JPH0413541B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an engine speed adjustment device during idling operation of an internal combustion engine. A control valve provided in a bypass passage communicating with the engine is set to a predetermined opening degree, and an idle adjust screw provided in parallel with the throttle valve is adjusted to control the intake air amount of the internal combustion engine, The present invention relates to an engine speed adjustment device during idling operation of an internal combustion engine that obtains a control amount during feedback control of a scheduled idle speed.

(Prior art) Conventionally, during so-called idling operation, in which the throttle valve provided in the intake passage of an internal combustion engine is maintained in an almost fully closed state, a throttle valve provided in the intake passage of the internal combustion engine is provided in a bypass passage communicating the upstream and downstream sides of the throttle valve. The intake air amount of the internal combustion engine is controlled by the control valve, and the idle speed of the internal combustion engine is controlled.

However, due to initial variations in control valve characteristics or changes in mechanical characteristics, the
The control amount during engine speed control during idling operation in a no-load state becomes a different value in feedback control to obtain a constant engine speed (idle speed). Therefore, in order to keep this value within an appropriate value, the idle adjust screw is manually adjusted.

Note that the idle adjust screw is provided in a bypass passage that is provided separately from the bypass passage in which the control valve is provided and communicates between the upstream and downstream sides of the throttle valve.

Also, when using an internal combustion engine, and therefore a vehicle equipped with one, when operating at high altitude, the control valve must be opened further to obtain the same engine speed than when operating on flat ground. need to be controlled. This is because the mass flow rate of the intake air amount decreases at high altitudes where atmospheric pressure is low.

In this way, even if the control valve responds to changes in atmospheric pressure,
Since the controlled variable becomes a different value, by adjusting the idle adjust screw, the controlled variable of the control valve becomes the appropriate value at standard atmospheric pressure (atmospheric pressure on flat ground), regardless of the atmospheric pressure at the adjustment location. It is desirable to adjust so that

By the way, there are approximately two methods for manually adjusting the idle speed control device in a no-load state after warm-up is completed: (a) and (b) below.

(b) By cutting off the control signal of the control valve whose opening changes proportionally, the opening is set to the fully closed state, and then by manually adjusting the idle adjust screw. How to set the engine speed to

(b) The control signal for the control valve whose opening changes proportionally is controlled by a known appropriate method to fix the opening of the control valve to, for example, 20% of the fully open state, and then the idle adjustment is performed. - A method of setting the desired engine speed by manually adjusting the screw.

Note that in the case of the latter method, the scheduled engine speed is set higher by the amount that the control valve is opened than in the method (a).

However, in both methods, the feedback control of the control valve is stopped to adjust the engine speed.

(Problems to be Solved by the Invention) The above-described conventional techniques had the following problems.

(1) Conventionally, when adjusting the engine speed during idling operation in a no-load state after completion of warm-up, atmospheric pressure conditions were not particularly taken into account.

For this reason, the above (a) and
When the idle adjust screw is adjusted and set to the scheduled engine speed using the method (b), the opening degree of the screw becomes larger than when the adjustment is made on level ground.

Therefore, when the vehicle is used on level ground, the idle speed in a no-load state after warm-up does not fall to the expected idle speed even if the control valve is fully closed.

(2) Furthermore, in the method (a), the engine combustion state becomes unstable because the engine speed is adjusted to a set rotation speed lower than the idling speed, and accurate adjustment cannot be performed.

The present invention has been made to solve the above-mentioned problems.

(Means and effects for solving the problem) In order to solve the above problem, the present invention provides a solenoid current command value that determines the excitation current of the solenoid that controls the opening degree of the control valve during idling operation. Detects the feedback control term of the feedback control term, and detects when the current command value of the feedback control term falls within the expected current command value range by adjusting the idle adjust screw. The unique feature is that the screw can be adjusted to the optimal position regardless of changes in atmospheric pressure.

As will be described later, the feedback control term for the solenoid current command value is determined based on the deviation between the target idle speed, which is a function of engine temperature, and the actual engine speed. (I term) and differential (D term) are PID feedback control terms that perform differential control. Further, the solenoid current command value is calculated from the feedback control term and an atmospheric pressure correction term separate from this, as will be described later.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic diagram of an embodiment of the present invention.

In the figure, when the throttle valve 32 reaches an opening close to fully closed, the intake air amount in the intake manifold 33 at this time is equal to
It is controlled by a control valve 30 provided at 1. The opening degree of the control valve 30 changes proportionally depending on the current flowing through the solenoid 16.

Further, the idle adjust screw 1 is arranged in a bypass passage 3 which is provided separately from the bypass passage 31 in which the control valve 30 is provided and communicates between the upstream and downstream sides of the throttle valve 32.

This idle adjust screw 1 is used to set the amount of intake air in the intake manifold 33 during idling operation to a predetermined value and obtain a predetermined idling speed by adjusting it manually. .

The amount of fuel injected from the injection nozzle 34 is determined according to the amount of intake air in the intake manifold 33 by known means. Note that the piston 38 within the cylinder 35 repeatedly reciprocates to apply rotational force to the crankshaft 36.

The engine rotation speed sensor 2 detects the engine rotation speed using any suitable method, and supplies a digital engine rotation speed signal corresponding to the detected engine rotation speed to the electronic control device 40 . The throttle opening sensor 4 supplies an opening signal of the throttle valve 32 as a digital signal to the electronic control unit 40 .

The engine temperature sensor 5 supplies, for example, an engine cooling water temperature signal to the electronic control device 40 as a digital signal. Further, the power steering sensor (PS sensor) 6 supplies a power steering inoperation signal to the electronic control device 40 when the power steering is not in operation.

The air conditioner sensor (AC sensor) 7 supplies an air conditioner inoperation signal to the electronic control device 40 when the air conditioner is not operating. AT position indicator 8
supplies a D range non-detection signal to the electronic control unit 40 when the selector position of the automatic transmission AT is not in the drive D range. Atmospheric pressure sensor (Pa sensor) 80 supplies an atmospheric pressure detection signal to electronic control device 40 .

As will be described later, the electronic control device 40 controls the current flowing through the solenoid 16 and determines whether the opening degree of the idle adjuster screw 1 is appropriate, and if it is not appropriate, causes the LED 9 to continuously light up or flash. A signal is output to the LED 9.

FIG. 3 is a circuit diagram showing a specific example of the internal configuration of the electronic control device 40 shown in FIG. In the figure,
The same reference numerals as in FIG. 2 represent the same or equivalent parts.

The electronic control unit 40 is a central processing unit (CPU)
50, a microcomputer 53 consisting of a storage device (memory) 51 and an input/output signal processing circuit (interface) 52, and according to the command (solenoid current command value) of the microcomputer 53,
A control valve drive circuit 54 that adjusts the current flowing through the solenoid 16 and a microcomputer 53
An LED blinking circuit 56 that drives the LED 9 to blink, an LED lighting circuit 55 that drives the LED 9 to turn on continuously, and an output of either the LED blinking circuit 56 or the LED lighting circuit 55 to the LED 9. and an OR circuit 57 for supplying the signal.

In FIG. 3, the throttle valve 32 (FIG. 2)
During idling operation in which the valve is almost fully closed, a solenoid current command value Icmd calculated by the CPU 50 is output from the interface 52 to the control valve drive circuit 54, for example, according to equation (1) described later.

Icmd=(Ifbn+Ie+Ips+Iat ＋Ihac）×Kpad……(1) The contents of each term in equation (1) are as follows.

Ifbn...Based on the deviation between the target idle speed, which is a function of engine temperature, and the actual engine speed detected by the engine speed sensor 2, proportional (P term), integral (I term), differential ( D) PID feedback control term (basic control term) for control.

Ie…alternator generator (ACG) load, i.e.
Addition correction term that adds the scheduled value according to the ACG field current.

Ips...Additional correction term that adds a scheduled value when power steering is activated.

Iat...An addition correction term that adds a scheduled value when the selector position of the automatic transmission AT is in the drive D range.

Ihac...Additional correction term that adds the scheduled value when the air conditioner is activated.

Kpad…A multiplication correction term by which the scheduled value is multiplied according to atmospheric pressure.

In addition, the method of determining the Ifbn term (basic control term),
In other words, the deviation between the target idle speed set for each scheduled engine temperature range and the actual engine speed detected by the engine speed sensor 2 is detected, and the basic control terms are determined according to this deviation. The method of
Since it is described in more detail in steps S14 to S19 and the explanatory portion thereof in the flowchart shown in the figure, detailed explanation will be omitted here.

In addition, the amount of air taken into the engine (mass flow rate) decreases as the atmospheric pressure decreases, so in order to compensate for this, the atmospheric pressure correction term, that is, the multiplication correction term Kpad, is adjusted to compensate for the decrease in atmospheric pressure. Set a value that increases accordingly.

Also, obtain each term in equation (1) above and set Icmd to CPU5
In order to calculate with 0, it is necessary to appropriately arrange various sensors in addition to the illustrated sensors 2 and 4 to 8, and supply the outputs of these sensors to the microcomputer 53. However, since this is natural and well known to those skilled in the art, these sensors have been omitted from illustration.

Icmd calculated by the above equation (1) is supplied to the control valve drive circuit 54 via the interface 52. The control valve drive circuit 54 outputs a control signal that adjusts the current flowing through the solenoid 16 according to the Icmd. That is, the control valve 30 (second
The opening degree in the figure) is controlled according to the Icmd.

In addition, in this example, as described later, the above-mentioned
If the current command value in the Ifbn term of Icmd is greater than or equal to the upper limit of the predetermined value range, a drive command signal is output to the LED lighting circuit 55. Therefore, in this case, the signal is sent to the LED 9 via the OR circuit 57.
Since the LED lighting signal is supplied, the LED 9 is in a continuous lighting state.

On the other hand, if the current command value in the Ifbn term is less than or equal to the lower limit of the predetermined value range, a drive command signal is output to the LED blinking circuit 56. Therefore, in this case, the signal is sent to the LED 9 via the OR circuit 57.
Since the LED blinking signal is supplied, the LED 9 is in a blinking state.

Hereinafter, with reference to the flowchart of FIG. 4, the adjustment operation of the engine speed during idling operation in a no-load state after completion of warm-up will be described.

FIG. 4 is a flowchart illustrating the operation of the microcomputer 53.

The operation of the flowchart starts with an interrupt signal synchronized with the engine speed.

Step S1: It is determined whether the excitation current control of the solenoid 16 is in the feedback mode.

Specifically, the opening signal supplied from the throttle opening sensor 4 indicates that the throttle valve 32 is almost fully closed, and the engine rotation speed signal supplied from the engine rotation speed sensor 2 is When the rotation speed is within a predetermined rotation speed range set with reference to the target idle rotation speed, it is determined that the feedback mode is in effect, and otherwise it is determined that the feedback mode is not in effect.

In the feedback mode, the opening degree of the solenoid 16 and therefore the control valve 30 (FIG. 2) is proportionally controlled in accordance with Icmd in equation (1).

If the judgment in step S1 is established, the process proceeds to step S2; if the judgment is not satisfied, the process proceeds to step S2.
Proceed to step 8.

Step S2...The engine temperature detected by the temperature signal supplied from the engine temperature sensor 5 is
It is determined whether the temperature has reached the scheduled warm-up completion temperature. When the determination is established, the process advances to step S3, and when it is not established, the process advances to step S8.

Step S3: Based on the presence or absence of a power steering inoperation signal supplied from the PS sensor 6, it is determined whether or not the power steering is in operation. If the determination is not satisfied, the process advances to step S4, and if it is true, the process advances to step S8.

Step S4: Based on the presence or absence of an air conditioner inoperation signal supplied from the AC sensor 7, it is determined whether or not the air conditioner is operating. When the judgment is not established, the process proceeds to step S5, and when it is satisfied, the process proceeds to step S8.
Proceed to.

Step S5...AT position indicator 8
Depending on the presence or absence of the D range detection signal supplied from
Determine whether the automatic transmission AT is in the D range.

If this determination is not established, it is determined that the engine is in an unloaded state and the process proceeds to step S6. Further, when the judgment is established, it is assumed that there is a load and the step S is executed.
Proceed to step 8.

Step S6...The current command value Ifbn of Icmd in equation (1) above, which is supplied to the control valve drive circuit 54, is set at a predetermined ratio (for example, 4% of full open current command value
6%) is greater than or equal to the upper limit value Iledh (6%). Note that the current command value corresponding to 4% to 6% of the full open current command value is stored in the memory 51.
is stored in advance.

When the upper limit value Iledh is exceeded, it is determined that the idle adjuster screw 1 (FIG. 2) is too tightened, and the process proceeds to step S9. Also,
When it is lower than the upper limit value Iledh, the process advances to step S7.

It should be noted that when step S6 is established, the idle adjust screw 1 is over-tightened.In order to obtain the expected engine speed, Ifbn is set above the upper limit value Iledh and the control valve 30 is tightened. This is because the opening degree of the idle adjust screw 1 is relatively too small since the opening degree is large.

Step S7: It is determined whether the Ifbn is less than or equal to the lower limit value Iledl (4%) of the scheduled ratio. If it is less than the lower limit value Iledl, it is determined that the idle adjust screw 1 is too open, and the process proceeds to step S10.

Further, when Ifbn is higher than the lower limit value Iledl, that is, when it is within the range of about 5% of the full open current command value, as an example, the opening degree of the idle adjust screw 1 is considered to be appropriate, and the process proceeds to step 1. S
Proceed to step 8.

Step S8...The drive command signal generated and output in step S9 and step S10, which will be described later, is canceled. Therefore, at this time, as is clear from the explanation regarding FIG.
is turned off. Processing then returns to the main program.

Step S9: Generate and output a drive command signal to be supplied to the LED lighting circuit 55. Therefore, at this time, as mentioned above, the LED 9 is turned on to indicate that the idle adjust screw 1 is too tightened.
is lit continuously. Then return to the main program.

Step S10: Generate and output a drive command signal to be supplied to the LED blinking circuit 56. Therefore,
At this time, as mentioned above, Idol Asia
LED to indicate that screw 1 is too open.
9 becomes blinking. Then return to the main program.

As can be easily understood from the above operation explanation,
In this embodiment, adjustment of the engine speed during idling operation in a no-load state after completion of warm-up, that is, adjustment of the idle adjust screw 1, is as follows:
It is done as follows.

First, it is confirmed that the operating state of the engine is in the engine speed feedback mode after a scheduled time has elapsed since the completion of starting, and that the engine is in a no-load state. When the engine operating state is in this state, the intake air amount of the internal combustion engine is adjusted by controlling the opening of the control valve 30 based on the Icmd.

Next, the idle adjuster screw 1 is manually rotated to increase or decrease its opening, and the LED 9 is brought into a blinking state or a continuous lighting state. After that, rotate the idle adjust screw 1 in the opposite direction to turn off the LED 9.

By doing this, the opening degree of the idle adjust screw 1 is adjusted so that the control valve 30 has an opening degree corresponding to about 5% of the full open current command value of Ifbn. Also, at this time, the engine speed is the scheduled idle speed.

In this embodiment, as is clear from the explanation regarding FIG. 4, the LED 9 is turned off when the feedback mode is not in effect, when warm-up is not completed, and even when the no-load condition is not present. However, as mentioned above, once the LED 9 is turned on continuously or blinks, and then turned off,
It can be confirmed that the opening degree of the idle adjust screw 1 has become the proper opening degree and the LED 9 has turned off.

Also, although such a situation is almost unthinkable, during the adjustment of the idle adjuster screw 1, the determinations in steps S1 and S2 in FIG.
~When the determination in step S5 is satisfied,
The LED 9 will turn off, and there is a risk of misjudging that the adjustment has been properly completed.

However, such a situation, if necessary,
The problem can be easily solved by displaying an indication of the improper adjustment of the idle adjust screw 1, as shown by the broken line in FIG.

Next, a functional block diagram of the present invention is shown in FIG. 1, and will be explained.

The feedback mode determining means 101 determines whether the operating state of the internal combustion engine during idling is
When the engine speed is under feedback control, a feedback mode determination signal (a signal with a logical value of "1") is output.

Warm-up completion determination means 102 outputs a warm-up completion signal (a signal with a logical value of "1") when the engine is in a warm-up completion state.

The power steering operation determination means 103 outputs a power steering inoperation signal (signal with logical value "1") when the power steering is not operating.
Output.

The air conditioner operation determining means 104 outputs an air conditioner inoperation signal (a signal with a logical value of "1") when the air conditioner is not operating.

The AT/D range determining means 105 is an automatic transmission
When AT is not in the D range, outputs a D range non-detection signal (signal with logical value "1").

The AND circuit 106 converts the engine operating state signal (signal with logical value "1") into a second signal when the "1" signal is supplied from each of the above-mentioned determination means.
is supplied to one terminal of the AND circuit 109. As a result, the second AND circuit 109 becomes open.

Ifbn detection means 107 is created, for example, when generating Icmd by performing the calculation of equation (1) above.
Ifbn is detected and supplied to the other terminal of the second AND circuit 109.

IfbnIledh determination means 110 determines whether Ifbn that has passed through the second AND circuit 109 is
(See Figure 2) When it is determined that the full-open current command value required to fully open the LED lighting circuit 5 is greater than the upper limit value Iledh of the planned ratio,
A drive command signal is output to 5.

Further, the IfbnIledl determination means 111
When it is determined that Ifbn passed through the AND circuit 109 is less than or equal to the lower limit value Iledl of the scheduled ratio, a drive command signal is output to the LED blinking circuit 56.

The LED lighting circuit 55 responds to the drive command signal from the IfbnIledh determination means 110 and supplies an LED lighting signal to the LED 9 via the OR circuit 112.

Therefore, at this time, as described above, it is assumed that the idle adjuster screw 1 is too tightened, and the LED 9 is in a continuous lighting state. Therefore, at this time, it is only necessary to manually adjust the idle adjust screw 1 in the opening direction so that Ifbn becomes small.

Further, the LED blinking circuit 56 is connected to the IfbnIledl
In response to a drive command signal from the determination means 111,
LED blinking signal is passed through OR circuit 112 to LED9
supply to

Therefore, at this time, as described above, it is assumed that the idle adjust screw 1 is too open, and the LED 9 is in a blinking state. Therefore, at this time, it is only necessary to manually adjust the idle adjust screw 1 in the closing direction so that Ifbn becomes large.

Note that in the above description, the two determining means 110 and 111 and the two LED circuits 55 and 56 corresponding to the determining means 110 and 111 are provided. For example, when there is an output from the LED 9, the LED 9 may be always turned on. However, in this case, it is not clear which direction the idle adjust screw 1 should be turned to the left or right to achieve the proper adjustment state.

In short, in the present invention, the feedback control term Ifbn of the solenoid current command value Icmd supplied to the solenoid 16 that controls the opening degree of the control valve 30 during idle operation is detected, and the feedback control term Ifbn is determined by adjusting the idle adjust screw 1. This makes it possible to detect when the engine has entered the range of 200 to adjust the idle adjust screw 1 to the optimum position regardless of changes in atmospheric pressure.

(Effects of the Invention) As is clear from the above description, according to the present invention, the following effects are achieved.

(1) Regardless of changes in atmospheric pressure, it is possible to properly adjust the engine speed during idle operation, that is, to properly adjust the idle adjust screw.

(2) Since the low engine speed at which the engine operating condition becomes unstable is not used for adjusting the idle adjust screw, it is possible to adjust the engine speed during idle operation with even higher precision.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of the present invention, FIG. 2 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 3 is a circuit diagram showing a specific example of the internal configuration of the electronic control device shown in FIG. FIG. 4 is a flowchart illustrating the operation of the microcomputer shown in FIG. 3. 1...Idol Asian Skrill, 9...
LED, 55...LED lighting circuit, 56...LED blinking circuit, 101...Feedback mode determination means, 102...Warm-up completion determination means, 103...Power steering operation determination means, 104...Air conditioner operation determination Means, 105...AT/D range determination means, 106...AND circuit, 107...Ifbn
Detection means, 109...Second AND circuit, 110
...IfbnIledh determination means, 111...Ifbn
Iledl determination means, 112...OR circuit.

Claims (1)

[Scope of Claims] 1. A control valve that is controlled based on a feedback control term calculated based on the deviation of the actual engine speed from the target idle speed and a correction term according to changes in atmospheric pressure, and the control valve. In the engine speed adjustment device during idling operation of an internal combustion engine, which controls the amount of intake air supplied downstream of a throttle valve of an internal combustion engine by a manual adjustment means provided separately from the means for determining whether the value is within a numerical value range and outputting a display means drive command signal when it is determined that the value is not within a predetermined numerical value range; and means for outputting a display means drive command signal in response to the display means drive command signal; is outside the expected numerical range,
display means for indicating that it is necessary to adjust the manual adjustment means for this purpose; and means for determining that the internal combustion engine is not in a state suitable for adjustment of the manual adjustment means and inhibiting activation of the display means. An engine rotation speed adjustment device during idling operation of an internal combustion engine, characterized by comprising: 2. The display means drive command signal output means outputs a first display means drive command signal when determining that the feedback control term is equal to or greater than the upper limit of the scheduled numerical range, and The engine rotation speed adjustment device during idling operation of the internal combustion engine according to claim 1, characterized in that the device is configured to output the second display means drive command signal when it is determined that the engine speed is below the specified value. . 3. The above-mentioned patent claim is characterized in that the fact that the internal combustion engine is not in a state suitable for adjustment by the manual adjustment means is a state in which at least one of the following conditions (a) to (e) is not satisfied. The engine speed adjustment device during idling operation of the internal combustion engine according to item 1 or 2. (a) The control valve is under feedback control. (b) Warm-up of the internal combustion engine is completed (c) Power steering is not operating (d) Air conditioner is not operating (e) Automatic transmission AT select position is not in D range. .