JP2006029142A - Engine start control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothen and stabilize driving of a vehicle by preventing a drop in battery output voltage in supplying an operating current of an engine starting system. <P>SOLUTION: Before start of an engine, a discharge control of a capacitor 120 is performed to become predetermined voltage or less, and after the engine start, the capacitor 120 is charged with a charging current from a battery 110. At the first engine start after start of a vehicle, current switches SW1, SW3 are turned on and a current switch SW2 is turned off to supply the operating current of a starter motor 60 by a starting current I1 from the battery 110. On the other hand, after the start of the engine and the charging of the capacitor 120 is finished, economy running is allowed. In the restart after a temporary stop of the engine by the economy running, the current switch SW1 is turned off and the current switches SW2, SW3 are turned on to supply the operating current of the starter motor 60 also from the capacitor 120. At this time, the battery 110 supplies starting current I1# through a current limiting resistor 140 to prevent the drop in output voltage Vb of the battery 110. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an engine start control device for a vehicle, and more particularly to an engine start control device for a vehicle including an engine start device that receives current supply from a plurality of power storage devices.

  2. Description of the Related Art Conventionally, a vehicle such as an automobile generally includes a secondary battery (battery) such as a lead storage battery as a power storage device. Secondary batteries such as lead-acid batteries can withstand relatively long use due to their high energy density, but once overdischarged, it takes time to recharge them. A system to be used is proposed. For example, a configuration has been proposed in which a capacitor (capacitor) is disposed separately from a battery for driving a starter motor (engine starter) that consumes a large current during operation (for example, Patent Documents 1 and 2).

  Recently, vehicles (hereinafter also referred to as “eco-run vehicles”) equipped with a so-called economy running system (hereinafter also simply referred to as “eco-run system”) have been developed for the purpose of improving fuel efficiency. In this eco-run system, when the vehicle is temporarily stopped, the engine idling is forcibly stopped in response to the establishment of a predetermined engine stop condition, and the engine is automatically turned on when the engine stop condition is not satisfied. Crank and restart. As a result, the idling time as a whole is shortened, the amount of exhaust gas discharged is reduced, and the fuel consumption is improved. In this type of eco-run car, it is necessary to restart the engine quickly. Therefore, a capacitor capable of instantaneously discharging large electric power is used as a starter motor power supply for cranking the engine, instead of a conventional battery. May be adopted.

  In such an engine starting device for an eco-run vehicle equipped with both a capacitor and a battery, even when the temperature is low, a sufficient and sufficient electric power is discharged from the capacitor to improve engine startability and vehicle start-up acceleration. Therefore, a configuration including a boosting unit that boosts the output voltage of the power storage device at a low temperature has been proposed (Patent Document 3).

Further, in a hybrid vehicle equipped with an engine and a motor generator as a driving force source, in order to prevent the electric energy of the capacitor for driving the motor generator from being consumed wastefully, when the engine start request is not generated, the capacitor A configuration for supplying electric power to an auxiliary battery has been proposed (for example, Patent Document 4).
JP-A-9-247856 JP-A-10-191576 JP 2003-219564 A JP 2000-156919 A

  However, in a configuration in which an operating current of a starter motor (engine starter) that consumes a large current is supplied by a battery (typically a lead storage battery) and a capacitor, the battery generally supplies power to other electrical devices. Is performed together. In such a configuration, if the output voltage of the battery is reduced when operating current is supplied to the starter motor, these auxiliary machines may not operate normally.

  For example, when these auxiliary machines include an electronic control unit (ECU) such as an engine control unit, the arithmetic unit (CPU) in the ECU may be in a reset state and normal operation may not be performed. . In particular, when such a phenomenon occurs at the time of return from the temporary engine stop by the eco-run system, that is, when the engine restarts, the operation cannot be resumed smoothly, and the drivability is greatly impaired.

  On the other hand, since the capacitor has a higher power density than the secondary battery but has a lower energy density, supplying the operating current to the starter motor with only the capacitor causes an increase in the size of the capacitor. In addition, leaving the capacitor with the remaining charge left for a long time leads to a decrease in the life, so that it is preferable to remove the remaining charge from the capacitor when the vehicle is stopped.

  Therefore, in the configuration in which the operating current of the engine starting device is supplied by a combination of a battery and a capacitor, depending on the vehicle state, specifically, after the engine is started at the time of starting the vehicle and then the engine is temporarily stopped by the eco-run system. It is necessary to appropriately change the current supply balance between the battery and the capacitor depending on the vehicle state during the engine restart.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a vehicle in which an operating current of an engine starting device can be supplied by both a battery and a capacitor (capacitor). According to the state, the current supply balance from both is made appropriate to make the vehicle operation smooth and stable.

  An engine start control device for a vehicle according to the present invention is an engine start control device for a vehicle equipped with an engine for generating a driving force of the vehicle and an engine start device for receiving the power supply to start the engine. 2 power storage devices and a starting current control unit. The first and second power storage devices can supply the accumulated power to the engine starting device. The starting current control unit is provided between the first and second power storage devices and the engine starting device, and the engine is operated by at least one of the first and second starting currents from each of the first and second power storage devices. Supply the operating current of the starter. Furthermore, the starting current control unit controls the ratios of the first and second starting currents in the operating current according to the state of the vehicle at the time of starting the engine.

  In the vehicle engine start control device according to the present invention, in the vehicle capable of supplying the operating current of the engine start device by both the first and second power storage devices, the vehicle state, more specifically, the first and second Considering the power that can be output from the power storage device, the operating current of the engine starting device can be supplied after the current supply balance from both is made appropriate. Therefore, when an operating current is supplied to the engine starter that consumes a large amount of power, any power storage device can be prevented from causing a decrease in output voltage due to an excessive output power, so that vehicle operation can be smoothed and stabilized.

  Preferably, the vehicle engine start control device according to the present invention further includes a power generation device that generates electric power by at least part of the driving force of the vehicle. The first power storage device is a secondary battery that can be charged by the power generated by the power generation device, supplies power to a load other than the engine starter, and the second power storage device is a capacitor. It is.

  According to the engine start control device for a vehicle described above, a combination of a secondary battery having a load other than the engine start device and a capacitor for the engine start device prevents the supply voltage to the load from being reduced. The structure which can supply the operating current to is realizable.

  More preferably, in the engine start control device for a vehicle according to the present invention, the vehicle temporarily stops the engine to stop idling in response to establishment of a predetermined condition when the vehicle is temporarily stopped after the engine is started. A system is further provided. For this reason, the engine start includes an engine start that is the first engine start after the start of the vehicle and an engine restart that is an engine start after the engine is temporarily stopped by the economy running system after the engine is started. The starting current control unit performs discharge control of the second power storage device so that the output voltage of the second power storage device is equal to or lower than a predetermined voltage before starting the vehicle, and at least partly after starting the engine. In this period, a charging path from the first power storage device to the second power storage device is formed. Further, the starting current control unit sets the first starting current when the engine is restarted smaller than the first starting current when the engine is started, and restarts the engine than the second starting current when the engine is started. The second starting current at the time is set large.

  According to the engine start control device for a vehicle described above, when the engine is started after the vehicle is started, the start current by the first power storage device (secondary battery) is mainly used, and when the engine is restarted after the eco-run, the second The operating current of the engine starting device can be supplied by increasing the ratio of the starting current from the power storage device (capacitor). Therefore, in the vehicle equipped with the eco-run system, it is possible to avoid a significant decrease in the output voltage of the first power storage device (secondary battery) when the engine is restarted after the engine is temporarily stopped, so that the vehicle operation is resumed smoothly and stably. be able to. Further, since the discharge control of the second power storage device (capacitor) is performed when the vehicle is stopped (before the engine is started), the life of the capacitor can be extended.

  More preferably, in the engine start control device for a vehicle according to the present invention, the starting current control unit includes a current limiting resistor provided between the first power storage device and the current output node, the first power storage device and the current output. A first switch provided in parallel with the current limiting resistor between the nodes, a second switch provided between the second power storage device and the current output node, and the current output node and the engine starter. And a third switch provided therebetween. The starting current control unit supplies current to the engine starting device by turning off the second switch and turning on the first and third switches when starting the engine, while turning off the first switch and turning off the first switch. A current is supplied to the engine starting device by turning on the second and third switches.

  According to the engine start control device for a vehicle described above, the first power storage device (secondary battery) can be used when the engine is started after the vehicle is started by a simple circuit configuration using the current limiting resistor and the first to third current switches. ) And when the engine is restarted after eco-run, the engine is started by the sum of the starting current from the secondary battery and the starting current from the second power storage device (capacitor) via the current limiting resistor. A starting current control unit capable of supplying the operating current of the apparatus can be configured.

  Particularly in such a configuration, in the engine start control device for a vehicle according to the present invention, the start current control unit includes at least a part of a period during which a charging path from the first power storage device to the second power storage device is formed. The second switch is turned on, and the first and third switches are turned off.

  According to the engine start control device for a vehicle described above, charging from the first power storage device (secondary battery) that can be charged by the generator to the second power storage device (capacitor) by connection via a current limiting resistor. A route can be easily formed. That is, the overall power efficiency can be improved as compared with charging accompanied by control by a DC / DC converter or the like.

  More preferably, in the engine start control device for a vehicle according to the present invention, the starting current control unit prohibits the engine from being temporarily stopped by the economy running system in accordance with the output voltage of the second power storage device after the engine is started. To do.

  According to the engine start control device for a vehicle described above, in the configuration in which the second power storage device (capacitor) is controlled to discharge when the vehicle is stopped (before the engine is started) in order to extend the life, the capacitor is sufficiently charged after the engine is started. Until this time, the engine is temporarily stopped by the eco-run system. Therefore, when the engine is restarted after the eco-run, the output from the first power storage device (secondary battery) is excessively prevented and the output voltage can be prevented more reliably. As a result, the stability of vehicle driving is further enhanced.

  Alternatively, preferably, in the engine start control device for a vehicle according to the present invention, the starting current control unit further includes a bidirectional converter provided between the first and second power storage devices, and the first and second power storage devices One can be charged by the output from the other of the first and second power storage devices.

  According to the engine start control device for a vehicle described above, in the configuration in which the second power storage device (capacitor) is controlled to discharge when the vehicle is stopped (before the engine is started) in order to extend the life, this discharge current is used as the first power storage. Since it can use for charge of an apparatus (secondary battery), energy efficiency in the whole vehicle improves. In addition, since the charging current can be controlled by the converter even when charging the capacitor from the secondary battery after the engine is started, the charging current is not excessive and the output voltage of the secondary battery is not reduced. The operation of each device can be further stabilized.

  According to the engine start control device for a vehicle according to the present invention, in the vehicle in which the operating current can be supplied to the engine start device by both the first power storage device (secondary battery) and the second power storage device (capacitor), the vehicle The current supply balance from both can be optimized according to the state. Therefore, when an operating current is supplied to the engine starter that consumes a large amount of power, any power storage device can be prevented from causing a decrease in output voltage due to an excessive output power, so that vehicle operation can be smoothed and stabilized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in a figure, and the description shall not be repeated in principle.

  FIG. 1 is a block diagram illustrating a schematic configuration of a vehicle 10 equipped with an engine start control device according to the present invention. FIG. 1 representatively shows a part related to the engine and its starting device in the overall configuration of the vehicle 10.

  Referring to FIG. 1, a vehicle 10 includes an engine 20, a transmission (T / M) 30, a generator 40, a differential (differential) 45, wheels 50, a starter motor 60, and auxiliary equipment. Class 90 and engine start control device 100.

  The engine 20 is an internal combustion engine such as a gasoline engine, a diesel engine, or an LPG engine. The engine 20 has a known structure including a fuel injection device (not shown), a lubrication device (not shown), an ignition device (not shown), a cooling device (not shown), and the like.

  In order to start the engine 20, a starter motor 60 that operates by supplying current from the engine start control device 100 is provided. Typically, as the starter motor 60, a known DC motor such as a magnetic shift type or a reduction gear type is used.

  Torque output from the starter motor 60 is transmitted to a flywheel (not shown) of the engine 20 to start the engine 20, and the engine 20 autonomously rotates by fuel injection by the fuel injection device and ignition of the ignition device.

  The transmission 30 and the differential device 45 are arranged in a power transmission path from the engine 20 to the wheels 50. The transmission 30 includes a transmission that can set a transmission ratio by manual operation, or an automatic transmission that can automatically control the transmission ratio based on a running state of a vehicle. The generator 40 is rotated by at least part of the rotational force generated by the engine 20 to generate power.

  The auxiliary machinery 90 includes an electronic control unit (ECU) for controlling the operation of the vehicle 10. That is, the output voltage of the battery 110 that supplies operating power to the auxiliary machinery 90 needs to be maintained at a predetermined voltage or higher so that at least a CPU (not shown) in the ECU is not in a reset state.

  The engine start control device 100 includes a battery 110, a capacitor 120, and a start current control unit 130.

  The battery 110 can be charged by the power generated by the generator 40. The starting current control unit 130 is provided between the battery 110 and the capacitor 120 and the starter motor 60, and supplies the operating current of the starter motor 60 by one of the currents from the battery 110 and the capacitor 120 or the sum of both. To do. Capacitor (capacitor) 120 is formed of, for example, an electric double layer capacitor.

  FIG. 2 is a circuit diagram illustrating in detail the configuration of the engine start control device shown in FIG.

  Referring to FIG. 2, battery 110 is typically formed of a lead storage battery. A voltage sensor 111 is provided at a node N1 connected to the positive terminal of the battery 110. The voltage detected by the voltage sensor 111, that is, the battery output voltage Vb is sent to the control unit 150.

  Capacitor 120 includes a plurality of capacitor cells connected in series with each other. A voltage sensor 121 is provided at a node N2 connected to the positive terminal of the capacitor 120. The voltage detected by the voltage sensor 121, that is, the capacitor output voltage Vc is sent to the control unit 150.

  Battery 110 corresponds to “first power storage device” in the present invention, and capacitor 120 corresponds to “second power storage device” in the present invention. Further, the generator 40 in FIG. 1 corresponds to the “power generation device” in the present invention.

  In this embodiment, the capacitor (capacitor) 120 is exemplified as the “second power storage device”. However, the same power storage function can be used as long as the target function of the present invention as described below can be achieved. It is also possible to apply a circuit or an element having

  The starting current control unit 130 includes current switches SW1 to SW3, a current limiting resistor 140, a control unit 150, and a DC / DC converter 160.

  The DC / DC converter 160 is a bidirectional converter that can form both a path for charging the capacitor 120 by the battery 110 and a path for charging the battery 110 by the capacitor 120. DC / DC converter 160 includes a switching element (not shown). By the on / off control of the switching element in response to the switching control signal Scv from the control unit 150, these charging paths can be selectively formed and the output current (charging current) can be controlled at a constant value.

  The control unit 150 controls the on / off of the current switches SW1 to SW3 according to the battery output voltage Vb and the capacitor output voltage Vc detected by the voltage sensors 111 and 121, and the bidirectional DC / A switching control signal Scv for controlling the operation of the DC converter 160 is generated.

  Current limiting resistor 140 is connected between nodes N1 and N3. Current switch SW1 is connected in parallel with current limiting resistor 140 between nodes N1 and N3. Current switch SW2 is connected between nodes N2 and N3. Current switch SW3 is connected between node N3 and starter motor 60. That is, the node N3 corresponds to the “current output node” in the present invention. Current switches SW1 to SW3 are turned on or off in response to control signals S1 to S3 from control unit 150, respectively.

  Further, an eco-run system is realized by a host ECU (not shown). Thereby, when the vehicle is temporarily stopped, the engine 20 (FIG. 1) is temporarily stopped in response to establishment of a predetermined engine stop condition. For example, the engine stop condition is satisfied when the vehicle speed = 0 and the accelerator opening = 0 continue for a predetermined time.

  Further, when the engine stop condition is no longer satisfied, typically, in response to the accelerator depression, the temporarily stopped engine 20 is restarted by the starter motor 60.

  That is, the engine start by the starter motor 60 is the first engine start (hereinafter also referred to as “engine start”) from the start of the vehicle corresponding to the turn-on of the ignition switch, and the engine after the engine is temporarily stopped by the eco-run system thereafter. It is performed for starting (hereinafter also referred to as “engine restart”). These engine start timings are instructed by a host ECU (not shown), and in response to an instruction from the host ECU, the start current control unit 130 starts the current I1 from the battery 110 (when the current limiting resistor is bypassed) or I1. At least one of # (when passing through the current limiting resistor) and starting current I2 from battery 110 is supplied to starter motor 60 as an operating current.

  Next, the operation of the engine start control device shown in FIG. 2 will be described using the flowcharts of FIGS. 3 and 4.

  3 and 4 are flowcharts illustrating an engine start control routine by the engine start control device according to the embodiment of the present invention. The engine start control described below is executed by the control unit 150 in accordance with a program stored in advance.

  Referring to FIG. 3, the engine start control according to the embodiment of the present invention operates differently when the ignition switch is on and off (step S100).

  When the ignition switch is turned off (N determination in step S100), that is, before starting the vehicle, the following steps S110 to S130 control the residual charge of the capacitor for extending the life of the capacitor below a predetermined level. Done.

  Before starting the vehicle, it is determined whether or not the capacitor output voltage Vc is smaller than the predetermined voltage V1 with the current switches SW1 to SW3 shown in FIG. 2 turned off (step S110). When the capacitor output voltage Vc is higher than the predetermined voltage V1 (N determination in step S110), the DC / DC converter 160 operates so that a charging current using the accumulated charge of the capacitor 120 as a source is supplied to the battery 110. (Step S120). That is, in order to discharge capacitor 120, control unit 150 generates switching control signal Scv for DC / DC converter 160 such that a predetermined constant current is generated in the direction from capacitor 120 to battery 110.

  The capacitor discharge control is executed until the capacitor output voltage Vc becomes lower than the predetermined voltage V1 in step S110. The predetermined voltage V <b> 1 is preset to a low voltage that does not adversely affect the life of the capacitor 120 based on the characteristics of the capacitor 120.

  On the other hand, when capacitor output voltage Vc is equal to or lower than predetermined voltage V1 (Y determination in step S110), the operation of DC / DC converter 160 is turned off and no current path is formed between battery 110 and capacitor 120.

  As described above, until the ignition switch is turned on, that is, before the vehicle is started, the capacitor 120 is sufficiently discharged for extending the life, and the capacitor output voltage Vc is insufficient for starting the starter motor 60. The level is suppressed.

  When the ignition switch is turned on (Y determination in step S100), that is, even when the vehicle is started, the current switches SW1 to SW3 are maintained in the off state until an engine start request is issued. At this stage, in order to avoid the output voltage drop of the battery 110, the operation of the DC / DC converter 160 is turned off, and the current path from the battery 110 to the capacitor 120 is not formed. Further, since the power stored in the capacitor 120 is insufficient and the capacitor output voltage Vc is low, the eco-run permission flag is set to “0” (step S140).

  The eco-run permission flag indicates whether eco-run operation can be performed. That is, when the eco-run permission flag = “1”, the engine 20 is temporarily stopped in response to establishment of a predetermined engine stop condition (that is, “eco-run permission”). On the other hand, when the eco-run permission flag = “0”, the engine is not temporarily stopped even if the same engine stop condition is satisfied, and the idling operation is continued (that is, “eco-run prohibition”).

  In this state, when an engine start command is issued from the host ECU (step S150), the operating current is supplied to the starter motor 60 by turning on the current switches SW1 and SW3 and turning off the current switch SW2. As a result, the starter motor 60 is supplied with the starting current I1 bypassing the current limiting resistor 140 from the battery 110, but is not supplied with the starting current from the capacitor 120 (step S160). This starting current is supplied until the start of the engine is completed (N determination in step S170).

  When the startup of the engine is completed (Y determination in S170), all the current switches SW1 to SW3 are once turned off (step S180). After the engine is started, power is generated by the generator 40 shown in FIG. 1, so that a charging current can be supplied to the battery 110. For this reason, in order to store the power for starting the starter motor 60 in the capacitor 120, the DC / DC converter 160 responds to the switching control signal Scv from the control unit 150 to generate a constant charging current from the battery 110 to the capacitor 120. The supply is controlled (step S190).

  Charging from the battery 110 to the capacitor 120 is continued until the voltage difference between the battery output voltage Vb and the capacitor output voltage Vc is equal to or less than a predetermined value Vr, that is, | Vc−Vb | <Vr (N determination in step S200).

  When the output voltage difference between battery 110 and capacitor 120 converges below predetermined voltage Vr, the operation of DC / DC converter 160 is turned off, charging of capacitor 120 is stopped, and current switch SW2 is turned on instead. Further, at this stage, the eco-run permission flag is updated to “1”, and the eco-run is permitted (step S210).

  It should be noted that step S140 and subsequent steps of engine start control are executed until the ignition switch once turned on is turned off. When the ignition switch is turned off (Y determination in step S220), the engine start control is once ended, and a new engine start control is started again, and the capacitor discharge control (steps S100 to S130) when the ignition switch is turned off is executed. Is done.

  Further, the step S220 for detecting the ignition switch OFF is not limited to the execution at the timing as shown in FIG. 4, and after the step S140, in response to the operation of the ignition switch by the driver or the like, the interrupt processing is performed. Executed.

  After the eco-run is permitted, while the ignition switch is kept on (NO determination in step S220), it is sequentially checked whether or not a predetermined engine stop condition is satisfied (step S230).

  When the engine stop condition is satisfied (Y determination in step S230), an engine stop command is issued by the host ECU with reference to the engine control permission flag = “1”. At this time, in the starting current control unit 130, the current switch SW2 is turned off (step S240). This state continues until the vehicle temporary stop is released and the engine stop condition is not satisfied (N determination in step S250).

  When the vehicle temporary stop is released and the eco-run condition is not satisfied (Y determination in step S250), an engine restart command is generated by the host ECU (step S260).

  In response to the engine restart command in step S260, at the time of engine restart, in the starting current control unit 130, the current switch SW1 is turned off while the current switches SW2 and SW3 are turned on. Thereby, starter motor 60 is supplied with the sum of starting current I1 # (<I1) via current limiting resistor 140 and starting current I2 from capacitor 120 from battery 110 (step S270). This supply of restart current is continued until the restart of the engine is completed (N determination in step S280).

  That is, compared to when the engine is started (step S160), the starting current from the battery 110 is smaller when the engine is restarted than when the engine is started (I1> I1 #), and the starting current from the capacitor 120 is The engine restart time is larger than the start time (I2> 0).

  When the engine restart is completed (Y determination in step S280), the current switches SW1 and SW3 are turned off in order to cut the current supply path to the starter motor 60. On the other hand, the current switch SW2 is turned on in order to recover the capacitor output voltage Vc that has decreased due to the supply of the starting current I2 (step S285).

  The required charge amount of the capacitor 120 at this stage is smaller than the required charge amount immediately after engine startup (step S190). For this reason, even if the capacitor 120 is charged from the battery 110 via the current limiting resistor 140 without performing the constant current control by the DC / DC converter 160, the battery output voltage Vb is reduced by the generation of an excessive charging current. It is unlikely that it will be reduced to a level that adversely affects the operation of 90 (FIG. 1). Therefore, the capacitor 120 can be charged without operating the DC / DC converter 160.

  Charging of the capacitor 120 in response to turning on of the current switch SW2 is continued until the capacitor output voltage Vc becomes equal to or higher than the predetermined voltage V2 necessary for supplying the starting current I2 (N determination in step S290), and during this time, the eco-run permission flag = "0" is set and the eco-run is prohibited (step S300).

  When the capacitor output voltage Vc reaches or exceeds the predetermined voltage V2 (Y determination in step S290), the eco-run permission flag is set to “1” and eco-run is permitted again (step S310). That is, the state immediately after step S210 is reproduced, and the engine can be temporarily stopped in response to the establishment of the engine stop condition again.

  By realizing such an eco-run system, the idling time of the entire vehicle is shortened, exhaust gas emissions are reduced, and fuel efficiency is improved.

  Further, during an eco-run operation other than when the vehicle output is not sufficiently increased, the starting current supply from the battery 110 is suppressed and the engine is restarted. The overall operation of the vehicle can be smoothed and stabilized without lowering the power supply voltage with respect to the auxiliary machines 90 and the like in FIG.

  In the control flow shown in FIGS. 3 and 4, after the capacitor output voltage Vc once rises (after step S200), when the current switch SW2 is turned on, the current is switched from the battery 110 to the capacitor 120 via the current limiting resistor 140. Although the charging path is formed (step S285), the capacitor charging at this stage may be configured such that the current switch SW2 is turned off and the charging of the capacitor 120 is controlled by the DC / DC converter 160. Is possible.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a block diagram illustrating a schematic configuration of a vehicle equipped with an engine start control device according to the present invention. FIG. 2 is a circuit diagram illustrating in detail the configuration of the engine start control device shown in FIG. 1. It is a flowchart explaining the engine start control routine by the engine start control apparatus by embodiment of this invention. It is a flowchart explaining the engine start control routine by the engine start control apparatus by embodiment of this invention.

Explanation of symbols

  10 Vehicle, 20 Engine, 30 Transmission, 40 Generator, 45 Differential, 50 Wheel, 60 Starter Motor, 90 Auxiliary Equipment, 100 Engine Start Control Device, 110 Battery, 111, 121 Voltage Sensor, 120 Capacitor (Condenser) ), 130 starting current control unit, 140 current limiting resistor, 150 control unit, 160 DC / DC converter, I1, I1 # starting current (from battery), I2 starting current (from capacitor), S1 to S3 control signal (current switch) ), Scv switching control signal, SW1 to SW3 current switch, V1, V2, Vr predetermined voltage, Vb battery output voltage, Vc capacitor output voltage.

Claims (7)

An engine start control device for a vehicle equipped with an engine that generates a driving force of the vehicle and an engine start device that receives power supply to start the engine,
First and second power storage devices capable of supplying the stored electric power to the engine starting device;
The engine starter is provided between the first and second power storage devices and the engine starter, and is driven by at least one of first and second start currents from each of the first and second power storage devices. A starting current control unit for supplying an operating current of
The engine start control device for a vehicle, wherein the start current control unit controls a ratio of the first and second start currents in the operating current according to a state of the vehicle at the time of engine start. A power generation device that generates electric power using at least part of the driving force of the vehicle;
The first power storage device is a secondary battery that can be charged by the generated power of the power generation device, and supplies power to a load other than the engine start device,
The vehicle engine start control device according to claim 1, wherein the second power storage device is a capacitor. The vehicle further includes an economy running system that temporarily stops the engine to stop idling in response to establishment of a predetermined condition when the vehicle is temporarily stopped after the engine is started,
The engine start includes an engine start that is an initial engine start after the vehicle is started, and an engine restart that is an engine start after the engine is temporarily stopped by the economy running system after the engine is started.
The starting current control unit performs discharge control of the second power storage device so that an output voltage of the second power storage device is equal to or lower than a predetermined voltage before starting the vehicle, while after starting the engine Forming a charging path from the first power storage device to the second power storage device in at least a part of the period,
The starting current control unit sets the first starting current at the time of restarting the engine to be smaller than the first starting current at the time of starting the engine, and from the second starting current at the time of starting the engine. The engine start control device for a vehicle according to claim 2, wherein the second start current at the time of restarting the engine is set to be large. The starting current controller is
A current limiting resistor provided between the first power storage device and a current output node;
A first switch provided in parallel with the current limiting resistor between the first power storage device and a current output node;
A second switch provided between the second power storage device and a current output node;
A third switch provided between the current output node and the engine starter,
The starting current control unit supplies current to the engine starting device by turning off the second switch and turning on the first and third switches at the time of starting the engine, while at the time of restarting the engine, 4. The engine start control device for a vehicle according to claim 3, wherein a current is supplied to the engine start device by turning off the first switch and turning on the second and third switches.   The starting current control unit turns on the second switch during at least a part of a period during which a charging path from the first power storage device to the second power storage device is formed, and The engine start control device for a vehicle according to claim 4, wherein the switch 3 is turned off.   4. The engine start control device for a vehicle according to claim 3, wherein the start current control unit prohibits temporary stop of the engine by the economy running system in accordance with an output voltage of the second power storage device after the engine is started. 5. . The starting current control unit further includes a bidirectional converter provided between the first and second power storage devices,
7. The vehicle engine start according to claim 1, wherein one of the first power storage device and the second power storage device can be charged by an output from the other of the first power storage device and the second power storage device. Control device.

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