WO2006121005A1

WO2006121005A1 - Engine starting device and automobile using the same

Info

Publication number: WO2006121005A1
Application number: PCT/JP2006/309249
Authority: WO
Inventors: Ichiro Aoki; Norio Nakajima; Toshiaki Shimizu; Susumu Nishimoto; Muneyoshi Noda; Hiroyuki Jinbo
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-05-13
Filing date: 2006-05-08
Publication date: 2006-11-16

Abstract

A device for starting an engine has an electric double layer capacitor, a rechargeable battery, a starter motor, and a power storage amount control section. Power to the starter motor is supplied from at least either the electric double layer capacitor or the battery. The power storage amount control section controls the amount of power storage in the electric double layer capacitor when a vehicle is in rest to not less than 24% and not more than 60% of the amount of power storage when the vehicle is in operation.

Description

Specification

Engine starter and car using it

Technical field

TECHNICAL FIELD [0001] The present invention relates to an engine starter optimum for an automobile having an idling stop function and an automobile using the same.

Background art

[0002] In recent years, technological innovation in automobiles has been remarkably advanced in response to the trend of protecting the global environment.

As part of this technology, noble and hybrid cars are already on the market. In addition, when an automobile is not running, an automobile having an idling stop function that stops the engine temporarily and automatically restarts it when certain conditions are met has been developed and marketed.

[0003] An electric double layer capacitor is one of the important components that support such technology. An electric double layer capacitor is generally used in combination with a lead-acid battery, which is a conventionally used battery. As a method for charging such an electric double layer capacitor, use of a control energy is proposed in, for example, Japanese Patent Application Laid-Open No. 11-122709. For example, Japanese Patent Laid-Open No. 2-259276 is a technology that reduces the load on a lead storage battery and extends its life by connecting a lead storage battery in series to an electric double layer capacitor and driving a starter motor to start the engine. Proposed in the gazette.

[0004] However, in the conventional engine starter, the electric charge charged when the vehicle is operating remains in the electric double layer capacitor when the vehicle is at rest. If the dormant state continues in this state, a large burden S is applied to the electric double layer capacitor, leading to a decrease in the service life.

[0005] Also, restart after idling stop requires a current of several tens of A at a voltage of about 12V. Therefore, frequent restarts put a heavy burden on the lead storage battery, resulting in a significant decrease in the life of the lead storage battery.

Disclosure of the invention

[0006] The present invention provides an engine starter excellent in long-term reliability, which can reduce the burden on the electric double layer capacitor and the battery and extend the life. Entry of a vehicle according to the invention An engine starter that starts gin includes an electric double layer capacitor, a rechargeable battery, a starter motor, and a storage amount control unit. The starter motor is powered by at least one of an electric double layer capacitor and a battery. The storage amount control unit controls the storage amount of the electric double layer capacitor when the vehicle is at rest to 24% to 60% of the storage amount when the vehicle is in operation. Thus, the engine starter according to the present invention controls so as to reduce the amount of electricity stored in the electric double layer capacitor when the vehicle is at rest. This control reduces the burden on the electric double layer capacitor. In addition, since the amount of electricity stored in the electric double layer capacitor is not zero, there is no significant burden on the battery. As a result, the burden on the electric double layer capacitor and the burden on the battery can be reduced, and the life can be extended.

Brief Description of Drawings

FIG. 1 is a circuit configuration diagram showing a configuration of an engine starter according to Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram of an automobile equipped with an engine starter according to Embodiment 1 of the present invention.

FIG. 3 is a graph showing the relationship between the amount of electricity stored in the electric double layer capacitor constituting the capacitor bank and the change in capacity.

FIG. 4 is a conceptual diagram showing a state where a battery and a capacitor bank are integrated together in the engine starting device according to Embodiment 1 of the present invention.

5 is an exploded perspective view showing a state in which the battery, the capacitor bank, and the engine control unit are removed from the state shown in FIG.

FIG. 6 is a circuit configuration diagram showing a configuration of an engine starting device according to Embodiment 2 of the present invention.

[Fig. 7] Fig. 7 is an explanatory diagram when the deterioration of the battery is predicted by the charge amount value in the engine starting device shown in Fig. 6.

[FIG. 8] FIG. 8 is an explanatory diagram in the case of predicting battery deterioration by internal DC resistance in the engine starting device shown in FIG.

Explanation of symbols 1 engine

2 On-vehicle generator

3 Notteri

4 Capacitor bank (electric double layer capacitor)

5 Starter motor

6 Changeover switch

7 DC / DC converter

8 Starter relay

9 Relay

10 Engine control unit

11 Charge / discharge controller

12 Storage amount control unit

13 Discharge section

14 Energy storage unit

15 Current sensor

16 Voltage measurement section

17 Timekeeping section

18 Ignition key

19 cases

21, 21 A Engine starter

22 Boai

23 Front wheel (steering wheel)

24 Rear wheel (drive wheel)

25 Steering

The best mode for carrying out the invention

(Embodiment 1)

FIG. 1 is a circuit configuration diagram showing the configuration of an engine starter according to Embodiment 1 of the present invention. is there. FIG. 2 is a schematic diagram of an automobile equipped with this engine starting device.

The engine 1 drives a rear wheel 24 that is a drive wheel and drives an on-vehicle generator (hereinafter referred to as a generator) 2. The front wheel 23 which is a steered wheel is operated by a steering 25 provided in the body 22. The front wheel 23 and the rear wheel 24 support the body 22. Engine 1 is started by an engine starter 21. The engine starter 21 is composed of a capacitor bank 4, a battery 3, a starter motor (hereinafter referred to as motor) 5, a switching switch 6, a DCZDC converter 7, a starter relay 8, a relay 9, and a storage amount control. It consists of 12 parts.

[0011] Generally, the rated voltage of the battery 3 composed of a lead-acid battery is 14V. Capacitor bank 4 consists of six electric double layer capacitors with a rated voltage of 2.5V connected in series to form one unit, and a plurality of these units connected in parallel. Motor 5 is powered by battery 3 or battery 3 and capacitor bank 4. Changeover switch 6 switches the circuit according to normal driving and when engine 1 is restarted. The DCZDC converter 7 converts the voltage of the electric power from the generator 2. The starter relay 8 turns the power supply circuit to the motor 5 on and off. The relay 9 is provided in a circuit that directly connects the notch 3 and the starter relay 8. The switching switch 6, the starter relay 8, and the relay 9 may be composed of electronic switching circuits in addition to the contact type switching device.

[0012] The storage amount control unit 12 includes a charge / discharge control unit 11, a storage amount measurement unit 14, and a discharge unit 13. The charging / discharging control unit 11 switches the switching switch 6 and controls the discharging unit 13 based on information from the charged amount measuring unit 14. The storage amount measuring unit 14 measures the storage amount charged in the capacitor bank 4. As will be described later, the discharge unit 13 discharges the capacitor bank 4 when the vehicle is at rest to adjust the amount of power stored in the capacitor bank 4 to a predetermined range. The discharge unit 13 can be composed of a fixed resistor, an electronic load device, a constant current power source, or the like. The charge / discharge control unit 11 can be composed of a microcomputer or the like. Further, two or more of the charge / discharge control unit 11, the storage amount measurement unit 14, and the discharge unit 13 may be integrally configured. Further, the engine control unit 10 may be integrated.

The engine control unit 10 controls starting and stopping of the engine 1. The engine control unit 10 can also be composed of a microcomputer or the like. Ignition key 18 starts engine from user Receives instructions and communicates to engine control unit 10. The ignition key 18 can be composed of a rotary switch or the like.

[0014] Regarding the operation of the engine starter 21 configured as described above, first, a normal case of starting the engine 1 only with the electric power of the battery 3 will be described. When the user turns the ignition key 18, the signal is input to the engine control unit 10. The engine control unit 10 receives this signal and turns on the relay 9 and the starter relay 8 respectively. As a result, electric power is supplied from the battery 3 and the motor 5 is driven. Then, the motor 1 is rotated and started by the motor 5. The power supplied from the battery 3 required to drive the motor 5 when the engine 1 is started is about 600 A at 12V.

Next, a charging operation performed while the engine 1 is in operation will be described. During normal travel, generator 2 is driven in conjunction with engine 1 rotation. The switching switch 6 is connected in the downward direction in the figure by the charge / discharge control unit 11. Then, the engine control unit 10 turns off the relay 9. As a result, the electric power from the generator 2 is charged into the battery 3 via the DC / DC converter 7 and the electric power from the generator 2 is directly charged into the capacitor bank 4.

[0016] Braking energy is generated when the vehicle is stopped by applying a brake while the vehicle is running. Recovering this braking energy is also preferable from the viewpoint of energy saving. However, the maximum current of braking energy reaches 200A, which is very large energy. Battery 3 is not capable of charging all braking energy. On the other hand, electric double layer capacitors are excellent in charge acceptance at large currents. For this reason, most of the braking energy is charged in the capacitor bank 4 and regenerated. Thus, it is preferable that the capacitor bank 4 is mainly charged by the power charged by the generator 2 using braking energy rather than the power generated by the operation of the engine 1 during normal driving.

[0017] Next, idling stop when the vehicle is not running and subsequent operation at restart will be described. The engine control unit 10 temporarily stops the engine 1 when certain conditions are met based on information from an accelerator, a brake, a vehicle speed sensor, a water temperature sensor, and the like (not shown). That is, the engine 1 is brought into a so-called idling stop state. After this idling stop, the engine control unit 10 causes the user to depress the accelerator. Restart engine 1 based on information such as That is, the engine control unit 10 turns off the relay 9 and connects the switching switch 6 upward in the drawing via the charge / discharge control unit 11. By these switching operations, the capacitor bank 4 is connected in series with the battery 3. When the starter relay 8 is turned on in this state, the electric power obtained by adding the voltage of the capacitor bank 4 to the notch 3 is supplied to the motor 5. When the motor 5 is driven, the engine 1 is restarted.

[0018] The idling stop is performed relatively frequently. And restarting after idling stops requires a current of several tens of A at a voltage of 12V. Therefore, the idling stop places a heavy burden on battery 3. However, the deterioration of the characteristic of the battery 3 can be suppressed by performing the restart after the idling stop with the capacitor bank 4 assisting as in the present embodiment. Thus, it is preferable to apply the operation that the capacitor bank 4 starts while assisting, particularly to restart after idling stop.

Next, when the engine 1 is stopped and the vehicle is put into a resting state, the charging / discharging control unit 11 controls the discharging unit 13 based on the information from the charged amount measuring unit 14 to discharge the capacitor bank 4. . Then, the charge / discharge control unit 11 adjusts the amount of electricity stored in the capacitor bank 4 to 24% or more and 60% or less of the amount of electricity stored when the vehicle is operating.

[0020] There are various methods for measuring the amount of electricity stored in the capacitor bank 4 by the electricity storage amount measuring unit 14. That is, the amount of electricity charged from the generator 2 and the battery 3 is measured, and the amount of electricity stored in the capacitor bank 4 is determined by measuring the amount of electricity discharged from the discharge unit 13 and the amount of electricity supplied to the motor 5. be able to. In this case, the storage amount measuring unit 14 is configured as an integrator for the amount of electricity flowing in and out of the capacitor bank 4.

[0021] The storage amount measuring unit 14 monitors the voltage of the capacitor bank 4 when the vehicle is running, and when the voltage of the capacitor bank 4 becomes equal to or higher than a predetermined value, the charge / discharge control unit 11 Is determined to be fully charged. The charge / discharge control unit 11 sets the amount of electricity stored at this time as the amount of electricity stored when the vehicle is operating. Alternatively, the charge / discharge control unit 11 uses the amount of electricity stored when the voltage of the capacitor bank 4 reaches the maximum during vehicle operation as the amount of electricity stored during vehicle operation.

[0022] Alternatively, the charged amount measuring unit 14 can measure the capacity of the capacitor bank 4 only by measuring the voltage. The amount of electricity stored in Sitabank 4 can be estimated. The voltage of the electric double layer capacitor correlates with the amount of electricity stored, and there is a nearly linear relationship between the two. Therefore, the amount of electricity stored in the capacitor bank 4 can be estimated by comparing the maximum operating voltage (for example, 2.5 V) with the voltage at that time. In such a method, the measurement accuracy is slightly lowered as compared with the above-described method, but the storage amount measuring unit 14 can be easily configured.

[0023] Next, the amount of electricity stored in the capacitor bank 4 when the automobile is at rest will be described. Judging from the long-term life potential of electric double layer capacitors, it is desirable to control the amount of electricity stored in capacitor bank 4 at rest to zero. However, if the amount of electricity stored is zero, it is necessary to charge the capacitor bank 4 from the battery 3, and the battery 3 is burdened. From this point of view, it is desirable that the amount of power stored in the capacitor bank 4 during a standstill maintains the amount of power stored when the vehicle is operating and is in a fully charged state.

FIG. 3 is a graph showing the relationship between the amount of electricity stored in the electric double layer capacitor constituting the capacitor bank 4 and the change in capacity at 50 ° C. This graph shows the results of measuring the rate of change in capacitance when a constant voltage continuous energization load test was performed on an electric double layer capacitor rated at 2.5V. In other words, the amount of electricity stored in the electric double layer capacitor is adjusted by changing the voltage level. A voltage value of 1.8V corresponds to 72% of the charged amount, and a voltage value of 0.6V corresponds to 24% of the charged amount. A voltage value of 0.9V corresponds to 36% of charge, a voltage value of 1.2V corresponds to charge of 48%, and a voltage value of 1.5V corresponds to charge of 60%.

As is apparent from FIG. 3, when the charged amount is controlled to 24% or 36%, no capacity decrease is observed even after 7000 hours. That is, it is possible to suppress the deterioration of the electric double layer capacitor by controlling the charged amount to 36% or less. On the other hand, when the amount of electricity stored is controlled to 48% or 60%, the capacity decreases in the initial stage, but is almost constant after 5000 hours. In contrast, when the amount of electricity stored is controlled to 72%, the capacity continues to decline even after 7000 hours. Therefore, capacitor deterioration can be suppressed to some extent by controlling the amount of stored electricity to 60% or less. Based on the above, it is preferable to control the amount of electricity stored in capacitor bank 4 at rest in the range of 24% to 60% of the amount of electricity stored during vehicle operation. preferable.

[0026] As described above, when the amount of electricity stored in the electric double layer capacitor is controlled to 36% or less, The capacity of the electric double layer capacitor hardly decreases. For this reason, even when the storage amount measurement unit 14 is configured as an integrator for the amount of electricity entering and exiting the capacitor bank 4, when the storage amount is controlled to 36% or less, the rated value should be used as the storage amount when the vehicle is in operation. Is possible. That is, the storage amount measuring unit 14 does not need to constantly update the storage amount when the vehicle is operating, and the calculation of the storage amount is simplified.

[0027] In addition, when the storage amount at the time when the voltage of the capacitor bank 4 becomes the maximum is the storage amount when the vehicle is operating, the charge / discharge control unit 11 compares this maximum voltage with the maximum use voltage, The amount of stored electricity may be changed. For example, when the maximum voltage per electric double-layer capacitor is 2.3V, 60% of the amount of electricity stored in the vehicle is discharged, and when the maximum voltage is 2.OV, the amount of electricity stored in the vehicle is 55%. You can discharge it.

[0028] As described above, the engine starter 21 performs control so as to decrease the amount of power stored in the capacitor bank 4 when the vehicle is at rest. As a result, the burden imposed on the electric double layer capacitor constituting the capacitor bank 4 and the burden imposed on the notch 3 are simultaneously reduced, thereby extending the life of both. The electric double layer capacitor is also used to restart the engine after idling stops. As a result, the burden on the battery 3 is greatly reduced, and deterioration of the battery 3 due to idling stop can be reduced.

[0029] Next, a description will be given of a case where the engine starter 21 is applied to normal engine start-up in addition to restart with idling stop force. Even during normal engine starting, in the initial driving, the engine 1 and the motor 5 are stopped, and the state force motor 5 is driven, so the load is large. Until the engine 1 starts, the load gradually decreases. Thus, large electric power is required for initial driving. On the other hand, when the voltage of the battery 3 decreases to some extent due to self-discharge or the like, the power that can be output decreases. For this reason, when the voltage of the battery 3 is below a predetermined value, the motor 5 cannot be driven initially.

[0030] For this reason, it is preferable to provide a voltage measuring unit 16 for measuring the voltage of the battery 3. Then, when the voltage of the notch 3 becomes equal to or lower than the value necessary for the initial drive of the motor 5, it is preferable that the charge / discharge control unit 11 switches the switch 6 to charge the capacitor bank 4 from the battery 3. The electric power from the capacitor bank 4 charged in this way drives the motor 5 in the initial stage. At this time, it is possible to drive the motor 5 initially with the capacitor bank 4 alone. As with the restart after the idling stop described above, the initial drive can be performed with the notch 3 and the capacitor bank 4 connected in series.

The capacitor bank 4 has a smaller charge / discharge capacity than the battery 3, but can be charged / discharged with a large current. For this reason, even when the voltage of the battery 3 drops, the battery 3 can be charged to the same voltage without using much of the battery 3's storage capacity. Since the battery 3 can be discharged at a higher current than the battery 3, the motor 5 can be driven initially.

It is preferable that the voltage measuring unit 16 is provided as described above, and the charge / discharge control unit 11 switches the switching switch 6 according to the voltage of the battery 3. With this configuration, the engine starter 21 can start the engine 1 using the capacitor bank 4 even when the motor 5 cannot be initially driven due to deterioration or abnormality of the battery 3. That is, the reliability of the engine starter 21 is further improved.

Next, the preference and arrangement of the battery 3 and the capacitor bank 4 will be described. FIG. 4 is a conceptual diagram showing a state in which the battery 3 and the capacitor bank 4 are integrated. FIG. 5 is an exploded perspective view showing a state in which the battery 3, the capacitor bank 4, and the engine control unit 10 are removed from the integrated state.

As shown in FIG. 4 and FIG. 5, it is preferable that the notch 3 and the capacitor bank 4 are housed integrally in a case 19 that is also configured with a force such as insulating grease. Since a large current is applied to the battery 3 and the capacitor bank 4 which are electrochemical elements, they cannot be installed indoors as they are. By storing such an electrochemical element in the case 19 as a whole, it is possible to prevent electric leakage and electric shock at the same time, thereby increasing safety.

It should be noted that the battery 3 and the capacitor bank 4 can be arranged at a place other than the engine compartment 26 if the safety is increased in this way. For example, it can be placed under the sheet shown in FIG. If the battery 3 and the capacitor bank 4 are arranged in a place other than the engine room 26 in a high temperature environment as described above, the life can be further extended.

[0036] Notch 3 needs to supply accessory power even when the ignition key is OFF. For example, current flows even when the vehicle is stopped and the vehicle is locked, as in keyless entry. This is called dark current. This dark current continues to flow even if the vehicle is exported by ship for about 30 days, 60 days, etc. During this time, engine 1 It cannot be started. Therefore, even if dark current flows for about 30 days, 60 days, etc., it is necessary to leave the battery 3 with enough charge to start the engine 1 the next time the vehicle is removed from the ship. Therefore, the conventional engine starter must use a large battery.

In contrast, in the present embodiment, a voltage measurement unit 16 is provided, and the charge / discharge control unit 11 switches the switching switch 6 according to the voltage of the battery 3. Therefore, even when the voltage of the battery 3 drops during export by sea as described above, the capacitor bank 4 can be charged by the battery 3, and the motor 5 can be initially driven by the charged capacitor bank 4.

Therefore, the battery 3 can be downsized as compared with the conventional engine starter.

The marginal space generated by this can be used. For this reason, even if the battery 3 and the capacitor bank 4 are integrally formed in the case 19, it does not become large in size, and there is not enough space. A mounting space for the capacitor bank 4 can be secured in the engine compartment 26. Further, as described above, it can be arranged in a place other than the engine compartment 26 such as a vehicle compartment.

As shown in FIGS. 4 and 5, it is preferable that the engine control unit 10 is also housed in the case 19. Although not shown, it is preferable to store the charge / discharge control unit 11 and the power storage amount control unit 12 including the engine control unit 10 in the case 19 together with the engine control unit 10. Alternatively, the charge / discharge control unit 11 or the storage amount control unit 12 may be housed in the case 19 instead of the engine control unit 10. Further, the switching switch 6 and the DCZDC converter 7 may be housed in the case 19. By storing at least one of these electrical components in the case 19, space is saved.

[0040] (Embodiment 2)

FIG. 6 is a circuit configuration diagram showing the configuration of the engine starter according to Embodiment 2 of the present invention. The engine starting device 21A according to the present embodiment differs from the engine starting device 21 according to the first embodiment in configuration in that a timer 17 is provided. The switch 6 is provided with a contact for supplying power from the battery 3 to the capacitor bank 4 via the DC / DC converter 7. Further, a current sensor 15 for measuring the current from the battery 3 is provided. The charge / discharge control unit 11 predicts deterioration of the battery 3. Other configurations are The same as in the first embodiment. That is, similar to the engine starter 21, the engine starter 21A connects the capacitor bank 4 in series with the battery 3 when restarting from the idling stop. In this state, the motor 5 is driven and the engine 1 is restarted. When the vehicle is at rest, the amount of electricity stored in the capacitor bank 4 is controlled to 24% to 60% of the amount of electricity stored during operation. In addition to this, the charge / discharge control unit 11 in the engine starting device 21A predicts the deterioration of the battery 3. This will be described below with reference to FIGS.

[0041] FIG. 7 is an explanatory diagram in the case of predicting the deterioration of the battery by the charge amount value in the engine starting device shown in FIG. First, the voltage measuring unit 16 measures the voltage of the battery 3. The voltage of battery 3 is usually about 14V. Next, the charge / discharge control unit 11 switches the switch 6 to charge the capacitor bank 4 from the battery 3 via the DC / DC converter 7 with a constant current (for example, 15 A). The charge / discharge control unit 11 measures the time T1 when the terminal voltage of the battery 3 becomes VI (for example, 12. OV) and the time T2 when it decreases to V2 (for example, 11. OV) by the time measuring unit 17. To do. The charge / discharge control unit 11 measures the current I from the battery 3 by the current sensor 15. The charge / discharge control unit 11 calculates the charge amount value C from (Equation 1). The charge / discharge control unit 11 predicts the deterioration of the battery 3 by determining what state the charge amount value C obtained in this way is with respect to a predetermined value.

[0042] C = I X (T2—T1) Z (V1—V2) (Equation 1)

When the battery 3 deteriorates, the voltage drops in a short time when a constant current is discharged. That is, the charge amount value C decreases. Thus, the charge / discharge control unit 11 determines that the deterioration of the notch 3 is proceeding when the charge amount value C becomes equal to or less than the predetermined value. At this time, since the temperature of the notch 3 affects the charge amount value C, a temperature sensor for measuring the temperature of the notch 3 is further provided, and the charge / discharge control unit 11 takes into account the information on the temperature sensor force to It is preferable to predict the deterioration of the material.

Next, another method for the charge / discharge control unit 11 to predict the deterioration of the battery 3 will be described with reference to FIGS. 6 and 8. FIG. FIG. 8 is an explanatory diagram when battery deterioration is predicted by the internal DC resistance by the engine starter shown in FIG. 6, and corresponds to the broken line portion of FIG.

First, the voltage measurement unit 16 measures the voltage of the battery 3. Next, the charge / discharge control unit 11 switches the switching switch 6 so that the capacitor band from the battery 3 through the DC / DC converter 7 is switched. Charge the battery 4 with a constant current (eg 15A). That is, the battery 3 is discharged. Calculate the voltage change force internal DC resistance immediately after the start of discharge. For example, the voltage measurement unit 16 measures the terminal voltage of the battery 3 0.5 seconds and 2.0 seconds after the start of discharge. The voltage measuring unit 16 scans the voltage of the battery 3 with an accuracy of lms immediately after the start of discharging.

The charge / discharge control unit 11 calculates this voltage difference Δν. The voltage measurement unit 16 may calculate Δν. On the other hand, the current sensor 15 measures the current I from the battery 3. Then, the charge / discharge control unit 11 calculates the internal DC resistance R from the voltage difference ΔV and the current I by (Equation 2).

[0046] R = ΔνΖΐ · · (Formula 2)

The charge / discharge control unit 11 predicts the deterioration of the battery 3 by determining the state of the internal DC resistance R thus determined with respect to a predetermined value.

[0047] Generally, when the storage battery deteriorates, the internal DC resistance R increases. In this way, the charge / discharge control unit 11 determines that the deterioration of the notch 3 is proceeding when the internal DC resistance R becomes a predetermined value or more. At this time, since the temperature of the battery 3 affects the internal DC resistance R, a temperature sensor for measuring the temperature of the battery 3 is further provided, and the charge / discharge control unit 11 takes into account the information from this temperature sensor to deteriorate the battery 3 Is preferably predicted.

[0048] In a conventional engine starter, main power is supplied by a lead storage battery.

Therefore, the performance of a lead storage battery deteriorates by repeating charging / discharging. Therefore, if the power required to start the engine by driving the starter motor cannot be taken from the lead-acid battery, the engine cannot be started on its own and the user uses a car. Can not ,.

[0049] On the other hand, the engine starter 21A discharges the battery 3 when the vehicle is at a standstill and grasps the state of the battery 3, so that it is possible to take a prior action according to the state. That is, the charge / discharge control unit 11 determines that the voltage of the notch 3 becomes lower than a predetermined value due to factors such as deterioration or abnormality and the motor 5 cannot be driven initially. In such a case, the charge / discharge control unit 11 can charge the capacitor bank 4 with the battery 3 and perform the initial drive of the motor 5 with the charged capacitor bank 4. This makes it possible to avoid the worst condition that the engine 1 cannot be started by itself. Thus, the engine starter 21A has higher reliability than the engine starter 21. As in the first embodiment, the notch 3 and the capacitor bank 4, the charge / discharge control unit 11, the engine control unit 10, and the like may be integrally formed in the case 19.

In the first and second embodiments, the case where a lead storage battery is used as the battery 3 is described as an example, but the present invention is not limited to this. Any rechargeable battery such as a nickel metal hydride battery or a lithium ion battery! Further, the number of series and parallel number of electric double layer capacitors constituting the capacitor bank 4 is not limited. In recent years, the voltage of automobile electrical systems has been increasing. Also, the capacity of the battery 3 used depends on the size of the vehicle. In accordance with this, the number and capacity of electric double layer capacitors can be changed as appropriate. In addition, depending on the difference in the configuration of the battery 3 and capacitor bank 4, the voltage value, current value, etc. at the time of predicting the deterioration of the battery 3 can be changed.

Industrial applicability

[0052] The engine starter according to the present invention has the effect of reducing the burden on the battery and the electric double layer capacitor and extending their life. This engine starter is useful for hybrid cars and cars with an idling stop function. It can also be applied to starters other than automobiles.

Claims

The scope of the claims

[1] An engine starter for starting a vehicle engine,

An electric double layer capacitor;

A rechargeable battery,

Power supplied by at least one of the electric double layer capacitor and the battery.

At

A power storage amount control unit that controls a power storage amount of the electric double layer capacitor when the vehicle is at rest to 24% or more and 60% or less of a power storage amount when the vehicle is operating,

Engine starter.

[2] The electric double layer capacitor is mainly charged by a generator mounted on the vehicle using braking energy.

The engine starter according to claim 1.

[3] For restarting after idling stop of the engine,

The engine starter according to claim 1.

[4] The battery further includes a charge / discharge control unit that charges the electric double layer capacitor from the battery when the capacity of the battery decreases below a value necessary for initial drive of the starter motor.

The engine starter according to claim 1.

5. The engine starter according to claim 1, further comprising a case for integrally storing the battery and the electric double layer capacitor.

[6] The case houses the storage amount control unit! /,

The engine starter according to claim 5.

[7] The battery further includes a charge / discharge control unit that charges the electric double layer capacitor from the battery when the capacity of the battery decreases below a value necessary for initial drive of the starter motor.

The case houses the charge / discharge control unit.

The engine starter according to claim 5.

[8] The electric double layer capacitor is charged with the current supplied from the battery when the vehicle is at rest, and further includes a charge / discharge control unit for predicting deterioration of the battery.

The engine starter according to claim 1.

[9] The battery further includes a case that houses the battery, the electric double layer capacitor, and the charge / discharge control unit.

The engine starter according to claim 8.

[10] The power storage amount control unit includes:

A storage amount measuring unit for measuring a storage amount of the electric double layer capacitor; a discharge unit for discharging the electric double layer capacitor;

A charge / discharge control unit that controls the discharge unit to adjust the storage amount of the electric double layer capacitor based on the measurement result of the storage amount measurement unit,

The engine starter according to claim 1.

11. The engine starter according to claim 10, wherein the storage amount measuring unit integrates the amount of electricity that enters and exits the electric double layer capacitor.

[12] The storage amount measuring unit measures the voltage of the electric double layer capacitor.

The engine starter according to claim 10.

[13] The storage amount control unit controls the storage amount of the electric double layer capacitor when the vehicle is at rest to a value between 24% and 36% of the fixed value, with the storage amount when the vehicle is in operation as a constant value. To

The engine starter according to claim 1.

[14] the body,

The engine starter according to claim 1, provided on the body,

An engine started by the engine starter;

Driving wheels driven by the engine and supporting the body;

A steering wheel provided on the body;

A steering wheel operated by the steering, and

Car.

[15] The engine further includes an engine control unit that controls driving of the engine,

The engine starter restarts the engine after the engine controller has stopped idling the engine;

The automobile according to claim 14.

[16] The battery further includes a case for integrally storing the battery, the electric double layer capacitor, and the engine control unit.

The automobile according to claim 15.

[17] The apparatus further includes a case for integrally storing the battery and the electric double layer capacitor, wherein the battery and the electric double layer capacitor are arranged in a location different from the engine compartment in the body for storing the engine. The

The automobile according to claim 14.