JP3666561B2 - Injection hole inspection apparatus and injection hole inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection hole inspection apparatus and an injection hole inspection method for inspecting a processing state of an injection hole by measuring a liquid column injected from the injection hole. The liquid column represents a columnar liquid that proceeds without being atomized even when ejected from the nozzle hole.
[0002]
[Prior art]
In recent years, there has been a demand for reducing exhaust gas and improving fuel consumption from the viewpoint of preventing environmental pollution. The concentration and diffusion state of the spray formed by injecting fuel from the injection hole of a fuel injection device used in an internal combustion engine (hereinafter referred to as “the internal combustion engine”) are deeply related to exhaust gas reduction and fuel efficiency improvement. . Therefore, as disclosed in JP-A-10-148599, various apparatuses and methods for inspecting fuel spray are disclosed.
[0003]
The spray characteristics vary depending on the processing conditions of the injection holes for fuel injection, that is, the number of injection holes, the inclination angle and formation position of the injection holes that determine the injection position, the size and shape of the injection holes, and so on. It is important to accurately inspect the processing state of the nozzle hole. However, even if the liquid is injected from the fuel injection device and the spray is measured, the processing state of the injection hole cannot be inspected.
[0004]
Conventionally, the inspection of the processing state of the nozzle hole is generally performed by the following methods (1) and (2). (1) Magnify and observe the shape of the surface injection hole from the outside of the fuel injection device with a microscope or the like. (2) The nozzle part having the injection hole is cut, and the shape and direction inside the injection hole and the relative positional relationship between the fuel passage on the upstream side of the fuel and the injection hole are measured.
[0005]
[Problems to be solved by the invention]
In the above method (1), the shape inside the nozzle hole cannot be inspected. In the method (2), since the nozzle portion is cut, even a good product cannot be used as a product. Furthermore, there is a problem that a long time is required for the inspection. In the case of a fuel injection device having a large number of injection holes, it is difficult to inspect all the injection holes by the method (2).
The objective of this invention is providing the nozzle hole inspection apparatus and nozzle hole inspection method which test | inspect the process state of a nozzle hole with high precision, without damaging an injection device.
[0006]
[Means for Solving the Problems]
According to the nozzle hole inspection device of the first aspect of the present invention, the pressure of the liquid supplied from the liquid supply device to the ejection device is set so that the liquid is ejected from the nozzle hole in a liquid column shape. The liquid column is measured in a cross section to be measured irradiated with a planar sheet light to inspect the processing state of the nozzle hole. By measuring the liquid column in the measurement cross-section, the number of injection holes, the inclination angle and the forming position of the injection hole can be tested the size and shape of the injection hole. Therefore, it is possible to easily and accurately inspect the processing state of the nozzle hole including the inside of the nozzle hole without cutting the nozzle portion having the nozzle hole. Even in the case of a porous fuel injection device, the liquid columns injected from the injection holes do not collide with each other, so that the processing state of each injection hole can be inspected with high accuracy. Furthermore, since inspection is easy, 100% inspection can be performed instead of sampling inspection.
[0007]
Further, the injection pressure of the liquid ejected from the nozzle hole is made lower than that during actual use of the ejection device, and the ejected liquid is used as a liquid column.
Injection hole inspection apparatus according to claim 2 of the present invention using the injection hole inspection apparatus according to claim 1, wherein in order to check the working condition of the injection hole of the internal combustion engine fuel injection system. The injection pressure than during actual use of the fuel injection system to lower, and the liquid column rather than spraying liquid by injecting liquid at a pressure of ^{0.5kgf / cm 2 ~1.2kgf / cm 2} .
[0008]
According to the injection hole inspection method according to claim 3 of the present invention, the processing state of the injection hole is inspected by measuring the liquid column injected from the injection hole in the cross section to be measured irradiated with the planar sheet light. Yes. By measuring the liquid column, the number of injection holes, the inclination angle and the forming position of the injection hole can be tested the size and shape of the injection hole. Therefore, it is possible to easily and accurately inspect the processing state of the nozzle hole including the inside of the nozzle hole without cutting the nozzle portion having the nozzle hole.
[0009]
In addition, by setting the injection time longer than that during actual use, the imaging period can be easily adjusted to the injection period .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, examples showing embodiments of the present invention will be described with reference to the drawings.
An injection hole inspection apparatus according to an embodiment of the present invention is shown in FIG.
The injection hole inspection apparatus according to the present embodiment is an apparatus that inspects the processing state of the injection hole of the fuel injection device 1 for a gasoline engine. The injection hole inspection device includes a liquid supply device 10, a first light projecting unit 20, a second light projecting unit 30, an image capturing unit 40, and a data processing unit 50, and from a liquid column of fuel irradiated with laser sheet light. It is an apparatus for inspecting the processing state of each nozzle hole by measuring the intensity of the scattered light emitted.
[0011]
The fuel injection device 1 has a total of twelve injection holes, and performs two-way injection with six injection holes. The liquid supply device 10 is a device that regulates the pressure of a dry sol belt, which is a liquid for measurement, and supplies the pressure to the fuel injection device 1. The liquid supply device 10 includes a liquid pump, a pressure regulating valve, a pressure gauge, and the like, and regulates the pressure of the liquid supplied to the fuel injection device 1 by measuring the output pressure regulated by the pressure regulating valve with the pressure gauge. The fuel injection device 1 injects the liquid supplied from the liquid supply device 10 from each nozzle hole as liquid columns 2 and 3 instead of spraying. The dry sol belt is generally used for injection inspection of a fuel injection device because the viscosity is almost equal to that of gasoline and hardly ignited.
[0012]
The first light projecting unit 20 and the second light projecting unit 30 are installed facing both sides of the liquid columns 2 and 3 so that the laser sheet light emitted from each of the first light projecting unit 20 and the second light projecting unit 30 overlaps the measured cross sections of the liquid columns 2 and 3. Yes. The first light projecting unit 20 and the second light projecting unit 30 have substantially the same configuration, and sheet forming means 22 and 32 using a telecentric optical system composed of a combination of semiconductor laser oscillators 21 and 31 and a cylindrical lens, respectively. It has. The sheet forming means 22 and 32 process the laser beam generated by the semiconductor laser oscillators 21 and 31 into a planar laser sheet light having a predetermined spread and thickness and having a uniform surface intensity parallel to the cross section to be measured. And output.
[0013]
The imaging unit 40 is installed closer to the nozzle hole side of the fuel injection device 1 than the measurement target cross section, and images the measurement cross sections of the liquid columns 2 and 3 from an angle of 45 degrees with respect to the axis of the fuel injection device 1. The imaging unit 40 includes a condensing lens, a CCD, and the like, and transmits a data signal representing the intensity of the scattered light to the data processing unit 50 by receiving and photoelectrically converting the scattered light of the liquid column in the cross section to be measured.
[0014]
The data processing unit 50 includes a microcomputer that processes the data signal input from the imaging unit 40 according to a predetermined algorithm. The display device 51 is connected to the data processing unit 50, and the cross-sectional shape of the liquid column in the cross section to be measured irradiated by the laser sheet light 100 is displayed on the screen as shown in FIG.
[0015]
Hereinafter, the operation of the above-described injection hole inspection apparatus will be described.
The fuel injection device 1 is installed by determining the distance from the injection hole to the cross section to be measured, and the liquid is injected at a predetermined time. The pressure of the liquid supplied from the liquid supply device 10 to the fuel injection device 1 is lower than the pressure (about 3 kgf / cm ² ) for injecting gasoline from the fuel injection device 1 during actual use, and is 0.5 kgf / cm ² to 1. It is set in the range of ² kgf / cm ² . In this embodiment, it is set to 0.8 kgf / cm ² . Thus, by lowering the injection pressure than during actual use, the liquid is injected from each nozzle hole as a liquid column instead of spray.
[0016]
The injection time injected from the fuel injection device 1 is set longer than the injection time of the fuel injection device 1 during actual use. It is easy to match the exposure time and the ejection time for photographing the liquid columns 2 and 3 with the imaging unit 40. For example, the liquid can be continuously ejected during a plurality of consecutive photographings by the imaging unit 40. Laser sheet light is projected from the first light projecting unit 20 and the second light projecting unit 30 onto the liquid columns 2 and 3 simultaneously after a predetermined time has elapsed since the ejection.
[0017]
By adjusting the control signals sent to the semiconductor laser oscillators 21 and 31, the first light projecting unit 20 and the second light projecting unit 30 can output the laser sheet light as pulsed light or continuous light. The laser sheet light projected from the first light projecting unit 20 and the second light projecting unit 30 is planar light perpendicular to the traveling direction of the liquid columns 2 and 3, and the liquid columns 2 and 3 are measured. The liquid columns 2 and 3 are entered so as to be cut at the cross section. Each laser sheet light travels while being attenuated by passing through the liquid columns 2 and 3. By irradiating laser sheet light from the opposite direction toward the other side so that the first light projecting unit 20 and the second light projecting unit 30 overlap each other in the measured cross section, laser sheet light having substantially uniform intensity in the measured cross section is obtained. Can be formed.
[0018]
The liquid columns 2 and 3 that have received the laser sheet light diverge scattered light in all directions. The imaging unit 40 that has received the scattered light transmits a data signal representing the intensity of the scattered light to the data processing unit 50. The exposure time of the imaging unit 40 is set in the range of 1/100 to 1/2 second. The spray positions of the liquid columns 2 and 3 are not limited to one point, and vary within a certain range without colliding with each other. Therefore, by extending the exposure time within the above-described time, the spray positions of the liquid columns 2 and 3 that vary within the exposure time can be averaged, and the spray positions of the liquid columns 2 and 3 can be measured with high accuracy. By measuring the injection positions of the liquid columns 2 and 3, the inclination angle and formation position of the injection holes can be inspected with high accuracy. If the exposure time is shortened within the above-described time, the variation in the ejection positions of the liquid columns 2 and 3 is small, and there is a possibility that the ejection positions of the liquid columns 2 and 3 cannot be measured with high accuracy. However, since the dispersion of the injection positions of the liquid columns 2 and 3 is reduced, the size and shape of the liquid columns 2 and 3 in the cross section to be measured, that is, the size and shape of the nozzle holes can be inspected with high accuracy.
[0019]
The data processing unit 50 geometrically corrects the coordinates of the data signal received from the imaging unit 40 based on the axial direction of the fuel injection device 1 and the angle at which the imaging unit 40 captures the cross section to be measured. That is, since the liquid columns 2 and 3 distributed in a hexagonal shape on the circumference of the cross section to be measured are distorted due to photographing the cross section to be measured from an oblique direction, a process for correcting this is taken. Execute. The scattered light image data captured a plurality of times by the imaging unit 40 may be input to the data processing unit 50, and the image data at each imaging point may be averaged to reduce scattered light variation.
The measurement value calculated by the above-described processing in the data processing unit 50 is transmitted to the display device 51 as a data signal, and a liquid column image on the cross section to be measured is displayed on the screen of the display device 51.
[0020]
According to the injection hole inspection apparatus and injection hole inspection method according to the present embodiment, the liquid injected from the fuel injection device 1 is not a spray but a liquid column, and the measured cross section of the liquid column is measured, whereby the number of injection holes and the injection hole It is possible to easily and accurately inspect the inclination angle and formation position of the nozzle and the size and shape of the nozzle hole in a short time without cutting the fuel injection device.
[0021]
Further, since the laser sheet light is projected onto the liquid column from the two directions facing each other, measurement errors due to the attenuation of the laser sheet light by the liquid column can be reduced, and measurement with high analysis accuracy can be performed.
Furthermore, since the laser sheet light is projected by using the sheet forming means 22 and 32 to which the telecentric optical system is applied, the measurement error due to the unevenness of the intensity of the laser sheet light can be reduced, and measurement with high analysis accuracy can be performed. .
[0022]
In this example, the liquid column was irradiated with laser sheet light using the first light projecting unit 20 and the second light projecting unit 30. However, the laser beam may be irradiated to the liquid column with one light projecting unit. Alternatively, the imaging units 40 may be arranged at substantially symmetric positions with respect to the axis of the fuel injection device 1, and an image of the liquid column in the cross section to be measured may be taken.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an injection hole inspection apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing the position of a liquid column on a surface to be measured.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection apparatus 10 Liquid supply apparatus 20 1st light projection part 30 2nd light projection part 40 Image pick-up part 50 Data processing part 100 Laser sheet light

Claims (4)

An injection hole inspection device for inspecting the processing state of the injection hole formed in the injection device,
A liquid supply device that supplies liquid to the ejection device, a light projecting unit that irradiates planar sheet light having a predetermined thickness and spread so as to overlap a cross section to be measured of the liquid ejected from the nozzle hole, An imaging unit that records an image of the measured cross section irradiated with sheet light, and a data processing unit that analyzes the image recorded by the imaging unit,
The pressure of the liquid supplied from the liquid supply device to the ejection device is set so that the liquid is ejected in a liquid column shape from the nozzle hole, and the pressure of the liquid ejected from the nozzle hole is the actual pressure of the ejection device. A nozzle inspection device characterized by being lower than in use . Used as the injection hole inspection apparatus for inspecting a processed state of the nozzle hole of the internal combustion engine fuel injection system, 0.5 kgf / cm ² ~ 1.2kgf / cm ² Injection hole inspection apparatus according to claim 1, wherein the jetting fluid at a pressure of. Measuring the liquid column in the cross section to be measured irradiated with the planar sheet light having a predetermined thickness and spread by making the injection time for injecting the liquid in the liquid column shape from the injection hole of the injection device longer than in actual use. injection hole inspection method characterized by checking the machining state of the nozzle hole by. 4. The nozzle hole inspection method according to claim 3, wherein an exposure time of an imaging unit that records an image of a liquid column in the cross section to be measured is set in a range of 1/100 to 1/2 second.

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