JP2002087233A - Control device of vehicular brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize holding torque at parking brake time, and to avoid useless energy consumption by an actuator. SOLUTION: This control device of a brake is provided with an electric motor 23 for applying rotation checking torque for resisting rotation of wheels by pressing a braking member (a brake shoe 22) to a braking object member (a drum 21) integrally rotating with the wheels, a service brake control means for applying the rotation checking torque at service brake time by controlling an electric current supplied to the electric motor according to an operation quantity of a brake pedal 60 and a parking brake control means for applying the rotation checking torque parking brake time by controlling the electric current supplied to the electric motor according to operation indication of a parking brake. The parking brake control means sets the rotation checking torque at parking brake time on the basis of actual rotation checking torque detected by a pressurizing force sensor 26 at service brake time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake control device for controlling a rotation preventing torque applied to a parking brake to prevent rotation of a wheel.

[0002]

2. Description of the Related Art This type of apparatus is disclosed, for example, in Japanese Utility Model 2-1.
As disclosed in Japanese Patent No. 7967, a braked member (rotating body) that rotates integrally with a wheel, and a braking member (friction member) provided on the vehicle body side to apply a braking torque to the braked member. An electromagnetic device for controlling activation and release of a parking brake, a stress sensor for detecting a stress corresponding to a frictional force generated between the braked member and the braking member, and a stress detected when the parking brake is activated. And control means for controlling the electromagnetic device so that the braking torque increases when the pressure decreases. Thus, the device prevents unnecessary increase in braking torque during parking braking, avoids wasteful energy consumption, and minimizes rolling down of the vehicle on a slope.

[0003]

However, in the above-mentioned prior art, since the braking torque of the parking brake is increased after the vehicle starts to roll, the vehicle moves greatly when parking on a road surface having a large inclination angle. There is a problem that.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is characterized by a member to be braked that rotates integrally with a wheel, and a rotation of the wheel by being pressed by the braking member. A braking member that generates a rotation inhibiting torque to withstand, an actuator that generates a force for pressing the braking member against the braked member, and an actuator that controls the actuator in accordance with a service brake operation amount; A vehicle brake comprising: service brake control means for applying rotation prevention torque; and parking brake control means for controlling the actuator in response to a parking brake operation request and applying rotation prevention torque to the wheels during parking brake. The control device according to claim 1, further comprising: a torque detecting means for directly detecting a rotation preventing torque applied to the wheel; The control means sets the rotation prevention torque at the time of the parking brake based on an actual rotation prevention torque detected by the torque detection means when the actuator is controlled by the service brake control means. This is to control the force generated by the actuator.

Another feature of the present invention is that a braking member is pressed against a member to be braked provided on each of a plurality of wheels provided on a vehicle and rotated integrally with each wheel, so that each wheel has A plurality of actuators that apply a rotation preventing torque against the rotation of each wheel, and a force generated by the plurality of actuators is controlled according to a service brake operation amount,
A service brake control means for applying a rotation preventing torque to the plurality of wheels during a service brake; and an actuator controlled at least one of the plurality of actuators in response to a parking brake actuation request. A vehicle brake control device comprising: a parking brake control unit configured to apply a rotation preventing torque to a wheel during parking braking, wherein the vehicle braking control unit is provided on at least one of the plurality of wheels, and controls a rotation preventing torque applied to the wheel. The parking brake control unit includes a torque detection unit that directly detects the rotation, and the parking brake control unit detects the actual rotation inhibition torque detected by the torque detection unit when the force generated by the actuator is controlled by the service brake control unit. Based on the setting, the rotation preventing torque at the time of the parking brake is set. Is that formed by controlling at least one serial actuator.

[0006] In the brake control device having any of the above features, the actuator controlled by the service brake control means and the actuator controlled by the parking brake control means may be the same actuator. , Different actuators. As an example of a different actuator, the actuator controlled by the service brake control unit includes an electric motor, and the actuator controlled by the parking brake control unit is configured to control hydraulic pressure with respect to a braking member of a wheel provided with the electric motor. Alternatively, a solenoid valve device or another electric motor that applies a force via a wire cable or the like or without such a wire cable may be used.

[0007] In the brake control device having such features, the braking member is pressed by the actuator against the member to be braked which rotates integrally with the wheel, and a rotation preventing torque against the rotation of the wheel is generated. I do. This rotation preventing torque is changed by controlling the force generated by the actuator according to the service brake operation amount such as the amount of depression of the brake pedal or the pedal depression force during the service brake, and is changed to the service brake operation amount during the parking brake. Accordingly, the setting (change) is made based on the actual rotation preventing torque detected by the torque detecting means when the force generated by the actuator is controlled.

[0008] The actual rotation preventing torque detected by the torque detecting means when the force generated by the actuator is controlled in accordance with the service brake operation amount during the service brake is, for example, the state in which the vehicle is in a running state to a stopped state. At a predetermined point in time, such as a point in time when the vehicle is shifted to or a point in time when a parking brake actuation request is issued.

Therefore, according to the above feature, since the rotation preventing torque at the time of parking brake has an appropriate value, the parking state can be reliably maintained without causing the actuator to perform unnecessary work. Further, according to the brake control device having the other features described above, the number of torque detecting means can be reduced.

[0010] In the brake control device having the above-mentioned other features, the brake control device for the wheel without the torque detecting means is obtained from the detected actual rotation preventing torque and the load distribution to each wheel of the vehicle. It is preferable that a rotation prevention torque is estimated, and a force generated by the actuator is controlled so as to set the rotation prevention torque at the time of the parking brake based on the estimated rotation prevention torque.

Since the load distribution is a unique value for each vehicle, it can be obtained by measurement in advance, so that it is possible to easily and accurately obtain the rotation preventing torque of a wheel having no torque sensor. Because you can.

Further, in the brake control device having any of the above features, the parking brake control means controls a force generated by the actuator during the parking brake according to a temperature of the braking member or the member to be braked. Preferably, it is configured to change.

When the temperature of the braking member or the member to be braked changes, the coefficient of friction between these members changes or the members shrink thermally, so that the same member is pressed against the member to be braked with the same force. This is because the rotation prevention torque is different even if the rotation is stopped.

Further, in the brake control device having any of the above features, the parking brake control means generates the actuator so as to change the rotation prevention torque at the time of the parking brake according to the weight of the vehicle. It is preferred to control the force applied.

[0015] This is because, when the number of occupants or the amount of load changes during parking and the vehicle weight changes, the rotation preventing torque required to keep the vehicle stopped changes.

Further, in the brake control device having any one of the above-mentioned features, the parking brake control means is provided on the basis of the actual rotation preventing torque detected at the time when the parking brake operation instruction request is issued. Preferably, the force generated by the actuator is controlled so as to set the rotation prevention torque at the time of the parking brake.

Since the parking brake activation request is normally issued immediately after the vehicle has shifted from the running state to the stopped state and the service brake is being actuated, the parking brake is activated. This is because the actual rotation prevention torque at the time when the request is issued has an appropriate value for obtaining the rotation prevention torque necessary to maintain the vehicle in a stopped state.

Further, in the brake control device having any one of the above features, the parking brake control means is configured to control the parking brake based on the actual rotation preventing torque detected when the vehicle is stopped. It is preferable to control the force generated by the actuator so as to set the rotation prevention torque at the time.

This is because the parking brake may be instructed immediately before the vehicle shifts from the running state to the stopped state, and the actual rotation preventing torque at the time when the vehicle is not completely stopped is Based on the knowledge that the torque is larger than the rotation prevention torque required to maintain the vehicle in a stopped state, the above configuration maintains the vehicle in a stopped state based on a more appropriate actual rotation prevention torque. Can be obtained.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a control system for a vehicle brake according to an embodiment of the present invention.

FIG. 1 shows an entire electric brake device including a vehicle brake control device according to a first embodiment. This electric brake device is composed of left and right front wheels FL, FR
And the right and left rear wheels R
It includes an electric drum brake 20, an electric control device 30, a drive circuit 40, and a brake pedal 60 as a brake operation member for a service brake provided on the L and RR.

The electric disc brake 10 is non-rotatably held by a disc rotor (not shown), which is a member to be braked, which rotates integrally with the wheels, and a mounting bracket, which is a vehicle body-side member. A brake pad (not shown) as a braking member disposed so as to have a predetermined clearance (interval);
DC electric motor 1 that generates a force according to the supplied current
1, a position sensor 12 for detecting the position X of the braking member,
The brake pad is moved (pushed) toward the disk rotor by the force generated by the electric motor 11 so that the brake pad is brought into contact therewith, and the brake pad is pressed against the disk rotor. A braking torque for suppressing the rotation of the wheel (rotation preventing torque against the rotation of the wheel) is generated.

The position sensor 12 detects the rotational position of the electric motor 11 to detect the position X of the braking member driven by the electric motor 11.
The pressing force sensor 13 includes a strain sensor attached to a member that is pressed with the same force as the force when the brake pad is actually pressed against the disk rotor,
The actual pressure P (actual pressure P) is detected from the amount of distortion detected by the distortion sensor.

The electric drum brake 20 is non-rotatably held by a drum 21 which is a member to be braked, which rotates integrally with the wheels, and a backing plate which is a vehicle body-side member, and has a predetermined clearance ( (A spacing), a brake shoe 22 as a braking member, a DC electric motor 23 that generates a force according to the supplied current, a switching motor 24 that operates during parking brake, and a brake shoe 22. And a force sensor 26 for detecting the position X of the brake shoe 22. The brake shoe 22 is moved (pushed) toward the inner peripheral surface of the drum 21 by the force generated by the electric motor 23, and the contact force is determined. The brake shoe 22 and the drum 21
By pressing against the inner peripheral surface of the wheel, a braking torque for suppressing the rotation of the wheel (rotation preventing torque against the rotation of the wheel) is generated.

The electric drum brake 20 is of a duo-servo type as shown in detail in FIG. 2, and is attached to a vehicle body-side member (not shown) in a non-rotatable manner and has a disc-shaped backing plate 200; A pair of brake shoes 202a, 202b (indicated by reference numeral 22 in FIG. 1) provided on the backing plate 200 and having a generally arc shape, and a friction surface 204 on the inner peripheral surface.
And a drum 206 that rotates with the wheels (indicated by reference numeral 21 in FIG. 1), and a pair of shoes 202.
a, and an electric actuator 300 for expanding one end of each 202b.

A pair of brake shoes 202a, 202b
Are engaged with anchor pins 208 fixed to the backing plate 200 at one end portions facing each other, and are rotatably held in a state where they are prevented from rotating with the drum 206.

Also, a pair of brake shoes 202a, 2
In 02b, the other ends are connected by struts 210, and the force acting on one shoe is transmitted to the other shoe by the struts 210.
Note that the pair of brake shoes 202a, 202b can be moved along the surface of the backing plate 200 by the shoe hold-down devices 212a, 212b.

A pair of brake shoes 202a, 202b
As shown in the figure, the other ends are biased toward each other by a spring 214, and one end is biased toward the anchor pin 208 by each of the shoe return springs 215a and 215b. Also, a strut 216 and a return spring 218 are provided at one end.
Is also provided.

Brake linings 219a and 219b as friction engagement members are held on the outer peripheral surface of each of the brake shoes 202a and 202b, and the pair of brake linings 219a and 219b are attached to the drum 206.
By frictionally engaging the inner peripheral surface 204 of the drum 206, a frictional force is generated between the brake linings 219a and 219b and the drum 206. In the present embodiment, the strut 210 has an adjustment mechanism, and the gap between the brake linings 219a and 219b and the drum inner peripheral surface 204 can be adjusted according to the wear of the brake linings 219a and 219b. .

Each of the brake shoes 202a and 202b is
Rim 224a, 224b and web 222a, 2 respectively
22b, and one end of a lever 230 is rotatably provided on the web 222a via a pin 232.
Notches are provided in the opposing portions of the lever 230, the web 222a, and the web 222b. The struts 216 engage these notches.

The other end of the lever 230 has an electric motor 2
3 are connected,
When the brake pedal 60 for the service brake is operated, the lever 230 is rotated by the driving of the electric motor 23 (electric actuator 300), and the brake shoe 202 a is moved to the strut 216 and the brake shoe 20.
2a and the lever 230 are pushed toward the drum inner peripheral surface 204 with the fulcrum as a fulcrum, and the brake shoe 202b is directed toward the drum inner peripheral surface 204 by the strut 216 receiving the reaction force from the drum inner peripheral surface 204. To be pushed. That is, the electric motor 23
Of the brake shoes 202a, 202
b is expanded, and the frictional engagement members (brake linings 219a and 219b) are pressed against the inner peripheral surface 204 of the drum 206, and the frictional engagement members are frictionally engaged with the inner peripheral surface 204 of the drum. The braking torque T is applied to the wheels by generating a frictional force therebetween and suppressing the rotation of the wheels.

In the above structure, the swinging force based on the frictional force generated in one shoe 202b and the brake operating force D by the electric actuator 300
(It can be considered as an expanding force for expanding the pair of shoes 202a and 202b.) Is transmitted from the other end to the other end of the other shoe 202a via the strut 210. I have. As a result, the other shoe 2
02a is pressed against the drum inner peripheral surface 204 by the sum of the swinging force and the expanding force, and one shoe 20a
A friction force greater than 2b occurs. Thus, the output of one shoe 202b becomes the input of the other shoe 202a, and a double servo effect is obtained, so that a large braking torque can be obtained in a duo servo type drum brake.

A strain sensor 312 for detecting a load applied to the anchor pin 208 is attached to the anchor pin 208 as the pressure sensor 26. As described above, in the duo-servo type electric drum brake 20, the swinging force based on the frictional force generated in one shoe and the expanding force by the electric actuator 300 are applied to the other end of the other shoe via the strut 210. The other shoe is pressed to the drum 206 by the sum of the squeezing force and the expanding force. The force transmitted to the other shoe via the strut 210 is further increased by the servo action of the other shoe, and acts on the anchor pin 208. As a result, if the braking torque is obtained based on the load applied to the anchor pin 208, the actual braking torque T (actual braking torque T) generated in the duo-servo type electric drum brake 20 can be detected. The actual braking torque T is applied to the shoes 202a and 202b (brake lining) as braking members when the wheels are rotating, or when the vehicle is on a sloping road or the like and a torque to rotate the wheels is applied. 2
19a, 219b) is a drum 206 as a member to be braked.
Represents the force actually pressed (actual pressure P). Further, since the actual braking torque can be referred to as an actual rotation preventing torque (actual rotation preventing torque) against the rotation of the wheels, the pressing force sensor 26 constitutes a torque detecting means for detecting the rotation preventing torque. Will be.

As shown in FIG. 3, the electric actuator 300 includes the electric motor 23 and a drive unit 304 that converts the rotational motion of the electric motor 23 into a reciprocating linear motion of the operating shaft 302. The electric motor 23 detects the rotational position of the electric motor
2a (202b) position sensor 2 for detecting position X
5 built-in. The brake shoe 202a
The position X of (202b) may be directly detected by a fixed gap sensor such as the backing plate 200.

An electric motor 23 is mounted on a housing 306 of the drive unit 304, and the housing 306 and the electric motor 23 are fixed to the backing plate 200. A pinion 3 is provided on a rotating shaft 23a of the electric motor 23.
08 is fixed. The pinion 308 meshes with the first reduction gear 310, and the first reduction gear 310 meshes with the second reduction gear 312. The second reduction gear 312 has an output shaft portion 312 in which a screw hole (not shown) is formed in the axial direction.
a.

The operating shaft 302 is supported by the housing 306 so as to be non-rotatable and movable in the axial direction, and has a connecting portion 302a connected to the lever 230 at one end.
And a worm portion 302b at the other end. The worm portion 302b is screwed with the output shaft portion 312a.

As shown in FIGS. 3 and 4, the output shaft 31 is moved from the operating shaft 302 into the housing 306.
One-way rotation of the pinion 308 due to an external force input via 2a (corresponding to a direction in which the operating shaft 302 moves leftward in FIG. 1 to reduce the braking torque).
, And a rotation preventing mechanism 320 that allows rotation in the other direction is provided.

The rotation preventing mechanism 320 includes the switching motor 32
2 and a regulating gear 324. Switching motor 3
Reference numeral 22 is attached to the housing 306, and a pinion 322a is provided on a rotation shaft of the switching motor 322. The restricting gear 324 is connected to the first reduction gear 31.
0 is rotatably supported coaxially on a shaft 310a for fixing the same.

The regulating gear 324, as shown in FIG.
It has a first meshing portion 324a for meshing with the pinion 322a of the switching motor 322, and a second meshing portion 324b for meshing with the pinion 308 of the electric motor 23. The second meshing portion 324b is connected to the first meshing portion 324a.
From the outside in an arc shape. The regulating gear 324 is rotated by the operation of the switching motor 322 so that the rotation is regulated at a predetermined angle by first and second regulating walls 306a and 306b formed in the housing 306 shown in FIG. Has become.

The anti-rotation mechanism 320 thus configured
As shown in FIG. 5, the second engagement portion 324b of the regulating gear 324 is moved to the pinion 30 by the switching motor 322.
8 so that the pinion 30 is not engaged.
Allow 8 free rotations. On the other hand, as shown in FIG.
4 is disposed at a position where the second meshing portion 324b meshes with the pinion 308, and when the pinion 308 in FIG.
The end face of the engagement portion 324b is brought into contact with the first regulating wall 306a, thereby preventing the rotation of the pinion 308 in the direction of arrow B.

Referring again to FIG. 1, the electric control device 3
0 executes a program stored in the memory including a microcomputer 31 having a memory and a CPU (not shown), and the position sensors 12 and 25;
The pressure sensors 13 and 26, a vehicle speed sensor 51 for detecting the speed (hereinafter referred to as vehicle speed) SPD of the vehicle by detecting the rotation of an output shaft of a transmission (not shown), and the operation of a parking brake are controlled. A parking brake operation switch 52 which is operated by the driver to generate a parking brake operation instruction signal PKB, and a brake pedal 60 which is operated by the driver.
, A stroke sensor 54 for detecting an operation stroke ST of the brake pedal 60, a motor current sensor 55, a four-wheel FL,
Wheel speed Vw of each wheel provided for FR, RL, RR
Is connected to a wheel speed sensor 56 for detecting the speed, and signals from these are input. this house,
The parking brake operation switch 52 sets the value of the parking brake operation instruction signal PKB to “1” (high-level signal) when an operation instruction for operating the parking brake is issued (when an operation request for the parking brake is issued). When the parking brake operation is released (when the parking brake operation request has disappeared), the value of the parking brake operation instruction signal PKB is set to “0” (low level signal).

The drive circuit 40 has an input side of the electric control unit 3.
0, a switching circuit whose output side is connected to the electric motors 11 and 23 and the switching motor 24 and connected to a vehicle battery (not shown) as a power supply. A current corresponding to the command signal is supplied to each of the electric motors 11 and 23, and a predetermined small current is supplied to the switching motor 24 based on a command from the electric control device 30. The motor current sensor 55 is connected to current supply lines of the drive circuit 40 and the electric motors 11 and 23. The motor current sensor 55 is connected to the electric motor 11,
An actual supply current I (a value obtained in consideration of a duty ratio) actually supplied to the motor 23 is detected. The detected actual supply current I is a force generated by the electric motors 11 and 23. The value approximates to (actual pressure P).

In the present embodiment, the actual pressure P is controlled to be equal to the target pressure P *.
The target pressure P * is the larger of the service brake target pressure PF * and the parking brake target pressure PP *, as described later. Therefore, first, a method of determining the parking brake target pressure PP * will be described. The parking brake target pressing force PP * is a target value of the pressing force P used as the target pressing force P * while the parking brake operation switch 52 is operated and the parking brake operation request is generated.

The parking brake target pressure PP * may be any value as long as the vehicle can be reliably stopped. If the parking brake target pressing force PP * is excessively large, it becomes necessary to supply a large amount of current to the electric motor 23, and wasteful energy is consumed. Therefore, in the brake control device, the torque required to maintain the vehicle in the parked (stopped) state (a torque that prevents the rotation of the wheels during parking brake, hereinafter referred to as a vehicle holding torque SHT). ) Is estimated, and the parking brake target pressure PP * is determined based on the vehicle holding torque SHT. The vehicle holding torque SHT can be obtained based on the braking torque (holding torque) SHT0 when the running vehicle is stopped by the service brake.

By the way, when stopping the running vehicle, the driver operates the brake pedal 60 to activate the service brake to stop the vehicle, and the parking brake is maintained while the operation of the brake pedal 60 is maintained. By operating the operation switch 52, the parking brake is operated. In particular, when torque is required to maintain the vehicle in a parked (stopped) state, such as when parking on a slope, the probability of performing the driving operation is high.

Therefore, in the present embodiment, "the brake pedal 60 is depressed and the pedal depression force F is" 0 ".
Not (or pedal stroke ST is not "0"),
Immediately after the vehicle speed SPD is "0" (the vehicle is stopped), the parking brake operation switch 52 is operated, and the value of the parking brake operation instruction signal PKB changes from "0" to "1". When the condition “Yes” is satisfied, the vehicle holding torque SHT is calculated based on the detection value of the pressing force sensor 26 that detects the actual braking torque (actual rotation prevention torque). The above conditions may be used alone, or in combination with and, or in combination with and.

Next, a specific method of obtaining the vehicle holding torque SHT will be described. The vehicle holding torque SHT0 at the time when the vehicle has transitioned from the running state to the stopped state is
This is the sum of the holding torques held by each wheel when the vehicle stops, and is divided into left and right front wheels FL, FR and left and right rear wheels RL, RR. This is the sum of the holding torque RHT assigned to the wheels RL and RR. On the other hand, if the vehicle weight increases due to an increase in occupants or loading of luggage or the like during parking, the vehicle holding torque SHT during parking increases by an amount corresponding to the change in vehicle weight. Assuming that the maximum value of the increase in the vehicle holding torque corresponding to the change in the vehicle weight is HHT, the vehicle holding torque SHT is expressed by the following equation 1.

[0048]

[Equation 1] SHT = FHT + RHT + HHT

In the brake control device according to the first embodiment, when the parking brake is operated, current flows only to the electric motors 23 of the left and right rear wheels RL and RR, and only the brakes of the rear wheels are operated. No current is supplied to the electric motor 11.

When the parking brake target pressing force PP * is taken into consideration, in addition to the pressing force corresponding to the vehicle holding torque SHT, a change in friction coefficient due to a temperature change of the braking member and the member to be braked during parking, and the like. In addition, it is necessary to consider shrinkage due to temperature changes of these members. This is because even when the braking member is pressed against the member to be braked by the same pressing force, the torque for preventing the rotation of the wheel changes.

Therefore, the pressure compensating amount for one rear wheel, which compensates for the effects of the change in the friction coefficient and the contraction of the members, is referred to as PMARGI.
N, and one rear wheel corresponding to the holding torque FHT held by the left and right front wheels FL and FR, the holding torque RHT held by the left and right rear wheels RL and RR, and the torque HHT corresponding to the change in the vehicle weight during parking. PFH
Assuming T, PRHT, and PHHT, the parking brake target pressure PP * for one rear wheel is expressed by the following equation (2).

[0052]

[Equation 2] PP * = PFHT + PRHT + PHHT + PMARGIN

Hereinafter, a method of actually obtaining each term in Expression 2 will be described.

"Pressing force PFHT corresponding to holding torque FHT assigned to left and right front wheels FL and FR" Holding torque FHT (front wheel 2 assigned to left and right front wheels FL and FR)
Wheel) is the sum of the detection values of the torque sensors provided on the left and right front wheels FL and FR when the vehicle transitions from the running state to the stopped state (or the detection value of any one of these torque sensors). (A value twice as large). Further, in the case of the first embodiment in which a torque sensor is not provided on the left and right front wheels FL and FR and a torque sensor is provided on each of the left and right rear wheels RL and RR, the holding torque FHT is determined by the left and right rear wheels. Holding of the left and right rear wheels RL, RR obtained as the sum of the detection values of the torque sensors RL, RR (pressurizing sensor 26) (or a value twice as large as the detection value of any one of these torque sensors) The torque RHT (for two rear wheels) and the load distribution of each wheel of the vehicle (in this case,
Estimated based on the front and rear axle weight distribution). That is, the ratio of the load carried by the left and right front wheels FL, FR to the load carried by the left and right rear wheels RL, RR is a: b (according to the experiment, a: b ≒ 7:
3), the holding torque of the left and right front wheels FL, FR
FHT is calculated by the following equation (3).

[0055]

[Formula 3] FHT = RHT × (a / b)

The pressing force PFHT for one rear wheel required for the left and right rear wheels RL and RR to receive the holding torque FHT that has been borne by the left and right front wheels FL and FR is obtained by the following equation (4). The reason for dividing by the value “2” on the right side of the following Expression 4 is that the two wheels that generate the rotation prevention torque during parking brake are the rear wheels. K1 is a coefficient for converting the holding torque into a pressing force. This coefficient K1
Varies depending on the friction coefficient between the braking member and the member to be braked, but can be treated as a constant value by setting the value near the minimum value among the possible values of the friction coefficient.

[0057]

[Equation 4] PFHT = FHT × k1 / 2

[Pressing force PRHT corresponding to holding torque RHT held by left and right rear wheels RL and RR] Holding torque RHT held by left and right rear wheels RL and RR (rear wheel 2)
Wheel) is the sum of the detection values of the torque sensors (pressurizing sensors 26) provided on the left and right rear wheels RL and RR when the vehicle shifts from the running state to the stopped state (or of these torque sensors). (Double value of any one of the detected values). Unlike the first embodiment, when the torque sensors are not provided on the left and right rear wheels RL and RR and the torque sensors are provided on each of the left and right front wheels FL and FR, the holding torque RHT becomes The holding torque FHT of the front-wheel-side wheels FL and FR (the front wheel 2) is obtained as the sum of the detection values of the front-wheel-side torque sensors (or twice the detection value of any one of these torque sensors).
For example, based on the load distribution of each wheel of the vehicle (in this case, the distribution of front and rear axle weights), it can be estimated by the following equation (5).

[0059]

## EQU5 ## RHT = FHT × (b / a)

The pressing force PHHT for one rear wheel required for the left and right rear wheels RL, RR to bear the holding torque RHT, which has been borne by the left and right rear wheels RL, RR, is obtained by the following equation (6). . The reason for dividing by the value “2” on the right side of Equation 6 below is that the two wheels that generate the rotation prevention torque during parking brake are the rear wheels.

[0061]

[Equation 6] PRHT = RHT × k1 / 2

"Pressure PHHT corresponding to the maximum value HHT of the increase in required torque corresponding to the change in vehicle weight" The pressure PHHT is the sum of the maximum load capacity of the vehicle and the occupant weight ΔM, the wheel tire diameter Is R, and the maximum possible gradient of the road surface (inclination angle of the road surface) is θ. The reason for dividing by the value “2” on the right side of the following equation 7 is that the two wheels that generate the rotation prevention torque during parking brake are the rear wheels.

[0063]

[Mathematical formula 7] PHHT = ΔM × R × sin θ / 2

[Pressure Compensation Component PMARGIN to Compensate for Effects of Change in Friction Coefficient and Shrinkage of Member] This pressure compensation component PMARGIN is used when a temperature sensor for detecting the temperature of the braking member or the member to be braked is provided. Can be determined so as to be lower as the temperature detected by the temperature sensor is higher (according to the detected temperature).
This is because the higher the temperature of these members is, the larger the friction coefficient is. Further, since the temperatures of the braking member and the member to be braked decrease according to the elapsed time after the vehicle stops, it is possible to determine that the pressure compensation amount PMARGIN increases according to the elapsed time after the vehicle stops. In the first embodiment, the pressure compensation amount PMARGIN is determined in advance as a constant value in consideration of the maximum value of these changes. As described above, the parking brake target pressing force PP * for one of the left and right rear wheels RL and RR is obtained.

Next, the operation of the above-described vehicle brake control device will be described. FIG. 7 shows the microcomputer 3
1 is a functional block diagram showing the operation of a program executed for brake control of the left rear wheel RL.
The microcomputer 31 performs exactly the same operation for the right rear wheel RR. FIG. 7 shows a program other than the program (for example, the electric motor 23, the brake, the brake pedal 60, and the pedaling force sensor 5) for easy understanding.
3 etc.) are also shown.

First, the case where the driver does not operate (do not depress) the brake pedal 60 and does not operate the parking brake by operating the parking brake operation switch 52 will be described. At this time, the pedaling force F detected by the pedaling force sensor 53 is “0”, and the parking brake operation switch 5
The value of the parking brake actuation instruction signal PKB output from the control unit 2 is also “0”.

The microcomputer 31 has a block B
1 to determine whether or not there is a braking request by the service brake by determining whether or not the pedal depression force F is "0", and to determine whether or not the parking brake activation instruction signal PKB is "0". It is determined whether or not there is a braking request by the parking brake. And the pedal effort F
When it is determined that both the parking brake activation instruction signal PKB and the parking brake activation instruction signal PKB are “0”, that is, when it is determined that there is no braking request by the service brake and the parking brake, the switch SW1
Is connected to a. Thereby, the electric motor 2
No current is supplied to 3 and the brake shoes 202a and 202b, which are braking members, are maintained at the initial position and are separated from the member to be braked, so that no braking torque is generated.

Next, a case where the driver depresses the brake pedal 60 to reduce the vehicle speed while the vehicle is running will be described. In this case, the pedaling force sensor 53 generates a pedaling force F. As a result, the pedal depression force F is no longer "0", and the microcomputer 31 determines that a braking request has been issued by the block B1. Further, the microcomputer 31 uses the block B1 to determine whether the position X of the braking member, which is detected by the position sensor 25, is at a position where the braking member is considered to be pressed against the member to be braked. "The reference position X when the distance between the braking member and the member to be braked is considered to be" 0 "by design.
It is determined based on whether it is greater than "0". Then, when the microcomputer 31 determines that the braking request is made and the position X of the braking member is smaller than the reference position X0 (when it is determined that the braking member and the member to be braked are separated). The movable contact of the switch SW1 is connected to the fixed contact c.

At this time, the microcomputer 31
The duty ratio Du is based on the table that defines the duty ratio Duty with respect to the position X of the braking member shown in the block B2 stored in the memory and the actual position X of the braking member.
Determine ty. And the microcomputer 31
Since the movable contact of the switch SW1 is connected to the fixed contact c, a signal having the determined duty ratio Duty is transmitted as shown in FIG.
To the drive circuit 40 shown in FIG. As a result, a current corresponding to the duty ratio Duty flows through the electric motor 23, and the braking member is pushed toward the member to be braked.

If this state continues, the braking member comes into contact with the member to be braked.
It is determined that the position X of the braking member detected by the position sensor 25 is larger than the reference position X0, and the movable contact of the switch SW1 is connected to the fixed contact b.

At this time, the microcomputer 31
The service brake target pressure PF * is determined based on the table shown in the block B3 stored in the memory and the detected pedal effort F. The table shown in block B3 shows the pedal depression force F and the target pressing force of the service brake.
It defines the relationship with PF *, and the pedal depression force F
And the service brake target pressure PF * have a substantially proportional relationship.

The microcomputer 31 determines the parking brake target pressure PP * by using the block B4. That is, when the parking brake operation switch 52 is operated and the value of the parking brake operation instruction signal PKB becomes "1" (when a parking brake operation request is made), the microcomputer 31 sets the parking brake target pressure PP *. Is determined based on the above-described method, and when the value of the parking brake activation instruction signal PKB becomes “0”, the parking brake target pressing force PP * is set to “0”. At this time, the parking brake operation switch 52 is not operated, and the value of the parking brake operation instruction signal PKB is “0”. Therefore, the microcomputer 31 sets the value of the parking brake target pressure PP * to “0”. I do.

Next, the microcomputer 31 uses the block B5 to select the one having the largest value (larger value) from the service brake target pressure PF * and the parking brake target pressure PP * determined as described above. The selected pressure is set as the target pressure P *. In this case, since the value of the parking brake brake target pressing force PP * is “0”, the service brake target pressing force PF * is set as the target pressing force P *.

Next, the microcomputer 31 determines the supply current I * based on the table shown in the block B6 stored in the memory and the target pressure P * determined by the block B5, and determines the determined supply current. Current I *
And the table shown in block B7 stored in the memory, the duty ratio Duty is obtained. At this time, since the movable contact of the switch SW1 is connected to the fixed contact b, the duty ratio Du obtained by the block B7 is used.
1 is given to the drive circuit 40 shown in FIG. 1, and a current corresponding to the same duty ratio Duty is supplied to the electric motor 23.
Is washed away. As a result, the braking member is pressed against the member to be braked with a force corresponding to the target pressure P *, and a braking torque is generated.

The actual pressure P is detected by the pressure sensor 26. However, since the pressure sensor 26 is a strain sensor attached to the anchor pin 208 and detects the actual braking torque T, when the vehicle speed is “0”, an output corresponding to the actual pressure P is generated. I can't.

Then, the microcomputer 31 determines whether or not the pressure sensor 26 can detect the pressure P by the block B1 by checking the vehicle speed SPD with the reference vehicle speed SPD0.
(That is, “0”), the vehicle speed is determined.
When it is determined that the SPD is greater than the reference vehicle speed SPD0 and the pressure sensor 26 can detect the actual pressure P, the switch SW2 is closed. As a result, the pressure P is feedback-controlled, and the duty ratio Duty is changed so that the actual pressure P approaches the target pressure P *. In this case, since the pressing force sensor 26 detects the actual braking torque T, feedback control is performed so that the actual braking torque T becomes equal to the target braking torque T * having a relation equivalent to the target pressing force P *. Will be.

The duty ratio Duty by the feedback control may be determined based on the difference between the target pressure P * and the actual pressure P, or may be determined based on the differential value of the difference. In this case, it may be determined based on the integral value, or may be determined based on two or more of the actual difference, the differential value, and the integral value.

On the other hand, when the microcomputer 31 determines that the pressing force sensor 26 cannot detect the pressing force P, the microcomputer 31 opens the switch SW2. Thus, the feedback control of the pressing force P based on the incorrect value is prohibited, and the feedforward control of the pressing force P is executed. If an extremely small vehicle speed SPD cannot be accurately detected due to the resolution of the vehicle speed sensor 51, the reference vehicle speed SPD0 is not "0".
The switch SW2 is opened and the pressure P
May be prohibited.

Next, referring to FIGS. 8 and 9, when the parking brake operation switch 52 is operated and the value of the parking brake operation instruction signal PKB is set to "1" (that is, the parking brake operation request is At some point, how the parking brake target pressure PP * is determined by the block B4 will be described. FIGS. 8 and 9 show the target pressure P * of the rear wheel RL when the vehicle is stopped by the service brake when the vehicle is traveling on a flat road and a downhill road, and then the parking brake is operated. An actual braking torque (rotation prevention torque) T detected by the torque sensor 26 of the same wheel RL is shown. In both figures, the target pressure P * is indicated by a solid line, and the actual braking torque T is indicated by a broken line.

As shown in FIG. 8, at time t0 when the vehicle is traveling on a flat road, depression of the brake pedal 60 is started and the pedaling force F
Increases, the target pressure P * increases, and accordingly, the current flowing through the electric motor 23 increases. As a result, the actual braking torque T increases, and the speed of the vehicle decreases. For this reason, the depression force of the brake pedal 60 is slightly weakened at the time t1. Accordingly, the target pressing force P * decreases, and accordingly, the current flowing through the electric motor 23 decreases, and the actual braking torque T also decreases. Vehicle speed SP until time t2
Since D is greater than the reference vehicle speed SPD0, the switch SW
2 is closed, and the feedback control of the pressing force P is performed.

Immediately before time t2 when the vehicle speed SPD becomes equal to or lower than the reference vehicle speed SPD0, the actual braking torque T sharply decreases. At this time, since the output value of the pressing force sensor 26 does not indicate the actual pressing force P, SW2 is opened, and feedforward control of the pressing force P is performed. Then, since the vehicle stops at time t2, the actual braking torque T becomes “0”.
This is because, on a flat road, a braking torque (rotation prevention torque) is not required to keep the vehicle stopped.

When the parking brake operation switch 52 is operated at the time t3, the parking brake target pressure PP * is determined by the block B4 according to the equation (2). In this case, since the pressurizing forces PFHT and PRHT are both "0", the parking brake target pressurizing force PP * is calculated based on the pressurizing force PHHT which compensates for the change in vehicle weight and the influence of the change in friction coefficient and the contraction of members. And the sum of the pressure compensation amount PMARGIN that compensates for

At this time, since the pedal effort F detected by the pedal effort sensor is "0", the target pressure PF * for service brake is "0". Accordingly, the parking brake target pressure PP * is selected as the target pressure P * by the block B5, and a current corresponding to the target pressure P * is supplied to the electric motor 23. When the value of the parking brake actuation instruction signal PKB is "1", the microcomputer 31 sets the movable contact of the switch SW1 if the actual position X of the braking member is larger than the reference position X0 by the function of the block B1. When the actual position X of the braking member is smaller than the reference position X0, the movable contact of the switch SW1 is connected to the fixed contact c.

When a predetermined time has elapsed in such a state, a pressing force corresponding to the parking brake target pressing force PP * is applied to the braking member. At this time, the microcomputer 31
A current flows through the switching motor 24 shown in FIG.
5 is rotated clockwise in FIG. 5, and as shown in FIG. 6, the second meshing portion 324b of the regulating gear 324 is arranged at a position meshing with the pinion 308, and then the current of the switching motor 24 is reduced. Cut off. At the same time, the microcomputer 31 stops supplying current to the electric motor 23.
As a result, the rotation of the pinion 308 in the direction of arrow B is prevented, so that the force (holding torque) for preventing the rotation of the wheels during parking brake is maintained, and the electric motor 2 is stopped.
3. The current supply to the switching motor 24 is stopped, and wasteful power consumption is suppressed. The above is the operation of the present embodiment on a flat road.

Next, the operation during downhill traveling will be described. As shown in FIG. 9, the time t0 during traveling on a downhill road
When the depression of the brake pedal 60 is started and the pedaling force F increases, the target pressure P * increases, and accordingly, the current flowing to the electric motor 23 increases. As a result, the actual braking torque T increases, and the speed of the vehicle decreases. For this reason, at time t1, the depression force of the brake pedal 60 is slightly weakened, the target pressure P * decreases, and accordingly, the current flowing through the electric motor 23 decreases, and the actual braking torque T
Also decrease. Until time t2, the vehicle speed SPD is equal to the reference vehicle speed SPD.
Since it is larger than 0, the switch SW2 is closed, and the feedback control of the pressing force P is performed.

Immediately before time t2 when the vehicle speed SPD becomes equal to or lower than the reference vehicle speed SPD0, the actual braking torque T sharply decreases. At this time, since the output value of the pressing force sensor 26 does not indicate the actual pressing force P, SW2 is opened, and feed-forward control of the pressing force P is performed. Thereafter, the vehicle stops at time t2. The operation up to this point is the same as during traveling on a flat road.

When the vehicle stops at time t2, the actual braking torque T becomes a predetermined value (not "0"). This is because a predetermined rotation preventing torque (holding torque) is required on a downhill road to maintain the vehicle in a stopped state. Note that the predetermined value is の of the holding torque RHT that the left and right rear wheels RL and RR bear.

Normally, even after the vehicle stops at time t2, the driver maintains the same depression force F of the brake pedal 60 until the parking brake operation switch 52 is operated at time t3. Then, when the parking brake operation switch 52 is operated at time t3, the depression of the brake pedal 60 ends. At this time t3, the microcomputer 31 obtains the pressurizing forces PFHT and PRHT from the above formulas 4 and 6 and the pressurizing force P (rotation preventing torque) detected by the pressurizing force sensor 26 functioning as a torque sensor, and according to the formula 2 And the sum of these pressures, the pressure PHHT, which compensates for the change in vehicle weight, and the pressure compensation PMARGIN, which compensates for the effects of changes in the coefficient of friction and contraction of members, etc., and adds the parking brake target pressure PP *. Ask for.

On the other hand, immediately after time t3, the pedaling force F detected by the pedaling force sensor is "0" and the service brake target pressure PF * is "0".
5, the parking brake target pressure PP * is selected as the target pressure P *, and a current corresponding to the target pressure P * is supplied to the electric motor 23. As a result, the actual pressure P
Becomes the target pressure P *, the microcomputer 31
As in the case of the flat road described with reference to FIG.
The second meshing portion 324b of No. 4 is arranged at a position meshing with the pinion 308, and thereafter, the supply of electric current to the electric motor 23 is stopped. The above is the operation of the present embodiment on a downhill road.

Next, a program for controlling the braking of the left and right front wheels FL and FR will be described. Left and right front wheels F
Regarding L and FR, no current is supplied to the electric motor 11 during parking. Accordingly, the brake control program for the left and right front wheels FL and FR deletes the block B4 for determining the parking brake target pressure PP * and the maximum value selection block B5 shown in FIG. , The position sensor 25 is replaced with the position sensor 12 and the pressure sensor 26 is replaced with the pressure sensor 13. Regarding the operation, the rear wheels RL, RR
The description is omitted because it is clear from the operation for.

As described above, the brake control device according to the first embodiment provides the braking torque when the vehicle comes to a stop (rotation preventing torque at the time of service brake) when a parking brake activation request is made. , A vehicle holding torque (rotation preventing torque at the time of parking brake) is determined, and the holding torque is generated on the left and right rear wheels RL and RR. Therefore, since the holding torque does not become excessive, the current supplied to the electric motor 23 can be reduced, and unnecessary energy consumption can be avoided. Also, the parking brake target pressure PP
After the pressure P equal to * is obtained, the required holding torque is maintained by the regulating gear 324, and no current is supplied to the electric motor 23 and the switching motor 24, so that the battery is consumed even when parking for a long time. The effect that it does not invite is produced.

Further, the left and right rear wheels RR, RL of the above-described embodiment.
With regard to the brake control described above, since the pressing force sensor 26 detects the actual braking torque T, the friction coefficient between the brake linings 219a and 219b as friction engagement members and the inner peripheral surface of the drum 206 changes. However, the actual braking torque can be controlled to a target value.

Next, a second embodiment of the vehicle brake control device according to the present invention will be described with reference to FIG. 10, which schematically shows the entire device.

The control device for the brake includes front left and right wheels F
L and FR differ from the first embodiment only in that a hydraulic disc brake device 70 is provided in place of the electric disc brake 10 and a device associated with the hydraulic disc brake device 70 is provided. Therefore, hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0095] The hydraulic brake device 70 includes the left and right front wheels F
A hydraulic brake 71 for applying a braking force to each of the L and FR is provided. These hydraulic brakes 71 are formed by frictionally engaging a brake pad as a friction engagement member, which is non-rotatably held by a mounting bracket, which is a vehicle body-side member, with a disk rotor that rotates together with the wheels by the operation of a wheel cylinder 72. , To suppress the rotation of the wheels.

Operation rod 60a of brake pedal 60
Are connected to a tandem master cylinder 61. The tandem master cylinder 61 generates a hydraulic pressure corresponding to the operation amount of the brake pedal 60 (pedal depression force F, pedal stroke ST) in each of the liquid chambers 61a communicating with the oil tank 62 storing the brake oil. I have. Each liquid chamber 61a is connected to each of the wheel cylinders 72.

Next, the operation of this device will be described. For the left and right rear wheels RL and RR, the same control as the brake control for the left and right rear wheels RL and RR of the first embodiment is performed by the electric control device 30. And a braking torque is generated in these. For the left and right front wheels FL and FR, a braking torque corresponding to the pedaling force F of the brake pedal 60 is supplied from the tandem master cylinder 61 to each wheel cylinder 72 to generate a braking torque.

The holding torque during the parking brake is generated by the electric drum brakes 20 of the left and right rear wheels RL and RR, as in the first embodiment. The parking brake target pressure PP * is determined in exactly the same manner as in the first embodiment.

As described above, also in the brake device according to the second embodiment in which the hydraulic brake device and the electric brake device are used in combination, the braking performed when the vehicle comes to a stop when the parking brake activation request is made. The vehicle holding torque (rotation preventing torque during parking brake) is determined based on the torque (rotation preventing torque during service brake), and the holding torque is generated on the left and right rear wheels RL, RR. Therefore, since the holding torque does not become excessive, the current supplied to the electric motor 23 can be reduced, and unnecessary energy consumption can be avoided. In the second embodiment, a master cylinder pressure detection sensor that detects the hydraulic pressure of the master cylinder 61 is used as a service brake operation amount detection sensor instead of, or in combination with, the pedal force sensor 53. Is also good.

As described above, according to each embodiment of the present invention, the holding torque during parking by the electric brake device is set to an appropriate value, so that the parking brake performance can be maintained well and wasteful. Energy consumption can be suppressed.

Note that the present invention is not limited to the above embodiment, and various modifications can be adopted within the scope of the present invention. For example, in the first and second embodiments, the parking brake target pressing force PP * is determined based on the output of the pressing force sensors 26 provided on the left and right rear wheels RL and RR.
However, a torque sensor capable of detecting the actual braking torque may be provided on the left and right front wheels FL and FR, and the parking brake target pressure PP * may be determined from this. The left and right front wheels F
L, FR, and the parking brake target pressing force from any one of the torque sensors provided on any of the left and right rear wheels RL, RR for detecting the actual torque applied to the corresponding wheel.
PP * may be determined.

In the above-described embodiment, the DC electric motors 11 and 23 are employed as the power source of the electric actuator. However, both are ultrasonic motors, the front wheel side is an ultrasonic motor, and the rear wheel side is a DC motor. Or D on the front wheel side
The C motor and the rear wheel side can be an ultrasonic motor.

Further, the electric actuator may be any as long as the brake can be operated by pressing the braking member (friction engaging member) against the member to be braked by the electric actuator. Therefore, the electric actuator can also be constituted by an actuator including a wheel cylinder and an electromagnetic control valve device capable of electrically controlling the hydraulic pressure of the wheel cylinder. Further, the brake used for each wheel may be a disc brake or a drum brake.

In the first embodiment, the actuator controlled during the service brake and the actuator controlled during the parking brake are the same electric motor 23, but they are different actuators. You may. That is, for example, the actuator controlled during the service brake may be the electric motor 23, and the actuator controlled during the parking brake may be the lever 230 via a cable or another electric motor directly connected to the lever 230. .

Further, in each of the above-described embodiments, the pressure PHHT is obtained by setting the variation of the vehicle weight as a constant value. However, the vehicle weight is estimated from the suspension stroke of the vehicle and the like.
The pressure PHHT may be variable according to the estimated value of the vehicle weight.

[Brief description of the drawings]

FIG. 1 is an overall view of an electric brake device including a vehicle brake control device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the electric drum brake shown in FIG.

FIG. 3 is a cross-sectional view taken along a line 1-1 of the electric actuator shown in FIG. 2;

FIG. 4 is a perspective view of a rotation preventing mechanism provided in the electric actuator shown in FIG. 2;

FIG. 5 is a sectional view taken along line 2-2 of FIG. 3, showing a rotation preventing mechanism.

FIG. 6 is a sectional view taken along line 2-2 of FIG. 3, showing the rotation preventing mechanism.

7 is a functional block diagram of a program executed by the microcomputer shown in FIG.

FIG. 8 is a time chart showing changes in target pressing force and actual braking torque when traveling on a flat road.

FIG. 9 is a time chart showing changes in target pressing force and actual braking torque during downhill traveling.

FIG. 10 is an overall view of an electric brake device including a vehicle brake control device according to a second embodiment of the present invention.

[Explanation of symbols]

10: electric disc brake, 11: DC electric motor,
12 ... Position sensor, 13 ... Pressure sensor, 20 ... Electric drum brake, 21 ... Drum, 22 ... Brake shoe,
23 ... DC electric motor, 24 ... Switching motor, 25 ... Position sensor, 26 ... Pressure force sensor (torque sensor), 30 ...
Electric control device, 31: microcomputer, 52: parking brake operation switch, 53: pedal force sensor, 60: brake pedal, 70: hydraulic disc brake device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoki Sawada 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (Reference) 3D046 BB02 CC06 EE01 EE02 HH02 HH03 HH15 HH29 HH52

Claims (7)

[Claims] A braking member which rotates integrally with a wheel; a braking member which is pressed by the braking member to generate a rotation preventing torque against rotation of the wheel; and wherein the braking member is a member to be braked. An actuator for generating a pressing force, a service brake control means for controlling a force generated by the actuator in accordance with a service brake operation amount, and applying a rotation preventing torque to the wheels during a service brake; A parking brake control means for controlling a force generated by the actuator in accordance with the above, and applying a rotation preventing torque to the wheels during parking braking. A torque detection unit for directly detecting a torque; and the parking brake control unit includes the service brake control. When the force generated by the actuator is controlled by a step, the actuator generates the rotation prevention torque during parking brake based on the actual rotation prevention torque detected by the torque detection means. A brake control device characterized by controlling force. 2. A brake member is pressed against a member to be braked, which is provided on each of a plurality of wheels provided on a vehicle and rotates integrally with each wheel, so that each wheel resists rotation of each wheel. A plurality of actuators for applying a rotation preventing torque to be applied, and a service brake control means for controlling a force generated by the plurality of actuators in accordance with a service brake operation amount, and applying the rotation preventing torque to the plurality of wheels during a service brake. Parking brake control means for controlling at least one of the plurality of actuators in response to a parking brake actuation request, and applying a rotation preventing torque at the time of parking brake to a wheel provided with the controlled actuator. A brake control device for a vehicle, comprising: a rotation control unit provided on at least one of the plurality of wheels to prevent rotation of the plurality of wheels. A torque detecting means for directly detecting a torque; and the parking brake control means includes an actual rotation prevention detected by the torque detecting means when the force generated by the actuator is controlled by the service brake control means. A control device for a brake, characterized in that at least one of the actuators is controlled so as to set a rotation prevention torque at the time of the parking brake based on a torque. 3. The vehicle brake control device according to claim 2, wherein the parking brake control unit is configured to detect the torque based on the detected actual rotation preventing torque and a load distribution to each wheel of the vehicle. Estimating the rotation inhibition torque of the wheel not provided with, and controlling the force generated by the actuator to set the rotation inhibition torque at the time of the parking brake based on the estimated rotation inhibition torque. Characteristic brake control device. 4. The vehicle brake control device according to claim 1, wherein the parking brake control unit controls the parking of the vehicle in accordance with a temperature of the braking member or the member to be braked. A brake control device configured to change a force generated by an actuator during braking. 5. The control device for a vehicle brake according to claim 1, wherein the parking brake control means controls the rotation preventing torque during the parking brake according to a weight of the vehicle. A control device for a brake, characterized by controlling a force generated by the actuator so as to change the brake force. 6. The control apparatus for a vehicle brake according to claim 1, wherein said parking brake control means detects the time when said parking brake operation request is issued. A brake control device, wherein a force generated by the actuator is controlled so as to set a rotation prevention torque at the time of the parking brake based on an actual rotation prevention torque. 7. The control apparatus for a vehicle brake according to claim 1, wherein the parking brake control unit detects the actual brake detected when the vehicle is stopped. A control device for a brake, wherein a force generated by the actuator is controlled so as to set a rotation prevention torque at the time of the parking brake based on the rotation prevention torque.