JPH038522Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention relates to an improvement of a valve device for a two-stage master cylinder used in automobiles and the like.

(Background of the invention) This type of valve device is known, for example, from Japanese Patent Application Laid-Open No. 57-194149.
Publication No., JP-A-58-202145, JP-A-58-202145
Publication No. 49426, Special Publication No. 59-2666 and Special Publication No.
This is already known from Publication No. 59-9384.

The valve devices according to each of the above-mentioned publications are provided between the reservoir and the low hydraulic pressure chamber and the high hydraulic pressure chamber, and prevent the flow of liquid from the low hydraulic pressure chamber to the reservoir in the low hydraulic pressure region at the beginning of brake operation. When the brake operation reaches the high hydraulic pressure region, the hydraulic pressure in the low hydraulic pressure chamber is transferred to the reservoir by a regulating valve that opens at a predetermined hydraulic pressure. It is intended to be open to the public.

Through the operation of the above-mentioned valve device, in the two-stage master cylinder, in the low hydraulic pressure region, the volume having the pressure receiving area of the sum of both hydraulic pressure chambers is changed by compressing the low hydraulic pressure chamber and the high hydraulic pressure chamber, When the amount of fluid supplied to the wheel brake is increased to save the amount of brake pedal depression, and the brake operation moves to a high fluid pressure region, the pressure increases only in the high fluid pressure chamber with a small pressure receiving area, which reduces the brake pedal depression force. A two-stage operation is performed to increase the degree of increase in output hydraulic pressure in response to an increase in .

In this type of valve device according to the prior art, when the brake is released, both the high and low hydraulic pressure chambers are communicated with the reservoir, and the minimum pressure is required to maintain the same pressure with the reservoir regardless of the expansion or contraction of the fluid in the brake system. A passageway must be provided.

However, by providing the minimum passage, during braking in a low hydraulic pressure region, a portion of the liquid that should be filled into the high hydraulic pressure chamber rather than the low hydraulic pressure chamber leaks into the reservoir, which causes If efficiency is lost and the amount of brake pedal depression increases, or if the filling fluid amount fluctuates depending on the pedaling speed and the predetermined depression amount corresponding to the amount of fluid supplied to the wheel brake becomes unstable. A problem arose.

(Purpose of the invention) The present invention solves the above-mentioned problems, eliminates leak loss in the low hydraulic pressure region, improves quick response and stability during brake operation, and minimizes the It is an object of the present invention to provide a valve device that can secure a passage and further improve the efficiency of suction from a reservoir to a low hydraulic pressure chamber.

(Characteristics of the invention) In order to achieve the above object, the present invention provides a small hole that is formed in a valve seat member having a valve seat of a regulating valve and that communicates with a reservoir, and an opening of the small hole on the low hydraulic pressure chamber side. an elastic suction valve body which covers the part while forming a compressible liquid reservoir chamber between the opening surface of the valve seat member including the low hydraulic pressure chamber side opening part, and whose tongue part comes in close contact with the opening surface; constitutes a suction valve, and a minimum passage is constituted by a small hole provided in the elastic suction valve body at a position away from the small hole and in a position communicating with the liquid reservoir chamber, and a low liquid When braking in a pressure region, the elastic suction valve element receives the hydraulic pressure in the low hydraulic pressure chamber, causing the liquid reservoir chamber to be crushed and the elastic suction valve element to come into close contact with the opening surface, thereby minimizing the It is characterized in that the passage is closed.

(Embodiment of the invention) FIG. 1 is a sectional view showing an embodiment of the invention, and FIG. 2 is a front view of the embodiment shown in FIG. 1 from below.

Below, FIG. 1 and FIG. 2 will be explained.
Note that the same parts are indicated by the same reference numerals.

The fixing member 2 and the valve seat member 3 of the valve device 1 are integrally engaged with each other through engagement holes 4 and 4' formed in the fixing member 2 and pawls 5 and 5' provided in the valve seat member 3. Ru.

A regulating valve 7 is loaded into the chamber 6 formed by the above engagement, and is pressed against the valve seat 9 by a diaphragm spring 8 held between the fixed member 2 and the valve seat member 3.

The diaphragm spring 8 closes the regulating valve 7 until the liquid flowing into the chamber 6 from the passage 10 provided in the center of the valve seat member 3 reaches a predetermined pressure. 1
1, 12, and 13 are liquid passages provided in the fixing member 2, and 14 is a threaded portion provided around the side surface.

The valve seat member 3 has small holes 15, 16, 17, 1
8, 19, 20, 21 and 22 are provided, which communicate with the chamber 6 at the top, and whose openings on the low hydraulic pressure chamber side are formed in the opening surface 23 at the bottom.

A boss 24 is provided at the center of the opening surface 23, and the disk-shaped elastic suction valve body 25 is supported along the opening surface 23 by the boss 24, and the low hydraulic pressure chamber side openings of the small holes 15-22 are supported by the boss 24. cover the area. A tongue portion 26 that comes into close contact with the opening surface 23 is formed on the outer periphery of the elastic suction valve body 25.
Further, curved portions 27 are formed concentrically. An annular liquid reservoir chamber 28 is formed between the curved portion 27 and the opening surface 23.

The elastic suction valve body 25 is provided with a pore 29 that communicates with the liquid reservoir chamber 28 as a minimum passage. In addition, the elastic suction valve body 25 has a square support hole 30 provided at the center of the base 3 of the boss 24, which is also formed in a square shape.
1, it is positioned non-rotatably. Due to the positioning described above, the pore 29 does not overlap any of the small holes 15, 16, 17, 18, 19, 20, 21 or 22.

Note that protrusions 32, 33, 34, and 35 are provided on the surface of the elastic suction valve body 25 as necessary.

FIG. 3 shows an example in which the embodiment shown in FIGS. 1 and 2 is used in a two-stage tandem master cylinder 36, and the same parts as in FIGS. 1 and 2 are designated by the same reference numerals. show.

A large-diameter cylinder 39 and a small-diameter cylinder 40 are coaxially cut into the cylinder body 37 by a stepped portion 38, and a flange 41 is provided on the left open end side to be attached to a vehicle body or a servo motor (not shown). It will be done.

The main piston 43, which is pushed by the input rod 42 shown by the two-dot chain line, has a large diameter portion 44 and a small diameter portion 4.
5, and is loaded movably within the large diameter cylinder 39 and the small diameter cylinder 40. The large diameter portion 44
A low hydraulic pressure chamber 46 is formed by the step portion 38 and the step portion 38 .

A floating piston 47 is movably loaded in the small diameter cylinder 40 . A first high hydraulic pressure chamber 48 is formed between the main piston 43 and the floating piston 47, and is connected to one brake system (not shown) through a first output hole 49. Note that the unidirectional flow of liquid from the low hydraulic pressure chamber 46 to the first high hydraulic pressure chamber 48 is as follows.
It is allowed through the small holes 50, 51 and the seal 52.

A second high hydraulic pressure chamber 54 is formed between the floating piston 47 and the cylinder end 53, and the second output hole 5
5 to the other brake system (not shown).

A first spring 56 is loaded into the first high hydraulic pressure chamber 48 . The first spring 56 is compressed between the spring seat 57 and the attachment 58 by a pin 59 which is fixed to the main piston 43 at one end and engaged with the attachment 58 at the other end.
Due to the above engagement, the main pistons 4 are urged away from each other by the first spring 56.
3 and the floating piston 47 is set.

In the second high hydraulic pressure chamber 54 , a second spring 61 is loaded between the spring seat 60 and the cylinder end 53 and biases the floating piston 47 in a direction away from the cylinder end 53 .

Note that the set load of the first spring 56 is equal to that of the second spring 56.
It is set higher than the set load of the spring 61, and the floating piston 47 simultaneously follows the initial movement of the main piston 43.

62 is a circlip that determines the return position of the main piston 43, and 63, 64 and 65 are seals.

A first connection part 66 and a second connection part 67 for attaching first and second reservoirs (not shown) are formed in the upper part of the cylinder body 37, and grommets 68 and 69 are attached thereto, respectively. First connection part 66
The valve device 1 shown in FIGS. 1 and 2 is loaded into the inside of the valve device 1 by means of a threaded portion 14, and a liquid chamber 70 is formed which is partitioned from a first reservoir. The liquid chamber 70 is
The passage 71 and the first port 72 communicate with the low hydraulic pressure chamber 46 and the first high hydraulic pressure chamber 48, respectively.
The liquid chamber 73 of the second connection part 67 is directly connected to the second reservoir, and communicates with the liquid chamber 76 and the second high hydraulic pressure chamber 54 formed around the floating piston 47 through a passage 74 and a second port 75. Ru.

Next, the operation will be explained with reference to FIGS. 1, 2, and 3.

When the input rod 42 is not pressed and the brake operation is released, both the valve device 1 and the two-stage tandem master cylinder 36 are in the state shown.

The low hydraulic pressure chamber 46 communicates with the liquid chamber 70 via the passage 71, and the first high hydraulic pressure chamber 48 communicates with the liquid chamber 70 via the first port 72.
The small holes 15 to 22 and the chamber 6 communicate with the first reservoir via passages 11 to 13, and are open to atmospheric pressure.

The second high hydraulic pressure chamber 54 also communicates with the second reservoir through a second port 75 and is open to atmospheric pressure.

When the input rod 42 is pushed for brake operation, the main piston 43 and the idle piston 47 are first
is pushed to the right against the second spring 61, and the seal 52 passes through the first port 72 and the seal 65 passes through the second port 75 at the same time. This operation compresses the low hydraulic pressure chamber 46 and the second hydraulic pressure chamber 54, and a hydraulic pressure in a low hydraulic pressure region is generated in the low hydraulic pressure chamber 46.

When the elastic suction valve body 25 is pressurized by the above-mentioned hydraulic pressure, the liquid reservoir chamber 28 is compressed and disappears, and the elastic suction valve body 25 moves toward the opening surface 2.
3 and the pore 29 is closed.

The liquid in the low hydraulic pressure region that is compressed in the low hydraulic pressure chamber 46 due to the closed circuit of the small hole 29 does not leak to the first reservoir, and the entire liquid amount passes through the small holes 50 and 51 and is distributed around the outer periphery of the seal 52. The fluid is then supplied to the expansion portion of the connected wheel brake via the first high hydraulic pressure chamber 48 and the first output hole 49.

In addition, the liquid in the second high pressure chamber 54 that is directly compressed by the floating piston 47 is supplied to the expansion part of the connected wheel brake via the second output hole 55.

When the supply of liquid to the expansion portion of each wheel brake is completed, even if the input rod 42 is continuously pushed, the amount of rightward movement of both the main piston 43 and the floating piston 47 becomes small. At the same time, the hydraulic pressure in the low hydraulic pressure chamber 46 continues to rise, and when the hydraulic pressure reaches a predetermined value, the regulating valve 7, which had been closed by the diaphragm spring 8, opens, and the low hydraulic pressure chamber 46 The hydraulic pressure of passes through the passage 71, the liquid chamber 70, and the passage 10,
The chamber 6 and the passages 11 to 13 are opened to the first reservoir, and the braking operation is shifted to a high hydraulic pressure region.

In the high hydraulic pressure region, the first high hydraulic pressure chamber 48 is compressed by the relative approach between the main piston 43 and the floating piston 47, and the second high hydraulic pressure chamber 54 is compressed by the continued rightward movement of the floating piston 47. Ru. Therefore, the force with which the input rod 42 presses the main piston 43 acts only on the small diameter cylinder 40.

As described above, in the low hydraulic pressure region, the large diameter cylinder 39 with a large amount of supplied fluid is used to save the brake pedal depression amount, and in the high hydraulic pressure region, the small diameter cylinder 40 is used to reduce the brake pedal depression force. A two-stage operation is performed to increase the degree of increase in output hydraulic pressure.

When the braking operation is completed and the input to the input rod 42 is released, the main piston 43 and the floating piston 47 are returned to the illustrated positions by the first and second springs 56 and 61.

At this time, the low hydraulic pressure chamber 46, the passage 71 and the liquid chamber 70
Due to the pressure drop, the curved portion 27 that was in pressure contact with the opening surface 23 returns to the state shown in the figure, and the liquid reservoir chamber 28 is formed again.At the same time, the tongue portion 26 is separated from the opening surface 23, and the first reservoir is opened. Liquid is drawn into the low hydraulic pressure chamber 46 . Therefore, the suction efficiency can be improved and the return of the main piston 43 can be made faster than when a flat elastic suction valve body without the curved portion 27 is used and suction is performed from the gap with the opening surface 23. .

When the main piston 43 returns to the position shown, the first high pressure chamber 48 is communicated with the first reservoir via the first port 72, the liquid chamber 70 and the pore 29, and the second high pressure chamber 54 is also connected to the second reservoir. A second reservoir is communicated through port 75, and each connected wheel brake is opened to the reservoir.

If the brake system connected to the first high hydraulic pressure chamber 48 fails, the main piston 43 and the floating piston 47 move rightward to generate hydraulic pressure in the second high hydraulic pressure chamber 54, and When the brake system connected to the hydraulic pressure chamber 54 fails, the main piston 43 and the floating piston 47 approach each other relatively to generate hydraulic pressure in the first high hydraulic pressure chamber 48. Similarly, when hydraulic pressure is generated from the first high hydraulic pressure chamber 48, hydraulic pressure that changes from a low hydraulic pressure region to a high hydraulic pressure region is supplied from the first output hole 49.

(Modified example) A ball valve is used as the regulating valve 7, and it is brought into pressure contact with the valve seat 9 by the diaphragm spring 8, but the valve is closed until the hydraulic pressure in the low hydraulic pressure chamber 46 reaches a predetermined value. It may be any regulating valve that opens later, and is not limited to the one shown.

Although the tandem master cylinder 36 is used as the master cylinder, it may be a one-system type or a two-system type, and is not limited to the illustrated tandem master cylinder.

Regarding the elastic suction valve body 25, the central part is supported by the boss 31 of the valve seat member 3, and the opening surface 23 is formed on the outer periphery.
Although the tongue portion 26 is provided in close contact with the valve seat member 3, the outer periphery of the tongue portion 26 can be supported by the valve seat member 3, and the tongue portion can be formed along a hole provided in the center. or,
Although the curved portion 27 is formed by a curved line, it is only necessary that a compressible liquid reservoir chamber 28 is formed.
It is not limited to what is shown in this example.

(Effects of the Invention) As explained above, according to the present invention, the small hole communicating with the reservoir is formed in the valve seat member having the valve seat of the regulating valve, and the low hydraulic pressure chamber side opening of the small hole is formed in the valve seat member having the valve seat of the regulating valve. an elastic suction valve body which covers the part while forming a compressible liquid reservoir chamber between the opening surface of the valve seat member including the low hydraulic pressure chamber side opening part, and whose tongue part comes in close contact with the opening surface; constitutes a suction valve, and a minimum passage is constituted by a small hole provided in the elastic suction valve body at a position away from the small hole and in a position communicating with the liquid reservoir chamber, and a low liquid When braking in a pressure region, the elastic suction valve element receives the hydraulic pressure in the low hydraulic pressure chamber, causing the liquid reservoir chamber to be crushed and the elastic suction valve element to come into close contact with the opening surface, thereby minimizing the Since the passage is closed, leak loss to the reservoir can be eliminated by closing the passage to a minimum, improving quick response and stability during brake operation, and furthermore, the formation of a liquid reservoir chamber. This makes it possible to increase the efficiency of suction into the low hydraulic pressure chamber.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a front view of the embodiment shown in FIG. 1, viewed from below;
FIG. 3 is a cross-sectional view of a two-stage tandem master cylinder showing an example of the use of the present invention, and FIG. 4 is a cross-sectional view showing a state in which the liquid reservoir chamber is extinguished in one embodiment of the present invention. 1...Valve device, 2...Fixing member, 3...Valve seat member, 7...Adjusting valve, 8...Diaphragm spring, 9...Valve seat, 15, 16, 17, 18, 1
9, 20, 21, 22...Small hole, 23...Opening surface, 24...Boss, 25...Elastic suction valve body, 26
... tongue part, 27 ... curved part, 28 ... liquid storage chamber, 2
9...Small hole, 30...Support hole, 36...Two-stage tandem master cylinder, 38...Step part, 39...
...Large diameter cylinder, 40...Small diameter cylinder, 43...
...Main piston, 44...Large diameter section, 45...Small diameter section, 46...Low hydraulic pressure chamber, 47...Idle piston,
48...first high hydraulic pressure chamber, 54...second high hydraulic pressure chamber.

Claims (1)

[Claim for Utility Model Registration] A regulating valve that releases the hydraulic pressure to a reservoir when the hydraulic pressure generated in the low hydraulic pressure chamber of the two-stage master cylinder reaches a predetermined value; In a valve device comprising a suction valve that allows liquid to flow in the direction, and a minimum passage communicating between a reservoir and a low hydraulic pressure chamber, a valve seat member having a valve seat of the regulating valve is provided with a valve seat member having a valve seat of the regulating valve. , a compressible liquid reservoir is provided between the small hole communicating with the reservoir, the low hydraulic pressure chamber side opening of the small hole, and the opening surface of the valve seat member including the low hydraulic pressure chamber side opening. The suction valve is made up of an elastic suction valve element that forms and covers the opening surface, and whose tongue portion is in close contact with the opening surface; The minimum passage is constituted by the pores provided at communicating positions, and when the brake is operated in a low hydraulic pressure region, the elastic suction valve body receives the hydraulic pressure of the low hydraulic pressure chamber, so that the A valve device characterized in that the minimum passage is closed by compressing the liquid reservoir chamber and bringing the elastic suction valve body into close contact with the opening surface.