JPH0847103A - Charge state alarm device - Google Patents

Abstract

PURPOSE:To efficiently recover energy generated at the time of braking a vehicle to a secondary cell and to reduce fuel consumption by setting a predetermined target capacity smaller than a rated charge capacity in the charged state of the cell, and warning the effect of the state that the charge state exceeds the target state to a driver. CONSTITUTION:A predetermined target state (50-70% of a rated charge capacity) smaller than a rated charge capacity of a secondary cell of a DC power source E is set to the cell. The effect that the charge capacity exceeds the target capacity is warned to a driver to expedite the driver positively by the use of auxiliary drive force. Thus, energy generated at the time of braking a vehicle can be efficiently regenerated to the cell to so expedite the driving as to save the fuel consumption of an internal combustion engine EO, and hence fuel consumption can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an electric braking system for automobiles. In particular, it is used for an electric braking device having a structure in which the electric energy generated from the electric braking device is regenerated in the secondary battery.

[0002]

2. Description of the Related Art Techniques for regenerating electric energy generated by an electric braking device in a secondary battery during braking have been researched, but the techniques up to now are not necessarily satisfactory and have not been applied to commercially available automobiles. .

However, by using a squirrel-cage polyphase induction machine and controlling the rotational speed of the rotating magnetic field applied to the stator of the squirrel-cage polyphase induction machine, the squirrel-cage polyphase induction machine is operated as a generator. Has been developed as a braking device and as an auxiliary drive by operating as a motor. The inventors of the present application have conducted a test of this technology and found that, when this technology is used, the electric energy generated by braking is regenerated in a considerable proportion in the secondary battery, and this can be effectively used as a power source for auxiliary power. It was

On the other hand, the secondary battery mounted in a conventional automobile is always charged to almost 100% of its rated charge capacity,
It is designed and controlled to utilize that charged energy. That is, in the conventional control method, the secondary battery is charged by the generator connected to the internal combustion engine, and charging is continued as long as the internal combustion engine is rotating. When the charging energy is used by the operation of the starter motor or the operation of various outfitting devices, the charging circuit is controlled so as to reach the full charge state of the rated charge capacity in the shortest possible time.

[0005]

However, as described above, the energy generated by braking is regenerated as electric energy to the secondary battery mounted on the vehicle, and the energy charged in the secondary battery is used to assist the running of the vehicle. Under the technology using power, if the secondary battery is always charged to the rated charge capacity, the energy generated by braking cannot be efficiently regenerated and used. That is, it is not possible to make the fuel used in an automobile more efficient with the above technology.

According to the present invention, it is possible to efficiently regenerate and use the electric energy to the secondary battery, and to reduce the fuel consumption, it is necessary for the driver to know that the state of charge of the electric braking device exceeds the target value. The purpose is to provide a device for issuing an alarm to that effect.

[0007]

SUMMARY OF THE INVENTION The present invention provides a secondary battery with a predetermined target capacity smaller than its rated charging capacity depending on the state of charge,
For example, 50 to 70% is set, and when the target capacity is exceeded, the driver is warned to that effect.

[0008]

The braking device cannot predict the occurrence state of the braking device in advance according to the driving condition of the automobile, and the braking device always occurs in an unexpected situation. As mentioned above, the charge capacity of the secondary battery is set to be small rather than the full charge rated capacity. As a result, when electric energy is generated by electric braking, the secondary battery has a margin for regenerative charging. By utilizing the regeneratively charged energy as the auxiliary driving force, the fuel consumption of the internal combustion engine can be reduced accordingly.

The predetermined target capacity is a value that should be selectively designed according to the performance of the braking device, the operating condition of the vehicle, the absolute capacity of the secondary battery, the operating temperature, and various other conditions. If this target capacity is set close to 100%, the energy generated by braking cannot be efficiently regenerated. Further, if the value is set too low, inconvenience may occur when the starting is repeated many times depending on the driving situation. Therefore, it is appropriate to set the target capacity to 50% or more and 70% or less.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the apparatus of the present invention. The rotary shaft of the cage multiphase induction machine I is directly connected to the internal combustion engine En of the automobile. A rotation sensor SS is attached to the squirrel cage polyphase induction machine I. This automobile is equipped with a DC power supply device E including a secondary battery. Inverter means In is inserted between the DC terminal of the DC power supply device E and the AC terminal of the cage multiphase induction machine I. The inverter means In uses a DC power source to apply a rotating magnetic field to the stator of the cage-type multiphase induction machine I, and converts the alternating current generated by the braking of the stator of the cage-type polyphase induction machine I into DC. The DC power supply device E is regeneratively charged.

Further, a discharge resistor R is connected to the DC power source device E via a switch circuit SW, and when a sudden braking is applied to the vehicle and an excessive amount of electric energy which cannot be regenerated is generated, this is supplied. It is configured to be dissipated by the discharge resistance R.

The inverter means In is provided with a control signal for giving a rotating magnetic field corresponding to the rotation of the rotor to the stator of the squirrel cage multiphase induction machine I.
Supplied from T. The rotation information from the rotation sensor SS is input to the control circuit CONT, and the information of the DC power supply device E regarding the charging state of the secondary battery is input. The control circuit CONT includes a microprocessor. Further, the control circuit CONT includes means for taking in an operation control signal which changes according to the driving condition by the driver's operation.

As described above, the inverter device In can supply the energy of the DC side terminal to the AC side terminal and the energy generated at the AC side terminal to the DC side terminal. Further, by controlling the control circuit CONT, the rotation speed of the rotating magnetic field is controlled so that the squirrel cage polyphase induction machine I becomes an electric motor, and a driving force is applied to the rotation shaft of the squirrel cage polyphase induction machine I to generate the internal combustion engine En. Can be operated as an auxiliary drive device of the. At this time, the electric energy charged in the DC power supply device E is used.

The inverter means In is specially designed for an automobile here, but its basic technique is known as a technique for elevators, cranes and the like.

Here, in the device of the present invention, the DC power supply device E
The secondary battery is characterized in that the state of charge of the secondary battery is controlled so as to reach a predetermined target capacity smaller than its rated charge capacity in a steady state. The target capacity is 50-
70% is suitable.

By doing so, when electric braking is performed and electric energy is generated in accordance with the driving of the vehicle, the electric energy can be regenerated by the secondary battery of the DC power supply device E. Like the conventional method, the secondary battery has a rated charging capacity.
If it is 100%, it cannot be recharged.

When the electric energy regenerated and charged as described above gradually increases and exceeds the predetermined target value, an alarm is issued to the driver to urge him to actively use the auxiliary driving force. As a result, the charged electric energy is given to the squirrel cage polyphase induction machine I to generate power and be effectively used.

Control device CO for monitoring the state of charge of the secondary battery
Regarding the information transmitted to the NT, the method of observing and identifying the terminal voltage of the secondary battery was used in the above-mentioned embodiment. According to this method, the state of charge can be monitored although the accuracy is low. In order to further improve accuracy, there are a method of monitoring the specific gravity of the electrolytic solution of the secondary battery, a method of measuring and integrating the charge and discharge of the secondary battery, and the like.

When the charge capacity exceeds the predetermined target value, the driver is warned of this and the auxiliary drive force is used to reduce the fuel consumption of the internal combustion engine.

The present invention can be similarly applied to not only the electric braking device using the squirrel-cage polyphase induction machine shown in the above example but also other types of electric braking devices for regenerating the generated electric energy.

[0022]

As described above, the present invention has an advantage that the energy generated when the vehicle is braked can be efficiently regenerated by the secondary battery. In particular, it is possible to output a warning to the driver and use the auxiliary driving force of the vehicle to encourage the driver to drive the vehicle so as to reduce the fuel consumption of the internal combustion engine. is there.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an electrical configuration of an embodiment of the present invention.

[Explanation of symbols]

 En Internal combustion engine I Cage type multi-phase induction machine SS Rotation sensor In Inverter means CONT Control circuit E DC power supply device including secondary battery SW switch circuit R Discharge resistance

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Obata 3-1-1 Hinodai, Hino-shi, Tokyo Hino Motor Co., Ltd. (72) Inventor Koji Sasaki 1-1-1 Shibaura, Minato-ku, Tokyo Toshiba Corporation Head Office Office (72) Inventor Hiroshi Uchino No. 1 Toshiba Town, Fuchu City, Tokyo Inside Toshiba Fuchu Factory

Claims (3)

[Claims] 1. An electric braking device and a secondary battery are mounted on an automobile, and a means for regenerating the electric energy generated from the electric braking device to charge the secondary battery is provided. An alarm device for charging state, which is provided with a predetermined target capacity smaller than the rated charging capacity, and is provided with an alarm output means for giving an alarm to the driver when the charging state exceeds the target capacity. . 2. The predetermined target capacity is 50% of the rated charge capacity.
The alarm device for the charged state according to claim 1, wherein the alarm device has a charging rate of 70% to 70%. 3. The charging state alarm device according to claim 1, wherein the electric braking device includes a squirrel-cage polyphase induction machine and means for controlling the rotation speed of a rotating magnetic field applied to the squirrel-cage polyphase induction machine.