JPH0932576A - Upper dead point detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an upper dead point detecting device to accurately detect an upper dead point position of a piston. SOLUTION: An upper dead point detecting device is provided with plural projection-shaped detecting object bodies 3 arranged in a peripheral part of a flywheel of a piston engine of a measuring object, a projection-shaped upper dead point detecting object body 3a arranged in a prescribed position of the peripheral part of the flywheel, a detecting sensor 4 of the detecting object bodies and the upper dead point detecting object body and a pressure detecting sensor 5 arranged in a cylinder of the piston engine, and is provided with an A/D converter 7 to receive output of the detecting sensor and the pressure detecting sensor, a computing element 8 to output the upper dead point of the piston of the piston engine by performing operation by receiving output of the A/D converter and a display device 9 to receive and display output of the computing element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a top dead center detection device applied to the top dead center detection of a piston engine.

[0002]

2. Description of the Related Art Conventionally, the top dead center of each piston of a piston engine is detected by attaching a detection object to a flywheel so that one detection object becomes the top dead center of a specific piston. By. Further, the top dead center of the other piston is determined by equally dividing the time from the detection of the detected object to the next detection by the number of cylinders.

[0003]

The conventional method of detecting the top dead center of the piston by detecting the detecting body mounted on the flywheel of the main engine by using a sensor is described below. If it is, it is extremely difficult to accurately detect the top dead center of the piston without the detector attached, and there is a risk of causing an error.

[0004]

The present invention employs the following means to solve the above-mentioned problems. (1) A plurality of protrusion-shaped detection objects provided around the flywheel of the piston engine to be measured, and projection-shaped top dead center detection objects provided at predetermined positions around the flywheel Body, detection sensors for the detection object and the detection object for top dead center, a pressure detection sensor provided in the cylinder of the piston engine, and an A / D converter that receives the outputs of the detection sensor and the pressure detection sensor And a computing device for receiving the output of the A / D converter and computing and outputting the top dead center of the piston of the piston engine, and a display device for receiving and displaying the output of the computing device.

In the above, the sensor for detecting the rotation of the flywheel detects and outputs the approach of each object and the object to be detected for the top dead center (rotational position of the flywheel) and outputs it. The output of this detection sensor and the output of the pressure detection sensor are A / D converted by the A / D converter and sent to the arithmetic unit.
The computing unit computes and outputs the top dead center of each piston based on the output signal of the top dead center detector of one piston from these input signals. The display device receives the same output and displays it.

In this way, the top dead center position of each piston is accurately detected and displayed. (2) A plurality of projecting objects to be detected, which are provided on the periphery of the flywheel of the piston engine to be measured, detection sensors for the objects, and are provided at predetermined positions on the periphery of the flywheel. Projected top dead center detection target, top dead center detection target top dead center detection sensor, pressure detection sensor provided on the cylinder of the piston engine, the detection sensor, top dead center The A / D converter that receives the output of the detection sensor and the pressure detection sensor and the output of the A / D converter and the top dead center data of the piston of the piston engine that has been input in advance are compared and compared. A top dead center shift determiner for determining and outputting the shift of the dead center and a display device for receiving and displaying the output of the shift determiner are provided.

In the above, the sensor for detecting the rotation of the flywheel detects that each subject is approaching (rotation position of the flywheel) and outputs it. Further, the top dead center detection sensor detects and outputs a predetermined top dead center position of the piston in the same manner as described above. The A / D converter receives the signals from these sensors and the pressure sensor, A / D converts them, and outputs them. The top dead center deviation determiner receives these signals, compares them with the basic top dead center data of the pistons that are input in advance, and determines the deviation of the top dead center of each piston and outputs it. The display device receives this signal and displays it.

In this way, the deviation of the top dead center position of each piston is accurately determined and displayed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) An embodiment of the present invention 1 will be described with reference to FIGS.

In FIG. 1, a plurality of rod-shaped objects to be detected 3, 3a are provided on the side surface of the flywheel 2 at the peripheral portion. A detection sensor 4 is provided at a predetermined position near the flywheel 2 so as to face the object 3 to be detected. The output of the detection sensor 4 is sent to the A / D converter 7. The outputs of the cylinder pressure detection sensor 5 and the fuel injection pressure sensor 6 are sent to the A / D converter 7. The output of the converter 7 is sent to the display device 9 via the calculator 8.

As the number of cylinders of the piston engine 1, for example, six cylinders are attached to the object to be detected 3 as shown in FIGS. 2 and 3. Further, the specific one 3a (for example, one corresponding to the top dead center position of the No. 1 cylinder) is shortened.

The characteristics of the detection sensor 4 are shown in FIG.

In the above, the detected objects 3, 3a attached to the flywheel 2 sequentially pass in front of the detection sensor 4 as the flywheel 2 rotates. Then, the detection sensor 4 outputs a pulse as shown in FIG. 5 (directed downward for easy viewing). In the case of 6 cylinders, combustion is performed sequentially in the order of 1 → 5 → 3 → 4 → 2 → 6 (cylinder). Therefore, 5p in FIG. 5 is the top dead center of the 1st cylinder, and 6p is 5 No. cylinder top dead center, 7
p is the top dead center of the third cylinder, 8p is the top dead center of the fourth cylinder, 9p is the top dead center of the second cylinder, 10p is the top dead center of the sixth cylinder, and 11p is the top dead center of the first cylinder. Is the output voltage. These signals and the outputs of the pressure detection sensor 5 and the fuel injection pressure detection sensor 6 are A / D converted and sent to the calculator 8. From these signals, the calculator 8 calculates and outputs the pressure waveform and the top dead center position with respect to the crank angle for each cylinder as shown in FIG. The display device 9 displays this. In this way, the top dead center of each piston is accurately measured. (2) An embodiment of the present invention 2 will be described with reference to FIGS.

7 and 8, a tooth profile a is formed on the circumference of the flywheel 2 of the piston engine 1a. This is the object to be detected. The detection sensor 4a is provided so as to face the tooth profile a. Further, a rod-shaped top dead center detection object 3a is provided at a predetermined peripheral side surface position of the flywheel 2 corresponding to the top dead center position of one piston. And piston engine 1
A detection sensor 4 for this is provided on the a side.

Detection sensors 4, 4a, pressure detection sensor 6,
The output of the fuel injection pressure detection sensor 7 is the A / D converter 7
And is sent to the top dead center deviation determiner 13. The output of the top dead center deviation determiner 13 is sent to the display device 9a. Also A / D
The output of the converter 12 is sent to the display device 9a.

In the above, the piston engine 1a is, for example, of three cylinders. When the flywheel 2 rotates, the outputs of the detection sensors 4 and 4a are as shown in FIG. The pulse b is generated by the top dead center detected object 3a. The pulse c is due to the tooth profile a. Further, FIG. 10 shows the output when the rotation speed is changing. These are A /
It is converted by the D converter 7, sent to the top dead center judgment device 13 and sent to the display device 9a and displayed as shown in FIG.

Further, a basic top dead center data signal 11s relating to the crank angle and the pressure indicating the top dead center which is obtained in advance as shown in FIG. 6 is sent to the top dead center deviation judging device 13. Judge 1
In 3, the waveform corresponding to FIG. 6 is created for each piston (A, B, C) and compared with the top dead center data signal 11s.
Then, the deviation of the top dead center is determined and displayed on the display unit 15.

In this way, the top dead center of each piston is accurately determined and the deviation is displayed.

[0019]

As described above, according to the present invention, the top dead center position of each piston can be accurately measured. Then, the deviation is displayed.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention 1. FIG.

FIG. 2 is a side view of a flywheel unit having the same configuration.

FIG. 3 is a view taken along line AA of FIG. 2 showing the same configuration.

FIG. 4 is an operation explanatory view of the same embodiment.

FIG. 5 is an operation explanatory view of the same embodiment.

FIG. 6 is an operation explanatory view of the same embodiment and one embodiment of the present invention 2;

FIG. 7 is a configuration block diagram of an embodiment of the present invention 2.

FIG. 8 is a side view of a flywheel unit having the same configuration.

FIG. 9 is an operation explanatory view of the same embodiment.

FIG. 10 is an operation explanatory view of the same embodiment.

[Explanation of symbols]

 1, 1a Piston engine 2 Flywheel 3 Detected body 3a Detected body for top dead center 4, 4a Detection sensor 5 Pressure detection sensor 6 Fuel injection pressure detection sensor 7 A / D converter 8 Computing unit 9, 9a Display device 13 Top dead center deviation detector

Claims (2)

[Claims] 1. A plurality of projecting objects to be detected provided around the flywheel of a piston engine to be measured, and a projecting top dead center provided at predetermined positions around the flywheel. A body to be detected, detection sensors for the body to be detected and the body to be detected for top dead center, a pressure detection sensor provided in a cylinder of the piston engine, and an A / D that receives outputs from the detection sensor and the pressure detection sensor. Same as converter
A top dead center detection device comprising: a calculator for receiving the output of the D converter and calculating and outputting the top dead center of the piston of the piston engine; and a display device for receiving and displaying the output of the calculator. . 2. A plurality of projecting objects to be detected provided on the periphery of a flywheel of a piston engine to be measured, detection sensors for the objects to be detected, and a predetermined position on the periphery of the flywheel. And a protruding object for top dead center detection,
Same as above, the top dead center detection sensor for the dead center detected object, the pressure detection sensor provided in the cylinder of the piston engine, and the output trust of the detection sensor, the top dead center detection sensor and the pressure detection sensor A A / D converter and the output of the A / D converter are compared with the top dead center data of the piston of the piston engine that has been input in advance and is compared in advance to determine the top dead center deviation and output the top dead center. A top dead center detection device comprising: a deviation determiner; and a display device for receiving and displaying an output of the deviation determiner.