JP2010255530A - Liquid flow rate measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid flow rate measuring device capable of accurately and efficiently measuring a liquid flow rate in a measured apparatus without being influenced by a temperature change of an environment even if the flow rate is minute. <P>SOLUTION: The device includes a liquid tank 1 storing liquid 2, a transparent thin pipe 3 having a smaller diameter then the liquid tank 1, a first supply control means 10 connecting the liquid tank 1 and the thin pipe 3, supplying and shutting off the liquid 2 to the thin pipe 3 from the liquid tank 1, and a second supply control means 11 supplying liquid 2 from to the measured apparatus I from the thin pipe 3. When the liquid introduced from the thin pipe 3 by the operation of the measured apparatus I is discharged after the supply of the liquid 2 to the thin pipe 3 is shut off by the first supply control means 10, a liquid discharge flow rate at the measured apparatus I is read out based on a liquid surface change in the thin pipe 3 accompanied by the discharge. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid flow rate measuring apparatus for measuring a liquid flow rate in a device to be measured, for example, a fuel injection flow rate of an electromagnetic fuel injection valve for an engine.

  A liquid flow rate measuring device for measuring a fuel injection flow rate of an electromagnetic fuel injection valve for an engine is already known as disclosed in Patent Document 1.

JP 2006-105656 A

  The liquid flow rate measuring device described in Patent Document 1 includes a housing having a sealed chamber that receives fuel injected from a fuel injection valve, and a volume change of fuel that is connected to the sealed chamber and injected from the fuel injection valve into the sealed chamber. Detecting means for detecting, and measuring the injection flow rate of the fuel injection valve from the volume change of the injected fuel detected by the detecting means.

  In such a conventional device, the fuel injected from the fuel injection valve is in an atomized state immediately after injection, so it is necessary to wait for it to become a liquefied state and detect the volume change of the fuel injected into the sealed chamber. Yes, it takes a long time to measure, and the measurement cannot be performed efficiently. In addition, when a small amount of fuel is injected into the sealed chamber, the volume change of the fuel in the sealed chamber is extremely small, and it is extremely difficult to obtain the fuel injection amount from the minute volume change. Therefore, for example, it is extremely difficult to obtain the single fuel injection flow rate of the fuel injection valve. Furthermore, since the volume change of the fuel injected into the sealed chamber is also affected by the ambient temperature change, there is a problem in the reliability of measurement accuracy.

  The present invention has been made in view of such circumstances, and a liquid flow rate measuring device capable of accurately and efficiently measuring a liquid flow rate in a device to be measured even if a small amount of liquid flow rate is not affected by ambient temperature changes. The purpose is to provide.

  In order to achieve the above object, a liquid flow rate measuring device according to the present invention comprises a liquid tank for storing liquid, a thin tube having a diameter smaller than that of the liquid tank, and a liquid tank and a thin tube connected to each other. The first supply control means for supplying and blocking the liquid to the apparatus, the second supply control means for supplying the liquid from the thin tube to the device to be measured, and the first supply control for supplying the liquid from the liquid tank to the thin tube And a flow rate reading means for reading the liquid discharge flow rate of the measured device from the change in the liquid level in the narrow tube that accompanies the discharge when the measured device discharges the fluid introduced from the narrow tube due to its operation. This is the first feature.

  In addition to the first feature, the second feature of the present invention is that the second supply control means is configured so that the supply of the liquid from the thin tube to the device to be measured can be shut off.

  In addition to the first or second feature, the third feature of the present invention is that the upper space in the liquid tank and the narrow tube communicate with each other.

  Furthermore, according to the present invention, in addition to any of the first to third features, the device to be measured is an electromagnetic fuel injection valve, the liquid is fuel, and a fuel injection pressure is applied to the fuel injection valve. Accordingly, a fourth feature is that a gas pressure source for applying a predetermined gas pressure to the liquid surface in the narrow tube is provided. The gas pressure source corresponds to the air pressure source 22 in the embodiment of the present invention described later.

  According to the first feature of the present invention, since the liquid flow rate in the device under measurement is measured based on the amount of change in the liquid level in the narrow tube, it is influenced by the temperature change at the outlet side of the device under measurement. Therefore, the liquid flow rate in the device to be measured can be measured efficiently and accurately. In particular, if the capillaries are formed with a very small diameter, the liquid level in the capillaries can be changed sensitively even when a small amount of liquid flows out of the capillaries, and therefore it is possible to measure a minute amount of liquid flow in the device being measured. Become.

  According to the second feature of the present invention, when the device to be measured is replaced, the second supply control means is turned off to prevent unnecessary liquid from flowing out of the narrow tube.

  According to the third aspect of the present invention, when the liquid is supplied to the liquid tank, the liquid level in the narrow tube rises smoothly while pushing the air in the upper part through the communication pipe to the liquid tank side. It becomes the same level as the liquid level. Accordingly, the level of liquid in the liquid tank can be known by looking at the level of liquid in the transparent thin tube, and the suitability of the replenishment amount of the liquid can be determined.

  According to the fourth aspect of the present invention, the fuel injection flow rate of the electromagnetic fuel injection valve can be measured efficiently and accurately. In particular, the use of a very small diameter tube allows the liquid level in the tube to be sensitively changed even when a small amount of fuel flows out of the tube, and therefore measurement of a small amount of fuel injection flow of the fuel injection valve once. Is also possible.

1 is a schematic side view of a liquid flow rate measuring apparatus according to a first embodiment of the present invention. The outline side view of the liquid flow measuring device concerning the 2nd example of the present invention. The outline side view of the liquid flow measuring device concerning the 3rd example of the present invention.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings. First, the description starts with the description of the first embodiment of the present invention shown in FIG.

  The liquid flow rate measuring device M is used for measuring the fuel injection flow rate of the engine electromagnetic fuel injection valve I, and is disposed adjacent to a fuel tank 1 for storing fuel 2 and one side of the fuel tank 1. And a thin tube 3 made of transparent glass. The thin tube 3 is formed to have a diameter much smaller than that of the fuel tank 1. The fuel tank 1 has a fuel filler opening 1b normally closed with a cap 9 at the top. The fuel tank 1 and the narrow tube 3 communicate with each other at the bottoms thereof via a first supply path 4, and a first shutoff valve 6 is provided in the middle of the first supply path 4. Be dressed. Thus, the first supply path 4 and the first cutoff valve 6 constitute a first supply control means 10 that supplies and shuts off the fuel 2 from the fuel tank 1 to the narrow tube 3.

  In addition, a communication passage 13 is directly connected to the upper spaces 1a and 3a of the fuel tank 1 and the narrow tube 3 so as to communicate them directly with each other.

  An electromagnetic fuel injection valve I as a device to be measured is connected to the lower end portion of the thin tube 3 via a second supply path 5, and a second cutoff valve 7 that can shut it off is connected to the second supply path 5. Is inserted. Thus, the second supply path 5 and the second cutoff valve 7 constitute second supply control means 11 that supplies and shuts off the fuel 2 from the narrow tube 3 to the fuel injection valve I.

  An injection signal means 15 for outputting an injection signal is connected to the fuel injection valve I, and a fuel reservoir 14 for receiving the fuel injected from the fuel injection valve I is installed immediately below the fuel injection valve I. Is done. Is done.

  On one side of the narrow tube 3, a CCD camera 17 is disposed as a liquid level sensor that reads the fuel liquid level L1 or L2 in the tube. The CCD camera 17 outputs the read liquid level signal in the narrow tube 3 to the electronic control unit 18, and the electronic control unit 18 detects the liquid level change amount h obtained from the liquid level signal, A map 19 showing the relationship with the fuel outflow amount Q from the corresponding narrow tube 3 is provided, and the fuel outflow amount obtained from the map 19 is displayed on the monitor 20 in a timely manner. Thus, the CCD camera 17, the electronic control unit 18, and the monitor 20 constitute a flow rate reading means 21 that reads the fuel injection flow rate of the fuel injection valve I from the liquid level change in the narrow tube 3.

  The upper spaces 1a and 3a of the fuel tank 1 and the narrow tube 3 are connected to branch pipes 23a and 23b that are bifurcated on the downstream side of the pressure conduit 23 extending from the air pressure source 22, and to the pressure conduit 23, , A third shut-off valve 8, a regulator valve 25, and a pressure sensor 26 are provided in this order from the upstream side. The regulator valve 25 adjusts the air pressure applied from the air pressure source 22 to the fuel liquid level L1 in the narrow tube 3 so as to correspond to the prescribed injection pressure of the fuel injection valve I. The regulator valve 25 is disposed upstream of the branch point 24 of the branch pipes 23 a and 23 b of the pressure conduit 23.

  Next, the operation of the first embodiment will be described.

  In measuring the injected fuel flow rate of the electromagnetic fuel injection valve I, first, the first shutoff valve 6 is opened, the second and third shutoff valves 7 and 8 are shut off, and the downstream of the second supply path 5 An electromagnetic fuel injection valve I to be measured is connected to the end. If fuel is supplied to the fuel tank 1 from the fuel filler port 1 b, the fuel is also supplied to the narrow tube 3 through the first supply path 4. At that time, since the fuel tank 1 and the upper spaces 1a, 3a of the narrow tube 3 communicate with each other via the communication passage 13, the liquid level L1 in the narrow tube 3 causes the air in the upper space 3a to pass through the communication passage 13. The fuel tank 1 rises smoothly while being pushed out to the upper space 1a side, and reaches the same level as the liquid level in the fuel tank 1. Accordingly, it is possible to know the liquid level in the fuel tank 1 by observing the liquid level in the transparent thin tube 3 and determine whether or not the fuel replenishment amount is appropriate.

  Next, by opening the second and third shut-off valves 7 and 8 and causing the pressure of the air pressure source 22 regulated by the regulator valve 25 to act on the fuel level in the fuel tank 1 and the narrow tube 3, An injection pressure is applied to the electromagnetic fuel injection valve I.

  Therefore, the fuel level L 1 in the narrow tube 3 at this time is read by the CCD camera 17 and the level signal is output to the electronic control unit 18. If the injection signal output means 15 is operated to give a predetermined number of injection signals to the electromagnetic fuel injection valve I, the fuel injection valve I will inject the fuel in the narrow tube 3 toward the fuel reservoir 14 a predetermined number of times. . As a result, the fuel level in the narrow tube 3 falls from L1 to L2, and when the CCD camera 17 reads the lowered fuel level L2 and outputs the level signal to the electronic control unit 18, the electronic control unit 18 Calculates the level change amount h from the liquid level signal and the initial level signal, and obtains the fuel outflow amount from the narrow tube 3, that is, the fuel injection flow rate of the fuel injection valve I from the map 19, and displays it on the monitor 20. To do.

  Thus, since the fuel injection flow rate of the fuel injection valve I is measured based on the change amount h of the fuel liquid level L1, L2 in the narrow tube 3, it is influenced by the temperature change on the outlet side of the fuel injection valve I. In addition, the fuel injection flow rate of the fuel injection valve I can be measured immediately and accurately. In particular, if the narrow tube 3 is formed with a very small diameter, the fuel level in the narrow tube 3 can be sensitively changed from L1 to L2 even when a small amount of fuel flows out of the narrow tube 3, and therefore the fuel injection valve I It is also possible to measure a small amount of fuel injection flow rate at the time of one valve opening.

  After the measurement, the second shutoff valve 7 is again shut off, and the fuel injection valve I newly measured in the second supply path 5 is replaced with the fuel injection valve I after the measurement. When the fuel injection valve I is replaced, unnecessary fuel outflow from the narrow tube 3 can be prevented by closing the second shutoff valve 7. During this time, the third shut-off valve 8 may remain open. Thereafter, the first shutoff valve 6 is opened, and the fuel in the fuel tank 1 is replenished to the narrow tube 3 side through the first supply path 4, and the fuel level in the narrow tube 3 is changed to the fuel level in the fuel tank 1. To match. Then, the fuel level in the narrow tube 3 is read by the CCD camera 17, and thereafter, the fuel injection flow rate of the new fuel injection valve I is measured in the same manner as described above.

  In the first embodiment, the fuel tank 1 and the upper spaces 1a, 3a in the narrow tube 3 are also communicated with each other by the pressure conduit 23 downstream of the third shut-off valve 8, so that both upper spaces 1a, Even if the communication path 13 that directly communicates 3a with each other is eliminated, the communication state between the upper spaces 1a and 3a can be ensured. However, if the communication path 13 is provided, the communication distance can be shortened as much as possible to reduce the flow resistance of the communication path 13 as much as possible, so that fuel can be smoothly supplied from the fuel tank 1 to the narrow tube 3.

  Next, a second embodiment of the present invention shown in FIG. 2 will be described.

  The second embodiment corresponds to the first embodiment in which the branch pipe 23a communicating with the upper space 1a of the fuel tank 1 of the pressure conduit 23 is eliminated. Therefore, the pressure conduit 23 is connected only to the upper space 3 a of the narrow tube 3. In FIG. 2, parts corresponding to those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  According to the second embodiment, the piping structure of the pressure conduit 23 can be simplified, and the communication path 13 ensures the communication between the upper spaces 1a and 3a of the fuel tank 1 and the narrow tube 3, Fuel can be replenished from the fuel tank 1 to the narrow tube 3 without hindrance.

  Finally, a third embodiment of the present invention shown in FIG. 3 will be described.

  This third embodiment corresponds to the pressure pipe 23 in which the branch pipe 23b communicating with the upper space 3a of the thin pipe 3 is eliminated in the first embodiment. Therefore, the pressure conduit 23 is connected only to the upper space 1 a of the fuel tank 1. In FIG. 3, parts corresponding to those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  According to the third embodiment, the piping structure of the pressure conduit 23 can be simplified, and the air pressure of the air pressure source 22 is applied to the fuel liquid levels L1 and L2 in the narrow tube 3 through the communication passage 13. be able to.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, instead of the air pressure source 22, a pressure source formed by compressing another gas can be used.

I: Equipment to be measured (electromagnetic fuel injection valve)
L1, L2 ... Liquid level M in the narrow tube ... Liquid flow measuring device 1 ... Liquid tank (fuel tank)
1a .. Upper space of liquid tank 2 ... Liquid (fuel)
3... Fine tube 3 a... Upper space 10 of the thin tube... First supply control means 11... Second supply control means valve element 13. Flow rate reading means 22... Gas pressure source (air pressure source)

Claims (4)

  A liquid tank (1) for storing the liquid (2), a thin tube (3) having a diameter smaller than that of the liquid tank (1), and the liquid tank (1) and the thin tube (3) are connected to each other. The first supply control means (10) for supplying and shutting off the liquid (2) from the 1) to the thin tube (3) and the liquid (2) from the thin tube (3) to the device to be measured (I). After the second supply control means (11) and the supply of the liquid (2) from the liquid tank (1) to the thin tube (3) are shut off by the first supply control means (10), the device to be measured (I) When the fluid introduced from the narrow tube (3) is discharged by the operation, the flow rate reading means (21) for reading the liquid discharge flow rate of the device to be measured (I) from the liquid level change in the narrow tube (3) accompanying the discharge A liquid flow rate measuring device characterized by comprising: In the liquid flow measuring device according to claim 1,
A liquid flow rate measuring apparatus, wherein the second supply control means (11) is configured to be able to block the supply of the liquid (2) from the narrow tube (3) to the device to be measured (I). In the liquid flow measuring device according to claim 1 or 2,
A liquid flow rate measuring device characterized in that the upper space (1a, 3a) in the liquid tank (1) and the narrow tube (3) communicate with each other. In the liquid flow measuring device according to claims 1 to 3,
The device to be measured is an electromagnetic fuel injection valve (I), and the liquid is fuel (2). The liquid level in the narrow tube (3) is applied to the fuel injection valve (I) to apply fuel injection pressure. A liquid flow rate measuring device comprising a gas pressure source (22) for applying a predetermined gas pressure to (L1).

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