JPH0745845B2 - Correction device for fuel injection control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a correction device that corrects a fuel injection amount of a diesel engine, and more specifically, to a variation in performance of component parts and a change over time. The present invention relates to a correction device that realizes a stable fuel injection amount.

[Prior Art] Conventionally, as a fuel injection device of a diesel engine, based on a signal of each sensor such as a sensor that detects a depression amount of an accelerator pedal, a rotation speed sensor or a water temperature sensor that detects an operating state or an environmental state, Controlling the control rack for adjusting the injection amount by calculating the target fuel injection amount from the specified fuel injection amount map and sending a signal corresponding to this target fuel injection amount to an actuator such as a linear solenoid of the fuel injection pump. Therefore, there is a device for controlling the injection amount (Japanese Patent Laid-Open No. 54-150519).

[Problems to be solved by the invention]

However, in the above conventional fuel injection control device, even if the target fuel injection amount is the same, the engine speed may fluctuate due to variations in engine characteristics, variations in injection characteristics of the fuel injection pump, or changes over time. There is a problem to do.

For example, in idle control, constant rotation control has been conventionally performed, but in this constant rotation control, the microcomputer controls the electric governor to perform fuel increase / decrease control regardless of the depression amount of the accelerator pedal. There is. But,
In the state where the no-load characteristic at the time of idling increases due to the change over time and the fuel injection amount is increased, the idle control is completed and the fuel injection amount is set by the predetermined injection amount fuel map by the depression amount of the accelerator pedal. However, there is a problem that the engine speed is apt to suddenly decrease or rise.

[Means for solving problems]

The present invention made to solve the above problems is, as shown in FIG. 1, a correction device for a control device that controls a fuel injection amount of a diesel engine, and an operation amount corresponding to a depression amount of an accelerator pedal. An operation amount detecting means for detecting the engine speed, a rotation speed detecting means for detecting the engine speed, a control means for controlling the fuel injection amount according to the operation amount of the accelerator pedal and the engine speed, and a constant rotation control. At this time, a constant rotation deviation detection means for detecting a rotation speed deviation between the rotation speed detection value from the rotation speed detection means and a predetermined rotation speed, and an accelerator pedal for obtaining the predetermined rotation speed in accordance with the rotation speed deviation. Virtual operation amount calculation means for obtaining the stepping amount of the virtual operation amount as a virtual operation amount, reference value setting means for setting a reference value of the virtual operation amount during the constant rotation control, the reference value and the virtual operation amount Comparing, the correction means for correcting the operation amount of the accelerator pedal during the normal operation other than the constant rotation control according to the deviation and the correction of the operation amount of the accelerator pedal by the correction means during the normal operation are performed by depressing the accelerator pedal. And a prohibition means for prohibiting the amount in a region of a predetermined value or more.

[Action]

The fuel injection amount of the diesel engine is controlled by the control unit according to the operation amount of the accelerator pedal detected by the operation amount detection unit and the engine rotation speed detected by the rotation speed detection unit. At the time of constant rotation control, the constant rotation deviation detecting means detects the deviation of the engine speed from the actual detected value of the engine speed and the predetermined rotation speed, and the virtual operation amount detecting means detects the accelerator. A virtual operation amount of the pedal depression amount is calculated. And in the correction means,
According to the deviation between the virtual operation amount and the reference value set by the reference value setting means, the operation amount of the accelerator pedal during the normal operation other than the constant rotation control is corrected. As a result, it is possible to prevent a sudden increase or decrease in the accelerator operation amount when shifting to the normal control that does not use the virtual operation amount, and it is possible to provide aging compensation even in a region other than the constant rotation control. Become.

Further, since the prohibiting means prohibits the correction of the operation amount of the accelerator pedal by the correcting means during the normal operation in the region where the accelerator pedal depression amount is the predetermined value or more, the correction in the unnecessary region is eliminated. , The drivability in the entire accelerator region can be improved.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a system configuration diagram of a diesel engine and a fuel injection control device, 1 is a diesel engine, 2 is a fuel injection pump, and fuel injection is performed by controlling the energization time to a solenoid of a known electric governor 2a. The amount can be controlled. 3 is a transmission connected to the output shaft of the diesel engine 1.

The system is provided with various sensors, that is, an engine speed sensor 11 for detecting the engine speed of the diesel engine 1, an accelerator pedal amount sensor 13 for detecting the accelerator pedal depression amount, and an output shaft of the transmission 3. The vehicle speed sensor 15 and the water temperature sensor 17 for detecting the water temperature of the engine are provided respectively in the vehicle. The outputs of these sensors 11 to 17 are input to the electronic control unit 21.

The electronic control unit 21 is composed of a well-known microcomputer, that is, an input unit 23 that performs signal processing such as A / D conversion of signals from each sensor, a CPU 25, and a RAM 25 as a temporary storage unit, The ROM 27 in which the programs shown in FIGS. 3, 4 and 6 and the fuel injection amount map of FIG. 5 are stored in advance, the common bus 29, and the control signals are used as signals to the electric governor 2a. The output unit 31 performs processing such as D / A conversion.

Next, the flow chart of FIG. 3 for obtaining the correction value of the fuel injection amount of the present embodiment, the flow chart of FIG. 4 for performing the idle control as the constant rotation control, and the normal FIG. 6 using this correction processing. The fuel control flowchart of FIG.

The flowchart of FIG. 3 is started once after the engine is started, for example. In FIG. 3, first, step 10
At 0, initialization processing of accelerator correction amount Δα (Δα → 0)
After is executed, it is determined in step 110 whether or not it is in the idle state. The idle state is performed by determining a signal from the idle switch or an electric signal corresponding to the accelerator operation amount. This step 11
When it is determined at 0 that the engine is in the idle state, the routine proceeds to the next step 120, where constant rotation control is performed. This constant rotation control is performed by the flow chart as shown in FIG. That is, after it is determined that the engine is in the idle state (step 200), the engine speed sensor 11 detects the engine speed N.
e is read (step 210), it is judged whether or not the rotation speed Ne is controlled to a predetermined rotation speed No which is a target during idling (step 220).
The virtual operation amount αb of the accelerator pedal is maintained unchanged (step 230) and the current fuel injection amount is maintained (step 24).
0) On the other hand, when it is not the predetermined rotation speed No, the fuel injection amount is increased or decreased by increasing or decreasing the virtual operation amount of the accelerator pedal (steps 250 and 260). That is, feedback is performed based on the detection value of the engine rotation speed sensor 11 to obtain a virtual operation amount, and the fuel injection amount is obtained using this virtual operation amount as a parameter to control the engine rotation speed to a predetermined rotation speed. The virtual operation amount αb is calculated so that the deviation becomes small according to the proportional amount, the integration amount, etc. of the deviation with respect to the predetermined rotation speed No. The constant rotation control is always performed in the normal idle state.

By the way, the fuel injection amount Q of the diesel engine is the fifth
Based on the fuel injection amount map as shown in the figure, it can be obtained from the actual accelerator depression amount α and engine speed Ne,
In the constant rotation control, the fuel injection amount Q is controlled according to the virtual operation amount αb regardless of the actual accelerator depression amount α. That is, for example, in the initial state where the no-load characteristic curve is indicated by a, the virtual operation amount αb1 at that time is
On the basis of the above, the fuel injection amount is set by the fuel injection amount Qa indicated by the intersection of the constant revolution speed Neo during idling and the no-load characteristic curve a. In the present embodiment, this is set from the accelerator depression amount αa in the idle state. It matches the calculated fuel injection amount.
However, when the no-load characteristic curve changes to b due to changes over time, the fuel injection amount Q is increased to Qb based on the virtual operation amount αb2 for controlling to the predetermined rotation speed No, and based on the accelerator depression amount αa. It does not match the calculated value.

Next, step 130 is executed and the accelerator depression amount sensor 1
The accelerator depression amount αa at idle is read from 3. The depression amount αa serves as a reference value for the virtual operation amount.

Then, at step 140, the difference (Δα = αb−αa) between the virtual operation amount αb of the accelerator pedal and the accelerator depression amount αa at the time of idling is calculated to obtain the correction value Δα. Then, this correction value Δα is used in the flow chart for controlling the fuel injection amount shown in FIG. 6 which is executed during normal traveling or the like. Note that Δα = 0 at the initial stage where there is no change with time as described above.

In the flowchart of FIG. 6, first, at step 300, the accelerator depression amount α is read, and then at step 310, it is determined whether or not the accelerator depression amount α is less than or equal to a predetermined value αA. This kind of judgment is made
When the accelerator depression amount α is a large value, the correction value Δα caused by a change over time or engine characteristics is the accelerator depression amount α.
This is because it does not significantly affect the Further, particularly when the correction is made in a region where the accelerator pedal depression amount α is close to full opening, although Δα has a small influence on α,
Since the injection amount is controlled near the maximum injection amount, which changes drastically from the beginning, the timing to shift to the maximum injection amount control for the actual accelerator pedal depression amount changes when the correction of Δα is added, and the driver's experience This is because the drivability may be deteriorated rather than being utilized.

For these reasons, it is judged that the correction in the region where the accelerator depression amount is large is unnecessary.

Next, when it is determined that the opening is equal to or smaller than the predetermined opening αA, the routine proceeds to step 320, where it is determined whether or not the correction value Δα is zero. That is, when there is a correction Δα, step 330
(Α + Δα) is set as the corrected accelerator depression amount α, while in step 310 above, when the accelerator opening αA or more and the correction value Δα is zero, the accelerator depression amount of the accelerator depression amount sensor 13 is set. The amount α is set as it is (step 340).

Next, the engine speed Ne is read from the engine speed sensor 11 (step 350), and the detection values of other sensors are read (step 360). Next, the basic fuel injection amount Q is calculated from the accelerator depression amount α, the engine speed Ne, and the fuel injection amount map (step 37).
0), further, by the detection value from the other sensor,
Various injection amount correction processing is performed (step 380).
With the fuel injection amount set in this way, the electric governor 2a
A control signal is sent to the solenoid of and fuel injection is performed (step 390).

Therefore, according to the above process, the virtual operation amount α for maintaining the constant rotation during the constant rotation control in the idle control.
b, the virtual operation amount αb and the accelerator depression amount sensor
The deviation Δα from the accelerator depression amount αa from 13 is obtained, and the accelerator depression amount α during operation is corrected by this deviation Δα. Therefore, from the constant rotation state by idle control,
When the accelerator pedal is depressed and the engine is controlled by the accelerator depression amount α, even if the engine no-load characteristic or fuel pump characteristic fluctuates due to engine characteristics or changes over time, the engine rotation The number does not change rapidly.

In the correction process according to the above-described embodiment, as shown in FIG. 7, the no-load characteristic of the virtual operation amount αb greatly changes depending on the engine water temperature.
The correction process of the present embodiment may be executed in the TA or higher area. This case can be realized by adding a step of processing when the water temperature is equal to or higher than the predetermined temperature TA after step 110 in FIG. This processing is effective in reducing the software capacity, simplifying the configuration, and increasing the ROM flexibility.

Next, another embodiment of the present invention will be described with reference to FIG. This embodiment is different from the above embodiment in that a target value α'a of the accelerator pedal depression amount which is predetermined and stored to obtain a predetermined idle rotation is used as the reference value of the virtual operation amount. That is, in the flow chart of FIG. 8, the CPU reads the target value α'a of the accelerator pedal depression amount at step 130 ', and at step 140 the correction value Δα is obtained by the calculation of αb-αa'. Here, the target value α'a is equivalent to the value of the accelerator depression amount αa in the characteristic diagram of FIG.

In the above embodiment, the virtual operation amount of the accelerator pedal is directly obtained from the rotational speed deviation at the time of idling, but the fuel injection amount is increased / decreased and corrected by the rotational speed deviation to reduce this deviation. The corresponding accelerator operation amount may be obtained from the map of FIG. 5 by the amount and the number of revolutions, and this may be used as the virtual operation amount.

〔The invention's effect〕

As described above, according to the present invention, the rotation speed is controlled to the predetermined rotation speed by using the virtual operation amount of the depression amount of the accelerator pedal during the constant rotation control, and the value of this virtual operation amount with respect to the reference value. Utilizing the property that the time-dependent change of the injection control device can be known by finding how much it is, by reflecting the deviation from the reference value of the virtual operation amount obtained during constant rotation control in normal control other than constant rotation control, While preventing a sudden increase or decrease in accelerator operation amount when shifting to normal control that does not use virtual operation amount, it is possible to compensate for changes over time in areas other than constant rotation control, and in particular, set the accelerator pedal depression amount to a predetermined value. Correction of accelerator pedal operation amount is prohibited in areas above the value, so correction in unnecessary areas is eliminated,
It is possible to improve drivability in the entire accelerator region.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of the configuration of the present invention, FIG. 2 is a system configuration diagram of a diesel engine according to an embodiment of the present invention, FIG. 3 is a flowchart showing a correction value calculation process according to the same embodiment, FIG. FIG. 4 is a flowchart showing a constant rotation control process, FIG. 5 is a graph showing a fuel injection map, FIG. 6 is a flowchart for calculating a fuel injection amount of a diesel engine, and FIG. 7 is an engine water temperature and an accelerator depression amount. FIG. 8 is a graph showing the relationship with, and FIG. 8 is a flowchart showing the correction value calculation processing according to another embodiment of the present invention. A: engine, B: correction means, C: operation amount detection means, D
...... Rotation speed detection means, E …… Constant rotation deviation detection means, F …… Virtual manipulated variable calculation means, G …… Correction means, H …… Reference value setting means, 21 …… Electronic control device.

Claims (1)

[Claims] 1. A correction device for a control device for controlling a fuel injection amount of a diesel engine, the operation amount detecting means for detecting an operation amount corresponding to a depression amount of an accelerator pedal, and an engine speed of the engine. A rotation speed detection means, a control means for controlling the fuel injection amount according to the operation amount of the accelerator pedal and the rotation speed of the engine, and a rotation speed detection value from the rotation speed detection means and a predetermined rotation speed during constant rotation control. A constant rotation deviation detecting means for detecting a deviation in the number of revolutions, and a virtual operation amount calculating means for obtaining a depression amount of an accelerator pedal for obtaining the predetermined rotation number as a virtual operation amount according to the deviation in the revolutions, Reference value setting means for setting the reference value of the virtual operation amount during constant rotation control is compared with the reference value and the virtual operation amount, and during normal operation other than constant rotation control according to the deviation. Compensation means for compensating the operation amount of the accelerator pedal, and prohibition means for inhibiting the compensation of the operation amount of the accelerator pedal by the compensating means during the normal operation in a region where the depression amount of the accelerator pedal is a predetermined value or more. A correction device for a fuel injection control device.