JP2001315550A - Hybrid vehicle and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration, and improve fuel consumption in a hybrid vehicle constituted so as to output motive power of a heat engine and an electric motor via a transmission. SOLUTION: An engine 10 and a motor 20 are mounted as a motive power source so that the hybrid vehicle is constituted for transmitting motive power of these motive power sources to a driving shaft via the transmission 100. In the engine 10 and the motor 20, the motive power distribution is set according to residual fuel for a fuel cell in a range for satisfying required motive power. A control unit 70 controls the transmission ratio and lockup of the transmission 100 according to a map with output torque of the motor 20 as a parameter besides a vehicle speed and accelerator opening. As the motive power of the motor 20 becomes large, the small transmission ratio is used, and a lockup area becomes wide. Control of the transmission is switched according to the motive power of the motor 20 to reduce the vibration of the engine 10 as well as to improve the fuel consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle which includes a heat engine and an electric motor as power sources and travels while outputting at least a power of the heat engine by a transmission while changing the power of the heat engine to a drive shaft. The present invention relates to a transmission control technique in a transmission.

[0002]

2. Description of the Related Art A hybrid vehicle having a heat engine and an electric motor as power sources has been proposed. Among hybrid vehicles, there is a type of vehicle that travels by shifting the power of a heat engine by a transmission and outputting the power to a drive shaft. The transmission is controlled in accordance with a map set in advance in accordance with a running state such as a vehicle speed and an accelerator opening, similarly to a normal vehicle using only a heat engine as a power source. The electric motor is operated to assist the torque of the heat engine.

[0003]

In a hybrid vehicle, even if the required power is constant, the distribution of power output from each of the heat engine and the electric motor can be changed according to the running state. Conventionally, transmission control has been performed in a manner that does not depend on the power distribution between the heat engine and the electric motor. When a relatively small gear ratio is set with emphasis on fuel efficiency, vibration of the heat engine is caused when the power distribution of the heat engine is large, resulting in a shock during shifting. When a relatively large gear ratio is set with emphasis on avoiding vibration or shock, fuel efficiency is impaired when the power distribution of the heat engine is small. Thus, it has been difficult to control the gear ratio so as to satisfy both fuel consumption and vibration and shock.

[0004] In addition, lock-ups are often performed on transmissions in order to suppress the slippage of the rotating shaft in order to improve the power transmission efficiency. Conventionally, lock-up has been performed under certain conditions that do not depend on the power distribution between the heat engine and the electric motor. Therefore, there are problems regarding vibration, shock, and fuel consumption depending on the power distribution of the heat engine. The present invention has been made to solve these problems, and an object of the present invention is to provide a technology for reducing vibration and shock and improving fuel efficiency in a hybrid vehicle that transmits power via a transmission. I do.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a heat engine and an electric motor as power sources, and a transmission for transmitting power of the heat engine to a drive shaft. In a hybrid vehicle including a transmission whose ratio can be changed, target power setting means for setting respective target powers of the heat engine and the electric motor, and at least a relationship between a target power of the heat engine and a target power of the electric motor are considered. Transmission control means for controlling the operating state of the transmission,
Control means for controlling the operation of the heat engine and the electric motor so as to output the target power.

[0006] The target power of the heat engine and the electric motor may be set by distributing the power required according to the running state of the vehicle at a predetermined ratio, or may be set individually using a map or a function. It may be a thing. It is preferable that the target power setting means adopts an aspect in which the target power of the heat engine and the electric motor can be set in various combinations with respect to one required power. As an example of such an aspect, there is an aspect in which respective target powers are set in consideration of parameters that affect the power distribution between the heat engine and the electric motor, for example, the power supply capability of the electric power supply of the electric motor, in addition to the required power. The hybrid vehicle of the present invention may have a configuration in which a heat engine, a transmission, and a drive shaft are provided in this order from the upstream side of the power transmission path, and the electric motor may be located either upstream or downstream of the transmission. Is also good. A path for transmitting the power of the heat engine to the drive shaft and a path for transmitting the power of the electric motor may be configured in parallel.

According to the present invention, the relationship between the target power of the heat engine and the target power of the electric motor can be reflected in the control of the transmission, and the vibration is suppressed in accordance with the power distribution between the heat engine and the electric motor. In addition, a gear ratio that improves fuel efficiency can be realized. That is, the present invention has a technical significance in that, in the control of the transmission, not only the total power output to the drive shaft but also the power distribution in each power source is considered. In a hybrid vehicle including a plurality of power sources, the power distribution of each power source may be different even when the total power to be output to the drive shaft is constant. The optimal operation state of the transmission that can achieve both suppression of vibration and improvement of fuel efficiency differs according to the power distribution of the power from the plurality of power sources. In the present invention, by paying attention to such a point, the transmission is controlled in consideration of the relationship between the target power of the heat engine and the target power of the electric motor, so that the power of the heat engine and the electric power of the electric motor are distributed. An appropriate operation state can be realized. As a result, vibration of the vehicle can be reduced and fuel efficiency can be improved.
The relationship between the target power of the heat engine and the target power of the electric motor is
The ratio or difference between the target power of the heat engine and the target power of the electric motor may be taken into account as a parameter. You may consider it according to the magnitude relation of both. Further, since the sum of the target power of the heat engine and the target power of the electric motor corresponds to the required power to be output to the drive shaft, an aspect indirectly considering the relationship between the target power of the heat engine and the target power of the electric motor. The relationship between the required power and the target power of either the heat engine or the electric motor may be considered.

The power is a value determined as the product of the number of revolutions and the torque. If the rotation speed is determined, the power and the torque uniquely correspond to each other. Therefore, the target power may be, for example, a torque corresponding to the vehicle speed or the rotation speed of the drive shaft as a parameter.
That is, the transmission control unit includes a rotation speed detection unit that detects a rotation speed of the drive shaft, and the transmission control unit uses a torque to be output to the drive shaft determined according to the rotation speed as a parameter representing the target power. The control unit may be a unit that performs the control. Furthermore, instead of setting the target power,
It is also possible to adopt a mode in which target torques of the heat engine and the electric motor are set, and the transmission is controlled in consideration of a relationship between the target torques of the two. This mode includes a mode in which the target torque is set indirectly by setting the power at each rotation speed.

As the control of the present invention, for example, the control is performed by changing the relationship between the running state of the vehicle and the gear ratio according to the relationship between the target power of the heat engine and the target power of the electric motor. I can do it. Further, when the transmission includes a fluid coupling provided between the two rotation shafts and a suppression mechanism for suppressing slippage of the fluid coupling, a relationship between a target power of the heat engine and a target power of the electric motor is provided. The range of the running state in which the sliding of the fluid coupling should be suppressed may be changed according to the condition. This is a mode in which a so-called lock-up region is switched according to the target power of the electric motor.

Normally, control of the operating state of the transmission is performed according to a map or other storage means in which the relationship between the running state and the operating state is stored in advance. Therefore, any of the above configurations can be realized by properly using the contents of the storage means according to the relationship between the target power of the heat engine and the target power of the electric motor. After setting the operation state based on a map that does not depend on the relationship between the two, it is also possible to adopt a control mode of performing a predetermined correction according to the relationship between the two.

In the present invention, various power supplies such as a battery can be used as the power supply of the electric motor, but it is particularly preferable to use a fuel cell. By using a fuel cell having a relatively high energy density as a power source for the electric motor, the electric motor can be used as a power source in a wide operating range, and the present invention can be effectively used.

In the hybrid vehicle according to the present invention, the control may always be performed in consideration of the target power of the motor. However, the power supply capability detecting means for detecting the power supply capability of the power source of the motor, Is less than or equal to a predetermined value, the transmission control means may include a prohibition means for prohibiting execution of control in consideration of a relationship between a target power of the heat engine and a target power of the electric motor. Good. The power supply capacity means the total power that can be output from the power supply. When using a fuel cell as a power source,
It can be detected based on parameters such as the remaining amount of fuel for the fuel cell. When a secondary battery is used as a power source, detection can be performed based on parameters such as remaining capacity.

When the power supply capacity is reduced, it is necessary to refrain from using the electric motor as a power source. When the control mode of the transmission is previously switched to a mode that does not depend on the relationship between the target power of the heat engine and the target power of the electric motor due to the action of the prohibiting means, thereby making it necessary to refrain from using the electric motor. However, it is possible to avoid a great change in driving sensation.

The present invention can be configured in various modes other than the hybrid vehicle. For example, the present invention may be configured as a control device or control method for controlling driving or a transmission of a hybrid vehicle. When configured as a control method, it may be configured as a method of controlling the transmission in consideration of the target power of the heat engine and the electric motor, or may be configured as a method of controlling the transmission in consideration of the target torque of both. May be.
In the former, the target torque may be used as a parameter.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below on the basis of examples with the following items. A. Device configuration: General operation: Travel control processing: Modification:

A. FIG. 1 is a schematic configuration diagram of a hybrid vehicle as an embodiment. The power sources of the hybrid vehicle of this embodiment are the engine 10 and the motor 20. As illustrated, the power system of the hybrid vehicle according to the present embodiment includes an engine 10, an input clutch 18,
It has a configuration in which the motor 20 and the transmission 100 are connected in series. That is, the crankshaft 12 of the engine 10 is connected to the motor 20 via the input clutch 18. By turning on / off the input clutch 18, transmission of power from the engine 10 can be interrupted. The rotation shaft 13 of the motor 20 is connected to the transmission 100. The output shaft 15 of the transmission 100 is connected to an axle 17 via a differential gear 16. Hereinafter, each component will be described in order.

The engine 10 is a normal gasoline engine. However, the engine 10 sets the opening / closing timing of an intake valve for sucking a mixture of gasoline and air into a cylinder and an exhaust valve for discharging exhaust gas after combustion from the cylinder relative to the vertical movement of the piston. It has an adjustable mechanism (hereinafter, this mechanism is called a VVT mechanism). Since the configuration of the VVT mechanism is well known, detailed description is omitted here. Engine 10
By adjusting the opening / closing timing so that each valve closes with a delay with respect to the vertical movement of the piston, a so-called pumping loss can be reduced. As a result,
When the engine 10 is motored, the torque to be output from the motor 20 can be reduced. When power is output by burning gasoline, the VVT mechanism is controlled so that each valve opens and closes at a timing with the highest combustion efficiency according to the rotation speed of the engine 10.

The motor 20 is a three-phase synchronous motor,
A rotor 22 having a plurality of permanent magnets on an outer peripheral surface and a stator 24 around which a three-phase coil for forming a rotating magnetic field is wound. The motor 20 is driven to rotate by interaction between a magnetic field generated by a permanent magnet provided on the rotor 22 and a magnetic field formed by a three-phase coil of the stator 24. When the rotor 22 is rotated by an external force, an electromotive force is generated at both ends of the three-phase coil by the interaction of these magnetic fields. The motor 20 includes the rotor 2
It is also possible to apply a sine wave magnetized motor in which the magnetic flux density between the stator 2 and the stator 24 has a sine distribution in the circumferential direction. However, in the present embodiment, a non-sine wave magnetized motor capable of outputting a relatively large torque is used. A magnetic motor was applied.

As a power source for the motor 20, a battery 50 is used.
And a fuel cell system 60. However, the main power supply is the fuel cell system 60. The battery 50 is used as a power supply for supplying electric power to the motor 20 to supplement the failure when the fuel cell system 60 has failed or is in a transitional operation state in which sufficient electric power cannot be output. The power of the battery 50 is mainly supplied to a control unit 70 that mainly controls the hybrid vehicle and power devices such as lighting devices.

A changeover switch 84 for switching the connection state is provided between the motor 20 and each power supply. The changeover switch 84 can arbitrarily switch the connection state among the three members of the battery 50, the fuel cell system 60, and the motor 20. The stator 24 has a changeover switch 84
And a drive circuit 51 to electrically connect to the battery 50. The changeover switch 84 and the drive circuit 52
Through the fuel cell system 60. Each of the drive circuits 51 and 52 is configured by a transistor inverter, and a plurality of transistors are provided for each of the three phases of the motor 20 by using a pair of a source side and a sink side. These drive circuits 51 and 52 are electrically connected to the control unit 70. When the control unit 70 performs PWM control of the on / off time of each transistor of the drive circuits 51 and 52, the pseudo three-phase alternating current using the battery 50 and the fuel cell system 60 as power sources is applied to the stator 2.
4 and a rotating magnetic field is formed. The motor 20 functions as an electric motor or a generator as described above by the action of the rotating magnetic field.

FIG. 2 is an explanatory diagram showing a schematic configuration of the fuel cell system. The fuel cell system 60 includes a methanol tank 61 for storing methanol, a water tank 62 for storing water, a burner 63 for generating combustion gas, a compressor 64 for compressing air, and an evaporator provided with the burner 63 and the compressor 64 in parallel. The main components are a reformer 65, a reformer 66 that generates a fuel gas by a reforming reaction, a CO reducing unit 67 that reduces the concentration of carbon monoxide (CO) in the fuel gas, and a fuel cell 60A that obtains an electromotive force by an electrochemical reaction. It is a component. The operations of these units are controlled by the control unit 70.

The fuel cell 60A is a solid polymer electrolyte fuel cell, and is formed by stacking a plurality of cells each including an electrolyte membrane, a cathode, an anode, and a separator. The electrolyte membrane is, for example, a proton-conductive ion exchange membrane formed of a solid polymer material such as a fluorine-based resin. The cathode and the anode are both formed of carbon cloth woven from carbon fibers. The separator is formed of a gas-impermeable conductive member such as dense carbon which is made gas-impermeable by compressing carbon. A flow path for the fuel gas and the oxidizing gas is formed between the cathode and the anode.

The components of the fuel cell system 60 are connected as follows. The methanol tank 61 is connected to the evaporator 65 by a pipe. The pump P2 provided in the middle of the pipe supplies methanol, which is a raw fuel, to the evaporator 65 while adjusting the flow rate. The water tank 62 is similarly connected to the evaporator 65 by piping. The pump P3 provided in the middle of the pipe supplies water to the evaporator 65 while adjusting the flow rate. The methanol pipe and the water pipe merge into one pipe downstream of the pumps P2 and P3, respectively, and are connected to the evaporator 65.

The evaporator 65 vaporizes the supplied methanol and water. The evaporator 65 is provided with a burner 63 and a compressor 64. The evaporator 65 boils and vaporizes methanol and water by the combustion gas supplied from the burner 63. The fuel of the burner 63 is methanol. The methanol tank 61 is connected to the burner 63 in addition to the evaporator 65 by piping. Methanol is supplied to a burner 63 by a pump P1 provided in the middle of the pipe.
Supplied to The burner 63 also has a fuel cell 60A.
Fuel exhaust gas not consumed by the electrochemical reaction in the above is also supplied. The burner 63 mainly burns the latter of methanol and fuel exhaust gas. The combustion temperature of the burner 63 is controlled based on the output of the sensor T1.
It is kept between 0 ° C and 1000 ° C. The combustion gas of the burner 63 rotates the turbine when being transferred to the evaporator 65,
The compressor 64 is driven. The compressor 64 takes in air from outside the fuel cell system 60, compresses the air, and supplies the compressed air to the anode side of the fuel cell 60A.

The evaporator 65 and the reformer 66 are connected by a pipe. The raw fuel gas obtained in the evaporator 65, that is, a mixed gas of methanol and steam, is transported to the reformer 66. The reformer 66 reforms the supplied raw fuel gas composed of methanol and water to generate a hydrogen-rich fuel gas. A temperature sensor T2 is provided in the middle of the transfer pipe from the evaporator 65 to the reformer 66, and the amount of methanol supplied to the burner 63 is controlled so that the temperature is normally a predetermined value of about 250 ° C. Controlled. Note that oxygen is involved in the reforming reaction in the reformer 66. In order to supply oxygen required for the reforming reaction, the reformer 66 is provided with a blower 68 for supplying air from outside.

The reformer 66 and the CO reducing section 67 are connected by a pipe. The hydrogen-rich fuel gas obtained in the reformer 66 is supplied to the CO reduction unit 67. In the reaction process in the reformer 66, usually, carbon monoxide (C
O) is contained in a certain amount. The CO reduction unit 67 reduces the concentration of carbon monoxide in the fuel gas. This is because, in a polymer electrolyte fuel cell, carbon monoxide contained in the fuel gas inhibits the reaction at the anode and lowers the performance of the fuel cell. The CO reduction unit 67 reduces the concentration of carbon monoxide by oxidizing carbon monoxide in the fuel gas to carbon dioxide.

The CO reducing section 67 and the anode of the fuel cell 60A are connected by a pipe. The fuel gas having a reduced carbon monoxide concentration is subjected to a cell reaction on the cathode side of the fuel cell 60A. Further, as described above, the fuel cell 6
A pipe for sending compressed air is connected to the cathode side of 0A. This air is supplied to the cell reaction on the anode side of the fuel cell 60A as an oxidizing gas.

The fuel cell system 60 having the above configuration
Can supply power by a chemical reaction using methanol and water. In the present embodiment, the operation state of the fuel cell is controlled according to the remaining amounts of methanol and water in the methanol tank 61 and the water tank 62. In order to realize such control, a capacity sensor 61 is provided in each tank.
a, 62a are provided. In the present embodiment, the fuel cell system 60 using methanol and water is mounted. However, the fuel cell system 60 is not limited to this. For example, gasoline / natural gas reforming, fuel cell using pure hydrogen, etc. Various configurations can be applied.

In the following description, the fuel cell system 6
0 are collectively referred to as a fuel cell 60. Also,
Methanol and water used for power generation by the fuel cell are collectively called FC fuel. Both capacities are not always the same. In the following description, the FC fuel amount means a capacity on a side that restricts power generation by the fuel cell. In other words, it means the capacity of methanol and water on the side that runs short first when power generation is continued.

FIG. 3 is an explanatory diagram showing the internal structure of the transmission 100. As illustrated, the transmission 100 includes a torque converter 30 and a stepped transmission mechanism including a plurality of gears, clutches, one-way clutches, brakes, and the like. The torque converter 30 is a known power transmission mechanism using a fluid. Motor 20 corresponding to the power input shaft
The turbine 31 coupled to the rotary shaft 13 of the first and second turbines and the turbine 32 coupled to the intermediate rotary shaft 14 are rotatable in a state in which they slide with respect to each other in the container in which the fluid is sealed. While transmitting power. The torque converter 30 is also provided with a lock-up clutch 33 that couples the rotating shafts 13 and 14 under predetermined conditions so that the rotating shafts 13 and 14 do not slip. ON / OFF of the lock-up clutch is controlled by the control unit 70.

The power transmitted through the torque converter 30 is converted into a torque by a stepped transmission mechanism. The transmission mechanism mainly includes a subtransmission unit 110 (a part on the left side of the broken line in the figure) and a main transmission unit 120 (a part on the right side of the broken line in the figure). A shift speed can be realized.

The structure of the transmission 100 will be described in order from the rotating shaft 14 side. As shown in the figure, the power input from the rotating shaft 14 is transmitted to the rotating shaft 119 after being shifted at a predetermined gear ratio by a subtransmission unit 110 configured as an overdrive unit. The auxiliary transmission unit 110 is configured by a clutch C0, a one-way clutch F0, and a brake B0 centering on a single-pinion type first planetary gear 112. The first planetary gear 112 is a gear also referred to as a planetary gear, and includes three types of gears: a sun gear 114 that rotates at the center, a planetary pinion gear 115 that revolves while rotating around the sun gear, and a ring gear 118 that rotates around the outer periphery of the planetary pinion gear. It is composed of The planetary pinion gear 115 is supported by a rotating part called a planetary carrier 116.

In the auxiliary transmission section 110, the rotating shaft 14 corresponding to the input shaft of the transmission 100 is connected to the planetary carrier 116. A one-way clutch F0 and a clutch C0 are arranged in parallel between the planetary carrier 116 and the sun gear 114. The one-way clutch F0 is provided in a direction in which the sun gear 114 is engaged when the sun gear 114 rotates forward relative to the planetary carrier 116, that is, when the sun gear 114 rotates in the same direction as the input shaft 14 to the transmission.
The sun gear 114 is provided with a multi-disc brake B0 that can stop the rotation. A ring gear 118 corresponding to the output of the subtransmission unit 110 is connected to the rotation shaft 119. The rotation shaft 119 corresponds to an input shaft of the main transmission unit 120.

The main transmission unit 120 includes three sets of planetary gears 1.
30, 140 and 150 are provided. Also, clutch C
1, C2, one-way clutches F1 and F2, and brakes B1 to B4. Each planetary gear includes a sun gear, a planetary carrier, a planetary pinion gear, and a ring gear, like the first planetary gear 112 provided in the subtransmission unit 110.
The three planetary gears 130, 140, 150 are connected as follows.

Sun gear 1 of second planetary gear 130
32 and the sun gear 142 of the third planetary gear 140 are integrally connected to each other.
2 can be coupled to the input shaft 119. On the rotation shaft to which these sun gears 132 and 142 are connected,
A brake B1 for stopping the rotation is provided. In addition, a one-way clutch F1 is provided in a direction in which the rotation shaft is engaged when the rotation shaft reversely rotates. Further, a brake B for stopping rotation of the one-way clutch F1
2 are provided.

The planetary carrier 134 of the second planetary gear 130 is provided with a brake B capable of stopping its rotation.
3 are provided. The ring gear 136 of the second planetary gear 130 is connected to the planetary carrier 144 of the third planetary gear 140 and the fourth planetary gear 15.
0 and the planetary carrier 154. Furthermore, these three are coupled to the output shaft 15 of the transmission 100.

The ring gear 146 of the third planetary gear 140 is connected to the sun gear 15 of the fourth planetary gear 150.
2 and to the rotating shaft 122. The rotating shaft 122 is connected to the main transmission unit 12 via the clutch C1.
0 can be coupled to the input shaft 119. The ring gear 156 of the fourth planetary gear 150 is provided with a brake B4 for stopping the rotation thereof and a one-way clutch F2 in a direction in which the ring gear 156 is engaged when the ring gear 156 reversely rotates.

The clutches C0 to C2 and the brakes B0 to B4 provided in the transmission 100 are engaged and released by hydraulic pressure, respectively. As shown in FIG. 1, hydraulic oil for operating these clutches and brakes is supplied to the transmission 100 from an electric hydraulic pump 102. Although not shown in detail, the transmission 100
Has a hydraulic control unit 104 provided with a hydraulic pipe enabling operation, a solenoid valve for controlling hydraulic pressure, and the like.
Thus, the hydraulic pressure can be controlled. In the hybrid vehicle of the present embodiment, the control unit 70
The operation of each clutch and brake is controlled by outputting a control signal to a solenoid valve in 4.

The transmission 100 of this embodiment has a clutch C0
C5 and the engagement and disengagement of the brakes B0 to B4 can be set to five forward speeds and one reverse speed (R). Regarding the forward movement, 1st is the low speed side and 5th is the high speed side. Also, a so-called parking (P) and neutral (N) state can be realized. FIG. 4 is an explanatory diagram showing the relationship between the engagement state of each clutch, brake, and one-way clutch and the shift speed. In this figure, ○ means that the clutch or the like is engaged, ◎ means that it is engaged at the time of power source braking, and △ means that it is engaged but does not affect power transmission. Means. What is power source braking?
This refers to braking by the engine 10 and the motor 20. Note that the engagement states of the one-way clutches F0 to F2 are not based on the control signal of the control unit 70, but based on the rotation direction of each gear. A mechanism having more and fewer shift stages may be applied. The gear ratio can also be set to various values. Note that the driver can change the range of the shift speed used during traveling by operating the shift lever provided beside the driver's seat.

In the hybrid vehicle of this embodiment, the power output from the power source such as the engine 10 is also used for driving the auxiliary equipment. As shown in FIG. 1, an accessory drive device 82 is connected to the engine 10. The auxiliary equipment includes a compressor for an air conditioner, a pump for power steering, and the like. Here, the accessories driven using the power of the engine 10 are collectively shown as an accessory drive 82. The accessory drive device 82 is specifically connected via a belt to a pulley provided on the crankshaft of the engine 10 via the accessory clutch 19, and is driven by the rotational power of the crankshaft.

The accessory driving device 82 is also connected with an accessory driving motor 80. Auxiliary drive motor 80
Is connected to the fuel cell 60 and the battery 50 via the changeover switch 83. The auxiliary drive motor 80 is
It has a configuration similar to that of the motor 20, is driven by the power of the engine 10, and can generate power. The electric power generated by the accessory driving motor 80 can charge the battery 50. Further, the accessory driving motor 80 is
Powering can also be performed by receiving power supply from the battery 50 and the fuel cell 60. In the hybrid vehicle of the present embodiment, the operation of the engine 10 is stopped under predetermined conditions, as described later. By powering the accessory driving motor 80, the accessory driving device 8
2 can be driven. Of course, when the engine 10 is stopped, the input clutch 18 is turned on,
The accessory drive device 82 may be driven by the power of the motor 20. When the accessory is driven by the accessory drive motor 80, the accessory clutch 19 between the engine 10 and the accessory drive 82 is released to reduce the burden.

In the hybrid vehicle of this embodiment, the control unit 70 controls the operation of the engine 10, the motor 20, the transmission 100, the auxiliary drive motor 80, and the like (FIG. 1).
reference). The control unit 70 includes a CPU, a RAM,
This is a one-chip microcomputer including a ROM and the like, and a CPU performs various control processes described later according to a program recorded in the ROM. Various signals are input to the control unit 70 in order to realize such control. FIG. 1 shows a vehicle speed sensor 7 as a representative input.
1, inputs from the accelerator position sensor 72 and the remaining battery capacity sensor 73 are shown. As shown in FIG. 2, the control unit 70 includes tank capacity sensors 61a and 61a.
2a is also input. In addition, signals from various sensor signals are input, but are not shown.

B. General operation: Next, a general operation of the hybrid vehicle of the present embodiment will be described. As described above with reference to FIG. 1, the hybrid vehicle of the present embodiment includes the engine 10 and the motor 20 as power sources. The control unit 70 travels by selectively using both according to the traveling state of the vehicle, that is, the required torque determined according to the vehicle speed and the accelerator opening. The proper use of both is set in advance as a map and stored in the ROM in the control unit 70.

FIG. 5 is an explanatory diagram showing the relationship between the running state of the vehicle and the power source. A region MG in the drawing is a region where the vehicle runs using the motor 20 as a power source. An area outside the area MG is an area in which the engine 20 is used as a main power source and the motor 20 performs torque assist to travel. Hereinafter, the former is referred to as EV traveling, and the latter is referred to as normal traveling.

The hybrid vehicle starts in EV running. In such a region, the vehicle travels with the input clutch 18 turned off. When the traveling state of the vehicle determined by the vehicle speed and the accelerator opening reaches near the boundary of region MG in the map of FIG. 5, control unit 70 turns on input clutch 18 and starts engine 10. When the input clutch 18 is turned on, the engine 10 is rotated by the motor 20. The control unit 70 controls the engine 10
The fuel is injected and ignited at the timing when the number of revolutions of the motor increases to a predetermined value. After the engine 10 is started in this way, the vehicle runs in the region EG with the engine 10 as the main power source.
The control unit 70 sets the power distribution between the engine 10 and the motor 20 based on predetermined conditions described later and controls the respective operations so as to output the required power determined from the vehicle speed and the accelerator opening. What is set here is
The power to be output from the engine 10 and the motor 20. Both operating points, that is, the rotational speed and the torque, are finally determined according to the speed ratio of the transmission 100.

The control unit 70 controls the transmission 100 as well as the power source. To change gears,
This is performed based on a map set in advance for the running state of the vehicle. The map differs depending on the shift position. FIG. 5 shows a map in a shift position in which all five gears are used. As shown in the map, the control unit 70 executes the gear change so that the gear ratio decreases as the vehicle speed increases.

In this embodiment, the gear ratio is determined in consideration of not only the vehicle speed and the accelerator opening, but also the assist torque output from the motor 20 to the axle 17. If the vehicle speed is determined, the relationship between the power output from the motor 20 and the assist torque to be output from the motor 20 to the axle 17 is uniquely determined. Therefore, the gear ratio is determined in consideration of the required power of the motor 20. You may do it. Regardless of the axle 17, the torque of any drive shaft located downstream of the transmission 100 may be used. As shown in FIG. 5, a map for giving the gear ratio is prepared according to the assist torque of the motor 20. In the figure, maps corresponding to three stages of assist torque are shown. A curve T0 indicated by a solid line is a map when the assist torque is very small, that is, when the vehicle runs almost only with the engine power. A curve TM indicated by a broken line is a map when the assist torque is medium. A curve TL indicated by a chain line is a map when the assist torque is large. As the assist torque increases, a higher gear position is set to be used in a lower vehicle speed, higher accelerator opening side region. Here, a map corresponding to three stages of assist torque is illustrated, but more maps may be prepared. A map that changes continuously with the assist torque may be used.

Control of the transmission 100 includes control of the lock-up clutch 33 in addition to the gear ratio. Normally, the torque converter 30 transmits power while the lock-up clutch 33 is disengaged and the turbines 31 and 32 are slid. However, under a predetermined condition in which a higher gear is used,
The lock-up clutch 33 is engaged. By performing lock-up, power loss due to slippage between the turbines 31 and 32 can be avoided, so that fuel efficiency can be improved. Lock-up is performed according to a prepared map. FIG. 6 is an explanatory diagram showing a map for lockup control. For the 5th speed, for a traveling state determined by the vehicle speed and the accelerator opening,
The boundary between the engagement area and the release area of the lock-up clutch 33 is shown. Lock-up may be performed at 4th or the like. For example, the area on the right side of the straight line T0 in the figure is:
This is an area where the lock-up clutch 33 is engaged. In this embodiment, a lock-up map is also prepared according to the assist torque to be output from the motor 20 to the axle 17. In the figure, a map corresponding to three stages of assist torque is illustrated. A straight line T0 is a map when the assist torque is very small, a straight line TM is a map when the assist torque is medium, and a straight line TL is a map when the assist torque is large. The lock-up region is set to be wider as the assist torque increases.

The reason why the gear ratio and the lockup region are switched according to the assist torque will be described. Fig. 5
Consider a case in which the vehicle is in a running state indicated by a middle point P. FIG.
FIG. 4 is an explanatory diagram illustrating a relationship between power distribution and a gear ratio. The vertical axis represents the torque output to the axle 17. CAS
As E1, the case where the assist torque of the motor 20 is relatively large is illustrated. The hatched area TL in the figure
Corresponds to the assist torque of the motor 20. CASE2
As an example, the case where the assist torque of the motor 20 is 0 is illustrated. Axle 1 from both engine 10 and motor 20
The total torque to be output to 7 is uniquely set according to the running state of the vehicle. Therefore, CASE1 and CASE2
Are different in the distribution of the output torque of the engine 10 and the motor 20 under the condition that the required torque is constant. In CASE1, the output torque of the engine 10 is relatively small (region T1 in the drawing), and in CASE2, it is relatively large (region T2 in the drawing).

On the other hand, the torque that can be output from the engine 10 has an upper limit. The right side shows the relationship between the torque that can be output only by the engine 10 and the shift speed. 5 as shown
Only relatively low torque can be output to the axle 17 at the th gear, and the 5th gear is selected by selecting the 4th gear.
The above torque can be output to the axle 17.

Here, the relationship between the magnitude of the assist torque and the gear ratio will be described. In the case of CASE2, the torque T2 to be output from the engine exceeds the range that can be output at 5th. If 5th is selected as the shift speed in such a state, the engine 10 cannot rotate smoothly and is accompanied by large vibration. Therefore, in the case of CASE2, it is desirable to select the fourth speed. On the other hand, in CASE1, the torque T1 to be output from the engine is in a range that can be output at 5th. Of course, it is possible to output even at 4th. In such a case, if 4th is selected as the shift speed, the engine 10 is operated with a relatively low torque and a high rotation speed. Generally, in such an operation state, the operation efficiency is low. 5th
Is selected as the gear position, the required torque can be output while operating the engine 10 at an operation point having a relatively high operation efficiency. As described above, by properly using the shift speed in accordance with the assist torque of the motor 20, the engine 10 can be operated stably, and the fuel consumption can be improved while reducing the vibration during the operation.

FIG. 7 has been described by taking as an example the use of different gears. The same applies to the lock-up area. Since the torque converter 30 is a mechanism for increasing the torque by slipping between the turbines 31 and 32, the motor 20
The necessity of increasing the torque changes for the same reason as shown in FIG. Therefore, by changing the lock-up region according to the assist torque, the engine 10 can be operated stably, and the fuel consumption can be improved while reducing the vibration during the operation.

C. Traveling control processing: Traveling control using the maps of FIGS. 5 and 6 properly is realized by the following processing. FIG. 8 is a flowchart of a traveling control processing routine. This is control processing when the vehicle runs using the engine 10 and the motor 20 as power sources, and is processing that the CPU of the control unit 70 repeatedly executes together with other control processing.

When this process is started, the CPU inputs the running state of the vehicle, that is, the vehicle speed and the accelerator opening (step S10). Further, it is determined whether or not sufficient FC fuel remains (step S12). In this embodiment,
The judgment is made based on the magnitude relationship between a predetermined value set in advance and the FC fuel. In the present embodiment, the fuel cell 60 is
Since the fuel cell is used as the main power source of 0, the assist by the motor 20 is not performed when the FC fuel does not remain sufficiently. Accordingly, the CPU does not consider the assist torque to be output from the motor 20 to the axle 17 (hereinafter, referred to as a “base shift map”) and a lockup map (hereinafter, referred to as a “base lockup map”). The operation state of the transmission 100 is set on the basis of (step S20). The base shift map and the base lockup map correspond to the maps shown by solid lines in FIGS. Step S10 is for determining whether or not the fuel cell 60 is in a state capable of generating power.
In addition to the C fuel, the warm-up state of the fuel cell 60 and the presence / absence of a failure may be determined to determine whether or not the power can be generated.

When it is determined that sufficient FC fuel remains (step S12), the vehicle travels with the assistance of the motor 20. For this reason, the CPU calculates the assist amount of the motor 20 based on the map (step S1).
4). FIG. 9 is an explanatory diagram of a map for providing a distribution of torque output from the engine 10 and the motor 20 to the axle 17. The map at a specific vehicle speed is illustrated. As shown, the required torque to be output from the axle 17 is set according to the accelerator opening. The map stores the torque of the engine 10 and the torque of the motor 20 to achieve the required torque. The curve EL in the figure is an example, and the area below the curve EL is the engine torque,
The upper region corresponds to the assist torque.

In this embodiment, the relationship between the engine torque and the assist torque changes according to the power generation capacity of the fuel cell 60. That is, the map of FIG. 9 is prepared according to the power generation capacity of the fuel cell 60. In this embodiment, the power generation capacity is represented by using the remaining amount of the FC fuel as a parameter. In the figure,
The maps ES, EM, and EL corresponding to the three levels of power generation capacity are shown. When the power generation capacity is low, the map ES is used to suppress the assist torque. When the power generation capacity is high, the map EL is used to increase the assist torque and utilize the motor 20. When the power generation capacity is medium, a map EM between the two is used. Here, a map corresponding to three levels of power generation capacity is illustrated, but more maps may be prepared. Further, a map in which the assist torque becomes 0, that is, a map that matches the curve of the required torque may be used.

In step S14 of FIG. 8, the assist torque Tm of the motor 20 is set with reference to the map of FIG. 9 according to the remaining amount of FC fuel. When the assist torque Tm set in this way is larger than the predetermined value Ta (step S16), the CPU sets the operation state of the transmission 100 by properly using the shift map and the lockup map according to the assist torque (step S16). Step S18). As described above with reference to FIGS. 5 and 6, as the assist torque increases, the speed ratio on the high-speed side is utilized in a wider range, and the lock-up clutch 3 is extended in a wider range.
3 is controlled.

On the other hand, when the assist torque Tm has a predetermined value Ta
If it is below (step S16), the map is not properly used according to the assist torque. That is, the operation state of the transmission 100 is set according to the base shift map and the base lockup map (step S20). Switching between the shift map and the lockup map has a considerable effect on the driving feeling, and also complicates the control processing. Therefore, in the present embodiment, when the assist torque is small, it is determined that the advantage of properly using the maps cannot be sufficiently obtained, and the base shift map and the base lockup map are used. Even when the assist torque is small, it is of course possible to adopt a mode in which the map is properly used. The predetermined value Ta used in step S16 is a value set based on such a purpose, and is set to a very small value in the present embodiment.

When the operating state of the transmission 100 is set according to each situation in this way, the CPU sets the transmission 1
00 and the operation of the motor 20 and the engine 10 are controlled (step S22). Motor 20 and engine 10
Are driven to output the required torque with the torque distribution set in step S14. When the FC fuel does not remain sufficiently, the engine 10 is operated so that all the required torques shown in FIG. Since the control method of the motor 20 and the engine 10 is well known, the description is omitted. The control of the transmission 100 is performed with a predetermined hysteresis.

By repeatedly executing the above processing, the vehicle of the present application can run using the engine 10 and the motor 20 as power sources. Here, the control in the normal traveling region in FIG. 5 has been described as an example, but the process in FIG. 8 is also applicable to the control in the MG region. In the MG range, the vehicle runs in principle using only the motor 20 as a power source.
The mode can be switched to a mode in which the vehicle travels with the torque assisted by the motor 20 while using the engine 10 as a power source.
In the MG region, when such an operation mode is applied,
The control processing of this embodiment shown in FIG. 8 can be applied as it is.

According to the hybrid vehicle of the present embodiment described above, the operation state of the transmission 100 can be changed according to the assist torque of the motor 20. As a result, according to the change in the power distribution between the engine 10 and the motor 20, both suppression of vibration and improvement of fuel efficiency can be achieved.

In the hybrid vehicle of this embodiment, when the assist torque is small or when the fuel cell 60 cannot generate power, the transmission 100 is not dependent on the assist torque.
Control. That is, the effect of the assist torque on the control of the transmission 100 is switched according to the magnitude of the assist torque. By doing so, the vehicle according to the present embodiment can realize control that can obtain the advantages of vibration suppression and improved fuel efficiency while suppressing the influence on the driving sensation caused by switching the control of the transmission 100. In the example,
The transmission 100 according to the torque to be output to the axle 17
The case where the control is performed is illustrated. If the vehicle speed is determined, the relationship between the power output from the power source such as the motor 20 and the torque output to the axle 17 is uniquely determined. Therefore, the control exemplified in the embodiment may be realized using the target power to be output from the engine 10 and the motor 20 as a parameter.

D. Modified Example: In the embodiment, the example in which the control mode of the transmission 100 is changed according to the magnitude of the assist torque has been described. A configuration may be employed in which the driver can manually select whether to change the control of the transmission 100 by the assist torque. For example, an operation mode changeover switch is provided in the vicinity of the shift lever, and the control of the embodiment is executed when the operation mode giving priority to fuel consumption is selected, and the base is always executed when the operation mode giving priority to torque is selected. A shift map and a base lockup map may be used.

The embodiment has exemplified the case where the stepped transmission 100 is used. The present invention is also applicable to a configuration using a so-called continuously variable transmission. In this case, in the map of FIG. 5, instead of giving the gear, the gear ratio may be given.

The present invention can be applied not only to the configuration shown in FIG. 1 but also to vehicles having various configurations. The transmission 100 may be provided between the engine 10 and the motor 20. The power transmission path from the motor 20 to the axle 17 may be provided in parallel with the power transmission path from the engine 10 to the axle 17.

In the embodiment, the case where the fuel cell 60 is used as the main power supply has been exemplified. On the other hand, the battery 50 may be used as the main power source, or the fuel cell 60 and the battery 5 may be used.
Instead of 0, another power storage means such as a capacitor may be used as a power supply. In the embodiment, the case where two types of power supplies are provided is illustrated, but only one type may be provided.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and may be implemented in various other forms without departing from the gist of the present invention. Obviously you can get it.
For example, although the gasoline engine is used in the hybrid vehicle of the present embodiment, a diesel engine or another heat engine can be used. In the present embodiment, a three-phase synchronous motor is used as a motor, but an induction motor or another AC motor or a DC motor may be used. In the present embodiment, various control processes are realized by executing software by the CPU, but such control processes may be realized by hardware.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hybrid vehicle as an embodiment.

FIG. 2 is an explanatory diagram showing a schematic configuration of a fuel cell system.

FIG. 3 is an explanatory diagram showing an internal structure of the transmission 100.

FIG. 4 is an explanatory diagram showing the relationship between the engagement state of each clutch, brake, and one-way clutch and the shift speed.

FIG. 5 is an explanatory diagram showing a relationship between a traveling state of a vehicle and a power source.

FIG. 6 is an explanatory diagram showing a map for lock-up control.

FIG. 7 is an explanatory diagram showing a relationship between power distribution and a gear ratio.

FIG. 8 is a flowchart of a traveling control processing routine.

FIG. 9 is an explanatory diagram of a map for giving a torque distribution between the engine 10 and the motor 20.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Crankshaft 13, 14 ... Rotating shaft 15 ... Output shaft 16 ... Differential gear 17 ... Axle 18 ... Input clutch 19 ... Auxiliary clutch 20 ... Motor 22 ... Rotor 24 ... Stator 30 ... Torque converter 31, 32 ... Turbine 33 Lock-up clutch 50 Battery 51, 52 Drive circuit 60, 60A Fuel cell 61 Methanol tank 62 Water tank 61a, 62a Capacity sensor 63 Burner 64 Compressor 65 Evaporator 66 Reforming Instrument 68 ... Blower 70 ... Control unit 71 ... Vehicle speed sensor 72 ... Accelerator position sensor 73 ... Remaining capacity sensor 80 ... Auxiliary equipment driving motor 82 ... Auxiliary equipment driving device 83,84 ... Changeover switch 100 ... Transmission 102 ... Hydraulic pump 104 ... Hydraulic control unit 110 ... Sub transmission unit 112 First planetary gear 114 Sun gear 115 Planetary pinion gear 116 Planetary carrier 118 Ring gear 119 Rotary shaft 120 Main transmission section 122 Rotary shaft 130 Second planetary gear 132 Sun gear 134 Planetary carrier 136 Ring gear 140 3 planetary gear 142 ... sun gear 144 ... planetary carrier 146 ... ring gear 150 ... fourth planetary gear 152 ... sun gear 154 ... planetary carrier 156 ... ring gear

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B60L 11/14 B60L 11/18 G 11/18 15/20 K 15/20 F02D 29/02 ZHVD F02D 29 / 02 ZHV F16H 61/14 601J F16H 61/14 601 B60K 9/00 EF term (reference) 3D041 AA01 AA26 AA53 AB01 AC01 AC09 AC15 AC18 AD01 AD02 AD10 AD31 AD51 AE02 AE03 AE22 AE31 3G093 AA01 DBA03 A0701 EB03 EC02 FA10 3J053 CA03 CB03 CB14 5H115 PA01 PA12 PC06 PG04 PI16 PI18 PI22 PI29 PI30 PU02 PU09 PU10 PU23 QA01 RB17 RB22 RE03 SE04 SE05 SE08

Claims (9)

[Claims] A heat engine and an electric motor as power sources;
A hybrid vehicle including a transmission capable of changing a gear ratio when transmitting power of the heat engine to a drive shaft, a target power setting means for setting respective target powers of the heat engine and the electric motor, Transmission control means for controlling an operation state of the transmission in consideration of a relationship between a target power of a heat engine and a target power of the electric motor; and controlling operations of the heat engine and the electric motor to output the target power. A hybrid vehicle comprising control means. 2. The hybrid vehicle according to claim 1, wherein the transmission control unit performs the control in consideration of a ratio or a difference between a target power of the heat engine and a target power of the electric motor. A hybrid vehicle. 3. A heat engine and an electric motor as power sources,
A hybrid vehicle including a transmission capable of changing a gear ratio when transmitting power of the heat engine to a drive shaft, a target torque setting means for setting respective target torques of the heat engine and the electric motor; Transmission control means for controlling an operation state of the transmission in consideration of a relationship between a target torque of a heat engine and a target torque of the electric motor; and controlling operations of the heat engine and the electric motor to output the target power. A hybrid vehicle comprising control means. 4. The hybrid vehicle according to claim 3, wherein the transmission control unit performs the control in consideration of a ratio or a difference between a target torque of the heat engine and a target torque of the electric motor. A hybrid vehicle. 5. The hybrid vehicle according to claim 1, wherein the transmission control means controls a traveling state of the vehicle and a gear ratio according to a relationship between a target power of the heat engine and a target power of the electric motor. Is a means for performing the control by changing the relationship. 6. The hybrid vehicle according to claim 1, wherein the transmission includes a fluid coupling provided between two rotation shafts, and a suppression mechanism that suppresses slippage of the fluid coupling. A hybrid vehicle which is a means for performing the control by changing a range of a running state in which slippage of the fluid coupling is to be suppressed in accordance with a relationship between a target power of the heat engine and a target power of the electric motor. . 7. The hybrid vehicle according to claim 1, further comprising a fuel cell as a power supply for the electric motor. 8. The hybrid vehicle according to claim 1, wherein said power supply capability detecting means detects a power supply capability of a power supply of said electric motor, and said shift is performed when said power supply capability is a predetermined value or less. A hybrid vehicle comprising: a prohibition unit that prohibits the machine control unit from performing control in consideration of a relationship between a target power of the heat engine and a target power of the electric motor. 9. A heat engine and an electric motor as power sources,
A method for controlling a hybrid vehicle including a transmission capable of changing a gear ratio when transmitting power of the heat engine to a drive shaft, comprising: (a) setting a target power of each of the heat engine and the electric motor; (B) controlling the operating state of the transmission in consideration of the relationship between the target power of the heat engine and the target power of the electric motor; and (c) controlling the operation of the heat engine and the electric motor to output the target power. Controlling the operation of the hybrid vehicle.