JP3371413B2 - Hybrid vehicle - Google Patents

Abstract

PURPOSE: To reduce fuel consumption and an exhaust gas and at the same time improve a travel feeling by continuing the charging of a battery when the actuating quantity of a brake is not more than a predetermined value and bringing an engine into a stand-by state when the actuating quantity of a brake exceeds the predetermined value. CONSTITUTION: In the case where torque is determined unnecessary with respect to a demand torque from the actuating quantity of a brake 39 detected by a brake sensor 49 and when the actuating quantity of the brake 39 detected by the brake sensor 49 is root more than a predetermined value, an engine controller 42 continues the charging of a battery 3. When the actuating quantity of the brake 39 detected by the brake sensor 49 exceeds the predetermined value, it brings an engine 1 into a stand-by state. Therefore, fuel consumption and an exhaust gas can be reduced and at the same time a travel feeling can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle, and more particularly to a parallel type hybrid vehicle having a motor and an engine as driving sources.

[0002]

2. Description of the Related Art Conventionally, a hybrid vehicle has been proposed in which the exhaust gas emitted from the engine is made cleaner by assisting the engine with a motor. For example, in the hybrid vehicle disclosed in Japanese Patent Laid-Open No. 5-229351, the engine is always driven in the optimum efficiency state, and when the required torque is larger than the maximum efficiency torque of the engine, the motor assists the shortage. When the required torque is smaller than the maximum efficiency torque of the engine, the motor electrically collects the surplus. When the required torque is less than or equal to zero, all the driving torque from the engine is electrically recovered by the motor.

[0003]

However, there is a limit value in the allowable charge amount of the battery. For this reason, if the brake energy is regenerated while regenerating all output from the engine that is driven at the maximum efficiency point with the throttle opening WOT (Wide Open Throttle), the allowable charge amount will exceed the limit value, and There was a case where it was charged. In order to prevent overcharging and rapid charging, it is necessary to reduce the engine output or prevent regeneration by braking, but in the former case, the exhaust gas increase or Fuel consumption is reduced, and in the latter case, regenerative energy is lost due to braking.

The present invention has been made to solve the above problems, and a first object of the present invention is to provide a hybrid vehicle in which fuel consumption is improved, exhaust gas is reduced, and traveling feeling is improved. . A second object is to provide a hybrid vehicle capable of preventing overcharging of the power supply device .

[0005]

According to a first aspect of the present invention, in a hybrid vehicle including a motor and an engine for generating a driving force of a vehicle , a brake detecting means for detecting a depression amount of a brake, and a vehicle Regenerative means for regeneratively charging the power supply device with energy due to deceleration ,
Depression amount of Kivu lake continues to charge the power source apparatus according to the engine drive torque when the predetermined value or less, before Symbol
Depression amount of brake exceeds a predetermined value, the engine
When the rotation speed is lower than the predetermined rotation, while the standby state of the engine, the amount of depression of the brake
Exceeds the specified value and the engine speed exceeds the specified value.
If it is too large, cut the fuel of the engine and
The reduction of the torque due to the charge cut is output by the motor.
The first purpose is achieved by supplementing with Luke. In the invention described in claim 2, in a hybrid vehicle having a motor and an engine for generating a driving force of the vehicle,
Brake detection means for detecting the amount of brake depression,
A charging power detection means for detecting a charging power of the power supply, the energy by the deceleration of the vehicle has a regenerative means for regenerative charging in the power supply device, the charging electric power of the power supply when the predetermined value or less of the engine continues to charge the electric <br/> supply device by the driving torque, the charging electric power exceeds a predetermined value,
The rotation speed of said engine is in <br/> is smaller than a predetermined rotation in the standby state the engine, the charging
The electric power exceeds a specified value, and the engine speed reaches the specified speed.
If it is greater than
The amount of torque reduction due to fuel cut is output from the motor.
The first purpose and the second purpose are supplemented by torque.
Achieve the purpose of.

[0006] In the invention described in claim 3, in the hybrid vehicle according to claim 1 or claim 2, before disappeared <br/> If the to standby state engine, and stopped or idling condition of said engine It is characterized by Claim 4
In the invention described in the hybrid vehicle according to claim 3, when the front disappeared engine to a standby state, further comprising a clutch releasing means for releasing the clutch for transmitting the output of said <br/> engine It is characterized by Claim 5
In the hybrid vehicle described in the present invention, in claim 4 according to, comprising a vehicle speed detecting means for detecting a vehicle speed, the clutch opening means, a pre disappeared engine even when in the standby state, and the vehicle speed It is characterized in that the clutch is opened when the vehicle speed detected by the detection means is equal to or lower than a predetermined value.

[0007]

According to the first aspect of the present invention, when the amount of depression of the brake is less than or equal to the predetermined value, the charging of the power supply device by the engine driving torque is continued, the amount of depression of the brake exceeds the predetermined value, and the engine speed becomes the predetermined value. When the rotation speed is smaller than the rotation speed, the engine is placed in a standby state, and when the brake depression amount exceeds a predetermined value and the rotation speed of the engine is higher than the predetermined rotation speed, the engine is fuel cut,
The amount of decrease in torque due to the fuel cut is supplemented by the output torque of the motor. According to the second aspect of the present invention, when the charging power of the power supply device is less than or equal to the predetermined value, the charging of the power supply device by the drive torque of the engine is continued, the charging power exceeds the predetermined value, and the engine speed is higher than the predetermined rotation speed. When it is smaller, the engine is placed in a standby state, and when the charging power exceeds a predetermined value and the engine speed is higher than the predetermined rotation, the engine is cut off with fuel, and the amount of torque reduction based on the fuel cut is output by the motor. Supplement with torque.

In the hybrid vehicle according to claim 3,
When putting the engine in the standby state, stop the engine or put it in the idling state. In the hybrid vehicle according to the fourth aspect, when the engine is in the standby state, the clutch that transmits the output of the engine is released. In the hybrid vehicle according to the fifth aspect, the clutch is disengaged when the engine is in the standby state and the vehicle speed detected by the vehicle speed detecting means is equal to or lower than the predetermined value.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the hybrid vehicle of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a skeleton diagram (bone diagram) showing an arrangement of drive devices for a hybrid vehicle. As shown in this figure, the hybrid vehicle is a parallel type hybrid vehicle. A drive device for a hybrid vehicle includes an engine (EG) 1, a clutch 2, a battery 3 as a power supply device, a motor (M).
4 and a differential gear 5 are provided, and they have a triaxial structure. The output shaft 1 of the engine 1 is on the first shaft.
a and the clutch 2 are arranged, the output shaft 1 of the engine
A and the output shaft 4a of the motor 4 are connected via the clutch 2. A counter drive gear 6 is connected to the output shaft 4a of the motor 4. A counter driven gear 8 and a diff pinion gear 9 are held on the counter shaft 7 that constitutes the second shaft. The counter drive gear 6 is meshed with the counter driven gear 8. The differential gear 5 is driven via a differential ring gear 10 arranged on the third shaft. The differential ring gear 10 and the differential pinion gear 9 are meshed with each other.

FIG. 2 is a block diagram showing the configuration of the circuit portion of the hybrid vehicle according to this embodiment. The hybrid vehicle of this embodiment includes a control unit 40 for controlling the overall operation of the vehicle. The control unit 40 includes a CPU (central processing unit) 51 that performs various controls.
ROM is connected to 51 via a bus line 52 such as a data bus
(Read only memory) 53, RAM (random
An access memory 54, an output I / F (interface) unit 56, and an input I / F unit 57 are connected to each other. The ROM 53 stores various programs and data for the CPU 51 to determine the traveling state and the like based on various signals input from the input I / F unit 57 and to appropriately control each unit. The RAM 54 is a working memory for the CPU 51 to perform processing in accordance with the programs and data stored in the ROM 53, and the input I / F unit 57.
Various signals input from the control signals output from the output I / F unit 56 are temporarily stored.

The output I / F section 56 has a clutch controller 41 for controlling engagement and disengagement of the clutch 2, an engine controller 42 for driving a starter at the time of starting and adjusting the opening of a throttle valve during driving,
A motor controller 43 that controls the output of the motor 4 and controls regenerative charging of the battery is connected to each. On the other hand, the input I / F section 57 includes a rotation sensor 46 that detects the rotation speed of the engine output shaft 1a, that is, the rotation speed of the clutch 2 on the input side, a vehicle speed sensor 47 that detects the rotation speed of the output shaft 22, and an accelerator 38. Accelerator sensor 48 for detecting the accelerator opening degree from the depression amount of the brake pedal, and brake sensor 4 for detecting the depression amount of the brake pedal 39.
9. A battery remaining amount sensor 50 for detecting the battery remaining amount from the voltage, current, etc. of the battery 3 is connected to each.

Next, the operation of the embodiment thus constructed will be described. FIG. 3 is a flow chart showing an output control routine of the operation of the first embodiment. In the first embodiment, the required driving force (required torque) is determined by looking at the amount of brake depression, and if it is not required, fuel cut is performed to improve fuel efficiency and reduce exhaust gas. It is intended. First, the CPU 51 of the control unit 40
Inputs from the accelerator sensor 48 the accelerator opening degree due to the depression of the accelerator 38 (step 11)
At the same time, the brake sensor 4 detects the depression amount of the brake 39.
Input from 9 (step 12).

Then, the CPU 51 determines whether or not the inputted brake depression amount is equal to or larger than a predetermined value (step 13). If the amount of depression is not more than the predetermined amount (step 1
3; N), the CPU 51 calculates the required drive torque Td from the brake depression amount (step 14), calculates the engine maximum efficiency torque Temax from the rotation speed of the engine 1 obtained from the rotation sensor 46, and at that time. Calculate the throttle opening Th (step 1
5). Further, the CPU 51 causes the required drive torque Td calculated in step 14 and the engine maximum efficiency torque Temax.
Therefore, the output torque Tm of the motor is Tm = Td−Tem
It is calculated by ax (step 16).

Then, the CPU 51 outputs the calculated output torque Tm to the motor controller 43 (step 17) and, at the same time, outputs the throttle opening Th to the engine controller 42 (step 18), and then ends the output control routine and finishes the main routine. Return to routine. The motor controller 43 drives and controls the motor 4 with the supplied output torque Tm, and the engine controller 42 drives and controls the engine 1 with the engine maximum efficiency torque Temax by setting the throttle opening to the supplied Th.

As described above, in the first embodiment, the brake 3
When the depression amount of 8 is small, the engine is driven at the maximum efficiency point of the engine in the routine (steps 11 to 18) for performing the normal parallel operation. On the other hand, if it is determined in step 13 that the brake depression amount is equal to or greater than the predetermined amount (Y), the brake depression process is performed (step 19) and then the process proceeds to step 17.

FIG. 4 is a flow chart showing a subroutine of the brake depression process. As shown in FIG. 4, the CPU 51 of the control unit 40 executes step 1 of FIG.
Regenerative torque Tdb from the brake depression amount input in 2
Is calculated (step 21), and the rotation speed of the engine 1 is input from the rotation sensor 46 (step 22). And C
The PU 51 determines whether the input engine speed is higher than a predetermined value, for example, 2000 rpm (step 23).

When the number of revolutions of the engine 1 is greater than 2000 (step 23; Y), if the clutch 2 is turned off during the fuel cut, the engine rotation fluctuation is large and the traveling feeling is deteriorated. A clutch ON command is output to the clutch controller 41 to put the clutch 2 in the engaged state (step 24).
After that, the CPU 51 outputs a fuel cut command to the engine controller 42 (step 25). At this time, the throttle is kept open to minimize engine braking. Further, the amount of decrease in torque due to the fuel cut, that is, the engine brake torque Teb is calculated from the throttle opening Th and the engine speed (step 26). Then, the CPU 51 supplements the torque reduction due to the engine 1 with the output torque of the motor 4, so that the output torque Tm of the motor 4 is Tm.
= Tdb-Teb is calculated (step 27), and the process returns to step 17 of the output control routine shown in FIG.

As described above, in step 23, when the engine 1 speed is higher than 2000 rpm, if the fuel is cut and the clutch is suddenly disengaged, the feeling is deteriorated. Step 23 to Step 2 until the number is 2000 rotations or less
The process of 7 is repeated. On the other hand, at the stage where the rotation speed of the engine 1 has dropped to 2000 rotations or less (step 23;
N), the CPU 51 outputs an OFF signal to the clutch controller 41 to disconnect the clutch 2 (step 28). Further, the throttle opening Th for driving the engine 1 in the idling state so as not to stall the engine 1
Is calculated (step 29), and the output torque Tm of the motor 4 is calculated from the regenerative torque Tdb calculated in step 21.
(Step 30) and returns to step 17 of the output control routine shown in FIG.

FIG. 5 shows a time chart of each part by such an output control routine. As indicated by the reference numeral, when a large driving force is required at the time of starting, that is, when the required driving torque Td is large, the engine (E / G) torque is set to the engine maximum efficiency torque Tema.
The driving force that is insufficient even if x is the torque of the motor 4 is Tm.
This is supplemented by setting Td-Temax. Then, as indicated by the reference numeral, during steady running, the surplus of the engine torque is generated by the motor 4 and the battery 3 is charged.

Further, as indicated by the reference numeral, during coasting, the engine 1 maintains the engine torque Temax by keeping the throttle opening WOT.
To drive the surplus (Tem to the required drive torque Td).
The electric power is generated by the motor 4 according to ax-Td) and the battery 3 is charged. When the brake 39 is depressed and the depression amount of the brake 39 becomes equal to or larger than a certain amount (indicated by symbol A), the electronically controlled fuel injection EFI is set as indicated by the symbol.
The fuel is cut by turning off (Electronic Fuel Injection). At this time, the engine torque decreases as indicated by arrow B, and therefore the regenerative torque of the motor 4 is reduced as indicated by arrow C. The throttle should be left open to minimize engine braking during fuel cut. Then, as indicated by a symbol, when the rotation speed of the engine 1 becomes equal to or lower than a predetermined value or the vehicle speed becomes equal to or lower than a predetermined value, the clutch 2 is released (OF
F) and at the same time make the throttle opening zero. Then, the EFI is turned on again to bring the engine 1 into the idling state.

Next, the operation of the second embodiment will be described.
In the second embodiment, if you do not require the output 1 of the engine, that the charging power of the battery is a fuel cut when a predetermined value or more, fuel efficiency while protecting the battery,
It is intended to reduce exhaust gas. FIG. 6 is a flowchart showing the output control routine of the operation in the second embodiment. First, the CPU 51 of the control unit 40 controls the accelerator 3
Accelerator opening and brake 3 by stepping on 8
The depression amount of 9 is input from the accelerator sensor 48 and the brake sensor 49 (step 21). Furthermore, C
The PU 51 inputs the battery current and the battery voltage (step 42).

Then, the CPU 51 uses the input accelerator
From the opening and the amount of brake depression, the required drive torque T
d is calculated (step 43). Here, the CPU 51
Is calculated from the accelerator opening degree when the torque is increased, and is calculated from the brake depression amount when the torque is decreased to calculate both acceleration and deceleration. After that, the CPU 51 determines from the input battery current and battery voltage whether or not the allowable battery charge amount is equal to or greater than a predetermined value (step 44).

When the battery charging power is less than the predetermined value (step 44; N), the engine maximum efficiency torque Te is calculated from the rotation speed of the engine 1 obtained from the rotation sensor 46.
max is calculated and the throttle opening T at that time is calculated.
Calculate h (step 45). Furthermore, the CPU 51
From the required drive torque Td calculated in step 43 and the engine maximum efficiency torque Temax, the motor output torque Tm is calculated by Tm = Td-Temax (step 46).

Then, the CPU 51 outputs the calculated output torque Tm to the motor controller 43 (step 47) and, at the same time, outputs the throttle opening Th to the engine controller 42 (step 48), and then ends the output control routine and finishes the main routine. Return to routine. The motor controller 43 drives and controls the motor 4 with the supplied output torque Tm, and the engine controller 42 drives and controls the engine 1 with the engine maximum efficiency torque Temax by setting the throttle opening to the supplied Th.

As described above, in the second embodiment, when the remaining amount of the battery is low, the engine is driven at the maximum efficiency point of the engine in the routine (steps 41 to 48) for performing the normal parallel operation. On the other hand, step 44
In the case where the battery charging power is judged as Ru der predetermined or more (; Y), after the allowable charge amount outside processing (step 49), the process proceeds to step 47. The sub-routine for the permissible charge process is the same as the operation shown in FIG. 4 in the first embodiment.

Next, the operation of the second embodiment described above will be described with reference to the time chart shown in FIG.
The operation of the second embodiment differs from that of the first embodiment in the state shown by the reference numeral. That is, the first
In the embodiment, the fuel is cut off under the condition that the brake 39 is depressed and the depression amount is equal to or more than the constant amount indicated by the symbol A. On the other hand, in the second embodiment, as indicated by the symbol D in FIG. 5, the electronically controlled fuel injection EFI (Electr) is provided on condition that the battery charging power exceeds the allowable charging power.
Turn off onicFuel Injection) to cut fuel. The other states indicated by reference numerals 1 to 3 operate in the same manner as in the first embodiment.

As described above, in the first and second embodiments, when the engine speed becomes equal to or lower than the predetermined value (step 23 in FIG. 4; Y), the clutch is turned off and the clutch is turned off. , The engine 1 is driven in the idling state. However, the present invention is not limited to this, and the engine 1 may be stopped instead of the idling state. By stopping the engine 1, the fuel economy can be further improved.
When the engine 1 is stopped, in the first embodiment, when the brake depression amount is no more than a predetermined value, and in the second embodiment, when the battery charging power becomes less than the predetermined value, the engine 1 The control for restarting is started.

In the operations of the first and second embodiments described above, it is possible to judge whether the vehicle speed is equal to or lower than a predetermined value,
Although it is determined in step 23 whether or not the rotation speed of the engine 1 is higher than a predetermined value (2000 rpm), it may be determined whether or not the vehicle speed detected by the vehicle speed sensor 47 is equal to or lower than the predetermined value. . In the first and second embodiments described above, the engine speed of the engine 1 is 2000 rp in step 23 of FIG.
It was judged whether or not it was larger than m.
It may be 0 rpm or 1000 rpm. Further, in the first and second embodiments described above, the fuel cut is performed with the clutch engaged, but in the present invention, the clutch is released simultaneously with the fuel cut so that the engine brake is not applied. Thus, the deceleration energy may be regenerated by the motor as much as possible.

Further, in the embodiment, the case where the battery 3 is used as a power supply device for exchanging electric power with the motor 4 has been described, but in the present invention, as another power supply device,
Other power supplies such as capacitors, flywheel batteries, hydraulic (pneumatic) accumulators may be used. As a capacitor, for example, an electric capacitor 2 having a large capacity per unit volume, a low resistance, and a large output density is used.
Multilayer capacitors and other capacitors are used. When a capacitor is used as the power supply device, the voltage value of the capacitor is used as the remaining power capacity (SOC). The flywheel battery is a battery that exchanges electric power by driving and regenerating the flywheel with a motor coaxially arranged on the flywheel. The rotational speed of the flywheel is used as the residual power capacity (SOC) when the flywheel battery is used as a power supply device. The hydraulic (pneumatic) accumulator
By moving the oil (pneumatic) pressure in and out of the accumulator with the oil (pneumatic) pressure pump connected to the accumulator,
It is a battery that exchanges electric power. Oil (pneumatic) pressure is used as the residual power capacity (SOC) when the hydraulic (pneumatic) accumulator power supply device is used.

[0030]

According to the invention described in claim 1, the fuel consumption is improved, the exhaust gas is reduced, and the traveling feeling can be improved. According to the invention described in claim 2, it is possible to further prevent the battery from being overcharged.

[Brief description of drawings]

FIG. 1 is a skeleton diagram (bone diagram) showing an array of drive devices for a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a circuit portion of the hybrid vehicle of the above.

FIG. 3 is a flowchart showing an output control routine of an operation in the first embodiment.

FIG. 4 is a flow chart showing a subroutine of a process when the brake pedal is depressed in the first embodiment.

FIG. 5 is a time chart of each part according to the output control routine in the first and second embodiments.

FIG. 6 is a flowchart showing an output control routine of the operation in the second embodiment.

[Explanation of symbols] 1 engine 2 clutch 3 battery 4 motor 38 accelerator 39 brakes 40 control unit 41 Clutch controller 42 Engine controller 43 Motor controller 48 accelerator sensor 49 Brake sensor 50 Battery level sensor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B60K 6/04 400 B60K 6/04 400 530 530 B60L 7/20 B60L 7/20 F02D 29/02 F02D 29/02 D 41/12 310 41/12 310 330 330 J (56) Reference JP-A-6-55941 (JP, A) JP-A-2-256843 (JP, A) JP-A-4-322105 (JP, A) JP-A-4- 297330 (JP, A) JP-A-6-144020 (JP, A) JP-A-5-137207 (JP, A) JP-A-8-308015 (JP, A) Actually open flat 2-310 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 6/02-6/04 B60L 11/00-11/18 F02D 29/00-29/06 F02D 41/00-41/40

Claims (5)

(57) [Claims] 1. A hybrid vehicle having a motor and an engine for generating a driving force of the vehicle, a brake detecting means for detecting the amount of depression of the brake, and the regenerative means for regenerative charging energy by the deceleration of the vehicle to the power supply has, prior to the depression amount of the Kivu lake continues to charge the power source apparatus according to the engine drive torque when the predetermined value or less, the amount of depression of the front Kivu rake exceeds a predetermined value, said engine
When the rotation speed of the emission is lower than the predetermined rotation, the end <br/> Jin with a standby state, the depression amount of the brake exceeds a predetermined value, said engine
If the engine speed is higher than the specified speed,
Fuel cut the gin and reduce the torque based on the fuel cut.
A hybrid vehicle, characterized in that a small amount is supplemented by the output torque of the motor . 2. A hybrid vehicle having a motor and an engine for generating a driving force of the vehicle, a brake detecting means for detecting the amount of depression of the brake, the charging electric power detecting means for detecting a charging power of the power supply device, the vehicle the energy from the deceleration anda regeneration means for regenerating charged in the power supply device, the charging electric power of the power supply when the predetermined value or less continues charging of the power supply according to the driving torque of the d <br/> engine However, when the charging power exceeds a predetermined value, the rotation of the engine
As the number is small sometimes standby state the engine than a predetermined rotation, said charging power exceeds the predetermined value, the rotational speed of the engine
If the engine speed is higher than the specified speed, the engine is
The amount of torque reduction due to the fuel cut.
A hybrid vehicle characterized by being supplemented by the output torque of the motor. 3. When the pre disappeared engine to a standby state, before
The hybrid vehicle according to claim 1 or claim 2, characterized in that the serial engine and stopped or idling condition. The 4. Before disappear engine when the standby state,
The hybrid vehicle according to claim 3, further comprising a clutch releasing means for releasing the clutch for transmitting the output of the engine. Provided 5. A vehicle speed detecting means for detecting a vehicle speed, said clutch release means is the case with prior disappeared engine to a standby state, and the detected vehicle speed by the vehicle speed detecting means is below a predetermined value The hybrid vehicle according to claim 4, wherein the clutch is disengaged when it is.