JPH0688742A - Flowmwter - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a highly reliable flow meter by measuring the flow rate of gas or liquid. [Structure] The fluid flow rate is detected by the flow rate detection means 19, the flow rate is obtained from the detected output signal, and the integrated value is calculated and displayed and stored in the nonvolatile integrated value storage means. Even if the display and the integrated value disappear, the integrated value can be read from the nonvolatile integrated value storage means, so that the usage amount up to immediately before can be known and the reliability of the flowmeter can be greatly improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow meter for measuring the flow rate of gas such as city gas and LPG gas, and fluid such as liquid.

[0002]

2. Description of the Related Art Conventionally, a flow meter of this type has a structure as shown in FIGS. 4 and 5, for example, as disclosed in Japanese Unexamined Patent Publication No. 3-95420.

That is, in the conventional flowmeter of FIG. 4, 1 is a flowmeter, 2 is a gas pipe, and 3 is a fluidic oscillation element, which causes fluid oscillation by utilizing the kinetic energy of the fluid. A sensor 4 detects the frequency of fluid oscillation. A shutoff valve 5 shuts off the gas supply when an abnormal use state is detected. Reference numeral 6 denotes a control device, an example of which is shown in FIG.

In FIG. 5, an analog amplifier 7 amplifies the flow rate signal detected by the sensor 4. A waveform shaping circuit 8 converts the amplified signal into a pulse signal. A rising point detection circuit 9 detects the rising edge of the flow rate pulse signal. Reference numeral 10 denotes a cycle measuring means, which measures the time from the rising point of the flow rate pulse to the next rising point, that is, the cycle. Reference numeral 11 is a memory circuit, and the relationship between the pulse constant and the flow rate or period is approximated by n polygonal lines, and means 12 for storing the period of the boundary of the n polygonal lines and a unit time t shorter than the period of the flow pulse. Unit time storage means 13 for storing,
Correction unit amount means 1 for storing the correction unit amount α of the pulse constant
4 and constant storage means 15 for storing the constant term a. These storage means are provided in units of n corresponding to the division of n broken lines. Reference numeral 16 denotes an adder circuit which calculates and adds a pulse constant K = a + Σα indicating a flow rate per pulse for each cycle. Reference numeral 17 denotes an integrating circuit, which integrates the calculated flow rate. Reference numeral 18 denotes a display, which displays the integrated result.

Next, the operation of the above conventional configuration will be described.
When some kind of gas instrument is used, the gas enters the fluidic oscillation element 3 to cause fluid oscillation, and the sensor 4 detects the change in the flow rate. The output signal of the analog amplifier 7
And the waveform shaping circuit 8 converts it into a pulse signal.

The relationship between the flow rate and the oscillation frequency is Q = a · F + b
Given in. This is the formula K for calculating the flow rate per pulse
= Q / F = a + b · T. Here, K is called a pulse constant and indicates a flow rate value per pulse. a and b are coefficients. The relationship between the pulse constant and the flow rate or the vibration frequency is not constant as shown in FIG.
When the cycle of the flow rate pulse exceeds the boundary of the polygonal line approximation, the coefficient is changed to calculate the pulse constant. Therefore, the coefficient is set for each broken line segment. Further, here, the multiplication process of b · T is not performed but the addition process is performed, and the pulse constant K is obtained.

The contents will be described with reference to FIG. First, the rising point detection circuit 9 detects the rising of the flow rate pulse output from the waveform shaping circuit 8. When the rising edge is detected, the cycle measuring means 10 starts measuring the cycle of the flow rate pulse. At the same time, the adder circuit 16 performs the following processing. Instead of performing the calculation of b · T, the unit correction amount α which is much smaller than the value of b · T is added to obtain. Addition is the cycle T of the flow rate pulse
It is performed for each unit correction time t for a relatively shorter time. Therefore, it can be said that α = b · t. Therefore, the unit correction amount α is continuously added every time the unit time t elapses from the rising point to the detection of the next rising point for one cycle of the flow rate pulse. The resulting K = a + Σα becomes the flow rate per pulse, that is, the pulse constant. Since the relationship between the pulse constant and the period of the flow rate pulse is approximated by a polygonal line, each polygonal line segment has a coefficient a, a unit correction amount α, and a unit correction time t. In FIG. 7, the boundary period T1 to T2 changes at α1, t1, and at T2 to T3 changes at α2, t2 and the boundary T2. Therefore, the adder circuit 16 determines whether the cycle measured by the cycle measuring means 10 has reached the cycle of the boundary of the polygonal line section (the cycle measuring means 10 measures the pulse cycle and also the boundary cycle), When the area of the next polygonal line segment is entered, the coefficient a, the unit correction amount α, and the unit correction time t are changed and the above processing is continued.

The flow rate thus obtained is used for the integrating circuit 17
The cumulative value used can be obtained by adding in. This integrated value is displayed on the display 18.

[0009]

However, in the above-mentioned conventional configuration, the calculated flow rate values are integrated and displayed. However, the integrated value when the circuit fails or the power supply is lost is disclosed. Not not.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a flow meter capable of storing a flow rate value as a result of flow rate measurement and reading the flow rate value in any case.

[0011]

In order to achieve the above object, a flowmeter of the present invention comprises a flow rate detecting means for detecting a fluid flow rate, a flow rate calculating means for calculating a flow rate from an output signal of the flow rate detecting means, and A flow rate integrating means for integrating the flow rate obtained by the flow rate calculating means, and a nonvolatile integrated value storage means for storing the integrated value of the flow rate integrating means and making it readable from the outside are provided.

Further, in order to achieve the above object, the present invention comprises a flow rate detecting means for detecting a fluid flow rate, and a function storing means for approximating a coefficient indicating a characteristic of the fluid flow rate and an output signal of the flow rate detecting means. , A flow rate calculating means for calculating a flow rate from an output signal of the flow rate detecting means and a function stored in the function storing means, a flow rate integrating means for integrating the flow rate obtained by the flow rate calculating means, and the integrated flow rate are displayed. And a non-volatile integrated value storage means that stores the coefficient or function used in the flow rate calculation means and further stores the integrated value of the flow rate integration means and that can be read out from the outside. .

[0013]

According to the first aspect of the present invention, the instantaneous flow rate is calculated from the output signal of the flow rate detecting means for detecting the fluid flow rate, and the integrated flow rate is further obtained. The calculated integrated flow rate value is periodically stored in the nonvolatile integrated value storage means. When the battery power source or the like disappears and the integrated value of the integrated flow rate calculating means disappears or the integrated value of the integrated display means disappears and cannot be understood due to an unexpected cause, the integrated value is read from the nonvolatile integrated value storage means.

Since the fluid flow rate measured in this manner is stored in the nonvolatile integrated value storage means, the integrated value can be read from the nonvolatile storage means at any time in the event of an abnormality, so the reliability of the flow meter in the event of an abnormality is enhanced.

According to the second aspect of the present invention, the instantaneous flow rate is calculated from the output signal of the flow rate detecting means for detecting the fluid flow rate, the coefficient corresponding to the output signal of the flow rate detecting means, and the output signal of the flow rate detecting means. Further, the integrated flow rate is calculated. The calculated integrated flow rate value and the coefficient used for the flow rate calculation are periodically stored in the nonvolatile integrated value storage means. When the battery power source or the like disappears and the integrated value of the integrated flow rate calculating means disappears or the integrated value of the integrated display means disappears and cannot be understood due to an unexpected cause, the integrated value is read from the nonvolatile integrated value storage means. Further, since the coefficient for obtaining the flow rate is stored, the situation of obtaining the flow rate can be analyzed.

Since the fluid flow rate measured in this way is stored in the nonvolatile integrated value storage means, the integrated value and the coefficient can be read from the nonvolatile storage means at any time in the event of an abnormality, so the reliability of the flow meter in the event of an abnormality is increased, Moreover, it is possible to quickly respond to abnormalities and improve usability.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the same parts as those in FIG. 4 are designated by the same reference numerals. The control device 6 is usually driven by a battery power source 19 or the like. FIG. 1 is a block diagram of a flow meter of the present invention driven by a battery 19. In FIG. 1, reference numeral 20 denotes a flow rate detecting means, which is composed of one or a plurality of flow rate detecting means for dividing the measured flow rate range and detecting each flow rate range. FIG. 3 shows an example of the configuration of the flow rate detecting means 20. The first flow rate detecting means 20a detects a small flow rate range, and the second flow rate detecting means 20b.
Measures a large flow area. The flow rate detecting means 20 generates fluid oscillation using, for example, the fluidic oscillation element 3 and detects the oscillation frequency of the fluid as pressure-voltage change, heat-resistance change using a piezoelectric sensor, a thermistor, or the like, or heat ray. For example, the flow velocity is calculated by a sensor.

Reference numeral 21 is a flow rate calculating means, which is a flow rate detecting means 20.
The instantaneous flow rate at that time is calculated and calculated from the detection signal of. Two
Reference numeral 2 denotes a flow rate integrating means, which integrates the obtained flow rates to obtain an integrated value. A non-volatile integrated value storage means 23 writes the calculated integrated flow rate value periodically, for example, every day, every week or every month. The nonvolatile integrated value storage means 23 retains the written integrated value even when the power is turned off. Reference numeral 24 is a display means for displaying the used or measured integrated value or the like.

Next, the operation of the above configuration will be described. When the gas starts to be used, the gas flow rate is detected by the flow rate detecting means 20 in the form of a signal such as a voltage signal. Next, the flow rate calculation means 21 converts the flow rate from the signal detected by the flow rate detection means 20. The integrated flow rate calculation means 22 adds the instantaneous flow rates to obtain the total used flow rate. The nonvolatile integrated value storage means 23 periodically writes the integrated flow rate value obtained by the integrated flow rate calculation means 21. Then, the integrated value display means 24 displays the calculated integrated flow rate value and the like.

According to the structure of this embodiment, the flow rate to be measured is detected by the flow rate detecting means 19 and the flow rate is obtained from the output signal thereof. By integrating the calculated flow rate in the integrated flow rate calculation means 21 for display on the integrated value display means 24 and periodically storing it in the nonvolatile integrated value storage means 23, even if the battery power suddenly disappears for some reason, it is nonvolatile. The usage amount can be known by reading the integrated flow rate value stored in the integrated property value storage means 23. When used as a meter for home use, for example, even if the battery power is exhausted, the charge can be calculated by reading the usage amount, which is very convenient. Further, as compared with the case of the backup power source (an example of this case is not shown), it is difficult to hold the integrated value if the power source of the backup power source itself is accidentally down, and the nonvolatile storage means 23 of the present invention. Is much more reliable.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same parts as those in FIGS. 1 and 4 are designated by the same reference numerals. FIG. 2 is a block diagram of a flow meter of the present invention driven by battery 19. A function storage means 24 stores a coefficient indicating the relationship between the flow rate of the fluid flowing through the flow rate detecting means 19 and the detection signal, a function approximating the coefficient, or the flow rate and the flow rate detecting means 2 in advance.
Set the table from the 0 output signal.

Next, the operation of the above configuration will be described. When the gas starts to be used, the gas flow rate is detected by the flow rate detecting means 20 in the form of a signal such as a voltage signal. At this time, the fluid flow rate and the signal of the flow rate detection means have a linear or non-linear relationship, and the relationship between the coefficient (coefficient given by the ratio of the flow rate and the output signal of the flow rate detection means 20) and the detection signal at that time is non-linear or It becomes a linear function. Therefore, in the function storage means 24, the characteristic of the coefficient is approximated and stored by an arbitrary function, or the coefficient is stored as table data.

Next, the flow rate calculating means 21 converts the flow rate into the signal detected by the flow rate detecting means 20 and the function storing means 2 described above.
The instantaneous flow rate is calculated by calculation from the function or coefficient of 4.
The integrated flow rate calculation means 22 adds the instantaneous flow rates to obtain the total used flow rate. The nonvolatile integrated value storage means 23 periodically writes the integrated flow rate value calculated by the integrated flow rate calculation means 21 and the coefficient used for the flow rate calculation. Then, the integrated value display means 24 displays the calculated integrated flow rate value and the like.

According to the configuration of this embodiment, the flow rate to be measured is detected by the flow rate detecting means 20, and the flow rate is obtained from the output signal from the coefficient indicating the relationship between the flow rate and the output signal. By integrating the calculated flow rate in the integrated flow rate calculation means 21 for displaying on the integrated value display means 24 and periodically storing it in the nonvolatile integrated value storage means 23, even if the power supply suddenly disappears for some reason, it is non-volatile. The usage amount can be known by reading the integrated flow rate value stored in the integrated value storage means 23. In addition, since the coefficient for calculating the flow rate is stored, the battery 1
Even if 9 goes down and the control device 6 cannot operate, the situation in which the flow rate is obtained can be analyzed.

Since the fluid flow rate measured in this way is stored in the nonvolatile integrated value storage means, the integrated value and coefficient can be read from the nonvolatile storage means at any time in the event of an abnormality, so that the reliability of the flow meter in the event of an abnormality is increased, Moreover, it is possible to quickly respond to abnormalities.

The present invention has exemplified the fluidic flow meter for measuring the fluid flow rate, but the above contents can be applied to other flow meters such as an electronic water meter or an electronic power meter.

[0028]

As described above, the flowmeter of the present invention is
A flow rate detecting means for detecting a fluid flow rate, a flow rate calculating means for calculating an instantaneous flow rate of the fluid flow rate from an output signal of the flow rate detecting means, a flow rate integrating means for integrating the flow rate obtained by the flow rate calculating means, and the flow rate It consists of non-volatile integrated value storage means that stores the integrated value of the integrating means and can be read from the outside.When the gas is started, the fluid flow rate is detected by the flow rate detecting means, and the flow rate and integrated flow rate are detected from the detected output signal. Since the integrated value is stored in the nonvolatile integrated value storage means, the nonvolatile integrated value storage means can be used even if the battery power is exhausted and the integrated display is turned off, or the integrated value disappears when the power is turned off. Since the integrated value is stored in the memory, it can be read out, the charge can be calculated when it is used as a weighing meter, and the reliability as a flow meter is greatly improved, making it easy to use. There is an effect that that.

Further, the flowmeter of the present invention includes a flow rate detecting means for detecting a fluid flow rate, and a function storing means for storing a coefficient indicating a characteristic of the fluid flow rate and an output signal of the flow rate detecting means or a function approximating the coefficient. A flow rate calculating means for calculating a flow rate from an output signal of the flow rate detecting means and a coefficient or a function stored in the function storing means; a flow rate integrating means for integrating the flow rate obtained by the flow rate calculating means; It is composed of an integrated display means for displaying the flow rate and a nonvolatile integrated value storage means for storing the integrated value of the flow rate integrating means and making it readable from the outside.When the gas is started to be used, the fluid flow rate is detected by the flow rate detecting means. Further, since the flow rate and integrated flow rate are calculated from the detected output signal and the integrated value is stored in the nonvolatile integrated value storage means, even if the battery power is exhausted and the integrated display is turned off, Even if the integrated value disappears when the power is turned off, it can be read because the integrated value is stored in the nonvolatile integrated value storage means, and the condition when reading the coefficient or function and analyzing the flow rate can be analyzed. It is possible to check the flow rate such as, and the reliability of the flow meter is greatly improved, and the usability is improved.

[Brief description of drawings]

FIG. 1 is a control block diagram of a flow meter according to a first embodiment of the present invention.

FIG. 2 is a control block diagram of a flow meter according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a flow rate detecting means of the present invention.

FIG. 4 is a system configuration diagram of a conventional flow meter.

FIG. 5 is a control block diagram of the flow meter.

FIG. 6 is a characteristic diagram of the control device of the flow meter.

FIG. 7 is a detailed diagram of the characteristic diagram.

[Explanation of symbols]

 20 flow rate detection means 21 flow rate calculation means 22 flow rate integration means 23 non-volatile integrated value storage means 24 display means

Claims (2)

[Claims] 1. A flow rate detecting means for detecting a fluid flow rate, a flow rate calculating means for calculating a flow rate from an output signal of the flow rate detecting means, a flow rate integrating means for integrating the flow rate obtained by the flow rate calculating means, and the flow rate. A flow meter comprising a non-volatile integrated value storage means that stores the integrated value of the integrating means and can be read out from the outside. 2. A flow rate detecting means for detecting a fluid flow rate, a function storing means for approximating a coefficient showing characteristics of the fluid flow rate and an output signal of the flow rate detecting means, an output signal of the flow rate detecting means and the function. The flow rate calculation means for calculating the flow rate from the function stored in the storage means, the flow rate integration means for integrating the flow rates obtained by the flow rate calculation means, the integration display means for displaying the integrated flow rate, and the flow rate calculation means A flow meter comprising a non-volatile integrated value storage means for storing the used coefficient or function, and further for storing the integrated value of the flow rate integrating means, which can be read out from the outside.