JPH11315895A - Auto-tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auto-tensioner which can be easily and surely mounted on a mounted item while the occurrence of damage and the like is being prevented at the time of mounting. SOLUTION: A fixed shaft 29 is inserted into the respective through holes 27 and 28 of the idler 13 and a damper 21, and concurrently, since a C-ring 32 is mounted to the tip end of the insertion, the idler 13 and the damper 21 are held in such a way that they can not be separated. A gap 33 in which the C-ring 32 can enter, is provided inside the through hole 28 of the damper 21. For this reason, when an auto-tensioner is to be mounted to a mounted object 68, the tip end of a male screw part 30 can be prevented from being projected out of the damper 21 by housing the fixed shaft 29 in such a way that the C-ring 32 enter into the inside of the gap 33. Under this condition, the idler 13 is pressed onto the whole surface of a belt 53 so as to allow the male screw part 30 to agree with the female screw part of the mounted object 68, so that the fixing shaft 29 is thereby threadedly engaged with the mounted object 68.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auto-tensioner provided for, for example, a timing belt of an engine and adjusting a tension of the timing belt.

[0002]

2. Description of the Related Art An automatic tensioner for applying a tension to a timing belt or the like includes, for example, an actual open flat tire 8-11.
As described in Japanese Patent Publication No. 97-97, there is one provided with a damper and a tension pulley. In recent years, including such an auto tensioner, an auto tensioner usually incorporates a damper so as to fit within the outer circumferential circle of the tension pulley to reduce its size. Such a conventional auto tensioner and a timing belt (power transmission mechanism) to which a tension is applied by the auto tensioner will be described with reference to FIGS.

[0003] As shown in FIG.
And the power receiving pulley 52 includes a power transmitting pulley 51.
A belt (timing belt) 53 for transmitting the rotational motion of the motor to the power receiving pulley 52 is wound. The auto tensioner 54 is supported by a fixed shaft 64, and is disposed between the pulleys 51 and 52 so as to apply a predetermined tension to the belt 53.

The auto tensioner 54 has an idler 55 for applying tension to the belt 53. Idler 55
A projection 57 is provided on the back surface of the inner ring 56. As shown by the broken line in FIG. 4, a damper 58 having a size that fits within the outer circumference of the idler 55 is disposed behind the idler 55. The damper 58 includes a boss 59 and a hydraulic cylinder 60. The hydraulic cylinder unit 60 includes a telescopic piston rod 61, and the tip of the piston rod 61 is in contact with the protrusion 57. The hydraulic cylinder unit 60 has a built-in spring (not shown), and the piston rod 61 is constantly urged in a projecting direction by the spring. A hydraulic pressure is sealed in the hydraulic cylinder portion 60, and the hydraulic pressure plays a role of buffering the urging force when the piston rod 61 is urged from the belt 53 in the contracting direction.

On the other hand, as shown in FIG. 5 as a cross-sectional view along the line CC of FIG. 4, a through hole 62 is provided at an eccentric position of the inner race 56, and the boss 59 of the damper 58 A through hole 63 is also provided at a position corresponding to the through hole 62. The fixed shaft 64 is inserted into each of the through holes 62 and 63. A sliding bearing (not shown) is interposed between the through hole 62 of the inner ring 56 and the fixed shaft 64. For this reason, the inner ring 56 can swing about the fixed shaft 64 as an axis.

In the fixed shaft 64, a damper 58 is provided.
A C-ring 66 is attached to the base end of the portion protruding from the C-ring. Therefore, even before the automatic tensioner 54 is attached, the idler 55 and the damper 58 are temporarily held inseparably. A male screw portion 67 is formed on the distal end side of the fixed shaft 64.

[0007] The auto tensioner 5 configured as described above.
5 is mounted at a predetermined position by screwing the male screw portion 67 into a female screw hole 69 provided in the mounted object 68 as shown in FIG. Further, a concave portion 70 for allowing the C-ring 66 is provided at an opening edge of the female screw hole 69. For this reason, when the screwing of the fixed shaft 64 is completed, the C ring 66 is allowed in the concave portion 70, so that the damper 58 comes into close contact with the object 68.

The thus mounted auto tensioner 5
As shown in FIG. 4, the inner ring 5 is formed by the projection 57 being urged by the piston rod 61.
6 swings toward the belt 53 and presses the belt 53. Thereby, tension is applied to the belt 53. Therefore,
When the belt 53 becomes loose, the idler 55 moves toward the belt 53 in accordance with the loosening, and a constant tension is always applied to the belt 53.

On the other hand, when the tension of the belt 53 fluctuates with a change in the rotation speed of the pulleys 51 and 52 and a high load is applied to the idler 55, the hydraulic cylinder portion 60 functions as a shock absorber. As a result, a sudden change in tension of the belt 53 is reduced.

[0010]

Since the movable stroke of the piston rod 61 of the hydraulic cylinder portion 60 is shortened with the downsizing of the damper 58, it is necessary to apply sufficient tension to the belt 53. It is necessary to attach the auto tensioner 54 to the attachment 68 while applying a certain amount of tension to the belt 53. That is,
When mounting the auto tensioner 54, first, the idler 55 is forcibly twisted so that the piston rod 61 of the hydraulic cylinder unit 60 is in the most contracted state (the direction of the arrow shown in FIG. 4). Then, while applying a certain amount of tension to the belt 53 in this state, the male screw portion 67 of the fixed shaft 64 is screwed and mounted on the female screw portion 69 of the attachment 68.

However, in the conventional auto tensioner 54, when the C ring 66 is attached to the fixed shaft 64, the separation of the idler 55 and the damper 58 can be avoided, but as shown in FIG. Then, the idler 55 and the damper 58 float from the attachment 68. For this reason, as shown in FIG. 6, the auto tensioner 54 is attached to the object 68 with the edge of the belt 53 hooked on the corresponding edge of the idler 55.
And the idler 55 and the belt 53
And the belt 53 may be damaged by the edge of the idler 55.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide an automatic mounting apparatus that can easily and accurately attach to an object to be mounted while preventing damage to a belt during mounting. To provide a tensioner.

[0013]

In order to achieve the above object, according to the first aspect of the present invention, an idler for applying tension to a belt and a damper for urging the idler toward the belt are provided with an idler. An auto-tensioner held inseparably by a temporary holding member attached to the insertion destination of the fixed shaft inserted from the side to the damper side, wherein the temporary holding member is inserted into an insertion hole through which the fixed shaft of the damper is inserted. The gist of the present invention is to provide a gap that allows infiltration.

According to this configuration, the fixed shaft can be fixed to the object while the idler is pressed against the entire surface of the belt while the idler and the damper are temporarily held inseparably. For this reason, when the auto tensioner is mounted on the object to be mounted, the mounting workability is improved, and there is no possibility that the belt is damaged by the idler during the mounting operation.

According to a second aspect of the present invention, in the auto-tensioner according to the first aspect, the infiltration allowable length of the gap that allows the temporary holding member to infiltrate is set to be longer than the effective mounting length of the fixed shaft tip. The gist of what has been done.

According to this configuration, the tip of the fixed shaft does not protrude from the damper when the auto tensioner is mounted on the object. For this reason, the damper can be brought into close contact with the object to be mounted, and the auto tensioner can be mounted on the object while the idler is securely pressed against the entire surface of the belt.

According to a third aspect of the present invention, in the automatic tensioner according to the first or second aspect, the gist is that the temporary holding member is a C-ring. According to such a configuration, the idler and the damper can be easily and inseparably retained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view of the auto tensioner according to the present embodiment, and FIG.
FIG. 3 is a cross-sectional view taken along line AA of FIG. It is assumed that the power transmission mechanism itself to which the tension is applied by the auto tensioner 11 is the same as that illustrated in FIG.

As shown in FIGS. 1 and 2, the auto tensioner 11 has an idler 13 for applying tension to the belt 53. The idler 13 includes an outer ring 16 rotatable around the inner ring 14 via an inner ring 14 and a bearing 15. Here, as shown in FIG.
A substantially hexagonal hole 17 and a square hole 18 are formed through the inner ring 14, and a protrusion 19 is provided on the rear surface of the inner ring 14.
Further, a coil spring 20 as an urging member is disposed in the inner ring 14, and one end is supported by the inner ring 14,
The other end is supported by the damper 21.

The damper 21 is formed to have a size that fits within the outer circumference of the idler 13 and is disposed behind the idler 13. The damper 21 has a boss 22 and a hydraulic cylinder 23. The hydraulic cylinder portion 23 includes a telescopic piston rod 24, and the tip of the piston rod 24 is in contact with the protrusion 19. A spring (not shown) is built in the hydraulic cylinder portion 23,
The piston rod 24 is always urged in a projecting direction by this spring. In the damper 21,
A support portion 25 is provided at a position corresponding to the other end of the coil spring 20 so as to protrude toward the inner race 14, and the other end of the coil spring 20 is supported by the support portion 25.

On the other hand, as shown in FIG. 2, a through hole 27 is provided at an eccentric position of the inner ring 14. Also,
In the boss portion 22 of the damper 21, a through hole 28 is also provided at a position corresponding to the through hole 27. And
A fixed shaft 29 is inserted into each of the through holes 27 and 28. In addition, a slide bearing (not shown) is interposed between the through hole 27 of the inner ring 14 and the fixed shaft 29. For this reason, the inner race 14 can swing about the fixed shaft 29 as an axis. Further, a lock pin 26 protrudes from the back surface of the damper 21, and the lock pin 26 allows the object 6 to be described later to be mounted.
8 can be more easily and reliably performed.

A male screw portion 30 is formed at a predetermined mounting length at the insertion end of the fixed shaft 29. A groove 31 is formed at the base end of the male screw portion 30, and a C ring 3 is formed in the groove 31.
2 are installed. For this reason, even before the automatic tensioner 11 is mounted, the idler 13 and the damper 21 are not mounted.
Is also temporarily held inseparably in the present embodiment. Further, a gap 33 is provided in the through hole 28 of the boss 22 to allow the C ring 32 to penetrate. Therefore, before the fixed shaft 29 is attached to the attachment 68, the fixed shaft 29 is movable in the insertion direction into the through holes 27 and 28. The permissible length of the gap 33 is set to be equal to or longer than the mounting length of the male screw portion 30.

The automatic tensioner 1 constructed as described above
1 is a female screw hole 69 of the attached object 68 as shown in FIG.
The male screw portion 30 is attached to a predetermined position by screwing it. Conventional auto tensioner 5 described above
Similarly to 4, the C-ring 32 is allowed in a concave portion 70 provided at the opening edge of the female screw hole 69, whereby the damper 21 is in close contact with the object 68. Further, the lock pin 26 of the damper 21 is inserted into the hole 34 provided in the attachment 68, and the swing of the damper 21 is regulated by the lock pin 26.

The auto tensioner 1 thus mounted
1, as shown in FIG. 1, when the protrusion 19 of the inner race 14 is urged by the piston rod 24, the idler 13 swings toward the belt 53 and presses the belt 53. Thereby, tension is applied to the belt 53. Further, in addition to the urging by the piston rod 24, the idler 13 also swings toward the belt 53 by the urging by the coil spring 20 built in the inner race 14, so that
A stronger tension is applied to the belt 53. Therefore, when the belt 53 becomes loose, the idler 13 swings toward the belt 53 in accordance with the looseness, and a constant tension is always applied to the belt 53.

On the other hand, when the tension of the belt 53 fluctuates and a high load is applied to the idler 13, the inside of the hydraulic cylinder portion 23 functions as a shock absorber, so that the sudden fluctuation of the tension of the belt 53 is reduced. .

Incidentally, in the automatic tensioner 11 of the present embodiment, the conventional automatic tensioner 54 described above is used.
Similarly to the above, the belt 53 is attached to the attachment 68 while applying a certain amount of tension to the belt 53. That is, the mounting of the auto tensioner 11 is performed according to the following procedure based on FIGS. In addition, FIG. 3 is BB of FIG.
It is shown as a cross-sectional view along the line.

First, a jig or the like (not shown) is mounted in the hole 17 shown in FIG. 1, and the idler 13 is forcibly biased in the direction of arrow a with the fixed shaft 29 as the axis. And
When the square hole 18 no longer interferes with the damper 21, a fixing pin (not shown) is inserted into the square hole 18 to maintain the state.

Subsequently, as shown in FIG.
The fixed shaft 29 is moved in the direction of insertion into each of the through holes 27 and 28 so that the ring 32 is sunk into the gap 33. At this time, in the present embodiment, as described above, the infiltration allowable length of the gap 33 that allows the C ring 32 to infiltrate is set to be equal to or longer than the attachment length of the male screw portion 30, and therefore, FIG. a) As shown in FIG.
The state where the leading end of the zero does not protrude from the damper 21 is brought about. Then, in this state, the damper 21 is brought into close contact with the attachment 68.

Next, the idler 13 is provided on the entire surface of the belt 53.
To make the male screw portion 30 coincide with the female screw portion 35 of the attachment 68, and the fixed shaft 29 is screwed to the attachment 68 as shown in FIG. That is, while the auto tensioner 11 is mounted on the mounting object 68, the idler 1
The positions of the belt 3 and the damper 21 do not change, and the belt 53 is maintained in a state where the entire surface thereof is constantly pressed against the idler 13. At this time, the lock pin 2 of the damper 21 is used.
Since the swing of the damper 21 is restricted by 6 (shown in FIG. 2), the position of the auto tensioner 11 itself does not shift when the fixed shaft 29 is screwed. Therefore, the mounting of the auto tensioner 11 is performed easily and reliably.

Thereafter, by removing the fixing pin attached to the square hole 18, the idler 13 is urged by the piston rod 24 and the coil spring 20 to move the idler 13 to the belt 5.
It swings to the third side, and tension is applied to the belt 53.

According to the auto-tensioner 11 of this embodiment, which is mounted in the manner described above, the following effects can be obtained. (1) By attaching the C ring 32 to the fixed shaft 29, the idler 13 and the damper 21 can be temporarily held inseparably. Moreover, the idler 1 is provided on the entire surface of the belt 53.
The auto-tensioner 11 can be mounted on the mounting object 68 with the 3 pressed. Therefore, the belt 53 is not damaged by the idler 13 when the auto tensioner 11 is mounted, while improving the workability of mounting the auto tensioner 11.

(2) Since the infiltration permissible length of the gap 33 allowing the infiltration of the C ring 32 is set to be equal to or longer than the mounting length of the male screw portion 30, when the auto tensioner 11 is mounted on the mounting object 68. Thus, the distal end of the male screw portion 30 of the fixed shaft 29 can be housed in the through hole 28 of the damper 21 without protruding from the damper 21. Therefore, it is possible to bring the damper 21 into close contact with the object 68,
The auto tensioner 11 can be attached to the attachment 68 while the idler 13 is securely pressed against the entire surface of the belt 13. As a result, the risk of damaging the belt 53 by the idler 13 when the automatic tensioner 11 is attached can be more reliably prevented.

(3) In order to temporarily hold the idler 13 and the damper 21 inseparably, the idler 13 and the damper 2
After the fixed shaft 29 is inserted through the through holes 27 and 28 of FIG.
All that is required is to mount the ring 32. Therefore, the idler 13 and the damper 21 can be temporarily and easily held inseparably.

(4) In the fixed shaft 29, the male screw portion 30
Since the groove 31 is formed at the base end portion, the mounting position of the C-ring 32 can be regulated. Therefore,
It is possible to prevent the inconvenience that the damper 21 cannot be in close contact with the attachment 68 when the C ring 32 is attached to the attachment 68 by mounting the C ring 32 at a position exceeding the permissible length of the C ring 32 in the damper 21. be able to.

(5) Connect the auto tensioner 11 to the object 6
8, the lock pin 26 of the damper 21 is inserted into the hole 34 of the attachment 68 so that the damper 2
1 is regulated. Therefore, the position of the auto tensioner 11 itself does not shift when the fixed shaft 29 is screwed. Therefore, the attachment of the auto tensioner 11 can be performed easily and reliably.

The embodiment of the present invention may be modified as follows. In the above embodiment, the C ring 32 is attached to the groove 31 provided in the fixed shaft 29, but the groove 31 may be omitted.

In the above embodiment, the C ring 32 is used as a temporary holding member for temporarily holding the idler 13 and the damper 21 inseparably, but this is changed to a nut or the like. That is, the idler 13 and the damper 21 are temporarily held inseparably by, for example, screwing a nut or the like in advance to the base end of the male screw portion 30 of the fixed shaft 29. In this case, it is necessary to set the gap 33 of the damper 21 to a size that allows the nut and the like.

Next, technical ideas other than the inventions described in the claims, which can be understood from the above embodiments, will be described below together with their effects. (1) The auto tensioner according to claim 3, wherein the fixed shaft includes a groove for mounting the C ring.

In this way, the position where the C-ring is mounted on the fixed shaft can be regulated, and the inconvenience that the damper cannot be brought into close contact with the object at the time of attachment to the object can be prevented.

(2) In the auto-tensioner according to any one of (1) to (3), the damper has a lock pin on a contact surface of the auto-tensioner with an object to be mounted. An auto tensioner characterized by the following.

In this way, the work of attaching the auto tensioner to the object can be easily and reliably performed.

[0042]

According to the first aspect of the present invention, when the auto-tensioner is mounted on an object to be mounted, the workability of mounting the auto-tensioner is improved, and the belt is not damaged by the idler during the mounting operation.

According to the second aspect of the present invention, the tip of the fixed shaft does not project from the damper when the auto tensioner is mounted on the object. Therefore, the damper can be brought into close contact with the object to be mounted, and the auto tensioner can be mounted on the object while the idler is securely pressed against the entire surface of the belt.

According to the third aspect of the present invention, the idler and the damper can be temporarily and easily held inseparably.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an auto tensioner according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an exemplary cross-sectional view showing a mounting state of the auto-tensioner according to the embodiment;

FIG. 4 is a front view showing an example of a conventional auto tensioner.

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a sectional view showing a mounting mode of a conventional auto tensioner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Auto tensioner, 12 ... Belt, 13 ... Idler, 20 ... Coil spring (biasing member), 21 ... Damper, 26 ... Lock pin, 27, 28 ... Through hole, 29 ... Fixed shaft, 31 ... Groove, 32 ... C ring (temporary holding member), 3
3: gap, 34 mounted objects.

Claims (3)

[Claims] An idler for applying tension to a belt and a damper for urging the idler toward a belt are separated by a temporary holding member attached to a fixed shaft insertion point inserted from the idler side to the damper side. An auto-tensioner that is immovably held, wherein a gap is provided in an insertion hole through which the fixed shaft of the damper is inserted so as to allow the temporary holding member to penetrate. 2. The automatic tensioner according to claim 1, wherein a permissible length of the gap that allows the temporary holding member to penetrate is equal to or greater than an effective mounting length of the fixed shaft tip. Tensioner. 3. The auto-tensioner according to claim 1, wherein the temporary holding member is a C-ring.