JP2003199209A - Drive control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive control device for a hybrid vehicle capable of reducing the discomfort of an occupant by releasing a shock in applying the driving force of an internal combustion engine. <P>SOLUTION: The drive control device for the hybrid vehicle comprising an electric motor 2 and the internal combustion engine 3 as a drive source is characterized in that: when a load has a value smaller than a prescribed value, a drive wheel is driven by the driving force of only the electric motor 2; when the load has a value larger than the prescribed value, the drive wheel is driven by driving forces of both the electric motor 2 and the internal combustion engine 3; a driving force detection sensor 16 that detects the driving force is arranged in a driving force transmission system between the drive wheel 4 and the internal combustion engine 3; and when the drive wheel is driven by both the electric motor 2 and the internal combustion engine 3, the electric motor is controlled so that the driving force from the electric motor 2 is decreased when a detection driving force by the driving force detection sensor 16 is largely changed at a change rate exceeding a prescribed value. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for a hybrid vehicle in which drive wheels are driven by both an electric motor and an internal combustion engine.

[0002]

2. Description of the Related Art A hybrid vehicle in which the rear wheels are driven through a mission by the driving force of a drive motor which is rotated by electric power from a battery and the battery is charged by a generator driven by an internal combustion engine is known. It has been proposed (see, for example, JP 2001-190004 A).

By the way, in the above-mentioned conventional hybrid vehicle, the rear wheels are driven only by the driving force of the electric motor. Therefore, even when a large external load is applied, for example, when traveling on an uphill road, a predetermined amount is applied. There is a problem that a large-sized and large-output electric motor is required to ensure the vehicle speed.

In order to avoid such a problem, it is possible to drive the drive wheels by both the electric motor and the internal combustion engine. That is, when the load is low, it is driven only by the electric motor,
At high load, it is driven by both the electric motor and the internal combustion engine.

[0005]

When both the electric motor and the internal combustion engine are provided and the driving by only the electric motor and the driving by both the electric motor and the internal combustion engine are switched according to the load, the load is small. When the driving force of the internal combustion engine is applied to the motor driving force when the driving force of the internal combustion engine is applied to the motor, a large impact acts on the vehicle at the moment when the driving force of the internal combustion engine is applied and May give a pleasant sensation.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a driving control device for a hybrid vehicle capable of reducing an impact when a driving force of an internal combustion engine is applied and reducing an occupant's discomfort. That is the issue.

[0007]

According to a first aspect of the present invention, in an operation control device for a hybrid vehicle having an electric motor and an internal combustion engine as a drive source, when the load is less than a predetermined value, the driving force of only the electric motor is used. When driving the drive wheels and the load is equal to or more than the predetermined value, the drive wheels are driven by the drive forces of both the electric motor and the internal combustion engine, and the drive force transmission system from the internal combustion engine to the drive wheels is in the middle. When a driving force detection sensor for detecting the driving force is arranged and the driving wheels are driven by both the electric motor and the internal combustion engine, the driving force detected by the driving force detection sensor is large at a rate of change of a predetermined value or more. The electric motor is controlled so that the driving force from the electric motor decreases when the electric motor changes in the direction.

Here, as a method of reducing the driving force from the electric motor, the driving force from the electric motor is reduced to a predetermined time after a rate of change above the predetermined value is detected. It is possible to employ a method of gradually reducing the amount at a predetermined reduction rate. In this case, various modes such as increasing the decrease rate or increasing the predetermined time as the rate of change of the driving force from the internal combustion engine in the large direction increases can be adopted.

According to a second aspect of the present invention, in a drive control device for a hybrid vehicle having an electric motor and an internal combustion engine as a drive source, when the load is less than a predetermined value, the drive wheels are driven by the drive force of only the electric motor. When the load is equal to or higher than the predetermined value, the drive wheels are driven by the driving forces of both the electric motor and the internal combustion engine, and a start detection sensor for detecting the start of the internal combustion engine is provided, and the start of the internal combustion engine is detected. At this time, the electric motor is controlled so that the driving force from the electric motor is reduced.

Here, regarding the start of the internal combustion engine, for example, it is determined that the internal combustion engine has started when the crankshaft rotation speed of the internal combustion engine increases from the rotation speed during cranking to a predetermined start determination rotation speed or more. The specific method of reducing the driving force is the same as in claim 1.

According to a third aspect of the present invention, in the first or second aspect, a vehicle speed detection sensor for detecting the vehicle speed is provided, and the smaller the detected vehicle speed, the larger the reduction amount of the driving force of the electric motor.

Here, to increase the amount of decrease in the driving force of the electric motor means, for example, gradually decreasing at a predetermined decrease rate for a predetermined time, and increasing the decrease rate, or the above predetermined time. Means to lengthen.

According to a fourth aspect of the present invention, in a drive control system for a hybrid vehicle having an electric motor and an internal combustion engine as a drive source, when the load is less than a predetermined value, the drive wheels are driven by the drive force of only the electric motor. When the load is equal to or higher than the predetermined value, the driving wheels are driven by the driving forces of both the electric motor and the internal combustion engine, and the V-belt type continuously variable transmission is provided in the middle of the driving force transmission system from the internal combustion engine to the driving wheels. It is characterized by interposing.

[0014]

According to the first aspect of the present invention, the driving force from the electric motor is reduced when the driving force from the internal combustion engine changes in a large direction at a rate of change of a predetermined value or more. It is possible to mitigate a sudden increase in the total driving force from the electric motor, and as a result, it is possible to mitigate the impact caused by the application of the driving force from the internal combustion engine and reduce the discomfort to the occupant.

According to the second aspect of the present invention, since the driving force from the electric motor is reduced when the start of the internal combustion engine is detected, when the increase rate of the driving force from the internal combustion engine is actually detected. In comparison, the impact due to the application of the driving force from the internal combustion engine can be alleviated while the structure is simplified, such as the need for the driving force detection sensor is eliminated, and the occupant's discomfort can be reduced.

It is considered that the lower the vehicle speed, the greater the impact due to the application of the driving force from the internal combustion engine. However, according to the invention of claim 3, the lower the detected vehicle speed, the more the driving force of the electric motor is increased. Since the reduction amount is increased, it is possible to suppress the discomfort to the occupant even when the vehicle speed is low.

According to the invention of claim 4, since the V-belt type continuously variable transmission is interposed in the middle of the driving force transmission system from the internal combustion engine to the drive wheels, the V-belt type continuously variable transmission can be rapidly operated. When the driving force is increased, slippage occurs between the pulley and the V-belt, and the structural feature that the driving force increase can be mitigated is effectively utilized to reduce the impact caused by the driving force applied from the internal combustion engine. It can be relieved and the discomfort given to the occupant can be reduced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 4 are views for explaining an operation control device for a hybrid vehicle, specifically, a golf cart according to the first embodiment of the present invention, and FIG. 1 is a block diagram thereof. FIG. 2 is a drive torque characteristic diagram for explaining the operation, and FIGS. 3 and 4 are schematic diagrams showing the usage state of the golf cart.

In FIG. 1, reference numeral 1 denotes a golf cart, which drives an electric motor 2 and an internal combustion engine 3 to drive a pair of left and right rear wheels (driving wheels) 4, 4. A pair of left and right front wheels 5 and 5 are provided as a source.
Is configured to travel while being steered by the steering wheel 6.

The golf cart 1 has a manual traveling mode in which an occupant travels by manipulating the steering wheel 6, the accelerator pedal 7 and the brake pedal 8 artificially,
It is configured such that any of the automatic traveling modes in which the vehicle automatically travels along the guide line embedded in the road surface while detecting the guide line is selectable. The manual drive mode and the automatic drive mode are switched by operating the main switch 10 and the mode switch 11 of the operation panel 9.

The golf cart 1 is, for example, a golf course 4
When the vehicle is moved from a parking lot (not shown) on the traveling path 40a, the vehicle is driven in the manual traveling mode,
When traveling on a, the vehicle is operated in the automatic traveling mode. In the case of the automatic traveling mode, while the guide wire 40c buried in the ground of the traveling path 40a is detected, automatic traveling control described below is performed along the guide wire 40c so that the set target traveling speed V0 is achieved.

The electric motor 2 is a transmission 1
The two input shafts are arranged so as to be rotationally driven, and electric power from the battery 20 is supplied to the drive motor 2 through the motor driver 24. By controlling the motor driver 24 with the controller 22, the driving force from the electric motor 2, specifically, the magnitude of the output torque is controlled. The driving force from the electric motor 2 is transmitted via the transmission 12 to the rear wheels 4 and 4. Further, the transmission 12 is provided with a vehicle speed sensor 29 for detecting the rotational speed of the output shaft of the transmission 12 and the traveling speed of the golf cart 1.

Further, the carburetor 25 of the internal combustion engine 3 is connected to a throttle motor 26 for controlling the opening / closing of a throttle valve 25a of the carburetor 25. The throttle motor 26 is supplied with electric power from the battery 20 by a motor driver 27. Supplied through. By controlling the motor driver 27 with the controller 22, the throttle valve opening and thus the driving force from the internal combustion engine 3, for example, the magnitude of the output torque is controlled. The opening of the throttle valve 25a is detected by the throttle sensor 28, and the detected throttle opening signal is sent to the controller 22.

The driving force from the internal combustion engine 2 is transmitted to the rear wheels 4, 4 via the driving force transmission system a and the transmission 12. The driving force transmission system a may be of a chain type in which a chain is wound around a driving side or a driven side sprocket, a belt type in which a toothed belt is wound around a driving side or a driven side pulley, or a drive shaft type. Things are adopted.

An electromagnetic clutch 15 which is on / off controlled by the controller 22 is interposed in the middle of the driving force transmission system a. This clutch 15
It is turned off in the driving range in which the rear wheels 4 are driven only by the electric motor 2, so that power transmission from the rear wheels to the internal combustion engine side is blocked.

As the clutch 15, in addition to the electromagnetic type, a one-way clutch that allows only power transmission from the internal combustion engine 13 to the rear wheel 4 side and disables power transmission in the opposite direction is adopted. Is also possible.

A driving force detecting sensor for detecting the transmitted driving force, specifically, a torque sensor 16 for detecting the transmitted torque is interposed upstream of the clutch 15 in the direction in which the driving force reaches.

A generator 17 is connected to the crankshaft of the internal combustion engine 3, and the current value from the generator 17,
The voltage value is sent to the controller 22. The rotation speed of the crankshaft of the internal combustion engine 3, that is, the rotation speed of the generator 17 is detected by the rotation speed sensor 23, and the detection signal is sent to the controller 22.

The output of the generator 17 is supplied to a battery 20 which is a power source of the electric motor 2 via a changeover switch 18 and an inverter / converter 19. The battery 20 is connected to a battery state detector 21 for detecting the battery state such as voltage, charge / discharge current amount, temperature and the like.

Next, the control operation and action and effect of the controller 22 will be described. In the manual running mode, when the occupant steps on the accelerator pedal 7 to reach a position with a large external load such as an uphill or to accelerate, the amount of stepping is detected by the accelerator sensor 7a, and the detected accelerator opening degree is detected. The accelerator opening signal corresponding to the degree is sent to the controller 22, and the controller 22 controls the operation of the electric motor 2 and the internal combustion engine 3 as follows.

On the other hand, in the automatic running mode, the driver does not step on the accelerator pedal, and therefore the load cannot be calculated based on the accelerator pedal step amount in the manual running mode. However, since the detected vehicle speed V1 changes according to the change in the external load, in the automatic driving mode, the external load, that is, the load required for the internal combustion engine and the electric motor 2 is detected by the difference between the target vehicle speed V0 and the detected vehicle speed V1. To be done. It is detected that the larger the target vehicle speed V0 is than the detected vehicle speed V1, the larger the load, and the smaller the target vehicle speed V0 is smaller than the detected vehicle speed V1, the smaller the load. When the detected vehicle speed V1 is lower than the target vehicle speed V0, a vehicle speed control signal corresponding to the difference ΔV is output.

A set load calculated based on the accelerator opening signal or the vehicle speed control signal (a load required by a person to the internal combustion engine 3 or the electric motor 2 in response to an external load, or a difference between a target vehicle speed and a detected vehicle speed). When the load required for the internal combustion engine and the electric motor (hereinafter, simply referred to as “load”) is less than a preset predetermined value, the rear wheel 4 is driven only by the driving force from the electric motor 2. When the load is equal to or more than the predetermined value, the electric motor 2 and the internal combustion engine 3 are
The driving of the electric motor 2 and the internal combustion engine 3 is controlled so that the driving wheels 4 are driven by both driving forces.

Specifically, when the load calculated based on the accelerator opening signal or the vehicle speed control signal is determined to be less than the predetermined value, the rear wheel 4 is driven by the driving force of only the electric motor 2. Then, the internal combustion engine 3 is held in a stopped state.
In this case, the clutch 15 is turned off and the rear wheels 4
Torque from the internal combustion engine 3 via the driving force transmission system a.
Is prevented from being transmitted to the internal combustion engine 3 and thus the internal combustion engine 3 is prevented from becoming a running resistance.

Further, as the accelerator pedal depression amount increases or the detected vehicle speed V1 becomes smaller than the target vehicle speed V0 in a range where the load is less than the predetermined value, the electric power supplied to the electric motor 2 is reduced. The motor dramber 24 is controlled to increase, so that the driving force from the electric motor 2 is controlled to a magnitude corresponding to the accelerator pedal depression amount or the difference between the target vehicle speed V0 and the detected vehicle speed V1. In the case of the automatic traveling mode, when the golf cart 1 reaches the uphill ab and the downhill cd d of the traveling path 40a as shown in FIG. 4, the difference ΔV in the vehicle speed becomes large or, conversely, becomes small. It will change slowly.

When the load exceeds the predetermined value, the crankshaft of the internal combustion engine 3 is cranked by a starter motor (not shown) in order to start the internal combustion engine 3, and
The operation of the ignition system and the fuel supply system is started. When the crankshaft rotation speed detected by the rotation speed sensor 23 exceeds the cranking rotation speed, which is greater than the cranking rotation speed, the internal combustion engine 3 is judged to have started, and the throttle valve 25a of the carburetor 25 is opened. The throttle motor 26 controls opening and closing so that the degree becomes an opening degree corresponding to the accelerator opening signal or the vehicle speed control signal.

When the internal combustion engine 3 is started, the torque detected by the torque sensor 16 changes in a large direction at a change rate of a predetermined value or more (see b in FIG. 2 (a)).
Then, the electric power supplied to the electric motor 2 is controlled via the motor driver 24 so that the drive torque from the electric motor 2 is gradually reduced at a predetermined rate (see c in FIG. 2B). The predetermined ratio in the case of reducing the drive torque from the electric motor 2 is set to be larger as the vehicle speed detected by the vehicle speed sensor 29 at the time of starting the internal combustion engine is lower, that is, the vehicle is traveling at a lower speed. As a result, the amount of decrease in the drive torque from the electric motor 2 increases as the vehicle travels at a lower speed.

Incidentally, after the time when the rate of change of the detected torque from the internal combustion engine 3 in the large direction detected by the torque sensor 16 becomes less than or equal to the return judgment value set smaller than the predetermined value, the electric motor The electric power supplied to the electric motor 2 is controlled so that the drive torque from the motor 2 increases (see d in FIG. 2B).

As described above, in this embodiment, when the load exceeds the predetermined value, the rear wheels 4 are operated by both the electric motor 2 and the internal combustion engine 3.
Since the electric motor 2 is driven, it is not necessary to make the electric motor 2 large and have a large output.

On the other hand, when the load exceeds a predetermined value and the internal combustion engine 3 is started, the torque detected by the torque sensor 16, that is, the output torque from the internal combustion engine 3 suddenly increases. May be given. In the present embodiment, when the drive torque from the internal combustion engine 3 rises sharply as shown in FIG.
As shown in (b), the driving torque by the electric motor 2 is reduced, and thus the total torque is gently increased, so that it is possible to prevent the occupant from feeling uncomfortable.

Further, as the vehicle speed becomes lower, the shock due to the start of the internal combustion engine is felt to be greater. Since it is increased, the occupant's discomfort when starting the internal combustion engine can be more reliably reduced.

Further, the driving force transmission system a has an electromagnetic clutch 1
5 is interposed, it is possible to prevent the internal combustion engine 3 from becoming a running resistance by turning off the clutch 15 in the operating range in which the internal combustion engine 3 is held in a stopped state. Further, in a driving range where it is desired to operate the engine brake such as traveling on a downhill road, the required engine brake can be obtained by turning on the clutch 15.

Here, in the first embodiment, the internal combustion engine 3
The drive torque from the electric motor 2 is reduced based on the change rate of the drive torque from the electric motor 2. However, when the start of the internal combustion engine 3 is detected, the drive torque from the electric motor 2 is reduced for a certain period of time. Alternatively, this is the second embodiment according to the inventions of claims 2 and 3.

In the second embodiment, when the load increases above a predetermined value while the vehicle is traveling with the drive output of the electric motor 2, cranking of the internal combustion engine 3 is started and the ignition system and fuel supply are started. The operation of the system is started, and the rotation speed of the crankshaft detected by the rotation speed sensor 23 is
When the startup determination rotation speed that is set higher than the cranking rotation speed is exceeded, it is determined that the internal combustion engine 3 has started (complete explosion).

When the start of the internal combustion engine 3 is detected,
The drive torque from the electric motor 2 varies from a magnitude corresponding to the throttle opening signal or the vehicle speed control signal for a certain period of time.
It is gradually decreased at a predetermined rate, and after the lapse of the predetermined time, it is gradually increased again at a predetermined rate toward the magnitude corresponding to the throttle opening signal or the vehicle speed control signal.

The predetermined ratio for reducing the drive torque from the electric motor 2 is set to be larger as the vehicle speed detected by the vehicle speed sensor 29 at the start of the internal combustion engine is lower, that is, the vehicle is traveling at a lower speed. It As a result, the amount of decrease in the drive torque from the electric motor 2 increases as the vehicle travels at a lower speed.

As described above, in the second embodiment, when it is determined that the internal combustion engine 3 has started, the drive torque from the electric motor 2 is reduced on the assumption that the drive torque suddenly rises. Therefore, as compared with the case where a rapid rise of the drive torque is actually detected, the torque sensor 16 can be eliminated and the structure can be simplified while avoiding discomfort to the occupant.

Further, the lower the vehicle speed when the start of the internal combustion engine 3 is detected, the more the shock at the time of starting the internal combustion engine is felt, but in the present embodiment, the reduction rate of the drive torque from the drive motor 2 is increased. Since the driving torque is set and the amount of decrease in the driving torque is increased, the discomfort of the occupant at the time of starting the internal combustion engine can be more reliably reduced.

FIG. 5 is a diagram for explaining a third embodiment according to the invention of claim 4, in which the same reference numerals as those in FIG. 1 denote the same or corresponding portions.

In the third embodiment, in the driving force transmission system a, the continuously variable transmission 14 is interposed upstream of the clutch 15 in the driving force transmission direction. This continuously variable transmission 14
Is a V-belt type continuously variable transmission in which a V-belt is wound around a drive pulley mounted on the output shaft of the internal combustion engine 3 and a driven pulley mounted on the input shaft of the transmission 12.

In the third embodiment, when the internal combustion engine 3 starts and the output torque from the internal combustion engine 3 suddenly increases,
At the initial stage of this increase, slippage occurs between the V-belt and the pulley due to the structural characteristics of the V-belt continuously variable transmission 14, and the transmission of the output torque to the rear wheels is relaxed. The discomfort given to the occupant can be reduced without providing such a mechanism.

[Brief description of drawings]

FIG. 1 is a block configuration diagram for explaining an operation control device for a hybrid golf cart according to a first embodiment of the present invention.

FIG. 2 is a drive torque characteristic diagram for explaining the operation and effect of the first embodiment.

FIG. 3 is a schematic plan view showing how the golf cart of the first embodiment is used.

FIG. 4 is a schematic sectional view showing how the golf cart of the first embodiment is used.

FIG. 5 is a block configuration diagram of a third embodiment of the present invention.

[Explanation of symbols]

1 hybrid golf cart 2 electric motor 3 Internal combustion engine 4 rear wheels (driving wheels) 14 V belt type continuously variable transmission 16 Torque sensor (driving force detection sensor) a Driving force transmission system

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 29/06 F02D 41/04 310D 41/04 310 45/00 362Q 45/00 362 364A 364 B60K 9/00 EF term (reference) 3G084 BA05 CA01 CA04 DA01 DA02 EA11 FA05 FA32 FA33 3G093 AA06 AA07 BA19 CA07 DA01 DB05 EA09 3G301 JA03 JA04 KA01 KA09 LA03 NA03 ND03 PA11A PE01 Z02P08 PI02 PI30 PI02 PV02 PI02 PV02 PI02 PV02 PI02 PV02 PI02 PI02 PI02 PV02 PI02 PV02 RE03 RE11 SE03 TE02 TE05 TO02 TO04

Claims (4)

[Claims] 1. An operation control device for a hybrid vehicle having an electric motor and an internal combustion engine as a drive source, wherein when the load is less than a predetermined value, the drive wheels of the hybrid vehicle are driven by the driving force of only the electric motor, and the load is the predetermined value. In the above case, the driving wheel is driven by the driving force of both the electric motor and the internal combustion engine, and the driving force detection sensor for detecting the driving force is arranged midway in the driving force transmission system from the internal combustion engine to the driving wheel. However, when driving wheels are driven by both the electric motor and the internal combustion engine, when the driving force detected by the driving force detection sensor changes in a large direction at a rate of change of a predetermined value or more, driving from the electric motor An operation control device for a hybrid vehicle, characterized in that the electric motor is controlled so as to reduce force. 2. A drive control device for a hybrid vehicle having an electric motor and an internal combustion engine as a drive source, wherein when the load is less than a predetermined value, the drive wheel is driven by the driving force of only the electric motor, and the load is the predetermined value. In the above case, the drive wheels are driven by the driving force of both the electric motor and the internal combustion engine, and a start detection sensor for detecting the start of the internal combustion engine is provided, and the start of the internal combustion engine is detected by the electric motor. An operation control device for a hybrid vehicle, wherein the electric motor is controlled so that the driving force of the electric vehicle is reduced. 3. The drive control device for a hybrid vehicle according to claim 1 or 2, further comprising a vehicle speed detection sensor for detecting a vehicle speed, and a decrease amount of the driving force of the electric motor increases as the detected vehicle speed decreases. . 4. An operation control device for a hybrid vehicle having an electric motor and an internal combustion engine as a drive source, wherein when the load is less than a predetermined value, the drive wheel is driven by the driving force of only the electric motor, and the load is the predetermined value. In the above cases, the drive wheels are driven by the drive forces of both the electric motor and the internal combustion engine, and the V-belt type continuously variable transmission is interposed in the drive force transmission system from the internal combustion engine to the drive wheels. A drive control device for a hybrid vehicle characterized by: