JPS6313173Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cap with intake and exhaust valves used in a reservoir tank that stores brake fluid to be supplied to a master cylinder.

Conventionally, the reservoir tank cap installed in the master cylinder incorporates an intake and exhaust valve in order to always maintain the tank internal pressure at approximately the counter pressure level against changes in the liquid level in the reservoir due to pad wear, reservoir tank temperature changes, etc. An example of this type of cap known as a so-called semi-moisture sealed cap is shown in Japanese Utility Model Application No. 57-41566.

However, in conventional caps with intake and exhaust valves, the valve part is formed by forming a lip in the radial direction of the elastic valve body, so the followability of the valve, which operates based on the difference between the tank internal pressure and atmospheric pressure, is limited. In order to increase the lip area, it is necessary to increase the diameter of the elastic valve body, and there is a limit to the number of elastic valve bodies that can be installed in the cap, resulting in poor followability. There was a problem.

Further, since the lip is formed in the radial direction, the elastic valve body has an asymmetrical shape, which complicates the shape and increases the manufacturing cost.

The present invention was developed in view of these conventional problems, and is a suction system that simplifies the elastic valve body and increases response by increasing the differential pressure acting area that contributes to valve operation. The purpose is to provide a cap with an exhaust valve.

To achieve this purpose, the present invention has an inner lid and an outer lid that are fitted into the opening of the reservoir tank, and a valve seat is formed on the inner peripheral surface of a cylindrical partition wall formed on the upper surface of the inner lid. A communication hole is provided to communicate the inside of the cylinder with the tank, and an elastic valve body with a hole in the center and a disk-shaped bellows portion on the outer periphery is attached to the cylinder, and this elastic valve body is attached to the inside of the outer lid. By pressing and fixing with the cylindrical ridge formed in the center, the outer circumference of the bellows part of the elastic valve body is pressed against the valve seat formed by the inner wall of the cylindrical partition of the inner cover, and the inner circumference of the bellows part is pressed against the cylindrical shape of the outer cover. Pressure contact at the tip of the ridge causes deformation of the outer periphery of the bellows part of the elastic valve body due to tank positive pressure.
Alternatively, the inside of the tank is made conductive to the atmosphere by deforming the inner periphery of the bellows part due to tank negative pressure.

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing the upper part of a reservoir tank according to an embodiment of the present invention. First, to explain the structure, numeral 1 is a reservoir tank in which brake fluid is stored, and an inner lid 2 and an outer lid 3, which constitute the cap with a suction valve of the present invention, are fitted into the upper opening of the reservoir tank 1. Ru. The inner lid 2 has a seal 4 on the outer periphery.
At the same time, a flange 5 is formed on the outside of the upper edge to fit onto the outer lid 3, and a flange 5 is formed at the lower center of the inner lid 2 to suppress the ripples of the brake fluid in the reservoir tank 1. A baffle plate 6 is integrally provided between the inner cover 2 and the outer cover 3 to prevent brake fluid from entering the valve storage portion.

On the other hand, the outer lid 3 has a threaded portion 7 formed on the inside of its outer periphery, and is screwed into the opening of the reservoir tank 1 to fix the inner lid 2 to the tank opening in a sealed state.

Next, a valve structure provided in the gap between the inner lid 2 and the outer lid 3 will be explained.

First, a cylindrical partition wall 8 is integrally formed on the upper surface at the center of the inner lid 2, and a tank communication hole 9 is provided at the bottom of the cylindrical partition wall 8. It is located at the back to prevent direct contact with brake fluid. Further, the cylindrical partition wall 8 is provided with a notch 10 as shown on the right side, and the inside of the cylindrical partition wall 8 is communicated with the outside via this notch 10. On the other hand, a cylindrical protuberance 11 is integrally provided on the inner side at the center of the outer cover 3, and this cylindrical protuberance 11 is a support that presses and fixes an elastic valve body 12 incorporated in the cylindrical partition wall 8. It has a function as a member. The elastic valve body 12 incorporated inside the cylindrical partition wall 8 is
It is made of elastic material such as rubber, and has a hole 13 in the center.
In addition, a disc-shaped inner bellows part 14 is formed on the outside of the hole 13, and a disc-shaped outer bellows part 15 is also formed on the outer periphery following the inner bellows part 14, and the inner bellows part 14 and It has a structure in which a base 16 for supporting the elastic valve body 12 is formed on the lower side between it and the outer bellows part 15. Further, the base 16 of the elastic valve body 12 is provided with a notch 17 as shown on the left side. As shown in the figure, this elastic valve body 12 presses the outer periphery of the outer bellows portion 15 against the inner circumferential surface 8a of the cylindrical partition wall 8 when it is assembled into the cylindrical partition wall 8 of the inner lid 2. Inner peripheral surface 8a of cylindrical partition wall 8
comes to form the valve seat of the outer bellows portion 15. In addition, the inner bellows portion 14 of the elastic valve body 12
is pressed by the tip of the cylindrical protuberance 11 formed on the outer lid 3, and the cylindrical protuberance 11 is pressed against the inner bellows part 14.
The tip of the valve forms the valve seat.

FIG. 2 is a cross-sectional view of FIG. We are trying to regulate. Further, the elastic valve body 12 has a disk-like planar shape, and each of the inner bellows part 14 and the outer bellows part 15 has a seating surface for the valve seat in the circumferential direction.

In addition, in order to conduct the inside of the cap to the atmosphere, the inner lid 2
An atmospheric air conduction path 19 is provided in the form of a notch on the left side of the upper edge.

Next, the operation of the embodiment of the present invention shown in FIGS. 1 and 2 will be explained.

First, when the difference between the internal pressure of the reservoir tank 1 and the atmospheric pressure is small, as shown in FIG. The inner bellows portion 14 is also pressed against the tip of the cylindrical protuberance 11 of the outer lid 3, cutting off the communication between the inside of the tank and the atmosphere, and preventing the inside of the tank from being connected to the atmosphere. Prevents moisture and dust from entering.

Next, if the internal pressure of the reservoir tank 1 rises due to an increase in the temperature of the brake fluid, etc., and becomes a positive pressure state higher than atmospheric pressure, this tank positive pressure is transferred to the lower side of the elastic valve body 12 through the tank communication hole 9. As shown in FIG. 3, a force pushing up the outer bellows part 15 is generated due to the pressure difference between the outer bellows part 15 and the atmospheric pressure, and the deformation of the outer bellows part 15 causes the tank communication hole 9, the outer bellows part 15, the notch 10, Further, the inside of the tank is communicated with the atmosphere through the atmosphere conduction path 19, and the positive pressure inside the reservoir tank 1 is exhausted. Of course, if the upward deformation force due to the differential pressure acting on the outer bellows part 15 due to exhaust due to such tank internal pressure decreases below the pushing force that reaches the inner circumferential surface 8a of the outer bellows part 15, the inner circumference of the outer bellows part 15 By pressing against the surface 8a, the inside of the tank is again sealed off from the atmosphere.

Next, if the liquid level in the reservoir tank 1 decreases due to wear of the pads of the desk brake, etc., the internal pressure of the reservoir tank 1 decreases below a certain value and becomes a negative pressure state.

This negative pressure in the reservoir tank 1 acts on the lower side of the elastic valve body 12 through the tank communication hole 9, and as shown in FIG. It deforms downward, and the atmosphere flows into the reservoir tank 1 through the notch 10, the inner bellows part 14, and the tank communication hole 9. Of course, when the force due to the differential pressure acting on the inner bellows part 14 decreases below the pressing force due to the elastic deformation of the elastic valve body 12, the inner bellows part 14 returns to its original position and shuts off the inside of the tank from the atmosphere. become.

As is clear from this intake/exhaust operation, in the present invention, the elastic valve body 1 is operated by positive or negative pressure in the tank.
The differential pressure acting area of 2 becomes the differential pressure acting area in the inner circumferential direction of the inner bellows part 14 and the outer bellows part 15, which are formed in a disc shape, and by obtaining a sufficient differential pressure acting area, it is possible to prevent changes in tank internal pressure. It is possible to perform intake and exhaust operations with high responsiveness. In addition, since the elastic valve body 12 has a disk shape, the shape can be simplified, and even if the elastic valve body 12 is made smaller, the differential pressure acting area in the circumferential direction made up of the inner and outer bellows parts can be realized. Because of this, high responsiveness of intake and exhaust operations to changes in tank internal pressure can be achieved. Furthermore, even if there is a dimensional error between the inner lid 2 and the outer lid 3, the dimensional error within a range that does not cause the tip of the cylindrical protuberance 11 of the outer lid 3 to come off from the inner bellows portion 14 of the elastic valve body 12 will be handled by the tank. The intake and exhaust operations due to internal pressure are not impaired in any way, and the allowable range of dimensional accuracy in manufacturing and assembling the cap can be widened. Furthermore, the inner bellows part 14 and the outer bellows part 15 of the elastic valve body 12 are pressed against the valve seat with only the deformation force due to elastic deformation due to the incorporation into the cap, so that the elastic valve body 12 is not inserted into the cap. Since no force for supporting and fixing is applied to each bellows portion, sufficiently high responsiveness of intake and exhaust operations to changes in tank internal pressure is realized.

Next, to explain the effects of the present invention, since a disc-shaped elastic valve body is used, the manufacturing cost is reduced by simplifying the shape, and the disc-shaped bellows part provides a seal in the circumferential direction. Since the intake and exhaust operations are performed in response to changes in tank internal pressure, it is possible to obtain sufficiently high responsiveness even if the elastic valve body is made smaller.Furthermore, by obtaining a seal area in the circumferential direction, it is possible to perform intake and exhaust operations in response to changes in tank internal pressure. The responsiveness of intake and exhaust operations can be sufficiently improved by increasing the differential pressure acting area.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a - cross-sectional view of Fig. 1, Fig. 3 is a cross-sectional explanatory view showing the exhaust operation in a tank positive pressure state, and Fig. 4 is a cross-sectional view showing an embodiment of the present invention. FIG. 2 is a cross-sectional explanatory diagram showing an intake operation in a tank negative pressure state. 1: Reservoir tank, 2: Inner lid, 3: Outer lid,
4: Seal, 5: Flange, 6: Full plate,
7: Threaded portion, 8: Cylindrical bulkhead, 9: Tank communication hole, 10, 17: Notch, 11: Cylindrical protuberance, 1
2: Elastic valve body, 13: Hole, 14: Inner bellows part, 15: Outer bellows part, 16: Base, 18: Support wall, 19: Atmospheric conduction path.

Claims (1)

[Scope of utility model registration request] It has an inner lid and an outer lid that are fitted into the opening of the reservoir tank, and a valve seat is formed on the inner peripheral surface of a cylindrical partition wall formed on the upper surface of the inner lid, and a communication line that communicates the inside of the cylinder with the tank. A cylindrical shape having a hole, a disk-shaped elastic valve body having a hole in the center and a disk-shaped bellows portion on the outside installed in the cylinder, and the elastic valve body being formed at the center of the inside of the outer lid. By pressing and fixing with the ridges, the outer periphery of the bellows part of the elastic valve body is pressed against the valve seat formed by the inner wall of the cylindrical partition wall, and the inner periphery of the bellows part is pressed against the tip of the cylindrical ridge of the outer cover. A cap with an intake and exhaust valve, characterized in that the inside of the tank is communicated with the atmosphere by deformation of the outer circumference of the bellows portion of the elastic valve body due to positive tank pressure or deformation of the inner circumference of the bellows portion due to negative tank pressure.