JP4496762B2 - Shift control device for motor four-wheel drive vehicle - Google Patents

Description

  The present invention relates to a shift control device for a motor four-wheel drive vehicle in which main drive wheels are driven by an engine, slave drive wheels are driven by an electric motor, and the electric motor is driven by electric energy generated by the engine. is there.

  Conventionally, a motor four-wheel drive vehicle is known in which main drive wheels are driven by an engine, slave drive wheels are driven by an electric motor, and the electric motor is driven by electric energy generated by the engine (for example, patents). Reference 1).

As one of the characteristics of this motor four-wheel drive vehicle, a high torque can be generated from a rotational speed of 0 as a characteristic of the motor. However, as the rotational speed increases, a counter electromotive voltage is induced in the motor. For this reason, when the vehicle speed increases and the motor rotation speed increases, the required applied voltage for driving the motor increases, and the drive engine speed necessary for generating the necessary power generation energy also increases. On the other hand, in a motor four-wheel drive vehicle using an automatic transmission that performs only automatic shifting, it is possible to ensure the engine speed by setting a shift map.
JP 2003-79004 A

  However, an automatic manual transmission (hereinafter referred to as “automatic MT”) in which the automatic transmission with a manual mode or the manual transmission clutch engaging / disengaging operation that can change gears according to the driver's upshift command or downshift command is automated. In this case, if the driver upshifts to the high speed side immediately after the start, there is a problem that sufficient engine speed cannot be secured and sufficient driving performance cannot be obtained as a motor four-wheel drive vehicle. It was.

  The present invention has been made paying attention to the above problems, and ensures the torque of the electric motor that drives the driven wheels even if the driver immediately shifts up to the high speed side by a manual shift operation immediately after starting. An object of the present invention is to provide a shift control device for a motor four-wheel drive vehicle capable of performing

In order to achieve the above object, in the shift control device for a motor four-wheel drive vehicle of the present invention, the main drive wheel is driven by the engine, the slave drive wheel is driven by the electric motor, and the electric motor is generated by the engine. In a motor four-wheel drive vehicle equipped with a transmission that is driven by electrical energy and performs a shifting operation according to a shift signal in accordance with a manual shift operation of the driver, any one of the following means (1), (2) It was adopted.
(1) When the speed of the transmission causes the engine speed to be less than the engine speed at which the electric motor can be driven by the electric energy generated by the engine, the speed change operation is performed even if the driver performs a manual speed change operation. Shift prohibiting means for prohibiting.
(2) 1-speed fixed mode selection means for selecting the 1-speed fixed mode for maintaining the 1st speed from the start of the start to the completion of the start, regardless of the driver's manual shift operation .

Therefore, in the shift control device for a motor four-wheel drive vehicle of the present invention, when the engine speed is equal to or lower than the engine speed at which the electric motor can be driven by the shift in the shift prohibiting means, the manual shift operation by the driver is performed. Even if there is a gear shift operation is prohibited. Alternatively, the first-speed fixed mode selection means selects the first-speed fixed mode that maintains the first speed regardless of the driver's manual shift operation from the start to the completion of the start when the four-wheel drive is started. As a result, it is possible to prevent the engine speed from being lowered due to the upshift, and to secure the torque of the electric motor that drives the driven wheels.

  Hereinafter, the best mode for realizing a shift control device for a motor four-wheel drive vehicle of the present invention will be described based on Example 1 and Example 2 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing the motor four-wheel drive vehicle of the first embodiment, and FIG. 2 is a block diagram showing a 4WD control system of the motor four-wheel drive vehicle of the first embodiment. As shown in FIG. 1, in this overall system, left and right front wheels 1L and 1R (main drive wheels) are driven by an engine 2 that is an internal combustion engine, and left and right rear wheels 3L and 3R (secondary drive wheels) are motors 4 that are electric motors. It is an example in the case of the vehicle which can be driven by (electric motor).

  As shown in FIG. 1, the output torque Te of the engine 2 is transmitted to the left and right front wheels 1L and 1R via the automatic transmission & differential gear 5 (transmission) with manual mode and manual mode. . A part of the output torque Te of the engine 2 is transmitted to the generator 7 via the endless belt 6.

  The generator 7 is rotated at a rotational speed Nh obtained by multiplying the engine rotational speed Ne by a pulley ratio, and becomes a load on the engine 2 in accordance with the field current Ifh adjusted by the 4WD controller 8. Power generated. The electric power generated by the generator 7 can be supplied to the motor 4 via the electric wire 9. A junction box 10 is provided in the middle of the electric wire 9.

  The drive torque of the motor 4 can be transmitted to the left and right rear wheels 3L and 3R via the gear reducer 11 and the 4WD clutch 12. Reference numeral 13 denotes a differential gear for the left and right rear wheels 3L, 3R.

  A throttle valve 15 is interposed in the intake pipe 14 (for example, intake manifold) of the engine 2. The throttle valve 15 is an accelerator-by-wire system in which the throttle opening is adjusted and controlled according to the depression amount of the accelerator pedal 17 and the like. That is, the throttle valve 15 uses the step motor 19 as an actuator, and the valve opening degree is adjusted and controlled by the rotation angle corresponding to the number of steps of the step motor 19. The rotation angle of the step motor 19 is adjusted and controlled by an opening signal from the engine controller 18.

  The throttle sensor 16 detects the valve opening of the throttle valve 15, and the throttle sensor 16 outputs a detection signal corresponding to the detected valve opening to the engine controller 18, the AT controller 30, and the 4WD controller 8. ing.

  The accelerator sensor 20 detects the depression amount of the accelerator pedal 17, and the acceleration sensor 20 outputs detection signals corresponding to the detected depression amount to the engine controller 18, the AT controller 30, and the 4WD controller 8. .

  Further, an engine speed detection sensor 21 (engine speed detection means) for detecting the speed of the engine 2 is provided. The engine speed sensor 21 outputs a detection signal corresponding to the detected depression amount to the engine controllers 18 and 4WD. It is output to the controller 8.

  In the engine controller 18, valve opening control processing is performed based on each input signal at every predetermined sampling time.

  Further, a torque sensor 28 for detecting the front wheel side drive torque on the output side of the automatic transmission & differential gear 5 with manual mode is provided, and the front wheel side drive torque Tf detected by the torque sensor 32 is input to the 4WD controller 8. Further, a 4WD switch 29 is provided in the vicinity of the driver's seat to select whether or not to set the four-wheel drive state, and a switch signal of the 4WD switch 29 is input to the 4WD controller 8.

  As shown in FIG. 2, the generator 7 includes a voltage regulator 22 (regulator) for adjusting the output voltage V, and the field current Ifh is adjusted by the 4WD controller 8, thereby generating power for the engine 2. The load torque Th and the voltage V to be generated are controlled. The voltage regulator 22 receives a generator control command (field current value) from the 4WD controller 8 and adjusts the field current Ifh of the generator 7 to a value according to the generator control command. The output voltage V can be detected and output to the 4WD controller 8. The rotational speed Nh of the generator 7 can be calculated from the rotational speed Ne of the engine 2 based on the pulley ratio.

  In addition, a current sensor 23 is provided in the junction box 10, and the current sensor 23 detects a current value Ia of power supplied from the generator 7 to the motor 4, and outputs the detected armature current signal. Output to the 4WD controller 8. In addition, a voltage value (voltage of the motor 4) flowing through the electric wire 9 is detected by the 4WD controller 8. In FIG. 2, reference numeral 24 denotes a relay, and the interruption and connection of electric power (current) supplied to the motor 4 are controlled by a command from the 4WD controller 8.

  In the motor 4, the field current Ifm is controlled by a command from the 4WD controller 8, and the drive torque Tm is adjusted by adjusting the field current Ifm. Reference numeral 25 denotes a thermistor that measures the temperature of the motor 4.

  A motor rotation speed sensor 26 that detects the rotation speed Nm of the drive shaft of the motor 4 is provided, and the motor rotation speed sensor 26 outputs the detected motor rotation speed signal to the 4WD controller 8.

  The 4WD clutch 12 is configured by a hydraulic clutch, an electromagnetic clutch, or the like, and transmits torque at a torque transmission rate according to a clutch control command from the 4WD controller 8.

  Each of the wheels 1L, 1R, 3L, 3R is provided with a wheel speed sensor 27FL, 27FR, 27RL, 27RR. Each wheel speed sensor 27FL, 27FR, 27RL, 27RR outputs a pulse signal corresponding to the rotation speed of the corresponding wheel 1L, 1R, 3L, 3R to the 4WD controller 8 as a wheel speed detection value.

  The 4WD controller 8 controls the drive transition of the motor 4 so as to generate a driving force corresponding to the accelerator opening from the accelerator sensor 20, and prevents the motor 4 from being rotated by the left and right rear wheels 3L, 3R. In order to reduce the friction, when the motor 4 is stopped by the motor drive transition control, the 4WD clutch 12 is controlled to be disconnected. The 4WD controller 8 receives mode information from the 4WD switch 28 that manually selects the 2WD mode, the 4WD mode, and the AUTO mode. The 4WD controller 8, the AT controller, and the AT controller 30 are connected by a bidirectional communication line.

  The automatic transmission & differential gear 5 with manual mode is, for example, the same as that described in the “RE4R01A automatic transmission maintenance manual” (A261C07) issued in March 1987 by the applicant of the present invention, and a control (not shown). A forward first speed to a fourth speed can be selected by a combination of ON and OFF of a plurality of shift solenoids in the valve.

  The AT controller 30 controls ON / OFF of the plurality of shift solenoids. This AT controller 30 is a lever position signal from a lever position sensor 32 for detecting the position of a shift lever 31 operated by a driver (range position signal by P, R, N, D, and L and manual shift signal by + and-. ), A throttle opening signal from the throttle sensor 16, a vehicle speed signal from the vehicle speed sensor 33 (vehicle speed detection means), an oil temperature signal from the transmission oil temperature sensor 34, and the like.

  Here, the shift lever 31 and the lever position sensor 32 will be supplementarily described. As described in the above-mentioned document, the known parking (P) range position, reverse travel (R) range position, neutral (N) range position, forward automatic shift (D) range position, engine brake (L) In addition to having the range position in a straight line, it has a manual shift (M) range position offset from the straight line.

  In manual shifting with the M range position selected, the shift lever 31 is elastically supported in a self-returning manner between the upshift (+) position and the downshift (−) position, and the driver can perform one-step high speed. The shift lever 31 is moved to the upshift (+) position whenever an upshift is desired, and the shift lever 31 is moved to the downshift (−) position every time a downshift is desired. Thus, a manual shift command is output to the AT controller 30.

  In the automatic shift at the D range position, a suitable shift speed is determined from the operating point based on the detected vehicle speed and the throttle opening based on the upshift line and the downshift line previously determined on the shift map by a control program (not shown). Search for. Next, it is determined whether or not the current shift stage matches the preferred shift stage. If not, the shift solenoid is switched ON / OFF so that the shift is executed to the preferred shift stage. Shift control along the D range shift map is executed by keeping the solenoid ON / OFF as it is.

  That is, when the driver desires manual shift and the shift lever 31 is set to the M range, the AT controller 30 executes a control program described later to perform manual shift control in the M range.

  Next, the operation will be described.

[M mode shift control process]
Each step will be described below with reference to a basic flowchart showing a flow (main routine) of an M-mode shift control process executed by the AT controller 30 of the first embodiment. This process is started when the driver desires manual shifting and sets the shift lever 31 to the M range.

  In step S1, the current shift speed, the vehicle speed (V) from the vehicle speed sensor 33, and the throttle opening (TVO) from the throttle sensor 16 are read, and the process proceeds to step S2.

  In step S2, the M mode shift map (M1, M2, M3, and M4 ranges) shown in FIG. 6 is read, and the process proceeds to step S3.

  In step S3, one M-mode shift map corresponding to the manual range position selected by the driver is selected, and the driving point based on the current vehicle speed (V) and throttle opening (TVO) is determined (substantially the vehicle speed). (V) is the only driving point) and is in the permission range of the manual range position selected by the driver on the M-mode shift map, that is, whether or not the current gear position is maintained. If YES, the process proceeds to step S5. If NO, the process proceeds to step S4.

In step S4, the speed is changed based on the M-mode shift map corresponding to the manual range position selected by the driver, and the process returns to RETURN.
For example, when the M1 range is selected, in FIG. 6A, if the driving point is A in the low vehicle speed range, the current manual first speed is permitted, but the driving point is B in the high vehicle speed range. In this case, the current first manual speed is prohibited, and in this step S4, the upshift is forcibly shifted to the second speed in order to prevent the engine 2 from over-rotating (over-rev). Further, when the M4 range is selected, in FIG. 6 (d), when the driving point is C in the low vehicle speed range, the current manual fourth speed is prohibited, and in this step S4, in order to prevent engine stall. The downshift is forcibly shifted to the third speed.

  In step S5, it is determined whether or not the current gear position is the manual first speed. If YES, the process proceeds to step S7, and if NO, the process proceeds to step S6.

  In step S6, normal shift control is executed according to the flowchart shown in FIG.

  In step S7, the start-response shift control is executed according to the flowchart shown in FIG.

[Normal shift control processing]
Each step will be described below with reference to a flowchart showing a flow (subroutine) of normal shift control processing executed by the AT controller 30 of the first embodiment. This process is started when the current manual second speed or higher is reached in the basic flowchart of FIG. 3 and the process proceeds to step S6.

  In step S21, it is determined whether or not an upshift signal ((+) manual shift signal) is input from the lever position sensor 32. If YES, the process proceeds to step S22. If NO, the process proceeds to step S24. .

  In step S22, it is determined whether or not the current operating point is in the permitted region on the post-upshift speed map by referring to the post-upshift speed map from the M-mode shift map of FIG. If YES, the process proceeds to step S23. If NO, the process proceeds to return.

  In step S23, based on the determination that the current operating point in step S22 is in the permitted area on the post-upshift speed map, an upshift of the first speed is executed from the current speed, and the process proceeds to return. To do.

  In step S24, it is determined whether or not a downshift signal ((−) manual shift signal) is input from the lever position sensor 32. If YES, the process proceeds to step S25, and if NO, the process proceeds to return.

  In step S25, the shift speed map after downshifting is referred to from the M mode shift map of FIG. 6, and it is determined whether or not the current operating point is in the permitted area on the shift speed map after downshifting. If YES, the process proceeds to step S26, and if NO, the process proceeds to return.

  In step S26, based on the determination that the current operating point in step S25 is in the permitted region on the shift map after the downshift, one shift down from the current shift stage is executed, and the process proceeds to return. To do.

[Transmission control process for starting]
Each step will be described below with reference to a flowchart showing a flow (subroutine) of the start-time corresponding shift control process executed by the AT controller 30 of the first embodiment. This process is currently in the manual first speed in the basic flowchart of FIG. 3, and is started when the process proceeds to step S7.

  In step S31, it is determined whether or not an upshift signal ((+) manual shift signal) is input from the lever position sensor 32. If YES, the process proceeds to step S32. If NO, the process proceeds to step S35. .

  In step S32, it is determined whether or not the 4WD switch 29 is ON (when the four-wheel drive mode is selected). If YES, the process proceeds to step S33, and if NO, the process proceeds to step S22 in FIG.

In step S33, based on the determination that the four-wheel drive mode is selected in step S32, the current driving point (V, TVO) is used using the 1 → 2 upshift line of the D-range shift map shown in FIG. Is determined to be in the shift prohibited area (D range 1st speed area). If YES, the process proceeds to step S34, and if NO, the process proceeds to step S22 in FIG.
Here, the threshold value of the vehicle speed (V) by the 1 → 2 upshift line in the D-range shift map shown in FIG. 7 is a limit for securing the engine speed at which the engine speed can drive the motor 4 by shifting to the second speed. This value is much larger than the threshold of the vehicle speed (V) (the limit value of the engine speed for preventing engine stall) by the 2 → 1 downshift line of the M2 range map shown in FIG. 6 (b).

  In step S34, based on the determination that the current operating point (V, TVO) in step S33 is in the shift prohibited area (D range 1st speed area), a prohibition flag that prohibits shifting from the 1st speed to the 2nd speed. D is rewritten from the prohibition flag D = 0 to D = 1, and the process proceeds to return.

  In step S35, based on the determination that there is no upshift signal in step S31, it is determined whether or not the prohibition flag D for prohibiting the shift from the first speed to the second speed is the prohibition flag D = 1. Shifts to step S36, and if NO, shifts to return.

  In step S36, it is determined whether or not the current operating point (V, TVO) is in the shift permission area (D range 2nd speed area) using the 1 → 2 upshift line of the D range shift map shown in FIG. If YES, the process proceeds to step S37, and if NO, the process proceeds to return.

  In step S37, based on the determination that the current operating point (V, TVO) in step S36 is in the shift-permitted region, an upshift (second speed) from the current gear position (first speed) is executed. Then, the process proceeds to step S38.

  In step S38, based on the execution of the upshift in step S37, the prohibition flag D for prohibiting the shift from the first speed to the second speed is rewritten from the prohibition flag D = 1 to the prohibition flag D = 0, and the process returns. Transition.

[Normal shift control action in M mode]
For example, during traveling as manual second speed, the process proceeds from step S1 to step S2 to step S3 to step S5 to step S6 in the flowchart of FIG. Then, when the driver performs an upshift operation to the third speed with respect to the shift lever 31, in the flowchart of FIG. 4, the flow proceeds from step S21 to step S22 to step S23, and in step S22, the current driving point ( As long as it is determined that (V, TVO) is in the third-speed allowed region in the M3 range map of FIG. 6 (c), the upshift from the second speed to the third speed is executed in step S23.

  On the other hand, when the driver performs a downshift operation to the first speed with respect to the shift lever 31, in the flowchart of FIG. 4, the process proceeds from step S21 to step S24 to step S25 to step S26. As long as it is determined that the operating point (V, TVO) is in the 1st-speed permitted region in the M1 range map of FIG. 6A, the downshift from the 2nd speed to the 1st speed is executed in step S26.

  That is, when the driver performs an upshift operation or a downshift operation on the shift lever 31 while traveling in the manual mode, the current driving point (V, TVO) is the M mode shift map shown in FIG. As long as the shift permission region is entered, the upshift shift and the downshift shift are executed with good response in response to the shift lever operation.

  However, if the current operating point (V, TVO) is a prohibited area where there is a possibility of engine overspeeding or engine stalling if a shift is executed, the driver will Regardless of the upshift operation or the downshift operation on the engine 31, the current gear position is maintained, and it is possible to prevent engine over-rotation and engine stall due to the execution of the shift.

[Forced shift control action in M mode]
For example, if the vehicle speed (V) increases while the vehicle is traveling with manual speed 1 and the driving point becomes point B in FIG. 6A, step S1 → step S2 → step in the flowchart of FIG. The process proceeds from S3 to step S4. In step S4, an upshift is forcibly performed from the first speed to the second speed to prevent engine overspeed. Further, for example, when the vehicle is traveling with manual 4th speed and the vehicle speed (V) decreases and the driving point (V, TVO) becomes the point C in FIG. 6 (d), in the flowchart of FIG. step S1 → proceeds to step S2 → step S3 → step S4, in step S4, Ru to forcibly 4 gear to third gear downshift is performed in order to prevent engine stall.

  In other words, if the driver is not performing a manual shift operation and the gear position at that time is maintained, there is a high possibility that the engine will be over-rotated or engine stalled. A shift for controlling the engine speed is executed. As a result, it is possible to prevent engine over-rotation and engine stall.

[Shift permission control action when starting in M mode]
For example, when starting at manual first speed, if the upshift operation is performed on the shift lever 31 immediately after starting, and if the two-wheel drive state is selected by turning off the 4WD switch 29, FIG. In the flowchart of FIG. 5, the process proceeds from step S31 to step S32 to step S22 to step S23. In step S23, the engine speed becomes equal to or lower than the engine speed at which the motor 4 can be driven by the upshift to the second speed. Even in this case, an upshift from the first speed to the second speed is executed in accordance with the upshift operation on the shift lever 31 (corresponding to the shift permission means in claim 4).

  That is, when the two-wheel drive state is selected, if the upshift operation is performed immediately after starting at the manual first speed, the engine speed is such that the engine speed can drive the motor 4 by the upshift to the second speed. Even if the number is less than or equal to the number, unless there is a possibility of an engine stall, an upshift from the first speed to the second speed is immediately executed, and the driver's intention to travel in the second speed is reflected.

  Also, for example, when starting at manual first speed, when a shift operation is performed on the shift lever 31 after some time has elapsed since starting, the 4WD switch 29 is turned on to select the four-wheel drive state. However, if the current operating point (V, TVO) is not in the shift prohibited area shown in FIG. 7, in the flowcharts of FIGS. 4 and 5, step S31 → step S32 → step S33 → step S22 → step S23. In step S23, an upshift from the first speed to the second speed is executed in response to an upshift operation on the shift lever 31.

  That is, although the four-wheel drive state is selected, the fact that the current driving point (V, TVO) is not in the shift prohibition region shown in FIG. 7 is already a traveling state in which the vehicle speed and engine speed are sufficiently high. In this case, since the engine speed does not become lower than the engine speed capable of driving the motor 4 by the upshift to the 2nd speed, the upshift from the 1st speed to the 2nd speed is immediately performed. Shifting is executed, and the driver's intention to travel in 2nd speed with 4WD is reflected.

  [Shift prohibition control action when starting in M mode]

  For example, when starting at manual first speed, an upshift operation is performed on the shift lever 31 immediately after starting, but the 4WD switch 29 is turned on to select the four-wheel drive state and the current operation When the point (V, TVO) is in the shift prohibition region shown in FIG. 7, the process proceeds to step S31 → step S32 → step S33 → step S34 in the flowchart of FIG. 5. In step S34, the shift prohibition flag D is set. The upshift from 1st gear to 2nd gear is prohibited. Thereafter, in the flowchart of FIG. 5, the process of step S31 → step S35 → step S36 → return is repeated until the condition of step S36 is satisfied, and the upshift shift prohibition from the first speed to the second speed is maintained ( (Corresponding to shift prohibiting means of claims 1, 2 and 3).

  If it is determined in step S36 that the current operating point (V, TVO) is in the speed change permission area (D range 2nd speed area) as time elapses after starting, from step S36 to step S37 → Proceeding to step S38, the upshift from the first speed to the second speed is executed, and the shift prohibition flag D is lowered.

  That is, in the time chart shown in FIG. 9, when starting at the manual first speed at time t1 and performing an upshift operation at time t2 immediately after starting, the conventional technique shows the dotted line characteristic. In addition, since the upshift is performed at the time t4, the engine speed decreases rapidly, and the engine speed falls below the generator speed limiter that can drive the motor that overcomes the induced voltage indicated by the one-dot chain line characteristic. As a result, the motor torque remains lowered and the four-wheel drive mode is selected, but high drive performance due to the four-wheel drive start with the motor torque added cannot be exhibited.

  On the other hand, in the first embodiment, even if the upshift operation is performed at time t2 immediately after starting, at this time, the vehicle speed is low and the current driving point (V, TVO) is in the shift prohibited area shown in FIG. In this case, the first speed state is maintained until time t5 when it is determined that the current operating point (V, TVO) is in the shift permission region, so that the solid line of the engine speed (= generator speed) is maintained. As shown in the characteristics, until t5, the engine speed exceeds the induced voltage that exceeds the induced voltage, and the motor speed is limited to the generator speed limiter speed. Corresponding to the above, high driving performance is exhibited by four-wheel drive starting with motor torque added.

Next, the effect will be described.
In the shift control apparatus for the motor four-wheel drive vehicle of the first embodiment, the effects listed below can be obtained.

  (1) The main drive wheel is driven by the engine 2 and the slave drive wheel is driven by the motor 4. The motor 4 is a motor four-wheel drive vehicle driven by electric energy generated by the engine 2. 2 and the main drive wheel, and an automatic transmission & differential gear 5 with a manual mode that performs a shift operation by a shift signal according to a shift command operation of a driver, and the engine speed is changed by the motor 4 by shifting. When the engine speed is less than or equal to the engine speed, a shift prohibiting means for prohibiting the shift operation even if the driver gives a shift command is provided. Even if the upshift is performed, the motor torque for driving the driven wheels can be secured.

  (2) A vehicle speed sensor 33 for detecting the vehicle speed is provided, and the shift prohibiting means prohibits a shift operation according to the shift command when the vehicle speed is equal to or lower than a predetermined vehicle speed. Even if the vehicle is upshifted to the high speed side, the motor torque for driving the driven wheels can be ensured until the vehicle speed reaches a predetermined vehicle speed.

  (3) An engine speed detection sensor 21 for detecting the engine speed is provided, and the shift prohibiting means prohibits a shift operation according to the shift command when the engine speed is equal to or lower than a predetermined engine speed. Even if the driver upshifts to the high speed side at an early stage by manual shifting operation, the motor torque for driving the driven wheels can be secured until the engine speed reaches a predetermined engine speed.

  (4) When a shift signal is input in response to a shift command operation by the driver, there is no four-wheel drive request even if the engine speed is equal to or lower than the engine speed at which the motor 4 can be driven by the shift by the shift signal. Since there is a shift permission means for permitting a shift operation by a driver's shift command during two-wheel drive, a shift is executed with good response to the driver's manual shift command during two-wheel drive that does not require motor torque, The driving intention of the driver can be reflected.

  (5) Forced upshift or downshift regardless of the driver's shift command operation when the engine speed is over-rotated or engine stalled due to the shift by the shift signal according to the driver's shift command operation Since the speed change means is provided, it is possible to prevent the occurrence of engine overspeed and engine stall.

  The second embodiment is an example in which the 1-speed fixed mode is selected while prohibiting manual gear shifting when starting with the 4WD mode selected. In addition, since it is the same as that of Example 1 in a structure, illustration and description are abbreviate | omitted.

  Next, the operation will be described.

[Vehicle start shift control process]
Each step will be described below with reference to a flowchart showing a flow of a shift control process executed by the AT controller 30 of the second embodiment. This process is started when the vehicle starts from a stop state.

  When vehicle start is detected in step S41, the process proceeds to step S42. In step S42, it is determined whether or not the 4WD mode is selected by the switch signal of the 4WD switch 29. If YES, the process proceeds to step S43, and NO. In this case, the process proceeds to step S46.

  In step S43, the first speed fixed mode is selected in which the gear position of the automatic transmission with differential mode & differential gear 5 is fixed to the first speed, and the process proceeds to step S44. That is, the shift to a speed other than the first speed is prohibited until the process proceeds to step S46.

  In step S44, even if the driver performs a manual shift operation with the shift lever 31, the shift signal based on the manual shift operation is ignored and the manual shift is prohibited, and the process proceeds to step S45.

In step S45, it is determined whether or not the start in the four-wheel drive mode is completed. If YES, the process proceeds to step S46, and if NO, the process returns to step S43.
For example, when the vehicle speed (body speed) exceeds a predetermined value (for example, 15 km / h), the front / rear wheel speed difference becomes less than the predetermined value, the load on the alternator is determined. Is less than a predetermined value, when the predetermined engine speed continues for a predetermined time or longer, or by a combination of two or more.

  In step S46, it is possible to select either the automatic shift mode or the manual shift mode, which is a shift mode based on normal start, and the process proceeds to step S47. In addition, when it transfers from step S45, 1st speed fixed mode is cancelled | released.

  In step S47, it is determined whether or not the vehicle has stopped due to wheel speed, brake operation, or the like. If YES, the process proceeds to the end, and if NO, the process returns to step S46.

[Vehicle speed change control action at vehicle start]
When the vehicle starts with the 2WD mode selected, the flow proceeds from step S41 to step S42 to step S46 to step S47. As long as the vehicle is kept running without stopping, the process proceeds to step S46 to step S47. The forward flow is repeated, and in step S46, the shift lever 31 maintains a selectable state in either the automatic transmission mode (D range) or the manual transmission mode (manual range).

When the vehicle starts with the 4WD mode selected, the flow proceeds from step S41 → step S42 → step S43 → step S44 → step S45, the first speed fixed mode is set in step S43, and manual shift is prohibited in step S44. The manual shift is prohibited and the first speed fixed mode is maintained until it is determined in step S45 that the start in the four-wheel drive mode is complete (first speed fixed mode selection means of claim 5 ).

When it is determined in step S45 that the vehicle speed exceeds the predetermined value and the start of the four-wheel drive mode is completed, the flow proceeds from step S45 to step S46 to step S47, not only allowing manual shifting but also shifting. A state that can be selected by the lever 31 in either the automatic transmission mode (D range) or the manual transmission mode (manual range) is maintained during traveling (first speed fixed mode selection means of claim 6 ).

  That is, when the manual shift operation is permitted at the time of starting with the 4WD mode selected, if the upshift operation is performed immediately after the start, as shown by the dotted line characteristic in FIG. There is a decrease in the number, and accordingly, the rotational speed of the generator 7 is also decreased, resulting in a decrease in motor torque.

  On the other hand, when the 4WD mode is selected and the first speed fixed control of the second embodiment is performed, the vehicle speed is 0 km / h to 15 km / h as shown by the solid line characteristics in FIG. In the region, the engine speed is maintained at a high speed, the motor torque is also maintained at a high torque, and high start driving performance by 4WD can be exhibited.

Next, the effect will be described.
In the shift control device for a motor four-wheel drive vehicle of the second embodiment, the effects listed below can be obtained.

  (6) The main drive wheel is driven by the engine 2 and the slave drive wheel is driven by the motor 4. The motor 4 is a motor four-wheel drive vehicle driven by electric energy generated by the engine 2. 2 and the main drive wheel, and a manual mode automatic transmission & differential gear 5 that performs a shift operation according to a shift signal according to a shift command operation by the driver, and when starting four-wheel drive, 1-speed fixed mode selection means for selecting the 1-speed fixed mode for maintaining the 1st speed regardless of the driver's gear shift command operation until the start is completed. Even when upshifting to the side, the motor torque for driving the driven wheels can be secured.

  (7) A vehicle speed sensor 33 for detecting the vehicle speed is provided, and the first speed fixed mode selecting means selects the first speed fixed mode only while the vehicle speed is equal to or lower than a predetermined value, and permits manual shift when the vehicle speed exceeds a predetermined value. Therefore, even if the driver immediately shifts up to the high speed side by a manual shift operation immediately after starting, the motor torque for driving the driven wheels can be secured until the vehicle speed reaches the predetermined vehicle speed.

  As mentioned above, although the gear change control apparatus of the motor four-wheel drive vehicle of this invention has been demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about a concrete structure, Claim Design changes and additions are permitted without departing from the spirit of the invention according to each claim of the scope.

  For example, in the first and second embodiments, an example of the automatic transmission & differential gear 5 with a manual mode is shown as the transmission. For example, as shown in FIG. A vehicle having a synchronous gear transmission mechanism and a differential gear device capable of selecting a gear, and having an automatic clutch gear transmission 5 ′ (= automatic MT) as a transmission, which disengages an automatic clutch and switches a transmission gear during the shift. Can also be applied.

  In the first embodiment, an example using the shift prohibiting means is shown, and in the second embodiment, an example using the first speed fixed mode selecting means is shown. However, for example, depending on the automatic shift mode for automatically shifting and the shift command operation by the driver. In a vehicle equipped with a shift mode switching means for switching between a manual shift mode for performing a shift operation according to a shift signal and a transmission for switching between an automatic shift and a manual shift according to the switch of the shift mode, By providing shift mode switching prohibiting means for prohibiting switching to the shift mode, the motor torque for driving the driven wheels is ensured immediately after the start even if the driver upshifts to the high speed side early by manual shift operation. You may make it acquire the effect.

  Although the shift control device of the present invention has been applied to a front-wheel drive base motor four-wheel drive vehicle in which left and right front wheels are driven by an engine, a rear-wheel drive base motor four-wheel drive in which left and right rear wheels are driven by an engine It can also be applied to cars.

1 is an overall system diagram illustrating a transmission control device for a motor four-wheel drive vehicle according to a first embodiment. 1 is a block diagram illustrating a control system of a transmission control device for a motor four-wheel drive vehicle according to Embodiment 1. FIG. 3 is a basic flowchart showing a flow of a shift control process in M mode executed by the AT controller according to the first embodiment. 6 is a flowchart showing a flow of normal shift control processing executed by the AT controller of the first embodiment. 6 is a flowchart illustrating a flow of a start-time corresponding shift control process executed by the AT controller according to the first embodiment. It is a figure which shows the M mode shift map memorize | stored and set to AT controller. It is a figure which shows the shift prohibition area | region map which shows the shift prohibition area | region in case the manual shift operation which upshifts to 2nd speed is performed at the time of start. It is a figure which shows the gear shift permission area | region map which shows the gear shift permission area | region when the manual gear shifting operation which upshifts to 2nd speed is performed at the time of start. 5 is a time chart showing characteristics of vehicle speed, throttle opening, upshift command, gear position, engine speed, and motor torque at the time of start. 6 is a flowchart illustrating a flow of a shift control process executed by an AT controller according to the second embodiment. FIG. 5 is a relationship characteristic diagram of engine speed-vehicle speed and a relationship characteristic graph of motor torque-vehicle speed at the time of start. It is a skeleton figure which shows an example of the automatic clutch type gear transmission applicable as a transmission.

Explanation of symbols

1L, 1R left and right front wheels (main drive wheels)
2 Engine
3L, 3R Left and right rear wheels (sub driven wheels)
4 Motor (electric motor)
5 Automatic transmission & differential gear with manual mode (transmission)
6 Endless belt 7 Generator 16 Throttle sensor 21 Engine speed detection sensor (engine speed detection means)
29 4WD switch 30 AT controller 31 Shift lever 32 Lever position sensor 33 Vehicle speed sensor (vehicle speed detection means)

Claims (6)

The main drive wheel is driven by an engine, the slave drive wheel is driven by an electric motor, and the electric motor is a motor four-wheel drive vehicle driven by electric energy generated by the engine.
A transmission that is interposed between the engine and the main drive wheel and performs a shift operation by a shift signal according to a manual shift operation of a driver;
By shifting of the transmission, the engine speed is, the case where the electric motor becomes drivable engine speed below by generated electric energy by the engine, the driver's manual shift operation there be the transmission Shifting prohibiting means for prohibiting the shifting operation of
A shift control apparatus for a motor four-wheel drive vehicle. In the shift control device for a motor four-wheel drive vehicle according to claim 1,
A speed control device for a motor four-wheel drive vehicle, comprising vehicle speed detecting means for detecting a vehicle speed, wherein the shift prohibiting means prohibits a shift operation by the manual shift operation when the vehicle speed is equal to or lower than a predetermined vehicle speed. In the shift control device for a motor four-wheel drive vehicle according to claim 1,
An engine speed detecting means for detecting an engine speed is provided, and the shift prohibiting means prohibits a shift operation by the manual shift operation when the engine speed is equal to or lower than a predetermined engine speed. Shift control device for driving vehicle. In the shift control apparatus for a motor four-wheel drive vehicle according to any one of claims 1 to 3,
When a shift signal is input in response to a manual shift operation by the driver, even if the engine speed is equal to or lower than the engine speed at which the electric motor can be driven by the shift based on the shift signal, the two-wheel drive that does not require a four-wheel drive A shift control device for a motor four-wheel drive vehicle, comprising a shift permission means for permitting a shift operation by a manual shift operation by a driver during driving. In the motor four-wheel drive vehicle, the main drive wheel is driven by an engine, the slave drive wheel is driven by an electric motor, and the electric motor is driven by electric energy generated by the engine.
A transmission that is interposed between the engine and the main drive wheel and performs a shift operation by a shift signal according to a manual shift operation of a driver;
1-speed fixed mode selection means for selecting a 1-speed fixed mode for maintaining the first speed regardless of the driver's manual shift operation from the start of the start to the completion of the start at the time of four-wheel drive start;
A shift control apparatus for a motor four-wheel drive vehicle. In the shift control device for a motor four-wheel drive vehicle according to claim 5,
Vehicle speed detecting means for detecting a vehicle speed is provided, and the first speed fixed mode selecting means selects the first speed fixed mode only while the vehicle speed is equal to or lower than a predetermined value, and permits manual shifting when the vehicle speed exceeds a predetermined value. A shift control device for a motor four-wheel drive vehicle.

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