JP6421039B2 - Tensioner - Google Patents

Description

  The present invention relates to a tensioner that is provided in, for example, an automobile multi-axis auxiliary machine drive belt system and applies tension to an endless belt that drives an auxiliary machine of an engine.

  In a conventional tensioner, a tensioner cup in which a lid of the tensioner arm is swingably attached has a coil spring for applying tension to the endless belt, and attenuates the swing of the tensioner arm due to fluctuations in the tension of the endless belt. (For example, patent document 1). The damping unit is rotationally displaced with a protrusion formed on the lid portion of the tensioner arm as a fulcrum, and slides against the inner wall surface of the tensioner cup to exert a damping action. In order for the damping unit to exert its damping action normally, the damping unit must be normally engaged with the projection of the tensioner arm. Therefore, the assembly operation of the tensioner is performed so that the damping unit is in a predetermined positional relationship with respect to the protrusion in the tensioner cup.

Special table 2013-515225 gazette

  For example, in order to prevent foreign matters from entering the tensioner cup from the outside, a labyrinth may be provided on the lid of the tensioner cup or the tensioner arm. However, this labyrinth causes a problem that, during the assembly operation of the tensioner, the gap between the tensioner arm lid and the tensioner cup is closed, making it difficult to observe the position of the damping unit. Therefore, conventionally, there is a possibility that the tensioner can be assembled with the damping unit riding on the protrusion, and in the performance inspection after the tensioner is assembled, an assembly failure is discovered for the first time. In such a case, the tensioner is disassembled and assembled. The work efficiency was poor.

  An object of the present invention is to provide a tensioner that can be assembled in a state where the damping unit is always set at a normal position regardless of the presence or absence of the labyrinth.

  The tensioner according to the present invention has a tensioner cup having an opening and a bottom, a coil spring whose one end is engaged with the bottom, and the other end is located near the opening, and a lid that covers the opening. A tensioner pulley is rotatably attached to an arm portion that extends outward from the lid portion of the tensioner cup, and is formed at a position corresponding to the tensioner arm that is swingably supported by the tensioner cup and the other end of the coil spring of the lid portion. And a pair of damping units that have a circular arc shape along the inner wall surface of the opening, are provided so that the ends abut against the protrusion, and are biased by the other end of the coil spring and pressed against the inner wall surface. An outer wall extending toward the bottom is formed at a portion corresponding to the outer peripheral surface of the protrusion attenuation unit, and an inner side extending toward the bottom at a portion corresponding to the inner peripheral surface of the protrusion attenuation unit. There is formed, the distance between the outer wall and the inner wall is being smaller than the width of the damping unit.

  The height of the outer side wall is preferably larger than the height of the inner side wall. The distance between the outer wall and the inner wall is preferably larger than the thickness of the coil spring.

  According to the present invention, it is possible to assemble the tensioner in a state where the damping unit is always set at a normal position.

It is sectional drawing which shows the tensioner which is one Embodiment of this invention. It is a perspective view which decomposes | disassembles and shows the tensioner of FIG.

Hereinafter, the present invention will be described with reference to the illustrated embodiments.
The tensioner of this embodiment is provided in a belt system of an automobile engine, for example. As shown in FIG. 1, the tensioner has a tensioner cup 11 having a bottomed cylindrical shape, and a pivot shaft 14 is inserted into a boss portion 13 formed at the center of the bottom portion 12 of the tensioner cup 11. The opening 16 of the tensioner cup 11 is covered with a lid portion 22 formed on the tensioner arm 21.

  A pivot hole 23 is formed in the lid portion 22 of the tensioner arm 21, and the pivot shaft 14 is press-fitted into the pivot hole 23. That is, the tensioner arm 21 is swingably supported by the tensioner cup 11 via the pivot shaft 14. The tensioner arm 21 has an arm portion 24 that extends outward from the lid portion 22 to the tensioner cup 11, and a ball bearing 26 that rotatably supports a tensioner pulley 25 is attached to the tip of the arm portion 24. The tensioner pulley 25 and the ball bearing 26 are fixed to the arm portion 24 by bolts 27.

  The coil spring 31 is provided to urge the tensioner arm 21 in the swinging direction. One end of the coil spring 31 is engaged with the bottom 12 of the tensioner cup 11, and the other end 31 a is located at a position close to the opening 16 of the tensioner cup 11. To do. As shown in FIG. 2, a protrusion 32 is formed at a position corresponding to the other end 31 a of the coil spring 31 of the lid portion 22. Inside the opening 16, a pair of attenuation units 33 and 34 are provided such that each end abuts against the protrusion 32.

  Each of the damping units 33 and 34 has an arc shape along the inner wall surface of the opening 16, and is configured by attaching resin friction members 37 and 38 to the outer peripheral surfaces of the metal main bodies 35 and 36. The damping units 33 and 34 are urged by the other end of the coil spring 31 and are rotationally displaced with the protrusion 32 as a fulcrum, whereby the friction members 37 and 38 are pressed against the inner peripheral wall surface of the opening 16. The tensioner is attached to an engine block (not shown) by engaging a tensioner pulley 25 with a belt (not shown) in a state where the tensioner arm 21 is twisted against the coil spring 31, and the belt is always a coil spring. A tension corresponding to the spring force of 31 is applied. When the belt tension is about to fluctuate during driving of the engine, the tensioner arm 21 swings according to the vibration of the belt, and the fluctuation of the belt tension is suppressed. The amplitude of the swing of the tensioner arm 21 is suppressed by the frictional resistance between the friction members 37 and 38 of the damping units 33 and 34 and the inner peripheral wall surface of the tensioner cup 11.

  The structure of the protrusion 32 will be described in detail. The protrusion 32 is formed on the surface of the annular raised portion 28 surrounding the pivot hole 23 of the tensioner arm 21, and the radial length of the protrusion 32 is substantially equal to the width of the attenuation units 33 and 34. equal. The end surfaces of the attenuation units 33 and 34 are in contact with the side surfaces of the protrusion 32. In the protrusion 32, an outer wall 41 is formed at a portion corresponding to the outer peripheral surface of the damping units 33, 34 (that is, the outer peripheral surface of the friction members 37, 38), and the inner peripheral surface (that is, the main body 35) of the damping units 33, 34. The inner wall 42 is formed at a portion corresponding to the inner peripheral surface 36. The outer side wall 41 and the inner side wall 42 extend toward the bottom 12 of the tensioner cup 11, and the height of the outer side wall 41 is larger than the height of the inner side wall 42. The distance between the outer side wall 41 and the inner side wall 42 is smaller than the width of the damping units 33 and 34 and larger than the thickness of the coil spring 31.

  Next, the assembly work of the tensioner of this embodiment will be described. First, the pivot shaft 14 is inserted into the boss portion 13 of the tensioner cup 11 and the coil spring 31 is disposed in the tensioner cup 11, and then the main bodies 35 and 36 of the damping units 33 and 34 engage with the other end 31 a of the coil spring 31. In this way, the damping units 33 and 34 are arranged on the coil spring 31. Then, the lid 22 of the tensioner arm 21 is placed on the opening 16 of the tensioner cup 11 so that the damping units 33 and 34 face the side surfaces of the protrusion 32 of the tensioner arm 21, and the coil spring 31 is compressed, while the tensioner arm 21 is compressed. The pivot shaft 14 is press-fitted into the pivot hole 23 of 21.

  In this assembling operation, even if the attenuation units 33 and 34 try to ride on the protrusion 32, the distance between the outer wall 41 and the inner wall 42 of the protrusion 32 is smaller than the width of the attenuation units 33 and 34. The damping units 33 and 34 do not overlap the protrusion 32 because they interfere with the outer side wall 41 and the inner side wall 42. That is, the protrusion 32 does not press the attenuation units 33 and 34 toward the bottom 12 of the tensioner cup 11. Therefore, the protrusion 32 is always located between the damping units 33 and 34, and the coil spring 31 is inserted between the outer wall 41 and the inner wall 42 of the protrusion 32, and the tensioner always has the damping units 33 and 34 normal. It is assembled in a state determined at a certain position.

DESCRIPTION OF SYMBOLS 11 Tensioner cup 12 Bottom part 16 Opening part 21 Tensioner arm 22 Lid part 31 Coil spring 31a Other end 32 Protrusion 41 Outer side wall 42 Inner side wall

Claims (3)

A tensioner cup having an opening and a bottom;
A coil spring whose one end is engaged with the bottom and whose other end is located near the opening;
A tensioner arm that has a lid that covers the opening, the tensioner pulley is rotatably attached to an arm that extends outward from the lid to the tensioner cup, and is swingably supported by the tensioner cup; ,
A protrusion formed at a position corresponding to the other end of the coil spring of the lid,
A pair of damping units having an arc shape along an inner wall surface of the opening, provided so that an end abuts against the protrusion, and urged by the other end of the coil spring to be pressed against the inner wall surface; Prepared,
An outer wall extending toward the bottom portion is formed at a portion corresponding to the outer peripheral surface of the attenuation unit of the protrusion, and toward the bottom portion at a portion corresponding to the inner peripheral surface of the attenuation unit of the protrusion. An extension inner wall is formed, and a distance between the outer wall and the inner wall is smaller than a width of an end surface contacting the protrusion of the attenuation unit.   The tensioner according to claim 1, wherein a height of the outer wall is larger than a height of the inner wall. The tensioner according to claim 1, wherein a distance between the outer wall and the inner wall is larger than a thickness of the coil spring.

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