JP2007313979A - Brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of operation of a valve for performing opening/closing of a flow passage as much as possible when performing brake-by-wire. <P>SOLUTION: The brake device for the vehicle is provided with a first pump 5d interposed on the flow passage for communicating a reservoir tank 2a with wheel cylinders 3FL-3RR; and a second pump 5u interposed between the first pump 5d and the reservoir tank 2a. A fluid pressure circuit is constituted such that a delivery pressure of the first pump 5d can be transmitted to the respective wheel cylinders 3FL-3RR and a delivery pressure of the second pump 5u can be transmitted to the respective wheel cylinders 3FL-3RR not through the first pump 5d. Further, a first valve 7i is provided on the first flow passage 6i and a second valve 9i is provided on the second flow passage 8i. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle brake device that performs brake-by-wire.

As a pressure source for the brake-by-wire, there is one in which two pumps for high pressure and low pressure are connected in parallel to a hydraulic circuit, and each pump is driven and controlled as necessary (see Patent Document 1).
Japanese Patent No. 3409721

However, in the conventional example described in Patent Document 1, since two pumps are connected in parallel to one flow path communicating with the wheel cylinder, naturally, each pump is independent. Therefore, it is not possible to control the hydraulic pressure of the two systems.
Therefore, for example, in order to individually control the braking force of the front and rear wheels according to the ideal braking force distribution, it is only possible to control the opening and closing of the valve interposed between the pump and the wheel cylinder. In other words, in the high-pressure side hydraulic system, the pump discharge pressure (number of revolutions) may be controlled while the valve is open, but in the low-pressure side hydraulic system, the valve is controlled to the desired hydraulic pressure by repeatedly opening and closing the valve. Therefore, there is a possibility that the number of operation of the valve is increased particularly in a low-pressure side hydraulic system, and a highly durable part is required, which may increase the cost.
An object of the present invention is to reduce the number of operation times of a valve for opening and closing a flow path as much as possible when performing brake-by-wire.

In order to solve the above-described problems, a vehicle brake device according to the present invention includes a fluid source in which fluid is stored, a wheel cylinder that generates a braking force by fluid pressure, and a flow that communicates the fluid source and the wheel cylinder. A first pump interposed in the passage; a second pump interposed between the first pump and the fluid source; and a first flow path between the first pump and the wheel cylinder. On the other hand, a first flow path and a second flow path that communicates between the first pump and the second pump and the wheel cylinder are provided. A plurality of brake systems are configured.
That is, the fluid pressure circuit can transmit the discharge pressure of the first pump to all the wheel cylinders, and can transmit the discharge pressure of the second pump to all the wheel cylinders without going through the first pump. It is characterized by comprising.

According to the vehicle brake device of the present invention, since the discharge pressure of the first pump can be transmitted to each wheel cylinder through the first flow path, the second pump and the first pump are driven in series. When this is done, it can act as one pressure source, and can exhibit discharge performance with excellent responsiveness.
In addition, since the discharge pressure of the second pump can be directly transmitted to each wheel cylinder via the second flow path, the second pump and the first pump can be driven in parallel, and each has independent discharge pressure. Can be transmitted to the wheel cylinders of each system. That is, when the second pump and the first pump are driven and controlled in a parallel state, the fluid pressures of the two systems can be individually controlled, so the number of actuations of the valve interposed between the pump and the wheel cylinder Can be reduced as much as possible.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration of a brake-by-wire according to the first embodiment. The master cylinder 2 that converts the driver's pedal effort input to the brake pedal 1 into hydraulic pressure has a primary side communicated with the front left wheel cylinder 3FL and a secondary side communicated with the front right wheel cylinder 3FR.

The front left and right wheel cylinders 3FL and 3FR and the rear left and right wheel cylinders 3RL and 3RR each have a disc brake that presses the disc rotor with a brake pad to generate braking force, and brake shoes on the inner peripheral surface of the brake drum. It is built in a drum brake that presses and generates braking force.
A gate valve 4p (4s) capable of closing the flow path is interposed between the master cylinder 2 and the wheel cylinder 3FL (3FR). These gate valves 4p and 4s are 2-port 2-position switching / spring offset type electromagnetically operated valves, and are configured to open the flow path at a non-excited normal position.

  On the other hand, a reservoir tank 2a (corresponding to a “fluid source”) of the master cylinder 2 is connected in series with a second pump 5u and a first pump 5d each constituted by a gear pump. The downstream side of the first pump 5d communicates with each wheel cylinder 3i via a first flow path 6i (i = FL, FR, RL, RR). The 1st valve | bulb 7i is arrange | positioned. Further, the second pump 5u and the first pump 5d communicate with each wheel cylinder 3i through the second flow path 8i, and the second flow path 8i has a second flow path, respectively. A valve 9i is provided. That is, a first pump 5d is interposed in a flow path connecting the reservoir tank 2a and the wheel cylinder 3i, and a second pump 5u is interposed between the first pump 5d and the reservoir tank 2a. The first flow path 6i is between the first pump 5d and the wheel cylinder 3i, and the flow path between the first pump 5d and the second pump 5u and the wheel cylinder 3i is the second flow path. Road 8i.

The wheel cylinder 3i, the first flow path 6i, the first valve 7i, the second flow path 8i, and the second valve 9i constitute a unit brake system.
Here, each of the first valve 7i and the second valve 9i is a two-port two-position switching / spring offset type electromagnetically operated valve, and is a first valve 7FL, 7FR that serves as a brake system on the front wheel side. And the second valves 9FL and 9FR close the flow path at the non-excited normal position (normally closed), and the first valves 7RL and 7RR and the second valves 9RL and 9RR that serve as a brake system on the rear wheel side. Is configured to open the flow path at a non-excited normal position (normally open). The first valves 7RL and 7RR and the second valves 9RL and 9RR serving as the brake system on the rear wheel side may close the flow path at the non-excited normal position.

With the above configuration, when the second pump 5u is rotated in the forward direction, the fluid stored in the reservoir tank 2a is sucked and the discharge pressure is transmitted to the second valve 9i through the second flow path 8i. Is done. Further, when the second pump 5u is rotated in the reverse direction, the fluid on the downstream side is returned to the reservoir tank 2a.
Therefore, if the gate valves 4p and 4s are closed, the first valve 7i is closed, and the second valve 9i is opened, the wheel cylinder 3i is increased in pressure when the second pump 5u is rotated forward. The Further, when the gate valves 4p and 4s are closed, the first valve 7i is closed, and the second valve 9i is closed, the hydraulic pressure of the wheel cylinder 3i is maintained by blocking the flow path. At this time, if the rotation of the second pump 5u is fixed, the hydraulic pressure of the wheel cylinder 3i is maintained even when the second valve 9i is opened. Furthermore, if the gate valves 4p and 4s are closed, the first valve 7i is closed, and the second valve 9i is opened, the wheel cylinder 3i is depressurized when the second pump 5u is rotated in the reverse direction. .

On the other hand, when the first pump 5d is rotated in the forward direction, the upstream fluid is sucked and the discharge pressure is transmitted to the first valve 7i via the first flow path 6i. Further, when the first pump 5d is rotated in the reverse direction, the downstream fluid is returned to the upstream side.
Therefore, if the gate valves 4p and 4s are closed, the first valve 7i is opened, and the second valve 9i is closed, the wheel cylinder 3i is increased in pressure when the first pump 5d is rotated forward. The Further, when the gate valves 4p and 4s are closed, the first valve 7i is closed, and the second valve 9i is closed, the hydraulic pressure of the wheel cylinder 3i is maintained by blocking the flow path. At this time, if the rotation of the first pump 5d is fixed, the hydraulic pressure of the wheel cylinder 3i is maintained even if the first valve 7i is opened. Furthermore, if the gate valves 4p and 4s are closed, the first valve 7i is opened, and the second valve 9i is closed, the wheel cylinder 3i is depressurized when the first pump 5d is reversely rotated. .

When the gate valves 4p and 4s are opened, the first valves 7FL and 7FR are closed, and the second valves 9FL and 9FR are closed, that is, when all the valves are de-energized, the hydraulic pressure of the master cylinder 2 remains unchanged. It is transmitted to the wheel cylinders 3FL and 3FR of the front wheels.
The controller 15 drives and controls the gate valves 4p and 4s, the second pump 5u, the first pump 5d, the first valve 7i, and the second valve 9i.

  When performing the brake-by-wire, the controller 15 controls the braking force by increasing, holding, or reducing the pressure of the wheel cylinder 3i according to the driver's brake operation with the gate valves 4p and 4s closed. That is, the second pump 5u, the first pump 5d, the first valve 7i, and the second valve 9i are driven and controlled so that a braking force according to the master cylinder pressure and the pedal stroke is generated.

  The master cylinder 2 is connected to a single-acting cylinder (hereinafter referred to as a stroke simulator) 10 that elastically strokes according to the hydraulic pressure. Therefore, when performing brake-by-wire, when the hydraulic pressure of the master cylinder 2 rises according to the driver's brake operation, the stroke simulator 10 elastically strokes, so that an appropriate pedal for the driver's brake operation is obtained. Stroke and pedal reaction force are produced.

  On the other hand, when brake-by-wire is not executed due to fail-safe operation, the master cylinder 2 and the front cylinder 2 are separated from each other by de-energizing all of the gate valves 4p and 4s, the first valves 7FL and 7FR, and the second valves 9FL and 9FR. The left and right wheel cylinders 3FL and 3FR are connected to each other and mechanically backed up to ensure the braking force of the front wheels. Here, only the braking force of the front wheels can be mechanically backed up, but of course, both the front and rear wheels or only the rear wheels may be mechanically backed up.

Next, the braking force control process of 1st Embodiment performed with the controller 15 is demonstrated based on the flowchart of FIGS. This process is executed by timer interruption every predetermined time (for example, 10 msec).
First, in step S1, target braking forces Ff ^* and Fr ^* for the front and rear wheels are calculated according to the amount of brake operation by the driver.
In the subsequent step S2, it is determined whether or not the brake-by-wire system is normal, that is, whether the pump and various valves are operating normally. Whether or not the pump operates normally is determined based on the rotation state of the motor with respect to the drive command, and whether or not various valves operate normally can be determined by electrically detecting the presence or absence of disconnection. The determination is made based on the change state of the hydraulic pressure with respect to the drive command. If there is an abnormality in the system, the process proceeds to step S36 in FIG. On the other hand, when the system is normal, the process proceeds to step S3.

In step S3, it is determined whether or not the target braking forces Ff ^* and Fr ^{* of the} front and rear wheels match. When the determination result is “Ff ^* ≠ Fr ^* ”, the process proceeds to step S9 described later. On the other hand, when the determination result is “Ff ^* = Fr ^* ”, the process proceeds to step S4.
In step S4, it is determined whether or not to increase / hold the wheel cylinder 3i in order to achieve the target braking force Ff ^* (= Fr ^* ). Here, when depressurizing the wheel cylinder 3i, the process proceeds to step S7 described later. On the other hand, when increasing or holding the wheel cylinder 3i, the process proceeds to step S5.

In step S5, the first valve 7i is opened and the second valve 9i is closed in all brake systems.
In the subsequent step S6, the first pump 5d is driven to rotate in the forward direction so as to obtain the wheel cylinder pressure necessary to achieve the target braking force Ff ^* (= Fr ^* ), and the same as the first pump 5d. The second pump 5u is rotationally driven in the forward direction so as to reach the discharge amount, and then returns to a predetermined main program.
On the other hand, in step S7, the first valve 7i is closed and the second valve 9i is opened in all brake systems.
In the subsequent step S8, the second pump 5u is rotationally driven in the reverse direction so as to obtain a wheel cylinder pressure necessary to achieve the target braking force Ff ^* (= Fr ^* ), and then returns to a predetermined main program. .

On the other hand, in step S9, it is determined whether or not to increase / hold the wheel cylinder 3i in all brake systems. Here, when there is a brake system for depressurizing the wheel cylinder 3i, the process proceeds to step S25 in FIG. On the other hand, when increasing or holding the wheel cylinder 3i in all brake systems, the process proceeds to step S10.
In step S10, it is determined whether or not the front wheel target braking force Ff ^* is greater than or equal to the rear wheel target braking force Fr ^* . When the determination result is “Ff ^* <Fr ^* ”, the process proceeds to step S18 described later. On the other hand, when the determination result is “Ff ^* ≧ Fr ^* ”, the process proceeds to step S11.

In step S11, it is determined whether or not the hydraulic pressure P1 (the hydraulic pressure in the second flow path 8i) on the downstream side of the second pump 5u is equal to or greater than the rear wheel target braking force Fr ^* . When the determination result is “P1 ≧ Fr ^* ”, the process proceeds to step S15 described later. On the other hand, when the determination result is “P1 <Fr ^* ”, the process proceeds to step S12.
In step S12, the first valves 7FL and 7FR are opened and the second valves 9FL and 9FR are closed in the high pressure side brake system, that is, the front wheel side brake system.

In the subsequent step S13, the first valves 7RL and 7RR are controlled so as to achieve the wheel cylinder pressure necessary to achieve the target braking force Fr ^* of the rear wheels in the brake system on the low pressure side, that is, the brake system on the rear wheel side. Controls opening and closing. Further, the second valves 9RL and 9RR are closed.
In the following step S14, the first pump 5d is driven to rotate in the forward direction so as to achieve the wheel cylinder pressure necessary to achieve the target braking force Ff ^*, and at the same time, it is necessary to achieve the target braking force Fr ^*. The second pump 5u is driven to rotate in the forward direction so that the wheel cylinder pressure is reached, and then the routine returns to a predetermined main program.

On the other hand, in step S15, the first valves 7FL and 7FR are opened and the second valves 9FL and 9FR are closed in the high pressure side brake system, that is, the front wheel side brake system.
In the subsequent step S16, the first valves 7RL and 7RR are closed and the second valves 9RL and 9RR are opened in the low pressure side brake system, that is, the rear wheel side brake system.

In the subsequent step S17, the first pump 5d is driven to rotate in the forward direction so as to achieve the wheel cylinder pressure necessary to achieve the target braking force Ff ^*, and it is necessary to achieve the target braking force Fr ^*. The second pump 5u is driven to rotate in the forward direction so that the wheel cylinder pressure is reached, and then the routine returns to a predetermined main program.
On the other hand, in step S18, it is determined whether or not the hydraulic pressure P1 (the hydraulic pressure in the second flow path 8i) on the downstream side of the second pump 5u is equal to or greater than the target braking force Ff ^{* for the} front wheels. When the determination result is “P1 ≧ Ff ^* ”, the process proceeds to step S22 described later. On the other hand, when the determination result is “P1 <Ff ^* ”, the process proceeds to step S19.

In step S19, the first valves 7RL and 7RR are opened and the second valves 9RL and 9RR are closed in the brake system on the high pressure side, that is, the brake system on the rear wheel side.
In the subsequent step S20, the first valves 7FL and 7FR are opened and closed so that the wheel cylinder pressure required to achieve the target braking force Ff ^* of the front wheels is reached in the brake system on the low pressure side, that is, the brake system on the front wheels. Control. Further, the second valves 9FL and 9FR are closed.

In the subsequent step S21, the first pump 5d is driven to rotate in the forward direction so as to achieve the wheel cylinder pressure necessary to achieve the target braking force Fr ^*, and it is necessary to achieve the target braking force Ff ^*. The second pump 5u is driven to rotate in the forward direction so that the wheel cylinder pressure is reached, and then the routine returns to a predetermined main program.
On the other hand, in step S22, the first valves 7RL and 7RR are opened and the second valves 9RL and 9RR are closed in the brake system on the high pressure side, that is, the brake system on the rear wheel side.

In the subsequent step S23, the first valves 7FL and 7FR are closed and the second valves 9FL and 9FR are opened in the brake system on the low pressure side, that is, the brake system on the front wheel side.
In the subsequent step S24, the first pump 5d is driven to rotate in the forward direction so as to achieve the wheel cylinder pressure necessary to achieve the target braking force Fr ^*, and it is necessary to achieve the target braking force Ff ^*. The second pump 5u is driven to rotate in the forward direction so that the wheel cylinder pressure is reached, and then the routine returns to a predetermined main program.

On the other hand, in step S25 of FIG. 3, it is determined whether or not the pressure of the wheel cylinder 3i is reduced in all brake systems. Here, when there are mixed brake systems for increasing / holding / depressurizing the wheel cylinder 3i, the process proceeds to step S33 described later. On the other hand, when depressurizing the wheel cylinder 3i in all brake systems, the process proceeds to step S26.
In step S26, it is determined whether or not the target braking force Ff ^{* for} the front wheels is greater than or equal to the target braking force Fr ^{* for the} rear wheels. When the determination result is “Ff ^* <Fr ^* ”, the process proceeds to step S30 described later. On the other hand, when the determination result is “Ff ^* ≧ Fr ^* ”, the process proceeds to step S27.

In step S27, the first valves 7FL and 7FR are opened and the second valves 9FL and 9FR are closed in the high pressure side brake system, that is, the front wheel side brake system.
In the subsequent step S28, the first valves 7RL and 7RR are closed and the second valves 9RL and 9RR are opened in the low pressure side brake system, that is, the rear wheel side brake system.
In the following step S29, the first pump 5d is driven to rotate in the reverse direction so that the wheel cylinder pressure required to achieve the target braking force Ff ^* is required, and at the same time, it is necessary to achieve the target braking force Fr ^*. The second pump 5u is rotationally driven in the reverse direction so that the wheel cylinder pressure is reached, and then the routine returns to a predetermined main program.
On the other hand, in step S30, the first valves 7RL and 7RR are opened and the second valves 9RL and 9RR are closed in the brake system on the high pressure side, that is, the brake system on the rear wheel side.

In the subsequent step S31, the first valves 7FL and 7FR are closed and the second valves 9FL and 9FR are opened in the low pressure side brake system, that is, the front wheel side brake system.
In the subsequent step S32, the first pump 5d is driven to rotate in the reverse direction so that the wheel cylinder pressure necessary for achieving the target braking force Fr ^* is reached, and it is necessary to achieve the target braking force Ff ^*. The second pump 5u is rotationally driven in the reverse direction so that the wheel cylinder pressure is reached, and then the routine returns to a predetermined main program.
On the other hand, in step S33, the first valve 7i is opened and the second valve 9i is closed in the brake system for increasing / holding pressure.

In the subsequent step S34, the first valve 7i is closed and the second valve 9i is opened in the brake system to be decompressed.
In the subsequent step S35, the first pump 5d and the second pump 5u are rotationally driven in the following manner, and then returned to a predetermined main program. First, the first pump 5d is rotationally driven in the forward direction so as to obtain a wheel cylinder pressure necessary to achieve the target braking force in the brake system for increasing / holding pressure. Further, the pressure reduction amount of the brake system to be reduced is compared with the pressure increase amount of the brake system to be increased. If the pressure reduction amount exceeds the pressure increase amount, the second pump 5u is rotationally driven in the reverse direction by the difference. If the pressure reduction amount and the pressure increase amount coincide with each other, the second pump 5u is stopped, and if the pressure reduction amount is less than the pressure increase amount, the second pump 5u is rotationally driven in the positive direction by the difference. .

On the other hand, in step S36 of FIG. 4, it is determined whether only the first pump 5d is abnormal. Here, when the first pump 5d is normal or when there is an abnormality in addition to the first pump 5d, the process proceeds to step S39 described later. On the other hand, when only the first pump 5d is abnormal, the process proceeds to step S37.
In step S37, the first valve 7i is closed in all brake systems, and the second valve 9i is opened and closed so that the wheel cylinder pressure necessary to achieve the target braking force is achieved in each brake system. Control.

  In the subsequent step S38, if there is a brake system that increases pressure, the second pump 5u is driven to rotate in the forward direction to reduce the pressure so that the wheel cylinder pressure necessary to achieve the maximum target braking force is reached. In the case of only the system, the second pump 5u is rotationally driven in the reverse direction so as to obtain the wheel cylinder pressure necessary to achieve the minimum target braking force, and then returns to a predetermined main program.

On the other hand, in step S39, it is determined whether only the first valve 7i is abnormal. Here, when the first valve 7i is normal or there is an abnormality in addition to the first valve 7i, the process proceeds to step S43 to be described later. On the other hand, when only the first valve 7i is abnormal, the process proceeds to step S40.
In step S40, the first valve 7i is a brake system that can keep the first valve 7i closed, here the first valve 7i is a front-side brake system that is configured by a normally closed type valve. The second valve 9FL / 9FR is opened while being deenergized and closed.

In the subsequent step S41, the first valve 7i is a brake system that can maintain the first valve 7i open, in this case, the first valve 7i is a brake system on the rear wheel side that is configured by a normally open type valve. 7RR is de-energized and opened, and the second valves 9RL and 9RR are closed.
In the subsequent step S42, the first pump 5d is driven to rotate in the forward or reverse direction so that the wheel cylinder pressure required to achieve the target braking force Fr ^* is achieved, and the target braking force Ff ^* is achieved. The second pump 5u is rotationally driven in the forward direction or the reverse direction so that the wheel cylinder pressure required for the rotation is obtained, and then returns to a predetermined main program.

On the other hand, in step S43, it is determined whether only the second valve 9i is abnormal. Here, when the second valve 9i is normal or when there is an abnormality in addition to the second valve 9i, the process proceeds to step S47 described later. On the other hand, when only the second valve 9i is abnormal, the process proceeds to step S44.
In step S44, the first valve 7FL, 7FR is operated by a brake system capable of keeping the second valve 9i closed, here, the second valve 9i is a front-wheel side brake system configured by a normally closed type valve. In addition to opening, the second valves 9FL and 9FR are de-energized and closed.

In the subsequent step S45, the brake system capable of maintaining the second valve 9i open, here the rear valve system in which the second valve 9i is constituted by a normally open valve, the first valve 7RL, 7 RR is closed and the second valves 9 RL and 9 RR are de-energized and opened.
In the subsequent step S46, the first pump 5d is driven to rotate in the forward or reverse direction so as to achieve the wheel cylinder pressure necessary to achieve the target braking force Ff ^* , and the target braking force Fr ^* is achieved. The second pump 5u is rotationally driven in the forward direction or the reverse direction so that the wheel cylinder pressure required for the rotation is obtained, and then returns to a predetermined main program.

On the other hand, in step S47, the brake-by-wire system is stopped and then the process returns to a predetermined main program. That is, the master cylinder 2 and the front left and right wheel cylinders 3FL and 3FR are made to communicate with each other by de-energizing all of the gate valves 4p and 4s, the first valves 7FL and 7FR, and the second valves 9FL and 9FR. Back up mechanically to ensure the braking force of the front wheels.
From the above, the braking force control process of FIGS. 2 to 4 corresponds to the “control means”.

Next, the operational effects of the first embodiment will be described.
In the first embodiment, the first pump 5d includes a second pump 5u and a first pump 5d arranged in series, and a plurality of wheel cylinders 3FL to 3RR that generate a braking force by fluid pressure. Fluid pressure circuit so that the discharge pressure of the second pump 5u can be transmitted to the wheel cylinders 3FL to 3RR without going through the first pump 5d. Is configured.
Thus, since the discharge pressure of the first pump 5d can be transmitted to each wheel cylinder 3i via the first flow path 6i, when the second pump 5u and the first pump 5d are driven in series. By acting as a single pressure source, it is possible to exhibit discharge performance with excellent responsiveness.

Further, since the discharge pressure of the second pump 5u can be directly transmitted to each wheel cylinder 3i via the second flow path 8i, the second pump 5u and the first pump 5d can be driven in parallel, respectively. Can transmit independent discharge pressures to the wheel cylinders 3i of each system. That is, when the second pump 5u and the first pump 5d are driven and controlled in parallel, the fluid pressures of the two systems can be individually controlled, so that the valve interposed between the pump and the wheel cylinder can be controlled. The number of operations can be reduced as much as possible.
Further, since the first valve 7i that opens and closes the first flow path 6i and the second valve 9i that opens and closes the second flow path 8i are provided, it is transmitted to the wheel cylinder 3i of each brake system. Hydraulic pressure can be controlled individually.

Here, specific operations according to several scenes will be described.
First, when unifying all wheel cylinder pressures (determination in step S3 is “Yes”), in order to increase / hold the wheel cylinder pressure (determination in step S4 is “Yes”), as shown in FIG. In all the brake systems, with the first valves 7FL to 7RR opened and the second valves 9FL to 9RR closed (step S5), the second pump 5u and the first pump 5d are moved in the forward direction. (Step S6).

At this time, since the back pressure of the first pump 5d is increased by the discharge pressure of the second pump 5u, the first pump 5d can exhibit a high-pressure and highly responsive discharge performance.
Further, by causing the two pumps to act as one pressure source, the discharge pressure is reliably transmitted to all the wheel cylinders 3FL to 3RR, so there is no variation. In addition, for example, it is conceivable that the discharge pressures of the two pumps are transmitted to different brake systems, and the discharge pressures of the respective pumps are made to coincide with each other. Since there is a possibility that an error will occur in the discharge pressure by the tolerance of this, the present embodiment is still more advantageous.

  On the other hand, to reduce the wheel cylinder pressure (determination in step S4 is “No”), as shown in FIG. 6, the first valves 7FL to 7RR are closed and the second valve is closed in all brake systems. With 9FL to 9RR opened (step S7), only the second pump 5u is rotationally driven in the reverse direction (step S8). In this case as well, all the wheel cylinders 3FL to 3RR can be uniformly depressurized as in the case of increasing / holding pressure.

  When the wheel cylinder pressure is different between the two systems (the determination in step S3 is “Yes”), in order to increase / hold all the wheel cylinder pressures (the determination in step S9 is “Yes”), one brake is applied. In the system, with the first valve 7i opened and the second valve 9i closed (step S15 or S22), the first pump 5d is driven to rotate in the forward direction (step S17 or S24). In the brake system, the second valve 5u is driven to rotate in the forward direction (step S17 or S24) with the first valve 7i closed and the second valve 9i opened (step S16 or S23). .

At this time, it is not necessary to control the desired hydraulic pressure by repeatedly opening and closing the first valve 7i and the second valve 9i in each brake system, and simply controlling the discharge pressure (rotation speed) of each pump. Therefore, the number of operations of each valve can be reduced as much as possible.
When different wheel cylinder pressures are used in the two systems, as shown in FIG. 7, the magnitudes of these target values are compared (step S10). In the high-pressure brake system, the first valve 7i is opened, and With the second valve 9i closed (step S15 or S22), the first pump 5d is driven to rotate in the forward direction (step S17 or S24), and the first valve 7i is closed in the low-pressure brake system. In addition, with the second valve 9i opened (step S16 or S23), the second pump 5u is rotationally driven in the forward direction (step S17 or S24).

  As described above, since the back pressure of the first pump 5d is increased by the discharge pressure of the second pump 5u, the first pump 5d has a high pressure and high response even if the power is not particularly increased. This is because the discharge performance can be exhibited. Therefore, it does not impose a heavy burden on one of the second pump 5u and the first pump 5d, but both can be driven without difficulty, and the wheel cylinder pressure of the brake system that is desired to be relatively high is quickly increased. be able to.

  However, when the wheel cylinder pressure is made different between the two brake systems from the state in which the wheel cylinder pressure is unified in all brake systems, the first flow path 6i corresponding to the discharge side of the first pump 5d is high. Compared to this, the second flow path 8i corresponding to the discharge side of the second pump 5u is at a low pressure. Accordingly, when the second valve 9i is opened in this state, even if the wheel cylinder 3i wants to increase the pressure, it is temporarily (until the discharge pressure of the second pump 5u increases) due to the communication with the second flow path 8i. ) It seems that the pressure is reduced.

Therefore, in the brake system on the low pressure side, the second valve 9i is opened after the hydraulic pressure P1 on the downstream side of the second pump 5u matches the wheel cylinder pressure (steps S11 to S17 or S18 to S24). ). That is, the second valve 9i is kept closed until the hydraulic pressure P1 on the downstream side of the second pump 5u becomes equal to or higher than the low-pressure side target braking force F ^* (the determination in step S11 or S18 is “Yes”). (Step S13 or S20). As a result, when the wheel cylinder pressure is made different between the two brake systems from the state in which the wheel cylinder pressure is unified in all brake systems, the wheel cylinder pressure is inadvertently reduced in the low pressure side brake system. It can be surely prevented.

Further, since the opening and closing of the first valves 7RL and 7RR are controlled so that the wheel cylinder pressure necessary to achieve the target braking force Fr ^* of the rear wheels is maintained even during the standby state in this way (step S13 or S20). ) The pressure increase of the wheel cylinder 3i is not delayed in the brake system on the low pressure side.
When different wheel cylinder pressures are used in three or more systems, as shown in FIGS. 8 and 9, the brake system on the high-pressure side that transmits the discharge pressure of the first pump 5d, and the second pump 5u The system is divided into a brake system on the low pressure side that transmits the discharge pressure, and each pump is driven and controlled in accordance with the brake system that has the highest pressure, and in the next brake system, the pump is connected between the pump and the wheel cylinder. Controls the opening and closing of the valves.

FIG. 8 shows that in the brake system on the rear wheel side that transmits the discharge pressure of the second pump 5u, the second pump 5u is driven and controlled in accordance with the brake system of the rear right wheel that becomes the highest pressure, and then the high pressure In the rear left wheel brake system, the opening and closing of the second valve 9RL is controlled so as to obtain a desired wheel cylinder pressure.
FIG. 9 shows that in the brake system on the rear wheel side that transmits the discharge pressure of the second pump 5u, the second pump 5u is driven and controlled in accordance with the brake system of the rear right wheel that becomes the highest pressure, and then the high pressure The rear left wheel brake system controls the opening and closing of the second valve 9RL so that the desired wheel cylinder pressure is obtained, and the front wheel brake system that transmits the discharge pressure of the first pump 5d has the highest pressure. The first pump 5d is driven and controlled in accordance with the brake system for the front left wheel, and then the opening and closing of the first valve 7FR is controlled so that the desired wheel cylinder pressure is achieved in the brake system for the front right wheel that becomes the next high pressure. It is in a state.

  On the other hand, in order to reduce all the wheel cylinder pressures (determination in step S25 is “Yes”), in one brake system, the first valve 7i is opened and the second valve 9i is closed. (Step S27 or S30), the first pump 5d is rotationally driven in the reverse direction (Step S29 or S32), and in the other brake system, the first valve 7i is closed and the second valve 9i is opened. In the state (step S28 or S31), the second pump 5u is rotationally driven in the reverse direction (step S29 or S32). Also in this case, since the discharge pressure (rotation speed) of each pump is simply controlled as in the case of increasing / holding pressure, the number of operations of each valve can be reduced as much as possible.

  Further, when different wheel cylinder pressures are used in the two systems, as shown in FIG. 10, the target values are compared (step S26), and the first valve 7i is opened in the high-pressure brake system, and With the second valve 9i closed (step S27 or S30), the first pump 5d is driven to rotate in the reverse direction (step S29 or S32), and the first valve 7i is closed in the low-pressure brake system. In the state where the second valve 9i is opened (step S28 or S31), the second pump 5u is rotationally driven in the reverse direction (step S29 or S32). In this case, the operation is opposite to the operation when increasing / holding the pressure, and the back pressure when the second pump 5u is reversely rotated is increased by the discharge pressure when the first pump 5d is reversely rotated. It is possible to quickly reduce the wheel cylinder pressure of the brake system that is desired to be low.

When different wheel cylinder pressures are used in three or more systems, as shown in FIGS. 11 and 12, a high-pressure side brake system that reduces pressure by the first pump 5d and a low pressure that decreases pressure by the second pump 5u. The pump system is divided into the brake system on the side, and each pump is driven and controlled in accordance with the brake system that has the lowest pressure, and the valve system between the pump and the wheel cylinder is controlled in the next brake system. To do.
FIG. 11 shows that in the brake system on the rear wheel side that is depressurized by the second pump 5u, the second pump 5u is driven and controlled in accordance with the brake system of the rear right wheel that is the lowest pressure, and then the rear pressure that is low. In the left wheel brake system, the opening and closing of the second valve 9RL is controlled so as to obtain a desired wheel cylinder pressure.

  FIG. 12 shows the rear-wheel brake system that is depressurized by the second pump 5u. The second pump 5u is driven and controlled in accordance with the brake system of the rear right wheel that is the lowest pressure, and then the rear-rear brake system that has the lower pressure. In the brake system for the left wheel, the opening and closing of the second valve 9RL is controlled so as to obtain a desired wheel cylinder pressure, and the brake system for the front right wheel that is the lowest pressure in the brake system on the front wheel side that is decompressed by the first pump 5d. Accordingly, the first pump 5d is driven and controlled, and then the opening and closing of the first valve 7FL is controlled so as to achieve a desired wheel cylinder pressure in the brake system of the front left wheel, which subsequently becomes the low pressure.

  On the other hand, when brake systems for increasing / holding / reducing pressure are mixed (the determination in step S25 is “No”), as shown in FIG. 13, the first valve 7i is first opened in the brake system for increasing / holding pressure. In addition, with the second valve 9i closed (step S33), the first pump 5d is rotationally driven in the forward direction (step S35). Further, in the brake system to be depressurized, with the first valve 7i closed and the second valve 9i opened (step S34), the depressurization amount of the brake system to be depressurized and the pressure increase amount of the brake system to be increased The rotation of the second pump 5u is driven and controlled according to the difference (step S35).

That is, if “pressure reduction amount> pressure increase amount”, the second pump 5 u is rotated in the reverse direction by the difference, and if “pressure reduction amount = pressure increase amount”, the second pump 5 u is stopped. If “pressure reduction amount <pressure increase amount”, the second pump 5 u is rotated in the forward direction by the difference. Thereby, rotation of the 2nd pump 5u can be controlled without excess and deficiency.
Also in this case, when the wheel cylinder pressure is varied in three or more systems, as shown in FIG. 14, the brake system on the side that is increased by the first pump 5d and the brake system on the side that is decreased by the second pump 5u Then, each pump is driven and controlled in accordance with the brake system having the highest pressure / minimum pressure, and then the brake system having the high pressure / low pressure is connected between the pump and the wheel cylinder. Controls the opening and closing of the valve.

  FIG. 14 shows that in the front wheel side brake system that transmits the discharge pressure of the first pump 5d, the first pump 5d is driven and controlled in accordance with the brake system of the front left wheel that is the highest pressure, and then the pressure becomes high. In the front right wheel brake system, the opening and closing of the first valve 7FR is controlled so as to obtain a desired wheel cylinder pressure, and the rear right wheel which is the lowest pressure in the rear wheel side brake system where the pressure is reduced by the second pump 5u. The second pump 5u is driven and controlled in accordance with the brake system, and the opening and closing of the second valve 9RL is controlled so as to obtain the desired wheel cylinder pressure in the brake system of the rear left wheel that is the next low pressure. It is.

It is assumed that the pump and the valve do not operate normally due to foreign matter mixing or freezing while the brake-by-wire is performed as described above (determination in Step S2 is “No”).
Here, when only the first pump 5d is abnormal (the determination in step S36 is “Yes”), the second pump 5u and the second pump 5u communicated with each wheel cylinder 3i from the second pump 5u. Since the flow path 8i is secured, it is not necessary to stop the brake-by-wire.

That is, if the opening and closing of the second valve 9i is driven and controlled with the first valve 7i closed (step S37) and the second pump 5u is driven and controlled (step S38), each wheel cylinder 3i is controlled. The pressure can be increased / held or the pressure reduced / held.
For example, if the second pump 5u is rotationally driven in the forward direction with the first valve 7i closed and the second valve 9i opened, the desired wheel cylinder 3i is increased by the discharge pressure. Can do. At this time, if the second valve 9i is closed, the pressure increase of the brake system can be prevented, and if the opening / closing of the second valve 9i is controlled, the pressure increase amount of the brake system can be adjusted. it can.

Further, if the second pump 5u is rotationally driven in the reverse direction, the desired wheel cylinder 3i can be decompressed. At this time, if the second valve 9i is closed, depressurization of the brake system can be prevented, and if the opening and closing of the second valve 9i is controlled, the depressurization amount of the brake system can be adjusted.
On the other hand, when only the first valve 7i is abnormal (the determination in step S39 is "Yes"), the second pump 5u, the first pump 5d, and the first pump 5d to each wheel cylinder 3i. Since the communicating first flow path 6i and the second flow path 8i communicating from the second pump 5u to each wheel cylinder 3i are secured, it is not necessary to stop the brake-by-wire.

  That is, even if there is an abnormality in the first valve 7i, if the closed state can be maintained, the second valve 9i is opened (step S40) and the second pump 5u is driven and controlled (step S42). It is possible to increase / hold / depressurize the wheel cylinder 3i of the brake system. If the open state of the first valve 7i can be maintained, the second valve 9i is closed (step S41) and the first pump 5d is driven and controlled (step S42). 3i can be increased / held / depressurized.

For example, when disconnection or the like occurs, the opening and closing of the valve cannot be controlled at all. Even in such a case, the first valves 7FL and 7FR of the front wheel system constituted by the spring offset type normally closed type valve are in the closed state. Can be maintained.
Therefore, in the brake system on the front wheel side, the second pump 5u is driven to rotate in the forward direction with the first valves 7FL and 7FR closed without being excited and the second valves 9FL and 9FR opened. Then, the wheel cylinders 3FL and 3FR can be increased by the discharge pressure. At this time, if the second valve 9FL / 9FR is closed, the pressure increase of the brake system can be prevented, and if the opening / closing of the second valve 9FL / 9FR is controlled, the pressure increase amount of the brake system can be reduced. Can be adjusted. Of course, the hydraulic pressure of the brake system may be maintained by fixing the rotation of the second pump 5u.

Further, if the second pump 5u is rotationally driven in the opposite direction, the wheel cylinders 3FL and 3FR can be depressurized. At this time, if the second valve 9FL / 9FR is closed, decompression of the brake system can be prevented, and if the opening / closing of the second valve 9FL / 9FR is controlled, the decompression amount of the brake system is adjusted. be able to.
On the contrary, the first valves 7RL and 7RR of the rear wheel system constituted by spring-offset type and normally open type valves can be kept open.

  Accordingly, in the brake system on the rear wheel side, the first pump 5d is rotated in the forward direction with the first valves 7RL and 7RR being de-energized and opened, and the second valves 9RL and 9RR are closed. If driven, the wheel cylinders 3RL and 3RR can be increased by the discharge pressure. At this time, if the rotation of the first pump 5d is fixed, the hydraulic pressure of the brake system can be maintained.

Further, if the first pump 5d is rotationally driven in the opposite direction, the wheel cylinders 3RL and 3RR can be decompressed. At this time, if the rotation of the first pump 5d is fixed, the hydraulic pressure of the brake system can be maintained.
On the other hand, when only the second valve 9i is abnormal (the determination in step S43 is “Yes”), the second pump 5u, the first pump 5d, and the first pump 5d to each wheel cylinder 3i. Since the communicating first flow path 6i and the second flow path 8i communicating from the second pump 5u to each wheel cylinder 3i are secured, it is not necessary to stop the brake-by-wire.

  That is, even if there is an abnormality in the second valve 9i, if the closed state can be maintained, the first valve 7i is opened (step S44) and the first pump 5d is driven and controlled (step S46). It is possible to increase / hold / depressurize the wheel cylinder 3i of the brake system. If the second valve 9i can be kept open, the first valve 7i is closed (step S45), and the second pump 5u is driven and controlled (step S46). 3i can be increased / held / depressurized.

For example, when disconnection occurs, the opening / closing of the valve cannot be controlled at all. Even in such a case, the second valves 9FL and 9FR of the front wheel system constituted by the spring-offset type normally closed type valve are closed. Can be maintained.
Accordingly, in the brake system on the front wheel side, the first pump 5d is driven to rotate in the forward direction with the first valves 7FL and 7FR opened and the second valves 9FL and 9FR closed with no excitation. Then, the wheel cylinders 3FL and 3FR can be increased by the discharge pressure. At this time, if the first valve 7FL / 7FR is closed, the pressure increase of the brake system can be prevented, and if the opening / closing of the first valve 7FL / 7FR is controlled, the pressure increase amount of the brake system can be reduced. Can be adjusted. Of course, the hydraulic pressure of the brake system may be maintained by fixing the rotation of the first pump 5d.

Further, if the first pump 5d is rotationally driven in the opposite direction, the wheel cylinders 3FL and 3FR can be decompressed. At this time, if the first valve 7FL / 7FR is closed, decompression of the brake system can be prevented, and if the opening / closing of the first valve 7FL / 7FR is controlled, the decompression amount of the brake system is adjusted. be able to.
On the contrary, the second valves 9RL and 9RR of the rear wheel system constituted by spring-offset type and normally open type valves can be kept open.

Therefore, in the rear wheel side brake system, the second pump 5u is rotated in the forward direction with the first valves 7RL and 7RR closed and the second valves 9RL and 9RR opened without being excited. If driven, the wheel cylinders 3RL and 3RR can be increased by the discharge pressure. At this time, if the rotation of the second pump 5u is fixed, the hydraulic pressure of the brake system can be maintained.
Moreover, if the 2nd pump 5u is rotationally driven to a reverse direction, wheel cylinder 3RL * 3RR can be pressure-reduced. At this time, if the rotation of the second pump 5u is fixed, the hydraulic pressure of the brake system can be maintained.

  However, there is an abnormality only in the second pump 5u, or there is an abnormality in a plurality of types of the second pump 5u, the first pump 5d, the first valve 7i, and the second valve 9i. In this case (determination in step S43 is “No”), the brake-by-wire is stopped by fail-safe. At this time, the master cylinder 2 and the front left and right wheel cylinders 3FL and 3FR are communicated and mechanically backed up, so that the braking force of the front wheels can be ensured.

  In the first embodiment, when the wheel cylinder pressure is unified in all brake systems, the discharge pressure from the second pump 5u + first pump 5d is transmitted to the wheel cylinders 3FL to 3RR. However, the present invention is not limited to this. For example, when the vehicle is slowly decelerated, if high response pressure increase by the second pump 5u + first pump 5d is not necessary, the pressure is increased only by the second pump 5u, and a sudden panic brake or the like is performed. The pressure increase by the second pump 5u + the first pump 5d may be performed only when the pressure increase is necessary. Also, when braking by means other than the hydraulic brake, such as a regenerative brake, the pressure is increased only by the second pump 5u, and when the braking force of the regenerative brake decreases just before the vehicle stops, the hydraulic brake suddenly When the pressure increase is necessary, the pressure increase by the second pump 5u + the first pump 5d may be performed. As described above, if the rotational driving of the first pump 5d is suppressed to the minimum necessary, there is an effect of suppressing an increase in power consumption.

Moreover, in said 1st Embodiment, although the hydraulic circuit which has four brake systems is comprised, it is not limited to this, If there are two or more brake systems, this embodiment is applied. Can do.
In the first embodiment, the hydraulic brake using the hydraulic pressure as the transmission medium is employed. However, the present invention is not limited to this, and an air brake using the compressed air as the transmission medium may be employed. Good.

Next, a second embodiment of the present invention will be described.
In the second embodiment, the brake-by-wire can be executed even when there is an abnormality only in the second pump 5u.
Therefore, as shown in FIG. 15, the upstream side and the downstream side of the second pump 5 u are communicated by the third flow path 20, and a third valve 21 is provided in the third flow path 20. Except for this, since it has the same configuration as in FIG. 1, the same reference numerals are given to corresponding parts to those in FIG. 1, and detailed description thereof will be omitted. The third valve 21 is a two-port two-position switching / spring offset type electromagnetically operated valve, and is configured to close the flow path at a non-excited normal position.

  With this configuration, when the first pump 5d is rotated in the forward direction with the third valve 21 opened, the fluid stored in the reservoir tank 2a is sucked through the third flow path 20, and the The discharge pressure is transmitted to the first valve 7i through the first flow path 6i. Further, when the first pump 5d is rotated in the reverse direction, the fluid on the downstream side is returned to the reservoir tank 2a via the third flow path 20.

  Therefore, if the third valve 21 is opened, the first valve 7i is opened, and the second valve 9i is closed, the wheel cylinder 3i increases pressure when the first pump 5d is rotated forward. Is done. Further, when the first valve 7i is closed and the second valve 9i is closed, the flow path is blocked, and the hydraulic pressure of the wheel cylinder 3i is maintained. At this time, if the rotation of the first pump 5d is fixed, the hydraulic pressure of the wheel cylinder 3i is maintained even when the first valve 7i is opened. Further, if the third valve 21 is opened, the first valve 7i is opened, and the second valve 9i is closed, the wheel cylinder 3i is depressurized when the first pump 5d is rotated in the reverse direction. The At this time, if the first valve 7i is closed and the second valve 9i is opened, the wheel cylinder 3i is depressurized by communication with the reservoir tank 2a without rotating the first pump 5d in the reverse direction.

Then, as shown in FIG. 16, the process of the new step S51 is executed before the process proceeds from step S2 to step S36, and the processes of steps S52 to S54 are appropriately executed. 4 is executed, the same reference numerals are assigned to corresponding parts in FIG. 4 and detailed description thereof is omitted.
In step S51, it is determined whether only the second pump 5u is abnormal. Here, when the second pump 5u is normal or when there is an abnormality in addition to the second pump 5u, the process proceeds to step S36. On the other hand, when only the second pump 5u is abnormal, the process proceeds to step S52.

In step S52, the third valve 21 is opened.
In the subsequent step S53, the second valve 9i is closed in all the brake systems, and the first valve 7i is opened and closed so that the wheel cylinder pressure necessary to achieve the target braking force is achieved in each brake system. To control.
In the subsequent step S54, if there is a brake system that increases pressure, the brake that reduces the pressure by rotating the first pump 5d in the forward direction so as to obtain the wheel cylinder pressure necessary to achieve the maximum target braking force. In the case of only the system, the first pump 5d is rotationally driven in the reverse direction so as to obtain the wheel cylinder pressure necessary to achieve the minimum target braking force, and then returns to a predetermined main program.
From the above, the braking force control process including FIG. 16 corresponds to the “control means”.

Next, the function and effect of the second embodiment will be described.
When only the second pump 5u is abnormal (determination in step S51 is “Yes”), the third flow path 20 communicating from the reservoir tank 2a to the first pump 5d, the first pump 5d, Since the second flow path 8i communicating from the first pump 5d to each wheel cylinder 3i is secured, it is not necessary to stop the brake-by-wire.
That is, the third valve 21 is opened (step S52), and the opening and closing of the first valve 7i is driven and controlled with the second valve 9i closed (step S53), and the first pump 5d is driven. If controlled (step S54), each wheel cylinder 3i can be increased / held or reduced / held.

  For example, if the first pump 5d is driven to rotate in the forward direction with the third valve 21 opened, the first valve 7i opened, and the second valve 9i closed, the desired pressure can be obtained depending on the discharge pressure. The wheel cylinder 3i can be increased in pressure. At this time, if the first valve 7i is closed, the pressure increase of the brake system can be prevented, and if the opening / closing of the first valve 7i is controlled, the pressure increase amount of the brake system can be adjusted. it can.

  Further, if the first pump 5d is rotationally driven in the reverse direction, the desired wheel cylinder 3i can be decompressed. At this time, if the first valve 7i is closed, decompression of the brake system can be prevented, and if the opening / closing of the first valve 7i is controlled, the decompression amount of the brake system can be adjusted. Note that the wheel cylinder 3i may be decompressed by opening the second valve 9i and the third valve 21 in a state where the first pump 5d is stopped. The decompression by opening the third valve 21 can be performed by other decompression processes such as the process of step S8. As described above, in the second embodiment, each wheel cylinder 3i can be depressurized by the third valve 21, so that the second pump 5u and the first pump 5d are reversible pumps such as gear pumps. There is no need, and an irreversible pump such as a plunger pump may be used.

It is a schematic structure of 1st Embodiment. It is the flowchart which showed the braking force control process. It is the time chart which showed braking force control processing (A). It is the time chart which showed the braking force control processing (B) of 1st Embodiment. It is an operation example in which all wheel cylinders are unified and increased in pressure. This is an operation example in which all wheel cylinders are decompressed in a unified manner. It is an operation example in which the wheel cylinder is increased in pressure divided into two systems. It is an operation example in which the pressure in the wheel cylinder is increased in three systems. It is an operation example in which the pressure in the wheel cylinder is increased in four systems. It is an operation example in which the wheel cylinder is decompressed in two systems. This is an operation example in which the wheel cylinder is decompressed in three systems. It is an operation example in which the wheel cylinder is decompressed in four systems. It is an operation example in which the wheel cylinder is pressure-intensified and depressurized in two systems. This is an operation example in which the wheel cylinder is pressure-increasing / decreasing in four systems. It is a schematic structure of 2nd Embodiment. It is the time chart which showed the braking force control processing (B) of 2nd execution form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brake pedal 2 Master cylinder 3FL-3RR Wheel cylinder 4p * 4s Gate valve 5u 2nd pump 5d 1st pump 6FL-6RR 1st flow path 7FL-7RR 1st valve 8FL-8RR 2nd flow path 9FL -9RR 2nd valve 10 Stroke simulator 15 Controller 20 3rd flow path 21 3rd valve

Claims (11)

A fluid source in which fluid is stored, a wheel cylinder that generates a braking force by fluid pressure, a first pump interposed in a flow path that connects the fluid source and the wheel cylinder, and the first pump And the second pump interposed between the first pump and the fluid source, and the first flow path between the first pump and the wheel cylinder as the first flow path. A second flow path communicating between the two pumps and the wheel cylinder,
A brake device for a vehicle, comprising a plurality of brake systems having the wheel cylinder, the first flow path, and the second flow path as a unit.   The vehicle according to claim 1, wherein the brake system includes a first valve that opens and closes the first flow path, and a second valve that opens and closes the second flow path. Brake device. The first pump and the second pump are driven and controlled, and control means for driving and controlling the first valve and the second valve for each brake system is provided.
When the fluid pressures of the wheel cylinders are unified in all the brake systems, the control means opens the first valve and closes the second valve in all the brake systems. Drive control of one pump and the second pump, or drive control of the second pump in a state in which the first valve is closed and the second valve is opened in all the brake systems The vehicle brake device according to claim 2. The first pump and the second pump are driven and controlled, and control means for driving and controlling the first valve and the second valve for each brake system is provided.
When the fluid pressure of the wheel cylinder is made different between the two brake systems, the control means opens the first valve and closes the second valve in one of the brake systems. Drive control of one pump and the second pump, and in the other brake system, drive control of the second pump with the first valve closed and the second valve open. The vehicle brake device according to claim 2, wherein the vehicle brake device is a vehicle brake device.   In the brake system on the high pressure side, the control means drives and controls the first pump and the second pump with the first valve opened and the second valve closed. 5. The vehicle brake device according to claim 4, wherein in the brake system, the second pump is driven and controlled in a state where the first valve is closed and the second valve is opened.   When the fluid pressures of the wheel cylinders are made different between the two brake systems from the state in which the fluid pressures of the wheel cylinders are unified in all the brake systems, the control means, in the brake system on the low pressure side, 6. The vehicle according to claim 5, wherein the second valve is opened after a fluid pressure between the second pump and the second valve matches a fluid pressure of the wheel cylinder. Brake device.   The said control means will drive-control the said 2nd pump in the state which open | released the said 2nd valve, if the abnormality of the said 1st pump is detected, The any one of Claims 3-6 characterized by the above-mentioned. The brake device for vehicles as described in. A third flow path that connects the upstream side and the downstream side of the second pump; and a third valve that opens and closes the third flow path.
When the control means detects an abnormality in the second pump, the control means drives and controls the first pump in a state where the third valve and the first valve are opened and the second valve is closed. The vehicular brake device according to any one of claims 3 to 7, wherein:   When the control unit detects an abnormality of the first valve, the control unit drives and controls the second pump with the second valve opened if the first valve can be kept closed. If the first valve can be kept open, the first pump and the second pump are driven and controlled with the second valve closed. The vehicle brake device according to any one of the above.   When the control means detects an abnormality of the second valve, the first pump and the second pump can be opened with the first valve open if the second valve can be kept closed. The second pump is driven and controlled with the first valve closed when the second valve is driven and controlled so that the second valve can be kept open. The vehicle brake device according to any one of the above. A fluid source in which fluid is stored; a plurality of wheel cylinders that generate a braking force by fluid pressure; a first pump interposed in a flow path that connects the fluid source and the wheel cylinder; A second pump interposed between the pump and the fluid source,
The discharge pressure of the first pump can be transmitted to all the wheel cylinders, and the discharge pressure of the second pump can be transmitted to all the wheel cylinders without going through the first pump. A vehicular brake device comprising a fluid pressure circuit.

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