JPH07277177A - Braking device for vehicle - Google Patents

Abstract

PURPOSE:To provide a braking device at low cost, which can prevent the hydraulic lock of a servo valve and which can secure the fail safe, by interposing a solenoid switching valve between a master cylinder, an oil pressure supplying source and a reservoir, each wheel brake, and a servo valve. CONSTITUTION:A solenoid switching valve V is interposed between a master cylinder M, an oil pressure supplying source P and a reservoir R, each wheel brake BF, BR and a servo valve S. A hydraulic actuator HA is interposed between an output port 19 of the servo valve S and each wheel brake BF, BR. When a coil is de-energized, the solenoid valve V respectively communicates the master cylinder M, each wheel brake BF, BR, and the reservoir R with an input port 18 of the servo valve V, and also interrupts the oil pressure supplying source P. On the other hand, when the coil 51 is energized, the solenoid valve V respectively interrupts the master cylinder M and the reservoir R, and also communicates the oil pressure supplying source P with each wheel brake BF, BR.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device applied to vehicles such as automobiles and motorcycles, and more particularly to a master cylinder, a hydraulic pressure source, a reservoir, a wheel brake, and an input port connected to the hydraulic pressure source. And a servo valve that has an output port connected to the wheel brakes, receives an operation input to the master cylinder as an electric quantity, and controls the hydraulic pressure supplied from the input port to the output port according to the electric quantity Regarding

[0002]

2. Description of the Related Art Conventionally, in such a braking device, when the master cylinder is at rest, the hydraulic pressure of the hydraulic pressure source continues to act on the input port of the servo valve for a long time, causing a hydraulic lock phenomenon in the servo valve. To prevent this, an opening / closing valve that closes when the master cylinder is idle is installed between the hydraulic pressure supply source and the servo valve input port, and the hydraulic pressure of the hydraulic pressure supply source is applied to the servo valve input port when the master cylinder is idle. In addition, the master cylinder, the output port of the servo valve, and the wheel brake are provided with a change valve that selectively connects the wheel brake to the output port of the master cylinder or the servo valve. Normally, the wheel brake is connected to the output port of the servo valve for boosting braking. Communicates with the cylinder of the output ports are known to allow manual brake (for example, see JP-A-4-107369).

[0003]

However, in such a conventional apparatus, since the opening / closing valve for preventing the hydraulic lock of the servo valve and the change valve for the fail safe are individually provided, they are constructed electromagnetically. At this time, at least two coils are required, which inevitably increases the cost.

The present invention has been made in view of the above circumstances, and provides an inexpensive braking device capable of ensuring hydraulic lock prevention and fail-safe of a servo valve by adopting one electromagnetic switching valve. With the goal.

[0005]

In order to achieve the above object, the present invention provides a master cylinder, a hydraulic pressure supply source and a reservoir, a wheel brake and a servo valve between the master cylinder and the master cylinder. It has a coil that is de-energized and in the de-energized state, the master cylinder and wheel brakes, the reservoir and the input port of the servo valve are electrically connected, and the hydraulic pressure supply source is cut off. In this case, a single electromagnetic switching valve that cuts off the master cylinder and the reservoir and connects between the hydraulic pressure source and the input port of the servo valve is installed, while the output port of the servo valve and the wheel brake are connected from the output port. The first feature is that a hydraulic actuator that can actuate the wheel brake in accordance with the output hydraulic pressure is installed.

In addition to the above features, the present invention provides a spool valve element and a poppet valve element, which come into contact with each other so as to be separable from each other, in the electromagnetic switching valve, and when energized, the poppet valve element together with the spool valve element in the first position. To a second position, and a return spring that returns the spool valve body to the first position together with the poppet valve body when the coil is deenergized, and the poppet valve body stores the poppet valve body when it occupies the first position. And the input port of the servo valve are communicated with each other, the reservoir is shut off when the second position is occupied, and the spool valve element is electrically connected between the master cylinder and the wheel brake when the first position is occupied. At the same time, the hydraulic pressure supply source is shut off, the master cylinder is shut off when it occupies the second position, and the hydraulic pressure supply source and the input port of the servo valve are electrically connected. An oil chamber that communicates with the reservoir when the poppet valve occupies the first position, but communicates with the hydraulic pressure source when the poppet valve occupies the second position, and an orifice on the other end side. A second feature is that pressure accumulating chambers that communicate with the oil chambers are provided respectively.

[0007]

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

First, a first embodiment of the present invention shown in FIGS. 1 and 2 will be described. In FIG. 1, a vehicle braking device includes a master cylinder M, a hydraulic pressure supply source P, a reservoir R, an electromagnetic switching valve V, a front wheel brake B _F , a rear wheel brake B _R , a front wheel modulator M _F, and a rear wheel modulator M _R. It consists of

A brake pedal 1 is connected to a piston 3 of a master cylinder M via a push rod 2, and an output port 4 of the master cylinder M is connected to a first inlet port 5 ₁ of an electromagnetic switching valve V. A stroke accumulator A is provided in the oil passage between the output port 4 and the first inlet port 5 _1.
When s is connected and the master cylinder M is operated by depressing the brake pedal 1, the output hydraulic pressure is accumulated to obtain the operation stroke and reaction force of the brake pedal 1.

The hydraulic pressure supply source P regulates the hydraulic pump 8 which pumps hydraulic oil from the reservoir R to generate a discharge pressure, the accumulator 9 which accumulates the discharge pressure of the hydraulic pump 8, and the discharge pressure of the hydraulic pump 8. Therefore, it comprises a pressure switch 10 for controlling the drive motor of the hydraulic pump 8, the high pressure part of which is connected to the second inlet port 5 ₂ of the electromagnetic switching valve V.

The reservoir R is connected to the return port 6 of the electromagnetic switching valve V.

The electromagnetic switching valve V further includes a pair of first outlet ports.
Heart 7₁, 7₂And the second exit port 7 ₂Have one
First exit port 7₁Front brake B_FBut again
First exit port 7₁Rear wheel brake B_RRespectively
Connected. Second exit port 7₂For front and rear wheels
Modulator M_F, M_RThe input port 18 described later in
Will be continued.

Each of the modulators M _F and M _R is composed of a servo valve S and a hydraulic actuator H _A operated by the output hydraulic pressure thereof. The servo valve S is connected to a spool valve 11 and an upper portion thereof. And a linear solenoid 12. The spool valve 11 includes a housing 13 and a spool valve body 15 that is fitted in the housing 13 so as to be capable of moving up and down. The housing 13 is provided with an input port 18, an output port 19 and a discharge port 20. When the spool valve body 15 occupies the upper limit closed position, the spool valve 11 shuts off the input port 18 and opens the output port 19 to the discharge port 20, but the spool valve body 15 descends. Then, the discharge port 2
By shutting off 0, the input port 18 and the output port 19 are communicated with each other, and the opening degree of the valve body 15 is increased as the valve body 15 descends. The discharge port 20 is opened to the reservoir R.

Below the spool valve body 15, a reaction force piston 21 which gives an upward reaction force to the spool valve body 15 in response to an increase in the hydraulic pressure of the output port 19, and a biasing force for the reaction force piston 21 toward the spool valve body 15. And a return spring 16 that operates.

The linear solenoid 12 is integrally formed with a cylindrical outer peripheral yoke 22 connected to the housing 13, an end yoke 23 fixed to the upper end of the outer peripheral yoke 22, and a lower end of the outer peripheral yoke 22. The fixed core 24, the coil 25 arranged in the outer peripheral yoke 22, and the fixed core 2
4 and a movable core 26 that is fitted in the end yoke 23 so as to be able to move up and down, and an operating rod 27 that projects from the lower end surface of the movable core 26. The operating rod 27 is a fixed core 24. Is supported so as to be able to move up and down, and abuts on the upper end of the spool valve body 15. Thus, the linear solenoid 12 is adapted to generate an electromagnetic force proportional to the amount of electricity applied to the coil 25 between the fixed core 24 and the movable core 26, and apply a downward thrust to the operating rod 27. .

The hydraulic actuator H _A has a cylinder hole 29 formed in the lower extension 13a of the housing 13 of the servo valve S, and is slidably fitted in the cylinder hole 29 so that the inside thereof is provided with an input hydraulic chamber 30 and an input hydraulic chamber 30. 2 of output hydraulic chamber 31
An operating piston 32 that partitions the chamber and a return spring 33 that is housed in the output hydraulic chamber 31 and biases the operating piston 32 toward the input hydraulic chamber 30 side are provided. The input hydraulic chamber 30 is connected to the output port 19 of the servo valve S, and the output hydraulic chamber 31
Are connected to the corresponding front and rear wheel brakes B _F and B _R , respectively.

In FIG. 2, the electromagnetic switching valve V includes the first and second inlet ports 5 ₁ and 5 ₂ , the return port 6, the pair of first outlet ports 7 ₁ and 7 ₁ and the second outlet port 7 ₂ . The housing 35, the valve cylinder 36 fitted in the housing 35, the spool valve body 37 slidably fitted in the valve cylinder 36, and the right end of the spool valve body 37 that can be separated from each other. A poppet valve body 38 in contact with the poppet valve body 38, a solenoid 39 capable of operating the poppet valve body 38 together with the spool valve body 37, and a return spring 40 for urging the spool valve body 37 toward the poppet valve body 38.

An oil chamber 41 facing the right end surface of the spool valve element 37 and a pressure accumulating chamber 42 facing the left end portion of the spool valve element 37 are provided in the valve cylinder 36. As members, sealing members 43, 44 around the valve cylinder 36
Is facing. Both chambers 41 and 42 communicate with each other through an oil passage having an orifice 45 that penetrates the spool valve body 37. The oil chamber 41 is always in communication with the second outlet port 7 ₂ and is in communication with the return port 6 via a valve seat 47 that is opened and closed by the poppet valve body 38.

The solenoid 39 includes a fixed core 48 joined to the right end surface of the housing 35, a cylindrical outer peripheral yoke 49 connected to the fixed core 48, and the outer peripheral yoke 49.
End yoke 50 coupled to the outer end of the coil, a coil 51 housed in the outer peripheral yoke 49, and a guide cylinder 52 fixed to the end yoke 50 slidably supported to be opposed to the fixed core 48. The fixed core 48 is provided with a core 53 and receives the outer end of the poppet valve body 38 to regulate the right limit thereof. The fixed core 48 is attached to the movable core 53.
An operating rod 54 that slidably passes through and abuts against the outer end of the poppet valve body 38 is fixed, and the operating rod 54 is fixed to the movable core 5.
Auxiliary spring 55 that urges the poppet valve body 38 side together with 3 is contracted between the movable core 53 and the end yoke 50. The auxiliary spring 55 holds the operating rod 54 in contact with the poppet valve body 38, and its set load is set to be weaker than that of the return spring 40.

Therefore, when the coil 51 is deenergized,
2, the spool valve body 37 and the poppet valve body 38
Is held in the right position by the elastic force of the return spring 40,
When the ill 51 is urged, as shown in FIG.
The operating rod 54 causes the poppet valve body 38 and the spool valve body to move.
37 pushes to the left position. Thus, the spool valve element 37
And when the poppet valve element 38 occupies the right position,
Entrance port 5₁And 1st exit port 7₁The communication between the two, the second
Entrance port 5₂Closed and return port 6 open
It When both valve bodies 37 and 38 occupy the right position,
First entrance port 5 ₁Is blocked and the second entrance port
To 5₂And the second exit port 7₂Communication between the two
6 is cut off.

Referring again to FIG. 1, the push rod 2 connecting the piston 3 of the master cylinder M and the brake pedal 1 is provided with a pedal force sensor 57 for detecting the magnitude of the pedal force applied to the brake pedal 1. The output signal of the pedaling force sensor 57 is input by the control unit 58, and the control unit 58 converts the input signal into an electric quantity, for example, an electric current, and applies it to the coil 25 of the servo valve S.

A brake sensor 59 for detecting the depression of the brake pedal 1 is provided opposite to the brake pedal 1, and an output signal of the brake sensor 59 is input to the control unit 58. When the control unit 58 receives the signal from the brake sensor 59, it energizes the coil 51 of the electromagnetic switching valve V, but receives the output signal of a failure sensor 60 that detects a failure of the hydraulic pressure supply source P or the servo valve S. Then, the signal from the brake sensor 59 is invalidated.

The operation of this embodiment will be described below.
If the master cylinder M is currently in the idle state, electromagnetic switching
Deactivate each coil 25 and 51 of the valve V and the servo valve S.
ing. Therefore, the spool valve element 37 of the electromagnetic switching valve V
And the poppet valve body 38 is moved to the right by the elastic force of the return spring 40.
The front and rear wheel brakes B are retained because_F, B _R
Each oil chamber of the corresponding first outlet port 7₁, 7₁And the
1 entrance port 5₁Via the oil chamber of the master cylinder M
Is open to the reservoir.

On the other hand, the second inlet port 5 ₂ connected to the hydraulic supply source P is disconnected, the input port of the servo valve S 18
Is opened to the reservoir R via the second outlet port 7 ₂ , the oil chamber 41, the valve seat 47 and the return port 6, so that the input port 18 is kept at a low pressure and the spool valve body 15 is not hydraulically locked. .

The brake pedal 1 is used for braking with this.
When the master cylinder M is operated by stepping on, the control unit
First, the vehicle 58 receives the signal from the brake sensor 59.
Since the coil 51 of the electromagnetic switching valve V is energized, the movable core
53 is an operating rod 54, and the poppet valve body 38 and the spool are
The valve element 37 is pushed to the left position. Then the first entrance port
To 5₁Is cut off. When the return port 6 is shut off
2nd entrance port 5 ₂And the second exit port 7₂Communication
As a result, the oil pressure source P and the input port of the servo valve S are
Since the ports 18 communicate with each other, the hydraulic pressure of the hydraulic pressure supply source P is
It is supplied to the input port 18 of the bovalve S.

Subsequently, when the linear solenoid 12 of the servo valve S is energized by an electric amount according to the output signal of the pedal force sensor 57 and the operating rod 27 presses the spool valve body 15 with a thrust force corresponding to the pedal force, the lock state is established. Not the valve body 15
Automatically moves between the input port 18 and the output port 19 to transmit the hydraulic pressure of the hydraulic pressure supply source P to the input hydraulic chamber 30 of the hydraulic actuator H _A through the input port 18 and the output port 19 in order, and the working piston 32 is moved to the output hydraulic chamber 31 side. This movement raises the pressure in the output hydraulic chamber 31, and the hydraulic pressure is transmitted to the corresponding front and rear brakes B _F and B _R to operate them.

During such braking, in the electromagnetic switching valve V, the hydraulic pressure supply source P transmitted from the second inlet port 5 ₂ to the oil chamber 41.
Oil pressure passes through the oil passage 46 of the spool valve body 37 and the accumulator chamber 4
2 is also introduced, and a compressive deformation is applied to the seal members 43 and 44, so that the pressure is accumulated.

Therefore, when the pedaling force is released from the brake pedal 1 to release the braking, the coils 51 and 25 of the electromagnetic switching valve V and the servo valve S are deenergized. At this time, especially in the electromagnetic switching valve V, The poppet valve body 38 is opened by the oil pressure of the oil chamber 41, and the oil chamber 41 is opened to the return port 6, that is, the reservoir R, so that a large pressure difference is generated between the oil chamber 41 and the pressure accumulating chamber 42, and Due to the pressure difference and the elastic force of the return spring 40, the spool valve element 37 is surely pushed back to the initial right position, and there is no hydraulic lock in the middle. After that, the hydraulic pressure of the pressure accumulating chamber 42 gradually returns to the oil chamber 41 side through the orifice 45, and finally the pressure accumulating chamber 42 also becomes a low pressure.

During braking, if the hydraulic pressure source P or the servo valve S is out of order, the control unit 58 receives the signal from the failure sensor 60 and invalidates the output signal from the brake sensor 59. The changeover valve V holds the original position where the first inlet port 5 ₁ and the first outlet ports 7 ₁ and 7 ₁ communicate with each other, and therefore the output hydraulic pressure of the master cylinder M is the same as that of the electromagnetic changeover valve V. The front and rear wheel brakes B _F and B _R can be transmitted via these to be manually operated, and fail-safe is ensured.

FIGS. 4 and 5 show a second embodiment of the present invention. In the solenoid operated directional control valve V, first and second inlet ports 5 ₁ , 5 ₂ and first outlet ports 7 ₁ , 7 ₁ and Except that the position of the second outlet port 7 ₂ is changed and that the pressure accumulating chamber 42 is formed in a large volume and the elastic air bag 61 is exposed to the chamber 42, the structure is the same as that of the previous embodiment. Therefore, in the figure, the parts corresponding to those in the previous embodiment are designated by the same reference numerals.

According to this embodiment, during braking, the oil chamber 41
Since a large amount of pressure oil can be stored in the pressure accumulation chamber 42 from
When the braking is released, the spool valve element 37 can be more reliably pushed back to the original position by the hydraulic pressure of the pressure accumulating chamber 42,
That is, the hydraulic lock of the valve element 37 can be prevented more reliably.

In each of the above embodiments, various design changes can be made without departing from the gist of the present invention. For example, front and rear wheel modulators M _F and M _R may be provided for each of the left and right wheels.

[0033]

As described above, according to the first feature of the present invention, the single solenoid operated directional control valve keeps the input port of the servo valve at a low pressure during non-braking to prevent hydraulic lock of the servo valve. In the event of a failure of the hydraulic pressure supply source or the like, the manual operation of directly operating the wheel brakes by the output hydraulic pressure of the master cylinder can be enabled, which can contribute to the cost reduction of the device.

Further, according to the second feature of the present invention, at the time of releasing the braking, the spool valve element of the electromagnetic switching valve can be surely pushed back to the original position by the hydraulic pressure of the pressure accumulating chamber accumulated during the braking. The hydraulic lock of the valve body can also be prevented.

[Brief description of drawings]

FIG. 1 is an overall view in which a part of a vehicle braking device according to a first embodiment of the present invention is longitudinally cut.

FIG. 2 is an enlarged vertical sectional view of an electromagnetic switching valve in the above braking device.

FIG. 3 is an operation explanatory diagram of the electromagnetic switching valve.

FIG. 4 is an overall vertical cross-sectional view of a part of a vehicle braking device according to a second embodiment of the present invention.

FIG. 5 is an enlarged vertical sectional view of an electromagnetic switching valve in the above braking device.

[Explanation of symbols]

B _F Front wheel brake (wheel brake) B _R Rear wheel brake (wheel brake) H _A Hydraulic actuator M Master cylinder P Hydraulic pressure supply source R Reservoir V Electromagnetic switching valve 37 Spool valve element 38 Poppet valve element 39 Solenoid 41 Oil chamber 42 Accumulation chamber 45 orifice

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takaomi Shirase 840 Kokubu, Ueda City, Nagano Prefecture Nissin Industry Co., Ltd.

Claims (2)

[Claims] 1. A master cylinder (M), a hydraulic pressure supply source (P), a reservoir (R), and wheel brakes ( _BF , B).
_R ) and an input port (18) connected to the hydraulic pressure source (P)
And an output port (19) connected to the wheel brakes (B _F , B _R ) and receives an operation input to the master cylinder (M) as an electric quantity, and the input port (1
In a vehicle braking device including a servo valve (S) that controls the hydraulic pressure supplied from 8) to the output port (19), a master cylinder (M), a hydraulic pressure supply source (P), a reservoir (R), and a wheel brake. Between ( _BF , _BR ) and the servo valve (S), there is a coil (51) that is deenergized / energized according to the rest / operating state of the master cylinder (M). the master cylinder is de-energized state of 51) (M) and the wheel brake (B _F, B _R), a reservoir (R)
And the input port (18) of the servo valve (S) are electrically connected to each other and the hydraulic pressure supply source (P) is cut off, and in the energized state, the master cylinder (M) and the reservoir (R) are cut off and the hydraulic pressure is supplied. Source (P) and servo valve (S)
A single solenoid operated directional control valve (V) is provided to connect between the input ports (18) of the servo valve (S) and the output port (19) of the servo valve (S) and the wheel brakes ( _BF , _BR ). _A braking device for a vehicle, wherein a hydraulic actuator ( _HA ) capable of operating the wheel brakes ( _BF , _BR ) according to the output hydraulic pressure from the output port (19) is interposed. 2. The electromagnetic switching valve (V) according to claim 1, wherein a spool valve body (37) and a poppet valve body (38) that come into contact with each other so as to be separable from each other, and a poppet valve body when energized. A coil (51) for moving the (38) together with the spool valve body (37) from the first position to the second position.
When the coil (51) is de-energized, the spool valve body (3
7) a return spring (40) for returning the poppet valve body (38) to the first position together with the poppet valve body (38), and when the poppet valve body (38) occupies the first position, the reservoir (R) and the servo valve (S). The input ports (18) of the above are communicated with each other, and the reservoir (R) is shut off when the second position is occupied,
When the spool valve element (37) occupies the first position, the spool valve element (37) is connected to the master cylinder (M) and the wheel brakes ( _BF , B).
_R ) is electrically connected, the hydraulic pressure supply source (P) is cut off, and when the second position is occupied, the master cylinder (M) is cut off, and the hydraulic pressure supply source (P) and the servo valve (S) are cut off.
The input ports (18) are connected to each other, and the poppet valve (38) is provided at one end of the spool valve body (37).
Communicates with the reservoir (R) when occupies the first position,
When occupying the second position, the oil chamber (41) communicating with the hydraulic pressure source (P) is provided, and the orifice (4) is provided at the other end side.
5) through which the pressure chamber (4) communicates with the oil chamber (41).
2) A braking device for a vehicle, characterized in that each of them is provided.