JP2007100660A - Vehicle engine start preparation device - Google Patents

Abstract

A battery voltage is lowered due to a start preparation performed before starting an engine, thereby avoiding a decrease in startability of the engine.
A plurality of devices such as an injector heater and a fuel pump are operated before the engine is started to improve engine startability and operability immediately after the start. Here, when the battery voltage becomes lower than the lower limit voltage in the start preparation state, the number of devices for stopping the operation is increased step by step in descending order of power consumption or in the order of low contribution to engine start improvement. Aims to revive voltage.
[Selection] Figure 5

Description

  The present invention relates to a vehicle engine start preparation device, and more particularly to an apparatus for preparing the engine start preparation before the engine is started.

In Patent Document 1, opening / closing of a vehicle door, insertion of a key into a key cylinder, seating of a driver, wearing of a seat belt, and the like are detected, and the engine start schedule is determined from these detection results. A start preparation system is disclosed that initiates start preparation for an engine when occurrence is determined.
As preparation for starting the engine, energization of an electric heater provided in a fuel injection valve for injecting fuel into the engine is started.
JP 2004-340028 A

By the way, the start preparation is performed using the battery as a power source in a stop state of the alternator before the engine is started. Therefore, by performing the start preparation, the voltage of the battery is lowered and the startability of the engine thereafter is lowered. There was a thing.
The present invention has been made in view of the above-described problems, and provides a start preparation device for a vehicle engine that can prevent a decrease in battery voltage due to start preparations that are performed before starting the engine, thereby reducing engine startability. The purpose is to do.

Therefore, according to the first aspect of the present invention, there is provided a start preparation device for a vehicle engine in accordance with start preparation means for preparing start of the engine and voltage of a battery as a power source of the start preparation means before starting the engine. And an operation restriction means for restricting the operation of the starting preparation means.
According to such a configuration, when a decrease in the battery voltage is detected, the operation of the start preparation unit is limited to reduce the power used for the start preparation, thereby suppressing the decrease in the battery voltage.

Therefore, by operating the start preparation means, it can be avoided that the battery voltage is lowered and the startability of the engine is lowered.
The restriction on the operation of the start preparation means includes stop of operation (shut off of power supply) and reduction of supplied power.
The invention according to claim 2 is a configuration in which the start preparation means operates a plurality of devices before starting the engine, and the operation restriction means sequentially restricts the operations of the plurality of devices according to a predetermined priority order. It is characterized by doing.

According to such a configuration, when a plurality of devices are operated before the engine is started in preparation for starting, which of the plurality of devices is to be limited in operation is determined according to a predetermined priority order.
Therefore, by setting priorities from the viewpoint of the degree to which the operation of the device affects the startability and how much power consumption can be reduced by restricting the operation of the device, effective start preparations are made as much as possible. Thus, it is possible to suppress a decrease in battery voltage or to effectively suppress a decrease in battery voltage.

The invention according to claim 3 is a configuration in which the start preparation means operates the plurality of devices before starting the engine, and the operation restriction means includes the plurality of devices as the battery voltage decreases. The number of devices that limit the operation is sequentially increased.
According to such a configuration, the excessive power consumption state is eliminated by sequentially increasing the number of devices that limit the operation as the battery voltage decreases.

Therefore, when the battery voltage decrease trend continues even after the device operation is restricted, this voltage decrease tendency can be prevented.
Here, when the number of devices whose operation is restricted is sequentially increased, the devices whose operation is to be stopped can be sequentially selected according to the priority order between the devices.
According to a fourth aspect of the present invention, when the operation restricting means determines that the battery voltage is restored after the operation of the start preparing means is restricted, the operation of the restricted start preparing means is at least partially canceled. It is characterized by doing.

According to such a configuration, when the battery voltage is restored as a result of restricting the operation of the start preparation means based on the decrease in the battery voltage in the start preparation state, at least a part of the previous restriction state is released, and the normal start preparation is performed. To implement.
Therefore, the required start preparation can be executed as much as possible while suppressing a decrease in the battery voltage.

The invention according to claim 5 is characterized in that the start preparation means prepares to start the engine when the start of the engine is predicted based on a passenger detection signal.
According to this configuration, when an occupant is detected, a subsequent start of the engine is predicted and preparation for starting the engine is performed.
Therefore, the start preparation to be performed before the engine is started can be appropriately started based on the engine start prediction.

Embodiments of the present invention will be described below.
FIG. 1 is a system configuration diagram of a vehicle engine in the embodiment.
In FIG. 1, an electronic control throttle 104 that opens and closes a throttle valve 103b by a throttle motor 103a is interposed in an intake pipe 102 of an engine 101 (gasoline engine).

Then, air is sucked into the combustion chamber 106 through the electronic control throttle 104 and the intake valve 105.
The intake port 130 of each cylinder is provided with an electromagnetic fuel injection valve 131, and each fuel injection valve 131 is provided with an injector heater 131a for heating the fuel.

When the fuel injection valve 131 is driven to open by an injection pulse signal from the control unit 114, the fuel injection valve 131 injects fuel adjusted to a predetermined pressure toward the intake valve 105.
The air-fuel mixture formed in the combustion chamber 106 is ignited and burned by spark ignition by a spark plug (not shown).
The combustion exhaust in the combustion chamber 106 is discharged to the exhaust pipe through the exhaust valve 107, purified by the front catalyst 108 and the rear catalyst 109, and then released into the atmosphere.

The intake valve 105 and the exhaust valve 107 are driven to open and close by cams provided on the intake side camshaft 111 and the exhaust side camshaft 110, respectively.
An electric fuel pump 136 is built in the fuel tank 135, and the fuel is pumped toward the fuel injection valve 131 by driving the fuel pump 136.
The distribution pipe 137 that distributes the fuel discharged from the fuel pump 136 to each fuel injection valve 131 is provided with a fuel pressure sensor 138 so that the fuel pressure detected by the fuel pressure sensor 138 becomes the target pressure. The discharge amount of the fuel pump 136 is feedback controlled by the control unit 114.

The control unit 114 includes a microcomputer and controls the electronic control throttle 104, the fuel injection valve 131, the injector heater 131a, the fuel pump 136, and the like by arithmetic processing based on detection signals from various sensors.
As the various sensors, in addition to the fuel pressure sensor 138, an accelerator opening sensor 116 that detects the depression amount (accelerator opening) of an accelerator pedal operated by a driver, and an air flow meter 115 that detects an intake air amount Q of the engine 101. A crank angle sensor 117 that detects the rotational position of the crankshaft 120, a throttle sensor 118 that detects the opening TVO of the throttle valve 103b, a water temperature sensor 119 that detects the coolant temperature of the engine 101, and the upstream side of the front catalyst 108. A heater-equipped air-fuel ratio sensor 121 and the like for detecting the exhaust air-fuel ratio based on the oxygen concentration in the exhaust gas are provided.

By the way, the control unit 114 functions as a function to prepare for starting the engine by predicting the starting of the engine in advance before starting the engine by the driver operating the ignition key or the start button. In the following, the preparation for starting the engine will be described.
The control unit 114 may be divided into, for example, a unit that controls the engine and a unit that performs engine start prediction and commands engine start preparation.

The flowchart in FIG. 3 shows a main routine for start preparation control.
In the flowchart of FIG. 3, first, in step S <b> 11, the start of the engine is predicted in advance by detecting the occupant's boarding or boarding intention.
For example, the following operation detection signal / system state detection / authentication signal is used as the detection signal for the passenger's boarding or boarding intention.
(1) Opening / closing of vehicle door (2) Unlocking door with key or remote control (3) Verification of ID signal of remote controller (4) Insertion of key into ignition key cylinder (5) Insertion of key into keyhole of door ( 6) Seating on the driver's seat (7) Wearing a seat belt in the driver's seat (8) Canceling the anti-theft system (9) Detection of moving objects around the vehicle (10) Personal authentication It is used to identify whether or not the person who has indicated his / her intention is one or more of those registered in advance. For example, release of the anti-theft system, automatic unlocking of the door, auto seat position, driving It is used for automatic change control of characteristics, automatic confirmation of driving qualifications and driving history.

And personal authentication is performed based on biometric authentication such as a fingerprint, property authentication such as a driver's license, knowledge authentication using a password, etc., and when authenticated as a pre-registered person, A specific driver's boarding or willingness to board is judged and it is predicted that the engine will be started.
However, the detection signal of the passenger's boarding or boarding intention is not limited to the above signal, and the method for predicting the start of the engine is not limited to the method based on the detection of the passenger's boarding or boarding intention. .

As shown in FIG. 2, the control unit 114 includes a door switch 81, a personal authentication device 82, a seating sensor 83, a seat belt switch 84, etc., as shown in FIG. The detection signal is input.
If the engine start is predicted in advance in step S11 as described above, the process proceeds to step S12, and the injector heater 131a, the heater of the air-fuel ratio sensor 121, the fuel pump 136, and the electric oil pump 141, etc. The engine starting device is activated before the engine is started.

Details of the operation control of the engine starting device in step S12 will be described later.
If the engine start device is operated before the engine is actually started (before the key switch is turned on), the engine start can be started after the engine is optimally set in advance. Immediate drivability can be improved.

Specifically, atomization of fuel spray can be promoted from the start of startup by energizing the injector heater 131a in advance and increasing the heater temperature.
Also, if the heater of the air-fuel ratio sensor 121 is energized in advance, the element temperature of the air-fuel ratio sensor 121 can be raised to the activation temperature or close to the activation temperature before starting the start, and the air-fuel ratio feedback control is performed. Can be started earlier.

Further, if the fuel pump 136 and the electric oil pump 141 are actuated in advance, the fuel / oil pressure can be increased in advance until the engine is actually started. The oil can be circulated satisfactorily.
In step S13, it is determined whether or not the ignition key switch is turned on.
When the ignition key switch is turned on, the process proceeds to step S14 and each device is controlled normally.

Here, the operation control of the engine starting device in step S12 will be described in detail according to the flowchart of FIG.
In the flowchart of FIG. 4, in step S21, the injector heater 131a as the engine starting device, the heater of the air-fuel ratio sensor 121, the fuel pump 136, and the electric oil pump 141 are operated using the battery 140 as a power source.

In the next step S22, it is determined whether or not the voltage VB of the battery 140 is lower than the lower limit voltage VBL.
This is to determine whether or not a voltage drop below the lower limit voltage VBL has occurred due to the engine starting device operating with the battery 140 as a power source.
Here, when a voltage equal to or higher than the lower limit voltage VBL is secured, the process proceeds to step S23, and it is determined whether or not 1 is set in a flag F indicating a stop history of the engine start device.

The initial value of the flag F is 0 and, as will be described later, is set to 1 when the voltage VB becomes lower than the lower limit voltage VBL. Therefore, after the operation of the engine starting device is started, the lower limit voltage VBL When the above voltage is held, the flag F = 0, and the process returns from step S23 to step S22 to maintain the operating state of the engine start device.
On the other hand, as a result of operating the engine starting device, when the voltage VB becomes lower than the lower limit voltage VBL, the process proceeds to steps S24 to S27 to perform processing for sequentially stopping the engine starting device, and then in step S28, the flag F is set. Set 1

In steps S24 to S27, a plurality of engine start devices (the injector heater 131a, the heater of the air-fuel ratio sensor 121, the fuel pump 136, and the electric oil pump 141) are sequentially stopped in accordance with preset priorities (power supply is cut off). The battery voltage VB is restored.
The above function corresponds to the operation limiting means in the present invention.

  The priority order is an order of priority for performing stop processing, for example, in order of increasing power consumption or in order of decreasing contribution to engine start improvement, and sequentially stopping devices in order of increasing power consumption. If this is done, the battery voltage can be quickly recovered, and if the devices are stopped in the order of the low contribution to the engine start improvement, the devices that greatly affect the engine start improvement are operated as long as possible. The improvement effect of engine starting can be maintained as much as possible.

  The degree of contribution to improvement in engine start can be determined each time based on the temperature and pressure conditions at that time. For example, if the engine temperature is high immediately after the engine is stopped, the injector heater 131a or If the priority of the heater of the air-fuel ratio sensor 121 is set high and the fuel pressure is sufficiently high, the priority of the fuel pump 136 can be set high.

In the flowchart of FIG. 4, the four engine starting devices are stopped according to the priority order. However, it is clear that the number of devices and the types of devices are not limited, and two or more devices are prepared for starting. Any system can be used.
Furthermore, instead of completely stopping the operation of each engine starting device, the operation of the device may be limited by lowering the applied voltage / energized current to each device to reduce the power consumption.

As described above, as a result of stopping the operations of the plurality of engine starting devices, it is determined in step S22 that the voltage VB is equal to or higher than the lower limit voltage VBL. When the process proceeds to step S23, 1 is set in the flag F. Since it is set, the process proceeds from step S23 to step S29.
In step S29, it is determined whether or not the battery voltage VB has exceeded the upper limit voltage VBH (> lower limit voltage VBL).

Here, when the battery voltage VB is equal to or lower than the upper limit voltage VBH, that is, when the battery voltage VB is equal to or higher than the lower limit voltage VBL as a result of stopping the engine starting device, the process proceeds to step S22. By returning as it is, the stop state of the engine start device is maintained.
On the other hand, if battery voltage VB exceeds upper limit voltage VBH, it is determined that the operation of the engine start device can be resumed, and the process proceeds to step S30.

In step S30, the operation of all engine starting devices is resumed. In the next step S31, the flag F is reset to zero.
As described above, in preparation for starting the engine starting device before starting the engine, if the operation of the engine starting device is stopped when the battery voltage decreases, the battery voltage at the time of starting the engine is greatly increased. It is possible to avoid the reduction, and it is possible to prevent the occurrence of starting failure due to insufficient voltage.

By the way, in the embodiment shown in the flowchart of FIG. 4, when the battery voltage VB becomes lower than the lower limit voltage VBL, all the engine starting devices are stopped. However, the battery voltage VB can be set without stopping all. In some cases, the voltage can be restored to the lower limit voltage VBL or higher.
Therefore, in the second embodiment shown in the flowchart of FIG. 5, the number of engine start devices to be stopped is increased in stages, and the minimum number required to restore the battery voltage VB to the lower limit voltage VBL or more. The engine start device was stopped.

In the flowchart of FIG. 5, in step S31, the injector heater 131a as the engine starting device, the heater of the air-fuel ratio sensor 121, the fuel pump 136, and the electric oil pump 141 are operated using the battery 140 as a power source.
In the next step S32, it is determined whether or not the voltage VB of the battery 140 is lower than the lower limit voltage VBL.

Here, when a voltage equal to or higher than the lower limit voltage VBL is secured, the process proceeds to step S33, and it is determined whether or not 1 is set in a flag F indicating a stop history of the engine start device.
The initial value of the flag F is 0 and, as will be described later, is set to 1 when the voltage VB becomes lower than the lower limit voltage VBL. Therefore, after the operation of the engine starting device is started, the lower limit voltage VBL When the above voltage is held, the flag F = 0, and the process returns from step S33 to step S32 to maintain the operating state of the engine start device.

On the other hand, as a result of operating the engine starting device, when the voltage VB becomes lower than the lower limit voltage VBL, the process proceeds to step S34 and subsequent steps, and processing for increasing the number of stops of the engine starting device in a stepwise manner is performed.
First, in step S34, it is determined whether or not the stop process has already been performed for the device set to the first priority in the stop process.

The priority order is the order in which the stop process is preferentially performed as in the previous embodiment, and is set, for example, in the order of increasing power consumption or in order of decreasing contribution to improvement of engine start.
If the stop process is not performed for the device with the first priority, the process proceeds to step S35 to stop the operation of the device with the first priority, and the flag F is set to 1 in the next step S36.

If the battery voltage VB is determined to have been restored to the lower limit voltage VBL or more when returning to step S32 after stopping the operation of the device having the first priority, the process proceeds to step S33, where the flag F is set. When it is determined that the value is 1, the process further proceeds to step S42.
In step S42, it is determined whether or not the battery voltage VB has exceeded the upper limit voltage VBH (> lower limit voltage VBL).

If the battery voltage VB is equal to or lower than the upper limit voltage VBH, the process returns to step S32 as it is to maintain the state where the operation of the device with the first priority is stopped.
When the battery voltage VB exceeds the upper limit voltage VBH, the process proceeds to step S43 to return to a normal start preparation state in which all engine start devices are operated. In the next step S44, the flag F is reset to 0. To do.

On the other hand, if it is determined that the battery voltage VB is still lower than the lower limit voltage VBL when returning to step S32 after stopping the operation of the device having the first priority, the process proceeds to step S34.
When the process proceeds to step S34 as described above, since the operation of the first priority device has already been stopped, the process proceeds from step S34 to step S37.

In step S37, it is determined whether or not the operation of the device with the second priority is already stopped.
If the device with the second priority is operating, the process proceeds to step S38, and the operation with respect to the device with the second priority is stopped.
When the device having the second priority is stopped in step S38, that is, when returning to step S32 with the devices having the first and second priority stopped, the battery voltage VB becomes equal to or higher than the lower limit voltage VBL. If it is determined that the battery voltage VB is equal to or lower than the upper limit voltage VBH, the first and second priority orders are maintained, and if the battery voltage VB exceeds the upper limit voltage VBH, the process proceeds to step S43. Proceed to release the stop condition and activate all engine starting devices.

Further, when the process returns to step S32 in a state where the devices with the first priority and the second priority are stopped, if the battery voltage VB is still lower than the lower limit voltage VBL, the process proceeds to step S34.
If it is determined in step S34 that the device with the first priority is already stopped, the process proceeds to step S37, and further, it is determined that the device with the second priority is already stopped. The process proceeds to step S39.

In step S39, it is determined whether or not the operation of the device with the third priority is stopped.
If the priority number 3 is in operation, the process proceeds to step S40, and the operation of the priority number 3 device is stopped.
When the device of priority 3 is stopped in step S40, that is, when the devices of priority 1, 2 and 3 are stopped and the process returns to step S32, the battery voltage VB becomes the lower limit voltage VBL. If it is determined that the battery voltage VB is equal to or higher than the upper limit voltage VBH, the stopped state of the priority ranks 1 to 3 is maintained. If the battery voltage VB exceeds the upper limit voltage VBH, the step is performed. It progresses to S43, a stop state is cancelled | released, and the operation | movement of all the engine starting devices is performed.

Further, when the process returns to step S32 in a state where the devices of the priority order 1 to 3 are stopped, if the battery voltage VB is still lower than the lower limit voltage VBL, the process proceeds to step S34 again.
Here, it is determined in step S34 that the device with the first priority is already stopped, it is determined in step S37 that the device with the second priority is already stopped, and the device with the third priority in step S39. Is determined to have already been stopped, the process proceeds to step S41.

In step S41, the operation of all the four engine starting devices is stopped by stopping the operation of the device with the fourth priority.
When it is determined that the battery voltage VB is equal to or higher than the lower limit voltage VBL when returning to step S32 in a state where the operation of all four engine starting devices is stopped, if the battery voltage VB is equal to or lower than the upper limit voltage VBH, If the state in which all the engine start devices are stopped is maintained and the battery voltage VB exceeds the upper limit voltage VBH, the process proceeds to step S43, the stop state is released, and all the engine start devices are operated.

According to the above embodiment, since the minimum number of devices necessary to restore the battery voltage VB are stopped, the operation of the engine start device is not excessively limited, and the decrease in the battery voltage VB is suppressed. However, it is possible to prepare for starting the engine in a state as close to normal as possible.
In the above embodiment, the number of devices whose operation is stopped is increased according to the priority order in order to eliminate the state where the battery voltage VB is lower than the lower limit voltage VBL, but also when the operation of the once stopped device is restarted. The number of devices whose operation is resumed can be sequentially increased according to the priority order, and an embodiment having such a configuration will be described with reference to the flowcharts shown in FIGS.

6 and 7, the processes in steps S51 to S62 are performed in the same manner as steps S31 to S42 in the flowchart of FIG. 5, and it is determined in step S62 that the battery voltage VB exceeds the upper limit voltage VBH. The processing after step S63 is different.
In step S63, the priority (priority for stopping the operation) is No. 4, that is, whether the operation of the lowest priority device is stopped, in other words, all the operations of the four engine start devices are performed. Determine whether it is stopped.

If all the operations of the four engine start devices are stopped, the process proceeds to step S64, and the operations of the device with the priority number 4 are resumed.
For example, when the priority is set as the order in which the power consumption is large or the contribution to the engine start improvement is low, the device with the lowest priority is the device with the least power consumption or the engine start improvement. It is a device that has a high contribution to, and is an engine start device that is unlikely to have a large voltage drop even when operation is restored, or that it is desired to operate as much as possible.

Therefore, if it is determined that there is a possibility that the engine start device can be restarted as a result of stopping the operation of all engine start devices so that the battery voltage VB exceeds the upper limit voltage VBH. First, restart the operation from the device with the lowest priority.
Accordingly, when it is determined in step S63 that the device with priority number 4 is activated, the process proceeds to step S65 to determine whether or not the operation of device with priority number 3 is stopped. When the operation of the device No. 1 is stopped, the process proceeds to Step S66, and the operation of the device with the priority number 3 is resumed.

Further, if the devices with priority numbers 4 and 3 are operating, the process proceeds to step S67 to determine whether or not the operation of the device with priority number 2 is stopped. If the operation is stopped, the process proceeds to step S68 to restart the operation of the device with the second priority.
If the second priority device is in operation, the operation of only the remaining first priority device is stopped, so the process proceeds to step S69, and the first priority device is operated. After restarting, the process proceeds to step S70 and the flag F is reset to zero.

Thus, the operation of the device once stopped is resumed step by step in the reverse order of the priority order in the stop process within the range where the battery voltage VB does not fall below the lower limit voltage VBL.
Therefore, it is possible to stably control the battery voltage VB so as not to fall below the lower limit voltage VBL while operating as many engine starting devices as possible.
Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) In the start preparation device for a vehicle engine according to claim 5,
The start preparation device for a vehicle engine, wherein the start preparation means predicts start of the engine based on a personal authentication signal as the boarding detection signal.

According to such a configuration, in order to specify an occupant (driver) for the vehicle, whether or not the occupant is a pre-registered person, for example, biometric authentication using a fingerprint or the like, property authentication using a driver's license, etc. Is based on knowledge authentication using a password and the like, and when it is recognized that the person is registered in advance, it detects the boarding or the intention of boarding and predicts the start of the engine.
(B) In the start preparation device for a vehicle engine according to any one of claims 1 to 5,
The start preparation means operates an engine start device including at least one of a fuel injection valve heater, an air-fuel ratio sensor heater, an electric fuel pump, and an electric oil pump as a start preparation before starting the engine. An engine start preparation device for a vehicle engine.

According to this configuration, the atomization of the fuel spray can be promoted from the start of the start by energizing the heater of the fuel injection valve, and the start of the air-fuel ratio feedback control can be accelerated by energizing the heater of the air-fuel ratio sensor. In addition, by operating the fuel pump and oil pump in advance, it is possible to increase the fuel and oil pressure to the desired pressure by the start of the engine. Can be demonstrated.
(C) In the vehicle engine start preparation device according to claim 2,
The start preparation device for a vehicle engine, wherein the operation limiting means limits the operation of the device in accordance with a priority order corresponding to power consumption.

According to such a configuration, for example, by preferentially restricting the operation of a device that consumes a large amount of power, it is possible to quickly suppress a decrease in battery voltage, while the power consumption is relatively small and greatly affects the battery voltage. Devices that are not given can be operated normally as much as possible.
(D) In the start preparation device for a vehicle engine according to claim 2,
The start preparation device for a vehicle engine, wherein the operation restricting means restricts the operation of the device in accordance with a priority order corresponding to a degree of contribution to improvement of engine start.

According to such a configuration, a device that has a low contribution to the improvement in engine start is preferentially limited in its operation so that a device that greatly affects the improvement in engine start is operated as much as possible while suppressing a decrease in battery voltage. be able to.
(E) In the vehicle engine start preparation device according to claim 2,
When the operation limiting means determines that the voltage of the battery is restored, the limitation of the operation of the device is sequentially released in an order opposite to the priority order when the operation of the device is limited. A start preparation device for a vehicle engine.

According to such a configuration, for example, when the priority order is set based on the degree of contribution to the improvement of the engine start, when the battery voltage decreases, the operation is limited first from the device that does not greatly affect the improvement of the engine start, When the battery voltage is restored, the operation restriction can be released first from the device that greatly affects the engine start improvement, and the device that greatly affects the engine start improvement can be operated as much as possible.
(F) In the vehicle engine start preparation device according to claim 4,
The operation limiting means limits the operation of the start preparation means when the battery voltage falls below a lower limit voltage, and the limit when the battery voltage exceeds an upper limit voltage higher than the lower limit voltage. A start preparation device for a vehicle engine, wherein at least part of the operation of the start preparation means is canceled.

According to such a configuration, when the battery voltage falls below the lower limit voltage, the operation of the start preparation means is restricted so that the battery voltage returns to the lower limit voltage or more. The hunting of the operation restriction process is prevented by releasing the operation restriction after the higher upper limit voltage is exceeded.
(G) In the vehicle engine start preparation device according to any one of claims 1 to 5,
The start preparation device for a vehicle engine, wherein the operation limiting means limits the operation of the start preparation means by stopping the operation of the start preparation means or suppressing power consumption.

  According to such a configuration, when the battery voltage decreases due to the operation of the start preparation means, the operation is stopped, or the operation is continued, but the power consumption is reduced by reducing the applied voltage or suppressing the energization current, so that the battery voltage is reduced. Suppresses the decline.

The system diagram of the engine for vehicles in an embodiment. The system figure of the control unit in an embodiment. The flowchart which shows the main routine of the engine starting time control. The flowchart which shows 1st Embodiment of start preparation control. The flowchart which shows 2nd Embodiment of start preparation control. The flowchart which shows 3rd Embodiment of start preparation control. The flowchart which shows 3rd Embodiment of start preparation control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 81 ... Door switch, 82 ... Personal authentication apparatus, 83 ... Seating sensor, 84 ... Seat belt switch, 101 ... Engine, 104 ... Electronic control throttle, 114 ... Control unit, 131 ... Fuel injection valve, 131a ... Injector heater, 135 ... Fuel tank 136 ... Fuel pump 138 ... Fuel pressure sensor 140 ... Battery

Claims (5)

Start preparation means for preparing the engine to start before starting the engine, and operation restriction means for restricting the operation of the start preparation means in accordance with the voltage of a battery as a power source of the start preparation means. A vehicle engine start preparation device. The start preparation means is configured to operate a plurality of devices before starting the engine, and the operation restriction means sequentially restricts the operations of the plurality of devices according to a predetermined priority order. The start preparation device for a vehicle engine according to 1. The start preparation means is configured to operate a plurality of devices before starting the engine, and the operation limiting means is a device that limits the operation of the plurality of devices as the voltage of the battery decreases. The start preparation device for a vehicle engine according to claim 1 or 2, wherein the number is sequentially increased. The operation limiting means cancels at least a part of the limited operation of the start preparation means when it is determined that the battery voltage is restored after the start preparation means is limited. Item 4. The vehicle engine start preparation device according to any one of Items 1 to 3. The vehicle engine according to any one of claims 1 to 4, wherein the start preparation means prepares to start the engine when the start of the engine is predicted based on a passenger detection signal. Start preparation device.

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