JP5986965B2 - 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.

  Generally, a tensioner is configured such that a tensioner arm is swingably attached to a tensioner cup fixed to an engine block, and a pulley for biasing an endless belt is pivotally attached to a swinging end of the tensioner arm. One end of the tensioner arm covers the opening of the tensioner cup and is supported by a pivot shaft provided on the tensioner cup so as to be swingable. In the tensioner cup, a coil spring and a damping mechanism for applying torque to the tensioner arm are accommodated.

  In the case of a so-called Z-type tensioner in which the tensioner cup is provided on the lower side and the tensioner pulley is provided on the upper side with respect to the tensioner arm, the belt is fitted to the pivot shaft by the moment acting on the tensioner pulley and the tensioner arm. There is a problem that uneven wear occurs in the pivot bush. Therefore, as a configuration that can solve such a problem, a configuration in which a tensioner cup and a tensioner pulley are arranged on the same side with respect to a tensioner arm has been proposed (Patent Document 1). That is, the tensioner cup and the tensioner pulley are provided on the engine block side with respect to the tensioner arm.

Special table 2009-519424

  In the multi-axis auxiliary machine drive belt system, when the belt is passed between the pulley shaft that is the rotation center of the tensioner pulley and the pivot shaft, according to the conventional configuration described above, the tensioner pulley is in relation to the tensioner arm. Since it is provided on the engine block side, the tensioner arm becomes an obstacle, and it is very difficult to attach the belt to the tensioner pulley.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a tensioner that is easy to attach an endless belt to a belt system and that does not easily cause uneven wear of a tensioner bush.

  The tensioner according to the present invention is disposed between a tensioner cup fixed to the engine block with the opening facing the engine block side, and disposed between the engine block and the tensioner cup, and is swingably supported by the tensioner cup. A tensioner arm that protrudes outward from the opening, and a tensioner pulley that is pivotally attached to the swinging end of the tensioner arm and is attached to the same side of the tensioner cup with respect to the tensioner arm. It is characterized by being fixed to the engine block across the tensioner arm so as not to interfere with the swinging of the engine.

  Preferably, the tensioner is fitted to a pivot shaft provided at the shaft center of the tensioner cup, and includes a bush for swingably supporting the tensioner arm, and a bearing attached to the tensioner arm and rotatably supporting the tensioner pulley. Further, a straight line connecting the axial center of the bush and the axial center of the bearing is substantially parallel to the tensioner arm. In this configuration, the outer peripheral surface of the tensioner pulley faces the outer peripheral surface of the opening of the tensioner cup.

  The tensioner cup may be fixed to the engine block via an attachment portion protruding from the outer peripheral surface of the opening.

  According to the present invention, it is possible to obtain a tensioner in which an endless belt can be easily attached to a belt system and uneven wear of the tensioner arm is less likely to occur.

It is a layout view showing a layout of pulleys of each auxiliary machine of a multi-axis auxiliary machine drive belt system having a tensioner according to an embodiment of the present invention. It is a top view of the tensioner which is one embodiment of the present invention. It is a bottom view of a tensioner. It is a side view which fractures | ruptures and shows a part of tensioner. It is sectional drawing which follows the VV line of FIG.

Hereinafter, the present invention will be described with reference to the illustrated embodiments.
FIG. 1 shows an example of the layout of a multi-shaft accessory drive belt system applied to an automobile engine. The endless belt 10 is wound around an engine crank pulley 11 as a drive source and auxiliary pulleys 12, 13, and 14 as driven devices. A tensioner pulley 21 is provided between the crank pulley 11 and the auxiliary pulley 12.

  The tensioner pulley 21 is disposed on the inner side of the line connecting the axes of the crank pulley 11 and the auxiliary pulley 12, and applies tension to the belt 10 in a direction close to the auxiliary pulley 13. As will be described later, the tensioner pulley 21 can swing around a pivot shaft 22 provided at the axial center of the tensioner cup. As is well known, the tensioner pulley 21 urges the belt 10 by the spring force of a coil spring and adjusts the tension of the belt 10 to a predetermined magnitude.

The configuration of the tensioner will be described with reference to FIGS.
The tensioner has a tensioner cup 23 having a bottomed cylindrical shape, and a pivot shaft 22 is press-fitted into a boss portion 25 formed at the center of the bottom 24 of the tensioner cup 23. A pair of attachment portions 27 protrude from the outer peripheral edge portion of the opening 26 of the tensioner cup 23. These attachment portions 27 protrude in directions perpendicular to the pivot shaft 22 and in opposite directions, and a hole 28 is formed in each attachment portion 27. The tensioner cup 23 is fixed to the engine block through a bolt in the hole 28 with the opening 26 facing the engine block (not shown).

  The tensioner arm 31 is disposed between the tensioner cup 23 and the engine block. The tensioner arm 31 includes a lid portion 32 that covers the opening 26 of the tensioner cup 23, and a cylindrical support portion 33 that extends from the inner surface of the lid portion 32 toward the boss portion 25. The pivot shaft 22 is inserted into the cylindrical support portion 33 through a hole formed in the lid portion 32 in a state where the pivot bush 34 is fitted. The distal end of the pivot shaft 22 protrudes from the cylindrical support portion 33 and is press-fitted into the hole of the boss portion 25 to be fixed.

  A recess 35 is formed on the outer surface of the tensioner arm 31, that is, the surface facing the engine block (the lower surface in FIGS. 4 and 5), and the disc-shaped head portion 29 of the pivot shaft 22 is fitted into the recess 35. The flange portion 36 of the pivot bush 34 is sandwiched between the concave portion 35 and the disc-shaped head portion 29. The pivot bush 34 extends from the recess 35 to the tip of the cylindrical support portion 33, and the tensioner arm 31 is swingably supported by the tensioner cup 23 via the pivot bush 34 and the pivot shaft 22.

  The tensioner arm 31 includes an arm portion 37 extending outward from the tensioner cup 23 from the lid portion 32, and a leg portion 38 extending in the opposite direction to the arm portion 37. A protruding portion 41 that protrudes in the same direction as the tensioner cup 23 (upward in FIGS. 4 and 5) is formed at the swing end that is the tip of the arm portion 37, and a shaft hole 42 is formed in the protruding portion 41. A ball bearing 43 that rotatably supports the tensioner pulley 21 is attached to the raised portion 41. A support pin 44 is screwed into the shaft hole 42 from the ball bearing 43 side. A dust seal 45 is provided on the upper surface of the inner race of the ball bearing 43, and the dust seal 45 is fixed to the inner race of the ball bearing 43 by a head 46 of the support pin 44.

  In this manner, the tensioner pulley 21 is attached to the tensioner arm 31 on the same side as the tensioner cup 23 and is pivotally attached to the swinging end of the tensioner arm 31. The tensioner pulley 21 and the tensioner cup 23 are in a positional relationship in which the outer peripheral surface 21 a of the tensioner pulley 21 faces the outer peripheral surface 26 a of the opening 26 of the tensioner cup 23. That is, the tensioner pulley 21 is located not in the bottom 24 side but in the vicinity of the opening 26 with respect to the tensioner cup 23. On the other hand, the pivot bush 34 and the ball bearing 43 are in a positional relationship such that a straight line connecting the axial center of the pivot bush 34 and the axial center of the ball bearing 43 is substantially parallel to the tensioner arm 31.

  An engaging portion 47 is formed on the leg portion 38 of the tensioner arm 31. The engaging portion 47 protrudes in the same direction as the tensioner cup 23 and has a hexagonal column shape. The engaging portion 47 is used for engaging the jig when the tensioner arm 31 is rotationally displaced against the spring force of a coil spring, which will be described later, in the operation of attaching the tensioner to the belt system.

  The coil spring 51 is provided to urge the tensioner arm 31 in the swinging direction. One end of the coil spring 51 is engaged with the bottom 24 of the tensioner cup 23, and the other end is a damping mechanism 52 provided on the lid portion 32 of the tensioner arm 31. The support member 53 is engaged. The friction member 54 of the damping mechanism 52 is in sliding contact with the inner peripheral wall surface of the opening 26 of the tensioner cup 23. The tensioner is attached to the engine block by engaging the tensioner pulley 21 with the belt 10 in a state where the tensioner arm 31 is twisted against the coil spring 51, whereby the belt 10 always responds to the spring force of the coil spring 51. Given tension. If the tension of the belt 10 is about to fluctuate during driving of the engine, the tensioner arm 31 swings according to the vibration of the belt, and the fluctuation of the tension of the belt 10 is suppressed. The swinging amplitude of the tensioner arm 31 is suppressed by the frictional resistance between the friction member 54 and the inner peripheral wall surface of the tensioner cup 23 in the damping mechanism 52.

  4 and 5, the belt 10 is wound around the tensioner pulley 21 and passes between the outer peripheral surface 21 a of the tensioner pulley 21 and the outer peripheral surface 26 a of the tensioner cup 23. The tensioner arm 31 swings when the tension of the belt 10 fluctuates, but the pair of attachment portions 27 are fixed to the engine block across the tensioner arm 31 so as not to interfere with the swinging of the tensioner arm 31. That is, although the bolt is passed through the hole 8 of the mounting portion 27 and is fixed to the engine block, the tensioner arm 31 swings within a range that does not interfere with the position of the bolt.

  As described above, in the present embodiment, the constituent members of the tensioner are arranged in the order of the tensioner arm 31 and the tensioner cup 23 from the engine block side, and the tensioner pulley 21 is provided on the same side as the tensioner cup 23 with respect to the tensioner arm 31. It has been. That is, the space between the tensioner pulley 21 and the tensioner cup 23 is open to the side opposite to the engine block with respect to the tensioner arm 31. Therefore, in the process of attaching the endless belt 10 to the tensioner, the belt 10 does not interfere with the tensioner arm 31, and therefore the operation of passing the belt 10 between the tensioner pulley 21 and the tensioner cup 23 is simple.

  The tensioner pulley 21 and the tensioner cup 23 are provided so that a straight line connecting the axial center of the pivot bush 34 and the axial center of the ball bearing 43 is substantially parallel to the tensioner arm 31. Therefore, the moment due to the force that the tension arm 31 receives from the belt 10 is suppressed as small as possible, thereby preventing the pivot bush 34 from tilting with respect to the pivot shaft 22 and preventing the pivot bush 34 from being unevenly worn.

  Further, by minimizing the distance between the tensioner pulley 21 and the tensioner cup 23 as necessary, that is, by providing an interval necessary for passing the belt 10, the arm portion 37 of the tensioner arm 31 can be moved. The length can be shortened. With such a configuration, the torque applied to the tensioner arm 31, that is, the spring force of the coil spring 51 can be reduced. Further, since the strength required for the tensioner arm 31 and the tensioner cup 23 is reduced, the design conditions of the tensioner arm 31 and the tensioner cup 23 are eased.

21 Tensioner pulley 22 Pivot shaft 23 Tensioner cup 26 Opening portion 27 Mounting portion 31 Tensioner arm

Claims (3)

A tensioner cup fixed to the engine block with the opening facing the engine block;
A tensioner arm disposed between the engine block and the tensioner cup and supported swingably by the tensioner cup and projecting outward from the opening;
A tensioner pulley pivotally attached to the swinging end of the tensioner arm and attached to the same side of the tensioner cup as the tensioner cup ;
A bush fitted to a pivot shaft provided at the axial center of the tensioner cup and supporting the tensioner arm in a swingable manner;
A bearing attached to the tensioner arm and rotatably supporting the tensioner pulley;
A tensioner characterized in that a straight line connecting the axial center of the bush and the axial center of the bearing is substantially parallel to the tensioner arm . The tensioner according to claim 1 , wherein an outer peripheral surface of the tensioner pulley faces an outer peripheral surface of an opening of the tensioner cup.   2. The tensioner according to claim 1, wherein the tensioner cup is fixed to the engine block via a mounting portion protruding from an outer peripheral surface of the opening.

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