JPH0235248A - Auto-tensioner device for belt - Google Patents

Abstract

PURPOSE:To facilitate installation by fitting a bolt to fix a straight motion actuator into an eccentric hole in a swing shaft, and allowing the swing shaft to work as a fulcrum shaft supporting swingably. CONSTITUTION:A fixing bolt 11 is set into a mounting hole 21 in the mounting part 19 of a straight motion actuator 17 and an eccentric hole in a swing shaft 6 and fastened light into a condition in which the actuator 17 is swingable. When a belt 1 is set on a tension pulley 2 and the actuator 17 swung in the direction of arrow, the pulley 2 moves to the place indicated by the broken line through a locked push rod 18 and a stopper 14. In this condition, the bolt 11 is tightened. When a set pin for locking 30 is drawn off as final process, the rod 18 is put in condition capable of advancing and retracting and stops in the position where a tension adjusting spring of the actuator 17 balances with the tension of the belt 1. Thus installation is completed.

Description

[Detailed description of the invention] [Industrial application field]

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

[Conventional technology]

In belt transmission devices built into automobile engines, belt tension changes due to changes in pulley center distance and torque fluctuations due to thermal expansion of the engine body during operation. Give the pulley the adjustment power of an auto-tensioner to help]
The tension is kept constant. As a prior art of the auto-tensioner device described in Section 2, an auto-tensioner device as illustrated in FIG. 8 is known (see Japanese Utility Model Publication No. 18663/1983). ([) A tension pulley 51 that tensions the belt 50 is rotatably supported by a bracket 52 via a bearing (not shown). On the other hand, the bracket 52 is swingably supported by a support shaft 53. Further, a front end mounting portion 55 of a tamper cylinder 54 is fixed to the support shaft 53. A tension adjustment spring 56 is engaged with the tension pulley 51, and this spring 56 causes the tension pulley 51 to be on the tension side of the belt 50. It is something that energizes. The bracket y+-52t has a contact portion 58 that contacts the rod 57 of the damper cylinder 54, and a stopper 59 that contacts the front end surface of the damper cylinder 54, respectively. moreover,
The front end mounting portion 55 of the damper cylinder 54 is fixed to the support shaft 53, while the rear end mounting portion 60 is fixed to the fixed pole l-
61, it is fixed to the engine body. The rear end mounting portion 60 has a mounting hole 62 formed as a long hole.
The entire damper cylinder 54 is rotatably provided around the support shaft 53. The rotation of the damper cylinder 54 has a structure in which the abutment restriction position of the stopper 59 with respect to the distal end surface of the damper cylinder 54 can be changed.

[Problem to be solved by the invention]

By the way, the auto tensioner device described above does not have a function to adjust the initial position of the tension pulley due to manufacturing variations in belt length, and the bracket, damper cylinder, tension adjustment spring, etc. are separate components, which takes up space. However, there is an inconvenience in that it takes time to install. Therefore, the present invention solves the above two disadvantages, is extremely easy to incorporate, and is a low-cost and compact Bell I.
The purpose is to provide an auto-tensioner device.

[Means to solve the problem]

In order to achieve the above object, an autotensioner device of the present invention includes a tension pulley that applies tension to a belt, a rolling bearing that rotatably supports the tension pulley, and an axial center of the rolling bearing. a swing shaft having a hole eccentric to the other and integrally fixed to the inner ring of the rolling bearing;
It consists of a stopper protruding from the end of the swing shaft, and a direct-acting actuator that accommodates a bushing rod that comes into contact with the stopper so that it can move forward and backward. We adopted a configuration in which the shaft is inserted into an eccentric hole and serves as a fulcrum shaft that supports the swing shaft in a freely swinging manner.

[Effect]

In such a belt autotensioner device,
The tension adjustment spring built into the direct-acting active actuator biases the tension pulley to maintain a constant tension on the dynamic bell I, and as the belt oscillates, the tension pulley is pushed by the belt to prevent slack. If the displacement is
The damper action of the direct-acting actuator suppresses sudden displacement and achieves smooth transmission.

【Example】

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional view (partial cross-sectional view in which only the rolling bearing portion is cut away) showing a first embodiment of the present invention, and FIG. 2 is a front view of the same. A tensile pulley 2 that applies tension to the belt 1 also serves as an outer ring 3 of a rolling bearing, and has a plurality of balls 5 between it and an inner ring 4.
It accommodates and is rotatable. A swing shaft 6 is press-fitted and fixed to the inner diameter of the inner ring 4 and is integrated therewith. An eccentric hole 8 eccentric to the axis of a rolling bearing 7 consisting of an outer ring 3, an inner ring 4, and balls 5 is formed in the swing shaft 6, and a sliding bearing 9 is press-fitted and fixed to the inner diameter of the eccentric hole 8. A fulcrum sleeve 10 is fitted into the sliding bearing 9 with an appropriate guide gap, and the swing shaft 6 can be rotated by Φ'2''J. The fulcrum sleeve 10
A fixed port 11 is inserted into and fixed to the engine body 12. Note that this fulcrum sleeve 10 has a fixed port 11.
It may be formed integrally with. Further, an r:y 13 is provided protrudingly from one end of the fulcrum screen 10Q), and is brought into contact with the bjh surface of the swing shaft 6 for positioning. On the other hand, a half-moon-shaped stopper 14 is fixed to the end surface of the swing shaft 6 by a spring pin 15 and a port 16, and comes into contact with a bushing rod 18 of a direct-acting actuator 17. Note that the stopper 14 may be integrated with the swing shaft 6. The direct acting actuator 17 may be a hydraulic type as shown in FIG. 3, or may be of another type. A mounting portion 20 protruding from the cylinder 19 of the direct-acting actuator 17 is provided with a mounting hole 21 into which a fixing hole I.11 is inserted. In FIG. 3 showing a cross-sectional view of the direct-acting actuator 17, a piston 22 is slidably inserted into the cylinder 19 and is engaged with the bushing rod 18. A communication hole 23 is formed in the piston 22 and allows liquid chambers 24 and 25 separated by the screw I/N 22 to communicate with each other. In addition, a valve 2G is disposed on the liquid chamber 25 side of the piston 22, and the above-mentioned belt tension adjustment spring 28 is housed between the bottom 27 of the cylinder 19. This is a diaphragm seal to prevent leakage of hydraulic oil. In order to lock the bushing rod 18 at a predetermined protrusion amount, a separator pin 30 passes through the cylinder 19 and is locked to the bushing rod 18. Next, the procedure for assembling this automatic tensioner device into the engine body will be explained with reference to FIG. 8
Insert the fixing port 11 into the hole and tighten it lightly so that the direct-acting actuator 17 can swing. belt 1
Direct-acting type actuator 1 that hangs on tensicom pulley 2
7 in the direction of the arrow, the tension pulley 2 moves to the locked bushing rod 18. It moves via the stopper 14 to the position shown by the broken line. In this state, the fixed port 11 is fastened. Finally, lock set pin 30
When pulled out, the bushing rod 18 becomes movable back and forth, and stops at a position where the tension adjustment spring (not shown) of the direct acting actuator 17 and the tension of the belt 1 are balanced, completing the installation. 5 to 7 show a second embodiment of the present invention, in which FIG. 5 is a sectional view, FIG. 6 is a front view of the same, and FIG. 7 is a perspective view of the same. The tensile pulley 31 is fitted around a rolling bearing 32 and rotatably applies tension to the belt 1. The swing shaft 33 fitted into the rolling bearing 32 has the same structure as in the first embodiment.
An eccentric hole 34 is formed, and a sliding bearing 3 is inserted into this eccentric hole 34.
A fulcrum sleeve 36 is rotatably inserted through 5. The fulcrum sleeve 36 has a positioning flange 3 for the swing shaft 33.
7 and a press-fitting part 41 for press-fitting and fixing into a mounting hole 40 formed in a mounting part 39 of a direct-acting actuator 38, which will be described later.
or is formed. 42 is a fixing port for fastening the fulcrum sleeve 36 and the direct-acting acticoator 38 to the engine body (not shown); 43 is a fixing port for fastening the fulcrum sleeve 36 and the direct-acting acticoator 38 to the engine body (not shown);
This is a thrust washer interposed between the A set pin 45 that temporarily fixes the protrusion of a bushing rod 44 that is movably housed in the direct-acting actuator 38 passes through the swing shaft 33, comes into contact with the direct-acting actuator 38, and stops its rotation. This is done by The direct-acting actuator 38 is further provided with a mounting portion 46, and can be firmly fixed by fastening a bolt 48 inserted into the elongated hole 47.

【Effect of the invention】

With the above configuration, the present invention has the following effects. (b) The initial position of the tension pulley can be easily adjusted without adding a special mechanism to adjust the initial position. (b) The number of parts is small, and it can be made into a unit, making it easy to handle and assemble. (c) It occupies less space in the engine body, making it easier to assemble.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention, FIG. 2 is a front view of the same as above, FIG. 5 is a sectional view showing a second embodiment of the invention, FIG. 6 is a front view of the same, and FIG. 8 is a perspective view of the same as above, and FIG. 8 is a front view showing a conventional belt auto-tensioner device. 2, 31 6, 33 7, 32 8, 34 10.36 11.42 17.38 18.44 20.39.46 Belt tension pulley Outer ring Inner ring swinging shaft Rolling bearing Eccentric hole fulcrum sleeve Fixed bolt stopper Direct acting actuator Busho cylinder mounting part mounting hole ＼r

Claims (1)

[Claims] A tension pulley that applies tension to the belt, a rolling bearing that rotatably supports the tension pulley, and a rocking device that has a hole eccentric to the axis of the rolling bearing and is integrally fixed to the inner ring of the rolling bearing. It consists of a shaft, a stopper protruding from the end of the swing shaft, and a direct-acting actuator that accommodates a push rod that contacts the stopper so that it can move forward and backward, and the bolt that fixes the direct-acting actuator is A belt auto-tensioner device, characterized in that it is fitted into an eccentric hole of a swing shaft and serves as a fulcrum shaft that swingably supports the swing shaft.