JPH0143969Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an improvement in the piston positioning structure of an automobile master cylinder.

[Prior Art] As shown in FIG. 3, in the piston positioning portion 3 at the open end of the cylinder body 1 into which the piston 2b of the master cylinder is inserted, a snap spring is attached to the large inner diameter portion 4 formed in the cylinder body 1 in order from the outer end. 5, a plate 6, and a blocking ring 7, oil seals 8, 8 are fitted on both sides of the inner diameter of the blocking ring 7, and packings 9, 9 are fitted on the outer diameter of the blocking ring 7, respectively.

Further, a step part 11 is formed between the large inner diameter part 4 and the small inner diameter part 10 in the cylinder body 1, and an annular stopper ring 17 as shown in FIG. The inner diameter portion of the stopper ring 17 is locked to a locking collar 19 that protrudes from a small diameter cutout portion 18 provided on the piston 2b. In addition, 16 is a connecting rod, 2c is a piston 2
This is the flange-like large diameter part of b.

[Problems to be solved by the invention] However, in such a conventional master cylinder piston positioning structure, in order to lock the annular stopper ring 17, the piston 2
It is necessary to specially provide a small diameter notch 18 and a locking flange 19 on b, which increases the length of dimension l, that is, the length of piston 2b, so the overall length of the master cylinder should be shortened as much as possible. There was a problem in that the piston 2b could not fully meet the requirements for the piston 2b, and there were problems in the strength and processing of the piston 2b due to the provision of the small diameter notched portion 18 and the like.

[Means for Solving the Problems] Means for solving the problems described above will be explained below using FIG. 1 and FIG. 2 corresponding to the embodiment.

In this invention, in the piston positioning part 3 at the open end of the cylinder body 1 into which the piston 2 is inserted,
A snap ring 5, an oil seal 8, etc. are arranged in a large inner diameter portion 4 formed in a cylinder body 1 in order from the outer end. A flange portion 13 of a short tubular stopper ring 12 is provided with a flange on the end surface of the stepped portion 11 formed between the large inner diameter portion 4 and the small inner diameter portion 10 following it.
and the stopper ring 12 is fitted so that the tip of the short pipe part 14 of the stopper ring 12 comes into contact with the flange-like large diameter part 2a of the piston 2 which is in sliding contact with the small inner diameter part 10. This is what I did.

[Function] Master cylinder piston positioning part 3
In place of the conventional annular stopper ring, a short tubular stopper ring 12 with a flange is fitted to the master cylinder. This contributes to shortening the overall length, and since there is no need to provide the small diameter notch 18 or the locking flange 19 unlike the conventional piston 2b, there is an advantage in that there are no problems in terms of strength or machining.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. 1 is a cylinder body, 2 is a piston, and 3 is a piston positioning portion at the open end of the cylinder body 1. The piston positioning part 3 has a large inner diameter part 4 formed in the cylinder body 1, and a snap ring 5, a plate 6, and a block ring 7 are arranged in this order from the outer end. Oil seals 8, 8 are fitted on both sides of the inner diameter of the blocking ring 7, and packings 9, 9 are fitted on the outer diameter thereof, respectively.

Further, a stepped portion 11 is formed between the large inner diameter portion 4 and the small inner diameter portion 10 of the cylinder body 1 following the large inner diameter portion 4,
A short tubular stopper ring 12 with a flange is fitted into this stepped portion 11 .

In other words, the stopper ring 12 has its flange 1
3 is in contact with the large inner diameter side end surface of the stepped portion 11, and the tip of the short tube portion 14 is in contact with the flange-like large diameter portion 2a of the piston 2 which is in sliding contact with the small inner diameter portion 10. A plurality of small holes 15 are arranged in an annular shape in the large diameter portion 2a, and a connecting rod 16 is screwed onto the tip of the piston 2.

[Effect of the invention] According to this invention, in order to provide the short tubular stopper ring 12 with a flange instead of the conventional annular stopper ring in the piston positioning part 3 of the master cylinder, the piston is not provided with a small diameter notch or an engaging part as in the past. There is no need to specially install a stopper flange, and the piston 2
It is possible to shorten the dimension L of the piston 2, thereby meeting the demand for shortening the master cylinder, and also improving the strength and processing problems of the piston 2.

[Brief explanation of the drawing]

1 and 2 are for explaining the piston positioning structure of a master cylinder for an automobile according to this invention. FIG. 1 is a vertical cut front view of the piston positioning structure, and FIG. FIG. 3 is a perspective view of a short tubular stopper ring with a flange. FIG. 3 is a vertically cut front view of a conventional master cylinder piston positioning structure, and FIG. 4 is a perspective view of an annular stopper ring provided in the same piston positioning structure. 1... Cylinder body, 2... Piston, 2a
...Flame-shaped large diameter part, 2b...Piston, 2c...Flame-shaped large diameter part, 3...Piston positioning part, 4...Large inner diameter part, 5...Snap spring, 6...Plate, 7...Block Ring, 8...Oil seal, 9...Packskin, 10...Small inner diameter part, 11...
... Stepped part, 12 ... Stopper ring, 13 ... Flange section, 14 ... Short pipe section, 15 ... Small hole, 16 ... Connecting rod, 17 ... Stopper ring, 18 ... Notch small diameter part, 19... Locking collar, L, L... Dimensions.

Claims (1)

[Scope of utility model registration request] At the piston positioning part at the open end of the cylinder body into which the piston is inserted, a snap spring is attached to the large inner diameter part formed in the cylinder body in order from the outer end.
In addition to arranging an oil seal or the like, the flange of a short tubular stopper ring with a flange is brought into contact with the end face of the step formed between the large inner diameter part and the small inner diameter part following it, and the short length of the stopper ring is A piston positioning structure for a master cylinder for an automobile, characterized in that the stopper ring is fitted so that the tip of the pipe portion comes into contact with the flange-like large diameter portion of the piston that is in sliding contact with the small inner diameter portion.