JP2010254203A - Power device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable power device coping with the failing of a motor. <P>SOLUTION: The power device includes: a plurality of motors 21a, 21b; a plurality of pumps 22a, 22b provided correspondingly to each of the plurality of motors 21a, 21b, and generating pressure by receiving the rotating power of the corresponding motors 21a, 21b; a plurality of piping passages 62a, 62b, 65a, 65b provided correspondingly to each of the plurality of pumps 22a, 22b; pipes 23 for communicating the plurality of piping passages 62a, 62b, 65a, 65b; and control valves 25a-25d provided to the pipes 23, and for controlling the communication of the plurality of piping passages 62a, 62b, 65a, 65b. In the power device, when abnormalities occur in one of the plurality of motors 21a, 21b, the control valves 25a-25d are controlled, and the plurality of piping passages 62a, 62b, 65a, 65b are communicated with each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique related to a power plant, typically a technique for improving reliability.

  For example, a technique disclosed in Patent Document 1 is known as a background art related to a power unit. Patent Document 1 discloses an in-wheel motor-type vehicle drive device that is mounted on an electric vehicle as a power device and applies rotational power independently to each of the front wheels or the left and right wheels of the rear wheels. The power device disclosed in Patent Document 1 requires cooling of the in-wheel motor itself, lubrication of a power transmission mechanism (gear mechanism such as a speed reducer) that mechanically connects the in-wheel motor and the axle, and the like. For this reason, the oil pump is operated by the rotational power of the in-wheel motor to circulate the oil to the in-wheel motor and the power transmission mechanism.

JP 2007-131027 A

  In recent years, the electrification of systems has become widespread because of the need to meet social demands such as reducing the burden on the global environment and promoting energy conservation. Recently, along with the widespread use, some systems have a plurality of motors mounted on one system. The motor is a power source preferable for environmental characteristics and the like, and has a feature that it has higher responsiveness and controllability to an operation request than an internal combustion engine such as an engine. On the other hand, in order to electrify the system, the system is constructed in consideration of the case where the motor fails, so that the influence does not reach the system or the influence on the system can be suppressed to a small level. This is very important. In this regard, there is no disclosure in the background art from the viewpoint of motor failure.

  One of the representative aspects of the present invention provides a highly reliable power unit that can cope with a motor failure.

  One of the representative aspects of the present invention is a power unit including a plurality of motors, a plurality of medium circulation pipes provided corresponding to each of the plurality of motors, and the plurality of medium circulation pipes. And a plurality of pumps that receive rotational power from the motors corresponding to each of the plurality of medium circulation pipes and generate pressure for medium circulation in the corresponding medium circulation pipes, and communicate with the plurality of medium circulation pipes. And a control valve for controlling the communication between the plurality of medium circulation pipes, which is provided in the communication pipe.

  According to one of the representative aspects of the present invention, when a failure occurs in one motor, the control valve is controlled to connect a plurality of medium circulation pipes so that the medium is supplied from the normal medium circulation pipes to the fail side. It is possible to operate the pump provided in the medium circulation pipe on the fail side by sending it to the medium circulation pipe and circulating the medium circulation pipe on the fail side. Thus, in one of the representative aspects of the present invention, power can be transmitted to the motor in which the failure has occurred, and the driven body that has been driven by the motor in which the failure has occurred is driven using the motor in which the failure has occurred as a power transmission mechanism. can do.

  As a result, according to one of the representative aspects of the present invention, when a failure occurs in one motor, the influence on the system can be suppressed, or the influence on the system can be reduced. Safety can be improved. Therefore, according to one of the representative aspects of the present invention, it is possible to provide a highly reliable power device that can cope with a motor failure.

The block diagram which shows the structure of the vehicle drive device which is 1st Example of this invention. The block diagram which shows the connection state (refer (a)) of the motor and pump which comprise the vehicle drive device of FIG. 1, and the connection state (refer (b)) of a motor, a reduction gear, and a pump. The flowchart which shows the control action at the time of the motor failure of FIG. The block diagram which shows the system operation state at the time of the motor failure of FIG. Explanatory drawing for demonstrating the behavior of the vehicle based on the control action at the time of the motor failure of FIG. The block diagram which shows the structure of the vehicle drive device which is 2nd Example of this invention. 7 is a flowchart showing a control operation at the time of motor failure in FIG. 6. The flowchart which shows the control action based on the vehicle operation state of FIG. The block diagram which shows the structure of the vehicle drive device which is 3rd Example of this invention. 10 is a flowchart showing a control operation at the time of motor failure in FIG. 9.

  Examples of the present invention will be described.

  In the embodiments of the present invention to be described below, the present invention is applied to a pure electric vehicle having a motor as the only drive source of the vehicle, particularly a pure electric vehicle equipped with an in-wheel motor type vehicle driving device. Will be described.

  The configuration of the power unit described below includes other vehicles, for example, a pure electric vehicle equipped with a vehicle drive device other than an in-wheel motor type vehicle drive device, a hybrid vehicle equipped with an engine and a motor as a drive source of the vehicle, an engine Forklifts used for loading and unloading heavy vehicles such as ordinary cars, buses (passenger vehicles), trucks (cargo vehicles), heavy vehicles that are heavier than ordinary cars, railway vehicles such as hybrid trains, etc. Of special vehicles (machines) equipped with equipment required for work, such as trucks, vehicles used for civil engineering work and construction work (machines), for vehicle drive, for other purposes, or for vehicle drive and other As an application, it may be applied to a vehicle equipped with two or more motors that generate rotational power.

  In addition, the configuration of the power device described below generates rotational power among power devices provided other than vehicles, for example, power devices provided in industrial facilities such as factories, power devices mounted on ships, and the like. You may apply to the motive power apparatus provided with two or more motors to make.

  An in-wheel motor vehicle drive device is a power device in which a motor is mounted on all two wheels (left and right wheels) or four wheels of an electric vehicle. The motor is more responsive and controllable to the required operation than the engine. For this reason, in an electric vehicle equipped with an in-wheel motor type vehicle drive device, taking advantage of its characteristics, either the front wheel or the rear wheel (left and right wheels), or all four wheels, depending on the driver's operation The driving force of the vehicle is appropriately controlled to achieve vehicle stability during traveling such as when the vehicle is traveling straight or turning.

  However, in an electric vehicle equipped with an in-wheel motor type vehicle drive device, when one motor falls into a state where it cannot generate rotational power due to a failure, either the front wheel or the rear wheel (left and right wheels), or It is considered that there is a difference in the rotational speed and output torque between the four-wheel motors, and a moment that turns around the wheel corresponding to the motor that has fallen into the wheel is generated. For this reason, the vehicle behavior is disturbed. It is considered that the operability of the vehicle is lowered. For this reason, in an electric vehicle equipped with an in-wheel motor type vehicle drive device, it is possible to minimize the influence of the motor failure on the vehicle behavior or the influence of the motor failure on the vehicle behavior. Thus, it is very important to plan for this.

  Incidentally, in-wheel motor type vehicle drive devices require cooling of the motor itself, lubrication of a power transmission mechanism (for example, a gear mechanism such as a speed reducer) that mechanically connects the motor and the axle. For this reason, the in-wheel motor vehicle drive apparatus includes a circulation system for circulating a refrigerant and a circulating medium (for example, oil) serving as a lubricant to a motor, a power transmission mechanism, and the like. Moreover, the circulation system is provided independently for each motor. Until now, the circulation system has been used only for cooling the motor and lubricating the power transmission mechanism.

  On the other hand, it is conceivable to introduce a new backup system as one of means for dealing with motor failure. However, the introduction of a new backup system leads to an increase in the size and cost of an in-wheel motor type vehicle drive device.

  For this reason, in-wheel motor type vehicle drive devices have been desired to realize means that can cope with motor failure at a small size and at low cost.

  Therefore, in the embodiments described below, attention is paid to the circulation system that has been used only for cooling the motor, lubricating the power transmission mechanism, and the like. A circulation system that is provided independently for the motor on the normal side is circulated to circulate the medium of the circulation system that corresponds to the motor on the normal side to the circulation system that corresponds to the motor on the failure side, and Operate. As a result, power is transmitted from the pump corresponding to the fail-side motor to the fail-side motor, and the fail-side motor is used as a power transmission mechanism to transmit rotational power to the wheels driven by the fail-side motor. Wheels can be driven.

  From the above, in the embodiment described below, it is possible to suppress the influence of the motor failure on the vehicle behavior or to suppress the influence on the vehicle behavior due to the motor failure. Therefore, in the embodiment described below, it is possible to improve the safety of an in-wheel motor type vehicle drive device and to provide a highly reliable in-wheel motor type vehicle drive device that can cope with a motor failure. Can do.

  Hereinafter, the present embodiment will be specifically described with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS.

  First, the configuration of the drive device mounted on the vehicle 10 will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the vehicle 10 includes wheels 11a to 11d, braking / driving motors 21a and 21b, pumps 22a and 22b, pipes 23 connecting the pumps 22a and 22b, a radiator 24, and a control valve. 25a to 25d, a motor controller 31 that transmits a drive command and the like to the motors 21a and 21b, a control valve controller 32 that transmits an opening and closing command to the control valves 25a to 25d, a vehicle speed, the motors 21a and 21b, and the control valves 25a to 25a A meter 33 for displaying a warning when an abnormality occurs in 25d and the like, and a signal line 34 for transmitting signals to the motors 21a and 21b and the control valves 25a to 25d are provided.

  The wheel 11a and the motor 21a, and the wheel 11b and the motor 21b are connected directly or via a reduction gear, respectively. The motor 21a and the pump 22a, and the motor 21b and the pump 22b are mechanically connected via shafts 61a and 61b, respectively, as shown in FIG. 2 (a), or as shown in FIG. 2 (b), the speed reducer 63a. And mechanically connected via a shaft 64a, a speed reducer 63b and a shaft 64b.

  In addition, a belt may be sufficient as the connection method of a motor, a reduction gear, and a pump.

  The motor 21a and the pump 22a, and the motor 21b and the pump 22b are connected by cooling pipes 62a and 62b shown in FIG. Oil pressurized by the pumps 22a and 22b flows through the cooling pipes 62a and 62b, and the motors 21a and 21b are cooled by the oil.

  2B, when the speed reducers 63a and 63b are provided, the speed reducer 63a and the pump 22a, and the speed reducer 63b and the pump 22b are connected by lubrication pipes 65a and 65b, respectively. Oil pressurized by the pumps 22a and 22b flows through the lubrication pipes 65a and 65b, and the gears of the reduction gears are lubricated by the oil.

  In FIG. 2B, the cooling pipes 62a and 62b and the lubrication pipes 65a and 65b are connected to one pump 22a and 22b, respectively, but may be connected to two or more different pumps.

  The pumps 22a and 22b, the control valves 25a to 25d, and the radiator 24 are connected by a pipe 23, and oil pressurized by the pumps 22a and 22b flows in the pipe 23. This oil flows through the radiator 24 and is cooled by the heat radiation action of the radiator 24.

  The number of control valves shown in FIG. 1 is the minimum necessary number, but may be increased or decreased according to the handling of the piping 23.

  In the case of a drive system that does not require lubrication of the gears of the speed reducer and only requires cooling of the motor, the medium in the pipe may be other liquid medium such as water or antifreeze.

  Furthermore, although the radiator 24 is integrated in the left and right in FIG. 1, it may be independent in the left and right. In FIG. 1, the radiator 24 is provided as a heat dissipation device for the oil in the pipe 23, but the radiator 24 may be a heat storage device. When used as a heat storage device, it can be used to increase the heat source of a heater or the temperature of a battery whose performance deteriorates at low temperatures, so that an effect of reducing energy consumption can be expected.

  In this embodiment, it is illustrated that a plurality of pipes are connected to each other by connecting a plurality of pipes to the pump 22, but actually, branch pipes are provided on the discharge side and the suction side of the pump, and the branches A plurality of pipes are connected by connecting a plurality of pipes therebetween.

  Although not shown, the motor controller 31 transmits to the motors 21a and 21b based on the driver's accelerator operation detected by various sensors such as an accelerator opening sensor, a wheel speed sensor, and a yaw rate sensor, and vehicle behavior such as vehicle speed and yaw rate. Determine the drive command. For example, when the vehicle behavior is disturbed, a drive command giving priority to stabilization of the vehicle behavior is output even if the accelerator operation is fully open. Further, the motor controller 31 detects, for example, detection values of wheel speed sensors with respect to drive commands transmitted to the motors 21a and 21b and electric power supplied to the motors 21a and 21b, and detection of temperature sensors provided in the motors 21a and 21b (not shown). When an abnormality occurs in the value, the warning lamp of the meter 33 is turned on to inform the driver of the abnormality of the drive system.

  The control valve controller 32 is provided on a pipe that connects the left and right drive systems to the control valves 25a and 25b provided on the left and right pipes according to the state of the drive systems such as the motors 21a and 21b. An open / close command to be transmitted to the control valves 25c and 25d is determined.

  Next, the operation of each controller and each actuator when the motor fails will be described with reference to FIGS.

  Here, each controller refers to the motor controller 31 and the control valve controller 32. Each actuator is the motors 21a and 21b and the control valves 25a to 25d connected to each controller through the signal line 34.

  Each controller detects a value necessary for determining the state of each actuator to be controlled by a wheel speed sensor provided on the wheels 11a to 11d or a pressure sensor provided on the pipe 23 (S1). Here, as a method for determining the state, for example, in the case of the motors 21a and 21b, the motor 21a and 21b are supplied with the same drive command and power supply, but the rotational speed detected by the wheel speed sensor exceeds a certain value. If the difference occurs, it is determined that an abnormality has occurred in the motor that outputs an invalid value for the drive command or the supplied power. In the case of the control valves 25a to 25d, the open / close state of the control valve is determined from the hydraulic pressure in the pipe 23 detected by the pressure sensor.

  Next, the motor controller 31 determines the state of the motors 21a and 21b from the rotational speed detected in step S1 (S2). For example, if the difference in the number of rotations detected by the wheel speed sensor is greater than or equal to a certain value as described above, it is determined that there is an abnormality, and the process proceeds to step S3. If not, the process proceeds to step 7. .

  Next, when it is determined in step S2 that there is an abnormality, the motor controller 31 determines whether one of the motors 21a and 21b is abnormal or whether both are abnormal (S3). Here, if it is determined that the one-system abnormality is detected, the motor controller 31 lights a warning lamp indicating the one-system motor abnormality on the meter 33, and then proceeds to step 6 (S4). When it is determined that both systems are abnormal, the motor controller 31 turns on a warning lamp indicating a running abnormality on the meter 33 (S5).

  Next, when an abnormality in one system is detected in step S3, the control valve controller 32 transmits an opening / closing command to the control valves 25a to 25d to adjust the flow path in the pipe. When an abnormality is detected in one system, for example, the motor 21b, the control valves 25a and 25b are closed and the control valves 25c and 25d are opened to operate the pump 22b as a hydraulic motor (S6). As a result, the flow paths of the left and right drive systems are connected, so that the oil 71a discharged from the pump 22a is sent to the pump 22b as shown in FIG. 4A, and the oil 71b discharged from the pump 22b returns to the pump 22a again. Thus, the motor 21b and the wheel 11b can be rotated.

  Next, when it is determined in step S2 that there is no abnormality in the motor, the control valve controller 32 opens to the control valves 25a and 25b and closes to the control valves 25c and 25d in order to maintain the independent state of the left and right drive systems. A command is transmitted (S7). In this case, as shown in FIG. 4B, the oil 71a discharged from the pump 22a returns to the pump 22a, and the oil 71b discharged from the pump 22b returns to the pump 22b, so that the left and right drive systems can be kept independent. it can.

  Next, the function and effect of this embodiment will be described with reference to FIG.

  When the flowchart of FIG. 3 is executed, for example, the vehicle behavior shown in FIG. 5 occurs. FIG. 5 shows the behavior of the vehicle when the right front wheel motor of the vehicle 81 traveling straight at a constant speed stops rotating at a point 82 due to an abnormality.

  Note that the target locus of the vehicle 81 in FIG. 5 is a locus 85 that maintains a straight traveling state.

  A trajectory 83 and a trajectory 84 are trajectories traveled by a vehicle equipped with a general left and right independent drive system that is not connected to the left and right by piping or the like. The trajectory 83 is uncorrected, and the trajectory 84 is a trajectory of the travel trajectory of the vehicle. This is the result of the driver or automatically steering or braking the four wheels independently to return to 85.

  The vehicle 81 traveling on the trajectory 84 eventually returns on the trajectory 85, but once deviates from the trajectory 85 in the same manner as the trajectory 83, and may collide with a road shoulder, a median strip, an oncoming vehicle, etc. on an actual road. There is. On the other hand, in the drive system of the present embodiment, the torque of the left front wheel motor is transmitted to the motor of the right front wheel at the same time as passing through the point 82. You can drive over 85.

  A second embodiment of the present invention will be described with reference to FIGS.

  This embodiment is an improved example of the first embodiment, and an accumulator 40 capable of accumulating pressure and control valves 26a to 26d for opening and closing a flow path of a pipe connecting the accumulator 40 and the left and right drive systems are newly provided in a vehicle. This is an example added to FIG.

  The other configuration is basically the same as that of the first embodiment. For this reason, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  The accumulator 40 accumulates surplus pressure that is not necessary for cooling and lubrication among the pressures generated by the rotation of the pumps 22a and 22b. The pressure accumulated in the accumulator 40 is used as auxiliary power according to the driving state of the motors 21a and 21b and the vehicle behavior. For example, when the motor torque is required more than usual, such as when starting or accelerating, the power consumption of the motor can be suppressed and the cruising distance can be extended.

  The control valves 26 a to 26 d open and close the inlet / outlet of the pipe 23 connected to the accumulator 40, and are controlled by the control valve controller 32.

  Next, the operation of each controller and each actuator when the motor fails will be described with reference to FIG.

  FIG. 7 is a control flow when the motor fails, as in FIG. Further, since steps S1 to S7 in FIG. 7 are the same as those in FIG. 3, the description thereof is omitted.

  When an abnormality in one system is detected in step S3, the motor controller 31 determines whether or not assistance by the pressure accumulated in the accumulator 40 is necessary (S8). Here, the condition for determining that the auxiliary power is necessary is, for example, that there is a large difference in rotational speed between a motor that is operating normally and a motor that has detected an abnormality. This is a case where the rotational speed of the motor in which the abnormality is detected cannot be increased quickly.

  Next, when it is determined in step S8 that auxiliary power is required, the control valve controller 32 opens to the control valves 26a and 26c to use the pressure accumulated in the accumulator 40. The control valves 26b and 26d include Send a close command.

  Next, when it is determined in step S2 that there is no abnormality in the motor, or when it is determined in step 8 that auxiliary power is not required, the control valve controller 32 controls the control valve 26b in order to maintain the accumulator 40 in the pressure accumulation state. , 26d, and a close command to the control valves 26a, 26c are transmitted (S10).

  When the flowchart of FIG. 7 is executed, basically the vehicle behavior similar to that of FIG. 5 of the first embodiment occurs. However, there is a large difference in the number of rotations between a motor that is operating normally and a motor that has detected an abnormality, and the power from a motor that is operating normally can be used to quickly increase the number of rotations of a motor that has detected an abnormality. If this is not possible, the disturbance of the vehicle behavior can be suppressed more quickly than in the first embodiment by using the pressure accumulated in the accumulator 40.

  Next, the operation of each controller and each actuator based on the driving state of the vehicle will be described with reference to FIG.

  FIG. 8 is a control flow when the motor fails as in FIG. Moreover, since step S1 of FIG. 8 is the same as that of FIG. 2, the description is abbreviate | omitted.

  The control valve controller 32 determines a driver request such as start or acceleration from the vehicle speed or the accelerator opening (S11). In step S11, when it is determined that there is a request for starting or acceleration from the driver, the control valve controller 32 transmits a command to open to the control valves 26a and 26c and to the control valves 26b and 26d (S9). Conversely, when it is determined in step 11 that there is no request for starting or acceleration from the driver, the control valve controller 32 transmits a command to open to the control valves 26b and 26d and to close to the control valves 26a and 26c (S10). .

  When the flowchart of FIG. 8 is executed, the motor power consumption is reduced by using the pressure accumulated in the accumulator 40 as auxiliary power when the motor torque is required more than usual, such as when starting or accelerating, and the cruising distance is extended. Can be achieved.

  A third embodiment of the present invention will be described with reference to FIGS.

  This embodiment is an improvement of the first embodiment. The pumps 22a and 22b of the first embodiment are divided into small pumps 27a and 27b and large pumps 28a and 28b, and the small pumps 27a and 27b and the large pump Clutches 51a and 51b for connecting 28a and 28b, a clutch controller 34 for controlling the engagement / release of the clutches 51a and 51b, and control valves 29a to 29d for opening and closing the passages of the large pumps 27a and 27b. This is an example.

  The other configuration is basically the same as that of the first embodiment. For this reason, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  The small pumps 27a and 27b are pumps having a minimum size necessary for cooling and lubrication.

  The large pumps 28a and 28b are pumps for transmitting the power of the motors 21a and 21b, and their sizes are determined by the torque to be transmitted.

  The clutches 51a and 51b are devices that connect the small pumps 27a and 27b and the large pumps 28a and 28b. Normally, the clutches 51a and 51b are released, but the motor controller 31 determines that the large pumps 28a and 28b are necessary. To be concluded.

  The clutch controller 34 controls the engagement / disengagement of the clutches 51a and 51b in accordance with a command from the motor controller 31.

  Next, the operation of each controller and each actuator when the motor fails will be described with reference to FIG.

Since steps S1 to S7 in FIG. 10 are the same as those in FIG. 3 and FIG.

  When an abnormality in one system is detected in step S3, the control valve controller 32 transmits an opening command to the control valves 29a to 29d (S12).

  Next, in order to rotate the large pumps 28a and 28b, the clutch controller 34 transmits an engagement command to the clutches 51a and 51b (S13).

  If it is determined in step S2 that there is no abnormality in the motor, or if it is determined in step S8 that auxiliary power is not required, the control valve controller 32 controls the control valve 29a in order to maintain the driving of only the small pumps 27a and 27b. -29d is sent (S14), and the clutch controller 34 sends a release command to the clutches 51a, 51b so as not to rotate the large pumps 28a, 28b (S15).

  When the flowchart of FIG. 10 is executed, basically the vehicle behavior similar to that of FIG. 5 of the first embodiment occurs. However, when the left and right motors are in a normal state, only the minimum necessary pump that is smaller than the first embodiment operates, so that it consumes less energy than the first embodiment and can be expected to extend the cruising distance.

Claims (7)

Multiple motors,
A plurality of pumps which are provided corresponding to each of the plurality of motors and generate pressure by receiving the rotational power of the corresponding motors;
A plurality of piping lines corresponding to each of the plurality of pumps;
Piping for communicating between the plurality of piping paths;
A control valve provided in the pipe for controlling communication of the plurality of pipe lines,
A power plant characterized by that. The power plant according to claim 1, wherein
A plurality of the pumps are provided for each of the plurality of motors,
In each of the plurality of motors, a clutch for controlling a mechanical connection between the rotation shafts of the plurality of pumps is provided.
A power plant characterized by that. The power plant according to claim 1 or 2,
Provided with an accumulator capable of accumulating the pressure generated by the pump;
A power plant characterized by that. The power plant according to any one of claims 1 to 3,
The control valve has a function of adjusting the flow rate in the pipe,
A power plant characterized by that. The power plant according to any one of claims 1 to 4,
When the plurality of motors are operating normally, the control valve is closed,
When an abnormality occurs in one of the plurality of motors, the control valve is opened.
A power plant characterized by that. The power plant according to claim 3,
Using the accumulator as an auxiliary power source for the motor, the pump is rotated by the accumulated pressure,
A power plant characterized by that.   A vehicle comprising the power unit according to claim 1 as a drive unit.

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