JP5994638B2 - Electric pump device - Google Patents

Description

  The present invention relates to an electric pump device mounted on a vehicle.

  Conventionally, in a vehicle having a so-called idle stop function for automatically stopping the engine when temporarily stopped, the supply of hydraulic pressure to the transmission or the like is ensured even during the idle stop by using an electric pump device. Since such an electric pump device is mounted in a limited space of a vehicle, there is a strong demand for downsizing. Therefore, conventionally, a pump that generates hydraulic pressure, a motor that drives the pump, and a control device that controls the operation of the motor are housed and integrated in a common housing, thereby reducing the size of the electric motor. A pump device has been proposed (see, for example, Patent Document 1).

  By the way, since the electric pump device may be submerged when the vehicle travels on a flooded road, the rainwater or the like is prevented from entering the housing by a seal member or the like. However, for example, when the seal member deteriorates due to secular change, rainwater or the like may be immersed in the housing. As a result, in the electric pump device in which the control device is integrated as described above, a short circuit occurs in the electric system that electrically connects the power source (battery) and the motor, or rainwater or the like in the electric system adheres. There is a risk that the damaged portion (wiring or the like) may be damaged due to deterioration.

  Assuming such a situation, the control device is usually provided with a failure detection function. Specifically, the control device has a microcomputer for controlling the operation of the motor, and the microcomputer detects a current value and a voltage value supplied to the motor. Then, the microcomputer determines that a failure has occurred when the detected current value or voltage value is an inaccessible value or a discontinuous value, and notifies the driver that the electric pump device has failed. It is like that.

JP 2010-112330 A

  However, in the conventional electric pump device, when the housing is inundated, the IC chip (fault detection circuit) constituting the microcomputer having a fault detection function is exposed to water before detecting a fault in the electrical system. By doing so, there is a possibility that a failure of the electric system cannot be detected, and there is still room for improvement in this respect.

  The present invention has been made to solve the above-described problems, and its object is to avoid failure of the failure detection circuit before detecting failure of the electric system, and to ensure the reliability of failure detection. An object of the present invention is to provide an electric pump device capable of increasing the pressure.

  In order to achieve the above object, a first aspect of the present invention includes a pump that generates hydraulic pressure, a motor that drives the pump, a control device that controls the operation of the motor, the pump, the motor, and the In the electric pump device including a housing that houses the control device and has a mounting portion to the vehicle body, the circuit board of the control device has a failure in an electrical system that electrically connects the motor and the power source. A failure detection circuit is provided, and the failure detection circuit is arranged on the circuit board so as to be above the lowest water level at which a failure occurs in the electrical system due to water immersion in the housing. This is the summary.

In other words, it is presumed that, when water has entered the housing, if the failure detection circuit is submerged, it is impossible to reliably detect a failure in the electrical system.
In this regard, in the above-described configuration, the failure detection circuit is arranged so as to be on the upper side in the gravity direction from the lowest water level at which a failure occurs in the electrical system. For this reason, when water intrudes into the housing, the failure detection circuit submerges and the failure detection (operation) cannot be performed reliably. The electric system will fail. In the above configuration, since the failure detection circuit is arranged on the upper side in the direction of gravity, even if no failure occurs in the electrical system, a part of the electrical system has rainwater before the failure detection circuit. Etc. are likely to adhere. Therefore, before the failure detection circuit can no longer detect the failure, a part of the electric system is deteriorated to cause a failure. Therefore, the failure detection circuit can detect the failure of the electric system more reliably and can improve the certainty of the failure detection.

Further, in the electric pump apparatus, the mounting portion, the circuit board in a state attached to the vehicle body is formed so as to be perpendicular to the horizontal direction. According to the above configuration, the failure detection circuit can be arranged far away from the lowest water level where the short circuit occurs in the electric system to the upper side in the direction of gravity, so that the failure detection circuit is submerged before the short circuit occurs in the electric system. Can be surely prevented.

  Furthermore, in the electric pump device, the failure detection circuit may be disposed above a range of ３ from the lower end in the gravity direction of the circuit board. According to the said structure, it can prevent suitably that a failure detection circuit is submerged before detecting the failure of an electric system.

  The electric pump device further includes current detection means for detecting a current supplied to the motor, and the failure detection circuit detects a failure of the electric system based on the current detected by the current detection means. Can do. According to the said structure, the failure of an electric system can be detected easily with a simple structure.

  The electric pump device further includes voltage detection means for detecting a voltage applied to the motor, and the failure detection circuit detects a failure of the electric system based on the voltage detected by the voltage detection means. Can do. According to the said structure, the failure of an electric system can be detected easily with a simple structure.

  ADVANTAGE OF THE INVENTION According to this invention, it can avoid that a failure detection circuit stops operating before detecting the failure of an electric system, and can provide the electric pump apparatus which can improve the certainty of failure detection.

FIG. 3 is a cross-sectional view illustrating a schematic configuration of the electric pump device according to the first embodiment. The rear view of the electric pump apparatus of Embodiment 1 of the state which removed the cover. FIG. 2 is a block diagram illustrating an electrical configuration of the electric pump device according to the first embodiment. Sectional drawing which shows schematic structure of the electric pump apparatus of Embodiment 2. FIG.

Embodiments 1 and 2 in which the present invention is embodied in an electric pump device that is mounted on a vehicle and supplies hydraulic pressure to a transmission or the like will be described below with reference to the drawings.
(Embodiment 1)
As shown in FIG. 1, the electric pump device 1 includes a housing 2 formed in a substantially cylindrical shape. In the housing 2, a pump 3 that generates hydraulic pressure, a motor 4 that drives the pump 3, and a control device 5 that controls the operation of the motor 4 are housed integrally. In the following description, one axial end side (left side in FIG. 1) of the housing 2 is a front side, and the other axial end side (right side in FIG. 1) is a rear side.

  The housing 2 includes a substantially annular pump case 11, a pump plate 12 disposed on the front side of the pump case 11, a cylindrical motor case 13 disposed on the rear side of the pump case 11, and a rear of the motor case 13. And a cover 14 for closing the opening end on the side. The pump case 11 and the pump plate 12 are made of a metal material, and the motor case 13 and the cover 14 are made of a resin material. The pump case 11, the pump plate 12, and the motor case 13 are connected to each other by bolts 15, and the cover 14 is fixed to the motor case 13 by welding (vibration welding or the like).

  In the present embodiment, a trochoid pump (internal gear pump) is employed as the pump 3. The motor 4 that is the drive source of the pump 3 employs a sensorless type brushless motor that does not have a rotation sensor for detecting the rotational position of the rotor, and the three-phase (U, V, Rotate based on the driving power of W).

  More specifically, the pump 3 includes an outer gear 21 having a tooth portion formed on the inner periphery, and an inner gear 22 having a tooth portion formed on the outer periphery. The outer gear 21 is rotatably accommodated in an accommodation hole 23 formed in the center of the pump case 11, and the inner gear 22 is disposed on the inner peripheral side of the outer gear 21. The pump plate 12 that closes the front end of the accommodation hole 23 is formed with an inlet 24 for sucking hydraulic oil and an outlet (not shown) for discharging hydraulic oil between the outer gear 21 and the inner gear 22. ing.

  O-rings 16 and 17 are interposed between the pump case 11 and the pump plate 12, and between the pump case 11 and the motor case 13, respectively. Since the cover 14 is welded to the motor case 13, the area other than the region where the hydraulic oil is introduced into the housing 2 is sealed in a liquid-tight manner to prevent rainwater and the like from entering from the outside.

  Further, the pump case 11 is formed with a cylindrical support portion 25 having a smaller diameter than the motor case 13 protruding rearward on the same axis as the accommodation hole 23. An output shaft 26 of the motor 4 serving as a drive shaft of the pump 3 is inserted into the support portion 25 in a state of projecting into the accommodation hole 23, and is separated by a bearing device 27 provided at the rear portion in the support portion 25. Has been supported. In the present embodiment, the bearing device 27 is composed of two rolling bearings adjacent to each other in the front-rear direction. An inner gear 22 is coupled to the front end of the output shaft 26 so as to be integrally rotatable. A seal member 28 is provided between the front portion of the pump case 11 relative to the support portion 25 and the output shaft 26 to prevent hydraulic fluid from leaking from the accommodation hole 23 toward the motor case 13. ing.

  The motor 4 includes a rotor 31 having the output shaft 26 and a stator 32 fixed to the inner periphery of the motor case 13. Specifically, the rotor 31 has a rotor core 34 fixed to the rear end of the output shaft 26 and a magnet 35 fixed to the rotor core 34. The rotor core 34 extends in the radial direction from the rear end of the output shaft 26, is formed in a bottomed cylindrical shape so as to surround the support portion 25, and is coupled to the rear end of the output shaft 26 so as to be integrally rotatable. The magnet 35 is fixed to the outer peripheral surface of the rotor core 34 so as to face the stator 32.

  On the other hand, the stator 32 is wound around each tooth portion 38 via an insulator 40 and a stator core 39 including a cylindrical portion 37 formed in an annular shape and a tooth portion 38 projecting radially inward from the cylindrical portion 37. And a three-phase motor coil 41. The insulator 40 is formed with a pedestal portion 42 that extends from the rear end of the cylindrical portion 37 and to which the control device 5 is fixed.

  As shown in FIGS. 1 and 2, a circuit board (printed board) 51 of the control device 5 includes a power IC chip 52 constituting a drive circuit 71 for supplying drive power to each motor coil 41, and a drive circuit. A control IC chip 53 constituting a microcomputer 72 for controlling 71 is mounted. The control device 5 is fixed to the rear side of the motor 4 by fastening the circuit board 51 to the pedestal portion 42 of the insulator 40 with a plurality of (six in this embodiment) screws 54 a to 54 f. .

  As shown in FIG. 1, the connection end 55 of each phase of the motor coil 41 is electrically connected to the control device 5 by being sandwiched between the circuit board 51 and the insulator 40. Specifically, a land 57 made of a conductive material is formed on the inner periphery of the through hole 56 through which three screws 54c, 54d, 54e (only the screw 54d is shown in FIG. 1) arranged in the vicinity of the power IC chip 52 are inserted. Is provided. The connection end 55 of the motor coil 41 is electrically connected to the control device 5 by being sandwiched between the circuit board 51 and the insulator 40 and contacting the land 57. As shown in FIG. 2, the control device 5 is connected to an in-vehicle power source (battery) 59 through a connector portion 58 formed in the motor case 13.

  And the electric pump apparatus 1 becomes a structure attached to the vehicle main body 61 so that the circuit board 51 may be orthogonal to a horizontal direction. Specifically, as shown in FIG. 2, the pump plate 12 has a mounting portion 63 that protrudes radially outward of the pump case 11 and has a bolt hole 62. And the attachment part 63 inserts a fastening bolt (not shown) into the bolt hole 62 and attaches the electric pump device 1 to the vehicle main body 61, so that the circuit board 51 is perpendicular to the horizontal direction, that is, in the direction of gravity. It is formed to be parallel.

  In the electric pump device 1 configured as described above, the three-phase driving power is supplied from the control device 5 to the motor 4, whereby the rotor 31 (the output shaft 26) rotates. When the inner gear 22 connected to the output shaft 26 rotates, the pump 3 is driven to supply hydraulic pressure to a transmission (not shown).

Next, the electrical configuration of the electric pump device will be described.
As shown in FIG. 3, the control device 5 outputs a motor control signal to the drive circuit 71 (power IC chip 52) that supplies three-phase drive power to the motor coils 41u, 41v, and 41w, and the drive circuit 71. A microcomputer 72 (control IC chip 53) for driving the motor 4 is provided. Then, the control device 5 supplies three-phase driving power to the motor 4 by energizing the motor coils 41u, 41v, and 41w of each phase with a 120-degree rectangular wave.

  Specifically, in the drive circuit 71, three switching arms corresponding to the motor coils 41u, 41v, 41w of each phase are connected in parallel with a pair of switching elements connected in series as a basic unit (switching arm). A known PWM inverter is employed. That is, the motor control signal output from the microcomputer 72 defines the on / off state (duty ratio of each phase switching arm) of each phase switching element constituting this drive circuit. The drive circuit 71 operates in response to the input of the motor control signal and supplies three-phase drive power to the motor.

  The microcomputer 72 is connected with voltage sensors 73u, 73v, 73w as voltage detecting means for detecting the terminal voltages Vu, Vv, Vw of the motor coils 41u, 41v, 41w. The microcomputer 72 estimates the rotational position (rotation angle) of the rotor 31 based on the induced voltage (back electromotive force) of each motor coil 41 detected by the voltage sensors 73u, 73v, 73w. Specifically, the rotational position of the rotor 31 is estimated by detecting the time point (zero cross point) at which the induced voltage becomes the reference potential. Then, the microcomputer 72 determines an energization pattern that is a combination of switching elements to be turned on according to the estimated rotational position of the rotor 31, that is, a combination of voltages applied to the motor coils 41u, 41v, and 41w.

The microcomputer 72 is connected to a current sensor 74 as current detection means for detecting an actual current value I supplied to the motor 4 and a host ECU for controlling the operation of the transmission. The microcomputer 72 executes a feedback control to cause the actual current value I to follow the current command value I ^* output from the host ECU, whereby a duty ratio corresponding to a deviation between the current command value I ^* and the actual current value I is obtained. To decide. Then, the microcomputer 72 outputs a motor control signal indicating the energization pattern and the duty ratio thus determined to the drive circuit 71. Thereby, three-phase drive power is supplied from the drive circuit 71, and the motor 4 rotates.

(Failure detection)
Next, failure detection in the electric pump device of this embodiment will be described.
The microcomputer 72 has a failure detection function for detecting a failure in the electrical system that electrically connects the motor 4 and the in-vehicle power supply 59. Specifically, the microcomputer 72 determines that a failure has occurred in the electrical system when the actual current value I detected by the current sensor 74 becomes a value that cannot be taken or a discontinuous value, and the electric pump device 1 The driver is informed that the vehicle has failed. That is, in this embodiment, the microcomputer 72 (control IC chip 53) corresponds to a failure detection circuit. The electric system includes a drive circuit 71, connection end portions 55 of the motor coils 41, wirings 75 and 76 between the in-vehicle power supply 59 and the drive circuit 71, and between the drive circuit 71 and the connection end portion 55. It consists of

  Here, for example, when the vehicle travels on a road flooded by heavy rain while the O-rings 16 and 17 are deteriorated due to secular change, the electric pump device 1 may be submerged, and rainwater or the like may be submerged in the housing 2. At this time, if the control IC chip 53 having a failure detection function is flooded, it may not be possible to detect a failure in the electrical system. In particular, when the control IC chip 53 is submerged, it is presumed that the failure of the electric system cannot be reliably detected.

  In consideration of this point, as shown in FIG. 2, the control IC chip 53 is disposed on the circuit board 51 at a position away from the power IC chip 52, and the electric pump device 1 is attached to the vehicle body 61. The electric system is disposed so as to be on the upper side in the gravity direction (upper side in FIG. 2) than the lowest water level Hmin at which a short circuit occurs. Specifically, the control IC chip 53 is disposed above the range of 1/3 from the lower end of the circuit board 51 in the gravity direction, and screws 54c and 54d to which the connection end portions 55 of the motor coils 41 are connected. , 54e and the power IC chip 52 are arranged on the upper side in the gravity direction. In the present embodiment, the position where the plurality of terminals 52a provided so as to extend downward from the power IC chip 52 in the direction of gravity is the minimum water level Hmin. As a result, when rainwater or the like is submerged in the housing 2, the terminals of the power IC chip 52 are submerged first and short-circuited to the electrical system before the control IC chip 53 having the failure detection function as described above. Has come to occur.

As described above, according to the present embodiment, the following operational effects can be achieved.
(1) With the electric pump device 1 attached to the vehicle main body 61, the attachment portion 63 to the vehicle main body 61 is formed so that the circuit board 51 of the control device 5 is orthogonal to the horizontal direction. Then, the control IC chip 53 constituting the microcomputer 72 for detecting the failure of the electric system is placed on the circuit board 51 in the direction of gravity with respect to the minimum water level Hmin that causes a short circuit in the electric system due to water immersion in the housing 2. It arranged so that it might become the upper side.

  According to the above configuration, when the housing 2 is submerged, a part of the electric system is submerged before the control IC chip 53 is submerged and cannot be reliably detected (operated). As a result of the short circuit, the electrical system fails. In the above configuration, since the control IC chip 53 is arranged on the upper side in the direction of gravity, even if there is no short circuit in the electrical system, the control IC chip 53 is partly connected to the electrical system. In addition, rainwater or the like is likely to adhere first. Therefore, before the control IC chip 53 can no longer detect a failure, a part of the electric system is deteriorated, resulting in a failure. Therefore, the control IC chip 53 can more reliably detect a failure in the electric system, and can improve the certainty of the failure detection.

  (2) Since the circuit board 51 is formed so as to be orthogonal to the horizontal direction in a state in which the attachment portion 63 is attached to the vehicle body 61, the control IC chip 53 is moved upward from the lowest water level Hmin at which the electrical system is short-circuited. Can be arranged far apart. Thus, it is possible to reliably prevent the control IC chip 53 from being submerged before a short circuit occurs in the electrical system.

  (3) Since the control IC chip 53 (microcomputer 72) detects the failure of the electric system based on the actual current value I, the failure of the electric system can be easily detected with a simple configuration. Become.

  (4) Since the control IC chip 53 is disposed above the range of 1/3 from the lower end of the circuit board 51 in the direction of gravity, it is preferable that the control IC chip 53 be submerged before detecting a failure in the electrical system. Will be able to prevent.

In addition, the said embodiment can also be implemented in the following aspects which changed this suitably.
In the above embodiment, the control IC chip 53 is arranged above the range of 1/3 from the lower end in the gravity direction of the circuit board 51, and the screw 54c to which the connection end 55 of each motor coil 41 is connected. 54d and 54e and the power IC chip 52 are arranged on the upper side in the gravity direction. However, the present invention is not limited to this, and it is only necessary that the control IC chip 53 is disposed above the lowest water level Hmin in the gravity direction. For example, the control IC chip 53 is disposed above the range of 1/3 from the lower end of the circuit board 51 in the gravity direction. May be. Further, for example, the control IC chip 53 and the power IC chip 52 are disposed above the straight line connecting the screws 54 c and 54 e, and the power IC chip 52 is disposed above the control IC chip 53. Good. In this case, the position of the straight line connecting the screws 54c and 54e is the lowest water level Hmin.

  In the above embodiment, the microcomputer 72 detects a failure in the electric system based on the actual current value I. However, the present invention is not limited to this, and the terminal voltages Vu, Vv detected by the voltage sensors 73u, 73v, 73w. , Vw may be a value that cannot be taken or a discontinuous value, it may be determined that a failure has occurred in the electrical system.

  In the above embodiment, the mounting portion 63 is formed so that the circuit board 51 is orthogonal to the horizontal direction in a state where the electric pump device 1 is attached to the vehicle body 61. However, the circuit board 51 is not limited to this, and the circuit board 51 is horizontal. You may form so that it may cross with respect to a direction.

(Embodiment 2)
In FIG. 4, the electric pump apparatus 1 of Embodiment 2 is shown. In the second embodiment, the configuration is the same as that of the first embodiment except for the attachment form of the control unit 5, and thus detailed description of each part is omitted.

  In the second embodiment, the attachment portion is formed so that the circuit board 51 is in the horizontal direction in a state where the electric pump device 1 is attached to the vehicle body. The circuit board 51 is fixed to the motor case 13 and the pump case 11 via screws 54. The control IC chip 53 is mounted on one surface of the circuit board 51, the power IC chip 52 is mounted on the other surface, and the control IC chip 53 is located above the power IC 52 chip in the gravity direction. Be placed. In the present embodiment, the position where a plurality of terminals protrude from the power IC chip 52 is the lowest water level Hmin. The cover 14 is fixed to the pedestal 42 of the motor case 13 by another bolt 60 and closes the lower opening end of the control unit 5.

  The operational effects of the second embodiment are the same as those of the first embodiment. That is, according to such a configuration, when the housing 2 is submerged, the control IC chip 53 is submerged and before the failure detection (operation) can be reliably detected (operation), the electrical system When the part is submerged and a short circuit occurs, the electrical system fails. In the above configuration, since the control IC chip 53 is arranged on the upper side in the direction of gravity, even if there is no short circuit in the electrical system, the control IC chip 53 is partly connected to the electrical system. In addition, rainwater or the like is likely to adhere first. Therefore, before the control IC chip 53 can no longer detect a failure, a part of the electric system is deteriorated, resulting in a failure. Therefore, the control IC chip 53 can more reliably detect a failure in the electric system, and can improve the certainty of the failure detection.

  This application is based on Japanese Patent Application No. 2011-000123 filed on January 4, 2011, the contents of which are incorporated herein by reference.

  ADVANTAGE OF THE INVENTION According to this invention, it can avoid that a failure detection circuit stops operating before detecting the failure of an electric system, and can provide the electric pump apparatus which can improve the certainty of failure detection.

  DESCRIPTION OF SYMBOLS 1 ... Electric pump apparatus, 2 ... Housing, 3 ... Pump, 4 ... Motor, 5 ... Control apparatus, 11 ... Pump case, 12 ... Pump plate, 13 ... Motor case, 14 ... Cover, 21 ... Outer gear, 22 ... Inner gear, 26 ... Output shaft, 31 ... Rotor, 32 ... Stator, 34 ... Rotor core, 35 ... Magnet, 39 ... Stator core, 40 ... Insulator, 41, 41u, 41v, 41w ... Motor coil, 51 ... Circuit board, 52 ... Power IC chip 53 ... Control IC chip, 55 ... Connection end, 59 ... In-vehicle power supply, 61 ... Vehicle body, 63 ... Mounting part, 71 ... Drive circuit, 72 ... Microcomputer, 73u, 73v, 73w ... Voltage sensor, 74 ... Current Sensor, 75, 76 ... wiring, Hmin ... lowest water level.

Claims (4)

A pump that generates hydraulic pressure, a motor that drives the pump, a control device that controls the operation of the motor, a housing that houses the pump, the motor, and the control device, and that has a mounting portion to the vehicle body; In the electric pump device provided with
The circuit board of the control device is provided with a failure detection circuit that detects a failure of an electrical system that electrically connects the motor and the power source,
The failure detection circuit is arranged on the circuit board so as to be on the upper side in the direction of gravity from the lowest water level at which failure occurs in the electrical system due to water immersion in the housing .
The electric pump device according to claim 1, wherein the attachment portion is formed so that the circuit board is orthogonal to a horizontal direction in a state of being attached to the vehicle body . 2. The electric pump device according to claim 1 , wherein the failure detection circuit is arranged above a range of １ ／ from the lower end in the gravity direction of the circuit board. 3. The electric pump device according to claim 1 , further comprising a current detection unit configured to detect a current supplied to the motor, wherein the failure detection circuit is configured to perform the electric detection based on the current detected by the current detection unit. An electric pump device characterized by detecting a system failure. 3. The electric pump device according to claim 1 , further comprising a voltage detection unit that detects a voltage applied to the motor, wherein the failure detection circuit is configured to perform the electric detection based on the voltage detected by the voltage detection unit. An electric pump device characterized by detecting a system failure.

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