JPS6264659A - Anti-skid control device - Google Patents

Abstract

PURPOSE:To simplify an electromagnetic valve and its circuit and to reduce their cost, by desiably controlling prompt pressurizing and slow pressurizing without pulsingly opening and closing a hold valve by providing a pressurizing piston device between an oil chamber at a pressure accumulating side and an oil chamber at a main passage side. CONSTITUTION:A pressurizing piston device 17 communicating through an orifice 22 is disposed between an oil chamber, which communicates with a main passage 1b between a gate valve 2 and a hold valve 3, and an oil chamber communicating with a pressure accumulating unit 6. Action of hydraulic pressure from the pressure accumulating device 6 causes the pressurizing piston device to move a predetermined distance so as to reduce an inside volume of the oil chamber communicating with the main passage 1b. With such a construction a passage communicating with a master cylinder M/C is isolated from pressure fluctuation for avoiding occurrence of a so-called kick back phenomenon. In addition, it is effective to prevent re-lock of wheels and permits an electromagnetic valve and its control system to be constructed simply at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an anti-skid control device for suitably eliminating the occurrence of wheel locking during braking of a vehicle.

[Background of the invention]

Recently, various types of anti-skid control technologies have been proposed to improve safety during vehicle braking.
A typical example of such a thing is that the brake hydraulic pressure transmission path (hereinafter referred to as the main path) that connects the master cylinder (hydraulic pressure generator) and the brake device is always open and requires a drop in brake hydraulic pressure. A normally open solenoid-type hold valve that sometimes closes is installed, and a bypass connection path (hereinafter referred to as the bypass path) is provided to this main path, and this bypass path and the main path are connected to the brake equipment side. The output system is divided between the output systems by a pressure reducing valve that is normally closed, and the brake pressure oil that flows into the bypass path through the pressure reducing valve, which is a normally closed solenoid valve that is opened when it is necessary to lower the brake oil pressure, is A reservoir mechanism traps the oil while decreasing the oil pressure by increasing the chamber volume, and furthermore, the oil stored in this redaper mechanism is pumped up to the main path by a pressure oil return mechanism including a bonder, and the hold valve (normally An electronic control circuit has been proposed in which the opening/closing operation of a pressure reducing valve (open type) and a pressure reducing valve (normally closed type) is performed by an electronic control circuit that detects wheel lock during vehicle braking.

By the way, in anti-skid control as typified by the above example, the main path for transmitting brake hydraulic pressure is divided into an input system path and an output system path by a normally open hold valve, Since the pressure oil in the brake equipment (i.e., the pressure oil in the output path) is pumped up to the master cylinder side (i.e., the input path side), the oil pressure fluctuation in the master cylinder increases, and this master There is a problem in that the brake pedal that is linked to the cylinder is given a so-called kick pack movement.

For this reason, measures have been taken in the past to avoid the kick pack phenomenon. It has also been proposed to install a check valve to allow oil to flow.

However, with this type of system, it is natural that a separate path is required to return the hydraulic pressure when the brake is released from the brake device (hereinafter referred to as ``&'' in some cases) side to the master cylinder (hereinafter referred to as VC in some cases) side. At the same time, this hydraulic return path reliably prevents the flow of pressure oil from the M/C-+ W/C in the opposite direction, and is also provided within the brake device W/C to prevent drag when the brake is released. Since it is essential not to leave any residual balls, it becomes very difficult to design the entire system or process accuracy.

Therefore, as an alternative to the above-mentioned reverse valve, the applicant has devised a system that blocks the main path between the input system and the output system only during anti-skid control, and enables brake hydraulic pressure to be reduced or increased in the output system. We provide gate valves. This gate valve utilizes a drop in oil pressure in the output system during anti-skid control to switch a normally open valve to close based on the oil pressure difference between the output system and the input system.

By the way, the anti-skid control device using this type of gate valve is suitable in terms of preventing kick-pack during control, but it is difficult to reduce or increase the brake hydraulic pressure to eliminate wheel lock. The pressure and retention depend on the operation of the hold valve and pressure reducing valve, which are solenoid valves, and in particular, to repressurize the brake oil pressure to prevent the wheels from relocking.
Sudden pressurization,
Post-pressurization must be selected.

However, in order to increase the versatility of the anti-skid control device, it is necessary to provide a device that is as inexpensive as possible and also satisfies most of the objectives of vehicle anti-skid control in terms of control characteristics. be.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned various viewpoints, and an object of the present invention is to provide a solenoid valve or its control system that is effective in preventing the occurrence of kick pack and in preventing relocking of wheels. The purpose of the present invention is to provide a device that can provide the following easily and inexpensively.

[Summary of the invention]

The features of the present invention that have been made to achieve such an object are, in the anti-skid control device having the above-mentioned gate valve, a one-sided oil chamber communicating with the main path between the r-) valve and the hold valve; A pressurizing piston device is provided which faces the other side oil chamber communicating with the pressure accumulator at both ends and moves a certain distance by the hydraulic action from the pressure accumulator to reduce the internal volume of the one side oil chamber. It has a configuration in which the side oil chambers are connected via an orifice.

[Embodiments of the invention] The present invention will be described below based on embodiments shown in the drawings.

In the figure, 1a to IC are outgoing paths (main paths) for transmitting brake hydraulic pressure, and are connected so as to communicate between a master cylinder Ic (not shown) and the wheel cylinder and cylinder of the brake device. It passes through the on-off valve chamber 2a, passes through the hold valve 3, and reaches the foil cylinder W/C. The hold valve 3 is a normally open valve that is closed by an electromagnetic trap, and the circuit is closed by an anti-skid control circuit (not shown).

It is activated by the brake hydraulic pressure holding (and pressure reduction advance signal) which is output to eliminate wheel lock during vehicle braking. Also, the e-) valve 2 is normally opened and closed in the open/close valve chamber 2a as described later. It is open and provides communication between the main paths 1a and lb.

4 is a pipe/four' path bypass-connected to the main path 1c downstream of the hold valve 3; a normally closed pressure reducing valve 5 which is electromagnetically opened by an anti-skid pressure reducing signal; Bonn F7, pressure accumulator Achimulator 8
, a return valve 9 with a built-in pressurizing piston (described later) is interposed in sequence, and when the pressure reducing valve 5 is opened, the brake hydraulic pressure (main path 1c
and oil pressure inside the foil cylinder W/C) wo, redeper 6
The pressure is reduced by letting pressure oil flow into the tank, and after pumping this pressure oil into an accumulator 8 with a pump 7, it is returned from a return valve 9 to the main path lb between the dart valve and the hold valve.

Next, the structure of the gate valve 2 will be explained.

The r-to-valve 2 of this example has a structure in which it is combined with a pressurizing piston device to be described later, but its function as a gate valve is substantially independent. That is, the gate valve 2 of this example has stepped cylinders 10 and 11 in a cylinder body (not shown).
The dart piston 12 is accommodated in the holder, and its small diameter end faces the main path 1c downstream of the hold valve 3, and the return spring 13 engaged with the large diameter part 7 runs at a predetermined position on the large diameter end side. It is designed to stand still in a biased state. It is located in the large-diameter end opening/closing valve chamber 21 of the stepped r-toviston 12, and cooperates with the valve seat 14.
e-) A valve body portion 15 that closes the on-off valve chamber 2& by movement of the piston 12 against the spring force of the return spring 13.
is provided to cut off communication between the main paths 1a and lbQ when the circuit is closed.

This movement of the gate piston 12 against the spring force of the return spring 13 is caused by the difference in hydraulic force acting in the axial direction, that is, the hydraulic pressure in the main path 1c downstream of the Halt valve (brake device side) acting on the small diameter end. This is done when there is a difference in the oil pressure in the on-off valve chamber 1a. Specifically, when anti-skid control is started, the hold valve 3 is closed and the pressure reducing valve 5 is opened, and the oil pressure in the brake device is reduced. This occurs due to reduced pressure.

Next, referring to the pressurizing piston device 17K, the pressurizing piston device of this example has one end facing the opening/closing valve chamber 2a, and the other end facing the pressurizing chamber 18 communicating with the achievator 8. A pressurizing piston 19 that is slidably fitted to the large diameter cylinder 11 of the stepped cylinder, a set spring 20 that initially biases the pressurizing piston 19 toward the pressurizing chamber 18 side, and a date piston 12 direction of the pressurizing piston 19. A stopper 1 fixed to the r-1 piston 12 determines the limit of movement to
6, and in the pressurizing piston 19, there is a small diameter orifice 2 that communicates the pressurizing chamber 18 and the on-off valve chamber 2a.
1 is provided.

In the initial stage (during non-anti-skid control), the pressurizing piston 19 stands still at the illustrated position due to the spring force of the set spring 20t7, and pressurized oil from the accumulator 8 is transmitted to the pressurizing chamber 18 during anti-skid control. Then, it moves so as to reduce the internal volume of the opening/closing valve chamber 2a until it engages with the stopper 16, and then it comes to rest in a state where it is integrated with the dart piston 12. Therefore, the oil pressure fluctuation in the on-off valve chamber 2a during anti-skid control is as follows.

The initial valve element 15 of the r-toviston 12 comes into contact with the valve seat 14, causing a disconnection with the main path input system (master cylinder side), and the pressure piston 19 being moved by the pressure oil from the accumulator 8. After the high pressure is maintained, and then the pressure decreases due to the opening of the hold valve 3, the pressure is gradually supplied from the accumulator 8 through the orifice 21.

According to such a configuration, the brake hydraulic pressure is reduced at the initial stage of anti-skid control by closing the hold valve 3 and opening the pressure reducing valve 5. In this state, the gate valve 2 is substantially closed, so that the brake oil pressure is reduced at the initial stage of the anti-skid control. Kick pack due to fluctuations in brake oil pressure will not occur at all. The repressurization of the brake oil pressure after the wheel lock is released is provided by the pressure reducing valve 5 returning to the closed circuit and the hold valve 3 returning to the open circuit, but in the case of this example, this repressurization is shown in FIG. As shown, it is applied as a characteristic rapid pressurization followed by a slow pressurization. That is, when the hold valve returns to open, the hydraulic pressure in the on-off valve chamber 2a becomes high due to the movement of the pressurizing piston 19, and therefore the pressurized state of the brake hydraulic pressure applied through the hold valve 3 is the same as that of the hold valve. Valve 3
It is determined by the flow path diameter. On the other hand, when the rise progresses to a certain extent, the differential pressure between the main paths 1b and lc decreases, and thereafter becomes fixed at the pressurized state applied from the achievator 8 to the entire orifice 21. In other words, according to the pressurizing piston device of this example, the pressurizing rate is determined by the hold valve 3 at the initial stage of repressurizing in anti-skid control, and the υ pressurizing rate is determined by the orifice 21 at the latter stage of repressurizing. It will be decided.

This repressurization characteristic of the brake oil pressure quickly increases the brake oil pressure, which is generally low enough to release the wheel lock, thereby preventing an extension of the braking distance, and also prevents the brake oil pressure from increasing after reaching a certain level of high pressure. This method is similar to the brake oil pressure pressurization method for anti-skid control, where it is desirable to gradually increase the brake oil pressure while taking into account the prevention of wheel relocking, and the pressurizing piston device of this example It can be understood from Figure 2 that the effectiveness is great.

Note that the present invention is not limited to the above-mentioned embodiments, and the pressurizing piston device may be provided separately from the date valve, or the orifice may be independent, and the pressurizing piston device may be provided separately from the date valve. , the rate of gentle pressurization, or each rate may be set to match the characteristics of various vehicles by selecting various pressurizing piston diameters, orifice diameters, hold valve diameters, etc.

〔Effect of the invention〕

As described above, by using the pressurizing piston device, the anti-skid control device according to the present invention can preferably control sudden pressurization and slow pressurization without randomly opening and closing the hold valve. In particular, the solenoid valve and its control circuit are advantageous in terms of simplification and low cost, and its usefulness is extremely great.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of the configuration of an anti-skid control device according to the present invention, and FIG. 2 is a diagram illustrating control characteristics of brake oil pressure. 1a to 1c...Main path 2...Gate valve 2a...
・Opening/closing valve chamber 3...Hold valve 4...Bino! Passage 5...Reducing valve 6...Redeva
7... Pump 8... Accumulator 9...
・Return valve 10.11...Stepped cylinder 12...Date piston 13...Return sealing 14...Valve seat 15...Valve body portion 16...
・Stopper 17...pressurizing piston device 18
... Pressure chamber 19 ... Pressure piston 20.
...Set spring 21...Orifice agent Teruo Taniyama--'1

Claims (1)

[Claims] In the brake hydraulic pressure transmission path from the master cylinder to the brake device, a normally open gate valve and a normally closed solenoid type hold valve, which is closed when an anti-skid hydraulic pressure holding signal is input, are sequentially installed from the upstream master cylinder side. At the same time, the pressure oil on the transmission path brake device side is pumped up to the pressure accumulator through the pressure reduction valve of the normally closed solenoid valve which is opened when the anti-skid pressure reduction signal is input, and the pressure oil in this pressure accumulator is held with the gate valve. In the anti-skid control device, a bypass path returning to the transmission path between the valves is provided, and the gate valve closes the transmission path when the downstream side oil pressure of the hold valve is smaller than the upstream side oil pressure. , both ends of which face an oil chamber on one side that communicates with the transmission path between the gate valve and the hold valve, and an oil chamber on the other side that communicates with the pressure accumulator; 1. An anti-skid control device comprising: a pressurizing piston device for reducing the internal volume of the anti-skid control device; and the oil chamber on one side and the oil chamber on the other side are connected through an orifice.