JPH11148397A - Hybrid type electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid type electric vehicle which can attain positive discrimination of engine start with the wasteful extension of engine start discrimination time avoided. SOLUTION: This hybrid type electric vehicle, which is provided with a generator for engine driving, a running battery, and a running motor whose running power is generated by power feeding from at least one of the generator and the running battery, conducts engine start discrimination (S126) based on whether an engine starting condition, for example, an engine rotational frequency exceeds a prescribed level (for example, a prescribed rotational frequency value) or not (S112) within the engine start discriminating period (S114) from engine start operation start point to elapse of a prescribed time. When the temperature of the engine is low, the engine start discriminating time is extended, and when the temperature of the engine is high, the engine start discriminating time is shortened (S110). It is thus possible to realize a hybrid type electric vehicle which can attain positive discrimination for engine start with wasteful extension of engine start discrimination time avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a hybrid electric vehicle.

[0002]

2. Description of the Related Art In a hybrid electric vehicle, an engine is started in a manual start mode or an automatic start mode. That is, in a hybrid electric vehicle, the vehicle starts running by the rotation of the running motor in a state where the engine is not started by the key switch-on, and usually after a predetermined condition (for example, a decrease in the capacity of the battery).
After the engine start condition is satisfied, the engine is started.

For this reason, even when the engine cannot be started due to various factors in the hybrid electric vehicle despite the engine start command, the vehicle itself maintains the running state without any problem by the running motor supplied by the battery. I do. Therefore, in the conventional hybrid electric vehicle, due to the continuous running in the engine start malfunction state, a serious shortage of the battery capacity (for example, overdischarge) occurs, the battery cannot reach the destination, or the engine cannot be started. There is a possibility that a problem that the battery capacity is reduced to the level or the like occurs.

[0004] Therefore, in the conventional hybrid electric vehicle, the engine start is determined. If the engine cannot be started, measures such as engine start / stop and abnormality warning, running output restriction, and system stop of the whole vehicle are taken. To address this issue. In the conventional hybrid electric vehicle, the start of the engine is determined to be completed when the engine speed reaches a predetermined threshold value or more within a predetermined engine start determination time from the start of the engine start, and a predetermined time elapses. Even if the engine does not rise above the predetermined number of revolutions, it is general to determine that it is abnormal.

Japanese Patent Laid-Open Publication No. Hei 8-98318 discloses a hybrid type electric motor including a generator driven by an engine, a running battery, and a running motor which is powered by at least one of the generator and the running battery to generate running power. It has been proposed to permit a vehicle to start running only when the engine speed is equal to or higher than a predetermined value (after engine start is completed) in an automobile.

[0006]

However, the engine of a vehicle has a slow increase in the engine speed, especially during a cold start.
For this reason, the engine speed may not reach the threshold speed within the engine start determination time described above, and as a result, it may be erroneously determined that the engine start is malfunctioning.

Of course, the engine start determination time may be set sufficiently long in advance. In this case, however, the time required for the determination is always long, and the processing is delayed. There is a problem in that the battery capacity, which is extremely valuable, is wasted when the engine is not operating properly due to the progress of discharge. In addition, this unnecessarily prolonged engine start determination time may cause the driver to perform a start stop operation during the abnormality determination, for example, making it impossible to detect a malfunction in the engine start, delaying the detection of the malfunction, or disabling the detection of the malfunction. There is also a possibility that it may cause the formation.

On the other hand, according to the technique disclosed in the above-mentioned publication, only when the engine speed is equal to or higher than a predetermined value (after the engine start is completed), the vehicle can start running promptly to permit the vehicle to start running. There was a problem that it was not easy to use. The present invention has been made in view of the above problems,
It is an object of the present invention to provide a hybrid electric vehicle capable of realizing a reliable determination of engine start while avoiding an unnecessary extension of the engine start determination time.

[0009]

According to the first or second aspect of the present invention, an engine-driven generator, a traveling battery,
In a hybrid electric vehicle including a traveling motor that is supplied with power by at least one of the generator and the traveling battery to generate traveling power, an engine start is performed within an engine start determination period from the start of the engine start operation until a predetermined time elapses. An engine start determination is made based on a state, for example, whether or not the engine speed exceeds a predetermined level (for example, a predetermined speed value).

Further, the engine start determination time is extended when the engine temperature is low, and the engine start determination time is reduced when the engine temperature is high. In this way, it is possible to realize a hybrid electric vehicle capable of realizing a reliable determination of engine start while avoiding an unnecessary extension of the engine start determination time.

According to the third aspect of the present invention, in the hybrid electric vehicle according to the first aspect, when it is determined that the engine has failed to start, information related to the remaining capacity of the traveling battery is output. In this way, the driver can judge whether or not it is necessary to perform emergency driving to the nearest repair station or charging station, and the hybrid electric vehicle does not get stuck on the way. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the hybrid electric vehicle according to the present invention will be described in detail with reference to the following examples.

[0013]

FIG. 1 shows a hybrid electric vehicle according to a first embodiment.
This will be described below with reference to the block diagram shown in FIG. Configuration 1 is a (power generation) engine, and 2 is a main battery for traveling. Reference numeral 3 denotes a generator, which is mechanically directly connected to the engine 1 and supplies generated power to the main battery 2 via a generator inverter 5. Reference numeral 4 denotes a traveling motor, which converts electric power supplied from the main battery 2 through the traveling inverter 6 into motive power.

7 is an engine and generator speed signal 71
This is a rotational speed detecting means for detecting 0, and includes, for example, means such as a crank angle sensor of an engine and a magnetic pole sensor of a generator. Reference numeral 8 denotes a radiator for cooling the engine, which is connected to the engine 1 so that the refrigerant can circulate. The refrigerant of the radiator 8 can be supplied to the generator 3, the traveling motor 6, and both the inverters 5, 6, and the like.

Reference numeral 9 denotes an engine temperature detecting means for detecting an engine temperature signal 910. In this embodiment, the temperature of the refrigerant is regarded as the engine temperature. Reference numeral 10 denotes a control controller, which controls power generation and traveling by controlling the power generation inverter 5 and the traveling inverter 6 based on input various sensor signals of the vehicle.
When various abnormalities of the vehicle are detected, the controller 10 causes the abnormal signal 1011 to be displayed on the meter panel 11 and controls the power generation and traveling inverters 5 and 6 via the control signals 1005 and 1006 when a known abnormality occurs. Control is performed in the control mode.

In this embodiment, the completion of the start of the engine is determined by the engine and generator speed signals 710. However, the completion of the start of the engine is determined by other annotations around the engine, such as a signal from an alternator. You may. In the present embodiment, the engine temperature signal 910 is extracted from the temperature of the refrigerant. However, the engine temperature can be estimated from another temperature, for example, the internal temperature of the controller 10 near the engine.

Operation The engine start determination operation of the hybrid electric vehicle executed by the controller 10 will be described with reference to the flowchart of FIG. At the same time as the control is started, it is determined whether or not the engine 1 needs to be started based on various data input from the various parts of the system (S100). To briefly explain an example of this determination, the remaining capacity (dischargeable amp hour) of the battery 2 is calculated or estimated, and when the remaining capacity becomes equal to or less than a predetermined value, the engine 1 needs to be started, that is, the battery 2 is charged. It is determined that it is necessary, and waits until it is determined that the engine 1 needs to be started. It is to be noted that under what conditions the engine is started is not the gist of the present embodiment, and further description will be omitted.

If it is determined in S100 that the engine needs to be started, an engine start command is output to a controller called an ECU (electronic control unit) attached to the engine 1 (S102), and the controller 10 controls the engine 1 The power is supplied to a starter attached to the motor or to a generator motor which is connected to the engine so as to be able to transfer power, thereby starting the engine.

Next, counting of the time elapsed after the start of the engine (also referred to as a start time) is started by a built-in timer (S104), and the engine temperature is detected (S106).
The engine speed is detected (S108), and the engine start determination time is determined based on a table stored in the ROM based on the detected engine temperature (S110). FIG. 3 shows an example of this table.

Next, it is determined whether or not the engine speed has exceeded a set speed, that is, a predetermined threshold speed (S
112) If not, it is determined whether the elapsed time (also referred to as the start time) exceeds the engine start determination time set in S110 (S114), and if not, the flow returns to S106. On the other hand, if the elapsed time (also referred to as the start time) exceeds the engine start determination time set in S110 in S114, it is determined that the engine has failed (S118), an alarm is displayed on the panel 11, and -2, the remaining battery capacity is calculated by a battery controller (not shown) having a microcomputer configuration attached to
Further, a travelable distance in which the vehicle can travel under predetermined average traveling conditions is calculated based on the remaining battery capacity (S122), and the blinking display is performed on the panel 11 (S124). Instead of the travelable distance, the travelable time during which the vehicle can travel under average traveling conditions may be calculated and displayed. This allows the driver to determine where to go, such as at home, at a charging station, at a destination, or at a repair center.

On the other hand, if the engine speed exceeds the set speed in S112, it is determined that the engine start has been completed successfully (S126), and the built-in timer for counting the start time is reset (S128). Next, it is determined whether or not the engine 1 needs to be stopped based on various data input from various parts of the system (S130). To briefly explain an example of this determination, the remaining capacity (dischargeable amp hour) of the battery 2 is calculated or estimated, and when the remaining capacity exceeds a predetermined value, the engine 1 is stopped, that is, the charging of the battery 2 is not required. If it is determined that the engine needs to be stopped, an engine stop command is issued (S132).
Output to U (electronic control unit) (S134).

According to the above-described control, even when the startability is deteriorated by the engine temperature at the time of start, a good start determination according to the startability can be realized, and a problem due to an erroneous determination at the time of engine start can be avoided. . (Modification) The technique for adjusting the engine start determination time according to the engine temperature according to the above-described embodiment according to the engine temperature is not limited to the above-described series hybrid electric vehicle, but also a so-called diagram for transmitting generated power of the engine to driving wheels. Of course, the present invention can be applied to a parallel hybrid electric vehicle as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a hybrid electric vehicle according to the present invention.

FIG. 2 is a flowchart showing an engine operation control routine by the controller of FIG. 1;

FIG. 3 is a characteristic diagram showing a storage table showing a relationship between an engine temperature and an engine start determination time.

FIG. 4 is a characteristic diagram showing a relationship between an elapsed time from the start of starting, an engine speed, and an engine temperature.

FIG. 5 is a block diagram showing another configuration of the hybrid electric vehicle of the present invention.

[Explanation of symbols]

1 is an engine, 2 is a running battery, 3 is a generator, 4 is a running motor, 10 is a controller (engine start determining means, engine start determining period changing means), 7 is a rotational speed detecting means (engine starting state detecting means). ) And 9 are engine temperature detecting means (engine temperature detecting means), and 11 is a remaining capacity displaying means.

Claims (3)

[Claims] An engine-driven generator, a running battery,
An engine temperature detecting means for detecting an engine temperature from a parameter related to the engine temperature in a hybrid electric vehicle including a traveling motor that is supplied with power by at least one of the generator and the traveling battery to generate traveling power. An engine start state detecting means for detecting a start state of the engine, and the engine start is completed based on the start state of the engine within an engine start determination period from the start of the start operation of the engine until a predetermined time elapses. Engine start determination means for determining whether or not the engine start determination time is extended when the engine temperature is low, and the engine start determination time change means for reducing the engine start determination time when the engine temperature is high; A hybrid electric vehicle comprising: 2. The hybrid electric vehicle according to claim 1, wherein said engine start state detecting means detects the engine speed from a parameter related to the engine speed, and said engine start determination. Means for performing the engine start determination based on whether the engine speed exceeds a predetermined value during an engine start determination period from the start of the engine start operation to the elapse of a predetermined time. Type electric car. 3. The hybrid electric vehicle according to claim 1, wherein when the engine start judging means judges that the engine start has failed, the remaining capacity display outputs information related to the remaining capacity of the traveling battery. A hybrid electric vehicle having means.