JPH0137330Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a master cylinder reservoir suitable for use in motorcycles, etc., and more specifically, an air communication hole is formed near the center of the air chamber between the diaphragm and the cap. To effectively prevent hydraulic fluid that has passed through a diaphragm from leaking out of a reservoir even if a motorcycle or the like leans due to banking during cornering by interposing a plate to divide the air chamber into two upper and lower chambers. The present invention relates to a master cylinder reservoir in which the periphery of the diaphragm can be reliably positioned and held by the plate.

The master cylinder reservoir has a thin diaphragm to allow smooth level changes in the hydraulic oil level in the reservoir. As a result, hydraulic oil passes through the thin diaphragm, passes through the breather device of the reservoir, and leaks to the outside, resulting in various negative effects such as oil stains, dirt due to adhesion of dust, clogging of the breather device, deterioration of paint on the reservoir, peeling, etc. Despite this, the bellows height of the diaphragm has been suppressed due to the need to keep the overall height of the reservoir low, and the hydraulic oil that has permeated through the diaphragm can be transferred to the outside through the breather device even if the vehicle is slightly tilted. leaks to.

Therefore, in order to prevent leakage of this hydraulic oil, the breather device was devised, and a screw cap with a long threaded groove was used to form an atmosphere communication hole (countermeasures such as those in Publication of Utility Model Publication No. 53-32220 were adopted). However, the present invention is a plate body for a diaphragm press frame that has conventionally been used only to maintain the position of the diaphragm (Utility Model Publication No. 48-303, Utility Model Publication No. 53-1983).
For master cylinders that allow smooth level changes of the diaphragm and prevent hydraulic oil leakage by controlling the hydraulic oil flow path until the hydraulic oil reaches the breather device. Provide a reservoir.

That is, the purpose of the present invention is to provide a master cylinder reservoir in which the reservoir body is sealed with a cap via a diaphragm that covers the liquid level of hydraulic oil.
The air chamber between the diaphragm and the cap is
In order to divide the reservoir into chambers, a plate is interposed between the cap and the diaphragm to hold the diaphragm periphery in contact with the mouth edge of the reservoir body, and a plate is inserted between the plate periphery and the cap periphery. A through hole is provided to communicate the air chamber between the two chambers with the atmosphere, and the plate is provided with an air communication hole near the center to communicate the two divided chambers, and the plate is bent to allow the air to flow through the air. One or more annular grooves are formed in the outer peripheral direction of the reservoir surrounding the communication hole, from the top surface of the plate toward the bottom of the reservoir, and an inverted L-shaped portion is formed by the outer wall of the annular groove and the lower surface of the peripheral edge of the plate; The present invention provides a reservoir for a master cylinder in which the peripheral edge of the diaphragm is held under pressure between the upper surface of the mouth edge of the reservoir body corresponding to the inverted L-shaped portion and the inner peripheral wall.

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

In FIG. 1, a resin reservoir body 14 for storing hydraulic oil 12 is fitted onto the upper surface of a master cylinder body 10 made of aluminum alloy, and the inside of the reservoir body 14 and the hydraulic piston in the master cylinder body 10 slide together. The cylinder chamber is communicated with the cylinder chamber in the conventional manner. The reservoir body 14 has a peripheral wall 1 whose planar shape is a rectangular shape with rounded corners.
6, and bolt insertion holes (not shown) are provided at the four corners of the peripheral wall 16. A flexible diaphragm 20 having bellows-shaped concave grooves 18, 18 arranged concentrically around the appropriate number of circumferences is provided on the reservoir body 14 to cover the hydraulic oil. 24
is a plate whose outer shape follows the outer shape of the mouth edge of the reservoir body 14, and is placed on the mouth edge of the reservoir body 14, covering the diaphragm 20. Annular grooves 22a and 22b are concentrically recessed therein, and an air communication hole 36 is provided in the central plane part. In this case, the inverted L-shaped portion formed by the outer wall of the outer concave groove portion 22b of the plate 24 and the lower peripheral surface of the plate 24 and the reservoir body 1
The diaphragm 20 is designed to be able to hold the peripheral edge raised portion 28 of the diaphragm 20 and the peripheral flat portion 30 that acts as a seal between the upper surface of the mouth edge of the diaphragm 20 and the inner peripheral wall. A metal cap 26 covers the plate 24 and is fixed to the reservoir body 10 via the diaphragm 20 and the plate 24 with four bolts (not shown). Therefore, there is an air chamber 3 between the diaphragm 20 and the plate 24.
2, an air chamber 34 is defined between the plate 24 and the cap 26, and both air chambers are communicated through the air communication hole 36 described above. A plurality of protrusions 38 are protruded from the upper surface of the plate 24 surrounding the air communication hole 36 to ensure the formation of the air chamber 34 between the cap 26 and the plate 24, 36 blockage is prevented. Reference numeral 40 designates bolt insertion holes provided at the four corners of the plate 24. Reference numeral 42 denotes a through hole as a breather device formed between the cap 26, the plate 24, and the diaphragm 20. By forming grooves on the inner wall surfaces of the left and right ends of the cap 26, a reservoir can be inserted. The air chamber 34 inside is communicated with the outside.

In the above configuration, the hydraulic oil 12 is connected to the diaphragm 2.
Even if the hydraulic oil passes through the air, it is stored in the air chamber 32 formed by the upper surface of the diaphragm 20 and the lower surface of the plate 24, and there is no risk of it being blocked by the plate and leaking to the outside, making it possible to avoid severe cornering. Even when the vehicle body is tilted due to banking, the air communication hole 36 is provided in the center of the reservoir, which prevents leakage of hydraulic oil during cornering in either the left or right direction. Furthermore, since the concave grooves 22a and 22b are provided on the top surface of the plate 24, even if there is hydraulic oil leaking onto the top surface of the plate 24, the concave grooves prevent it from directly flowing into the breather device. In addition, since a plurality of protrusions 38 are provided at the highest position on the top surface of the plate 24, abnormalities such as thermal deformation of the plate itself or expansion of air remaining between the top surface of the hydraulic oil and the bellows part on the bottom surface of the diaphragm 20 can cause the plate to be pushed up. Even at times,
It is possible to prevent the air communication hole 36 from being blocked by the cap and ensure communication between the air chambers 32 and 34.

Since the periphery of the diaphragm 20 is pinched between the inverted L-shaped portion on the periphery of the plate and the upper surface of the mouth edge and the inner circumferential wall of the reservoir body 14, the sealing performance is improved.
Furthermore, even when the hydraulic fluid is low, the periphery of the diaphragm is reliably held by the plate and will not come off.

FIG. 3 shows yet another embodiment.

In the figure, reference numeral 50 denotes a plate, which is formed into a flat plate shape, and has a protrusion on the lower surface along the inner circumferential wall of the rim of the reservoir body 14 so as to leave a slight gap between the inner circumferential wall of the rim of the reservoir body 14. A wall 52 is formed. Therefore, the circumferential edge of the diaphragm 20 is pressed between the inverted L-shaped portion formed by the outer circumferential wall of the projecting wall 52 and the lower surface of the plate circumferential edge, and the upper surface and inner circumferential wall of the mouth edge of the reservoir body 14 to prevent positional displacement. I'm starting to do that. A cap 26 is placed above the plate 50, and a bolt 54 connects the diaphragm 20 and the reservoir body 14 via the plate 50.
Fixed. The air chamber between the diaphragm 20 and the cap 26 is divided into two by this plate 50, and both chambers are communicated with each other through an air communication hole 36 provided in the center of the plate 50. 56 is plate 5
0 is a presser plate that hangs down in an approximately
Even if the diaphragm 20 is pushed up toward the lower surface of the plate 50 due to air expansion between the
6. By pressing with the lower surface, the diaphragm 20
This prevents the air communication hole 36 from being blocked. Further, the outer side of the presser plate 56 comes into contact with the inner wall of the central recess of the diaphragm 20 to prevent the diaphragm 20 from being deformed in the lateral direction.

58 is the air communication hole 3 on the upper surface of the plate 50.
It is a ring-shaped protruding peripheral portion surrounding the cap 6 , and its upper end surface is in contact with the lower surface of the cap 26 .

This projecting peripheral portion 58 functions as a partition wall to prevent the hydraulic oil that has permeated onto the diaphragm 50 from spreading further outward even if it leaks onto the plate 50 from the air communication hole 36. . It also has the effect of preventing dirt and the like from entering onto the diaphragm 20 from the outside. Note that a groove 60 is formed on the upper surface of the projecting peripheral wall 58 to ensure air circulation. Furthermore, the upper surface of the protruding peripheral portion 58 does not necessarily have to be in contact with the lower surface of the cap 26; even if there is a slight gap, it still functions as an oil reservoir, and if the plate 50 is pushed up by the diaphragm 20, This also prevents the air communication hole 36 from being blocked by the lower surface of the cap 26.

62 is a concave groove provided on the peripheral edge of the plate 50 so as to cross the bolt insertion hole 64 of the cap (see FIG. 4) and reach the end of the plate 50, as shown in FIG. By interposing the thread groove space of the bolt 54 between the upper chamber of the air chamber divided by the plate 50 and the outside of the reservoir body 10, intrusion of dirt and the like from outside the reservoir body 14 can be more effectively prevented. ing.

In this embodiment as well, since the air communication hole 36 is provided in the center of the plate 50, even when the two-wheeled vehicle is tilted due to a cornering bank, the hydraulic oil that has passed through the diaphragm 20 does not easily leak onto the plate 50. Therefore, leakage to the outside of the reservoir body 10 is further prevented.

In this embodiment as well, the plate 50 may be provided with an annular groove portion similar to that of the previous embodiment, although not shown.

As described above, the present invention provides the following remarkable effects.

Since the air communication hole is transparent near the center of the plate, even when the vehicle body is tilted due to banking during severe cornering, the hydraulic oil that has passed through the diaphragm is blocked by the plate and does not leak to the outside. Furthermore, even if the hydraulic oil should flow out to the upper surface of the plate through the air communication hole, it will be stored in the annular groove and will be prevented from flowing directly into the breather device.

Furthermore, since the annular groove is recessed from the plate surface toward the inside of the reservoir body, the overall height of the reservoir can be reduced.

Furthermore, the diaphragm periphery is held under pressure between the inverted L-shaped portion on the plate periphery created by forming the annular groove, and the upper surface of the mouth edge of the reservoir body and the inner peripheral wall, so that the diaphragm is reliably positioned and held. This also improves sealing performance.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway front view of a master cylinder, and FIG. 2 is a plan view of a plate. 3 to 5 show other embodiments, in which FIG. 3 is an overall sectional view, FIG. 4 is a bottom view of the plate, and FIG. 5 is an enlarged sectional view showing the breather device portion thereof. 10... Master cylinder body, 12... Hydraulic oil, 14... Reservoir body, 16... Surrounding wall, 18
...Concave groove, 20...Diaphragm, 22a, 2
2b... Concave groove portion, 24... Plate, 26... Cap, 28... Peripheral standing portion, 30... Peripheral flat portion, 32, 34... Air chamber, 36... Air communication hole, 38... Protrusion , 40... Bolt insertion hole,
42... Through hole, 50... Plate, 52... Projecting wall, 54... Bolt, 56... Holding plate, 58...
Projected peripheral portion, 60, 62...concave groove, 64...bolt insertion hole.

Claims (1)

[Claim for Utility Model Registration] In a master cylinder reservoir where the reservoir body is sealed with a cap via a diaphragm that covers the liquid level of hydraulic oil, the air chamber between the diaphragm and the cap is divided into two upper and lower chambers. A plate is interposed between the cap and the diaphragm to press and hold the diaphragm periphery with the mouth edge of the reservoir body, and an air chamber between the plate and the cap is provided between the plate periphery and the cap periphery. An air communication hole is provided in the plate near the center to communicate the two divided chambers, and the plate is bent to surround the air communication hole. One or more annular grooves are formed in the outer peripheral direction of the reservoir from the top surface of the plate toward the bottom of the reservoir, and an inverted L-shaped portion formed by the outer wall of the annular groove and the lower surface of the plate periphery; A reservoir for a master cylinder, the diaphragm periphery being press-fitted and held between the upper surface of the reservoir body mouth rim corresponding to the portion and the inner peripheral wall.