JPH05214908A - Initial tension adjusting tool for valve system - Google Patents

Abstract

PURPOSE:To easily perform the whole initial tension adjusting work and improve workability by fixing a fixed bracket to an engine main body, coupling a rotary carrier with an eccentric carrier, and fixing a rotary member with a lock mechanism. CONSTITUTION:A rotary ring 22 is rotated to a preset position and fixed by a lock mechanism 14 at this position, a fixed bracket 8 is fixed to an engine main body 1a, and the rotary ring 22 is coupled with an eccentric carrier 13. When the lock mechanism 14 is released, the eccentric carrier 13 can be rotated at the preset rotational torque by the energizing force of a spring member 26, and the applying work of initial tension is easy. The rotary ring 22 is finally fixed by the lock mechanism 14, an eccentric axis bolt 16a is fastened to fix the eccentric carrier 13 to the fixed bracket 8, and corotation can be prevented when the bolt 16a is fastened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an initial tension adjusting tool for applying an appropriate initial tension to a timing band (belt, chain) of a valve train, and more particularly to an eccentric ring type pressing wheel abutting the timing band. In this case, the present invention relates to the improvement of the structure of the initial tension adjusting tool capable of significantly improving the workability of applying the initial tension and fixing the pressing wheel.

[0002]

2. Description of the Related Art A valve operating system for an engine is constructed such that a cam shaft is rotationally driven by a crank shaft via, for example, a timing belt, thereby opening and closing intake and exhaust valves at predetermined timings. In this valve operating device, it is necessary to constantly apply a predetermined tension to the timing belt, and in many cases, an automatic tensioner device that automatically adjusts the tension is conventionally provided. This device uses a support bracket that is swingably supported by the engine and uses a pressure wheel (tension pulley).
Is rotatably supported, and the support bracket is biased in the swinging direction by a tensioner main body such as a hydraulic type.

In mounting the engine of the auto tensioner device, it is necessary to apply so-called initial tension by pressing the tension pulley against the timing belt with a predetermined force. In order to be able to apply this initial tension, conventionally, as the tension pulley, a rotating wheel that comes into contact with the belt,
In some cases, a so-called eccentric ring type, which is eccentrically inserted into the rotary wheel and is configured to include an eccentric support member fixed to the support bracket by an eccentric shaft bolt, may be used.

By the way, in order to apply an initial tension to the conventional eccentric wheel type tension pulley, the autotensioner device is set at a predetermined position, the swing of the support bracket is prevented by some method, and the eccentricity is increased. The shaft bolt is loosened, and the eccentric support is rotated with a predetermined rotation torque by a torque wrench. Then, the torque wrench is fixed at this rotated position, and in this state, another wrench is used to tighten and fix the eccentric shaft bolt.

[0005]

However, in the above-mentioned conventional apparatus, the torque of the eccentric support is applied by one torque wrench while the eccentric shaft bolt is tightened by another torque wrench, and at the same time, the eccentric support is prevented from rotating together. There is a problem in that mounting workability is low because it requires extremely difficult work that must be done.

The present invention has been made in view of the above-mentioned problems of the prior art. The initial tension adjusting tool for a valve operating system for a vehicle, which greatly simplifies the difficult work described above and greatly improves the initial tension adjusting workability. Is intended to provide.

[0007]

According to the present invention, there is provided a support bracket swingably attached to an engine body, a tensioner body for biasing the bracket in the swing direction, and a support bracket rotatably supported by the support bracket. An initial tension adjusting tool for applying a predetermined initial tension to the timing band in a valve operating device including a tensioner device configured to press the slack side portion of the timing band, wherein the pressing ring is A rotary wheel rolling on the timing band, and an eccentric support member eccentrically inserted and arranged in the rotary wheel,
An eccentric ring type capable of applying an initial tension by rotating the eccentric support, a fixed bracket fixed to the engine body, and the bracket rotatably supported around the axis of the eccentric support, A rotatable member that can be engaged with and disengaged from the support, a spring member that urges the rotatable member to rotate with a rotational torque corresponding to the initial tension, and the rotatable member is fixed at a desired rotation angle position with respect to the fixed bracket. It is characterized by having a lock mechanism for locking.

[0008]

In the valve gear in which the support bracket having the pressing wheel and the tensioner body are mounted at predetermined positions, the initial tension is set by using the initial tension adjusting tool according to the present invention. It is rotated to a position and fixed to the position by a lock mechanism. In this state, the fixing bracket is fixed to the engine body, and the rotating member is engaged with the eccentric support. Next, when the lock mechanism is released, the rotating member is rotated by the spring member, and the eccentric support member of the pressing wheel is rotated around the eccentric axis, whereby the rotating wheel of the pressing wheel applies a predetermined initial tension to the timing band. Give. Finally, the rotating member is fixed by the lock mechanism, and in this state, the eccentric shaft bolt is tightened to fix the eccentric support member to the support bracket.

As described above, according to the present invention, the fixing bracket is fixed to the engine body, the rotary support is engaged with the eccentric support, and the lock mechanism is released, so that the eccentric support is moved by the urging force of the urging spring. Since it can be rotated with a predetermined rotation torque, it is easy to apply the initial tension, and it is possible to prevent accompanying rotation when tightening the eccentric shaft bolt by fixing the rotating member by the lock mechanism.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 are views for explaining an initial tension adjusting tool for a vehicle valve operating system according to an embodiment of the present invention. FIG. 1 is a sectional view taken along line I-I of FIG. 3, and FIG. 2 is an initial tension. FIG. 3 is a side view showing a state before application, FIG. 3 is a side view showing a state after application, and FIG. 4 is a side view around the tensioner device in a state in which the adjustment tool is removed, showing a state in which the timing belt cover is removed. ing.

In the figure, reference numeral 1 is a cylinder block of an engine in which the device of the present embodiment is adopted, and a crankshaft 2 is inserted and arranged below the block 1 in a direction perpendicular to the plane of FIG. A crank pulley 3 is fixed to the outward protruding portion of the crank shaft, and the pulley 3 is connected by a timing belt 4 to a cam pulley (not shown) of a cam shaft.

On the end surface 1a of the cylinder block 1,
The tensioner device 5 has the slack side 4 of the timing belt 4.
It is arranged so as to be located outside a. The tensioner device 5 includes a tension pulley (pressing wheel) 6 that presses the slack side 4 a of the timing belt 4 inward, a support bracket 8 that supports the tension pulley 6, and a swinging biasing force of the support bracket 8. The tensioner main body 7 is used.

The support bracket 8 has a swing boss portion 8a.
The support boss portion 8b and the pressing boss portion 8c are integrally formed into a lump. A collar 11 is inserted into the swing boss portion 8a via a bearing 12, and the collar 11 is fixed to the end surface 1a of the cylinder block 1 with bolts, nuts 10a and 10b. As a result, the support bracket 8 can swing around the bearing 12. The tension rod 7a of the tensioner main body 7 is in contact with the lower surface of the pressing pin 8d protruding from the pressing boss portion 8c. The tensioner body 7 is bolted and fixed to the end surface 1a.

The tension pulley 6 has a cylindrical pulley body (rotating wheel) 9 and a ball bearing 15 in the pulley body 9.
And an eccentric support body 13 in the shape of a thick disk that is inserted and arranged through. The rotation axis C1 of the eccentric support 13 is eccentric from the rotation axis C2 of the pulley body 9. An eccentric shaft bolt 16a is inserted into the rotary shaft C1, and the bolt 16a is screwed into a nut 16b embedded and fixed in the support boss portion 8b. Thus, by rotating the eccentric support 13 around the eccentric shaft bolt 16a, a pressing force of the pulley body 9 to the timing belt 4, that is, an initial tension can be applied.

Reference numeral 17 denotes an initial tension adjusting tool which is a feature of this embodiment. This adjusting tool 17 is mainly
Fixed bracket 18, rotating ring (rotating member) 22 pivotally supported by the bracket 18, and rotating ring 2
An urging spring 26 that urges 2 to rotate in the initial tension applying direction;
The lock mechanism 14 fixes the rotating ring 22 at a predetermined angle position.

The fixing bracket 18 is a fixing bolt 1
9b, a fixed arm 18b fixed to the side surface 1b of the cylinder block 1 and a support arm 18a rotatably connected to the tip of the arm 18b by a connecting bolt 19a. A steel ball 20a is provided between the two. A moderation mechanism including the spring 20b is provided. As a result, the fixed bracket 18 is rotatable about an axis perpendicular to the rotary shafts C1 and C2.

The tip portion 18c of the support arm 18a
Is located in front of the tension pulley 6. The rotary ring 22 is inserted and arranged in the tip portion 18c via a bearing 21a, and the rotary ring 22 is arranged so as to be coaxial with the rotary shaft C1. A lid plate 23 is fixed to the outer end surface of the rotary ring 22 by bolts, and work holes 22a and 23 formed in the lid plate 23 are fixed.
A is a hole for inserting a torque wrench when rotating the eccentric shaft bolt 16a. Two locking pins 24 are planted on the inner end surface of the rotating ring 22. The locking pin 24 can be engaged with and disengaged from a locking hole 13a provided in the outer end surface of the eccentric support body 13.

An outer ring 25 is rotatably mounted on the rotary ring 22 via a bearing 21b.
A stopper rod 27 is fixed to the water ring 25. The stopper 27 is a rod-shaped body extending toward the end surface 1a, and the inner end portion of the stopper 27 is in contact with the upper surface of the pressing pin 8d provided on the pressing boss portion 8c of the support bracket 8.

Further, one end of the biasing spring 26 is locked to the outer ring 25 and the other end is locked to the rotating ring 22, so that the rotating ring 22 is rotated clockwise as seen in FIG. Each of 25 is urged to rotate counterclockwise.

The lock mechanism 14 has the following structure. Ratchet teeth 23b are formed on a part of the outer peripheral edge of the lid plate 23, and subsequently, stopper recesses 23c are formed. In addition, the fixed bracket 18
A stopper pin 28b that engages with the stopper recess 23c is planted in the tip portion 18c of the support arm 18a, and the ratchet arm 28 is pivotally supported by a shaft 28d. Then, by engaging the claw 28a of the ratchet arm 28 with the ratchet tooth 23b, the rotary ring 2
It has a structure that prevents 2 from rotating clockwise. In addition, 28c is a spring for urging the ratchet arm 28 to the engaging position, and 29 is the ratchet arm 2
8 is a cover for covering.

Next, the function and effect of this embodiment will be described. A procedure for adjusting the initial tension using the tool 17 of this embodiment will be described. The tensioner device 5 is attached to the cylinder block 1.
In this case, the tension main body 9 is pressed against the timing belt 4 with the eccentric shaft bolt 16a of the tension pulley 6 loosened, and the tension rod 7a of the tensioner main body 7 is in contact with the pressing pin 8d of the pressing boss 8c. To do. As a result, the eccentric support 13 rotates counterclockwise in the drawing and is positioned at the retracted end thereof.

The tool 17 is set to a use state. First, the rotation ring 22 is locked by the locking recess 23c of the locking pin 2
It is rotated counterclockwise in FIG. 2 until it is locked to 8b, and it is locked by the ratchet arm 28 at this position. Further, the support arm 18a of the fixed bracket 18 is tilted outward.

Fixed arm 18b of fixed bracket 18
Is fixed to the side surface 1b of the cylinder block 1 with a fixing bolt 19b. Then, the support arm 18a is connected to the connecting bolt 19a.
Rotate inward (counterclockwise in Figure 1). As a result, the locking pin 24 of the rotating ring 22 is inserted and locked in the locking hole 13a of the eccentric support body 13, and the stopper rod 27 presses the pressing pin 8d of the support bracket 8 to be in a state before initial tension application ( See FIG. 2).

By rotating the ratchet arm 28 clockwise in FIG. 2, the engagement between the pawl 28a and the ratchet tooth 23b of the ratchet arm 28 is released. As a result, the rotating ring 22
Is rotated clockwise around the eccentric shaft bolt 16a by the urging force of the urging spring 26, and the eccentric support 13 is also rotated clockwise with a predetermined rotational torque. As a result, the pulley body 9 presses the timing belt 4 and a predetermined initial tension is applied to the belt 4. Also at this time,
When the ratchet arm 28 is released, the arm locks the rotating ring 22 in the initial tension application state (see FIG. 3).

A torque wrench is applied to the eccentric shaft bolt 16a, and the bolt 16a is tightened with a predetermined rotational torque. At this time, since the rotary ring 22 is locked in the above state by the lock mechanism 14, the eccentric support 13
Is also locked in that position, and thus the eccentric support 1
3 does not rotate together with the eccentric shaft bolt 16a.

As described above, in this embodiment, the rotating ring 22 of the tool 17 is rotationally urged by the spring 26 to rotate the eccentric support 13 with a predetermined torque, thereby applying an initial tension to the timing belt 4. Since this is done, the initial tension application work is extremely easy. Further, at this time, since the stopper rod 27 biased in the direction opposite to the rotating ring 22 presses the pressing pin 8d of the support bracket 18 downward, the rotation of the support bracket 18 can be automatically prevented.

Further, the eccentric support 1 is brought into the initial tension applied state.
Since 3 is locked and the eccentric shaft bolt 16a is tightened in this state, the eccentric support body 13 can be prevented from rotating together, and the entire initial tension adjustment work can be easily performed.

[0028]

As described above, according to the initial tension adjusting tool for the valve gear of the present invention, the biasing spring is fixed by fixing the fixing bracket to the engine body and engaging the rotating member with the eccentric support. Since the eccentric support is rotated with a predetermined torque by the urging force of, the initial tension application work is easy, and since the rotating member is fixed by the lock mechanism, when tightening the eccentric shaft bolt, It is possible to prevent entrainment, to perform the entire initial tension adjustment work extremely easily, and to improve workability significantly.

[Brief description of drawings]

1 is a view showing a usage state of an initial tension adjusting tool of a valve train according to an embodiment of the present invention, and is a sectional view taken along line II of FIG.

FIG. 2 is a side view showing a state before application of initial tension by the tool of the embodiment.

FIG. 3 is a side view showing a state after the initial tension is applied by the tool of the embodiment.

FIG. 4 is a side view showing a state in which the tool of the embodiment is removed.

[Explanation of symbols]

 1a End surface of cylinder block (engine body) 4 Timing belt (timing band) 5 Tensioner device 6 Tension pulley (pressing wheel) 7 Tensioner body 8 Support bracket 9 Pulley body (rotating wheel) 13 Eccentric support 14 Lock mechanism 16a Eccentric shaft bolt (Eccentric shaft) 17 Tool 18 Fixed bracket 22 Rotating ring (rotating member) 26 Spring member

Claims (1)

[Claims] 1. A support bracket swingably attached to an engine body, a tensioner body for biasing the bracket in the swing direction, and a slack side portion of a timing band rotatably supported by the support bracket. An initial tension adjusting tool for applying a predetermined initial tension to the timing band in a valve operating device including a tensioner device that is composed of a pressing wheel that presses the pressing wheel, and a rotating wheel that contacts the timing band. An eccentric support body that is eccentrically inserted and arranged in the rotating wheel, and is an eccentric ring type that can apply initial tension by rotating the eccentric support body, and a fixing bracket fixed to the engine body, A rotating member that is rotatably supported by the bracket about the axis of the eccentric support member and that can be engaged with and disengaged from the eccentric support member; Initial tension adjusting tool for a valve train, comprising: a spring member that is urged to rotate by a rotating torque; and a lock mechanism that fixes the rotating member to a desired rotation angle position with respect to the fixed bracket. ..