JPH0694837B2 - Fuel injector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel injection device for a diesel engine, and more particularly to a fuel injection device having an all-speed governor.

(Prior Art) As a fuel injection device of a diesel engine, a type including an all-speed governor is widely used in general. This type of fuel injection device includes a fuel injection pump,
It is composed of a governor for controlling the rack of the fuel injection pump, and the accelerator pedal depression amount (engine speed).
The governor is controlled by a control lever which is interlocked with the control lever, and the governor further controls the amount of movement of the rack. By the movement amount control of the rack, the stroke of the plunger of the fuel injection pump is changed, so that the fuel injection amount from the fuel injection nozzle is changed according to the engine speed. Also, control means are used to adjust the rack for optimal linear movement between the idle position and the full throttle position. In the conventional control means, the rack position is detected by a rack sensor (for example, a differential transformer type rack sensor), the detected rack sensor output is converted into a voltage level by a rack amplifier, and the engine is output as shown in FIG. The maximum output point, that is, the rack position at the full throttle position was adjusted to be the output (voltage) of the rack amplifier.

(Problems to be Solved by the Invention) However, in an actual engine, the friction between the respective components of the engine is not constant, and the amount of friction varies from engine to engine. Therefore, the fuel injection amount required at the idling position also increases. It will be different for each engine. Therefore, just by adjusting the output of the rack amplifier at the maximum output point (full throttle position) of the engine as in the conventional adjustment method, the rack amplifier output at the idling position will be different for each engine. ,
The variation shown by the one-dot chain line in FIG. 3 occurs. Therefore, a fuel injection device equipped with an all-speed governor
It was impossible to always control with the optimum fuel injection amount in the entire range from the idling position to the full throttle position.

Therefore, the object of the present invention is not only to adjust the output of the rack amplifier at the maximum output point of the engine, but also to learn the rack amplifier output value at the idle position,
An object of the present invention is to provide a fuel injection device that can solve the above problems.

(Means for Solving Problems) In order to achieve the above object, according to the present invention, an all-speed governor for controlling a rack position of a fuel injection pump,
A lever position detecting means for detecting a position of a control lever for controlling the all speed governor, an output value setting means for a rack sensor for detecting a rack position, and a rotation speed detecting sensor for detecting an engine speed are provided. In the fuel injection device, when the output value setting means of the rack sensor recognizes the idling operation state of the engine from the output signal of the lever position detection means, it is detected that the engine speed is within the idling operation state range. Rotation range detection means, a water temperature detection means for detecting that the cooling water temperature is equal to or higher than a set value when the engine speed is in the idling operation range, and the outputs from the rotation range detection means and the water temperature detection means are normal. At this time, the rack position at the idling position of the engine is corrected by the actual output value of the rack sensor. One is to learn. A fuel injection device characterized by the above.

(Operation) As described above, according to the present invention, the means for setting the output value of the rack sensor (that is, the output value of the rack amplifier) is
In addition to simply adjusting the output of the rack-amplifier at the maximum output point of the engine, it is also configured to adjust the output of the rack-amplifier at the idling position by means of learning the rack-amp output value at the idling position of the engine. Therefore, just as in the conventional case, simply adjusting the rack amplifier output value at the maximum output point of the engine can automatically determine the optimum rack amplifier output value at the idling position that differs depending on the engine. The function of the fuel injector equipped with the speed governor can always be maximized.

EXAMPLES Examples of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a schematic configuration of a fuel injection device of the present invention, and FIG. 2 is a flow chart showing its control procedure.

In FIG. 1, 1 is an engine, 2 is a fuel injection pump,
3 is a governor (all speed governor), 3a is a control lever for controlling the governor 3, for example, an idling position (position shown by a solid line) and a full throttle position (position shown by a broken line) by a stepping motor 4 which is interlocked with an accelerator pedal depression amount. Driven between. 3b is a sensor for detecting the position of the control lever 4. A rack 2a is built in the fuel injection pump 2, and the moving amount of the rack 2a is controlled by the governor 3. Rack 2a
When the fuel cell moves, the fuel injection pump 2
The stroke of the inner plunger is changed so that the amount of fuel injected from the injection nozzle (not shown) into the combustion chamber of the engine is controlled. 5 is a rack sensor for detecting the amount of movement of the rack 2a, 6 is a rack amplifier for converting the output of the rack sensor 5 into a voltage level, 1a is a rotation speed detection sensor of the engine 1, and 1b is a water temperature detection sensor of the engine 1. is there. Reference numeral 7 denotes an electronic control device including a microcomputer, which receives signals from the rotation speed detection sensor 1a, the water temperature detection sensor 1b, the rack amplifier 6, the control lever position detection sensor 3b, etc., and performs the arithmetic processing of the present invention described below. In addition, the control signal is output to the stepping motor 4 to control the control lever 4.

Next, the control of the fuel injection device of the present invention will be described based on the flowchart of FIG.

In this control, the rack sensor output value (that is, the rack amplifier output value) at the idling position of the engine 1 is learned. First, based on the input signal from the control lever position detection sensor 3a, the control lever 3a moves to the idling position. Then, it is determined whether or not (step 1). When it is determined that the engine is in the idling position, whether the engine speed N of the engine 1 is equal to or less than a predetermined set value I or not based on an input signal from the rotation speed detection sensor 1a (step 2) and a predetermined set value. It is judged whether or not it is II or more (step 3). As a result, when it is determined that the engine speed N is within the predetermined set range (set value II <N ≦ set value I), the water temperature detection sensor 1b
On the basis of the input signal from, it is determined whether or not the temperature of the cooling water of the engine 1 is equal to or higher than a predetermined set value (step 4). This is to confirm that the engine 1 has improved the warm-up operation state. Next, the output (voltage) value of the rack amplifier 6 is read (step 5). It is determined whether or not the rack amplifier output value V is less than or equal to a predetermined set value A (step 6) and is greater than or equal to a predetermined set value B (step 7). Accordingly, when it is determined that the output value V of the rack amplifier is within the predetermined setting range (setting value B <V ≦ setting value A), this output value V is stored as the idle rack learning value (step 8 ), Finally, the average value processing of this idle rack learning value and the previously determined idle rack learning value is performed (step 9), the obtained average value is used as the rack control value, and the stepping motor 4 is driven according to this average value. To be done.

Since the above learning is performed for each engine, even if the friction is different for each engine, the engine is always operated with the optimum fuel injection amount in the idling state, and variations in the idling speed are caused. Disappear.

The rack amplifier output (voltage) value read in step 5 is converted into a rack control value according to the processing shown by the following mathematical formula.

here, From the above formula, the rack control value from OO (idle) to FF (full throttle) is obtained.

(Effects of the Invention) As described above, the fuel injection device of the present invention does not simply adjust the output of the rack amplifier only at the maximum output point of the engine as in the prior art, but also adjusts the output at the idling position. The output adjustment at the idling position is performed according to the rack control value obtained as a result of the learning process based on the data that is different for each engine, so even if the friction of the moving parts is different for each engine, it is always optimal for that engine. You can get the fuel injection amount,
The accuracy of engine control can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a fuel injection device of the present invention, FIG. 2 is a flow chart showing control of the fuel injection device of FIG. 1, and FIG. 3 is a conventional method for adjusting the output of a rack amplifier. It is explanatory drawing which shows the characteristic in a case. 1 ... Engine, 2 ... Fuel injection pump, 3 ... Governor, 4 ... Stepping motor, 5 ... Rack sensor,
6 ... Rack amplifier, 7 ... Electronic control unit.

Claims (1)

[Claims] 1. An all-speed governor for controlling a rack position of a fuel injection pump, a lever position detecting means for detecting a position of a control lever for controlling the all-speed governor, and an output value setting of a rack sensor for detecting a rack position. Means and a rotation speed detection sensor for detecting the rotation speed of the engine, the output value setting means of the rack sensor recognizes an idling operation state of the engine from an output signal of the lever position detection means. When the engine speed is within the idling operation range, a rotation range detection means for detecting that the engine speed is within the idling operation state, and when the engine speed is within the idling operation range,
Water temperature detection means for detecting that the cooling water temperature is equal to or higher than a set value, and when the output from the rotation range detection means and the water temperature detection means is normal, the rack position at the idling position of the engine is determined by the actual output value of the rack sensor. A fuel injection device, comprising: a means for learning while making a correction.