JP6337768B2 - Motor device, high pressure source unit - Google Patents

Description

  The present invention relates to brush wear detection of an electric motor with a brush.

  Patent Documents 1 to 4 describe brush wear detection devices for brushed electric motors. In the wear detection device described in Patent Document 1, the movement amount of the electric motor, the current integrated value, the temperature, and the like are converted into wear amount influence coefficients, respectively, and the sum of the wear amount influence coefficients is larger than a predetermined set value. If so, it is detected that the brush is worn to the extent that it needs to be replaced. In the wear detection device described in Patent Document 2, when the amplitude of the periodic change in current is large, it is detected that the wear of the brush is more advanced than when the amplitude is small. The surface of the brush becomes rough due to wear, and an arc is easily generated between the brush and the commutator, so that the amplitude of the current increases. In the wear detection device described in Patent Document 3, when the difference between the starting current and the steady current is small, it is detected that the wear of the brush is more advanced than when the difference is large. Due to the wear of the brush, the contact area with the commutator is reduced and the resistance is increased, so that the starting current is reduced. In the wear detection device described in Patent Document 4, the brush wear amount at that time is estimated based on the operating state of the electric motor, and the cumulative value of the wear amount is acquired.

JP 2014-107946 A JP 2008-301567 A JP 2013-021873 A Japanese Patent Laid-Open No. 06-141513

The subject of this invention is obtaining the motor apparatus provided with the electric motor suitable for detection of abrasion of a brush , and a high voltage source unit .

Means and effects for solving the problem

Motor device according to the present invention, all SANYO comprising an electric motor having a brush that changes resistivity in the longitudinal direction, and a wear detector for detecting wear of the brush of the electric motor, according to the present invention The high-pressure source unit includes a motor device, a pump, and an accumulator.
As the brush wears, the specific resistance value of the portion in contact with the commutator of the brush changes, and the physical quantity representing the operating state of the electric motor, such as the rotational speed of the electric motor and surge current, changes. Therefore, the wear state of the brush can be acquired based on a physical quantity that represents the state of the electric motor during operation or a change in the physical quantity.
The surge current is a current that flows due to a change in inductance of the electric motor, and is a current that changes in a pulse manner.
The state of wear of the brush can be represented by the amount of wear of the brush or the degree of progress of wear. The degree of progress of wear is normal (the wear is not progressing so much and can be referred to as normal) and needs to be replaced (the wear is in progress and can be referred to as the end). ), Close to a state that requires replacement (can be referred to as near-end). Further, the state of wear of the brush can also be acquired based on a physical quantity representing the operating state of an operating device (for example, a pump or the like) driven by an electric motor. This is because the operating state of the pump or the like corresponds to the operating state of the electric motor.
Thus, since the specific resistance value of the brush changes in the longitudinal direction, an electric motor suitable for detecting the state of wear of the brush can be obtained. Moreover, in the motor device provided with the electric motor, the wear of the brush can be detected well.

Patentable invention

Hereinafter, the invention recognized as being capable of being claimed in the present application, or features of the invention will be described .

(1) An electric motor including a brush whose specific resistance value changes in the longitudinal direction.
The longitudinal direction of the brush is the direction of progress of wear and is the direction orthogonal to the contact surface with the commutator. In the longitudinal direction, the specific resistance value may change continuously or may change stepwise. In the latter case, it may be changed in two steps or may be changed in three or more steps. The specific resistance value may be increased or decreased as wear progresses, but it is desirable to increase the specific resistance value to prevent overheating. This is because the operation of the electric motor can be continued even when the rotational speed is reduced.
ADVANTAGE OF THE INVENTION According to this invention, the electric motor which can detect the abrasion of a brush appropriately can be obtained.
(2) An electric motor including a brush made of a plurality of constituent materials that are different from each other in the longitudinal direction.
The constituent material is a material that constitutes the brush, and includes one type of material, two types or more of materials, and “a plurality of different constituent materials” includes a plurality of different types of materials. This includes a constituent material, a plurality of constituent materials having different blending ratios, a plurality of constituent materials having different ratios of materials to binders, and the like.
For example, if the blending ratio of a plurality of materials in each of the constituent materials and the ratio of the material to the binder are changed continuously or stepwise along the longitudinal direction, the specific resistance value can be changed continuously or stepwise. it can.
It is desirable that the constituent materials have excellent heat resistance and wear resistance. In particular, in the case of a new brush, the constituent material on the side in contact with the commutator is excellent in heat resistance and wear resistance. Is desirable.
(3) A wear detecting device for detecting a state of wear of the brush of the electric motor according to (1) or (2).
(4) The wear detection device detects the state of wear of the brush based on at least one of a physical quantity representing a state of the electric motor during operation and a change in the physical quantity. The wear detection apparatus described in 1.
(5) The wear detection device according to (3) or (4), wherein the wear detection device includes a wear amount detection unit that detects a wear amount of the brush.
(6) The electric motor according to any one of (1) or (2), and the wear detection device according to any one of (3) to (5). A motor device provided.
The wear detection device can be included in a motor control device that controls the electric motor. The motor control device controls the operating state of the electric motor and detects the state of wear of the brush.
(7) In the state where the motor device described in the above item (6), the pump operated by the electric motor described in the above item (1) or (2), and the fluid discharged from the pump are pressurized High pressure source unit with accumulator for storage.
For example, the electric motor is controlled and the pump is operated so that the fluid pressure stored in the accumulator is within a predetermined setting range. As the wear of the brush advances, the number of rotations of the electric motor changes and the operating time of the pump changes.

It is a circuit diagram of a high voltage source unit according to an embodiment of the present invention including a motor device according to an embodiment of the present invention . It is sectional drawing of the electric motor contained in the said motor apparatus. (a) It is a partial cross section figure which shows the principal part of the said electric motor. (b) It is a conceptual diagram of the said motor apparatus. (a) It is the schematic of the brush contained in the said electric motor. (b) It is a figure which shows the change of the surge current accompanying abrasion of the said brush. (c) It is a figure which shows the change of the rotation speed of the electric motor accompanying the abrasion of the said brush. (d) It is a figure which shows the change of the operating time of the pump accompanying the abrasion of the said brush. It is a figure which shows the change of the electric current accompanying rotation of an electric motor in each of the normal state and end state of a brush. It is a figure which shows the change of the voltage accompanying rotation of an electric motor in each of the normal state and end state of a brush. It is a flowchart showing the brush wear state detection program memorize | stored in the memory | storage part of motor ECU of the said motor apparatus. (a) It is the schematic of the brush of the electric motor contained in the motor apparatus which concerns on another Example of this invention. This motor device is included in a high-voltage source unit according to another embodiment of the present invention. (b) It is a figure which shows the change of the surge current accompanying abrasion of the said brush. (c) It is a figure which shows the change of the rotation speed of the electric motor accompanying the abrasion of the said brush. (d) It is a figure which shows the change of the operating time of the pump accompanying the abrasion of the said brush. (a) It is the schematic of the brush of the electric motor contained in the motor apparatus which concerns on another Example of this invention. The motor device is included in a high-voltage source unit according to still another embodiment of the present invention. (b) It is a figure which shows the change of the surge current accompanying abrasion of the said brush. (c) It is a figure which shows the change of the rotation speed of the electric motor accompanying the abrasion of the said brush. (d) It is a figure which shows the change of the operating time of the pump accompanying the abrasion of the said brush.

Embodiment of the Invention

Hereinafter, the high-pressure source unit will be described in detail based on the drawings. The high-pressure source unit is capable of supplying a high-pressure fluid, and is connected to a fluid pressure actuator. The fluid pressure actuating device can be a component of a hydraulic brake device of an automobile or a component of a drive transmission device and a suspension device.
The electric motor, which is a component of the motor device included in the high-voltage source unit, can be used as an engine starting motor, a machine tool other than an automobile, or the like.

  As shown in FIG. 1, the high-pressure source unit includes a motor device 10, a pump 12, an accumulator 14, and the like. The motor device 10 includes an electric motor 16 and a motor ECU 18 mainly composed of a computer that controls the electric motor 16. The pump 12 is operated by the driving force of the electric motor 16, and pumps up and discharges a working fluid as a fluid stored in the reservoir 20. The hydraulic fluid discharged from the pump 12 is stored in the accumulator 14 in a pressurized state. The hydraulic pressure of the accumulator 14 is detected by the accumulator pressure sensor 22, and the detected value is supplied to the motor ECU 18.

The electric motor 16 is a brush-type DC motor as shown in FIG. 2, and includes a housing 30, one or more pairs of magnets 32 provided inside the housing 30 in a circumferential direction, and an inner circumference of the pair of or more magnets 32. The rotor 34 provided on the side is included. The rotor 34 includes a rotary shaft 36 rotatably supported by the housing 30, a plurality of coils 38 provided on the rotary shaft 36, a commutator 40 provided from the plurality of coils 38 in the axial direction L, and the like. The commutator 40 includes a plurality of commutator pieces 42 provided extending in the axial direction L and spaced apart in the circumferential direction, an insulator 44 provided between the plurality of commutator pieces 42, and the like. A plurality of coils 38 are connected to each of these. In this embodiment, the rotary drive shaft of the pump 12 is connected to the rotary shaft 36.
A pair of brush housings 48 extending in the radial direction and having an opening on the inner peripheral side are provided on the inner peripheral side of the housing 30, and each of the brush housings 48 has a brush 50 having a longitudinal shape. Are fitted so as to be relatively movable in the radial direction. Each of the brushes 50 (a pair of brushes is shown in FIGS. 2 and 3 (a)) has an inner peripheral end that contacts the commutator 40, and an elastic force of the spring 52 acts on the outer peripheral end. Provided in a state. The brush 50 is worn and shortened by sliding contact with the commutator 40, but is pushed out to the inner peripheral side by the elastic force of the spring 52, and the contact with the commutator 40 is maintained.

In each of the pair of brushes, one brush 50 is connected to the positive electrode of the power source 60 through the pigtail 58, and the other brush 50 is connected to the negative electrode through the pigtail 59, as shown in FIG. In addition, a circuit 66 including an electric motor 16, a power source 60, a current monitor 62, a switch 64 and the like is formed. The electric power of the power source 60 is supplied to the coil 38 through the brush 50 and the commutator 40, and the electric motor 16 is rotated. The current monitor 62 detects the current flowing through the circuit 66.
In addition, as shown in FIG. 4A, each of the plurality of brushes 50 is configured with a constituent material Y (1) having a specific resistance value X (1) on the inner peripheral side in contact with the commutator 40. The outer peripheral portion that receives the elastic force of the spring 52 is made of the constituent material Y (2) having the specific resistance value X (2). In this embodiment, the specific resistance value X (2) is larger than the specific resistance value X (1).
Constituent materials Y (1) and Y (2) contain different types of materials, have different ratios of the same type of material to the binder, or have different mixing ratios of multiple types of materials And so on. For example, the constituent materials Y (1) and Y (2) may have different ratios of copper or graphite powder to a binder such as a resin.
In each brush 50, the length of the constituent material Y (2) in the longitudinal direction is approximately a. The length a is, for example, a value that the wear length of the brush 50 is greater than (R−a) and needs to be replaced, or a value slightly longer than the length that needs to be replaced. be able to. The length a can be referred to as an end state determination length.

As the wear of the brush 50 progresses and the length of the brush 50 becomes a or less, the specific resistance value of the portion of the brush 50 that contacts the commutator 40 changes from X (1) to X (2). Thus, the surge current, the motor speed, the operation time of the pump 12 and the like change. Hereinafter, in this specification, the state in which the length of the brush 50 is a or less and the constituent material Y (2) having the specific resistance value X (2) is in contact with the commutator 40 is referred to as the end state (exchange) of the brush 50. It is called a state that needs to be done).
[1] Surge Current FIG. 5 shows the result of simulating the current flowing through the coil 38 as the rotor 36 rotates. The solid line represents the current that flows when the component Y (1) of the specific resistance value X (1) is in contact with the commutator 40 (hereinafter sometimes referred to as the normal state), and the broken line is the end state. It represents the flowing current. As the rotor 36 rotates, the inner peripheral end of the brush 50 comes into contact with the commutator piece 42 or faces the insulator 44, so that the current changes periodically. A pulsed current flows due to a change in the impedance of the coil 38. This pulsed current is called a surge current. The surge current decreases when the specific resistance value of the brush 50 is large, as indicated by the solid line and the broken line in FIG.
Therefore, as shown in FIG. 4B, at least when (i) the surge current is less than or equal to the threshold current value Isth and (ii) the surge current is less than or equal to the change threshold current value ΔIs. In one case, it can be determined that the specific resistance value of the portion of the brush 50 in contact with the commutator 40 changes from X (1) to X (2) and changes from the normal state to the end state. The surge current is a peak current value, an amplitude (for example, a difference between the peak current and the minimum value), or an average value of the current within a set time including the peak current. You can do it.
In addition, as shown in FIG. 6, it is also possible to detect the state of wear of the brush 50 based on a change in surge voltage that is a voltage corresponding to the surge current.
5 and 6, the change cycle differs between the current represented by the solid line and the current represented by the broken line. This is due to the difference in the number of commutator pieces 42 in the commutator 40. However, even if the number of commutator pieces 42 is different and the change period is different, the surge current and the surge voltage are the same when the specific resistance value is large compared to when the specific resistance value is small.

[2] Number of revolutions of electric motor 16 As shown in FIG. 4 (c), when the specific resistance value of the portion of the brush 50 that contacts the commutator 40 increases, the number of revolutions of the electric motor 16 decreases. Therefore, at least one of (i) when the rotational speed of the electric motor 16 is smaller than the threshold rotational speed Nmth and (ii) when the rotational speed of the electric motor 16 is smaller than the threshold rotational speed ΔNm. In this case, it can be determined that the brush 50 is in the end state. The number of rotations of the electric motor 16 can be, for example, an average value of the number of rotations within a set time during the operation of the electric motor 16.
[3] Operating time of pump 12 In the high pressure source unit, the electric motor 16 is operated and the pump 12 is operated so that the hydraulic pressure of the hydraulic fluid stored in the accumulator 14 is within a predetermined setting range. . When the accumulator pressure detected by the accumulator pressure sensor 22 becomes lower than the lower limit value PL of the setting range, the electric motor 16 is started, the operation of the pump 12 is started, and when the accumulator pressure becomes equal to or higher than the upper limit value PH of the setting range, The electric motor 16 is stopped and the pump 12 is stopped. Thus, the pump 12 is operated until the accumulator pressure is lower than the lower limit value PL of the setting range until the upper limit value PH of the setting range is reached. Become. As described above, when the specific resistance value of the portion of the brush 50 in contact with the commutator 40 is increased, the rotational speed of the electric motor 16 is decreased. Therefore, as shown in FIG. Longer operating time. One operation time of the pump 12 can be an average value of the operation time when the pump 12 is operated a plurality of times.
From the above, (i) when one operation time of the pump 12 is longer than the threshold time Tpth, and (ii) when one operation time of the pump 12 is longer than the threshold time ΔTp. In at least one of the cases, it can be determined that the brush 50 is in the end state. One operation time of the pump 12 corresponds to one operation time of the electric motor 16. Further, the operation time for one operation of the pump 12 can be a time from the time when the accumulator pressure becomes smaller than the lower limit value PL to the time when the accumulator pressure becomes equal to or higher than the upper limit value PH.

  The motor ECU 18 is mainly a computer and includes an execution unit 18c, a storage unit 18m, an input / output unit 18i, and the like as shown in FIG. An accumulator pressure sensor 22 and a current monitor 62 are connected to the motor ECU 18, and a switching element 64, a notification device 70 and the like are connected to the motor ECU 18. For example, the notification device 70 can be a display or the like. The storage unit 18m stores a brush wear state detection program and the like represented by the flowchart of FIG.

In the present embodiment, the wear state of the brush is detected based on a physical quantity representing the state of the electric motor 16 during operation or a change in the physical quantity, and is detected by executing the brush wear state detection program. .
In step 1, a surge current as a physical quantity representing a state at the time of operation of the electric motor 16, the number of revolutions of the electric motor 16, the operation time of the pump 12, and the like are acquired. The surge current is acquired based on the detection value of the current monitor 62.
In step 2, as shown in FIGS. 4B, 4C, and 4D, based on the surge current, the rotation speed of the electric motor 16, the value of the operating time of the pump 12, or the change thereof, the brush It is determined whether or not 50 has been worn down to a length a or less and an end state has been reached. Whether or not the end state has been reached is determined based on one or more of the surge current, the rotational speed of the electric motor 16, and the operation time of the pump 12.
If it is determined that the end state has been reached, this is notified through the notification device 70 in step 3. In addition, when it is determined that it is not in the end state, it is not notified.

As described above, the electric motor 16 included in the motor device 10 according to the present embodiment includes the brush 50 made of the constituent materials Y (1) and Y (2) having different specific resistance values in the longitudinal direction. This is suitable for detecting the state of wear of the brush 50. Therefore, in the motor device according to the present embodiment, the state of wear of the brush 50 can be detected well.
Further, the progress of wear of the brush 50 is not uniform. For example, when the operation frequency of the pump 12 increases, the progress of wear of the brush 50 is accelerated. Also, when the temperature is high, the wear progresses faster than when the temperature is low. On the other hand, since the brush 50 is accommodated in the brush housing 48 of the electric motor 16, in order to check the wear state of the brush 50, it is necessary to disassemble the electric motor 16, which is troublesome. On the other hand, in the present embodiment, the state of wear of the brush 50 is well detected and it is notified that the end state has been reached, so that the brush 50 is brought into the end state without disassembling the electric motor 16. Can be acquired and exchanged at the appropriate time.
In the brush 50, the specific resistance value X (2) is made larger than the specific resistance value X (1). If the specific resistance value X (2) is smaller than the specific resistance value X (1), problems such as excessive current flow occur when wear progresses, but the specific resistance value X (2) Since the specific resistance value X (1) is larger than the specific resistance value X (1), the number of revolutions is reduced by the progress of wear, but an excessive current can be prevented from flowing, and the electric motor 16 can be continuously operated.
In the present embodiment, the wear detection device is constituted by a portion for storing the brush wear state detection program of the motor ECU 18, a portion for executing the program, a current monitor 62, and the like.

The structure of the brush is not limited to that of the above embodiment.
For example, as shown in FIG. 8A, the brush 100 may have a structure in which the specific resistance value X continuously changes in the longitudinal direction and the constituent materials continuously change. . In the brush 100, for example, the ratio of the constituent material Y (i) having a specific resistance value X (i) to the constituent material Y (ii) having a specific resistance value X (ii) is continuously increased with respect to a binder such as copper powder or carbon. It can be a structure that changes or a structure in which the blending ratio of a plurality of materials changes continuously. In these cases, it is considered that the composition ratio of the constituent material Y (1) and the constituent material Y (2) is continuously changed, or the constituent materials are changed from Y (1) to Y ( It can be considered that the structure changes to 2). FIG. 8 (a) conceptually shows changes in the ratio of copper powder and the like and the blending ratio of a plurality of materials, and the two constituent materials Y (i) and Y (ii) are inclined. It does not indicate that it is provided.
In the brush 100, the specific resistance value of the portion in contact with the commutator 40 continuously changes with wear. Therefore, as shown in FIGS. 8B to 8D, the surge current, the motor rotation speed, and the operation time of one operation of the pump 12 continuously change with wear. The near-end threshold value can be set closer to the physical quantity in the normal state, and the brush 100 is in the near-end state (the state close to the end state and reaches the end state when the wear progresses more than the set value. ) Can be detected and notified.
For example, as shown in FIG. 8B, when the surge current is smaller than the near-end threshold value Isthn, the brush 100 reaches the near-end state and when the surge current is smaller than the end threshold value Isth, the end state is reached. Is reached, or the near-end state is reached when the surge current becomes smaller than the near-end change threshold value ΔIsn, and the end state is reached when the surge current becomes smaller than the end-use change threshold value ΔIs. It can be determined that it has been done. The same applies to the motor rotation speed and the operation time of the pump 12.
It should be noted that the wear amount (which can be represented by the wear length of the brush 100 or the remaining length) can be continuously detected and notified.

Further, the brush 120 may have a structure shown in FIG. The brush 120 is composed of a plurality of constituent materials Y (k) {k = a, b, c...} Having different specific resistance values X (k) {k = a, b, c. Can be. For example, the brush 120 can include a plurality of constituent materials whose blending ratio of copper or carbon to the binder changes in a plurality of stages. In the brush 120, as shown in FIGS. 9B to 9D, since the surge current, the motor rotation speed, and the operation time of one time of the pump 12 change in a plurality of stages, the wear state of the brush 120 is changed. It can be acquired in stages.
For example, as shown in FIG. 9B, when the surge current becomes smaller than the normal threshold value Istho, it is determined that the latter half is in the normal state (standard state) and becomes smaller than the near-end threshold value Isthn. In this case, it is determined that the state is in the near-end state, and when the state is smaller than the end threshold value Isth, it is determined that the state is in the end state. The same applies to the rotation speed of the electric motor 16 and the operation time of the pump 12. Further, the wear state can be acquired based on the surge current, the number of rotations of the electric motor 16, and the amount of change in the operation time of the pump 12 as in the first and second embodiments.

  As described above, the present invention has been described based on a plurality of embodiments. However, the present invention is not limited to the above embodiments, and can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.

  10: Motor device 12: Pump 14: Accumulator 18: Motor ECU 34: Rotor 40: Commutator 42: Commutator piece 50, 100, 120: Brush 52: Spring 62: Current monitor 64: Switching element

Claims (3)

An electric motor having a brush that changes resistivity in a longitudinal direction, on the basis of the change in the state of the electric motor due to a change in resistivity of the portion in contact with the brush of the commutator of the electric motor, A motor device including a wear detection device for detecting a state of wear of the brush ;
A pump operated by the electric motor;
An accumulator for storing the fluid discharged from the pump in a pressurized state;
A high pressure source unit comprising:
The motor device starts the electric motor when the pressure of the fluid stored in the accumulator becomes lower than a lower limit value of a predetermined setting range, and the electric motor is turned on when the electric motor exceeds the upper limit value of the setting range. Including a motor control device to stop,
The wear detection device has a single operation time of the pump which is a single operation time of the electric motor from a state where the pressure of the fluid stored in the accumulator is lower than the lower limit value to the upper limit value or more. A high pressure source unit for detecting a state of wear of the brush based on the above. The brush is such that the specific resistance value increases stepwise or continuously as the wear progresses,
  2. The wear detection device detects that the brush has entered an end state that requires replacement when the operating time of the pump is longer than a threshold time. High pressure source unit as described. Based on a change in the state of the electric motor resulting from a change in the specific resistance value of a portion of the electric motor that contacts the commutator of the brush of the electric motor with a brush whose specific resistance value changes in the longitudinal direction, A motor device including a wear detection device for detecting a state of wear of the brush,
  The motor device, wherein the wear detection device detects a state of wear of the brush based on a surge voltage that is a voltage generated in a pulse manner in the coil of the electric motor.

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