JPH051640A - Static injection timing measurement device of diesel engine - Google Patents

Abstract

PURPOSE:To improve measurement precision of fuel injection timing by lessening personal difference and error in measuring a static injection timing of a diesel engine. CONSTITUTION:A stepping motor 1 for crank shaft drive, a nozzle 2 for fuel discharge confirmation, a fuel discharge start detector 3, crank angle standard position detector 4, a motor rotation angle detector 5 and a fuel discharge start timing computing device 6 are provided, and this stepping motor 1 is interlocked and connected to a crank shaft 7 free to rotationally drive at very low speed. The nozzle 2 for fuel discharge confirmation is connected to a discharge port 9 of a fuel injection pump 8, and the fuel discharge start detector 3 faces a discharge space of the nozzle 2 for fuel discharge confirmation. The discharge start timing computing device 6 starts counting rotation angle of the stepping motor 1, finishes counting by a detection signal of the detector 3 and displays the counting result on an injection time display part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static injection timing measuring device for a diesel engine.

[0002]

2. Description of the Related Art Conventionally, the static injection timing of a diesel engine has been measured by the following method as shown in FIG. That is, the fuel discharge port 9 of the fuel injection pump 8
Then, the fuel injection confirmation jig 11 is attached, the crankshaft 7 of the engine is manually rotated, and the discharge of the fuel 12 (slight swelling) from the fuel injection confirmation jig 11 is visually confirmed to perform static injection. I was starting

[0003]

The above-mentioned prior art has the following problems. 1. Since the crankshaft 7 is rotated manually, the rotational angular velocity of the crankshaft 7 varies, and the crankshaft 7 may be over or under rotated. 2. Since the discharge of the fuel 12 (slight swelling) from the fuel injection confirmation jig 9 is visually confirmed, it is difficult to confirm the start of injection. Due to the above 1 and 2, errors in measured values and individual differences are large. An object of the present invention is to improve the accuracy of measurement of fuel injection timing in measuring static injection timing of a diesel engine.

[0004]

In order to achieve the above object, the present invention provides a static injection timing measuring device for a diesel engine as follows, for example, as shown in FIGS. 1 and 2. It is configured to. That is,
This diesel engine static injection timing measuring device includes a crankshaft driving stepping motor 1, a fuel discharge confirmation nozzle 2, a fuel discharge start detector 3, a crank angle reference position detector 4, a motor rotation angle detector 5, and a fuel. The discharge start timing calculation device 6 is provided. The stepping motor 1 is linked to the crankshaft 7 of the engine so as to be rotationally driven at an extremely low speed. Further, the fuel discharge confirmation nozzle 2 is
Connect to the fuel outlet 9 of the fuel injection pump 8 of the engine,
The fuel discharge start detector 3 faces the fuel discharge space of the fuel discharge confirmation nozzle 2. Further, the crank angle reference position detector 4 faces the rotation space of the crank angle reference position T that rotates integrally with the crank shaft 7. Further, the motor rotation angle detector 5 is the stepping motor 1
Attached to. Then, the fuel discharge start timing calculation device 6
Is a reference position detection signal of the crank angle reference position T from the crank angle reference position detector 4, a rotation angle detection signal of the crankshaft 7 from the motor rotation angle detector 5 via the stepping motor 1, and A fuel injection start detection signal is input from the fuel discharge start detector 3 to calculate an injection start angular position S of the fuel injection pump 8 with respect to the crank angle reference position T to display a static injection timing display. It is configured to be displayed on the section 10.

[0005]

The present invention operates as follows. First, the fuel discharge confirmation nozzle 2 is connected to the fuel discharge port 9 of the fuel injection pump 8 of the engine 20, and the fuel discharge start detector 3 is exposed to the fuel discharge space of the fuel discharge confirmation nozzle 2.
Crankshaft drive stepping motor 1 and engine 2
The 0 crankshaft 7 is rotated at an extremely low speed. The fuel discharge start timing calculation device 6 receives a reference position detection signal of the crank angle reference position T from the crank angle reference position detector 4 installed on the crankshaft 7, and a crankshaft reference signal from the motor rotation angle detector 5 via the stepping motor 1. Based on the input of the rotation angle detection signals of 7, the crank angle reference position T is used as a starting point and the rotation angle θ of the stepping motor 1 is started to be counted. Next, the fuel injection pump 8 is operated by the rotation of the crankshaft 7, and the fuel 12 is ejected from the tip of the fuel discharge confirmation nozzle 2. The jetting of the fuel 12 is detected by the infrared detectors such as the LED 13 and the photodiode 14 of the fuel discharge start detector 3, and the fuel discharge start detection signal is input to the fuel discharge start timing calculation device 6 to generate the fuel. The discharge start timing calculation device 6 finishes counting the rotation angle θ of the stepping motor 1, calculates the injection start angular position S of the fuel injection pump 8 with respect to the crank angle reference position T, and outputs the result to the static of the diesel engine. The injection timing is displayed on the static injection timing display unit 10.

[0006]

The present invention has the following effects because it is constructed and operates as described above. 1. The crankshaft 7 of the engine with the stepping motor 1
Since the crankshaft is rotated at an extremely low speed, there is no variation in the rotational angular velocity of the crankshaft 7, and there is no case where the crankshaft 7 is excessively rotated or insufficiently rotated. 2. The ejection of the fuel 12 from the fuel discharge confirmation nozzle 2 is easy to confirm, and the fuel discharge start detector 3 automatically detects it and calculates it by the fuel discharge start timing calculation device 6.
The result is used as the static injection timing, and the static injection timing display unit 10
Since it is displayed in, there is no individual difference. Due to the above 1 and 2, the measurement error is reduced, and the measurement accuracy of the fuel injection timing can be improved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an operation system diagram of a static injection timing measuring device for a diesel engine, and FIG. 2 is a side view of a fuel discharge start detector. In the figure, in a diesel engine 20, a cylinder block 22 is integrally formed above a crankcase 21, and a cylinder head 23 and a head cover 24 are sequentially placed and fixed on the upper surface of the cylinder block 22 to form an engine body. There is. The cylinder block 22
There are cylinders, pistons, etc. inside, and the output of the engine 20 is taken out from the crankshaft 7. Further, the cooling fan 25 is driven by a fan drive pulley 27 installed at the front end of the crankshaft 7 via a conduction belt 26.
A fuel injection pump 8 is attached to the front side surface of the engine 20, and is linked to the crankshaft 7 by a timing gear 28. A static injection timing measuring device for a diesel engine includes a crankshaft driving stepping motor 1, a fuel discharge confirmation nozzle 2, a fuel discharge start detector 3, a crank angle reference position detector 4, a motor rotation angle detector 5, and a fuel discharge. A start timing calculation device 6 is provided. The stepping motor 1 is linked to the crankshaft 7 of the engine 20 so as to be rotationally driven at an extremely low speed. The fuel discharge confirmation nozzle 2 is connected to the fuel discharge port 9 of the fuel injection pump 8 of the engine. As shown in FIG. 2, the fuel discharge start detector 3 is composed of, for example, an infrared detector to which the LED 13 and the photodiode or the phototransistor 14 are applied, and is provided in the fuel discharge space of the fuel discharge confirmation nozzle 2. I am facing. Further, the crank angle reference position detector 4 faces the rotation space of the crank angle reference position T of the fan drive pulley 27 that rotates integrally with the crank shaft 7, for example. The motor rotation angle detector 5 is attached to the stepping motor 1. Then, the fuel discharge start timing calculation device 6 outputs a reference position detection signal of the crank angle reference position T from the crank angle reference position detector 4 and a crankshaft from the motor rotation angle detector 5 via the stepping motor 1. The rotation angle θ of the stepping motor 1 is started to be counted starting from the crank angle reference position T on the basis of the respective inputs of the rotation angle detection signals of 7. Next, the fuel injection pump 8 is operated by the rotation of the crankshaft 7, and the fuel 12 is ejected from the tip of the fuel discharge confirmation nozzle 2. The jetting of the fuel 12 is detected by the infrared detectors such as the LED 13 and the photodiode 14 of the fuel discharge start detector 3, and the fuel discharge start detection signal is input to the fuel discharge start timing calculation device 6 to generate the fuel. The discharge start timing calculation device 6 finishes counting the rotation angle θ of the stepping motor 1, calculates the injection start angular position S of the fuel injection pump 8 with respect to the crank angle reference position T, and outputs the result to the static of the diesel engine. The injection timing is displayed on the static injection timing display unit 10.

The crank angle reference position detector 4 is
Instead of facing the rotation space of the crank angle reference position T of the fan drive pulley 27 that rotates integrally with the crankshaft 7,
Face the outer circumference of the flywheel 29, and place the flywheel 2
It is also possible to detect a match between the fuel injection mark 30 engraved on the outer periphery of 9 and the convex portion 33 of the timing window 32 of the flywheel housing 31. It is also possible to connect the detection signal of the fuel discharge start detector 3 in the embodiment of the present invention to another measuring device so that the measured data can be utilized in a wide range.

[Brief description of drawings]

FIG. 1 is an operation system diagram of a static injection timing measuring device for a diesel engine, showing an embodiment of the present invention.

FIG. 2 is a side view of a fuel discharge start detector according to the embodiment of the present invention.

FIG. 3 is a diagram corresponding to FIG. 2 showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Crank shaft driving stepping motor, 2 ... Fuel discharge confirmation nozzle, 3 ... Fuel discharge start detector, 4 ... Crank angle reference position detector, 5 ... Motor rotation angle detector, 6 ... Fuel discharge start timing calculation device , 7 ... Crankshaft, 8 ... Fuel injection pump, 9 ... Fuel discharge port, 10 ... Static injection timing display, T ... Top dead center position, θ ... Rotation angle.

Claims (1)

Claims: 1. A stepping motor for driving a crankshaft.
(1) -Fuel discharge confirmation nozzle (2) -Fuel discharge start detector
(3) A crank angle reference position detector (4), a motor rotation angle detector (5) and a fuel discharge start timing calculation device (6) are provided, and the stepping motor (1) is a crankshaft of an engine.
The nozzle (2) for confirming the fuel discharge is connected to (7) so that it can be driven to rotate at an extremely low speed,
The fuel discharge start detector connected to the fuel discharge port (9) of
(3) faces the fuel discharge space of the fuel discharge confirmation nozzle (2), and the crank angle reference position detector (4) rotates the crank angle reference position (T) that rotates integrally with the crankshaft (7). )
Facing the rotation space of the motor rotation angle detector (5),
The fuel discharge start timing calculation device (6) attached to the stepping motor (1) is provided with the crank angle reference position detector.
The reference position detection signal of the crank angle reference position (T) is obtained from (4), and the rotation angle detection signal of the crank shaft (7) is transmitted from the motor rotation angle detector (5) via the stepping motor (1).
Then, based on the input of the fuel discharge start detection signals from the fuel discharge start detector (3) respectively, the injection start angular position (S) of the fuel injection pump (8) with respect to the crank angle reference position (T). Static injection timing display
(10) A static injection timing measuring device for a diesel engine, characterized by being configured to display.