JPS637560Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a master cylinder used in a brake device or a clutch device of an automobile, in which the cylinder body and the mounting flange are constructed as separate members.

In this type of conventional master cylinder,
The mounting flange is attached to the cylinder body by screwing or press-fitting the mounting flange onto the cylinder body.

In such conventional master cylinders, when the mounting flange is screwed onto the cylinder body, not only does it require threading on the cylinder body and the mounting flange, but since both are threaded together, the mounting flange is attached to the cylinder body. There are problems in that the mounting direction is not constant and the cylinder body rotates relative to the mounting flange due to loosening of screws during use. There is a problem in that the cylinder body may fall off the mounting flange due to axial pushing force. Furthermore, when installing the master cylinder to a mating device such as a vacuum booster, if the positioning is performed only by the flange, the piston of the master cylinder will not be concentric with the push rod of the vacuum booster, etc., and the piston may be twisted during operation. Alternatively, there is a problem of seal failure due to uneven wear.

The present invention was made in view of the above-mentioned problems, and the purpose is to provide a master cylinder that has a simple structure and can securely attach a mounting flange to a cylinder body, and in order to achieve this purpose, The mounting flange is fitted from the open end side of the cylinder hole, and the front surface thereof is brought into contact with a step formed on the outer peripheral surface of the cylinder body near the opening, and the mounting flange is fitted into the part exhibiting a non-circular cross-sectional shape. , a fixing member for fixing the mounting flange,
The fixing member is brought into contact with the rear surface of the mounting flange and fitted into a groove provided on the outer peripheral surface, and the outer periphery of the fixing member is used as a fitting portion for concentric positioning with the mating member.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, in which the present invention is applied to a tandem master cylinder, the tandem master cylinder, indicated as a whole by 1, has a cylinder body 3 in which a cylinder hole 2 is bored. A second piston 5 is slidably inserted, and a first hydraulic pressure generating chamber 6 and a second hydraulic pressure generating chamber 7 are respectively defined in front of both pistons. The first hydraulic pressure generating chamber 6 is connected to each wheel brake cylinder via a discharge port 8, and the second hydraulic pressure generating chamber 7 is connected via a discharge port 9. A step 12 is formed on the outer circumferential surface 11 of the cylinder body 3 near the opening 10 of the cylinder hole 2, and the front surface 14 of the mounting flange 13 fitted into the outer circumferential surface 11 of the cylinder body 3 is formed in the step 12. is in contact with. A groove 15 provided on the outer circumferential surface 11 of the cylinder body 3
The fixing member 16 fitted into the cylinder body prevents the mounting flange 13 from coming off from the cylinder body 3 by having its front surface 17 abut against the rear surface 18 of the mounting flange 13 . Outer periphery 19 of fixing member 16
The outer diameter of the master cylinder 1 is determined so as to form a fitting part that fits with a mounting part of the master cylinder 1, for example, a vacuum booster, and as will be described later, this produces an effect of concentric positioning of both parts. 20 is a projection partially provided on the hole 30 side of the mounting flange 13.

In FIG. 2, which is a side view of FIG. 1, the fixing member 16 is fitted into the groove 15 of the cylinder body 3 through a notch 21 provided below, and the protrusion 20 provided on the mounting flange 3 is inserted into the groove 15 of the cylinder body 3. , the fixing member 16 cooperates with both end surfaces of the notch 21 to fix the cylinder body 3.
It restricts rotation relative to the 22 is a mounting hole for the master cylinder 1.

As clearly shown in FIG. 3, which shows the cross section taken along the line 1 in FIG. Because of this, the mounting flange 13 is held at the illustrated position without rotating relative to the cylinder body 3. In this case, by changing the position of the recess 24, the orientation of the mounting flange 13, that is, the relative position of the mounting hole 22 with respect to the cylinder body 3 can be easily changed, so the mounting flange 13 can be changed to another one. The mounting positional relationship between the master cylinder 1 and the mounting partner can be easily selected by simply selecting the mounting position.

The above-described recess 24 and protrusion 25 function to fit the mounting flange 13 and the cylinder body 3 into each other with a non-circular cross-sectional shape.

Next, the method for attaching the mounting flange 13 to the cylinder body 3 will be described. First, the mounting flange 13 is inserted into the outer peripheral surface 11 of the cylinder body 3, and the concave portion 24 of the mounting flange 13 is fitted into the convex portion 25 of the cylinder body 3. Then, the front surface 14 of the mounting flange 13 is brought into contact with the stepped portion 12 on the outer peripheral surface of the cylinder body 3. Next, the fixing member 16 is inserted into the groove 15 so that its front surface 17 abuts the rear surface 18 of the mounting flange 13.
fit inside. In this case, the protrusion 20 provided on the mounting flange 13 connects to the notch 21 provided on the fixing member 16.
be located within. When attaching the master cylinder 1 with the mounting flange 13 attached to the cylinder body 3 in this way to a mating part of this master cylinder, for example, a vacuum booster, the outer periphery 19 of the fixing member 16 is connected to the fitting part of the vacuum booster. After that, it may be fixed to the main body of the vacuum booster through the mounting hole 22 formed in the mounting flange 13 using bolts or the like. After the master cylinder 1 is fixed to the vacuum booster, the fixing member 16 is inserted into the fitting part of the vacuum booster, so the fixing member 16 does not fall off from the cylinder body 3.

Regarding the operation of the master cylinder 1, when the first piston 4 moves forward by a push rod (not shown), hydraulic pressure is generated in the first hydraulic pressure generating chamber 6.
This hydraulic pressure causes the second piston 5 to move forward, and a hydraulic pressure approximately equal to the hydraulic pressure within the first hydraulic pressure generating chamber 6 is generated in the second hydraulic pressure generating chamber 7 as well. The hydraulic pressures in the two hydraulic pressure generating chambers 6 and 7 are transmitted to the respective wheel brake cylinders through the discharge ports 8 and 9, respectively, and the brake devices act.

As explained in detail above, the present invention has a non-circular cross-sectional shape by fitting the mounting flange from the open end side of the cylinder hole and bringing the front surface into contact with the step formed on the outer peripheral surface of the cylinder body near the opening. At the same time, a fixing member for fixing the mounting flange is brought into contact with the rear surface of the mounting flange and fitted into a groove provided on the outer circumferential surface, and the outer circumference of the fixing member is connected to the mounting counterpart. The fitting part allows concentric positioning of the mounting flange, so the mounting flange can be reliably prevented from rotating.Also, by changing the inner hole shape of the mounting flange, the mounting direction of the mounting flange can be easily changed, and the structure is simple. This has the effect that the mounting flange can be reliably attached to the cylinder body, and the master cylinder can be attached to the mating part without separately providing a fitting part on the cylinder body or the mounting flange. This has the effect that positioning can be performed concentrically with the

[Brief explanation of the drawing]

1 is a sectional view of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a sectional view taken along the line - in FIG. 1. DESCRIPTION OF SYMBOLS 1... Tandem master cylinder, 3... Cylinder body, 10... Opening, 11... Outer peripheral surface, 12
...Stepped portion, 13...Mounting flange, 15...Groove,
16...Fixing member, 19...Outer periphery, 20...Protrusion, 21...Notch, 22...Mounting hole, 24...
Concave portion, 25...Convex portion.

Claims (1)

[Scope of utility model registration request] In a master cylinder in which a cylinder body having a cylinder hole that is open at one end and a mounting flange provided on the outer periphery of the cylinder body are constructed as separate members, the mounting flange is fitted from the open end side of the cylinder hole. The front surface of the cylinder body is brought into contact with a step formed on the outer peripheral surface near the opening of the cylinder body, and the fixing member that fixes the mounting flange is fitted onto a portion having a non-circular cross-sectional shape, and the fixing member that fixes the mounting flange is attached to the rear surface of the mounting flange. The master cylinder is fitted into a groove provided on the outer circumferential surface while being brought into contact with the fixing member, and the outer circumference of the fixing member is used as a fitting part for concentric positioning with a mating member.