JPS63158421A - Drip quantity measuring instrument for liquid injector - Google Patents

Abstract

PURPOSE:To easily, accurately and quantitatively measure oil drips hanging on an injection surface of an injector by bringing a thin pipe into contact with the injection surface and collecting liquid hanging from, remaining on and dropping from a nozzle part. CONSTITUTION:A thin pipe 15 is made such that its distal open end portion is oppositely set below a part from which an oil drip 114 hangs in particular, that is, the injection nozzle 111 of the injection surface 113 of an injector 11. A drive unit 17 drives a holder 16 by a command from a control circuit 18 and controls such that the distal open end portion of the thin pipe 15 is brought into contact with or separated from the injection surface 113. The oil drip 114 taken in to be collected by the thin pipe 15 is picked up by a television camera 22. The control circuit 18 calculates the amount of the oil drip on the basis of resultant image data.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is directed to the treatment of a small amount of fuel that hangs down, stagnates, and drips from the injection nozzle portion of a fuel injector used in an engine, for example, without being injected. This invention relates to a droplet amount measuring device for a liquid injector that measures.

[Prior Art] A fuel injector used in an engine injects pressure-fed fuel from its injection nozzle in the form of a mist. In this case, most of the pressure-fed fuel is ejected from the injection nozzle in the form of mist, but some of it becomes oil droplets that hang down from the injection nozzle.

The oil droplets that hang down from the injection nozzle part of the injector in this way are generated not only due to the valve tightness of the injector but also due to the poor flow of fuel in the injection nozzle, and therefore It is not possible to detect all of the conditions in which oil droplets are generated by means such as automatically measuring valve tightness.

Therefore, the state of oil droplet generation is measured using unique means. For example, oil droplets hanging below the injection nozzle are directly photographed using a television camera. It is thought to be something to observe.

However, in reality, oil droplets are formed thinly on the injection surface of the injector, so the image on the television screen should clearly detect the extent of oil droplets on the end surface of the injector. It is extremely difficult to do so.

Therefore, at present, the injection surface of the fuel injector is observed with the naked eye and the accumulation of dripping fuel oil is evaluated by the operator's visual sense. It is difficult to measure quantitatively due to the large size of the

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and it is an object of the present invention to easily and accurately spray oil droplets dripping onto the injection surface of a fuel injector used in an engine. The present invention aims to provide a droplet amount measuring device for a liquid ejector that can quantitatively measure the droplet amount of a liquid injector.

[Means for Solving the Problems] That is, in the droplet volume Δ-1'' constant device for a liquid injector according to the present invention, a thin tube made of a transparent material is provided on the ejection surface of the injector. The contact is made selectively, and the liquid that hangs down from the nozzle portion, accumulates, and drips is collected in the thin tube.
This thin tube is optically observed to measure the extent of the liquid collected within the tube.

[Operation] In other words, in the above-mentioned measuring device, the liquid such as fuel that hangs down and stays on the injection surface of the injector is brought into contact with the thin tube of the collecting means, so that it drips into the thin tube by capillary phenomenon. Fluid can be inhaled and collected. This collected liquid becomes visible as an image in which the state of light transmission changes within the capillary, for example.
By observing this with an optical means such as a television camera, the extent of the liquid within the tube can be measured, and from this the amount of the retained liquid can be calculated. Therefore, it becomes possible to quantitatively measure the amount of dripped liquid that hangs and stagnates with high precision in a simple state.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a device for measuring the amount of oil droplets in a fuel injector, and the fuel injector 11 to be measured includes:
Fuel is supplied from a hydraulic pump 12. This hydraulic pump 12 is driven by a motor 13 and is configured to set test oil in a fuel tank 14 to a predetermined pressure state and supply it to the injector 11 via a hydraulic vibrator 121. . The fuel is injected in the form of a spray 112 from the injection nozzle Ill of the injector 11, and a portion of the injected fuel is deposited on the injection surface 113 of the injector 11 as oil droplets 114. It starts to droop.

Oil droplets 114 generated on the injection surface 113 of the injector 11
The measurement is performed by collecting the oil droplets 114, and a thin tube 15 made of a transparent material such as glass is used as the oil droplet collecting means. The thin tube 15 is configured such that its tip openings are opposed to the part of the injection surface 113 of the injector 11 where the oil droplets 114 hang down, specifically, the lower side of the injection nozzle 111.

The thin tube 15 is held by a holder 1B, and this holder 1B is supported by a thin tube drive device 17. This drive device 17 drives the holder 16 according to a command from a control circuit 18 constituted by a microcomputer or the like, so that the tip opening of the thin tube 15 comes into contact with the injection surface 113 of the injector 11, and this surface 113 It is controlled so that it is separated from the target.

Here, the drive device 17 is integrally held by the injector ll and the support frame 19, and the relative positional relationship thereof is fixed.

The control circuit 18 further includes air nozzles 20 and 2.
1, the air nozzle 20 blows an air flow to the injection surface 113 of the injector 11 according to a command from the control circuit 18, and blows off the oil droplets 114 accumulated on that surface.
The surface tta is kept in a clean state. Further, the air nozzle 21 sends an air flow into the hollow part of the thin tube 15 in response to a command from the control circuit 18, and discharges the collected oil inside the thin tube 15.

The frame 19 further holds a television camera 22. This camera 22 is connected to the thin tube 1
The video signal taken by this camera 22 is converted into a digital signal by an A/D converter 23 and stored in an image memory 24. The A/D converter 23 and the image memory 24 are controlled by the control circuit 18.
The measurement results based on the video stored in the image memory 24 are displayed on the display device 25 as appropriate.

In the injector 11, when fuel oil is supplied under pressure by the pressure pump 12, the fuel oil is injected into the injection nozzle! At the same time, the oil that is not atomized becomes oil droplets 114 and is sprayed onto the spray surface 11.
It will accumulate to 3. Then, when such a jetting state continues and the amount of oil droplets 114 increases and reaches a state where they cannot be collected on the jetting surface 113, the oil droplets 114 separate from the injector 11 and begin to drip. .

In the above device, in the normal injection state, the thin tube 1
5 is set in a state away from the injection surface 11B, and by injecting air through the nozzle 20 prior to measuring the amount of oil droplets, the oil droplets 114 that had accumulated until then are removed, and the nozzle 21 The oil in the thin tube 15 is discharged by this. Then, the initial state for measuring the amount of oil droplets is set.

When collecting oil droplets 114 for measuring the amount of oil droplets 114, the open tip of the thin tube 15 is brought into contact with the tip surface 113 of the injector 11 as shown in FIG. In this state, the above surface 113
The oil droplets 114 that had accumulated in the tube 15 are now sucked into the hollow part of the thin tube 15 by capillary action.

To further explain the operation of measuring the amount of oil droplets, the nozzle 20
and 21 to remove the oil present in the injection surface 113 and the thin tube 15. Once the initial measurement state is set in this way, the oil droplets 114
wait for generation. When the set time has elapsed in this manner, the control circuit 18 issues a command to the drive device 17 to move the thin tube 15 forward, and the drive device 17 advances the holder 1B of the thin tube 15 in the direction of the injector 11. . And the thin tube 15
The opening at the tip thereof is set in contact with the injection surface 113 as shown in FIG. 2, and in this state, oil droplets 114 are sucked into the thin tube 15.

In this way, the oil droplet 114 is sucked into the thin tube 15,
Once sampled, the control circuit 18 commands the drive 17 to retract so that the capillary tube 15 is moved away from the injector 11 and returned to its initial position.

The television camera 22 photographs the thin tube 15 in this state, and its video signal is output to the A/D converter 23.

In this state, the control circuit 18 generates an image input custard signal and issues a conversion command to the A/D converter 23 based on this signal. Therefore, the A/D converter 23
converts the input video signal into a digital signal, outputs it to the image memory 24, and stores it.

That is, the image memory 24 is configured to store and set digital data of an image as shown in FIG. The amount of oil droplets is calculated based on this image data.

Processing of this image data will be explained based on FIG. 4. First, the control circuit 1B analyzes the brightness in the X direction (horizontal) as shown in step 100 based on the image data stored in the image memory 24. The luminance integral value of the Y1 coordinate at this time is yt-jEoL (Xj, Yl), where the luminance of the coordinate L (Xj, Yl) is (Xj, Yl).

As shown in FIG. 4(B), in step 101, the center Y coordinate of the waveform of the luminance integration result is set as Ya, and the center line rY=Ya J of the thin tube 15 is calculated from this.

Next, as shown in step 102, the coordinates Xa of the two peak points of the image data are determined from the brightness on the center line of the thin tube 15.
and find xb. That is, when oil droplets are collected in the thin tube 15, light is applied to a portion of the thin tube 15 corresponding to the oil 30 due to the collected oil droplets, which becomes brighter, as shown in (C) in FIG. As such, brightness peak points are generated at positions Xa and xb on the Ya axis.

Once the luminance peak point has been obtained in this manner, the distance ΔX between the peak points Xa and xb is determined in step 103. In this case, since the cross-sectional area A of the hollow part of the thin tube 15 can be known in advance, in step 104, the oil droplet Rq collected in the thin tube is determined based on the cross section [A and the distance ΔX. Then, by dividing the calculated amount q of oil droplets by the waiting time for oil droplet generation, the amount of oil droplets generated per unit time is calculated. In this case, if the quality determination level for the amount of oil droplets produced per unit time is set, the quality of the injector 11 can also be determined. At the same time, the above calculation results and pass/fail judgment results are displayed.

In the above embodiment, in order to observe the extent of the oil collected in the thin tube 15, a two-way camera such as a television camera is used.
We decided to use a dimensional sensor, which is based on the thin tube 15.
For example, it is also possible to use a one-dimensional sensor such as a linear sensor or a line sensor, as long as the center line of the sensor can be fixed.

Further, although the air nozzle 20 is used to remove oil droplets from the injection surface 113 of the injector 11, other methods such as wiping them off with a sponge or cloth, or sucking them up with a vacuum pump are also possible.

[Effects of the Invention] As described above, according to the droplet amount measuring device for a liquid injector according to the present invention, it is possible to easily and reliably quantify, for example, the amount of fuel that hangs down and drips from the injection nozzle portion of a fuel injector. It can be measured and evaluated easily and reliably.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram illustrating a droplet amount measuring device according to an embodiment of the present invention, FIG. 2 is a diagram showing an extracted oil droplet collecting portion in the above embodiment, and FIG. 3 is a diagram showing a detection signal in the above device. FIG. 4, which is a diagram explaining the processing state, is a flowchart similarly explaining the processing of the detection signal. 11...Fuel injector, 111...Injection nozzle, 11
2... Spray, 113... Injection surface, 114... Oil droplet, 12 Pressure pump, 15... Thin tube, 17... Drive device (of the thin tube), 18... Control circuit, 20. 21...
Air nozzle, 22... Television camera, 24...
...Image memory, 25...Display device.

Claims (2)

[Claims] (1) means for force-feeding a liquid to be injected to an injector to be measured, and for injecting the force-fed liquid from the injector; A liquid droplet collecting means including a thin tube made of a transparent body, and a detection system that optically reads the transparent thin tube of the collecting means and measures the range of existence of the liquid collected in the thin tube. means, controlling the collection means and the detection device, driving the capillary to bring it into contact with the injection surface of the injector, and further optically reading an image of the capillary in a state in which liquid is collected in the capillary. A control means for causing the liquid that hangs down, stagnates, and drips on the injection surface of the injector to be sucked and collected by the thin tube of the collecting means, and optically measures the amount of liquid sucked into the thin tube. 1. A droplet amount measuring device for a liquid injector, characterized in that the droplet amount measuring device is adapted to read the droplet amount. (2) The droplet amount measuring device for a liquid ejector according to claim 1, wherein the liquid droplet collecting device includes an air pressure feeding means for discharging the liquid in the thin tube.