JP2000233667A - Hybrid vehicle and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the fluctuation of driving feeling caused by switching of power sources used during a travel in a hybrid vehicle. SOLUTION: An engine 10, a motor 20, a torque converter 30, a transmission 100 and an axle 17 are connected in series to form the power system of a vehicle. A control unit switches power sources and gear ratios according to the state of the vehicle speed, accelerator opening and battery. The gear shift stage is set to the first speed when the vehicle is started by the motor 20, it is set to the second speed when the vehicle is started by the engine 10, i.e., a gear shift stage with a low gear ratio is adapted when a power source with large output torque is used. The fluctuation of the torque outputted to the axle caused by the switching of the power sources can be suppressed, and the sense of incompatibility during driving can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle including an engine and an electric motor as power sources, and a transmission, and a control method thereof.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles using an engine and an electric motor as power sources have been proposed. For example, JP-A-9
The hybrid vehicle described in -37407 has a configuration in which an electric motor is added in series between an engine and a transmission with respect to a power system of a normal vehicle in which an output shaft of an engine is coupled to a drive shaft via a transmission. It is a vehicle. According to such a configuration, it is possible to travel by using two power sources of the engine and the electric motor properly. Generally, when the vehicle starts moving, the fuel efficiency of the engine is poor. The hybrid vehicle starts using the power of the electric motor to avoid such driving. After the vehicle reaches a predetermined speed, the engine is started and the vehicle runs using the power. Therefore, the hybrid vehicle can improve fuel efficiency at the time of starting.

[0003] Such a hybrid vehicle can be started using an engine as a power source. Electric power is required for starting using an electric motor as a power source. Therefore, the hybrid vehicle having the above-described configuration usually starts with the electric motor as the power source when the remaining battery capacity is sufficient, and starts with the engine as the power source when the remaining battery capacity is insufficient. .

[0004]

In such a hybrid vehicle that travels by using different power sources, the driver can drive without discomfort regardless of the type of power source selected according to conditions such as the remaining capacity of the battery. Preferably it is possible. That is, it is desirable that the amount of operation of the accelerator and the feeling of acceleration of the vehicle be equal between the case where the engine is used as the power source and the case where the electric motor is used as the power source.

[0005] However, the conventional hybrid vehicle is equipped with any power source and transmission from such a viewpoint.
There was not enough consideration on how to control. In a hybrid vehicle having an electric motor as an auxiliary power source at the time of starting, it is preferable to mount a small electric motor having a relatively small output torque suitable for the purpose. In a conventional hybrid vehicle, as a result of reducing the size of the electric motor, the driving sensation sometimes significantly changes depending on the type of power source used during traveling. Such changes are:
This caused a sense of discomfort while driving, which impaired the operability of the hybrid vehicle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and in a hybrid vehicle that runs by selectively using an engine and an electric motor as power sources, driving sensation caused by the type of power source is provided. It is an object of the present invention to provide a hybrid vehicle in which the fluctuation of the vehicle is suppressed and a control method therefor.

[0007]

Means for Solving the Problems and Their Functions and Effects In order to solve at least a part of the above-mentioned problems, the present invention has the following configuration. An engine and an electric motor are provided as power sources, and the power source, a transmission capable of selecting a plurality of speed ratios at the time of power transmission, and a drive shaft are coupled, and output from the power source according to an accelerator opening. A hybrid vehicle capable of traveling by adjusting power, detecting means for detecting the accelerator opening, and when starting the vehicle, when the accelerator opening is larger than the first opening, the engine is activated. Power source selecting means for selecting one of the engine and the electric motor as a power source based on predetermined conditions when the accelerator opening is selected to be a power source and the accelerator opening is equal to or less than the first opening; A transmission that switches the first transmission ratio or a second transmission ratio smaller than the first transmission ratio by controlling the transmission according to the selection of the power source and the accelerator opening. Control means and the power And a power source control unit that operates in an operation state corresponding to the accelerator opening, wherein the transmission control unit is configured to control the first gear ratio when the electric motor is selected as a power source. Is selected, and when the engine is selected as the power source, if the accelerator opening is equal to or less than the second opening, the second gear ratio is selected, and the accelerator opening is set to the second opening. If the degree is larger than the degree, the gist is that it is means for selecting the first gear ratio.

In such a hybrid vehicle, the transmission is controlled in accordance with the type of power source and the accelerator opening when the vehicle starts. At this time, at a specific accelerator opening, the second speed ratio selected when using the engine as the power source is smaller than the first speed ratio selected when using the electric motor as the power source. Generally, when the accelerator opening is fixed,
The output torque of the engine is larger than the output torque of the electric motor. According to the present invention, when the engine is the power source, by reducing the gear ratio, it is possible to reduce discomfort during operation due to the type of the power source. When a motor is used as a power source, a large gear ratio is applied.
The motor can be downsized. On the other hand, when the accelerator opening is a high opening that is equal to or greater than the second opening, the first gear ratio is used while using the engine as a power source, so that a sufficient torque according to the driver's request is output. Can be. As a result, according to the hybrid vehicle of the present invention, it is possible to reduce the driver's discomfort due to the switching of the power source used during traveling, and to improve the operability of the hybrid vehicle.

The effect of suppressing discomfort due to the type of power source will be specifically described. FIG. 1 is an explanatory diagram showing the relationship between the power source torque, the drive shaft torque, and the gear ratio in such a case. Here, a case has been exemplified in which the gear ratio can take a value of four steps in which the gear ratio becomes smaller in the order of k1, k2, k3, and k4. The gear ratio corresponds to a torque ratio of the drive shaft torque to the power source torque. That is, it corresponds to the inclination of the graph when the power source torque is plotted on the horizontal axis and the drive shaft torque is plotted on the vertical axis. FIG.
As shown in FIG. 7, the slope of the graph decreases as the gear ratio decreases.

Here, it is assumed that the output torque of the electric motor is T1 and the output torque of the engine is T2 (T1 <T2). For the output torque T1 of the motor, the gear ratio is set to a value k1.
Then, the drive shaft torque becomes Tb1, and the gear ratio is set to the value k2.
Then, the drive shaft torque becomes Ta1. Ta1 is Tb1
Smaller than. On the other hand, if the gear ratio is set to the value k2 with respect to the engine output torque T2, the drive shaft torque becomes Tb2
If the gear ratio is a value k3, the drive shaft torque is Ta2
Becomes If the same gear ratio k2 is applied to the electric motor and the engine, the drive shaft torque when the electric motor is used as the power source is Ta.
On the other hand, when the engine is used as a power source, the drive shaft torque is Tb2, which is a large difference. On the other hand, when the electric motor is used as the power source, the first speed ratio k1
Is applied, and when the engine is used as a power source, if the second speed ratio k2 is applied, the drive shaft torques of both the motors become T.
b1 and Tb2, and the difference becomes small. In the hybrid vehicle according to the present invention, the use of the gear ratio according to the power source can reduce the sense of discomfort during driving.

The present invention is highly effective when a power source having different characteristics such as an engine and an electric motor is mounted. Generally, an electric motor has a characteristic of being excellent in operation efficiency at a low rotation speed. The engine has a characteristic that the output torque at the time of high speed rotation is large. On the other hand, while an electric motor can control output torque relatively easily and accurately, it is difficult for an engine to accurately control output torque when low torque is required. If the present invention is applied to a hybrid vehicle having different power source characteristics as described above, a difference in output torque that cannot be eliminated by controlling the power source can be suppressed by controlling the transmission. As a result, the operability and running stability of the hybrid vehicle can be greatly improved while taking advantage of the respective power sources.

Incidentally, it is also possible to apply k2 as the first speed ratio when the electric motor is used as the power source and to use k3 as the second speed ratio when the engine is used as the power source. However, in this case, each drive shaft torque is T
a1 and Ta2. This is smaller than the drive shaft torque Tb1 when k1 is applied as the first gear ratio. Therefore, in order to effectively use the torque output from the power source, it is preferable to set the first speed ratio to a value as large as possible.

[0013] In the hybrid vehicle of the present invention, various conditions can be set for the predetermined condition for selecting the power source. For example, when an electric motor is used as the power source, the power source may be selectively used depending on the charging state of a battery or other power storage means for supplying power to the electric motor. Further, the power source may be selectively used based on the power required during traveling. Other various conditions can be set.

The above control is performed when the vehicle starts. The starting time of the vehicle can be not only the moment when the vehicle is accelerated from the stopped state, but also a relatively low vehicle speed range up to the vehicle speed used for normal traveling. Of course, the above control may be applied not only at the time of starting the vehicle, but also at the time of normal running and acceleration.

In the hybrid vehicle of the present invention, the first opening and the second opening can be set in various ways.
It is preferable that the second opening is equal to or less than the first opening.

With this arrangement, it is possible to prevent the gear ratio from frequently changing when the vehicle starts moving. FIG. 9 is an explanatory diagram showing how the power source and the gear ratio are switched according to the accelerator opening. The value A1 in the figure corresponds to the first opening, and the value A2 corresponds to the second opening. The first speed corresponds to a first speed ratio, and the second speed corresponds to a second speed ratio. In the figure, the hatched portions indicate that the electric motor is used as the power source, and the white portions indicate that the engine is used as the power source. In the hybrid control shown in the upper part, the vehicle runs at the first speed ratio using the electric motor as the power source until the accelerator opening reaches A1. When the accelerator opening becomes A1 or more, the vehicle runs using the engine as a power source with the first gear ratio.

In the non-hybrid control shown in the lower part,
It runs with the engine as the power source. In this case, the vehicle travels at the second gear ratio until the accelerator opening reaches A2, and travels at the first gear ratio when the accelerator opening is higher. A2 is smaller than A1. In the region where the accelerator opening is A1 or less, the power source selecting means selects which of the electric motor and the engine is to be used as the power source. If it explains according to FIG. 9, it will drive by using hybrid control and non-hybrid control selectively according to predetermined conditions. The choice between the two may change after the launch begins.

Consider a case where the power sources are properly used according to the path pa1 in the figure. In this case, the vehicle initially starts using the electric motor as the power source at the first gear ratio in accordance with the hybrid control. Thereafter, when the mode is switched to the non-hybrid control, the mode is switched to the running using the engine as the power source at the first gear ratio. Although the power source is switched, the gear ratio is not switched.

On the other hand, FIG. 10 shows a case where "A1 <A2". It is assumed that the map is properly used according to the locus pa2 in FIG. In this case, the vehicle initially runs using the electric motor as the power source at the first gear ratio according to the hybrid control. Thereafter, when switching to the non-hybrid control, the vehicle switches to running using the engine as a power source at the second speed ratio. At this time, switching of the power source and switching of the gear ratio occur simultaneously. Further, when the accelerator opening increases, the speed ratio is switched to the first speed ratio again. In other words, the gear ratio can be set to “the first gear ratio → the second gear ratio → the first gear ratio” in a relatively short time.
Will be switched frequently.

By setting the second opening to a value equal to or less than the first opening, frequent switching of the gear ratio can be avoided even when the power source is changed during traveling. In the above-described example, the case where the first opening and the second opening are set to different values is illustrated, but both may be made to coincide with each other.

In the present invention, the first gear ratio and the second gear ratio
Can be set to various values, but the first and second gear ratios are different from those in the case where the engine is used as a power source at an accelerator opening smaller than the first opening. It is preferable that the value be a value capable of realizing an equivalent acceleration amount when the electric motor is used as a power source.

This makes it possible to almost eliminate the sense of discomfort during operation caused by the selection of the power source. The equivalent amount of acceleration means that the vehicle acceleration or the driving torque is made substantially equivalent. Equivalent in this case means that values such as acceleration do not have to be strictly the same, and are included within a range that does not cause a great discomfort for the driver.

In the present invention, the transmission may have various configurations, and may be a transmission capable of continuously changing the speed ratio or a transmission capable of changing the speed ratio stepwise. .

According to the former transmission, the first transmission ratio and the second transmission ratio can be flexibly set, so that the case where the electric motor is used as the power source and the case where the engine is used as the power source are different.
There is an advantage that control can be performed so that the torque of the output torque to the drive shaft substantially matches. According to the latter transmission, there is an advantage that the control of the gear ratio is relatively easy.

The present invention can be configured as an invention of a control method for a hybrid vehicle as described below. That is, the control method of the present invention includes an engine and an electric motor as power sources, and couples the power source, a transmission capable of selecting a plurality of speed ratios at the time of power transmission, and a drive shaft, and adjusts the accelerator opening degree. A method for controlling a hybrid vehicle capable of traveling by adjusting the power output from the power source in accordance therewith, wherein: (a) a step of detecting the accelerator opening; and (b) an accelerator when the vehicle starts. When the opening is larger than the first opening, the engine is selected as a power source. When the accelerator opening is equal to or less than the first opening, either of the engine or the electric motor is determined based on a predetermined condition. (C) controlling the speed ratio of the transmission to a first speed ratio when the electric motor is selected as the power source in step (b); d) In step (b), the engine is If the accelerator opening is equal to or less than the second opening when the power source is selected, the speed ratio of the transmission is controlled to a second speed ratio smaller than the first speed ratio. Controlling the speed ratio of the transmission to the first speed ratio when the opening is greater than the second opening; and (e) controlling the power source to respond to the accelerator opening. And a step of operating in an operating state.

According to this control method, it is possible to reduce discomfort during traveling by the same operation as that described above as the invention of the hybrid vehicle. Further, the operability and running stability of the hybrid vehicle can be greatly improved.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples. (1) Configuration of device: FIG. 2 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 shown in the figure, the power system of the hybrid vehicle according to the present embodiment includes:
As shown below, the engine 10 and the motor 2
0, the torque converter 30, and the transmission 100. Specifically, motor 20 is coupled to crankshaft 12 of engine 10.
The rotating shaft 13 of the motor 20 is connected to the torque converter 30. The output shaft 14 of the torque converter is connected to the transmission 100. The output shaft 15 of the transmission 100 corresponds to a drive shaft of a hybrid vehicle, and is connected to an axle 17 via a differential gear 16.

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 the 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, a detailed description is omitted here. Engine 10
The so-called pumping loss can be reduced by adjusting the opening / closing timing so that each valve closes with a delay with respect to the vertical movement of the piston. As a result,
It is possible to reduce a braking force by a so-called engine brake. Further, the torque to be output from the motor 20 when the engine 10 is motored can be reduced. When power is output by burning gasoline, V
The VT mechanism is controlled such 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 interaction between these magnetic fields generates an electromotive force at both ends of the three-phase coil. 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. A magnetic motor was applied.

The stator 24 is electrically connected to a battery 50 via a drive circuit 40. The drive circuit 40 is a transistor inverter, and is provided with a plurality of transistors for each of the three phases of the motor 20 by using two sets, one on the source side and the other on the sink side. As illustrated, the drive circuit 40 is 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 circuit 40, a pseudo three-phase alternating current using the battery 50 as a power supply flows through the three-phase coil of the stator 24, and a rotating magnetic field is formed. The motor 20 functions as an electric motor or a generator as described above by the rotating magnetic field.

In this embodiment, the motor 20 having the maximum output torque lower than the output torque of the engine 10 is used. As will be described later, in the present embodiment, the motor 20 plays a role as an auxiliary power source used in a relatively low speed region and a relatively low torque region at the time of starting. Therefore,
In this embodiment, the size of the power source is reduced by applying a motor having an output rating suitable for the purpose.

The torque converter 30 is a known power transmission mechanism using a fluid. The input shaft of the torque converter 30, that is, the output shaft 13 of the motor 20, and the output shaft 14 of the torque converter 30 are not mechanically coupled,
They can rotate with each other slipping. Turbines each having a plurality of blades are provided at both ends, and the turbine of the output shaft 13 of the motor 20 and the turbine of the output shaft 14 of the torque converter 30 are assembled inside the torque converter in a state where they face each other. ing. The torque converter 30 has a closed structure, and transmission oil is sealed therein. This oil acts on each of the aforementioned turbines,
Power can be transmitted from one rotating shaft to the other rotating shaft. In addition, since both can rotate in a slipping state, it is possible to convert the power input from one of the rotating shafts into a rotating state having a different number of rotations and a different torque and transmit the converted power to the other rotating shaft.

The transmission 100 includes a plurality of gears, clutches, brakes, and the like therein, and can change the torque and the number of revolutions of the output shaft 14 of the torque converter 30 by switching the gear ratio, and transmit the converted torque and rotation speed to the output shaft 15. Mechanism.
FIG. 3 is an explanatory diagram showing the internal structure of the transmission 100.
The transmission 100 of the present embodiment has a forward
It is possible to realize a first gear and a reverse gear.

FIG. 3 is an explanatory diagram showing the structure of the transmission 100. The transmission 100 of the present embodiment is composed of three clutches C1, C2, C3 and three brakes B1, B2, B3 centered on three single pinion type planetary gears 130, 140, 150. The planetary gears 130, 140, 150 are gears also called planetary gears, and sun gears 132, 142, 1, which rotate at the center.
52, planetary pinion gears 133, 143, 153 that revolve around the sun gear while rotating, and a ring gear 136, 1 that rotates around the outer periphery of the planetary pinion gear
It is composed of three types of gears, 46 and 156. The planetary pinion gears 134, 144, 154 are pivotally supported by rotating parts called planetary carriers 134, 144, 154, respectively.

In general, a planetary gear has such a property that when the rotational state of two of the three gears is determined, the rotational state of the remaining one gear is determined. The rotation state of each gear of the planetary gear is given by a calculation formula (1) well-known in mechanics. Ns = (1 + ρ) / ρ × Nc−Nr / ρ; Nc = ρ / (1 + ρ) × Ns + Nr / (1 + ρ); Nr = (1 + ρ) Nc−ρNs; Ts = Tc × ρ / (1 + ρ) = ρTr; Tr = Tc / (1 + ρ); ρ = number of teeth of sun gear / number of teeth of ring gear (1);

Here, Ns is the rotation speed of the sun gear; Ts is the torque of the sun gear; Nc is the rotation speed of the planetary carrier; Tc is the torque of the planetary carrier; Nr is the rotation speed of the ring gear;

The input shaft 14 of the transmission 100 can be connected to the rotating shaft 116 by a first clutch C1. The rotation shaft 116 is the sun gear 1 of the first planetary gear 130.
32. Further, it can be connected to the ring gear 146 of the second planetary gear 140 via the third clutch. The input shaft 14 is connected to the second clutch C
2, the first planetary gear 130 can be coupled to the planetary carrier 134. Second clutch C2
A brake B1 for stopping the rotation is provided between the brake B1 and the planetary carrier 134. The first planetary gear 130 has a ring gear 13 in addition to the above-described connected state.
6 is integrally connected to the planetary carrier 156 of the third planetary gear 150.

The planetary carrier 144 of the second planetary gear 140 is integrally connected to the ring gear 156 of the planetary gear 150. Also, the transmission 100
Is also coupled to the output shaft 15. The sun gear 142 of the second planetary gear 140 is the third planetary gear 15
0 sun gear 152 is integrally connected. Also,
The rotation of the sun gears 142 and 152 can be stopped by the brake B3.

The clutches C1 to C3 and the brakes B1 to B3 provided in the transmission 100 are engaged and released by hydraulic pressure, respectively. Although not shown, each clutch and brake is provided with a hydraulic pipe for enabling such an operation, a solenoid valve for controlling hydraulic pressure, and the like. In the hybrid vehicle of the present embodiment,
The control unit 70 controls the operation of each clutch and brake by outputting control signals to these solenoid valves and the like.

The transmission 100 of this embodiment includes a clutch C1
7 through C3 and the combination of engagement and release of the brakes B1 through B3 can set seven forward speeds and one reverse speed. Also, so-called parking and neutral states can be realized. FIG. 4 is an explanatory diagram showing the relationship between the engagement state of each clutch and brake and the shift speed. In this figure, the symbol ○ means that the clutch or the like is engaged. FIG. 4 also shows the speed ratios achieved in each engagement state. In this embodiment, the gear ratio ρ1 of the first planetary gear 130 is
Is 0.355, the gear ratio ρ2 of the second planetary gear 140 is 0.312, and the gear ratio ρ3 of the third planetary gear 150 is 0.385. The numerical values in FIG.
This is a gear ratio realized by such a gear ratio.

As shown in FIG. 4, in the case of parking (P) and neutral (N), all clutches are released and the brake B1 is engaged. Since both the clutch C2 and the clutch C1 are in the disengaged state, the power from the input shaft 14 is supplied to the first planetary gear 130 and thus the output shaft 1
Not transmitted to 5.

In the case of the first speed (1st), the first clutch C1, the third clutch C3 and the first brake B1 are engaged. In this state, the sun gear 132 of the first planetary gear 130 and the ring gear 146 of the second planetary gear 140 are connected to the input shaft 14. Also, the first
The planetary carrier 134 of the planetary gear 130 is fixed. Therefore, the first planetary gear 130 is connected to the sun gear 13 with the planetary carrier 134 fixed.
2 rotates with the input shaft 14. As a result, the ring gear 136 rotates reversely with respect to the input shaft 14. Ring gear 1
The rotation of 36 is transmitted to planetary carrier 154 of third planetary gear 150. In the third planetary gear 150, since the load from the output shaft 15 is applied to the ring gear 156, the reverse rotation of the planetary carrier 156 causes the sun gear 152 to rotate more quickly in the reverse direction. The light is transmitted to the sun gear 142. This second planetary gear 1
Since the 40 ring gear 146 is connected to the input shaft 14, the sun gear 142 rotates in the reverse direction, so that the planetary carrier 144 and the ring gear 156 of the third planetary gear 150 connected thereto slowly rotate forward. As a result, the rotation of the input shaft 14 is reduced and transmitted to the output shaft 5. The gear ratio is represented by the equation shown in FIG. 4, and in the present embodiment, has a value of 3.528.

In the case of the second speed (2nd), the first clutch C1, the third clutch C3 and the second brake B2 are engaged. In this case, the first planetary gear 130 does not perform the acceleration / deceleration action because the rotation of the planetary carrier 134 is not restricted. The ring gear 146 of the second planetary gear 140 rotates together with the input shaft 14. Since the load from the output shaft 15 is applied to the planetary carrier 144, the sun gear 142 rotates in the reverse direction. Also, the third
The sun gear 152 of the planetary gear 150 also rotates in the reverse direction. The planetary carrier 156 of the third planetary gear 150 is fixed by the brake B2. Therefore,
When the sun gear 152 rotates in the reverse direction, the ring gear 156, the planetary carrier 144 of the second planetary gear 140 connected to the ring gear 156, and the output shaft 15 are decelerated with respect to the input shaft 14 to rotate forward. As a result, the second planetary gear 140 and the third planetary gear 150 perform a deceleration operation, and the speed ratio is expressed by the equation shown in FIG. 4, and in this embodiment, the value is 2.122.

In the case of the third speed (3rd), the first clutch C1, the third clutch C3 and the third brake B3 are engaged. The first planetary gear 130 is in the second speed (2nd)
No acceleration / deceleration action is performed as in the case of (1). Also, the third planetary gear 150 does not perform the acceleration / deceleration action because the rotation of the planetary carrier 156 is not restricted. The sun gear 142 of the second planetary gear 140 is a brake B3
Is fixed. The ring gear 146 rotates together with the input shaft 14. Therefore, the planetary carrier 144 is decelerated with respect to the input shaft 14 and rotates forward.
5 is transmitted. That is, the rotation of the input shaft 14 is reduced by only the second planetary gear 140 and transmitted to the output shaft 15. The gear ratio is represented by the equation shown in FIG. 4, and in the present embodiment, has a value of 1.312.

In the case of the fourth speed (4th), the first clutch C1 to the third clutch C3 are engaged. Further, all the brakes B1 to B3 are released. First planetary gear 13
In the case of 0, the sun gear 132 and the planetary carrier 134 are connected to the input shaft 14, and the whole rotates together with the input shaft 14. The ring gear 146 of the second planetary gear 140 also rotates with the input shaft 14. The planetary carrier 156 of the third planetary gear 150 is also connected to the input shaft 14.
It rotates forward at the same speed as. Further, the second planetary gear 1
40 and the sun gear 14 of the third planetary gear 150
Since the second and second gears 152 are connected to each other, the second planetary gear 140 and the third planetary gear 150 rotate integrally as a whole. As a result, the planetary gear 13
The whole of 0, 140, and 150 becomes constant and rotates together with the input shaft 14. Therefore, no increase / decrease action occurs in the transmission 100, and the speed ratio becomes the value 1 as shown in FIG.

In the case of the fifth speed (5th), the second clutch C2, the third clutch C3 and the third brake B3 are engaged. In the first planetary gear 130, the planetary carrier 134 rotates with the input shaft 14,
The ring gear 136 rotates forward at a lower speed than the input shaft 14, and the sun gear 132 rotates forward at a higher speed than the input shaft 14. Ring gear 146 of second planetary gear 140 coupled to sun gear 132 also rotates forward faster than input shaft 14. On the other hand, the sun gear 142 of the second planetary gear 140 and the sun gear 152 of the third planetary gear 150 are fixed by the brake B3. Third planetary gear 15
The zero planetary carrier 156 rotates forward at a lower speed than the input shaft 14. Therefore, the ring gear 156 rotates forward faster than the planetary carrier 156. As a result, the planetary carrier 144 and the output shaft 15 of the second planetary gear 140 connected to the ring gear 156 are connected to the input shaft 14.
Rotate faster and faster. The gear ratio is represented by the equation shown in FIG. 4, and in the present embodiment, has a value of 0.877.

In the case of the sixth speed (6th), the first clutch C1, the second clutch C2 and the third brake B3 are engaged. The first planetary gear 130 rotates together with the input shaft 14 as a whole. The planetary carrier 154 of the third planetary gear 150 connected to the ring gear 136 also rotates forward at the same speed as the input shaft 14. On the other hand,
The sun gear 152 of the third planetary gear 150 is fixed by the brake B3. Accordingly, the speed of the ring gear 156 and the output shaft 15 connected to the ring gear 156 are increased with respect to the input shaft 14 to make a forward rotation. Note that the second planetary gear 14
In the case of 0, the third clutch C3 is disengaged, and thus no acceleration / deceleration action is performed. That is, in this case, only the third planetary gear 150 performs the speed increasing action. The gear ratio is
It is represented by the equation shown in FIG.
Becomes

In the case of the seventh speed (7th), the second clutch C2, the third clutch C3 and the second brake B2 are engaged. Ring gear 136 of first planetary gear 130
Is fixed by the brake B2. The planetary carrier 134 rotates with the input shaft 14. Therefore, the sun gear 132 rotates forward much faster than the input shaft 14. This rotation is transmitted to the ring gear 146 of the second planetary gear 140 connected to the sun gear 132. Accordingly, in the second planetary gear 140, the sun gear 142 rotates in the reverse direction, and the rotation is transmitted to the sun gear 152 of the third planetary gear 150. Since the planetary carrier 156 of the third planetary gear 150 is fixed by the brake B2, the ring gear 156 rotates forward. As a result, the planetary carrier 1 of the second planetary gear 140
Ring gear 1 of 44 and third planetary gear 150
The output shaft 15 connected to 56 rotates forward more quickly than in the case of the fifth speed. The gear ratio is represented by the equation shown in FIG.
In this embodiment, the value is 0.566.

In the case of reverse (R), the first clutch C1, the first brake B1, and the third brake B3 are engaged. That is, the sun gear 132 of the first planetary gear 130 is connected to the input shaft 14. The planetary carrier 134 is fixed by the brake B1. Therefore, the ring gear 136 rotates reversely with respect to the input shaft 14. This rotation is transmitted to the planetary carrier 156 of the third planetary gear 150. On the other hand, the third planetary gear 15
The zero sun gear 152 is fixed by the brake B3. Accordingly, the ring gear 156 and the output shaft 15 connected thereto rotate in the reverse direction faster than the planetary carrier 156. Note that the second planetary gear 140 does not perform the acceleration / deceleration action because the clutch C3 is released. As a result, the rotation of the input shaft 14 is inverted and reduced by the first planetary gear 130 and the third planetary gear 150 and transmitted to the output shaft 15. The gear ratio is represented by the equation shown in FIG.
034.

As described above, the transmission 1 of this embodiment is
00 can realize seven forward speeds and one reverse speed. The power input from the input shaft 14 is output from the output shaft 15 as power having different rotation speed and torque.
The power output is from the first gear (1st) to the seventh gear (7t
The rotation speed increases in the order of h), and the torque decreases. In addition,
As the transmission 100, in addition to the configuration applied in the present embodiment,
Various known configurations are applicable. Either one where the speed is smaller than or larger than the seventh forward speed is applicable.

The gear position of the transmission 100 is controlled by the control unit 7.
0 is set according to the vehicle speed or the like. The driver can manually operate a shift lever provided in the vehicle to select a shift position, thereby changing a range of a shift speed to be used. The driver can park (P),
A shift position of reverse (R), neutral (N), drive position (D), fourth position (4), third position (3), second position (2) and low position (L) can be selected. .

The parking (P), the reverse (R), and the neutral (N) respectively correspond to the engaged state shown in FIG. The drive position (D) means selection of a mode in which the vehicle travels using the first speed (1st) to the seventh speed (7th) shown in FIG. Hereinafter, the fourth position (4) is the third position (3) until the fourth speed (4th).
Is the third speed (3rd), the second position (2) is the second
Up to the speed (2nd) and the low position (L) mean the selection of a mode in which the vehicle runs using only the first speed (1st). In addition, a mode for using the fifth speed (5th) and a mode for using the sixth speed (6th) may be provided.

In the hybrid vehicle of this embodiment, the engine 10, the motor 20, the torque converter 30, and the transmission 1
2 is controlled by the control unit 70 (FIG. 2).
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 input / output signals are connected to the control unit 70 to realize such control. FIG. 5 is an explanatory diagram showing connection of input / output signals to the control unit 70. A signal input to the control unit 70 is shown on the left side of the drawing, and a signal output from the control unit 70 is shown on the right side.

The signals input to the control unit 70 are signals from various switches and sensors. Such a signal includes, for example, a hybrid cancel switch that instructs operation using only the engine 10 as a power source, an acceleration sensor that detects the acceleration of the vehicle, the number of revolutions of the engine 10,
The water temperature of the engine 10, the ignition switch, the remaining capacity SOC of the battery 50, the crank position of the engine 10,
Defogger on / off, air conditioner operating status, vehicle speed,
The oil temperature and shift position of the torque converter 30 (FIG. 3)
), Side brake on / off, foot brake depression, catalyst temperature for purifying exhaust of engine 10, accelerator opening, auto cruise switch on / off, turbocharger turbine speed, snowy road, etc. There are a snow mode switch for instructing a running mode on a road surface having a low friction coefficient, a fuel lid signal from a fuel gauge, and the like.

The signal output from the control unit 70 is
These are signals for controlling the engine 10, the motor 20, the torque convertor 30, the transmission 100, and the like. Such signals include, for example, an ignition signal for controlling the ignition timing of the engine 10, a fuel injection signal for controlling the fuel injection, a starter signal for starting the engine 10, and switching of the drive circuit 40 to operate the motor 20. MG control signal to control,
A transmission control signal for switching the gear position of the transmission 100, an AT solenoid signal and an AT line pressure control solenoid signal for controlling a hydraulic pressure of the transmission 100, a signal for controlling an actuator of an antilock brake system (ABS), a driving force Drive power source indicator signal indicating the power source, air conditioner control signal, control signal for preventing various alarm sounds, control signal of electronic throttle valve of engine 10, snow mode indicator signal indicating selection of snow mode, engine There are a VVT signal for controlling the opening / closing timing of the ten intake valves and exhaust valves, a system indicator signal for displaying the operating state of the vehicle, and a set deceleration indicator signal for displaying the set deceleration.

(2) Travel Control Processing: Next, the operation of the hybrid vehicle of this embodiment will be described along a travel control routine executed by the control unit 70. FIG. 6 is a flowchart of a traveling control routine. This process
This is a process that the control unit 70 repeatedly executes at a predetermined timing together with other various control routines.

When the travel control routine is started, the control unit 70 inputs the accelerator opening, the vehicle speed, and the remaining capacity SOC of the battery 50 as various parameters required for control (step S10). These are as shown in FIG.
It is detected by each sensor. The accelerator opening refers to the ratio (%) of the actual operation amount to the entire movable range of the accelerator. Next, the control unit determines whether the remaining capacity SOC is equal to or greater than a predetermined reference value HL (step S20). In this embodiment, the engine 10 and the motor 20
Are selected according to the remaining capacity SOC in accordance with a map stored in the ROM in advance.
In step S20, the remaining capacity SOC is compared with the reference value HL in order to properly use the map.

If the state of charge SOC is equal to or greater than the predetermined reference value, a gear ratio switching process is executed based on the hybrid map with reference to the hybrid map (step S3).
0). The hybrid map is a map for selectively using both power sources of the engine 10 and the motor 20 according to the running state of the vehicle, that is, the vehicle speed and the accelerator opening.

FIG. 7 is an explanatory diagram showing an example of the hybrid map. As shown in the figure, the map gives the type of power source to be used and the shift speed according to the vehicle speed and the accelerator opening. A region MG in the drawing is a region where the vehicle runs with the motor 20 as the power source, and the other region is a region where the vehicle runs with the engine 10 as the power source. Hereinafter, the former is referred to as EV traveling, and the latter is referred to as normal traveling.
According to the configuration of FIG. 2, it is possible to run using both the engine 10 and the motor 20 as power sources, but in the present embodiment, such a running region is not provided.

When traveling control is performed based on the hybrid map, the hybrid vehicle of the present embodiment first
Start with V running. The hybrid vehicle of the present embodiment is configured such that the engine 10 and the motor 20 rotate integrally. Therefore, the engine 10 is also rotating during the EV traveling. However, the motoring is being performed without performing fuel injection and ignition. As explained earlier,
The engine 10 is provided with a VVT mechanism. The control unit 70 controls the VVT mechanism to reduce the load applied to the motor 20 during the EV traveling and to effectively use the power output from the motor 20 for traveling of the vehicle, thereby controlling the intake valve and the exhaust valve. Delay open / close timing.

The control unit 70 starts the engine 10 when the vehicle started by EV running reaches the running state near the boundary of the area MG in the map of FIG. Since the engine 10 has already been rotated at a predetermined rotation speed by the motor 20, the control unit 70 injects fuel into the engine 10 at a predetermined timing and ignites it. VV
By controlling the T mechanism, the opening / closing timing of the intake valve and the exhaust valve is changed to a timing suitable for the operation of the engine 10.

After the engine 10 is started in this way, the vehicle runs using only the engine 10 as a power source. When traveling in such an area is started, the control unit 70
Shut down all 0 transistors. As a result, the motor 20 simply turns idle.

The control unit 70 performs the control of switching the power source according to the running state of the vehicle as described above, and also performs the process of switching the gear position of the transmission 100. The switching of the shift speed is performed according to the map of FIG. 7, similarly to the switching of the power source. As shown, the control unit 70
Executes the changeover of the gear stage such that the gear ratio decreases as the vehicle speed increases. The switching of the shift speed is realized by outputting a predetermined signal as a transmission control signal (see FIG. 5) and controlling the on / off of the clutch and brake of the transmission 100 according to the shift speed.

However, this switching is restricted by the shift position. In the drive position (D), the vehicle travels using gears up to the fifth speed (5th). In the four positions, the vehicle travels using gears up to the fourth speed (4th). In this case, the fourth speed (4th) is used even in the region of 5th in FIG. In addition to the switching based on this map, the shift speed is switched by so-called kick down, in which the driver shifts the shift speed to a higher one-speed ratio by rapidly depressing an accelerator pedal. These switching controls are the same as in a known vehicle using an engine alone as a power source and having an automatic transmission. In the present embodiment, the same switching is performed when the vehicle is traveling in the EV mode (the area MG). The setting of the shift speed will be described later in detail.

On the other hand, in step S20, the remaining capacity S
If OC is determined to be smaller than the reference value HL,
The control unit refers to the non-hybrid map and executes the gear change process based on the map (step S40). The non-hybrid map is a map that runs using only the engine 10 as a power source regardless of the running state of the vehicle. That is, in the control based on the non-hybrid map, all the transistors of the drive circuit 40 of the motor 20 are always shut down, and the motor 20 simply runs idle.

FIG. 8 is an explanatory diagram showing an example of a non-hybrid map. For comparison with the hybrid map, a region corresponding to the EV running is indicated by a broken line in the figure. In the non-hybrid map, even in such a region, only the engine 10 is selected as the power source. The gear position is set in accordance with the vehicle speed and the accelerator opening, and is set such that the lower the gear ratio, the higher the vehicle speed, as in the hybrid map. However, the non-hybrid map differs from the hybrid map (FIG. 7) in that the second speed (2nd) is used in the hatched area α in the figure. That is, the first speed (1st) is used at the time of starting in the hybrid map, whereas the second speed (2nd) is used at the time of starting in the non-hybrid map. Such a difference will be described later in detail.

The reference value HL in step S20 is a reference value for selectively using the hybrid map (FIG. 7) and the non-hybrid map (FIG. 8). When traveling using the motor 20 as a power source, the power of the battery 50 is consumed. Therefore, it is desirable to perform traveling using the motor 20 as a power source when the remaining capacity of the battery 50 has a sufficient margin. The reference value HL can be set in advance by experiment or analysis in consideration of the power consumption when the motor 20 is used as the power source and the lower limit of the remaining capacity SOC desirable for the battery 50.

The running control routine is a process repeatedly executed at a predetermined timing. Therefore, even when the remaining capacity SOC is determined to be equal to or higher than the reference value HL at the beginning of the start and the operation based on the hybrid map is executed, the power of the battery 50 is consumed, and the remaining capacity SOC is reduced to the reference value H.
If it becomes smaller than L, the operation is switched to the operation based on the non-hybrid map.

With the above processing, when the proper use of the power source and the change of the gear position are executed according to the remaining capacity SOC, the control unit 70 controls the engine 10 and the motor 2.
The control of operation 0 is executed (step S50). The control of the engine 10 controls an opening of a throttle valve to the engine 10, a fuel injection amount, an ignition timing, a VVT mechanism, and the like according to an accelerator opening and a vehicle speed. These controls are the same as in the case of a normal vehicle using only the engine as a power source, and a detailed description thereof will be omitted.

The motor 20 is operated by so-called PWM control. The control unit 70 sets a voltage value to be applied to the coil of the stator 24. Such a voltage value is given according to the vehicle speed and the accelerator opening based on a table set in advance. The control unit 70 controls ON / OFF of each transistor of the drive circuit 40 so that the voltage is applied to the coil. Since the PWM control is a well-known technique, further detailed description will be omitted.

By repeatedly executing the running control routine described above, the hybrid vehicle of this embodiment can run using the power sources of the engine 10 and the motor 20 properly.

(3) Map setting: Here, a hybrid map (FIG. 7) and a non-hybrid map (FIG. 8)
The setting will be described in detail. In traveling based on the hybrid map, switching of the power source and switching of the shift speed are performed in parallel. In order to drive the vehicle stably, it is preferable to avoid simultaneous switching of the power source and the shift speed. The hybrid map is set such that the switching between the two is unlikely to occur at the same time.

For example, in the map shown in FIG.
Let us consider a case where the running state of the vehicle changes according to the route indicated by. In this case, the vehicle initially travels at the first speed (1st) using the motor 20 as a power source. Thereafter, the power source is switched to the engine 10, but the gear position remains at the first speed (1st). Then, as the vehicle speed increases, the gear position is switched to the second speed (2nd) while the power source remains the engine 10. When the running state changes along the locus p1, switching of the power source and switching of the gear position do not occur at the same time.

As another example, consider a case where the running state of the vehicle changes along the path indicated by locus p2 in the figure. In this case, the first speed (1s)
Travel at t). After that, the power source remains the motor 20,
The gear is switched to the second speed (2nd). Then, as the vehicle speed increases, the gear position remains at the second speed (2nd).
The power source is switched to the engine 10. When the vehicle speed further increases, the gear position is changed to the third speed (3
rd). When the traveling state changes along the locus p2, the switching of the power source and the switching of the gear position do not occur at the same time. Trajectory p3 when accelerator opening is lower
Similarly, the switching of the power source and the switching of the gear position do not occur at the same time.

Under the above conditions, the hybrid map
The setting is such that as the vehicle speed increases, a shift speed with a lower gear ratio is used. This setting is set such that the required torque and the power of the rotation speed are transmitted to the drive shaft at each vehicle speed, as in a normal vehicle using only the engine as a power source. As previously shown in FIG. 1, for example, when a predetermined torque T2 is output from the power source, the drive shaft torque increases as the speed ratio increases. Conversely, the rotational speed of the drive shaft decreases as the gear ratio increases. When the vehicle speed is low, rotate the drive shaft at a low speed,
Since a high torque is required for acceleration, a gear with a large gear ratio is used. When the vehicle speed is high, the drive shaft is rotated at a high rotational speed, and a high torque is not required. Therefore, a shift speed with a low speed ratio is used. Similar considerations apply to non-hybrid maps,
Basically, the setting is such that a shift speed with a lower gear ratio is used as the vehicle speed increases.

The hybrid map and the non-hybrid map of the present embodiment are set in consideration of the mutual relationship between them. In the present embodiment, the control unit 70
The vehicle travels by using the hybrid map and the non-hybrid map selectively according to the remaining capacity SOC of 0. In order for the driver to operate the hybrid vehicle without feeling uncomfortable, it is desirable that substantially the same driving feeling be obtained regardless of which of the engine 10 and the motor 20 is selected as the power source. In the case where the engine 10 is used as the power source and the case where the motor 20 is used as the power source, if the acceleration feeling according to the amount of depression of the accelerator is the same, it is possible to drive without discomfort, and the operability of the vehicle is improved. .

In this embodiment, from this point of view, the gear position is set in the hybrid map and the non-hybrid map so that the drive shaft torque according to the driving state of the vehicle is substantially equal. As described above, the motor 20
Is lower than the output torque of the engine 10.
If the same gear is used for both power sources, the drive shaft torque will be greater when the engine 10 is used as the power source. Therefore, the sense of acceleration with respect to the accelerator opening differs depending on the type of the power source, and a sense of discomfort occurs during driving. Such discomfort is particularly felt when starting.

In this embodiment, the engine 10 and the motor 20 are driven by using different speeds depending on the power source.
The difference of the output torque is suppressed. As shown in FIG.
In the non-hybrid map, the second speed (2nd) is used in a predetermined area at start (the hatched area α in the figure). In the hybrid map, the area α
The first speed (1st) is used in this region corresponding to. When the vehicle speed and the accelerator opening correspond to this range, the vehicle runs at the first speed (1st) using the motor 20 as a power source according to the hybrid map, and the engine 10 according to the non-hybrid map according to the non-hybrid map. Second while using as a power source
The vehicle is driven at a high speed (2nd).

In the present embodiment, the first speed (1) is set such that the drive shaft torque corresponding to the accelerator opening becomes substantially constant regardless of the type of power source when the gears are switched in this manner.
The speed ratio k1 of the first speed (st) and the speed ratio k2 of the second speed (2nd) are set. Such setting will be described with reference to FIG.

In FIG. 1, it is assumed that power source torque T1 corresponds to the torque output from motor 20, and power source torque T2 corresponds to the torque output from engine 10. Each torque is a torque corresponding to a representative vehicle speed and accelerator opening within the region α. The drive shaft torque to be output during traveling with respect to the vehicle speed and the accelerator opening is represented by a value Tb
Set to 1. This value can be set in a range in which the driver can easily operate the relationship between the accelerator depression amount and the feeling of acceleration of the vehicle without feeling uncomfortable. The drive shaft torque Tb1 set in this way and the output torque T1 of the motor 20
From this ratio, the gear ratio k1 of the first speed (1st) is determined.
That is, k1 = Tb1 / T1.

Next, the first speed (1s)
The speed ratio of the second speed (2nd) is set based on the speed ratio of t). The gear ratio of the second speed (2nd) is such that the torque T2 from the engine 10 is the drive shaft torque T substantially equal to the value Tb1.
The value is converted to b2 and set to a value that can be output. That is, k2
= Tb2 / T2. When the drive shaft torque is equal between the case where the engine 10 is used as the power source and the case where the motor 20 is used as the power source, that is, when the speed ratio is set so that Tb1 = Tb2, the speed ratios k1 and k2 are The relationship is inversely proportional to the power source torques T1 and T2. In the present embodiment, a difference is allowed between the drive shaft torques Tb1 and Tb2 to such an extent that the driver does not feel uncomfortable, and the torque is set in consideration of a required torque at a vehicle speed other than at the time of starting.

By setting the gear ratios k1 and k2 in this way and setting the shift speed and the power source properly as shown in the maps of FIGS. 7 and 9, the hybrid vehicle of this embodiment is
Regardless of the type of power source used during traveling, almost constant drive shaft torque can be obtained with respect to the accelerator opening. Therefore, the driver can drive without discomfort.

In order to avoid that the driving sensation according to the accelerator opening differs depending on the power source, in the region MG in the hybrid map, the region where the second speed (2nd) or the third speed (3rd) is used is described. Alternatively, the non-hybrid map may be set so that the third speed (3rd) and the fourth speed (4th) are used.
In the present embodiment, since the difference in such a region is relatively small, a common shift speed is used in the hybrid map and the non-hybrid map in order to facilitate control.

In the present embodiment, in the hybrid map (FIG. 7), in the region β where the accelerator opening is larger than the region MG, the vehicle runs at the first speed (1st) with the engine 10 as the power source. . Similarly, in the non-hybrid map (FIG. 8), in a region corresponding to the non-hybrid map, the vehicle runs with the engine 10 as the power source at the first speed (1st) speed. With this setting, the same driving feeling can be realized in the hybrid map and the non-hybrid map. Further, it is possible to prevent the switching of the power source and the switching of the gear stage from occurring simultaneously in the hybrid map. Furthermore, by using the maximum gear ratio k1 for the engine 10, it is possible to output a large torque that meets the driver's requirements. As a result, the torque of the engine 10 can be fully utilized, and the traveling area of the hybrid vehicle can be sufficiently secured.

In this embodiment, the area α in the non-hybrid map is set smaller than the area MG in the hybrid map. That is, the maximum value A2 of the accelerator opening in the region α is set smaller than the maximum value A1 of the accelerator opening in the region MG. This setting is for preventing switching of the shift speed when the two maps are properly used during traveling as described below.

For example, consider a case where the running state changes according to the locus p4 shown in FIG. When the traveling control is performed based only on the non-hybrid map, the second speed (2nd) is used in the region α while the power source is the engine 10, and the first speed (1s)
is switched to t). In this case, the maximum values A1, A2
Regardless of the magnitude relationship, the switching of the power source and the switching of the gear position do not occur at the same time. Also, there is no switching of the gear position.

Next, let us consider a case where the hybrid map is changed to the non-hybrid map while the running state is changing along the locus p4. That is, at the beginning of the start, the remaining capacity SOC of the battery 50 has a margin, and the vehicle starts running according to the hybrid map.
Consider a case where power is consumed and the driving is switched to running according to the non-hybrid map.

FIG. 9 is an explanatory diagram showing the manner of switching between the power source and the shift speed by properly using the map. A state where the accelerator opening changes along the locus p4 in FIG. 8 is shown. The upper part shows the switching state in the hybrid map. In the figure, the hatched portions indicate that the motor 20 is used as a power source, and the white portions indicate that the engine 10 is used as a power source. As shown in the drawing, the motor 20 runs using the motor 20 as a power source until the accelerator opening reaches A1 (the hatched portion in the figure). Engine 1 when the accelerator opening exceeds A1
The vehicle runs with 0 as a power source. The gear position is always the first gear (1
st).

The lower part shows the switching in the non-hybrid map. In this case, the power source is always the engine 10. The vehicle travels in the second speed (2nd) until the accelerator opening reaches A2, and travels in the first speed (1st) when the accelerator opening is higher. A2 is smaller than A1.

Consider a case where the maps are properly used according to the route pa1 in the figure. In this case, the vehicle starts with the motor 20 as the power source at the first speed (1st) speed according to the hybrid map. Thereafter, when the remaining capacity of the battery 50 decreases, the map is switched to the non-hybrid map. As a result, at the first speed (1st), the engine 1
The mode is switched to running using 0 as the power source. Although the power source is switched according to the use of the map, the shift speed is not switched.

On the other hand, FIG. 10 shows a case where the magnitude relation between the values A1 and A2 is reversed. In FIG. 10, a case is considered in which the map is properly used according to the locus pa2. In this case, the vehicle starts with the motor 20 as the power source at the first speed (1st) speed according to the hybrid map. Thereafter, when the remaining capacity of the battery 50 decreases, the map is switched to the non-hybrid map. As a result,
The vehicle switches to running using the engine 10 as a power source at the second speed (2nd). At this time, switching of the power source,
Shifting of the gear stage occurs simultaneously. Further, when the accelerator opening increases, the shift speed is switched again to the first speed (1st). In other words, the gear position is changed in a relatively short time from “first speed (1st) → second speed (2nd) → first speed (1s)
t) ".

In this embodiment, the maximum value A2 of the accelerator opening in the area α in FIG. 8 is set smaller than the maximum value A1 of the accelerator opening in the area MG in FIG. This prevents the power source and the shift speed from being switched at the same time, and prevents the shift speed from being frequently switched, even when the switching between the power sources is performed properly. Of course, the value A2 may be set to match the value A1.

In FIG. 9 as well, if the maps are properly used with the accelerator opening A2 or less, there is a possibility that the gears will be switched. However, when a large torque is required during the actual start, the accelerator is depressed relatively quickly. Therefore, the accelerator opening becomes the value A2
It is rare that the vehicle travels for a long period of time so that the map can be properly used in the following conditions, and such switching does not cause a problem.

In this embodiment, the battery 50
By switching the power source in consideration of not only the remaining capacity SOC of the vehicle but also the traveling state of the vehicle, it is possible to avoid switching between the power source and the transmission at the same time. For example, let us consider a case where the remaining capacity SOC of the battery 50 becomes high enough to allow the hybrid map to travel when traveling according to the non-hybrid map. At this time, switching of the power source from the engine 10 to the motor 20 and switching of the shift speed from the second speed (2nd) to the first speed (1st) are performed, as indicated by the broken line locus pa3 in FIG. Can occur at the same time.

When the state of charge SOC of the battery 50 is high, the vehicle can run using either the engine 10 or the motor 20 as a power source. Therefore, in such a case, the switching to the motor 20 is suspended and the vehicle travels with the engine 10 as the power source, and after the hybrid vehicle has once stopped, switching of the power source and the gear position is executed. In this way, it is possible to prevent the power source and the shift speed from being simultaneously switched during traveling. Also, after the accelerator opening increases during traveling with the engine 10 as a power source and the gear position is switched to the first speed (1st), the power source is switched to the motor 20.
May be switched to. Thus, the battery 5
If the control of the power source and the transmission is performed in consideration of not only the remaining capacity SOC of 0 but also the running state of the vehicle, it is possible to more appropriately switch between the two.

According to the hybrid vehicle of the present embodiment described above, the hybrid map and the non-hybrid map are selectively used according to the remaining capacity SOC of the battery 50, so that the vehicle travels while maintaining the battery 50 in an appropriate charged state. be able to. In this case, in the hybrid vehicle of the present embodiment, the shift speed is set such that the acceleration amount is substantially constant regardless of the difference in the output torque between the engine 10 and the motor 20. Therefore, the driver can drive the vehicle with a constant driving feeling regardless of the type of the selected power source. As a result, the hybrid vehicle according to the present embodiment can improve operability and running stability.

This embodiment has exemplified the case where the transmission 100 that changes the gear ratio stepwise is applied. In contrast,
It is also possible to apply a mechanism capable of continuously changing the gear ratio as a transmission. In such a case, if the gear ratio is controlled so as to be inversely proportional to the output torque of the power source, the drive shaft torque can be made substantially constant, and the sense of discomfort can be further reduced.

In the present embodiment, an embodiment has been described in which two types of maps, a hybrid map (FIG. 7) and a non-hybrid map (FIG. 8), are prepared for the entire traveling area. On the other hand, a plurality of maps may be prepared only in an area where the power source can be properly used. According to the present embodiment, there is a possibility that the power source may be properly used in the area MG in FIG. Therefore, the area M
A hybrid map and a non-hybrid map may be prepared only for the map corresponding to G, and a common map may be used for other areas.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and may be implemented in various other forms without departing from the gist of the present invention. Obviously you can get it.
The various control processes described in the present embodiment may be realized by hardware.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a relationship among a power source torque, a drive shaft torque, and a gear ratio.

FIG. 2 is a schematic configuration diagram of a hybrid vehicle as an embodiment.

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.

5 is an explanatory diagram showing connection of input / output signals to a control unit 70. FIG.

FIG. 6 is a flowchart of a traveling control routine.

FIG. 7 is an explanatory diagram showing an example of a hybrid map.

FIG. 8 is an explanatory diagram showing an example of a non-hybrid map.

FIG. 9 is an explanatory diagram showing a state of switching between a power source and a shift speed by properly using a map.

FIG. 10 is an explanatory diagram showing a second state of switching between the power source and the shift speed by properly using the map.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Crankshaft 13, 14, 15 ... Rotating shaft 16 ... Differential gear 17 ... Axle 20 ... Motor 22 ... Rotor 24 ... Stator 30 ... Torque converter 40 ... Drive circuit 50 ... Battery 70 ... Control unit 100 ... Transmission 110 ... Sub-transmission unit 112 ... First planetary gear 114 ... Sun gear 115 ... Planetary pinion gear 116 ... Planetary carrier 118 ... Ring gear 119 ... Rotation shaft 120 ... Main transmission unit 122 ... Rotation shaft 130,140,150 ... Planetary gear 132,142,152 … Sun gears 134, 144, 154… Planetary carriers 136, 146, 156… Ring gears

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B60L 11/14 B60L 15/20 K 15/20 F02D 29/00 H F02D 29/00 29/02 D 29 / 02 F16H 3/66 B F16H 3/66 B60K 9/00 EF term (reference) 3D039 AA04 AB27 AC36 AC39 AC54 AC74 AC78 AD23 AD53 3D041 AA30 AA31 AA51 AA66 AB00 AC01 AC06 AC08 AC15 AC18 AC19 AD00 AD01 AD41 AD32 AD32 AD32 AE02 AE03 AE04 AE07 AE09 AE31 AE32 AE40 AF00 3G093 AA01 AA04 AA06 AA07 BA02 BA14 CB05 CB06 DA01 DA05 DA06 DA12 DB00 DB05 DB11 DB12 DB15 EA02 FCA EA09 EA13 EA15 EB00 EB03 EB03 EB03 EB00 HC06 HC15 5H115 PA02 PC06 PG04 PI16 PI24 PI29 PU10 PU23 PV09 PV23 QE01 QE02 QN03 RB08 RB22 RE01 RE03 RE05 RE06 RE07 SE04 SE05 SE08 TB01 TE02 TE08 TI0 2 TO02 TO21

Claims (6)

[Claims] An engine and an electric motor are provided as power sources, and the power source, a transmission capable of selecting a plurality of speed ratios at the time of power transmission, and a drive shaft are coupled to each other. A hybrid vehicle capable of traveling by adjusting the power output from the power source, wherein a detecting means for detecting the accelerator opening, and when the vehicle starts, the accelerator opening is larger than the first opening Power source selecting means for selecting the engine as a power source, and selecting one of the engine and the electric motor as a power source based on predetermined conditions when an accelerator opening is equal to or less than a first opening. When the vehicle starts moving, the transmission is controlled in accordance with the selection of the power source and the degree of accelerator opening so that the first transmission ratio or the second transmission ratio smaller than the first transmission ratio is controlled. Transmission control for switching And a power source control unit that controls the power source to operate in an operation state according to the accelerator opening, wherein the transmission control unit is configured to control when the electric motor is selected as the power source. Selecting the first gear ratio; selecting the second gear ratio when the accelerator opening is equal to or less than a second opening when the engine is selected as the power source; A hybrid vehicle as means for selecting the first gear ratio when the degree is larger than the second opening degree. 2. The hybrid vehicle according to claim 1, wherein the second opening is equal to or less than the first opening. 3. The first speed ratio and the second speed ratio are determined based on the case where the engine is used as a power source and the case where the electric motor is used as a power source when the accelerator opening is equal to or less than the first opening. 2. A value capable of realizing an equivalent acceleration amount with
A hybrid vehicle as described. 4. The hybrid vehicle according to claim 1, wherein the transmission is a transmission capable of continuously changing the speed ratio. 5. The hybrid vehicle according to claim 1, wherein the transmission is a transmission capable of changing the gear ratio stepwise. 6. An engine and an electric motor are provided as power sources, and the power source, a transmission capable of selecting a plurality of speed ratios at the time of power transmission, and a drive shaft are coupled to each other, and the power is transmitted in accordance with an accelerator opening. A method for controlling a hybrid vehicle capable of traveling by adjusting the power output from a power source, the method comprising: (a) detecting the accelerator opening; and (b) detecting the accelerator opening when the vehicle starts. If the opening is larger than 1, the engine is selected as a power source. If the accelerator opening is equal to or less than the first opening, either the engine or the electric motor is used as a power source based on predetermined conditions. (C) controlling the speed ratio of the transmission to a first speed ratio when the electric motor is selected as a power source in step (b); and (d).
When the engine is selected as the power source in step (b), if the accelerator opening is equal to or less than the second opening, the second gear ratio of the transmission is smaller than the first gear ratio. Controlling the gear ratio of the transmission to the first gear ratio when the accelerator opening is larger than the second opening;
(E) controlling the power source to operate in an operating state corresponding to the accelerator opening.