Driving device

Abstract

To improve operability.SOLUTION: A driving device includes a motor for driving a driving shaft connected to an axle shaft, a shift device for changing a shift range by pressing operation by a driver, and a control device for controlling the motor so as to output a torque based on the changed shift range, when the shift range has been changed, wherein the control device permits the change of the shift range for each predetermined time, when the torque after speed change output from the motor when the shift range is further changed satisfies a predetermined condition, in a case in which the pressing operation to the shift device is continuous.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a drive device. [Background technology]

[0002] Conventionally, as this type of drive device, one that has been proposed is one that includes a motor that drives a drive shaft connected to an axle, and a shift lever that allows the driver to select a shift range (see, for example, Patent Document 1). In this drive device, the motor is controlled so that a target torque based on the currently selected shift range is output. Then, when the shift lever is operated and a change in the shift range is detected, the motor is controlled so that a torque that has been subjected to first-order delay processing with a predetermined gain for a post-change target torque based on the post-change shift range is output. This is said to be able to suppress shock when changing the shift range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-77585 A Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in a drive device equipped with a shift device that changes the shift range by a pressing operation by a driver, when the shift device is pressed, a process is performed to control the motor so that a target torque set using the target range and the vehicle speed is output, with a predetermined range changed from the shift range at the time of pressing being set as a target range. In this drive device, depending on the shift range desired by the driver, the driver needs to perform a pressing operation on the shift device multiple times. Such multiple pressing operations can be annoying to the driver, and it is desired to improve operability.

[0005] A primary object of the present disclosure is to improve operability. [Means for solving the problem]

[0006] The driving device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The drive device of the present disclosure is A motor that drives a drive shaft connected to the axle; A shift device that changes a shift range by a driver's pressing operation; a control device that controls the motor when the shift range is changed so that a torque based on the changed shift range is output; A drive device comprising: When the pressing operation on the shift device continues and a post-shift torque output from the motor when the shift range is further changed satisfies a predetermined condition, the control device permits the change of the shift range at predetermined time intervals. The gist of the present invention is as follows.

[0008] In the drive device disclosed herein, when the pressing operation on the shift device continues, if the post-shift torque output from the motor when the shift range is further changed satisfies a predetermined condition, the shift range is permitted to be changed at predetermined time intervals. As a result, when the post-change torque satisfies the predetermined condition, the shift range can be changed at predetermined time intervals by continuing the pressing operation on the shift device, and the shift range can be changed continuously. As a result, operability can be improved. Here, the "predetermined condition" can be, for example, a condition that the torque that can be output from the motor is equal to or less than a predetermined torque. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing an outline of the configuration of an electric vehicle 20 equipped with a drive device according to the present embodiment. [Diagram 2]4 is a flowchart showing an example of a downshift processing routine executed by an ECU 50. [Diagram 3] 4 is an explanatory diagram showing an example of a state of a downshift command and a change over time in the torque (motor torque) output from the motor 32. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of an electric vehicle 20 equipped with a drive device of the present embodiment. As shown in the figure, the electric vehicle 20 includes a motor 32 for running, an inverter 34, a battery 36, an electronic control unit (control device, hereinafter referred to as "ECU") 50, and a shift lever (shift device) 61.

[0011] The motor 32 is configured as a three-phase AC motor and includes a rotor having a permanent magnet embedded in a rotor core and a stator having a three-phase coil wound around the stator core. The rotor of the motor 32 is connected to a drive shaft 26 that is connected to the drive wheels 22a, 22b via a differential gear 24.

[0012] The inverter 34 is used to drive the motor 32. The inverter 34 is connected to the battery 36 via a power line 38, and has six transistors T11-T16 as switching elements, and six diodes D11-D16 connected in parallel to the six transistors T11-T16, respectively. The transistors T11-T16 are arranged in pairs, two at a time, so as to be on the source side and the sink side of the positive and negative lines of the power line 38, respectively. The connection points of the two transistors in each pair are connected to the coils of the corresponding phases (U-phase, V-phase, W-phase) of the motor 32. Therefore, when a voltage is applied to the inverter 34, the ECU 50 adjusts the ratio of the on-time of the paired transistors T11-T16, thereby forming a rotating magnetic field in the three-phase coils, and the motor 32 is driven to rotate.

[0013] The battery 36 is configured as a lithium ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the inverter 34 via a power line 38. A smoothing capacitor 39 is attached to the power line 38.

[0014] The ECU 50 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, and input / output ports. The ECU 50 receives inputs of the rotational position θm of the rotor of the motor 32 from the rotational position sensor 32a, the phase currents Iu and Iv of the U-phase and V-phase of the motor 32 from the current sensors 32u and 32v, the voltage Vb of the battery 36 from the voltage sensor 36a, the current Ib of the battery 36 from the current sensor 36b, and the voltage VL of the power line 38 (capacitor 39) from the voltage sensor 39a. The ECU 50 also receives inputs of a start signal from a start switch 60, a shift range SP that is the operation position of the shift lever 61 from a shift range sensor 62, an accelerator opening Acc that is the depression amount of the accelerator pedal 63 from an accelerator pedal sensor 64, and a brake pedal range BP that is the depression amount of the brake pedal 65 from a brake pedal sensor 66. The ECU 50 also receives inputs of a vehicle speed V from a vehicle speed sensor 67.

[0015] As the shift range SP of the shift lever 61, a parking range (P range) used when parking, a reverse range (R range) for backward driving, a normal drive range (D range) for forward driving, a third-speed range M3, a second-speed range M2, a first-speed range ML, etc. are prepared. Each time the shift lever 61 is pressed in a first direction (for example, toward the driver's seat as viewed from the driver's seat, downward (-) direction in FIG. 1) from a predetermined neutral position, the shift range SP is changed to a third-speed range M3, a second-speed range M2, or a first-speed range L, and a downshift command is sent to the ECU 50. Also, each time the shift lever 61 is pressed in a second direction (for example, toward the driver's seat as viewed from the driver's seat, upward (+) direction in FIG. 2) from the neutral position N, the shift range SP is changed to a first-speed range L, a second-speed range M2, or a third-speed range M3, and an upshift command is sent to the ECU 50. A control signal to the motor 32 and the like are output from the ECU 50.

[0016] In the electric vehicle 20 of the embodiment, the ECU 50 sets the traveling torque requirement (target torque) Td* required for traveling (required for the drive shaft 26) as the torque command Tm* of the motor 32, and controls the transistors T11 to T16 of the inverter 34 so that the motor 32 is driven by the torque command Tm*. Here, the traveling torque requirement Td* is set based on the shift range SP, the accelerator opening Acc, and the vehicle speed V. The traveling torque requirement Td* is set so that it increases in the order of the shift range SP from D range, to the third range M3, to the second range M2, to the first range L, and is larger when the accelerator opening Acc is large compared to when it is small, and is larger when the vehicle speed V is small compared to when it is large. Through such control, the motor 32 is controlled so that the behavior of the torque output from the motor 32 based on the operation (shift operation) of the shift lever 61 by the driver is the behavior of the torque in an engine vehicle equipped with an engine and a manual transmission when traveling. In other words, it is possible to drive in a manner that simulates driving an engine vehicle equipped with an engine and a manual transmission, and the driver can feel as if he or she is driving an engine vehicle equipped with an engine and a manual transmission. Note that the P range and the R range are not the core of this disclosure, so detailed explanations will be omitted.

[0017] Next, the operation of the electric vehicle 20 of this embodiment configured as described above, in particular the operation when the shift lever 61 is pushed in a first direction (downshift side) from the neutral position N, will be described. Figure 2 is a flowchart showing an example of a downshift processing routine executed by the ECU 50. This routine is executed when the shift lever 61 is pushed in the first direction from the neutral position N to issue a downshift command.

[0018] When this routine is executed, the ECU 50 executes downshift control (step S100). In the downshift control, a traveling torque requirement Td* is set based on the shift range SP after the downshift, the accelerator opening Acc, and the vehicle speed V, the set traveling torque requirement Td* is set as a torque command Tm* for the motor 32, and the transistors T11 to T16 of the inverter 34 are controlled so that the motor 32 is driven by the torque command Tm*.

[0019] Next, it is determined whether the pushing operation in the first direction is continuing (step S110). When the pushing operation in the first direction is not continuing, that is, when the shift lever 61 is returned to the neutral position N, this routine ends.

[0020] If the pressing operation in the first direction is continuing in step S110, it is then determined whether or not the elapsed time Td of the timer, which starts measuring after the execution of the downshift control in step S100 is started, is equal to or greater than a predetermined time Tdref (step S120). The predetermined time Tdref is a threshold value for determining whether or not the driver desires a further downshift, and is set to, for example, 1 sec, 2 sec, 3 sec, etc. If the elapsed time Td is less than the predetermined time Tdref, the process returns to step S110.

[0021] When the elapsed time Td is equal to or greater than the predetermined time Tdref in step S120, the current vehicle speed V from the vehicle speed sensor 67 and the current accelerator opening Acc from the accelerator pedal sensor 64 are input (step S130), and a post-shift torque Tmaf output from the motor 32 after the shift range SP is downshifted by one gear is set (step S140). In step S140, the post-shift torque Tmaf is set in the same manner as the setting of the torque command Tm* described above, and the traveling torque requirement Td* set using the post-shift shift range SP, the vehicle speed V and accelerator opening Acc input in step S130 is set as the post-shift torque Tmaf.

[0022] Next, an upper limit torque Tmax is set as the upper limit value of the torque that can be output from the motor 32 (step S150). The upper limit torque Tmax is set by storing the relationship between the vehicle speed V and the upper limit value of the torque that can be output from the motor 32 as a map in the ROM, deriving the corresponding upper limit value from the map when the vehicle speed V is given, and setting the derived upper limit value.

[0023] Next, it is determined whether the post-shift torque Tmaf is equal to or less than the upper limit torque Tmax (whether the post-shift torque Tmaf satisfies a predetermined condition) (step S160). If the post-shift torque Tmaf is equal to or less than the upper limit torque Tmax, it is determined that the torque (post-shift torque Tmaf) corresponding to the shift range SP can be output from the motor 32 when downshifting, and a further downshift is permitted and downshift control is executed in the same manner as in step S100 (step S170). Then, the elapsed time Td is reset to a value of 0 (step S180), and the process returns to step S110. If the post-shift torque Tmaf is equal to or less than the upper limit torque Tmax in step S160, steps S110 to S170 are repeated, and a downshift of the shift range SP is permitted and downshift control is executed every predetermined time Tdref.

[0024] FIG. 3 is an explanatory diagram showing an example of a state of a downshift command and a change over time in the torque (motor torque) output from the motor 32. When the shift lever 61 is pushed from the neutral position N in the first direction to issue a downshift command (time t0), the motor torque increases due to downshift control (time t1). If the shift lever 61 is subsequently continuously pushed in the first direction without being returned to the neutral position N, the downshift command continues to be issued, and when a predetermined time Tdref has elapsed from time t1, if the post-shift torque Tmaf is equal to or less than the upper limit torque, the motor torque increases due to downshift control (time t2). In this way, when the shift lever 61 is continuously pushed without being returned to the neutral position N, downshift control is executed every predetermined time Tdref, and the motor torque increases. By this process, the shift range SP can be continuously changed by simply pushing the shift lever 61 in the first direction, and operability can be improved.

[0025] When the post-shift torque Tmaf exceeds the upper limit torque Tmax in step S160, this routine ends. When the post-shift torque Tmaf exceeds the upper limit torque Tmax, further downshift control is not executed, so that the motor 32 can be protected.

[0026] According to the electric vehicle 20 equipped with the drive unit of the embodiment described above, when the pressing operation on the shift lever 61 continues, if a predetermined condition is satisfied that the post-shift torque Tmaf output from the motor 32 when the shift range SP is further changed is equal to or less than the upper limit torque, changing of the shift range SP is permitted every predetermined time Tdref, thereby improving operability.

[0027] In the above-described embodiment, a downshift is commanded by pushing the shift lever 61 in a first direction from the neutral position N, and an upshift is commanded by pushing the shift lever 61 in a second direction from the neutral position N. However, a downshift switch and an upshift switch may be provided on a steering wheel (not shown), and a downshift may be commanded by pressing the downshift switch, and an upshift may be commanded by pressing the upshift switch.

[0028] In the above embodiment, a case where a downshift is performed in the electric vehicle 20 is illustrated as an example, but the same can be applied to a case where an upshift is performed as in the case of a downshift.

[0029] In the above-described embodiment, an example is given of the case where the drive device of the present disclosure is mounted on the electric vehicle 20. However, since the drive device of the present disclosure only needs to be configured as a device that drives the drive shaft 26, it may also be applied to a device other than the electric vehicle 20.

[0030] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be described below. In the embodiment, the motor 32 corresponds to the "motor", the shift lever 61 corresponds to the "shift device", and the ECU 50 corresponds to the "control device".

[0031] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0032] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0033] The present disclosure is applicable to the drive device manufacturing industry and the like. [Explanation of symbols]

[0034] 20 electric vehicle, 22a, 22b drive wheels, 32 motor, 34 inverter, 36 battery, 50 electronic control unit (ECU), 61 shift lever.

Claims

[Claim 1] A motor that drives a drive shaft connected to the axle; A shift device that changes a shift range by a driver's pressing operation; a control device that controls the motor when the shift range is changed so that a torque based on the changed shift range is output; A drive device comprising: When the pressing operation on the shift device continues and a post-shift torque output from the motor when the shift range is further changed satisfies a predetermined condition, the control device permits the change of the shift range at predetermined time intervals. Drive unit.

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