JP7359421B2 - hybrid vehicle - Google Patents

Description

The present invention relates to a hybrid vehicle that includes an engine that drives a first wheel and a motor that drives a second wheel that is spaced apart from the first wheel in the longitudinal direction. In addition, it is related to the realization of starting performance that is close to the driver's intention.

Conventionally, as described in Patent Document 1, a hybrid vehicle has been described in which a front wheel is driven by an engine and left and right rear wheels are driven by a pair of left and right motors. In this vehicle, when the operation amount of the accelerator pedal (acceleration instruction section) is 0 and the operation amount of the brake pedal is less than a predetermined value, the motor causes the vehicle to creep. Further, if the amount of operation of the accelerator pedal is other than 0, the driving force of the engine is assisted by the drive of the motor, and the assistance by the motor ends as the amount of operation of the accelerator pedal increases. This is said to minimize the use of areas with poor energy efficiency, contributing to reduced fuel consumption.

Japanese Patent Application Publication No. 10-75505

By the way, in a hybrid vehicle where the first wheel is driven by an engine and the second wheel is driven by a motor, when a small motor is used, it is possible to achieve starting performance close to the driver's intention, as well as improve energy efficiency and motor efficiency. Improved durability is desired. For example, in order to start smoothly in the low speed range, it is possible to start by only driving the second wheel driven by the motor, but continuing to use a small motor in the high speed range when starting is important for energy efficiency and motor efficiency. This is not desirable from the viewpoint of improving durability. Further, when the driver operates the acceleration instruction section, depending on the driving situation, there are cases where the driver desires a slow start or a sudden start, and it is desirable to be able to respond to these requests.

An object of the present invention is to achieve starting performance close to the driver's intention according to the driving situation when using a small motor in a hybrid vehicle in which the first wheel is driven by an engine and the second wheel is driven by a motor. The objective is to realize this and improve energy efficiency and motor durability.

A hybrid vehicle according to the present invention includes an engine that drives a first wheel, and a motor that drives a second wheel that is spaced apart from the first wheel in the longitudinal direction, and (1) uses only the motor as a drive source to drive the vehicle. (2) a sudden start support that drives the vehicle using the engine and the motor as the drive sources; (3) initially the motor is the only drive source that drives the vehicle; The vehicle is driven by the engine and the motor as the drive source, and a smooth start support is provided in which the vehicle is driven only by the engine as the drive source in a later stage, and when the operation amount of the acceleration instruction section is not 0, The present invention is a hybrid vehicle in which any of the supports described above is performed depending on the operation status of the acceleration instruction section.

According to the hybrid vehicle according to the present invention, in a hybrid vehicle in which the first wheel is driven by an engine and the second wheel is driven by a motor, when a small motor is used, the driver's intention can be adjusted according to the driving situation. It is possible to achieve similar starting performance. At the same time, energy efficiency and motor durability can be improved.

1 is a side view, partially in section, of a hybrid vehicle according to an embodiment of the present invention; FIG. 2 is a diagram showing the overall configuration of a mobile body drive unit mounted on the vehicle of FIG. 1. FIG. 3 is a diagram showing a group of operating elements connected to a control device in FIG. 2. FIG. FIG. 3 is an enlarged view of part A shown in FIG. 2 including a centrifugal clutch. FIG. 2 is a diagram showing the configuration of an electric motor drive circuit and a control device in an embodiment of the present invention. FIG. 4 is a diagram showing a first display area in which a plurality of driving mode selection sections are provided on the operation panel of FIG. 3; 4 is a diagram illustrating a second display area in which a plurality of support selection sections are provided on the operation panel of FIG. 3. FIG. 4 is a diagram showing a third display area in which a plurality of charging mode selection sections are provided on the operation panel of FIG. 3. FIG. 2 is a flowchart illustrating a control method when selecting start support in an embodiment of the present invention. FIG. 7 is a diagram illustrating an example of a plurality of switching between slow start support, sudden start support, and smooth start support when starting support is selected in the embodiment according to the present invention. 8 is a diagram showing support switching conditions in FIG. 7. FIG. FIG. 6 is a diagram showing the relationship between accelerator opening and motor torque in slow start support. FIG. 3 is a diagram showing the relationship between accelerator opening and engine torque in sudden start support. FIG. 3 is a diagram showing the relationship between accelerator opening and motor torque in sudden start support. FIG. 6 is a diagram showing motor operation, engine operation, and timing of switching to the next stage in smooth start support. In smooth start support, it is a diagram showing the time course of vehicle driving force, vehicle speed, and engine rotation speed when the accelerator opening is constant. FIG. 6 is a diagram showing the relationship between accelerator opening and motor torque at the initial stage of start in smooth start support. FIG. 3 is a diagram showing the relationship between elapsed time, vehicle speed, and engine torque in the first stage of the mid-start period in smooth start support. FIG. 7 is a diagram showing the relationship between the accelerator opening, the vehicle speed, and the motor torque in the second stage of the mid-start period in smooth start support. FIG. 4 is a diagram showing a state in which the hybrid vehicle transitions from traveling on a flat road to traveling downhill, and a state in which regeneration support is executed during downhill traveling. FIG. 6 is a diagram showing the relationship between the regenerative torque of the electric motor, the vehicle speed, and the inclination angle of a downhill slope in control when selecting regeneration support. FIG. 3 is a diagram showing the transition of the vehicle from a normal straight-ahead state to a rear wheel slip state and a rear wheel grip recovery state, and the relationship between the front wheel rotation speed and the rear wheel rotation speed in each state in control when slip support is selected. It is a figure showing the relationship between accelerator opening degree and engine torque in control when slip support is selected. It is a figure which shows the relationship between the elapsed time and motor torque in control when slip support is selected. It is a figure showing the relationship between accelerator opening degree and motor torque in control when sudden acceleration support is selected. FIG. 6 is a diagram showing the time course of vehicle driving force and vehicle speed when the accelerator opening degree is kept constant in control when sudden acceleration support is selected. FIG. 4 is a diagram showing a vehicle position (a) when traveling on a flat road, a vehicle position (b) when starting slope support, and a vehicle position (c) when the target vehicle speed is reached by performing slope support. 5 is a flowchart illustrating a method of switching battery charging modes in an embodiment. 7 is a flowchart illustrating a method for switching battery charging modes in another example of the embodiment according to the present invention. It is a side view of another example of a hybrid vehicle of an embodiment concerning the present invention.

Hereinafter, embodiments of the present invention will be described in detail using the drawings. In the following, a case will be explained in which the mobile body on which the mobile body drive unit is mounted is an off-road utility vehicle or a tractor that has a loading platform and travels on uneven terrain such as forests, wastelands, and rocky mountains. , snow removal work, excavation work, civil engineering work, and agricultural work, or may be an All Terrain Vehicle (ATV) or a Recreational Vehicle (ROV). In the following description, similar elements are designated by the same reference numerals in all drawings.

1 to 25 illustrate embodiments. FIG. 1 is a side view, partially in cross section, of a hybrid vehicle 10 according to an embodiment. FIG. 2 is a diagram showing the overall configuration of the mobile body drive unit mounted on the hybrid vehicle 10. FIG. 3A is a diagram showing a group of operating elements connected to the control device in FIG. 2. FIG. 3B is an enlarged view of part A in FIG. 2 including the centrifugal clutch. FIG. 4 is a diagram showing the configuration of an electric motor drive circuit and a control device.

The hybrid vehicle 10 shown in FIG. 1 is an off-road multipurpose vehicle having a cargo platform 19, and includes an engine 21 that drives two left and right rear wheels 16, and a motor 22 that drives two left and right front wheels 15. be done. Hereinafter, the hybrid vehicle 10 may be referred to as vehicle 10. Motor 22 is an electric motor. The front wheel 15 is separated from the rear wheel 16 in the front-rear direction (left-right direction in FIG. 1). The rear wheel 16 corresponds to a first wheel, and the front wheel 15 corresponds to a second wheel. Specifically, a platform 12 serving as a basic structure is fixed to the upper side of a frame 11 constituting the vehicle body, and a front cover 13 is fixed to the front side of the frame 11 (the right side in FIG. 1). In the platform 12, a driver's seat 14 is fixed to the rear side of the front cover 13, and a cargo platform 19 is fixed to the rear side of the driver's seat 14. The vehicle 10 includes two left and right front wheels 15 and two left and right rear wheels 16, which are wheels supported at the front and rear of a frame 11, an operating element group 18, and a mobile body drive unit 20. As shown in FIG. 1, a battery 23, which will be described later, is disposed below the driver's seat 14 and inside a frame portion of the frame 11 at an intermediate portion in the longitudinal direction.

The mobile body drive unit 20 includes an engine 21 and a motor 22 that are power sources, a battery 23 (FIGS. 1 and 2) that is a power source, and two motors that are driven by the engine 21 and generate electricity that is stored in the battery 23. Generators GE1 and GE2 (FIG. 2), rear power transmission section 25 (FIG. 2), front power transmission section 41 (FIG. 2), sensor switch group 50 (FIG. 2), and control device 70 (FIG. 2). including. As shown in FIG. 2, the generator GE1 includes a rotor fixed to the output shaft 21a of the engine 21 and a stator facing the rotor. The generator GE2 is connected so that the power of the engine 21 is transmitted via an output shaft 21b extending on the opposite side of the engine 21 from the CVT 26 and a belt pulley mechanism 21c. Generators GE1 and GE2 are controlled by an inverter 24b, and charge the battery 23 with the generated power. Note that one of the two generators GE1 and GE2 may be omitted. A battery monitoring module (BCM) 65 that detects the temperature and voltage of the battery 23 is attached to the battery 23 . The battery monitoring module 65 corresponds to a charging monitoring section. The battery monitoring module 65 also has a function of detecting the amount of charge that is the remaining amount of charge of the battery 23. A detection signal of the amount of charge from the battery monitoring module 65 is transmitted to the control device 70 . The vehicle 10 is also provided with a tilt angle sensor 66 that detects the tilt angle of the road surface on which the vehicle 10 is located with respect to a horizontal plane. A detection signal from the tilt angle sensor 66 is also transmitted to the control device 70.

Furthermore, the vehicle 10 has (1) slow start support, (2) sudden start support, and (3) smooth start support. (1) The slow start support drives the vehicle 10 using only the motor 22 as the drive source at the time of start. (2) Sudden start support drives the vehicle 10 using the engine 21 and motor 22 as drive sources at the time of start. (3) Smooth start support drives the vehicle 10 with only the motor 22 as the drive source in the early stages of start, drives the vehicle 10 with the engine 21 and motor 22 as the drive sources in the middle stage, and drives the vehicle 10 with only the engine 21 as the drive source in the later stage. to drive the vehicle 10. When the amount of operation of the accelerator pedal 60, which will be described later, is not 0, the vehicle 10 performs any of (1) slow start support, (2) sudden start support, and (3) smooth start support depending on the operation status of the accelerator pedal 60. is configured to run. Even when the operation amount of the accelerator pedal 60 is 0, either (1) slow start support or (2) sudden start support may be executed. The accelerator pedal 60 corresponds to an acceleration instruction section. As a result, when using the small motor 22 in the vehicle 10, it is possible to achieve starting performance that is close to the driver's intention according to the driving situation, and it is also possible to improve the energy efficiency and the durability of the motor 22.

Furthermore, the vehicle 10 is capable of performing at least one of (A) regeneration support, (B) slip support, (C) sudden acceleration support, and (D) slope support when the engine 21 is driven. It is. (A) Regenerative support utilizes the regenerative brake of the motor 22 when the vehicle 10 decelerates on a downhill slope. (B) Slip support uses the driving force of the motor 22 to return the rear wheels 16 to a non-slip state when the rear wheels 16 slip. (C) Rapid acceleration support adds the driving force of the motor 22 to the driving force of the engine 21 to accelerate the vehicle. (D) The slope support drives the motor 22 so that the uphill entry speed and the uphill passing speed are equal. For example, the driver selects and instructs (A) regeneration support, (B) slip support, (C) sudden acceleration support, and (D) slope support by touching the operation panel 52, which will be described later. be able to. This makes it easier for the driver to drive comfortably in the vehicle 10 when the engine 21 is driven.

The operating element group 18 includes an accelerator pedal 60 and a brake pedal 63 (FIG. 3A) which are provided on the front side of the driver's seat 14 as a braking instruction section, and a steering operator that is a turning instruction section provided on the front side of the driver's seat 14. 61, a forward/reverse lever 62 (FIG. 3A), and an operation panel 52.

The steering operator 61 is constituted by a steering wheel fixed to a steering shaft that projects diagonally rearward above the front cover 13. The steering operator 61 is connected to the two left and right front wheels 15 via an Ackermann steering mechanism so that the front wheels 15 can be steered.

As shown in FIG. 3A, the forward/reverse lever 62 has four positions: a low-speed forward position (L position), a high-speed forward position (H position), a neutral position (N position), and a reverse position (R position). The operating position can be switched between the two. The low-speed forward position is a position where a gear position suitable for low-speed driving is selected, and the high-speed forward position is a position where a gear position suitable for high-speed driving is selected. The forward/backward lever 62 is supported by the vehicle body so as to be swingable in the front/rear direction (vertical direction in FIG. 3A). The forward/reverse lever 62 may be configured to be able to switch its operation position between three positions: a forward position, a neutral position, and a reverse position.

As shown in FIG. 1, the engine 21 is fixed to the frame 11 behind the driver's seat 14 and below the cargo platform 19. The engine 21 is started at an idle speed by turning on a start switch (not shown). As the engine 21, any one of a plurality of types including a gasoline engine and a diesel engine can be used. The power of the engine 21 is transmitted to the two left and right rear wheels 16 via the rear power transmission section 25, thereby driving the two rear wheels 16.

The motor 22 is arranged inside a front case 40 (FIG. 2), which will be described later, which is fixed to the front side of the driver's seat 14 in the frame 11. A battery 23 (FIG. 2) is electrically connected to the motor 22 via an inverter 24a (FIG. 2). The battery 23 may be placed inside the front cover 13 or under the driver's seat 14 or the cargo platform 19. The motor 22 is activated when a start switch (not shown) provided on the front side of the driver's seat 14 is turned on, and an instruction is given to constantly drive the front wheels 15 and rear wheels 16 from the operation panel 52 (FIG. 5A), which will be described later. It is started when the constant 4WD mode representing constant four-wheel drive or the EV mode is selected.

Various types of motors can be used for the motor 22, such as a DC motor, a permanent magnet motor, and an induction motor. The power of the motor 22 is transmitted to the two left and right front wheels 15 via the front power transmission section 41, thereby driving the two front wheels 15. Thereby, the motor 22 drives the front wheels 15.

The rear power transmission section 25 and the front power transmission section 41 will be explained. As shown in FIG. 2, the rear power transmission section 25 includes a CVT 26 that is a belt-type continuously variable transmission, a gear transmission 30, a differential device 36, an output shaft 37, and a rear axle 38. The rear power transmission section 25 is connected between the engine 21 and the rear wheels 16 so that power can be transmitted from the engine 21 to the rear wheels 16. For this reason, the rear wheels 16 and the engine 21 are connected via a CVT 26.

The CVT 26 is configured by a belt 29 being engaged with a driving pulley 27 and a driven pulley 28 so as to be wound around them. The drive pulley 27 includes a first fixed sheave 27a connected to the output shaft 21a of the engine 21 via a centrifugal clutch 80 (FIG. 3B), and a first fixed sheave 27a that is movably supported in the axial direction by the output shaft 21a. and a first movable sheave 27b opposite to the first movable sheave 27b. The first fixed sheave 27a is rotatably supported by the output shaft 21a by a bearing or the like, and does not move in the axial direction.

As shown in FIG. 3B, the centrifugal clutch 80 rotates the output shaft 21a and the first fixed sheave 27a when the engine rotational speed per minute, which is the rotational speed of the engine 21, is less than a predetermined value, belt gripping rotational speed N1, which will be described later. The connection is cut off. On the other hand, when the engine rotational speed is equal to or higher than the belt gripping rotational speed N1, the centrifugal clutch 80 connects the output shaft 21a and the first fixed sheave 27a via the centrifugal clutch 80. Thereby, the power of the output shaft 21a is transmitted to the first fixed sheave 27a. For example, in the centrifugal clutch 80, one end of a rotating shaft provided at one circumferential end of a plurality of clutch weights 80b is supported by a clutch plate 80a fixed to an output shaft 21a, and the other end of the rotating shaft of each clutch weight 80b is supported by a clutch plate 80a fixed to an output shaft 21a. , supported by the side plate 80c. The plurality of clutch weights 80b are arranged in a row in the circumferential direction between the clutch plate 80a and the side plate 80c, and are urged inward in the radial direction by a spring 80d. A clutch shoe 80e is provided at the other end in the circumferential direction of the clutch weight 80b, and the other end in the circumferential direction of the clutch weight 80b is displaced radially outward due to the centrifugal force generated when the output shaft 21a rotates, so that the clutch shoe 80e is disposed in the second circumferential direction. The output shaft 21a and the first fixed sheave 27a rotate together by frictionally engaging with the inner peripheral surface of the first fixed sheave 27a.

As shown in FIG. 2, the driven pulley 28 is supported by a second fixed sheave fixed to the input shaft 31 of the gear transmission 30, and is movably supported by the input shaft 31 in the axial direction, and faces the second fixed sheave. and a second movable sheave. The gear transmission 30 corresponds to a wheel-side power transmission section. The first movable sheave 27b (FIG. 3B) of the drive pulley 27 is moved in the axial direction by an actuator 26a (FIG. 3B) including a motor. An elastic force is applied to the second movable sheave of the driven pulley 28 by a spring (not shown) so that the second movable sheave approaches the second fixed sheave. The actuator 26a moves the first movable sheave 27b of the drive pulley 27 closer to the first fixed sheave 27a as the rotational speed of the engine 21 increases. As a result, when the rotational speed of the engine 21 is low, the width between the first movable sheave 27b and the first fixed sheave 27a (inter-sheave width) increases as shown in FIG. Therefore, the CVT 26 is continuously variable, and the ratio (Na/Nb) between the rotation speed Na of the drive pulley 27 and the rotation speed Nb of the driven pulley 28, which is the reduction ratio of the CVT 26, increases. Conversely, as the rotational speed of the engine 21 increases, the width between the sheaves of the drive pulley 27 becomes smaller, so that the CVT 26 is continuously variable, and the reduction ratio (Na/Nb) of the CVT 26 becomes smaller. This makes it possible to increase the torque of the input shaft 31 when running at low speeds, and to improve fuel efficiency when running at high speeds.

The gear transmission 30 includes a rear case 35 fixed to the rear side of the engine 21 in the frame 11, and an input shaft 31, a shift shaft 32, and a final shaft 33 rotatably disposed within the rear case 35. There is. The gear transmission 30 allows power to be transmitted from the input shaft 31 to the final shaft 33 via a gear mechanism and a slide gear provided around the transmission shaft. The slide gear is connected to a forward/reverse lever 62. In response to the operation of the forward/backward lever 62, the slide gear moves in the axial direction and the engaged gear switches, thereby switching the relationship between the rotation direction of the input shaft 31 and the rotation direction of the final shaft 33. The power transmitted to the final shaft 33 is transmitted to the transmission gear 36a of the differential device 36 via a gear mechanism. Two left and right output shafts 37 are differentially connected to the differential device 36 . The differential device 36 is arranged inside the rear case 35. The rear wheel 16 is connected to the output shaft 37 via a universal joint and a rear axle 38 . Thereby, the rear wheels 16 are driven by the engine 21.

When the forward position is selected with the forward/reverse lever 62 (FIG. 3A), the vehicle 10 can move forward. When the reverse position is selected using the forward/reverse lever 62, the vehicle 10 can move backward. When the neutral position is selected with the forward/reverse lever 62, the width between the sheaves of the drive pulley 27 increases, thereby blocking power transmission between the output shaft 21a of the engine 21 and the belt 29 of the CVT 26.

As shown in FIG. 2, the front power transmission section 41 includes a gear mechanism 42, a differential device 43, an output shaft 44, and a front axle 45. The front power transmission section 41 is connected between the motor 22 and the front wheels 15 so that power can be transmitted from the motor 22 to the front wheels 15. The power of the rotating shaft of the motor 22 is transmitted to the transmission gear 43a of the differential device 43 via the gear mechanism 42. Two left and right output shafts 44 are differentially connected to the differential device 43 . The front wheel 15 is connected to the output shaft 44 via a universal joint and a front axle 45 . The motor 22, gear mechanism 42, and differential device 43 are arranged inside the front case 40. The front case 40 is fixed to the front side of the frame 11 (FIG. 1). Thereby, the front wheels 15 are driven by the motor 22.

As shown in FIGS. 2 and 3A, the sensor switch group 50 includes a steering sensor 51, a lever sensor 53, a first pedal sensor 54, a second pedal sensor 64, a rear axle speed sensor 55, a front axle speed sensor 56, and an engine. It includes a speed sensor 57.

Steering sensor 51 detects the operating angle of steering operator 61 and transmits the detection signal to control device 70, which will be described later. The steering sensor 51 may be omitted.

The lever sensor 53 detects the position of the forward/reverse lever 62 and sends a detection signal to a control device 70, which will be described later. When the control device 70 determines that the forward/reverse lever 62 is in the neutral position based on the detection signal of the lever sensor 53, the control device 70 moves the first movable sheave 27b of the drive pulley 27 far away from the first fixed sheave 27a, and The deflection may be used to control the drive pulley 27 so that its power is not transmitted to the belt 29.

The first pedal sensor 54 detects the operation amount of the accelerator pedal 60 as an accelerator opening degree, and transmits the detection signal to the control device 70 . The accelerator opening corresponds to the amount of accelerator operation, and represents the ratio of the amount of depression to the fully open state, with the case where the accelerator is depressed to the maximum being a 100% fully open state. The control device 70 includes an engine control section 71 (FIG. 4). The engine control unit 71 controls the throttle valve so that the opening degree of the throttle valve (not shown) of the engine 21 increases as the accelerator opening degree corresponding to the operation amount of the accelerator pedal 60 increases. A valve drive motor controlled by the engine control section 71 may be provided to drive the throttle valve. The opening degree of the throttle valve changes depending on the drive of the valve drive motor. The rotational speed of the engine 21 is adjusted by the opening degree of the throttle valve, and the rotational speed of the engine 21 increases as the opening degree of the throttle valve increases. Note that the meaning of "rotational speed" also includes the number of rotations, which is the rotational speed per unit time, for example, per minute.

A throttle valve driving section may be connected to the accelerator pedal 60 via a link or a cable, and the opening degree of the throttle valve may be increased as the amount of operation of the accelerator pedal 60 becomes larger. In this case, the first pedal sensor does not directly detect the pedal position of the accelerator pedal 60, but is provided near the throttle valve to detect the opening degree of the throttle valve, thereby indirectly detecting the pedal position of the accelerator pedal 60. may be detected.

The brake pedal 63 is connected to a hydraulic pressure generating mechanism (not shown) via a link. A brake disc (not shown) is fixed to one or both of the front wheels 15 and the rear wheels 16, and two brake pads (not shown) are arranged on both sides of the brake disc, one on the inside and one on the outside of the vehicle. . The hydraulic pressure generating mechanism generates a braking force that pinches the brake disc by applying hydraulic pressure to one of the two brake pads.

Signals from the operation panel 52 (FIG. 3A) are also input to the control device 70 (FIG. 2). The operation panel 52 is provided, for example, on the driver's seat 14 side of the front cover 13 so that the driver can operate it, and instructs the drive mode of the vehicle 10 by operating it. The operation panel 52 is, for example, a touch panel display, and includes six display areas including first, second, and third display areas 81, 83, and 85. FIG. 5A is a diagram showing a first display area 81 in the operation panel 52 in which a plurality of driving mode selection sections are provided. The plurality of driving mode selection sections include an EV mode selection section 82a, an engine driving mode selection section 82b, a constant 4WD mode selection section 82c, and an OFF mode selection section 82d. "EV mode" is a mode in which the engine 21 is always stopped and the vehicle runs using only the motor 22 as a drive source, and when the EV mode selection section 82a is touched, a signal indicating the EV mode instruction is sent to the control device 70. sent to. "Engine running mode" is a mode in which the motor 22 is always stopped and the vehicle runs using only the engine 21 as a drive source, and when the engine running mode selection section 82b is touched, a signal indicating the engine running mode is output. It is transmitted to the control device 70. The "continuous 4WD mode" is a mode in which both the engine 21 and the motor 22 are used as drive sources for the vehicle, and the vehicle travels in four-wheel drive at all times, and when the constant 4WD mode selection section 82c is touched, a signal indicating the constant 4WD mode is sent. is transmitted to the control device 70. "OFF mode" is a mode in which EV mode, engine running mode, or 4WD mode is always fixed and not selected, and when the OFF mode selection section 82d is touched, a signal indicating the OFF mode instruction is turned off to the control device. 70. For example, the OFF mode is selected before selecting any of the support modes shown in FIG. 5B described below. Note that when one of the support modes is selected, the control device 70 may automatically select the OFF mode.

Further, the vehicle 10 has a drive changeover switch or a drive changeover lever that can switch between EV mode, engine running mode, constant 4WD mode, and OFF mode, and by switching the drive changeover switch or drive changeover lever, a signal indicating the instruction of the corresponding mode is sent to the control device 70. may be sent to.

Further, the control device 70 includes a motor control section 72 (FIG. 4). The motor control unit 72 controls the motor 22 such that the rotational speed of the motor 22 increases as the amount of operation of the accelerator pedal 60 increases when the EV mode or the constant 4WD mode is instructed.

Furthermore, when the constant 4WD mode is executed, electric power corresponding to the output generated by the motor 22 may be generated by the generators GE1 and GE2 by driving the engine 21. For example, the total power generation torque, which is the torque that causes the generators GE1 and GE2 to generate electricity, is a torque equivalent to the output of the motor 22, and can be set to (output of the motor 22) x 60/(2π x engine rotation speed). Thereby, it is possible to travel in four-wheel drive while suppressing a decrease in the amount of charge of the battery 23.

The rear axle speed sensor 55 detects the rotational speed of the transmission gear 36a (FIG. 2) of the differential device 36. The transmission gear 36a is fixed to a rear differential case of the differential device 36. The rear differential case rotates at the average rotational speed of the two left and right rear axles 38. Thereby, the rear axle speed sensor 55 can detect the average rotational speed of the two left and right rear axles 38. A detection signal from the rear axle speed sensor 55 is input to the control device 70 as the rear wheel rotation speed.

The front axle speed sensor 56 detects the rotational speed of the transmission gear 43a (FIG. 2) of the differential device 43. The transmission gear 43a is fixed to a front differential case of the differential device 43. The front differential case rotates at the average rotational speed of the two left and right front axles 45. Thereby, the front axle speed sensor 56 can detect the average rotational speed of the two left and right front axles 45. A detection signal from the front axle speed sensor 56 is input to the control device 70 as the front wheel rotation speed. The vehicle speed calculated from the rear wheel rotation speed, the front wheel rotation speed, or the average value of both of these rotation speeds can be used as the vehicle speed detection value, which will be described later.

The engine speed sensor 57 detects the engine rotational speed as the rotational speed of the output shaft 21 a of the engine 21 and transmits the detection signal to the control device 70 . The control device 70 controls the actuator 26a to move the first movable sheave 27b (FIG. 3B) of the drive pulley 27 of the CVT 26 according to the detected value of the engine speed sensor 57.

In the above, a case has been described in which the CVT 26 is an electric type including an actuator 26a having a motor, but a CVT is a hydraulic type that moves a movable sheave using a hydraulic device, or a machine that moves a movable sheave using a pressing force generation mechanism including a torque cam. It may also be a formula.

The control device 70 is called an ECU (Electronic Control Unit), and is composed of, for example, a microcomputer, and includes a CPU as an arithmetic processing unit, a storage unit including memories such as RAM and ROM, and input/output ports. The CPU has a function of reading and executing a control program stored in advance in a storage unit. Generally, the functions of each means of the control device 70 are realized by executing a control program. The control device 70 includes the above-described engine control section 71 (FIG. 4) that controls the engine 21 and a motor control section 72 (FIG. 4) that controls the motor 22.

As shown in FIG. 4, a battery 23 is connected to the motor 22 via an inverter 24a. The inverter 24a converts the direct current output from the battery 23 into alternating current that is the drive current for the motor 22.

The motor control unit 72 controls the drive of the motor 22 by controlling the inverter 24a in a state where the EV mode or the constant 4WD mode is instructed. The motor control unit 72 selects the forward position with the forward/reverse lever 62 (FIG. 3A) based on the detection signal from the lever sensor 53, and operates the accelerator pedal 60 (FIG. 3A) based on the detection signal from the first pedal sensor 54. If it is determined that the vehicle is moving forward, the motor 22 is controlled to rotate in a direction corresponding to forward motion. At this time, drive current is supplied from the battery 23 to the motor 22.

On the other hand, if the motor control unit 72 determines that the neutral position has been selected by the forward/reverse lever 62, the motor control unit 72 stops the current supply from the battery 23 to the motor 22.

When the EV mode or the constant 4WD mode is instructed, the motor control unit 72 adjusts the rotational speed of the rear wheels 16 to the rotational speed of the front wheels 15 based on the detection signals of the rear axle speed sensor 55 and the front axle speed sensor 56 (FIG. 2). The motor 22 is controlled so that the rotational speeds of the motors match.

Furthermore, the control device 70 controls the actuator 26a to change the width between the sheaves of the drive pulley 27 of the CVT 26 in accordance with the rotational speed of the engine 21. Furthermore, a centrifugal clutch 80 (FIG. 3B) connected to the CVT 26 disconnects the output shaft 21a from the drive pulley 27 when the rotational speed of the engine 21 is less than a predetermined speed, and when the rotational speed of the engine 21 exceeds a predetermined speed, the connection between the output shaft 21a and the drive pulley 27 is cut off. are connected via a centrifugal clutch 80. The predetermined speed is higher than the speed corresponding to the idle rotation speed. As a result, when the accelerator pedal 60 is not depressed and the engine 21 is rotating at an idle speed, the power of the engine 21 is not transmitted to the drive pulley 27.

Furthermore, the control device 70 also has a function of executing one of slow start support, sudden start support, and smooth start support according to the selection of a start support selection section 84a (FIG. 5B) among a plurality of support selection sections described below. have

FIG. 5B is a diagram showing a second display area 83 in the operation panel 52 in which a plurality of support selection sections are provided. The plurality of support selection sections include a start support selection section 84a, a regeneration support selection section 84b, a slip support selection section 84c, a sudden acceleration support selection section 84d, and a slope support selection section 84e. When the start support selection section 84a is selected by touch, slow start support, sudden start support, and smooth start support are selected based on the operation status of the accelerator pedal 60 (FIG. 3A), the detected vehicle speed value, and the detected engine speed value. Switch start support. This switching will be explained in detail later.

When any one of the regeneration support selection section 84b, slip support selection section 84c, sudden acceleration support selection section 84d, and slope support selection section 84e is selected by touch, a signal indicating the instruction of the selected support is sent to the control device. 70. The control device 70 executes the corresponding support in response to the input of the signal. When the vehicle 10 is driven by the engine 21 and is running, it is capable of performing regeneration support, slip support, sudden acceleration support, and slope support.

FIG. 5C is a diagram showing a third display area 85 on the operation panel 52 in which a plurality of charging mode selection sections are provided. The plurality of charging mode selection sections include a low power charging mode selection section 86a, a high power charging mode selection section 86b, and a charging stop mode selection section 86c. Both the low power charging mode and the high power charging mode are modes for charging the battery 23. The high power charging mode is a mode in which the battery 23 is charged at a higher rate than the low power charging mode. The charging stop mode is a mode in which charging of the battery 23 is stopped. When any one of the low power charging mode selection section 86a, the high power charging mode selection section 86b, and the charging stop mode selection section 86c is selected by touch, a signal indicating the instruction of the selected mode is sent to the control device 70. Sent. The vehicle 10 is capable of executing either a low power charging mode or a high power charging mode when the engine 21 is driven and the vehicle is stopped. More specifically, vehicle 10 is configured to be switchable between low power charging mode, high power charging mode, and charging stop mode.

Next, a control method when selecting start support will be explained. FIG. 6 is a flowchart showing a control method when starting support is selected in the embodiment. In the following, the description will be made using the symbols in FIGS. 1 to 5C as appropriate. The processing in steps S11 to S16 is executed by the control device 70. In step S11, it is determined whether start support has been selected by touching the operation panel 52. If the determination in step S11 is affirmative (in the case of YES), the process moves to step S12. If step S11 is a negative determination (NO), the process of step S11 is repeated.

In step S12, it is determined whether a slow start support condition is satisfied. For example, if the vehicle speed detection value is less than or equal to the maximum vehicle speed for slow start V1, which is a predetermined speed, and the detected accelerator opening is less than the first predetermined value, it is determined that the slow start support condition is met. For example, when the accelerator opening is less than (predetermined maximum slow start opening AO1-α), it is determined that the slow start support condition is met. At this time, α is a predetermined margin amount other than 0, for example. The slow start maximum opening degree AO1 is a first predetermined value. If the determination in step S12 is affirmative, "very slow start support" is executed in step S13.

If the determination in step S12 is negative, it is determined in step S14 whether the sudden start support condition is satisfied. For example, when the rate of change of the detected accelerator opening over time is greater than or equal to the predetermined sudden start determination change rate VA1, and the detected accelerator opening is greater than or equal to (predetermined sudden start determination opening AO2+α), It is determined that the sudden start support condition is met. The sudden start determination change rate VA1 corresponds to a predetermined time change rate. The sudden start determination opening degree AO2 is a second predetermined value that is larger than the first predetermined value. If the determination in step S14 is affirmative, "sudden start support" is executed in step S15.

If the determination in step S14 is negative, "smooth start support" which is the remaining start support is executed in step S16. Each of the above starting supports may be executed when the accelerator pedal 60 is continued to be depressed.

When starting support is selected on the operation panel 52, the starting support may be switched through the processes shown in FIGS. 7 and 8. FIG. 7 is a diagram showing an example of a plurality of switches among slow start support, sudden start support, and smooth start support when starting support is selected in the embodiment. FIG. 8 is a diagram showing the support switching conditions in FIG. 7.

In the examples shown in FIGS. 7 and 8, slow start support, sudden start support, and smooth start support are switched from the current or previous support when the conditions corresponding to the arrow numbers are satisfied. The numbers on the arrows in FIG. 7 correspond to the numbers in the table in FIG. For example, switching from slow start support to smooth start support is performed when the detected accelerator opening is equal to or greater than (slow maximum opening + α), as shown in column 1 of FIG.

Switching to slow start support is performed when the vehicle speed detection value is below the slow start maximum vehicle speed V1 and the detected accelerator opening is (slow start maximum opening AO1), as shown in columns 2 and 5 of FIG. -α) Executed in the following cases:

As shown in columns 3 and 6 of FIG. 8, switching to sudden start support is performed when the detected accelerator opening change speed is sudden start judgment change speed VA1 or more, and the accelerator opening is (sudden start judgment development). This is executed when the degree AO2+α) or higher is reached.

Switching from sudden start support to smooth start support is performed when the detected accelerator opening is less than (sudden start judgment opening AO2-α) and the detected vehicle speed value is as shown in column 4 of Fig. 8. This is executed when the engine drive start vehicle speed is less than or equal to a predetermined engine drive start vehicle speed V2, and the engine rotational speed detection value is less than or equal to a predetermined belt gripping rotational speed N1. The engine drive start vehicle speed V2 is the vehicle speed at which the smooth start support switches from driving only by the motor 22 to driving by both the motor 22 and the engine 21. The belt gripping rotation speed N1 is the engine rotation speed when the rotation speed of the engine 21 increases, the centrifugal clutch 80 is connected, and transmission of the driving force of the engine 21 to the belt 29 of the CVT 26 is started.

A method of executing slow start support will be explained using FIG. 9. FIG. 9 is a diagram showing the relationship between accelerator opening and motor torque in slow start support. The slow start support controls the vehicle to be driven only by the motor 22 as the drive source. When performing slow start support, the drive of the motor 22 is controlled using the relationship shown in FIG. The slow start support can be executed even when the accelerator opening is 0. When performing slow start support, the relationship between the torque of the motor 22 and the accelerator opening is such that a predetermined torque T1 is generated when the accelerator opening is 0. The torque T1 is maintained when the accelerator opening is from 0 to AOa, and the motor torque increases linearly when the accelerator opening is from AOa to AOb. At the accelerator opening degree AOb, the motor torque is a torque T2 corresponding to the maximum vehicle speed V1 at slow start in terms of flat road driving, and this torque is maintained even if the accelerator opening degree is increased further. The maximum vehicle speed V1 for slow start can be empirically set to an optimal vehicle speed based on, for example, actual driving of the vehicle. In addition, when the vehicle driving force determined from vehicle conditions such as motor torque, wheel radius, and reduction ratio matches the vehicle running resistance, which varies depending on vehicle speed and road surface inclination (gradient), a constant The maximum vehicle speed is obtained. As a result, the torque T2 of the motor 22 to obtain the maximum vehicle speed V1 from a slow start when traveling on flat ground can be calculated from the vehicle speed V1, vehicle conditions, and the like.

Further, in the slow start support, the engine torque becomes idle torque at the idle rotation speed, and the inverter 24b connected to the generators GE1 and GE2 is controlled so that the generated torque of the generators GE1 and GE2 becomes zero. The above-mentioned slow start support allows for smooth starts at low speeds.

A method of executing sudden start support will be explained using FIGS. 10 and 11. FIG. 10 is a diagram showing the relationship between accelerator opening and engine torque in sudden start support. FIG. 11 is a diagram showing the relationship between accelerator opening and motor torque in sudden start support. The sudden start support controls the vehicle to be driven by the engine 21 and motor 22 as drive sources. When performing sudden start support, the drive of the engine 21 is controlled using the relationship shown in FIG. When the accelerator opening degree is 0, the engine 21 generates idle torque at the idle rotation speed. Engine torque increases linearly as the accelerator opening increases.

When performing sudden start support, the drive of the motor 22 is controlled using the relationship shown in FIG. A solid line L1 in FIG. 11 indicates the motor torque when the sudden start support is executed, and a dashed line L2 in FIG. 11 indicates the motor torque when the slow start support is executed. When performing sudden start support, the relationship between the torque of the motor 22 and the accelerator opening is such that a predetermined torque T1 is generated when the accelerator opening is 0. As the accelerator opening increases from 0, the motor torque increases linearly until it reaches the motor rated torque, and then the motor torque is maintained at the motor rated torque. When executing sudden start support, the degree to which the motor torque increases as the accelerator opening increases until the motor rated torque is reached is the same as when executing slow start support, the motor torque increases as the accelerator opening increases. greater than the degree of As a result, it is possible to obtain a torque that increases rapidly even with only the motor 22 compared to the case of starting at a slow speed. Further, since the vehicle is driven by adding the torque of the engine 21 to the torque of the motor 22, a sudden start can be realized.

A method for executing smooth start support will be explained using FIGS. 12 to 16. FIG. 12 is a diagram showing motor operation, engine operation, and timing of switching to the next stage in smooth start support. FIG. 13 is a diagram showing the time course of vehicle driving force, vehicle speed, and engine rotational speed when the accelerator opening is kept constant in smooth start support. In FIG. 13(a), the overall driving force of the vehicle is the sum of the driving force by the motor 22 and the driving force by the engine 21.

Smooth start support drives the vehicle 10 using only the motor 22 as the drive source in the early stages of starting, drives the vehicle 10 with the engine 21 and motor 22 as the drive sources in the middle stage, and drives the vehicle 10 with only the engine 21 as the drive source in the latter stages. control to drive. Smooth start support can be executed, for example, when the accelerator opening is kept constant. Smooth start support realizes early drive, middle drive, and late drive when the accelerator pedal 60 is continuously depressed, so if the accelerator pedal 60 is turned off during smooth start support, it will not be possible to drive in the early, middle, or late stages. Execution is stopped in this state.

As shown in FIGS. 12 and 13, when performing smooth start support, the control device 70 outputs motor torque in accordance with the detected increase in the accelerator opening at the beginning of the start when the accelerator pedal 60 is turned on. let FIG. 14 is a diagram showing the relationship between accelerator opening and motor torque at the initial stage of start in smooth start support. As shown in FIG. 14, the motor torque maintains torque T1 when the accelerator opening is from 0 to AOc, and increases linearly as the accelerator opening increases from AOc to AOd. After the accelerator opening degree AOd, the motor torque is maintained even if the accelerator opening degree is increased. The vehicle driving force in FIG. 13(a) is realized by motor torque. At this time, the engine rotation speed in FIG. 13(c) is an idle rotation speed less than the belt grip rotation speed N1, and the power of the engine 21 is not transmitted to the belt 29 of the CVT 26. As shown in FIG. 13(b), when the vehicle speed reaches engine drive start vehicle speed V2 due to an increase in motor torque, the running state is switched to the first stage of the next mid-start stage.

FIG. 15 is a diagram showing the relationship between elapsed time, vehicle speed, and engine torque in the first stage of the mid-start period in smooth start support. In the first stage of the mid-start period, the control device 70 increases the engine speed as the accelerator opening increases, as shown in FIG. 13(c), and changes the elapsed time and vehicle speed as shown in FIG. Outputs the corresponding engine torque. Specifically, the engine torque increases linearly as the time elapses from the time of switching to the mid-start period, but the slope of the straight line increases as the vehicle speed increases. The motor torque in the first stage in the middle of the start is similar to that shown in FIG. After the engine rotational speed when the power of the engine 21 is transmitted to the belt 29 of the CVT 26 reaches the belt gripping rotational speed N1, the driving force of the entire vehicle is the driving force of both the engine 21 and the motor 22. It is realized by Then, as shown in the column of the first stage of the mid-start period in FIG. 12, a belt gripping determination time (FIG. 13) has elapsed during which the engine rotational speed is continuously equal to or higher than the belt gripping rotational speed N1 for a predetermined period of time. In this case, the driving state is switched to the second stage in the next mid-start period.

FIG. 16 is a diagram showing the relationship between the accelerator opening degree, vehicle speed, and motor torque in the second stage of the mid-start period in smooth start support. The control device 70 controls the drive of the motor 22 using the relationship shown in FIG. 16 in the second stage of the middle start period. Specifically, the motor torque decreases linearly as the vehicle speed increases. Further, a plurality of straight lines representing the relationship between vehicle speed and motor torque are set according to the accelerator opening degree, and a straight line is set such that the motor torque increases as the accelerator opening degree increases. On the other hand, the engine 21 outputs engine torque according to the accelerator opening degree. For example, similar to the engine torque of the sudden start support shown in FIG. 10, the engine torque increases linearly as the accelerator opening increases. As a result, as shown in FIG. 13(a), in the second stage of the mid-start period, the driving force of the vehicle by the motor 22 gradually decreases, rather than suddenly, and reaches 0. In accordance with the decrease, the driving force by the engine 21 increases to exceed the decrease, thereby increasing the driving force of the vehicle. Further, when executing the smooth start support, the control device 70 increases and then decreases the output of the motor 22 as time passes, and increases the output of the engine 21 from the time when the output of the motor 22 is near the maximum value. Increase as time progresses. This allows the output of the motor 22 to be reduced while smoothly increasing the driving force of the vehicle in the middle of the starting period, as indicated by the arrow β in FIG. 13(a). Further, in the middle of starting, the torque of the motor 22 is reduced after a predetermined belt gripping determination time has elapsed after the engine rotational speed reaches the belt gripping rotational speed N1, so that the driving force of the vehicle can be increased more smoothly.

Next, control when selecting each of regeneration support, slip support, sudden acceleration support, and slope support will be explained in order using FIGS. 17 to 24. FIG. 17 is a diagram showing a state in which the vehicle 10 transitions from traveling on a flat road 91 to traveling on a downhill slope 90, and a state in which regeneration support is executed during downhill traveling.

When selecting regeneration support, the control device 70 controls the vehicle 10 when the vehicle 10 enters a downhill slope 90 while being driven by the engine 21 and the accelerator pedal 60 changes from on to off, that is, when it is not operated. As the braking force, an engine brake and a braking force due to the regenerative torque of the motor 22 are generated. For example, the control device 70 receives an instruction to select regeneration support, the forward/reverse lever 62 is in a position other than the neutral position, the engine 21 is driven, the accelerator pedal 60 is turned off, the detected vehicle speed is within a predetermined range, and the brake A configuration may be adopted in which regeneration support is executed when a regeneration support execution condition in which the pedal 63 is turned off is satisfied. When performing regeneration support, the control device 70 controls the inverter 24a connected to the motor 22 to generate regeneration torque. As a result, the vehicle speed can be reduced more quickly than when braking is performed using engine braking alone. This makes it easier for the driver to drive comfortably.

In addition to the regeneration support execution conditions described above, the control device 70 executes regeneration support only when the inclination angle θ of the downhill slope 90 detected by the inclination angle sensor 66 is equal to or greater than a predetermined regeneration support determination inclination angle. It is also possible to have a configuration in which This prevents frequent generation of regenerative torque and sudden deceleration on downhill slopes with small inclination angles. For example, as shown in FIG. 17(a), when the accelerator pedal 60 is turned on and the vehicle 10 is running on a flat road 91 driven by the engine, the inclination angle of the road surface is 0, so regeneration support is not performed. As shown in FIG. 17(b), when the vehicle 10 enters a downhill slope 90 with an inclination angle θ equal to or greater than the regeneration support determination inclination angle, if the accelerator pedal 60 is still turned on, regeneration support is not performed. . On the other hand, as shown in FIG. 17(c), when the accelerator pedal 60 is turned off while the vehicle 10 is traveling downhill 90 and the regeneration support execution condition is satisfied, regeneration support is executed and the motor 22 Regenerative torque is generated. As a result, the braking force due to the regenerative torque is added to the braking force due to the engine brake, and the vehicle speed can be reduced more quickly.

FIG. 18 is a diagram showing the relationship between the regenerative torque of the motor 22, the vehicle speed, and the inclination angle of the downhill slope in the control when regeneration support is selected. When the vehicle speed is within a predetermined range, the regenerative torque gradually increases as the vehicle speed increases, and above a predetermined value, the regenerative torque decreases as the vehicle speed increases. Furthermore, the larger the inclination angle of the downhill slope, the larger the regenerative torque. The control device 70 may calculate the regenerative torque from the relationship shown in FIG. 18, the detected vehicle speed value, and the detected tilt angle value, and may control the inverter 24a to output the calculated regenerative torque. Thereby, when the vehicle speed is high and/or when the inclination angle is small, it is possible to suppress the application of impact force to the driver at high deceleration due to the generation of large regenerative torque.

FIG. 19 shows the transition of the vehicle 10 from the normal straight-ahead state to the rear wheel slip state and the rear wheel grip recovery state, and the front wheel rotational speed Vf and rear wheel rotational speed Vr in each state in the control when slip support is selected. It is a figure showing a relationship. When the slip support is selected, when the vehicle 10 is running in an engine running mode or the like with the engine 21 being driven and the motor 22 stopped, the rear wheels 16 enter a low friction area 92 such as mud and slip. , when the rotational speed Vr of the rear wheels 16 exceeds the rotational speed Vf of the front wheels 15, the control device 70 drives the motor 22, and uses its driving force to return from the slip state to a non-slip state.

At this time, the forward force can be increased by driving the motor 22 during forward movement, and when the rear wheel 16 escapes from the low friction portion 92 and the rear wheel rotational speed Vr becomes high enough to match the front wheel rotational speed Vf. , the motor 22 is stopped to end the slip support. For example, as shown in FIG. 19(a), when the engine 21 is driven, the motor 22 is stopped, and the vehicle is moving forward in a normal straight line, the front wheel rotational speed Vf and the rear wheel rotational speed Vr match. On the other hand, when the rear wheel 16 enters the low friction portion 92 and slips as shown in FIG. 19(b), the motor 22 is driven because the rear wheel rotational speed Vr exceeds the front wheel rotational speed Vf. When the rear wheel 16 escapes from the low friction portion 92 as shown in FIG. 19(c), the grip of the rear wheel 16 is restored and the rear wheel rotational speed Vr matches the front wheel rotational speed Vf, thereby providing slip support. finish. Even when slip support is executed in this way, it becomes easier for the driver to drive comfortably.

Furthermore, the control device 70 can also cause the generators GE1 and GE2 to generate electric power equivalent to the output generated by the motor 22 when performing slip support. In this case, for example, the control device 70 receives a slip support selection instruction, the forward/reverse lever 62 is in a position other than the neutral position, the engine 21 is being driven, the amount of charge in the battery 23 is less than a predetermined amount, and the accelerator pedal 60 is turned on, the value obtained by subtracting the front wheel rotational speed Vf from the rear wheel rotational speed Vr is greater than or equal to a predetermined value, the brake pedal 63 is turned off, and when the slip support execution condition is satisfied that regeneration support is not being executed, a slip occurs. Perform support. When performing slip support, the control device 70 can drive the motor 22 and cause the generators GE1 and GE2 to generate electric power equivalent to the output generated by the motor 22. For example, the output of the motor 22 is expressed as (required motor)×2π×(motor rotation speed)/60. At this time, the total of the power generation torque, which is the torque that causes the generators GE1 and GE2 to generate power, can be calculated as (output of the motor 22) x 60/(engine rotation speed x 2π). When the vehicle is provided with only one of the generators GE1 and GE2, the generated torque can be determined by (output of motor 22) x 60/(engine rotation speed x 2π). Thereby, a decrease in the amount of charge of the battery 23 can be suppressed.

FIG. 20 is a diagram showing the relationship between accelerator opening and engine torque in control when slip support is selected. The control device 70 generates engine torque according to the accelerator opening when performing slip support. At this time, as shown in FIG. 20, the engine torque can be increased linearly as the accelerator opening degree increases.

FIG. 21 is a diagram showing the relationship between elapsed time and motor torque in control when selecting slip support. As shown in FIG. 21, when performing slip support, the control device 70 controls the motor 22 as the elapsed time increases from the start of driving the motor 22 until the motor torque reaches an allowable torque for a short period of time higher than the continuous rated torque. The torque can be increased and maintained for a predetermined time ta. The predetermined time allowable torque is a torque that is allowed to be output from the viewpoint of motor protection only within a short predetermined time ta. The controller 70 can then reduce the motor torque to the continuous rated torque and maintain it. Thereby, by rapidly increasing the motor torque, it becomes easier to shift to a state without slip.

Note that when turning in any direction during engine-driven forward movement, the rotational speed Vf of the front wheels 15 becomes higher than the rotational speed Vr of the rear wheels 16 due to the steering of the front wheels 15. It is possible to prevent the motor 22 from being driven unnecessarily when it is not being used.

FIG. 22 is a diagram showing the relationship between accelerator opening and motor torque in control when sudden acceleration support is selected. FIG. 23 is a diagram showing the time course of vehicle driving force and vehicle speed when the accelerator opening degree is kept constant in control when sudden acceleration support is selected. When selecting rapid acceleration support, if the vehicle 10 is running under the drive of the engine 21, the control device 70 adds the driving force of the motor 22 to the driving force of the engine 21 to accelerate the vehicle. For example, the control device 70 receives an instruction to select sudden acceleration support, the forward/reverse lever 62 is in a position other than the neutral position, the engine 21 is driven, and the amount of charge of the battery 23 is equal to or greater than a predetermined amount of sudden acceleration support, The detected accelerator opening is equal to or higher than a predetermined sudden acceleration support determination opening, and the accelerator change speed, which is the time change rate of the accelerator opening, is equal to or higher than the predetermined sudden acceleration support determination speed, and the brake pedal 63 is turned off. When regeneration support, slip support, or start support is not in progress and a sudden acceleration support execution condition is met, sudden acceleration support is executed. By executing this rapid acceleration support, the engine 21 is driven, and the speed of the vehicle 10 can be increased more rapidly than when the motor 22 is stopped, making it easier for the driver to drive comfortably. .

For example, as shown in FIG. 22, by starting execution of the sudden acceleration support, the control device 70 rapidly increases the motor torque until it reaches the motor rated torque according to the increase in the accelerator opening, and the accelerator opening increases. Even its motor torque can be maintained. Thereby, as shown in FIG. 23(a), when the vehicle 10 is driven by the engine, driving of the motor 22 can be started by depressing the accelerator pedal 60 at time t1. Thereby, together with the increase in the driving force by the engine 21, the overall driving force of the vehicle can be increased. Therefore, as shown in FIG. 23(b), the vehicle speed can be rapidly increased after the accelerator pedal 60 is depressed. At this time, the relationship between the accelerator opening degree and the engine torque is the same as that shown in FIG. 20, and the engine torque can be increased in accordance with the increase in the accelerator opening degree.

FIG. 24 shows the vehicle position (a) when traveling on a flat road 91, the vehicle position (b) at the start of slope support, and the vehicle position (c) when the target vehicle speed is reached by performing slope support. It is a diagram. When selecting slope support, when the vehicle 10 is running under the drive of the engine 21, the control device 70 determines whether the vehicle speed V1a, which is the speed of entering the uphill slope 93, and the vehicle speed Vm, which is the speed of passing the uphill slope 93. The motor 22 is driven so that they are equal. For example, the control device 70 determines that the slope support selection instruction is input, the forward/reverse lever 62 is in a position other than the neutral position, the engine 21 is being driven, the amount of charge of the battery 23 is greater than or equal to a predetermined slope support determination amount, and the forward/reverse lever 62 is in a position other than the neutral position. When the inclination angle θ detected by the angle sensor 66 is greater than or equal to the predetermined slope support inclination angle, the accelerator pedal 60 is turned on, the brake pedal 63 is turned off, and regeneration support, slip support, sudden acceleration support, or starting support is being executed. Slope support is executed when the slope support execution condition is satisfied. For example, as shown in FIG. 24(a), when the vehicle 10 is running on a flat road 91 driven by an engine, slope support is not performed because the inclination angle of the road surface is 0. As shown in FIG. 24(b), when the vehicle 10 enters an uphill slope 93 with an inclination angle θ greater than or equal to the slope support inclination angle, execution of slope support is started and the motor 22 is driven. The control device 70 stores the vehicle speed V1a at the start of execution of this slope support in the storage unit. While the vehicle 10 is running on an uphill slope 93, the control device 70 controls the motor 22 using the vehicle speed V1a as the target vehicle speed. For example, the vehicle speed Vm when the vehicle 10 is located at the position shown in FIG. 24(c) is made to match the vehicle speed V1a. This allows the driver to drive the vehicle while automatically maintaining the same vehicle speed as the speed at which the vehicle enters the uphill slope 93, making it easier for the driver to drive comfortably. Therefore, by performing any of the regeneration support, slip support, sudden acceleration support, and slope support described using FIGS. 17 to 24, it becomes easier for the driver to realize comfortable driving.

FIG. 25 is a flowchart showing a method of switching the charging mode of the battery 23 in the embodiment. Steps S1 to S8 are executed by the control device 70. In step S1, it is determined based on the detection signal of the lever sensor 53 whether the forward/reverse lever 62 is in the neutral position. When step S1 is affirmatively determined (YES), it is determined that the vehicle is in a stopped state, and the process moves to step S2, where the stopped charging process of steps S2 to S7 is executed. If the determination in step S1 is negative (NO), the process moves to step S8, and the running process is executed. For example, if a condition is satisfied in which only the engine 21 is driven as the drive source, the running process by engine drive is executed.

On the other hand, in step S2, it is determined whether the charging stop mode has been selected by touching the operation panel 52. If the determination in step S2 is affirmative, the charging stop mode is executed in step S3. In the charging stop mode, the engine is driven, for example, with idle torque at an idle rotation speed as the required engine torque. At this time, power generation by the generators GE1 and GE2 is stopped, and charging of the battery 23 from the generators GE1 and GE2 is stopped.

On the other hand, if the determination in step S2 is negative, it is determined in step S4 whether or not the low power charging mode has been selected by touching the operation panel 52. If the determination in step S4 is affirmative, the low power charging mode is executed in step S5. In the low power charging mode, the engine 21 is driven with, for example, the required engine torque (idle torque + predetermined low power charging torque). The low power charging torque is lower than the high power charging torque described below. Further, the generators GE1 and GE2 generate electricity with low power charging torque as the required generator torque. As a result, low-power charging in which the battery 23 is charged at a low speed is performed by generating electricity from the generators GE1 and GE2.

If the determination in step S4 is negative, it is determined in step S6 whether or not the high power charging mode has been selected by touching the operation panel 52. If the determination in step S6 is affirmative, the high power charging mode is executed in step S7. In the high power charging mode, the engine 21 is driven with, for example, the required engine torque (idle torque + predetermined high power charging torque). High power charging torque is higher than low power charging torque. Further, the generators GE1 and GE2 generate electricity with low power charging torque as the required generator torque. As a result, high-power charging is performed in which the battery 23 is charged at a higher speed than in the low-power charging mode by the power generation of the generators GE1 and GE2. In any of the charging stop mode, low power charging mode, and high power charging mode of steps S3, S5, and S7, the required motor torque of the motor 22 is 0 Nm, and the required motor rotation speed is 0 min ^-1 . On the other hand, if the determination in step S6 is negative, the charging mode switching control ends. The control of charging mode switching also ends when the execution of steps S3, S5, and S7 ends.

Since the charging mode can be switched between the low power charging mode and the high power charging mode as described above, it is possible to switch the battery 23 to an appropriate charging mode. For example, by allowing the user to switch charging modes, an appropriate charging mode can be selected in terms of efficiency or battery protection depending on the stop time of the vehicle 10.

According to the vehicle 10 described above, in the vehicle 10 in which the rear wheels 16 are driven by the engine 21 and the front wheels 15 are driven by the motor 22, when the amount of operation of the accelerator pedal 60 is not 0, the operation status of the accelerator pedal 60 changes. Accordingly, one of slow start support, sudden start support, and smooth start support is executed. As a result, slow start support is realized when the driver desires a smooth start in the low speed range by operating the accelerator pedal 60, and sudden start support is realized when the driver wants to quickly reach the high speed range. The motor 22 and engine 21 accelerate the vehicle. As a result, it is possible to achieve starting performance that is close to the driver's intention according to the driving situation, and when using a small motor 22, it is possible to prevent excessive load from being applied to the motor 22 in the high speed range. can improve the durability of In addition, when performing smooth start support, the driving force of the motor 22 is reduced in the high-speed range, and acceleration can be performed only by the engine 21, so that energy efficiency can be improved.

Note that the support selection in FIG. 5B may not be performed using the operation panel 52, but may be selected using one or more switches.

FIG. 26 is a flowchart showing a method of switching the charging mode of the battery 23 in another example of the embodiment. In the configurations shown in FIGS. 1 to 25, it has been explained that the battery charging mode can be switched by selecting the operation panel 52, as described with reference to FIG. On the other hand, in this example, the battery charging mode is automatically switched by the control device 70. Specifically, according to the charge amount of the battery 23 detected by the battery monitoring module 65, if the charge amount is less than a predetermined charge permission amount, the high power charging mode is executed, and when the charge amount is equal to or greater than the predetermined charge permission amount. In this case, low power charging mode is executed. The high power charging mode and the low power charging mode are the same as in the case of the configuration described using FIG. 25.

Specifically, the processing of steps S1a to S7a in FIG. 26 is executed by the control device 70. In step S1a, it is determined based on the detection signal of the lever sensor 53 whether the forward/reverse lever 62 is in the neutral position. If the determination in step S1a is affirmative (YES), the process moves to step S2a, and the stationary charging process of steps S2a to S6a is executed. If the determination in step S1a is negative (NO), the process moves to step S7a, and the running process is executed.

On the other hand, in step S2a, it is determined whether the amount of charge of the battery 23 is equal to or greater than a predetermined upper limit amount of charge. The predetermined upper limit charge amount is a charge amount higher than a predetermined charge permission amount, which will be described later, and is set to protect the battery 23 by preventing overcharging of the battery 23. If the determination in step S2a is affirmative, the charging stop mode is executed in step S3a. The charging stop mode is the same as the configuration described using FIG. 25.

If the determination in step S2a is negative, it is determined in step S4a whether the amount of charge of the battery 23 is less than the predetermined charge permission amount. If step S4a is affirmative, that is, if the amount of charge of the battery 23 is less than the predetermined charging permission amount, there is a large margin until the amount of charge reaches full charge, so the high power charging mode is executed in step S5a. be done. If the determination in step S4a is negative, that is, if the amount of charge of the battery 23 is equal to or greater than the predetermined charge permission amount, the margin of charge amount until full charge is small, so the low power charging mode is executed in step S6a. . When the execution of steps S3a, S5a, and S6a is completed, the charging mode switching control is completed.

In the case of this example as well, the charging mode can be switched between the low power charging mode and the high power charging mode, as in the configurations shown in FIGS. 1 to 25, so that it is possible to switch to an appropriate charging mode for the battery 23. . Further, in the case of this example, since the charging mode is automatically switched by the control device 70 according to the amount of charge, an appropriate charging mode is executed in terms of efficiency or battery protection depending on the amount of charge. In this example, other configurations and operations are the same as those in FIGS. 1 to 25.

In each of the above embodiments, the hybrid vehicle uses one or more of regeneration support, slip support, sudden acceleration support, and slope support when the engine is driving and when traveling. A configuration may be adopted in which two or any three types of support can be executed.

Furthermore, in each of the above embodiments, a case has been described in which regeneration support, slip support, sudden acceleration support, and slope support are executed when selected on the operation panel 52. On the other hand, a hybrid vehicle is configured to be able to perform at least two of regeneration support, slip support, sudden acceleration support, and slope support, and any one of these supports is performed depending on the driving situation of the vehicle. Good too.

For example, a hybrid vehicle may be configured to be able to perform all of regeneration support, slip support, sudden acceleration support, and slope support. At this time, in the configurations of FIGS. 1 to 25, the control device may execute regeneration support when a condition excluding input of a regeneration support selection instruction from the regeneration support execution conditions is satisfied. Furthermore, in the configurations of FIGS. 1 to 25, the control device may execute slip support when a condition excluding input of a slip support selection instruction from the slip support execution conditions is satisfied. Furthermore, in the configurations shown in FIGS. 1 to 25, when a condition that excludes input of a sudden acceleration support selection instruction from the sudden acceleration support execution conditions is satisfied, the control device executes sudden acceleration support. It's okay. Furthermore, in the configurations of FIGS. 1 to 25, the control device may execute slope support when a condition excluding input of a slope support selection instruction from the slope support execution conditions is satisfied.

FIG. 27 is a side view of a hybrid vehicle 10a according to another example of the embodiment. In the configurations of each of the above examples, the case where the vehicle 10 (FIG. 1) is an off-road multi-purpose vehicle having a loading platform has been described. However, in this example, the hybrid vehicle 10a has a working machine (not shown) on the rear side. ) can be connected to a tractor. For example, the hybrid vehicle 10a is an agricultural tractor having a working machine for performing agricultural work. The hybrid vehicle 10a includes a front wheel 15 and a rear wheel 16a supported on the front and rear sides of a frame 111, and an engine 21 and a motor 22 supported on the front side of the frame 111. The front wheels 15 are driven by a motor 22, and the rear wheels 16a are driven by an engine 21. The engine 21 is covered with a front cover 13a having a bonnet and side covers. A working machine can be connected to the rear of the vehicle, and a PTO shaft 112 for driving the working machine protrudes from the rear end of a case 113 having a power transmission section that transmits power from the engine 21. Further, an accelerator pedal 60 is arranged in front of the driver's seat 14, and a detection signal of the accelerator opening degree is transmitted from the first pedal sensor 54 (see FIG. 3A) to the control device 70 (see FIG. 3A).

In such a hybrid vehicle 10a as well, the vehicle has slow start support, sudden start support, and smooth start support, as in the configurations of each of the above examples, and the above support is activated depending on the operation status of the accelerator pedal 60. configured to run one of the following: In this example, other configurations and operations are similar to the configurations in FIGS. 1 to 25 or the configuration in FIG. 26.

In each of the above examples, the rear wheels 16, 16a may be driven by a motor, and the front wheels 15 may be driven by an engine. At this time, the first wheel becomes the front wheel 15, and the second wheel becomes the rear wheels 16, 16a.

Further, the acceleration instruction section is not limited to the accelerator pedal, and may be configured by, for example, a pair of operation levers supported swingably in the front and rear directions on each of the left and right sides of the driver's seat. For example, the right front wheel is driven by the right motor, and the left front wheel is driven by the left motor. By tilting the left and right control levers forward, the front wheels corresponding to the control levers can be rotated in the forward direction, and by tilting them backward, the front wheels can be rotated in the reverse direction.

Furthermore, in each of the above examples, a case has been described in which one of the starting supports is executed when the starting support is selected by the operation panel 52 or the switch, but the operation panel is omitted and the operation status of the acceleration instruction section is Either one of the starting supports may be executed depending on the vehicle.

Furthermore, in each of the above examples, a configuration may be adopted in which regeneration support, slip support, sudden acceleration support, slope support, and charging mode switching are not performed.

10, 10a hybrid vehicle, 11 frame, 12 platform, 13, 13a front cover, 14 driver's seat, 15 front wheel, 16, 16a rear wheel, 18 operating element group, 19 loading platform, 20 mobile body drive unit, 21 engine, 22 motor , 22a rotating shaft, 23 battery, 24a, 24b inverter, 25 rear power transmission section, 26 CVT, 26a actuator, 27 drive pulley, 28 driven pulley, 29 belt, 30 gear transmission, 31 input shaft, 32 speed change shaft, 33 final shaft, 35 rear case, 36 differential device, 37 output shaft, 38 rear axle, 40 front case, 41 front power transmission section, 42 gear mechanism, 43 differential device, 44 output shaft, 45 front axle, 50 sensor switch group, 51 steering sensor, 52 operation panel, 53 lever sensor, 54 first pedal sensor, 55 rear axle speed sensor, 56 front axle speed sensor, 57 engine speed sensor, 60 accelerator pedal, 61 steering operator, 62 forward/reverse lever , 63 brake pedal, 64 second pedal sensor, 65 battery monitoring module, 66 tilt angle sensor, 70 control device, 71 engine control section, 72 motor control section, 80 centrifugal clutch, 81 first display area, 82a EV mode selection Part, 82b Engine running mode selection part, 82c Constant 4WD mode selection part, 82d OFF mode selection part, 83 Second display area, 84a Start support selection part, 84b Regeneration support selection part, 84c Slip support selection part, 84d Rapid acceleration Support selection section, 84e Slope support selection section, 85 Third display area, 86a Low power charging mode selection section, 86b High power charging mode selection section, 86c Charging stop mode selection section, 90 Downhill, 91 Flat road, 92 Low Friction part, 93 Uphill, 111 Frame, 112 PTO shaft, 113 Case.

Claims (7)

an engine that drives the first wheel;
comprising: a motor that drives a second wheel that is spaced apart from the first wheel in the front-rear direction; and a control device that controls the motor and the engine ;
(1) A slow start support that drives the vehicle using only the motor as a drive source;
(2) a sudden start support that drives the vehicle using the engine and the motor as the drive source;
(3) In the early stage, the vehicle is driven only by the motor as the drive source, in the middle stage, the vehicle is driven by the engine and the motor as the drive source, and in the later stage, the vehicle is driven only by the engine as the drive source. It has a starting support,
When the operation amount of the acceleration instruction section is not 0, one of the supports is executed according to the operation status of the acceleration instruction section,
The control device executes the slow start support when the operation amount of the acceleration instruction section is less than a first predetermined value and the vehicle speed is less than or equal to a predetermined speed;
The slow start support can be executed even when the operation amount is 0,
When performing the slow start support, the relationship between the torque of the motor and the manipulated variable is such that a predetermined torque is generated when the manipulated variable is 0, and a predetermined torque is generated when the manipulated variable is 0. The torque of the motor is maintained at the predetermined torque until the amount of operation is reached, and when the amount of operation is equal to or greater than the predetermined amount of operation, the torque of the motor increases as the amount of operation increases.
hybrid vehicle. an engine that drives the first wheel;
comprising: a motor that drives a second wheel that is spaced apart from the first wheel in the front-rear direction; and a control device that controls the motor and the engine;
(1) A slow start support that drives the vehicle using only the motor as a drive source;
(2) a sudden start support that drives the vehicle using the engine and the motor as the drive source;
(3) In the early stage, the vehicle is driven only by the motor as the drive source, in the middle stage, the vehicle is driven by the engine and the motor as the drive source, and in the later stage, the vehicle is driven only by the engine as the drive source. It has a starting support,
When the operation amount of the acceleration instruction section is not 0, one of the supports is executed according to the operation status of the acceleration instruction section,
The control device provides the sudden start support when the manipulated variable of the acceleration instruction section is equal to or higher than a second predetermined value that is larger than the first predetermined value, and when the time change rate of the manipulated variable is equal to or higher than the predetermined time change rate. run the
The degree to which the torque of the motor increases as the manipulated variable increases when performing the sudden start support is the degree to which the torque of the motor increases as the manipulated variable increases when performing the slow start support. bigger,
hybrid vehicle . When executing the sudden start support, the relationship between the torque of the motor and the manipulated variable is such that a predetermined torque is generated when the manipulated variable is 0;
The hybrid vehicle according to claim 2 . comprising a control device that controls the motor and the engine,
The control device increases and then decreases the output of the motor when executing the smooth start support, and increases the output of the engine as time passes from when the output of the motor is near a maximum value.
A hybrid vehicle according to any one of claims 1 to 3 . The centrifugal clutch includes a belt engaged with a drive pulley connected to the output shaft of the engine via a centrifugal clutch and a driven pulley fixed to the input shaft of the wheel-side power transmission section, and the centrifugal clutch is configured to rotate the engine at a predetermined speed. a CVT that cuts off the connection between the output shaft and the drive pulley when the rotational speed of the engine is less than a predetermined speed, and connects the output shaft and the drive pulley when the rotational speed of the engine is equal to or higher than a predetermined speed;
The hybrid vehicle according to claim 4 . The first wheel driven by the engine is a rear wheel, and the second wheel driven by the motor is a front wheel.
A hybrid vehicle according to any one of claims 1 to 5 . An off-road multi-purpose vehicle or tractor that has a loading platform and travels on rough terrain.
A hybrid vehicle according to any one of claims 1 to 6 .

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