JPS5839553A - Master cylinder - Google Patents

Abstract

PURPOSE:To enable the one-touch fitting of a plate for preventing the working oil of a master cylinder from gushing upwards, by making the plate of an elastic material and elastically deforming the plate as inverted U to fit the plate. CONSTITUTION:An anti-gushing-upwards plate 20 is made of an elastic metal sheet of small thickness. The length l of side edge of the plate 20 is made larger than the distance (m) between the opposed inner walls of a reservoir 7. The plate 20 is provided with an anti-gushing-upwards part 21 by cutting and bending it. The part 21 extends horizontally over an opening 23. Both the ends of the plate 20 are provided with rising parts 24 and notches 25. The plate 20 is elastically deformed as inverted U and put in elastic pressure contact with the inner walls of the reservoir 7 so that the plate cannot move.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mask cylinder, and in particular to a blow-up prevention plate for blocking hydraulic oil from being squirted from a boat that communicates a reservoir constituting the mask cylinder with a pressure chamber of a master cylinder. .

Conventionally, the mask cylinder of a hydraulic brake is provided with a master cylinder main body 1 and a master cylinder main body 1, as shown in FIGS.
(not shown), a spring 4 that constantly presses the piston 3 housed in the master cylinder body 1 in the non-actuating force direction, a piston cup 5, a dust boot 6, and the mask cylinder. A reservoir 7 fixed to the upper side of the main body 1 and having an open upper end;
It is composed of a diaphragm 8 which is provided to close the opening of the reservoir T and has elasticity, and a lid body 9 which closes the upper end side of the reservoir T. The lid 9 is fixed with screws 10. Further, the bottom side of the reservoir 7 is provided with a supply port 11 and a relief boat 12 for communicating the reservoir 7 and the mass cylinder body 1.

In such a configuration, pressure is applied to the piston 3 to increase the pressure of the hydraulic oil led from the relief boat 12 to the pressure chamber side of the master cylinder body 1, and by sending the hydraulic oil to the foil cylinder from the discharge port 2. It is possible to perform braking by operating the brake device.

However, in the conventional mask cylinder, when the piston 3 operates and pressure is applied to the hydraulic oil in the pressure chamber, a part of this hydraulic oil flows back from the relief boat 12 and supply boat 11 to the reservoir 7 side. The hydraulic oil is blown upward, and the blown-up hydraulic oil is blown out from the surface of the hydraulic oil and mixed with air, resulting in the generation of air bubbles in the hydraulic oil. When these bubbles are generated, a problem may occur in that the bubbles reach the pressure chamber of the mask cylinder body and even if the piston 3 is pushed, the bubbles are simply crushed.

A partition plate 13 is provided in the mask cylinder glue reservoir 7 to separate the upper and lower parts, and a hole 14 is provided in the partition plate 13.
, 12 side is blocked, and the above-mentioned blown-up hydraulic oil is prevented from mixing with the air of the lyrics, thereby preventing the generation of air bubbles. Note that the partition plate 13 is provided with holes 14 through which hydraulic oil flows.

Conventionally, when attaching the partition plate 13 to the inner wall side of the reservoir 7, a groove is provided in the inner wall of the reservoir 7, and the partition plate 1 is attached to the groove.
3, or dividing the reservoir 7 into upper and lower parts and sandwiching the outer periphery of the partition plate 13 between the divided parts.
It is not easy to manufacture because it requires machining, and it also has the disadvantage that it easily separates from the inner wall of the reservoir due to vibrations of the vehicle.

Purpose of the Invention A spray-up prevention plate for blocking hydraulic oil sprayed from the boat side that communicates the H'J reservoir and the pressure chamber of the mask cylinder is bent into an approximately inverted U shape, and in this state, the reservoir 7 The end of the blocking plate is placed in pressure contact with the inner wall of the reservoir 7, and the blocking plate is fixed by the elastic force of the blocking plate, which will be explained in detail below using an actual example.

3 to 5 are a sectional view, a perspective view, and a plan view showing an example of a mask cylinder according to the present invention, and the same parts as in FIGS. 1 and 2 are designated by the same reference numerals. In each figure, 20 is a blowout prevention plate that is a feature of the present application, and is made of an elastic thin metal plate and has a long side shape, with a length l on the -side side of the reservoir. The blocking piece 21 is set longer than the distance m between the mutually opposing inner walls of No.
A blocking piece 211ri is formed and protrudes almost horizontally so as to face the upper side of the window 23, and a rising piece 24 is formed on both sides of the blocking plate 20, which is bent upward and inclined. , this plate 200 in history
A notch 25 is formed at the center of both sides.

To attach such a blow-up prevention plate 20 to the reservoir 7, pinch the notch 25.25 of the plate 20 with your fingers and bend it into an approximately inverted U shape, and in this state, insert the rising piece 24. The tips a of 24 are brought into pressure contact with the mutually opposing inner walls of the reservoir T. In this case, the bent portion of the rising piece 24 is brought into contact with the bottom surface of the reservoir 7,
There is two-point contact between parts a and b. Therefore, the plate 20 is fixed to the reservoir 7 while being deformed into an approximately inverted U-shape as shown in FIG. 3 due to the pressing force of the portions a and b. Therefore, both ends of the blow-up prevention plate are firmly pressed against the inner wall side of the reservoir 7 due to the repulsive force caused by the deflection, and the problem of the plate being easily separated from the reservoir 7 due to vibration or the like can be solved. Further, when hydraulic oil is sprayed up from the boat 11゜12ilIII, this hydraulic oil can be blocked by the blocking piece 21, so that generation of bubbles due to agitation can be prevented.

Furthermore, even if air bubbles are generated in the hydraulic oil located below the blowout prevention plate, the air bubbles will be guided toward the window 237i along the inclination of the plate 20 because the plate 20 is shaped like an inverted U. and is emitted from the window 23.

Similarly, in the present invention, the blow-up prevention plate is
．． Although the area of the reservoir T is set to a minimum so as to cover at least 12, the present invention is not limited to this, and the area of the reservoir T may be set to cover almost the entire bottom part. In addition, the blow-up prevention plate 20
Instead of being attached so as to be in contact with the bottom side of the reservoir 7, it may be attached somewhere in the middle on the inner wall side thereof. Further, uneven portions extending in multiple directions may be provided on the end side of the blow-up prevention plate, thereby increasing the frictional force between the plate and the inner wall side of the reservoir γ. -! Cut out piece 2
1 may be tilted so that the hydraulic oil spouted from the port is diffused, thereby suppressing agitation.

As explained above, according to the mask cylinder of the present invention, in the blow-up prevention plate that faces the upper side of the port that communicates the reservoir and the pressure chamber of the mask cylinder and that blocks the hydraulic oil jetted from the port, It is made of an elastic plate and is bent so as to form an inverted U-shape, and its end side is fixed in pressure contact with the opposing inner 1111 surface of the reservoir, so that the blowout prevention plate is not bent. Based on this, the end side of the plate can be kept in constant pressure contact with the inner wall side of the reservoir. This may cause the reservoir to fall sharply due to vehicle vibrations, and
It can be installed with one touch, and there is no need to perform any processing to attach the blow-up prevention plate to the reservoir, thereby reducing costs.

[Brief explanation of the drawing]

1 and 12 are cross-sectional views showing an example of a conventional mask cylinder, and FIGS. 3 to 5 are a cross-sectional view, a perspective view, and a plan view showing an embodiment of a mask cylinder according to the present invention. 1...Mask cylinder body, 7...Reservoir, 11
．． 12...Port, 20...Blowout prevention plate,
21...Cut and raised piece, 23...Window, 24...Rise piece, 25...Notch. Patent Applicant Nissin Kogyo Co., Ltd. Agent Patent Attorney Jun Miyazono −

Claims (2)

[Claims] (1) In a master cylinder that includes a blow-up prevention plate that covers the upper side of the port that communicates the reservoir and the pressure chamber of the mask cylinder, the blow-up prevention plate is formed from an elastic plate material and has an approximately inverted U shape. 1. A master cylinder, which is fixed in a bent state by pressing both ends of the cylinder against opposing inner walls of a reservoir. (2) The blowout prevention plate has a window in the portion facing the boat, and a blocking piece facing the upper side of the window to block the hydraulic oil spouted from the port. Master cylinder for range 1 JJi2e.