JPH0365460A - Modulator of anti-lock device - Google Patents

Abstract

PURPOSE:To enable more secure anti-lock control by forming a chamber for storing exhaustion of an air chamber on a rear stage of a decay valve and an orifice on an exhaust path to an exhaust port communicating with the chamber. CONSTITUTION:At the time of first control of anti-lock, rapid pressure reduction is possible by a chamber 11 for temporarily storing exhaustion in a pneumatic chamber 5 wherein pneumatic pressure and retreat response of hydraulic pistons 6, 20 and wheel locking at the time of first braking can be securely prevented. In addition, at the time of fine adjustment, an orifice 12 provided on the exhaust path to an exhaust port 19 communicating with the chamber 11 is used to slow down pressure reduction in the chamber 11 so that the fine adjustment of the pressure in the pneumatic chamber 5 is possible by controlling a hold valve 7 and a decay valve 10. Thus pressure reduction rate in the pneumatic chamber 5 varies between the first control and the fine adjustment at the time of anti-lock control, thereby allowing more secure anti-lock control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique that is effective when applied to a modulator of an anti-lock device for a vehicle equipped with an air-over-hydraulic master cylinder.

[Conventional technology]

As this type of technology, a modulator shown in FIG. 3 is known.

The outline of this modulator is as follows.

That is, the modulator includes a man-powered boat 16 connected to the hydraulic pressure chamber 15 of the air master cylinder 1 in the casing 14.
In addition, an output boat 17 connected to the foil cylinder 2 is provided, and a valve device 4 is arranged in a liquid passage PI 3 that connects the human-powered boat 16 and the output boat 17. The casing 14 has a small diameter cylinder part 18 and a large diameter cylinder part 21. A hydraulic piston 20 is fitted into the small diameter cylinder gPJ1B, and a pneumatic piston 6 is integrally connected to the hydraulic piston 20. is the large diameter cylinder part 21
The hydraulic piston 20 moves forward (moves to the left in the figure) to open the valve device 4, and the hydraulic piston 20 retreats (moves to the right in the figure) to close the valve device 4. , the small diameter cylinder portion communicating with the output port 17 is formed so that the hydraulic pressure chamber 27 can be expanded.

Furthermore, the pneumatic chamber 5 of the large-diameter cylinder portion 21 is connected to the brake valve 22, and the pneumatic chamber 5 sequentially valves the decay valve 10 and the exhaust passage 8 to open the exhaust port 19.
It is connected to the.

In the modulator having the above structure, the brake pedal 23
When the brake valve 22 is depressed, the compressed air in the air tank 24 is introduced into the air master cylinder 1, presses the piston 25 in the air master cylinder 1, and compresses the brake fluid in the hydraulic chamber 27. . At the same time, compressed air led out from the brake valve 22 passes through the hold valve 7 from the intake port 26 of the modulator, is introduced into the pneumatic chamber 5 of the large diameter cylinder section 21, and presses the pneumatic piston 6. . As the pneumatic piston 6 moves forward, the hydraulic piston 20 also moves forward, and the valve device 4 is held in the open position. As a result, the brake fluid in the hydraulic pressure chamber 15 of the air master cylinder 1 is transferred to the manual boat 16 of the modulator.
The foil cylinder 2 via the liquid passage 3 and the output boat 17
is introduced to brake the wheels.

On the other hand, if there is a risk that the wheels may lock during braking, a lock signal from an electronic control device (not shown) closes the hold valve 7, closing the pneumatic passage 9 that communicates the air intake port 26 and the pneumatic chamber 5. , subsequently the decay valve 10 is opened. By such an operation, the compressed air in the pneumatic chamber 5 is discharged from the exhaust port 19 via the exhaust passage 8, and the pressure in the pneumatic chamber 5 is reduced. This pressure reduction causes the hydraulic piston 2
0 and the pneumatic piston 6 are pushed back by the hydraulic pressure in the hydraulic chamber 27, and the valve device 4 shuts off the liquid passage 3.

When the compressed air in the pneumatic chamber 5 is further discharged, the hydraulic piston 20 moves back further, the hydraulic chamber 27 expands, and the pressure inside the hydraulic chamber 27 is reduced.

This operation reduces the braking force of the wheel cylinder 2 and prevents the wheels from locking.

[Problem to be solved by the invention]

Incidentally, in the modulator having the above structure, an orifice 13 is provided in a part of the exhaust passage 8 from the pneumatic chamber 5 to the decay valve 10 to narrow the cross-sectional area of the passage.

The reason for providing such an orifice 13 is as follows.

That is, anti-lock control requires fine adjustment of the internal pressure in the pneumatic chamber 5 by the hold valve 7 and decay valve 10 after the pressure in the pneumatic chamber 5 has been lowered to a certain level. If the rate of pressure reduction is sudden and always constant, the pressure reduction will be too rapid and the above yII adjustment will be difficult.
This may result in insufficient braking, making it difficult to perform appropriate anti-lock control.

For this purpose, an orifice 13 is provided to slowly reduce the pressure in the air pressure chamber 5 to enable the above-mentioned fine adjustment.

However, in the modulator with the above structure, the pressure reduction rate of the air pressure chamber 5 is always constant in a slow pressure reduction state due to the presence of the orifice 13, so there is a delay in the initial control pressure reduction when the anti-lock control state is entered, and the initial lock is caused. There were concerns that this would occur.

That is, in the above-mentioned prior art, no consideration was given to the fact that the optimum pressure reduction rate characteristics of the pneumatic chamber 5 are different between the initial control state and the fine adjustment control state during anti-lock control.

The purpose of the present invention is to simply add a simple structure, and the pneumatic chamber 5 is
The object of the present invention is to provide a technology that enables more reliable anti-lock control by making the pressure reduction rate variable.

[Means to solve the problem]

The present invention has the following means to solve the above problems.

That is, a valve device 4 that controls the opening and closing of the liquid passage 3 communicating between the air master cylinder 1 and the foil cylinder 2, and a pneumatic piston 6 that moves within the pneumatic chamber 5 in conjunction with the valve device 4.
, a hold valve 7 disposed in the pneumatic passage 9 into the pneumatic chamber 5 to open and close the pneumatic passage 9, and an exhaust port 1 from the pneumatic chamber 5.
Regarding a modulator equipped with a decay valve 10 disposed on an exhaust passage 8 to the air pressure chamber 5 for opening and closing this exhaust passage 8, the exhaust from the pneumatic chamber 5 is temporarily disposed after the decay valve 10 on the exhaust passage 8. It has a structure in which an orifice 12 is formed in a chamber 11 for storing water and an exhaust passage 8 leading to an exhaust port 19 communicating with the chamber 11.

[Effect]

According to the above-described means, at the time of initial control of anti-lock control, the chamber 1 temporarily stores the exhaust gas in the pneumatic chamber 5.
1 makes it possible to rapidly reduce the pressure in the pneumatic chamber 5, increase the backward response of the pneumatic piston 6 and the hydraulic piston 20, and reliably prevent wheels from locking during initial control.

In addition, during fine:A adjustment control, the orifice 12 provided in the exhaust passage 8 to the exhaust port 19 communicating with the chamber 11 causes the pressure inside the chamber 11 to be reduced slowly, so that the hold valve 7 and the decay valve 10 enables fine adjustment of the pressure within the pneumatic chamber δ.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

The modulator includes a man-powered boat 16 connected to the hydraulic pressure chamber 15 of the air master cylinder 1 in the casing 14, an output boat 17 connected to the foil cylinder 2, and a hydraulic boat 17 connected to the man-powered boat 16 and the output boat 17. A valve device 4 is arranged in the passage 3. The above casing 14
The inside has a small diameter cylinder part 1 and a large diameter cylinder part 21, and a hydraulic piston 20 is fitted into the small diameter cylinder part 1, and a pneumatic piston is integrally connected to the hydraulic piston 20. 6 fits into the large diameter cylinder portion 21, the hydraulic piston 20 moves forward (moves to the left in the figure), opens the valve device 4, and the hydraulic piston 20 retreats (moves to the right in the figure). closes the valve device 4 and closes the hydraulic pressure chamber 2 of the small-diameter cylinder portion communicated with the output boat 17.
7 can be enlarged.

Further, the pneumatic chamber 5 of the large diameter cylinder portion 21 has a hold valve 7 formed of a normally open electromagnetic valve between the brake valve 22 and the intake port 26 communicating with the brake valve 22 . This hold valve 7 has a valve body 30 that is biased in the opening direction by a coil spring 28, and when the solenoid S is energized, the valve body 30 is biased in the closing direction and the air pressure chamber 5 is It has a structure that closes the pneumatic passage 9. Further, a ball valve 33 biased in the closing direction by a coil spring 32 is disposed on the bypass path from the intake port 26 to the pneumatic chamber 5, and is structured to prevent an overpressure state in the pneumatic chamber 5. It becomes.

The decay valve 10 provided on the exhaust passage 8a from the pneumatic chamber 5 is composed of a normally closed electromagnetic valve, and communicates/closes the exhaust passage 8a and the exhaust passage 8b by energizing the solenoid S. It's in control. Note that, as a feature of this embodiment, the exhaust passage 8a between the pneumatic chamber 5 and the decay valve 10 is not provided with the orifice 13 as described in the prior art.

On the exhaust passage 8b, a chamber 11, an orifice 12, and an exhaust port 19 are provided at the top of II at the downstream stage of the decay valve 10, so that the air pressure chamber 5 is evacuated. The volume of the chamber 11 is determined in relation to the volume of the pneumatic chamber 5.

Further, the back pressure chamber 34 on the non-pneumatic chamber side of the pneumatic piston 6 and the exhaust port 19 are communicated through a back pressure passage 35.

The reason why such a back pressure passage 35 is provided is to send a part of the exhaust gas from the pneumatic chamber δ into the back pressure chamber 34 to assist the pneumatic piston 6 in retreating.

Although not shown in the figure, a bypass passage to the outside of the casing is provided in a part of the back pressure passage 35 with a valve that opens when the pressure in the back pressure chamber 34 reaches a certain level or higher. It is also possible to prevent the pneumatic piston 6 from returning too far.

Further, in the figure, 36a, 36b, and 36c each indicate a V-shaped gasket that seals each chamber.

Next, the operation of this embodiment will be explained.

In the modulator having the above structure, the brake pedal 23
When the brake valve 22 is depressed, the compressed air in the air tank 24 is introduced into the air master cylinder 1, presses the piston 25 in the air master cylinder 1, and compresses the brake fluid in the hydraulic chamber 15. . At the same time, compressed air led out from the brake valve 22 passes through the hold valve 7 from the intake port 26 of the modulator, is introduced into the pneumatic chamber 5 of the large diameter cylinder section 21, and presses the pneumatic piston 6. . As the pneumatic piston 6 moves forward, the hydraulic piston 20 also moves forward, and the valve device 4 is held in the open position. As a result, the brake fluid in the overnight pressure chamber 15 of the air master cylinder 1 is transferred to the input port 16 of the modulator.
, is introduced into the wheel cylinder 2 via the liquid passage 3 and the output boat 17 to brake the wheels.

Next, the anti-lock control during braking will be explained.

If there is a risk that the wheels may lock during the above-mentioned braking, a lock signal from an electronic control device (not shown) is sent to the second
As shown in the figure, the signal HV to the solenoid S of the hold valve 7 becomes "ON", the hold valve 7 is closed, and the supply of air from the brake valve 22 to the pneumatic chamber 5 is cut off. Approximately in synchronization with this, the signal DV to the solenoid S of the decay valve 10 becomes "ON", the decay valve 10 is opened, and the pressure reduction of the pneumatic chamber 5 is started (A in the figure).
point). At this time, in this embodiment, the exhaust passage 8a between the pneumatic chamber 5 and the decay valve 10 is not provided with the orifice 13 as in the prior art. compressed air flows into the chamber 11 via the decay valve 10. by this,
The internal pressure Pa of the pneumatic chamber 5 rapidly decreases until it becomes balanced with the internal pressure Pc of the chamber 11 (point B in the figure). The larger the pressure reduction amount ΔP from point A to point B at this time, that is, the faster the response to the initial control pressure reduction, the more reliable the locking of the wheels becomes.

Regarding this point, in this embodiment, as described above, the exhaust passage 8
Since the chamber 11 is provided on the air pressure chamber 5 to realize rapid pressure reduction in the air pressure chamber 5, the pressure reduction rate during the initial control is very high, and the initial locking of the wheels can be reliably prevented.

Next, after the internal pressure PA of the pneumatic chamber 5 is balanced with the internal pressure Pc of the chamber 11 (after point B), from the chamber 11 to the exhaust port 1
Due to the orifice provided around 9, the pressure inside the pneumatic chamber PA is reduced to a gradual pressure reduction state. Further, when the internal pressure PA of the pneumatic chamber 5 falls below a certain pressure (point C in the figure), the decay valve 10 is closed, and thereafter, the pneumatic chamber 5 is controlled by the hold valve 7 and the decay valve 10 at any time. The internal pressure PA inside is finely adjusted. In this way, in the fine adjustment control state, the pressure reduction rate of the pneumatic chamber 5 is a slow pressure reduction, so the internal pressure PO of the pneumatic chamber 5 can be finely adjusted by controlling the hold valve 7 and the decay valve 10. ing.

In FIG. 2, PM indicates the pressure change in the pneumatic chamber of the air master cylinder 1 corresponding to the above, Pc indicates the pressure change in the hydraulic pressure chamber 15, and Po indicates the pressure change in the foil cylinder 2.

In this way, in this embodiment, the chamber 11 and the orifice 1
2, the pressure reduction rate of the pressure reduction (sudden pressure reduction) in the pneumatic chamber 5 in the control initial state (from point A to point B) and the pressure reduction (slow pressure reduction) in the fine adjustment state g (from point B to 0 point) is determined respectively. Since it achieves variable and optimal pressure reduction, anti-lock control can be performed more reliably.

〔Effect of the invention〕

According to the invention, the exhaust passage 8 from the decay valve 10
By simply adding a simple structure in which a chamber 11 and an orifice 12 are formed on top b, the depressurization rate of the pneumatic chamber 5 can be made variable during initial control and fine adjustment control during anti-lock control, resulting in a more reliable system. Anti-lock control can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a modulator that is an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the relationship between the operation of the hold valve and decay valve and pressure changes in the pneumatic chamber and the chamber according to the present embodiment. , FIG. 3 is a sectional view showing the structure of a modulator for explaining the prior art. DESCRIPTION OF SYMBOLS 1...Air master cylinder, 2...Wheel cylinder, 3...Liquid passage, 4...Valve device, 5...Pneumatic chamber, 6...Pneumatic piston, 7...Hold Valve, 7...exhaust port,
8... Exhaust passage, 9... Pneumatic passage,
10... Decay valve, 11... Chamber,
12... Orifice, 13... Orifice,
14... Casing, 15... Hydraulic pressure chamber,
16...Human powered boat, 17...Output boat, 1
8...Small diameter cylinder part, 19...Exhaust port,
20... Hydraulic piston, 21... Large diameter cylinder part, 22... Brake valve, 23... Brake pedal, 24... Air tank, 25... Piston, 26
...Intake port, 27...Hydraulic pressure chamber, 28...
Coil spring, 30... Valve body, 2... Coil spring, 3... Ball valve, 34... Back pressure chamber, 5... Back pressure passage, 6a, 36b, 36c = -V shape Patsukin.

Claims (1)

[Claims] (1) A valve device 4 that controls the opening and closing of the liquid passage 3 that communicates the air master cylinder 1 and the foil cylinder 2, and a pneumatic piston 6 that moves within the pneumatic chamber 5 in conjunction with the valve device 4.
A hold valve 7 is disposed on the pneumatic passage 9 leading into the pneumatic chamber 5 and opens and closes this pneumatic passage 9; A decay valve 10 that opens and closes, and a chamber 11 that temporarily stores exhaust gas from the pneumatic chamber 5 downstream of the decay valve 10 on the exhaust passage 8;
A modulator of an anti-lock device in which an orifice 12 is formed in an exhaust passage 8 leading to an exhaust port 19 communicating with this chamber 11.