JP2005219615A - Electric motor control device and hydraulic brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress heating of a semiconductor switch in an electric motor control device including a circuit for low speed rotation provided with a semiconductor switch and a circuit for high speed rotation provided with a mechanical switch. <P>SOLUTION: When the temperature of the semiconductor switch is lower than a second set temperature, both of determinations in S3 and S4 become NO, and the semiconductor switch is duty-controlled so that rotational speed of the electric motor may be close to a target value in S5 to S7. When the temperature is lower than a first set temperature and higher than the second set temperature, the determination in S4 becomes YES, and the semiconductor switch is made a continuous ON state in S8. When the temperature becomes higher than the first set temperature, the determination in S3 becomes YES, and the semiconductor switch is made a continuous OFF state and the mechanical switch is made a continuous ON state in S9. As a result, the rotational speed of the electric motor can be controlled, while suppressing heating of the semiconductor switch. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric motor control device that controls the rotational speed of an electric motor and a hydraulic brake device that includes a hydraulic pressure source device that includes the electric motor control device.

In Patent Document 1, (a) a hydraulic brake that is operated by hydraulic pressure of a brake cylinder and suppresses rotation of a vehicle wheel, and (b) a hydraulic pressure source that can supply high-pressure hydraulic fluid to the brake cylinder. A device including (i) a pump, (ii) an electric motor that drives the pump, and (iii) an electric motor control device that controls the rotational speed of the electric motor by controlling a switch. A hydraulic brake device is described.
In this hydraulic brake device, since the rotation speed of the electric motor is controlled based on the vehicle speed and the brake operation state, the operating noise is reduced as compared with the case where the rotation speed is always constant. Can do.
JP-A-8-127331

  The subject of this invention is improvement of an electric motor control apparatus, for example, suppressing heat_generation | fever of a switch.

Means and effects to solve the problem

The electric motor control device according to the first aspect of the invention includes (a) a low-speed rotation circuit including a low-speed rotation switch, (b) a high-speed rotation circuit including a high-speed rotation switch, and (c) the low-speed rotation circuit. It is obtained by including a switch control unit that controls the rotational speed of the electric motor by switching the duty of the switch and switching the continuous high speed rotation switch between the continuous ON state and the continuous OFF state.
The electric motor is driven by a low-speed rotation circuit or a high-speed rotation circuit under the control of a low-speed rotation switch and a high-speed rotation switch. When driven by a circuit for low speed rotation, the electric motor has a low rotation high torque type characteristic with a large starting torque and a low rotation speed at no load, and when controlled by a circuit for high speed rotation, This is a high-rotation low-torque type characteristic in which the starting torque is smaller and the rotational speed at no load is larger than in the case of using a low-speed circuit. When driven by the low speed rotation circuit, the rotation speed or output torque of the electric motor is continuously controlled by duty control of the low speed rotation switch.

  “Duty control” is variable control when the duty ratio D {ON time / (ON time + OFF time)} is 0 or more and 1 or less (0 ≦ D ≦ 1), and the duty ratio D is greater than 0 and less than 1. (0 <D <1), 1 (continuous ON state), 0 (continuous OFF state). However, in this specification, “duty control” refers to control including making the duty ratio variable at least within a range larger than 0 and smaller than 1 (0 <D <1). Controls that are only scheduled to be either of these are not included. The continuous OFF state can also be considered as a state in which the control of the low-speed rotation switch itself is not performed.

  In the electric motor, the operating noise is lower when rotating at a low speed than when rotating at a high speed. Therefore, it is desirable to reduce the rotation speed as much as possible by controlling the low-speed rotation switch. Further, when the electric motor is usually operated in a region where the rotational speed is low, it is desirable that the rotational speed be finely controlled by duty control of the low-speed rotation switch. Furthermore, when high rotation is required, the necessity for controlling the rotation speed is often low. Further, it is possible to reduce power loss by controlling the rotation speed in the low-speed rotation circuit rather than controlling the rotation speed in the high-speed rotation circuit. For these reasons, it is appropriate that the low-speed rotation switch is duty-controlled so that the high-speed switch is switched between the continuous ON state and the continuous OFF state.

On the other hand, if the low-speed rotation switch is duty-controlled while the duty ratio D is greater than 0 and smaller than 1, heat is likely to be generated, and the temperature of the low-speed rotation switch increases. In that case, if the low-speed rotation switch is continuously turned on, the low-speed rotation switch is continuously turned off, and the high-speed rotation switch is turned on continuously, heat generation of the low-speed rotation switch can be suppressed. .
As described above, if the switch of the low-speed rotation circuit is duty-controlled, the rotation speed of the electric motor can be controlled while reducing the operating noise as much as possible. If the low-speed rotation switch is continuously turned on, or if the low-speed rotation switch is continuously turned off and the high-speed rotation switch is turned on continuously, the rotation of the electric motor is suppressed while suppressing the heat generation of the low-speed rotation switch. The speed can be controlled.

  Note that both the low-speed rotation switch and the high-speed rotation switch may be semiconductor switches, or one of them may be a semiconductor switch and the other a mechanical switch. However, as described in claim 2, it is desirable that the low-speed rotation switch for which duty control is performed be a semiconductor switch, and the high-speed rotation switch to be switched between a continuous ON state and a continuous OFF state be a mechanical switch. This is because the semiconductor switch is a non-contact switch and has higher responsiveness than a mechanical switch that is a contact switch having a movable part.

According to a third aspect of the present invention, there is provided an electric motor control device in which the switch control unit includes at least a first state in which the semiconductor switch is duty-controlled with at least the mechanical switch in a continuous OFF state, and the mechanical switch is continuously connected. By switching to a second state in which the semiconductor switch is in a continuous ON state and a third state in which the semiconductor switch is in a continuous OFF state and the mechanical switch is in a continuous ON state in the OFF state. can get.
In the first state and the second state, the electric motor is operated with the characteristics of a low rotation high torque type. In the first state, the rotation speed and output torque of the electric motor are controlled, but not in the second state. In the third state, the electric motor is operated with high rotation and low torque characteristics.

An electric motor control device according to a fourth aspect of the present invention includes a semiconductor switch state detection unit that detects a state of the semiconductor switch, and the switch control unit is configured to detect the semiconductor switch based on a detection result of the semiconductor switch state detection unit. And a semiconductor switch state-dependent control unit that controls at least one of the mechanical switch.
The semiconductor switch state detection unit detects a heat generation state of the semiconductor switch. For example, the semiconductor switch state detection unit includes a temperature detection unit that detects the temperature of the semiconductor, or the semiconductor switch continues to perform duty control (except for a continuous OFF state). Or the detected time can be detected. Since the semiconductor switch generates heat due to ON / OFF switching in duty control and the temperature becomes high, it can be estimated that the temperature of the semiconductor switch is higher when the duty control time is long than when it is short.
For example, the state in which the temperature of the semiconductor switch is higher than the set temperature is a state in which the semiconductor switch may be in an overheated state or an overheated state, and may be an abnormal state. Further, when the temperature is high, the level of abnormality of the semiconductor switch can be higher than when the temperature is low. The level of abnormality may be changed continuously or stepwise. Specifically, when the temperature is equal to or higher than the first set temperature, the abnormal level can be higher than when the temperature is lower than the first set temperature and equal to or higher than the second set temperature. Further, when the duty control duration is equal to or longer than the set time, the semiconductor switch can be in an overheated state or a state where there is a possibility of overheating, and can be in an abnormal state.

When the semiconductor switch is in an abnormal state, for example, the duty ratio D in the duty control of the semiconductor switch is set to 1 (second state), the duty ratio D is set to 0, and the mechanical switch is turned on (third). State). Thereby, heat generation of the semiconductor switch can be suppressed. In the semiconductor switch, heat generation is suppressed when the switch is continuously turned on rather than when ON / OFF switching is performed in the duty control.
Further, in the second state and the third state, when the temperature of the semiconductor switch becomes lower than the third set temperature (temperature lower than the first set temperature and the second set temperature described above), the duty control is continuously performed. When the non-existing time (the time of the continuous OFF state) exceeds the set time, it is assumed that the temperature of the semiconductor switch has been sufficiently lowered and returned to the first state.

An electric motor control device according to a fifth aspect of the invention includes an operation time ratio acquisition unit that acquires a ratio of an operation time of the electric motor to a non-operation time, and the switch control unit is acquired by the operation time ratio acquisition unit. It is obtained by including an operation time ratio dependence control unit that controls at least one of the semiconductor switch and the mechanical switch based on the result.
When the operating time ratio of the electric motor is high, the temperature of the semiconductor switch can be relatively higher than when it is low. Therefore, based on the operating time ratio of the electric motor, as described above, the semiconductor switch is continuously turned on (second state), or the semiconductor switch is continuously turned off and the mechanical switch is turned on (third state). Thus, heat generation of the semiconductor switch can be suppressed.
In the second state or the third state, when the non-operation time of the electric motor exceeds the set time, it can be switched to the first state. In this case, when switching from the second state to the first state, the threshold value for the non-operation time can be made smaller than when switching from the third state to the first state. Further, in the third state, when the non-operation time of the electric motor exceeds the first set time, the first state is switched, and when the second set time shorter than the first set time is exceeded, the second state is switched. It can also be made.

  The electric motor control device includes an acquisition unit that acquires a ratio of the duty control time to the non-duty control time for the semiconductor switch, or the time during which the semiconductor switch is duty controlled with a value in which the duty ratio is larger than 0 and smaller than 1. It is possible to include an acquisition unit that acquires a ratio with respect to the time when the duty ratio is 0 or 1, and based on these ratios, control similar to that described above can be performed.

The electric motor control device according to any one of claims 1 to 5 is an electric motor of a hydraulic pressure source device capable of supplying high-pressure hydraulic fluid to a brake cylinder of a hydraulic brake that suppresses rotation of a vehicle wheel by the operation of the electric motor. The present invention can be applied to an electric motor control device that controls a motor. The hydraulic pressure source device may include a pump operated by an electric motor or include a hydraulic cylinder.
The hydraulic pressure of the brake cylinder is controlled by controlling the output hydraulic pressure of the hydraulic pressure source device, or by the control of the hydraulic pressure control valve device provided between the hydraulic pressure source device and the brake cylinder. There is a case. In the former case, the hydraulic pressure of the brake cylinder is controlled by controlling the electric motor included in the hydraulic pressure source device. In other words, the electric motor is controlled based on the required braking force. In the latter case, when an accumulator that stores hydraulic fluid in a pressurized state is provided in the hydraulic pressure source device, the electric motor is controlled so that the pressure of the hydraulic fluid stored in the accumulator is within a set range.

A hydraulic brake device according to a sixth aspect of the invention includes (a) a hydraulic brake that is operated by the hydraulic pressure of the brake cylinder and suppresses rotation of a vehicle wheel, and (b) a high-pressure hydraulic fluid in the brake cylinder. A hydraulic pressure source device capable of supplying a pump, comprising: (i) a pump; (ii) an electric motor that drives the pump; and (iii) an electric motor control device according to any one of claims 1 to 5. It is obtained by including.
The brake cylinder is supplied with hydraulic fluid from the hydraulic pressure source device, thereby operating the hydraulic brake. The hydraulic pressure source device includes a pump, an electric motor that drives the pump, and an electric motor control device. The pump is operated by driving the electric motor, and high-pressure hydraulic fluid is output.

According to a seventh aspect of the invention, the hydraulic brake device includes the electric motor control device including a rotation speed detection unit that detects an actual rotation speed of the electric motor, and the switch control unit includes the mechanical switch continuously. In the OFF state, the semiconductor switch includes a duty control unit that performs duty control so that the rotation speed detected by the rotation speed detection unit approaches a target rotation speed predetermined in design for each vehicle. Obtained by.
The semiconductor switch is duty-controlled so that the actual rotation speed of the electric motor approaches the target rotation speed. The target rotational speed is a rotational speed that is predetermined for each vehicle, and can be designed to be a rotational speed that can reduce the operating noise of the entire vehicle by design.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a hydraulic brake device according to an embodiment of the present invention will be described in detail with reference to the drawings. The hydraulic brake device includes a power hydraulic pressure source, and the power hydraulic pressure source includes an electric motor control device.
The hydraulic brake device shown in FIG. 1 includes a brake pedal 10 as a brake operating member, a master cylinder 12 including two pressurizing chambers, a pump device 14 as a power hydraulic pressure source operated by power, and a front and rear position. Brakes 16 to 19 and the like provided respectively corresponding to the wheels to be operated. The brakes 16 and 17 are left and right front wheel brakes, and the brakes 18 and 19 are left and right rear wheel brakes. The brakes 16 to 19 are hydraulic brakes that are operated by the hydraulic pressure of the brake cylinders 20 to 23.
The master cylinder 12 includes two pressure pistons, and fluid pressure corresponding to the operation force is generated in the fluid pressure chambers in front of the two pressure pistons by operating the brake pedal 10 by the driver. Be made. The left and right front brake cylinders 20 and 21 are connected to the two pressurizing chambers of the master cylinder 12 via master passages 26 and 27, respectively. Master cutoff valves 29 and 30 are provided in the middle of the master passages 26 and 27, respectively. The master shut-off valves 29 and 30 are normally open electromagnetic on-off valves.
Further, four brake cylinders 20 to 23 are connected to the pump device 14 via a pump passage 36. The brake cylinders 20 to 23 are supplied with hydraulic pressure from the pump device 14 while being disconnected from the master cylinder 12, and the hydraulic brakes 16 to 19 are operated. The hydraulic pressure of the brake cylinders 20 to 23 is controlled by a hydraulic pressure control valve device 38.

The pump device 14 includes a pump 56 and a pump motor 58 that drives the pump 56. The suction side of the pump 56 is connected to the reservoir 62 via the suction passage 60, and the accumulator 70 is connected to the discharge side. The hydraulic fluid in the reservoir 62 is pumped up by the pump 56, supplied to the accumulator 70, and stored in a pressurized state.
Further, a portion on the downstream side (brake cylinder side) of the discharge side accumulator 70 of the pump 56 and a portion on the suction side of the pump 56 are connected by a relief passage 74.
A relief valve 76 is provided in the relief passage 74. The relief valve 76 switches from the closed state to the open state when the hydraulic pressure on the accumulator side, which is the high pressure side, exceeds the set pressure.

An electric motor control circuit 80 shown in FIG. 2 is connected to the electric motor that is the pump motor 58. In this embodiment, the electric motor 58 is a DC motor with a brush, and includes a common brush 82, a low speed brush 84, and a high speed brush 85. The common brush 82 is a low potential side brush and is grounded. The low speed brush 84 and the high speed brush 85 are brushes on the high potential side, and are connected to the power supply 90 in parallel via a low speed switch 86 and a high speed switch 88, respectively. The common brush 82 is a low potential brush provided in common with the high potential side brushes 84 and 85. A resistor 91 is connected to the common brush 82, and the rotational speed of the electric motor 58 is detected according to the current flowing through the resistor.
In the present embodiment, the circuit including the common brush 82, the low speed brush 84, the low speed switch 86, and the power supply 90 is the low speed rotation circuit 92. The common brush 82, the high speed brush 85, the high speed switch 88, and the power supply 90 Is a circuit for high speed rotation 94.

In the electric motor 58, the low speed brush 84 is provided at a relative position where the starting torque is maximum with respect to the common brush 82, and the high speed brush 85 is compared with the case where the power supply 90 is connected to the low speed brush 84. Although the starting torque is small, it is provided at a relative position where the rotational speed at no load increases. Specifically, the common brush 82 and the low-speed brush 84 are provided at relative positions with an electrical angle of 180 degrees apart, and the common brush 82 and the high-speed brush 85 are separated by an angle different from 180 degrees. Provided.
As a result, when the high-speed switch 88 is turned on, the effective magnetic flux of the electric motor 58 is smaller than when the low-speed switch 86 is turned on, so the starting torque is small and the rotation speed at no load is low. growing.

The characteristic of the electric motor 58 in a state where the low speed switch 86 is turned on and the high speed switch 88 is turned off is referred to as a low rotation high torque type characteristic. The high speed switch 88 is turned on and the low speed switch 86 is turned on. The characteristic in the OFF state is referred to as a high rotation low torque type characteristic. In the characteristics of the low rotation high torque type and the characteristics of the high rotation low torque type, the rotation speed in the no-load state is larger in the case of the high rotation low torque type characteristic, and the load when the rotation speed is 0 is larger. The characteristics of the low rotation high torque type are larger. FIG. 3 shows the characteristics of the low rotation high torque type and the high rotation low torque type.
The low speed rotation switch 86 is a semiconductor switch, and the high speed rotation switch 88 is a mechanical switch (mechanical relay). The semiconductor switch 86 is duty-controlled, and the mechanical switch 88 is switched between a continuous ON state and a continuous OFF state.

  The reason why the semiconductor switch 86 is provided in the low-rotation circuit 92 is as follows. In the electric motor 58, when it rotates at a low speed, the operation noise is smaller than when it rotates at a high speed. Therefore, it is desirable to reduce the rotation speed as much as possible by duty control of the semiconductor switch 86. When the electric motor 86 is normally operated in a region where the rotational speed is low, it is desirable that the rotational speed be finely controlled by the duty control of the semiconductor switch 86. Furthermore, when high rotation is required, the necessity for controlling the rotation speed is often low. Further, it is possible to reduce power loss by controlling the rotation speed in the low-speed rotation circuit 90 rather than controlling the rotation speed in the high-speed rotation circuit 92.

  In the present embodiment, a rotational speed control state (first state) in which the semiconductor switch 86 is duty controlled and the rotational speed of the electric motor is controlled based on the state of the semiconductor switch 86 in the continuous OFF state of the mechanical switch 88; A low rotation state (second state) in which the semiconductor switch 86 is in a continuous ON state (duty ratio is 1) when the mechanical switch 88 is in a continuous OFF state, and a state in which the semiconductor switch 86 is continuously OFF (a duty ratio is 0) And the mechanical switch 88 is switched between a high rotation state (third state) in which the mechanical switch 88 is continuously turned on.

The hydraulic control valve device 38 (see FIG. 1) is provided with a pressure increasing linear valve 150 to 153 provided in a pump passage 36 as a pressure increasing passage, and a pressure reducing passage 156 that connects the brake cylinders 20 to 23 and the reservoir 62. And pressure-reducing linear valves 160 to 163 provided. The hydraulic pressures of the brake cylinders 20 to 23 can be individually and independently controlled by the control of the pressure increasing linear valves 150 to 153 and the pressure reducing linear valves 160 to 163.
The pressure-increasing linear valves 150 to 153 and the front wheel side pressure reducing linear valves 160 and 161 are normally closed electromagnetic control valves, and the rear wheel side pressure reducing linear valves 162 and 163 are normally open electromagnetic control valves. These pressure-increasing linear valves 150 to 153 and pressure-decreasing linear valves 160 to 163 include a solenoid having a coil or the like and a seating valve, and the hydraulic pressure of the brake cylinders 20 to 23 is controlled by controlling the current supplied to the coil. Is controlled.

  A stroke simulator device 180 is provided in the master passage 26. The stroke simulator device 180 includes a stroke simulator 182 and a normally closed simulator opening / closing valve 184, and the opening / closing of the simulator opening / closing valve 184 prevents the stroke simulator 182 from communicating with the master cylinder 12. Switched to the shut-off state.

The hydraulic brake device is controlled based on a command from the brake ECU 200. The brake ECU 200 mainly includes a computer, and includes an execution unit 202, a storage unit 204, an input / output unit 206, and the like. The input / output unit 206 includes a stroke sensor 211, a master pressure sensor 214, a brake fluid pressure sensor 216, a wheel speed sensor 218, a fluid pressure source fluid pressure sensor 220, a temperature sensor 222 that detects the temperature of the semiconductor switch, and a rotation of the electric motor. An electric motor rotation speed detecting device 224 for detecting the speed is connected, and the solenoids of the pressure-increasing linear valves 150 to 153, the pressure-decreasing linear valves 160 to 163, the master shut-off valves 29 and 30, and the simulator control valve 184 are not shown. In addition to being connected via a circuit, a semiconductor switch 86 and a mechanical switch 88 of the electric motor control circuit 80 are connected. The electric motor rotation speed detection device 224 includes a resistor 91, and the temperature sensor 222 is an aspect of a semiconductor switch state detection device that detects the state of the semiconductor switch 86.
The storage unit stores an electric motor control program and the like represented by the flowchart of FIG.

During normal braking, the master cutoff valves 29 and 30 are closed, whereby the brake cylinders 20 to 23 are shut off from the master cylinder 12 and the brakes 16 to 19 are operated by the hydraulic pressure of the pump device 14. The hydraulic pressure of the brake cylinders 20 to 23 is controlled by the control of the hydraulic pressure control valve device 38.
In the pump device 14, the electric motor 58 is controlled so that the hydraulic pressure stored in the accumulator 70 is within the set range. The hydraulic pressure stored in the accumulator 70 is detected by the hydraulic pressure source hydraulic pressure sensor 220.
The driver's required braking force is determined based on the operation stroke detected by the stroke sensor 211, the master pressure detected by the master pressure sensor 214, etc., and the target hydraulic pressure of the brake cylinder hydraulic pressure is obtained so as to obtain the required braking force. Is determined. The supply current to the solenoids of the pressure increasing linear valves 150 to 153 and the pressure reducing linear valves 160 to 163 is controlled so that the actual brake cylinder hydraulic pressure becomes the same as the target hydraulic pressure.

  Further, the braking slip state of each wheel is obtained based on the wheel speed detected by the wheel speed sensor 218, and when it is detected that the braking slip is large, anti-lock control is performed. In the anti-lock control, the hydraulic pressure of each brake cylinder is adjusted according to the execution of the anti-lock control program so that the braking slip of each wheel has an appropriate magnitude with respect to the friction coefficient of the road surface. It is controlled separately by the control.

The electric motor 58 is started when the pressure of the accumulator 70 becomes equal to or lower than the lower limit value of the set range, and is stopped when the upper limit value of the set range is reached.
In principle, the electric motor 58 is controlled by duty control of the semiconductor switch 86 in the continuous OFF state of the mechanical switch 88 so that the rotation speed is predetermined for each vehicle and approaches the target rotation speed that can reduce the operation noise by design. Controlled (first state). However, the semiconductor switch 86 generates heat by switching between ON and OFF in duty control.
Therefore, when the semiconductor switch 86 is in an overheated state or may be in an overheated state and is estimated to be abnormal, the semiconductor switch 86 is continuously turned on (second state), or the semiconductor switch 86 is turned on. Are continuously turned off and the mechanical switch 88 is turned on (third state). If the semiconductor switch 86 is continuously turned on, heat generation is suppressed as compared with the case where ON / OFF is switched in the duty control.
In this embodiment, when the temperature of the semiconductor switch 86 is equal to or higher than the first set temperature, the level of abnormality is higher than when the temperature is lower than the first set temperature and equal to or higher than the second set temperature, and the heat generation of the semiconductor switch 86 is suppressed. There is a high need to do. Therefore, when the abnormality level is high (in this embodiment, the abnormality level is 1), the third state is set, and when the abnormality level is low (in this embodiment, the abnormality level is 2), the second state is set. The

The electric motor control program represented by the flowchart of FIG. 4 is executed at predetermined time intervals.
In step 1 (hereinafter abbreviated as S1. The same applies to other steps), it is determined whether or not there is an operation request for the electric motor. As described above, the presence or absence of an operation request is determined based on the accumulator pressure. If there is an operation request, the temperature of the semiconductor switch 86 is detected in S2, whether or not the temperature is equal to or higher than the first set temperature in S3, and is lower than the first set temperature and higher than or equal to the second set temperature in S4. It is determined whether or not.
When the temperature of the semiconductor switch 86 is lower than the second set temperature and is normal, the first state is set. In S5, the mechanical switch 88 is continuously turned off. In S6, the actual rotational speed of the electric motor 58 is detected. In S7, the semiconductor switch 86 is duty-controlled so that the actual rotational speed approaches the target rotational speed. The

On the other hand, when the temperature of the semiconductor switch 86 is equal to or higher than the second set temperature and lower than the first set temperature, the determination in S4 is YES, and in S8, the mechanical switch 88 is continuously turned off. 86 is continuously turned on (second state).
If the temperature of the semiconductor switch 86 is equal to or higher than the first set temperature, the determination in S3 is YES, and in S9, the semiconductor switch 86 is continuously turned off and the mechanical switch 88 is turned on (first). 3 states).
When there is no operation request, in S10, both the semiconductor switch 86 and the mechanical switch 88 are turned off.

Thus, in this embodiment, the semiconductor switch 86 is controlled based on the temperature of the semiconductor switch 86. When the temperature of the semiconductor switch 86 is not so high and the abnormality level is low, the semiconductor switch 86 is continuously turned on. When the temperature is high and the abnormality level is high, the semiconductor switch 86 is continuously turned off. Thereby, heat generation of the semiconductor switch 86 can be suppressed. In addition, a self-diagnosis device may be provided for the semiconductor switch, and the operation may be prohibited when the temperature exceeds a set temperature. However, according to the electric motor control device of the present embodiment, the heat generated by the semiconductor switch 86 is generated. Therefore, the prohibition of the operation is avoided. Furthermore, since the rotation speed of the electric motor 58 is controlled so as to be a target rotation speed that can reduce the operation sound predetermined for each vehicle by design, the operation sound of the electric motor 58 can be reduced.
As described above, in the present embodiment, the switch control unit is configured by a portion that stores S5, 7 to 9 of the electric motor control program represented by the flowchart of FIG. The switch control unit is also a semiconductor switch state-dependent control unit.

In the above-described embodiment, the temperature sensor 222 that detects the temperature of the semiconductor switch 86 is provided. However, the provision of the temperature sensor 222 is not essential. Based on the operating state of the electric motor 58, it is estimated whether or not the semiconductor switch 86 is in an overheated state, and control can be performed based on the estimated state.
In the present embodiment, the electric motor 58 is in the operation state by the control of the semiconductor switch 86 during the operation time (the time that is driven by the low-speed rotation circuit 92) in which the electric motor 58 is in the operation state by the control of the semiconductor switch 86. An operating time ratio that is a ratio to a non-operating time (a time during which the semiconductor switch 86 is in a continuous OFF state, including a time during which the electric motor 58 is stopped and a time when the mechanical switch 88 is in an ON state) is acquired. Since the time for which the mechanical switch 88 is in the ON state is not so long, in the present embodiment, it is assumed that it is a non-operation time.
The third state is set when the operating time ratio is equal to or higher than the first set value, and the second state is set when the operating time ratio is lower than the first set value and equal to or higher than the second set value. This is because when the operating time ratio is large, the temperature of the semiconductor switch 86 is high and the necessity of suppressing heat generation is high.
Further, in the third state, the first state is set when the previous non-operation time is equal to or longer than the first set time, and in the second state, the previous non-operation time is shorter than the first set time and is equal to or longer than the second set time. In this case, the first state is set. This is because if the non-operation time becomes longer, it can be estimated that the temperature of the semiconductor switch 86 has decreased, and therefore it may be possible to perform duty control in the first state.

In the present embodiment, the electric motor control program represented by the flowchart of FIG. 5 is executed. If there is an operation request, the operation time ratio γ is acquired in S22. As will be described later, the operation time ratio γ is acquired in accordance with the execution of the operation time ratio acquisition program represented by the flowchart of FIG. In the execution of the operation time ratio acquisition program, the immediately previous non-operation time Toff (n) of the semiconductor switch is also acquired.
Next, in S23 and S24, whether or not the operating time ratio γ is equal to or greater than the first set value γ1 (for example, can be set to the abnormal level 1), is smaller than the first set value γ1 and equal to or greater than the second set value γ2. It is determined whether or not (for example, an abnormal level 2 can be set).
If it is smaller than the second set value γ2, the duty control of the semiconductor switch 86 is performed in S5-7 as in the case described above.
If it is smaller than the first set value γ1 and greater than or equal to the second set value γ2, the determination in S24 is YES, and in S25, the previous non-operation time Toff (n) of the semiconductor switch 86 is the second set time Ts2. It is determined whether or not this is the case. When the immediately preceding non-operation time Toff (n) is shorter than the second set time Ts2, the second state is set at S8, but when it is equal to or longer than the second set time Ts2, the duty control of the semiconductor switch 86 is set at S5-7. Is done.
If the operating time ratio γ is equal to or greater than the first set value γ1, the determination in S23 is YES, and whether the non-actuated time Toff (n) of the immediately preceding semiconductor switch is equal to or greater than the first set time Ts1 in S27. It is determined whether or not. If it is shorter than the first set time Ts1, the third state is set in S9, and if it is longer than the first set time Ts1, the duty control of the semiconductor switch 86 is performed in S5-7.

The operating time ratio etc. acquisition program is executed at predetermined time intervals. In the present embodiment, the operation time ratio is acquired for each brake operation, and each data is initialized when the one (series) brake operation is completed.
In S41, it is determined whether or not the semiconductor switch 86 is in a duty controlled state (including a state where the duty ratio is 1). When the semiconductor switch 86 is duty controlled, the electric motor 58 is controlled by the control of the semiconductor switch 86. When the semiconductor switch 86 is in the continuous OFF state, the electric motor 58 is in the stopped state. Or driven by the high-speed rotation circuit 92.
When the semiconductor switch 86 is in the continuous OFF state, the determination in S41 is NO, and when the non-operation time is acquired in S42 to 44 and the duty control is performed, the determination in S41 is YES. Thus, the operation time is acquired in S45 to 48, and the operation time ratio γ is acquired.

If the semiconductor switch 86 is in the continuous OFF state, in S42, whether or not the determination in S41 was YES during the previous execution of this program, in other words, the semiconductor switch 86 was duty controlled during the previous execution. Therefore, it is determined whether or not the continuous OFF state is set for the first time this time. If it has been executed for the first time, the counter n is incremented by 1 in S43, and the non-operation time is measured in S44. The counter n is provided in order to measure the time during which the non-operating state continues. The non-operation time Toff (n) is a time during which the determination in S41 is continuously NO.
On the other hand, if the semiconductor switch 86 is duty controlled, it is determined in S45 whether or not it is the first time. As in the case described above, when this program is executed last time, it is determined whether or not the semiconductor switch 86 is in the continuous OFF state and duty control is executed for the first time this time. If it is the first time, the sum of the non-operation time Toff (n) so far is obtained in S46, and the operation time Ton is measured in S47. The operation time Ton is the operation time of the electric motor 58 after the brake is started this time. In S48, the operating time ratio γ is obtained by dividing the operating time Ton by the sum ΣToff (n) of the non-operating time.

In the present embodiment, the temperature of the semiconductor switch 86 is estimated based on the motor operating time ratio, and the semiconductor switch 86 and the mechanical switch 88 are controlled based on the estimated temperature. Thereby, even if no temperature sensor is provided, the temperature state of the semiconductor switch 86 can be acquired, and heat generation of the semiconductor switch 86 can be suppressed.
As described above, in the present embodiment, the switch control unit is configured by the part that stores S5, 7 to 9 of the electric motor control program represented by the flowchart of FIG. The switch control unit is also a motor operation time ratio dependent control unit. In addition, an operation time ratio acquisition device is configured by a portion that stores a motor operation time ratio acquisition program represented by the flowchart of FIG.

In the above embodiment, the electric motor operating time ratio is acquired as a value corresponding to the semiconductor switch operating time ratio. However, the time controlled by the control of the mechanical switch 88 is added to the operating time. You can also.
Furthermore, the operation time ratio of the electric motor can be acquired based on the operation time and the non-operation time after the ignition switch is switched from the OFF state to the ON state.
Further, the duty ratio is controlled based on the ratio of the duty control time of the semiconductor switch 86 to the non-duty control time, or the duty ratio with respect to the time when the duty ratio of the semiconductor switch 86 is duty controlled within a range larger than 0 and smaller than 1. Or may be controlled based on a ratio to the time when is 0 or 1.
Furthermore, the duty control of the semiconductor switch 86 can be performed based on the difference between the actual hydraulic pressure of the accumulator 70 and the target setting range. For example, when the actual accumulator pressure is lower than the lower limit value of the target setting range by a set value or more, the duty control is performed so that the rotational speed of the electric motor 58 becomes larger than the case where it is not. . In this way, the accumulator pressure can be quickly brought within the target setting range.
Moreover, in the said embodiment, although the switch for high-speed rotation was a mechanical switch, it can also be set as a semiconductor switch.
Furthermore, the electric motor control device according to the present invention is not limited to the electric motor control device of the hydraulic pressure source device of the hydraulic brake device, but can be applied to control of an electric motor that operates an electric friction brake, It can also be applied to control.

  The present invention can be practiced in various modifications and improvements based on the knowledge of those skilled in the art, in addition to the aspects described above.

It is a circuit diagram of the hydraulic brake device which is one embodiment of the present invention. The hydraulic brake device includes an electric motor control device that is an embodiment of the present invention. It is a circuit diagram of the said electric motor control apparatus. It is a figure which shows the characteristic of the electric motor in the said electric motor control apparatus. It is a flowchart showing the electric motor control program memorize | stored in the memory | storage part of the said electric motor control apparatus. It is a flowchart showing the electric motor control program memorize | stored in the memory | storage part of the electric motor control apparatus which is another one Embodiment of this invention. It is a flowchart showing the motor operation time ratio acquisition program memorize | stored in the memory | storage part of the said electric motor control apparatus.

Explanation of symbols

58: Electric motor 86: Semiconductor switch 88: Mechanical switch 200: Brake ECU 222: Temperature sensor 224: Electric motor rotation speed detection device

Claims (7)

A circuit for low-speed rotation including a switch for low-speed rotation;
A high-speed rotation circuit including a high-speed rotation switch;
And a switch control unit that controls the rotational speed of the electric motor by switching between the duty control of the low-speed rotation switch and the continuous ON state and the continuous OFF state of the high-speed rotation switch. Motor control device. The electric motor control device according to claim 1, wherein the low-speed rotation switch is a semiconductor switch, and the high-speed rotation switch is a mechanical switch. The switch control unit continuously turns on the semiconductor switch in a state in which the mechanical switch is in a continuous OFF state, at least in a first state in which the semiconductor switch is duty controlled, and in a state in which the mechanical switch is in a continuous OFF state. 3. The electric motor control device according to claim 2, wherein the electric motor control device switches between a second state to be in a state and a third state in which the semiconductor switch is in a continuous OFF state and the mechanical switch is in a continuous ON state. The electric motor control device includes a semiconductor switch state detection unit that detects a state of the semiconductor switch, and the switch control unit detects whether the semiconductor switch and the mechanical switch are based on a detection result by the semiconductor switch state detection unit. The electric motor control device according to claim 2, further comprising a semiconductor switch state-dependent control unit that controls at least one of them. The electric motor control device includes an operation time ratio acquisition unit that acquires a ratio of an operation time of the electric motor to a non-operation time, and the switch control unit is configured to perform the semiconductor operation based on a result obtained by the operation time ratio acquisition unit. The electric motor control device according to any one of claims 2 to 4, further comprising an operation time ratio dependence control unit that controls at least one of the switch and the mechanical switch. A hydraulic brake that is actuated by the hydraulic pressure of the brake cylinder and suppresses the rotation of the wheels of the vehicle;
A hydraulic pressure source device capable of supplying high-pressure hydraulic fluid to the brake cylinder, the pump, an electric motor that drives the pump, and the electric motor control device according to any one of claims 1 to 5. A hydraulic brake device comprising: The electric motor control device includes a rotation speed detection unit that detects an actual rotation speed of the electric motor, and the switch control unit rotates the semiconductor switch while the mechanical switch is in a continuous OFF state. The hydraulic brake device according to claim 6, further comprising a duty control unit that performs duty control so that the rotational speed detected by the speed detection unit approaches a target rotational speed that is predetermined in design for each vehicle.

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