JPH0348928Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial field of application In this invention, a piston that divides the cylinder part into a hydraulic chamber and an air chamber is slid onto a cylinder part provided in a casing. The present invention also relates to a brake hydraulic control device for a vehicle, including a brake hydraulic modulator whose lid member for closing an air chamber is coupled to a casing, and in which an output port of a master cylinder including a reservoir having a liquid level warning sensor communicates with the hydraulic chamber.

(2) Conventional technology Conventionally, in such a vehicle brake hydraulic control device, if water or dust enters the air chamber, the smooth operation of the piston will be inhibited, so it is common to keep the air chamber in a sealed state. be.

(3) Problems to be solved by the invention However, even if a seal defect were to occur between the piston and the cylinder, the conventional method could not detect that the seal defect had occurred. .

Therefore, the present applicant installed a one-way seal member between the lid member and the casing to allow leakage of hydraulic oil from the air chamber to the outside, thereby eliminating the seal defect between the piston and the seal member. A vehicle brake hydraulic control system has already been proposed that detects a decrease in the amount of hydraulic fluid in a brake hydraulic system connected to the brake system.

A so-called cup seal, which has a lip around the entire circumference, is generally used as this unidirectional seal member, but when the tension of the lip decreases due to deterioration of the material, the sealing performance may be impaired. be.

The present invention has been developed in view of the above circumstances, and makes it possible to extremely easily detect seal defects between the piston and cylinder sections, and
An object of the present invention is to provide a brake hydraulic control device for a vehicle that can reliably prevent water and dust from entering an air chamber from the outside.

B. Structure of the invention (1) Means for solving the problem According to the invention, between the casing and the lid member, there is an annular shape that partially has a lip part that allows hydraulic oil to flow out from the hydraulic chamber to the outside. A sealing member is interposed.

(2) Effect If a seal defect occurs between the piston and cylinder and hydraulic oil leaks from the hydraulic chamber to the air chamber, the hydraulic oil will leak outside from the lip of the seal member, reducing the amount of hydraulic oil in the braking hydraulic system. The level warning sensor is activated and seal defects are easily detected. Moreover, since the lip part of the seal member is partially provided, it is supported on both sides, so even if the material deteriorates, the decrease in tension can be kept small.
One-way sealing is maintained.

(3) Embodiment Hereinafter, embodiments of the present invention will be explained with reference to the drawings. First, in FIG. 1 showing an embodiment of the present invention, a tandem master cylinder Mc having a reservoir R equipped with a liquid level warning sensor Ls is shown. Oil passages 2a and 2b are connected to the pair of output ports 1a and 1b, and the output oil pressure from one output port 1a is transmitted to the brake oil pressure modulator Mfr for the right front wheel and the brake oil pressure for the left rear wheel via the oil passage 2a. The output oil pressure from the other output port 1b is supplied to the left front wheel brake oil pressure modulator Mfl and the right rear wheel brake oil pressure modulator Mrl via the oil passage 2b. The brake hydraulic modulators Mfl and Mfr for the left and right front wheels act to provide brake hydraulic pressure corresponding to the output hydraulic pressure of the master cylinder Mc to the brakes Bfl and Bfr for the left and right front wheels,
Brake hydraulic modulator Mrl for left and right rear wheels,
Mrr is the braking hydraulic pressure that is proportionally reduced from the output hydraulic pressure of the master cylinder Mc.
It acts to give Brr.

In addition, in order to reduce the braking hydraulic pressure when each wheel is about to lock up, the control hydraulic pressure source 5, the reservoir R, the brake hydraulic modulators Mfl, Mfr for the left and right front wheels, and the brake hydraulic pressure for the left and right rear wheels are used. Antilock control valve means 6a and 6b are interposed between the modulators Mrl and Mrr. i.e. brake hydraulic modulator for left and right front wheels
The antilock operation of Mfl and Mfr is controlled by the operation of one antilock control valve means 6a,
Brake hydraulic modulator Mrl for left and right rear wheels,
The antilock operation of Mrr is controlled by the operation of the other antilock control valve means 6b.

In Figure 2, each brake hydraulic modulator
Mfl, Mfr, Mrl, and Mrr are provided in a common casing 7. Furthermore, the brake hydraulic modulators Mfl and Mfr for the left and right front wheels and the brake hydraulic modulators Mrl and Mrr for the left and right rear wheels are arranged in parallel with each other. Also, the brake hydraulic modulator in the same hydraulic system, that is, the master cylinder Mc
The left front wheel brake hydraulic modulator Mfr and the left rear wheel brake hydraulic modulator Mrl are supplied with hydraulic pressure from one output port 1a of the left front wheel, and the left front wheel brake hydraulic pressure is supplied with hydraulic pressure from the other output port 1b of the master cylinder Mc. Modulator Mfl
The brake hydraulic modulators Mfl, Mfr, Mrl, and Mrr are arranged so that the brake hydraulic modulators Mfl, Mfr, Mrl, and Mrr are adjacent to each other on a straight line parallel to each other. Furthermore, one anti-lock control valve means 6a is arranged on the extension of a straight line connecting the brake hydraulic modulators Mfl and Mfr for the left and right front wheels,
Brake hydraulic modulator Mrl for left and right rear wheels,
The other anti-lock control valve means 6b is arranged on the extension of a straight line connecting Mrr, and both anti-lock control valve means 6a, 6b are integrally supported by a mounting part 85 provided on the side of the casing 7. A reservoir R is disposed above the anti-lock control valve means 6a, 6b.

Each brake hydraulic modulator Mfl, Mfr, Mrl,
Mrr is a brake hydraulic modulator for the left and right front wheels that extends vertically and is arranged parallel to each other.
The configurations of Mfl and Mfr are basically the same, and the configurations of the brake hydraulic modulators Mrl and Mrr for the left and right rear wheels are basically the same as the brake hydraulic modulators Mfl and Mfr for the left and right front wheels, with some exceptions. It is.
Therefore, the structure of the brake hydraulic modulator Mfl for the left front wheel will be explained in detail below, and the brake hydraulic modulator Mrr for the right rear wheel will be explained in detail.
Only the parts that are different from the brake hydraulic modulators Mfl and Mfr for the right front wheel will be explained, and the main parts corresponding to the brake hydraulic modulator Mfl for the left front wheel will only be illustrated with the same reference numerals.

In FIG. 3, the left front wheel brake hydraulic modulator Mfl is constructed by assembling components from above into a bottomed cylinder hole 8 bored in the casing 7 and having an open upper end. That is, cylinder hole 8
The elastic member 12, the disc-shaped partition wall 9, and the cylindrical sleeve 10 are fitted inside. The partition wall 9 is fitted into the cylinder hole 8 with an O-ring 11 interposed between it and the inner surface of the cylinder hole 8, and the sleeve 10 is fitted into the cylinder hole 8 with a C-ring 13 interposed between the inner surface of the cylinder hole 8. Inserted. A stepped portion 8a facing upward is provided in the middle of the cylinder hole 8. Also, a cover member 1 is provided in the casing 7 corresponding to the open end of the cylinder hole 8.
4 is attached, and the elastic member 12, the partition wall 9, and the sleeve 10 are clamped and fixed between the lid member 14 and the step portion 8a. Note that the sleeve 10 may be integrated with the partition wall 9.

In FIG. 4, the elastic member 12 is formed into a disk shape of synthetic resin, rubber, or the like. On the other hand, partition wall 9
A small-diameter cylindrical portion 9a is integrally provided in the center of the sleeve 10 and protrudes toward the side opposite to the sleeve 10, and an engagement groove 30 is provided on the outer surface of the tip of the small-diameter cylindrical portion 9a over the entire circumference. It will be done. In the center of the elastic member 12, there is a through hole 3 having a peripheral edge that can be engaged with the engagement groove 30.
1 is provided.

Furthermore, notches 32 are provided at a plurality of positions spaced apart from each other on the inner peripheral edge of the elastic member 12, and these notches 32 allow the elastic member 12 to
can be engaged with the engagement groove 30 by bending the inner edge of the engagement groove 30. Moreover, if the inlet oil passage 21 is bored in the casing 7 at the part facing the input oil pressure chamber 18, a wasted part will be created between the inlet oil passage 21 and the partition wall 9, which not only increases the length of the brake hydraulic modulator Mfl but also makes it difficult to Although problems such as air easily entering between the elastic member 12 and the partition wall 9 occur, when the elastic member 12 is locked to the partition wall 9, by providing the notch 32, the inlet oil passage 2
1 can be disposed at a position corresponding to the partition wall 9, and the above-mentioned inconvenience is solved.

By fixing the partition wall 9 and the sleeve 10 in the cylinder hole 8, the partition wall 9 is formed in the casing 7.
A first cylinder portion 15 located below the partition wall 9 and a second cylinder portion 16 located above the partition wall 9 are formed concentrically.

A first piston 17 is slidably connected to the first cylinder portion 15 , an input hydraulic pressure chamber 18 is defined between the first piston 17 and the partition wall 9 , and a control chamber 19 is defined between the bottom of the casing 7 and the first piston 17 . defined.

An annular oil passage 28 is defined between the lower outer surface of the partition wall 9 and the inner surface of the cylinder hole 8, and an annular oil passage 20 is formed in the partition wall 9 to communicate between the input hydraulic chamber 18 and the annular oil passage 28. This annular oil passage 20 communicates with the input hydraulic pressure chamber 18 via a notch 32 .

Further, the casing 7 is provided with an inlet oil passage 21 that opens on the side surface on the left front wheel brake hydraulic modulator Mfl side and communicates with the annular oil passage 28 . Further, the brake hydraulic modulator Mrr for the right rear wheel is also provided with an annular oil passage 28, and the annular oil passage 28 and the brake hydraulic modulator for the left front wheel are connected to each other.
The annular oil passage 28 of Mfl is communicated with through a communication passage 29, and this communication passage 29 is bored in the casing 7 on an axial extension of the inlet oil passage 21. Therefore, when machining the casing 7, the inlet oil passage 21 and the communication passage 29 are bored simultaneously. Moreover, the open end of the inlet oil passage 21 is connected to an oil passage 2b that continues to the output port 1b of the master cylinder Mc. Therefore, both brake hydraulic modulators Mfl,
The input hydraulic pressure chamber 18 of Mrr is supplied with the output hydraulic pressure from the output port 1b.

A second piston 22 having the same diameter as the first piston 17 is slid into the second cylinder portion 16 , an output hydraulic chamber 23 is defined between the second piston 22 and the partition wall 9 , and the second piston 22 and the lid member 14 are provided with an output hydraulic pressure chamber 23 . A spring chamber 24 as an air chamber is defined between them. An oil passage 25 is bored in the sleeve 10 so as to constantly communicate with the output oil pressure chamber 23, and an oil passage 3b (see Fig. 1) that leads to the brake hydraulic modulator Mfl for the left front wheel.
An outlet oil passage 26 bored in the side wall of the casing 7 connects the output oil pressure chamber 2 through the oil passage 25.
3. In addition, the outlet oil passage 26 is the inlet oil passage 2.
It is opened in the side surface of the casing 7 on the same side as 1.

The lid member 14 that closes the spring chambers 24, 24' is
This is common to the brake hydraulic modulator Mfl for the left front wheel and the brake hydraulic modulator Mrr for the right rear wheel, and the open ends of the bottomed cylindrical parts 33 and 34 corresponding to both modulators Mfl and Mrr are connected to the flange part 35.
It is formed by connecting. This lid member 14 has an annular seal member 36 between it and the open end of each cylinder hole 8.
The casing 7 is attached by a plurality of bolts 37 through the
is connected to the upper end surface of.

A hole 39 is concentrically formed in the center of the partition wall 9 between the inlet hydraulic chamber 18 and the output hydraulic chamber 23, and a piston rod 40 is inserted through the hole 39 so as to be freely movable in the axial direction. In addition, a sealing member 4 is provided on the outer surface of the piston rod 40 and is in sliding contact with the inner surface of the hole 39.
1 is fitted.

The first piston 17 is integrally provided at the lower part of the piston rod 40, and the second piston 22 is mounted at the upper part of the piston rod 40 so as to allow relative movement in the axial direction. That is, a step 42 facing upward is provided at the top of the piston rod 40, and a receiving member 43 that abuts the step 42 is fixed to the upper end of the piston rod 40 by a nut 44. The second piston 22 is movable relative to the piston rod 40 in the axial direction between the receiving member 43 and the partition wall 9.
An O-ring 45 that slides into contact with the inner surface is fitted.

A pair of seal members 46 and 4 are provided on the outer surface of the first piston 17 and are in sliding contact with the inner surface of the first cylinder portion 15.
7 are fitted at intervals in the axial direction, and an O-ring 48 and a seal member 49 are fitted onto the outer surface of the second piston 22 so as to be in sliding contact with the inner surface of the second cylinder portion 16, that is, the inner surface of the sleeve 10. It will be worn.

The receiving member 43, that is, the piston rod 40 and the lid member 1
A first spring 50 is interposed between the piston rod 40 and the piston rod 40 due to the spring force of the first spring 50.
The downward direction, that is, the first piston 17 is urged away from the partition wall 9 . Moreover, between the receiving member 43, that is, the piston rod 40 and the second piston 22,
A second spring 51 is interposed that exerts a spring force to relatively move the second piston 22 toward the partition wall 9, and the set load of the second spring 51 is applied to the first spring 5.
Set to less than 0.

The partition wall 9 is provided with a valve mechanism 52 that communicates and blocks communication between the input hydraulic chamber 18 and the output hydraulic chamber 23. This valve mechanism 53 has a valve chamber 54 provided in the partition wall 9 that communicates with the input hydraulic chamber 18, and a valve hole 55 provided between the valve chamber 54 and the output hydraulic chamber 23.
, a spherical valve body 56 housed in the valve chamber 54 to open and close the valve hole 55 , and a drive rod 5 that is integrated with the valve body 56 and extends through the valve hole 55 and faces into the output hydraulic chamber 23 .
7, the valve body 56 is accommodated in the valve chamber 54, and the valve body 5
and a spring 58 biasing toward the 5 side. A conical valve seat 59 whose diameter becomes smaller toward the valve hole 55 side is provided on the end surface of the valve chamber 54 on the valve hole 55 side.
The length of the drive rod 57 is such that when the second piston 22 is maximally displaced toward the partition wall 9, the second piston 22
The pressure is set to a value sufficient to separate the valve body 56 from the valve seat 59.

In this valve mechanism 53, the spring 58 is supported by the elastic member 12, and the valve chamber 58 is
4 is communicated with the input hydraulic chamber 18.

In the second piston 22, when there is a seal defect between the output hydraulic chamber 23 and the spring chamber 24, that is, a seal defect in the O-ring 48 and the seal member 49, the hydraulic oil leaking into the spring chamber 24 leaks to the outside. The lid member 14 and the casing 7
The sealing member 36 interposed therebetween has a unidirectional sealing function that allows hydraulic oil to flow out from the spring chamber 24 to the outside and prevents water and dust from entering into the spring chamber 24 from the outside. .

In FIGS. 5 and 6, the seal member 36
is basically formed in a ring shape from an elastic material such as rubber, but for example, recesses 36a are formed on the outer surface at two positions on the diameter line, so that the recesses 36a are spaced at equal intervals in the circumferential direction. A lip portion 36 elastically abuts on one of the lid member 14 and the casing 7, for example, the lid member 14, at two positions.
b is formed. This lip portion 36b is formed in the recessed portion 36a when pressure is applied from the inside to the outside.
It is capable of flexing to the side and therefore
The lip portion 36b allows hydraulic oil to flow out from the spring chamber 24 to the outside.

Regarding the brake hydraulic modulator Mrr for the right rear wheel, the first piston 17' is set to have a smaller diameter than the second piston 22, and the inner diameter of the first cylinder portion 15' becomes smaller accordingly. Moreover, the set load of the first spring 50' is set larger than that of the first spring 50 of the brake hydraulic modulator Mfl for the left front wheel, and the first spring 50'
It becomes longer than 0. Accordingly, the bottomed cylindrical portion 34 of the lid member 14 becomes longer than the bottomed cylindrical portion 33.

The outlet oil passage 26' of the brake hydraulic modulator Mrr for the right rear wheel is connected to the brake hydraulic modulator for the left front wheel.
It is opened in the side surface of the casing 7 adjacent to the outlet oil passage 26 of Mfl, and an oil passage 4b (see FIG. 1) leading to the right rear wheel brake Brr is connected to this outlet oil passage 26'.

The other structure of the right rear wheel brake hydraulic modulator Mrr is basically the same as that of the left front wheel brake hydraulic modulator Bfr.

The brake hydraulic modulator Mfr for the right front wheel and the brake hydraulic modulator Mrl for the rear left wheel are configured in the same manner as described above. hydraulic modulator
The outlet oil passages 72 and 72', which communicate with the output hydraulic chambers 23 of Mfr and Mrl, respectively, are the same as the inlet oil passage 21 and the outlet oil passages 26 and 26'.
It is opened on the side. The inlet oil passage 71 has an oil passage 2a.
are connected to the outlet oil passages 72 and 72', and oil passages 3a and 3a are connected to the outlet oil passages 72 and 72'.
4a are connected to each other.

Referring again to FIG. 1, the control fluid pressure source 5 consists of a hydraulic pump P that pumps control fluid, such as hydraulic oil, from a reservoir R, and an accumulator Ac.
Hydraulic pump P is driven as necessary during vehicle operation. Further, a hydraulic pressure sensor S is attached to the control hydraulic pressure source 5 for detecting a failure of the hydraulic pump P, a hydraulic failure, and the start and stop of driving the hydraulic pump P.

The anti-lock control valve means 6a, 6b consists of first solenoid valves V1a, V1b which are closed during normal times and second solenoid valves V2a, V2b which are open during normal times, and when each wheel is about to lock, 1st
The solenoid valves V1a and V1b are driven to open, and the second solenoid valves V2a and V2b are driven to close.

The first solenoid valves V1a and V1b are located in the control chamber 19 of the brake hydraulic modulators Mfl and Mfr for the left and right front wheels.
and a supply oil path 73b that communicates with the control chamber 19 of the left and right rear wheel brake hydraulic modulators Mrl and Mrr. Further, the second solenoid valves V2a and V2b are connected to the supply oil path 7 between the first solenoid valves V1a and V1b and the control chamber 19.
The return oil passages 75a and 75b branch from 3a and 73b and return to the reservoir R.

Next, the operation of this embodiment will be explained. First, the brake hydraulic modulators Mfl and Mfr for both front wheels will be explained.
To explain the operation of the piston rod 40, when the brake pedal 38 is not operated and the brake pedal 38 is not operated, the piston rod 40 is moved downward by the spring force of the first spring 50, and the second piston 22 is in contact with the partition wall 9. ing. Therefore, in the valve mechanism 53, the drive rod 57 is pressed by the pressing portion 60 of the second piston 22, and the valve body 56 is separated from the valve seat 59 to open the valve. Therefore, from the output ports 1a, 1b of the master cylinder Mc through the input hydraulic chamber 18, the valve chamber 54, the valve hole 55, the output hydraulic chamber 23, the oil passage 25, the outlet oil passages 26, 71, and the oil passages 3a, 3b. A hydraulic path leading to each brake Bfl, Bfr is formed. As a result, the brake hydraulic path can be filled with hydraulic oil extremely easily in the same manner as in a brake hydraulic system not equipped with a brake hydraulic control system for anti-lock control.

When the brake pedal 83 is used to perform a brake operation, the output ports 1a, 1 of the master cylinder Mc
The braking oil pressure from b passes through the hydraulic path to both brakes.
Supplied to Bfl and Bfr. At this time, since the control fluid pressure from the control fluid pressure source 5 is not supplied to the control chamber 9, the second piston 22 remains displaced to the maximum extent toward the partition wall 9 by the spring force of the first spring 50. The valve mechanism 53 remains open.

If the braking force becomes excessive during brake operation and the wheels are about to lock, the second solenoid valve V2
a closes and the first solenoid valve 1a opens, so the control room 1
9 is supplied with anti-lock control hydraulic pressure from a control hydraulic pressure source 5. As a result, the first piston 17 and the piston rod 40 are pressed upward against the downward force generated by the first spring 50 and the hydraulic pressure of the input hydraulic chamber 18 . At this time, the second piston 22 moves upward together with the piston rod 40 while in contact with the receiving member 43 until the upward power generated by the hydraulic pressure of the output hydraulic chamber 23 is balanced with the downward force generated by the second spring 51.
Along with this, the second piston 22 separates from the partition wall 9, so that the valve body 56 of the valve mechanism 53
9 and close the valve, both brakes Bfl of the braking hydraulic pressure,
At the same time as the supply to Bfr is cut off, the output hydraulic chamber 2
3 has a large volume. As a result, the brake hydraulic pressure is reduced and the wheels are prevented from locking up.

Brake hydraulic modulator for both rear wheels Mrl, Mrr
basically operates in the same way as the brake hydraulic modulators Mfl and Mfr for both front wheels, but the pressure receiving area of the first piston 17' is set to be smaller than the pressure receiving area of the second piston 22. Since the set load of the spring 50' is also large, the braking oil pressure reduced in proportion to the oil pressure in the input oil pressure chamber 18 can be outputted from the output oil pressure chamber 23, and functions as a proportional pressure reducing valve. Therefore, the output hydraulic pressure of master cylinder Mc is proportionally reduced and supplied to both rear wheel brakes Brl and Brr.

In such a vehicle brake hydraulic control device,
It is assumed that hydraulic oil leaks from the output hydraulic chamber 23 to the spring chamber 24 due to a seal defect between the output hydraulic chamber 23 and the spring chambers 24, 24', that is, due to a seal defect in the O-ring 48 and the seal member 49. In this case, since leakage of hydraulic oil from the spring chamber 24 to the outside is allowed by the seal member 36, the liquid level alarm sensor Ls installed in the reservoir R is activated due to the decrease in the amount of hydraulic oil, and the seal Defects can be detected.

Moreover, since the lip portion 36b of the sealing member 36 is only partially provided at two locations in the circumferential direction, even if the material deteriorates, the lip portion 36b is supported on both sides in the circumferential direction, so there is no tension. Therefore, it is possible to reliably prevent water and dust from entering into the spring chamber 24 from the outside.

FIGS. 7 and 8 show a sealing member 36' according to another embodiment of the present invention, and as in this embodiment, a large number of lip portions 36b' are provided on the sealing member 36' in the circumferential direction, and each A structure may be adopted in which ribs 36c' are provided between the recesses 36a', and the same effects as in the above embodiment can also be achieved with this structure.

C. Effects of the invention As described above, according to the invention, an annular seal member partially having a lip portion that allows hydraulic oil to flow from the air chamber to the outside is interposed between the casing and the lid member. Therefore, when a seal defect occurs between the piston and cylinder section, the liquid level warning sensor can be activated to easily detect the occurrence of the seal defect. The sealing function can be maintained sufficiently.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention, in which FIG. 1 is an overall hydraulic system diagram of a vehicle brake hydraulic control device, FIG. 2 is a plan view of a vehicle brake hydraulic control device, and FIG. 3 is an enlarged sectional view taken along the - line in FIG. 2, FIG. 4 is an enlarged sectional view taken along the - line in FIG. 3, FIG. 5 is an enlarged plan view of the sealing member, and FIG.
7 and 8 show other embodiments of the present invention, FIG. 7 is a plan view of the sealing member, and FIG. 8 is a sectional view taken along the line -- in FIG. 7. 1a, 1b...Output port, 7...Casing, 16...Cylinder part, 22...Piston, 2
3... Hydraulic chamber, 24, 24'... Spring chamber as an air chamber, 36, 36'... Seal member, 36b,
36b'...Lip part, Ls...Liquid level alarm sensor,
Mc……Master cylinder, Mfl, Mfr, Mrl, Mrr
...Brake hydraulic modulator, R...Reservoir.

Claims (1)

[Scope of utility model registration request] The cylinder part provided in the casing has a brake hydraulic modulator in which a piston that divides the cylinder part into a hydraulic chamber and an air chamber is slid together, and a lid member that closes the air chamber is connected to the casing. In a vehicle brake hydraulic control device in which an output port of a master cylinder including a reservoir having an alarm sensor communicates with the hydraulic chamber, a lip portion is provided between the casing and the lid member to allow hydraulic oil to flow out from the air chamber to the outside. 1. A brake hydraulic control device for a vehicle, characterized in that an annular seal member having a portion thereof is interposed therein.