阅读说明：本技术 制动装置及电动制动装置、以及电机控制装置 (Brake device, electric brake device, and motor control device ) 是由 藤田治彦 于 2019-02-20 设计创作，主要内容包括：制动装置包括从第一蓄电装置接受电力供给而进行驱动的电动机、以及能够蓄电比第一蓄电装置高的电压的第二蓄电装置,在电动机被请求比规定的转速高的转速下的驱动的情况下,从第二蓄电装置向电动机进行电力供给。(The brake device includes a motor that is driven by receiving power supply from the first power storage device, and a second power storage device that can store a voltage higher than that of the first power storage device, and when the motor is requested to be driven at a rotation speed higher than a predetermined rotation speed, power is supplied from the second power storage device to the motor.)

1. A brake apparatus, characterized in that the brake apparatus comprises:

a brake mechanism that generates a braking force by a motor that is driven by receiving power supply from the first power storage device; and

a second power storage device configured to supply electric power to the motor when a voltage of the first power storage device is equal to or lower than a predetermined value,

the second power storage device is capable of storing a voltage higher than that of the first power storage device,

the second power storage device supplies electric power to the electric motor when the electric motor is requested to be driven at a rotation speed higher than a predetermined rotation speed.

2. The brake apparatus of claim 1,

the case where the motor is requested to be driven at a rotational speed higher than the predetermined rotational speed is a time of emergency braking.

3. An electric brake apparatus, characterized by comprising:

a brake mechanism that transmits thrust to a piston that moves a brake pad pressed against a brake disc by a motor that is driven by receiving power supply from a first power storage device; and

a second power storage device configured to supply electric power to the motor when a voltage of the first power storage device is equal to or lower than a predetermined value,

the second power storage device is capable of storing a voltage higher than that of the first power storage device,

the second power storage device supplies electric power to the electric motor when the electric motor is requested to be driven at a rotation speed higher than a predetermined rotation speed.

4. An electric brake apparatus according to claim 3,

the case where the motor is requested to be driven at a rotational speed higher than the predetermined rotational speed is a time of emergency braking.

5. An electric brake apparatus according to claim 3,

the case where the motor is requested to be driven at a rotational speed higher than a predetermined rotational speed is when the piston is pushed toward the brake disc from a position farthest from the brake disc.

6. A motor control device for switching between a first power storage device and a second power storage device capable of storing a voltage higher than that of the first power storage device to supply electric power to an electric motor,

the motor control device supplies electric power from the second power storage device to the electric motor when the electric motor is requested to be driven at a rotation speed higher than a predetermined rotation speed.

Technical Field

The present invention relates to a brake device and an electric brake device that generate a braking force by a motor, and a motor control device.

Background

For example, patent document 1 discloses an electric brake device including a piston and a caliper (caliper) formed by incorporating a caliper body with a spherical ramp mechanism that converts rotation of a motor into linear motion and transmits the linear motion to the piston, the electric brake device operating the spherical ramp mechanism in accordance with the rotation of the motor to advance the piston and pressing a brake pad (brake pad) against a disc rotor (disk rotor) to generate a braking force.

Disclosure of Invention

Problems to be solved by the invention

In order to increase the response speed of the brake device, it is necessary to increase the power supply current of the power supply for driving the motor, which leads to an increase in the component cost of the device.

Means for solving the problems

The purpose of the present invention is to provide a brake device and an electric brake device, and a motor control device, which can prevent or suppress an increase in power supply current and can achieve a higher speed of response.

An embodiment of the present invention is characterized by including a motor that is driven by receiving power supply from a first power storage device, and a second power storage device that can store a voltage higher than that of the first power storage device, and when the motor is requested to be driven at a rotation speed higher than a predetermined rotation speed, power is supplied from the second power storage device to the motor.

According to one embodiment of the present invention, it is possible to increase the response speed of the brake device while preventing or suppressing an increase in the power supply current.

Drawings

Fig. 1 is a block diagram showing a main part of an electric brake device according to a first embodiment of the present invention.

Fig. 2 is a block diagram showing a main part of a motor control device of the electric brake device of fig. 1.

Fig. 3 is a diagram showing an example of the timing of switching between the first power storage device and the second power storage device in the electric brake device of fig. 1, where (a) is a graph showing a change with time in the power supply voltage of each of the first power storage device and the second power storage device, and (b) is a graph showing a change with time in the power supply voltage output from the main control unit to the motor drive unit of the caliper-side control unit.

Fig. 4 is a block diagram showing a main part of a brake device according to a second embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a block diagram showing a main part of an electric brake device 1 according to a first embodiment of the present invention. Fig. 2 is a block diagram showing a main part of motor control device 20 of the electric brake device of fig. 1. The electric brake device 1 is a brake device that applies a braking force to each wheel by sandwiching a brake disc D that rotates together with each wheel (not shown) of a vehicle. As shown in fig. 1, the electric brake device 1 includes a brake mechanism 10 for each wheel to be braked by the electric brake device 1, and the brake mechanism 10 includes brake pads 2 and 3 pressed against a disc D and a piston 4 for moving the brake pads 2 and 3. The brake mechanism 10 further includes an electric motor 11 and a rotation-linear motion conversion mechanism 12 that converts rotation of the electric motor 11 into linear motion and transmits the linear motion to the piston 4.

As described above, the electric brake device 1 includes the brake mechanism 10 for each wheel to be braked by the electric brake device 1, and typically, there are a plurality of brake mechanisms 10 (for example, for all four wheels in the case of a four-wheel vehicle). In the present specification, for the sake of simplicity of illustration and description, description will be given mainly of the electric brake device 1 associated with one brake mechanism 10 and its constituent elements. In this case, unless otherwise specified, the same applies to the description relating to one brake mechanism 10 as to any other brake mechanism.

The electric brake device 1 further includes a motor control device 20 that controls the operation of the electric motor 11, and first and second power storage devices 27 and 28 that supply electric power to the electric motor 11 via the motor control device 20, and the second power storage device 28 can store a voltage higher than the voltage of the first power storage device 27. As described in detail below, the motor control device 20 is configured to switch between the first power storage device 27 and the second power storage device 28 to supply electric power to the electric motor 11.

In the present embodiment, the first power storage device 27 is constituted by a power storage device (for example, a lead-acid battery) serving as a vehicle power supply, and the second power storage device 28 is constituted by an Electric Double Layer Capacitor (EDLC). The voltage of first power storage device 27 is, for example, a voltage in the range of 12V to 14V, and second power storage device 28 can store power such that the voltage thereof is, for example, a voltage in the range of 24V to 30V.

Here, in fig. 1, the electric motor 11 and the rotation-to-linear motion conversion mechanism 12 are shown outside the caliper 5 as separate blocks from the caliper 5, but this is merely to schematically show the electric motor 11 and the rotation-to-linear motion conversion mechanism 12 as functional blocks, and the spatial arrangement structure of these components 11 and 12 is not limited at all. In the brake device 1, the electric motor 11 and the rotation-to-direct motion conversion mechanism 12 are provided in the caliper 5 together with the piston 4. The brake mechanism 10 in the present embodiment may include any other suitable component (for example, a speed reduction mechanism that reduces the rotation of the electric motor 11) in order to have a function of a brake device that applies a braking force to each wheel by sandwiching the disc rotor D that rotates together with the wheel.

As shown in fig. 2, the motor control device 20 included in the electric brake device 1 includes a main control unit 21 and a caliper control unit 41, and the main control unit 21 includes first and second input side switching circuits 22 and 23, first and second output side switching circuits 24 and 25, and a controller 26. The caliper control unit 41 includes a motor drive unit 42 and a controller 36.

Here, the controller 26 and/or the controller 36 may be connected to a vehicle data bus (not shown), and may exchange various information including information necessary for controlling the motor drive unit 42, which will be described later, with each other and/or with another Electronic Control Unit (ECU) by communication via the vehicle data bus.

In the main control section 21, the first and second input-side switching circuits 22 and 23 are circuit devices having at least two states of a conducting state (hereinafter, also referred to as an ON (ON) state or simply as ON) and a non-conducting state (hereinafter, also referred to as an OFF (OFF) state or simply as OFF), and these two states are switched by control signals 32 and 33 from the controller 26, respectively.

The first power storage device 27 is connected to a power supply line 29 in the main control unit 21 via the first input-side switching circuit 22, and the second power storage device 28 is connected to the power supply line 29 in the main control unit 21 via the second input switching circuit 23. Therefore, when first input side switching circuit 22 is turned on and second input side switching circuit 23 is turned off by control signals 32 and 33 from controller 26, the voltage from first power storage device 27 is input to power supply line 29. When first input side switching circuit 22 is turned off and second input side switching circuit 23 is turned on by control signals 32 and 33 from the controller, the voltage from second power storage device 28 is input to power supply line 29.

In the motor control device 20, a power supply line 30 that outputs a power supply voltage from the main control section 21 to the caliper control section 41 is connected to a power supply line 29 in the main control section 21. Although not shown in fig. 2, the motor control device 20 includes another caliper control section similar to the caliper control section 41, and the power supply line 25 that outputs the power supply voltage to the caliper control section is connected to the power supply line 29 in the main control section 21.

For example, in the case where the electric brake device 1 includes the right rear wheel brake mechanism 10 and the left rear wheel brake mechanism 10, the caliper control unit 41 shown in fig. 2 is a control unit for one of the left and right rear wheel brake mechanisms 10 including the electric motor 11, and the other caliper control unit is a control unit for the other rear wheel brake mechanism 10. In the case where the electric brake device 1 further includes a plurality of brake mechanisms, the motor control device 20 may include a caliper control unit similar to the caliper control unit 41, which is connected to the main control unit 21 via each output-side switching circuit, in correspondence with each brake mechanism 10.

Here, although the present invention is not limited to the specific configuration of the first and second input side switching circuits 22 and 23, it is preferable that these switching circuits 22 and 23 are formed of semiconductor switching elements (for example, MOS-FETs). For example, when each of the switching circuits 22 and 23 is formed of a MOS-FET, the control signals 32 and 33 correspond to gate drive voltages for controlling on/off of the corresponding MOS-FET.

The controller 26 and the controller 36 are preferably configured as a well-known microcomputer system having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an I/O (Input/Output) interface, and the like. However, as long as the controller 26 and/or the controller 36 can perform the motor drive control described in detail later, a part or the whole of them may be configured by any appropriate hardware or software, or a combination thereof.

In the electric brake device 1, the electric motor 11 is constituted by, for example, a three-phase synchronous motor. Correspondingly, the motor drive unit 42 of the caliper control unit 41 is configured by a three-phase inverter device that converts the dc power supplied via the power supply line 30 into three-phase ac power and outputs the three-phase ac power to the electric motor 11. The controller 36 outputs a switching control signal 37 for controlling on/off of a semiconductor switching element (not shown) constituting the three-phase inverter device to the motor drive unit 42, and the motor drive unit 42 drives the motor 11 in accordance with the switching control signal 37. At this time, the controller 26 of the main control unit 21 corresponds to a command signal corresponding to a target value of an operation parameter of the motor 11 such as the rotational speed of the motor 11, for example, and the controller 36 controls the motor drive unit 42 based on the command signal 31.

However, the motor drive unit 42 may be directly on-off controlled by the controller 26 of the main control unit 21.

The electric brake device 1 configured as described above operates as follows. In the following description, the voltage of the first power storage device 27 is a voltage in the range of 12V to 14V, and the second power storage device 28 is stored so that the voltage thereof becomes a voltage in the range of 24V to 30V.

First, in the electric brake device 1, during normal driving, the controller 26 turns on the first input side switching circuit 22 and turns off the second input side switching circuit 23 by the control signals 32, 33. At this time, the voltage of first power storage device 27 is supplied to power supply line 29. In this state, for example, in response to an operation of a brake pedal by a driver of the vehicle, the voltage of the first power storage device 27 is output from the control unit 21 to the motor drive unit 42 of the caliper control unit 41 through the power supply line 30. At the same time, the controller 26 of the main control unit 21 outputs the command signal 31 corresponding to the predetermined rotation speed to the controller 36 of the caliper-side control unit 41, and the controller 36 operates the motor drive unit 42 based on the command signal 31, whereby the motor 11 rotates at the predetermined rotation speed. Then, the rotation of the electric motor 11 driven by the supply of electric power from the first power storage device 27 is converted into linear motion by the rotation-linear motion conversion mechanism 12 of the brake mechanism 10, and thrust is transmitted to the piston 4 by the linear motion, so that the brake pads 2 and 3 moved by the piston 4 press the disc D to generate braking force.

In the electric brake device 1, the second power storage device 28 first has a function as a backup power supply for preventing a power supply voltage from being reduced due to a defect or the like occurring in the first power storage device 27. Specifically, when the voltage of the first power storage device 27 is equal to or lower than a predetermined value (for example, 10V), the controller 26 turns off the first input side switching circuit 22 and turns on the second input side switching circuit 23 by the control signals 32 and 33. As a result, the voltage of second power storage device 28 is supplied to power supply line 29. In this state, for example, in response to an operation of a brake pedal by a driver, a voltage of second power storage device 28 is output from main control unit 21 to motor drive unit 42 of caliper control unit 41 through power supply line 30. At the same time, the controller 26 of the main control unit 21 outputs the command signal 31 corresponding to the predetermined rotation speed to the controller 36 of the caliper-side control unit 41, and the controller 36 operates the motor drive unit 42 based on the voltage of the second power storage device 28 and the command signal 31, thereby rotating the electric motor 11 at the predetermined rotation speed. In this way, the rotation of the electric motor 11 driven by the supply of electric power from the second power storage device 28 generates a braking force by the operation of the brake mechanism 10 as described above.

When the electric motor 11 is requested to be driven at a rotation speed higher than the predetermined rotation speed, the electric brake device 1 supplies electric power from the second power storage device 28 to the electric motor 11. That is, when the motor 11 is requested to be driven at a rotation speed higher than the predetermined rotation speed, the controller 26 turns off the first input side switching circuit 22 and turns on the second input side switching circuit 23 by the control signals 32 and 33. As a result, the voltage of second power storage device 28 is supplied to power supply line 29. In this state, the voltage of second power storage device 28 is output from main control unit 21 to motor drive unit 42 of caliper control unit 41 via power supply line 30. At the same time, the controller 26 of the main control unit 21 outputs the command signal 31 corresponding to the requested rotation speed higher than the predetermined rotation speed to the dedicated controller 36 of the caliper-side control unit 41, and the controller 36 operates the motor drive unit 42 based on the voltage of the second power storage device 28 and the command signal 31, whereby the electric motor 11 rotates at the requested rotation speed higher than the predetermined rotation speed. In this way, the rotation of the electric motor 11 driven by the supply of electric power from the second power storage device 28 generates a braking force by the operation of the braking mechanism 10 as described above.

Here, the case where the motor 11 is requested to be driven at a rotation speed higher than the predetermined rotation speed includes the time of emergency braking. The emergency braking may be Automatic Emergency Braking (AEB) in which an obstacle is detected using, for example, a radar, a camera, an infrared laser, or the like, and braking control is automatically performed when the obstacle approaches the obstacle. Further, the emergency braking may include a case where the urgency is determined based on an operation amount and/or a pedal speed of a brake pedal by a driver of the vehicle. The case where the motor 11 is requested to be driven at a rotational speed higher than the predetermined rotational speed may include, for example, a case where the piston 4 is pushed toward the disk D from a position farthest from the disk D, such as when the electric brake device 1 is started, in which the piston 4 is retracted from the brake pad 2 due to replacement of the brake pads 2 and 3, or the like.

Fig. 3 shows an example of the timing of switching between first power storage device 27 and second power storage device 28. Fig. 3(a) is a graph showing a change over time in the voltage 52 of the first power storage device 27 and the voltage 51 of the second power storage device 28, and fig. 3(b) is a graph showing a change over time in the power supply voltage (in other words, the motor drive voltage) output from the main control unit 21 to the motor drive unit 42 of the caliper-side control unit 41 via the power supply line 30. In fig. 3(a) and (B), the period denoted by reference sign a corresponds to a period during normal driving of the electric brake device 1 or during non-operation of the electric brake device 1, and the period denoted by reference sign B corresponds to a period during emergency braking.

First, the voltage 52 of the first power storage device 27 is constant throughout the entire period (about 13.5V in the illustrated example). Then, in the initial period a (0 to 1 second), the first input side switching circuit 22 is in the on state and the second input side switching circuit 23 is in the off state, and as shown in fig. 3(b), the motor drive voltage 53 becomes the voltage 52 of the first power storage device 27. As shown in fig. 3 a, in this period a, voltage 51 of second power storage device 28 is also constant (28V in the illustrated example).

In a period B (about 1 to 1.2 seconds) following the period a, the first input side switching circuit 22 is turned off, and the second input side switching circuit 23 is turned on. Thereby, the power supply for supplying electric power to the electric motor 11 is switched to the second power storage device 28, and as shown in fig. 3(b), the motor drive voltage 53 becomes the voltage 51 of the second power storage device 28. Here, since the second power storage device 28 is formed of an Electric Double Layer Capacitor (EDLC), as shown in fig. 3(a), the voltage 51 (and hence the motor drive voltage 53) thereof decreases due to discharge as the period B continues. In the illustrated example, at the end of this period B, the voltage 51 of the second power storage device 28 becomes 24V.

In the next period a (about 1.2 to 3 seconds), the first input side switching circuit 22 is turned on again, the second input side switching circuit 23 is turned off, and the power supply that supplies electric power to the motor 11 is switched to the first power storage device 27. Therefore, as shown in fig. 3(b), motor drive voltage 53 becomes voltage 52 of first power storage device 27. On the other hand, second power storage device 28 is charged at the same time as the start of period a, and the voltage thereof returns to the initial voltage (28V in the illustrated example) at a time point (about 2 seconds in the illustrated example) after the elapse of the predetermined period.

Thereafter, switching between first power storage device 27 and second power storage device 28 is repeated according to period a and period B.

Here, in the conventional brake device, since the motor is driven by a single power supply voltage of, for example, 12V, it is necessary to increase the power supply current of the power supply for driving the motor in order to increase the rotation speed of the motor and thereby to increase the response speed of the brake device. If the current is increased, the copper loss is increased, and in order to reduce the copper loss, it is necessary to increase the size of the drive motor and/or the inverter device for the motor, and therefore the component cost is also increased.

On the other hand, in the brake device (electric brake device 1) and the motor control device (motor control device 20) according to the present invention, since the electric motor 11 that receives electric power from the first power storage device 27 and is driven and the second power storage device 28 that can store a voltage higher than that of the first power storage device 27 are provided, and when the electric motor 11 is requested to be driven at a rotation speed higher than the predetermined rotation speed, electric power is supplied from the second power storage device 28 to the electric motor 11, it is possible to prevent or suppress an increase in the power supply current, to drive the electric motor 11 at a high rotation speed without causing voltage saturation due to the induced voltage of the electric motor 11, and to increase the response of the electric brake device 1 as needed.

In order to reliably avoid collision during emergency braking, a high-speed response of the brake device (electric brake device 1) according to the present invention is particularly desirable.

Further, in the brake device (electric brake device 1) and the motor control device (motor control device 20) according to the present invention, the second power storage device 28 supplies electric power to the electric motor 11 when the voltage of the first power storage device 27 is equal to or lower than a predetermined value, in other words, in the conventional brake device, the power storage device functioning as a backup power supply for use when the first power storage device 27 is defective is used as the second power storage device 28 according to the present invention while maintaining the same function as the conventional one. Therefore, from this viewpoint, the present invention can also achieve a higher response speed of the electric brake device 1 described above without increasing the component cost of the conventional brake device. In addition, since the conventional backup power supply is basically prepared for an event that occurs only rarely, such as a defect in first power storage device 27, the present invention is also desirable from the viewpoint of effective use of components.

In particular, in electric brake device 1 and motor control device 20 according to the present embodiment, second power storage device 28 is formed of an Electric Double Layer Capacitor (EDLC), and since no chemical reaction is involved in charging and discharging, second power storage device 28 having excellent durability can be formed.

In the electric brake device 1 and the motor control device 20 according to the present embodiment, since the motor control device 20 drives the electric motor 11 through a closed circuit separated from an external factor, when the charging voltage of the second power storage device 28 is set to about 24V to 30V with respect to the voltage of the first power storage device 27 of about 12V which is equivalent to the conventional voltage, the motor drive unit 42 may have a voltage withstanding performance (for example, 40V) equivalent to that of the motor drive unit (specifically, the inverter device) in the conventional brake device. In view of this, the electric brake device 1 and the motor control device 20 according to the present embodiment can also achieve the above-described speeding up of the response of the electric brake device 1 without increasing the component cost of the conventional brake device and the motor control device.

Further, in the electric brake device 1 and the motor control device 20 according to the present embodiment, the conventional motor control device having the power storage device functioning only as a backup power supply includes the first and second input side switching circuits 22 and 23. These switching circuits 22 and 23 (preferably semiconductor switching elements) may have the same withstand voltage performance as that of the corresponding components used in the conventional motor control device, and are similar to the motor drive unit 42 described above. Therefore, the motor control device 20 according to the present embodiment can be realized by merely changing the control timing of the first and second input-side switching circuits 22 and 23 by the controller 26, without changing the hardware configuration and increasing the component cost from the conventional motor control device.

In the present embodiment, a high-speed response of the electric brake device 1 is particularly desirable in order to quickly generate a braking force even when the piston 4 is advanced from the position farthest from the disc D toward the disc D.

Next, a brake device 60 according to a second embodiment of the present invention will be described mainly focusing on differences from the first embodiment with reference to fig. 4. The same reference numerals and the same names are given to the same or corresponding portions as those in the first embodiment.

The brake device 60 is a hydraulic brake device that applies a braking force to each wheel by sandwiching the disc rotor D that rotates together with each wheel (not shown) of the vehicle. The brake device 60 includes a brake mechanism 61 for each wheel to be braked by the brake device 60, and the brake mechanism 61 includes: the brake pads 2 and 3 pressed against the disc D, and the piston 4 slidably provided on the inner periphery of the hydraulic cylinder 66 of the caliper 5 to move the brake pads 2 and 3.

The brake device 60 further includes: a master cylinder 67 for generating hydraulic pressure to be supplied to the hydraulic cylinder 66 of the caliper 5, and an electric power multiplying device 70 for transmitting the hydraulic pressure to the master cylinder 67. The electric force multiplier 70 includes: an electric motor 11 that drives an assist piston (not shown) capable of adjusting the hydraulic pressure in the master cylinder 67, and a rotation-linear motion conversion mechanism 72 that converts the rotation of the electric motor 11 into linear motion and transmits the linear motion to the assist piston. The electric power multiplier 70 can perform various brake controls such as regenerative cooperative control, brake assist, automatic braking, and the like, by the electric motor 11 driven and controlled by the motor control device 20 described later, together with or independently of the depression operation of a brake pedal (not shown).

The brake device 60 further includes: a motor control device 20 that controls the operation of the electric motor 11, and first and second power storage devices 27 and 28 that supply electric power to the electric motor 11 via the motor control device 20.

In this way, the brake device 60 is configured to generate a hydraulic pressure in the master cylinder 67 and further generate a braking force in the brake mechanism 61 of each wheel by the electric motor 11 driven under the drive control of the motor control device 20.

Here, the electric motor 11 and the first and second power storage devices 27 and 28 of the brake device 60 are devices common to the respective corresponding components of the electric brake device 1 in the first embodiment, and the motor control device 20 in the brake device 60 realizes the same function as the motor control device 20 in the electric brake device 1 in the first embodiment with respect to switching between the first power storage device 27 and the second power storage device 28 and driving of the electric motor 11.

With the above-described configuration, the brake device 60 and the motor control device 20 achieve the same operational effects as those described above in connection with the electric brake device 1 and the motor control device of the first embodiment.

The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments are described in detail for easy understanding of the present invention, and are not limited to having all the configurations described. Further, a part of the structure of one embodiment may be replaced with the structure of another embodiment, and the structure of one embodiment may be added to the structure of another embodiment. Further, a part of the structures of the respective embodiments can be added, deleted, and replaced with other structures.

The present application claims priority from japanese patent application No. 2018-060359 filed on 3/27 of 2018. The entire disclosure of the specification, patent claims, drawings and abstract, including the japanese patent application No. 2018-060359 filed on 3/27 of 2018, is incorporated by reference in its entirety.

Description of the reference symbols

1 electric brake device (brake device), 2 and 3 brake pads, 4 pistons, 11 motors, 10 and 61 brake mechanisms, 20 motor control devices, 27 first electric storage devices, 28 second electric storage devices, 60 brake devices and D brake discs.