JP4562849B2 - Electric brake device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates Dobu rake device collector which generates a braking force by the rotational force of the electric motor.
[0002]
[Prior art]
As a braking device for a vehicle such as an automobile, a so-called dry brake device is known in which braking force is generated by the output of an electric motor without using brake fluid.
As a dry brake device, for example, as disclosed in JP-A-60-206766, a motor built in a brake caliper is driven by a battery, and the rotational force of the motor is linearly converted and transmitted to a piston. In addition, there is an electric disc brake device that generates a braking force by pressing a brake pad against a disc rotor by the piston.
[0003]
In this type of electric disc brake device, a brake pedal depression force (or displacement amount) by a driver is detected by a sensor, and a rotation state of the electric motor is controlled by a controller according to the detected value to obtain a desired braking force. I am doing so.
In the electric disc brake device as described above, various sensors are used to detect the vehicle state such as the rotational speed of each wheel, the vehicle speed, the vehicle acceleration, the steering angle, the vehicle lateral acceleration, and the like. Based on the control of the rotation state of the electric motor based on the controller, functions such as boost control, anti-lock control, traction control and vehicle stabilization control can be incorporated relatively easily.
[0004]
[Problems to be solved by the invention]
The dry brake described above has a structure in which a rotary servo motor is linearly converted and presses a brake pad, and the electric power required for the motor to generate a braking force is currently several hundred W to 1 kW. . When this electric power is supplied from a battery mounted on an automobile, the output voltage of the battery is low (for example, 12V or 36V), so the current value of the current supplied to the motor becomes very large, and the battery There was a problem that the power loss on the cable leading to the motor increased.
[0005]
In addition, in order to reduce the size and weight of the brake caliper in consideration of the mountability of the vehicle, it is necessary to reduce the size of the motor built in the brake caliper. However, if the motor is reduced in size, the torque will be reduced. A reduction gear is required. In order to perform a braking operation to obtain a necessary braking force when this reduction gear is provided, the motor is required to rotate at a high speed, and therefore it is necessary to supply a high voltage to the motor.
The present invention has been made in view of such circumstances, and by boosting the output voltage of the battery and supplying power to the motor with the current value of the current flowing through the cable lowered, it is possible to reduce the power loss on the cable leading to the motor, and an object thereof is to provide a can collector Dobu rake device to meet the demand for size and weight of the brake caliper.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 in order to achieve the above object, drives the brake generating a braking force based on the driving force of the motors, a battery, said motor based on the output voltage of said battery in the electric brake system and a motor driving circuit, the provided between the battery and the motor drive circuit, have a booster circuit configured to boost the voltage supplied from said battery, said during vehicle parking The step-up operation of the step-up circuit is stopped, and the output voltage of the battery is supplied to the motor drive circuit .
[0007]
According to Dobu rake device electrodeposition according to claim 1, because it has a boosting circuit for boosting a voltage supplied from the battery between the battery side and the motor drive circuit to a predetermined level, the high voltage to the motor drive circuit can be supplied, and therefore, it is possible to reduce the power loss on the cable leading to the motor from the battery, it is possible to meet demands for size and weight of the brake.
[0008]
The invention according to claim 2, in Dobu rake device electrodeposition according to claim 1, wherein the booster circuit is characterized in that provided in the vicinity of the battery.
[0009]
According to the invention described in claim 2, in Dobu rake device electrodeposition according to claim 1, since the booster circuit was provided in the vicinity of the battery as much as possible the cable a low voltage and a large current flows, The power loss in the cable connected between the booster circuit and the battery can be reduced.
[0010]
According to a third aspect of the present invention, in the electric brake device according to the first or second aspect , the vehicle stop detection means for detecting the stop of the vehicle, and the stop of the vehicle is detected by the vehicle stop detection means. And control means for controlling to stop the boosting operation of the booster circuit.
[0011]
According to the invention described in claim 3, stops at Dobu rake device electrodeposition according to claim 1, the boosting operation of the boosting circuit by the control means when a stop of the vehicle is detected by the vehicle stop detection means Thus, when a large braking force is not required when the vehicle is stopped, the power consumption required for the boosting operation in the boosting circuit can be reduced, and the life of the battery can be increased.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of an electric disk brake device according to an embodiment of the present invention. In FIG. 1, an electric disc brake device according to a first embodiment of the present invention includes a battery 2 mounted on a vehicle 1 and a brake caliper that includes a motor and generates a braking force based on the driving force of the motor. 5, a booster circuit 3 that boosts and outputs a voltage (for example, 12V or 36V) supplied from the battery 2 to a predetermined level (for example, 300V), and a motor that receives the output voltage of the booster circuit 3 and drives the motor And a drive circuit 4. The booster circuit 3 and the motor drive circuit 4 are controlled by a controller (not shown) based on, for example, the depression amount (displacement amount) of the brake pedal.
[0013]
The booster circuit 3 is provided in the vicinity of the battery 2, and the cable connecting the battery 2 and the booster circuit 3 is made as short as possible.
In the above configuration, when the brake is operated, the boosting operation of the booster circuit 3 is started by a control signal output from a controller (not shown) based on the operation signal of the brake pedal. A high voltage obtained by boosting the output voltage is supplied, and the motor drive circuit 4 drives the motor in the brake caliper 5 with the high voltage.
[0014]
In this embodiment, the cable connecting the battery 2 and the booster circuit 3 is made as short as possible, and the power supply cable from the booster circuit 3 to the brake caliper 5 is long, but the brake caliper Since the voltage supplied to the motor in 5 is a high voltage, the current value of the current flowing through the cable can be small, and the power loss of the cable is small. As a result, the diameter of the cable for wiring can be reduced.
Further, since the cable connecting the battery 2 and the booster circuit 3 through which a large current flows is made as short as possible, there is an effect of reducing electromagnetic noise.
[0015]
As the connection form of the battery 2, the booster circuit 3, the motor drive circuit 4, and the brake caliper 5 in the electric disk brake device shown in FIG. 1, there are those shown in FIGS. In the connection form shown in FIG. 2, the booster circuit 3 and the motor drive circuit 4 are configured to control four brake calipers 5. In this connection form, independent brake control cannot be performed for each wheel.
In the connection form shown in FIG. 3, four motor drive circuits 4 are provided, and the four motor drive circuits 4 are connected to the four brake calipers 5 so as to correspond one-to-one. In this connection form, independent brake control can be performed for each wheel.
[0016]
In the connection form shown in FIG. 4, in consideration of fail-safe, the booster circuit 3 is further provided on the motor drive circuit 4 in a one-to-one correspondence with the connection form shown in FIG. 3. By comprising in this way, the danger that all the brakes provided for each wheel may become inoperable can be avoided.
Further, in the connection form shown in FIG. 5, two booster circuits 3 are provided, and one of the two booster circuits 3 and 3 is connected to one pair of brake calipers located on the vehicle 1 diagonally. 5 (F.R), 5 (R.L) and another booster circuit 3 corresponding to the other pair of brake calipers 5 (R.R) and 5 (F.L), respectively, Each brake caliper 5 is connected to each brake caliper 5 via a motor drive circuit 4 provided in a one-to-one correspondence.
[0017]
In this connection mode, even when one booster circuit fails, the brake caliper 5 on the diagonal line operates if the other booster circuit is operating normally, so that the vehicle is difficult to spin and effective braking is achieved. It becomes possible.
According to the electric disc brake device according to the first embodiment, the booster circuit that boosts the voltage supplied from the battery to a predetermined level is provided between the battery side and the motor drive circuit. A voltage can be supplied. Therefore, power loss on the cable from the battery to the motor can be reduced, and a demand for a smaller and lighter brake caliper can be met.
[0018]
Further, according to the present embodiment, not only the power loss of the cable can be reduced, but also a stable voltage can be supplied to the motor drive circuit 4 by the booster circuit 3, so that the control is performed regardless of the output voltage of the battery 2. Power can be generated.
[0019]
The configuration of an electric disc brake device according to the second embodiment of the present invention is shown in FIG. The electric disc brake device according to the present embodiment differs from the electric disc brake device according to the first embodiment shown in FIG. 1 in terms of configuration in that a battery for supplying voltage to the booster circuit 3 is used as a power battery. 2-1 (for power: 36V), 2-2 (for weak electricity: 12V), provided, and voltage can be supplied to the booster circuit 3 from any of these batteries. Since the configuration of is the same, redundant description is omitted.
[0020]
In other words, in a car equipped with two types of batteries, 36V for power and 12V for low power, when a 36V battery fails or a trouble such as disconnection of a cable or disconnection of a battery terminal occurs, Supply power to the brake caliper. 6 is a diode. This is possible because the booster circuit 3 is provided. Note that not only the battery but also the output of the generator may be supplied to the brake caliper via the booster circuit 3.
According to the electric disk brake device of the present embodiment, stable braking is possible regardless of fluctuations in the input voltage. A 36V battery or a 12V battery can be used, and by using both batteries, a braking force can be reliably obtained and safety can be improved.
[0021]
Next, FIG. 7 shows an example of a specific configuration of the booster circuit in the electric disc brake device according to each embodiment of the present invention. In the figure, in the booster circuit, a coil 8 and a transistor 7 as a switching element are connected in series between input terminals 21 and 22 to which a battery voltage is applied. The collector of the transistor 7 is connected to the output terminal 23 via the diode 9, and the emitter is connected to the output terminal 24. A capacitor 10 is connected between the cathode of the diode 9 and the emitter of the transistor 7.
[0022]
In the above configuration, when the battery voltage applied between the input terminals 21 and 22 is turned on by causing the transistor 7 to be turned on, current is passed through the coil 8, energy is accumulated in the coil 8, and the transistor 7 is turned off. The voltage at the collector of the transistor rises, a charging current flows into the capacitor 10 via the diode 9, and the capacitor 10 is charged, so that a stable high voltage is generated between the output terminals 23 and 24.
[0023]
Here, when the control of the boosting operation of the booster circuit is disabled, that is, when the switching control of the transistor 7 by a controller (not shown) is disabled due to the malfunction of the transistor 7 or other causes, the coil 8 and the diode 9 through 36 can be supplied to the motor in the brake caliper, so that the brakes will not completely fail. When the reduction ratio of the motor in the brake caliper is large, the boosting operation of the boosting circuit is not performed, so that the rotation speed does not increase and the brake operation speed becomes slow, but the braking force generated when the rotation stops is large. . When the reduction ratio of the motor in the brake caliper is small, the braking force is fast, but the generated braking force is small.
[0024]
In the electric disc brake device according to each embodiment of the present invention, a braking force (a braking force sufficient to stop the vehicle in the same manner as the parking brake in the braking operation by the output voltage of the battery without boosting by the booster circuit). For example, the braking force that can be stopped at a 30 percent gradient) can be generated, and the braking force required for ABS (Anti brake System) operation, VDC (Vehicle Dynamics Control) operation and sudden braking required when the vehicle is running, and the brake operation speed. Therefore, a brake caliper having motor characteristics and a reduction ratio that requires the boosting operation of the boosting circuit is required.
[0025]
With this configuration, when the boosting circuit is not performing a boosting operation, the braking force necessary for stopping the vehicle by the battery voltage can be obtained, so that the booster circuit is boosted when the booster circuit fails. It is possible to improve safety when parking is not performed.
The booster circuit is not limited to the circuit shown in FIG. 7, and various known circuits such as a DC-DC converter can be used.
[0026]
The configuration of an electric disc brake device according to the third embodiment of the present invention is shown in FIG. The electric disc brake device according to the present embodiment is characterized in that the boosting operation of the booster circuit in the electric disc brake device is stopped when the vehicle is in a stopped state. As shown in FIG. 8, the electric disc brake device according to the present embodiment includes a vehicle stop detection unit 30 that detects the stop of the vehicle, and a booster circuit 3 when the vehicle stop detection unit 30 detects the stop of the vehicle. Control means 32 for controlling to stop the step-up operation.
[0027]
In order to maintain a high voltage by the boosting operation of the booster circuit, a small amount of power is consumed even when no braking force is generated. Therefore, when the automobile has not been driven for a long time, such as when parking, it is desirable not to perform the boosting operation of the booster circuit from the viewpoint of reducing power consumption. Therefore, as a condition for performing the boosting operation of the booster circuit 3,
(1) When the key switch is ON (2) When the automatic parking position is released (3) When the parking brake is released (4) When the brake pedal is depressed (5) Wheel rotation is detected When all the conditions are satisfied.
[0028]
The conditions for stopping the boosting operation of the booster circuit 3 are as follows:
(6) When the key switch is OFF (7) When the brake pedal is not depressed (8) When all the conditions are satisfied when the rotation of the wheel is not detected. That is, when the vehicle stop detecting means 30 detects that all the conditions (6) to (8) are satisfied, the control means 32 outputs a control signal for instructing the boosting circuit 3 to stop the boosting operation. The boosting operation in the booster circuit 3 is stopped.
[0029]
According to the electric disc brake device of the third embodiment of the present invention, when the stop of the vehicle is detected by the vehicle stop detecting means 30, the boosting operation of the boosting circuit is stopped by the control means 32. Since the control is performed, when a large braking force is not required when the vehicle is stopped, the power consumption required for the boosting operation in the boosting circuit can be reduced, and the life of the battery can be extended.
[0030]
【The invention's effect】
As described above, according to the electric brake device of the first aspect, the motor has a booster circuit that boosts the voltage supplied from the battery to a predetermined level between the battery side and the motor drive circuit. A high voltage can be supplied to the drive circuit. Therefore, power loss on the cable from the battery to the motor can be reduced, and the demand for a smaller and lighter brake can be met. Further, since the boosting operation of the boosting circuit is stopped when the automobile is parked and the output voltage of the battery is supplied to the motor drive circuit, safety can be improved during parking.
[0031]
According to the invention described in claim 2, in Dobu rake device electrodeposition according to claim 1, since the booster circuit was provided in the vicinity of the battery as much as possible the cable a low voltage and a large current flows, The power loss in the cable connected between the booster circuit and the battery can be reduced.
[0032]
According to the invention described in claim 3, in Dobu rake device electrodeposition according to claim 1, when the stop of the vehicle is detected by the vehicle stop detecting means, stops the boosting operation of the boosting circuit by the control means Therefore, when a large braking force is not required when the vehicle is stopped, the power consumption required for the boosting operation in the boosting circuit can be reduced, and the life of the battery can be increased.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of an electric disc brake device according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing an example of a connection form from a booster circuit to a brake caliper in the electric disk brake device shown in FIG.
3 is a block diagram showing an example of a connection form from a booster circuit to a brake caliper in the electric disk brake device shown in FIG. 1. FIG.
4 is a block diagram showing an example of a connection form from a booster circuit to a brake caliper in the electric disk brake device shown in FIG. 1. FIG.
5 is a block diagram showing an example of a connection form from a booster circuit to a brake caliper in the electric disk brake device shown in FIG. 1. FIG.
FIG. 6 is a block diagram showing a configuration of a main part of an electric disc brake device according to a second embodiment of the present invention.
FIG. 7 is a circuit diagram showing an example of a specific configuration of a booster circuit in the electric disc brake device according to each embodiment of the present invention.
FIG. 8 is a block diagram showing a configuration of a main part of an electric disc brake device according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle 2 Battery 3 Booster circuit 4 Motor drive circuit 5 Brake caliper 30 Vehicle stop detection means 32 Control means

Claims (3)

In an electric brake device having a brake that generates a braking force based on a driving force of a motor, a battery, and a motor driving circuit that drives the motor based on an output voltage of the battery,
Provided between said battery motor drive circuit, have a booster circuit configured to boost the voltage supplied from the battery,
An electric brake device characterized in that when the automobile is parked, the boosting operation of the boosting circuit is stopped and the output voltage of the battery is supplied to the motor drive circuit .   The electric brake device according to claim 1, wherein the booster circuit is provided in the vicinity of the battery. Vehicle stop detection means for detecting stop of the vehicle;
3. The electric brake device according to claim 1, wherein when the vehicle stop is detected by the vehicle stop detection unit, the boosting operation of the boosting circuit is stopped.

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