JPH01155052A - Fuel injection timing controller for diesel engine - Google Patents

Abstract

PURPOSE:To abate the extent of engine noises by setting fuel injection timing after warming to such injection timing that is commensurate to medium and low loads upon making exhaust temperature a parameter. CONSTITUTION:In a fuel injection timing controller for a Diesel engine E, an exhaust temperature sensor 7 of the engine E is connected to an input terminal of a controller 4. At the time of low and medium loads in normal driving, since the exhaust temperature sensor 7 detects a low temperature, the controller 4 operates an injection timing adjuster of a fuel injection pump 1 to the timing delay side, and delays fuel injection timing at angular revolution as compared with large load time, restraining a pressure rise in a cylinder, and diesel knocking is prevented from occurring.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a fuel injection timing control device for a diesel engine. To provide a structure that can be implemented at low cost by simplifying its structure.

<Prior art> The basic structure of a fuel injection timing control device for a diesel engine, which is the subject of the present invention, is shown in FIG. 1, FIG. 2, FIG. 3, or FIG.
As shown in the figure, an adjustment device 2 for adjusting the injection timing of a fuel injection pump 1 of a diesel engine E is configured to be controllable by a control device 4 via an actuator 3. Sensor 5 and rotation speed sensor 6
The controller 4 is of a type configured to adjust the adjuster 2 toward the advance side as the temperature detected by the body temperature sensor 5 is lower and the speed detected by the rotational speed sensor 6 is faster. be.

In the conventional technology of the above type, a rotational speed sensor 6 is provided on the flywheel of the engine E to detect the engine rotational speed, a water temperature sensor 5 is attached to the control device 4 to detect the body temperature of the engine, and the rotational speed is There is a system in which the fuel injection timing of the engine E is controlled by the control device 4 by 7 degrees based on information on the number and temperature.

That is, as shown in Figs. 6 and 7, the relationship between engine speed and advance angle at each water temperature from low water temperature WL (e.g. 10°C) to high water temperature WH (e.g. 60'C) is controlled. The device 4 is programmed to: (1) When the equivalent temperature T≦WL detected by the water temperature sensor 5, calculate the injection timing according to the rotation speed according to the low water temperature Wl+ program; (2) When Wll<T, Takagi〆=Calculate the injection timing according to the rotation speed according to the wn program, (3) When Wl, <T≦Wll, calculate the injection timing according to the rotation speed according to each intermediate water temperature program between the low water temperature program and the high water temperature program. The actuator 5 calculates the injection timing and receives this control signal to actually adjust the injection timing of the fuel injection pump l.

<Problems to be solved by the invention> In the above conventional technology, when warming up the engine E,
In response to a rise in the airframe temperature of engine E (i.e., in response to a rise to around Takagi R, W If after passing through the low water temperature WL)
If the advance timing can be controlled, or if the engine is in normal operating condition after warm-up, the engine temperature of engine E will be higher than the set high water temperature WH, so the high water temperature WH program will be used for the entire operation. Applicable across areas.

Therefore, in normal operation, for a certain rotation speed of the engine E, a specific advance angle corresponding to the high water temperature program, that is, the injection timing is uniquely determined, and the injection timing is determined by the load on the engine E. In this case, the injection timing is set to the most advanced side in order to operate the engine E smoothly, taking safety into account and not corresponding to a predetermined large load.

As a result, even if the load on engine E is not very large, the injection timing is mechanically set to the most advanced side = 3-, so the injection timing is earlier than the injection timing appropriate for the medium/low load. , the advance angle becomes too large), causing premature ignition, resulting in diesel knock, and the noise becomes louder.

The technical objective of the present invention is to reduce engine noise even during medium and low load during normal operation.

Means for solving the above problems> Means for achieving the above two problems will be explained below using drawings corresponding to embodiments.

That is, the present invention provides a fuel injection timing control device for a diesel engine having the basic structure described above, in which the exhaust gas temperature sensor 7 of the engine E is connected to the input terminal of the control device 4.
This is characterized in that when the temperature detected by the exhaust temperature sensor 7 is low, the end adjuster 2 is adjusted to the retard side.

Effect> During low to medium load during normal operation of the engine E, the bleed air temperature sensor 7 detects a low exhaust temperature, so the control device 4
operates the regulator 2 to the retarded side to delay the fuel injection timing at each rotation speed compared to that during heavy load during normal operation, suppressing the pressure rise in the cylinder and preventing diesel knock. .

<Effects of the Invention> (1) By controlling the fuel injection timing of a day cell engine based on rotational speed and body temperature, and by adding information on exhaust temperature, it is possible to correct the injection timing according to the engine load. Therefore, during normal engine operation at low or medium load, the injection timing can be changed to the retarded side to reduce engine noise.

(2) Since the structure is simple, just adding an exhaust temperature sensor provided in the exhaust path of the engine to the control device, it can be implemented at low cost using an existing injection timing control device.

<Example> Hereinafter, embodiments of the present invention will be described based on the drawings.

Figure 1 shows the flowchart 1 of the injection timing control system for a diesel engine, Figure 2 is a schematic plan view of the same engine, and Figure 3 shows the flowchart of the injection timing control device for a diesel engine.
The figure is a schematic vertical cross-sectional view of the fuel injection pump, Figure 4 is a diagram of advance angle control versus rotation speed, and Figure 5 is a diagram of advance angle control versus υl temperature. A chamber 10 is provided, the fuel injection pump 1 is accommodated in the accommodation chamber IO, the plunger 11 of the pump 1 is driven by a fuel injection camshaft 12 linked to the crankshaft, and the fuel outlet 14 of the pump 1 is connected to the fuel injection nozzle 15. Connect to.

An actuator 3 is attached to the side wall of the pump housing chamber 10, and the actuator 1 is linked to the injection timing adjuster 2 of the fuel injection pump 1 so that the injection timing can be advanced or retarded.
The actuator 1 is interlocked with a control device 4 incorporating a PU.

The rotational speed sensor 6 is attached to the flywheel 16 attached to the left side of the engine E, and the water jacket 17 of the engine E is attached to the flywheel 16 attached to the left side of the engine E.
A water temperature sensor 5 is attached to the engine E, and an exhaust temperature sensor 7 is attached to an exhaust manifold 18 attached to the rear wall of the engine E, and these sensors are connected to the control device 4.

As shown in FIG. 2, the fuel injection pump 1 is composed of a casing 22, a plunger 11, a fuel metering device 21, and a fuel injection timing adjustment device 2. At the same time, the upper part of the plunger 11 is linked to the rotary fuel injection timing adjustment tool 2, and the plunger 11 is slidably moved up and down by the adjustment tool 2, thereby advancing or advancing the fuel injection timing. Configure to enable retardation.

Then, the rotational speed sensor 6 detects the rotational speed of the engine E, the water temperature sensor 5 detects the airframe temperature, and the exhaust temperature sensor 7 detects the load on the engine E, and inputs them into the control device 4. Appropriate fuel injection timing, ie, advance angle, is calculated from information on temperature and load, and control device 4 operates actuator 3 to adjust adjuster 2, thereby adjusting the advance angle of fuel injection pump 1.

Therefore, the functions of the control device 4 will be explained based on FIG. 3.

FIG. 7 is a program diagram at each water temperature used in the prior art, in which the relationship between the rotational speed of the engine E and the advance angle at a predetermined water temperature is uniquely programmed. I also use =8-.

That is, if the temperature calculated from the detection signal of the water temperature sensor 5 is T, the low water temperature preset by the control device 4 is WL, and the high water temperature is WH, (1) When T≦WL, the low water temperature program is executed. The advance angle at each rotation speed is calculated according to the line.

(2) When WL<T (・WM)≦WH, the advance angle at each rotation speed is calculated according to the intermediate water temperature (・WM) program line corresponding to each temperature.

(3) On the other hand, FIG. 4 is a program diagram at each exhaust temperature, and the relationship between the engine E rotation speed and advance angle at a predetermined exhaust temperature (i.e., a predetermined load) is uniquely programmed. When W+(<T, the advance angle is calculated as follows according to the exhaust gas temperature calculated from the exhaust gas temperature sensor 7.

That is, the temperature calculated from the detection signal of the exhaust temperature sensor 7 is T.
and the low exhaust temperature preset by the control device 4, that is,
(corresponding to low load) is GL, and high exhaust temperature (i.e. corresponding to high load) is GH. (a) When T≦GL, the advance angle at each rotation speed is calculated according to the low exhaust temperature program line. .

(0) When GL<T(-GM)<GH, the advance angle at each rotation speed is calculated according to the intermediate exhaust temperature (.GM) program line corresponding to each temperature.

(c) When Wll≦T, the advance angle at each rotation speed is calculated according to the high exhaust temperature program line.

As a result, the load on engine E and the exhaust temperature are proportional, so
During normal operation of the diesel engine E during medium/low load, the exhaust temperature sensor 7 detects a low exhaust temperature Gl and operates the regulator 2 to the retard side to control the fuel injection, as shown in FIG. By delaying the injection timing of the pump 1 and reducing the pressure peak in the cylinder, diesel knock can be suppressed.

Conversely, when the engine E is under a high load, the exhaust temperature sensor 7 detects the high exhaust temperature Gl and operates the adjuster 2 to the advance side to adjust the injection timing of the fuel injection pump 1. Let it proceed;
Engine E can be maintained at high output.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention, FIG. 1 is a flowchart of the control device of the injection timing control device of the Tee Cell engine, FIG. 2 is a schematic plan view of the engine, and FIG. 3 is the fuel injection timing control device of the T-cell engine. Figure 4 is a schematic longitudinal cross-sectional view of the injection pump, and Figure 4 is a program diagram of engine speed and advance angle at each exhaust temperature.
The figure is a program diagram of the exhaust temperature and advance angle at a given engine speed, Figure 6 is a diagram equivalent to Figure 3 showing the conventional technology, and Figure 7 is the engine revolution speed and advance angle at various water temperatures showing the conventional technology. This is a program diagram. 1. Fuel injection pump, 2. Injection timing adjuster, 3. Actuator, 4. Control device, 5. Aircraft temperature sensor, 6.
Rotational speed sensor, 7 - Exhaust temperature sensor, E...Engine. Patent distributor Kubota Iron Works Co., Ltd.

Claims (1)

[Claims] 1. The injection timing adjuster 2 of the fuel injection pump 1 of the diesel engine E is configured to be controllable by a control device 4 via an actuator 3, and the body temperature sensor 5 and rotational speed sensor of the engine E are connected to input terminals of the control device 4. Connect 6 and
The lower the temperature detected by the aircraft body temperature sensor 5, the lower the temperature detected by the control device 4 is.
In a diesel engine fuel injection timing control device configured such that the faster the detection speed of the rotational speed sensor 6 is, the more the adjuster 2 is adjusted to the advance side, the exhaust temperature sensor 7 of the engine E is connected to the input terminal of the control device 4. Connect and control device 4
is a fuel injection timing control device for a diesel engine, characterized in that the lower the temperature detected by the exhaust temperature sensor 7, the more the adjuster 2 is adjusted to the retarded side.