JP2016044661A - Injection measuring device and injection measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an appropriate measurement to be carried out without requiring any troublesome works.SOLUTION: A measurement control device 8 of this invention injects liquid from an injection nozzle 2 into a closed vessel 1, calculates a frequency fof a pressure oscillation and a rise amount ΔPof pressure, measures a mass Nof discharged liquid in order to return a pressure in the closed vessel 1 to a prescribed back-pressure with a mass flow meter 7 and sets a coefficient M in view of an equation of M=N×f/ΔP. The measurement control device 8 calculates an injection-quantity Iq in reference to an equation of Iq=M×(ΔP/f) under application of a frequency (f) of pressure oscillation calculated in respect to injection of liquid in subsequent measurement of liquid injection amount, a rise amount of pressure ΔP and a coefficient M.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for improving measurement accuracy in an injection measurement device.

  As the injection measuring device, as shown in FIG. 4, a cylinder-shaped measurement container 100 filled with a test liquid, a nozzle (valve needle) 101 for spraying the test liquid into the measurement container 100, and a test in the measurement container 100 There is known an injection measuring device including a pressure sensor 103 disposed at a node of a first pressure natural vibration 102 that vibrates along a longitudinal axis of a liquid measurement container 100 (Patent Document 1).

  Here, in this injection measurement device, the pressure fluctuation accompanying the injection of the inspection liquid from the nozzle 101 into the measurement container 100 is detected by the pressure sensor 103, the detected pressure fluctuation is subjected to frequency analysis, and the first pressure inherent The speed of sound is obtained from the frequency of the first harmonic of the vibration 102 and the estimated wavelength that is the wavelength of the first harmonic estimated from the distance in the longitudinal direction of the measurement container 100. Then, from the calculated sound velocity, the volume of the measurement container 100, and the pressure increase amount of the test liquid in the measurement container 100 detected by the pressure sensor 103, the injection amount of the test liquid injected from the nozzle 101 into the measurement container 100 Is calculated.

  According to such an injection measurement device, since the pressure sensor 103 is arranged at the node of the first pressure natural vibration 102 that vibrates along the longitudinal axis of the measurement container 100 of the test liquid in the measurement container 100, The influence of the first pressure natural vibration on the pressure sensor 103 is suppressed. Therefore, it is not necessary to remove the frequency component of the first pressure natural vibration as noise when detecting the pressure variation, and the pressure variation of the test liquid can be detected in a wide frequency range including the frequency component of the first pressure natural vibration. Can be detected.

Japanese Patent No. 4130823

  As described above, according to the jet measurement device that measures the injection speed of the test liquid based on the sound speed obtained from the frequency of the pressure natural vibration and the estimated wavelength of the pressure natural vibration, and the volume of the measurement container, there are the following problems. .

  That is, first, since the volume of the measurement container 100 may change depending on the type of the nozzle 101 used for measurement, the measurement container 100 may be replaced when the nozzle 101 used for measurement is replaced in order to perform appropriate measurement. The complicated work of measuring and setting the volume again is required.

  In addition, according to the jet measurement device that measures the sound velocity from the frequency of the pressure natural vibration and the estimated wavelength of the pressure natural vibration as described above, and measures the injection amount of the test liquid using the measured sound velocity, the pressure of the estimated wavelength is measured. Errors depending on the characteristics of the individual injection devices, such as errors due to differences in natural vibration with respect to the actual wavelength, may occur.

  Therefore, the present invention provides an injection measurement device that measures the injection amount of the test liquid from the frequency of the pressure natural vibration, the estimated wavelength of the pressure natural vibration, and the volume of the measurement container, and performs an appropriate measurement without requiring complicated work. The challenge is to be able to do it.

In order to achieve the above object, the present invention provides a sealed container filled with liquid at a predetermined pressure, a nozzle for ejecting liquid toward the inner space of the sealed container, and a liquid in the inner space of the sealed container. A pressure sensor for detecting the pressure of the liquid, a discharge means for discharging the liquid in the sealed container so that the pressure of the liquid becomes the predetermined pressure, a discharge mass measurement means for measuring the mass of the liquid discharged by the discharge means, There is provided an injection measuring device comprising coefficient setting means for setting a coefficient and measuring means for measuring a liquid injection amount using the coefficient set by the coefficient setting means. Here, the coefficient setting means causes the liquid to be ejected from the nozzle, measures a change in pressure due to the ejection of the liquid using the pressure sensor, and then causes the ejecting means to eject the liquid, thereby causing the ejected mass measuring means to The mass of the discharged liquid is measured, and the frequency of the pressure vibration represented by the measured pressure fluctuation and the amount of increase in the measured pressure are calculated, the calculated frequency is f _d , and the calculated amount of increase is ΔP _d The mass of the liquid measured by the discharged mass measuring means is N _d , and the coefficient M is
M = N _d × f _d ² / ΔP _d
The measurement means ejects a liquid from the nozzle, measures a pressure variation due to the ejection of the liquid using the pressure sensor, and expresses a frequency of pressure vibration represented by the measured pressure variation. And the measured pressure increase amount, the calculated frequency as f, the calculated increase amount as ΔP, and the liquid injection amount Iq using the coefficient M set by the coefficient setting means,
Iq = M × (ΔP / f ² )
It is calculated by.

  Here, such an injection measurement device has a spherical inner space of the sealed container, and the nozzle is disposed so as not to form irregularities on the spherical spherical surface of the inner space of the sealed container, It is preferable that the pressure sensor is arranged so as not to be uneven with respect to the spherical spherical surface of the inner space of the sealed container.

  By doing so, the vibration generated by the ejection of the liquid can be made into a single mode vibration without disturbance, and the frequency of the liquid vibration can be calculated with high accuracy. As a result, it is possible to satisfactorily measure the liquid ejection amount or ejection rate.

In addition, the liquid for which the injection measuring device measures the injection amount may be an automobile engine or other fuel.
According to the injection measuring apparatus as described above, when the measurement conditions change, such as when the nozzle is replaced, only the simple operation of setting the coefficient M to the coefficient setting means is performed. Thereafter, the discharge mass measuring means is used. In addition, a high-speed and appropriate injection amount can be measured using a pressure sensor.

  As described above, according to the present invention, the injection measurement apparatus that measures the injection amount of the test liquid based on the frequency of the pressure natural vibration, the estimated wavelength of the pressure natural vibration, and the volume of the measurement container requires complicated work. It becomes possible to perform proper measurement without any problems.

It is a block diagram which shows the structure of the injection measuring device which concerns on embodiment of this invention. It is a figure which shows the example of arrangement | positioning of the pressure sensor which concerns on embodiment of this invention. It is a block diagram which shows the function structure of the measurement part of the injection measuring device which concerns on embodiment of this invention. It is a figure which shows the structure of the conventional injection measuring device.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 shows the configuration of an injection measuring apparatus according to this embodiment.
As shown in the figure, the injection measuring device includes a sealed container 1 filled with fuel, an injection nozzle 2 for injecting fuel into the sealed container 1, an injection pump 3 for supplying fuel to be injected into the injection nozzle 2, and an inside of the sealed container 1 A pressure sensor 4 for detecting the pressure of the fuel, a discharge valve 5 connected to the sealed container 1 via a connecting pipe, and a fuel in the sealed container 1 during a period when the discharge valve 5 is connected to the discharge valve 5 and is open. Are provided with a relief valve 6 for discharging the fuel in the sealed container 1 until the pressure reaches a specified back pressure Pb, a mass flow meter 7 for measuring the mass of the fuel discharged from the relief valve 6, and a measurement control device 8.

Next, the measurement control device 8 includes a sequence control unit 81 that controls the measurement sequence, and a measurement unit 82 that measures the fuel injection amount and the injection rate according to the measurement sequence.
Next, FIG. 2 a shows the shape of the sealed container 1 and the arrangement of the injection nozzle 2 and the pressure sensor 4 with respect to the sealed container 1.
As shown in the figure, the sealed container 1 is provided with a spherical internal space 11 and a discharge flow path 12 connected to the internal space 11. The internal space 11 and the discharge flow path 12 are filled with fuel. Yes. And as shown in FIG. 1, the discharge valve 5 mentioned above is connected with the discharge flow path 12 via the connection pipe.

  In addition, the injection nozzle 2 is fixed to the sealed container 1 so that the injection port at the tip thereof is positioned without unevenness with respect to the spherical spherical surface of the internal space 11, and fuel is injected from the injection nozzle 2 into the internal space 11. Injected toward the center of the spherical shape.

  The pressure sensor 4 is fixed so that the probe at the tip is positioned without unevenness with respect to the spherical spherical surface of the internal space 11. Here, in the example shown in FIG. 2a, the pressure sensor 4 is directed from the center of the internal space 11 to the injection port at the tip of the injection nozzle 2, and from the center of the internal space 11 to the probe at the tip of the pressure sensor 4. It arrange | positions so that the absolute value of angle (theta) between the directions may become 135 degree | times.

  Here, as described above, in the present embodiment, the shape of the internal space 11 in which the fuel in the sealed container 1 is filled is made spherical, and the tip of the injection nozzle 2 and the tip of the pressure sensor 4 are made spherical in the internal space 11. It arrange | positions so that a part of spherical surface may be formed. Therefore, there is no foreign matter other than fuel inside the spherical shape of the internal space 11 of the sealed container 1, and when the fuel is injected from the injection nozzle 2 into the internal space 11, the single mode natural vibration is It is generated in a form that is not disturbed by foreign matter in the internal space 11. Therefore, the natural vibration can be favorably detected by the pressure sensor 4 in a form that is not hindered by other vibrations.

  In addition, since the natural vibration of the spherical single mode of the internal space 11 is generated in this way, the pressure sensor 4 can be arbitrarily selected as long as the tip is located on the spherical spherical surface of the internal space 11. Can be placed in position.

  That is, as shown in FIG. 2a, the pressure sensor 4 can be arranged so that the tip of the pressure sensor 4 is positioned obliquely downward from the center of the inner space 11 of the sealed container 1, for example, FIG. As shown in c and d, the pressure sensor 4 can also be arranged so that the tip of the pressure sensor 4 is positioned obliquely upward, laterally, or downwardly from the center of the inner space 11 of the sealed container 1. .

Next, FIG. 3 shows a functional configuration of the measurement unit 82 of the measurement control device 8.
As shown in the figure, the measurement unit 82 of the measurement control apparatus 8 includes an FFT processing unit 821, a peak frequency calculation unit 822, a filter 823, a rising pressure calculation unit 824, an injection measurement unit 825, and a coefficient setting unit 826.

Hereinafter, the measurement principle of the fuel injection amount (mass) of such an injection measuring device will be described.
When the volume of the sealed container 1 is V and K is the bulk modulus of the fuel, the pressure increase ΔP of the fuel in the sealed container 1 when the fuel is injected into the sealed container 1 by the volume ΔV is expressed by the equation (1). expressed.

ΔP = (K × ΔV) / V (1)
On the other hand, the speed of sound c in the liquid is expressed by equation (2), where ρ is the fuel density.
c = (K / ρ) ^1/2 (2)
Therefore, the fuel injection amount Iq is expressed by equation (3) from equations (1) and (2).
Iq = ΔV × ρ = (ΔP × V) / c ² (3)
Here, the speed of sound c in the fuel in the spherical inner space 11 of the sealed container 1 is expressed by the equation (4) where λ is the wavelength of the fundamental vibration of the fuel in the inner space 11 and f is the frequency of the fundamental vibration of the fuel in the inner space 11. ).

c = f × λ (4)
Substituting equation (4) into equation (3) yields equation (5).
Iq = (ΔP × V) / (f ² × λ ² ) (5)
Now, if the coefficient M is determined as in equation (6),
M = V / λ ² (6)
Formula (5) can be represented by Formula (7).

Iq = M × (ΔP / f ² ) (7)
Here, the volume V of the airtight container 1 and the wavelength λ of the fundamental vibration are constants that are fixedly determined without depending on the volume elasticity coefficient, density, or injection amount of the fuel, which varies depending on the temperature. It is a constant that does not depend on the injection amount. Therefore, if the coefficient M is obtained and set in advance from the equation (7), the liquid injection amount Iq can be appropriately calculated from the frequency f of the basic vibration of the fuel and the liquid pressure increase ΔP.

Further, the fuel injection rate (mass) can also be calculated by differentiating the injection amount Iq with respect to time.
Hereinafter, the operation of measuring the fuel injection amount using the equations (6) and (7) as described above in the injection measuring device will be described.
The calculation of the injection amount is realized by a calibration operation for setting the coefficient M performed before the execution of the fuel injection amount measurement operation and a fuel injection amount measurement operation performed after the coefficient M is set.

First, the calibration operation will be described.
In the calibration operation, the sequence control unit 81 of the measurement control device 8 drives the injection pump 3, injects fuel into the sealed container 1 from the injection nozzle 2, controls opening / closing of the discharge valve 5, and closes the sealed container 1. The process of returning the internal fuel pressure to the specified back pressure and measuring the mass of the fuel discharged by the mass flow meter 7 is performed once or repeatedly.

On the other hand, the measurement unit 82 of the measurement control device 8 sets the coefficient M as follows under the control of the sequence control unit 81 in the calibration operation.
That is, the FFT processing unit 821 performs FFT processing on the pressure signal that is output from the pressure sensor 4 and represents the pressure fluctuation of the fuel in the sealed container 1, and calculates the magnitude of each frequency component of the fuel pressure oscillation. The peak frequency calculation unit 822 calculates a frequency at which the magnitude of each frequency component of the fuel pressure vibration calculated by the FFT processing unit 821 reaches a peak (maximum) as the frequency f _d of the basic vibration of the fuel.

The filter 823 removes noise in the high frequency region of the pressure signal output from the pressure sensor 4, and the rising pressure calculation unit 824 raises the pressure of the fuel in the sealed container 1 from the pressure signal from which the filter 823 has removed noise. ΔP _d is calculated.

Then, the coefficient setting unit 826 obtains from the mass flow meter 7 the mass N _{d of} the fuel discharged to restore the fuel pressure in the sealed container 1 to the specified back pressure. The coefficient M is calculated from the acquired mass N _d , the frequency f _d of the basic vibration of the fuel calculated by the peak frequency calculation unit 822, and the pressure increase ΔP _d calculated by the rising pressure calculation unit 824 as follows. , Set in the injection measuring unit 825.

That is, the coefficient setting unit 826 uses the equation (7) to
N _d = Iq = M × (ΔP _d / f _d ² )
Since the relationship of
M = N _d × f _d ² / ΔP _d
As a result, the coefficient M is calculated.

Next, when the coefficient M is set by the calibration operation as described above, the fuel injection amount measurement operation is performed as follows.
That is, the sequence control unit 81 of the measurement control device 8 drives the injection pump 3, injects fuel into the sealed container 1 from the injection nozzle 2, controls opening / closing of the discharge valve 5, and controls the fuel in the sealed container 1. The process of returning the pressure to the specified back pressure is performed once or repeatedly.

On the other hand, the measurement unit 82 of the measurement control device 8 measures the fuel injection amount Iq every time the fuel is injected into the sealed container 1 under the control of the sequence control unit 81 as follows.
That is, the FFT processing unit 821 performs FFT processing on the pressure signal that is output from the pressure sensor 4 and represents the pressure fluctuation of the fuel in the sealed container 1, and calculates the magnitude of each frequency component of the fuel pressure oscillation. The peak frequency calculation unit 822 calculates a frequency at which the magnitude of each frequency component of the pressure vibration of the fuel calculated by the FFT processing unit 821 reaches a peak (maximum) as the frequency f of the basic vibration of the fuel.

  On the other hand, the filter 823 removes noise in the high frequency region of the pressure signal output from the pressure sensor 4, and the rising pressure calculation unit 824 raises the pressure of the fuel in the sealed container 1 from the pressure signal from which the filter 823 has removed the noise. ΔP is calculated.

  The injection measurement unit 825 then calculates the coefficient M set in the calibration operation, the frequency f of the basic vibration of the fuel calculated by the peak frequency calculation unit 822, and the pressure increase ΔP calculated by the increase pressure calculation unit 824. The fuel injection amount Iq is calculated according to the equation (7). The injection measurement unit 825 may calculate the fuel injection rate (mass) by differentiating the fuel injection amount Iq with respect to time.

So far, the operation of calculating the fuel injection amount Iq in the injection measuring device has been described.
By the way, the above-described calibration operation may be performed only when the measurement conditions change, such as when the injection nozzle 2 is replaced, and need not be performed every time the measurement operation is performed. Further, when the calibration operation is completed, the mass flow meter 7 may be removed.
The embodiment of the present invention has been described above.

In the above embodiment, the mass flowmeter 7 is used to measure the mass N _d of the discharged fuel in order to return the fuel pressure in the sealed container 1 to the specified back pressure. Instead of the flow meter 7, a mass meter that measures the mass N of the discharged fuel may be used. Alternatively, in place of the mass flow meter 7, a flow meter that measures the volume flow rate of the discharged fuel and a thermometer that measures the temperature of the discharged fuel are used. more and volume flow measured may be measured by mass N _d of the discharged fuel.

Moreover, this embodiment can be similarly applied to measurement of the injection amount and injection rate of any liquid other than fuel.
As described above, according to the present embodiment, if the calibration operation is performed using the mass flow meter 7 only when the measurement conditions change, such as when the injection nozzle 2 is replaced, only the pressure sensor 4 is used thereafter. Thus, it is possible to measure the injection amount and the like at high speed and appropriately.

  DESCRIPTION OF SYMBOLS 1 ... Airtight container, 2 ... Injection nozzle, 3 ... Injection pump, 4 ... Pressure sensor, 5 ... Discharge valve, 6 ... Relief valve, 7 ... Mass flow meter, 8 ... Measurement control apparatus, 11 ... Internal space, 12 ... Discharge Flow path 81. Sequence controller 82 Measure unit 821 FFT processing unit 822 Peak frequency calculator 823 Filter 824 Increase pressure calculator 825 Injection measurement unit 826 Coefficient setting unit

Claims (4)

A sealed container filled with liquid at a predetermined pressure;
A nozzle for injecting liquid toward the internal space of the sealed container;
A pressure sensor for detecting the pressure of the liquid in the internal space of the sealed container;
Discharging means for discharging the pressure of the liquid in the sealed container to be the predetermined pressure;
Discharged mass measuring means for measuring the mass of the liquid discharged by the discharging means;
Coefficient setting means for setting a coefficient;
Measuring means for measuring the ejection amount of the liquid using the coefficient set by the coefficient setting means,
The coefficient setting unit ejects a liquid from the nozzle, measures a pressure variation due to the ejection of the liquid using the pressure sensor, and then discharges the liquid to the discharge unit to be discharged to the discharge mass measurement unit. In addition to measuring the mass of the measured liquid, the frequency of the pressure oscillation represented by the measured pressure fluctuation and the amount of increase in the measured pressure are calculated, the calculated frequency is f _d , the calculated amount of increase is ΔP _d , and the discharge the mass of the liquid as N _d which is measured by the mass measuring means, the coefficient M
M = N _d × f _d ² / ΔP _d
Set by
The measuring means ejects a liquid from the nozzle, measures the pressure fluctuation caused by the liquid ejection using the pressure sensor, and measures the frequency of pressure vibration represented by the measured pressure fluctuation and the rise in the measured pressure. With the calculated frequency f, the calculated increase amount ΔP, and the liquid injection amount Iq using the coefficient M set by the coefficient setting means,
Iq = M × (ΔP / f ² )
An injection measuring device characterized by the following calculation.
The injection measurement device according to claim 1,
The internal space of the sealed container has a spherical shape,
The nozzle is arranged so as not to form irregularities with respect to the spherical spherical surface of the inner space of the sealed container,
The injection sensor according to claim 1, wherein the pressure sensor is arranged so as not to form irregularities on the spherical spherical surface of the inner space of the sealed container.
The injection measurement device according to claim 1 or 2,
An injection measuring apparatus, wherein the liquid is fuel.
A sealed container filled with liquid at a predetermined pressure;
A nozzle for injecting liquid toward the internal space of the sealed container;
A pressure sensor for detecting the pressure of the liquid in the internal space of the sealed container;
In an injection measurement device comprising a discharge means for discharging so that the pressure of the liquid in the sealed container becomes the predetermined pressure, an injection measurement method for measuring an injection amount of the liquid injected by the nozzle,
After the liquid was ejected from the nozzle and the pressure fluctuation due to the ejection of the liquid was measured using the pressure sensor, the liquid was discharged to the discharge means, and the mass of the discharged liquid was measured and measured. Calculate the frequency of the pressure vibration represented by the pressure fluctuation and the amount of increase in the measured pressure. The calculated frequency is f _d , the calculated amount of increase is ΔP _d , and the mass of the liquid measured by the discharged mass measuring means is calculated. N _d and coefficient M
M = N _d × f _d ² / ΔP _d
Step to set by
The liquid is ejected from the nozzle, the pressure fluctuation due to the liquid ejection is measured using the pressure sensor, and the frequency of the pressure vibration represented by the measured pressure fluctuation and the measured pressure increase amount are calculated. The calculated frequency f is f, the calculated increase amount is ΔP, and the liquid injection amount Iq is set using the set coefficient M,
Iq = M × (ΔP / f ² )
An injection measurement method comprising the step of calculating by: