JPS583952Y2 - chientensiyona - Google Patents

Description

[Detailed explanation of the invention] This invention relates to an improved ceno tensioner that has a simple structure and can be manufactured at low cost.

Chain 7 stretches and loosens with use, causing noise due to vibration, so a chain tensioner is installed to keep it tensioned at all times.

There is a type of chain tensioner that automatically moves forward according to the length of the chain 7 to maintain a good tension at all times, but the structure is complicated and expensive.

In view of these points, this invention has been improved to have a simple structure, low cost, and automatic extrusion.Examples of the invention shown in the drawings will be described below.

A camshaft 2 having a swash plate-like cam surface 1 at one end is rotatably inserted into a case 3.

A holding plate 4 is integrally attached to the other end of the camshaft 2, and both ends of a coiled spring 5 are latched between the holding plate 4 and the case 3.
The camshaft 2 is urged in the rotational direction.

Further, a push shaft 6 is slidably inserted into the case 3, the cam surface 1 is brought into contact with the base end of the push shaft 6, and the back surface of the guide rail 7 is brought into contact with the tip of the push shaft 6.

The guide rail 7 is swingably held at one end by a shaft 8 and is arranged along a check 79.

The screw 10 fixes the push shaft 6.

The effect will be explained.

At the position where the push shaft 6 is placed inside, the tip of the screw 10 is tightened with 1 that hits the push shaft 6 to fix the push shaft 6.

Then, the coiled spring 5 is loaded in the rotational direction and both ends are latched to the case 3 and the holding plate 4.

After setting in this way, the case 3 is fixed to a predetermined position of the machine frame on which the check 79 is attached with bolts or the like.

When the button is pressed and the screw 10 is loosened, the cam shaft 2 rotates, the cam surface 1 pushes out the push shaft 6, and the guide rail 7 is pressed against the check 79.

When the chain 79 is extended during use, the camshaft 2 is rotated by the coiled spring 5 by that amount, and the push shaft 6 is pushed out.

In this way, the check 79 is always maintained in a tensioned state.

Since the cam surface 1 pushes the push shaft 6 with its sloped portion and is biased by the coiled spring 5, it does not rotate in the return direction.

Therefore, once pushed out, the push shaft 6 will not return even if torque is applied to the chain 79, and the chain 79 can be maintained in a tensioned state.

As explained above, this idea involves inserting a camshaft with a cam surface on one end into the case so that it can rotate freely, and then elastically inserting a coiled spring between the other end of the camshaft and the case to move the camshaft in the rotational direction. The cam surface is brought into contact with the push shaft that is slidably inserted into the case, and the push shaft is applied to the back of the guide rail along the chino to push out the guide rail, reducing the number of components. Can be done cheaply.

In particular, since the push shaft is pushed out by the cam surface, it does not rotate in the reverse direction, eliminating the need for a detent such as a ratchet device that only moves in a certain direction.
Becomes cheaper.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, with Figure 1 being a longitudinal sectional view and Figure 2 being a longitudinal sectional view.
The figure is a view taken along the line A-A in FIG. 1...Cam surface, 2...Cam shaft, 3...Case, 5
...Wound spring, 6...Push shaft, 7...Guide rail, 9...
・Chain O

Claims (1)

[Scope of utility model registration request] A camshaft with a cam surface on one end is rotatably inserted into the case, and a coiled spring is elastically inserted between the other end of the camshaft and the case to bias the camshaft in the direction of rotation, allowing it to slide freely into the case. A chain tensioner characterized in that a cam surface is brought into contact with a push shaft inserted into the chain, and the push shaft is brought into contact with the back of a guide rail along the chain, thereby pushing out the guide rail.