JP2001315629A - Braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a brake unit and to reduce energy consumption by miniaturizing a pump a motor in a braking device having the motor-driven pump capable of intensifying wheel cylinder pressure. SOLUTION: The pump 21 driven to rotate normally and reversely by the motor M serving as a drive source, and an accumulator 22 are provided as a hydraulic pressure source 20. A first suction discharge port 21a of the pump 21 is connected to a brake circuit 1, and a second suction discharge port 21b is connected to the accumulator 22 through a connecting circuit 22a. A part between the pump 21 and each pressure intensifying valve 5 is connected to a reservoir RES through a communicating passage 11. A selector valve 22b is provided on the way of a connecting circuit 22a. A part between the pump 21 and the selector valve 22b is connected to a master cylinder MC through an suction circuit 21d, and a check valve 21f is provided on the way of the suction circuit 21d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ABS control which has a pump for discharging brake fluid to a brake circuit connected to a wheel cylinder and prevents a wheel from being locked during braking, or the driver performs a braking operation. The present invention relates to a brake device that includes an assist control that assists when it is performed, and that can execute an automatic brake control that generates a braking force by discharging a pump.

[0002]

2. Description of the Related Art In recent years, various brake control devices for controlling a braking force have been proposed. Controls in such a brake control device include, for example, ABS control and automatic brake control. The ABS control is a control for preventing wheel lock during braking. The hydraulic pressure adjusting means provided in a brake circuit connected to the wheel cylinder is operated to reduce and increase the wheel cylinder pressure, and the wheel is controlled by the pressure reduction. The brake fluid released from the cylinder is sucked by the pump and returned to the brake circuit.

[0003] The automatic brake control referred to in this specification includes a brake assist control, an automatic brake control for automatically performing braking in accordance with an inter-vehicle distance to an oncoming obstacle such as a preceding vehicle, and an over-understeer state during turning. When the vehicle is in an over-steer state, the wheel cylinder pressures of the outer front wheel and the inner rear wheel are automatically controlled to generate a braking force, thereby generating a yaw moment for returning the vehicle to the neutral steering direction. Such as a vehicle behavior control that stabilizes the behavior of the vehicle or a torque slip control that applies a braking force to the drive wheel when the drive wheel slips to suppress the slip, etc. In addition to the control to generate the braking force, the braking operation by the driver is detected, and the wheel cylinder pressure is automatically generated based on the detected value. Iwaiya control and, more to the brake fluid pressure generated by the braking operation by the driver, with pressurized by addition pumps, etc. assist control for assisting the braking operation by controlling the wheel cylinder pressure. At the time of executing the various automatic braking controls described above, the brake fluid of the hydraulic pressure source is sucked by the pump and discharged toward the wheel cylinder through the brake circuit, and the hydraulic pressure is adjusted by the hydraulic pressure adjusting means to obtain a desired pressure. This is to obtain a braking force.

In the above-described brake device, a brake device having an accumulator and a pump as a control hydraulic pressure source in order to achieve both responsiveness and feeling is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-29023. Are known. In this prior art, high pressure brake fluid is supplied from an accumulator to a wheel cylinder during braking when responsiveness is required, while low pressure is supplied from a pump during braking when a feeling that does not cause shock or squeal is required. The brake fluid is supplied to perform gentle braking.

[0005]

However, the above-mentioned prior art has the following problems to be solved. That is, in the prior art, the hydraulic pressure accumulated in the accumulator is supplied to the wheel cylinder during braking that requires responsiveness. Therefore, the pressure that can be accumulated in the accumulator is set to the maximum pressure required in the automatic brake control. Therefore, the discharge capacity (= pump capacity) of the pump needs to be set to a capacity that can accumulate the accumulator at the maximum pressure. Therefore, the pump displacement is set to the maximum pressure required in the automatic brake control.

[0006] Incidentally, a pump, an electromagnetic valve as a fluid pressure adjusting means, and a circuit for connecting the two are generally provided with one-piece.
Stored in one brake unit. This brake unit is desired to be downsized for the convenience of mounting on a vehicle. However, in this brake unit, the largest component in reality is a motor that applies a driving force to the pump, and the size of this motor is determined according to the pump capacity. It was determined by the required maximum pressure, and it was difficult to reduce the size.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. In a brake device having a hydraulic pressure source comprising a motor-driven pump for increasing the pressure of a wheel cylinder, a motor and a pump are miniaturized. The main purpose is to reduce the size of the brake unit and reduce energy consumption. It is another object of the present invention to achieve the above object and to improve the sound and vibration performance, the responsiveness, and the reliability of the apparatus.

[0008]

According to the present invention, there is provided a hydraulic pressure source for supplying brake fluid to a wheel cylinder via a supply circuit, the hydraulic pressure source being provided in the supply circuit, A fluid pressure adjusting means capable of adjusting the supply state of the brake fluid supplied from the fluid pressure source to increase and decrease the pressure of the wheel cylinder to adjust the wheel cylinder pressure; and In a brake device comprising a return circuit for releasing and a brake fluid source connected to the return circuit, the hydraulic pressure source is provided with a pump driven by a motor and an accumulator capable of accumulating a predetermined pressure. The pump includes a first suction / discharge port and a second suction / discharge port, and is configured to be capable of a normal / reverse rotation operation of sucking brake fluid from one of the two suction / discharge ports and discharging the brake fluid from the other. One suction / discharge port is connected to a supply circuit, and the second suction / discharge port is connected to and installed in an accumulator. In the supply circuit, the brake fluid source is connected between a pump and hydraulic pressure adjusting means. A check valve that is connected through a passage and that prevents backflow to the brake fluid source is provided in the middle of the communication passage, and is connected in the middle of a connection circuit that connects the accumulator and the second suction / discharge port. A switching valve for communicating and shutting off the circuit is provided, and a position between the pump and the switching valve of the connection circuit is connected to a brake fluid source via a suction circuit, and the suction circuit is provided in the middle of the suction circuit. And a check valve for restricting the flow of the brake fluid from the brake fluid source to the connection circuit direction only is provided.

The invention described in claim 2 is the first invention.
In the brake device according to the above, the brake fluid source,
A master cylinder that generates hydraulic pressure by a driver's braking operation, and a reservoir of the master cylinder, wherein the return circuit is connected to the reservoir, and the master cylinder and the supply circuit include a hydraulic pressure adjusting unit and a pump. Between the main supply circuit and a gate valve for communicating and shutting off the main supply circuit is provided in the middle of the main supply circuit, and the suction circuit is connected to a master cylinder in the main supply circuit. A position between the gate valve and
The connection circuit is connected to the connection circuit. According to a third aspect of the present invention, in the brake device according to the first or second aspect, the pump is a gear pump. According to a fourth aspect of the present invention, in the brake device according to any one of the first to third aspects, the pump performs a reverse rotation operation of sucking brake fluid from the first suction and discharge port and discharging from the second suction and discharge port. An accumulator charge control for opening the switching valve to supply the brake fluid from the brake fluid source to the accumulator;
Low pressure gradient pressure increase by executing the normal rotation operation to discharge from the suction / discharge port and discharging the brake fluid from the brake fluid source toward the supply circuit and increasing the wheel cylinder pressure with a low pressure gradient by the fluid pressure adjusting means Control, the pump is operated in the normal direction, the switching valve is opened, and the pressure of the accumulator is increased by the pump. And a high pressure gradient pressure increasing control for increasing the pressure with a high pressure gradient.

[0010] The invention described in claim 5 is the first invention.
In the brake device according to any one of (4) to (4), a bypass path is provided, which bypasses the pump and connects a position between the switching valve of the connection circuit and the pump and a position between the pump and the hydraulic pressure adjusting means of the supply circuit. In addition, a second switching valve that connects and disconnects the bypass passage is provided in the middle of the bypass passage. The invention according to claim 6 is the invention according to claim 5
In the brake device according to (1), the control means, during the high pressure gradient pressure increase control, first, the switching valve and the second
The switching valve is opened for a predetermined time to perform an initial rapid pressure increase to supply the brake fluid stored in the accumulator to the supply circuit via the bypass path, and the pump is rotated in the forward direction in parallel with the initial pressure increase to perform the charging operation. Is performed.

According to a seventh aspect of the present invention, in the brake device according to any one of the first to sixth aspects, a relief circuit for connecting the connection circuit and the return circuit is provided. A relief valve is provided, which opens when the hydraulic pressure exceeds a set pressure and releases it to the return circuit.

According to an eighth aspect of the present invention, in the brake device according to any one of the first to seventh aspects, a second relief circuit connecting the supply circuit and the return circuit is provided, and in the middle of the second relief circuit, A second relief valve is provided, which opens when the hydraulic pressure on the supply circuit side exceeds a set pressure and releases it to the return circuit. According to a ninth aspect of the present invention, in the brake device according to the second to sixth aspects, when a master cylinder pressure is generated between the master cylinder and the gate valve in the main supply circuit, a predetermined reaction force is generated. And a reservoir for permitting the movement of the brake fluid is provided, and a third switching valve for communicating and shutting off the connection circuit is provided in a connection circuit connecting the reservoir and the main supply circuit. . According to a tenth aspect of the present invention, in the brake device according to the ninth aspect, the control means normally increases a master cylinder pressure by opening a gate valve and closing a third switching valve. When the operation to perform the operation is performed, the gate valve is closed and the third switching valve is opened to absorb the volume change in the master cylinder by the reservoir. It is characterized in that it is configured to execute pressure gradient pressure increase control and high pressure gradient pressure increase control.

[0013]

The operation of the brake device according to the present invention will be described for each case. (At the time of accumulator charge) In a state where the switching valve provided in the connection circuit connecting the pump and the accumulator is opened, the pump is sucked from the first suction and discharge port,
When the pump is reversely operated to discharge from the second suction / discharge port, the pump sucks the brake fluid from the brake fluid source through the communication passage and discharges the brake fluid toward the accumulator. Therefore, the hydraulic pressure determined by the pump capacity can be stored in the accumulator.

(At the time of pressure increase control) When increasing the wheel cylinder pressure, two types of pressure increase are possible. One is a pressure increase with a low pressure gradient only by the pump. In this case, the pump is normally operated with the switching valve closed. Accordingly, the pump sucks the brake fluid of the brake fluid source from the second suction / discharge port via the suction circuit and discharges the brake fluid from the first suction / discharge port toward the supply circuit. Therefore, the necessary pressure increase is performed by operating the hydraulic pressure adjusting means. At this time, the maximum pressure is determined by the maximum discharge capacity of the pump.

Another type of pressure increase is a high pressure gradient pressure increase performed by connecting an accumulator in series with the pump. In this case, the pump is driven to rotate forward with the switching valve opened. Thus, the pump sucks the high-pressure brake fluid stored in the accumulator from the second suction and discharge port, further increases the pressure, and discharges the pressure from the first suction and discharge port. Therefore, the hydraulic pressure supplied to the supply circuit may be a value obtained by adding the boosting amount determined by the pump displacement to the hydraulic pressure stored in the accumulator, that is, the boosting pressure up to twice the pump displacement. it can.

As described above, in the present invention, as the maximum pressure increase amount, a pressure increase that is twice the maximum pressure increase amount determined by the maximum discharge capacity of the pump can be executed. Therefore, assuming that the maximum pressure increase amount is the same as in the conventional technology,
It is possible to reduce the capacity of the pump and the motor to about half that of the conventional one.
In addition, the effect of reducing energy consumption can be obtained.

According to the second aspect of the present invention, when the accumulator is charged, when the pump is operated in reverse, the brake fluid in the reservoir of the master cylinder is sucked in through the return circuit and the communication passage and accumulated in the accumulator.
If the gate valve is opened at this time, the pump draws brake fluid from the master cylinder via the main supply circuit and accumulates the pressure in the accumulator in parallel with the above.
Further, in the invention described in claim 2, normally, the gate valve is opened and the switching valve is closed. Therefore, when the driver performs the braking operation, the brake fluid of the master cylinder is supplied to the wheel cylinder via the main supply circuit and the supply circuit, and a braking force corresponding to the braking operation is generated. At this time, since the switching valve is closed, the master cylinder pressure does not escape to the accumulator, and the master cylinder pressure does not escape to the return circuit by the check valve. Next, during pressure increase control of a low pressure gradient only by the pump, the brake fluid of the master cylinder is sucked through the suction circuit. At the time of the pressure increase control of the high pressure gradient, the pump is rotated forward while the switching valve is opened and the accumulator is charged.

According to the third aspect of the present invention, since the gear pump is used as the pump, noise and vibration are less generated by driving, and the sound and vibration performance can be improved. In addition, a remarkable effect of the accumulator can be obtained.

According to the fourth aspect of the present invention, the above-described accumulator charge, the increase in the low pressure gradient, and the increase in the high pressure gradient can be executed based on the control of the control means.

According to the fifth aspect of the present invention, when the second switching valve is opened, the brake fluid of the accumulator can be supplied to the wheel cylinder by bypassing the pump by the bypass. That is, in the pressure increasing control of the high pressure gradient as in the invention according to claim 6, first, the second switching valve is opened for a predetermined time to supply the brake fluid of the accumulator to the wheel cylinder. By executing the above, it is possible to eliminate the rising delay in the initial stage of the pump operation, and to improve the control response.

According to the invention described in claim 7, when the accumulator is charged due to a problem, or the accumulator becomes high temperature after accumulating at low temperature, the internal pressure of the accumulator becomes high and exceeds the set pressure. Then, the relief valve of the relief circuit opens to release high pressure to the return circuit. Therefore, it is possible to prevent the accumulator from being damaged and improve the reliability and durability of the device.

According to the present invention, the portion surrounded by the first suction / discharge port of the pump, the fluid pressure adjusting means, and the gate valve becomes higher than the set pressure, for example, when the pressure increase control is performed. When this occurs, the second relief valve opens to release high pressure to the return circuit. Therefore, it is possible to prevent damage to the gate valve and the fluid pressure adjusting means, and to improve the reliability and durability of the device.

According to the ninth aspect of the invention, when the master cylinder is operated with the gate valve closed and the third switching valve opened, the hydraulic pressure generated in the master cylinder accumulates in the reservoir. Is done. That is, a normal operation feeling can be obtained while preventing the master cylinder pressure from being supplied to the wheel cylinder side. Therefore, when the driver performs the braking operation, the invention does not supply the master cylinder pressure to the wheel cylinders, but performs the low pressure gradient pressure increase control by the forward rotation of the pump, as in the invention according to claim 10.
Alternatively, a high-pressure gradient control in which an accumulator is added to the pressure is executed to control the wheel cylinder pressure according to the braking operation of the driver, that is, a so-called by-wire control is performed without giving a sense of incongruity to the driver. be able to.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Embodiment 1 is an example corresponding to the first to fourth aspects of the present invention, and FIG. 1 is a brake circuit diagram showing a brake device of Embodiment 1. In the figure, M
C is a master cylinder, which is a well-known type that supplies brake fluid to the wheel cylinder WC via a main supply circuit and a brake circuit 1 constituting a part of the supply circuit when the brake pedal BP is depressed. is there. In the figure, RES is a reservoir. Although only two wheel cylinders WC are shown in the figure, the brake circuit 1 and the brake circuit 1 shown in FIG.
, Another system is provided,
A total of four wheel cylinders WC are provided.

In the middle of the brake circuit 1, a gate valve 3 is provided.
Is provided. The gate valve 3 is connected to the brake circuit 1
A normally open solenoid valve that switches between communication and shutoff.
The gate valve 3 is provided in parallel with a check valve 3a that allows only the flow of brake fluid from the master cylinder MC side (hereinafter, referred to as upstream) to the wheel cylinder WC side (hereinafter, referred to as downstream). Have been.

In the brake circuit 1, a normally open ON / OFF of a solenoid drive is provided downstream of the gate valve 3.
A pressure increasing valve 5 comprising a valve is provided.
A pressure reducing valve 6 composed of a normally closed ON / OFF valve driven by a solenoid is provided in the middle of a return circuit 10 connecting the position further downstream and the reservoir RES. That is, the pressure increasing valve 5 and the pressure reducing valve 6 constitute a hydraulic pressure adjusting means,
If the pressure increasing valve 5 is opened and the pressure reducing valve 6 is closed while the brake circuit 1 is at a high pressure, the wheel cylinder pressure can be increased. The cylinder pressure can be maintained, and the wheel cylinder pressure can be reduced by closing the pressure increasing valve 5 and opening the pressure reducing valve 6. The pressure increasing valve 5 is provided in parallel with a check valve 5a that allows only the flow in the direction in which the brake fluid of the wheel cylinder WC returns to the master cylinder MC. The return circuit 10 and the brake circuit 1 are connected via a communication path 11, and in the middle of the communication path 11, the flow of the brake fluid is restricted only to the flow from the return circuit 10 to the brake circuit 1. A check valve 11a is provided.

The brake circuit 1 has a hydraulic pressure source 2
0 is connected. This hydraulic pressure source 20 includes a pump 21 and an accumulator 22. The pump 21
Is constituted by a bidirectionally rotatable pump such as an external gear pump or an internal trochoid pump, and has a first suction / discharge port 21a and a second suction / discharge port 21b for performing suction and discharge. Operates in response to forward / reverse drive. The first suction / discharge port 21a is connected to the connection circuit 21c.
The second suction / discharge port 21b is connected to the upstream of the gate valve 3 in the brake circuit 1 via the suction circuit 21d via the suction circuit 21d. In the first embodiment, the motor M
Is driven in the forward direction, the pump 21
b, and discharged from the first discharge port 21a, while the motor M was driven in reverse rotation, the pump 2
1 is drawn from the first suction and discharge port 21a and is discharged from the second discharge port 21b.
Discharge from.

The suction circuit 21d has a check valve 21f for allowing only the flow from the brake circuit 1 to the pump 21.
Is provided. In the suction circuit 21d, a position between the second suction / discharge port 21b and the check valve 21f is connected to the accumulator 22 via a connection circuit 22a. The connection circuit 22a is provided with a switching valve 22b composed of a solenoid valve that connects and disconnects the connection circuit 22a, and a pressure sensor 22c is provided on the accumulator 22 side of the switching valve 22b. I have. In the hydraulic pressure source 20,
The accumulator 22 accumulates a predetermined pressure P0 determined by the capacity of the pump 21, and the capacity of the pump 21 is set to about 1/2 of the conventional capacity.

In the brake device of the present embodiment, a control unit (not shown) executes automatic brake control including brake assist control and ABS control. Here, each control will be briefly described. In the case of the present embodiment, as the automatic brake control, automatic brake control, by-wire control, brake assist control, and vehicle motion control are executed.

In the automatic braking control, as part of the control for setting the inter-vehicle distance to the preceding vehicle as the optimum inter-vehicle distance in accordance with the vehicle speed, control for generating a desired braking force when the inter-vehicle distance becomes too close is executed.

In the by-wire control, when the driver operates an operation means such as a manual brake switch provided other than the brake pedal BP, a control for generating a braking force corresponding to the operation amount is executed.

In the brake assist control, when the driver operates the brake pedal BP, control is performed to supply a higher pressure than the pressure actually generated in the master cylinder MC to the wheel cylinder WC.

Common to the above control is that the hydraulic pressure is supplied to all of the four wheel cylinders WC and that the hydraulic pressure supplied to the wheel cylinders WC is relatively low. . By the way, in this embodiment,
Although a description will be given assuming that a common pressure is supplied to the four wheel cylinders WC, a slightly higher pressure may be supplied to the front wheels than to the rear wheels.

In the vehicle motion control, when the vehicle is over-steered or over-steered during turning, a braking force is generated in the wheel cylinder WC of a desired wheel, and the yaw moment for returning the vehicle to the neutral steer state is obtained. This is a control for stabilizing the vehicle attitude.

In the ABS control, when it is detected that the wheels have a tendency to lock during braking, the wheel cylinder pressure is repeatedly reduced, maintained, and increased in order to generate the maximum braking force while preventing the wheel lock. And execute
In this case, the pump 21 basically performs an operation of returning the brake fluid released from the wheel cylinder WC to the brake circuit 1.

Next, the operation of the first embodiment will be described. A) During normal braking Normally, as shown in FIG. 1, the gate valve 3 and the pressure increasing valve 5 are opened and the pressure reducing valve 6 is closed. When the driver performs a braking operation in this state, the brake fluid is supplied from the master cylinder MC to the wheel cylinder WC via the brake circuit 1 as shown by a solid arrow in FIG. When the driver finishes the braking operation, the brake fluid in wheel cylinder WC flows in the direction opposite to the illustrated arrow and returns to master cylinder MC.

(B) At the time of charging the accumulator In the first embodiment, the accumulator charging for accumulating the pressure in the accumulator 22 is executed when the above-described normal brake and the following control are not executed. At the time of this accumulator charging, the reverse rotation drive of the motor M is performed so that the switching valve 22b is opened and the pump 21 performs a reverse rotation operation in which the pump 21 sucks from the first suction and discharge port 21a and discharges from the second suction and discharge port 21b. Let it. Therefore, as shown in FIG.
From a, the brake fluid of the master cylinder MC is sucked through the brake circuit 1 and the brake fluid of the reservoir RES is sucked through the return circuit 10 and discharged from the second suction / discharge port 21b toward the accumulator 22.

Based on this operation, the accumulator 22
A predetermined pressure P0 determined by the capacity of the pump 21 is accumulated. In the first embodiment, the detection value of the pressure sensor 22c is reduced to the set pressure Pc which is a pressure slightly lower than the predetermined pressure P0. When this happens, the switching valve 22b is closed,
The operation of the motor M is stopped, and the set pressure Pc is accumulated in the accumulator 22.
This set pressure Pc is set slightly lower than the maximum discharge pressure of the pump 21.

C) Automatic Brake Control At the time of automatic brake control, the pressure control of the wheel cylinder pressure is performed while supplying the hydraulic pressure from the hydraulic pressure source 20 to the brake circuit 1. In this control, the wheel cylinder pressure is increased, maintained, and reduced. However, in the present embodiment, the pressure increase is characteristic, and therefore will be described.
In this pressure increase, the operation differs between when the wheel cylinder pressure is increased with a low pressure / low pressure gradient and when the wheel cylinder pressure is increased with a high pressure / high pressure gradient. The pressure increase at the low pressure / low pressure gradient is mainly performed during automatic brake control, and the pressure increase at the high pressure / high pressure gradient is
Mainly during vehicle motion control.

When the pressure is to be increased at a low pressure / low pressure gradient, the supply from the hydraulic pressure source 20 by only the pump 21 is executed.
That is, the motor M is driven to rotate in the normal direction, and the pump 21 performs a normal rotation operation in which the pump 21 sucks in from the second suction and discharge port 21b and discharges from the first suction and discharge port 21a. Thereby, as indicated by the solid arrow in FIG. 4, the brake fluid of the master cylinder MC is sucked into the pump 21 via the upstream portion of the gate valve 3 of the brake circuit 1 and the wheel cylinder WC
It is discharged toward.

At this time, the pressure increase amount is adjusted by the drive amount of the motor M while the gate valve 3 is closed,
Alternatively, it can be adjusted according to the open / close state of the pressure increasing valve 5. Further, the pressure reduction amount can be adjusted by the open / closed state of the pressure reducing valve 6 or by the open / closed state of the gate valve 3. By the way, when the pressure reducing valve 6 is opened,
The brake fluid is supplied to the reservoir RE via the return circuit 10.
Returning to S, when the gate valve 3 is opened, the brake fluid is released upstream of the gate valve 3 and is sucked again by the pump 21.

On the other hand, when the pressure is to be increased at a high pressure / high pressure gradient, the accumulator 22 supplies the pressure. That is, in this case, the motor M is driven to rotate forward and the pump 2
1 and the switching valve 22b is opened, and the pump 21 sucks the brake fluid accumulated in the accumulator 22 as shown by the solid arrow in FIG. Accordingly, the pump 21 sucks the brake fluid of the set pressure Pc, and adds the hydraulic pressure by the operation of the pump 21 to the set pressure Pc and discharges it from the first suction / discharge port 21a. Is, as shown in FIG.
It is possible to discharge at a maximum, approximately twice the liquid pressure of the set pressure Pc. That is, since the pump 21 is supplied by the pressure of the accumulator 22, the maximum hydraulic pressure can be obtained with approximately half the current value of the conventional one, and the pressure can be increased with high responsiveness because the pressure is supplied by the accumulator 22. . The hydraulic pressure of the wheel cylinder WC at the time of the pressure increase of the high pressure / high pressure gradient controls the pressure increase amount based on the operation of the pump 21 or the operation of the pressure increase valve 5 as in the case of the automatic brake control described above. Then, the amount of pressure reduction is controlled by the operation of the gate valve 3 or the operation of the pressure reducing valve 6.

D) At the time of the ABS control If the wheels are likely to be locked at the time of the normal braking described above or at the time of braking by the automatic brake control or the vehicle motion control, the ABS control for preventing the locking is executed. During the ABS control, first, the gate valve 3 is closed, and the pressure increasing valve 5 is closed, while the pressure reducing valve 6 is closed.
, And the brake fluid in the wheel cylinder WC is released to the return circuit 10 to reduce the pressure as shown by the dotted arrow in FIG. If the wheel lock is avoided by this pressure reduction, the wheel cylinder pressure is increased so as to obtain as large a braking force as possible. Further, pressure reduction and pressure increase are repeated as appropriate so that the wheel lock does not occur again due to the pressure increase. In this pressure increase, since it is necessary to recover the braking force instantaneously, the motor M is driven to rotate forward with the maximum driving force, and the switching valve 22b is opened to perform feeding by the accumulator 22. Thus, the pressure increase is performed at the maximum hydraulic pressure (see FIG. 7).

As described above, in the brake device of the first embodiment, the hydraulic pressure source 20 that is independent of the master cylinder MC is provided with the pump 21 that performs the forward / reverse rotation operation, and the hydraulic pressure source 20 is stored in the pump 21. When the hydraulic pressure source 20 does not require a large pressure (increase of a high pressure gradient), only the pump 21 is operated, and the vehicle motion control and the ABS control are performed. When a large pressure (increase in high pressure gradient) is required, as in the case of pressure increase, a high pressure can be supplied instantaneously by using the accumulator 22 in series with the pump 21 to obtain a charging action. . Therefore, as compared with the prior art, the maximum output capacity of the pump 21 can be reduced, whereby the pump 21 and the motor M can be reduced in size and the brake unit can be reduced in size, and the energy consumption can be reduced. However, the required maximum pressure and the required responsiveness can be secured. Further, when a gear pump is used as the pump 21, it is possible to obtain an effect that noise and vibration can be reduced, and it is excellent in boosting performance when charging is performed from the accumulator 22 to the pump 21. The effect is obtained.

(Embodiment 2) A brake device according to Embodiment 2 is a modification of Embodiment 1 and corresponds to claims 5 and 6 of the present invention. As shown, the hydraulic pressure source 200 according to the second embodiment includes a pump 2
1 that connects the accumulator 22 and a position downstream of the gate valve 3 of the brake circuit 1 by bypassing the
1 and a normally closed switching valve 202 for opening and closing the bypass passage 201 is provided. Since other configurations are the same as those of the first embodiment, common configurations are denoted by common reference numerals, and description thereof is omitted.

The operation of the brake device according to the second embodiment differs from that of the brake device according to the first embodiment in that the pressure increase control of the high pressure / high pressure gradient of the wheel cylinder pressure is performed. in this case,
In the second embodiment, first, the switching valve 22b is opened and the switching valve 202 is opened for a predetermined time.
The operation of the pump 21 is started. Therefore, the switching valve 2
By opening the switching valve 2b and the switching valve 202, the brake fluid of the accumulator 22 is instantaneously supplied to the brake circuit 1. Therefore, as shown in FIG. 9, the pressure rise at the time of sudden pressure increase becomes better than when the bypass path 201 is closed. In the second embodiment, the other operations and the obtained effects are the same as those in the first embodiment, and thus the description thereof will be omitted.

(Third Embodiment) A brake device according to a third embodiment is a modification of the first embodiment, and corresponds to the invention described in claims 7 and 8 of the claims. As shown in FIG. 10, a communication path 301 connecting the accumulator 22 and the return circuit 10, and the communication path 301
And a first relief valve 302 that opens when the accumulator 22 side exceeds a predetermined pressure to release the hydraulic pressure to the return circuit 10, and furthermore, in the communication passage 11, in parallel with the check valve 11 a, , The second relief valve 303 opens to release the hydraulic pressure to the return circuit 10.
Is provided. A check valve 304 that allows only the flow in the pressure accumulation direction is provided in parallel with the switching valve 22b. Other configurations are the same as those in the first embodiment, and thus the same configurations are denoted by the same reference numerals and description thereof is omitted.

In the brake device according to the third embodiment, an abnormally high pressure is generated in the accumulator 22 due to some trouble at the time of charging the accumulator, or the pressure is charged to the accumulator 22 at a low temperature, and If an abnormally high pressure occurs in the accumulator 22 due to a change in the environmental temperature to a high temperature, the first relief valve 302 opens to release the pressure of the accumulator 22 to the return circuit 10. Therefore, the accumulator 22 is abnormally high pressure.
Thus, it is possible to improve the reliability and durability of the device by preventing the device from being damaged.

Further, in the automatic brake control and the ABS control, when the pressure is increased at a high pressure / high pressure gradient,
An abnormality occurs in which the booster valve 5 and the gate valve 3 are maintained in the closed state, and an abnormally high pressure is generated in a portion surrounded by the pump 21, the gate valve 3, and the booster valves 5, 5 in the brake circuit 1 and the connection circuit 21c. When this occurs, the second relief valve 303 opens to release pressure to the return circuit 10. Therefore, due to the abnormally high pressure, the pipelines constituting the brake circuit 1 and the connection circuit 21c and the gate valve 3
Also, it is possible to prevent the pressure-intensifying valves 5 and 5 and the check valves 3a and 5a from being damaged, and to improve the reliability and durability of the device.

(Embodiment 4) Embodiment 4 corresponds to the inventions set forth in claims 9 and 10, and executes the by-wire control even during normal braking. This is an example. FIG. 11 shows a brake device according to a fourth embodiment. In the brake circuit 1, a reservoir 401 for absorbing a volume change when the brake pedal BP is stroked is provided between the gate valve 3 and the master cylinder MC. And this reservoir 4
A switching valve 403 that is normally closed is provided in the middle of a communication path 402 connecting the brake control circuit 01 and the brake circuit 1 and opens and closes the communication path 402.
A check valve 404 that opens only in the direction in which the brake fluid returns to the brake circuit 1 is provided. Embodiment 4
In the hydraulic pressure source 400, the second suction / discharge port 21a side of the pump 21 is connected to the return circuit 10 by a suction circuit 405, and the suction circuit 405 is provided with a check valve 406. In the brake circuit 1, the check valve 3a in parallel with the gate valve 3 is eliminated because the actual flow of the brake fluid is lost. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the brake device of the fourth embodiment, at the time of normal braking, the driver operates the brake pedal BP and simultaneously closes the gate valve 3 and opens the switching valve 403. , The brake fluid corresponding to the volume change in the master cylinder MC is supplied to the reservoir 40.
Absorb at 1. As a result, the driver can obtain the same operational feeling as a general brake device, and does not feel uncomfortable with the braking operation.

When the driver performs the braking operation, the operation state is detected by a sensor (not shown).
When this braking operation corresponds to the pressure increase of the low pressure / low pressure gradient, the pump 21 is driven to suck the brake fluid of the master cylinder MC via the return circuit 10 as shown by a solid line arrow in FIG. To discharge toward the brake circuit 1. Further, the pressure increase valve 5 and the pressure reduction valve 6 are appropriately opened, and the pressure increase and the pressure reduction are performed, whereby the wheel cylinder pressure is optimally controlled.

When the braking operation corresponds to an increase in pressure at a high pressure / high pressure gradient, the switching valve 22b is opened in addition to the above operation, and the accumulator 22 is supplied with hydraulic pressure.

According to the fourth embodiment, in the brake device that executes the by-wire control even during the normal braking,
The same effect as in the first embodiment can be obtained. In addition,
In the fourth embodiment, when a malfunction occurs in the above-described by-wire control, when the brake pedal BP is operated, the master cylinder pressure is supplied to the wheel cylinder WC via the brake circuit 1. Excellent fail-safe property. At the time of other automatic brake control, accumulator charging, and ABS control, the same operation as that of the first embodiment is executed.

(Fifth Embodiment) A fifth embodiment is a modification of the fourth embodiment, and as shown in FIG.
00 is a brake device according to the fourth embodiment,
This is an example in which the bypass path 201 and the switching valve 202 are provided, and the accumulator 22 is used to supply power at the initial stage of the rapid pressure increase, thereby improving the rising characteristics.

Although the embodiment has been described with reference to the drawings, the present invention is not limited to the configuration of the above embodiment. For example, the configuration for executing the by-wire control described in the fourth embodiment can be added to the configuration described in the first to third embodiments.

[Brief description of the drawings]

FIG. 1 is a brake circuit diagram showing a brake device according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating an operation during normal braking according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating an operation at the time of accumulator charging according to the first embodiment.

FIG. 4 is an explanatory diagram illustrating an operation at the time of pressure increase control based on a low pressure / low pressure gradient according to the first embodiment.

FIG. 5 is an explanatory diagram for explaining an operation at the time of pressure increase control by a high pressure / high pressure gradient according to the first embodiment;

FIG. 6 is an explanatory diagram illustrating an operation during ABS control according to the first embodiment.

FIG. 7 is a pressure increase characteristic diagram of the first embodiment.

FIG. 8 is a brake circuit diagram showing a brake device according to a second embodiment.

FIG. 9 is a pressure increase characteristic diagram in the second embodiment.

FIG. 10 is a brake circuit diagram showing a brake device according to a third embodiment.

FIG. 11 is a brake circuit diagram showing a brake device according to a fourth embodiment.

FIG. 12 is a brake circuit diagram showing a brake device according to a fifth embodiment.

[Explanation of symbols]

 Reference Signs List 1 brake circuit 3 gate valve 3a check valve 5 booster valve 5a check valve 6 pressure reducing valve 10 return circuit 11 communication path 11a check valve 20 hydraulic pressure source 21 pump 21a first suction / discharge port 21b second suction / discharge port 21c connection Circuit 21d Suction circuit 21f Check valve 22 Accumulator 22a Connection circuit 22b Switching valve 22c Pressure sensor 200 Hydraulic pressure source 201 Bypass path 202 Switching valve 301 Communication path 302 Relief valve 303 Relief valve 401 Reservoir 402 Communication path 403 Switching valve 404 Check valve 405 Suction circuit BP brake pedal M Motor MC Master cylinder RES Reservoir WC Wheel cylinder

Claims (10)

[Claims] 1. A hydraulic pressure source for supplying a brake fluid to a wheel cylinder via a supply circuit, and a hydraulic pressure source provided in the supply circuit for adjusting a supply state of the brake fluid supplied from the hydraulic pressure source. A fluid pressure adjusting means capable of adjusting the wheel cylinder pressure by increasing and decreasing the pressure of the wheel cylinder, a return circuit for releasing the brake fluid when the fluid pressure adjusting means releases the pressure, and a brake fluid source connected to the return circuit; The hydraulic pressure source is provided with a pump driven by a motor and an accumulator capable of accumulating a predetermined pressure, wherein the pump has a first suction / discharge port and a second suction / discharge port. With an exit,
The first suction / discharge port is connected to a supply circuit, and the first suction / discharge port is connected to a supply circuit.
The suction / discharge port is installed connected to the accumulator, and in the supply circuit, between the pump and the hydraulic pressure adjusting means.
The brake fluid source is connected via a communication passage, and a check valve for preventing backflow to the brake fluid source is provided in the middle of the communication passage, and a connection connecting the accumulator and the second suction / discharge port. A switching valve for connecting and disconnecting the connection circuit is provided in the middle of the circuit, and a position of the connection circuit between the pump and the switching valve is connected to a brake fluid source via a suction circuit, and the suction circuit A brake valve, which is provided in the middle of the valve to limit the flow of the brake fluid in the suction circuit only from the brake fluid source to the connection circuit. 2. The brake fluid source is a master cylinder that generates a fluid pressure by a driver's braking operation, and a reservoir of the master cylinder. The return circuit is connected to the reservoir, In the supply circuit, a position between the fluid pressure adjusting means and the pump is connected via a main supply circuit, and a gate valve for communicating and shutting off the main supply circuit is provided in the middle of the main supply circuit. The brake device according to claim 1, wherein the circuit connects a position between a master cylinder and a gate valve in the main supply circuit and the connection circuit. 3. The brake device according to claim 1, wherein the pump is a gear pump. 4. A reverse rotation operation in which the pump sucks brake fluid from a first suction / discharge port and discharges the brake fluid from a second suction / discharge port, and opens the switching valve to discharge brake fluid from a brake fluid source. Accumulator charge control to be supplied to the accumulator, and a forward rotation operation in which the pump sucks the brake fluid from the second discharge port and discharges the brake fluid from the first suction and discharge port,
A low pressure gradient pressure increasing control for discharging the brake fluid from the brake fluid source toward the supply circuit and increasing the wheel cylinder pressure with a low pressure gradient by a fluid pressure adjusting means; High pressure gradient pressure increase control in which the valve is opened and the accumulator pressure is increased by the pump and supplied to the supply circuit while being supplied to the supply circuit, and the wheel cylinder pressure is increased with a high pressure gradient by the hydraulic pressure adjusting means. 4. The brake device according to claim 1, further comprising control means for performing the following. 5. A bypass which bypasses the pump and connects a position between the switching valve of the connection circuit and the pump and a position between the pump of the supply circuit and the hydraulic pressure adjusting means, The brake device according to any one of claims 1 to 4, wherein a second switching valve that communicates with and shuts off the bypass path is provided at an intermediate portion of the path. 6. The control means, during the high pressure gradient pressure increase control, first opens the switching valve and the second switching valve for a predetermined time to release the brake fluid stored in the accumulator via the bypass. The brake device according to claim 5, wherein the initial abrupt pressure increase to be supplied to the supply circuit is performed, and the pumping operation is performed by performing a forward rotation operation of the pump in parallel with the initial pressure increase. 7. A relief valve for connecting the connection circuit and the return circuit, wherein a relief valve is opened in the middle of the relief circuit and released to the return circuit when the hydraulic pressure on the connection circuit side exceeds a set pressure. The brake device according to claim 1, wherein the brake device is provided. 8. A second relief circuit for connecting the supply circuit and the return circuit is provided. In the middle of the second relief circuit, when the hydraulic pressure on the supply circuit side exceeds a set pressure, the valve is opened to return to the return circuit. The brake device according to any one of claims 1 to 7, further comprising a second relief valve for releasing. 9. In the main supply circuit, a reservoir is provided between the master cylinder and the gate valve, the reservoir allowing movement of the brake fluid with a predetermined reaction force when a master cylinder pressure is generated. In the middle of the connection circuit connecting the main supply circuit,
7. The brake device according to claim 2, further comprising a third switching valve that connects and disconnects the connection circuit. 10. The control means normally opens the gate valve and closes the third switching valve, and closes the gate valve when an operation for increasing the master cylinder pressure is performed. At the same time, the third switching valve is opened, the volume change in the master cylinder is absorbed by the reservoir, and the low pressure gradient pressure increasing control and the high pressure gradient pressure increasing control are executed in accordance with the operation state of the master cylinder. The brake device according to claim 9, wherein: