vehicle

Abstract

The present invention provides a vehicle capable of generating electricity using the power of the internal combustion engine to power the electric motor, even when the vehicle is stopped with a selected drive range. [Solution] The vehicle V is equipped with an internal combustion engine 3, an electric motor 4, and a battery 6, and changes the driving mode by switching control of the drive sources of the internal combustion engine 3 and the electric motor 4. The transmission 10 is equipped with an input shaft 13, an electric motor connection shaft 60, a switching shaft that transmits power between the input shaft 13 and the electric motor connection shaft 60, an output shaft 15, a first switching mechanism (clutch 71) that releases the transmission of power between the electric motor connection shaft 60 and the input shaft 13, and a second switching mechanism (forward clutch 51, reverse clutch 55) that releases the transmission of power between the input shaft 13 and the output shaft 15. When the electric motor 4 is operated to generate power using the power output from the internal combustion engine 3, the first switching mechanism is set to the connected state and the second switching mechanism is set to the released state.

Description

Technical Field

[0001] The present invention relates to a vehicle that includes an internal combustion engine and an electric motor, and that changes a travel mode by performing switching control of the drive sources of the internal combustion engine and the electric motor.

Background Art

[0002] Conventionally, hybrid vehicles equipped with an electric motor (motor) and an internal combustion engine (engine) are known (for example, Patent Document 1). In such hybrid vehicles, one or both of the electric motor and the internal combustion engine are used as drive sources. Further, the electric motor in a hybrid vehicle is configured to exhibit a function as a generator that generates electric power using regenerative torque during vehicle braking.

[0003] In conventional control of hybrid vehicles, control is performed to engage a clutch corresponding to the traveling direction in accordance with the shift range selected by the driver using the shift lever. This enables travel control that matches the driver's intention.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0005] However, if a control system is adopted that engages the clutch based solely on the shift range, as described in the prior art document 1 mentioned above, there is a problem in that power generation cannot be performed while the vehicle is stopped. Specifically, when either the forward or reverse shift range is selected, and either the forward or reverse clutch is engaged, and the vehicle is stopped, the rotation of the CVT's input shaft and output shaft stops. As a result, the electric motor that rotates synchronously with either of them via the dog clutch cannot rotate, and charging cannot be performed. If the above condition persists when the battery's state of charge (SOC) is low, there is a concern that in the worst case, the battery may die.

[0006] Therefore, the present invention aims to provide a vehicle that can generate electricity using the power of the internal combustion engine, even when the vehicle is stopped with a drive range selected. [Means for solving the problem]

[0007] (1) The present invention, provided to solve the above-mentioned problems, is a vehicle equipped with an internal combustion engine and an electric motor, which changes the driving mode by switching control between the drive sources of the internal combustion engine and the electric motor, wherein the vehicle has a transmission, and the transmission comprises an input shaft for transmitting power output from the internal combustion engine, an electric motor connection shaft connected to the electric motor, a switching shaft for transmitting power between the input shaft and the electric motor connection shaft, an output shaft for transmitting power to the drive wheels of the vehicle, a first switching mechanism provided on the switching shaft for transmitting and releasing power between the electric motor connection shaft and the input shaft, and a second switching mechanism for transmitting and releasing power between the input shaft and the output shaft, and a control unit which, when the electric motor is operated to generate power using power output from the internal combustion engine, connects the first switching mechanism and releases the second switching mechanism.

[0008] As described in (1) above, the vehicle of the present invention is configured to have a control unit that connects the first switching mechanism and opens the second switching mechanism when the electric motor is powered by the power output from the internal combustion engine. Thus, because the vehicle of the present invention has the control unit described above, even when the vehicle is stopped with a drive range selected, it is possible to power the electric motor using the power of the internal combustion engine. As a result, the vehicle of the present invention can properly maintain the battery charge state. In other words, even when the battery charge level decreases, the vehicle of the present invention can efficiently charge the battery while stopped, thus preventing battery drain. Furthermore, because the vehicle of the present invention has a power generation function while stopped, it is possible to achieve both idling stop and power generation, which can contribute to improved fuel efficiency.

[0009] (2) The vehicle of the present invention provided to solve the above-mentioned problems is the vehicle described in claim 1, characterized in that when it is determined that the vehicle will not be started, the control unit sets the first switching mechanism to a connected state and the second switching mechanism to a released state.

[0010] As described in (2) above, the vehicle of the present invention is configured such that, when it is determined that the vehicle will not be started, the control unit connects the first switching mechanism and releases the second switching mechanism. In this way, the vehicle of the present invention can prevent hesitation during starting by determining whether or not a starting operation is performed and controlling accordingly. In other words, if a starting operation is performed, power generation control is not performed, and the system switches to normal driving control, thereby enabling a smooth start that is in line with the driver's intentions.

[0011] (3) The vehicle of the present invention provided to solve the above-mentioned problems is the vehicle according to claim 1 or 2, characterized in that the first switching mechanism and the second switching mechanism are composed of a clutch.

[0012] As described in (3) above, the vehicle of the present invention has a first switching mechanism and a second switching mechanism composed of clutches. In this way, by using a clutch in the switching mechanism of the vehicle of the present invention, the switching of the power transmission path can be performed quickly and reliably. By using a clutch, the control of engagement and disengagement becomes easier, and the transition to and release of power generation operation can be performed smoothly.

[0013] (4) The vehicle of the present invention provided to solve the above-mentioned problems is the vehicle according to any one of claims 1 to 3, wherein the control unit, when it is determined that the vehicle is stopped on an incline, performs control to maintain the stopped state of the vehicle by the brake device, and then sets the first switching mechanism to the connected state and the second switching mechanism to the released state.

[0014] As described in (4) above, the vehicle of the present invention is configured such that, when it is determined that the vehicle is stopped on an incline, the braking system is controlled to maintain the vehicle's stopped state, and then the first switching mechanism is connected and the second switching mechanism is released. In this way, the vehicle of the present invention can perform power generation control while ensuring vehicle safety by combining it with brake hold control when stopped on an incline. In particular, on an uphill incline, even if the second switching mechanism is released, the vehicle's stopped state is maintained by the brake hold control, thus preventing the vehicle from unexpectedly rolling backward. This makes it possible to perform power generation control safely without causing anxiety to the driver.

[0015] (5) The vehicle of the present invention provided to solve the above-mentioned problems is the vehicle according to any one of claims 1 to 4, wherein the control unit is characterized in that when the charge level of the battery is less than a predetermined value, the first switching mechanism is connected and the second switching mechanism is released.

[0016] As described in (5) above, the vehicle of the present invention is configured such that when the battery charge level is below a predetermined value, the first switching mechanism is connected and the second switching mechanism is released. In this way, the vehicle of the present invention can perform power generation control according to the battery charge level, thereby generating power using the internal combustion engine only when necessary and performing idle stop when not necessary. This makes it possible to maintain the battery charge level appropriately while minimizing fuel consumption. For example, when the battery charge level is above a predetermined value, fuel efficiency can be improved by maintaining the idle stop state.

[0017] (6) The present invention, provided to solve the above-mentioned problems, is a vehicle control method according to any one of claims 1 to 5, characterized in that when the electric motor is operated to generate power using power output from the internal combustion engine, the first switching mechanism is in a connected state and the second switching mechanism is in a disconnected state.

[0018] The method of the present invention, as described in (6) above, involves setting the first switching mechanism to the connected state and the second switching mechanism to the unconnected state when the electric motor is powered by the power output from the internal combustion engine. In this way, by performing the switching control described above, the method of the present invention makes it possible to power the electric motor using the power of the internal combustion engine even when the vehicle is stopped with a drive range selected. This makes it possible to improve fuel efficiency while appropriately maintaining the battery charge state.

[0019] Furthermore, the components described in the above embodiments and each claim can be implemented in appropriate combinations. In particular, by combining control based on the battery charge level, control based on whether or not the vehicle is started, and brake hold control on inclines, safer and more efficient power generation control while stationary can be achieved. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a vehicle capable of causing an electric motor to perform a power generation operation using power of an internal combustion engine even when the vehicle is stopped with a drive range selected. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] [Figure 1] FIG. 2 is an overall front view of a vehicle according to an embodiment of the present invention, with a cover of a transmission cut away. [Figure 2] FIG. 2 is a skeleton diagram of an embodiment of the transmission of FIG. 1. [Figure 3] FIG. 2 is a block diagram showing a configuration of a control system included in a vehicle according to an embodiment of the present invention. [Figure 4] FIG. 2 is a flowchart showing a control method of a power generation operation performed during stop in a vehicle according to an embodiment of the present invention. MODES FOR CARRYING OUT THE INVENTION

[0022] Hereinafter, a vehicle V according to an embodiment of the present invention and a transmission 10 mounted thereon will be described in detail with reference to the drawings. It should be noted that each drawing is schematically represented for ease of understanding, and may differ from the actual shape, size, and arrangement of component parts. It should also be noted that the fact that each shaft is rotatably supported by appropriate bearings or the like may be omitted. In the following description, the front side of the vehicle V may be referred to as front Fr, and the rear side thereof may be referred to as rear Rr.

[0023] Basic Configuration of Transmission As shown in FIGS. 1 and 2, the vehicle V includes an internal combustion engine 3, an electric motor 4, and a battery 6, and changes a travel mode by switching and controlling the drive sources of the internal combustion engine 3 and the electric motor 4. The vehicle V includes a transmission 10. Further, the internal combustion engine 3 and the electric motor 4 are connected to the transmission 10.

[0024] The internal combustion engine 3 is composed of, for example, a gasoline engine or a diesel engine. The drive shaft (not shown) of the internal combustion engine 3 is connected to the input shaft 13 of the transmission 10. Therefore, the power output by the internal combustion engine 3 is input to the transmission 10 through the input shaft 13.

[0025] As shown in Figures 1 and 2, the electric motor 4 is configured, for example, as a motor generator, and can output driving force and generate electricity. The motor shaft 4A of the electric motor 4 is connected to the motor connection shaft 60 in the transmission 10 via a universal joint 5. Therefore, the power output by the electric motor 4 is input to the transmission 10 via the motor connection shaft 60.

[0026] The transmission 10 has multiple gears and is configured to change the speed of the power generated by the internal combustion engine 3 and the electric motor 4, and to transmit the regenerated energy to the electric motor 4.

[0027] As shown in Figures 1 and 2, the transmission 10 includes a torque converter 12, an input shaft 13, a continuously variable transmission 20 (CVT 20), a reverse transmission mechanism 40, a forward clutch 51 (clutch device 50), a reverse clutch 55 (clutch device 50), and an output shaft 15. The transmission 10 also includes an electric motor connecting shaft 60, a primary shaft 21, a secondary shaft 23, a first driven shaft 30, a second driven shaft 35, a reverse idler shaft 41, and a switching mechanism 70, etc.

[0028] As shown in Figures 1 and 2, the torque converter 12 includes a pump impeller 12A, a turbine runner 12B, and a lock-up mechanism 12C (lock-up clutch), etc. The input shaft 13 is connected to the pump impeller 12A and is able to rotate integrally with the input shaft 13 around the same axis of rotation. The turbine runner 12B is rotatable around the same axis of rotation as the pump impeller 12A.

[0029] The lock-up mechanism 12C is provided to directly connect / disconnect the pump impeller 12A and the turbine runner 12B. When the lock-up mechanism 12C is engaged (lock-up on), the pump impeller 12A and the turbine runner 12B are directly connected, and when the lock-up mechanism 12C is released (lock-up off), the pump impeller 12A and the turbine runner 12B are separated.

[0030] The input shaft 13 is positioned so that its axis coincides with the rotation axis of the torque converter 12. The input shaft 13 can transmit power output from the internal combustion engine 3. An input shaft gear 14 is integrally formed on the input shaft 13. The front end Fr of the input shaft 13 is inserted into the torque converter 12.

[0031] The output shaft 15 is positioned at a rearward (Rr) distance from the input shaft 13. The output shaft 15 is positioned so that its axis aligns with the axis of the input shaft 13. Although not shown in the illustration, the output shaft 15 can transmit power to the drive wheels of the vehicle V via a drive shaft or the like. An output shaft gear 16 is integrally formed on the output shaft 15.

[0032] The continuously variable transmission 20 is provided with a primary shaft 21, a secondary shaft 23, a primary pulley 26, a secondary pulley 27, and a belt 28. A primary input gear 22 (also called a driven gear 22) is mounted on the primary shaft 21 so as to be rotatable relative to it. The primary input gear 22 meshes with an input shaft gear 14 and a second driven gear 36, which will be described later.

[0033] A secondary input gear 24 and a secondary output gear 25 are mounted on the secondary shaft 23. The secondary input gear 24 is rotatable relative to the secondary shaft 23. The secondary output gear 25 is mounted so as not to rotate relative to the secondary shaft 23. The secondary output gear 25 meshes with an output shaft gear 16 provided on the output shaft 15.

[0034] In the continuously variable transmission 20, a belt 28 is stretched between a primary pulley 26 and a secondary pulley 27. In the continuously variable transmission 20, the hydraulic pressure supplied to the hydraulic chambers (not shown) of the primary pulley 26 and the secondary pulley 27 is controlled, and the groove widths of the primary pulley 26 and the secondary pulley 27 are changed, thereby continuously changing the belt gear ratio (pulley ratio between the primary pulley 26 and the secondary pulley 27) within a constant gear ratio range. The rotational force (power) of the shifted secondary shaft 23 is transmitted to the output shaft 15 via the secondary output gear 25 and the output shaft gear 16, driving the drive wheels (not shown).

[0035] The reverse transmission mechanism 40 is a mechanism that transmits power (rotation) from the input shaft 13 to the secondary input gear 24. The reverse transmission mechanism 40 is equipped with a reverse idler shaft 41 and reverse idler gears 42 (first reverse idler gear 42A and second reverse idler gear 42B).

[0036] The reverse idler shaft 41 is a shaft located midway between the secondary shaft 23 and the first driven shaft 30, which will be described later. As shown in Figure 1, the reverse idler shaft 41 is rotatably supported at both ends by a front bearing 44 and a rear bearing 46. The front bearing 44 and the rear bearing 46 are each held in the transmission case 10A. The front bearing 44 is located at the end of the reverse idler shaft 41 on the side of the first reverse idler gear 42A. The rear bearing 46 is located at the end on the side of the second reverse idler gear 42B.

[0037] As shown in Figures 1 and 2, the first reverse idler gear 42A is integrally formed with the reverse idler shaft 41 and meshes with the input shaft gear 14. In other words, the first reverse idler gear 42A can reverse the rotation direction of the input shaft gear 14 (input shaft 13).

[0038] The second reverse idler gear 42B is formed integrally with the reverse idler shaft 41 at the rear Rr of the first reverse idler gear 42A and meshes with the secondary input gear 24.

[0039] The forward clutch 51 (clutch device 50) is provided to allow / prevent the rotation of the primary input gear 22 relative to the primary shaft 21. The forward clutch 51 forms a clutch device 50 that includes a clutch drum, clutch piston, friction material, and hydraulic chamber, although these are not shown in the figures. The forward clutch 51 controls the engagement of the clutch by controlling the supply of oil to the hydraulic chamber according to the output value of a solenoid (not shown).

[0040] When the forward clutch 51 is engaged (engaged state), relative rotation of the primary input gear 22 with respect to the primary shaft 21 is prohibited. In other words, the engagement of the forward clutch 51 causes the primary shaft 21 and the primary input gear 22 to rotate as a single unit. As a result, a driving force in the forward direction is transmitted to the output shaft 15 via the continuously variable transmission 20, and the drive wheels (not shown) are driven in the forward direction.

[0041] The reverse clutch 55 (clutch device 50) is provided to allow / prevent the rotation of the secondary input gear 24 relative to the secondary shaft 23. The reverse clutch 55 has the same configuration as the forward clutch 51.

[0042] When the reverse clutch 55 is engaged (engaged state), relative rotation of the secondary input gear 24 with respect to the secondary shaft 23 is prohibited. In other words, the engagement of the reverse clutch 55 causes the secondary shaft 23 and the secondary input gear 24 to rotate together. This transmits a driving force in the reverse direction to the output shaft 15, and drives the drive wheels (not shown) in the reverse direction. On the other hand, when the reverse clutch 55 is released (released state), relative rotation of the secondary input gear 24 with respect to the secondary shaft 23 is permitted. Therefore, even if the secondary input gear 24 rotates, that rotation is not transmitted to the secondary shaft 23.

[0043] The motor connecting shaft 60 has a first motor connecting shaft 60A and a second motor connecting shaft 60B (hereinafter, the first motor connecting shaft 60A may be referred to as the front end side (Fr side) of the motor connecting shaft 60, and the second motor connecting shaft 60B may be referred to as the rear end side (Rr side) of the motor connecting shaft 60). As shown in Figures 1 and 2, a universal joint 5 is connected to the front end (front Fr side / first motor connecting shaft 60A) of the motor connecting shaft 60. The motor shaft 4A of the electric motor 4 (for example, a motor generator) is connected to the front end side (Fr side) of the universal joint 5. A motor connecting shaft gear 61, an output side gear 33, a switching mechanism 70, and a second motor connecting shaft 60B are provided on the axis of the first motor connecting shaft 60A.

[0044] The motor connecting shaft gear 61 is located on the first motor connecting shaft 60A, which is on the front end (front Fr side) of the motor connecting shaft 60. The motor connecting shaft gear 61 has an outer sleeve shape and is connected to a clutch 71 which is part of the switching mechanism 70. The motor connecting shaft gear 61 is designed so that the motor connecting shaft 60 and the motor connecting shaft gear 61 can rotate synchronously when the switching mechanism 70 is in a state that enables power transmission between the motor connecting shaft 60 and the input shaft 13 (input side connection state), as will be described in detail later. The motor connecting shaft gear 61 meshes with the third driven gear 32A on the first driven shaft 30. Therefore, when the motor 4 is driven, the power output from the motor 4 is transmitted to the first driven shaft 30. As will be described in more detail later, when the first driven shaft 30 is driven by the internal combustion engine 3, the power output from the internal combustion engine 3 is transmitted to the first driven shaft 30 and then used to generate electricity for the electric motor 4 via the motor connecting shaft gear 61 and the motor connecting shaft 60.

[0045] As shown in Figure 2, the first driven shaft 30 is provided between the motor connection shaft 60 and the input shaft 13. The first driven shaft 30 is rotatably supported at both its front end (front Fr side) and rear end (rear Rr side). A first driven gear 32 is also fixed to the middle of the first driven shaft 30.

[0046] The first driven gear 32 comprises a third driven gear 32A and a fourth driven gear 32B positioned on the rear side (Rr) of the third driven gear 32A.

[0047] The third driven gear 32A meshes with the motor connection shaft gear 61. Therefore, the first driven shaft 30 can transmit the power output from the motor connection shaft 60.

[0048] The fourth driven gear 32B is located on the opposite side of the first driven shaft 30 from the internal combustion engine 3 side (towards the transmission 10 side) in the axial direction of the first driven shaft 30. The fourth driven gear 32B meshes with the second driven gear 36, which is fixed to the second driven shaft 35, which will be described later.

[0049] As shown in Figures 1 and 2, the second driven shaft 35 is positioned parallel to the first driven shaft 30, with a gap between them. The second driven gear 36 is mounted to the second driven shaft 35.

[0050] The second driven gear 36 meshes with the primary input gear 22 (driven gear 22) and the fourth driven gear 32B. Therefore, when the clutch 71 of the switching mechanism 70 is in the "input side engaged state", the second driven gear 36 can rotate together with the second driven shaft 35 in accordance with the rotation of the primary input gear 22. That is, the power output from the internal combustion engine 3 is transmitted to the motor connection shaft 60 via the primary input gear 22, the second driven shaft 35, and the first driven shaft 30, and is used for generating electricity in the motor 4. Also, the second driven gear 36 can rotate together with the second driven shaft 35 in accordance with the rotation of the first driven shaft 30. That is, the power output from the motor 4 is transmitted to the first driven shaft 30, the second driven shaft 35, and the input shaft 13, and is used for starting the internal combustion engine 3.

[0051] The output gear 33 is fixed to the second motor connecting shaft 60B. The output gear 33 meshes with the output transmission shaft gear 18 (also called the output idler gear 18), which is fixed to the output transmission shaft 17 (described later). (Note that although the diagram shows the output gear 33 and the output transmission shaft 17 as being separated, they are actually meshed with each other.)

[0052] The output transmission shaft 17 is mounted parallel to the motor connection shaft 60, with a gap between them. An output transmission shaft gear 18 is mounted on the output transmission shaft 17. The output transmission shaft gear 18 meshes with the output shaft gear 16 on the output shaft 15. The output transmission shaft gear 18 also meshes with the output side gear 33 on the first driven shaft 30. The output transmission shaft gear 18 also meshes with the output shaft gear 16 on the output shaft 15. Therefore, the output transmission shaft 17 can transmit power from the first driven shaft 30 to the output shaft 15 as the first driven shaft 30 rotates.

[0053] The switching mechanism 70 is located between the first motor connecting shaft 60A and the second motor connecting shaft 60B. The switching mechanism 70 includes a clutch 71 and the like.

[0054] The switching mechanism 70 can switch between an "input-side connection state" that enables power transmission between the motor connection shaft 60 and the input shaft 13, and an "output-side connection state" that enables power transmission between the motor connection shaft 60 and the output shaft 15, by switching the connection state of the clutch 71 by hydraulics or the like. Specifically, the motor connection shaft 60 is divided into a first motor connection shaft 60A and a second motor connection shaft 60B via the clutch 71 of the switching mechanism 70, with a motor connection shaft gear 61 located on the first motor connection shaft 60A and an output-side gear 33 located on the second motor connection shaft 60B.

[0055] Therefore, in the "input-side connected state," the second motor connecting shaft 60B is not connected (the rear Rr side of the clutch 71 is not engaged), and only the first motor connecting shaft 60A rotates. That is, the motor connecting shaft gear 61 (input-side gear 61) rotates in conjunction with the rotation of the first motor connecting shaft 60A. Therefore, when the internal combustion engine 3 is driven in the "input-side connected state," the power output from the internal combustion engine 3 is used to generate electricity for the motor 4 via the input shaft 13, primary shaft 21, second driven shaft 35, first driven shaft 30, and motor connecting shaft 60. On the other hand, when the internal combustion engine 3 is stopped in the "input-side connected state," the power output from the motor 4 is used to start the internal combustion engine 3 via the motor connecting shaft 60, first driven shaft 30, second driven shaft 35, primary shaft 21, and input shaft 13.

[0056] Furthermore, in the "output-side connected state," the clutch 71 engages, connecting the second motor connecting shaft 60B, causing the first motor connecting shaft 60A and the second motor connecting shaft 60B to rotate together. Therefore, when the motor 4 is driven in the "output-side connected state," the power output from the motor 4 is used to drive the drive wheels (not shown) via the first motor connecting shaft 60A and the second motor connecting shaft 60B (EV driving state or assisted driving (HEV driving) state). On the other hand, when the drive wheels are braked (decelerated) in the "output-side connected state," the braking force acting on the output shaft 15 is used for regeneration (power generation) of the motor 4 via the motor connecting shaft 60.

[0057] ≪Control Unit≫ As shown in Figure 3, the vehicle V is equipped with a control unit 80 that controls the entire vehicle. The control unit 80 is composed of, for example, an ECU (Electronic Control Unit). The control unit 80 controls the internal combustion engine 3, the electric motor 4, and the transmission 10, etc. In particular, for the transmission 10, it controls the engagement state of the clutch 71 of the switching mechanism 70, the engagement state of the forward clutch 51, and the engagement state of the reverse clutch 55, etc.

[0058] The control unit 80 includes a CPU for performing calculations, memory such as ROM or RAM for storing various programs and calculation data, and input / output interfaces. The control unit 80 also receives signals indicating the vehicle's driving state from various sensors. For example, the control unit 80 receives signals from an accelerator sensor that detects the amount of accelerator pedal operation, a brake switch that detects brake pedal operation, a gradient sensor that detects the vehicle's gradient, a shift sensor that detects the selected shift range, and a charge level sensor that detects the charge level (SOC: State of Charge) of the battery 6. Based on these signals, the control unit 80 performs various controls, including motor power generation control when the vehicle is stopped, which will be described later.

[0059] ≪Control method for power generation operation when the vehicle is stopped≫ Next, the control method for the power generation operation when the vehicle V is stopped in this embodiment will be described. In the configuration described above, the transmission 10 of the vehicle V can be controlled to generate electricity using the power of the internal combustion engine 3 while the vehicle is stopped. Figure 4 is a flowchart showing the flow of the control method for the power generation operation when the vehicle is stopped in this embodiment.

[0060] The control unit 80 first determines whether a drive range (R range or forward range) is selected (step S1). This determination is made based on the signal from the shift sensor. If a drive range is not selected (step S1: NO), that is, if the P range or N range is selected, the system is in a hardware-neutral state, and this control is terminated.

[0061] If a drive range is selected (step S1: YES), the control unit 80 then determines whether the state of charge (SOC) of the battery 6 is less than a predetermined value (step S2). This determination is made based on a signal from the charge level sensor. If the SOC is greater than or equal to the predetermined value (step S2: NO), it is determined that charging is unnecessary and the system switches to an idle stop state to reduce fuel consumption (step S10).

[0062] If the State of Control (SOC) is less than a predetermined value (Step S2: YES), the control unit 80 determines whether the vehicle V is stationary or not (Step S3). This determination is made based on the signal from the vehicle speed sensor. If the vehicle V is moving (Step S3: NO), this control ends and the system transitions to normal driving control (Step S11).

[0063] If vehicle V is stationary (Step S3: YES), the control unit 80 then determines whether or not the driver has initiated a start (Step S4). This determination is made based on signals from the accelerator sensor and brake switch. If the driver has initiated a start (Step S4: YES), the system switches to normal start control to prevent any delay in starting (Step S12).

[0064] If the driver does not initiate movement (Step S4: NO), the control unit 80 determines whether the vehicle V is stopped on the slope (Step S5). This determination is made based on the signal from the gradient sensor. If the vehicle is stopped on the slope (Step S5: YES), the control unit 80 implements brake hold control using the brake device (Step S6). Brake hold control is a control method in which the brake device automatically maintains braking force in order to maintain the vehicle's stopped state.

[0065] If the vehicle is not stopped on an incline (step S5: NO), or after brake hold control has been performed (after step S6), the control unit 80 engages the clutch 71 (dog clutch) which constitutes the first switching mechanism in the switching mechanism 70 (step S7). The control unit 80 also disengages the clutch 50 (both the forward clutch 51 and the reverse clutch 55 in this embodiment) which constitutes the second switching mechanism in the switching mechanism 70 (step S8). This control creates a path through which power from the internal combustion engine 3 is transmitted to the electric motor 4 via the motor connection shaft 60, while simultaneously interrupting power transmission from the input shaft 13 to the output shaft 15, making it possible to rotate the internal combustion engine 3 while the vehicle V remains stationary.

[0066] With the above control, even when the vehicle V is stopped with a drive range selected, it is possible to operate the electric motor 4 using the power of the internal combustion engine 3 to generate electricity. Power from the internal combustion engine 3 is transmitted to the electric motor 4 via the input shaft 13, the second driven shaft 35, the first driven shaft 30, and the motor connection shaft 60, and the electric motor 4 uses this power to generate electricity and charge the battery 6.

[0067] ≪Control details under specific conditions≫ Next, we will explain the control details under specific conditions. The power generation operation control while the vehicle is stopped, as described above, is controlled in more detail depending on various driving environments and vehicle conditions.

[0068] The following will explain in more detail the cases in which it is determined that there is no vehicle starting operation. The control unit 80 determines whether or not the driver has started the vehicle based on the amount of accelerator pedal operation and the brake switch signal, but it may also use other information. For example, based on information acquired from the front camera, it can be determined that there is no driver starting operation if the traffic light is red or if the vehicle in front is stopped. Also, if brake hold control is activated, it can be determined that there is no driver starting operation.

[0069] When determining whether the battery charge level (SOC) is below a predetermined value, it is possible to change the threshold value according to the vehicle's driving conditions, rather than simply comparing it to a fixed threshold. For example, if prolonged stopping or low-speed driving is expected due to traffic congestion, setting a higher threshold than usual allows for proactive power generation control. On the other hand, if the driving distance to the destination is short and low power consumption is expected, setting a lower threshold prioritizes idle stop to reduce fuel consumption.

[0070] The control system for stopping on inclines will be explained in detail. If the vehicle is stopped on an incline, especially an uphill incline, and the gear is set to neutral, there is a risk that the vehicle may roll backward immediately after the driver takes their foot off the brake pedal. Therefore, when the control unit 80 determines, based on the signal from the gradient sensor, that the vehicle is stopped on an incline, it performs brake hold control and then releases both the forward clutch 51 and the reverse clutch 55. Brake hold control maintains the vehicle's stopped state even after the driver takes their foot off the brake pedal, thus preventing the vehicle from rolling backward unexpectedly.

[0071] In principle, this power generation control will not be performed on inclines and brake hold control will not be activated, and normal clutch control will be maintained. However, if the battery charge level drops significantly and it is determined that immediate charging is necessary, power generation control may be performed even under these conditions. In such cases, it is desirable for the control unit 80 to display a warning or otherwise alert the driver.

[0072] ≪Switching between various driving modes≫ Next, we will explain the switching of control in various driving modes. Vehicle V can switch between multiple driving modes depending on the driving conditions and the driver's operation.

[0073] As a condition for transitioning from normal driving to the stationary power generation mode, when all the conditions from steps S1 to S5 described above are met, the control unit 80 switches from normal driving mode to the stationary power generation mode. At this time, if the internal combustion engine 3 is stopped (idling stop state), the internal combustion engine 3 is started before transitioning to power generation operation.

[0074] The system returns from the stationary power generation mode to the normal driving mode when any of the following conditions are met. First, when a starting operation by the driver (such as pressing the accelerator pedal) is detected, the control unit 80 immediately engages either the forward clutch 51 or the reverse clutch 55 according to the selected shift range, and returns to the normal driving mode.

[0075] Furthermore, if the battery charge level exceeds a predetermined upper limit, the control unit 80 terminates the stationary power generation mode and switches to idle stop control to reduce fuel consumption. In addition, if the vehicle starts moving again (for example, if the brake hold control is released on an incline), it immediately returns to the normal driving mode.

[0076] It is important that the switching between each driving mode is performed smoothly so as not to cause any discomfort to the driver. For this reason, the control unit 80 appropriately controls the rotational speed of the internal combustion engine 3 and the engagement pressure of each clutch when switching modes, thereby controlling the vehicle's behavior to ensure stability.

[0077] ≪Variations≫ Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0078] In the above embodiment, the amount of accelerator pedal operation and the brake switch signal were used as conditions for determining whether or not the vehicle was started, but other information can also be used. For example, information from the navigation system can be utilized. Specifically, based on destination information and traffic congestion information set in the navigation system, if a long stop is expected, a decision can be made to proactively implement power generation control. On the other hand, if the vehicle is approaching its destination and is expected to arrive in a short time, idling stop can be prioritized over power generation control to reduce fuel consumption.

[0079] Furthermore, information from the front camera can also be utilized. For example, if a red light is detected ahead, or if the distance to the vehicle in front becomes small and stopping is anticipated, preparations for power generation control can be started in advance. This makes it possible to generate power efficiently immediately after stopping.

[0080] The threshold for determining the state of charge (SOC) can also be changed according to various conditions. For example, the threshold can be adjusted based on factors such as ambient temperature and vehicle usage history. In low-temperature environments, battery performance deteriorates, so setting a higher threshold than usual can help maintain a good battery charge state. Furthermore, setting a higher threshold may be considered when traffic congestion or long-distance driving is anticipated.

[0081] In the above embodiment, brake hold control was implemented when stopping on an incline, but it can also be applied when stopping on a flat road. For example, if a long stop is expected, or if the frequency of starting is expected to be low, implementing brake hold control even on a flat road can reduce the burden on the driver.

[0082] Furthermore, the operating status of vehicle auxiliary equipment such as air conditioners can also be considered as a condition for implementing power generation control. If a large amount of power consumption is expected due to the use of the air conditioner, power generation control can be implemented even when the battery charge level is relatively high, thereby preventing over-discharge of the battery.

[0083] In this embodiment, an example of applying the present invention to a hybrid vehicle equipped with an internal combustion engine 3, an electric motor 4, and a battery 6 has been shown. However, the present invention is not limited to this, and can be applied to various vehicles as long as the electric motor 4 and the internal combustion engine 3 are connected in a way that enables power transmission.

[0084] <Effects> The vehicle V described above has the following characteristic configurations (a) to (f). Therefore, the vehicle V of this embodiment can achieve the following unique effects that cannot be achieved with the prior art.

[0085] (a) The vehicle V of this embodiment is equipped with an internal combustion engine 3 and an electric motor 4, and is a vehicle that changes the driving mode by switching control of the drive sources of the internal combustion engine 3 and the electric motor 4, and the vehicle V has a transmission 10, the transmission 10 is characterized by comprising an input shaft 13 that transmits power output from the internal combustion engine 3, an electric motor connection shaft 60 connected to the electric motor 4, a switching shaft that transmits power between the input shaft 13 and the electric motor connection shaft 60, an output shaft 15 that transmits power to the drive wheels of the vehicle V, a first switching mechanism (switching mechanism 70: clutch 71) provided on the switching shaft that transmits and releases power between the electric motor connection shaft 60 and the input shaft 13, and a second switching mechanism (clutch 50: forward clutch 51, reverse clutch 55) that transmits and releases power between the input shaft 13 and the output shaft 15, and a control unit 80 that puts the first switching mechanism in a connected state and the second switching mechanism in a released state when the electric motor 4 is operated by power output from the internal combustion engine 3.

[0086] As described in (a) above, the vehicle V of this embodiment is configured to have a control unit 80 that connects the first switching mechanism and opens the second switching mechanism when the electric motor 4 is powered by the power output from the internal combustion engine 3. In this way, since the vehicle V of this embodiment has the control unit 80 described above, even when the vehicle V is stopped with a drive range selected, it is possible to power the electric motor 4 using the power from the internal combustion engine 3. As a result, the vehicle V of this embodiment can properly maintain the charge state of the battery 6. In other words, even when the charge level of the battery 6 decreases, the vehicle V of this embodiment can efficiently charge it while stopped, thus preventing the battery from running out. Furthermore, by having a power generation function while stopped, the vehicle V of this embodiment can achieve both idling stop and power generation, contributing to improved fuel efficiency.

[0087] (b) In this embodiment, when it is determined that the vehicle V will not be started, the control unit 80 sets the first switching mechanism to the connected state and the second switching mechanism to the unconnected state.

[0088] In this embodiment, as described in (b) above, when it is determined that the vehicle V will not be started, the control unit 80 is configured to connect the first switching mechanism and release the second switching mechanism. In this way, the vehicle V of this embodiment can prevent hesitation when starting by determining whether or not a starting operation is performed and controlling accordingly. In other words, if a starting operation is performed, power generation control is not performed, and the system switches to normal driving control, thereby achieving a smooth start that is in line with the driver's intentions.

[0089] Although the vehicle V in this embodiment is equipped with the configuration described in (b) above, the present invention is not limited thereto. The vehicle V may also be equipped with some or all of the configuration described in (b) above. For example, power generation control may be performed at all times when the charge level of the battery 6 is extremely low, regardless of whether or not a starting operation is performed. In that case, prioritizing power generation will reliably prevent the battery 6 from running out, but charging will be prioritized over responsiveness during starting.

[0090] (c) The vehicle V of this embodiment is characterized in that the first switching mechanism and the second switching mechanism are composed of a clutch 50 and a clutch 71.

[0091] In this embodiment, vehicle V, as described in (c) above, has a first switching mechanism and a second switching mechanism composed of a clutch 50 and a clutch 71. In this way, by using clutches 50 and 71 in the switching mechanism of vehicle V, this embodiment enables quick and reliable switching of the power transmission path. By using clutches 50 and 71, vehicle V can easily control engagement and disengagement, and can smoothly transition to and release from power generation operation.

[0092] Although the vehicle V in this embodiment is equipped with the configuration described in (c) above, the present invention is not limited thereto. The vehicle V may also be equipped with some or all of the configuration described in (c) above.

[0093] (d) The vehicle V of this embodiment is characterized in that, when the control unit 80 determines that the vehicle V is stopped on an incline, it performs control to maintain the stopped state of the vehicle V by the braking device, and then sets the first switching mechanism to the connected state and the second switching mechanism to the released state.

[0094] In this embodiment, as described in (d) above, when it is determined that the vehicle V is stopped on an incline, the braking system is controlled to maintain the stopped state of the vehicle V, and then the first switching mechanism is connected and the second switching mechanism is released. In this way, the vehicle V of this embodiment can perform power generation control while ensuring the safety of the vehicle V by combining it with brake hold control when stopped on an incline. In particular, on an uphill incline, even if the second switching mechanism is released, the stopped state of the vehicle V is maintained by the brake hold control, so that the unexpected backward movement of the vehicle V can be prevented. This makes it possible to perform power generation control safely without causing anxiety to the driver.

[0095] Although the vehicle V in this embodiment is equipped with the configuration described in (d) above, the present invention is not limited thereto. The vehicle V may also be equipped with some or all of the configuration described in (d) above. For example, power generation control may not always be performed when the vehicle is stopped on an incline, but only when it is stopped on a flat road. In that case, the system will be simpler and the complexity of the control will be reduced, but the opportunities to charge the battery 6 when stopped on an incline will be reduced.

[0096] (e) The vehicle V of this embodiment is characterized in that the control unit 80 connects the first switching mechanism and opens the second switching mechanism when the charge level of the battery 6 is less than a predetermined value.

[0097] As described in (e) above, the vehicle V of this embodiment is configured such that when the charge level of the battery 6 is below a predetermined value, the first switching mechanism is connected and the second switching mechanism is released. In this way, the vehicle V of this embodiment can perform power generation control according to the charge level of the battery 6, thereby generating power with the internal combustion engine 3 only when necessary and performing idle stop when not necessary. This makes it possible to maintain the charge level of the battery 6 appropriately while minimizing fuel consumption. For example, when the charge level of the battery 6 is above a predetermined value, fuel efficiency can be improved by maintaining the idle stop state.

[0098] Although the vehicle V in this embodiment is equipped with the configuration described in (e) above, the present invention is not limited thereto. The vehicle V may also be equipped with some or all of the configuration described in (e) above. For example, power generation control may be performed at all times when the vehicle is stopped, regardless of the battery charge level of the battery 6. In that case, the battery charge level of the battery 6 can always be kept high, but there is a possibility that fuel consumption will increase due to unnecessary power generation.

[0099] (f) The method of this embodiment is characterized in that, when the motor 4 is operated to generate power using the power output from the internal combustion engine 3, the first switching mechanism is in the connected state and the second switching mechanism is in the unconnected state.

[0100] In this embodiment, as described in (f) above, when the electric motor 4 is powered by the power output from the internal combustion engine 3, the first switching mechanism is connected and the second switching mechanism is released. In this way, by performing the switching control as described above, the method of this embodiment makes it possible to power the electric motor 4 using the power of the internal combustion engine 3 even when the vehicle V is stopped with a drive range selected. This makes it possible to improve fuel efficiency while appropriately maintaining the charge state of the battery 6.

[0101] Furthermore, the components described in the above embodiments and features can be combined as appropriate. In particular, by combining control based on the charge level of the battery 6, control based on whether or not the vehicle V is started, and brake hold control on inclines, safer and more efficient power generation control while stationary can be achieved.

[0102] The present invention is not limited to the configurations described in the embodiments, etc. above, and can be modified as appropriate without departing from the scope of the technical idea of ​​the present invention. The components of each embodiment and modification described above can be arbitrarily selected and combined. Furthermore, any component of each embodiment and modification can be arbitrarily combined with any component described in the means for solving the problem, the form for carrying out the invention, etc., or a component that embodies any component described in the means for solving the problem, the form for carrying out the invention, etc. The present application also intends to obtain rights in this application or in divisional applications, amendment applications, etc. based on this application. [Industrial applicability]

[0103] The present invention can be suitably used in all types of vehicles that include an internal combustion engine, an electric motor, and a battery, and that change the driving mode by switching and controlling the drive source between the internal combustion engine and the electric motor. [Explanation of Symbols]

[0104] 3: Internal combustion engine 4: Electric motor 6: Battery 10: Transmission 13: Input axis 15: Output axis 50: Clutch (Second switching mechanism) 60: Motor connecting shaft 70: Switching mechanism (first switching mechanism) 71: Clutch 80: Control Unit V: Vehicle

Claims

1. A vehicle equipped with an internal combustion engine and an electric motor, which changes the driving mode by switching and controlling the drive sources of the internal combustion engine and the electric motor, The aforementioned vehicle has a transmission, The aforementioned transmission is, An input shaft that transmits power output from the internal combustion engine, The motor connection shaft connected to the aforementioned motor, A switching shaft that transmits power between the input shaft and the motor connection shaft, An output shaft that transmits power to the drive wheels of the aforementioned vehicle, A first switching mechanism is provided on the switching shaft and transmits and releases power between the motor connection shaft and the input shaft, A second switching mechanism for transmitting and releasing power between the input shaft and the output shaft, Equipped with, When the motor is operated to generate electricity using power output from the internal combustion engine, the control unit sets the first switching mechanism to a connected state and the second switching mechanism to a disconnected state, A vehicle characterized by being equipped with the following features.

2. The vehicle according to claim 1, characterized in that, when it is determined that the vehicle will not be started, the control unit sets the first switching mechanism to a connected state and the second switching mechanism to a released state.

3. The vehicle according to claim 1 or 2, characterized in that the first switching mechanism and the second switching mechanism are composed of clutches.

4. The vehicle according to claim 1 or 2, characterized in that, when the control unit determines that the vehicle is stopped on an incline, it performs control to maintain the vehicle's stopped state using the braking device, then connects the first switching mechanism and releases the second switching mechanism.

5. The vehicle according to claim 1 or 2, characterized in that the control unit connects the first switching mechanism and disconnects the second switching mechanism when the battery charge level is below a predetermined value.

Images