JP3463578B2 - Hybrid car - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle that drives a vehicle by using driving forces of an engine and a motor.

[0002]

2. Description of the Related Art As a drive system for reducing the fuel consumption of an engine, there is a hybrid vehicle that uses the driving force of a motor or a generator. In such a system, a first method of locking the generator by using an engagement device for stopping the rotation of the generator has been proposed as a method of applying the engine brake. In particular, JP-A-9-156387
The publication describes a method of controlling the relative speed of a fastening device (engagement device) within a predetermined range to reduce the impact associated with fastening. Further, Japanese Patent Application Laid-Open No. 9-109706 describes a second method in which a generator is fixed in a hybrid vehicle using a planetary gear so that the engine can be started even at high speeds.

Further, as a third method, Japanese Patent Laid-Open No. 9-468
In No. 21, a high-efficiency drive system that can drive both series hybrid system and parallel hybrid system by using a clutch is described, and it is stated that the clutch life is improved by performing uniform speed. Has been done.

[0004]

However, even if the first method is used, a certain amount of torque is generated in the fastening device at the time of fastening, and therefore the fastening device maintains the fastening state even if such torque is generated. As described above, it is necessary to have a fastening and holding function such as utilizing hydraulic pressure. Even when the second method is used, the fastening device for fixing the generator needs to use a wet brake or the like in order to generate a holding torque. Also,
Even in the case of the third method, it is necessary to apply a certain amount of force to the engaged state when engaging the clutch. for that reason,
In these hybrid vehicle systems, there are problems that the size of the fastening device becomes large and the drive device that drives the clutch becomes large, which hinders downsizing of the entire system.

[0005] The purpose of the present invention, with respect to the fastening device used in a hybrid vehicle, while ensuring the holding force, it is to reduce the size of that size.

[0006]

In order to solve the problems] high to achieve the above purpose
Brides vehicle includes an engine that will be driven me by the combustion of the fuel, a motor that will be driven me by the electrical energy, together with the motor is connected, controlling the motor child
Of the engine whose rotational speed has been changed by
A differential mechanism for transmitting drive torque to the vehicle, a control device for controlling the driving torque of the vehicle by controlling the said engine motor, rotating the rotation of said motor in predetermined
A fastening device for mechanically locked in position, the motor times
And a position detecting device for detecting the translocation, the control device
But of the motor detected by said position detecting device
The rotation position is used to determine the rotation position of the motor
Controlling the motor such rolling a position, a rotation of the motor I by the said fastening device <br/> can be accomplished I by the <br/> mechanically be locked.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows a hybrid vehicle in which the energy of the engine 1 is used to rotate tires 3a and 3b via drive shafts 2a and 2b to drive a vehicle body. A planetary gear 4 is provided between the engine 1 and the drive shafts 2a and 2b. The planetary gear 4 includes a sun gear 4s, a planetary 4p, and a ring gear 4r, and a generator 5 connected to the sun gear 4s.
By controlling the generator speed .omega.g, the speed change function is provided. The planetary gear 4 has a planetary 4p for the engine 1 and a ring gear 4r for the gears 15 and 10.
Are connected to the drive shafts 2a and 2b on the output side respectively. The motor 6 is arranged on the output side of the ring gear 4r in order to assist the driving torque of the engine 1. The generator 5 and the motor 6 are driven by the power converters 7 and 8, respectively, to charge or discharge the battery 12 with electric power. The generator 5 and the motor 6 can both generate and drive the battery 12 by controlling the power converters 7 and 8 by the control device 13. Further, the control device 13 can also perform control so as to drive the motor 6 using the electric power generated by the generator 5. Further, the control device 13 can control the engine 1 to arbitrarily generate a driving force.

A method of controlling the generator 5, which is a feature of the present invention, will be described below. The position detector 14 attached to the generator 5 detects the rotational position θg of the generator 5, and the position θg is input to the control device 13. In addition, the accelerator signal Xa, the brake signal Xb, the vehicle speed V obtained from the speed detector 26, and the current signals iu and iv of the generator 5 are input to the control device 13. Based on these signals, the fastening device 11 provided between the generator 5 and the sun gear 4s is controlled by the control method described later. When the sun gear 4s is fastened by the fastening device 11, the sun gear 4s can be locked without passing a current through the generator 5. FIG. 2 is an example of a configuration diagram of the fastening device 11, and FIG. 3 is an overview diagram thereof. The fastening device 11 is composed of a stator 11a, a rotor 11b, a straight-movable portion 11c, and a fastening hole 11d. The rotor 11b is rotated by a small force by the drive unit provided on the stator 11a. With this rotation, the straight-movable portion 11c moves straight and can be inserted into the fastening hole 11d. When the insertion into the fastening hole 11d is completed, the sun gear 4s can be continuously fixed without using energy. Next, a control method of the entire system will be described with reference to FIG. FIG. 4 is a flowchart showing a control method of the system of FIG. In step 101 of FIG. 4, a driving command intended by the driver, such as an accelerator depression amount Xa, a brake depression amount Xb, a switching signal Xc for instructing forward / reverse or neutral, etc., is input, and the vehicle speed ωv and the battery 12 are charged. The vehicle state such as the state and the temperature of each part is also input. In step 102, the driving force command value τr of the vehicle is calculated based on the value of the information indicating the vehicle state and the driver command input in step 101. Next, step 103 determines how to distribute the driving force of the engine 1, the generator 5, and the motor 6 based on the vehicle driving force command value τr and the vehicle speed ωv. Thereby, each drive command value (torque command value or speed command value) is determined. In step 104, an engine control calculation is performed based on the driving force command value of the engine 1, and the engine 1 is adjusted so that the driving force command value is obtained.
To control. In step 105, a motor control calculation is performed on the drive force command value of the motor 6 to generate a predetermined drive force. Furthermore, in step 106, the command state of the generator 5 is checked. If the command of the generator 5 determined by the driving force distribution calculation of step 103 is a stop command, the fastening process of step 107 is performed to set the output of the generator 5 to 0 and lock the fastening device 11. If it is not a stop command, control calculation of the generator 5 is performed in step 108. Steps 107 and 108 are detailed flowcharts shown in FIGS. 5 and 6, respectively.

The processing method of FIG. 5 will be described. First, in step 111, the state of the fastening device 11 is determined. If the current state is already the fastened state, the process jumps to step 115 to stop the control of the generator 5. When the fastening device 11 is in the fastening state, it is not necessary to generate power by the generator 5, so control is stopped and electrical loss is set to zero. If the fastening device 11 is still open in step 111, the position of the generator 5 is controlled in step 112. The position detector 1 is used to control the position of the generator 5.
The rotational position θg of the generator 5 input from 4 is fed back. As a result, as shown in FIG. 3, the generator 5 is moved to the position θg0 where the straight-movable portion 11c coincides with the fastening hole 11d.
Control the rotational position θg of. In step 113, it is determined whether the rotational position θg is positioned at the position θg0.
Here, when it is determined that the positioning is completed, in step 114, the driving unit provided on the stator 11a of the fastening device 11 is driven so as to fasten the fastening device 11, and the fastening is completed. After the fastening device 11 is fastened,
In step 115, the process of stopping the control of the power generator 5 is performed to cut off the flow of current through the power generator 5. Step 113
In the above, when the positioning of the generator 5 is not completed, steps 114 and 115 are jumped so that the process of driving the fastening device 11 is not performed until the positioning is completed. As described above, by performing the position control by the generator 5, the drive portion of the stator 11a that drives the fastening device 11 has a feature that the fastening operation can be performed with a small force.

Next, the processing performed in step 108 of FIG. 4 will be described in detail with reference to the flowchart of FIG. In step 121, the state of the fastening device 11 is determined, and if it is in the open state, the process of step 125 is performed. That is, when the fastening device 11 is opened,
The generator 5 can be controlled without any problems. Therefore, in step 125, the generator speed ωg of the generator 5 is calculated based on the rotational position θg obtained from the position detector 14, and the speed control of the generator 5 is performed by feedback control. By controlling the speed of the generator 5, the difference between the vehicle speed ωv and the engine speed ωe of the engine 1 is controlled, so that it is possible to realize the gear shift function of always driving the engine 1 in the high torque region. In step 121,
When it is determined that the fastening device 11 is in the fastened state, the processing from step 122 onward is performed. First, step 122
Then, the process of controlling the torque of the generator 5 is performed. Here, the torque to be generated by the generator 5 is controlled to a value that balances the torque generated by the engine 1 when the fastening device 11 is open in the planetary gear 4. Under the state in which the generator is controlled in this way, in step 123, the driving unit provided on the stator 11a of the fastening device 11 is driven to open the fastening device 11. In particular, by generating torque in the generator 5 and balancing it with the torque of the engine 1, the force applied to the fastening device 11 can be made 0 on average, so that the driving portion of the stator 11a can be driven with a small driving force. There is a feature that the fastening device 11 can be opened. Next step 12
When it is confirmed in step 4 that the fastening device 11 is opened, the speed control of the generator 5 is performed in step 125, and the shift operation is performed. Further, in step 124, the processing from step 122 to step 124 is performed every predetermined time until the fastening device 11 changes from the fastening state to the open state. Since the torque of the engine 1 is intermittently pulsating, if the torque of the generator 5 is near the average torque of the engine 1, there is always a point at which the torque applied to the planetary gears 4 is balanced, so only a small driving force is required. Even in the drive part of the stator 11a which cannot be generated, the fastening device 11
There is an advantage that can be opened. In addition, when the fastening device is used, a large driving force of the engine can be transmitted to the vehicle.

Therefore, according to this embodiment, in a hybrid vehicle having a planetary gear and a generator, by engaging a part of the planetary gear with a fastening device, it is possible to reduce the loss of electric energy and to reduce the size of the fastening device. There is an effect that can be converted. In other words, while improving fuel efficiency,
There is an effect that a hybrid vehicle system can be provided at low cost.

FIG. 7 shows another embodiment different from FIG. 1 showing a method of constructing a hybrid vehicle having a plurality of planetary gears controlled by a motor (or a generator). The drive path for transmitting the rotation of the engine 1 to the axles 2a, 2b is a gear 16,
17 and 18, the path through the planetary gears 4, the gears 15 and 10, and the gears 16, 17, 19, and 20, the planetary gear 9, and the gear 2
There are two routes through 1, 22. The planetary gears 4 and 9 are respectively sun gears 4s and 9s and planetary gears 4p and 9s.
p and ring gears 4r and 9r. The sun gears 4s and 9s each have a motor (or a generator).
5, motors (or generators) 6 are connected, and the planetary gears 4, 9 are controlled by these motors. Here, the fastening device 11 is arranged between the sun gear 4s and the motor 5, and as in the case of FIG.
Used when mechanically locking r. That is, when it is desired to lock the sun gear 4r, the fastening can be completed with a small driving force by controlling the position by the motor 5 and electrically locking the position and then controlling the fastening device 11. A clutch 23 is arranged between the sun gear 9r and the motor 6 to engage and disengage the clutch 23 as needed.

Here, the ratio of the engine speed ωe to the vehicle speed ωv when the sun gear 9r is locked is the gear ratio N1 (= ωe / ωv), and the vehicle speed ωv and the engine speed ωe when the sun gear 4r is locked. Gear ratio N2
(= Ωe / ωv). In FIG. 7, the gear ratio has the following relationship.

[0015]

## EQU1 ## N1 = kN2 However, k> 1. Normally, k is designed to have a value of about 4 to 5. In this system, the vehicle speed ωv
When is small, the sun gear 9r locks. As a result, the drive torque generated in the vehicle becomes larger than the torque of the engine 1, and the acceleration torque required to drive the vehicle in the low speed region can be secured. Further, when the vehicle is traveling at a constant speed in the high speed range, the engine 1 can be operated in the high torque range by locking the sun gear 4r, and the engine can be operated with high efficiency. ing. At that time, Sun Gear 9
r is in a free run state. Further, in the case of accelerating when the vehicle speed is medium speed or higher, the stepless speed changing function can be obtained by performing the cooperative control of the motor 5 and the motor 6.

In such a system, the motor 6 may be rotated at a high speed when the sun gear 4r is locked during high-speed traveling. To prevent this, the motor 6 is disengaged from the sun gear 9r by the clutch 23. There is a need. Further, as described above, it is necessary to engage the clutch 23 and electrically lock the motor 6 in order to lock the sun gear 9r during low speed traveling (including when the vehicle is stopped). A method of opening and closing the clutch 23 using the method of the present invention will be described below. Note that FIG.
In addition, in addition to the information as shown in FIG. 1, the following information is input to the control device 13. That is, the motor 6
Motor position θ from the position detector 24 that detects the position of
m, the sun gear position θs from the position detector 34 that detects the position of the sun gear 9r, the engine speed ωe of the engine 1 detected by the speed detector 25, and the current of the motor 6 are input to the control device 13.

The basic control method performed by the control device 13 is shown in the flow chart of FIG. 4, and the details of the method of processing the motor 6 control calculation in step 105, which is a characteristic part of this embodiment. Is shown in the flowchart of FIG. First, in step 131, the state of the clutch 23 is checked. If the clutch 23 is in the engaged state, the processes in and after step 132 are performed, and if it is in the released state, the processes in and after step 136 are performed. If the clutch 23 is in the engaged state, in step 132 the clutch 23
Judge whether there is a release command to release. If there is no opening command, a process for controlling the torque of the normal motor 6 is performed in step 133. That is, the torque control is performed by feeding back the motor position θm and the current of the motor 6 so that the torque command of the motor 6 determined in step 103 in the flowchart of FIG. 4 is generated. If there is an instruction to release the clutch 23 in step 132, the motor 6 does not need to generate torque with respect to the sun gear 9r, so the control of the motor 6 is stopped in step 134 to release the clutch 23. Step 1
35. Accordingly, in FIG. 7, the control device 1
The clutch 23 is disengaged by the signal from 3. When it is determined in step 131 that the clutch 23 is in the disengaged state, it is determined in step 136 whether or not there is a clutch 23 engagement command. If there is no engagement command, it is sufficient to keep the clutch 23 in the disengaged state, and therefore the processes of steps 134 and 135 described above are performed. If it is determined in step 136 that there is an engagement command for the clutch 23, the following processing is performed. In step 137, the sun gear position θs of the sun gear 9r and the motor position θm of the motor 6 are input, and the relative position θc is detected from the difference between them. Next, in step 138, the rotation fluctuation of the engine 1 is estimated from the engine speed ωe, and a position control command is generated according to the future rotation fluctuation caused by the influence of the pulsating torque generated by the engine 1. This position control command and relative position θ
The position control of the motor 6 is performed in step 139 from the feedback value of c. As a result, when it is determined in step 140 that the relative position θc has become 0, step 141
The engaging process of the clutch 23 is performed. When it is determined in step 140 that the relative position θc is not yet 0, the engagement process of the clutch 23 is not performed and the position control of the motor 6 is continued. As described above, when the method of engaging the clutch 23 after positioning by the position control of the motor 6 is adopted, as shown in FIG. 9, the clutch 23 having two engaging portions 23a and 23b without backlash is used. You can Further, since the clutch that is simple and has a strong engaging force can be used as described above, the hybrid vehicle has an advantage that a smaller and simpler drive system can be provided. The clutch 23 shown in FIG. 9 is an example of the embodiment, and may be a sawtooth-shaped clutch or a clutch having another shape.

The system of FIG. 10 is a block diagram showing another embodiment different from those of FIGS. 1 and 7. In this system, when the clutch 23 is released, the driving force of the engine 1 is changed to the generator 5
The electric power is converted into electric energy and the battery 12 is charged by the series hybrid method. In this case, the energy of the battery 12 is used to drive the motor 6 to control the driving torque of the tires 3 a and 3 b via the transmission 27. Further, when the clutch 23 is engaged, it is necessary to drive the vehicle by controlling the generator 5 and the motor 6 to add the drive torque of the engine 1 and the drive torque of the generator 5 and the motor 6. It is a parallel hybrid system that generates torque. The former method has a feature that the efficiency of the engine 1 can always be set to the maximum operating point, and the latter method has an advantage that the driving efficiency from the engine 1 to the tires can be transmitted without lowering. Therefore, control for switching between the two may be performed according to the operating point required by the vehicle. Therefore, the control device 13 performs the following control calculation. First, the torque calculator 30 calculates the vehicle drive torque τ * required by the driver from the accelerator signal Xa, the brake signal Xb, and the vehicle speed V. Next, the drive mode selection unit 31 inputs the vehicle drive torque τ *, the vehicle speed V, and the battery state Sb to determine the optimum operation mode M. That is, a mode such as a series hybrid system, a parallel hybrid system, an electric vehicle system in which the engine 1 is stopped, an engine system in which the driving of the motor 6 and the generator 5 is stopped and only the engine 1 is driven is determined according to the driving operation state. To do. Further, here, the clutch opening / closing reference value Xc * determined by the operation mode M is output to the clutch / generator control unit 33. The driving force distribution unit 32 to which the operation mode M is input calculates how to optimally distribute the vehicle driving torque τ * to each device according to the operation mode M. as a result,
Engine torque command τe of engine 1, generator speed reference value ωg * of generator 5, motor torque command τ of motor 6
m and the gear ratio command Xt of the transmission 27 are output to the respective devices.

The generator speed reference value ωg * is input to the clutch / generator control unit 33 because it needs to be controlled by the engagement state of the clutch 23. The clutch / generator control unit 33 outputs the generator speed reference value ωg * as it is to the generator 5 as the generator speed command ωg when the clutch 23 is continuously engaged or released. Similarly, the opening / closing reference value Xc * is also directly input to the clutch 23 as the opening / closing command Xc.

When the open / close reference value Xc * of the clutch 23 changes from the open state to the engaged state, the generator position θ1 and the motor position θ2 are input to the clutch / generator control unit 33 from the position detectors 28 and 29, respectively. And its relative position is 0
The position of the generator 5 is controlled so that After that, when the relative position between the generator position θ1 and the motor position θ2 becomes 0, the opening / closing command Xc of the clutch 23 is set to the engaged state. As a result, it is possible to shift to the operation mode of the parallel hybrid system.

Further, in order to change the open / close reference value Xc * of the clutch 23 from the engaged state to the released state, the generator 5 is controlled so that the driving torque transmitted through the clutch 23 by the engine 1 becomes zero. Generates torque. Next, when the torque applied to the clutch 23 becomes 0, the opening / closing command Xc of the clutch 23 is opened. By controlling in this way, the driving force for opening and closing the clutch 23 can be reduced, so that there is an advantage that a small clutch can be adopted as the system. Therefore, there is an effect that the hybrid vehicle drive system can be realized in a small size and at low cost. In particular, a small actuator may be used to drive the clutch and the fastening device, and it is not necessary to use a drive mechanism using hydraulic pressure as in a conventional automobile, which is very effective as a hybrid vehicle.

The above is one embodiment of the present invention, and the description has been given of the example of the hybrid vehicle, the series-parallel hybrid vehicle and the like using the planetary gears for the fastening device and the clutch, but it is also applied to the case of other hybrid vehicles. it can. For example, the present invention can be applied to a case where three or more planetary gears are used or a method in which several hybrid methods are combined. Further, it goes without saying that the clutch and the fastening device can be used not only in a device that can be fastened at one place per one rotation but also when they can be fastened multiple times.

[0023]

According to the present invention, since the fastening device and the clutch can be downsized by utilizing the motor and the generator used in the hybrid vehicle, it is possible to provide a cheaper hybrid vehicle drive system.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment when the present invention is applied to a hybrid vehicle using a planetary gear that controls a sun gear by a motor.

FIG. 2 is a configuration diagram showing a specific configuration method of the fastening device 11 of FIG.

3 is a schematic view showing an outline of the fastening device 11 of FIG.

4 is a flowchart showing an outline of a control method for driving the hybrid vehicle of FIG.

5 is a flowchart showing a fastening processing method of the fastening device 11 in FIG.

FIG. 6 is a flowchart showing a method of controlling the generator 5 in FIG.

FIG. 7 is a configuration diagram showing another embodiment of the present invention in a hybrid vehicle using two sets of planetary gears controlled by a motor.

8 is a flowchart showing a method of controlling the clutch 23 and the motor 6 of FIG.

9 is a configuration diagram showing an outline of the clutch of FIG. 7. FIG.

FIG. 10 is a configuration diagram showing another embodiment of the present invention applied to a series-parallel hybrid type hybrid vehicle.

[Explanation of symbols]

1 ... Engine, 2a, 2b ... Drive shaft, 3a, 3b ... Tire, 4, 9 ... Planetary gear, 5 ... Generator (motor), 6 ... Motor, 7, 8 ... Power converter 10, 15, 16, 17,
18, 19, 20, 21, 21, 22 ... Gears, 11 ... Fastening device, 12 ... Battery, 13 ... Control device, 14, 24,
28, 29, 34 ... Position detector, 23 ... Clutch, 2
5, 26 ... Speed detector, 27 ... Transmission, 30 ... Torque calculating section, 31 ... Driving mode selecting section, 32 ... Driving force distributing section,
33 ... Clutch / generator control unit.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI F02D 29/02 F02D 29/02 D (72) Inventor Ryozo Masaki 7-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Inside Hitachi Research Laboratory (72) Inventor Toshimichi Minowa 1-1-1 Omika-cho, Hitachi City, Ibaraki Hitachi Ltd. Inside Hitachi Research Laboratory (56) Reference JP-A-9-156387 (JP, A) JP-A-6- 210504 (JP, A) JP 10-35301 (JP, A) JP 7-269603 (JP, A) JP 7-172196 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60L 11/14 B60K 6/04 B60K 41/02 F02D 29/02

Claims (3)

(57) [Claims] And 1. A engine that will be driven me by the combustion of the fuel, a motor that will be driven me by the electrical energy, together with the motor is connected, controlling the motor child
Of the engine whose rotational speed has been changed by
A differential mechanism that transmits drive torque to a vehicle, a control device that controls the drive torque of the vehicle by controlling the engine and the motor, and rotation of the motor to a predetermined rotation.
A fastening device for mechanically locked in position, the motor times
And a position detecting device for detecting the translocation, the control device of the motor detected by said position detecting device
The rotation position is used to determine the rotation position of the motor
Controlling the motor such rolling a position mechanically by locking the rotation of the motor I by the said fastening device <br/>
Is a hybrid vehicle. 2. The hybrid vehicle according to claim 1.
To estimate the rotation fluctuation of the engine,
A hybrid vehicle characterized by controlling the rotational position . 3. The hybrid vehicle according to claim 1.
The differential mechanism controlled by the motor
Equipped with at least two sets to control the rotational position of each motor.
A hybrid vehicle characterized by having means for controlling .