JPS5839250Y2 - master cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a part of a master cylinder fluid reservoir particularly suitable for motorcycles.

In a master cylinder for a motorcycle, a cap is fixed to a resin reservoir separate from the cylinder body with screws or the like.

Conventionally, as this type of master cylinder, the cylinder body and the reservoir, and the reservoir and the cap are each fixed by separate fixing means such as screws, and the cylinder body, the reservoir, and the cap are fixed by a single screw etc. Something has been proposed.

In the former case, the reservoir has a bottom and the bottom is tightened to the cylinder body with screws, etc., so there is no possibility of damage such as chips generated during screw hole machining or debris scraped by washers etc. during tightening. There is a risk that it will get mixed with the oil inside and damage the piston seal of the master cylinder, and the cost will be high because a screw hole is cut in the cylinder body.

The latter also requires a screw hole to be cut in the cylinder body, resulting in high costs.

Furthermore, in order to prevent the reservoir from coming off from the cylinder body when the cap is removed, it is necessary to provide retaining portions to prevent removal and rotation on the reservoir and the cylinder body, which increases the cost.

The purpose of this invention is to eliminate the mixing of chips, etc. into the oil, and to reduce costs by eliminating the need for screw holes in the cylinder body and retaining parts for preventing rotation between the reservoir and the cylinder body. Our goal is to provide a master cylinder that can

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

1 and 2 show an embodiment of the present invention.

A cylinder body 1 made of metal has a cylinder hole 2, and a piston 3 is slidably disposed in the cylinder hole 2.

During braking, the piston 3 is driven forward by the operation of the brake lever 4, increasing the hydraulic pressure in the hydraulic chamber 5.

This oil pressure is applied to the wheel cylinder (not shown) from the discharge port 6.
sent to.

When the brake is released, the push of the piston 3 by the brake lever 4 is released, and the piston 3 is returned to the return position by the return spring 7.

A piston seal 8 is attached to the tip of the piston 3, and an oil passage hole 9 and an annular groove 10 are provided behind the piston seal 8.

The upper part of the cylinder body 1 includes a hydraulic chamber 5 and an annular groove io.
A reservoir 13 communicating with the return boat 11 and the compensating port 12 is fixed.

That is, the fitting part 16 formed at the lower part of the reservoir 13 is inserted into the circular groove 15 provided in the reservoir receiving part 14 of the cylinder main body 1, and the fitting part 16 formed on the side wall of the groove 15 is inserted into the circular groove 15 provided in the reservoir receiving part 14 of the cylinder body 1. When the engagement recess 18 of the fitting part 16 is engaged, the removal is prevented.

The reservoir 13 is made of, for example, transparent or translucent synthetic resin.

An oil seal 19 is attached to the side wall of the groove 15 to seal between the reservoir receiving part 14 and the fitting part 16.

A bolt 21 is attached to the side wall of the reservoir 13 and the cap 20.
Bolt insertion holes 22 and 23 into which the bolts are inserted are respectively provided.

A nut upper fitting recess 25 that communicates with the bolt insertion hole 22 and into which the upper part of the nut 24 fits is provided at the bottom of the side wall of the reservoir 13, and is provided between the bolt insertion hole 22 and the nut upper fitting recess 25. A stepped portion 26 for locking the nut 24 is formed.

A nut lower fitting recess 27 into which the lower part of the nut 24 fits is provided in the upper part of the reservoir receiving part 14.

The nut 24 is fitted into the nut upper fitting recess 25 and the nut lower fitting recess 27, the bolt 21 is inserted into the bolt insertion holes 22 and 23, and the bolt 21 is screwed into the nut 24 and tightened. A cap 20 is secured to the reservoir 13.

28 is a diaphragm. Since the cylinder main body 1 is not provided with a screw hole for fixing the reservoir or the cap, chips and the like are not generated, and it is possible to prevent chips and the like from getting mixed into the oil in the reservoir.

Moreover, by using a standard nut for the nut 24, costs can be reduced.

Furthermore, since the nut 24 serves to prevent rotation between the cylinder main body 1 and the reservoir 13, there is no need to provide an engaging portion for preventing rotation, and costs can be further reduced.

In the present invention, since the reservoir and the cap are fixed with bolts and nuts, there is no need to provide a screw hole in the cylinder body for fixing the reservoir or the cap, so that it is possible to prevent chips and the like from getting mixed into the oil.

Moreover, since the nut is fitted into the nut upper fitting groove provided at the bottom of the side wall of the reservoir and the nut lower fitting recess provided in the cylinder body, the reservoir is prevented from rotating. Costs can be reduced by eliminating the need for a screw hole and an engaging portion for preventing rotation between the reservoir and the cylinder body.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a sectional view thereof. 1...Cylinder body, 2...Cylinder hole, 3...Piston, 13...Reservoir, 16...Fitting part , 17...
Engagement protrusion, 18...Engagement recess, 20...
- Cap, 21... Bolt, 22, 23...
...Bolt insertion hole, 24...Nut, 25
. . . Upper nut fitting recess, 26 . . . Step portion, 27 . . . Lower nut fitting recess.

Claims (1)

[Scope of utility model registration request] The fitting part formed at the bottom of the reservoir is inserted onto the cylinder body having a cylinder hole in which the piston is slidably disposed, and the cutout provided in both the cylinder body and the fitting part is inserted. The locking engaging part is engaged, bolt insertion holes into which the bolts are inserted are provided in the side wall of the reservoir and the cap, respectively, and the bottom of the side wall of the reservoir communicates with the bolt insertion holes, and the upper part of the nut is fitted. A nut upper fitting recess is provided, a stepped portion for locking the nut is formed between the bolt insertion hole of the reservoir and the nut upper fitting recess, and a nut lower fitting is provided in which the lower part of the nut fits into the cylinder body. A master cylinder that has a mating recess, fits a nut into the nut upper fitting recess and the nut lower fitting recess, inserts the bolt into the bolt insertion hole of the reservoir and cap, and screws into the nut.