JP2002070699A - Fuel consumption saving type automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the current consumption for restarting an engine by a starter motor after the temporary stop of the engine in a fuel consumption saving type automobile attended the temporary stop of the engine. SOLUTION: When the condition for the temporary stop of the engine is established, the supply of fuel to the engine is interrupted to rotate the engine by the inertia. In the restart of the engine, the starter motor is connected to the engine while synchronizing the rotating speed of the starter motor to the rotating speed of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel-conservation-type vehicle that saves energy resources and protects the environment.

[0002]

2. Description of the Related Art In order to save energy resources and preserve the environment, it is conceivable to temporarily stop an engine when predetermined conditions permitting the engine to be temporarily stopped during operation of a vehicle. Of vehicles. When the engine is temporarily stopped to save fuel consumption, the engine is restarted by driving the engine with a starter motor, as in the first start of the engine.

[0003]

In a structure in which the starter motor is connected to the engine only when the engine is started, the engine is stopped when the engine is started for the first time. Once connected to the engine, there is no particular difficulty in connecting. However, when the engine is temporarily stopped to save fuel while driving, the engine may be required to be restarted immediately after the start of the pause. If not, it is difficult to connect the starter motor to the engine, and in a structure in which the two are connected by gears meshing with each other, there is a possibility that chipping may occur. Therefore, in a conventional fuel-saving vehicle, when a control signal to restart the engine is issued immediately after the start of the temporary stop and the inertia rotation is still left, the engine is temporarily stopped. Waiting for the operation to connect the starter motor.

However, agility in restarting a fuel-saving vehicle after the engine is temporarily stopped is one of the most important issues to be solved in this type of vehicle.

The present invention has been made in view of the above-described problems in a fuel-saving vehicle, and has as its object to provide a fuel-saving vehicle improved in this regard.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a fuel-consumption-saving type in which the engine is temporarily stopped when a predetermined condition that allows the engine to be temporarily stopped while the vehicle is operating is satisfied. When the predetermined condition is satisfied, the supply of fuel to the engine is shut off to cause the engine to rotate inertia. When the engine is restarted, at least when the rotation speed of the engine is not zero, the starter It is an object of the present invention to propose an automobile characterized in that a starter motor is connected to an engine by synchronizing the rotation speed with the rotation speed of an engine by applying a regulated electric current to the motor.

[0007]

The purpose of the present invention is to temporarily stop the engine during operation of the fuel-saving vehicle, in order to save fuel consumption, not to stop the rotation of the engine. Therefore, if the drive system that drives the wheels from the engine is cut off as needed,
A predetermined condition that allows the engine to be stopped is satisfied,
There is no problem with the engine whose fuel supply has been cut off continuing to rotate inertia afterwards. If the engine still has inertial rotation when restarting the engine, the engine restarts, starting with inertial rotation and increasing the rotational speed. Is more reasonable. However, at this time, in order to restart the engine once the supply of fuel has been cut off, the starter motor is required in most cases, so that a configuration in which the starter motor is connected to the rotating engine is required.

At this point, when restarting the engine as described above, when the rotational speed of the engine is not zero, the starter motor is energized at a controlled speed to synchronize the rotational speed with the rotational speed of the engine. If the starter motor is connected to the engine, the engine that has been driven into a suspended state by shutting off the fuel supply can be operated more quickly using the remaining inertial rotation effectively. It can be returned to the state.

In this case, if the exhaust valve of the engine is opened together with the shut-off of the fuel for the temporary stop of the engine, the inertia rotation can be better utilized for the return after the temporary stop of the engine.

Further, the supply of the current to the starter motor may be performed at a voltage lower than the full-power energization when the engine is driven, in order to control the speed for energizing the engine as described above. As an example, these may be made from different power supplies having different voltages.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;

FIG. 1 is an exploded view of an example of a drive structure for starting an engine by a starter motor. In the figure, reference numeral 10 denotes a starter motor, and a current is supplied through terminals 12 and 14 of the starter motor, so that a rotating shaft 16 is driven to rotate. A spool 20 is slidably engaged with the rotary shaft 16 in a spline portion 18 in a torque transmitting relationship and in an axial direction. A pinion 22 is provided at the left end of the spool in the drawing. I have. Reference numeral 24 denotes a flywheel attached to an engine crankshaft (not shown). The flywheel 24 has teeth 26 which can mesh with the teeth of the pinion 22.

The spool 20 is splined by a movable iron core 30 of a solenoid 28 via a pivoting lever 34 pivotally supported around a pivot 32 in accordance with the on / off (energized and deenergized) of the solenoid 28. It is adapted to be moved left and right along the part 18 in the figure. As is apparent from the configuration shown, when the solenoid 28 is not energized and the movable iron core 30 is biased to the left in the figure by the action of the compression coil spring 36, the spool 20 is in the illustrated position. When the pinion 22 does not mesh with the teeth 26 of the flywheel 24 and the solenoid 28 is energized and the movable iron core 30 is driven rightward in the drawing, the spool 20 is driven leftward in the drawing, and the pinion 22 Meshes with the teeth 26 of the flywheel 24.

As is apparent from this configuration, when the engine is to be started, the solenoid 28 is first energized,
The pinion 22 is meshed with the teeth 26 of the flywheel 24, and then the starter motor 10 is energized for driving the engine. After the engine is started, the solenoid 28 is turned off, the movable iron core 30 returns to the position shown in the figure by the action of the compression coil spring 36, and the pinion 22 is disengaged from the teeth 26 of the flywheel 24.

FIG. 2 is a diagram schematically showing a control structure for controlling the operation of the starter motor shown in FIG. Reference numerals 10 and 28 in FIG. 2 indicate the starter motor and the solenoid in FIG. 1, respectively. Starter motor 1
0 indicates ON / OFF of the relay switch 38 and the transistor 4
The current from the low-voltage battery 42 is selectively supplied in accordance with the on / off state of 0, and the current from the high-voltage battery 46 is supplied by turning on the relay switch 38 and the transistor 40 when the relay switch 44 is on. It has become so.

The solenoid 28 is selectively supplied with a current from the low voltage battery 42 in accordance with the on / off state of the relay switch 48 and the on / off state of the transistor 50. The relay switches 38, 44, 48 and the transistors 40 and 50 are all controlled by a controller 52 including a microcomputer to control engine start by a starter motor described below with reference to the flowchart of FIG. ing. In FIG. 2, reference numeral 54 denotes a conventional start switch for starting the engine operated by the driver. Reference numeral 56 denotes a neutral switch for detecting that the transmission is in the neutral position when the start switch 54 starts the engine. It is. An engine speed sensor 58 detects the engine speed.

Next, with reference to the flowchart of FIG. 3, the start-up control of the engine by the starter motor, which is an essential part of the invention in the fuel-saving vehicle according to the present invention, will be described. FIG. 4 shows an example of a change in the rotation speed generated in the engine and the starter motor by such control.

The operation of the fuel-saving vehicle according to the invention can be effected by closing a key switch of the vehicle not shown or by closing a suitable switch not shown in the figure which selects the implementation of the invention. When started, it is determined in step 10 whether or not a brake switch (not shown) is turned on, that is, whether or not the driver has depressed the brake pedal beyond a predetermined depression depth. When the determination result is yes, the control proceeds to step 20, the vehicle speed is equal to or a predetermined small threshold value V ₀ or less or not. If the determination is yes, control proceeds to step 3.
The process proceeds to 0, and it is determined whether or not the running distance since the previous stop is 15 meters or more. The travel distance of “15 meters or more” is an example of the travel distance for performing the fuel-saving operation without causing inappropriate consumption of the battery. When the result of the determination is yes, the control proceeds to step 40.

In step 40, the flag F is set to 1
Is determined. The flag F is set to 0 by initialization at the start of the control, and is set to 1 in step 70 described below. In the first step 40 after the start of the control, the judgment result is NO, the control proceeds to a step 50, in which the supply of fuel to the engine is cut off, and in a step 60, the exhaust valve of the engine is opened. You. Thereafter, the control sets the flag F to 1 in step 70, and returns to step 10.

Thus, in the illustrated embodiment, the brake
Key switch is on and vehicle speed is V ₀Less than the previous
If the mileage from the temporary stop of fuel is more than 15 meters
When the condition is satisfied, the fuel
Supply is shut off, the exhaust valve is opened, the engine is inertial
Enter the rotation state. The engine speed is now shown in FIG.
Time t₁It starts and gradually decreases.

Thereafter, at time t ₂ , step 10,
If the condition in either one of 20 or 30 is broken,
Control proceeds to step 80. After the start, if the three conditions of Steps 10, 20, and 30 are not satisfied at the same time, the control naturally proceeds to Step 80 from the beginning.

When the control reaches the step 80 after passing the steps 40 to 70 once, the flag F is 1, and the control proceeds to the step 90 at this time. If the decision result in the step 80 is no, the control bypasses the following steps 90 to 120 and immediately proceeds to the step 1
Return to 0.

In step 90, it is determined whether or not the starter motor equivalent speed Ne of the engine speed detected by the engine speed sensor 58 is 400 rpm or more. The starter motor equivalent speed Ne of the engine rotation speed is, as apparent from the structure of FIG. 1, between the rotation speed of the engine flywheel 24 and the rotation speed of the rotation shaft 16 of the starter motor, between the pinion 22 and the flywheel. In consideration of the fact that there is a difference in inverse proportion to the ratio of the number of teeth of the twenty-four teeth 26, the engine speed is converted into a value equivalent to the speed of the starter motor. In the following, for the sake of simplicity, the starter motor equivalent speed Ne of the engine speed with respect to the engine speed will be simply referred to as the engine speed Ne within a range that does not cause misunderstanding. When the judgment is yes,
Control proceeds to step 100, where fuel supply is resumed.

The supply of fuel to the engine is interrupted once,
When the engine is in the inertial rotation state, the rotation speed is 4
If it is about 00 rpm or more, there is a high possibility that the engine is restarted only by restarting the fuel supply without accelerating the engine by the starter motor. In the next step 110, it is determined whether or not the engine has been started. If the determination result is yes, the control resets the flag F to 0 in step 120, and then returns to step 10. This is the case where the engine is restarted without using the starter motor by restarting the supply of fuel to restart the engine while the engine is still rotating inertia after the engine is temporarily stopped. is there.

The degree of inertial rotation of the engine after the supply of fuel to the engine is cut off depends on the rotation speed of the engine when the fuel is cut off and the state of the load applied to the engine at that time. When the wheels are driven by an automatic transmission including the above, the inertia rotation time until the engine stops can be extended by opening the exhaust valve at the same time as the fuel cutoff.

When the result of the determination in step 90 is NO, that is, when the speed of the inertial rotation of the engine is reduced to 400 rpm or less, or when the result of the determination in step 90 is YES, the fuel supply Is restarted, but the engine is not restarted, and if the determination result in step 110 is no, the control proceeds to step 130.
Then, it is determined whether or not the difference between the engine rotation speed Ne and the starter motor rotation speed Ns is equal to or less than a predetermined threshold value ΔN.

If the result of the determination in step 130 is NO, the control proceeds to step 140, where the controller 52 calculates a current Im for regulating the power supply to the starter motor for synchronizing the starter motor rotation speed with the engine rotation speed. Is done. This calculation is as shown in FIG.
PID control based on the difference ΔN between the engine rotation speed Ne and the starter motor rotation speed Ns may be used. Next, at step 150, the relay switch 38 is turned on by the controller 52 using the current of the low-voltage battery 42, and the on / off duty control of the transistor 40 is performed, so that the speed control energization to the starter motor 10 is performed.

When the result of determination in step 130 is YES as a result of the speed control energization of the starter motor (FIG. 4)
At time t ₃ ), or when the control first reaches step 130 and the result of the determination in step 130 is yes because the inertial rotation of the engine has already ended, the control proceeds to 160 and the low-voltage battery When the relay switch 48 is turned on by the controller 52 and the on / off duty control of the transistor 50 is performed based on the current of 42, the solenoid 28 is appropriately energized, and the starter motor is connected to the engine.

Next, in step 170, the full power is supplied to the starter motor under the control of the controller 52 using the current of the high-voltage battery 46, and the starter motor is driven by the starter motor. Next, at step 180, it is determined whether or not the engine has been started,
When the determination result is NO, the control returns to step 130, and when the determination result is YES, that is, when the engine is restarted, the control proceeds to step 190, and the energization to the starter motor is stopped. (Time point t _{4 in} FIG. 4) Next, in step 200, the starter motor is disconnected from the engine, and the control proceeds to step 12
Step 1 after resetting flag F to 0 at 0
Return to 0. Note that the starter motor 1 for releasing the pinion 22 from engagement with the teeth 26 of the flywheel 24
The timing of releasing the current supply to 0 may be determined as appropriate.

Thus, according to the present invention, in the operation of a fuel-saving automobile with a temporary stop of the engine, the inertial rotation of the engine is utilized as effectively as possible even during the temporary stop of the engine, and the engine is restarted. The energy consumption of the starter motor at the time of starting can be reduced as much as possible, and at the same time, the agility of restarting the engine can be improved.

While the present invention has been described in detail with reference to a preferred embodiment, it will be apparent to those skilled in the art that various modifications can be made to the illustrated embodiment without departing from the scope of the invention. There will be.

[Brief description of the drawings]

FIG. 1 is an exploded view showing an example of a starter motor incorporated in a fuel-saving vehicle according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a control device for operating the starter motor shown in FIG.

FIG. 3 is a flowchart showing a procedure for operating the starter motor shown in FIG. 1 according to the present invention by the control device shown in FIG. 2;

FIG. 4 is a graph showing an example of a change in rotation speed generated in an engine and a starter motor by control according to the flowchart of FIG. 3;

FIG. 5 is a diagram showing a calculation in step 140 of the flowchart in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Starter motor 12, 14 ... Terminal 16 ... Starter motor rotating shaft 18 ... Starter motor rotating shaft spline part 20 ... Spool 22 ... Pinion 24 ... Engine flywheel 26 ... Flywheel teeth 28 ... Solenoid 30 ... Solenoid Movable iron core 32 ... Pivot 34 ... Pivoting lever 36 ... Compression coil spring 38 ... Relay switch 40 ... Transistor 42 ... Low voltage battery 44 ... Relay switch 46 ... High voltage battery 48 ... Relay switch 50 ... Transistor 52 ... Controller 54 ... Start Switch 56: Neutral switch 58: Engine speed sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G092 BA03 BB10 CA02 CB05 EA08 EA27 EC08 FA24 FA30 GA01 GA10 HE01Z HF13Z HF19Z HF21Z HF26Z 3G093 BA19 BA21 BA22 CA02 DA01 DA12 DB05 DB12 DB15 EA03 EC02 FA11 FA14

Claims (2)

[Claims] 1. A fuel-consumption type automobile in which an engine is temporarily stopped when a predetermined condition for allowing the engine to be temporarily stopped during operation of the vehicle is satisfied. The fuel supply to the engine is cut off, the engine is rotated by inertia, and when the engine is restarted,
At least when the rotation speed of the engine is not zero, the starter motor is connected to the engine by synchronizing the rotation speed with the rotation speed of the engine by energizing the starter motor. 2. The motor vehicle according to claim 1, wherein the speed control energization of the starter motor is performed at a voltage lower than a voltage at which an engine is driven by the starter motor.