JPH0425555Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to an auto-tensioner device for a power transmission belt used in an engine, and particularly to a belt auto-tensioner device for adjusting the tension of a toothed timing belt that transmits power from an automobile engine crankshaft.

[Conventional technology]

For example, in an automobile engine, an automatic engine as shown in FIGS. 4 and 5 is used to prevent loosening and adjust the tension of a toothed timing belt stretched between a crankshaft pulley and a camshaft pulley. A tensioner device is known (see Japanese Patent Laid-Open No. 121344/1983). This is because the timing belt 3 is placed between the crankshaft pulley 31 and the camshaft pulley 32 provided on the engine body 30, which is a fixed object.
An idler pulley 34 and an autotensioner 35 are provided, respectively, to adjust the tension of the timing belt 33, which extends over the timing belt 33 and rotates in synchronization with the timing of both pulleys 31 and 32. The idler pulley 34 is rotatably supported by an arm 36, and the arm 36 is swingably supported about a pin 37 as a fulcrum. Also, the auto tensioner 35 has a damper 38.
and a spring 39, which engages with the arm 36 and presses the idler pulley 34 toward the tension side of the timing belt, imparting a predetermined tension to the timing belt 33, and also tightens the timing belt 33 by its damper action. It is designed to absorb vibrations.

[Problem that the invention attempts to solve]

However, in this type of conventional device, the arm 36 and autotensioner 35 are connected to the engine body 3.
Since each is fixed to 0 separately,
Not only is workability poor, but timing belt 3
There is a problem that it is not possible to reliably apply a predetermined tension to the tensioner 3, and it is difficult to set the autotensioner 35, which has a small stroke, at an appropriate position. Further, even when integrated with the bracket, the initial tension of the belt cannot be set in the case shown in FIG. 5, so there is a problem that the appropriate tension cannot be applied to the belt by the stroke of the autotensioner alone.

[Means to solve the problem]

In order to solve the above problems, this invention includes an inner member and an outer member rotatably fitted on the inner member,
an idler pulley that engages with a belt that transmits the power of the engine to apply tension to the belt; an arm to which the idler pulley is attached and has a fulcrum hole with a swing center at one end; and an arm that connects the arm to the belt. A belt auto-tensioner device comprising an auto-tensioner that presses against the tension side of the belt, wherein an eccentric hole is provided in the inner member, and the idler pulley is attached to the arm by a fixing bolt inserted into the eccentric hole. The structure is as follows.

[Effect]

Fix the bracket that holds the arm and autotensioner together to the engine body, and while holding the arm in the proper position of the autotensioner rod,
The inner member is swung around the fixing bolt inserted into the eccentric hole provided in the inner member of the idler pulley as a fulcrum.
Adjust the initial tension of the belt and tighten the bolt to the arm to fix the idler pulley. Thereafter, the proper tension is applied to the belt by removing the stopper pin of the arm. Even if the arm and autotensioner are separate, the initial belt tension can be adjusted using the eccentric hole provided in the arm.

【Example】

Hereinafter, the present invention will be explained in detail based on the embodiments shown in FIGS. 1 to 3. FIG. 1 is a front view showing an embodiment of a belt autotensioner device according to the present invention, and FIG. 2 is a sectional side view thereof. An idler pulley 2 that performs initial adjustment of the tension of the timing belt 1 is fixed to a substantially L-shaped arm 3. The arm 3 is swingably attached to a bracket 5 via a fulcrum pin 4 inserted into one end thereof, and the other end is arranged to abut against a rod 7 of an autotensioner 6 fixed to the bracket 5. The bracket 5, which holds the arm 3 and autotensioner 6 together, is fixed to the engine body 8 with bolts 9. It is also possible to separate the autotensioner and the arm and install a Mydra pulley with an eccentric hole in the arm, eliminating the need for a bracket. The idler pulley 2 consists of a shaft-shaped inner member 10 and an outer tube 12 rotatably attached to the inner member 10 via a ball bearing 11. Inner member 10
An eccentric hole 13 is provided on one side, and a pretension hole 14 is provided on the opposite side to engage a pretension jig (not shown).
is provided. Numeral 15 is a bolt for fixing the idler pulley 2 to the arm 3, and serves as a fulcrum when the idler pulley 2 is swung by a pretension jig. The arm 3 is approximately L-shaped, and includes a bent portion 16 to which the idler pulley 2 is attached, and a fulcrum hole 1.
7, and an operating portion 19 that abuts against the rod 7 of the autotensioner 6 and swings as the rod 7 moves forward and backward. Between the fulcrum hole 17 and the fulcrum pin 4, a synthetic resin bush or oil-impregnated bearing 20, which is highly wear resistant and has good sliding characteristics, is inserted to smooth the swinging motion of the arm 3. Note that the outer surface of the fulcrum pin 4 or the fulcrum hole 17
This type of resin may be directly coated on the inner surface of the holder. On the other hand, the stroke of the rod 7 of the autotensioner 6 cannot be made too long due to its strength, and is usually limited to around 10 mm. Therefore, in order to make effective use of this short stroke, it is necessary to initially adjust the mounting position of the autotensioner device on the engine body 8.
Among the dimensional variations of each part, the variation in the length of the belt 1 is particularly large, and usually has an error of about ±6 mm. For the initial adjustment mentioned above, idler pulley 2
When swinging the arm 3, the work efficiency is improved by locking the stopper pin 21, which is temporarily locked to the bracket 5 set at a predetermined angle, on the action part 19 of the arm 3.
The stopper pin 21 is removed after the initial adjustment is completed,
The pressing force of the autotensioner 6 is applied to the action portion 19 of the arm 3, the arm 3 is swung around the fulcrum pin 4, and a required tension is applied to the belt 1 via the idler pulley 2. Note that by cutting a thread on the outer periphery of the autotensioner 6 and screwing it into the bracket 5, the position of the autotensioner 6 can be finely adjusted during repairs or the like. FIG. 3 is a front view showing another embodiment of the idler pulley applied to the present invention. A fulcrum pin 24 serving as a pivot center is inserted into an eccentric hole in the inner member 23 of the idler pulley 22, and an arc-shaped hole 25 centered around the fulcrum pin 24 is provided on the opposite side of the fulcrum pin 24. provided. In this case, when the force acting on the idler pulley 22 is large, a fixing bolt 26 is screwed together in addition to the fulcrum pin 24, so that the two bolts receive the load.

【effect】

Since the present invention has the above configuration, it has the following unique effects. (a) Since the idler pulley is attached to the swing arm so that it can be adjusted at the initial stage, the position of the idler pulley can be adjusted after the device is fixed to the engine body, etc.
Work efficiency is greatly improved and initial adjustments can be made with high precision. (b) Even auto tensioners with small effective strokes can be easily adjusted. (c) Since the position of the idler pulley can be adjusted after the device is fixed to the engine body, etc., it is possible to provide a substantially compact belt autotensioner device without being subject to restrictions around the device.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the belt autotensioner device according to the present invention, Fig. 2 is a cross-sectional side view of the same, and Fig. 3 is a diagram showing another embodiment of the idler pulley applied to the present invention. A front view, FIG. 4 is a schematic diagram showing a state in which a conventional auto-tensioner device is installed, and FIG. 5 is a front view of the conventional auto-tensioner device. 2, 22...Idler pulley, 3...Arm,
4...Fully pin, 5...Bracket, 6...Auto tensioner, 10, 23...Inner member, 11...
... Ball bearing..., 13... Eccentric hole, 14... Pretension hole, 17... Fulcrum hole, 19... Action part,
21...Stotsupapin.

Claims (1)

[Scope of utility model registration request] an inner member; an idler pulley rotatably fitted on the inner member; and an idler pulley that engages with a belt that transmits engine power to apply tension to the belt; A belt auto-tensioner device comprising an arm having a fulcrum hole serving as a center of movement, and an auto-tensioner that presses the arm toward the tension side of the belt, wherein an eccentric hole is provided in the inner member and the idler A belt autotensioner device, characterized in that a pulley is attached to the arm with a fixing bolt inserted into the eccentric hole.