JPH084861A - Automatic tensioner - Google Patents

Abstract

PURPOSE:To provide a both-ends supported-type automatic tensioner for improving workability when the rod of a direct driven-type automatic tensioner is set into the initial position, and also the load on a rod is supported at two points of a set pin. CONSTITUTION:A through hole 4 for a set pin 3 is radially provided on the tip of a rod 2, and a pin hole 5 is provided on one side in the symmetrical position of the tip part peripheral wall of a cylinder 1, and a lateral pin hole 8 is provided on the other side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autotensioner for applying a constant tension to a belt of an automobile engine, and more particularly to a structure for setting a rod pressed by a tension adjusting spring to an initial position. It is about.

[0002]

2. Description of the Related Art In a direct-acting type automatic tensioner, a cylinder 1 is installed as shown in FIG. 8 in order to facilitate assembly work to an engine or the like.
The rod 2 housed in the cylinder is pushed into the cylinder 1 against the elasticity of the tension adjusting spring, and the rod 2 is set to the initial position.

As the setting means, in the case of FIG. 8, a through hole 4 of a set pin 3 is provided in the distal end portion of the rod 2 in the radial direction, and a pair of pin holes 5 are provided at positions symmetrical about the center of the peripheral wall of the distal end portion of the cylinder 1. 5 was adopted.

However, in this setting means, when the through hole 4 of the rod 2 and the pin holes 5, 5 of the cylinder 1 are aligned in the vertical direction, when the rod 2 is pushed in, the previously aligned positional relationship is displaced. However, there was a drawback that workability was poor.

In order to eliminate such a defect, as shown in FIG. 9, one in which one of the pair of pin holes 5 and 5 has a notch 6 is known (actual flat opening 4-). 45
48). In this case, the set pin 3 can be passed through the through hole 4 of the rod 2 first, and since there is flexibility in the lateral direction, workability is improved.

However, although this setting means has good workability, the spring load acting on the setting pin 3 causes one of the pin holes 5 to move.
Since it has a cantilever structure that is supported only by
There is a restriction that the fitting gap between the pin hole 5 and the set pin 3 must be reduced in order to increase the rigidity of the rod 2 or prevent the rod 2 from tilting.

Therefore, an object of the present invention is to provide an automatic tensioner which has good workability when set to an initial position and can support a spring load acting on a rod with a double-supported structure.

[0008]

In order to achieve the above object, the invention according to claim 1 stores a rod and a spring for tension adjustment in a cylinder, and the spring force exerts the rod force. In the automatic tensioner configured to apply tension to the belt via, a through hole of the set pin is provided in the radial direction at the tip of the rod, and a pin hole is provided at one of the center symmetrical positions of the peripheral wall of the tip of the cylinder, On the other hand, a horizontally long pin hole is provided.

In the auto tensioner having the above structure,
The set pin can be inserted while adjusting the positional deviation between the through hole of the rod and the pin hole of the cylinder within the range of the horizontally long pin hole.

Further, the invention according to claim 2 is an autotensioner in which a rod and a tension adjusting spring are housed in a cylinder, and a tension is applied to the belt via the rod by the spring force, A pin hole is provided in a part of the peripheral wall of the tip end portion of the cylinder, and an L-shaped cutout portion is provided in the other portion, and the engaging portion of the cutout portion is formed at a position symmetrical to the pin hole.

In the auto tensioner having the above structure,
The rod is pushed in a state where the set pin is passed through the through hole of the rod in advance, the set pin is fitted into the L-shaped notch, and the tip is inserted into the other pin hole after being hooked on the engaging portion.

According to a third aspect of the present invention, there is provided an autotensioner in which a rod and a tension adjusting spring are housed in a cylinder, and a tension is applied to a belt via the rod by the spring force. Is provided with a step portion for engaging the set pin, and a pair of pin holes facing each other are provided on the peripheral wall of the tip portion of the cylinder.

In the auto tensioner having the above structure,
Since the stepped portion of the rod exists on the entire circumference thereof, there is no displacement from the pin hole of the cylinder. When the set pin is inserted into the pin hole after pushing the rod in, the set pin is always placed on the step.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 is shown in FIGS. In the autotensioner of this embodiment, the tension adjusting spring 6 and the rod 2 engaged with the tension adjusting spring 6 are housed inside the cylinder 1 whose upper end is open, as in the conventional case. The rod 2 slidably penetrates the seal member 7. Although illustration is omitted,
A piston is provided at the lower end of the rod 2, a lower part of the piston is a pressure chamber filled with hydraulic oil, and an upper part thereof is a reservoir chamber. When the belt tension is increased and the rod 2 is pushed, the hydraulic oil is When the pressure chamber leaks to the reservoir chamber and the belt relaxes, the elastic force of the spring 6 pushes out the rod 2.

A radial through hole 4 is provided at the tip of the rod 2. In addition, the seal member 7 of the cylinder 1
At a higher position, a pin hole 5 is provided at one of the positions of center symmetry of the peripheral wall, and a horizontally elongated pin hole 8 is provided at the other side in the lateral direction.

The through hole 4 and the pin hole 5 have diameters that fit the set pin 3. Also, the laterally elongated pin hole 8 has a vertical minor axis that is suitable for the set pin 3,
The major axis in the left-right direction is set to be about twice as long.

The procedure of the setting method in this case will be described with reference to FIGS.

The directions of the through hole 4 of the rod 2 and the pin hole 5 of the cylinder 1 are substantially aligned (FIG. A).

The rod 2 is pushed in so that the through holes 4 and the pin holes 5 are aligned at the same height (FIG. B).

From the horizontally long pin hole 8 to the through hole 4 of the rod 2.
Insert the settet pin 3 (Fig. C).

The set pin 3 is moved left and right within the range of the major axis of the horizontally elongated pin hole 8 to align the through hole 4 and the pin hole 5 (FIG. D).

The set pin 3 is passed through the pin hole 5 to fix the rod 2 (Fig. E).

Next, an embodiment of the invention described in claim 2 will be described with reference to FIGS. 4 and 5.

In this embodiment, an L-shaped notch 9 is provided in place of the horizontally elongated pin hole 8 of the above embodiment.
The notch 9 is provided with a vertical groove 10 opened at the upper end surface of the cylinder 1 and an engaging portion 11 at a right angle from the lower end of the vertical groove 10, and the engaging portion 11 has the other pin hole. It is located in a centrally symmetrical position with respect to 5.

The procedure of the setting method in this case is shown in FIG.
Description will be made based on (e).

The set pin 3 is inserted into the through hole 4 of the rod 2 (Fig. A).

The set pin 3 and the vertical groove 10 of the notch 9 are aligned (FIG. B).

In the above state, the rod 2 is pushed in, the set pin 3 is moved to the engaging portion 11, and the through hole 4
And pin hole 5 are aligned (Fig. D).

The set pin 3 is passed through the pin hole 5 and the rod 2 is fixed (see e figure).

Next, an embodiment of the invention described in claim 3 will be described with reference to FIGS. 6 and 7.

In this embodiment, the tip portion of the rod 2 is the small diameter portion 13 via the step portion 12, and when the rod 2 is not pushed (see FIG. 7A), the step portion is formed. 12 is outside the cylinder 1. A pair of opposed pin holes 5 ', 5'are provided at the upper end of the cylinder 1 at positions separated from the center line by a length corresponding to the radius of the small diameter portion 13 and the radius of the pin 3. Each of these pin holes 5'is formed to have a diameter that matches the diameter of the set pin 3.

The procedure of the setting method in this case will be described with reference to FIGS.

Push in the rod 2 (FIGS. A and b).

A pair of pin holes 5 ′, 5 ′ of the cylinder 1
When the set pin 3 is penetrated into the
2 and the rod 2 is fixed.

[0035]

As described above, in any of the inventions described in claims 1 to 3, since the work of inserting the set pin is easy, the workability in setting the rod to the initial position is improved, and In any case, pin holes provided on the cylinder side,
Since the accuracy with respect to the cylinder axis such as the horizontally long pin hole and the cutout can be reduced, the manufacturing becomes easy.

Further, in any case, since the load acting on the rod is supported at two points of the pin, which is a so-called double-support type, the rigidity of the pin may be the same as that of the conventional double-support type.

[Brief description of drawings]

FIG. 1 is a partially omitted perspective view of an embodiment according to the invention described in claim 1.

FIG. 2 is a partially omitted sectional view of the above.

FIG. 3 (a) to (e) an explanatory view of the same as above.

FIG. 4 is a partially omitted perspective view of an embodiment according to the invention described in claim 2;

FIG. 5 (a) to (e) an explanatory view of the same as above.

FIG. 6 is a partially omitted perspective view of an embodiment according to the invention described in claim 3;

FIG. 7 (a) to (c) an explanatory view of the same as above.

FIG. 8 is a partial perspective view of a conventional example.

FIG. 9 is a partial perspective view of another conventional example.

[Explanation of symbols]

 1 Cylinder 2 Rod 3 Set Pin 4 Through Hole 5, 5'Pin Hole 6 Tension Adjusting Spring 7 Sealing Member 8 Horizontally Long Pin Hole 9 Notch 10 Vertical Groove 11 Engaging Part 12 Step 13 Small Diameter Part

Claims (3)

[Claims] 1. An automatic tensioner in which a rod and a tension adjusting spring are housed in a cylinder, and a tension is applied to a belt via the rod by the spring force.
A through hole for a set pin is provided in a radial direction at the tip of the rod, and a pin hole is provided at one of the center symmetrical positions of the peripheral wall of the tip of the cylinder, and a horizontally elongated pin hole is provided at the other. Tensioner. 2. An automatic tensioner in which a rod and a tension adjusting spring are housed in a cylinder, and a tension is applied to a belt via the rod by the spring force,
An auto tensioner characterized in that a pin hole is provided in a part of the peripheral wall of the tip end portion of the cylinder, and an L-shaped notch is provided in the other part, and the engaging portion of the notch is formed at a position symmetrical with the pin hole. . 3. An automatic tensioner in which a rod and a tension adjusting spring are housed in a cylinder, and the spring force applies a tension to the belt via the rod,
An auto tensioner characterized in that a step portion for engaging a set pin is provided at a tip portion of the rod, and a pair of pin holes facing each other are provided on a peripheral wall of a tip portion of the cylinder.