JP2000213375A - Method and device for stop controlling internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve engine startability in an internal combustion engine. SOLUTION: When an ignition switch 66 is turned off, an electronic control unit 33 performs full-closing control in which the throttle opening specifying state of a stepping motor 30 is so controlled that the throttle opening θ of an intake throttle valve 29 may be zero. The electronic control unit 33 continues control for making the throttle opening of the intake throttle valve 29 zero while the engine inertia speed is not less than the preset speed No. When the engine inertia speed is less than the preset speed No, the electronic controller 33 performs the piston stop position control in which the throttle opening specifying state of the stepping motor 30 is so controlled that the throttle opening of the intake throttle valve 29 may be larger than zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop control method and apparatus for an internal combustion engine having an intake throttle valve on an intake passage for supplying air to a combustion chamber of the internal combustion engine having a reciprocating piston. is there.

[0002]

2. Description of the Related Art Japanese Unexamined Utility Model Publication No. 5-57333,
In an internal combustion engine such as a diesel engine or a gasoline engine disclosed in Japanese Patent Publication No. 0-18864 or the like, when the engine is stopped, an intake throttle valve on an intake passage is arranged at a fully closed position. Even after the combustion in the combustion chamber is stopped, the piston reciprocates about tens of times by inertia until the piston completely stops, and the reciprocating operation of the piston after the combustion stops causes the engine to vibrate. Placing the intake throttle valve in the fully closed position when stopping the engine can improve the vibration characteristics of the engine when the engine stops.
You can expect a smooth engine stop.

[0003]

However, if the intake throttle valve is arranged at the fully closed position to close the intake passage, the reciprocating operation of the piston after the combustion is stopped causes the intake passage from the intake throttle valve to the combustion chamber to reach the combustion chamber. To a large negative pressure. Therefore, the piston to be stopped tends to stop near top dead center due to a large negative pressure in the intake passage. The state where the piston stops near the top dead center is an inconvenient state at the time of the next engine start. That is, the reciprocating motion of the piston is converted into the rotational motion of the crankshaft via the crank mechanism. When the piston is at the top dead center, the crank arm and the crank rod constituting the crank mechanism are in a serial state. The torque required for shifting the piston to the bottom dead center side from such a state is larger than the torque required for moving the piston from a state where the piston is at a position other than the top dead center. Moreover, when the engine temperature is low, the viscosity of the oil is high, and the viscous resistance of the oil at the time of starting the engine, which often occurs when the engine temperature is low, further increases the required torque. Therefore, the torque required to move the piston at the time of starting the engine is maximized. In addition, when the battery voltage is low, the smoothness of starting the engine is low. Therefore, from the viewpoint of engine startability, it is not preferable that the piston stops near the top dead center.

Further, when the piston stops at the top dead center with the stop of the engine, fuel is fed to the injection nozzle by an injection pump having a so-called timer device as disclosed in Japanese Patent Application Laid-Open No. 9-303194. The following problems occur in electronically controlled diesel engines.

[0005] A timer device having a timer piston adjusts the position of the timer piston by the oil pressure during operation of the engine, and controls the fuel injection timing at the injection nozzle by adjusting the position of the timer piston. A plunger for pumping fuel to the injection nozzle moves in a direction away from the roller ring while rotating together with the cam plate, and pumps fuel to the injection nozzle. The pressure feeding timing, that is, the injection timing of the injection nozzle, is when the cam roller on the roller ring that forms the cam mechanism together with the cam plate rides on the peak of the cam surface of the cam plate, and adjusts the rotational position of the roller ring. Thus, the pumping timing can be adjusted according to the engine state. For example, in the idling state, the pumping timing is controlled to the retard side, and when the engine is stopped, the pumping timing is controlled to the advance side. When the engine stops, the hydraulic pressure acting on the timer piston is released, and the timer piston becomes easy to move. That is, the roller ring easily rotates when the engine is stopped, but the roller ring does not rotate unless the cam roller on the roller ring rides on the mountain of the cam surface. The time when the piston stops at the top dead center is when the cam roller on the roller ring rides on the mountain of the cam surface. In this riding state, the spring force urging the cam plate toward the roller ring rotates the roller ring through the engagement between the peak and the cam roller. As a result, even if the roller ring is arranged at a rotation position suitable for starting the engine when the engine is stopped, if the piston stops near the top dead center position, the roller ring moves from the rotation position suitable for starting the engine. As a result, the startability of the engine deteriorates.

An object of the present invention is to improve the startability of an engine in an internal combustion engine.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an internal combustion engine having an intake throttle valve on an intake passage for supplying air to a combustion chamber of the internal combustion engine having a reciprocating piston. According to the first aspect of the present invention, when the internal combustion engine is stopped, after the intake throttle valve is disposed at a fully closed position that closes the intake passage, the throttle opening degree at which the intake passage is opened before the internal combustion engine is stopped. The intake throttle valve is arranged at a position.

[0008] Even when the intake throttle valve is kept at the fully closed position, the pressure in the intake passage in the negative pressure state increases with time. When the intake passage is opened before the internal combustion engine is stopped after the intake passage is closed, the pressure in the intake passage in a negative pressure state is increased faster than in the case where the intake passage is kept closed. The control for accelerating the pressure increase greatly reduces the rate at which the piston stops at the top dead center, and improves the startability of the engine.

According to a second aspect of the present invention, there is provided a stop shift notifying means for notifying the shift of the internal combustion engine to a stop, a throttle opening degree defining means for defining a throttle opening of the intake throttle valve so as to be changeable, and the intake throttle. A stop control device comprising a throttle opening control means for controlling a throttle opening degree specified state of the throttle opening degree setting means with respect to a valve, wherein the throttle opening control means comprises a stop shift notification means of the stop shift notification means. After performing the full-close control of arranging the intake throttle valve at the fully-closed position that closes the intake passage based on the above, the intake throttle valve is positioned at a throttle opening position that opens the intake passage before the internal combustion engine is stopped. Stopping position control of the arranged piston is performed.

When the stop transition notifying means performs the stop transition notification, the throttle opening control means controls the throttle opening defining state of the throttle opening defining means so as to arrange the intake throttle valve at the fully closed position. The throttle opening control means controls the throttle opening defining state of the throttle opening defining means so that the intake throttle valve is arranged at the position of the throttle opening that opens the intake passage before the internal combustion engine is stopped.

According to the third aspect of the present invention, in the second aspect,
The stop control device includes start determination means for determining whether to start the piston stop position control, and the throttle opening control means controls the piston stop position control based on the determination of the start of the start determination means. To start.

The rotational speed of the internal combustion engine that is about to stop suddenly shifts from zero to zero. The start timing of the piston stop position control is set as a time when the rotational speed of the internal combustion engine does not suddenly shift to zero.

According to a fourth aspect of the present invention, in any one of the second and third aspects, the aperture opening defining means is a stepping motor. The stepping motor is suitable as a throttle opening defining means for the intake throttle valve.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the internal combustion engine is a diesel engine, and an injection nozzle for injecting fuel into the combustion chamber; An injection pump for pumping fuel to the injection pump, the injection pump having a cam roller, a roller ring whose rotational position is adjusted, and a cam that reciprocates in the opposite direction in a state facing the roller ring. A plate and biasing means for biasing the cam plate toward the roller ring side, wherein the injection pump is configured such that when the cam roller faces a peak of a cam surface of the cam plate, the biasing means When the cam plate reciprocates against the urging action of the reciprocating motion, the fuel is pumped when the cam plate reciprocates, and the injection pump further controls the fuel pumping timing. The timer device includes a timer piston whose position is adjusted by hydraulic pressure during operation of the internal combustion engine. The rotation position of the roller ring is interlocked with the position of the timer piston. The timing was when the piston was near top dead center.

Since the rate at which the piston stops near the top dead center is greatly reduced, the possibility that the roller ring changes its rotation position while the engine is stopped is significantly reduced, and the engine startability is improved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention applied to a diesel engine will be described below with reference to FIGS.

A diesel engine 11 shown in FIG. 1 has a plurality of cylinders provided with a combustion chamber 12. In the intake stroke of the diesel engine 11, an intake valve 14 that opens and closes an intake port 13 provided for each cylinder is arranged at an open position, and the outside air is moved downward by a piston 19 to move the air cleaner 1.
The air is sucked into the combustion chamber 12 via the intake passage 5 and the intake passage 16. An injection nozzle 17 provided for each cylinder injects fuel, which is pumped from an injection pump 18 via a fuel supply path 171, into the combustion chamber 12.

In the compression stroke of the diesel engine 11,
The fuel injected into the combustion chamber 12 and the sucked outside air are pressurized by the upward movement of the piston 19 to explode and burn. The piston 19 moves down due to the explosion-combustion in the combustion chamber 12,
The force at the time of this downward movement is transmitted to the crankshaft 22 via the crank rod 20 and the crank arm 21, and the crankshaft 22 rotates.

In the exhaust stroke of the diesel engine 11, an exhaust valve 24 for opening and closing an exhaust port 23 provided for each cylinder is arranged at an open position, and exhaust gas generated in the combustion chamber 12 is discharged to an exhaust passage 25. You. Exhaust passage 25
And the intake passage 16 are connected by a passage 26, and the passage 2
A flow regulating valve 27 is interposed on 6. The opening of the flow control valve 27 is adjusted by the operation of the actuator 28. The actuator 28 is controlled by the electronic control unit 33. Part of the exhaust gas discharged from the combustion chamber 12 to the exhaust passage 25 can flow into the intake passage 16 via the passage 26. The passage 26, the flow control valve 27, and the actuator 28 constitute an EGR type exhaust gas purification device.

An intake throttle valve 29 is provided on the intake passage 16. The intake throttle valve 29 rotates around a support shaft 291, and the intake throttle valve 29 is rotated by a stepping motor 30. The stepping motor 30 serves as a throttle opening regulating means for regulating the rotational position of the intake throttle valve 29, that is, the throttle opening.

The depression amount of the accelerator pedal 31 is detected by an accelerator sensor 32. Accelerator sensor 32
The information on the depression amount of the accelerator pedal 31 detected by the controller is sent to the electronic control unit 33. Electronic control unit 33
Controls the aperture opening regulation state of the stepping motor 30 based on the depression amount information obtained from the accelerator sensor 32.

As shown in FIG. 1, the injection pump 18 is moved from the crankshaft 22 of the diesel engine 11 to the injection pump 1.
Driving force is obtained via the drive pulley 34 on the 8 side. FIG.
Shows the internal structure of the injection pump 18. Drive pulley 3
A fuel feed pump 36 and a disk-shaped pulser 37 are attached to a drive shaft 35 connected to the drive shaft 4. The drive shaft 35 is connected to a cam plate 38. A plurality of cam rollers 40 are mounted on a roller ring 39 disposed between the pulsar 37 and the cam plate 38. Each cam roller 40 faces the cam surface 381 of the cam plate 38, and the cam plate 38 is pressed against the cam roller 40 by a spring 41.
FIG. 4A shows a state in which the cam roller 40 has the peak 3 of the cam surface 381.
A state facing 82 is shown.

A plunger 42 for pressurizing the fuel is rotatably accommodated in a cylinder 44 of the pump housing 43, and the plunger 42 is attached to the cam plate 38 so as to be integrally rotatable. The cam plate 38 and the plunger 42 are separated from the drive shaft 35 by the cam plate 3.
8 is reciprocated in the left-right direction in FIG. A high-pressure chamber 45 is provided between the distal end surface of the plunger 42 and the cylinder 44.

When the fuel feed pump 36 is driven based on the rotation of the drive shaft 35, the fuel in a fuel tank (not shown) is supplied to the fuel chamber 51 through a fuel supply port 50.
Supplied inside. In the suction stroke in which the plunger 42 returns to the left in FIG.
2 a plurality of intake grooves 46 (diesel engine 1
(The same number as one cylinder) communicates with the suction port 49 in the pump housing 43 and the fuel in the fuel chamber 51 is supplied to the high-pressure chamber 4.
5 is introduced. The plunger 42 has a plurality of distribution ports 4
7 (the same number as the number of cylinders of the diesel engine 11). The plunger 42 moves to the right in FIG.
In the compression stroke in which is pressurized, the fuel in the high-pressure chamber 45 is fed to the injection nozzle 17 of each cylinder via the distribution port 47 and the distribution passage 48. This pumping timing is determined by the piston 19
Is near top dead center.

The spill passage 52 in the pump housing 43
An electromagnetic spill valve 53 is provided above. In the non-energized state, the valve element 55 of the electromagnetic spill valve 53 opens, and the fuel in the high-pressure chamber 45 overflows to the fuel chamber 51. In the energized state, the valve element 55 of the electromagnetic spill valve 53 closes, and the high pressure chamber 45
The fuel spill to the river is stopped. Normally open electromagnetic spill valve 53
The overflow of fuel from the high-pressure chamber 45 to the fuel chamber 51 is adjusted by controlling the energization time in the coil 54. If the power supply to the electromagnetic spill valve 53 is stopped during the compression stroke of the plunger 42, the pressure in the high-pressure chamber 45 is reduced, and the fuel injection from the injection nozzle 17 is stopped. If the opening / closing timing of the electromagnetic spill valve 53 is controlled during the compression stroke of the plunger 42, the fuel injection amount from the injection nozzle 17 is controlled.

A timer device 56 is provided below the pump housing 43. As shown in FIGS. 4A and 4B, the timer device 56 includes a timer housing 57, a timer piston 58 that divides the inside of the timer housing 57 into a low-pressure chamber 59 and a pressurizing chamber 60, and a timer piston 58 that is a low-pressure chamber. Timer spring 6 for urging the pressure chamber 60 side from the 59 side
1. A slide pin 62 for connecting the timer piston 58 to the roller ring 39 is provided. The position of the timer piston 58 is determined by the pressure opposition between the pressurizing chamber 60 into which the fuel pressurized by the fuel feed pump 36 is introduced and the spring force of the timer spring 61. By this position determination, the roller ring 3 in the rotation direction of the drive shaft 35 is
9, the reciprocating timing of the plunger 42 is determined. Accordingly, by controlling the reciprocating timing of the plunger 42, the engagement timing between the cam roller 40 and the peak 382 of the cam surface 381 is controlled, and the fuel injection timing at the injection nozzle 17 is adjusted. Pressurizing chamber 60
The pressure inside the communication passage 6 connecting the pressurizing chamber 60 and the low-pressure chamber 59 is
4 is adjusted by controlling the duty ratio of the timing control solenoid valve 63 above.

A rotation speed sensor 65 installed facing the peripheral surface of the pulsar 37 detects the passage of a projection on the peripheral surface of the pulsar 37 and outputs a timing signal corresponding to the engine rotation speed, that is, engine rotation speed detection information. Output to the electronic control unit 33.

The electronic control unit 33 includes a central processing unit (CP)
U) 331, read-only memory (ROM) 332, random access memory (RAM) 333, and backup random access memory (backup RAM) 33
4 is provided. The electronic control unit 33 includes a CPU 331,
ROM 332, RAM 333 and backup RAM 3
, An external input circuit 335 and an external output circuit 336 are connected by a bus 337 to form a logical operation circuit. RO
M332 stores various control programs including a stop control program shown in the flowchart of FIG.
The AM 333 temporarily stores the calculation result of the CPU 331 and the like. The backup RAM 334 stores data set in advance. The engine speed No in the flowchart of FIG. 6 is one of the data stored in the backup RAM 334. The external input circuit 335 captures an ON-OFF signal due to the ON operation of the ignition switch 66, depression amount information from the accelerator sensor 32, and engine speed detection information from the speed sensor 65.
The CPU 331 controls the actuator 28, the stepping motor 30, the electromagnetic spill valve 5 via the external output circuit 336.
3 and the operation of the timing control solenoid valve 63 are controlled.

Next, the stop control of the diesel engine 11 will be described with reference to the flowchart of FIG. 6 showing the stop control program. It is assumed that the diesel engine 11 is in an idling state in which it rotates at the idling speed N1 in FIG. The curve M in FIG. 5 represents the change in the engine speed,
A curve Θ represents a change in the throttle opening θ of the intake throttle valve 29. A curve P represents a change in the pressure in the intake passage 16, and a curve T represents a change in the injection timing of the injection nozzle 17. The vertical axis indicating the engine speed in the timing chart of the curve M indicates a higher engine speed as it goes upward. The vertical axis representing the throttle opening θ in the timing chart of the curve Θ represents a larger throttle opening as it goes downward. The vertical axis representing the pressure in the timing chart of the curve P represents higher pressure as it goes upward.

The electronic control unit 33 grasps the idling state of the diesel engine 11 based on the engine speed detection information from the engine speed sensor 65. A portion M1 of the curve M represents an idling state. In this idling state, the electronic control unit 33 controls the throttle opening regulation state of the stepping motor 30 so that the throttle opening of the intake throttle valve 29 is set to θ2 as shown by the portion # 1 of the curve Θ. In the idling state, the electronic control unit 33 controls the operation of the timing control solenoid valve 63 of the timer device 56 as shown by a portion T1 in the curve T.

When the ignition switch 66 is turned off, the electronic control unit 33 as the throttle opening control means controls the electromagnetic spill valve 53 so as to stop the fuel injection in response to the input of the OFF signal accompanying the turning off of the ignition switch 66.
Control. The time t1 in FIG.
6 represents the OFF state. Further, when the ignition switch 66 serving as a stop transition notification unit is turned off, the electronic control unit 3
3 performs the full-close control of controlling the throttle opening regulation state of the stepping motor 30 so that the throttle opening θ of the intake throttle valve 29 is set to zero as indicated by the portion # 2 of the curve Θ. FIG. 3A shows a state in which the intake throttle valve 29 is arranged at the fully closed position by the fully closed control. The throttle opening θo is θ = 0
The intake throttle valve 29 is pivotally disposed at a fully closed position that closes the intake passage 16.

After stopping the injection of the injection nozzle 17 and disposing the intake throttle valve 29 at the fully closed position, the rotational speed of the diesel engine 11 that is coasting decreases as shown by a portion M2 of the curve M. When the engine coasting speed is significantly reduced, the engine coasting speed becomes a portion M of the curve M.
As shown by 3, it suddenly shifts to zero. Electronic control unit 33
Keeps the throttle opening of the intake throttle valve 29 at zero while the engine coasting speed is equal to or higher than the preset speed No. When the engine inertia rotation speed falls below a preset rotation speed No, the electronic control unit 33 sets the throttle opening of the intake throttle valve 29 to θ as shown by the portion # 3 of the curve Θ.
Piston stop position control is performed such that the throttle opening degree regulation state of the stepping motor 30 is controlled to be 1.
That is, the electronic control unit 33 constitutes start determination means for determining whether to start the piston stop position control together with the rotation speed sensor 65, and the electronic control unit 33 operates when the engine rotation speed falls below the rotation speed No. Judge whether to start the stop position control. FIG. 3B shows a state in which the intake throttle valve 29 is arranged at the position of the throttle opening θ1 by the piston stop position control. The throttle opening θ1 is a value slightly larger than 0 °.

When the engine speed Ne becomes zero, the electronic control unit 33 sets the throttle opening of the stepping motor 30 so that the throttle opening of the intake throttle valve 29 is set to θ3 as shown by the portion # 4 of the curve Θ. Control the specified state. The throttle opening θ3 is a fully open position of the intake throttle valve 29 that fully opens the intake passage 16.

The electronic control unit 33 controls the operation of the timing control solenoid valve 63 so as to shift the injection timing of the injection nozzle 17 to the advance side as shown by a portion T2 of the curve T after the ignition switch 66 is turned off. . The injection timing of the injection nozzle 17 is set to a desired injection timing before the engine speed Ne becomes zero as shown by a portion T3 of the curve T. Injection nozzle 1 when engine is stopped
The control for shifting the injection timing of 7 to the advanced side is performed to enhance the ignitability at the time of starting the engine.

The first embodiment has the following advantages. (1-1) The pressure in the intake passage 16 in the idling state is a substantially constant pressure state as shown by a portion P1 of the curve P in FIG. However, the pressure in the intake passage 16 decreases as shown by the portion P2 of the curve P due to the inertial rotation of the engine after the ignition switch 66 is turned off, that is, the coasting reciprocation of the piston 19. That is, the negative pressure in the intake throttle valve 29 increases due to the inertial rotation of the engine. After the negative pressure increases, as the coasting speed of the engine decreases, the pressure in the intake passage 16 increases. This is because the intake passage 16 is not completely closed even when the intake throttle valve 29 is in the fully closed position. Therefore, as shown by the line # 2 and the chain line # 22 in FIG. 5, the throttle opening degree of the intake throttle valve 29 is set to θ until the engine speed becomes zero.
Also in the conventional stop control at o (= 0 °), the pressure in the intake passage 16 in the negative pressure state increases with time as shown by a chain line curve P4.

In this embodiment, the throttle opening of the intake throttle valve 29 is set to θ1 before the engine speed becomes zero after the intake throttle valve 29 is disposed at the fully closed position and the intake passage 16 is closed. . That is, the intake passage 16 is slightly opened before the engine completely stops. Therefore, as shown by the portion P3 of the curve P in FIG.
Is boosted faster than in the state where the is kept in the fully closed position. The piston stop position control for accelerating the pressure increase greatly reduces the rate at which the piston 19 stops at the top dead center. Conventionally, the rate at which the piston 19 stops at the top dead center is 6 to 7
However, the piston stop position control according to the present embodiment reduces the rate at which the piston 19 stops at the top dead center to about several percent. Therefore, the engine startability is improved.

(1-2) When the throttle opening of the intake throttle valve 29 is θo
The control of the piston stop position, which shifts from .theta.1 to .theta.1, is meaningless unless performed before the complete stop of the engine. The rotation speed of the diesel engine 11, which is coasting after the ignition switch 66 is turned off, suddenly shifts from zero to zero as shown by the curve portions M2 and M3 in FIG. The start timing of the piston stop position control is set as the time when the engine coasting speed falls below No. The rotational speed No for determining whether to start the piston stop position control must be an engine rotational speed within a range where the engine inertial rotational speed does not suddenly shift to zero. In addition, if the start of the piston stop position control is performed too early after the ignition switch 66 is turned off, the vibration due to the inertial rotation of the engine cannot be suppressed. Considering such circumstances, the rotational speed No.
By properly setting, it is possible to suppress engine vibration when the engine is stopped, and to significantly reduce the rate at which the piston 19 stops at the top dead center. An appropriate rotation speed No is about 1/2 to 1/4 of the idle rotation speed N1.

(1-3) Intake throttle valve 2 indicated by curve portion # 3
The throttle opening .theta.1 of the intake throttle valve 29 during idling is
Is smaller than the throttle opening θ2. If the throttle opening θ1 is too large, the vibration at the time of stopping the engine deteriorates. By making the throttle opening θ1 smaller than the throttle opening θ2, the vibration characteristics when the engine is stopped are not impaired.

(1-4) The stepping motor 30 can finely control the throttle opening degree of the intake throttle valve 29 during all operations of the engine, the engine stop control, and the engine start control. Therefore, the stepping motor 30 is suitable as a throttle opening defining means for the intake throttle valve 29.

(1-5) When the piston 19 stops near the top dead center when the engine speed becomes zero, the cam roller 40 moves to the peak 38 of the cam surface 381 as shown in FIG.
2 opposite. When the diesel engine 11 is completely stopped, the hydraulic pressure acting on the timer piston 58 is released, and the timer piston 58 becomes easy to move. That is, the roller ring 39 easily rotates when the engine is stopped. The time when the piston 19 stops at the top dead center is when the cam roller 40 on the roller ring 39 rides on the peak 382 of the cam surface 381. In this riding state, the spring 41, which is an urging means for urging the cam plate 38 toward the roller ring 39, rotates the roller ring 39 through the engagement between the peak 382 and the cam roller 40. As a result, even when the roller ring 39 is arranged at the rotation position that brings the injection timing of the injection nozzle 17 suitable for starting the engine when the engine is stopped, as shown by the curve T in FIG. If stopped near, the roller ring 39 deviates from a rotation position suitable for starting the engine. If the roller ring 39 moves so that the injection timing is shifted to the retard side, the engine startability is particularly deteriorated at the next start.

In the present embodiment in which the rate at which the piston 19 stops near the top dead center is greatly reduced, the roller ring 39
Is much less likely to change the turning position while the engine is stopped, and the engine startability is improved.

In the present invention, the following embodiments are also possible. (1) The intake throttle valve 29 is mechanically linked with the accelerator pedal 31 so that the intake throttle valve 29 is moved from the fully closed position by one to the intake passage.
Use a separate actuator to move the aperture 6 to the position of the throttle opening. (2) Based on the rotation speed information from the rotation speed sensor 65, the engine inertia rotation state in the transition period to the engine stop is grasped, and based on this grasping, the intake throttle valve 29 is arranged at the fully closed position. Perform stop position control. By doing so, the ignition switch 66
The piston stop position control can also be performed in a case where the engine is stopped even though the switch is not turned off. (3) As disclosed in JP-A-9-317528, the present invention is applied to a diesel engine having a pair of intake throttle valves arranged in parallel. In this case, when the engine is stopped, the two intake throttle valves may be arranged at the fully closed position, and then the other may be moved to the throttle opening position for opening the intake passage while keeping one at the fully closed position. (4) The present invention is applied to a gasoline engine. (5) The present invention is applied to an internal combustion engine without an EGR type exhaust gas purification device.

[0043]

As described above in detail, according to the present invention, when the internal combustion engine is stopped, the intake throttle valve is disposed at the fully closed position for closing the intake passage, and then the intake passage is stopped before the internal combustion engine is stopped. Since the intake throttle valve is arranged at the position of the opening of the throttle opening, an excellent effect that the engine startability can be improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a diesel engine system showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of the injection pump.

FIG. 3A is a sectional view of a main part showing a state in which an intake throttle valve is arranged at a fully closed position. (B) is a sectional view of a principal part showing a state where an intake throttle valve is arranged at a position where an intake passage is slightly opened.

FIG. 4 shows the structure of a roller ring and a timer device,
FIG. 4A is a cross-sectional view illustrating a state in which a cam roller faces a mountain portion of a cam surface. FIG. 4B is a cross-sectional view illustrating a state in which the cam roller is displaced from a peak of the cam surface.

FIG. 5 is a timing chart for explaining piston stop position control.

FIG. 6 is a flowchart showing a stop control program.

[Explanation of symbols]

Reference numeral 11 denotes a diesel engine which is an internal combustion engine, 12 denotes a combustion chamber, 16 denotes an intake passage, 17 denotes an injection nozzle, 18 denotes an injection pump, 19 denotes a piston, 29 denotes an intake throttle valve, and 30 denotes a stepping motor serving as a throttle opening defining means. 33, an electronic control device serving as a throttle opening control means, 38, a cam plate,
Reference numeral 39 denotes a roller ring, 40 denotes a cam roller, 41 denotes a spring serving as an urging means, 56 denotes a timer device, 58 denotes a timer piston, 65 denotes a rotation speed sensor that constitutes start determination means together with the electronic control unit 33, and 66 denotes a stop transition notification. Ignition switch as a means.

Claims (5)

[Claims] In an internal combustion engine having an intake throttle valve interposed on an intake passage for supplying air to a combustion chamber of the internal combustion engine having a reciprocating piston, when the internal combustion engine stops, the intake passage A stop control method for an internal combustion engine in which the intake throttle valve is arranged at a throttle opening degree at which the intake passage opens to open the intake passage before the internal combustion engine is stopped after the intake throttle valve is arranged at a fully closed position for closing the engine. 2. An internal combustion engine in which an intake throttle valve is interposed on an intake passage for supplying air to a combustion chamber of an internal combustion engine having a reciprocating piston, a stop transition notification for notifying a transition to a stop of the internal combustion engine. Means, a throttle opening defining means for defining a throttle opening of the intake throttle valve so as to be changeable, and a throttle opening control means for controlling a throttle opening defining state of the throttle opening defining means with respect to the intake throttle valve. The throttle opening control means, after performing the full closing control to arrange the intake throttle valve at the fully closed position to close the intake passage based on the stop transition notification of the stop transition notification means, A stop control device for an internal combustion engine that performs a piston stop position control in which the intake throttle valve is arranged at a position of a throttle opening degree that opens the intake passage before the stop. 3. A start determining means for judging whether or not to start the piston stop position control, wherein the throttle opening control means starts the piston stop position control on the basis of the start judgment of the start judging means. The stop control device for an internal combustion engine according to claim 2. 4. The stop control device for an internal combustion engine according to claim 2, wherein said throttle opening degree defining means is a stepping motor. 5. The internal combustion engine is a diesel engine, and an injection nozzle for injecting fuel into the combustion chamber;
An injection pump for pumping fuel to the injection nozzle, the injection pump having a cam roller,
A roller ring whose rotational position is adjusted, a cam plate that reciprocates in the opposite direction in a state facing the roller ring, and biasing means that biases the cam plate toward the roller ring. The injection pump pressurizes the fuel when the cam plate moves forward when the cam roller moves forward against the urging action of the urging means when the cam roller faces the peak of the cam surface of the cam plate. Further, the injection pump includes a timer device for controlling fuel pumping timing, the timer device includes a timer piston whose position is adjusted by a hydraulic pressure during operation of the internal combustion engine, and a rotation of the roller ring. The moving position is interlocked with the position of the timer piston, and the pumping timing of the injection pump is set when the piston is near top dead center. Stop control apparatus in an internal combustion engine according to one of claims Zureka.