JP3092389B2 - Rotation speed control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine such as a diesel engine, and more particularly, to controlling the rotation speed of an internal combustion engine when an auxiliary device such as an air conditioner is turned on during idle operation of the internal combustion engine. The present invention relates to a rotational speed control device for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, for example, the following control is generally performed as this kind of technology. That is, in an engine that performs idle speed control (ISC), when the air conditioner is turned on when the engine is idling, the engine rotation speed is increased (so-called idle up) by adjusting the opening degree of a valve that adjusts the intake air amount. ) Control is performed. Due to this idle-up, even if a load is applied to the engine by the operation of the air conditioner, a decrease in the engine rotation speed is reduced.

In the processing routine of the idle-up control as described above, as shown in FIG.
1 to perform idle-up control. The switch flag YAC1 is switched by reading the on / off state of the air conditioner. More specifically, the on / off state of the air conditioner is read twice. That is, when the switch flag YAC1 is "1" at the time of the first and second readings, that is, when the switch flag YAC1 is "ON", the double reading switch flag WAC1 changes from "0" to "1".
Is set to Then, the twice read switch flag WAC
When 1 becomes "1", the idle-up control determination flag XAC1 is set from "0" to "1", and idle-up is performed (two-dot chain line in the figure).

[0004] When the air conditioner is switched on and off, a pressure switch provided inside the engine actively turns on and off the operation of the air conditioner based on internal pressure and the like. Here, when a contact such as a relay is turned “ON” or “OFF”, it is immediately turned “ON”.
Alternatively, a phenomenon called so-called chattering in which opening and closing (on / off) are repeated without being turned off may occur. Then, with the chattering, the twice-read switch flag WAC1 repeats "1" and "0", and as a result, the operation / cancellation of the idle-up is repeated, which may cause hunting.

Therefore, conventionally, in order to prevent the occurrence of the hunting, delay control of idle-up has been performed. That is, as shown by the solid line in the figure, after the twice-read switch flag WAC1 becomes "1",
AC1 = “1” indicates a predetermined delay time (“20” in the figure).
0 ms "), the idle-up control determination flag XAC1 is set to" 1 "for the first time, and the idle-up control is performed.

[0006]

However, in the above-mentioned prior art, when chattering occurs (the lower side of the figure), the effect is somewhat recognized, and although hunting is suppressed, chattering does not occur. In such a case, the above delay control has no meaning. That is, during the above-described delay time, idle-up is not performed even though the air conditioner is operating. Therefore, during the predetermined time, a load is applied to the engine, and the rotation speed of the engine decreases. Then, in a case where an additional load is applied to the engine such as stationary power steering or lighting of a headlight in the lowered state, there is a possibility that the engine may stall.

The present invention has been made in view of the above circumstances, and has as its object to suppress a decrease in the rotational speed of an internal combustion engine when an auxiliary machine is operated while the internal combustion engine is idling. Accordingly, it is an object of the present invention to provide a rotational speed control device for an internal combustion engine that can prevent stalls from occurring.

[0008]

In order to achieve the above object, according to the present invention, as shown in FIG.
In the idle operation of No. 1, the idle speed of the internal combustion engine M1 is increased and released in response to the ON / OFF operation of the accessory switch M3 of the auxiliary machine M2 operated based on the rotation of the internal combustion engine M1. A rotational speed control device for the internal combustion engine that suppresses control hunting accompanying chattering of the auxiliary device switch contact when the auxiliary device switch M3 is turned on , including chattering of the auxiliary device switch contact. Monitor behavior and this is on
The first switching information is set each time
Every time the set time of the switching information of 1 is continued for more than a predetermined time
Auxiliary machine operation detecting means M4 for setting second switching information;
When the second switch information is first set by the accessory operation detection means M4 in accordance with the ON operation of the accessory switch M3 , the idle rotation speed is increased for a predetermined time during which the chattering is converged. And an idle-up forced continuation means M7 forcibly continuing. Soshi
More specifically, the idle-up forced continuation means
M7 is the auxiliary with the ON operation of the auxiliary switch M3.
In parallel with the operation of the machine M2,
The state was to be forcibly continued.

[0009]

According to the above arrangement, as shown in FIG. 1, when the internal combustion engine M1 is idling, the auxiliary switch M3 of the auxiliary machine M2, which is operated based on the rotation of the internal combustion engine M1, is turned on and off. Accordingly, the idle rotation speed of the internal combustion engine M1 is increased and released. When the auxiliary switch M3 is turned on, the auxiliary switch contact is
The first switching information every time the chattering is turned on.
Is set and the first switching information is set.
The second switching information is set each time the time is continued for a predetermined time or more . The chattering converges from the point in time when the second switching information is set by the accessory operation detection means M4 by the idle-up forced continuation means M7 of the present invention.
The idle rotation speed is continuously increased for a predetermined period of time.

Therefore, when the auxiliary switch M3 is turned on,
Since the increase of the idle rotation speed is started immediately after the operation of the auxiliary machine M2, the reduction of the idle rotation speed of the internal combustion engine due to the load being applied by the start of the operation of the auxiliary machine M2 is avoided. . In addition, the increase in the idling speed causes the chattering of the auxiliary switch contacts to converge.
Since the is forcibly continues for a predetermined time, the accessory even chattering occurs in the switching contact, the rotational speed along with their generation from increasing state of the idle rotational speed when the accessory switch M3 is turned on It does not drop. Therefore, control hunting does not occur due to chattering.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an internal combustion engine according to the present invention;

FIG. 2 shows a schematic configuration of a diesel engine system with a supercharger in this embodiment, and FIG. 3 shows the distribution type fuel injection pump 1 in an enlarged manner. The fuel injection pump 1 includes a drive pulley 2, and the drive pulley 2 is drivingly connected to a crankshaft 40 of a diesel engine 3 as an internal combustion engine via a belt or the like. When the drive pulley 2 is rotated by the crankshaft 40 and the fuel injection pump 1 is driven, a fuel pipe is provided to the fuel injection nozzle 4 provided for each cylinder (four cylinders in this embodiment) of the diesel engine 3. Fuel is pumped through the passage 4a.

In this embodiment, the fuel injection nozzle 4
Is an automatic valve having a built-in needle valve and a spring for adjusting the valve opening pressure of the needle valve, and is opened by obtaining a fuel pressure of a predetermined level or more. Therefore, the fuel injection pump 1
Is supplied to the fuel injection nozzle 4 through the fuel line 4a by a fuel pressure higher than a predetermined level, whereby fuel is injected from the nozzle 4 to the diesel engine 3.

The fuel injection pump 1 has a drive shaft 5
The drive pulley 2 is attached to the tip of the drive shaft 5. In the middle of the drive shaft 5 is provided a fuel feed pump 6 (developed by 90 degrees in this figure) composed of a vane type pump. A disk-shaped pulsar 7 is attached to the base end side of the drive shaft 5. On the outer peripheral surface of the pulsar 7, missing teeth of the same number as the number of cylinders of the diesel engine 3, that is, four (in total, “eight”) missing teeth are formed at equal angular intervals in this embodiment. Also, between each missing tooth,
Fourteen projections (a total of "56") are formed at equal angular intervals. The base end of the drive shaft 5 is connected to the cam plate 8 via a coupling (not shown).

A roller ring 9 is provided between the pulsar 7 and the cam plate 8. A plurality of cam rollers 10 facing the cam face 8a of the cam plate 8 are mounted in the circumferential direction of the roller ring 9. The cam faces 8 a are provided in the same number as the number of cylinders of the diesel engine 3. The cam plate 8 is a spring 1
1 is urged to engage with the cam roller 10.

A base end of a plunger 12 for pressurizing fuel is attached to the cam plate 8 so as to be integrally rotatable. Then, the cam plate 8 and the plunger 12 are integrally driven to rotate as the drive shaft 5 rotates.
That is, the rotational force of the drive shaft 5 is transmitted to the cam plate 8 via the coupling, so that the cam plate 8 rotates while engaging with the cam roller 10. As a result, the cam plate 8 is reciprocated in the horizontal direction in the figure by the same number as the number of cylinders while being rotated, and the plunger 12 is reciprocated in the same direction while being rotated. That is, the cam face 8a is the cam roller 1 of the roller ring 9.
Plunger 12 moves forward (lift) in the process of climbing to zero
Is done. On the contrary, the cam face 8a is
Plunger 12 moves back in the process of getting over 0 (down)
Is done.

A cylinder 14 is formed in the pump housing 13, and the plunger 12 is fitted into the cylinder 14. A high-pressure chamber 15 is provided between the tip surface of the plunger 12 and the bottom surface of the cylinder 14. In addition, suction grooves 16 and distribution ports 17 are formed on the outer periphery of the distal end side of the plunger 12 by the same number as the number of cylinders. Further, corresponding to the suction groove 16 and the distribution port 17,
A distribution passage 18 and a suction port 19 are formed in the pump housing 13.

In the pump housing 13 of this embodiment, a delivery valve 3 comprising a constant pressure valve (CPV) is provided at the outlet side of each distribution passage 18.
6 are provided. The delivery valve 36 is for preventing a backflow of the fuel pressure-fed from the distribution passage 18 to the fuel pipe 4a, and is opened by obtaining a fuel pressure of a certain level or more.

When the drive shaft 5 is rotated and the fuel feed pump 6 is driven, fuel is introduced from a fuel tank (not shown) into the fuel chamber 21 through the fuel supply port 20. In the suction stroke in which the plunger 12 is moved back and the high-pressure chamber 15 is depressurized, the suction groove 1
The fuel is introduced from the fuel chamber 21 to the high-pressure chamber 15 when one of the ports 6 communicates with the suction port 19. On the other hand, in the compression stroke in which the plunger 12 is moved forward and the high-pressure chamber 15 is pressurized, fuel is pressure-fed from the distribution passage 18 to the fuel injection nozzle 4 of each cylinder through the fuel pipe 4a and injected.

In the pump housing 13, the high pressure chamber 1
A spill passage 22 for causing fuel to overflow (spill) is formed between the fuel chamber 5 and the fuel chamber 21. An electromagnetic spill valve 23 is provided in the middle of the spill passage 22. Then, the electromagnetic spill valve 23 is opened and closed to adjust the spill of the fuel from the high-pressure chamber 15. The electromagnetic spill valve 23 is a normally open type valve. When the coil 24 is not energized (off), the spill passage 22 is opened by the valve body 25, that is, the valve is opened, and the fuel in the high-pressure chamber 15 is released from the fuel chamber 21. Spilled into On the other hand, when the coil 24 is energized (turned on), the spill passage 22 is closed by the valve body 25, that is, the valve is closed, and the spill of fuel from the high-pressure chamber 15 to the fuel chamber 21 is shut off.

Therefore, when the electromagnetic spill valve 23 is turned on and off by energization, the valve 23 is controlled to close and open, and the spill of fuel from the high-pressure chamber 15 to the fuel chamber 21 is adjusted. When the electromagnetic spill valve 23 is opened during the compression stroke of the plunger 12, the high-pressure chamber 1 is opened.
The fuel in the fuel injection nozzle 4 is depressurized and the fuel injection from the fuel injection nozzle 4 is stopped. That is, even when the plunger 12 moves forward, while the electromagnetic spill valve 23 is opened,
The fuel pressure in the high-pressure chamber 15 does not increase and the fuel injection nozzle 4
Is not injected. Also, during the forward movement of the plunger 12, by controlling the valve opening timing of the electromagnetic spill valve 23, the end timing of the fuel injection from the fuel injection nozzle 4 is adjusted, and the fuel injection amount to the cylinder is controlled. .

Below the pump housing 13, there is provided a timer device (expanded by "90 degrees" in this figure) 26 for controlling the fuel injection timing to the advance side or the retard side. . This timer device 26 changes the rotation position of the roller ring 9 with respect to the rotation direction of the drive shaft 5 to change the timing at which the cam face 8a engages with the cam roller 10, that is, the timing at which the plunger 12 reciprocates. belongs to.

The timer device 26 is driven by control hydraulic pressure, and includes a timer housing 27 and a timer piston 28 fitted in the housing 27. Further, both sides of the timer piston 28 in the timer housing 27 are a low-pressure chamber 29 and a pressurizing chamber 30, respectively. The low-pressure chamber 29 has a timer piston 28
A timer spring 31 is provided to urge the pressure chamber 30 into the pressure chamber 30. Further, the timer piston 28 is connected to the roller ring 9 via a slide pin 32.

The fuel pressurized by the fuel feed pump 6 is introduced into the pressurizing chamber 30. The position of the timer piston 28 is determined by the balance between the fuel pressure and the urging force of the timer spring 31. Further, by determining the position of the timer piston 28, the position of the roller ring 9 is determined, and the reciprocating timing of the plunger 12 via the cam plate 8 is determined.

As the control oil pressure of the timer device 26, the fuel pressure inside the fuel injection pump 1 is used. To adjust the fuel pressure, the timer device 26 is provided with a timer control valve (TCV) 33. That is, a communication path 34 is provided between the pressurizing chamber 30 and the low-pressure chamber 29 of the timer housing 27, and the communication path 34
The TCV 33 is provided in the middle of. The TCV 33 is an electromagnetic valve whose opening is controlled by a duty-controlled energization signal. The opening of the TCV 33 is controlled, so that the fuel pressure in the pressurizing chamber 30 is adjusted. Then, by adjusting the fuel pressure, the reciprocating timing of the plunger 12 is controlled.
Is controlled to be advanced or retarded.

On the upper part of the roller ring 9, a rotation speed sensor 35 composed of an electromagnetic pickup coil is mounted so as to face the outer peripheral surface of the pulser 7. This rotation speed sensor 35
Detects the passage of the pulsar when it is crossed by a projection or the like of the pulsar 7 and outputs the signal as a pulse signal. That is, the rotation speed sensor 35 outputs an engine rotation pulse signal for each constant crank angle. At the same time, the rotation speed sensor 35 outputs an engine rotation pulse signal corresponding to a fixed crank angle due to a missing tooth of the pulser 7 as a reference position signal. Further, the rotation speed sensor 35 outputs a series of engine rotation pulse signals as signals for obtaining a rotation speed (engine rotation speed NE). Since the rotation speed sensor 35 is integrated with the roller ring 9, it can output a reference engine rotation pulse signal at a fixed timing with respect to the reciprocation of the plunger 12 regardless of the control operation of the timer device 26. .

Next, the diesel engine 3 will be described. 2, in the diesel engine 3, a main combustion chamber 44 corresponding to each cylinder is formed by a cylinder bore 41, a piston 42, and a cylinder head 43. In the cylinder head 43, sub combustion chambers 45 communicating with the main combustion chambers 44 are formed. Then, fuel is injected into each sub-combustion chamber 45 from each fuel injection nozzle 4. Each sub-combustion chamber 45 is provided with a well-known glow plug 46 as a start-up assist device.

On the other hand, the diesel engine 3 is provided with an intake passage 49 and an exhaust passage 50 communicating with each cylinder. Further, a compressor 52 of a turbocharger 51 constituting a supercharger is provided in the intake passage 49,
A turbine 53 of a turbocharger 51 is provided in the exhaust passage 50.
Is provided. Further, a waste gate valve 54 is provided in the exhaust passage 50. As is well known, the turbocharger 51 uses the energy of the exhaust gas to rotate the turbine 53, and rotates the compressor 52 coaxially therewith to increase the pressure of the intake air. Then, by increasing the pressure of the intake air, high-density air is sent into the main combustion chamber 44 and a large amount of fuel injected through the sub-combustion chamber 45 is burned, so that the output of the diesel engine 3 is increased. The opening and closing of the waste gate valve 54 causes the turbocharger 5 to open and close.
The boost pressure level of the intake air by 1 is adjusted.

Between the intake passage 49 and the exhaust passage 50,
Exhaust gas recirculation valve passage (EG
An R path 56 is provided. Then, a part of the exhaust gas in the exhaust passage 50 is recirculated by the EGR passage 56 near the intake port 55 in the intake passage 49.
An EGR valve 57 is provided in the middle of the EGR passage 56, and the EGR valve 57 controls the exhaust gas recirculation amount (E
GR amount) is adjusted. Further, in order to open and close the EGR valve 57, an electric vacuum regulating valve (EVRV) 58 whose opening is adjusted is controlled.
Is provided. Then, EGRV58 is used for EGR
When the valve 57 is driven to open and close, the EGR passage 5
E guided from the exhaust passage 50 to the intake passage 49 through
The GR amount is adjusted.

A throttle valve 59 is provided in the middle of the intake passage 49. The throttle valve 59 opens and closes in conjunction with the depression of an accelerator pedal 60. In addition, a bypass passage 61 is provided in the intake passage 49 alongside the throttle valve 59, and a bypass throttle valve 62 is provided in the passage 61. In order to open and close the bypass throttle valve 62, a two-stage diaphragm chamber type actuator 6 is used.
3 are provided. Further, two vacuum switching valves (VSV) 64 and 65 for driving the actuator 63 are provided. And each V
By turning on and off the SVs 64 and 65 to drive the actuator 63, the bypass throttle valve 62 is controlled to open and close. For example, the bypass throttle valve 62 is controlled to be in a half-open state in order to reduce noise and vibration during idling operation, is controlled to be in a fully open state in normal operation, and is controlled to be in a fully closed state in order to smoothly stop the operation. Is done.

In addition, near a transmission (not shown), a neutral switch 6 for detecting whether or not the shift position is in an N range (neutral range).
7 are provided.

Further, the vehicle of this embodiment is provided with an air conditioner (A / C) as an auxiliary device (not shown) driven in conjunction with the diesel engine 3. The air conditioner is provided with an air conditioner switch 68 as an auxiliary switch that works in conjunction with a magnet clutch of a compressor of the air conditioner. The air conditioner is of a type that is automatically operated / stopped according to the indoor temperature or the like when the push button switch on the front of the instrument panel is turned on. You. When the air conditioner is operating, an air conditioner signal indicating the operation is output, and the switch flag YAC is set to “1”.
On the other hand, when the air conditioner is not operated, the switch flag YAC is set to “0”.

The above-described electromagnetic spill valve 23, TCV3
3, glow plug 46, EVRV58 and each VSV6
4 and 65 are electronic control units (hereinafter simply referred to as “ECU”).
71 are electrically connected to each other. The drive timing of each of the members 23, 33, 46, 58, 64, 65 is controlled by the ECU 71.

As sensors for detecting the operating state of the diesel engine 3, the following various sensors are provided in addition to the rotation speed sensor 35 described above. That is, near the air cleaner 69 provided at the inlet of the intake passage 49, the temperature of the air taken into the intake passage 49, that is, the intake air temperature THA is detected and a signal corresponding to the detected value is output. An intake air temperature sensor 72 is provided. The accelerator sensor 73 includes a fully-closed switch (not shown) for detecting the fully-closed position of the throttle valve 59. Accordingly, when the diesel engine 3 is idling, the throttle valve 59 is placed in the fully closed position, whereby the fully closed switch is turned on, and the accelerator sensor 73 outputs a fully closed signal LL indicating this. or,
When the throttle valve 59 is opened during non-idling, the fully closed switch is turned off, and the accelerator sensor 73 outputs the accelerator opening ACCP at that time.
In the vicinity of the throttle valve 59, an accelerator sensor 73 which detects the accelerator opening ACCP from the open / close position of the valve 59 and outputs a signal corresponding to the magnitude of the detected value.
Is provided. In the vicinity of the intake port 55, an intake pressure sensor 74 that detects the pressure of the intake air after being supercharged by the turbocharger 51, that is, the supercharging pressure PiM, and outputs a signal corresponding to the magnitude of the detected value. Is provided. Further, the diesel engine 3 is provided with a water temperature sensor 75 which detects the temperature of the cooling water, that is, the cooling water temperature THW, and outputs a signal corresponding to the magnitude of the detected value. Further, the diesel engine 3 is provided with a crank angle sensor 76 that detects a rotation reference position of the crankshaft 40, for example, a rotation position of the crankshaft 40 with respect to a top dead center of a specific cylinder, and outputs a signal corresponding to the rotation position. Have been. Further, the transmission is provided with a vehicle speed sensor 77 that detects a vehicle speed (vehicle speed) SPD and outputs a signal corresponding to the magnitude of the detected value.

The ECU 71 is connected to the sensors 35, 72 to 77 and the switches 67, 68, respectively. In addition, the ECU 71 controls the sensors 35, 72
Based on the signals outputted from the switches 77 and 68 and the switches 67 and 68, the electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 58, and the VSVs 64 and 65 are suitably controlled. In the present embodiment, the ECU 71 constitutes accessory operation detecting means, idle-up means, idle-up releasing means, and idle-up delay releasing means.

Next, the configuration of the ECU 71 will be described with reference to the block diagram shown in FIG. The ECU 71 includes a central processing unit (CPU) 81, a read-only memory (ROM) 8 in which a predetermined control program, a map, and the like are stored in advance.
2, a random access memory (RAM) 83 for temporarily storing the calculation results of the CPU 81, a backup RAM 84 for storing the stored data, and the like. And
The ECU 71 is configured as a logical operation circuit in which these units 81 to 84 are connected to an input port 85, an output port 86, and the like via a bus 87.

At the input port 85, the above-described intake air temperature sensor 72, accelerator sensor 73, intake pressure sensor 74, and water temperature sensor 75 are connected to buffers 88, 89, 90, 91, respectively.
They are connected via a multiplexer 94 and an A / D converter 95. Similarly, the input port 85 is connected to the above-described rotation speed sensor 35, crank angle sensor 76, and vehicle speed sensor 77 via a waveform shaping circuit 96. Further, the neutral switch 67 and the air conditioner switch 68 described above are connected to the input port 85 with the respective buffers 97 and 97.
98. Then, the CPU 81 receives the signals from the sensors 35 and 72 through the input port 85.
The signals from the switch 77 and the switches 67 and 68 are read as input values. The output ports 86 are connected to the respective driving circuits 100, 101, 102, 103, 104, 105.
The electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 58, and the VSVs 64, 65, etc., are connected to each other via the. Then, the CPU 81 controls each sensor 3
5, 72 to 77 and the input values read from the switches 67 and 68, the electromagnetic spill valve 23, the TCV 33,
Glow plug 46, EVRV58 and VSV64,6
5 and the like are suitably controlled.

The CPU 81 of this embodiment also has a timekeeping function. Further, in this embodiment, the glow plug 46 is provided for each cylinder of the diesel engine 3, but only one of them is shown in the block diagram of FIG. 4 for convenience.

Next, the processing operation of the rotational speed control during idling of the diesel engine 3 executed by the ECU 71 will be described with reference to FIGS. FIG. 5 is a flowchart showing an “idle-up determination routine” in idle-up control when the air conditioner is operated during idling, among the processes executed by the ECU 71. This routine is executed only when it is determined that the current time is the idle time based on the detection signals from the fully-closed switch LL, the neutral switch 67, and the like, and is executed for a predetermined time (in this embodiment, " 8 ms ") as a periodic interrupt process.

When the processing shifts to this routine, first,
In step 101, it is determined whether or not the switch flag YAC is "1". When the switch flag YAC is "1", the process proceeds to step 102 on the assumption that the probability that the air conditioner is operating is high.

In step 102, it is determined whether or not the switch flag YAC in the previous routine is "1". If the previous switch flag YAC is not "1", the switch flag Y
Assuming that AC has become "1", the routine jumps to step 107. In step 107, the value of the off-delay counter CACDLY is incremented by "1", and the subsequent processing ends once. The increment of the off-delay counter CACDLY here has no meaning.

In step 102, when the previous switch flag YAC is "1", the switch flag YAC is "1" twice in succession, and it is determined that the air conditioner has been reliably operated. At 103, the twice-read switch flag WAC is set to "1".

In step 104, an idle-up determination flag XAC for performing idle-up control described later is set to "1". Next, step 1
At 05, it is determined whether or not the twice read switch flag WAC in the previous routine is “1”. If the previous double reading switch flag WAC is not “1”, the current double reading switch flag W
Assuming that AC has been set to "1", the value of the off-delay counter CACDLY is set to "0". And
In step 107, the off-delay counter CAC
The value of DLY is incremented by "1", and the subsequent processing is temporarily terminated.

On the other hand, if the previous double reading switch flag WAC is "1" in step 105,
Jump to step 107 and set the off-delay counter C
The value of ADDLY is further incremented by “1”,
Thereafter, the processing is temporarily terminated.

If the switch flag YAC is not "1" in step 101, it is determined that there is a high probability that the air conditioner has not been operated, and step 1 is executed.
08. In step 108, the twice-read switch flag WAC is set to "0".

Next, at step 109, it is determined whether or not the value of the off-delay counter CACDLY is "13" or more. That is, the idle-up determination flag XAC is set to “1”, and it is determined whether or not a predetermined time (“8 ms” × 13 ≒ “about 100 ms”) has elapsed since the counting was started. If the value of the off-delay counter CACDLY is not equal to or more than "13", it is determined that the predetermined time has not yet elapsed, and the step 107
Then, the value of the off-delay counter CACDLY is incremented by "1".

Also, an off-delay counter CACDLY
Is equal to or greater than "13", it is determined that the predetermined time has elapsed and the air conditioner has not been operated, and that step 110
Move to In step 110, the idle-up determination flag XAC is set to “0”. Then, the process proceeds to a step 107, wherein the off-delay counter CADL is performed.
The value of Y is incremented by “1”, and the subsequent processing is temporarily terminated. In this case, the increment of the off-delay counter CACDLY has no meaning.

As described above, the twice-read switch flag WA
When C is set to “1”, the idle up determination flag XAC is set to “1”. On the other hand, when the switch flag YAC is “0”, the twice-read switch flag WAC is set to “0”, and the idle-up determination flag XAC is also set to “0”.

Then, idle-up control is executed based on the idle-up determination flag XAC set as described above. FIG. 6 is a flowchart showing an “idle-up control routine” in idle-up control during idling among the processes executed by the ECU 71. As described above, this routine is executed only when it is determined that the current time is the idle time based on the detection signals from the fully-closed switch LL, the neutral switch 67, and the like. In this case, it is executed as a regular interrupt process every "8 ms").

When the processing shifts to this routine, first,
In step 201, it is determined whether or not the idle-up determination flag XAC set in the above-described routine is "1". If the idle-up determination flag XAC is not "1", it is determined that there is no need for idle-up, and the subsequent processing is temporarily terminated. On the other hand, when the idle-up determination flag XAC is “1”, it is determined that the air conditioner is operating and the idle-up is required, and the fuel injection amount control for the idle-up is executed in step 202. That is, control is performed to increase the fuel injection amount so that the engine speed NE becomes a predetermined target value. Then, the subsequent processing ends once.

As described above, in the idle-up control routine, the idle-up control is performed based on the idle-up determination flag XAC. Next, the operation related to the idle-up control in switching and "idle-up control routine" of the flags to be set in the "idle-up determination control routine" above will be described with reference to the timing chart of FIG.

First, it is assumed that the switch flag YAC is changed from "0" to "1" at the timing t1.
Then, at the timing t2, that is, after "8 ms" has elapsed from the timing t1, the twice-read switch flag WAC is set to "1" (step 103). Accordingly, the idle-up determination flag XAC is set to "1" (step 104). At this time, the count of the off-delay counter CACDLY is started (steps 106 and 107). On the other hand, since the idle-up determination flag XAC is set to “1”, the fuel injection amount control for idling-up is performed.

Thereafter, if chattering occurs,
At the timing t3, the switch flag YAC becomes “1”.
Is changed to "0". As a result, although the twice-read switch flag WAC is set to "0" (step 108), the off-delay counter CACDLY has not become "13" or more at this time. That is, a predetermined time “100 ms” from the start of counting.
Has not yet passed. Therefore, the idle-up determination flag XAC is not switched to “0”, and the state of “1” is maintained. That is, even if chattering occurs and the switch flag YAC is switched from "1" to "0", it is determined that this is temporary and the idle-up determination flag XAC is set to "1".
Is held. Therefore, the idle-up control is not released, and the engine speed NE is still increased.

Even if chattering occurs at timings t4, t5, and t6 and the switch flag YAC is switched between "1" and "0", the off-delay counter CACDLY becomes "13" or more as described above. The idle-up determination flag XA
C is held at "1". Therefore, even when chattering occurs and the switch flag YAC is switched, the idle-up control is not executed or canceled due to the switching. As a result, it is possible to prevent the occurrence of hunting due to the repeated execution and release of the idle-up control.

Further, the twice read switch flag WA
After C is set to “1”, the idle-up control is not executed with a delay. That is, when the twice-read switch flag WAC is set to “1”, the idle-up determination flag XAC is also set to “1”, so that the idle-up control is performed immediately. Therefore, a situation in which idle-up is not performed even though the air conditioner is operating does not occur.
As a result, it is possible to prevent the engine speed NE from lowering due to the generation of a load due to the operation of the air conditioner, and it is possible to reliably prevent engine stall.

The above-mentioned effect is particularly remarkable when chattering does not occur. That is, when chattering does not occur, the twice-read switch flag WA
If C is set to "1", it is necessary to execute idle-up control. In this embodiment, as described above, if the twice-read switch flag WAC is set to “1”, the idle-up determination flag XAC is immediately set to “1” without performing the delay control as in the related art. You. As a result, the engine speed NE increases quickly,
The occurrence of engine stall can be reliably prevented.

On the other hand, the off-delay counter CACDLY
When the switch flag YAC is switched to "0" after the predetermined time has elapsed after the predetermined time (after timing t7), the air conditioner switch 68 is turned off instead of chattering, and the operation of the air conditioner is started. Is definitely stopped. In this case,
The idle-up determination flag XAC is reliably set to "0". Then, the idle-up control that has been performed up to that point is released, and the engine speed NE is controlled at the time of normal idling. Therefore, when the operation of the air conditioner is stopped after the elapse of the predetermined time, the idle-up control can be reliably released. as a result,
Even when no load is applied to the diesel engine 3, it is possible to reliably prevent the occurrence of a problem that the engine speed NE increases.

It should be noted that the present invention is not limited to the above-described embodiment, and may be implemented as follows by appropriately changing a part of the configuration without departing from the spirit of the invention. (1) In the above embodiment, the present invention is embodied in the diesel engine 3 including the turbocharger 51 as a supercharger.
It can be embodied as a diesel engine with a supercharger as a supercharger or a diesel engine without a supercharger.

(2) In the above embodiment, the idle-up control is embodied in the diesel engine 3, but may be embodied in another internal combustion engine such as a gasoline engine. (3) In the above-described embodiment, in the "idle-up determination routine", even when the count of the off-delay counter CACDLY is unnecessary, the counting operation is performed for convenience of description in the flowchart. The counting operation may be omitted.

[0060]

As described above in detail, according to the rotational speed control apparatus for an internal combustion engine of the present invention , chattering occurs at the auxiliary equipment switch contact with the ON operation of the auxiliary equipment switch.
Even if this happens, each time the auxiliary switch contact is turned on,
The first switching information is set in the
Every time the switching information set time exceeds a predetermined time,
The information is set. Then, when the auxiliary switch is turned on
Accordingly, since the idle-up control is started promptly from the time when the second switching information is set first ,
When the auxiliary machine is operated when the internal combustion engine is idling, it is possible to suppress a decrease in the rotation speed of the internal combustion engine, thereby providing an excellent effect that stalls can be prevented from occurring. In addition, auxiliary the idle-up state
Since the chattering of the switch contacts is forcibly continued for a predetermined period of time to converge , even if chattering occurs at the auxiliary switch contact when the auxiliary switch is turned on, occurrence of control hunting can be suppressed. It has an excellent effect.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic diagram showing a supercharged diesel engine system according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a distribution type fuel injection pump in one embodiment.

FIG. 4 is a block diagram showing a configuration of an ECU and the like in one embodiment.

FIG. 5 is a flowchart illustrating an “idle-up determination routine” among processes executed by the ECU in one embodiment.

FIG. 6 is a flowchart illustrating an “idle-up control routine” among processes executed by the ECU in one embodiment.

FIG. 7 is a timing chart illustrating an operation related to switching of a switch flag, a twice-read switch flag, and an idle-up determination flag in one embodiment.

FIG. 8 is a timing chart illustrating an operation related to switching of a switch flag, a twice-read switch flag, and an idle-up determination flag in the related art.

[Explanation of symbols]

Reference numeral 3 denotes a diesel engine as an internal combustion engine; 68 an air conditioner switch as an auxiliary switch; 71 an ECU which constitutes auxiliary equipment operation detecting means, idle-up means, idle-up releasing means, and idle-up delay releasing means.

Claims (2)

(57) [Claims] An idle speed of the internal combustion engine is increased in response to an on / off operation of an accessory switch of an accessory operated based on the rotation of the internal combustion engine during an idle operation of the internal combustion engine. And release the increase,
A rotation speed control device for an internal combustion engine that suppresses control hunting accompanying chattering of the auxiliary device switch contact when the auxiliary device switch is turned on, wherein a behavior including chattering of the auxiliary device switch contact is monitored.
And sets the first switching information each time this is turned on.
And the set time of the first switching information is longer than a predetermined time.
And auxiliary operation detecting means for setting the second switching information each time it is continuously above, the second switching information is set initially by the auxiliary operation detecting means with the on-operation of the auxiliary switch An idle-up forcible continuation unit for forcibly continuing the increase state of the idle speed for a predetermined time during which the chattering is converged from a point in time. 2. The system according to claim 1, wherein
At the same time as the operation of the auxiliary equipment accompanying the ON operation of the auxiliary equipment switch
To forcibly continue the increased state of the idle speed.
2. The rotation speed control device for an internal combustion engine according to claim 1, wherein
Place.