JPH0281754A - Combined antilock and traction controller for vehicle - Google Patents

Abstract

PURPOSE:To provide a simple compact structure by incorporating a traction controller having a braking operation in an antilock controller under the merged condition to use the negative pressure of an engine or positive pressure of a power steering gear as a drive source. CONSTITUTION:When a slip of a drive wheel is detected, an electromagnetic change-over valve 17 is adapted to occupy an A position, and a traction cylinder 12 communicates to a negative pressure source 18 to close a traction valve 26 and a second liquid path 28 so that pressurized liquid generated in a reservoir cylinder 13 is reserved in a reservoir 6. Almost at the same time, when a hydraulic pump 7 is turned on operatively braking liquid is supplied to a wheel cylinder 4 to brake the drive wheel. Next, when an electromagnetic decay valve 5 is adapted to occupy a (b) position, the braking liquid in the wheel cylinder 4 is rapidly returned to the reservoir 6 and pressurized so that the excessive slip of the drive wheel can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an anti-lock control and traction control device for a vehicle.

[Conventional technology]

An anti-lock control device for a vehicle releases the wheel locks when the vehicle is suddenly braked to prevent the vehicle from turning and becoming unable to control the vehicle and shorten the braking distance. Conventional anti-lock control devices for vehicles include: For example, JP-A-55-767
There is one disclosed in Publication No. 32. This anti-lock control device opens and closes an electromagnetic valve according to a command from a computer during anti-lock control, and increases, decreases, or maintains brake fluid pressure to prevent wheels from locking.

This brake fluid pressure reduction operation drives a hydraulic pump,
This is done by returning pressure fluid from the wheel cylinders to the master cylinder.

[Problem to be solved by the invention]

However, in vehicles equipped with this type of conventional anti-lock control device, the traction control device, that is, the device that suppresses acceleration slip, is installed in a vehicle that is equipped with a hydraulic pump for traction control in addition to a hydraulic pump for anti-lock control. Pressure fluid is supplied to the wheel cylinders from an accumulator that constantly stores high-pressure fluid via an electromagnetic valve, which requires a dedicated hydraulic pump, which not only requires a large amount of storage space but also has a structurally However, it was complicated, expensive, and impractical.

[Means to solve the problem]

The present invention was made in view of the above-mentioned conventional technical problems, and consists of a closed circuit in which an electromagnetic decay valve, a reservoir, a hydraulic pump, and an electromagnetic hold valve are sequentially connected, and the electromagnetic decay valve and A wheel cylinder connected between the electromagnetic hold valve, a master cylinder connected to the electromagnetic hold valve, and a traction drive device interposed between the master cylinder and the electromagnetic hold valve; The device includes a traction cylinder connected to a positive pressure source or a negative pressure source via an electromagnetic switching valve, a traction piston slidably fitted to the traction cylinder, and a traction piston integrally formed with the traction piston and connected to a reservoir cylinder. a slidably fitted hydraulic traction piston connected to the reservoir cylinder via a first fluid passage and connected to the master cylinder via a second fluid passage;
a valve accommodating chamber connected to the electromagnetic hold valve via a third liquid passage; a traction valve built in the reservoir cylinder and closing the first liquid passage when the traction piston moves forward; and the valve housing. A shut valve that is built in the chamber and closes the first fluid passage when the traction piston returns, a cut valve that closes the second fluid passage when the traction piston moves forward, and a pressure in the reservoir cylinder. The present invention is an anti-lock control and traction control device for a vehicle, comprising a pipe having a check valve capable of supplying liquid to the reservoir.

[Effect]

The function as an anti-lock control device will be explained.

When acting as an anti-lock control device, the vehicle is in a braking state, so the traction drive does not act;
Initially, the electromagnetic decay valve is in the cutoff position, the electromagnetic hold valve is in the open position, and the hydraulic pump is in the non-driven state.

When the brake pedal is depressed, pressure fluid generated in the master cylinder passes through a valve housing chamber and an electromagnetic hold valve, reaches the wheel cylinder, and generates a braking force on the driving wheels. At this time, the traction piston is in the return state, and the shut valve closes the first fluid passage. When a wheel lock is detected and the electromagnetic hold valve is set to the cutoff position, the increase in pressure in the wheel cylinder is suppressed and the pressure is maintained at a nearly constant level.Next, the brake fluid pressure in the wheel cylinder is reduced by the electromagnetic decay valve. While keeping the communication position in place and the electromagnetic hold valve in the cutoff position,
This is done by driving a hydraulic pump to circulate brake fluid back to the master cylinder side. Further, the pressure in the wheel cylinder is increased by placing the electromagnetic decay valve in the blocking position, placing the electromagnetic hold valve in the communicating position, and supplying pressure fluid from the master cylinder to the wheel cylinder.

By combining this pressure holding, pressure reduction, or pressure increase, it is possible to control the brake fluid pressure to a predetermined mode and suppress wheel locking.As a result, it is possible to prevent vehicle body turning and loss of control, and shorten braking distance. can do.

Next, the operation as a traction control device will be explained. When acting as a traction control device, the vehicle is in an accelerating state, so it is not necessary to act as an anti-lock control device. Initially, the electromagnetic decay valve is in the cutoff position, the electromagnetic hold valve is in the communication position, and the hydraulic pump is in the closed position. is in a non-driven state.

When the vehicle travels on a road with a low friction coefficient or the like and slippage of the driving wheels is detected, the electromagnetic switching valve is switched to connect the traction cylinder to a positive pressure source or a negative pressure source. As a result, the traction piston and the hydraulic traction piston move and operate together, and after the traction valve closes the first fluid passage, pressure fluid is generated in the reservoir cylinder, and this pressure fluid passes through the check valve and is stored in the reservoir. In addition, the cut valve closes the second fluid passage due to the forward movement of the traction piston, so if the hydraulic pump is driven in this state, the brake fluid supplied to the reservoir will pass through the electromagnetic hold valve. Then, when the electromagnetic decay valve is set to the communicating position, the brake fluid in the wheel cylinder returns to the reservoir and the pressure is reduced. be done. Further, the pressure of the brake fluid is increased by causing the electromagnetic decay valve to take a cutoff position while the hydraulic pump is being driven.

Such a combination of increasing or decreasing the pressure of the brake fluid in the wheel cylinders can prevent the driving wheels from slipping and improve the starting performance and running stability of the vehicle on road surfaces with a low coefficient of friction. .

〔Example〕

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

Figures 1-4 show one embodiment of the invention. In the figure, reference numeral 1 denotes a tandem-type master cylinder, one of which has a liquid feed port 1a connected to a wheel cylinder 4 of a driving wheel via a traction drive device 2 and an anti-lock control device 3. Here, the wheel cylinder 4 is a drum brake wheel cylinder or a disc brake cylinder. The other liquid feeding port 1b is connected to a wheel cylinder of a driven wheel (not shown) only via an anti-lock control device.

The anti-lock control device 3 is constituted by an annular closed circuit in which an electromagnetic decay valve 5, a reservoir 6, a hydraulic pump 7, and an electromagnetic hold valve 8 are sequentially connected by a pipe 9. The electromagnetic decay valve 5 is a normally closed valve that has a shutoff position a and a communicating position, and is biased by a spring 5a to assume the shutoff position a when the solenoid 5b is turned off. The reservoir 6 has a piston 6b in a cylinder 6a.
It has a structure in which the piston 6b is slidably inserted and urged by a relatively weak spring 6C, and when the piston 6b is pressed by the spring 6C and reaches the minimum volume position, the protrusion 6d pushes the piping 9. It functions to open up. 36 is a seal ring. The hydraulic pump 7 is driven by a motor (not shown) and sends out brake fluid from the reservoir 6 side to the electromagnetic hold valve 8 side.The electromagnetic hold valve 8 is located between the blocking position f(a) and the communicating position ( b), and in the normal state with the solenoid 8b turned off, the spring 8a
This is a normally open valve that assumes the communicating position (b) when energized by the valve.

A traction drive device 2 is interposed in a pipe 10a 1ob that connects the electromagnetic hold valve 8 and the liquid feeding port 1a of the master cylinder 1.

The traction drive device 2 includes a traction cylinder 12
, has a traction body 15 in which a reservoir cylinder 13 having a smaller diameter than the traction cylinder 12 and a valve housing chamber 14 are formed. The traction cylinder 12 is configured such that a traction piston 16 is slidably fitted therein, and a small hole 20a at the top is connected to a negative pressure source 18 such as an engine intake pipe or the atmosphere via an electromagnetic switching valve 17. If the solenoid 17b of the electromagnetic switching valve 17 is energized to take the A position, the traction piston 16 moves forward due to the negative pressure, and if the spring 17a is urged to take the B position, it is connected to the atmosphere. , the traction piston 1 is moved by the elastic force of the return spring 19.
6 returns and operates. Note that 20b is a breathing hole drilled in the bottom of the traction cylinder 12, and 37 is a seal ring.

A first liquid passage 21 communicating with the valve housing chamber 14 and a fourth liquid passage 22 communicating with the outside are formed in the reservoir cylinder 13, and a hydraulic traction piston 23 is formed integrally with the traction piston 16. are slidably fitted together, and by the forward movement of the hydraulic traction piston 23, brake fluid is supplied to the reservoir 6 via the piping 24 which is connected to the fourth fluid passage 22 and includes a check valve 25. ing. 38 is a seal ring. 2
Reference numeral 6 denotes a traction valve, in which a valve body 26a, which is biased in the protruding direction by a spring 27 against the hydraulic traction piston 23, is moved toward the valve seat 26 by forward movement.
b, and closes the first fluid passage 21 to prevent the hydraulic fluid from flowing into the valve housing chamber 14 from the reservoir cylinder 13.

Further, in the valve housing chamber 14, a second liquid passage 28 is connected to the liquid feeding port 1a of the master cylinder l via a pipe 10a.
A third liquid passage 30 is formed and connected to the electromagnetic hold valve 8 via a pipe 10b, and a shut valve 31 and a cut valve 32 are built in.

In the shut valve 31, when the traction piston 16 returns, the valve body 31a, which is urged toward the reservoir cylinder 13 by the spring 34, is elastically seated in a valve seat 31b formed at the periphery of the first fluid passage 21. Then, the first liquid passage 21 is closed. Then, when the traction piston 16 moves forward, the rod portion 31c formed on the valve body 31a and loosely inserted into the first fluid passage 21 is pushed up by the valve body 26a of the traction valve 26, and the valve body 31a is pushed up. It moves away from the valve seat 31b and opens the first liquid passage 21.

Thus, the spring 34 that urges the valve body 31a of the shut valve 31 to seat is connected to the traction valve 26.
Its elastic force is set to be weaker than that of the spring 27 that biases the valve body 26a.

Further, the cut valve 32 is slidably supported by a frame 31d formed on the valve body 31a of the shut valve 31, and the valve body 32a, which is biased in the seating direction by the spring 35, is connected to the second liquid passage 28. It seats elastically on the valve seat 32b formed on the periphery and blocks the second fluid passage 28 when the traction piston 16 moves forward, thereby preventing brake fluid from flowing out from the valve housing chamber 14 toward the master cylinder l. do. This spring 35 is also set to have a weaker elastic force than the spring 27.

By the way, the electromagnetic decay valve 5, the electromagnetic hold valve 8, the hydraulic pump 7, and the electromagnetic switching valve 17 are each controlled by a computer (not shown).

Next, the effect will be explained.

First, let's talk about the function as an anti-lock control device.
．． This will be explained with reference to FIGS. 2 and 3. When acting as an anti-lock control device, the vehicle is in a braking state, so
It does not act as a traction control device, and the traction drive device 2 is in the state shown in FIG. 12. Initially, the electromagnetic decay valve 5 and the electromagnetic hold valve 8 are in the normal state shown in FIG. 1, and the hydraulic pump 7 is in a non-driving state.

When the brake pedal 29 is depressed, the pressure fluid generated in the master cylinder 1 passes through the pipe 10a, the 1ob valve storage chamber 14, and the pipe 9, and also passes through the electromagnetic hold valve 8 located at the position (b), and is transferred to the wheel cylinder 4. This results in a braking force being applied to the drive wheels. At this time, the first liquid passage 21 is closed by the shut valve 31. now,
When the hydraulic pressure in the wheel cylinder 4 rises to point (a) shown in Fig. 3 and a decrease in the coefficient of friction between the tires and the road surface is detected from the wheel speed and vehicle speed, a computer (not shown) turns on the power. Then, the electromagnetic hold valve 8 is turned on to take the position (a) (the electromagnetic decay valve 5 is turned off).
actuated and remains in position a). Thereby, the pressure increase of the brake fluid in the wheel cylinder 4 is suppressed and the pressure is maintained at a substantially constant pressure.

Next, to reduce the brake fluid pressure in the wheel cylinder 4 from point (b) to point (c) in FIG.
is turned on to take position b, and the hydraulic pump 7 is turned on.
This is done by driving the brake fluid in the wheel cylinder 4 to flow back to the master cylinder l side. At this time, some brake fluid can be stored in the reservoir 6.

In addition, in order to increase the pressure in the wheel cylinder 4 between points (d) and (e) in the third time, the magnetic decay valve 5 is turned OFF and a
In this state, the electromagnetic hold valve 8 is appropriately set to the (b) position, and the pressure fluid of the master cylinder 1 is supplied to the wheel cylinder 4.

In this way, it is possible to control the brake fluid pressure in the wheel cylinder 4 to a predetermined mode shown in FIG. The distance can be shortened.

Next, let's talk about the function as a traction control device.
．． This will be explained with reference to FIGS. 2 and 4. When acting as a traction control device, the vehicle is under acceleration;
It is not necessary to act as an anti-lock control device, and initially, the electromagnetic decay valve 5 and the electromagnetic hold valve 8 were
In the normal state shown in FIG. 1, the hydraulic pump 7 is in a non-driving state.

When the vehicle runs on a road with a low friction coefficient, the slip rate between the tires and the road surface during acceleration is calculated based on the difference in rotation speed between the driving wheels and the driven wheels, and the calculated slip rate is higher than the set slip rate. If the slippage of the drive wheel is detected, the solenoid 17b is energized to cause the electromagnetic switching valve 17 to take the A position, and the traction cylinder 12 is connected to the negative pressure source 18, thereby reducing the traction piston 16 and the hydraulic pressure. The traction piston 23 moves forward and operates as one unit against the repulsive force of the return spring 19, and the traction valve 26
After blocking the first fluid passage 21, the reservoir cylinder 13
A pressurized liquid is generated, and this pressurized liquid passes through the check valve 25 and is stored in the reservoir 6. Also, traction valve 2
6, the rod portion 3 of the shutter valve 31 closes.
1c is pushed in, and the valve body 31a is pressed against the spring 34.
The valve body 32a of the cut valve 32 compresses the spring 35 and elastically seats on the valve seat 32b, thereby closing the second fluid passage 28.

Almost at the same time as the electromagnetic switching valve 17 is set to the A position, the hydraulic pump 7 is turned on as shown in FIG.
The brake fluid is supplied to the wheel cylinder 4 through the electromagnetic hold valve 8, which increases the brake fluid pressure to the level shown in FIG. 4, producing a braking force on the drive wheels.

Next, when the electromagnetic decay valve 5 is turned on to take position b, the brake fluid in the wheel cylinder 4 is quickly returned to the reservoir 6 and depressurized. By the way, during this pressure reduction, the reservoir 6 provided by the spring 6C
The set hydraulic pressure (po between points ■ and ■ shown in Figure 4) remains in wheel cylinder 4, but during traction control, the engine driving force is acting on the drive wheels, and the drive wheel speed can be sufficiently recovered. Thus, if the set load of the spring 6c is selected, the residual hydraulic pressure in the wheel cylinder 4 will hardly be a problem for traction control.

In addition, when increasing the pressure of the brake fluid (from 0 to 0 points), the electromagnetic decay valve 5 is turned OFF while the hydraulic pump 7 is being driven as described above to take position a, and the reservoir 6 is filled with water. The liquid is sent to the wheel cylinder 4 through an electromagnetic hold valve 8.

By such a combination of increasing or decreasing the pressure of the brake fluid in the wheel cylinder 4, excessive slip of the drive wheels is prevented, and the starting performance and driving stability of the vehicle on a road surface with a low coefficient of friction are improved. be able to.

Once the slippage of the drive wheels has subsided, the electromagnetic switching valve 17 is set to the B position and the traction cylinder 12 is communicated with the atmosphere, and the traction piston 16 and hydraulic traction piston 23 are It works as one unit. At that time, reservoir 6
The brake fluid is recirculated by causing the electromagnetic decay valve 5 to take the position b and the electromagnetic hold valve 8 to take the position (b), and flows through the third fluid passage 30, the valve storage chamber 14, and the first fluid passage. through the passage 21 to the reservoir cylinder 13
flows into. When the traction piston 16 and the hydraulic traction piston 23 return sufficiently, the shut valve 31 is closed.

Since the electromagnetic decay valve 5 is a normally closed valve and the electromagnetic hold valve 8 is a normally open valve, it functions as a fail-safe against braking action in the event of an electrical defect.

FIG. 5 shows another structural example of the traction cylinder 12. In this structural example, the traction cylinder 1
The pore 20b of No. 2 is connected to a positive pressure source 40 such as the oil pump side of a power steering device via the electromagnetic switching valve 17.
It is connected to the.

According to this structural example, if the electromagnetic switching valve 17 located at the B position and connected to the reservoir 41 is switched to give the A position, the traction piston 16 moves forward against the return spring 19. The same effect as in the embodiment can be obtained. In this case, the traction cylinder 12 is allowed to breathe through the pores 20a.

[Effects of the Invention] As understood from the above explanation, according to the present invention, a traction control device that performs traction control by braking operation rather than engine driving force control is integrated into a vehicle anti-lock control device. The anti-lock control and traction control device has a simple and compact structure, is lightweight and inexpensive, and can be incorporated into the engine's negative pressure or the positive pressure of the power steering device as the drive source for the traction drive device. In this respect, the structure is simple and the application to actual vehicles is extremely easy.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, in which FIG. 1 is a cross-sectional layout diagram showing a vehicle anti-lock control and traction control device, FIG. 2 is a cross-sectional view showing a traction drive device, and FIG. The figure shows the changes in brake fluid pressure during anti-lock control and the operational relationship of each device. Figure 4 shows the change in brake fluid pressure and the operational relationship of each device during traction control. Figure 5 shows the traction control. FIG. 7 is a sectional view showing another structural example of the cylinder. 1: Master cylinder, la: liquid feeding 0.2: traction drive device, 3: anti-lock control device, 4: wheel cylinder, 5: ' [day-key valve, 6: reservoir, 6
a Niji cylinder, 6b: piston, 6c Niji spring, 7
: Hydraulic pump, 8: Electromagnetic hold valve, 9: Piping, 1
0a, lOb: Piping, 11 Traction cylinder, 13
: Reservoir cylinder, 14; Valve accommodation chamber, ts: Traction body, +6: Traction piston 917 two electromagnetic switching valves, 1B: Negative pressure source, 19: Return spring, 21: First fluid passage, 22: Fourth passage fftFIP,,
23: H, pressure traction piston, 24: Piping, 25
: Check valve, 26: Traction valve, 27:
Spring, 28: 21st liquid passage, 30: 3rd liquid passage, 3
1: Shut valve, 31a: Valve body, 31b: Valve seat, 31C: Rod part, 31d: Frame body, 32: Cut valve, 32a: Valve body, 32b: Valve seat, 34.35 Spring, 40: Positive pressure source. Agent Patent Attorney Mae 1) Hiroshi 1st figure 1 so0b 3rd figure 4th figure Azuma Bonfu. . ,,ON Fig. 2 1 so 1 0b Fig. 5

Claims (1)

[Claims] (1) A closed circuit in which an electromagnetic decay valve, a reservoir, a hydraulic pump, and an electromagnetic hold valve are connected in sequence, a wheel cylinder connected between the electromagnetic decay valve and the electromagnetic hold valve, and a master connected to the electromagnetic hold valve. a cylinder, and a traction drive device interposed between the master cylinder and the electromagnetic hold valve, the traction drive device being connected to a positive pressure source or a negative pressure source via an electromagnetic switching valve. , a traction piston slidably fitted to the traction cylinder; a hydraulic traction piston integrally formed with the traction piston and slidably fitted to the reservoir cylinder; and a first fluid passage in the reservoir cylinder. a valve accommodating chamber connected to the master cylinder via a second liquid passage, and connected to the electromagnetic hold valve via a third liquid passage; a traction valve that closes the first fluid passage when the piston moves forward; a shutter valve that is built in the valve housing chamber and closes the first fluid passage when the traction piston moves back; An anti-lock control and traction control device for a vehicle, comprising: a cut valve that closes the second fluid passage when activated; and a pipe having a check valve capable of supplying the pressure fluid of the reservoir cylinder to the reservoir. .