JP2001289273A - Method for controlling motor-driven brake device for vehicle and the motor-driven brake device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling a motor-driven brake device for a vehicle capable of easily releasing parking and to provide the motor-driven brake device for a vehicle. SOLUTION: Power supply fed to an electric motor 11 is set such that a supply voltage applied on the electric motor 11 when the electric motor 11 is reversed and displacement is effected in a direction in which a brake pad is brought into non-contact (separation from) with a disc is increased to a value higher than a supply voltage applied on the electric motor 11 when the electric motor 11 is rotated forward and displacement is effected in a direction in which the brake pad is brought into contact with the disc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an electric brake device for a vehicle and an electric brake device for a vehicle.
In particular, the present invention relates to a control method of a vehicle electric brake device suitable for a parking brake device and a vehicle electric brake device.

[0002]

2. Description of the Related Art In recent years, there has been proposed a parking brake device for a vehicle which is operated by an actuator using an electric motor as a drive source. That is, this type of parking brake device is designed to apply the parking brake by directly pressing the brake pad with the electric motor when the vehicle is parked (or stopped).

In general, in electric parking, an electric motor drives a brake pad in less than one second from a no-load rotation speed at the time of braking to press a rotating body interlocking with wheels to apply a parking brake. That is, the rotating body is restrained by the brake pad driven by the electric motor in a short time and falls into a restrained state. Therefore, between the rotating body and the brake pad, a braking force is generated by the restraining torque of the electric motor, and also an inertial force of the brake pad as the moving body is generated.

The largest contribution to the inertial force is the inertia torque T (I) generated by the rotor of the electric motor. That is, T (I) = I × dω / dt (where I is the moment of inertia of the motor and dω / dt is the angular acceleration of the motor).
(I) is increased in the deceleration part of the brake device, resulting in a large inertial force.

Therefore, an inertial force is generated between the rotating body and the brake pad, so that a braking force equal to or greater than the restraining braking force generated only by the restraining torque is generated. In order to maintain this braking force while continuing electric parking (parking), a mechanical loss is intentionally created in the mechanical force transmission path, and the reaction force is continuously received. The release of the electric parking (parking) is performed by rotating the electric motor in the reverse direction to separate the brake pad from the rotating body.

[0006]

By the way, conventionally,
When the electric parking (parking) is released, the control means of the brake device supplies a current of the same magnitude to the electric motor as when the electric parking (parking) is activated. Only a torque (starting torque) that opposes the torque is generated.

Therefore, it takes time for the electric motor to overcome the braking force equal to or greater than the restraint braking force to separate the brake pad from the rotating body, and it is difficult to release the electric parking (parking).

In general, when parking, the voltage of the battery power supplied to the motor is high immediately after the vehicle is running. On the other hand, when the parking is released, the voltage of the battery power is low immediately after the start of the engine and immediately after the battery power is consumed by the starter or the like. For this reason, when the parking is released, the driving voltage supplied to the electric motor is low, so that the starting torque generated in the electric motor is small. As a result, it is more difficult to release the parking by the electric motor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for controlling an electric brake device for a vehicle, which can easily release parking (parking) by an electric motor. An object of the present invention is to provide an electric brake device for a vehicle.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a method of contacting / non-contacting a friction member with a rotating body which rotates with an axle based on the action of an electric motor. In the control method of the vehicular electric brake device that is displaced between the contact states to generate a desired braking force, the electric power supplied to the electric motor may be set such that the friction member is displaced in a direction in which the friction member is brought into contact. The gist of the present invention is to make it larger when displacing in the non-contact direction.

According to a second aspect of the present invention, there is provided a rotating body which rotates together with an axle, a brake pad which a friction member presses against the rotating body, an electric motor which rotates forward and reverse, and a forward and reverse rotation of the electric motor. Decelerating means for decelerating, movement transmitting means for displacing a friction member of the brake pad between a contacting state and a non-contacting state with respect to a rotating body based on forward / reverse rotation decelerated by the decelerating means, and the electric motor Supply electric power to be supplied, than when the electric motor is rotated forward to displace the friction member of the brake pad in the direction of contact.
Control means for controlling the electric motor to rotate in the reverse direction to displace the friction member of the brake pad in a direction in which the friction member is not in contact with the electric motor is provided.

(Operation) According to the first aspect of the present invention,
When the friction member is displaced in the non-contact direction, that is, when the brake is released, the electric power supplied to the electric motor is increased, so that the electric motor can generate a large starting torque. The release force of the friction member from the contact position due to the large starting torque can overcome the braking force equal to or greater than the restraint braking force generated when the friction member presses the rotating body. As a result, the brake can be easily released.

According to the second aspect of the present invention, the electric power supplied to the electric motor is increased when the friction member is displaced in the non-contact direction by the control means, that is, when the brake is released. The motor can generate a large starting torque. The release force of the friction member from the contact position due to the large starting torque can overcome the braking force equal to or greater than the restraint braking force generated when the friction member presses the rotating body. As a result, the brake can be easily released.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an electric parking brake device as an electric brake device for a vehicle will be described with reference to the drawings.

As shown in FIG. 1, the electric motor 11 of the electric parking brake device 10 according to the present embodiment includes an armature 1
2 and a motor housing 1 for housing and supporting the armature 12
3 is provided. A worm 15 that rotates together with the rotating shaft 14 is fixed to an output end of the rotating shaft 14 of the armature 12. The worm 15 is meshed with a worm wheel 17 rotatably provided on a worm housing 16. The worm wheel 17 is meshed with a rotating worm 18 that constitutes a movement conversion unit. That is, the worm wheel 17 and the rotating worm 18
That is, the rotation of the motor 11 is decelerated, and is configured as a deceleration means of the electric parking brake device 10.

On both upper and lower surfaces of the rotary worm 18, there are formed roller screws 19 constituting a movement converting means. The roller screw 19 is drivingly connected to a screw portion 21 of a slider 20. That is, the roller screw 19
Is adapted to convert the rotation of the rotary worm 18 into a linear motion of the slider 20.

The slider 20, as shown in FIG.
The brake case 22 is held so as to be able to reciprocate, and the tip 23 is inserted into the cylinder mechanism 24. The cylinder mechanism 24 includes a hydraulic cylinder 25 and a piston 26 reciprocally arranged in the hydraulic cylinder 25. The hydraulic cylinder 25 is configured such that when a brake pedal (not shown) is depressed, pressure oil is introduced into the cylinder chamber from an inlet 25a formed in the hydraulic cylinder 25. The piston 26 has the slider 2 at its base end.
Contact recess 27 as a contact portion contacting the leading end 23 of
Is formed, and a brake pad 28 as a friction member is fixed to a tip end thereof. A brake pad 29 is provided on the pad fixing member 30 so as to face the brake pad 28. The pad fixing member 30 is connected to the hydraulic cylinder 25 via a caliper (not shown).
A disk 3 as a rotating body fixed to the axle (not shown) of the vehicle is provided between the brake pads 28 and 29.
1 is arranged. The rotating worm 18, the roller screw 19, the slider 20, and the cylinder mechanism 24 constitute a movement transmitting unit of the electric parking brake device 10.

In this embodiment, the piston 26
When the hydraulic cylinder 25 moves in the direction of arrow A shown in FIG. 1 by pressing the slider 20 or the pressure oil, the hydraulic cylinder 25 moves in the direction of arrow B opposite to the direction of arrow A by the reaction force pressing the piston 26. . Therefore, the brake pads 28 and 29 are moved so as to be separated from each other by the reciprocating movement of the piston 26. A piston seal (not shown) is provided between the piston 26 and the hydraulic cylinder 25.
Is provided. When the piston 26 is not pressed by the return action of the piston seal, the piston 26
Always acts so that the brake pads 28 and 29 are separated from the disk 31 by a predetermined gap.

Next, the electrical configuration of the electric parking brake device 10 configured as described above will be described. In FIG. 2, a brake controller 4 as control means
0 is connected to the brake operation switch 41. The brake operation switch 41 is turned on / off based on an operation of a parking brake operation lever provided on the vehicle, and outputs an on / off signal to the brake controller 40. That is, when the parking brake operation lever is operated to the parking position, the brake operation switch 41 outputs an ON signal to the brake controller 40. When the parking brake operation lever is operated to the parking release position, a brake operation switch 41 off signal is output to the brake controller 40.

The brake controller 40 executes the parking brake mode in response to the rise of the on signal from the off signal of the brake operation switch 41, and parks in response to the fall of the off signal from the on signal of the brake operation switch 41. Execute the brake release mode.

In the parking brake mode, the electric motor 11 is rotated forward to apply the brake pads 28 and 29 to the disc 31.
This is a mode in which pinching and pressing are performed. More specifically, when the electric motor 11 rotates forward, the forward rotation is reduced by the worm 15 and the worm wheel 17, and the brake pads 28, 29 move in the clamping direction by the rotating worm 18, the roller screw 19, and the slider 20. Is converted to linear movement.

The parking brake release mode is a mode in which the electric motor 11 is rotated in the reverse direction so that the brake pads 28 and 29 are pressed against the disk 31 by nipping. More specifically, when the electric motor 11 rotates in the reverse direction, the reverse rotation is reduced by the worm 15 and the worm wheel 17, and the brake pads 28 and 29 are moved in the anti-clipping direction by the rotating worm 18, the roller screw 19 and the slider 20. Converted to linear movement as if moving.

In the parking brake mode, the brake controller 40 outputs first and second parking control signals PRK1, PRK2 to the motor drive circuit 42 to rotate the electric motor 11 forward. Conversely,
The brake controller 40 outputs first and second parking release control signals REL1 and REL2 for reversely rotating the electric motor 11 to the motor drive circuit 42 in the parking release brake mode.

The motor drive circuit 42 includes first and second forward rotation switching elements Tf1, Tf2 and first and second forward rotation switching elements Tf1, Tf2.
And the reverse rotation switching elements Tr1 and Tr2.

The first forward rotation switching element Tf1 and the first reverse rotation switching element Tr1 are composed of PNP transistors, and the first forward rotation switching element Tf.
The first base receives a first parking control signal PRK1 via a resistor R1, and the base of the first reverse rotation switching element Tr1 receives a first parking release control signal REL1 via a resistor R2. The emitters of the first forward rotation switching element Tf1 and the first reverse rotation switching element Tr1 are both connected to a positive power supply terminal of a battery mounted on the vehicle.

The second forward rotation switching element Tf2 and the second reverse rotation switching element Tr2 are composed of PNP transistors, and the second forward rotation switching element Tf.
The second base receives a second parking control signal PRK2 via a resistor R3, and the base of the second reverse rotation switching element Tr2 receives a second parking release control signal REL2 via a resistor R4. The emitters of the second forward rotation switching element Tf2 and the second reverse rotation switching element Tr2 are both connected to a negative power terminal (ground) of a battery mounted on the vehicle.

The collector of the first reverse rotation switching element Tr1 and the collector of the second forward rotation switching element Tf2 are connected to each other, and the collector of the first forward rotation switching element Tf1 and the second reverse rotation switching element Tf1 are connected to each other. The collectors of the rotation switching element Tr2 are connected to each other via a supply voltage adjusting resistor 43. The electric motor 11 is connected between the collector of the first reverse rotation switching element Tr1 and the collector of the second reverse rotation switching element Tr2.

When the first and second parking control signals PRK1 and PRK2 are output from the brake controller 40, the first and second forward rotation switching elements Tf1 and Tf2 are turned on. As a result, the current flows through the path of the first forward rotation switching element Tf1 → supply voltage adjusting resistor 43 → electric motor 11 → second forward rotation switching element Tf2, and the electric motor 11
Rotates forward.

On the other hand, the brake controller 40
And the second parking release control signals REL1, REL2
Is output, the first and second reverse rotation switching elements Tr1 and Tr2 are turned on. As a result, the current is changed from the first reverse rotation switching element Tr1 to the electric motor 1
The electric motor 11 rotates in the reverse direction through a path of 1 → second switching element for reverse rotation Tr2.

In this embodiment, when the electric motor 11 rotates forward, the current supplied to the electric motor 11 is supplied via the supply voltage adjusting resistor 43. Therefore, FIG.
As shown in the figure, the voltage V1 applied to the electric motor 11 at the time of forward rotation is smaller than the voltage V2 applied to the electric motor 11 at the time of reverse rotation by the voltage drop Δ in the supply voltage adjusting resistor 43.
V smaller. In other words, when the electric motor 11 rotates in the reverse direction, a larger supply power is supplied than when the electric motor 11 rotates in the forward direction.

That is, when the electric motor 11 rotates in the reverse direction, that is, when the parking brake is released, the electric motor 11
Of the brake pads 28 and 29 due to the large starting torque,
The brake pads 28 and 29 can overcome a braking force equal to or greater than a restraining braking force generated when the brake pads 28 and 29 are pressed against the disk 31 in the parking brake mode.

In this embodiment, the brake controller 40 supplies the motor 11 when the vehicle is in the normal braking state, that is, when the brake pedal (not shown) is depressed without operating the parking brake operation lever. Control is performed so that pressure oil is supplied to the cylinder mechanism 24 without supplying power. At this time, the cylinder mechanism 24 moves the piston 26 in the direction of the arrow A shown in FIG. 1 by the supply of the pressurized oil, and the hydraulic cylinder 25 moves the arrow shown in FIG. It is moved in the B direction. Then, the disc 31 is moved to both brake pads 28, 2
9 and the brake is normally applied. Thereafter, when the brake pedal is released, the action of the pressure oil is released, and the hydraulic cylinder 25 is returned by the return action of the piston seal (not shown) in the cylinder mechanism 24. Then, both brake pads 28 and 29 are separated from the disk 31 and the normal brake is released.

According to the electric parking brake device 10 of the present embodiment, the following features can be obtained. (1) In the present embodiment, the supply voltage applied to the electric motor 11 when the electric motor 11 is displaced in the direction of bringing the brake pads 28 and 29 into contact with the disk 31 by rotating the electric motor 11 forward by rotating the electric motor 11 forward. The supply voltage V2 applied to the electric motor 11 when the electric motor 11 is rotated in the reverse direction to displace the brake pads 28 and 29 to the disk 31 in a non-contacting (separating) direction from V1 is increased.

Accordingly, a large starting torque can be generated by the electric motor 11 when the electric motor 11 is rotated in the reverse direction to displace the brake pads 28 and 29 to the disc 31 in the direction of non-contact (separation). The release force of the brake pads 28 and 29 from the contact position due to the large starting torque can overcome the braking force equal to or greater than the restraining braking force generated when the brake pads 28 and 29 press the disk 31 against each other. As a result, parking release of the electric parking brake device 10 can be easily performed.

(2) In the present embodiment, the movement transmitting means
The rotating worm 18 and the roller screw 19 for converting the forward / reverse rotation decelerated by the worm 15 and the worm wheel 17 into a reciprocating linear movement of the slider 20 are fixed to the brake pads 28 and 29, and are moved by the pressing of the slider 20. And a cylinder mechanism 24 having a piston 26 that moves under the action of pressure oil by a brake pedal operation.

Accordingly, the parking brake and the ordinary brake can be integrated, and the brake system of the vehicle can be simplified. In addition, this embodiment may be changed as follows.

The motor drive circuit 42 may be implemented by a circuit shown in FIG. Specifically, in the motor drive circuit 42 shown in FIG. 4, the supply voltage adjusting resistor 43 is omitted. Then, instead of omitting the supply voltage adjusting resistor 43, the brake controller 40 outputs a pulse width modulated (PWM) second parking control signal PRK2 to the base of the second positive rotation switching element Tf2. . Thus, when the electric motor 11 is rotating forward, the electric motor 1 is controlled based on pulse width modulation (PWM).
1 is adjusted, and the electric power supplied to the electric motor 11 during forward rotation is
Less than the power supplied to the In other words, a larger supply power is supplied when the electric motor 11 rotates in the reverse direction than when the electric motor 11 rotates in the forward direction. Therefore, it has the same effect as the above embodiment.

The motor drive circuit 42 may be implemented by a circuit shown in FIG. More specifically, in FIG. 5, one motor input terminal of the electric motor 11 is connected to a first relay switch 51. The first relay switch 51 switches to connect either the negative power supply terminal (ground) of the 12 volt battery or the positive power supply terminal to the motor input terminal via the supply voltage adjusting resistor R10. ing. The other motor input terminal of the electric motor 11 is connected to the second relay switch 5.
2 are connected. The second relay switch 52 is switched so as to connect either the negative power supply terminal (ground) or the positive power supply terminal to the motor input terminal.

That is, when the electric motor 11 is rotated forward, the first relay switch 51 and the second relay switch 52 are controlled to be switched, and one motor input terminal is connected to the resistor R.
10 and a positive power supply terminal, and the other motor input terminal to ground. Electric motor 1
When 1 is rotated in the reverse direction, the first relay switch 51 and the second relay switch 52 are switched and controlled so that one motor input terminal is connected to the ground and the other motor input terminal is connected to the positive power supply terminal.

The first relay switch 51 is switched by energizing / de-energizing the relay coil 54a of the first relay circuit 54. When the relay coil 54a is energized (energized), the relay coil 54a connects the first relay switch 51 between one motor input terminal and the positive power supply terminal via the resistor R10. Conversely, the relay coil 54
When a is not excited (de-energized), the relay coil 54a connects the first relay switch 51 between one motor input terminal and the ground, as shown by the solid line in FIG.

The energization / non-excitation of the relay coil 54a provided in the first relay circuit 54 is controlled by the second parking control signal PRK from the brake controller 40 of the above embodiment.
2 is controlled. That is, when the second parking control signal PRK2 is input, the first transistor T1
Is turned on. When the first transistor T1 is turned on, a 12-volt battery power is applied to the first relay circuit 54, and the relay coil 54a is excited. When the second parking control signal PRK2 disappears, the first transistor T1 is turned off. Based on the turning off of the first transistor T1, the supply of the 12-volt battery power to the first relay circuit 54 is cut off, and the relay coil 54a is de-energized.

The second relay switch 52 is switched by energizing / de-energizing the relay coil 55a of the second relay circuit 55. When the relay coil 55a is excited,
The relay coil 55a connects the second relay switch 52 between the other motor input terminal and the positive power supply terminal.
Conversely, when the relay coil 55a is not excited, the relay coil 55a connects the second relay switch 52 between the other motor input terminal and the ground as shown by the solid line in FIG.

The energization / non-excitation of the relay coil 55a provided in the second relay circuit 55 is controlled by the second parking release control signal R from the brake controller 40 of the above embodiment.
Controlled by EL2. That is, when the second parking release control signal REL2 is input, the second transistor T2 is turned on. Based on the turning on of the second transistor T2, a 12-volt battery power is applied to the second relay circuit 55, and the relay coil 55a is excited. When the second parking release control signal REL2 disappears, the second transistor T2 is turned off. When the second transistor T2 is turned off, the supply of the 12-volt battery power to the second relay circuit 55 is cut off, and the relay coil 55
a is de-energized.

Therefore, the second parking control signal PRK
The electric motor 11 performs normal rotation during parking when 2 is input, and performs reverse rotation during parking when the second parking release control signal REL2 is input.

Also in this case, the voltage applied to the electric motor 11 during the forward rotation is smaller than the voltage applied to the electric motor 11 during the reverse rotation by the voltage drop at the supply voltage adjusting resistor R10. Therefore, the same effects as those of the above embodiment can be obtained.

In the above embodiment, the contact recess 27 is formed at one end of the piston 26 as a contact portion that contacts the tip 23 of the slider 20. However, the contact recess 27 is formed at the tip 23 of the slider 20. May be formed so as to form a contact protruding portion at one end of the piston 26 so as to contact the contact concave portion. In this case, the feature (1) of the above embodiment
The same effect as the effect described in (2) can be obtained.

In the above embodiment, the slider 20 is connected to the brake pads 28 and 29 via the cylinder mechanism 24. However, as shown in FIG.
The distal end portion 23 may be connected to the brake pads 28 and 29 via a pad connecting member 32 fixed to the distal end portion 23 for implementation. That is, the rotary worm 18, the roller screw 19, the slider 20, and the pad connecting member 32 constitute a movement transmitting means of the electric parking brake device 10, and are of a direct acting type. In this case, effects similar to the effects described in the features (1) and (2) of the above embodiment can be obtained.

In the above embodiment, the rotating body is the disk 3
1, but the rotating body may be implemented by a drum. In this case, effects similar to the effects described in the features (1) and (2) of the above embodiment can be obtained.

In the above embodiment, the present invention is embodied in the electric parking brake device of the vehicle, but the present invention may be embodied in other electric brake devices. In this case, the features (1) and (2) of the above embodiment
And an effect substantially similar to the effect described in (1).

[0050]

As described in detail above, according to the first and second aspects of the present invention, the brake can be easily released.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an electric brake device for a vehicle according to an embodiment.

FIG. 2 is a control circuit of the vehicle electric brake device.

FIG. 3 is an explanatory diagram showing a voltage applied to an electric motor and a braking force of an electric brake device.

FIG. 4 is a control circuit of another example of an electric brake device for a vehicle.

FIG. 5 is a control circuit of another example of an electric brake device for a vehicle.

FIG. 6 is another example of an electric brake device for a vehicle.

[Explanation of symbols]

10: electric brake device for vehicle, 11: electric motor, 1
Reference numeral 5 denotes a worm constituting the deceleration means; 17 represents a worm wheel constituting the deceleration means; 18 a rotating worm constituting the movement conversion means; 19 a roller screw constituting the movement conversion means; 20 a slider; 24 a cylinder mechanism; ... Hydraulic cylinders constituting a cylinder mechanism, 26 ... pistons constituting a cylinder mechanism, 28, 29 ... brake pads as friction members, 31 ... discs as rotating bodies.

Claims (2)

[Claims] 1. A friction member (28, 29) is displaced between a contact state and a non-contact state based on the action of an electric motor (11) with respect to a rotating body (31) rotating with an axle,
In the method for controlling a vehicular electric brake device that generates a desired braking force, the electric power supplied to the electric motor (11) is displaced in a direction in which the friction members (28, 29) are brought into contact with each other. , 29) is made larger when displaced in the non-contact direction. 2. A rotating body (31) rotating with an axle, a brake pad against which friction members (28, 29) are pressed against the rotating body (31), an electric motor (11) rotating forward and reverse, and Speed reduction means (15, 17) for reducing the forward / reverse rotation of the electric motor (11); and friction members (28, 29) of the brake pad based on the forward / reverse rotation reduced by the speed reduction means (15, 17). ) Contacts the rotating body (31).
Movement transmission means (18, 1) for displacing between non-contact states
9, 20, 24, 32) and the electric power supplied to the electric motor (11) are displaced in a direction in which the electric motor (11) is rotated forward to bring the friction members (28, 29) of the brake pads into contact. Control means (40) for controlling the electric motor (11) to rotate in the reverse direction to displace the friction members (28, 29) of the brake pad in a direction in which the friction members (28, 29) are brought into non-contact with the electric motor (11). Vehicle electric brake system.