CN107489575B - A multi-parameter measurement device and measurement method for engine fuel injection performance - Google Patents

Abstract

The invention discloses a multi-parameter measuring device and method for engine fuel injection performance. The device comprises a measuring plate, a crankshaft installation hole, a crankshaft rotation angle dial, a dial pointer, a fuel injector installation hole, an oil beam measurement scale line and a camera. The device, the multi-parameter measurement method of the fuel injection performance of the two-stroke aviation heavy oil piston engine of the present invention uses the designed multi-function measuring board, which can measure the fuel injection advance angle, the fuel injection duration angle, the injection penetration, the fuel injection wide angle, and the fuel injection quantity. , injection rate, and analysis of normal injection conditions. It solves the problems that the traditional engine fuel injection performance measurement method can only measure one or two parameters, but cannot collect all parameters in place, and has many instruments, complicated operation and high measurement cost. It has the advantages of multi-function, low cost, high efficiency, convenient and quick operation and so on.

Description

A multi-parameter measurement device and measurement method for engine fuel injection performance

technical field

The invention relates to the field of measurement of fuel injection performance parameters of piston engines, in particular to a multi-parameter measurement device and measurement method for fuel injection performance of a two-stroke aviation heavy oil piston engine.

Background technique

Two-stroke aviation heavy oil piston engines play a very important role in general aviation and unmanned aerial vehicles. Obtaining all the parameters of the engine fuel injection performance is an essential step in the management of the engine fuel supply system. The engine fuel injection performance measurement methods involved in the prior art can only measure one or two of these parameters, and measure all the fuel injection of the entire engine. Performance parameters require a lot of equipment, which is not only expensive, but also complicated and cumbersome in the process, inconvenient to operate, and low in measurement efficiency. Therefore, it is necessary to develop a measurement method that can measure the multi-parameters of the fuel injection performance of the full two-stroke aviation heavy oil piston engine.

The traditional engine fuel injection performance parameter measurement method, such as the fuel injector opening time measuring device disclosed in Chinese utility model patent CN201110261378, although it can relatively accurately determine the fuel injector opening time, it cannot measure other important injectors such as fuel injection advance angle. Oil performance parameters; another example is the method for measuring the fuel injection law disclosed in patent CN201410248080, which can accurately measure the fuel injection quantity, but the whole system has many components, and cannot measure other fuel injection performance parameters such as the penetration of oil jet; The disclosed device for observing the fuel injection situation of the diesel engine injector has complex additional devices such as exhaust fans and spiral exhaust pipes, and the measured fuel injection quality has a large error with the actual fuel injection situation of the engine.

SUMMARY OF THE INVENTION

Based on the above technical problems of incomplete measurement of engine fuel injection performance parameters, complex device and high cost, the present invention provides a device and method for measuring multiple parameters of fuel injection performance of a two-stroke aviation heavy oil piston engine. The designed multifunctional measurement board can meet the requirements of multi-parameter measurement of fuel injection performance. Compared with the traditional measurement method, this method has the advantages of multi-function, low cost, high efficiency, convenient and quick operation and so on.

The complete technical solution of the present invention includes:

A multi-parameter measuring device for engine fuel injection performance, comprising a measuring plate, a crankshaft installation hole, a crankshaft rotation angle dial, a dial pointer, an injector installation hole, an oil beam measurement scale line and a camera device.

The measuring plate is provided with a crankshaft angle dial, a crankshaft installation hole and an injector installation hole, the crankshaft installation hole is located at the center of the crankshaft angle dial, and is installed on the crankshaft through the crankshaft installation hole, and the crankshaft angle dial is concentric with the crankshaft, There is a clearance fit between the crankshaft installation hole and the engine crankshaft. The crankshaft angle dial has an angle scale. The dial pointer is located in the installation hole on the crankshaft surface and can rotate with the crankshaft, that is, the dial pointer can indicate the crankshaft angle. The installation hole of the fuel injector is installed on the fuel injector, and the oil beam measurement scale line is arranged on the measuring plate, and is located at the position where each fuel injection hole is directly facing out.

The scales on the crankshaft angle dial are in units of 1 degree, with a total of 360 scales.

There is an interference fit between the dial pointer and the mounting hole on the crankshaft surface.

The crankshaft of the engine is mounted on the left side of the measuring plate, and the injectors are mounted on the right side of the measuring plate.

The important scales on the crankshaft angle dial are indicated in red. Preferably, the crankshaft angle dial is the scale pointed by the dial pointer when the engine piston reaches the top dead center, and 9 degrees before reaching the top dead center. The corresponding scale at 12 degrees and 15 degrees.

There is a small interference fit between the injector mounting hole and the injector, and the injector and the measuring plate form a tight fit and are perpendicular to it without relative movement;

After installation, the position of the injection hole of the injector is 5mm away from the measuring plate.

The number of oil beam measurement scale lines is determined according to the number of fuel injection holes of the fuel injector, preferably 4 or 5.

The oil beam measurement scale line scale is 300mm long, the minimum scale is 1mm, and the 0 scale is the position of the oil injection hole.

The surface of the measuring plate is frosted.

The imaging device is a high-speed camera. Preferably, the high-speed camera can capture 1000 frames per second.

The method for measuring the fuel injection performance parameters using the multi-parameter measuring device for fuel injection performance of the engine is characterized in that, the method for measuring the fuel injection advance angle is as follows: the measurement starts when the dynamometer reverses the engine speed to a certain speed, and uses The camera device records the entire process of fuel injection by the fuel injector, and observes the fuel injection situation in the image processing software. When the fuel beam first appears at the exit of the fuel injection hole in a certain frame, the position of the dial pointer and the top dead center The included angle Φ of the position is the fuel injection advance angle.

Said certain rotational speed is 600 rpm.

The measurement method of the fuel injection duration angle is as follows: the measurement starts when the dynamometer reverses the engine speed to a certain speed, records the entire fuel injection process of the fuel injector with a camera device, and observes the fuel injection situation in the image processing software. When the frame oil beam starts to leave the outlet of the injection hole, the angle △Φ between the position pointed by the dial pointer and the position of the injection advance angle is the injection duration angle.

Said certain rotational speed is 600 rpm.

The fuel injection penetration measurement method is as follows: when the dynamometer reverses the engine speed to the first speed, the second speed, and the third speed, use the camera to record the whole process of the fuel injection of the fuel injector, and observe the corresponding fuel injection in the image processing software. In the case of fuel injection at rotational speed, when the oil beam begins to leave the outlet of the injection hole in a certain frame, record the position where the beginning of the oil beam reaches the measurement scale line of the oil beam and the position where the end of the oil beam is located. The size of the oil penetration.

Preferably, the first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm.

The fuel injection quantity measurement method is as follows: when the dynamometer reverses the engine speed to the first speed, the second speed and the third speed, use the camera to record the whole process of the fuel injector, and calculate the corresponding speed in the image processing software. The pixel area of the picture occupied by the oil beam when the oil beam leaves the injector, and the fuel injection amount is determined according to the relationship between the calibrated pixel area and the oil amount.

Preferably, the first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm.

The fuel injection wide-angle measurement method is: when the dynamometer reverses the engine speed to the first speed, the second speed, and the third speed, use the camera to record the whole process of the fuel injector; observe the corresponding speed in the image processing software The shape of the oil beam, the angle α between the upper boundary and the lower boundary of the oil beam is the wide angle of injection.

Preferably, the first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm.

The injection rate measurement method is: when the dynamometer reverses the engine speed to the first speed, the second speed, and the third speed, the camera device is used to record the whole process of the fuel injector, and the corresponding speed is recorded in the image processing software. The scale value L ₁ of the beginning of the oil beam on the scale line at T1 and the scale value L ₂ of the beginning of the oil beam _on the scale line at the next frame T2 are calculated by using the difference ΔL of the _two scales and the time interval ΔT The fuel injection rate at the moment.

Preferably, the first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm.

The injection situation analysis method is: when the dynamometer reverses the engine speed to the first speed, the second speed, and the third speed, and the plunger angle is adjusted to the single-cylinder circulating oil volume at the first oil volume and the second oil volume respectively. When it is in position, use a camera to record the whole process of fuel injection of the fuel injector in multiple cycles of the engine, and observe whether there are abnormal injections such as alternate injection and secondary injection in the image processing software. Whether the difference in fuel injection quantity between adjacent cycles meets the requirements, and when secondary injection occurs, it can be measured whether the fuel injection duration angle and the fuel injection penetration meet the requirements.

Preferably, the first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm.

Preferably, the first oil amount is 3 mg, and the second oil amount is 12 mg.

Preferably, the multiple cycles are 10 cycles.

The advantages of the present invention relative to the prior art are:

(1) The multifunctional measuring plate of the present invention simultaneously includes a crankshaft angle dial and an oil beam measurement scale, which can be coupled with a variety of measurement methods, and has the advantages of multifunctionality and high efficiency.

(2) The measuring method of the present invention requires less instruments and has the advantage of low cost.

(3) The measurement method of the present invention has the advantages of simple operation, reliable measurement results and strong practicability.

Description of drawings

FIG. 1 is a plan view of the multifunctional measuring board of the present invention.

FIG. 2 is a schematic diagram of the method for measuring the fuel injection advance angle of the present invention.

3 is a schematic diagram of the method for measuring the fuel injection persistence angle of the present invention.

FIG. 4 is a schematic diagram of the method for measuring injection penetration, wide angle of fuel injection and fuel injection quantity according to the present invention.

FIG. 5 is a schematic diagram of the method for measuring the injection rate of the present invention.

In the picture: 101- crankshaft mounting hole, 102- crankshaft angle dial, 103- dial pointer, 104- important scale, 105- fuel injector mounting hole, 106- oil beam measurement scale line, 201- where the dial pointer is located Position, 202-injector, 203-fuel beam, 204-fuel injection advance angle.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

One aspect of the present invention provides a multifunctional measuring board, the embodiment is as follows:

As shown in FIG. 1 , the multifunctional measuring plate of the present invention includes five parts: crankshaft installation hole 101 , crankshaft angle dial 102 , dial pointer 103 , fuel injector installation hole 105 , and oil beam measurement scale line 106 . The crankshaft of the engine is mounted on the left side of the measuring plate, and the injectors are mounted on the right side of the measuring plate.

The crankshaft mounting hole 101 and the engine crankshaft are in clearance fit, and there will be no mutual friction between the two, so the vibration of the engine crankshaft will not be transmitted to the measuring plate, which ensures the stability of the measuring plate.

The said dial is installed at the position concentric with the crankshaft, with 1 degree as the unit, there are 360 scales in total, among which the important scale 104, such as the scale pointed by the dial pointer 103 when the engine piston reaches the top dead center, the top dead center. The corresponding scales at the first 9 degrees, 12 degrees and 15 degrees are drawn with red lines, which is convenient for comparing the actual fuel injection advance angle with the theoretical fuel injection advance angle during measurement.

The dial pointer 103 is seated in the mounting hole on the surface of the crankshaft, and the two are interference fit. During installation, super glue is added to the hole to ensure that the dial pointer 103 after installation will not be damaged due to the centrifugal force of the high-speed rotation of the crankshaft. It is thrown out, and the pointer can indicate the crankshaft angle.

The surface of the measuring plate is frosted to ensure that the lens will not be reflected when shooting for fuel injection performance measurement. The performance measurement needs to be used in conjunction with a high-speed camera capable of shooting 1,000 frames per second.

There is a small interference fit between the injector installation hole 105 and the injector. After the injector is installed, it forms a tight fit with the measuring plate and is perpendicular to it, and there is no relative movement to ensure that the injector is in the process of performance measurement. The position is fixed, which improves the reliability of the measurement; the position of the injection hole of the injector after installation is 5mm away from the measuring plate.

The oil beam measurement scale line 106 is pasted on the measuring plate through Velcro, which is firmly pasted and will not loosen during the measurement process; 5 pieces, attached to the position facing each injection hole after the injector is installed on the measuring plate, to ensure the accuracy of measuring the relevant fuel injection performance parameters; the length of the scale line is 300mm, the minimum scale is 1mm, and the 0 scale is It is considered to be where the injection hole is located.

According to another aspect of the present invention, there is provided a method for measuring fuel injection advance angle, fuel injection duration angle, injection penetration, fuel injection wide angle, fuel injection quantity, injection rate and analyzing normal injection conditions. The embodiments are:

A schematic diagram of the fuel injection advance angle measurement method of the present invention is shown in FIG. 2 . The measurement starts when the speed of the dynamometer anti-drag engine reaches 600 rpm, and the whole process of fuel injection by the fuel injector 202 is recorded with a high-speed camera. Observe the situation of fuel injection in professional image processing software. When the oil beam 203 appears for the first time at the exit of the fuel injection hole in a certain frame, the angle Φ204 between the position 201 where the dial pointer 103 is located and the top dead center position is the fuel injection. advance angle.

A schematic diagram of the fuel injection persistence angle measurement method of the present invention is shown in FIG. 3 . The measurement started when the dynamometer reversed the engine speed to 600 rpm, and a high-speed camera was used to record the whole process of fuel injection by the fuel injector. Observe the situation of fuel injection in professional image processing software. When the oil beam 303 of a certain frame starts to leave the outlet of the fuel injection hole, the angle △Φ between the position 301 pointed by the dial pointer 103 and the position of the fuel injection advance angle is the injection Oil persistence angle.

A schematic diagram of the method for measuring injection penetration, wide angle of fuel injection, and fuel injection quantity of the present invention is shown in FIG. 4 .

The fuel injection penetration measurement was started when the dynamometer anti-trag engine speed reached 600, 1800, and 2400 rpm, and a high-speed camera was used to record the entire fuel injection process of the fuel injector. Observe the fuel injection situation at the corresponding speed in professional image processing software. When a certain frame of oil beam 303 begins to leave the outlet of the injection hole, record the position where the beginning of the oil beam reaches the oil beam measurement scale line 106 and the position where the end of the oil beam is located. , the scale difference L401 of the two positions can represent the size of the injection penetration.

The fuel injection wide-angle measurement starts when the dynamometer anti-trag engine speed reaches 600, 1800, and 2400 rpm, and a high-speed camera is used to record the entire process of fuel injection by the fuel injector. Observe the shape of the oil beam at the corresponding speed in professional image processing software. The angle α402 between the upper boundary and the lower boundary of the oil beam is the wide angle of injection.

The fuel injection quantity measurement starts when the dynamometer anti-drag engine speed reaches 600, 1800, and 2400 rpm, and a high-speed camera is used to record the entire process of fuel injection by the fuel injector. In professional image processing software, calculate the pixel area of the picture occupied by the oil beam 403 when the oil beam at the corresponding speed leaves the injector, and determine the fuel injection amount according to the relationship between the calibrated pixel area and the oil amount.

The schematic diagram of the injection rate measurement method of the present invention is shown in FIG. 5 . The measurement started when the dynamometer reversed the engine speed to 600, 1800, and 2400 rpm, and a high-speed camera was used to record the whole process of fuel injection by the fuel injector. In the professional image processing software, record the scale value L ₁ of the beginning of the oil beam 502 on the scale line at _a certain time T1 of the corresponding rotation speed and the scale value L ₂ of the beginning of the oil beam 501 _on the scale line at the next frame T2. The difference between the scales ΔL503 and the time interval ΔT is used to calculate the fuel injection rate at the moment.

The analysis of the normal injection situation is started when the dynamometer anti-trag engine speed reaches 600, 1800, 2400 rpm, the plunger angle is adjusted to the position of 3 mg and 12 mg of circulating oil in a single cylinder, and the injector is recorded with a high-speed camera. In the whole process of the 10-cycle fuel injection of the engine, a total of 6 groups are measured. In the professional image processing software, observe whether there are abnormal injections such as alternate injections and secondary injections. When the alternate injection occurs, the adjacent cycles can be measured. Whether the difference in fuel injection quantity meets the requirements, and when secondary injection occurs, it can be measured whether the fuel injection duration angle and the fuel injection penetration meet the requirements.

The above are only preferred embodiments of the present invention and do not limit the present invention. Any simple modifications, changes and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still belong to the technology of the present invention. within the scope of the program.

Claims (8)

1. an engine fuel injection performance multi-parameter measuring device, is characterized in that, comprises measuring plate, crankshaft mounting hole, crankshaft angle dial, dial pointer, fuel injector mounting hole, oil beam measuring scale line and camera device, The measuring plate is provided with a crankshaft angle dial, a crankshaft installation hole and a fuel injector installation hole. The crankshaft installation hole is located at the center of the crankshaft angle dial and is in clearance fit with the engine crankshaft; the crankshaft angle dial is concentric with the crankshaft, so the There is a clearance fit between the crankshaft installation hole and the engine crankshaft, the crankshaft angle dial has an angle scale, and the dial pointer is located in the installation hole on the crankshaft surface and can rotate with the crankshaft, that is, the dial pointer can indicate the crankshaft rotation angle; The fuel injector installation hole is installed on the fuel injector, and the oil beam measurement scale line is set on the measuring plate, and is located at the position facing each fuel injection hole, The scale on the crank angle dial is in units of 1 degree, with a total of 360 scales. There is an interference fit between the dial pointer and the mounting hole on the surface of the crankshaft. The crankshaft of the engine is installed on the left side of the measuring plate, the injector is installed on the right side of the measuring plate, The important scales on the crankshaft angle dial are indicated in red, and the important scales refer to the scales pointed by the dial pointer when the engine piston reaches the top dead center, 9 degrees, 12 degrees, and 15 degrees before the top dead center. corresponding scale; The injector and the measuring plate form a tight fit and are perpendicular to it, and there is no relative movement; After installation, the position of the injection hole of the injector is 5mm away from the measuring plate. The number of oil beam measurement scale lines is determined according to the number of fuel injection holes of the injector, which is 4 or 5. The oil beam measurement scale line scale is 300mm long, the minimum scale is 1mm, and the 0 scale is the position of the oil injection hole. The surface of the measuring plate is frosted, The imaging device is a high-speed camera, and the high-speed camera can capture 1000 frames per second. 2. utilize the multi-parameter measuring device of engine fuel injection performance according to claim 1 to measure the method for fuel injection performance parameter, it is characterized in that, the fuel injection advance angle measurement method is: in the dynamometer reverse drag engine speed to a certain Start at the speed of rotation, use a camera to record the whole process of fuel injection by the injector, and observe the fuel injection situation in the image processing software. The angle Φ between the position and the top dead center position is the fuel injection advance angle, and a certain rotational speed is 600 rpm. 3. utilize the multi-parameter measuring device of engine fuel injection performance according to claim 1 to measure the method for fuel injection performance parameter, it is characterized in that, the fuel injection duration angle measurement method is: in the dynamometer reverse drag engine speed to a certain Start at the speed of rotation, use a camera to record the whole process of fuel injection by the injector, and observe the fuel injection situation in the image processing software. The included angle △Φ of the fuel injection advance angle position is the fuel injection sustained angle, Said certain rotational speed is 600 rpm. 4. utilize the multi-parameter measuring device of engine fuel injection performance as claimed in claim 1 to measure the method for fuel injection performance parameter, it is characterized in that, the fuel injection penetration measurement method is: in the dynamometer reverse drag engine speed to the first When the rotational speed, the second rotational speed and the third rotational speed are used, the whole process of fuel injection by the injector is recorded by the camera device, and the fuel injection situation of the corresponding rotational speed is observed in the image processing software. When a certain frame of oil beam starts to leave the outlet of the injection hole When , record the position where the beginning of the oil beam reaches the measuring scale line of the oil beam and the position where the end of the oil beam is located. The difference L between the two positions represents the size of the injection penetration. The first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm. 5. utilize the multi-parameter measuring device of engine fuel injection performance as claimed in claim 1 to measure the method for fuel injection performance parameter, it is characterized in that, the fuel injection quantity measurement method is: in the dynamometer reverse drag engine speed to the first speed , the second rotational speed and the third rotational speed, respectively use a camera to record the whole process of fuel injection of the injector, and calculate the pixel area of the picture occupied by the oil beam at the corresponding speed when the oil beam leaves the injector in the image processing software. The relationship between the pixel area and the fuel quantity to determine the fuel injection quantity, The first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm. 6. utilize the multi-parameter measuring device of engine fuel injection performance according to claim 1 to measure the method for fuel injection performance parameter, it is characterized in that, the fuel injection wide-angle measurement method is: at the dynamometer reverse drag engine rotational speed to the first rotational speed , the second speed, and the third speed, use the camera to record the whole process of the fuel injector respectively; observe the shape of the oil beam at the corresponding speed in the image processing software, the angle α between the upper boundary and the lower boundary of the oil beam is the injection oil wide angle, The first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm. 7. utilize the multi-parameter measuring device of engine fuel injection performance according to claim 1 to measure the method for fuel injection performance parameter, it is characterized in that, the injection rate measuring method is: in the dynamometer reverse drag engine rotating speed to the first rotating speed, At the second rotational speed and the third rotational speed, the camera device is used to record the whole process of fuel injection of the injector, and the scale value L1 at the beginning _of the oil beam on the scale line at _a certain time T1 of the corresponding rotational speed and the next frame are recorded in the image processing software. The scale value L ₂ at the beginning of the oil beam on the scale line at the time of T ₂ , the difference ΔL between the two scales and the time interval ΔT are used to calculate the fuel injection rate at this moment, The first rotational speed is 600 rpm, the second rotational speed is 1800 rpm, and the third rotational speed is 2400 rpm. 8. utilize the multi-parameter measuring device of engine fuel injection performance as claimed in claim 1 to measure the method for fuel injection performance parameters, it is characterized in that, the injection situation analysis method is: in the dynamometer reverse drag engine rotating speed to the first rotating speed, When the second rotational speed and the third rotational speed are used, and the plunger angle is adjusted to the position of the single-cylinder circulating oil amount at the first oil amount and the second oil amount respectively, use a camera to record the fuel injection of the injector in multiple cycles of the engine. During the process, observe whether there is abnormal injection in the image processing software. When the second injection occurs, it can measure whether the difference in the fuel injection volume of the adjacent cycle meets the requirements. whether the degree meets the requirements, The first rotating speed is 600 rpm, the second rotating speed is 1800 rpm, and the third rotating speed is 2400 rpm. The first oil amount is 3mg, the second oil amount is 12mg, The multiple cycles described are 10 cycles.

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