JP4165758B2 - Hybrid vehicle variable transmission ratio steering device - Google Patents

Description

  The present invention relates to a transmission ratio variable steering apparatus for a hybrid vehicle.

It is disclosed that a transmission ratio variable steering device that varies a steering angle ratio between a steering angle of a steering wheel and a turning angle of a steered wheel is applied to a hybrid vehicle (see, for example, Patent Document 1).
JP 2004-75013 A

  However, when the hybrid vehicle is driven by the driving electric motor, the engine is stopped, so that the noise is very low. Therefore, particularly when the transmission ratio variable steering device is driven when the engine is stopped, the operating sound of the transmission ratio variable motor constituting the transmission ratio variable steering device is heard by the occupant as an uncomfortable feeling.

  The present invention has been made in view of such circumstances, and the operation sound of the transmission ratio variable motor is not transmitted to the occupant when the engine of the hybrid vehicle is stopped. An object of the present invention is to provide a transmission ratio variable steering device.

(1) 1st invention The transmission ratio variable steering apparatus for a hybrid vehicle according to the 1st invention is a hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor. And an output shaft connected to the steered wheel side and an output shaft connected to the steered wheel side, and the transmission ratio between the input shaft and the output shaft is changed by the rotational drive of the transmission ratio variable motor. Variable transmission ratio of hybrid vehicle comprising transmission ratio variable means, lock means for limiting relative rotation between the input shaft and the output shaft, and control means for controlling the transmission ratio variable means and the lock means. In the steering apparatus, the control means performs a transmission ratio non-variable process for bringing the lock means into a locked state when the internal combustion engine is stopped.

  Further, vehicle speed detection means for detecting a vehicle speed of the hybrid vehicle is provided, and the control means performs the transmission ratio non-variable processing when the internal combustion engine is stopped and the vehicle speed is equal to or lower than a predetermined speed. Good.

(2) Second Invention A variable transmission ratio steering apparatus for a hybrid vehicle according to a second invention is a hybrid vehicle that is equipped with an internal combustion engine and a drive motor and is capable of traveling by driving at least one of the internal combustion engine and the drive motor. And an output shaft connected to the steered wheel side and an output shaft connected to the steered wheel side, and the transmission ratio between the input shaft and the output shaft is changed by the rotational drive of the transmission ratio variable motor. Variable transmission ratio of hybrid vehicle comprising transmission ratio variable means, lock means for limiting relative rotation between the input shaft and the output shaft, and control means for controlling the transmission ratio variable means and the lock means. In the steering apparatus, the control means puts the lock means into an unlocked state when the internal combustion engine is stopped, and keeps the target angle of the output shaft at the steering angle of the input shaft. A transmission ratio non-variable process for controlling the transmission ratio variable means so as to hold is performed.

  Further, vehicle speed detection means for detecting a vehicle speed of the hybrid vehicle is provided, and the control means performs the transmission ratio non-variable processing when the internal combustion engine is stopped and the vehicle speed is equal to or lower than a predetermined speed. Good.

(3) Third invention A transmission ratio variable steering apparatus for a hybrid vehicle according to a third invention is a hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor. And an output shaft connected to the steered wheel side and an output shaft connected to the steered wheel side, and the transmission ratio between the input shaft and the output shaft is changed by the rotational drive of the transmission ratio variable motor. Variable transmission ratio of hybrid vehicle comprising transmission ratio variable means, lock means for limiting relative rotation between the input shaft and the output shaft, and control means for controlling the transmission ratio variable means and the lock means. In the steering apparatus, the control means rotates the output shaft by rotating the transmission ratio variable motor with respect to the input shaft. A transmission ratio variable motor angle calculation means for calculating a target angle of the machine, an angle control means for controlling the transmission ratio variable motor based on the target angle of the transmission ratio variable motor, and when the internal combustion engine is stopped And a target angle transmission ratio reduction processing means for reducing a target angle transmission ratio which is a target angle of the transmission ratio variable motor with respect to the steering angle of the input shaft.

(4) Fourth Invention A transmission ratio variable steering apparatus for a hybrid vehicle according to a fourth invention is a hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor. And an output shaft connected to the steered wheel side and an output shaft connected to the steered wheel side, and the transmission ratio between the input shaft and the output shaft is changed by the rotational drive of the transmission ratio variable motor. Variable transmission ratio of hybrid vehicle comprising transmission ratio variable means, lock means for limiting relative rotation between the input shaft and the output shaft, and control means for controlling the transmission ratio variable means and the lock means. In the steering apparatus, the control means performs a rotation speed limiting process for setting a rotation speed of the transmission ratio variable motor to a predetermined speed upper limit value or less when the internal combustion engine is stopped. Features.

(5) Fifth Invention A variable transmission ratio steering apparatus for a hybrid vehicle according to a fifth invention is a hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor. And an output shaft connected to the steered wheel side and an output shaft connected to the steered wheel side, and the transmission ratio between the input shaft and the output shaft is changed by the rotational drive of the transmission ratio variable motor. Variable transmission ratio of hybrid vehicle comprising transmission ratio variable means, lock means for limiting relative rotation between the input shaft and the output shaft, and control means for controlling the transmission ratio variable means and the lock means. In the steering apparatus, the control means performs the operation of the locking means to the locked state and the operation to the unlocked state when the internal combustion engine is started or stopped. It is a sign.

  The control means of the transmission ratio variable steering apparatus for a hybrid vehicle according to the fifth aspect of the invention is configured to perform the operation of the locking means to the locked state and the operation to the unlocked state during the operation of the internal combustion engine. Good.

(1) Advantages of the First Invention According to the transmission ratio variable steering device for a hybrid vehicle of the first invention, the transmission ratio variable motor is prevented from being driven by being locked by the locking means when the internal combustion engine is stopped. Yes. In other words, when the internal combustion engine is stopped, the operating noise of the transmission ratio variable motor is not generated, and it can be prevented that the passenger feels uncomfortable.

  Furthermore, when the internal combustion engine is stopped and the vehicle speed is lower than the predetermined speed, the lock means is used to lock the engine so that it can be locked only in the low speed range where the noise is low during driving by the drive motor. It will be in a state. In other words, in the high speed range when the motor is driven by the drive motor, the lock means is in the unlocked state so that normal transmission ratio variable control (VGR control) can be performed. And since the noise by the drive motor in the high speed range is relatively large compared to the low speed range, the operating sound of the transmission ratio variable motor is not so much audible. As a result, it is possible to reliably prevent the operating noise of the transmission ratio variable motor in the low speed region of the driving motor and to exert the effect of the VGR control by performing the VGR control in the high speed region of the driving motor. .

(2) Effect of the Second Invention According to the variable transmission ratio steering apparatus for a hybrid vehicle of the second invention, the target angle of the output shaft is held at the steering angle of the input shaft when the internal combustion engine is stopped. That is, when the input shaft rotates, the transmission ratio variable means is controlled so that the output shaft rotates by the same rotation angle as the rotation angle. At this time, the transmission ratio variable motor is not driven. Specifically, control is performed so that the relative angular position between the rotor and the stator of the variable transmission ratio motor is always a constant position. Thus, since the control is performed so as not to drive the transmission ratio variable motor, the operation noise of the transmission ratio variable motor does not occur when the internal combustion engine is stopped, and it can be prevented that the passenger feels uncomfortable.

  Further, when the internal combustion engine is stopped and the vehicle speed is equal to or lower than a predetermined speed, the target angle of the output shaft is maintained at the steering angle of the input shaft, so that the noise during driving by the drive motor is reduced. Therefore, control is performed so that the transmission ratio variable motor is not driven only in a low speed range. That is, normal transmission ratio variable control (VGR control) is performed in a high speed range when driven by the drive motor. And since the noise by the drive motor in the high speed range is relatively large compared to the low speed range, the operating sound of the transmission ratio variable motor is not so much audible. As a result, it is possible to reliably prevent the operating noise of the transmission ratio variable motor in the low speed region of the driving motor and to exert the effect of the VGR control by performing the VGR control in the high speed region of the driving motor. .

(3) Advantages of the Third Invention According to the hybrid vehicle transmission ratio variable steering apparatus of the third invention, the target angle transmission ratio is lowered when the internal combustion engine is stopped. Here, when the target angle transmission ratio is reduced, the target angle of the transmission ratio variable motor is reduced. The smaller the target angle of the transmission ratio variable motor, the smaller the transmission ratio variable operation by the transmission ratio variable motor. That is, the rotational speed of the transmission ratio variable motor is reduced. Thus, by reducing the target angle transmission ratio, the rotational speed of the transmission ratio variable motor can be reduced, and as a result, the operating noise of the transmission ratio variable motor can be suppressed. Therefore, it is possible to make it difficult for the occupant to hear the operating sound of the transmission ratio variable motor as an uncomfortable feeling.

  Here, the target angle of the output shaft is the sum of the steering angle of the input shaft and the target angle of the variable transmission ratio motor transmitted to the output shaft by driving the variable transmission ratio motor with respect to the input shaft. . The reduction of the target angle of the transmission ratio variable motor as in the present invention acts so that the transmission ratio of the target angle of the output shaft to the steering angle of the input shaft approaches 1.

(4) Effects of the Fourth Invention According to the transmission ratio variable steering device for a hybrid vehicle of the fourth aspect of the invention, the rotation speed of the transmission ratio variable motor is set to a predetermined speed upper limit value or less when the internal combustion engine is stopped. That is, by not increasing the rotation speed of the transmission ratio variable motor, the operation noise of the transmission ratio variable motor can be suppressed. Thus, since the operating noise of the transmission ratio variable motor can be suppressed when the internal combustion engine is stopped, it can be made difficult for the occupant to feel uncomfortable.

(5) Effects of the fifth invention According to the variable transmission ratio steering apparatus for a hybrid vehicle of the fifth invention, the lock means is operated when the internal combustion engine is started or stopped when the lock means is moved to the locked state and when the lock means is released. I am doing so. Here, when the locking means operates from the unlocked state to the locked state, and when it operates from the locked state to the unlocked state, a slight locking sound is generated. However, by matching the operation to the locked state and the operation to the unlocked state with the start or stop of the internal combustion engine, it is possible to make it difficult to hear the lock sound generated by the lock means.

  Further, by performing the operation to the locked state and the operation to the unlocked state during the operation of the internal combustion engine, the lock sound can be mixed with the drive sound of the internal combustion engine, making it difficult for the occupant to hear the lock sound.

  By applying the control to the lock means of the transmission ratio variable steering device for the hybrid vehicle of the first invention, the effects of both can be achieved. As a result, the operation sound by the transmission ratio variable motor and the lock sound by the lock means are less likely to be heard by the occupant as uncomfortable, making it more comfortable.

  Next, the present invention will be described in more detail with reference to embodiments.

(1) 1st Embodiment (1.1) Whole structure of hybrid vehicle The whole structure of the hybrid vehicle in 1st Embodiment is demonstrated with reference to FIG. FIG. 1 is a diagram illustrating an overall configuration of a hybrid vehicle. As shown in FIG. 1, the hybrid vehicle includes an engine (internal combustion engine) 1 and a drive motor 2 as power transmission sources. The engine 1 rotationally drives the rear wheels via the power system speed reducer 3 and the differential 4. The engine 1 is disposed in an engine room (shown as “outside the vehicle compartment” in FIG. 1) located on the front side of the vehicle interior. In addition, the drive motor 2 rotationally drives the rear wheels via the power system speed reducer 3 and the differential 4. The drive motor 2 is selectively used as a drive source with the engine 1. That is, the drive motor 2 is driven while the engine 1 is stopped. In general, the motor is driven by the drive motor 2 in the low speed range, and is driven by the engine 1 in the high speed range.

  The hybrid vehicle includes a hybrid ECU 5 that controls driving of the engine 1 and the driving motor 2. The hybrid ECU 5 further outputs a stop signal for the engine 1 and a drive signal for the engine 1 to the VGR-ECU 13 described later. Here, the stop signal of the engine 1 is a signal generated by the hybrid ECU 5 when the operating engine 1 is about to stop soon and is switched to driving by the driving motor 2. The drive signal of the engine 1 is a signal generated by the hybrid ECU 5 when the stopped engine 1 starts driving.

  Further, the hybrid vehicle has a steering handle 6, an upper steering shaft (input shaft) 7, a lock means 8, a transmission ratio variable motor 9, a steering speed reducer 10, a lower steering shaft (as a steering transmission system). Output shaft) 11 and an electric power steering device 12. The upper steering shaft 7 is a shaft that is connected to the steering handle 6 and transmits a first steering angle of the steering handle 6 by the driver.

  The transmission ratio variable motor (transmission ratio variable means) 9 and the steering system speed reducer (transmission ratio variable means) 10 are connected to the lower end side of the upper steering shaft 7 and to the upper end side of the lower steering shaft 11. Yes. Specifically, the stator of the transmission ratio variable motor 9 is connected to the lower end side of the upper steering shaft 7, and the rotor output shaft of the transmission ratio variable motor 9 is connected to the steering system speed reducer 10. Further, the output side of the steering system speed reducer 10 is connected to the upper end side of the lower steering shaft 11. The second steering angle (target angle of the output shaft) θ2 of the lower steering shaft 11 with respect to the first steering angle (steering angle) θ1 of the upper steering shaft 7 by the transmission ratio variable motor 9 and the steering system speed reducer 10. The transmission ratio R1 can be varied. Specifically, the second steering angle θ2 of the lower steering shaft 11 is equal to the first steering angle θ1 of the upper steering shaft 7, the third steering angle (for transmission ratio variable) by the transmission ratio variable motor 9 and the steering system speed reducer 10. This is the sum of the target angle (θ3) of the electric motor. Here, the third steering angle θ3 is a rotational steering angle transmitted to the lower steering shaft 11 through the steering system speed reducer 10 when the transmission ratio variable motor 9 is driven with respect to the upper steering shaft 7. . That is, by changing the third steering angle θ3, the second steering angle θ2 can be changed with respect to the first steering angle θ1 as a result.

  The lock means 8 is means for bringing the upper steering shaft 7 and the rotor output shaft of the transmission ratio variable motor 9 into an integrated locked state. In other words, the lock unit 8 can switch between a lock state in which the upper steering shaft 7 and the rotor output shaft of the transmission ratio variable motor 9 are integrated and a lock release state that is not in the lock state. When the lock means 8 is brought into the locked state, the upper steering shaft 7 and the lower steering shaft 11 are integrally rotated. That is, in the locked state, the first steering angle θ1 of the upper steering shaft 7 and the second steering angle θ2 of the lower steering shaft 11 are the same.

  The electric power steering device 12 is a rack and pinion type electric power steering device. That is, a pinion (not shown) is formed on the lower end side of the lower steering shaft 11, and the pinion meshes with a rack (not shown). Then, an auxiliary steering force that turns the front wheels (steered wheels) is generated by the assist electric motor that constitutes the electric power steering device 12. The hybrid vehicle further includes a VGR-ECU (control means) 13 that controls at least the drive of the transmission ratio variable motor 9 and the drive of the lock means 8.

  Here, the transmission ratio variable steering device includes a lock unit 8, a transmission ratio variable motor 9, a steering system speed reducer 10, and a VGR-ECU 13.

(1.2) Configuration of VGR-ECU 13 Here, the VGR-ECU 13 will be described with reference to FIG. FIG. 2 is a block diagram of the VGR-ECU 13 of the first embodiment. As shown in FIG. 2, the VGR-ECU 13 inputs a detection signal from a first steering angle sensor 21 that detects a first steering angle θ <b> 1 of the upper steering shaft 7. Further, the VGR-ECU 13 receives a detection signal from a vehicle speed sensor 22 that detects the vehicle speed Vs of the hybrid vehicle. Further, the VGR-ECU 13 inputs drive information such as a stop signal of the engine 1 and a drive signal of the engine 1 from the hybrid ECU 5.

  The VGR-ECU 13 includes a lock control unit 23 that controls the drive of the lock unit 8 and an electric motor control unit 24 that controls the drive of the transmission ratio variable motor 9. The lock control unit 23 switches the operation of the lock unit 8 between the locked state and the unlocked state based on the detection signal input from the vehicle speed sensor 22 and the drive information input from the hybrid ECU 5. Details of the processing operation of the lock control unit 23 will be described later.

  The motor control unit 24 controls the drive of the transmission ratio variable motor 9 based on detection signals input from the first steering angle sensor 21 and the vehicle speed sensor 22. For example, the electric motor control unit 24 controls the transmission ratio R1 that is the second steering angle with respect to the first steering angle to be larger than 1 in the low speed range, and the transmission ratio R1 is smaller than 1 in the high speed range. Control to be. That is, control is performed so that the front wheels (steered wheels) are largely cut off by a slight steering in the low speed range, and the front wheels are not cut off greatly even in the high speed range even if the steering is performed largely.

(1.3) Processing Operation of Lock Control Unit 23 Next, the processing operation of the lock control unit 23 will be described with reference to the flowcharts of FIGS. FIG. 3 is a flowchart showing a driving process of the lock unit 8 by the lock control unit 23. FIG. 4 is a flowchart showing the process of the lock control unit 23 when the switching process between the locked state and the unlocked state is performed.

  First, with reference to FIG. 3, the drive process of the locking means 8 by the lock control part 23 is demonstrated. As shown in FIG. 3, it is determined whether or not the ignition switch (IG) is in an ON state (step S1). If the IG is not in the ON state (step S1: No), the process is terminated as it is. On the other hand, when the IG is in the ON state (step S1: Yes), it is determined whether or not the engine 1 is operating (step S2).

  When the engine 1 is operating (step S2: Yes), a process for setting the lock unit 8 to the unlocked state is performed (step S3). Then, the process ends. On the other hand, when the engine 1 is stopped (step S2: No), it is further determined whether or not the vehicle speed Vs is greater than a predetermined speed threshold value Vth (step S4). When the vehicle speed Vs is greater than the predetermined speed threshold value Vth (step S4: Yes), a process for bringing the lock unit 8 into the unlocked state is performed (step S3). Then, the process ends.

  On the other hand, if the engine 1 is stopped (step S2: No), and the vehicle speed Vs is equal to or lower than the predetermined vehicle speed threshold Vth (step S4: No), a process of setting the lock means 8 to the locked state is performed. (Transmission ratio non-variable processing) (step S5). Then, the process ends.

  That is, when the engine 1 is operating and when the engine 1 is stopped and the vehicle speed Vs is greater than the predetermined vehicle speed threshold value Vth, the lock unit 8 is unlocked. Then, the transmission ratio variable motor 9 is driven, and the transmission ratio R1 is variably controlled.

  On the other hand, when the engine 1 is stopped and the vehicle speed Vs is equal to or lower than the predetermined vehicle speed Vth, the lock means 8 is locked. That is, the first steering angle θ1 steered by the driver is transmitted to the lower steering shaft 11 as it is. That is, the first steering angle θ1 of the upper steering shaft 7 and the second steering angle θ2 of the lower steering shaft 11 are the same. At this time, since the transmission ratio variable motor 9 cannot be driven, the motor control unit 24 does not drive the transmission ratio variable motor 9.

  However, as will be described later with reference to FIG. 4, there are limitations when switching from the locked state to the unlocked state and when switching from the unlocked state to the locked state. That is, even when the lock state is to be set, the lock process may not be immediately performed and the unlocked state may be maintained. Further, even if the lock release state is to be set, the lock release process may not be performed immediately and the lock state may be maintained.

  Next, with reference to FIG. 4, the process of the lock control unit 23 when the switching process between the locked state and the unlocked state is performed will be described. As shown in FIG. 4, it is determined whether or not an instruction signal (lock instruction signal) for switching to the locked state is generated (step S11). The instruction signal for switching to the lock state is generated when the lock release processing in step S3 is performed in FIG.

  When the lock instruction signal is generated (step S11: Yes), it is subsequently determined whether or not a stop signal for the engine 1 is input from the hybrid ECU 5 (step S12). The stop signal of the engine 1 is a signal generated by the hybrid ECU 5 when the operating engine 1 is about to stop soon and is switched to driving by the driving motor 2 as described above.

  And when the stop signal of the engine 1 is not input from hybrid ECU5 (step S12: No), the process of step S12 is repeated until the stop signal of the engine 1 is input. On the other hand, when the stop signal of the engine 1 is input from the hybrid ECU 5 (step S12: Yes), the lock unit 8 is switched from the unlocked state to the locked state (step S13). Then, the process ends.

  On the other hand, when the lock instruction signal has not been generated (step S11: No), it is subsequently determined whether or not an instruction signal (lock release instruction signal) for switching to the unlocked state has been generated (step S14). In FIG. 3, the instruction signal for switching to the unlocked state is generated when the lock process in step S5 is performed in the unlocked state.

  When the unlock instruction signal is generated (step S14: Yes), it is subsequently determined whether or not a drive signal for the engine 1 is input from the hybrid ECU 5 (step S15). As described above, the drive signal of the engine 1 is a signal generated by the hybrid ECU 5 when the stopped engine 1 starts driving.

  If the drive signal for the engine 1 is not input from the hybrid ECU 5 (step S15: No), the process of step S15 is repeated until the drive signal for the engine 1 is input. On the other hand, when the drive signal of the engine 1 is input from the hybrid ECU 5 (step S15: Yes), the lock unit 8 is switched from the locked state to the unlocked state (step S16). Then, the process ends. Note that when the lock instruction signal and the lock release signal are not generated (step S14: No), the processing is ended as it is.

(1.4) Effects of First Embodiment As described above, when the engine 1 is stopped and the vehicle speed is low, the lock means 8 is locked and the transmission ratio variable motor 9 is not operated. In addition, it is possible to prevent the operating sound of the transmission ratio variable motor 9 from being heard by the occupant as being uncomfortable. Furthermore, the effect of the VGR control can be surely exhibited by performing the VGR control in the high speed region of the drive motor 2. Further, by performing the operation to the locked state and the operation to the unlocked state while the engine 1 is operating, the locking sound of the locking means 8 is mixed with the driving sound of the engine 1 so that it is difficult for the occupant to hear the locking sound. Can do.

(2) 2nd Embodiment Next, the hybrid vehicle in 2nd Embodiment is demonstrated. Here, the hybrid vehicle of the second embodiment is different in the internal configuration of the VGR-ECU 13 from the hybrid vehicle of the first embodiment. Hereinafter, the VGR-ECU 13 will be described. In the hybrid vehicle of the second embodiment, the same components as those of the hybrid vehicle of the first embodiment other than the VGR-ECU 13 are denoted by the same reference numerals, and detailed description thereof is omitted.

(2.1) Configuration of VGR-ECU 13 of Second Embodiment A VGR-ECU 13 of the second embodiment will be described with reference to FIG. FIG. 5 shows a block diagram of the VGR-ECU 13 in the second embodiment. As shown in FIG. 5, the VGR-ECU 13 includes a target angle calculation unit 31, a subtracter 32, an angle control unit 33, a third steering angle calculation unit 35, and a lock control unit 36.

  The target angle calculator 31 is a third rudder in which the lower steering shaft 11 is rotated by the transmission ratio variable motor 9 and the steering system speed reducer 10 based on detection signals input from the first rudder angle sensor 21 and the vehicle speed sensor 22. A target angle θ3 * of the corner is calculated. For example, when the vehicle speed Vs is low, the target angle transmission ratio (target gear ratio) R2 that is the target angle θ3 * of the third steering angle with respect to the first steering angle θ1 is a positive value, and when the vehicle speed Vs is high. The target gear ratio R2 is a negative value. That is, when the vehicle speed Vs is low, the target angle θ3 * of the third steering angle is the same direction as the first steering angle θ1. Therefore, when the vehicle speed Vs is small, the second steering angle θ2 of the lower steering shaft 11 is larger than the first steering angle θ1 by the target angle θ3 * of the third steering angle. That is, the transmission ratio R1 that is the second steering angle θ2 with respect to the first steering angle θ1 is greater than 1. In addition, when the vehicle speed Vs is high, the target angle θ3 * of the third rudder angle is an angle opposite to the first rudder angle θ1. Therefore, when the vehicle speed Vs is high, the second steering angle θ2 of the lower steering shaft 11 is smaller than the first steering angle θ1 by the target angle θ3 * of the third steering angle. That is, the transmission ratio R1 that is the second steering angle with respect to the first steering angle θ1 is smaller than 1. Here, such VGR control is referred to as normal VGR control in order to distinguish it from the target angle constant processing described later.

  Further, the target angle calculation unit 31 performs a target angle constant process based on the detection signal input from the vehicle speed sensor 22 and the drive information input from the hybrid ECU 5. The target angle constant process is a process in which the target angle θ3 * of the third steering angle is maintained at a constant value. When the target angle θ3 * of the third steering angle becomes a constant value, the second steering angle θ2 of the lower steering shaft 11 is always the same as the first steering angle θ1 of the upper steering shaft 7.

  Then, the subtractor 32 is a deviation third steering angle Δθ3 (= θ3 * −θ3) obtained by subtracting the actual third steering angle θ3 from the target angle θ3 * of the third steering angle calculated by the target angle calculation unit 31. ) Is calculated. The actual third rudder angle θ3 is calculated by a third rudder angle calculation unit 35, which will be described later, to calculate the third rudder angle θ3 at which the lower steering shaft 11 is rotated by the transmission ratio variable motor 9 and the steering reduction gear 10. The The angle control unit (angle control means) 33 receives the deviation third steering angle Δθ3 calculated by the subtractor 32, and applies a voltage to the transmission ratio variable motor 9 based on the input deviation third steering angle Δθ3. A command value Vm is calculated.

  The third steering angle calculation unit 35 receives a detection signal from the angle detection unit 34 that detects the rotation angle θm of the rotor output shaft of the transmission ratio variable motor 9, and the transmission ratio variable motor 9 and the steering system speed reducer 10. The third steering angle θ3 of the actual lower steering shaft 11 is calculated. Specifically, the third steering angle θ3 is obtained by multiplying the rotation angle θm of the rotor output shaft of the transmission ratio variable motor 9 input from the angle detector 34 by the reduction ratio of the steering system speed reducer 10. And the 3rd steering angle calculation part 35 outputs to the subtractor 32 mentioned above.

  The lock control unit 36 switches the operation of the lock unit 8 between the locked state and the unlocked state based on the detection signal input from the vehicle speed sensor 22 and the drive information input from the hybrid ECU 5. Details of the processing operation of the lock control unit 36 will be described later.

(2.2) Processing Operation of VGR-ECU 13 Next, the processing operation of the VGR-ECU 13 of the second embodiment will be described with reference to the flowchart of FIG. FIG. 6 is a flowchart showing the processing of the VGR-ECU 13 of the second embodiment.

  As shown in FIG. 6, first, it is determined whether or not the ignition switch (IG) is in an ON state (step S21). If the IG is not in the ON state (step S21: No), the process is terminated as it is. On the other hand, when the IG is in the ON state (step S21: Yes), it is determined whether or not the engine 1 is operating (step S22).

  When the engine 1 is operating (step S22: Yes), a process for setting the lock unit 8 to the unlocked state is performed (step S23). Subsequently, normal VGR control is performed (step S24). As described above, the normal VGR control is transmitted according to the target angle θ3 * of the third steering angle calculated by the target angle calculation unit 31 based on the detection signals input from the first steering angle sensor 21 and the vehicle speed sensor 22. This is control for controlling the angle of the variable ratio motor 9. Then, the process ends.

  On the other hand, when the engine 1 is stopped (step S22: No), it is further determined whether or not the vehicle speed Vs is greater than a predetermined speed threshold value Vth (step S25). When the vehicle speed Vs is greater than the predetermined speed threshold Vth (step S25: Yes), a process for setting the lock unit 8 to the unlocked state is performed (step S23), and normal VGR control is performed (step S24). Then, the process ends.

  If the engine 1 is stopped (step S22: No) and the vehicle speed Vs is equal to or lower than the predetermined vehicle speed threshold Vth (step S25: No), a process of setting the lock unit 8 to the unlocked state is performed. (Transmission ratio non-variable processing) (step S26). Subsequently, a target angle constant process is performed (transmission ratio non-variable process) (step S27). Here, as described above, the target angle constant process is a process in which the target angle θ3 * of the third steering angle is maintained at a constant value. Then, the process ends.

  That is, when the engine 1 is operating and when the engine 1 is stopped and the vehicle speed Vs is greater than the predetermined vehicle speed threshold Vth, the lock means 8 is unlocked and normal VGR control is performed. Is called. That is, the transmission ratio variable motor 9 is driven and the transmission ratio R1 is variably controlled.

  On the other hand, when the engine 1 is stopped and the vehicle speed Vs is equal to or lower than the predetermined vehicle speed Vth, the lock unit 8 is in the unlocked state, but the target angle constant process is performed. That is, the transmission ratio variable motor 9 is controlled not to be driven. That is, the first steering angle θ1 steered by the driver is transmitted to the lower steering shaft 11 as it is. That is, the first steering angle θ1 of the upper steering shaft 7 and the second steering angle θ2 of the lower steering shaft 11 are the same.

(2.3) Effects of Second Embodiment As described above, when the engine 1 is stopped and the vehicle speed is low, the target angle constant process is performed and the transmission ratio variable motor 9 is not operated. It is possible to prevent the operating sound of the transmission ratio variable motor 9 from being heard by the occupant as being uncomfortable. Furthermore, the effect of the VGR control can be surely exhibited by performing the VGR control in the high speed region of the drive motor 2. Further, since the lock unit 8 is not switched between the locked state and the unlocked state, no locking sound is generated.

(3) Third Embodiment Next, a hybrid vehicle in the third embodiment will be described. Here, the hybrid vehicle of the third embodiment is different from the hybrid vehicle of the second embodiment in the internal configuration of the target angle calculation unit 31 of the VGR-ECU 13. Hereinafter, the target angle calculation unit 31 will be described, and the processing operation of the VGR-ECU 13 of the third embodiment will be described. In the hybrid vehicle of the third embodiment, the same components as those of the hybrid vehicle of the second embodiment other than the target angle calculation unit 31 are denoted by the same reference numerals, and detailed description thereof is omitted.

(3.1) Configuration of Target Angle Calculation Unit 31 of Third Embodiment The target angle calculation unit 31 of the third embodiment will be described with reference to FIG. FIG. 7 shows a block diagram of the target angle calculation unit 31 of the third embodiment. As shown in FIG. 7, the target angle calculation unit 31 includes a reference target angle calculation unit 41, a target gear ratio reduction processing unit 42, an electric motor speed calculation unit 43, an electric motor speed upper limit storage unit 44, and a corrected target angle. And a calculation unit 45.

  The reference target angle calculation unit (motor target angle calculation means) 41 is based on the detection signals input from the first rudder angle sensor 21 and the vehicle speed sensor 22, and the lower steering shaft is driven by the transmission ratio variable motor 9 and the steering system speed reducer 10. A reference value (hereinafter referred to as “reference target angle”) of the target angle θ3 * of the third steering angle at which 11 is rotated is calculated. The reference target angle is a value obtained by multiplying the first steering angle θ1 by the target gear ratio R2. Here, the target gear ratio R2 is a positive value when the vehicle speed Vs is low, and is a negative value when the vehicle speed Vs is high. That is, the target gear ratio R2 is made different depending on the vehicle speed Vs. Here, the target gear ratio R2 is changed by a target gear ratio reduction processing unit 42 described later. In this case, the reference target angle calculation unit 41 calculates the reference target angle based on the changed target gear ratio R2.

  The target gear ratio reduction processing unit (target angle transmission ratio reduction processing means) 42 is a process for reducing the absolute value of the target gear ratio R2 based on the detection signal input from the vehicle speed sensor 22 and the drive information input from the hybrid ECU 5. (Hereinafter referred to as “target gear ratio lowering process”). Note that when the absolute value of the target gear ratio R2 decreases, the target angle θ3 * of the third steering angle decreases.

  The motor speed calculation unit 43 is configured to change the transmission ratio variable motor 9 when the lower steering shaft 11 is rotated by the reference target angle calculated by the reference target angle calculation unit 41 by the transmission ratio variable motor 9 and the steering system speed reducer 10. The rotation speed V1 is calculated. Then, the motor speed calculation unit 43 outputs the calculated rotation speed V1 to the corrected target angle calculation unit 45 described later. The motor speed upper limit storage unit 44 stores the upper limit value Vmax of the rotation speed of the transmission ratio variable motor 9.

  The corrected target angle calculation unit 45 inputs the reference target angle calculated by the reference target angle calculation unit 41. Then, the corrected target angle calculation unit 45 determines whether or not it is in a state of correcting the input reference target angle based on the detection signal input from the vehicle speed sensor 22 and the drive information input from the hybrid ECU 5. Further, when it is determined that the reference target angle is being corrected, it is determined whether or not the rotation speed V1 calculated by the motor speed calculation unit 43 exceeds the upper limit value Vmax of the rotation speed. When the rotational speed V1 exceeds the upper limit value Vmax of the rotational speed, the target angle θ3 * of the third steering angle such that the rotational speed V1 of the transmission ratio variable motor 9 becomes the upper limit value Vmax of the rotational speed. Is calculated (rotational speed limiting process). Then, the corrected target angle calculation unit 45 outputs the calculated target angle θ3 * of the third steering angle to the subtractor 32.

(3.2) Processing Operation of VGR-ECU 13 of Third Embodiment Next, the processing operation of the VGR-ECU 13 of the third embodiment will be described with reference to the flowchart of FIG. FIG. 8 is a flowchart showing the processing of the VGR-ECU 13 of the third embodiment.

  As shown in FIG. 8, it is determined whether or not the ignition switch (IG) is in an ON state (step S31). If the IG is not in the ON state (step S31: No), the process is terminated as it is. On the other hand, when the IG is in the ON state (step S31: Yes), it is determined whether or not the engine 1 is operating (step S32).

  When the engine 1 is operating (step S32: Yes), a process for setting the lock unit 8 to the unlocked state is performed (step S33). Subsequently, VGR control is performed (step S34). Then, the process ends.

  On the other hand, when the engine 1 is stopped (step S32: No), it is further determined whether or not the vehicle speed Vs is greater than a predetermined speed threshold value Vth (step S35). When the vehicle speed Vs is greater than the predetermined speed threshold Vth (step S35: Yes), a process for setting the lock unit 8 to the unlocked state is performed (step S33), and VGR control is performed (step S34). Then, the process ends.

  If the engine 1 is stopped (step S32: No) and the vehicle speed Vs is equal to or lower than the predetermined vehicle speed threshold Vth (step S35: No), a target gear ratio reduction process is performed (step S36). . The target gear ratio reduction process is a process for reducing the absolute value of the target gear ratio R2 in the target gear ratio reduction processing unit 42 as described above. That is, the reference target angle calculation unit 41 calculates the reference target angle based on the reduced target gear ratio R2.

  After the target gear ratio reduction process is performed, a rotation speed limiting process is performed (step S37). Here, in the rotation speed limiting process, as described above, the rotation speed V1 calculated by the motor speed calculation unit 43 exceeds the upper limit value Vmax of the rotation speed stored in the motor speed upper limit storage unit 44. It is a process performed in the case. Specifically, in the rotation speed limiting process, in the above case, the corrected target angle calculation unit 45 calculates the target angle θ3 * of the third steering angle such that the rotation speed V1 becomes the upper limit value Vmax of the rotation speed, This is a process of outputting the calculated target angle θ3 * of the third steering angle to the subtractor 32.

  After the rotation speed limiting process is performed, a process for bringing the lock unit 8 into the unlocked state is performed (step S33), and VGR control is performed (step S34). Then, the process ends.

  That is, when the engine 1 is operating and when the engine 1 is stopped and the vehicle speed Vs is greater than the predetermined vehicle speed threshold Vth, the target gear ratio R2 is not reduced and the transmission is performed. VGR control is performed without limiting the rotational speed of the ratio variable motor 9. That is, the transmission ratio variable motor 9 is driven based on the target angle θ3 * of the third steering angle calculated based on the first steering angle θ1 and the vehicle speed Vs.

  On the other hand, when the engine 1 is stopped and the vehicle speed Vs is equal to or lower than the predetermined vehicle speed Vth, the VGR control is performed in a state where the target gear ratio R2 is reduced and the rotational speed of the variable transmission ratio motor 9 is limited. Is done. That is, the rotation speed of the transmission ratio variable motor 9 is controlled to be as small as possible.

(3.3) Effect of Third Embodiment As described above, when the engine 1 is stopped and the vehicle speed is low, the target gear ratio lowering process and the rotation speed limiting process are performed, thereby changing the transmission ratio variable motor. The rotational speed of 9 is controlled to be as small as possible. As a result, in the above case, it is possible to suppress the operating sound of the transmission ratio variable motor 9 from being heard by the occupant as being uncomfortable. Furthermore, the effect of the VGR control can be surely exhibited by performing the VGR control in the high speed region of the drive motor 2. Further, since the lock unit 8 is not switched between the locked state and the unlocked state, no locking sound is generated.

(4) Other Embodiments In the above embodiment, the variable transmission ratio steering apparatus has been described as a so-called column-mounted type disposed between the upper steering shaft and the lower steering shaft. However, the present invention is not limited to this. . For example, the transmission ratio variable steering device may be a rack housing integrated type.

It is a figure showing the whole hybrid vehicle composition. It is a block diagram which shows VGR-ECU13 of 1st Embodiment. 7 is a flowchart showing a driving process of the lock unit 8 by the lock control unit 23. It is a flowchart which shows the process of the lock control part 23 at the time of the switching process of a lock state and a lock release state being performed. It is a block diagram which shows VGR-ECU13 in 2nd Embodiment. It is a flowchart which shows the process of VGR-ECU13 of 2nd Embodiment. It is a block diagram which shows the target angle calculation part 31 of 3rd Embodiment. It is a flowchart which shows the process of VGR-ECU13 of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Engine (internal combustion engine), 2: Electric motor for drive, 3: Power system reduction gear, 4: Differential, 5: Hybrid ECU, 6: Steering handle, 7: Upper steering shaft, 8: Locking means, 9: Transmission ratio Variable motor, 10: Steering speed reducer, 11: Lower steering shaft, 12: Electric power steering device, 13: VGR-ECU

Claims (7)

A hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor,
A transmission ratio that has an input shaft connected to the steering wheel side and an output shaft connected to the steered wheel side, and changes the transmission ratio between the input shaft and the output shaft by the rotational drive of the transmission ratio variable motor. Variable means;
Locking means for restricting relative rotation between the input shaft and the output shaft;
Control means for controlling the transmission ratio variable means and the locking means;
In a transmission ratio variable steering apparatus for a hybrid vehicle comprising:
The transmission ratio variable steering apparatus for a hybrid vehicle, wherein the control means performs a transmission ratio non-variable process for bringing the lock means into a locked state when the internal combustion engine is stopped. A hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor,
A transmission ratio that has an input shaft connected to the steering wheel side and an output shaft connected to the steered wheel side, and changes the transmission ratio between the input shaft and the output shaft by the rotational drive of the transmission ratio variable motor. Variable means;
Locking means for restricting relative rotation between the input shaft and the output shaft;
Control means for controlling the transmission ratio variable means and the locking means;
In a transmission ratio variable steering apparatus for a hybrid vehicle comprising:
The control means sets the lock means to the unlocked state when the internal combustion engine is stopped, and controls the transmission ratio variable means so as to maintain the target angle of the output shaft at the steering angle of the input shaft. A transmission ratio variable steering apparatus for a hybrid vehicle characterized by performing variable processing. Furthermore, a vehicle speed detecting means for detecting the vehicle speed of the hybrid vehicle is provided,
3. The transmission ratio variable steering of a hybrid vehicle according to claim 1, wherein the control means performs the transmission ratio non-variable processing when the internal combustion engine is stopped and the vehicle speed is equal to or lower than a predetermined speed. apparatus. A hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor,
A transmission ratio that has an input shaft connected to the steering wheel side and an output shaft connected to the steered wheel side, and changes the transmission ratio between the input shaft and the output shaft by the rotational drive of the transmission ratio variable motor. Variable means;
Locking means for restricting relative rotation between the input shaft and the output shaft;
Control means for controlling the transmission ratio variable means and the locking means;
In a transmission ratio variable steering apparatus for a hybrid vehicle comprising:
The control means includes
A transmission ratio variable motor angle calculation means for calculating a target angle of the transmission ratio variable motor that rotationally drives the output shaft by rotating the transmission ratio variable motor with respect to the input shaft;
Angle control means for angle-controlling the transmission ratio variable motor based on the target angle of the transmission ratio variable motor;
Target angle transmission ratio reduction processing means for reducing the target angle transmission ratio which is the target angle of the transmission ratio variable motor with respect to the steering angle of the input shaft when the internal combustion engine is stopped;
A transmission ratio variable steering apparatus for a hybrid vehicle, comprising: A hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor,
A transmission ratio that has an input shaft connected to the steering wheel side and an output shaft connected to the steered wheel side, and changes the transmission ratio between the input shaft and the output shaft by the rotational drive of the transmission ratio variable motor. Variable means;
Locking means for restricting relative rotation between the input shaft and the output shaft;
Control means for controlling the transmission ratio variable means and the locking means;
In a transmission ratio variable steering apparatus for a hybrid vehicle comprising:
The transmission ratio variable steering apparatus for a hybrid vehicle, wherein the control means performs a rotation speed limiting process for setting a rotation speed of the transmission ratio variable motor to a predetermined speed upper limit value or less when the internal combustion engine is stopped. A hybrid vehicle equipped with an internal combustion engine and a drive motor and capable of traveling by driving at least one of the internal combustion engine and the drive motor,
A transmission ratio that has an input shaft connected to the steering wheel side and an output shaft connected to the steered wheel side, and changes the transmission ratio between the input shaft and the output shaft by the rotational drive of the transmission ratio variable motor. Variable means;
Locking means for restricting relative rotation between the input shaft and the output shaft;
Control means for controlling the transmission ratio variable means and the locking means;
In a transmission ratio variable steering apparatus for a hybrid vehicle comprising:
The transmission ratio variable steering apparatus for a hybrid vehicle, wherein the control means performs the operation of the locking means to the locked state and the operation to the unlocked state when the internal combustion engine is started or stopped.   The transmission ratio variable steering apparatus for a hybrid vehicle according to claim 6, wherein the control means performs the operation of the locking means to the locked state and the operation to the unlocked state during the operation of the internal combustion engine. .

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