JPS6022550A - Antilock device for wheel - Google Patents

Abstract

PURPOSE:To step up durability, safety and responsiveness, by installing a normally opened valve, which is opened by pressing force from the outside and expands its volume for decompression, in position between a master cylinder and a braking device, in case of an antilock device. CONSTITUTION:When a second solenoid valve 22 is closed of its circuit as a first solenoid valve 19 is left opened intact, discharged oil out of a pump 18 is fed to an oil chamber C, causing pressing force from the side of the oil chamber C to act on a decay piston 17, and the pressing force from the outside is given to a decay rod 15. With strength of this pressing force, interception of a route ranging from a master cylinder 2 to a braking device 4 and decompression in brake oil pressure take place inside a brake oil pressure control valve 6. Next, when the solenoid valve 19 is closed as the solenoid valve 22 is left closed intact, hydraulic pressure is kept constant whereby the hydraulic pressure can be decompressed and closed with only making the solenoid valve 22 open, permitting of keeping the pressure, thus a decrease in oil quantity inside the oil chamber C causes the brake oil pressure to produce its repressurizing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-lock device that eliminates wheel lock that may occur during braking of a vehicle by loosening the brake, thereby ensuring good braking stability.

Various anti-lock methods have been proposed in the past to prevent the occurrence of wheel locks, but this control basically uses the brake oil pressure once raised to detect an excessive brake force condition that causes wheel locks. This is to prevent the wheels from sliding on the road surface, and also to raise the brake oil pressure again when the wheel CI7 is resolved to prevent unnecessary extension of the braking distance. This system requires extremely high responsiveness, requiring a series of hydraulic controls to be performed within a few seconds.

The 7" V-key hydraulic pressure reducing device used in such an anti-lock system is generally a pneumatic or hydraulic operated type /4 that uses a vacuum or hydraulic source from the vehicle's engine system or steering system. 'Most of them are war piston-driven, but these types are subject to various limitations because they require operational connections with various parts of the vehicle.

In recent years, small-sized brake systems that control brake oil pressure using electromagnetic valves have also been applied to practical vehicles.

However, the conventional control type using this type of solenoid valve has the excellent advantage of being a small device, but the control cycle is slow (responsiveness suffers), so the behavior of the wheels during braking is In addition, in models that use a pump to repressurize the brake oil pressure, the control characteristics of the drop in brake oil pressure and repressurization affect the performance of the pump. In addition to problems such as being controlled and making delicate control difficult, there is also the problem that the hydraulic circuit is often a complex closed circuit type, making it difficult to bleed air.

In view of these points, the present inventor has conducted extensive studies with the aim of developing a novel anti-lock device that has excellent control responsiveness and control state selectivity for releasing and repressurizing the brake when a wheel lock occurs. This led to the invention. That is, the present invention adjusts the brake hydraulic pressure based on the brake release signal and brake repressurization signal that are output for anti-lock control in accordance with electrically detected patterns such as sudden drop and recovery of wheel speed. It is an object of the present invention to provide an anti-lock device which can take suitable control modes for lowering, repressurizing, and holding the anti-lock device, and which is structurally simple.

That is, in the present invention, in the hydraulic transmission system (hereinafter referred to as the first thread) from the mask cylinder to the brake device,
A normally open valve mechanism is provided, and this valve mechanism is configured to reduce the brake hydraulic pressure by increasing the internal volume of the oil chamber on the brake device side after closing the flow path by an external pressing force. In addition, a piston mechanism is provided which applies a pressing force for valve closing and movement to the valve mechanism using hydraulic pressure from a hydraulic system (hereinafter referred to as a second system) provided separately from the brake hydraulic pressure transmission system. This system is characterized in that the brake hydraulic pressure can be easily reduced, maintained, and raised again by the hydraulic control of the second system.

The main features of the present invention to achieve such an object are a first system for transmitting brake hydraulic pressure connected from a mask cylinder of a vehicle to a brake system, and a first thread and a brake hydraulic pressure transmission system connected to a brake system. a second thread that independently transmits the discharge hydraulic pressure from the pump; a brake hydraulic control pulp that is interposed in the middle of the first system; A piston mechanism for driving the brake oil pressure control pulp, and a piston mechanism for driving the brake oil pressure control pulp, and a piston mechanism for driving the brake oil pressure control pulp. Open type □The valve mechanism is provided so that the internal volume of the output oil chamber is increased after the valve is closed by the pressing force from the piston mechanism, and the piston mechanism is configured to increase the internal volume of the output oil chamber. The switching operation normally releases the oil pressure in the oil chamber C to the reservoir, and when the brake oil pressure needs to drop during wheel anti-lock control, the electromagnetic pulp switching operation causes the oil pressure to be maintained in the oil chamber C. There is an anti-lock device on the wheels.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows an outline of the configuration of an embodiment of the present invention. In the figure, 1 is a brake pedal, 2 is a master cylinder, 3 is a reservoir, 4 is a brake device, and 5 is a mask cylinder 2 to the brake device. A brake hydraulic pressure control device 6 is interposed in a brake hydraulic pressure transmission pipe (hereinafter referred to as a first unpiped system) in the middle of this first system pipe.

This brake hydraulic control device 6 includes a normally open valve formed by a valve seat body 9 and a valve body 10 in seven rings 8 of a pulp body 7, and input oil into the cylinder 8. The valve seat body 9 and the valve body 10, which are divided into a chamber a and an output oil Wb, are biased and fixed at a limit position on the output oil chamber side by tort springs 11 and 12, respectively.

In this example, the valve seat body 9 is provided in a stepped shape, and the piston cup 13 is fitted into the small diameter portion on the input oil la side to provide liquid-tight sealing between the input and output oil chambers. There is. Further, the valve body 1o has a rubber 7-t attached to a shaft-shaped piston to form a valve seat 14 that abuts against the valve seat, and after the valve seat 14 is slightly deformed, it engages with the valve seat body 9. A ring-shaped body is assembled.

A decay rod 15 is engaged with the end of the valve body 1o on the input oil chamber side, and this applies an external pressing force to the valve body 1o by a piston mechanism of a drive device fc to be described later.

In the brake hydraulic control device having the above configuration, the valve body 10 is normally spaced apart from the valve seat body 9, and the input/output oil chamber a,
l), thereby allowing hydraulic pressure from the master cylinder to be transmitted to the brake device, and when the valve body 10 comes into contact with the valve seat 9 under the pressure from the decay rod 15, both the When the communication between the output oil chambers a and l) is cut off, and the pressing force from the decay rod 15 increases and the valve seat body 9 is moved via the valve body 10, the amount corresponding to the distance moved is By increasing the internal volume of the output oil chamber in the cylinder, the brake hydraulic pressure can be reduced.

The moving distance of the valve body and the valve seat body is determined by the balance between the hydraulic pressure of the input oil chamber a and the output oil chamber A and the pressing force from the decay rod 15.
By controlling the pressing force from 5 to increase or decrease or hold it appropriately, the brake oil pressure can be controlled to an appropriate state.

Next, to congratulate the above-mentioned piston mechanism, in this example, another cylinder 16 that is coaxial with the cylinder 8 is formed in the valve seat 7 on the outside of the outlet oil chamber,
A decay piston 17 is slid into this cylinder 16, and the decay rod 15 is fitted onto this decay piston/17.
is engaged. The two oil megd partitioned by this decay piston F are one of them (the side that applies hydraulic pressure in the direction of pressing the decay rod 15).
The oil chamber C is a control oil chamber that generates hydraulic pressure, and the other oil chamber d is an oil chamber that does not generate hydraulic pressure. system(
(hereinafter referred to as the second thread pipe). That is,
A hydraulic pressure supply pipe 20 from a hydraulic pressure discharge cylinder f18 is connected to an oil chamber C via a normally open first solenoid valve 19, and the oil chamber C is connected to a separate hydraulic discharge pipe 21, which is a normally open type. 2'-th hexagonal valve 22f: is connected to the oil chamber d, the reservoir 3, and the pump 18 via the second ′-th point valve 22f.

Note that 23 is a check pulp interposed in a bypass path connecting from the pump 18 to the hydraulic discharge pipe 21, and functions to determine the maximum hydraulic pressure that can be supplied to the oil chamber C. Therefore, with such a check valve 23, the pump 18 can be driven all the time or driven only during anti-lock control, and there is no need for precise design attention to the amount of oil discharged.

The operation of the piston mechanism configured as described above is as follows.
This occurs under the control of the oil pressure value given to the oil chamber C by the operation of the second solenoid valve 19.22. That is,
In the illustrated normal state, no hydraulic pressure is applied to the decay piston 17 in the interaxial direction, and therefore the above-mentioned external pressing force is not applied to the decay rod 15 as well.

When the first solenoid valve 19 is left open and the second solenoid valve 22 is closed, the oil discharged from the pump 18 is supplied to the oil chamber c.
Therefore, a hydraulic pressure acts on the f' squid piston 17 from the oil chamber C side, thereby applying a pressing force to the decay rod 15 from the outside. As described above, depending on the magnitude of this pressing force, the yarn path from the mask cylinder to the brake device is cut off and the brake hydraulic pressure is reduced in the brake hydraulic control pulp 6.

Next, by continuing to close the second solenoid valve 22, the first solenoid valve 1 is opened.
9 is closed, the oil pressure in the oil chamber C is maintained at the current oil pressure value.

Then, if only the second solenoid valve 22 is opened or closed again from this state, the oil pressure value in the oil chamber C can be appropriately reduced or maintained, and the decrease in the amount of oil in the oil pressure C means that the brake oil pressure can be restored. This will occur as pressurization.

In this way, the pressure reduction, holding, and P+ pressurization of the brake oil pressure are ultimately the same as described in the above-mentioned step 1. Since this is achieved by controlling the opening and closing of the second solenoid valve 19.22, the second unpiped system is independent from the first system piping, so it is possible to give a sufficiently large and rapid hydraulic pressure change. This results in excellent effects.

Note that the signal for operating the eleventh second solenoid valve 19.22 for wheel anti-lock control can be obtained using an electrical control circuit according to a known anti-skid control method. FIG. 2 shows an example of the initiation of such anochronic lock control.

In Fig. 2, the upper stage shows the pump 12 using the wheel speed signal vw (detected as a voltage signal) and the pseudo deceleration signal ■a.
The relationship that determines the time point at which the drive of the first solenoid valve 19.22 starts and the time point at which the operation of the eleventh second solenoid valve 19.22 starts (normally open (off)→closed (on)) is determined. The relationship between the drive of the second electric pump and the change characteristics of the brake oil pressure is shown by the same time chart.

In the anti-lock control method shown in FIG. 2, the wheel speed signal VW suddenly drops during vehicle braking, and when this exceeds a certain maximum deceleration Gnax, the second solenoid valve 22 is turned on at Ato, and at the same time the pump 18 is turned on. And at this point t. However, after a minute delay ΔT, the second
The solenoid valve 22 is turned on. Through this series of operations, oil pressure is first supplied to the oil chamber C, and the brake oil pressure control valve is initially closed. When stopping the brake oil pressure increase alone is not sufficient, the brake oil pressure is reduced in the following manner. In other words, a constant value Δ is determined from the wheel speed signal VW.
The first solenoid valve 19 is opened (off) at time t1 when this signal 7 intersects the wheel speed signal ).

As described above, according to the anti-lock device of the present invention, the structure of each hydraulic piping system is simple, air bleeding is easy, and the various parts of the device do not slide during normal braking. It has the advantage of being excellent in durability and safety, and its practical usefulness is extremely great.

[Brief explanation of the drawing]

The first factor is a diagram showing a schematic configuration of a wheel anti-lock device according to the present invention, and FIG. 2 is a diagram showing an example of control characteristics at the start of anti-skid control.
: Master 7 cylinder, 3: Reservoir, 4 Brake device, 5: Piping, 6: Brake hydraulic control valve, 7: Valve body, 8 Niji cylinder, 9: Valve seat body, 10: Valve body, 11.12: Hold spring, 13: Piston cup, 14: Pulbu seat, 15: Decay rod, 16: Cylinder, 17: Decay piston, 18: Pump, 19: First solenoid valve, 20: Hydraulic supply piping, 21: Hydraulic discharge piping, 22: Second
A magnetic valve, 23; check valve. Figure 1 Figure 2 V-Cho Procedure Amendment Book Showa Gin, October 2, 2013 2φ day? Relationship with Patent Application No. 131-23 of 2007 Applicant 4, Agent Address Tokyo 1st generation [11-ku, 2-6-2, 90-nai, Marunouchi to Shigesu Building 330] - Old 18 Contents of the amendment Amend the specification and drawings of the present application as shown in the attached sheet 1': No. 911 < MJ correction (・Note 1, page 12, line 7, r C1naxJ Correct it as "Cmax". 2. Correct "the second solenoid valve 22" on line 10 of page 12 to "the first solenoid valve 19". 3. Correct the phrase "the first solenoid valve 19" on line 10 of page 8. 4. Correct "Figure 1" in the drawing to the drawing submitted today.

Claims (1)

[Claims] A first thread for transmitting brake hydraulic pressure connected from the master 7 cylinder of the vehicle to the brake device, a second thread that is independent of the first thread and transmits the discharge hydraulic pressure from the pump, and the first thread. The brake hydraulic pressure control valve interposed in the middle of the brake V-
Equipped with a piston mechanism that drives the hydraulic control valve,
The brake oil pressure control valve has a normally open valve mechanism that divides the valve cylinder into an input oil chamber a on the mask cylinder side and an output oil chamber on the brake device side, and closes the valve by the pressing force from the piston mechanism. The piston mechanism normally releases the hydraulic pressure in the oil chamber C to the reservoir by the switching operation of the electromagnetic valve device, and reduces the brake hydraulic pressure during wheel anti-lock control. An anti-lock device for a wheel, characterized in that when descent is necessary, hydraulic pressure is maintained in the oil chamber C by switching the electromagnetic valve.