JP6186259B2 - Auto tensioner - Google Patents

Description

  The technology disclosed in the present specification relates to an auto tensioner used for a vehicle or the like.

  An auto tensioner is used that applies a predetermined tension to a belt that drives an engine accessory such as an automobile and that also damps fluctuations in the belt tension.

  The auto tensioner described in Patent Document 1 is provided with a cutout portion in a state in which a part of the boss portion in the circumferential direction is cut out at a boss portion of the rotating member, and a sliding member is provided in the cutout portion. It has been. The sliding member is slidably pressed against the shaft portion of the fixed member by a reaction force with the torsional torque of the torsion coil spring as a fulcrum, and is in contact with the shaft portion when the rotating member rotates. Sliding resistance is generated between them.

  In addition, the auto tensioner described in Patent Document 2 includes a base member, a rotatable tension member, a spring element disposed between the base member and the tension member, and a relative relationship between the base member and the tension member. And a friction device that attenuates the movement.

JP-A-11-13843 Special table 2009-533619

  In the conventional auto tensioner, the damping force is generated by the provision of the sliding member or the friction device. However, as the engine rotation fluctuation and the load on the auxiliary machine increase in recent years, further improvement in damping characteristics is desired for the auto tensioner.

  An object of the present invention is to provide an auto tensioner having more excellent damping characteristics.

The auto tensioner disclosed in the present specification has a boss portion at the center, a fixing member having a cylindrical outer wall on the outer periphery, and an arm having a shaft rotatably attached to the inner peripheral side of the boss portion. A pulley that is rotatably supported by the arm portion , a substantially cylindrical noose ring fitted to the outside of the shaft, and a substantially cylindrical spring support fitted to the outside of the nous ring , Which surrounds the outside of the boss portion of the fixing member, is arranged on the inner peripheral side of the nose ring, urges the arm portion in the circumferential direction of the boss portion, and a tongue which is an end portion is attached to the arm portion a torsion coil spring that locked the said disposed on the inner peripheral side of the torsion coil spring, and the first sliding member capable outer peripheral surface and the sliding of the boss portion, provided on the outside of the noose ring, wherein the inner peripheral surface of the outer wall of the fixed member and the sliding And a capacity of the second sliding member, said first sliding member is at least provided from said tongue when viewed from the axial direction of the boss portion at a position of 270 ° in the winding direction of the torsion coil spring The second sliding member is provided at least at a position of 90 ° from the tongue in the winding direction of the torsion coil spring as seen from the axial direction of the boss portion .

  The auto tensioner disclosed in this specification has excellent damping characteristics.

It is a perspective view showing the appearance of the auto tensioner concerning one embodiment of the present invention. FIG. 2 is a cross-sectional view showing a configuration of an auto tensioner according to an embodiment of the present invention. FIG. 3 is a cross-sectional view when the fixing member side of the auto tensioner according to the embodiment is cut in the horizontal direction. FIG. 4 is a diagram illustrating an auto tensioner and a belt driving device according to an embodiment.

  FIG. 1 is a perspective view showing an external appearance of an auto tensioner according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the auto tensioner according to the present embodiment. This figure is a view as seen from the side closer to the pulley 7 in the axial direction of the elastic member 11. FIG. 3 is a cross-sectional view when the fixing member side of the auto tensioner is cut in the horizontal direction.

As shown in FIGS. 1 to 3, the auto tensioner 1 of the present embodiment includes a fixed member 9 having a boss portion 9 a at the center and a cylindrical outer wall 9 b on the outer periphery, and is rotatable to the fixed member 9. The arm portion 5 having the attached shaft 3, the pulley 7 provided on the arm portion 5, and the portion fitted to the fixing member 9 of the arm portion 5 (ie, the shaft 3) is fitted to the outside. A cylindrical noose ring 27, a substantially cylindrical spring support 22 fitted to the outside of the nous ring 27, and, for example, is in contact with the noose ring 27 and surrounds the outside of the boss portion 9 a of the fixing member 9. And an elastic member 11 that biases the arm portion 5 in a direction around the boss portion 9a . The arm portion 5 can rotate in the direction around the axis of the shaft 3 and can swing in the axial direction of the shaft 3.

  The fixing member 9 is, for example, a spindle bracket made of metal or the like. A thrust washer 25 made of resin or the like is attached under the fixing member 9, and a base plate 23 made of metal or the like is attached under the thrust washer 25. The spring support 22 and the thrust washer 25 are made of, for example, resin. The base plate 23 is made of metal or the like.

The elastic member 11 only needs to have elasticity so that the vibration of the arm portion 5 can be attenuated, and is preferably a spring made of metal or the like. For example, the spring is interposed in the hollow portion of the fixing member 9. This spring has an axis extending in the same direction as the shaft 3. A spring tongue (tang fulcrum) 19 is locked to the arm portion 5 . The spring is preferably made of a metal such as silicon chrome steel.

  The pulley 7 is fixed to the arm member 5 by a bolt 13 and has, for example, a ball bearing, a dust shield, and the like.

The auto tensioner 1 is disposed inside the elastic member 11 and is slidable with the fixed member 6. The autotensioner 1 is disposed outside the elastic member 11 and is slidable with the fixed member 6 . The sliding member 15 is provided. The first sliding member 17 and the second sliding member 15 may be made of a material having a certain degree of friction coefficient, for example, a thermoplastic resin such as nylon, polyethylene, or polyethersulfone (PES). It may be configured.

In the example shown in FIG. 3, the second sliding member 15 is a portion that slides on the inner diameter side of the outer wall 9 b of the fixed member 9 in the spring support 22, but is provided as a separate member from the spring support 22. Also good.

When the elastic member 11 is a spring, the first sliding member 17 and the second sliding member 15 have different directions as viewed from the spring tongue 19 (clockwise as viewed from the axial direction of the boss portion 9a). Position) . Here, the second sliding member 15 is disposed at least on the spring outer diameter side (that is, outside the spring) at a position of 90 ° along the circumferential direction of the spring as viewed from the tongue 19, and at least as viewed from the tongue 19. A first sliding member 17 is disposed on the inner diameter side of the spring (that is, the inner side of the spring) at a position of 270 ° along the circumferential direction of the spring. Here, the angle of the direction seen from the tongue 19 means an angle based on the winding direction of the spring. Both the first sliding member 17 and the second sliding member 15 are fixed.

In this configuration, by twisting the arm portion 5, the spring (elastic member 11) moves in a direction shifted by 90 ° from the tongue 19 with the tongue 19 as a fulcrum. Then, the second sliding member 15 slides on the inner diameter side of the outer wall 9b of the fixing member 9 in the direction of 90 ° as viewed from the tongue 19, and the first sliding member in the direction of 270 ° as viewed from the tongue 19. 17 slides with the outer diameter portion of the boss portion 9a . The first sliding member 17, second sliding member 15 may be slid while interposing another member between the fixed member 6, thereby directly sliding a fixed member 6 May be.

  Thereby, since a damping force can be generated both inside and outside the spring, a large damping force can be obtained without increasing the size of the device. Further, since the first sliding member 17 and the second sliding member 15 are provided at different positions, the force exerted by the spring on the arm portion 5 is equalized, so that the damping force can be stabilized for a long time. Can also be realized.

  FIG. 4 is a diagram schematically showing the auto tensioner and the belt driving device of the present embodiment. The auto tensioner 1 transmits torque generated by an elastic member 11 such as a spring (see FIG. 2) to the accessory driving belt 21 via the pulley 7. The belt drive device includes, for example, a drive pulley 4 and pulleys 2a and 2b. The arm portion 5 of the auto tensioner 1 rotates so that the tension of the belt 21 becomes constant. That is, when the tension of the belt 21 decreases, the belt 21 rotates in the biasing direction due to the torsional torque of the elastic member 11. On the other hand, when the tension of the belt 21 increases, the arm portion 5 rotates in the direction opposite to the urging direction against torsional torque.

At this time, if the tension of the belt 21 fluctuates abruptly, it is between the inner diameter side of the outer wall 9b of the fixing member 9 and the second sliding member 15 and between the outer diameter portion of the boss portion 9a and the first diameter. A sliding resistance is generated between the sliding member 17 and the rotation of the arm portion 5 is damped. As a result, the vibration of the belt 21 can be effectively reduced.

  As described above, according to the auto tensioner 1 of the present embodiment, an excellent damping force can be stably obtained. Therefore, the displacement of the arm portion 5 is effectively suppressed, and the engine rotation fluctuation and the auxiliary machine Even when the load increases, the accessory drive belt system can be driven stably. In the belt driving device of the present embodiment, the number and size of pulleys are not limited to the example in FIG.

  The configuration of the auto tensioner described above is an example of the embodiment, and the configuration, shape, and the like of each member can be appropriately changed without departing from the gist of the present invention. For example, the sizes of the first sliding member 17 and the second sliding member 15 can be changed as appropriate.

  As described above, the auto tensioner according to an example of the present disclosure can be applied to various vehicles.

DESCRIPTION OF SYMBOLS 1 Auto tensioner 2a, 2b Pulley 3 Shaft 4 Drive pulley 5 Arm part 7 Pulley 9 Fixing member
9a Boss
9b outer wall 11 elastic member 15 second sliding member 17 first sliding member 19 tongue 21 belt 22 spring support 23 base plate 25 thrust washer 27 nous ring

Claims (1)

A fixing member (9) having a boss portion (9a) in the center and a cylindrical outer wall (9b) on the outer periphery ;
An arm portion (5) having a shaft (3) rotatably attached to the inner peripheral side of the boss portion (9a) ;
A pulley (7) rotatably supported by the arm portion (5) ;
A substantially cylindrical noose ring (27) fitted outside the shaft (3);
A substantially cylindrical spring support (22) fitted outside the nous ring (27);
Surrounds the outside of the boss portion of the fixing member (9a), said noose is disposed on the inner peripheral side of the ring (27), biased in the circumferential direction the arm portion (5) of the boss portion (9a) A torsion coil spring (11) in which a tongue (19) as an end is locked to the arm portion (5) ;
A first sliding member (17) disposed on the inner peripheral side of the torsion coil spring (11) and slidable with the outer peripheral surface of the boss portion (9a) ;
A second sliding member (15) provided outside the nous ring (27) and slidable with an inner peripheral surface of an outer wall (9b) of the fixing member (9) ;
The first sliding member (17) is provided at least at a position of 270 ° in the winding direction of the torsion coil spring (11) from the tongue (19) when viewed from the axial direction of the boss portion (9a). And
The second sliding member (15) is provided at least at a position of 90 ° from the tongue (19) in the winding direction of the torsion coil spring (11) when viewed from the axial direction of the boss portion (9a). Auto tensioner.

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