JPS5888426A - Fuel injection controller for diesel engine - Google Patents

Abstract

PURPOSE:To accurately perform fuel injection and improve fuel consumption, by changing a target injection quantity in accordance with a loading condition of a vehicle when a fuel injection quantity is controlled in accordance with a deviation between the target injection quantity and actual injection quantity on the basis of a signal from an operational condition detector. CONSTITUTION:The captioned device is operated such that a signal from an operational condition detector consisting of each sensor 2a-2e of speed, accelerator, intake pressure, intake temperature and cooling water and key switch 2f is input to a control circuit 5, here on the basis of the above each signal, a target injection quantity is calculated. Then the target injection quantity and actual injection quantity signal are compared, in accordance with this deviation, an actuator 8 for a fuel adjusting member 7 of a fuel injection pump 9 is driven and controlled. Here a loading condition detector 3 detecting a loading condition of a vehicle is equipped to input a signal of L level to a CPU4 in case of loading at least a prescribed level and suitably correct the above target injection quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection control device for a diesel engine, that is, a governor for an internal combustion engine that electrically controls the fuel of a fuel injection pump using an electromagnetic actuator or the like. More specifically, in order to obtain the target injection amount characteristics, the R in the microcomputer is
C based on the governor pattern pre-stored in the OM.
When calculating the target injection amount with PU, the loading condition of the vehicle 1
This invention relates to an electric governor in which a maximum injection amount pattern (maximum injection amount at each rotation speed) of a governor pattern is changed according to No. 1, and a target injection amount is calculated.

In general, a pneumatic governor is used as a fuel regulating governor in a diesel engine's fuel injection pump, which operates by the negative pressure generated in the venturi section installed in the engine's intake pipe, and a pneumatic governor that utilizes the centrifugal force generated by the rotation of the flyweight. There is a mechanical governor.

A pneumatic governor has a venturi section and a governor section. The governor section is divided into an atmospheric chamber and a negative chamber by a diaphragm, and the atmospheric chamber is connected to the atmosphere or an air cleaner, and the negative chamber is connected to the negative pressure outlet of the pepper/cherry.

There is a main spring in the negative pressure chamber, and the spring presses the fuel injection amount-node member in the direction of the "injection amount" through the diaphragm.The negative pressure generated in the venturi section is caused by the opening of the throttle valve. It is determined by the rotational speed of the engine. The position of the control rack is 1,7' where the negative pressure and the main spring force are in equilibrium. It all ends there.

Here, the maximum injection amount pattern is determined by the adapter device of the air automatic governor, depending on the correlation between the stop lever position, the elastic coefficient of the spring, and the negative pressure in the negative pressure chamber.

The mechanical governor balances the centrifugal force generated in the flyweight by the rotation of the injection pump's drive shaft and the spring restoring force, and controls the above fuel injection amount adjusting member by changing the position of the control lever (-) that is linked to the accelerator pedal. The maximum injection amount pattern is determined by the correlation among the rotational speed, spring elastic coefficient, and full-load stop point (position).

In this way, in the conventional system, the amount of fuel injection is controlled based on the same governor pattern regardless of the loading condition of the vehicle. Therefore, in response to sudden changes in engine load or sudden accelerator operations by the driver, the amount of fuel injected transiently until the engine speed reaches the target speed is almost different from the loaded state of the vehicle. Controlled independently. Therefore, when the vehicle is empty, the amount of fuel injected must be wasted compared to when the vehicle is fully loaded. Furthermore, in order to make the maximum injection amount pattern variable using conventional mechanical mechanisms, a complicated link mechanism is required or an auxiliary actuator must be used.

In consideration of the above points, the present invention changes the large injection amount pattern according to the loaded state of the vehicle, and when load fluctuation occurs or the driver operates the accelerator at will, the target rotation speed is reached. A fuel for a diesel engine that can sufficiently suppress excess fuel injected during the transient period until production, improve fuel efficiency, and that can smoothly change the maximum injection amount pattern without requiring a complicated mechanism. The purpose is to provide an injection control device.

The present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention applied to a distribution type fuel injection pump.

In this embodiment, the operating condition detectors 2a to 2f detect the operating conditions of the diesel engine l as electrical signals, the loading state detector 3 detects the loading state of the vehicle 'f11, and the electric signal is inputted into the target injection. target value control means for calculating the amount;
That is, a control circuit 5 equipped with a central processing tool (referred to as a CPU) 4, and an actual injection amount detector (referred to as a CPU) for detecting the actual injection amount.
This is called a spill position.

) 6 and a fuel injection pump 9 having an electromagnetic actuator 8 that adjusts a fuel adjustment member (referred to as a spill ring) 7 to a position corresponding to the target injection amount.

The operating condition detector 2& or 2f includes a rotation speed sensor 2a,
It is composed of an accelerator sensor 2b, an intake pressure sensor 2C, an intake temperature sensor 2d, an engine coolant sensor 2, and a middle switch 2f.

The rotational speed sensor 2a detects the rotational speed of the drive shaft lO of the fuel injection pump 9, and its configuration is as shown on the left side of FIG.

That is, the rotation speed sensor 21 is connected to the gear 2ml directly connected to the drive shirt 10, and the voltage waveform at point a in FIG. 2 changes as shown in FIG.
The electromagnetic pickup 2a2 generates an additive AC voltage signal as shown in FIG. The AC voltage signal output from the rotation speed sensor 2a is waveform-shaped by a waveform shaping circuit 11 having an electric circuit configuration as shown in FIG.
A pulse voltage signal as shown in FIG. 3 is input to the CPU 4, with the voltage waveform indicated by the dotted line in FIG.

As shown in FIG. 4, the accelerator sensor 2b uses a potentiometer to output an analog voltage signal proportional to the amount of accelerator operation. And this output signal is analog/
The signal is converted into a digital signal by the digital conversion circuit 12 and then input to the CPU 4.

As shown in FIG. 5, (6), the loading state detector 3 includes a limit switch 32 installed on a differential gear box 31 and a plate 34 interlocked with a body (loading platform) 33. In state III (referred to as a light load state) where the live load is below a predetermined level, the limit switch 3 is activated as shown in FIG. 5 (2).
2 is maintained in the OFF state and the load exceeds a predetermined level (referred to as a heavy load state), the light switch 32 is suppressed by the plate 34 as shown in FIG. remains on. stop·
If the loading status detector 3 is represented in an electrical circuit diagram as shown in Figure #I6, a high level voltage signal is input to the CPU 4 when the v-main switch 32 is in the off state, while a low level voltage signal is input to the CPU 4 when it is in the on state. A level voltage signal is input to the CPU 4. It is more preferable to provide a filter circuit between the loading state detector 3 and the CPU 4 to ignore short-term chattering of the limit switch.

The spill position t6 is of the variable inductance type as shown in FIG. That is, it is preferable to have a primary coil 62 and a secondary coil 63 in a hollow bobbin 61. A core 64 is inserted into the hollow part. - When an excitation signal of constant amplitude and constant frequency is applied to the secondary coil 62, the secondary coil 62
3 is terminated with a resistor, a voltage is generated across the resistor. Now, the core 64 inserted into the hollow part is connected to the secondary coil 6.
Assuming that the length of the overlapping portion with 3 is 4, the relationship between 4 and the voltage Vp generated across the secondary coil is as shown in FIG. 8. The spill position detector of this embodiment has this characteristic. The straight part of is used. Note that the core 64 is adapted to interlock with a connecting rod 84 of an electromagnetic actuator 8, which will be described later.

The magnetic actuator 8 has a structure as shown in FIG. The electromagnetic actuator 8 (
A linear solenoid) has a core 82 that holds a coil 81 and forms a magnetic circuit, a moving core 83 that is a movable part,
Connecting rod 84% spring 85 directly connected to moving core 83
It consists of The moving core 83 and the connecting rod 84 are
It is possible to move in both directions a and b. moving core 83
is the arrow a generated by the current l flowing through the coil 81.
The electromagnetic actuator stops when the force in the direction is balanced with the restoring force in the direction indicated by the arrow, which is generated by the nine springs 85 attached inside the electromagnetic actuator. The relationship between the current flowing through the coil 81, the length m of the gap between the core 82 and the moving core 83, and the force F generated in the direction of the arrow a from the electric current fILiK is shown in Fig. 1θ. In FIG. 1O, a dashed line indicates the force generated by the spring 85 in the direction of the arrow. As can be seen from this figure, in order to control the position of the fuel adjustment member in this embodiment, it is sufficient to control the current flowing through the coil 81, and the electromagnetic actuator 8 is operated by the arrow a generated by the current flowing through the coil 81. Balance between the force in the direction and the force in the direction of the arrow 9 generated by the spring 85
The position of the moving core is determined by the alignment, and the moving core is connected to the connecting rod U and the link mechanism 13 (Fig. 1).
The spill ring 7 is moved to adjust the fuel injection amount.

As shown in FIG. 1, the control circuit 5 includes the CPU 4,
It is composed of the waveform shaping circuit 11, the analog/digital conversion circuit 12, the RDM 14, the RAM 15, the digital/analog conversion circuit 16, and the positioning servo circuit 17.

A program for executing processing is stored in the ROM 14 in advance. In addition, the ROM 14 stores basic injection amount data corresponding to the injection amount characteristic governor pattern as shown in FIG. 11, as well as a two-dimensional map as shown in FIG. The basic injection amount QP (NN m ) data corresponding to the address specified by the data is stored in advance as a storage pattern. In addition, in FIG. 11, the accelerator operation amount α of the polygonal lines A, C, C, II, and H is O1, 25%, 50gII, 751, respectively.
A one-dimensional map of the basic maximum injection quantity, which represents a pattern when G is 1oos -t' and is addressed by the rotational speed N data, is also stored in the ROM 14 in advance.

The CPU 4 executes the first program based on the program in the ROM 14.
A series of processes as shown in the main routine of FIG. 3 are repeated.

First, in step 101, it is determined whether or not the key switch 2f is turned on based on the input signal from the key switch 2f. If the determination result is "YES J", the CPU is initialized in step 102.

Then, in step 103, it is determined based on the input signal from the key switch 2f whether or not it is in the starter position state.

If this determination result is rYE8J, in step 104, various input signals v from the operating condition detectors 2a to 2g are
Furthermore, in step 105, the loading status signal from the loading status detector 3 is input.

Then, in step 106, a target injection amount Q is calculated.

This step 106 is represented by a flowchart as shown in FIG.

In calculating the target injection amount, first, in step 201, the governor pattern in the ROM 14 is searched. Here, this putter 4 search is performed in step 104 above.
The calculation is performed based on the input rotational speed N and accelerator operation amount α and K, and the corresponding basic injection amount qp (Nsα) data is C.
Transferred to PU4.

Next, in step 202, the nine basic injection quantities QP(N, α) transferred as described above are corrected and the corrected basic injection intake temperature is set/
Intake temperature information from sensor 2d and engine coolant sensor 2e
Based on the cooling water temperature information from
(N sα) and corrected basic injection amount Q'p(N,
α) is calculated.

Next, in step 203, the ROM is stored in advance from the rotation speed N.
The basic maximum injection amount Qys (Nlt) is calculated based on the one-dimensional map stored in the 14. Note that this basic maximum injection amount Qys (N) is calculated based on the injection amount characteristic Gano (a - b - in the na pattern in Fig. 11). This corresponds to the basic maximum injection amount pattern consisting of c - d.

Next, in step 204, the basic maximum injection amount Qys (Nl) is corrected based on the intake pressure information, the intake temperature information, and the engine cooling water information, and the corrected basic maximum injection amount Q', , (N) is calculated. calculate.

Next, in step 204, the p
Based on the loaded loading status signal, it is determined whether the vehicle is in a lightly loaded condition as described above or in a heavily loaded condition.

If it is determined that the vehicle is in a lightly loaded state, the maximum injection amount Qy is calculated in step 206. Here, this maximum injection amount Q
, is obtained by multiplying the corrected basic maximum injection amount Q' calculated in step 204, , elaK constant, for example, 0.8.

On the other hand, if it is determined that the load is heavy, step 207
-, the corrected basic maximum injection amount Q', , (N) calculated in step 204 above is set as the maximum injection amount Q.

Then, in step 208, the maximum injection amount Q obtained in step 206 or step 207K is determined, and the nine corrected basic injection amount Q'p(N) calculated in step 202 is determined.

α), and the smaller value is set as the target injection amount Q.

When the target injection amount Q is calculated as described above in step 106, a process is performed to output a command injection amount digital signal corresponding to the target injection amount Q in step 107. /Analog converter circuit 16 command injection amount analog signal (command injection amount signal)
and is input to one input terminal of the positioning servo circuit 17.

Here, the relationship between the command injection amount signal and the target injection amount Q is as follows:
The rotation speed Nt parameter is determined as shown in Fig. 1s. This is the ninth case in which the spill ring 7 for adjusting the fuel injection amount is fixed at the same position and the fuel injection amount at the end of the % change varies depending on the rotation speed N.

Next, in step 109, it is determined whether the key switch 2f is turned off, and if the determination result is "NO",
Execute step 104 again, and then step 109
At step 104, the judgment result is reversed to YE8J.
, step 105, step 106, step 107,
Step 108 is repeatedly executed to output a command injection amount digital signal.

After that, when the key switch 2f is turned off, a command injection amount digital signal corresponding to a zero-value target injection amount is output in step 110K.

The positioning servo circuit 17 sends an actuator drive signal to the actuator so that a current proportional to the difference between the command injection amount signal from the digital/analog conversion circuit 16 and the actual injection amount signal from the spill position sensor 6 flows through the actuator. Output.

The circuit configuration of this positioning navigation circuit 17 is as shown in FIG. In FIG. 16, the command injection amount signal Vs from the digital/analog conversion circuit 16 is applied to one input terminal 17m, and the actual injection amount signal Vp from the spill position sensor 6 is applied to the other input terminal 17m.

Here, the relationship between the command injection amount signal Vm and the injection amount Q is the first
7, the relationship between the actual injection amount signal Vp and the injection amount Q is shown in the first
It is as shown in Figure 8. t7't171 is an amplification circuit that superimposes and amplifies the commanded injection amount signal Vm and the actual injection amount signal Vp, and adds an offset voltage Vofl. Note that the capacitors C1 and C2 and the resistor R perform differential compensation and integral compensation, and the command injection amount signal Vs and the actual injection amount signal vp.
is the injection amount Q as shown in Fig. 17 and Fig. 4118, respectively.
The output voltage of the amplifier circuit 171 is obtained as an error amplification value between Vs and Vp because the slopes are the same and have opposite positive and negative slopes.

16 is a coil of the electromagnetic actuator 8, and a resistor 17c is a resistor for detecting the current value flowing through the coil 81, and generates a voltage proportional to the current value at both ends. The amplification stage 172 amplifies a voltage proportional to this current value, adds an offset voltage Vof2, and outputs the amplified voltage.

The comparison circuit 173 compares the error amplified voltage obtained by the amplifier circuit 171 and the feedback voltage of the electromagnetic actuator current obtained by the amplifier stage 172, and outputs the result. Another comparison circuit 174 chops the comparison value of the comparison circuit 173 using the constant frequency charge/discharge waveform obtained by the oscillation circuit 175, and controls the electromagnetic actuator drive circuit 176.

FIG. 19 shows the voltage waveform in the comparator circuit 174.

An oscillation waveform a as shown in FIG. 19 (D) is applied to the point 17d in the figure.The comparison value between the error amplification voltage applied to the other point 17 and the electromagnetic actuator current feedback voltage is as shown in FIG. In the case of IVfl, illustrated point 17f
The output waveform of is chopped as shown in FIG. 19 (11), and when the comparison value is Vfl as shown in FIG. 19, it becomes as shown in FIG. 19 (lii). And above (11)
, (ill), the electromagnetic actuator drive circuit 176 is controlled by a rectangular wave voltage such as
On average, nine levels of current are supplied to the coil 81 in proportion to the pulse width of the rectangular wave. Note that the current detection resistor 17c
The amplification stage 172 serves to correct current fluctuations in the coil 81 due to voltage fluctuations of the battery 18, and also to correct changes in the resistance value of the coil 81 due to changes in self-heating, ambient temperature, etc.

In this manner, the positioning servo upper path 17 outputs nine actuator drive signals in proportion to the error between the command injection amount signal from the digital/analog conversion circuit 16 and the actual injection signal from the spill position sensor 6. The electromagnetic actuator 8 is driven in accordance with this drive signal, moves the Subiruri/Gua in a direction to cancel the above-mentioned error via the sliding mechanism 13, and injects the target injection amount of fuel into the diesel engine 1 from the fuel injection pump 9. supply

9 and 21 show an example of the loading state detector 3 in the second embodiment of the present invention and a ninth injection amount characteristic governor pattern for explaining the maximum injection amount.

In contrast to the above-described first embodiment, which has a configuration in which the maximum injection amount is selected between the light loading state and the heavy loading state, this embodiment uses a load sensor as shown in FIG. 3, the loading state from the minimum loading state (empty load I! state) to the maximum loading state is continuously detected, and the maximum injection amount is determined from the 21st
The selections are made consecutively as shown in the figure. In FIG. 9, the load sensor 3 is fixed to the distal gear box 31, and is constructed such that its resistance value is selected by a lever holder that is linked to the body wing.

The analog output signal of the load sensor 3 is input to the CPU 4 via the analog/digital conversion circuit 12 shown in FIG.

Figure n shows a loading state detector 3 in a third embodiment of the present invention.
An example of this is shown.

That is, in this embodiment, a 1-meter meter as shown in FIG. The electromagnetic actuator 8 is driven in accordance with the difference between the target injection amount and the actual injection amount, which are calculated in the same manner as in the second embodiment.

As explained above, the present invention includes an actuator that operates the fuel adjustment member of a fuel injection pump to adjust the fuel injection amount, an actual injection amount detector that generates an actual injection signal corresponding to the actual fuel injection amount, and an engine. an operating condition detector that detects operating conditions as an electrical signal; and a target injection amount of the engine is calculated based on the signal from the operating condition detector, and the target injection amount signal and the actual injection amount signal are and a control circuit for controlling the drive of the actuator so as to compare and correct an error between the two, the target value control for changing the target injection amount according to the loading state of the vehicle. I prepared the means.

According to the present invention, it is possible to supply the diesel engine with an injection amount of fuel suitable for the loading condition of the vehicle, and it is possible to sufficiently improve fuel efficiency.

Although the embodiments described above are applied to a distribution type pump, the present invention is not limited thereto, and does not exclude application to a size type pump or the like.

[Brief explanation of drawings]

Figure 1 shows an example of the configuration of a fuel injection system to which an embodiment of the present invention is applied, Figure 2 shows an example of the configuration of a rotation speed sensor and a waveform shaping circuit, and Figure 3 (6) explains its operation. Figure 4 shows an example of the configuration of the Acrylic sensor, and Figure 5 (2
), (6) are rounded diagrams illustrating an example of the configuration and operation of the loading state detector, FIG. 6 is its electrical equivalent circuit diagram, FIG. 7 is a sectional view showing an example of the configuration of the spill position sensor, and FIG. 8 is an output voltage characteristic diagram to explain its operation, Figure 9 is a sectional view showing an example of the configuration of an electromagnetic actuator, Figure 10 is a ninth characteristic diagram to explain its operation, and Figure 11 is an injection amount characteristic. An example of the configuration of a governor pattern, Figure n is a storage pattern diagram of the memory pattern in the ROMK, Figures 13 and 14 are freechards for explaining the processing operation of the target value control means (CPU), and Figure 15 is a target diagram. A diagram showing the relationship between injection amount and rotation speed, Figure 16 is a configuration example of a positioning servo circuit,
Figures 17 and 18 show the relationship between the command injection signal, the actual injection signal, and the injection amount, respectively, and show the factors, Figure 19 is the ninth time chart explaining the operation of the servo circuit, and Figure 4 is the loading state. Another configuration example of the detector, FIG. 21 is a rounded governor pattern diagram illustrating the maximum injection amount when the detector is used, and FIG. N shows still another configuration example of the loading state detector. 1.--Daisel engine 2a to 2f.■Operating condition detector 40.Target value control means (CPU) 6..Control circuit 7..Fuel adjustment member 8..
Actuator 9o/Fuel Injection Pump Agent Patent Attorney Tsutomu Adachi Fig. 2 B Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 17 Fig. 8 Fig. vp (v ) Figure 19 Figure 21/V σ, ° Acceleration L Crop Amount M,・ Junior high school 11th meeting 1 Figure η

Claims (1)

[Claims] An actuator that operates the fuel adjustment member of the fuel injection pump to adjust the fuel injection amount, an actual injection amount detector that generates an actual injection amount signal corresponding to the actual fuel injection amount, and an electric signal that indicates engine operating conditions. an operating condition detector to detect;
The control unit calculates a target injection amount for the engine and the engine in response to a signal from the operating condition detector, and compares the target injection amount signal with the actual injection amount signal to correct the difference between the two. A fuel injection control device for a diesel engine comprising a control circuit for controlling drive of an actuator, further comprising target value control means for changing the target injection amount according to a loading state of a vehicle. Injection control device.