JPS6291650A - Fuel injection quantity control device for diesel engine - Google Patents

Abstract

PURPOSE:To allow the quantity of fuel delivery from a fuel injection pump to be easily adjusted by providing a fuel temperature changing device which changes the temperature of fuel to a set value by heating or cooling fuel, between a fuel tank and the fuel injection pump. CONSTITUTION:A fuel injection pump M3 which feeds fuel supplied from a fuel tank M1 to a diesel engine M2 with pressure, is provided. The quantity of fuel lead from a gap between a pump plunger and a spill ring is increased in the fuel injection pump M3 as fuel is increased in temperature because viscosity becomes lower. Accordingly, a jerk pump system is employed where the quantity of injected fuel is reduced. And a fuel temperature changing device M4 which allows the temperature of fuel to be regulated to a set value by heating or cooling fuel, is provided between the above said fuel injection pump M3 and the fuel tank M1, besides, the above said set value can be set by a temperature setting unit M5.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a fuel injection target control device for a diesel engine that adjusts the amount of fuel injection executed by a fuel injection pump for an i-easel engine. .

[Prior Art 1 Conventionally, 16
In this case, a mechanical or negative pressure governor is installed on a rack that controls the amount of fuel injected by the fuel injection pump to maintain a predetermined engine output and rotation speed. ? was.

However, in the case where the above control is performed using a vane, the injection amount control characteristics are uniformly determined by the accelerator pedal distance or engine speed, so-called all-speed or half-all-speed characteristics. Therefore, in order to perform control more responsive to the operating conditions, a fuel increase/decrease device is added to the injection pump, such as the device shown in Japanese Utility Model Application Publication No. 60-43141, or an electronic control device is used. Corrective measures were being taken.

[Problems to be Solved by the Invention] However, when adding a fuel increase/decrease device, the increase in smoke, A-va heat, or changes in the governor over time may occur. soil of defeat.

It was possible to reduce the fuel injection amount when a backlash occurred, and increase the fuel injection amount during acceleration, but it was possible to increase or decrease the fuel injection amount for each control. Since it was necessary to add an additional position, there were problems such as the complexity of the governor section and the lack of space for J3 and installation.

On the other hand, if electronic control is used, it is possible to perform detailed control, but there are problems in that the device becomes complicated and high in speed.

Therefore, the present invention aims to solve the above problems.

[Means for solving the problem] In order to solve the above problem and achieve the purpose, as shown in Fig. 1, the fuel supplied from the fuel tank M1 is adjusted according to the operating status of the diesel engine. A fuel injection pump M3 that pressure-feeds the fuel to the diesel engine M2, and a fuel temperature that changes the temperature of the fuel to a predetermined set value by heating or cooling the fuel provided between the fuel tank M1 and the fuel injection pump M3. The gist is a fuel injection tA suspension limit 1+ device for a diesel engine characterized by comprising: a change device M4; and a temperature setting device M5 for setting a predetermined set value of the fuel temperature change device M4.

The fuel injection pump M3 is one that employs, for example, a jerk pump system. In the pump system, when the temperature of the fuel supplied to the system is increased, the viscosity of the fuel It decreases, causing the fuel V1 to leak from the gap between the pump plunger and the spill ring.
As a result, the injection amount decreases.

The fuel temperature changing device M4 changes the temperature of the fuel supplied to the fuel injection pump M3 to a predetermined temperature by heating or cooling, for example, by A-Pun or feedback control.

The humidity setting device M5 is, for example, a device that is provided with a switch and manually sets the temperature, or detects the operating condition and automatically determines and sets the temperature based on the detection result. At the temperature set in 1-, the temperature is lowered when a reduction in fuel l1t1 injection is required, and the temperature is increased when a reduction in fuel l1t1 injection is required.

[Function 1] As shown in the example of the embodiment shown in FIG. This was done with a view to reducing the number of layers. Note that when the fuel temperature IW is increased as shown in FIG. 3, the injection timing of the fuel I is delayed. The cause of the decrease in fuel injection 04 fit mentioned above is the fuel ii! This is due to an increase in the amount of fuel leaking from the gap between the pump plunge 11 and the spill ring in the fuel pump, in addition to the decrease in viscosity due to the increased stomach.

Therefore, the cause of the delay in the timing of fuel injection a' described in - is that due to the increase in leaked fuel, νY of the timing when the injection pressure is reached.
This is the cause. Therefore, by heating or cooling the fuel supplied to the fuel injection pump M3 by the fuel F4 temperature changing device M4, the amount of fuel a pumped to the diesel engine M2 is reduced or increased. As a result, in the fuel temperature changing device M4, since the fuel temperature is variably controlled to the optimum fuel temperature by the temperature 1 regulator M5, the temperature setting P
9M5 increases or decreases the amount of fuel that is pumped to the Deep Pill engine.

Examples will be described below, but the examples of the present invention are not limited thereto, and various embodiments C can be implemented without departing from the gist.

[Example] The configuration of the first embodiment is shown in FIG. 4 and will be explained.

1 is a fuel tank, 2 is a fuel filter, 3 is a combustion temperature change device for heating or cooling fuel, 4 is a fuel injection pump,
5 is an injection nozzle, 6 is a fuel line, 7 is a fuel line,
8 is a control circuit for the fuel temperature changing device 3; 9 is a battery that supplies power to the control circuit; 10 is an engine rotation speed sensor; 11 is a temperature sensor 111; A smoke sensor outputs a proportional output voltage, and 13 is an accelerator opening sensor. The engine rotation speed sensor 10, υ1 air pressure sensor 4/11, smoke sensor 12, 113, and accelerator opening sensor 13 are connected to the control circuit 8, respectively, and output data without indicating various driving conditions.

Next, the details of the fuel temperature changing device 3 (1'4
This will be explained using a diagram. In the fuel temperature changing device 3, [
Well, a fuel vibrator 20 whose both ends are connected to the fuel line 6 to flow fuel to be supplied to the fuel injection pump 4;
a heater 21 installed around the fuel vibrator 20 to heat the fuel; a cooler 22 installed around the fuel vibrator 20 to cool the fuel; and a fuel outlet 23 of the fuel temperature changing device 3.
The basic configuration is a fuel temperature sensor 24 that detects the temperature of the fuel. In the heater 21, the electric power applied to the +B electric wire terminal 25 is applied to the hot wire 27 via the relay 26. The relay 26 is composed of a spinnable contact 26a, a contact 26b, and two excitation coils that turn on and off. One end of the two excitation coils is grounded, and the other end is provided with an input Qi<28) for inputting an excitation current. Therefore, the input terminal a (2
By applying the [';A>j signal to 8), power can be supplied to the heater 21 to perform heating. On the other hand, the cooler 22
In this case, a refrigerant passage 32 is connected to a compressor (not shown) via a solenoid valve 31 that opens when a current is applied to input terminal b (30). The refrigerant passage 32 is in contact with the fuel pipe 20 via fins 35 that conduct heat. Therefore, by turning on the solenoid valve 31 (30), the refrigerant liquefied in the compressor flows into the refrigerant passage 32, thereby insulating the refrigerant. Cooling can be performed by expansion.

Next, since the fuel temperature sensor 24 generates an output proportional to temperature, the fuel temperature T is outputted to the output terminal 40.

Next, a block diagram of the configuration of the control circuit 8, sensors, etc. is shown in FIG. 6, and will be explained. In the practical control IH system 3, the well-known CPU 40, ROM 41, RAM 42,
It is composed of an A/D converter 43, an I10 device 14, and a common bus 45. Then, the A/D converter 4
3 includes the exhaust gas 41+ detected by the exhaust temperature sensor +J11, the exhaust gas detected by the smoke sensor 12, the accelerator opening θ detected by the accelerator sensor 13, and the fuel temperature detected by the sensor 32. The detected combustion temperature T is added to each. On the other hand, the I10 device 44 has the engine speed N detected by the engine speed sensor 10 at t+11.
Terminals a (28) and j of the heater and terminal b (30) of the cooler are connected. The terminal a1J3
and b, three circuits driven by the above-mentioned 17.'O device 44 are built in so that electric power can be supplied to them.

Next, a flowchart of the injection control 11 routine performed using the configuration shown in FIGS. 4 to 6 is shown in FIG. 7, and will be described in detail below. The 1lr3 shooting control field 1 routine is:
It is activated regularly and performs the control described below. First, the operating conditions that become the basis for performing water control TA11 are engine rotation speed N (step 100), exhaust temperature 11 (step 110), sill suspension S (step 120), and axle opening θ (step 130), J and fuel temperature T (step 140). After reading each of the above driving conditions,
temperature T within the range of ff+'l 1211, for example 40
℃ to below 80°C (steps 150 to 180) In this process, if the fuel temperature 112T is below a predetermined temperature x, for example, 40°C, Step 1
50. J3 and 160), energize the terminal a (28) to supply power to the heater 27 and heat it.Step 17
0), On the other hand, if the temperature of the king is at a predetermined temperature y, for example, 80°C or higher (steps 150 and 1Go), the terminal b
<30> Two letters? 'S to supply refrigerant to the refrigerant passage 32 and turn on the cold IJ (step 180). By performing this process, the temperature of the fuel can be brought to an appropriate state.

Therefore, it is possible to prevent problems such as waxing caused by the fuel temperature being too low, or problems such as vaporization caused by the fuel temperature being too low.

Next, if the fuel temperature is within the control range, for example over 40°C but below 80°C, and the engine speed is overspeed (
step 190), in the case of g-bar heat (step 210), or when there is a lot of smoke (step 230).
> , and if either is true, energize terminal a and heat it: +-! j
jikusuup200>, increase the temperature of the fuel to reduce the fuel vr11J'J suspension.

On the other hand, if the request is not made in any of the above, it is determined whether the driver's request is for high output (step 25o).
). If it is determined that high output is required, the terminals are energized to cool the fuel 741 (step 260). In the determination of overspeed, it is determined whether the engine rotation speed N exceeds a predetermined rotation speed f (step 190). In the determination of overheat 1, the determination is made based on whether or not the exhaust gas temperature [1 exceeds a predetermined temperature 0 (step 210). In the determination of the smoke amount, it is determined whether or not the smoke amount S exceeds a predetermined smoke amount ff1h (step 230). In determining the driver's requested load, it is determined whether or not the opening degree 0 exceeds the predetermined opening degree I (step 250).

In the control of this embodiment, as explained above, various operating conditions are periodically detected, and it is determined whether or not it is necessary to heat or cool the fuel depending on the situation, and heating or cooling is performed according to the rll settings. It will be done.

As explained above, by using the first embodiment, when the combustion temperature is out of range, when over-speeding, when overheating,
The fuel temperature can be changed when the amount of smoke generated increases or when the demand is large. Therefore, waxing caused by engine overspeed, A-bar heat, an increase in smoke amount, or an excessive drop in fuel temperature can be properly corrected by I-[1 heat of combustion v1. , an increase in the required power in driving considerations, or an excessively high fuel temperature can be coped with by using a cold 7Jl combustion engine.

Note that altitude compensation control can be performed by increasing the fuel temperature as the human pressure decreases. On the other hand, the idle speed can be controlled by changing the fuel temperature to 1 as the idle speed changes.

Next, a second embodiment will be explained. This embodiment uses the configuration of the first embodiment to perform a control t21+ in which the fuel temperature is lowered in proportion to the increase in engine speed, as shown in FIG. By controlling in this manner, the A original fuel injection damping characteristic changes from the one shown by the solid line in Figure 9, which shows a decrease in injection 1G1ffi as the upper limit of the engine speed increases, to the Jj1 line. As shown in the figure, the amount of injection increases as the engine speed increases. Therefore, by performing the above control on a fuel injection pump equipped with a governor having the A-le speed 14 characteristics of the J original shown by the solid line in Fig. 10, the characteristics of the intermediate governor with a gentle slope as shown by the dotted line can be achieved. (C7 can be done.

14 characteristics of the above intermediate governor! '7 By doing so, IJII
It is possible to reduce 1-hour shock, jerking, or abnormal vibration of the 1-engine.Furthermore, by changing the fuel temperature change characteristics according to the driving situation or the driver's demands, the output 1-hour performance can be reduced. Characteristics can be made according to driving conditions or driving fee requirements.

Next, another example of the fuel fit temperature changing device whose structure was shown in the first embodiment is shown in FIG. 11 and will be described. The fuel 1) l (Shinma modification 'I (203 in a3, the fuel r1 vibe 220
The fuel supplied from the 3-bot 2-position valve 204i1,
and 2041), the flow is switched to the a fuel vibe 220a or the b fuel vibe 220b. This a
A heater 221 is provided around the fuel vibe 220a, and a cooler 234 is provided around the fuel vibe 220b. Therefore, while the heater 221 and the cooler 234 are always operating, the coil power is applied to the main coil terminals 240 of the three-point/two-position valves 204a, 204b, and 204b under duty control. As a result, fuel passes through the cooler 234 or the heater 221 depending on the duty control ratio. In that case, the control can be performed by changing the duty control ratio at the temperature of the fuel that is mixed again after passing through the cooler 234 or the heater 221.

[Effect of the invention] By using the present invention explained in 1- below, it is possible to achieve
Pump M3 sends 1 fuel to deep pill engine M2
The 'il suspension can be increased or decreased by changing the fuel temperature using the fuel temperature change device M4. Therefore, by using the present invention, without changing the conventional fuel pump M3, the fuel pumped by the fuel injection pump M3 can be increased or decreased by just adding 61 points of in-cylinder peg device. . As a result, when the fuel temperature increases, when it goes over -1, or when it goes over -1, or due to a change in the fuel injection rate, the temperature of the fuel decreases when the rotational speed increases, etc. You can rise to the top and achieve it. On the other hand, the output can be increased by lowering the fuel temperature and increasing the fuel injection amount. Furthermore, various operating characteristics can be achieved by changing the temperature of the fuel based on various operating conditions. .

[Brief explanation of drawings]

Figure 1 is a basic configuration diagram of the present invention, and Figures 2 and 3 show the injection characteristics of the fuel 1 injection control pump as a function of fuel temperature.
Graph, FIG. 4 is a block diagram of the first embodiment, FIG. 5 is a block diagram of the fuel temperature changing device of the first embodiment, FIG. 6 is a block diagram of the first embodiment, and FIG. 7 is a block diagram of the first embodiment. A flowchart of the routine for executing the example, FIG. 8 is a graph showing the control characteristics of the second embodiment, FIG. 9 is a graph showing the change characteristics of the injection amount when the control of the second embodiment is performed, FIG. 10 is a graph showing the characteristics of engine rotation speed and engine torque when the second embodiment is used, and FIG. 11 is a configuration diagram of the pond fuel temperature changing device. Ml...Fuel tank M2...Diesel engine M3...Fuel injection pump M4...Fuel temperature change device M5...Temperature setting device 1...Fuel tank 3.203...Fuel temperature change Device 4...Fuel injection pump 8...Control circuit

Claims (1)

[Claims] A fuel injection pump that pumps fuel supplied from a fuel tank to a diesel engine depending on the operating status of the diesel engine, and a fuel injection pump that is provided between the fuel tank and the fuel injection pump to heat or cool the fuel. A fuel injection device for a diesel engine, comprising: a fuel temperature changing device that changes the temperature of the fuel to a predetermined setting value by changing the temperature of the fuel; and a temperature setting device that sets the predetermined setting value of the fuel temperature changing device. charge control device.