JPH02118249A - Automatic tensioner - Google Patents

Abstract

PURPOSE:To facilitate the installation of a belt onto a pulley by fixing an arm piece in a position off of a pulley on the outer peripheral face of an oscillating sleeve and providing a tension spring between the engaging bolt of an oscillating board which can be oscillated centering around a bolt and the arm piece. CONSTITUTION:An oscillating sleeve 4 is eccentrically fitted on the pivot 3 of a bolt 2 screwed into an installing base body 1 and a pulley 10 is rotatably supported on the outer peripheral face thereof. An arm piece 14 is fixed to the outer peripheral face of the oscillating sleeve 4, while providing an oscillating board 24 which can be oscillated centering around the bolt 2. A tension spring 16 is engaged with the end portions of the arm piece 14 and the oscillating board 24. At the time of installing a belt 17, as the bolt 2 is loosened bringing the oscillating board 24 close to the arm piece 14 to remove the tensile force of the spring 16, the pressing force of the pulley 10 to the belt 17 is removed, to facilitate the installation of the belt 17 on the pulley 10. By oscillating the oscillating board 24 centering around the bolt 2, tensile force is given to the spring 16 and, in this condition, the bolt 2 is fastened to fix the oscillating board 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The autotensioner according to the present invention is used to constantly apply appropriate tension to bolts such as timing bolts of automobile engines.

(Prior art) In the case of OHC type and DOHC type engines, in order to rotate the camshaft in synchronization with the rotation of the crankshaft, a driving pulley fixed to the end of the crankshaft and a driven pulley fixed to the end of the camshaft are used. It is widely practiced to synchronize the rotations of both shafts by passing a timing bolt between them.

In this way, when using a timing bolt to synchronize the rotations of the crankshaft to which the driving pulley is fixed and the camshaft to which the driven pulley is fixed, the tension of the timing bolt passed between the two pulleys is maintained at a predetermined value. things are necessary.

In other words, the overall length of the timing bolt changes slightly due to changes in temperature and elongation due to use, but if this is left as is, the tension on the timing bolt will be insufficient, causing tooth skipping, etc., and the crankshaft and The phase with the camshaft will shift, and the engine will not perform as expected.

For this reason, conventionally, an auto tensioner as shown in Figure 6 has been used to tighten various bolts such as engine timing bolts.
Appropriate tension is applied.

This conventional auto tensioner has a pivot 3 fixed to a fixed mounting base 1 such as an engine block with a bolt 2, and a sliding bearing 6 (
Regarding the internal structure, it is inserted through the holes (see FIGS. 3 to 5, which show embodiments of the present invention). This through hole 23 is formed at a position off the center of the swing sleeve 4 whose outer peripheral surface is a cylindrical surface, and as a result, the outer peripheral surface of the swing sleeve 4 is freely displaceable about the pivot shaft 3. .

An inner ring 8 constituting a rolling bearing 7 is fitted and fixed on the outer peripheral surface of such a swing sleeve 4, and an outer raceway 9.9 formed on the outer peripheral surface of this inner ring 8 and a short cylindrical A plurality of rolling elements 12.12 are provided between the inner raceway 11.11 formed on the inner peripheral surface of the pulley 10, and this pulley 10 is rotatably supported on the outer peripheral surface of the swing sleeve 4. There is.

Further, a bracket 13 is externally fitted and fixed on the outer circumferential surface of the end of the swinging sleeve 4 at a portion that is detached from the pulley 10.
A tension spring 16 is provided between the arm piece 14 of the bracket 13 and the pin 15 fixed to the mounting base 1 to impart elasticity to the swing sleeve 4 in the direction of pressing the outer peripheral surface of the pulley 10 against the bolt 17. are doing.

Since the conventional auto tensioner is configured as described above, the pulley 10 is pressed against the bolt 17 with an almost constant elasticity regardless of changes in the overall length of the bolt 17.
As a result, a constant tension is always applied to this bolt 17.

A damper mechanism 18 is provided between the inner circumferential surface of the swing sleeve 4 and the outer circumferential surface of the pivot shaft 3 to damp the fine vibrations of the bolt 17.

(Problem B to be Solved by the Invention) However, in the case of the conventional autotensioner configured and operated as described above, the following disadvantages occur.

That is, when applying tension to the bolt 17 using an auto-tensioner, the first method is to remove the tension spring 16 as shown in FIG. The bolts 17 are passed through all the pulleys including the pulley 10. After that, the tension spring 1 with one end locked in the small hole 19 at the tip of the arm piece 14
6 is stretched, and the other end of this tension spring 16 is locked to a pin 15 provided on the mounting base 1.

When the tension spring 16 is later attached by such a method, there is a drawback that it is troublesome to stretch the tension spring 16 in a narrow space, and the assembly work efficiency is poor.

As a second method, as shown in FIGS. 8 and 9, the tip of a tool 21 such as a hex wrench is locked in a hexagonal hole 20 formed on the side surface of the swing sleeve 4, and the tool 21 is operated. By doing this, as shown in FIG. 8, the tip of the arm piece 14 and the bottle 1 are
While stretching the tension spring 16 installed between the pulley 5 and the pulley 10, the pulley 10 is retracted from the part where the bolt 17 runs, and the bolt 17 is passed through all the pulleys including the pulley 10. The bolt 17 should be hung with tool 2 after the passing work is completed.
1, the counterclockwise force applied to the swinging sleeper 4 in FIG. 8 is released, and the tension spring 1 is released as shown in FIG.
6 presses the pulley 10 against the bolt 17.

However, in the case of the second method as described above, it is not always possible to secure a sufficient space for moving the tool 21, and in some cases, it becomes impossible to perform bolting and passing work. Furthermore, even if sufficient space is secured for moving the tool 21, the bolt 17 cannot be hung during passing work.
Since the tension spring 16 is stretched considerably, there is a risk that the spring 16 will be damaged.

The autotensioner of the present invention eliminates all of the above-mentioned disadvantages.

(Means for Solving the Problems) The autotensioner of the present invention includes a bolt screwed into a screw hole provided in a fixed mounting base, a circular tubular pivot shaft through which the bolt passes, and a shaft formed at an off-center position. A swinging sleeper that can freely swing around the pivot shaft by inserting the pivot shaft into the through hole, a pulley that is rotatably supported on the outer peripheral surface of the swinging sleeper, and a pulley that is rotatably supported on the outer peripheral surface of the swinging sleeper. An arm piece fixed on the outer peripheral surface at a position away from the pulley, a rocking plate that can swing freely around the bolt, a locking part such as a pin provided on a part of the rocking plate, and the above-mentioned A tension spring is provided between the end of the arm piece and has elasticity in the direction of pressing the pulley against the bolt, and the rocking plate can be fixed to the mounting base by tightening the bolt.

(Function) In the case of the auto-tensioner of the present invention constructed as described above, when carrying out the handing work, the bolt is loosened and the swing plate is swung around the bolt. The locking part such as a pin provided on this rocking plate is brought closer to the end of the arm piece fixed to the swinging sleeve, and the tension of the tension spring provided between the locking part and the end of the arm piece is applied. Release.

As a result, the elasticity that presses the pulley against the bolt is also released, so there is no interference from the auto tensioner pulley.
Bolt hooking allows for easy passing work.

Once the passing work is completed, the bolts can be hung by swinging the rocking plate around the bolt, so that the locking part on the rocking plate and the end of the arm piece fixed to the rocking sleeve are connected. is moved away, tension is applied to the tension spring provided between the locking part and the end of the arm piece, and the bolt is tightened to prevent the rocking plate from swinging from this state.

As a result, the pulley is pushed toward the bolt, applying proper tension to the bolt.

(Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

Figures 1 to 3 show the first embodiment of the present invention, Figure 1 is a front view showing the state in which the bolt is hooked during passing work, and Figure 2 is the front view showing the condition when tension is applied to the bolt. A front view showing the state, and FIG. 3 is a sectional view taken along the line AA in FIG. 1.

A screw hole 2 is installed on a fixed mounting base l such as an engine block.
2 is formed, and a bolt 2 is screwed into this screw hole 22. The bolt 2 passes through the circular tubular pivot 3 and is screwed into the screw hole 22 to support the pivot 3 on the mounting base 1.

Reference numeral 4 denotes a swing sleeve, and a through hole 23 extending in the axial direction (horizontal direction in FIG. 3) is formed at a position off the center of the swing sleeve 4. By inserting the pivot shaft 3 into the through hole 23 via the sliding bearing 6, the swing sleeve 4 is supported to freely swing around the pivot shaft 3.

In this way, the inner ring 8 constituting the rolling bearing 7 is provided on the outer peripheral surface of the swing sleeve 4 which is swingably supported on the pivot shaft 3.
is fitted and fixed on the outside, and between the outer raceway 9.9 formed on the outer peripheral surface of the inner ring 8 and the inner raceway 11.11 formed on the inner peripheral surface of the short cylindrical pulley 10. Multiple rolling elements 1
2.12 is provided, and this pulley 10 is rotatably supported on the outer peripheral surface of the swing sleeve 4.

A bracket 13 is externally fitted and fixed on the outer circumferential surface of the end of the swinging sleeve 4 at a portion detached from the pulley 10, and a small hole 19 (
A tension spring 16 is hooked between the locking tool 26 (FIG. 3) and a pin 25 provided at the tip of the rocking plate 24, which will be described next.

A circular hole 27 having an inner diameter large enough to insert the tip of the bolt 2 is formed at the base of the rocking plate 24 made of a thick plate with sufficient rigidity, such as a steel plate. After passing through the bolt 2 through the circular hole 27,
It is screwed into a screw hole 22 of the mounting base 1. Therefore, when the bolt 2 is loosened, the rocking plate 24 can swing around the bolt 2, and when the bolt 2 is tightened, the rocking plate 24 is attached to the base end surface of the pivot shaft 3 (the right end surface in FIG. 3). It is strongly held between the base body 1 and becomes immovable with respect to the mounting base body 1.

At the tip of the swing plate 24, there is a pin 2, which is a locking part for locking one end of the tension spring 16, as described above.
5 is set.

In the case of the auto-tensioner of the present invention configured as described above, the bolt 17 should not be hooked during the handing operation.
, and as shown in FIG. 1, swing the rocking plate 24 counterclockwise around this bolt 2 so that the pin 25 provided on the rocking plate 24 and the rocking sleeper 4 are connected to each other. Distance lI between the small hole 19 or the locking tool 26 provided at the end of the fixed arm piece 14
Shorten k. As a result, the tension of the tension spring 16 provided between the pin 25 and the small hole 19 or the locking tool 26 is released, and the pulley 10 supported by the swing sleeve 4 is pressed against the bolt 17. It disappears.

Therefore, the bolt 17 can be easily hooked and passed without being obstructed by the pulley 10 constituting the auto-tensioner.

When the passing work is completed, bolt 17 should be hung by bolt 2.
The rocking plate 24 is rocked in the clockwise direction in FIGS. 1 and 2 with
5 and a small hole 19 at the end of the arm piece 14 fixed to the swing sleeve 4
Alternatively, the distance 1111fL to the locking tool 26 may be increased. As a result, tension is generated in the tension spring 16 provided between the bottle 25 and the small hole 19 or the locking device 26, and this tension causes the swinging sleeper 4 to move around the pivot 3 as shown in FIG. A clockwise force of 11111 is applied, and the pulley 10 supported by the swing sleeve 4 is pressed against the bolt 17.

Therefore, in this state, the bolt 2 is tightened and the base end of the rocking plate 24 is strongly clamped between the base end surface of the pivot shaft 3 and the mounting base 1, so that the rocking plate 24 can be left in this state. Fix it and prevent it from swinging in any direction.

As a result, the pulley 10 rotatably supported on the outer peripheral surface of the swing sleeve 4 remains pressed toward the bolt 17 based on the tension of the tension spring 16, and an appropriate tension is always applied to the bolt 17. be done.

In the case of the first embodiment described above, a circular hole 27 is formed at the base end of the rocking plate 24, and the bolt 2 is inserted into the circular hole 27, and when the bolt 2 is loosened, Although the swing plate 24 is configured to swing not only across the mounting base but also against the swing sleeper 4, when configuring the auto tensioner of the present invention, the swing plate 24 on the outer peripheral surface of the base end of the pivot 3, and further fix both members 24.3 to each other by welding, or as shown in FIG. It can also be formed integrally with this pivot 3 on the outer peripheral surface of the part.

In the case of the second and third embodiments shown in FIGS. 4 and 5, if the pivot 3 is fixed to the mounting base 1 by tightening the bolt 2, the swing plate 24 fixed to the pivot 3 is also fixed to the mounting base 1. Fixed against. In addition, the hook of bolt 17 is for handing work.
When rocking the rocking plate 24, the pivot 3 also rotates in the twisting direction accordingly.

(Effects of the Invention) Since the auto tensioner of the present invention is configured and operates as described above, it is possible to easily perform the work of hooking and passing a bolt onto a pulley while maintaining the functions of a conventional auto tensioner. .

[Brief explanation of drawings]

Figures 1 to 3 show the first embodiment of the present invention, Figure 1 is a front view showing the state in which the bolt is hooked during passing work, and Figure 2 is a front view showing the state when tension is applied to the bolt. FIG. 3 is a sectional view taken along the line A-A in FIG. 1, and FIGS. 4 and 5 are sectional views similar to FIG. Figure 6 is a front view showing an example of a conventional auto tensioner, Figure 7 is a front view showing the auto tensioner with the tension spring removed for bolting and passing work, and Figure 8 is a front view showing an example of a conventional auto tensioner. FIG. 9 is a front view showing a state in which the bolt is hooked and passed while stretching the spring, and FIG. 9 is a front view showing the state after the hooking and passing work is completed. 1: Mounting base, 2: Bolt, 3: Pivot, 4: Swing sleep, 6: Sliding bearing, 7: Rolling bearing, 8: Inner ring, 9: Outer raceway, 10: Pulley, 11: Inner raceway, 12 : rolling element, 13 nib bracket, 14: arm piece, 15: bottle, 16:
Tension spring, 17, bolt, 18: damper mechanism, 19
: Small hole, 20: Hexagonal hole, 21: Tool, 22: Screw hole, 2
3: Through hole, 24: Swing plate, 25: Bin, 26: Locking 2
7: Circular hole. Honseiko Co., Ltd. Yamakinzo (1 idiot) A Figure 1

Claims (4)

[Claims] (1) A bolt screwed into a screw hole provided in a fixed mounting base, a circular tubular pivot through which the bolt passes, and the pivot is inserted into a through hole formed at an off-center position, and this pivot A swinging sleeper that can swing freely around the center, a pulley that is rotatably supported on the outer circumferential surface of the swinging sleeper, and a pulley that is fixedly mounted on the outer circumferential surface of the swinging sleeper at a position away from the pulley. a rocking plate that can swing freely around the bolt, a locking part provided on a part of the rocking plate, and an end of the arm, and the pulley is connected to the bolt. and a tension spring having elasticity in the direction of pressing the tensioner, and the swing plate can be fixed to the mounting base by tightening the bolt. (2) The bolt passes through a circular hole drilled in the base of the rocking plate, and when tightening the bolt, the base of the rocking plate is strongly pinched between the base end surface of the pivot and the surface of the mounting base. The auto tensioner according to claim 1, wherein the swing plate is fixed to the mounting base by. (3) Claim 1, wherein the rocking plate is fixed to the outer peripheral surface of the base end of the pivot by welding, and the rocking plate is fixed to the mounting base by tightening bolts to fix the pivot to the mounting base.
Auto tensioner listed in . (4) A rocking plate is integrally formed on the outer peripheral surface of the base end of the pivot, and the rocking plate is fixed to the mounting base by tightening the bolts to fix the pivot to the mounting base; An autotensioner according to claim 1.