plate member is integrally fixed to the tip portion, and the end surface of the plate member and the boss portion A plurality of disc springs are interposed between the two in a compressed state.

  In the second aspect of the invention, since the plurality of disc springs are compressed and overlapped between the plate member fixed to the tip end portion of the shaft portion and the end surface of the boss portion, the damping characteristic has a compact structure. Can be designed accurately.

  In the third invention, in the first or second invention, the damping force is changed by changing at least one of the number of the plurality of disc springs, the spring force of each disc spring, and the direction of two adjacent disc springs. It is characterized by being adjustable.

  In the third aspect of the invention, the damping force can be adjusted by changing at least one of the number of the plurality of disc springs, each spring force, and the direction of the plurality of adjacent disc springs. Can be designed to

  According to a fourth invention, in the first or second invention, the disc spring is a ring-shaped plate inclined in a taper shape so as to be directed to one side in the center line direction toward the radially outer side, and a plurality of disc springs The disc springs are arranged so that the inclination directions of two adjacent disc springs are opposite to each other.

  In this 4th invention, since the inclination directions of two adjacent disc springs are opposite to each other, the inner peripheral portions or the outer peripheral portions thereof are in pressure contact with each other by the spring force of each disc spring. It comes to slide in the state where the slidable contact area is small, and the damping force can be reduced correspondingly.

  According to a fifth aspect, in the first or second aspect, the disc spring is a ring-shaped plate inclined in a taper shape so as to be directed to one side in the center line direction toward the radially outer side, The disc springs are characterized in that the two disc springs adjacent to each other are arranged so that the inclination directions thereof are the same.

  In the fifth aspect of the invention, since the two tilting directions of the two disc springs are the same as each other, they are all pressed against each other by the spring force of each disc spring, and the sliding contact area between the disc springs is large. In this state, the damping force can be increased.

  As described above, in the first invention, in the auto tensioner including the first member having the shaft portion and the second member having the boss portion that is swingably fitted to the shaft portion, A plurality of attenuating means for attenuating the swinging between the first and second members are compressed and overlapped between the first and second members and generate a damping force at least by mutual sliding resistance. A disc spring was provided. In the second invention, the plate member is integrally fixed to the tip portion of the shaft portion protruding from the end surface of the boss portion, and a plurality of disc springs are compressed and overlapped between the plate member and the end surface of the boss portion. Was interposed. According to these inventions, a stable and high damping force can be applied, and an optimum damping characteristic can be accurately designed for each belt transmission system at a low cost without adding a device or the like. A good belt transmission system can be constructed.

  According to the third invention, the damping characteristic can be easily designed by changing the number of the plurality of disk springs, the spring force, and the direction of the adjacent disk springs so that the damping force can be adjusted. Can do.

  According to the fourth aspect of the present invention, the disc spring is in the shape of an annular plate inclined in a tapered shape, and a plurality of disc springs are arranged so that the inclination directions of two adjacent disc springs are opposite to each other. The inner peripheral portions or the outer peripheral portions of the adjacent disc springs can be brought into pressure contact with each other, the sliding contact area between the disc springs can be reduced, and the damping force can be reduced.

  According to the fifth aspect of the present invention, the disc spring is in the shape of an annular plate inclined in a tapered shape, and a plurality of disc springs are arranged such that the inclination directions of two adjacent disc springs are the same as each other. It is possible to increase the damping force by press-contacting the entire adjacent disc springs and increasing the sliding contact area between the disc springs.

1 is a cross-sectional view taken along the line II of FIG. FIG. 2 is a plan view showing the auto tensioner according to the embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view showing a main part of the auto tensioner. 4 shows a first disc spring, FIG. 4 (a) is a plan view, FIG. 4 (b) is a side view, FIG. 4 (c) is a perspective view, and FIG. 4 (d) is a sectional view. FIG. 5 shows the second disc spring, FIG. 5 (a) is a plan view, FIG. 5 (b) is a side view, and FIG. 5 (c) is a perspective view. FIG. 6 is a view corresponding to FIG. 3 showing a first modification of the auto tensioner. FIG. 7 is a view corresponding to FIG. 3 showing a second modification of the auto tensioner. FIG. 8 shows a flat washer with a claw, FIG. 8 (a) is a plan view, FIG. 8 (b) is a side view, and FIG. 8 (c) is a perspective view. FIG. 9 is a view corresponding to FIG. 3 showing a third modification of the auto tensioner.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

  1 and 2 show an auto tensioner A according to an embodiment of the present invention, and this auto tensioner A is used as a part of a belt transmission system that constitutes, for example, an auxiliary drive device (not shown) for an automobile engine. It has been.

  Although not shown in the drawings, the accessory driving device is, for example, a crank pulley composed of a V-ribbed pulley attached to a crankshaft of an in-vehicle engine, a similar compressor pulley attached to a rotating shaft of an air conditioner compressor (auxiliary machine), and power steering. A similar PS pump pulley attached to the rotating shaft of a pump (auxiliary machine), a similar alternator pulley attached to the rotating shaft of an alternator (auxiliary machine), a similar idler pulley, and a cooling fan A fan pulley comprising a flat pulley is provided, and a transmission belt B comprising a V-ribbed belt (shown in phantom lines in FIG. 2) is provided between these pulleys so that the inner surface of the belt is in contact with the pulley. In the case of a fan pulley consisting of flat pulleys, Wound respectively in opposite bending state of being contacted to, and wound in a so-called serpentine layout, so that the belt B by the rotation of the engine is run between the pulleys to drive each accessory.

  In the belt B of the layout described above, the arm type auto tensioner A is disposed on the slack side span coming out of the crank pulley, and the auto tensioner A presses the slack side span from the belt outer surface side to apply belt tension. It adjusts automatically.

  As shown in FIG. 2, the auto tensioner A includes a fixing member 1 that is attached and fixed to the engine as a fixed body, and a swinging member 10 that is swingably supported by the fixing member 1. Yes. The fixing member 1 constitutes a first member in the present invention, and the swing member 10 constitutes a second member. That is, the fixing member 1 has a bottomed cylindrical (cup-shaped) fixing member body 2 made of, for example, an aluminum alloy having one end (upper end in FIG. And a shaft portion 3 (spindle) that protrudes from the opening of the fixing member main body 2. The shaft portion 3 is composed of a large-diameter portion 3a located near the base end portion close to the bottom portion of the fixing member main body 2, and an annular surface perpendicular to the axis of the shaft portion 3 on the distal end side of the large-diameter portion 3a. It has a middle diameter part 3c that is continuous through the large diameter side step part 3b and has a smaller diameter than the large diameter part 3a. The fixing member main body 2 is attached and fixed to the engine by an attaching bolt or the like at an attaching portion (not shown).

  On the other hand, the oscillating member 10 is made of a metal made of, for example, an aluminum alloy, like the fixed member 1, and includes a bottomed cylindrical oscillating member main body 11 having an open end (the lower end in FIG. 1). The outer diameter of the swing member main body 11 is substantially the same as that of the fixed member main body 2.

  A cylindrical boss portion 12 is integrally protruded from the bottom of the swing member main body 11 so as to protrude from the opening of the swing member main body 11. A boss hole 13 (bore) penetrating the bottom wall of the main body 11 is formed. The boss hole 13 is a through-hole whose inner diameter is slightly larger than the shaft portion 3 of the fixing member 1. A circular concave portion 14 concentric with the boss hole 13 is formed in a step shape around the boss hole 13 opened on the outer surface of the bottom portion of the swing member main body 11. The boss portion 12 has a distal end surface of the boss portion 12 from the distal end side of the boss portion 12 to the large-diameter side step portion 3b of the shaft portion 3 with respect to the middle diameter portion 3c of the shaft portion 3 of the fixing member 1. The oscillating member 10 is externally fitted so as to face each other with a gap, so that the oscillating member 10 can be oscillated (rotatable) via the bush 20 via the boss portion 12 to the shaft portion 3 of the fixing member 1. It is supported. The bush 20 is a cylindrical member made of a solid lubricant such as nylon, POM, PPS, PTFE, etc., and has no function to attenuate the swing of the swing member 10 and functions as a simple sliding lubricant. Then, dry lubrication is performed between the boss portion 12 of the swing member 10 and the shaft portion 3 of the fixing member 1 without supplying lubricating oil.

  Further, the fixed member main body 2 and the swing member main body 11 are arranged so that the respective openings face each other, and a substantially sealed annular space is formed between the fixed member main body 2 and the swing member main body 11 and the boss portion 12. Yes.

  A first friction disk 21 is disposed between the base end portion of the intermediate diameter portion 3 c of the shaft portion 3 and the tip end portion of the boss portion 12. The first friction disk 21 includes a cylindrical portion 21a located between the outer peripheral surface on the proximal end side of the medium diameter portion 3c of the shaft portion 3 and the inner peripheral surface of the distal end portion of the boss portion 12, and a radial direction from one end of the cylindrical portion 21a The disc portion 21b extends outward and is located between the large-diameter side step portion 3b of the shaft portion 3 and the tip surface of the boss portion 12.

  In addition, a second friction disk 22 is disposed between a portion near the distal end of the middle diameter portion 3 c of the shaft portion 3 and a base end portion of the boss portion 12. The second friction disk 22 includes a cylindrical portion 22a located between the outer peripheral surface near the distal end of the medium diameter portion 3c of the shaft portion 3 and the inner peripheral surface of the base end portion of the boss portion 12, and a radial direction from one end of the cylindrical portion 22a. The disk portion 22b extends outward and is fitted into the stepped recess 14 on the bottom surface of the rocking member main body 11. In each of the friction disks 21 and 22, the disk portions 21 b and 22 b are fixed to the boss portion 12 side of the swinging member 10 so as to rotate integrally, and the cylindrical portions 21 a and 22 a are connected to the shaft portion 3 (medium diameter) of the fixing member 1. It rotates relative to the part 3c) so as to be slidable.

  An arm portion 1614 extending outward in the radial direction is integrally formed on the outer peripheral portion on the bottom wall side of the swing member main body 11, and the arm portion 16 swings on the opposite side (upper side in FIG. 1) to the fixed member 1. The moving member main body 11 has a distal end portion 16 a that protrudes from the bottom. A tension pulley 17 composed of a flat pulley having a rotation axis parallel to the axis of the boss portion 12 is rotatably attached to and supported by the tip portion 16a via a bearing (not shown). Reference numeral 17 denotes a shaft 16 that is rotatably supported by a tip portion 16a that is offset with respect to the swing center of the swing member 10, and presses the transmission belt B in a reverse bending state.

  Although not shown in the drawings, the side wall of the fixing member main body 2 is provided with a spring locking portion formed by a notch or a through hole cut out from the opening side, and the side wall of the swinging member main body 11 is provided from the opening side. Spring locking portions each formed of a notch or a through hole are formed.

  A belt pressing direction in which the tension pulley 17 presses the belt B by the torsional torque in the annular space formed outside the boss portion 12 inside the fixed member main body 2 and the swing member main body 11. A torsion coil spring 18 that is urged to rotate is accommodated. The torsion coil spring 18 is disposed around the boss portion 12 of the swing member 10 with both end portions (tangs) (not shown) protruding outward in the radial direction. One end thereof is engaged with the spring engaging portion of the fixing member main body 2 and the other end thereof is engaged with the spring engaging portion of the swinging member main body 11. However, the swinging member 10 is urged to rotate in the belt pressing direction in which the tension pulley 17 presses the belt B by, for example, a torsional torque in an expanding direction.

  Further, the auto tensioner A is provided with an attenuating means for attenuating the oscillation of the oscillating member 10, and this attenuating means is a feature of the present invention. That is, as shown in FIG. 1, the distal end portion of the shaft portion 3 (medium diameter portion 3 c) of the fixing member 1 passes through the boss hole 13 (bottom wall of the swinging member main body 11) in the boss portion 12. It protrudes to the outer surface side. A cylindrical small-diameter portion 3e having a smaller diameter than the medium-diameter portion 3c is formed at the tip portion, and the small-diameter portion 3e has a small diameter composed of an annular surface perpendicular to the tip of the medium-diameter portion 3c and the axis of the shaft portion 3. It is continuous via the side step part 3d. A disc-shaped front plate 26 (plate member) made of metal for preventing the swinging member 10 from being inserted into the small-diameter portion 3e, which is the tip portion of the shaft portion 3, allows the small-diameter portion 3e to be inserted into the center hole thereof. The distal end portion of the small diameter portion 3e is fixed and fixed in a non-rotatable manner by caulking or the like that deforms radially outward. The front plate 26 is disposed so as to face the second friction disk 22 in the axial direction. Between the front plate 26 integrated with the fixing member 1 and the boss portion 12 of the swinging member 10, for example, three pieces of spring steel or the like positioned around the middle diameter portion 3c of the shaft portion 3 are used. The metal disc springs 30, 30, and 31 are arranged in a state where they are compressed and overlapped in the center line direction, and these disc springs 30, 30, and 31 constitute damping means.

  The three disc springs 30, 30 and 31 are of two types, and the two first disc springs 30 and 30 located on the front plate 26 side are shown in FIGS. 4 (a) to 4 (d). As described above, both are circular plate-like ones inclined in a tapered shape so as to go to one side in the centerline direction (the other side in the centerline direction) toward the radially outer side (radially inner side), and have the same shape The middle diameter portion 3c of the shaft portion 3 of the fixing member main body 2 is inserted through the center hole.

  On the other hand, one second disc spring 31 located on the boss portion 12 side has basically the same shape as the first disc spring 30 as shown in FIGS. 5 (a) to 5 (c). The ring-shaped plate is inclined in a tapered shape so as to be directed to one side in the center line direction toward the outside in the radial direction, and the middle diameter portion 3c of the shaft portion 3 in the fixing member main body 2 is inserted into the center hole. Yes. A plurality (three in the illustrated example) of claw portions 31a, 31a,... Are integrally projected on the outer peripheral portion of the second disc spring 31 so as to be equally spaced in the circumferential direction. Each claw portion 31a extends along the center line direction so that the outer peripheral portion of the second disc spring 31 faces the side located with respect to the inner peripheral portion.

  As shown in FIG. 3 in an enlarged manner, the three disc springs 30, 30, 31 are arranged such that the inclination directions of the two adjacent disc springs 30, 30 and 30, 31 are opposite to each other, The first disc spring 30 located closest to the front plate 26 has an inner peripheral portion positioned closer to the front plate 26 than the outer peripheral portion, and the central first disc spring 30 has an outer peripheral portion conversely. Similarly to the first disc spring 30 located at the front plate 26 side end, the second disc spring 31 located further closest to the boss portion 12 so as to be located on the front plate 26 side than the inner peripheral portion. The inner peripheral portion is disposed so as to be located closer to the front plate 26 than the outer peripheral portion.

  Each claw portion 31a on the outer peripheral portion of the second disc spring 31 is engaged with a locking recess 11a formed on the end surface of the boss portion 12 corresponding to the claw portion 31a. The second disc spring 31 swings integrally with the swing member 10 by engagement with the stop recess 11a.

  With such an arrangement structure, the three disc springs 30, 30, 31 are in a compressed state, and the inner peripheral portions or the outer peripheral portions are brought into pressure contact with each other by the spring force of the disc springs 30, 31. The first disc springs 30 arranged at the positions closest to the front plate 26 are also pressed against the front plate 26 by the same spring force, and are in pressure contact with each other, between these disc springs 30, 30, 31 themselves. And a sliding resistance between the front plate 26 and the inner peripheral portion of the first disc spring 30 in contact with the front plate 26, a damping force is generated.

  Therefore, in this embodiment, during operation of the automobile engine, when each auxiliary machine (air conditioner compressor, power steering pump, alternator, fan) is driven via the belt B by the auxiliary machine drive device, The swinging member 10 is urged to rotate by the torsion coil spring 18 of the auto tensioner A, and the tension pulley 17 at the tip of the arm portion 16 presses the span of the transmission belt B by this urging force. Is granted.

  Further, when the arm portion 16 of the swinging member 10 swings (vibrates) around the shaft portion 3 of the fixing member 1 together with the tension pulley 17 due to a change in the tension of the belt B, the swinging is a damping means, that is, mainly a disc spring 30. , 30, 31 itself is braked and attenuated by the sliding resistance, and the tension of the belt B is automatically adjusted.

  At that time, since the claw portion 31a of the outer peripheral portion of the second disc spring 31 is engaged with the locking recess 11a of the end surface of the boss portion 12, the sliding with respect to the swinging member 10 is restricted and integrated therewith. Swing. Therefore, sliding resistance is generated between the disc springs 30, 30, 31 itself and between the first disc spring 30 and the front plate 26.

  As described above, since the damping force is generated by the sliding resistance between the metal disc springs 30, 30, 31, a stable high damping force can be applied. In addition, it is possible to accurately design optimum damping characteristics for each belt transmission system that is an accessory drive device at low cost without requiring addition of a device or the like, and an efficient belt transmission system can be constructed.

  A front plate 26 is integrally fixed to the distal end portion of the shaft portion 3 of the fixing member 1, and a plurality of disc springs 30, 30, 31 are arranged between the front plate 26 and the end surface of the boss portion 12. 26 and the boss part 12 are compressed and overlapped, so that the damping characteristic can be accurately designed with a compact structure.

  In this embodiment, the number of the plurality of disc springs 30, 30, 31, the spring force (surface pressure) of each spring 30, 31, and the two adjacent disc springs 30, 30 (and 30, 31). The damping force can be adjusted by changing at least one of the directions. Modifications for adjusting the damping force will be described (in the following modifications, the same parts as those in FIGS. 1 to 5 are denoted by the same reference numerals and detailed description thereof is omitted).

(Modification 1)
FIG. 6 shows a first modification in which the number and direction of the disc springs are changed. That is, in the first modification, three first disc springs 30, 30,... And one second disc spring 31 are provided as damping means. Among them, the second disc spring 31 is constituted by a disc spring with claws as in the first embodiment, and is arranged so that the inner peripheral portion is located closer to the front plate 26 than the outer peripheral portion. It is engaged with the locking recess 11a on the end face of the portion 12. On the other hand, the three first disc springs 30, 30,... Are all arranged in the same direction as the second disc spring 31 so that the inner peripheral portion is located closer to the front plate 26 than the outer peripheral portion. Yes.

  Accordingly, the four disc springs 30, 30,..., 31 are in pressure contact with each other when the two adjacent disc springs 30, 30 (or 30, 31) are overlapped with each other in the same direction. Are arranged as follows. In FIG. 6, 32 is a flat washer interposed between the second friction disk 22 and the second disc spring 31. Other configurations are the same as those shown in FIG.

  Also in this modified example 1, since the claw portion 31a on the outer peripheral portion of the second disc spring 31 is engaged with the locking recess 11a on the end surface of the boss portion 12, the second disc spring 31 slides with respect to the swing member 10. To be regulated. Therefore, sliding resistance is generated between the disc springs 30, 30, 31 itself and between the first disc spring 30 and the front plate 26.

  And two adjacent disc springs 30 and 30 (or 30, 31) are arranged in the reverse direction as shown in FIG. The contact area between the disc springs 30 and 30 (or 30, 31) is increased as compared with the existing structure. Accordingly, the damping force can be set large. Further, since the number of the disc springs 30 and 31 is increased, the damping force can be increased by increasing the number of the disc springs 30 and 31.

  Further, the damping force can be changed by changing the spring force of the disc springs 30 and 31, and the damping force can be increased by increasing the spring force.

  Therefore, in this way, at least the number of the plurality of disc springs 30, 30,... 31, the spring force of each disc spring 30, 31, and the direction of the two adjacent disc springs 30, 30 (or 30, 31). By changing one, the damping force can be adjusted, so that the damping characteristics can be easily designed.

  That is, as the number of disc springs 30 and 31 is increased and the spring force (surface pressure) of each disc spring 30 and 31 is increased, the contact between two adjacent disc springs 30 and 30 (or 30, 31) is increased. As the area is increased, the damping force can be increased, and the damping force may be adjusted by selecting one of these three changing conditions or combining a plurality of conditions appropriately.

(Modification 2)
In the second modification shown in FIG. 7, four first disc springs 30, 30,... Are provided as damping means. These first disc springs 30, 30,... Are arranged such that the inner peripheral portion is located closer to the front plate 26 than the outer peripheral portion. Are arranged so as to be in pressure contact with each other in the same direction.

  And the flat washer 33 with a nail | claw is arrange | positioned instead of the 2nd disc spring 31 between these 1st disc springs 30, 30, ... and the boss | hub part 12 end surface. As shown in FIG. 8, the flat washer 33 with a claw is an annular plate shape, and the middle diameter portion 3 c of the shaft portion 3 in the fixing member main body 2 is inserted through the center hole thereof. A plurality (three in the illustrated example) of claw portions 33a, 33a,... Are integrally projected on the outer peripheral portion of the flat washer 33 with the claw so as to be equally spaced in the circumferential direction. Each nail | claw part 33a is extended so that it may face one side along a centerline direction, and is engaged with the latching recessed part 11a of the boss | hub part 12 end surface. Other configurations are the same as those of the first modification shown in FIG.

  In the second modification, the claw portion 33a of the flat washer 33 with the claw disposed between the four first disc springs 30, 30,... And the end surface of the boss portion 12 has the locking recess 11a on the end surface of the boss portion 12. Therefore, the sliding of the flat washer 33 with claws relative to the swinging member 10 is restricted. Therefore, sliding resistance is generated between the first disc springs 30, 30,... And between the first disc spring 30, the front plate 26 and the flat washer 33 with claws.

  Accordingly, in this case as well, the two adjacent disc springs 30 and 30 are arranged so as to be in pressure contact with each other with the inclined directions being in the same direction, and the contact area between the disc springs 30 and 30 is increased. Therefore, the damping force can be set to a large one. Further, since the number of disc springs 30 is increased, the damping force can be increased.

(Modification 3)
In the third modification shown in FIG. 9, as in the first modification (see FIG. 6), the three first disc springs 30, 30,... Located on the front plate 26 side and the first 1 located on the boss portion 12 side are used. Each of the second disc springs 31 is disposed in the same direction with the inner peripheral portion positioned closer to the front plate 26 than the outer peripheral portion. A flat washer 33 with a claw is interposed between the second disc spring 31 and the end surface of the boss portion 12. Yes.

  Further, a locking recess 33b that engages with each claw portion 31a of the second disc spring 31 is formed on the surface of the flat washer 33 with claw on the front plate 26 side, and the claw portion of the second disc spring 31 is formed. The second disc spring 31 is swung by the engagement between the hook 31a and the locking recess 33b of the flat washer 33 with claw and the engagement between the claw portion 33a of the flat washer 33 with claw and the locking recess 11a at the end face of the boss portion 12. It swings integrally with the moving member 10.

  In this modification, the claw portions 31a on the outer periphery of the second disc spring 31 are engaged with the locking recesses 33b of the claw flat washer 33, and the claw portions 33a of the claw flat washer 33 are on the end surface of the boss portion 12. Since it engages with the locking recess 11a, the second disc spring 31 is restricted from sliding relative to the swing member 10. Therefore, sliding resistance is generated between the disc springs 30, 30, 31 itself and between the first disc spring 30 and the front plate 26.

  Therefore, also in this case, the two adjacent disc springs 30 and 30 (or 30, 31) are arranged so as to be in pressure contact with each other in the same direction of inclination, and the disc springs 30 and 30 ( Alternatively, since the contact area between 30, 31) increases, the damping force can be set large.

(Other embodiments)
In addition, in the said embodiment and modification, although the circular plate-shaped thing inclined in the taper shape is used as the disc spring 30, it is uneven | corrugated alternately in the direction along a center direction toward the circumferential direction. It is also possible to use an annular disc spring that is waved so as to be bent.

  In the above embodiment, a plurality of disc springs 30, 30, and 31 are arranged in a state of being overlapped between the front plate 26 at the tip of the shaft portion 3 and the end surface of the boss portion 12 facing the front plate 36. However, the present invention is not limited to this structure, and a plurality of disc springs 30, 30, and 31 may be arranged in a state of being overlapped between the fixing member 1 and the swinging member 10. For example, it can be arranged between the opening of the fixing member main body 2 and the opening of the swinging member main body 11.

  In the above embodiment, the fixed member 1 is provided with the shaft portion 3 and the swing member 10 is provided with the boss portion 12, but conversely, the swing member 10 is provided with the shaft portion and the fixed member 1 is provided with the boss portion. May be provided respectively.

  The present invention is extremely useful because it can provide a stable and high damping force and can accurately design optimum damping characteristics for each belt transmission system at a low cost without adding a device or the like. Yes, industrial applicability is high.

A Auto tensioner B Transmission belt 1 Fixed member (first member)
2 Fixed member body 3 Shaft portion 10 Oscillating member (second member)
DESCRIPTION OF SYMBOLS 11 Swing member main body 11a Locking recessed part 12 Boss part 16 Arm part 17 Tension pulley 18 Torsion coil spring 26 Front plate (plate member)
30 1st disc spring 31 2nd disc spring 31a Claw part 33 Flat washer with claw 33a Claw part 33b Locking recess

Claims (5)

A first member having a shaft portion, and a second member having a boss portion that is swingably fitted to the shaft portion,
One of the first and second members is fixed to a fixed body, and on the other side, a pulley that is in contact with the belt is rotatably supported on a portion offset from the swing center of the boss portion.
A torsion coil spring that biases the first and second members relatively in a direction in which the pulley presses the belt;
In an auto tensioner comprising damping means for damping swinging between the first and second members,
The damping means includes a plurality of disc springs interposed between the first and second members in a compressed and overlapped state and generating a damping force at least by mutual sliding resistance. Auto tensioner. In claim 1,
The tip portion of the shaft portion protrudes from the end surface of the boss portion, and a plate member is integrally fixed to the tip portion,
An auto tensioner, wherein a plurality of disc springs are interposed between the plate member and the end face of the boss portion in a compressed state. In claim 1 or 2,
An auto tensioner, wherein a damping force is adjustable by changing at least one of the number of a plurality of disc springs, the spring force of each disc spring, and the direction of two adjacent disc springs. In claim 1 or 2,
The disc spring is in the shape of an annular plate inclined in a tapered shape so as to be directed to one side in the center line direction toward the radially outer side,
The plurality of disc springs are arranged so that the inclination directions of two adjacent disc springs are opposite to each other. In claim 1 or 2,
The disc spring is in the shape of an annular plate inclined in a tapered shape so as to be directed to one side in the center line direction toward the radially outer side,
The plurality of disc springs are arranged such that two adjacent disc springs are inclined in the same direction.

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