WO2022024216A1

WO2022024216A1 - Setting-off assistance device

Info

Publication number: WO2022024216A1
Application number: PCT/JP2020/028871
Authority: WO
Inventors: 智之原; 幸浩稲満
Original assignee: 株式会社ユニバンス
Priority date: 2020-07-28
Filing date: 2020-07-28
Publication date: 2022-02-03
Also published as: JPWO2022024216A1

Abstract

Provided is a setting-off assistance device that can reduce the consumption of power during a stop, and reduce any discomfort when setting off. This setting-off assistance device comprises: a first gear mechanism (20) that transmits, to an output shaft, the torque of a first shaft (14) to which the torque of a first drive device (12) is transmitted; a second gear mechanism (30) that transmits, to the output shaft, at a lower reduction ratio than the reduction ratio of the first gear mechanism, the torque of a second shaft (15) positioned coaxially with respect to the first shaft, the torque of a second drive device (13) being transmitted to the second shaft; a first clutch (40) that transmits/interrupts driving power between the first shaft and the second shaft; a second clutch (23) comprising a one-way clutch that transmits, to the output shaft, the rotation of the first gear mechanism when the vehicle is moving forward; and a control device (50) that operates the first clutch. At least one of the first drive device and the second drive device is a motor, and the control device engages the first clutch when the vehicle is at or below a prescribed speed and is on an uphill slope.

Description

Start assist device

The present invention relates to a start assist device that prevents the vehicle from moving backward when starting on a slope.

Vehicles equipped with a function to prevent the vehicle from retreating when starting on a slope (so-called hill start assist) are known. In the technique disclosed in Patent Document 1, the vehicle is stopped by using the braking force of the vehicle braking device (hydraulic brake).

In the technology disclosed in Patent Document 2, in a vehicle equipped with a motor that outputs the driving force of the vehicle, the driving force of the motor is used to stop the vehicle. However, since the rotation angle of the motor does not change while the vehicle is stopped, current may continue to flow in a specific circuit of the motor, which may cause the motor to overheat. Therefore, the temperature of the motor and the driving force of the motor are used to monitor the time when the vehicle has stopped, and when they meet the predetermined conditions, the output of the motor is stopped, and instead of the driving force of the motor, the braking device of the vehicle is used. The braking force is used to stop the vehicle.

Japanese Unexamined Patent Publication No. 9-295562 Japanese Unexamined Patent Publication No. 2018-182824

However, in the techniques of

Patent Documents

1 and 2, since the vehicle is stopped by using the braking device on a slope, it takes some time from the starting operation until the braking force of the braking device disappears. If the braking force of the braking device is large, there is a risk of feeling uncomfortable due to the braking force when starting. If the braking force of the braking device is small or the braking force is lost before the driving force is generated, the vehicle may move backward. In particular, since the motor disclosed in Patent Document 2 has a large starting torque, the speed at which the braking force of the braking device decreases tends to be slower than the speed at which the driving force of the motor increases. Easy to remember. There is a problem that the electric power cost deteriorates because the electric power is consumed while the vehicle is stopped by using the driving force of the motor.

The present invention has been made to solve this problem, and an object of the present invention is to provide a start assisting device capable of reducing power consumption at the time of stopping and reducing discomfort at the time of starting.

In order to achieve this object, the start assist device of the present invention has a first gear mechanism that transmits the torque of the first shaft to which the torque of the first drive device is transmitted to the output shaft, and a first gear mechanism arranged coaxially with the first shaft. The second gear mechanism, which has two axes and transmits the torque of the second axis to which the torque of the second drive device is transmitted to the output shaft at a reduction ratio smaller than the reduction ratio of the first gear mechanism, and the first and second axes. A second clutch consisting of a first clutch that transmits / disconnects power between the two, a one-way clutch that transmits the rotation of the first gear mechanism when the vehicle moves forward to the output shaft, and a control device that operates the first clutch. , Equipped with. At least one of the first drive device and the second drive device is a motor, and the control device engages the first clutch when the vehicle is below a predetermined speed and is uphill.

According to the start assist device according to claim 1, the control device engages the first clutch when the vehicle is at a predetermined speed or less (including a speed of 0 at which the vehicle is stopped) and the vehicle is on an uphill slope. .. When the vehicle to which the first clutch is engaged tries to retreat uphill, the wheels rotate in the reverse direction and the output shaft rotates in the reverse direction. The rotation of the output shaft is transmitted to the second shaft via the second gear mechanism, and is transmitted to the first shaft and the first gear mechanism via the first clutch. Since the reduction ratio of the second gear mechanism is smaller than the reduction ratio of the first gear mechanism, the second clutch composed of the one-way clutch is engaged. Since double meshing occurs here, it is possible to mechanically prevent the reverse rotation of the output shaft without consuming electric power. This prevents the vehicle from retreating.

At the time of starting, when at least one of the motors of the first drive device and the second drive device is started, the output shaft rotates in the forward direction and the vehicle starts. In addition to the braking force not acting on the starting assist device when starting, the motor has a large starting torque, so it is possible to reduce the discomfort when starting.

According to the start assist device according to claim 2, the control device disengages the first clutch when the vehicle starts. As a result, in addition to the effect of claim 1, the output shaft can rotate via the first gear mechanism, so that acceleration at the time of starting can be improved.

According to the start assist device according to claim 3, the control device disengages the first clutch when the vehicle is at a predetermined speed or higher. Therefore, in addition to the effect of claim 2, the frequency of switching the operation of the first clutch after the vehicle starts can be reduced.

According to the start assist device according to claim 4, the vehicle can be set to at least a forward mode in which the vehicle is advanced by the forward rotation of the output shaft and a reverse mode in which the vehicle is retracted by the reverse rotation of the output shaft. Since the control device disengages the first clutch when it is set to a mode other than the forward mode, in addition to the effect of any one of claims 1 to 3, it is possible not to interfere with the function of the mode other than the forward mode.

According to the starting assist device according to claim 5, the control device rotates the first shaft so that the first gear mechanism rotates in the forward direction when the first clutch, which is the meshing clutch, is disengaged. Therefore, in addition to the effect of any one of claims 1 to 4, the first clutch engaged can be easily disengaged and the acceleration at the time of starting can be improved.

It is a functional block diagram of the vehicle in one embodiment. It is a functional block diagram of a control device. It is a figure which shows the combination of the operation of the 1st drive device, the 2nd drive device, and the 1st clutch. It is a flowchart of the assist process in 1st Embodiment. It is a flowchart of the assist process in 2nd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a functional block diagram of the vehicle 10 in one embodiment. The vehicle 10 is equipped with a start assist device 11, a first drive device 12, and a second drive device 13. The vehicle 10 is an automobile.

The start assist device 11 has a function (hill start assist) to prevent the vehicle 10 from retreating when starting on a slope. The start assist device 11 transmits the torques of the first shaft 14 connected to the first drive device 12, the second shaft 15, the output shaft 16, and the first shaft 14 connected to the second drive device 13 to the output shaft 16. It includes a second gear mechanism 30, a first clutch 40, and a control device 50 that transmit the torque of the first gear mechanism 20, the second clutch 23, and the second shaft 15 to the output shaft 16.

The first drive device 12 and the second drive device 13 are devices that output the drive force of the vehicle 10. In this embodiment, the first drive device 12 and the second drive device 13 are motors. The motor is an AC motor such as a winding type motor or a cage type motor. The first drive device 12 and the second drive device 13 have the same torque characteristics.

The first axis 14 and the second axis 15 are arranged coaxially. The output shaft 16 is arranged parallel to the first shaft 14 and the second shaft 15. In the present embodiment, the first shaft 14 is arranged coaxially with the output shaft of the first drive device 12 and is coupled to the output shaft of the first drive device 12. The second shaft 15 is arranged coaxially with the output shaft of the second drive device 13 and is coupled to the output shaft of the second drive device 13. The first shaft 14 and the second shaft 15 are arranged so as to be rotatable relative to each other via a pilot bearing (not shown).

The mechanical output of the output shaft 16 is transmitted to the differential device 18 arranged in the center of the axle 17. The axle 17 is arranged parallel to the output shaft 16. The differential device 18 distributes the driving force to the left and right axles 17. Of course, it is possible to provide a limiting device that limits the operation of the differential device 18. Wheels 19 are arranged at both ends of the axle 17. The vehicle 10 has a plurality of wheels (not shown) arranged in addition to the wheels 19, and travels by rotationally driving the axle 17 and the wheels 19.

The first gear mechanism 20 is a mechanism that slows down the rotation of the first shaft 14 and transmits it to the output shaft 16. The first gear mechanism 20 includes a first gear 21 coupled to the first shaft 14, and a second gear 22 coupled to the output shaft 16 by the second clutch 23 or idling the output shaft 16. The second gear 22 meshes with the first gear 21. The first gear mechanism 20 is set to a reduction ratio due to the engagement between the first gear 21 and the second gear 22.

The second clutch 23 is a one-way clutch that transmits the positive rotation of the first gear mechanism 20 to the output shaft 16. In the present embodiment, the second clutch 23 is arranged on the output shaft 16 and is interposed between the output shaft 16 and the second gear 22. Forward rotation refers to the direction in which mechanical elements such as gears rotate when the vehicle 10 moves forward, and reverse rotation refers to the direction in which the mechanical elements rotate when the vehicle 10 moves backward.

The second clutch 23 transmits the positive rotation of the second gear 22 to the output shaft 16 in the relative rotation between the output shaft 16 and the second gear 22, while transmitting the positive rotation from the output shaft 16 to the second gear 22. To shut off. Further, the second clutch 23 cuts off the transmission of the reverse rotation of the second gear 22 to the output shaft 16 in the relative rotation between the output shaft 16 and the second gear 22, while the reverse rotation of the output shaft 16 is caused by the second gear. Communicate to 22.

The second gear mechanism 30 is a mechanism that decelerates the rotation of the second shaft 15 and transmits it to the output shaft 16. The second gear mechanism 30 includes a third gear 31 that is coupled to the second shaft 15 and a fourth gear 32 that is coupled to the output shaft 16 and meshes with the third gear 31. The second drive device 13 can always transmit power to the output shaft 16 via the second gear mechanism 30. The second gear mechanism 30 is set to a reduction ratio smaller than the reduction ratio of the first gear mechanism 20 by the engagement between the third gear 31 and the fourth gear 32. The first gear mechanism 20 is a low-speed transmission path, and the second gear mechanism 30 is a high-speed transmission path.

The fifth gear 33 coupled to the output shaft 16 meshes with the sixth gear 34 coupled to the differential device 18. The fifth gear 33 and the sixth gear 34 transmit the power of the output shaft 16 to the axle 17 via the differential device 18.

The first clutch 40 transmits / disconnects power between the first shaft 14 and the second shaft 15. In the present embodiment, the first clutch 40 is a meshing clutch. Examples of the meshing clutch include a gear clutch, a tooth clutch, and a jaw clutch. However, the first clutch 40 is not limited to this, and it is naturally possible to adopt a clutch other than the meshing clutch, such as a friction clutch, or to incorporate a synchromesh.

The control device 50 is a device for controlling the first drive device 12, the second drive device 13, and the first clutch 40. The control device 50 includes a CPU that is an arithmetic processing unit, a ROM that stores programs and arithmetic parameters used by the CPU, and a RAM that temporarily stores parameters that change appropriately in the execution of the CPU (none of which is shown). ) Is provided.

The control device 50 uses the actuator 41 to engage and disengage the first clutch 40. The actuator 41 moves the sleeve 43 in the axial direction via the spring 42. An axial restoring force of the spring 42 is applied to the sleeve 43 in conjunction with the operation of the actuator 41.

Inverters

61 and 62 are connected to the control device 50 via the CAN communication line 60. The inverter 61 is connected to the first drive device 12, and the inverter 62 is connected to the second drive device 13. The control device 50 controls the first drive device 12 and the second drive device 13 by using the

inverters

61 and 62.

The control device 50 includes a first rotation sensor 63, a second rotation sensor 64, a vehicle speed sensor 65, an acceleration sensor 66, an accelerator pedal sensor 67, a brake pedal sensor 68, a sleeve position sensor 69, a shift lever 70, and other input / output devices. 71 and the power storage device 72 are connected.

The first rotation sensor 63 is a device for detecting the rotation speed (rotational speed) of the first drive device 12. The first rotation sensor 63 includes an output circuit (not shown) that detects the rotation speed of the first shaft 14, processes the detection result, and outputs the detection result to the control device 50. The second rotation sensor 64 is a device for detecting the rotation speed (rotational speed) of the second drive device 13. The second rotation sensor 64 includes an output circuit (not shown) that detects the rotation speed of the second axis 15, processes the detection result, and outputs the detection result to the control device 50.

The control device 50 controls the torque of the first drive device 12 by detecting and feeding back the amount of current flowing through the inverter 61, and by detecting and feeding back the amount of current flowing through the inverter 62, the second drive device 13 Control torque. Further, the control device 50 controls the rotation speed of the first drive device 12 by detecting and feeding back the rotation speed of the first shaft 14 by the first rotation sensor 63, and the second rotation sensor 64 controls the rotation speed of the second shaft 15. The rotation speed of the second drive device 13 is controlled by detecting and feeding back the rotation speed.

The vehicle speed sensor 65 is a device for detecting the speed of the vehicle 10 (hereinafter referred to as "vehicle speed"). The vehicle speed sensor 65 detects the rotational speed of the output shaft 16, calculates the vehicle speed in consideration of the reduction ratio of the fifth gear 33, the sixth gear 34, the differential device 18, the size of the wheels 19, and the like, and controls the control device. It is equipped with an output circuit (not shown) that outputs to 50. Not limited to this, the vehicle speed sensor 65 may detect the rotational speed of the axle 17 and calculate the vehicle speed in consideration of the size of the wheels 19 and the like.

The acceleration sensor 66 includes an output circuit (not shown) that detects the acceleration generated in the vehicle 10, processes the detection result, and outputs the detection result to the control device 50. Examples of the acceleration sensor 66 include a sensor that detects acceleration of three axes and a gyro sensor.

The accelerator pedal sensor 67 includes an output circuit (not shown) that detects the amount of depression of the accelerator pedal (not shown) by the driver, processes the detection result, and outputs the detection result to the control device 50. The output of the accelerator pedal sensor 67 is proportional to the driving force (torque / radius of the wheel 19) required by the driver.

The total torque required by the driver, that is, the torque required by the output shaft 16 (hereinafter referred to as "target torque") is the detection result of the accelerator pedal sensor 67 (the amount of operation of the accelerator pedal) and the detection result of the vehicle speed sensor 65 (hereinafter referred to as "target torque"). It is determined by the vehicle speed). In the present embodiment, the target torque is expressed as the torque of the output shaft 16 in consideration of the reduction ratio of the fifth gear 33, the sixth gear 34 and the differential device 18 and the radius of the wheel 19.

The brake pedal sensor 68 includes an output circuit (not shown) that detects the amount of depression of the brake pedal (not shown) by the driver, processes the detection result, and outputs the detection result to the control device 50. The braking device (not shown) of the vehicle 10 operates based on the brake pedal depression force. Examples of the braking device include those that utilize the braking torque of the motor (reverse-phase braking, single-phase braking, etc.), hydraulic brakes, and electromagnetic brakes.

The sleeve position sensor 69 includes an output circuit (not shown) that detects the position of the sleeve 43 of the first clutch 40, processes the detection result, and outputs the detection result to the control device 50. Based on the detection result of the sleeve position sensor 69, the control device 50 detects whether the first clutch 40 is engaged or disengaged.

The shift lever 70 is an input device for the driver to select a shift position. Examples of the shift position selected by the shift lever 70 include a forward mode for moving the vehicle 10 forward, a backward mode for moving the vehicle 10 backward, a neutral mode, and a stop mode. In the neutral mode, the

inverters

61 and 62 stop the output.

Examples of the other input / output device 71 include a notification device and a navigation device that notify the driver that the hill start assist is functioning by sound or light. The navigation device detects that the vehicle 10 is located on an uphill and outputs it to the control device 50.

The power storage device 72 is a battery, a capacitor, or the like that supplies electric power to the

inverters

61, 62, the control device 50, and the like. In addition to being supplied with external power, the power storage device 72 is charged with power generated when the first drive device 12 and the second drive device 13 are regeneratively braked.

FIG. 2 is a functional block diagram of the control device 50. The control device 50 includes a determination unit 51 and a control unit 56. The determination unit 51 determines whether or not to exert the hill start assist function and outputs the output to the control unit 56. The control unit 56 controls the first drive device 12 and the first clutch 40 based on the determination result of the determination unit 51.

The mode determination unit 52 determines whether or not the vehicle 10 is in the forward mode based on the input by the shift lever 70. The vehicle stop determination unit 53 determines whether or not the vehicle 10 is stopped (vehicle speed V = 0) based on the detection result of the vehicle speed sensor 65. Based on the detection result of the vehicle speed sensor 65, the vehicle speed determination unit 54 determines whether or not the vehicle 10 has a predetermined speed V ₀ (V ₀ ≠ 0) or less, and the vehicle 10 has a predetermined speed V ₁ (V ₁ > V ₀ ). It is determined whether or not the above is the case.

The gradient determination unit 55 calculates, for example, the pitch angle, which is the angle of inclination of the vehicle 10 in the pitch direction, as the slope of the road surface based on the detection result of the acceleration sensor 66, and the vehicle 10 is positioned on an uphill based on the slope. Judge whether or not. The gradient determination unit 55 may determine whether or not the vehicle 10 is located on an uphill based on the detection result of the navigation device.

The drive control unit 57 controls the first drive device 12. The first clutch control unit 58 operates the actuator 41 to connect and disconnect the first clutch 40. The brake control unit 59 controls the braking device (not shown) of the vehicle 10 based on the brake pedal depression force and other signals.

FIG. 3 is a diagram showing a combination of operations of the first drive device 12, the second drive device 13, and the first clutch 40 in the forward mode and the reverse mode. In FIG. 3, the first drive device 12, the second drive device 13, and the first clutch 40 that operate in each mode are indicated by x.

The control device 50 controls to set one of the first mode, the second A mode, the second B mode, the third mode, and the fourth mode based on the map stored in the ROM according to the target torque in the forward mode. .. The control device 50 controls to operate the second drive device 13 in the backward mode.

In the first mode, the control device 50 is in a state where the first clutch 40 is disengaged, the second drive device 13 is de-energized, and the first drive device 12 is power-controlled. The first mode is used when starting or running at low speed. Since the torque of the first drive device 12 is output to the output shaft 16 via the first gear mechanism 20 having a reduction ratio larger than that of the second gear mechanism 30, a large drive torque is obtained from a low speed to obtain a powerful start and low speed running. Is possible.

In the second mode (second A and second B mode), the control device 50 controls the power running of the second drive device 13. Since the torque of the second drive device 13 is output to the output shaft 16 via the second gear mechanism 30 having a reduction ratio smaller than that of the first gear mechanism 20, high-speed running with good electricity cost is possible. Since the second clutch 23 including the one-way clutch does not transmit the forward rotation of the output shaft 16 to the second gear 22, the second drive device 13 drives the output shaft 16 in the second A mode in which the first clutch 40 is disengaged. The drag loss due to the first gear mechanism 20 and the first drive device 12 can be suppressed.

In the 2nd B mode, the 1st clutch 40 is engaged, so the 1st drive device 12 is carried around. At this time, when there is a request to switch to the fourth mode in which the first clutch 40 is connected to drive the first drive device 12 and the second drive device 13, the mode is smoothly switched to the fourth mode. Further, by de-energizing the first drive device 12 in the second mode, the power consumption in the second mode can be reduced by that amount.

The first drive device 12 may be energized in the second mode. Since the second clutch 23 is arranged on the output shaft 16, the rotation speed of the second gear 22 driven by the first drive device 12 is the fourth gear 32 (output shaft 16) driven by the second drive device 13. ) Is smaller than the rotation speed of), the second clutch 23 is disengaged and the driving force of the first driving device 12 is not transmitted to the output shaft 16.

If the first drive device 12 is energized in the second mode to increase the rotation speed of the first drive device 12, the time required to match the rotation speeds of the first axis 14 and the second axis 15 can be shortened. The first clutch 40 can be easily connected. Therefore, the switching time from the second mode to the fourth mode can be shortened.

In the third mode, the control device 50 controls the power running of the first drive device 12 and the second drive device 13 with reference to the map with the first clutch 40 disengaged. When the rotation speed of the second gear 22 driven by the first drive device 12 is larger than the rotation speed of the fourth gear 32 (output shaft 16) driven by the second drive device 13, the second gear consisting of a one-way clutch is used. Since the clutch 23 is engaged, the driving force of the first driving device 12 and the second driving device 13 is transmitted to the output shaft 16.

On the other hand, when the rotation speed of the second gear 22 driven by the first drive device 12 is smaller than the rotation speed of the fourth gear 32 (output shaft 16) driven by the second drive device 13, the second clutch 23 is engaged. Since it is cut off, the driving force of the second driving device 13 is transmitted to the output shaft 16. Since the second clutch 23 composed of the one-way clutch is arranged on the output shaft 16 as described above, the state in which the first drive device 12 and the second drive device 13 drive the output shaft 16 and the state in which the second drive device 13 outputs. The state of driving the shaft 16 can be seamlessly switched.

In the fourth mode, the control device 50 controls the power running of the first drive device 12 and the second drive device 13 with the first clutch 40 connected. In the fourth mode, since the output shaft 16 is always driven by the first drive device 12 and the second drive device 13, the torque output to the output shaft 16 can be increased. In particular, since both the first drive device 12 and the second drive device 13 drive the second gear mechanism 30 of the transmission path for high speed, sufficient drive torque can be obtained and acceleration can be achieved even at high speed.

In the reverse mode, the control device 50 controls the power running of the second drive device 13 in the reverse rotation with the first clutch 40 disengaged. Since the torque of the reverse rotation of the second drive device 13 is transmitted to the output shaft 16 via the second gear mechanism 30, the vehicle 10 can be retracted. The reverse rotation of the output shaft 16 is transmitted to the first gear mechanism 20 and the first shaft 14 via the second clutch 23, but since the first clutch 40 is disengaged, the second shaft 15 is the rotation of the first shaft 14. Not affected.

The start assist process (hereinafter referred to as "assist process") will be described with reference to FIGS. 4 and 5. FIG. 4 is a flowchart of the assist process according to the first embodiment. The assist process is a process for preventing the vehicle 10 from retreating when starting on a slope. The assist process is repeatedly executed (for example, at 0.2 second intervals) by the control device 50 while the power is turned on to the control device 50.

In the assist process shown in FIG. 4, the control device 50 determines whether or not it is in the forward mode (S1). In the forward mode (S1: Yes), it is determined whether or not the vehicle 10 is stopped (vehicle speed V = 0) (S2). When the mode is other than the forward mode (S1: No), the process of S6 is executed.

When the vehicle 10 is stopped in the process of S2 (S2: Yes), the control device 50 determines whether or not the vehicle 10 is located on an uphill (S3). When the vehicle 10 is not stopped (S2: No), the process of S6 is executed.

When the vehicle 10 is located on an uphill in the process of S3 (S3: Yes), the control device 50 operates the actuator 41 to engage the first clutch 40 (S4), and the brake control unit 59 disengages the braking device (S3). S5), the assist flag is turned ON (S6). When the vehicle 10 is not on the uphill (S3: No), the process of S7 is executed. Since the first clutch 40 is a meshing clutch, after the first clutch 40 is engaged, the first clutch 40 can be engaged without applying an operating force to the first clutch 40.

Since the first drive device 12 and the second drive device 13 are not operating in the vehicle 10 that has stopped with the first clutch 40 engaged on the uphill, when the driver releases the brake pedal, the vehicle will retreat uphill. And. Then, the wheel 19 rotates in the reverse direction, and the output shaft 16 rotates in the reverse direction. The rotation of the output shaft 16 is transmitted to the second shaft 15 via the second gear mechanism 30, and is transmitted to the first shaft 14 and the first gear mechanism 20 via the first clutch 40. Since the reduction ratio of the second gear mechanism 30 is smaller than the reduction ratio of the first gear mechanism 20, the second clutch 23 is engaged. Since double engagement occurs here, the reverse rotation of the output shaft 16 can be mechanically prevented. Therefore, even if the braking device (not shown) is turned off or the driver releases the brake pedal, the vehicle 10 does not move backward.

Since the first drive device 12 and the second drive device 13, which are motors, do not consume electric power when the vehicle 10 is stopped, the power consumption by the first drive device 12 and the second drive device 13 can be reduced. Further, when the vehicle 10 is stopped, it is not necessary to pass a current through the first drive device 12 and the second drive device 13, so that overheating of a specific circuit of the motor can be prevented. Therefore, it is possible to reduce the deterioration of the motor performance due to overheating when the vehicle 10 is stopped.

In a vehicle 10 stopped with the first clutch 40 engaged on an uphill, a mode other than the forward mode is input by operating the shift lever 70 (S1: No), or the accelerator pedal is stepped on to increase the vehicle speed. (S2: No), the control device 50 determines whether or not the assist flag is ON (S7). When the assist flag is OFF (S7: No), the first clutch 40 is disengaged, so this assist process is terminated.

When the driver depresses the accelerator pedal (S2: No), at least one of the first drive device 12 and the second drive device 13 is driven and the vehicle 10 starts. Since the first clutch 40 is engaged at the time of starting, the first shaft 14 and the second shaft 15 rotate together. When the assist flag is ON (S7: Yes), the braking device (not shown) is turned off in the process of S5. Since the vehicle 10 is stopped by the engagement of the second clutch 23, the braking force of the braking device does not act on the start assisting device 11 at the time of starting. Therefore, it is possible to reduce the discomfort caused by the braking force of the braking device when starting. Further, since the first drive device 12 and the second drive device 13, which are motors, have a large starting torque, the driving feeling at the time of starting can be improved.

When the assist flag is ON (S7: Yes), the control device 50 determines whether or not the vehicle 10 has a predetermined vehicle speed V ₁ (V ₁ ≠ 0) or more (S8). When the vehicle 10 has _a predetermined vehicle speed V1 or higher (S8: Yes), the control device 50 drives the first drive device 12 to rotate the first shaft 14 in the positive direction (S9), and operates the actuator 41. The first clutch 40 is disengaged (S10), and the assist flag is turned off (S11).

In the process of S9, the control device 50 rotates the first shaft 14 so that the first gear mechanism 20 rotates in the forward direction. As a result, the differential rotation between the second shaft 15 and the first shaft 14 can be reduced via the first clutch 40. Therefore, the first clutch 40 can be easily disengaged in the process of S10. Further, when the first drive device 12 is continuously driven after the first clutch 40 is disengaged, torque is transmitted to the output shaft 16 via the first gear mechanism 20, so that acceleration at the time of starting can be improved.

When the speed of the vehicle 10 started on the uphill is V ₁ (V ₁ ≠ 0) or more (S8: Yes), the control device 50 disengages the first clutch 40 (S10), so that after the vehicle 10 starts. When the vehicle speed is less than V ₁ , the operation of the first clutch 40 can be prevented from being switched. After the first clutch 40 is disengaged, the output shaft 16 can be rotated via the first gear mechanism 20 having a reduction ratio larger than that of the second gear mechanism 30. Therefore, the acceleration of the vehicle 10 can be improved.

When the vehicle 10 stopped on an uphill with the first clutch 40 engaged is set to a mode other than the forward mode (S1: No), the control device 50 determines that the _first clutch 40 is when the vehicle speed is V1 or higher. Since it is turned off, it is possible not to interfere with the functions of modes other than the forward mode.

The assist process in the second embodiment will be described with reference to FIG. The same parts as those of the assist process in the first embodiment are designated by the same reference numerals, and the following description will be omitted. FIG. 5 is a flowchart of the assist process in the second embodiment.

In the assist process shown in FIG. 5, the control device 50 determines whether or not it is in the forward mode (S12). In the forward mode (S12: Yes), it is determined whether or not the accelerator pedal is depressed (S13). When the mode is other than the forward mode (S12: No), the process of S7 is executed.

When the accelerator pedal is not depressed in the process of S13 (S13: No), the control device 50 determines whether or not the vehicle 10 has a predetermined vehicle speed V ₀ (V ₀ ≠ 0, V ₀ <V ₁ ) or less. Judgment (S14). When the accelerator pedal is depressed (S13: Yes), the process of S7 is executed.

When the accelerator pedal is depressed (S13: Yes), the brake pedal depression force is zero, so the brake control unit 59 turns off the braking device (not shown) based on the brake pedal depression force. When the assist flag is ON (S7: Yes), the first clutch 40 is engaged (S4), and the reverse rotation of the output shaft 16 is mechanically prevented, so that the motor is driven with the braking device turned off. It is possible to prevent the vehicle 10 from retreating uphill even when the force is small or the motor is not driven.

In the process of S14, when the vehicle speed is a predetermined vehicle speed V ₀ or less (S14: Yes), the control device 50 determines whether or not the vehicle 10 is located on an uphill (S3). When the vehicle speed exceeds the predetermined value V ₀ (S14: No), the process of S7 is executed.

When the vehicle 10 is located on an uphill in the process of S3 (S3: Yes), the control device 50 operates the actuator 41 to engage the first clutch 40 (S4) and turns on the assist flag (S6). When the vehicle 10 is not on the uphill (S3: No), the process of S7 is executed.

When the vehicle 10 decelerates below a predetermined speed V ₀ (V ₀ ≠ 0) (S14: Yes), the control device 50 engages the first clutch 40 when the condition of S3 is satisfied (S4). Therefore, when the vehicle 10 exceeds the predetermined value V ₀ and travels uphill, the total torque (target torque) required by the driver can be ignored and the first clutch 40 can be prevented from being engaged. Therefore, the driving feeling when the vehicle 10 is traveling uphill can be made suitable. Further, the first clutch 40 can be activated immediately when the vehicle 10 is stopped.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It is easy to guess.

In the embodiment, a case where a motor having the same torque characteristics is used for the first drive device 12 and the second drive device 13 has been described, but the present invention is not necessarily limited to this. Of course, it is possible to use motors with different torque characteristics. For example, the motor having the torque characteristic for low speed is referred to as the first drive device 12, and the motor having the torque characteristic for high speed is referred to as the second drive device 13.

In the embodiment, the case where both the first drive device 12 and the second drive device 13 are motors has been described, but the present invention is not necessarily limited to this. Of course, it is possible to use either the first drive device 12 or the second drive device 13 as an engine.

In the embodiment, in the process of S8 of the assist process, a case where the first drive device 12 is operated to rotate the first shaft 14 in the forward direction before the first clutch 40 is disengaged has been described, but the present invention is not limited to this. .. Of course, it is possible to omit the processing of S8. This is because the actuator 41 moves the sleeve 43 of the first clutch 40 in the axial direction via the spring 42, and the restoring force in the axial direction of the spring 42 is applied to the sleeve 43 in conjunction with the operation of the actuator 41. Even if the process of S8 is omitted, when the torque transmitted by the first clutch 40 becomes small, the first clutch 40 is disengaged by the spring 42.

In the embodiment, the control device 50 is one of the first mode, the second A mode, the second B mode, the third mode, and the fourth mode based on the map based on the information input from the vehicle speed sensor 65, the accelerator pedal sensor 67, and the like. The case of controlling to switch to is described, but the present invention is not limited to this. Of course, it is possible to switch the mode by using the rotation speed, the angular velocity, or the like of the output shaft 16 or the axle 17 instead of the vehicle speed. This is because the rotation speed and the angular velocity of the output shaft 16 and the axle 17 are proportional to the vehicle speed and are essentially the same. Further, it is naturally possible to use other factors as long as they are factors proportional to the torque required by the driver, such as the speed of the accelerator pedal (the speed of change of the accelerator pedal). Of course, it is possible to add the detection result of the brake pedal sensor to this factor.

In the embodiment, the case where the intermediate axis is not arranged between the first axis 14 and the second axis 15 and the output axis 16 has been described, but the present invention is not necessarily limited to this. Of course, it is possible to provide one or more intermediate shafts, arrange gears on the intermediate shafts, and provide a part of the gear trains constituting the first gear mechanism 20 and the second gear mechanism 30 on the intermediate shafts. Of course, it is possible to arrange the second clutch 23 on the intermediate shaft on which a part of the first gear mechanism 20 is arranged.

In the embodiment, the case where the first axis 14 and the second axis 15 are directly coupled to the output axes of the first drive device 12 and the second drive device 13 has been described, but the present invention is not limited to this. Of course, it is possible to interpose a gear, a belt, or the like between the first drive device 12 and the first shaft 14, or between the second drive device 13 and the second shaft 15.

In the embodiment, the case where the first gear mechanism 20 is arranged separately from the first drive device 12 has been described, but it is naturally possible to integrally assemble the first gear mechanism 20 to the first drive device 12 like a geared motor. Is. Similarly, it is of course possible to integrally assemble the second gear mechanism 30 to the second drive device 13.

In the embodiment, the case where the wheel 19 is attached to the axle 17 arranged in parallel with the output shaft 16 has been described, but the present invention is not necessarily limited to this. For example, it is naturally possible to connect a pair of propeller shafts to the differential device 18 and connect the propeller shafts to the axles. As a result, a four-wheel drive vehicle can be obtained.

10 Vehicle 11 Start assist device 12 1st drive device 13 2nd drive device 14 1st axis 15 2nd axis 19 Wheels 20 1st gear mechanism 23 2nd clutch 30 2nd gear mechanism 40 1st clutch 50 Control device

Claims

It is a vehicle start assist device in which the power of the output shaft is transmitted to the wheels.
A first gear mechanism that transmits the torque of the first shaft to which the torque of the first drive device is transmitted to the output shaft, and
The torque of the second shaft arranged coaxially with the first shaft and to which the torque of the second drive device is transmitted is transmitted to the output shaft at a reduction ratio smaller than the reduction ratio of the first gear mechanism. 2nd gear mechanism and
A first clutch that transmits / disconnects power between the first axis and the second axis,
A second clutch including a one-way clutch that transmits the forward rotation of the first gear mechanism to the output shaft when the vehicle moves forward, and
A control device for operating the first clutch is provided.
At least one of the first drive device and the second drive device is a motor.
The control device is a start assist device that engages the first clutch when the vehicle is at a predetermined speed or less and is on an uphill slope.
The start assist device according to claim 1, wherein the control device disengages the first clutch when the vehicle starts.
The start assist device according to claim 2, wherein the control device disengages the first clutch when the vehicle is at a predetermined speed or higher.
The vehicle can be at least set to a forward mode in which the vehicle is advanced by the forward rotation of the output shaft and a reverse mode in which the vehicle is retracted by the reverse rotation of the output shaft.
The start assist device according to any one of claims 1 to 3, wherein the control device disengages the first clutch when the control device is set to a mode other than the forward mode.
The first clutch is a meshing clutch.
The start assist device according to any one of claims 1 to 4, wherein the control device rotates the first shaft so that the first gear mechanism rotates in a normal direction when the first clutch is disengaged.