WO2005045218A1

WO2005045218A1 - Hybrid vehicle

Info

Publication number: WO2005045218A1
Application number: PCT/JP2004/016645
Authority: WO
Inventors: Koichi Yamaguchi
Original assignee: Hino Motors, Ltd.
Priority date: 2003-11-10
Filing date: 2004-11-10
Publication date: 2005-05-19
Also published as: JP2005140080A

Abstract

A hybrid vehicle capable of avoiding that a driver declares that a battery is defective when a battery for auxiliary traveling does not yet require maintenance. When the charged amount of the battery is lower than a specified value, operating conditions for idle/stop control are changed without any optical display such as indications by lamp so that the idle/stop control is not performed frequently.

Description

Specification

Hybrid car

Technical field

The present invention is applied to a hybrid vehicle that runs using both mechanical power from an internal combustion engine and electric power from a motor generator. The present invention relates to an apparatus for monitoring the state of charge of a battery mounted on an hybrid vehicle and serving as an energy source of electric power. In particular, it relates to improvement of means for alerting a driver when the state of charge of a battery deteriorates for some reason.

[0002] The present invention is intended to be applied to a hybrid vehicle of a type in which one vehicle is equipped with one rotating machine (motor generator), and is controlled to be switched so as to act as an electric motor or a generator. Although the device has been developed, the present invention can be similarly applied to a hybrid vehicle in which a motor and a generator are provided as separate devices.

Background art

[0003] In a hybrid vehicle, a relatively large battery serving as an electric power source is mounted. This is to supply electric energy as a power source for vehicle running, not just to start the internal combustion engine or to supply power to lamps and other electric devices installed in the vehicle. . (2) When the vehicle is in a braking state, the hybrid vehicle is capable of generating electric energy and charging the battery mounted on the vehicle by connecting the rotational power of the axle to the rotational shaft of the generator. it can. The electric energy charged in the battery can be supplied to the electric motor when the vehicle is started or when the vehicle is accelerated, and the fuel consumption of the internal combustion engine can be reduced. This effect not only makes the fuel consumption economical, but also reduces the output load of the internal combustion engine when the vehicle starts, accelerates, or climbs a hill, so that the amount of harmful exhaust gas generated by the internal combustion engine power is reduced. Can be reduced. This is known to be extremely effective for environmental purification.

[0004] The battery of the above-described size mounted on a hybrid vehicle is a secondary battery that can be charged and discharged. This battery power is also charged when running energy is supplied. Different control is executed according to the amount of electricity. That is, when the charge amount of the battery is large, control can be performed so as to increase the ratio of the auxiliary acceleration by the electric power executed when the vehicle starts or climbs a hill. When the battery charge becomes low, control such as reducing the ratio of assisted acceleration by electric power or prohibiting assisted acceleration by electric power is performed. Further, when the charge amount of the battery is reduced, the generator can be rotationally driven by the internal combustion engine while the vehicle is stopped, and control for charging the battery can be performed. If the charge / discharge performance of the large battery mounted on this hybrid vehicle deteriorates, it will be necessary to replace the battery or perform maintenance such as replacing or cleaning the electrolyte and electrodes. .

[0005] In the conventional example, in the case of the hybrid vehicle, when the charge / discharge capability of the large-capacity battery for driving is reduced, this is detected and an optical display such as displaying a lamp in the driver's seat is detected. To promote battery maintenance. Various methods are known for detecting the deterioration of the charge / discharge capability. From the simple monitoring of the terminal voltage of the battery to the monitoring of the terminal voltage of the battery corresponding to the load of the battery, the monitoring of the terminal voltage corresponding to the discharge current of the battery, Various types are known, such as a type in which the electrolyte temperature of a battery is monitored in association with the terminal voltage or current. Some of them are exemplified in the following patent documents.

[0006] On the other hand, a technique of providing an idle stop means for a vehicle equipped with an internal combustion engine is conventionally known. This is configured to automatically stop the rotation of the internal combustion engine after a set time has elapsed when the load of the internal combustion engine of the vehicle is reduced (idling state). When the engine is automatically stopped by the idle stop means, the starter motor is automatically started by, for example, depressing the clutch pedal, operating the shift lever, or depressing the accelerator pedal. The internal combustion engine restarts. Such an idle stop means works effectively for vehicles traveling on congested roads and buses where passengers are getting on and off, contributing significantly to fuel economy and environmental cleanup. I have.

[0007] This idle'stop means can be similarly implemented for a hybrid vehicle.

In a hybrid vehicle in which the rotating shaft of the generator is directly connected to the internal combustion engine, When the state of charge of the battery is good according to the conditions, the rotation of the internal combustion engine can be stopped. Also, in a hybrid vehicle in which an electric motor for driving an axle is provided separately from a generator connected to an internal combustion engine, the vehicle is stopped or the load of the electric motor is small. Even when the vehicle is traveling, if the charged amount of the battery is equal to or more than a predetermined value, the control can be performed so that the rotation of the internal combustion engine is stopped and the battery is not charged.

[0008] Hereinafter, in this specification, a motor and a generator are referred to as "motor generator" without distinction.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-348780

Patent Document 2: JP-A-11-121048

Patent Document 3: JP-A-8-336202

Patent Document 4: Japanese Patent No. 2936454

Patent Document 5: JP-A-4183203

Patent Document 6: JP-A-6-261411

Disclosure of the invention

Problems to be solved by the invention

[0010] Generally, the control system of a hybrid vehicle is provided with a monitoring circuit that monitors the state of charge of the battery by some method. When the state of charge of a battery detected by a monitoring circuit becomes worse than a set condition, a hybrid vehicle that performs an optical display such as turning on a lamp in a driver's seat has been widely implemented. However, from various tests and actual use, it was found that in this configuration, the driver tends to recognize the battery abnormality early.

[0011] That is, the abnormality in which the charging capability of the battery is reduced rarely occurs at once, and in most cases, the charging capability is gradually reduced, and the degree of the abnormality gradually increases. In general, the deterioration of a battery is often caused by a decrease in the chemical action of the battery, and therefore, a decrease in the charging capacity hardly appears sharply. Furthermore, since the batteries of hybrid vehicles are used to repeatedly charge and discharge according to the driving conditions, even if the batteries are discharged, they are automatically charged during driving and their capacity is increased. Recovers. When the battery starts to deteriorate, you will be alerted to the charging status at first The driver's seat lamp will be repeatedly turned on and off, and if used continuously, the driver's seat lamp will be lit for a long time.

[0012] When the battery starts to deteriorate and this progress is followed, the driver (or from the vehicle owner) has an abnormality around the battery when the lamp on the driver's seat starts blinking. The maintenance is required. Therefore, the driver repeatedly reported that there was no abnormality even if the battery was inspected, that there was no abnormality in the charging system, and that no maintenance was required yet.

[0013] As described above, the decrease in the charging capacity of the battery progresses little by little. Even if a temporary alarm is generated in the charge / discharge cycle in the vehicle running state, the alarm is immediately dealt with. Must be of nature. Even if the charging capacity of the battery is reduced, the operation of the vehicle is not hindered at the initial stage. The vehicle will not be able to operate due to a failure on the road due to a decrease in the charging capacity of the battery. However, it is necessary to warn the driver in some way that the battery's charging capacity has dropped.

[0014] The present invention addresses such a situation, and instead of displaying a lamp display on the driver's seat for the deterioration of the state of charge of the battery, the driver power S is more reasonably recognized. It is an object of the present invention to provide a device capable of performing the above. It is an object of the present invention to provide a display method in which even when the state of charge of a battery starts to deteriorate, a driver notices an abnormality only after the degree of the deterioration has progressed appropriately and requests vehicle maintenance. I do. An object of the present invention is to provide a device that warns the driver of the state of charge of the battery, but allows the driver to slowly recognize this.

Means for solving the problem

[0015] The most characteristic feature of the present invention is that when an abnormality is detected in the battery charge state monitoring means, control is performed to change the idle / stop control conditions. As described above, the idle-stop control is a control for automatically stopping the rotation of the internal combustion engine without a special driving operation while the vehicle is stopped. That is, when the state of charge of the battery is normal, the vehicle stops and the load on the internal combustion engine becomes smaller than a predetermined value. If the load continues for a predetermined time, idle-stop control is automatically activated to rotate the internal combustion engine. To stop. In the device of the present invention, when an abnormality is detected in the state of charge of the battery, • Stop the stop control, or idle the condition to execute the idle stop control. • Change the direction to the direction in which the stop is not performed frequently. Originally, the charge state of the battery of the hybrid vehicle is not directly related to the idle-stop control, but this is linked as described above and replaced with the display of the abnormal state of charge of the battery.

[0016] With such a configuration, the driver must recognize that idle stop control is not frequently performed, rather than directly recognizing that an abnormality in the state of charge of the battery has occurred. Become. Idle 'stop control is not performed by the driver's driving operation. That is, the idle-stop control is automatically executed, and the internal combustion engine is automatically started by depressing a clutch pedal, operating a shift lever, or the like in an attempt to start. Therefore, even if the operating state of the idle 'stop becomes slightly slow, the driver does not require maintenance immediately without any serious inconvenience. The driver does not immediately recognize this as an abnormal condition even if idle / stop control is executed or not in accordance with a slow change in the state of charge of the battery.

[0017] If the charging capability of the battery further deteriorates, controlling in a direction in which the execution of the idle stop is not performed may be a desirable direction from the viewpoint of the idle stop control. In other words, in a configuration in which a battery for a hybrid vehicle is used for starting the internal combustion engine, the idle-stop control uses the battery power, which has started to deteriorate, by taking the current to restart the internal combustion engine. However, since the configuration of the present invention controls the frequency to be reduced, it does not further promote the deterioration of the charging capability of the battery. However, this is an irrelevant event when the battery for starting the internal combustion engine is separate from the battery for the hybrid vehicle!

That is, the present invention provides an internal combustion engine, a motor generator, a battery, an inverter for electrically coupling the battery and the motor generator, a control circuit for controlling the inverter, Charge state monitoring means for monitoring the state of charge, and the internal combustion engine automatically starts rotating when its load is smaller than a set value for a predetermined time. In the case of a hybrid vehicle equipped with an idle stop means for stopping, the charge state displayed on the driver's seat when the charge state monitor detects that the charge state of the battery falls below a set condition. Shortage Means for changing operating conditions of the idle stop means without accompanying optical indications.

[0019] Here, "without an optical display on the driver's seat regarding the insufficient charge state" described above means "all the optical displays on the driver's seat regarding the insufficient charge state". It is not excluded. The optical display on the driver's seat regarding the insufficient charge state does not prevent the display from being performed when the battery is further deteriorated. An optical display on the driver's seat indicating the insufficient charge state is also provided, and the operating conditions of the idle-stop means are first changed according to the degree of deterioration of the battery. The present invention can be implemented by designing so as to perform optical display.

[0020] The means for changing the operation condition of the idle'stop means may include a means for inhibiting the operation of the idle'stop. The means for changing the operating condition of the idle stop means changes the predetermined time (t) to a larger value (t> t).

It is possible to adopt a configuration including means for performing the above operation. Further, the means for changing the operation condition of the idle stop means may reduce a preset value (L) of the load to a smaller value.

0

A configuration including means for changing to a value (L <L) is also possible.

Ten

The invention's effect

[0021] According to the present invention, when the charging capacity of a large-capacity battery mounted on a hybrid vehicle starts to deteriorate, the driver rarely needlessly reacts to this and frequently requests maintenance.

Brief Description of Drawings

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a control operation corresponding to a battery charge amount of the device of the embodiment of the present invention.

FIG. 3 is a flowchart for controlling a main part of an idle stop means according to the embodiment of the present invention.

Explanation of symbols

[0023] 1 Internal combustion engine

2 Motor generator

3 clutch 4 transmission

5 Propeller shaft

6 Inverter

7 Control circuit

8 Battery

BEST MODE FOR CARRYING OUT THE INVENTION

An apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a device according to an embodiment of the present invention. The apparatus of this embodiment is a hybrid vehicle in which a hybrid engine is mounted on a four-wheel medium-sized cargo vehicle.

First, the configuration of this hybrid vehicle will be briefly described. A motor generator 2 is fixedly connected to an output shaft of an internal combustion engine 1. A clutch 3 is connected to an output shaft of the motor generator 2, and an output shaft of the clutch 3 is connected to an input shaft of the transmission 4. The output shaft of the transmission 4 is a propeller shaft 5.

[0026] The opening and closing of the clutch 3 including the half-clutch state is controlled by a clutch control device (not shown). The transmission 4 is a mechanical device including six forward gears and a reverse gear. This is also controlled by a transmission control device (not shown). The clutch control device and the transmission control device are controlled by a clutch control circuit and a transmission control circuit each constituted by a program control circuit. To the clutch control circuit and the transmission control circuit, rotation information of the internal combustion engine 1, vehicle speed information, and information of a shift lever provided at a driver's seat and other operation terminals are respectively input via interfaces.

[0027] The inverter 6 is a three-phase AC / DC converter. It is a static device composed of semiconductor devices as its main components. A battery 8 is connected to the DC terminal, and a field winding of the motor generator 2 is connected to the AC terminal. The phase rotation speed of the AC terminal is controlled by the control circuit 7. The control circuit 7 is a program control circuit. The control circuit 7 is connected to the clutch control circuit, the transmission control circuit, the control circuit of the internal combustion engine, and other information signals via a control bus, and the rotation information of the internal combustion engine 1, the opening and closing information of the clutch, the transmission It is configured to be able to share 4 setting information, accelerator and pedal operation information and more! RU [0028] Briefly describing the operation of this hybrid vehicle, when the vehicle load is large, such as when the vehicle starts, climbs a slope, or accelerates, the field winding of the motor generator 2 has the armature of its armature. Control is performed such that a rotating magnetic field having a rotation speed higher than the rotation speed is generated. This is performed by the control circuit 7 controlling the AC phase of the inverter 6. As a result, the motor generator 2 acts as a motor, and assists the rotation axis of the internal combustion engine 1, that is, the axle, by using electric energy supplied from the battery 8. This is called assist running mode.

[0029] When the vehicle is decelerating, descending, or traveling downhill, the vehicle is controlled to perform regenerative braking. That is, when the vehicle speed is appropriate, the accelerator pedal is released (or almost released), and the internal combustion engine 1 is accelerated by the rotation of the propeller shaft 5, that is, when the engine is in the state of engine braking. In addition, control is performed so that the motor generator 2 acts as a generator to perform auxiliary braking. At this time, an alternating current whose phase is controlled so that the rotating magnetic field has a rotation speed smaller than the rotation speed of the armature is supplied to the field winding of the motor generator 2. As a result, part of the mechanical rotation energy supplied from the propeller shaft 5 is converted into electric energy, and further converted into DC current by the inverter 6 to charge the battery 8. This is called a regenerative braking mode.

[0030] Further, when the charged amount of the battery 8 is reduced to a predetermined value or less while the vehicle is stopped, the motor generator 2 is controlled and set as the generator while the transmission 4 is set to the neutral position. The motor generator 2 is rotationally driven by the internal combustion engine 1. As a result, power can be generated while the vehicle is stopped, and the battery 8 can be charged. This is called the stationary power generation mode!

[0031] In the thus constructed vehicle, this device executes different control according to the charge amount of the battery. This will be described with reference to FIG. FIG. 2 is a diagram for explaining what operation each device performs according to the charge amount of the battery. The abscissa indicates the charge (SOC, unit: kAH) of the battery 8 as a percentage (%) of the maximum charge. The vertical axis shows the operation of each device in a diagram. This will be described in order of the lower force in FIG.

FIG. 2 (5) shows the range of use of this battery. Indicates that charging or discharging of the maximum allowable power (unit: kW) per unit time is possible between the charging amount of 20% and 80%. When the charge is 80% or more, the allowable maximum power is reduced linearly, and when the charge is 86%, the allowable maximum power is reduced. Indicates that the force is controlled to be zero.

FIG. 2 (4) shows the operation range of the regenerative braking mode. It is controlled to be effective when the charged amount is 80% or less. When the charge exceeds 80%, it drops linearly to 86%, and when the charge exceeds 86%, regenerative braking is prohibited.

FIG. 2 (3) shows an operation range in the assist traveling mode. When the battery charge is high, 100% assisted driving is performed, the assisting amount is gradually reduced between 35% and 25% of the charged amount, and the assisted driving is prohibited when the charged amount is 25% or less.

FIG. 2 (2) shows an operation range in the power generation mode. When the battery charge falls to 50% or less, the mode is set to power generation while the vehicle is stopped, and the battery is charged auxiliary. The battery is charged by the power generation mode, and the power generation mode is canceled when the charged amount exceeds 60%.

The operation shown in FIG. 2A is a characteristic operation of the present invention. This is a diagram for explaining the operation relating to the idle-stop control. When the vehicle stops and the load decreases, after a predetermined time t (for example, 2 to 5 seconds) elapses, if the driver does not perform any operation during that time, the internal combustion engine 1 starts operating. It controls to stop the rotation automatically. Then, the driver must press the accelerator pedal, operate the shift lever to the start position, or depress the clutch pedal (when the clutch pedal is provided). The control is performed so that the internal combustion engine 1 is automatically started by rotating the motor generator 2 without operating the start switch. This is a control for suppressing the internal combustion engine 1 from unnecessarily rotating while the vehicle is stopped and consuming fuel or discharging exhaust gas.

The device of the present invention is characterized in that it is configured to execute this according to the charge amount of the battery 8. That is, when the battery charge becomes 30% or less, the idle stop means is not started, that is, the control for automatically stopping the rotation of the internal combustion engine while the vehicle is stopped is prohibited. When the battery's charge capacity recovers to 0%, the prohibition state is released and the idle stop means is restored to a valid state.

[0038] In addition to executing the control as described above, in the apparatus of the present invention, the optical display for warning the driver of the deterioration of the state of charge of the battery 8 is stopped. That is, in the apparatus of the present invention, the driver can determine that the state of charge of the battery 8 has deteriorated by an optical display such as a lamp display. Therefore, it is configured to recognize when the idle idle stop means does not operate properly.

With this configuration, it is possible to prevent the driver from declaring the deterioration of the battery 8 in a state where the deterioration of the battery 8 starts as described above and no maintenance is required. In other words, the deterioration of the battery progresses slowly and gradually as the discharge and charge are repeated, rather than the phenomenon that occurs suddenly as described above. Can not be recognized. When the lamp starts blinking, many drivers will recognize that the battery has degraded. On the other hand, in the configuration of the present invention, since the operation of the idle-stop means has become slightly slower, the battery deterioration is indicated to the driver, and the driver responds sensitively to this. Such inconvenience can be avoided. In fact, they will declare that "this vehicle seems to have lost idle / stop control recently". At this time, the maintenance person should check the battery.

FIG. 3 is a flowchart of main part control of the apparatus according to the embodiment of the present invention. That is, the idle stop means is installed in the control circuit 7 as software. The idle stop means is executed whenever the vehicle stops while the internal combustion engine is rotating. In Fig. 3, the operation can be understood by following the flow, and the explanation is not repeated here.

Industrial applicability

In the above description, a hybrid vehicle having a configuration in which only one electric rotating machine is provided as a motor generator and this motor generator is directly connected to the rotating shaft of the internal combustion engine has been described. The present invention can be applied to any type of hybrid vehicle. Similar effects can be expected for any type of hybrid vehicle.

Claims

The scope of the claims

[1] An internal combustion engine, a motor / generator, a battery, an inverter for electrically coupling the battery and the motor / generator, a control circuit for controlling the inverter, and monitoring a charge state of the battery. Charging state monitoring means, and an idler for automatically stopping the rotation of the internal combustion engine under the operating condition that the load of the internal combustion engine is smaller than a set value for a predetermined time. In a hybrid vehicle with stop means,

When the state of charge of the battery is detected to be lower than a set condition by the state of charge monitoring means, the idle state stop means is not accompanied by an optical display on the driver's seat regarding the state of charge shortage. A hybrid vehicle comprising means for changing operating conditions.

[2] The hybrid vehicle according to claim 1, wherein the means for changing the operation condition relating to the idle'stop means includes a means for inhibiting the idle'stop operation.

[3] The means for changing the operating condition according to the idle 'stop means is the predetermined time (t)

2. The hybrid automatic transmission according to claim 1, further comprising means for changing 0 to a larger value (t> t).

Ten

car.

[4] The means for changing the operating conditions related to the idle stop means includes means for changing a value (L) preset for the load to a smaller value (L <L).

0 1 0

The hybrid vehicle according to claim 1.