JPH0228133Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-skid device for a rear independent dual brake system of an automobile.

In order to improve safety, automobiles are required to have two braking systems, and these two braking systems have left and right rear brake devices connected to independent hydraulic circuits. be. In addition, in automobiles,
BACKGROUND ART Devices have been developed that effectively prevent skidding of wheels (usually rear wheels) during sudden braking, that is, electronically controlled skid control devices (also simply referred to as anti-skid devices). by the way,
In this electronically controlled skid control device, this electronically controlled expensive actuator is disposed in the hydraulic circuit leading to the rear brake device, and the operation of this actuator is controlled according to the rotational state of the rear wheel. to control the hydraulic pressure to the rear brake system. Therefore, when this electronically controlled skid control device is used in the above-mentioned two-system brake system, it is necessary to install an expensive actuator in each hydraulic circuit, which increases the cost of the device. .

In order to deal with this, the applicant first filed a patent application
No. 55-158459 (Japanese Unexamined Patent Publication No. 57-80955) provided an inexpensive anti-skid device for a rear independent dual brake system. This anti-skid device has an actuator for an electronically controlled skid control device disposed in the hydraulic pressure circuit leading to the rear brake device in the first hydraulic pressure circuit of the rear independent two-brake system, while the actuator of the electronic skid control device A modulator valve is disposed in the hydraulic pressure circuit leading to the rear brake device at each end, and the modulator valve receives each hydraulic pressure applied to both rear brake devices at each end. A balance piston that moves due to a pressure difference between the two fluids and balances the two fluid pressures, and a balance piston that is removably engaged with the balance piston and is brought into an open state by the balance piston when the balance piston is not in operation, and is in an open state when the balance piston is in operation. a check valve that is sometimes closed to prevent fluid from flowing from the inlet port to the outlet port of the modulator valve; When the circuit is normal, it is pressed by the hydraulic pressure of the first hydraulic pressure circuit to open the communication passage, and closes the bypass passage that bypasses the check valve and communicates the two ports. Each of the switching valves has a built-in switching valve that is pushed by the hydraulic pressure of the second system hydraulic pressure circuit to close the communication passage and open the bypass passage when the system hydraulic circuit fails. be.

The present invention relates to an improvement of such an anti-skid device, and its gist includes: a base having an annular small-diameter stepped portion of a predetermined width as a valve body of the switching valve that opens and closes the communication passage; The main purpose of the valve body is to improve the durability of the valve body. It is in.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows an example in which an anti-skid device 20 according to the present invention is implemented in a diagonal two-system brake system 10 of an automobile. In this brake system 10, a left front brake device 11 and a right rear brake device are used. 12 is the rear liquid chamber 1 of the master cylinder 13 as the first system.
3a, and a front brake device 14 on the right side and a rear brake device 15 on the left side are connected to the front fluid chamber 13b of the master cylinder 13 as a second system.

The anti-skid device 20 is an actuator 30 of a known electronic skid control device.
and a modulator valve 40. The actuator 30 is disposed in a hydraulic pressure circuit a leading to the rear brake device 12 in a first system hydraulic circuit A. As is well known, during braking, the operation is electronically controlled according to the rotational state of the right rear wheel, and the hydraulic pressure of the hydraulic pressure circuit _a1 communicating with the rear brake device 12 is controlled.

The modulator valve 40 is disposed in the hydraulic pressure circuit B leading to the rear brake device 15 in the hydraulic pressure circuit B of the second system, and is connected to a housing 41 and a balance piston 4 built in the housing 41.
2. Consists of a check valve 43 and a switching valve 44. The housing 41 has an inlet port 41a and an outlet port 41b (communicated with the rear brake device 15 through the hydraulic circuit _b1 ) that communicate with each other and constitute a part of the hydraulic circuit b, and a hydraulic circuit a. ₁
a port 41c that communicates with the through a hydraulic circuit c;
A port 41d is provided at a portion of the hydraulic circuit a closer to the master cylinder 13 than the actuator 30 and communicates through the hydraulic circuit d. This housing 41
Inside, there is an inlet port 41a at the left end.
A first inner hole 41e that communicates with the port 41c at the right end and accommodates the balance piston 42 and the check valve 43, and a first inner hole 41e that communicates with the outlet port 41b at the left end and communicates with the port 41d at the right end. A second inner hole 41f that accommodates the switching valve 44 is formed therein. Also, inside the housing 41, there is a first communication hole 41 that opens at the upper end into the center of the first inner hole 41e and opens at the lower end into the step part of the second inner hole 41f.
g, and a second communication hole 41h that opens at the left end of the first inner hole 41e at the upper end and opens at the left end of the second inner hole 41f at the lower end. 41g of first communication holes
, together with a portion of both inner holes 41e and 41f, constitutes a communication passage _P1 that communicates both ports 41a and 41b, and a check valve 43 and a switching valve 44 are interposed in this communication passage _P1 . The second communication hole 41h is connected to the tick valve 4 along with a portion of both inner holes 41e and 41f.
A bypass passage P ₂ is configured to bypass the port 3 and communicate between the ports 41a and 41b, and a switching valve 44 is interposed in the bypass passage P ₂ .

The balance piston 42 integrally has left and right symmetrical rods 42a, 42a formed in consideration of ease of assembly, and is slidably fitted in the first inner hole 41e in the axial direction via a seal member 45. inserted, the first
A first hydraulic pressure chamber R ₁ communicating with the port 41c and a second hydraulic pressure chamber R ₂ communicating with the outlet port 41b via a switching valve 44 are formed in the inner hole 41e. The balance piston 42 is biased leftward by a return spring _S1 , and in the non-operating state shown in the figure, it is positioned by engaging with the stepped portion of the first inner hole 41e, and is positioned by the left rod. 42a
The check valve 43 is opened. This balance piston 42 has a function of balancing the hydraulic pressures in both hydraulic pressure chambers R ₁ and R ₂ by moving to the right due to the difference in the hydraulic pressures in both hydraulic pressure chambers R ₁ and R ₂ . Check valve 43
is biased to the right by spring S ₂ ,
When the balance piston 42 moves to the right, communication between the inlet port 41a and the second hydraulic pressure chamber _R2 is cut off,
Brake fluid is prevented from flowing from the inlet port 41a to the outlet port 41b through the communication path _P1 .

The switching valve 44 integrally has valve bodies V ₁ and V ₂ that open and close the passages P ₁ and P ₂ at its head, and seals in the small diameter portion of the second inner hole 41f at its legs. Part 4
6 so as to be slidable in the axial direction,
A third hydraulic pressure chamber _R3 communicating with the port 41d and a fourth hydraulic pressure chamber _R4 communicating with the outlet port 41b are formed in the second inner hole 41f. The switching valve 44 is biased to the left by a return spring _S3 , and in the non-operating state shown in the figure,
The valve body V ₁ opens the communication passage P ₁ and the valve body V ₂ closes the bypass passage P ₂ . This switching valve 44 is activated when the first hydraulic pressure circuit A fails (the third
(When no hydraulic pressure is applied in the hydraulic pressure chamber _R3 ), the valve body V2 is pushed to the right by the hydraulic pressure of the second hydraulic pressure circuit B (in the fourth hydraulic pressure chamber _R4 ), and the valve body _V2 is bypassed. The passage P ₂ is opened, and substantially at the same time, the valve body V ₁ closes the communication passage P ₁ .

Therefore, in this embodiment, the valve body V ₁ of the switching valve 44 is as shown in FIGS. 1 and 2.
Base 44A and elastic seal ring (O-ring) 4
It is composed of 4B. The base 44A has an annular small-diameter stepped portion 44a having a predetermined width W, and the right end portion of the annular small-diameter stepped portion 44a in the drawing has an enlarged diameter (to prevent falling off) shape that holds an elastic seal ring 44B. The elastic seal ring 44B is fluid-tightly fitted to the annular small-diameter stepped portion 44a of the base 44A by utilizing its elasticity, and its cross-sectional diameter, that is, the width, is larger than the width W of the annular small-diameter stepped portion 44a described above. Slightly larger. The valve body _V2 of the switching valve 44 is composed of a base 44A and a seal ring 44C that is liquid-tightly adhered to the top surface of the base 44A.

In this embodiment configured in this way, when both hydraulic pressure circuits A and B are normal, the brake pedal 1 is
6, both liquid chambers 1 of the master cylinder 13
3a and 13b, approximately the same hydraulic pressure is generated and applied to each hydraulic pressure circuit A, B, and this is applied to each brake device 11,
12, 14, and 15, respectively, and the vehicle is braked.

During this braking, if the actuator 30 is inactive, the hydraulic pressure in the hydraulic chamber 13a is of course directly transmitted to the right rear brake device 12, and the first hydraulic pressure chamber of the modulator valve 40 is
The hydraulic pressure applied to _R1 is approximately equal to the hydraulic pressure applied to the second hydraulic pressure chamber _R2 , the balance piston 42 and the check valve 43 are in the illustrated state, and the third hydraulic pressure chamber
The hydraulic pressure of the hydraulic pressure circuit a is applied to _R3 , and the switching valve 4
4 is in the non-operating state as shown in the figure, the inlet port 41a and outlet port 41b of the modulator valve 40 communicate through the communication path _P1 which is in the open state, and the fluid pressure in the fluid chamber 13b is applied to the left rear brake. It is directly transmitted to the device 15.

By the way, when the actuator 30 operates during this braking, the right rear brake device 12
The hydraulic pressure in the hydraulic circuit a ₁ leading to this is controlled to be reduced, and this reduced hydraulic pressure is also applied to the first hydraulic chamber R ₁ of the modulator valve 40 through the hydraulic pressure circuit c, so that the balance piston 42 is It moves to the right due to the hydraulic pressure difference in the hydraulic pressure chambers R ₁ and R ₂ , and at the initial stage, the check valve 43
interrupts the communication between the inlet port 41a and the second hydraulic pressure chamber _R2 , and at the later stage the communication between the inlet port 41a and the second hydraulic chamber R2 is interrupted.
The hydraulic pressure in _R2 is reduced, and this reduced hydraulic pressure is applied to the left rear brake device 15 through the outlet port 41b and the hydraulic pressure circuit _b1 .

Further, in this embodiment, if the hydraulic pressure circuit A of the first system fails, hydraulic pressure cannot be applied to both hydraulic pressure chambers R ₁ and R ₃ of the modulator valve 40, and during braking, the hydraulic pressure circuit A of the first system fails. The balance piston 42 moves to the right due to the hydraulic pressure applied in the hydraulic pressure chamber _R2 , and the check valve 43 closes, and at the same time, the switching valve 44 moves to the right due to the hydraulic pressure applied to the fourth hydraulic pressure chamber _R4 . Then, the bypass passage _P2 opens and the communication passage _P1 closes. Therefore, at this time, the hydraulic pressure in the front liquid chamber 13b of the master cylinder 13 is low not only in the right front brake device 14 but also in the left rear brake device 1.
The braking force is also directly transmitted to the brake pedal, compensating the braking force. Also, at this time, the communication path _P1 is connected to the switching valve 44.
Since the fourth hydraulic pressure chamber _R4 is closed by the second
Liquid flow to the hydraulic chamber ₂ is regulated. Therefore,
There is almost no loss stroke of the balance piston 42 due to liquid flow to the second hydraulic pressure chamber _R2 , and braking can be achieved quickly.

By the way, at this time, the valve body V ₁ closes the communication passage P ₁ by the rightward movement of the switching valve 44 as described above, but at that time, as shown in FIG.
With the elastic seal ring 44B in contact with the stepped portion of the second inner hole 41f and slightly compressed, the base 4
The annular small-diameter step portion 44a of 4A contacts the step portion of the second inner hole 41f. Therefore, the elastic seal ring 4
4B, the amount of compression thereof can be suppressed to a certain limit, improving the durability of the elastic seal ring 44B and, by extension, the durability of the valve body _V1 .

In the above embodiment, the valve body V ₁ of the switching valve 44 is fitted into the base 44A having the annular small-diameter stepped portion 44a with a predetermined width W, and is fluid-tightly fitted into the annular small-diameter stepped portion 44a of the base 44A. Annular small diameter stepped portion 44
Elastic seal ring 44B with a width larger than the width W of a
However, the valve body _V2 of the switching valve 44 can also be constructed and implemented in the same manner.

In addition, the present invention is not limited to the above-mentioned embodiment, and the present invention is not limited to the above-mentioned embodiment. It goes without saying that the device can be similarly implemented in a two-system brake system in which the left and right rear brake devices are connected to independent hydraulic circuits. The system braking system can also be modified and implemented as appropriate.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention;
FIG. 2 is an enlarged view of the same essential parts, and FIG. 3 is an explanatory diagram of the operation of the portion shown in FIG. 2. Explanation of symbols, 10...Two-system brake system, 12...Right rear brake device, 15...
Left rear brake device, 20... anti-skid device, 30... actuator, 40... modulator valve, 41a... inlet port,
41b... Outlet port, 42... Balance piston, 43... Check valve, 44... Switching valve, 44A... Base, 44a... Annular small diameter step, 44B... Elastic seal ring, A... First Hydraulic pressure circuit of the system, a... Hydraulic pressure circuit leading to the rear brake device in the hydraulic pressure circuit of the first system, B... The second hydraulic pressure circuit
Hydraulic pressure circuit of the system, b...Hydraulic pressure circuit leading to the rear brake device in the hydraulic pressure circuit of the second system, P ₁ ...
Communication passage, P ₂ ... bypass passage, V ₁ ... valve body that opens and closes the communication passage, V ₂ ... valve body that opens and closes the bypass passage.

Claims (1)

[Scope of utility model registration request] In a two-system brake system for automobiles in which the left and right rear brake devices are connected to independent hydraulic circuits, electronic control is performed in the hydraulic pressure circuit leading to the rear brake device in the first hydraulic pressure circuit of the two-system brake system. An actuator for the skid control device is disposed, and a modulator valve is disposed in the hydraulic pressure circuit leading to the rear brake device in the second system hydraulic pressure circuit, and this modulator valve has a A balance piston that receives each hydraulic pressure applied to the brake device at each end and moves due to the difference between the two hydraulic pressures to balance the two hydraulic pressures, and a balance piston that is removably engaged with the balance piston and a check valve that is opened by the balance piston when the piston is inactive and closes when the balance piston is activated to prevent liquid flow from the inlet port to the outlet port of the modulator valve;
The check valve is interposed in the communication passage between the check valve and the outlet port, and when the first hydraulic pressure circuit is normal, it is pressed by the hydraulic pressure of the first hydraulic pressure circuit to open the communication passage. A bypass passage that bypasses the check valve and communicates the two ports is closed, and when the first hydraulic pressure circuit fails, it is pushed by the hydraulic pressure of the second hydraulic pressure circuit to open the communication passage. A base includes a switching valve that closes the bypass passage and opens the bypass passage, and has an annular small-diameter stepped portion of a predetermined width as a valve body of the switching valve that opens and closes the communication passage. An anti-skid device for a rear independent two-brake system, characterized in that a valve body is formed of an elastic seal ring that is fluid-tightly fitted into the annular small-diameter step and has a width larger than the width of the annular small-diameter step.