JPS63149249A - Hydraulic gear for car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention has a pair of front wheels and a pair of rear wheels, at least one pair of the first and second wheels being driving wheels, and each wheel A type of vehicle hydraulic system that is equipped with hydraulically operated brakes, which includes a combination booster or servo that operates all brakes, a hydraulic master cylinder assembly, and a speed sensor that senses the rotational speed of each wheel. a modulator means for modulating the supply of fluid from said assembly to the brake; and a modulator means operable to receive a signal from the speed sensor and actuate the modulator means to control operation of the brake; The present invention relates to a vehicle hydraulic system of the type having an electronic control module that controls the behavior of the respective wheel depending on the type and duration of the signal.

[Prior Art and Problems to be Solved by the Invention] The latest trend in motor vehicles, especially medium- and small-sized vehicles, which are equipped with large engines, or at least engines capable of generating relatively large amounts of power, is that the amount of power applied to the wheels There is a problem of preventing a driving wheel from spinning when the driving torque exceeds the pressure force between that wheel's tire and the road or other surface. The crimp force is, of course, primarily dependent on the coefficient of friction (μ) between the tire and the road surface, which depends on the coefficient of friction (μ) on the road itself, and the reaction force at that point, which depends on the load applied to its wheels by the weight of the bouncing vehicle. determined by For this reason, even if the road surface has a relatively high coefficient of friction (μ), the torque of the engine connected to it cannot exceed, for example, the weight on the drive wheels multiplied by the coefficient of friction multiplied by the rotation radius of the tires. Wheel spinning may still occur.

When the driving wheels on one side of the vehicle spin due to the presence of the differential, insufficient drive torque is transmitted from the engine through the gearbox to the non-spinning wheels on the opposite side of the vehicle. Because insufficient traction is provided, no forward motion is imparted from the engine to the vehicle.

It is known to equip motor vehicles, especially large luxury models, with complex electronic means to prevent wheel spinning. Obviously, the installation of such electronic means is expensive and adds considerably to the total price of the vehicle.

British patent A-2168771 is known in which a pedal-actuated combined booster and parent cylinder assembly has a booster chamber and an auxiliary chamber, the booster chamber being normally operated by displacement by the pedal of a valve spool incorporated in the brake control valve. Normally pressurized to actuate the assembly for braking, fluid is vented from the booster chamber into the auxiliary chamber upon release of the pedal, and a separate valve is connected to the pedal in response to drive wheel spin. independently actuating the assembly, the separate valve directing fluid under pressure into the booster chamber and directing a portion of the fluid first into the auxiliary chamber through the brake valve, which acts as a restrictor. It is configured to flow.

Means and Effects for Solving the Problems According to the invention, in a hydraulic system of the type described above, a pedal is provided for actuating said composite assembly and the brake is normally used as a vehicle retarder, and a servo pressure is provided. traction control valve means responsive to a spin signal from the drive wheels and received by the control module, the control valve being operative to control generation of servo assist for said assembly in response to pressure generated by pedal actuation; controls generation of servo assist for said assembly, thereby actuating said assembly independent of pedals to apply brakes to said driving wheels, and generation of servo assistance by means of a traction control valve is controlled by a servo pressure control valve. be independent of and bypass it.

By actuating the assembly independently of the pedals, traction control can be provided automatically by preventing spinning of the respective wheel, without assistance from the driver and independently of the servo pressure control valve; The induced torque from the braked wheel is then transmitted to the other non-spinning wheel of the driven wheel pair to impart forward drive motion to the vehicle.

Conveniently, the brakes on said one driving wheel are applied at a rate and in a sequence determined by the operation of the modulator means. As a result, the brakes are released when the acceleration of the wheels decreases from a critical value, and traction can then be applied from the wheels to the vehicle.

Preferably, the assembly is adapted to be actuated independently of the pedal by the provision of a solenoid actuated valve, the solenoid actuated valve comprising a solenoid responsive to a signal from the control module and actuated by the solenoid. a valve member adapted to alternately cooperate with a pair of first and second spaced apart valve seats, the cooperation of the valve member with the first seat being energization of the booster by a solenoid-operated valve; but to prevent
The assembly permits application of the brake when actuated by the pedal, and cooperation of the valve member with the second seat applies the brake under control of the modulator means to the driving wheel spinning due to energization of the booster and to the trailing wheel. brake application is prevented.

In some configurations, a first solenoid-operated valve is operable in series with the first solenoid-operated valve and is operable to isolate the brake to the trailing wheel from the source of the brake application prior to application of the brake to the one driving wheel. It may be necessary to include two solenoid operated valves.

Embodiments and Effects of the Invention Several embodiments of the invention are illustrated in the accompanying drawings.

In the hydraulic system illustrated in FIG. 1 of the accompanying drawings, the front wheel 1
, 2 are driven from the vehicle's engine through a conventional gearbox and differential assembly. The wheels 3, 4 are not driven and can rotate freely.

The front wheels 1 and 2 are provided with brakes 5 and 6, respectively.
In addition, the rear wheels 3 and 4 are provided with brakes 7 and 8, respectively.

A compound hydraulic booster and tandem parent cylinder assembly 10 actuated by a pedal 11 for service braking is incorporated into the device.

The assembly 10 has primary and secondary pressure spaces 12 and 13 in front of primary and secondary pistons 14 and 15 operating in a common bore 16 in a housing 17. -Next piston 1
4 has a different profile that operates in the stepped portion of the hole 16. The portion 18 of the piston 14 having a larger diameter passes through a sealed opening from which an axial extension 21 of reduced diameter projects rearwardly into the end closure 20 of the piston 14 and its end of the bore 16. Booster space 1 defined between
9 constitutes a booster piston exposed to pressure.

- The primary pressure space 12 in front of the secondary piston 14 normally communicates with the fluid reservoir through a recovery port in the wall of the housing 17 of the assembly.

Similarly, the secondary pressure space 13 in front of the secondary piston 15 normally communicates with the reservoir through a recovery port 23 in the wall of the piston 15 itself.

The primary piston 14 forms an auxiliary bore 30 in which an auxiliary piston 31 operates, and the piston 31 is connected to the inner end of a push rod 32 actuated by the pedal 11.

A damper chamber 33 defined in the auxiliary bore 30 by the inner end of the auxiliary piston 31 is connected to the reservoir through a one-way valve 34, a restricted radial passage 35 and a flat opening 36 in the wall of the housing 17. . One-way valve 34 is normally biased to the closed position by a weak spring 37.

To operate the booster by pressurizing the booster space 19, hydraulic fluid under pressure is supplied from the hydraulic accumulator 41 to the booster space through the internal passage 40 under the control of a servo pressure control valve 42 incorporating a control spool 43. be done. Spool valve 42 is contained within housing 17 and is actuated by a relatively small forward movement of piston 14 sufficient to slightly pressurize pressure space 12 and expose one end of spool 43 thereto.

The brake 5 of the front wheel 1 and the brake 8 of the diagonally opposite rear wheel 4 are both pressurized from the pressure space 13 of the parent cylinder assembly 10, and the brake 6 of the front wheel 2 and the diagonally opposite rear wheel 4 are pressurized from the pressure space 13 of the parent cylinder assembly 10. 3 are both pressure spaces 12
Pressurized from For this reason, the device is of rXJ split type.

The fluid supply to the brakes is modulated by a modulator assembly 44 which is adapted to independently control the operation of the brakes in response to energizing current from an electronic control module 45.

Modulator assembly 44 includes four separate modulators 5 of known type.
It has 0.51.52.53. Specifically, a single pump assembly driven by electric motor 54 provides a source to replenish fluid drawn from the brakes at the end of the skid signal and the pump assembly charges accumulator 41 with fluid drawn from the source. It can work like this. For convenience, the pump assembly is disclosed in the applicant's patent application filed on the same date.
constitutes the subject matter of this issue and requires no further explanation here.

Each modulator 60, 51, 52, 53 responds to a signal from a respective speed sensor 81, 62, 63, 64 to output a signal from a respective pressure space 13, 12 to a respective brake 5, 6.
, 7.8 incorporates a solenoid-operated valve that initiates modulation of the fluid supply to . The electrical signal from the sensor is fed into an electronic control module 25 that can generate an energizing current depending on the type and duration of the signal.

When the brakes 5, 6, 7.8 are applied for service operation to cause vehicle retardation, the pedal 11 acts to advance the boost piston 18 in the bore 16. This piston actuates the spool valve 42 as described above and the accumulator 4 which is supplied to the booster space 19.
The high pressure fluid from 1 acts to advance piston 14 in bore 16 to increase the force from pedal 11. Pressurized fluid is simultaneously supplied from both pressure spaces 12 and 13 to the brakes 5 and 6 of the driving wheels 1 and 2, and from the diagonally opposite front wheel brakes 5, 6 to the rear wheel brakes 8 and 7, respectively. be done.

The behavior of the braked front wheels 1, 2 and rear wheels 3, 4 is determined in a known manner depending on the energizing current from the control module 45 depending on the signal from the respective speed sensor Or, 82.83.84. controlled by their respective modulators.

When the pressure applied to one of the brakes 5.6, 7.8 is relieved to correct a skid condition, brake fluid is driven by the electric motor 54 and the modulator assembly 4.
4 is automatically refilled by the built-in pump.

The assembly IO can be actuated independently of the pedals 11 to prevent the front wheels from spinning when it is subjected to a drive torque that exceeds the pressure force between the tires of the front wheels and the road and other surfaces. It will be corrected as follows.

As illustrated in FIG. 1, the assembly incorporates a traction control solenoid operated valve 65. Valve 65 has a solenoid 66 adapted to be energized by electrical current from control module 45 and adapted to control a valve head 67 which can engage alternately spaced valve seats 68 and 69. . Seat 69 connects two different parts 70 and 7 of passage 40
1 to control communication between them. seat 6
8 is located between the spool valve 42 and the passageway section 71 to provide direct communication between the accumulator 41 and the booster space 19.

Typically, when solenoid 66 is energized, valve head 87 is urged into engagement with seat 68 by a spring (not shown). This places the two passage sections 70 and 71 in direct communication, but blocks direct communication between the accumulator 41 and section 71. However, accumulator 4
1 may still be in communication with passage 40 under the control of spool valve 42 to control booster operation of assembly 10 and brakes 5, 6, 7.8 for vehicle retardation as described above.
apply.

When one of the driving wheels, for example driving wheel 1, is subjected to excessive wheel acceleration indicating a "wheel spin" condition, the control module 4
A signal from each speed sensor 61 received by 5 causes the module to issue an electrical signal that energizes a solenoid 68 to move the head 67 away from the seat 68 and into the seat 69.
Press to engage. This insulates passageway section 70 from section 71 and places accumulator 41 in direct communication with passageway section 71 to pressurize booster space 19 . Assembly 10 is then operated as described above to
and 13 to a modulator assembly 44, which supplies fluid under pressure to the brake 5 and the wheel 1.
Brake only.

When traction is restored to wheel 1, the signal from sensor 61 drops and solenoid 66 is deenergized by valve 65 returning to its initial position.

The control module 45 has a speed sensor 61.62.63.6
a sensor 61 or 6 operative to distinguish signals from 4 and which indicate a "wheel spin" condition on any wheel;
When receiving a signal from 2, the control module 45 not only energizes the solenoid 66 as described above, but also the solenoid of the valve of the modulator 51 or 50 leading to a non-spinning wheel on a surface with a high coefficient of friction (μ). energizes the wheel to prevent the brakes on that wheel from being applied. It also energizes the solenoids of modulators 52 and 53 and rear brakes 7 and 8.
prevent it from being applied.

Thus, in the "wheel spin" prevention mode,
Modulator assembly 44 operates in a manner opposite to the anti-lock mode modulator assembly described above.

When the assembly 10 is actuated to normally apply the brakes, the auxiliary piston 31 acts on the primary piston 14 to advance it into the bore and initiate actuation of the assembly with boost assistance in a known manner. do.

Therefore, the effective volume of chamber 33 is minimal. During such braking operations, traction control solenoid operated valve 65 is not activated.

During "traction control," the assembly 10 is operated independently of the pedals to control "wheel spin" as described above. Since the pedal 11, the push rod 37 and the auxiliary piston 31 are immovably restrained, the secondary piston 14 moves relatively away from the auxiliary piston 31, and the effective volume of the chamber 33 is increased and the weak spring 37 The one-way valve 34, which opens against a load, is filled with fluid flowing through it.

When the driver moves his foot from the accelerator to the brake pedal 11,
The brake application force is transmitted to the auxiliary piston 31 through the push rod 32 and the chamber 33 is pressurized. Meanwhile, valve 34 is closed and fluid is forced out of chamber 33 at a rate determined by the flow through passageway 35.

During this operation, the driver does not experience a sudden long travel, but feels a momentary pedal recoil and braking effect as the brake pedal slowly lowers as the effective volume of the chamber 33 decreases as described above.

In the brake system illustrated in FIG. 2, assembly 10 includes a pneumatically actuated booster and auxiliary parent cylinder assembly 80 and a tandem parent cylinder 81 remote from booster 80. Afterwards, the brakes of the wheels 3, 4 are applied independently of the brakes of the front wheels by a pipeline 83 from the pressure space 84 of the auxiliary main cylinder 82 of the booster 80, and the booster 80 is applied from the branch line 83 from the pipeline 82 to the main cylinder. Also provides servo pressure for 81.

Assembly 80 has a booster 85 that actuates an auxiliary parent cylinder 83. Booster 80 and parent cylinder 81 are disclosed in patent application No. 8, filed January 9, 1987 by the applicant.
Similar in structure to the booster and parent cylinder that constitute the subject of No. 00484, there is no need to describe it in detail, and the two units have external connections 86 and 87 to facilitate installation.
and energization of booster 80 is normally controlled by servo pressure control valve 42 .

Traction control solenoid operated valve 85 is connected to control module 45
in response to a "wheel spin" signal from and independently of the normally inactive pedal 11 and associated input mechanism.
The booster 80 is configured to be energized.

The motor actuated modulator assembly 44 has a single modulator 89 with a single solenoid actuated valve, but two separate modulators 52.
and brakes of the two rear wheels of the vehicle instead of 587.
Modified to provide for modulating the supply of fluid to 8. The modulator 89 is connected to the wheel speed sensor 63 or 6
4.Respond to a signal from any of 4.

Solenoid actuated traction control valve 65 has a double acting valve member 90 that alternately engages between spaced apart valve seats 91 and 92. Valve seat 91 is located between the booster's air energizing passage 93 and its energizing boost chamber 94, and seat 92 is located between the air inlet passage 95 and boost chamber 94.

In the normal, inoperative position of the device, solenoid operated valve 65 is deenergized to move valve member 90 away from seat 91 and into engagement with seat 92.

During normal braking, the remote booster 80 applies the brake directly to the rear wheels 3.4 and provides servo assistance to the parent cylinder 81 to apply the brake to the front wheels 1.2.

During ring lock control of any wheel, the motor actuated modulator assembly 44 controls the release and reapplication of pressure to the brakes of the wheel undergoing antilock control and the booster takes no corrective action.

When the front wheels spin, this is sensed by their respective speed sensors, and controller 45 energizes the solenoid of valve 64 to force double-acting valve member 90 into engagement with seat 91 , causing passage 93 is insulated from the boost chamber 94 and air is admitted into the boost chamber 94 to energize the booster 80 independent of pedal motion.

Remote booster 80 is activated to begin applying brakes to both the front and rear wheels.

The brakes of the driven rear wheels 3, 4 are released by actuation of the anti-lock solenoid valve behind the modulator 89, and the front driven wheels 1, 2 are controlled as in the system of FIG. 1 to prevent wheel spin. .

Specifically, when pressure is applied to the front wheels 1, 2, a front wheel that does not spin will energize its ring lock solenoid of modulator assembly 50 to prevent pressure from being applied.

Meanwhile, the solenoid on the valve corresponding to the "spinning" wheel remains deenergized, allowing pressure to be applied to that wheel's brake to prevent it from spinning. At the same time, the electric motor of assembly 54 rotates to operate the pump.

When the wheels stop spinning, braking pressure escapes to the expansion chamber and the pump returns fluid to the parent cylinder 81.

When the wheels start spinning again, the braking pressure is reduced to 4°4
is reapplied if its corresponding ring lock solenoid is deenergized. In this way, the speed of the driven wheels 1.2 can be controlled many times per second by control of the anti-lock modulator 45 and energized by the electric motor 54.

The booster 80 continues to apply brakes to the front wheels 1, 2 independently of the pedal, but no further modification of its pressure is required.

When the vehicle is in motion and no further control is required, the solenoid of valve 65 is deenergized and the hook system returns to normal.

If the brakes are applied before the device returns to normal, valve 65
The solenoid is deenergized, pressure builds up in the booster chamber 96 of the current cylinder 91 to brake the front wheels, and the rear wheel brakes 7.8 are reconnected to the auxiliary booster 83. Immediately following traction control, the primary piston of the parent cylinder 81 can be displaced from its normal position. However, pedal travel does not increase because as soon as the control chamber defined between the pedal-actuating piston and the -next piston is isolated from the reservoir, a fluid column is formed between the pedal-actuating piston and the -next-piston. .

The device illustrated in FIG. 3 is for a rear wheel drive type vehicle in which the rear wheels 3, 4 tend to spin.

In this arrangement, the solenoid-operated anti-lock modulator valve 89 has been replaced by two similar valves 97,98, each of which operates in accordance with a signal from a respective speed sensor 63.84 for each rear wheel 4. 3, the release and reapplication of the brakes are controlled. A single action solenoid operated valve 100 is included to isolate the auxiliary cylinder 83 from the parent cylinder 81 to prevent application of front wheel 1, 2 brakes when traction control is required.

In this manner, the solenoids of both valves 65 and 100 are energized when traction control is required.

The booster 80 is activated to brake the rear wheels 3, 4 for traction control according to a signal from the speed sensor 83.64 and under control of the respective anti-lock valve 97.98. However, since the valve 100 is closed to insulate the auxiliary main cylinder 83 and the main cylinder 81, the front wheels 1 and 2 are not braked.

[Brief explanation of the drawing]

Figure 1 is a layout diagram of a hydraulic system for a four-wheeled vehicle, and Figure 2 is a layout diagram similar to Figure 1, but includes a pneumatic booster remote from the main cylinder; The figure is the second
It is a layout similar to the figure, but suitable for use in a rear wheel drive type vehicle. 1.2... Front wheel 3, 4... Rear wheel 5,
6.7.8... Brake 10... Combined booster and tandem parent cylinder assembly 11... Pedal 12.18... Pressure space 14, 15... Piston 16... Hole 1
7...Housing 19...Booster space 41...Hydraulic pressure accumulator 42...Servo pressure control valve 44...Modulator assembly 45...Electronic control module 61, 62.63.64. ... Speed sensor 65 ... Traction control solenoid operated valve 68 ... Solenoid 67 ... Valve head 8
8, 69.91.92...Valve seat 80...Pneumatically actuated booster and auxiliary master cylinder assembly

Claims (6)

[Claims] (1) A pair of front wheels (1, 2) and a pair of rear wheels (3,
4), the at least one pair of first and second wheels being driving wheels, and each wheel having a hydraulic brake (5, 6).
, 7, 8), a combination booster or servo for applying all brakes, and a hydraulic master cylinder assembly (10), and sensing the rotational speed of each wheel. speed sensors (61, 62, 63, 64),
modulator means (44) for modulating the supply of fluid from the assembly to the brake; and operative to receive a signal from the speed sensor and actuate the modulator means to control operation of the brake; electronic control module (which controls the behavior of each wheel depending on the type and duration of the
45), comprising a pedal (11) for normally applying the brakes to actuate said composite assembly (10) for service vehicle delay, and comprising a servo pressure control valve ( 42) a traction control operative to control generation of servo assistance for said assembly in response to pressure generated by pedal actuation, responsive to spin signals from the drive wheels and accepted by a control module; Valve means (65, 100) control the generation of servo-assistance for said assembly, thereby actuating said assembly independent of pedals to apply brakes to said drive wheels, and servo-assistance by traction control valve means. 1. A vehicle hydraulic system characterized in that the generation of the servo pressure control valve is independent of the servo pressure control valve and bypasses the servo pressure control valve. 2. Hydraulic system according to claim 1, characterized in that said one drive wheel is applied at a speed and sequence determined by the operation of modulator means (44). (3) the assembly (10) is adapted to be actuated independently of the pedal by a solenoid-operated valve (65), the solenoid-operated valve being responsive to a signal from a control module; a pair of first and second spaced apart valve seats (91, 92);
and a valve member (67) adapted to cooperate alternately with the first seat, the cooperation of the valve member with the first seat being such that upon actuation of said assembly by the pedal a booster (19) by means of a solenoid-operated valve is provided.
, 80) to prevent energization but permit application of the brake, and cooperation of the valve member with the second seat allows energization of the booster to cause the driving wheels to spin under control of the modulator means (44). 3. The hydraulic system according to claim 1, wherein the hydraulic system applies a brake and prevents application of the brake to a driven wheel. (4) a second solenoid-operated valve (100) operable in series with the solenoid-operated valve (65) to isolate the brake of the driven wheel from the source of braking application prior to application of the brake to said one driving wheel; 4. The hydraulic device according to claim 3, wherein the hydraulic device is operable. (5) The assembly (10) is connected to the first and second pressure spaces (12
, 13) and a booster space (19) adapted to be pressurized by fluid from a high pressure source (41), the source (41) for the service delay. and the booster space (19) is controlled by a servo pressure control valve (42) in response to the initial pressurization of one of the pressure spaces (12) upon actuation of the pedal and a source (41) for traction control. ) and the booster space (19) is controlled by a traction control valve member (65, 100).
Hydraulic device according to any one of paragraphs. (6) The assembly (10) includes a tandem hydraulic parent cylinder (81) having first and second pressure spaces and a booster (80).
) and a pneumatically actuated booster having an auxiliary parent cylinder (83) and a booster space (96) associated with the auxiliary parent cylinder assembly (80), the booster space having a booster (
The booster (80) for service delay is pressurized by the fluid pressure generated in the pressure space (84) of the auxiliary master cylinder (83) in response to the energization of the assembly (10).
) is controlled by a servo pressure control valve in response to the initial pedal actuation of the booster (80) for traction control, and the energization of the booster (80) for traction control is controlled by traction control valve means (65, 100). The hydraulic device according to any one of the ranges 1 to 3.