JPH0656028A - Booster brake device for vehicle - Google Patents

Abstract

PURPOSE:To set freely the operation stroke of a brake operater without relation to the operation stroke of a booster piston and provide an excellent brake sense. CONSTITUTION:A booster main body 10 inside is divided into an operation oil pressure chamber 14 ranging to a vehicle wheel brake 8 and a relay oil pressure chamber 16 ranging to a stroke accumulator 19 by means of a booster piston 12 driven by means of a drive device 13, and an input port 5 ranging to the output port 3 of a master cylinder 2 is provided at the booster main body 10. This input port 5 opens to the operation oil pressure chamber 14 by the retreat limit of the booster piston 12, and opens to the relay oil pressure chamber 16 at the time of booster piston 12 advance, and the output signals of a stepping-on force sensor 21, a lock approximation sensor 22 and a spin sensor 23 are inputted into a controller 20 controlling the operation of the drive 13. As a result, the anti-lock and spin control of a vehicle wheel becomes possible, and fail-safe at the time of drive device trouble can be secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster braking system for vehicles such as automobiles and motorcycles.

[0002]

2. Description of the Related Art Conventionally, there has been known a booster device in which a booster piston is operated so as to follow the forward / backward movement of a valve piston interlocked with a brake operator, and the brake master cylinder is operated by the booster piston. (See, for example, Japanese Patent Publication No. 3-44015).

[0003]

In such a device, since the stroke equivalent to that of the booster piston must be given to the valve piston interlocked with the brake operating element, the stroke of the brake operating element can be freely set in consideration of the braking feeling. It cannot be set.

The present invention has been made in view of such circumstances, and the stroke of the brake operator can be freely set independently of the stroke of the booster piston while accurately obtaining the feeling of braking, and the wheel can be It is an object of the present invention to provide a booster system for a vehicle, which enables anti-lock control for avoiding locking of the vehicle, traction control for preventing wheel spin, and the like.

[0005]

In order to achieve the above object, the present invention provides a booster body, and a booster body which divides a cylinder hole of the booster body into a front working hydraulic chamber and a rear relay hydraulic chamber. A booster cylinder is formed from the piston, and a drive device capable of driving the booster piston forward and backward is connected to the booster piston, a wheel brake is connected to the working hydraulic chamber, and a stroke accumulator is connected to the relay hydraulic chamber. An input port, which communicates with the working hydraulic chamber at the backward limit of the booster piston but communicates with the relay hydraulic chamber when the booster piston moves forward, is provided in the booster body, and this input port is operated by a brake operator. The output port of the master cylinder is in communication, and the drive unit is connected to the operating state of the brake operator and the state of the wheels. Flip and is characterized in that to connect the control device for controlling operation of the driving device.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially longitudinal side view of a vehicle booster braking device to which the present invention is applied. In the figure, an output port 3 of a known master cylinder 2 operated by a brake pedal 1 (brake operator) is connected to an input port 5 of a booster cylinder 4 via a hydraulic hose 6, and an output port of the booster cylinder 4 is also shown. 7 is connected to a hydraulically operated portion of the wheel brake 8 via a hydraulic hose 9.

The booster cylinder 4 comprises a booster body 10
And a booster piston 12 that slides in the cylinder hole 11 of the booster body 10. At the rear end of the booster piston 12, a drive device 13 that drives the booster piston 12 back and forth.
Are connected.

The booster piston 12 is constructed by integrally connecting a pair of front and rear piston portions 12a and 12b arranged at a constant interval by a rod portion 12c. The front piston portion 12a defines an operating hydraulic chamber 14 between the front piston 12 and the front end wall of the booster body 10, and the output port 7 is connected to the operating hydraulic chamber 14. A return spring 15 for urging the booster piston 12 in the backward direction is housed in the working hydraulic chamber 14.

The front and rear piston parts 12a and 12b define a relay hydraulic chamber 16 therebetween. On the side wall of the booster body 10, the input port 5 and an accumulator port 17 located behind the input port 5 are provided. The input port 5 opens into the working hydraulic chamber 14 when the booster piston 12 is located at the backward limit. When the booster piston 12 moves forward from the backward limit even slightly, it is switched to the opening to the relay hydraulic chamber 16. Further, the accumulator port 17 is always open to the relay hydraulic chamber 16, and the stroke accumulator 1 is connected to this via a hydraulic hose 18.
9 is connected.

The drive unit 13 controls its operation,
A control device 20 including a computer is connected to the control device 20, and output signals from a pedaling force sensor 21, a wheel lock approach sensor 22, a wheel spin sensor 23, and the like provided in an operation system of the master cylinder 2 are input to the control device 20. To be done.

FIG. 2 is a vertical sectional side view of the drive unit 13. In the figure, the drive unit 13 includes an electric motor 25,
The electric motor 25 includes a rotor 26 and an operating shaft 28 screwed through a ball screw 27. The housing 29 of the electric motor 25 is bolted to the rear end of the booster body 10, and the front end surface of the housing 29 receives the booster piston 12 to regulate the backward movement limit thereof. The operating shaft 28 has a front end projecting forward of the housing 29 to push the booster piston 12. Further, the actuating shaft 28 has a rear end projecting into a spring chamber 30 formed in the rear portion of the housing 29, and a return spring 32 for biasing a stopper plate 31 fixedly provided at the rear end rearward is accommodated in the spring chamber 30. To be done. The stopper plate 31 contacts the rear wall of the spring chamber 30 to regulate the backward movement limit of the operating shaft 28. The stopper plate 31 has a protrusion 31a on its outer periphery, and the protrusion 31a is slidably engaged with a key groove 33 formed on the inner peripheral surface of the spring chamber 30. In this way, the operating shaft 28 is prevented from rotating and can move in the axial direction, and can be moved forward / backward by the forward / reverse rotation of the rotor 26.

3 and 4 are a vertical sectional side view and a partially cutaway plan view of the stroke accumulator 19, respectively. In these figures, the accumulator body 35 of the stroke accumulator 19 has circular recesses 36, 3 on both upper and lower end surfaces.
6, and several bolts 38 on the upper and lower end surfaces of the core plate 37 so as to close the open ends of the recesses 36, 36.
It is composed of a pair of end plates 39, 39 which are bound together.
A metal diaphragm 40 is provided in each recess 36, and an expansion regulating plate 4 that holds the outer peripheral portion of each diaphragm 40 between the core plate 37.
And 1 are accommodated.

Each diaphragm 40 cooperates with a seal member 42 interposed between the outer peripheral portion of the diaphragm 40 and the core plate 37, and the pressure accumulating chamber 43 and the expansion regulating plate 41 on the core plate 37 side inside each recess 36.
And the air chamber 44 on the side. Upper and lower accumulator chambers 43, 43
Together with the hydraulic hose 1 through the through hole 45 of the core plate 37.
Connect to 8. After all, both pressure accumulating chambers 43, 43 are always in communication with the relay hydraulic chamber 16 via the hydraulic hose 18.

Next, the operation of this embodiment will be described.

Master cylinder 2 and booster cylinder 4
1, the input port 5 of the booster cylinder 4 is open to the working hydraulic chamber 14. Therefore, when the hydraulic oil expands or contracts due to temperature changes,
The working oil flows between the working hydraulic chamber 14 and the master cylinder 2.

If the master cylinder 2 is actuated by depressing the brake pedal 1 for braking, the pedal force sensor 2
1 detects the pedaling force applied to the brake pedal 1, emits a pedaling force signal corresponding to the pedaling force, and the control device 20 receives this signal.
First, regardless of the strength of the pedaling force signal, the electric motor 25 is driven to rotate in the normal direction by a predetermined angle, and as shown in FIG.
Thus, the booster piston 12 is moved forward by a predetermined amount, the input port 7 is opened to the relay hydraulic chamber 16 side, and then the electric motor 25 is normally driven according to the strength of the pedaling force signal. When the booster piston 12 is pushed forward by the forward movement of the operating shaft 28 due to the forward drive of the electric motor 25, hydraulic pressure corresponding to the forward movement amount is generated in the operating hydraulic chamber 14, and this is output from the output port 7. It is transmitted to the wheel brakes 8. In this way, the wheel brake 8 can exert a braking force according to the pedaling force applied to the brake pedal 1. On the other hand, input port 5
According to the switching of the opening to the relay hydraulic chamber 16, the relay hydraulic chamber 1
Accumulator chamber 4 of the stroke accumulator 19 via 6
Connect to 3,43. Therefore, the hydraulic oil is supplied from the master cylinder 2 to the pressure accumulating chambers 43, 43 through the relay hydraulic pressure chamber 16 in response to the depression of the brake pedal 1, and the diaphragms 40, 40 are moved to the pressure accumulating chamber 4 in accordance with the increase in the amount of the supplied oil.
It expands and deforms so as to increase the volume of 3,43. In other words, the diaphragms 40, 40 are pulled in all directions,
The repulsive force generates a hydraulic pressure in the pressure accumulating chambers 43, 43, and this hydraulic pressure is transmitted to the master cylinder 2 as a reaction force, and the operator can obtain a brake feeling in response to this.

By the way, the stroke accumulator 19
The pressure accumulation characteristic of can be freely set by selecting the spring constant and the maximum deformation amount of the diaphragm 40. Therefore, the setting allows the brake pedal 1 to have a desired operation reaction force regardless of the stroke of the booster piston 12. And the operation stroke can be given.

When the wheels are about to lock during this braking, the lock proximity sensor 22 outputs a lock proximity signal, and the control device 20 receiving this signal rotates the electric motor 25 in the backward direction, which causes the working hydraulic chamber 14 to rotate. Since the pressure is reduced, it is possible to reduce the braking force of the wheel brakes 8 and avoid the locked state of the wheels.

When the master wheels 2 and the booster cylinders 4 are in a resting state and the drive wheels spin due to their excessive driving force or the low friction coefficient of the road surface, the spin sensor 23 sends a spin signal to the controller 20. , The control device 20 drives the electric motor 25 in the normal direction,
The booster piston 12 is moved forward by the actuating shaft 28, thereby raising the pressure of the actuating hydraulic chamber 14 and actuating the wheel brakes 8 to suppress spin of the drive wheels.

Next, due to a failure such as a disconnection, the electric motor 25
The case where the device becomes inoperable will be described. In such a case, the operating shaft 28 continues to be held in the retracted limit by the return spring 32, so that the booster piston 12 also returns to the return spring 15.
Is held in the reverse limit by the
It will continue to open to 4. If the master cylinder 2 is operated in such a case, the output hydraulic pressure is changed to the input port 5
Since the hydraulic pressure is transmitted to the working hydraulic chamber 14 via the, the pressure in the chamber 14 can be increased to operate the wheel brake 8. Therefore, fail safe is achieved. In this case, since the booster piston 12 blocks the master cylinder 2 and the relay hydraulic chamber 16, the hydraulic oil sent from the master cylinder 2 is not sent to the stroke accumulator 19, and the hydraulic oil chamber 14 is not operated. Is supplied to.
Therefore, there is no liquid loss, and it is possible to suppress an unnecessary increase in the depression amount of the brake pedal.

Although the electric motor 25 is used as the drive unit 13 in the above embodiment, a linear solenoid may be used instead.

[0023]

As described above, according to the present invention, the booster cylinder is formed from the booster body and the booster piston which divides the cylinder hole of the booster body into the working hydraulic chamber at the front part and the relay hydraulic chamber at the rear part. A drive device capable of driving the booster piston forward and backward is connected to the booster piston, a wheel brake is connected to the working hydraulic chamber, and a stroke accumulator is connected to the relay hydraulic chamber. In the booster body, an input port that communicates with the working hydraulic chamber but communicates with the relay hydraulic chamber when the booster piston moves forward is provided with an output port of a master cylinder operated by a brake operator. In communication with the drive device, the drive device operates according to the operation state of the brake operator and the state of the wheels. Since a control device for controlling is connected, the operation accumulator characteristics of the stroke accumulator give an operation reaction force to the brake operator, and its operation stroke can be freely set, giving the driver a good braking feeling. You can In addition, the anti-lock control and spin control of the wheels can be performed by operating the drive device by the control device according to various states of the wheels. Further, when the drive device fails, the wheel brake can be operated by the output hydraulic pressure of the master cylinder, and fail-safe can be secured.

[Brief description of drawings]

FIG. 1 is a side view, partly in vertical section, of a booster brake system for an automobile according to an embodiment of the present invention.

FIG. 2 is a partially longitudinal side view of the drive device in FIG.

FIG. 3 is a vertical sectional side view of the stroke accumulator in FIG.

FIG. 4 is a partially cutaway plan view of FIG.

5 is an explanatory diagram of the operation of the booster cylinder in FIG.

[Explanation of symbols]

 1 Brake pedal as a brake operator 2 Master cylinder 3 Output port of master cylinder 4 Brake cylinder 5 Input port of booster cylinder 7 Output port of booster cylinder 8 Wheel brake 10 Booster body 11 Cylinder hole 12 Booster piston 13 Drive device 14 Hydraulic pressure Chamber 16 Relay hydraulic chamber 19 Stroke accumulator 20 Controller

Claims (1)

[Claims] 1. A booster body for partitioning a booster body (10) and a cylinder hole (11) of the booster body (10) into a front working hydraulic chamber (14) and a rear relay hydraulic chamber (16). (12) and booster cylinder (4)
And a drive device (13) capable of driving the booster piston (12) to advance and retract the booster piston (12), a wheel brake (8) in the working hydraulic chamber (14), and a relay hydraulic chamber (16). ) Is the stroke accumulator (1
9) communicate with each other, and the booster piston (12)
The booster body (10) is provided with an input port (5) that communicates with the working hydraulic chamber (14) in the backward movement limit of the above, but communicates with the relay hydraulic chamber (16) when the booster piston (12) advances. This input port (5) has a master cylinder (2) operated by a brake operator (1).
A control device (20) which communicates with the output port (3) of the drive device (13) and controls the operation of the drive device (13) according to the operating state of the brake operator (1) and the state of the wheels. ) Is connected to the vehicle booster braking device.