JP2003224904A - Hybrid type motorized vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a fuel consumed by an engine for charging a battery, by increasing the amount of the kinetic energy which is recovered. <P>SOLUTION: A battery 25 for a drive motor is charged with the electric power generated by driving a motor generator 44 using an engine 41. An engine stop means 63 performs regenerative braking with the motor generator 44, when the engine 41 stops. <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 a hybrid electric vehicle in which a battery for supplying electric power to a motor for driving wheels is charged by an engine-driven generator.

[0002]

2. Description of the Related Art A conventional hybrid electric vehicle of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-157310. The hybrid electric vehicle shown in this publication is a so-called series hybrid type vehicle that runs using only a motor as a power source, and includes a generator for charging a battery for supplying power to the motor, and an engine for driving the generator. Are mounted on the car body.

In this conventional electric vehicle, the engine is started when the charge amount of the battery is reduced, and the battery is charged with the electric power generated by the generator. The engine is stopped after the battery is fully charged. Further, this electric vehicle employs a configuration in which the motor functions as a generator during deceleration to perform regenerative braking, convert kinetic energy when the vehicle body and the motor drive system move due to inertia into electrical energy, and collect the electrical energy in a battery. ing.

[0004]

However, in the above-mentioned conventional electric vehicle, the kinetic energy is converted into electric energy by regenerative braking, and the electric energy is recovered.
In recent years, in order to reduce the fuel consumed by the battery charging engine, it has been required to recover more kinetic energy and shorten the engine operating time.

The present invention has been made in response to such a demand, and an object thereof is to increase the amount of kinetic energy recovered and reduce the fuel consumed by the battery charging engine.

[0006]

In order to achieve this object, a hybrid electric vehicle according to the present invention is provided with a control device for performing regenerative braking by a generator when an engine for battery charging is stopped. is there. After the stop operation is performed, the engine stops due to consumption of kinetic energy due to, for example, friction between the piston and the cylinder.
According to the present invention, kinetic energy due to inertia after the stop operation can be converted into electric energy by regenerative braking and can be recovered in a battery.

A hybrid electric vehicle according to a second aspect of the present invention is the hybrid electric vehicle according to the first aspect, wherein the engine is connected to a motor drive system via a clutch and the clutch is connected. By doing so, a braking means for performing regenerative braking by the generator is provided. According to the present invention, the kinetic energy of the motor drive system can be recovered by performing the regenerative braking by the generator with the clutch connected.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a hybrid electric vehicle according to the present invention will be described in detail below with reference to FIGS. Here, an example in which the present invention is applied to a golf cart will be described. FIG. 1 is a side view of a golf cart as a hybrid electric vehicle according to the present invention,
2 is a block diagram showing the configuration of the golf cart, FIG. 3 is a block diagram showing the configuration of the rear wheel drive system, FIG. 4 is a graph showing changes in the charge amount, and FIG. 5 is a graph showing changes in the load.

In these drawings, the reference numeral 1 indicates the golf cart according to this embodiment. This golf cart 1 is provided with two front wheels 2 and two rear wheels 3, and the rear wheels 3 are driven by a traveling device 4 (see FIG. 2) described later to travel. The front wheel 2 is steered by the traveling device 4 so that the vehicle body travels along a guide line (not shown) in addition to being steered by the steering wheel 5 by the occupant.
In FIG. 1, reference numeral 6 indicates a chassis, 7 a front seat, 8 a rear seat, 9 a back carrier, and 10 a roof.

The traveling device 4 of the golf cart 1 is shown in FIG.
As shown in FIG. 1, an automatic steering device 11 for automatically steering the front wheels 2 and a drive device 1 for running or stopping the vehicle body.
2 and a main controller 14 having a CPU 13 that controls both of these devices.

The automatic steering device 11 includes a sensor 15 for detecting a guide wire, a steering motor 17 for rotating a steering shaft 16, and a steering for switching between a manual steering mode and an automatic steering mode. Clutch 18
And is controlled by the main controller 14. The control of the automatic steering device 11 by the main controller 14 is performed in a state where the manual traveling mode is switched to the automatic traveling mode by a mode changeover switch (not shown).

In the automatic driving mode, first, the CPU 13 of the main controller 14 sends a control signal to the clutch motor relay 19 to disconnect the steering handle 5 from the steering shaft 16 by the clutch 18. After the disconnection control, the CPU 13 sends a control signal to the steering driver 21 based on the detection signal of the sensor 15 input through the induction sensor amplifier 20 so that the guide wire sensor 15 follows the induction wire. To control the steering motor 17.

As shown in FIGS. 2 and 3, the drive unit 12 includes a transmission 23 on an axle 22 of the rear wheel 3.
A drive motor 24 connected through the battery 24, a battery 25 that supplies power to the drive motor 24, an engine-type auxiliary power unit 26 that supplements the power for driving the rear wheels and that generates power to charge the battery 25, A drum brake 27 for braking each wheel is provided.

The driving motor 24 is supplied with electric power from the main controller 14 to drive the input member of the transmission 23, and is rotated by the input member to function as a generator to generate a regenerative current. Are using what can be supplied to. In this embodiment, the drive motor 24 is provided with an electromagnetic brake 28 for a parking brake.

The output of the drive motor 24 is controlled by the CPU 13 so as to correspond to the depression amount of the accelerator pedal 29 in the manual traveling mode. That is, by depressing the accelerator pedal 29, a control signal is sent from the accelerator potentiometer 30 and the accelerator switch 31 which are interlocked with the accelerator pedal 29 to the CPU 13, and the CPU 13 sets the motor output based on the control signal. On the other hand, in the automatic travel mode, the CPU 13 controls the motor output so that the current vehicle speed matches the target vehicle speed. The current vehicle speed is detected by a vehicle speed sensor 32 provided in the transmission 23, and the target vehicle speed is set by an input device provided on the vehicle body or a remote control device for remote input. In addition, on the road surface, feedback control is temporarily performed to match the current vehicle speed with the target vehicle speed that is set in order to respond to the requirements for running conditions on the course, such as the need for a primary stop, the ups and downs of the road surface, and fine irregularities. The permanent magnet mark (not shown) provided so that it can be discriminated that the response of the feedback control is temporarily interrupted or temporarily improved by the trigger sensor 33 and the fixed point sensor 34 on the chassis 6 side, and the CPU 13 Takes in the set target vehicle speed and analyzes and sets the traveling request of the course indicated by the mark.

In both the manual traveling mode and the automatic traveling mode, the driving motor 24 functions as a generator to perform regenerative braking during braking. The electric power generated by the regenerative braking is supplied from the main controller 14 to the battery 25 as a regenerative current so as to charge the battery 25.

Braking in the manual traveling mode is performed by an occupant depressing the brake pedal 35. When the occupant depresses the brake pedal 35, the pedaling force is transmitted from the switching mechanism 36 to the drum brakes 27 of the respective wheels via the brake wires, and the drum brakes 27 operate to generate braking force. A brake switch 37 is provided so as to interlock with the brake pedal 35 so that the CPU 13 can detect the braking in the manual traveling mode and perform the regenerative braking. Braking in automatic driving mode,
When there is a deceleration resetting of a set vehicle speed in a human power device or a remote control device, an input of an emergency stop switch, and a deceleration instruction based on a mark on the course, in addition to the regenerative braking, the switching mechanism 36 is connected via a gear 38. The CPU 13 sends a control signal from the brake motor driver 40 to the brake motor 39.

The engine type auxiliary power unit 26 includes an engine 41 and a motor generator 44 connected to a crankshaft 42 of the engine 41 via a V-belt type transmission unit 43.
And a V-belt continuously variable transmission 45 and first and second clutches 46 and 47, which are interposed between the engine 41 and the input member of the transmission 23.

The operation / stop of the engine 41 is switched by the CPU 13 of the main controller 14, and at the time of operation, the throttle motor 52 for opening / closing the throttle valve of the carburetor 51 is driven by the CPU 13.
The rotation speed is controlled. The rotation speed of the engine 41 is detected by a rotation speed sensor 53 provided in the motor generator 4.

As the motor generator 44, a motor generator that functions as a starter motor when the engine is started and functions as a generator at other times is used. This motor generator 44
When the CPU 13 switches the start switch 54 to the ON side, power is supplied from the battery 25 to function as a starter motor to rotate the crankshaft 42 of the engine 41.

On the other hand, this motor generator 44 has a CPU 1
3 switches the start switch 54 to the OFF side to rotate by the power of the engine 41 to generate electricity. The electric power generated by the motor generator 44 is supplied to the battery 25 via the inverter / converter 55. That is, the motor 25 is driven by the engine 41 to charge the battery 25.
The motor generator 44 also outputs a current value and a voltage value to the CPU 13 during power generation.

The V-belt type continuously variable transmission 45 is equivalent to a conventionally well-known one for scooters, and as shown in FIG. 3, two pulleys 57, around which a V-belt 56 is wound, Transmission 23 out of 58
Side driven pulley 57 is connected to the input member of the transmission 23 via the first clutch 46, and the drive pulley 58 on the engine 41 side is connected to the crankshaft 42 of the engine 41 via the second clutch 47. ing.

In the present embodiment, both the first clutch 46 and the second clutch 47 are electromagnetic clutches, and the connection and disconnection can be switched by the CPU 13. As the first clutch 46, the driven pulley 57 to the transmission 23 are used.
It is possible to use a one-way clutch in which power is transmitted only to.

First clutch 46 and second clutch 47
Is connected to the motor generator 44 even when the power of the engine 41 is transmitted to the transmission 23 to assist the drive motor 24 and when the engine 41 does not assist the drive motor 24. This is the time when power is transmitted from the transmission 23 side to perform regenerative braking by the motor generator 44. Both clutches 46, 47
Is disconnected when traveling only by the power of the drive motor 24 and when the motor 41 is driven by the engine 41 to generate power to charge the battery 25.

In this embodiment, the transmission 23 and the engine 41 are connected to the V-belt type continuously variable transmission 45 via the first clutch 46 and the second clutch 47. Since the power is not transmitted to the V-belt type continuously variable transmission 45 in any case by disconnecting the drive motor 2, the drive motor 2
It is possible to reduce power loss when traveling with only the power of four or when the power of the engine 41 is exclusively used for power generation.

In the engine-type auxiliary power unit 26, a torque sensor indicated by reference numeral 59 in FIGS. 2 and 3 is provided in the middle of a power transmission system from the engine 41 to the rear wheels 3, and the power of the engine 41 is increased. Is transmitted to the rear wheel 3 to assist the drive motor 24, the engine 4
1 torque fluctuation of the crankshaft 42 is detected by the torque sensor 5
9 and outputs to the CPU 13. At this time,
The CPU 13 increases or decreases the output of the drive motor 24 so as to cancel the torque fluctuation. As a result, although the engine 41 is assisting, the torque for driving the rear wheels 3 becomes substantially constant, so that the vehicle body runs smoothly.

The position where the torque sensor 59 is provided is between the second clutch 47 and the V-belt type continuously variable transmission 45 as shown in FIG. 2, or in the middle of the axle of the rear wheel 3 as shown in FIG. As long as the power of the engine 41 is transmitted, it can be appropriately changed. The engine 41 is the drive motor 2
4 is assisted by increasing the preset vehicle speed in the automatic drive mode, resetting the set vehicle speed, sudden acceleration based on the mark on the course or climbing the hill, and further depressing the accelerator pedal 29 in the manual drive mode. When it exceeds the value.

The battery 25 is connected to a battery remaining amount detecting means 61 for detecting the remaining amount of the battery 25 based on the battery voltage, the battery temperature, and the charging / discharging current amount of the battery 25. The battery remaining amount detecting means 61 uses the detected battery remaining amount as the CP
Output to U13. When the remaining amount of the battery becomes less than a predetermined value, the CPU 13 starts the engine 41 and causes the motor generator 44 to generate electric power to charge the battery 25.

As described above, the CPU 13 includes the braking means 62 (see FIG. 2) for controlling the braking force by the drum brake 27 and the braking force by the regenerative braking of the drive motor 24 and the motor generator 44, and Engine 4
When the battery 25 is charged by 1 or when the engine 41 generates auxiliary power, the engine 41 is started, charging is completed, the load of the drive motor 24 is reduced, and the power of the engine 41 becomes unnecessary. The engine stop means 63 is provided to stop the engine 41 by disengaging the first and second clutches 46 and 47 when the engine is opened.

The braking means 62 employs a circuit that performs regenerative braking by the drive motor 24 during normal braking and also regenerative braking by the motor generator 44 during sudden braking. During the sudden braking, the braking means 62 transmits the power from the transmission 23 side to the motor generator 44 via the V-belt type continuously variable transmission 45 by connecting the first and second clutches 47, and this motor generator Power is generated by 44. By also using the regenerative braking by the motor generator 44 in this way, the kinetic energy of the motor drive system can be recovered by the motor generator 44 during the sudden braking, so that more kinetic energy can be recovered.

The engine stopping means 63 starts the engine 41 when the charge amount of the battery 25 falls below a predetermined reference amount X%, as shown in FIG.
The engine 41 is stopped when the charged amount reaches the reference amount X% by charging. Further, the engine stopping means 63 detects the load of the drive motor 24 in addition to the charge amount of the battery 25, and when the load of the drive motor 24 exceeds the reference load X, as shown in FIG. The engine 41 is started, and when the load is reduced and falls below the reference load X, the engine 41 is stopped. There are four possible methods for detecting the load, as described below.

(1) The current vehicle speed is compared with the target vehicle speed set by the input device or the remote control device, and it is determined that the load is large when the target vehicle speed is high and the load is small when the target vehicle speed is opposite. . (2) The deceleration of the vehicle body is compared with a predetermined deceleration, and it is determined that the load is large when the deceleration of the vehicle body is larger than the set deceleration and the load is small when the deceleration of the vehicle body is opposite. (3) If the degree of increase of the accelerator value (the amount of depression of the accelerator pedal 29) is larger than a predetermined degree of increase, the load is large, and the brake value (the amount of brake operation by the remote control or the amount of depression of the brake pedal 35) is set in advance. The load is determined to be small when the increase is larger than the defined increase. (4) It is determined that the load is large when the gear ratio of the V-belt type continuously variable transmission 45 is larger than a predetermined gear ratio, and the load is small when the gear ratio is opposite. It is judged that the load is large or small based on the mark embedded in the course.

In order to stop the engine 41, the engine stopping means 63 cuts off the ignition current supplied to the spark plug (not shown), or the throttle valve of the carburetor 51 is fully closed and supplied to the carburetor 51. This is done by shutting off the fuel. When the engine is stopped, the engine stop means 63 causes the motor generator 44 to generate power after performing the ignition stop control and the fuel stop control. That is, the motor generator 44 continues the power generation even after the charge amount of the battery 25 reaches X% in FIG. Further, the motor generator 44 also generates electric power after the load of the drive motor 24 is reduced and the engine 41 is stopped.

Therefore, the kinetic energy of the engine 41 is consumed by the engine 41 continuing to rotate the motor generator 44 even after the stop control, and the engine 41 is completely stopped when the kinetic energy disappears. To do. As a result, the kinetic energy due to inertia after the engine stop operation can be converted into electric energy by regenerative braking and can be recovered in the battery 25.
As shown in, the engine 41 is stopped in a state (X%) where the charge amount of the battery 25 has not reached 100%, and the battery 25 is generated by the electric power generated after the stop operation.
Can be charged until the charge reaches 100%. Therefore, according to the golf cart 1, it is possible to shorten the time for driving the engine 41 to charge the battery 25.

[0035]

As described above, according to the present invention, after the operation of stopping the engine is performed, the kinetic energy of the engine is converted into electric energy by regenerative braking,
Can be collected in the battery. Therefore, the time for operating the engine to charge the battery can be shortened and the fuel for the engine can be saved.

According to the second aspect of the invention, since the kinetic energy of the motor drive system can be recovered by performing the regenerative braking by the generator with the clutch engaged, the motor functions as the generator. By using both regenerative braking and regenerative braking of the engine-side generator, rapid braking can be performed and more kinetic energy can be recovered.

[Brief description of drawings]

FIG. 1 is a side view of a golf cart as a hybrid electric vehicle according to the present invention.

FIG. 2 is a block diagram showing a configuration of a golf cart.

FIG. 3 is a block diagram showing a configuration of a rear wheel drive system.

FIG. 4 is a graph showing a change in charge amount.

FIG. 5 is a graph showing changes in load.

[Explanation of symbols]

1 ... Golf cart, 3 ... Rear wheels 3, 13 ... CPU, 14 ...
Main controller, 24 ... Driving motor, 25 ... Battery, 44 ... Motor generator, 41 ... Engine, 46 ...
1st clutch, 47 ... 2nd clutch, 62 ... Braking means, 63 ... Engine stopping means.

Claims (2)

[Claims] 1. A hybrid electric vehicle in which a battery for supplying electric power to a motor for driving wheels is charged by an engine-driven generator, comprising a control device for performing regenerative braking by the generator when the engine is stopped. Hybrid electric vehicle. 2. The hybrid electric vehicle according to claim 1, further comprising braking means for connecting the engine to a motor drive system via a clutch and connecting the clutch for regenerative braking by a generator. Electric vehicle.