WO2015166818A1

WO2015166818A1 - Engine start control device

Info

Publication number: WO2015166818A1
Application number: PCT/JP2015/061817
Authority: WO
Inventors: 祥太原田
Original assignee: スズキ株式会社
Priority date: 2014-04-28
Filing date: 2015-04-17
Publication date: 2015-11-05
Also published as: DE112015002022B4; DE112015002022T5; JP6303774B2; JP2015209139A

Abstract

A start control unit (13c) starts an engine (11) after causing a vehicle (1) to travel by increasing an engine rotational speed to a first rotational speed by the output of a motor (12) on condition that a detected charge amount (J) detected by a charge amount detection unit (13a) is not smaller than a first threshold value, while starting the engine (11) after increasing the engine (11) rotational speed to a second rotational speed by the output of the motor (12) on condition that the detected charge amount (J) is smaller than the first threshold value and not smaller than a second threshold value set lower than the first threshold value.

Description

Engine start control device

The present invention relates to an engine start control device, and more particularly to an engine start control device that starts an engine by a motor driven by electric power supplied from a battery.

Conventionally, a motor using a motor generator (hereinafter referred to as a motor) having both functions of an electric motor and a generator is known as a motor serving as a drive source for running the vehicle.

For example, Japanese Patent No. 3447937 (Patent Document 1) proposes a switch capable of switching between running a vehicle with a motor or running a vehicle with an engine according to the amount of charge of a battery.

Japanese Patent No. 3447937 proposes that when the charge amount of the battery is greater than or equal to a predetermined amount, the vehicle is started and driven with relatively large power output from the motor, while the charge amount of the battery is predetermined amount. When the value is less than 1, the engine is started with relatively small power output from the motor, and the vehicle is started to run with the power output from the engine.

Japanese Patent No. 3447937

However, in the one proposed in Japanese Patent No. 3447937, since the control for switching from the vehicle running by the motor to the vehicle running by the engine is based on a predetermined amount of charge of the battery, charging of the battery When the amount is less than the predetermined amount, all are switched to the running of the vehicle by the engine. If the predetermined amount is set to a large value, even if the vehicle can be driven by the motor when the amount is below the predetermined amount, the vehicle is switched to driving by the engine, and the battery power cannot be used efficiently. There is a problem that there is.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an engine start control device that can efficiently use battery power.

In order to solve the above problems, a first aspect of the present invention includes a motor that rotates an engine by output, a battery that supplies electric power to the motor, a charge amount detection unit that detects a charge amount of the battery, An engine start control device comprising: a start control unit that controls start, wherein the start control unit is configured to provide a motor on condition that the detected charge amount detected by the charge amount detection unit is equal to or greater than a first threshold value. With the output of the engine, the engine speed is increased to the first speed and the vehicle is started, and then the engine is started. The detected charge amount is set to be lower than the first threshold and lower than the first threshold. On the condition that it is equal to or greater than the second threshold, the engine is started after the engine speed is increased to the second speed by the output of the motor.
As a second aspect of the present invention, the start control unit may start the engine immediately after the output of the motor on condition that the detected charge amount is less than the second threshold value.

A third aspect of the present invention includes an air amount detection unit that detects an air amount in an intake pipe that circulates intake air supplied to the engine, and the start control unit has a detected charge amount that is less than a first threshold value, When the air amount detected by the air amount detection unit is less than a predetermined amount after the engine is rotated by the output of the motor on the condition that it is equal to or higher than the second threshold value set lower than the first threshold value, the engine It is also possible to start.

According to the first aspect, the start control unit starts the engine after performing the so-called EV creep running on the condition that the detected charge amount is equal to or greater than the first threshold, and the detected charge amount is the first charge amount. The engine is started after so-called motoring on the condition that it is less than the threshold and greater than or equal to the second threshold, and the engine is started on the condition that the detected charge amount is less than the second threshold. ing. Therefore, the start control by the start control unit is executed based on detailed conditions corresponding to the detected charge amount, and the power of the battery is efficiently utilized.
According to the second aspect, the start control unit starts the engine immediately after the output of the motor on the condition that the detected charge amount is less than the second threshold value. Therefore, the start control by the start control unit is executed based on detailed conditions corresponding to the detected charge amount, and the power of the battery is efficiently utilized.

According to the third aspect described above, the start control unit is configured such that the detected charge amount is less than the first threshold value and is equal to or greater than the second threshold value set lower than the first threshold value. After the engine is rotated with the output, the engine is started when the amount of air in the intake pipe detected by the air amount detection unit is less than a predetermined amount, so that vibration generated when the engine is started is reduced. be able to.

FIG. 1 is a schematic configuration diagram of an engine start control device according to an embodiment of the present invention. FIG. 2 is a flowchart showing a control operation of the engine start control device according to the embodiment of the present invention.

Hereinafter, an engine start control device according to an embodiment of the present invention will be described with reference to the drawings.

First, the configuration will be described.
The engine start control device according to this embodiment is mounted on a vehicle 1. As shown in FIG. 1, the vehicle 1 includes an engine 11, a motor 12, an engine control unit (hereinafter referred to as ECU) 13, and a battery 14. The vehicle 1 is a so-called hybrid vehicle that is driven by a power source of at least one of the engine 11 and the motor 12.

Further, the vehicle 1 includes a crankshaft pulley 21 provided on the crankshaft 11 a of the engine 11, a motor pulley 22 provided on a rotor shaft (not shown) of the motor 12, a belt 23, and a transmission ( T / M) 24. Further, the vehicle 1 includes a differential gear 25 connected to the transmission 24, left and right drive shafts 26 connected to the differential gear 25, and left and right drive wheels 27.

In the present embodiment, a mechanism for transmitting and shutting off the output of a clutch or the like is provided between the components of the engine 11, the motor 12, the transmission 24, the differential gear 25, the left and right drive shafts 26, and the left and right drive wheels 27. However, when the motor 12 is driven, the output of the motor 12 is transmitted to the left and right drive wheels 27.

The engine 11 is configured by, for example, a four-cycle engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. The engine 11 includes an intake manifold 11b. An intake passage for supplying intake air into the engine 11 is formed in the intake manifold 11b.

The motor 12 is composed of a motor generator (MG) having both a function of an electric motor serving as a drive source for running the vehicle 1 and a function of a generator for charging the battery 14 by power generation. The motor 12 includes a rotor (not shown), a rotor shaft, and a stator, and is driven by electric power supplied from the battery 14.

A belt 23 is wound around the motor pulley 22 and the crankshaft pulley 21 described above, and the power of the motor 12 is transmitted to the crankshaft 11a of the engine 11 by the motor pulley 22, the crankshaft pulley 21 and the belt 23. .

The ECU 13 is constituted by a microcomputer. The microcomputer includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an input port, an output port, and a network module. The network module can communicate with another electronic control unit such as a transmission electronic control unit via a CAN (Controller Area Network).

ECU13 performs arithmetic processing based on the data and program stored in ROM. For example, when the ECU 13 detects that the accelerator is turned off while the vehicle 1 is traveling, the ECU 13 executes fuel injection cut control for cutting the fuel injection to the engine 11, and the vehicle speed is reduced to idle. When the condition necessary for the stop is satisfied, the engine 11 is stopped idling.

The ECU 13 supplies power from the battery 14 to generate power in the motor 12 while continuing fuel injection cut control triggered by the release of the brake during idling stop. The power generated by the motor 12 is transmitted to the crankshaft 11a via the motor pulley 22, the belt 23, and the crankshaft pulley 21, whereby the engine 11 is motored.

The power transmitted to the crankshaft 11a is input to the transmission 24 and transmitted to the left and right drive wheels 27 via the differential gear 25 and the left and right drive shafts 26.

The charge amount detection unit 13a includes sensors such as a current sensor (not shown) that detects a current flowing out or inflow from the battery 14 and a voltage sensor (not shown) that detects a terminal voltage of the battery 14. Based on the detection value detected by the sensor, the charge amount detection unit 13a determines the current charge state (SOC: State Of Charge) of the battery 14, the so-called current remaining capacity, as a detected charge amount (hereinafter referred to as a detected charge amount J). )).

The air amount detection unit 13b includes a sensor that detects an air amount, such as an air amount sensor provided in an intake passage of an intake pipe (not shown), and detects the air amount in the intake pipe.

The start control unit 13c rotates the engine at the first rotation speed with the power output from the motor 12 on condition that the detected charge amount J detected by the charge amount detection unit 13a is equal to or greater than a predetermined first threshold value. Then, the engine 11 is started after the vehicle 1 travels.
In the present embodiment, the start control unit 13c, when the detected charge amount J satisfies a pattern A including a plurality of conditions including a condition that the detected charge amount J is equal to or greater than a predetermined first threshold, The engine 11 is started after performing a so-called EV creep running, which is a low-speed running when the accelerator is off, for a predetermined time tmax.

The first threshold value is a minimum charge amount of the battery 14 that enables EV creep running, and is a preset value. The first engine speed is a minimum engine speed that enables EV creep running.

Specifically, the pattern A condition includes an A1 condition or an A6 condition described below.
The A1 condition is that the air conditioner mounted on the vehicle 1 is OFF. The A2 condition is that the detected charge amount J is equal to or greater than the first threshold value. The A3 condition is that the temperature of the cooling water for cooling the engine 11 is equal to or higher than a predetermined threshold value. The A4 condition is that the temperature of ATF, which is the hydraulic oil of the transmission 24, is equal to or higher than a predetermined threshold value.

Furthermore, the A5 condition is that the slope of the road surface on which the vehicle 1 is traveling is within a predetermined threshold. The A6 condition is that the electric load of the vehicle 1 is not more than a predetermined threshold value. Each of these predetermined threshold values is a value set in advance so as to meet each condition.

The A1 condition and the A2 condition are for avoiding a situation in which EV creep running and start assist cannot be sufficiently performed assuming a load applied to the motor 12 when performing EV creep running of the vehicle 1 and starting assistance of the engine 11. Is set.

As for the A3 condition and the A4 condition, if the temperature of the cooling water or the ATF is high, the friction in the engine 11 or the transmission 24 is reduced, and the load on the motor 12 is reduced when performing EV creep running or start assist. It is set in consideration of.

The A5 condition is that, when EV creep running is performed when the slope of the road surface is an uphill above a predetermined threshold, the load applied to the motor 12 increases more than usual, and there is a possibility that EV creep running and start assist cannot be performed. It is set to avoid being.

The A6 condition is set to prevent excessive power consumption of the battery 14 and to prevent the battery 14 from being insufficiently charged or deteriorated. That is, when EV creep running or start assist is performed by the start control unit 13c when the electric load of the vehicle 1 is equal to or greater than a predetermined threshold, the load due to EV creep running or start assist is added to the battery in addition to the electric load. 14, the amount of charge of the battery 14 may be insufficient or deteriorate.

The determination as to whether or not the electrical load is equal to or less than a predetermined threshold is performed by using, for example, a sensor such as a current sensor to calculate the power supplied from the battery 14 by the operation of each element connected to the battery 14 and supplied with power. Detection is performed by comparing the detected value with a reference value.

In addition, the start control unit 13c outputs the power output from the motor 12 on condition that the detected charge amount J is less than the first threshold value and is equal to or greater than a predetermined second threshold value set lower than the first threshold value. Thus, the engine 11 is started after the rotational speed of the engine 11 is increased to a predetermined rotational speed.

The second threshold value is a value that is set in advance, with the detected charge amount J serving as a reference for allowing the above-described start assist. In the present embodiment, the start control unit 13c sets a condition that the detected charge amount J is less than the first threshold and not less than a predetermined second threshold set lower than the first threshold, as will be described later. The start assist is executed by satisfying a pattern B condition including a plurality of conditions including the condition.

Specifically, the start assist performs motoring that raises the engine 11 to a second rotational speed that is about the engine idling rotational speed until the pressure in the intake manifold 11b of the engine 11 reaches a predetermined value. The engine 11 is started with the output power.

The pressure in the intake manifold 11b is detected by a negative pressure sensor that detects the negative pressure in the intake manifold 11b.

Since the pressure in the intake manifold 11b and the air amount in the intake manifold 11b are in a proportional relationship, the start controller 13c replaces the pressure in the intake manifold 11b with the air amount detected by the air amount sensor. Thus, the start assist may be executed. That is, the start control unit 13c performs motoring to raise the engine 11 to a second rotational speed that is about the engine idling rotational speed until the air amount in the intake manifold 11b of the engine 11 reaches a predetermined value, and outputs from the motor 12 The engine 11 may be started with the motive power.

Specifically, the pattern B condition includes a B1 condition, an A3 condition, an A4 condition, an A5 condition, and an A6 condition. The B1 condition is that the detected charge amount J is equal to or greater than a predetermined threshold value that permits start assist.

The pattern B condition does not include the A1 condition, which is one of the pattern A conditions. During the execution of the idle stop that stops the engine when the predetermined condition is satisfied, the operation amount of the air conditioner, that is, the degree of cooling or heating becomes small, and the load applied to the battery 14 becomes relatively small. It is not necessary to include in the B condition. In addition, since the start assist control based on the pattern B condition is performed while the operation amount of the air conditioner is small, it is not necessary to include the A1 condition in the pattern B condition.

During start assist control under the pattern B condition, even if the air conditioner is operating, the amount of operation of the air conditioner is kept low, and the load on the motor 12 is relatively small when executing the start assist according to the pattern B condition. It is not necessary to include the A1 condition in the pattern B condition.

The start control unit 13c starts the engine 11 with the power output from the motor 12 on condition that the detected charge amount J is less than the second threshold value. Specifically, the start control unit 13c starts the engine 11 with the power output from the motor 12 when the pattern C condition, which is a condition in which the pattern A condition and the pattern B condition are not satisfied, and Restart fuel injection.

The start control unit 13c starts the engine 11 with power output from the battery 14 on condition that the air amount in the intake pipe detected by the air amount detection unit 13b is less than a predetermined amount.

The battery 14 is formed of a known secondary battery such as a lead storage battery or a lithium ion storage battery that supplies power to various electric loads of the vehicle 1 and elements such as the motor 12, and is sequentially charged and discharged.

The transmission 24 is composed of a transmission that shifts the power generated by the engine 11, and includes a plurality of planetary gear mechanisms (not shown) and a plurality of friction engagement elements that constitute clutches and brakes (not shown). Yes. The transmission 24 forms a desired gear stage by changing the gripping of each friction engagement element in accordance with hydraulic fluid supplied from a hydraulic control device (not shown), thereby determining the gear ratio of the transmission 24. The

The transmission 24 forms, for example, any one of six forward shift stages from 1st to 6th speed and one reverse shift stage. The power changed by the transmission 24 is transmitted to the differential gear 25.

The differential gear 25 is connected to the left and right drive shafts 26, and the power input from the output shaft of the transmission 24 is transmitted from the left and right drive shafts 26 to the left and right drive wheels 27, respectively.

Next, the operation of engine start control in the engine start control device of this embodiment will be described with reference to FIG.

First, the ECU 13 determines whether or not the engine 11 is performing idling stop control (step S11). If the ECU 13 determines that the engine 11 is not performing idling stop control, the ECU 13 ends the operation. When the ECU 13 determines that the engine 11 is performing idling stop control, the ECU 13 determines whether a brake (not shown) of the vehicle 1 is OFF (step S12).

When the ECU 13 determines that the brake is OFF in step S12, the ECU 13 acquires detection information such as the state of charge of the battery 14 detected by each sensor, the temperature level, and the magnitude of the electric load applied to the battery 14 (step S13). .

Next, the ECU 13 determines whether or not the pattern A condition is satisfied based on the acquired detection information (step S14). That is, the ECU 13 determines whether or not all of the A1 condition to the A6 condition are satisfied.

When the ECU 13 determines that the pattern A condition is satisfied, the ECU 13 starts driving the motor 12 to rotate the engine 11 and starts counting time (step S21). Subsequently, the ECU 13 determines whether or not an accelerator (not shown) of the vehicle 1 is ON (step S22).

ECU13 will restart the fuel injection of the engine 11, if it judges that the accelerator of the vehicle 1 is ON (step S17), and will complete | finish operation | movement. When the ECU 13 determines that the accelerator of the vehicle 1 is not ON, the ECU 13 determines whether or not the engine 11 is requested to forcibly start the engine such as a start switch ON (step S23).

When the ECU 13 determines that the forced start is requested, the ECU 13 restarts the fuel injection of the engine 11 (step S17), starts the engine, and ends the operation. When determining that there is no request for forced engine start, the ECU 13 determines whether or not the duration t after starting the time count exceeds the maximum time tmax of EV creep travel (step S24).

If the ECU 13 determines that the duration t does not exceed the maximum time tmax, the ECU 13 returns to the determination of whether the accelerator of the vehicle 1 is ON (step S22). When the ECU 13 determines that the duration t exceeds the maximum time tmax, the ECU 13 restarts the fuel injection of the engine 11 (step S17), starts the engine, and ends the operation.

If it is determined in step S14 that the pattern A condition is not satisfied, the ECU 13 determines whether the pattern B condition is satisfied (step S15). That is, the ECU 13 determines whether or not all of the B1 condition, the A3 condition, and the A6 condition are satisfied.

When the ECU 13 determines that the pattern B condition is satisfied, the ECU 13 starts driving the motor 12 and rotates the engine 11 (step S31). Subsequently, the ECU 13 determines whether or not the accelerator of the vehicle 1 is ON (step S32).

ECU13 will restart the fuel injection of the engine 11, if it judges that the accelerator of the vehicle 1 is ON (step S17), and will complete | finish operation | movement. When the ECU 13 determines that the accelerator of the vehicle 1 is not ON, the ECU 13 determines whether there is a request for forced engine start such as a start switch ON for the engine 11 (step S33). When the ECU 13 determines that there is a request for forced start, the ECU 13 restarts fuel injection of the engine 11 (step S17), starts the engine, and ends the operation.

When the ECU 13 determines that there is no request for forced engine start, the ECU 13 determines whether or not the pressure p in the intake manifold 11b of the engine 11 is equal to or lower than a pressure pth at which fuel injection is permitted (step S34). When the ECU 13 determines that the pressure p is not equal to or lower than the pressure pth, the ECU 13 determines again whether or not the accelerator of the vehicle 1 is ON (step S32). If ECU13 judges that the pressure p is below the pressure pth, it will restart the fuel injection of the engine 11 (step S17), will start an engine, and will complete | finish operation | movement.

In step S15, when the ECU 13 determines that the pattern B condition is not satisfied, the ECU 13 starts driving the motor 12 and rotates the engine 11 (step S16). The ECU 13 resumes fuel injection immediately after the start of rotation of the engine 11 (step S17), starts the engine, and ends the operation.

Since the engine start control device of the present embodiment is configured as described above, the following effects can be obtained.
That is, the engine start control device of the present embodiment includes a charge amount detection unit 13a and a start control unit 13c. When the start control unit 13c has a large detected charge amount J, the EV creep travel is performed. When the detected charge amount J is small, the engine 11 is started. When the detected charge amount J is medium, the engine 11 is started after motoring.

As a result, since the start control is executed based on detailed conditions corresponding to the detected charge amount J, the power of the battery 14 is more efficiently utilized, and further, the battery 14 is prevented from deteriorating. The durability of the battery 14 is further improved.

Specifically, in the engine start control device of the present embodiment, in the pattern A condition, the air conditioner mounted on the vehicle 1 is OFF (A1 condition) and the detected charge amount J permits EV creep running. The condition is that it is equal to or greater than a predetermined threshold value (A2 condition).

As a result, the engine start control device of the present embodiment can avoid the case where the EV creep running cannot be performed sufficiently, and can ensure the detected charge amount J and perform the EV creep running. Therefore, the power of the battery 14 is utilized more efficiently, the deterioration of the battery 14 is prevented, and the durability of the battery 14 is further improved.

Further, in the engine start control device of the present embodiment, in the pattern A condition, the temperature of the cooling water for cooling the engine 11 is equal to or higher than a predetermined threshold (A3 condition), and the ATF temperature of the transmission 24 is a predetermined threshold. This is the condition (A4 condition).

As a result, EV creep travel is possible in a state where friction in the engine 11 and the transmission 24 is reduced. Therefore, the engine start control device of the present embodiment can perform EV creep travel without burden on the battery 14. The battery 14 can be prevented from deteriorating and the durability of the battery 14 can be further improved.

In addition, since the engine start control device of the present embodiment is based on the condition that the gradient of the road surface on which the vehicle 1 is traveling is within a predetermined threshold (A5 condition) in the pattern A condition, the EV creep travel is performed. The inability to do so is avoided.

That is, when the EV creep travel is performed when the road surface slope is an uphill with a predetermined threshold value or more, the load on the motor 12 increases more than usual, and thus the EV creep travel cannot be performed. The engine start control device of the present embodiment can continue the EV creep running by satisfying the A5 condition.

Further, the engine start control device of the present embodiment is based on the condition that the electric load of the vehicle 1 is not more than a predetermined threshold (A6 condition) in the pattern A condition. Thus, the start control by the start control unit 13c is avoided, and excessive power consumption is prevented, and the amount of charge of the battery 14 is prevented from being insufficient or deteriorated.

In addition, when the pattern B condition is satisfied, the engine start control device of the present embodiment controls the rotation speed of the engine 11 with the power output from the motor 12 until the pressure in the intake manifold 11b of the engine 11 reaches a predetermined value. After motoring to increase the engine speed to a predetermined number of revolutions, start assist control of the engine 11 is executed.

As a result, the engine start control device of the present embodiment can suppress the generation amount of output torque at the time of engine start and suppress vibration at the time of engine start.

The engine start control device of the present embodiment includes the B1 condition and the A3 or A6 condition in the pattern B condition, so that the start assist can be performed reliably and the power of the battery 14 is utilized more efficiently. In addition, the durability of the battery 14 can be further improved by preventing the battery 14 from deteriorating.

Further, since the detected charge amount J is based on the pattern C condition, the engine start control device of the present embodiment avoids excessive EV creep travel and start assist when the detected charge amount J is small. The engine 11 can be started with the power output from the engine 14. As a result, excessive consumption of the battery 14 can be avoided, the battery 14 can be prevented from deteriorating, and the durability of the battery 14 can be further improved.

In addition, the engine start control device of the present embodiment starts the engine 11 with the power output from the battery 14 on condition that the air amount in the intake pipe detected by the air amount detection unit 13b is less than a predetermined amount. As a result, vibration of the engine 11 can be further reduced when the engine 11 is started.

The engine start control device according to the present embodiment can suppress the power consumption particularly when the power of the battery 14 is not sufficient, so that the frequency of idling stop can be ensured, and consequently the fuel consumption of the engine 11 can be ensured. Can be improved.

Although embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

11 Engine 12 Motor 13 ECU
13a Charge amount detection unit 13b Air amount detection unit 13c Start control unit 14 Battery J Detected charge amount

Claims

A motor that rotates the engine by output;
A battery for supplying power to the motor;
A charge amount detection unit for detecting a charge amount of the battery;
A start control unit for controlling the start of the engine;
An engine start control device comprising:
The start control unit increases the engine speed to the first rotation speed by the output of the motor on the condition that the detected charge amount detected by the charge amount detection unit is not less than a first threshold value. Start the engine after running the vehicle,
On the condition that the detected charge amount is less than the first threshold value and is equal to or greater than a second threshold value set lower than the first threshold value, the engine speed is set to the second rotation by the output of the motor. An engine start control device, wherein the engine is started after being increased to a number.
2. The engine start control according to claim 1, wherein the start control unit starts the engine immediately after the output of the motor on the condition that the detected charge amount is less than the second threshold value. apparatus.
An air amount detection unit that detects an air amount in an intake pipe that distributes intake air supplied to the engine, wherein the start control unit is configured such that the detected charge amount is less than the first threshold value and is less than the first threshold value; If the air amount detected by the air amount detection unit is less than a predetermined amount after the engine is rotated by the output of the motor on the condition that it is equal to or higher than a second threshold value set to be lower, the engine The engine start control device according to claim 1, wherein the engine start control device is started.