JPH0379843A - Oil filling method for oil type tensioner - Google Patents

Abstract

PURPOSE:To lower cost and heighten the reliability of function, by pushing in a diaphragm to discharge an oil quantity approximately equal to an oil quantity which should be discharged due to the fitting of a sealing member, and pressing in a sealing member while the diaphragm is being returned to an original shape, and sealing oil in a cylinder. CONSTITUTION:A condition in which an oil amount approximately equal to an oil quantity which should be discharged due to the fitting of a sealing mem ber 28, has been discharged, is realized by pushing in a diaphragm 26 of an oil reserver 24, and oil is sealed in a cylinder 12 by pressing the sealing member 28 as the diaphragm 26 is being returned to an original form. Thus, even though no oil sealing opening is provided at all, sealing of a predetermined oil quantity inside the cylinder 12 can be done by simultaneous execution of recovery of the original form of the diaphragm 26 and the pressing-in of the sealing member 28. Accordingly, constitutions such as an oil sealing opening, a blind stopper plug, which become the cause of an oil leakage, can be entirely eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for filling an oil tensioner with oil.

Prior art and its problems Oil-type tensioners use a so-called check valve mechanism, and when a chain, belt, etc. becomes slack, the piston (or sleeve) immediately protrudes to eliminate the slack, but it is difficult to return in the opposite direction. The tensioner is Conventionally, in order to fill such a tensioner with oil, an oil sealing port is required in the piston rear chamber 52 or the piston front chamber 54, as shown in FIGS. rear,
Since this oil sealing port must be blocked by the blind plugs 56 and 58, there is a problem that the number of parts is large, and the blind plugs 56 and 5
There is a problem in that it requires work to attach 8. Furthermore, there is a risk that the blind plugs 56 and 58 may loosen or come off due to vibration or corrosion during use.

As a result, the filling oil may leak and the tensioner may not function properly.

a! Means and action to solve the problem The present invention relates to a piston that slides inside a cylinder.

In an oil tensioner, the oil tensioner includes a piston rod connected to the piston and having a sealing member interposed between it and the cylinder, and an oil reservoir connected to the cylinder and covered by a diaphragm, in which the diaphragm of the oil reservoir is pushed. As a result, approximately the same amount of oil as should be discharged by installing the seal member is discharged, and the seal member is press-fitted while restoring the diaphragm to its original shape, thereby releasing oil into the cylinder. The above problem was solved by an oil filling method that seals the container.

Before installing the seal member, if you push the diaphragm inside and remove a volume approximately equal to the amount of oil that should be discharged when installing the seal member, the diaphragm can return to its original shape and the seal member can be press-fitted. By doing this at the same time, it is possible to seal a predetermined amount of oil into the cylinder without providing any oil filling port.

This oil filling method may cause oil leakage.
It is possible to completely eliminate the need for oil seal ports, blind plugs, etc.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

An example of a tensioner to which the oil filling method of the present invention is applied is shown in FIGS. 1 and 2. The tensioner 10 is connected to the cylinder 1
2, a piston 14 that loosely fits into the cylinder 12 with a small gap, and a piston rod 16 that is continuously M (press-fitted) into the piston 14. The structure is divided into two parts.

The oil reservoir 24 is primarily used to absorb changes in volume within the cylinder 12 caused by the back and forth movement of the piston 14, and communicates with the piston front chamber 20 and is isolated from the outside by a diaphragm 26. The diaphragm 26 is made of rubber and can be deformed relatively freely. One end of the cylinder 12 on the piston front chamber 20 side is open, and a seal (oil seal) member 28 for sealing the piston front chamber 20 is press-fitted into this opening 18 .

The tensioner 10 is filled with oil in the following procedure.

[Procedure 1] (1) Fill the piston front chamber 20, the piston rear chamber 22, and the oil reservoir 24 with oil.

(2) Attach the diaphragm 26 and fix it with the cylindrical diaphragm holding member 30. (Of course.

As in step 2 described below, diaphragm 26 before filling with oil.
may be attached. ) At this time, the seal member 28 has not yet been attached.

(3) Place the seal member 28 near the opening 1.8.

(4) The diaphragm 26 is pushed in from the outside to the inside by the pushing member 32. The pushing member 32 has a T-shape, and a certain amount of oil is expelled by abutting the enlarged diameter head against the top of the diaphragm holding member. With this operation,
The oil in the piston front chamber 20 is discharged to the outside through the gap between the seal member 28 and the opening 18 (FIG. 1).

5) Remove the pushing member 32 and press-fit the sealing member 28 using the jig 34. As a result, the diaphragm 26 returns to its original shape (Fig. 12). The press-fitting amount of the sealing member 28 is sintered to a certain amount when the enlarged diameter head of the jig 34 hits the opening 18 of the cylinder 12 and stops. In this way, the point at which the diaphragm 26 has returned to its original shape is the normal position of the diaphragm 26, and the point at which the oil seal has been press-fitted is set.

Filling oil into the tensioner 1o using the above method 1
In this embodiment, in order to facilitate the use of the push-in fitting 32,
The holding member 30 of the diaphragm 26 is cylindrical and is finally fitted with a cap 38 having a small hole 36, as shown in FIG.

[Step 2] Attach the fi+ diaphragm 26 and fix it with a cylindrical diaphragm holding member 30.

(2) Before filling with oil, push the diaphragm 26 from the outside toward the inside using the pushing member 32.

This eliminates in advance a volume equal to the oil to be discharged by attaching the seal member 28.

(3) Piston front chamber 20. Piston rear chamber 2. ．． 2 and the oil reservoir 24 are filled with oil.

(4) The rest is the same as step 1; the pushing member 32 is removed and the sealing member 28 is press-fitted using the jig 34. As a result, the diaphragm 26 returns to its original shape, and the oil member 2
8 is pressed into place (FIG. 2).

Effects of the Invention As described above, according to the present invention, there is no need for a hole for sealing oil in the cylinder or a plug for plugging the hole, and the number of parts per unit is small. This eliminates the need for man-hours for installation, leading to cost reductions. By eliminating the above-mentioned parts, the cause of oil leakage is eliminated, and in particular, the rear chamber of the piston, which is subject to high pressure, is completely sealed, making it possible to improve the reliability of the tensioner's function.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the tensioner just before the seal member is pushed in, Figure 2 is a cross-sectional view of the tensioner after the seal member has been press-fitted from the state shown in Figure 1, and Figure 3 is an enlarged cross-section of the oil reservoir after filling with oil. Fig. 4 and f! FIG. 15 is an enlarged sectional view of a blind plug portion of a conventional tensioner. 10... Tensioner 14... Piston rod 24... 26... 28... 32... ・Oil reservoir, diaphragm, seal member, pushing member 34・ 12 ・ 16 ・ ・Cylinder, piston, jig Fig. 2 4

Claims (1)

[Scope of Claims] A piston that slides within a cylinder, a piston rod that is connected to the piston and has a sealing member interposed between it and the cylinder, and an oil reservoir that is connected to the cylinder and covered by a diaphragm. In the oil-type tensioner, by pushing the diaphragm of the oil reservoir, an amount of oil approximately equal to the amount of oil that should be discharged by attaching the seal member is discharged, and the diaphragm is returned to its original shape. 1. A method for filling an oil-type tensioner with oil, the method comprising: sealing oil in the cylinder by press-fitting the sealing member while