JP2006098176A - Flow measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow measuring instrument capable of enhancing measurement resolution to allow accurate measurement. <P>SOLUTION: When a fluid to measure the flow rate is supplied and discharged to/from a measuring chamber 4, a diaphragm 11 provided in the measuring chamber 4 is reciprocation-moved, and a circulation part R1 is circulated in accompaniment to the reciprocation moving of the diaphragm 11. Since a magnet 5 or an azimuth sensor 6 is provided in the circulation part R1, the magnet 5 or the azimuth sensor 6 is also circulation-moved. A position of the diaphragm 11 is detected by detecting the circulation moving by the azimuth sensor 6 to find a relative position between the both, and the measurement resolution is thereby enhanced to allow the accurate measurement. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flow rate measuring device for measuring a flow rate of a fluid, and more particularly to a membrane type flow rate measuring device.

2. Description of the Related Art Conventionally, as a flow measuring device for measuring a flow rate of a fluid such as a gas, a membrane type device having a membrane that reciprocates once when a predetermined amount of fluid is supplied to and discharged from a measuring chamber is disclosed (for example, Patent Document 1). reference).
As shown in FIG. 9, such a flow rate measuring device 100 is provided with a film part (not shown) that reciprocates by supplying and discharging gas to and from the measurement chamber. A link mechanism 101 is connected to the moving blade shaft. The link mechanism 101 is configured by combining a pair of long elbows 101a and a pair of short small elbows 101b. In addition, a pair of magnets 103 are provided at the periphery of the rotating body 102 at symmetrical positions with respect to the center, and a reed switch 104 that operates when the magnets 103 are rotated to a specific rotation phase is provided. . Further, a controller 105 is provided for obtaining the flow rate based on the signal from the reed switch 104 and displaying the obtained flow rate on the display unit 106.

  The rotating body 102 includes a crankshaft 102a that is rotatably provided on a support base 107 that is provided on an upper portion of a casing (not shown), and a rotating disk 102b that is attached to the crankshaft 102a. A crank arm 108 is attached to the crankshaft 102a. The crank arm 108 is provided with a swing valve 112 that opens and closes a gas supply / exhaust port 110 and a gas exhaust port 111 via a pair of crank rods 109, 109.

Accordingly, when the membrane reciprocates once by supplying and discharging gas to the measuring chamber, the rotating disk 102b rotates once, so that the pair of magnets 103 and 103 attached to the rotating disk 102b rotate in the same manner. The reed switch 104 detects the rotation of the magnets 103 and 103 and sends a signal to the controller 105 to calculate the flow rate and display it on the display unit 106. The pair of oscillating valves 112 oscillate with the rotation of the rotating disk 102b, and the gas supply / exhaust port 110 and the gas exhaust port 111 are appropriately opened and closed to supply and exhaust gas. Yes.
Japanese Patent Laying-Open No. 2004-93497 (FIG. 4)

By the way, in the flow rate measuring apparatus 100 described above, the rotation of the rotating disk 112b is detected using the reed switch 104 that operates when the magnet 103 reaches a specific rotation phase, and a plurality of magnets are used to increase the resolution. 103 is used.
However, when the magnet 103 is in a phase other than the specific rotation phase, the reed switch 104 does not operate, and the intermediate state cannot be detected, so that there is a problem that accurate measurement cannot be performed.
Further, when the flow rate measuring device 100 as described above is used for city gas piped in parallel to many households, the gas reciprocates immediately before the flow rate measuring device 100 in a household that uses a large amount of gas. The pulsation may be transmitted to the flow measurement device 100 in another home. In such a case, if a plurality of magnets 103 are used, the magnets 103 reciprocate and the reed switch 104 is turned on / off, and counting is performed as if using gas. There was a problem that there was a possibility that it could not be done.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a flow rate measuring apparatus capable of improving measurement resolution and performing accurate measurement.

  The flow rate measuring device of the present invention comprises a membrane that reciprocates once in accordance with the supply and discharge of a predetermined amount of fluid to and from the measurement chamber, and a revolving portion that revolves in response to the reciprocating movement of the membrane. A flow rate measuring device for measuring, comprising a magnet and an orientation sensor for detecting the orientation of the magnet, wherein one of the magnet and the orientation sensor is provided in the circulating portion, and the magnet and the orientation sensor The flow rate of the fluid is measured from the relative position.

Here, the circular motion refers to a motion that moves in one direction along a closed curve as well as a perfect circle, an ellipse, an ellipse, and the like.
With this configuration, when a fluid for measuring the flow rate is supplied to or discharged from the measurement chamber, the membrane provided in the measurement chamber reciprocates, and the revolving part revolves with the reciprocation of the membrane. At this time, since the magnet or the azimuth sensor is provided in the orbiting portion, the magnet or the azimuth sensor also moves around. The azimuth sensor detects this orbiting motion and obtains the relative position of the two so that the position of the film can be detected. Therefore, the measurement resolution can be improved and accurate measurement can be performed.

  Further, as described above, the flow rate measuring device according to the present invention is a flow rate measuring device in which one of the magnet and the orientation sensor is provided in the circulating portion, and the magnet is disposed in the circulating portion, and the orientation The sensor is arranged at the center of the circular motion of the magnet.

  With this configuration, since the position of the azimuth sensor is regular with respect to the magnet, the azimuth sensor can accurately detect the relative position of the magnet that circulates around the azimuth sensor, and performs accurate weighing based on this. Can do.

  Furthermore, as described above, the flow rate measuring device according to the present invention is a flow rate measuring device in which one of the magnet and the orientation sensor is provided in the revolving part, and the orientation sensor is arranged at the center of the revolving motion of the magnet, The magnet is configured to always go around the same magnetic pole with respect to the azimuth sensor.

  With this configuration, the direction of the magnetic flux changes around the azimuth sensor, and when the magnet makes one revolution, both the azimuth and the change change by one. Therefore, the coordinates of the magnet that circulates around the position of the azimuth sensor can be clearly detected. .

  In the present invention, since the magnet or the azimuth sensor is provided in the orbiting portion, the magnet or the azimuth sensor also circulates, and the azimuth sensor detects the circulatory motion and obtains the relative position of both. The position of the film can be detected. Accordingly, it is possible to provide a flow rate measuring device having an effect that the measurement resolution can be improved and accurate measurement can be performed.

Hereinafter, a flow rate measuring device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing the entirety of a membrane gas meter which is a flow rate measuring apparatus according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the main part of the membrane gas meter, and FIG. 3 is a main part of the membrane gas meter. FIG. 4 is an exploded perspective view, and FIG. 4 is a plan view of a main part of the membrane gas meter according to the embodiment.

  As shown in FIGS. 1 to 4, a membrane gas meter 1 that is a flow rate measuring device includes a membrane 11 that reciprocates once in accordance with the supply and discharge of a gas as a predetermined amount of fluid to and from the metering chamber 4, And a rotating plate 20 as a rotating part that rotates in response to the reciprocating movement. And it has the magnet 5 and the direction sensor 6 which detects the direction of this magnet 5, One of the said magnet 5 and the said direction sensor 6 is provided in the said rotation part (rotary plate 20), The flow rate of the gas is measured from the relative position of the azimuth sensor 6.

  Furthermore, it demonstrates in detail. As shown in FIG. 1, a membrane gas meter 1 as a flow rate measuring device according to an embodiment of the present invention is assembled by using a casing C having a gas supply port 2a and a gas discharge port 2b. The supply port 2a and the gas discharge port 2b are connected in the middle of a gas supply pipe (not shown) for supplying gas to a gas demand destination such as a house, and the flow rate of the gas flowing through the gas supply pipe is measured. The measured gas flow rate is displayed on the display unit 3 provided outside the display. The casing C includes a lower casing part C1 and an upper casing part C2.

  As shown in FIG. 3, the membrane gas meter 1 includes a valve portion V that controls supply and discharge of gas to and from the measurement chamber 4, a membrane portion F that reciprocates by supply and discharge of gas to and from the measurement chamber 4, and the film portion F And the controller 7 serving as a calculation unit for obtaining the flow rate and displaying the obtained flow rate on the display unit 3 as described above. Is assembled in the casing C.

  Although detailed description and illustration are omitted because they are well known, in the upper casing portion C2, in addition to the controller 7 described above, an orientation sensor 6 (see FIG. 5) for detecting the orientation of a magnet 5 (see FIG. 4) described later. Reference) is provided. Further, although not shown, a pressure sensor for detecting the gas pressure supplied to the membrane gas meter 1, a seismic device for detecting earthquake vibration, and a gas supply shut-off valve are provided, and the pressure sensor detects abnormal pressure. When an abnormality occurs, such as when it is detected or when the seismic device detects an earthquake, the above-described controller 7 controls the gas supply shut-off valve to be shut off and displays the abnormality information on the display unit. In FIG. 1, reference numeral 8 denotes a return shaft cap that covers an operating portion of a return shaft (not shown) for releasing the shut-off state of the gas supply shut-off valve.

  As shown in FIGS. 2 and 3, the lower casing portion C <b> 1 is partitioned by a partition wall 9 at the center, and a substantially cylindrical measuring chamber forming space having the partition walls 9 as bottom portions on both sides of the partition wall 9. And partitioning the central portion of each measurement chamber forming space with the membrane portion F, and closing the opening of each measurement chamber forming space with the lid 10 so that the measurement chamber 4 is provided on each side of each membrane portion F. It is formed. That is, a pair of film portions F is provided, and four measuring chambers 4 are formed.

Referring to FIGS. 2 and 3, the film portion F will be described. The film portion F includes a film 11, a circular film plate 12 held at the center of each of both surfaces of the film 11, and an outer film plate. The film part F is provided in a state in which the peripheral part of the film 11 is held in the lower casing part C1 by the frame-shaped film regulating plate 14. .
One end of a blade 15 is pivotally supported on each hinge 13 of each membrane portion F, and the blade shaft 16 is hermetically sealed in a hole formed in the upper wall of the lower casing portion C1 with its axial center directed vertically. The lower end of the blade shaft 16 is connected to the opposite side of the blade 15 from the pivot support side.

  As shown in FIGS. 3 and 4, the link mechanism L includes two sets of a large elbow 17 and a small elbow 18 in which ends are pivotally connected to each other. One end of each large elbow 17 is pivotally connected to the upper end of each blade shaft 16.

As shown in FIGS. 3 and 4, the valve portion V is provided on the upper wall of the lower casing portion C <b> 1 so as to control the supply and discharge of the gas in the four measurement chambers 4, and the valve portion V is the membrane portion F. Are opened and closed by reciprocating motion.
The valve portion V will be described with reference to FIG. 4. Two gas supply / exhaust ports X respectively communicating with the two measuring chambers 4 opposed to each other through the membrane 11 are provided on the upper wall of the lower casing portion C1. Are arranged side by side at intervals, so that two sets of gas supply / exhaust ports X in which two gas supply / exhaust ports X are arranged are provided, and a gas exhaust port Y is provided between the gas supply / exhaust ports X of each set. It is provided. In other words, two rows of supply / discharge openings are formed on the both sides of the gas discharge port Y, in which two gas supply / discharge ports X are arranged.

  A gas discharge port Y of each supply / discharge opening row is connected to a gas discharge connection port Z provided on the upper wall of the lower casing portion C1 through a gas discharge path (not shown). The connection port Z is connected to the gas discharge port 2b through a gas discharge path (not shown) provided in the upper casing portion C2 with the upper casing portion C2 provided on the lower casing portion C1. Yes.

An oscillating valve 23 is provided at the upper part of each supply / discharge opening row so as to be swingable in the direction in which the openings of the supply / discharge opening rows are arranged by a vertical shaft portion. Are connected by a rotating plate 20 described later and a pair of arms 21 and 25.
The back surface of the oscillating valve 23 is provided with a communication recess (not shown). The oscillating valve 23 is positioned at each oscillating end, and the gas supply / exhaust port X and the gas outlet on the oscillating end side. Y is connected to the communication recess and the gas supply / exhaust port X on the side opposite to the swinging end is opened, and both the gas supply / exhaust ports X are closed in the state of being located at the center of the swinging direction. It is configured.

As shown in FIG. 4, the rotating portion R <b> 1 has one end of the small elbow 18 rotatably attached and the other end of the arm 21 whose one end is connected to the swing valve 23 is rotatably supported. A rotating plate 20 is provided.
A magnet 5 is attached on the rotating plate 20 so as to make a circular motion as the rotating plate 20 rotates. A counter 19 is provided below the rotating plate 20 so as to count the number of rotations of the rotating plate 20.

  Therefore, when the gas is supplied to and discharged from the measuring chamber 4, the membrane 11 reciprocates and the blade shaft 16 rotates. By the rotation of the blade shaft 19, the large elbow 17 of the link mechanism L is swung, and the rotating plate 20 is rotated via the small elbow 18. By the rotation of the rotating plate 20, the arm 21 is swung and the swing valve 23 is operated.

FIG. 5 shows the positional relationship between the magnet 5 attached to the rotating plate 20 and the azimuth sensor 6 provided on the lower surface of the upper casing portion C2.
Since the direction sensor 6 is already well known and will not be described in detail, a two-axis magnetic direction sensor integrated with an MR element, a thin film coil, a drive circuit, etc. is generally used, and the direction of the magnetic flux Can be detected.
As the direction sensor 6, a three-dimensional sensor such as a Wheatson bridge may be employed.

  As shown in FIG. 5, the magnet 5 attached on the rotating plate 20 that rotates is linked with the reciprocating movement of the film 11 to operate the link mechanism L to rotate the rotating plate 20. Perform circular motions such as perfect circles, ellipses, ellipses, and closed curves. Therefore, the orientation sensor 6 is attached to the lower surface of the upper casing C2 so as to correspond to the inside of this circular motion. It is desirable to provide the azimuth sensor 6 so as to correspond to the center of the circular motion.

As shown in FIG. 5, when the rotating plate 20 is rotated by the link mechanism L, the magnet 5 provided on the rotating plate 20 also rotates. However, as shown in FIG. The magnetic pole to be performed (for example, the S pole) is always constant.
That is, as shown in FIG. 6 (A), when the magnet 5 rotates around the direction sensor 6 with the same magnetic pole directed toward the direction sensor 6, the direction sensor 6 is shown in FIG. 6 (B). Moreover, since the direction of magnetic flux changes with the circular motion of the magnet 5, the position of the magnet 5 can be detected from the direction of magnetic flux.

  Thereby, the rotation angle of the rotating plate 20 can be known, and further, the state of the reciprocating movement of the film part F can be detected, so that the measurement resolution of the flow rate can be improved. In addition, although it is possible to always detect the rotation state of the rotating plate 20, it is desirable to detect at an arbitrary interval in order to reduce the consumption of the battery provided in the flow rate measuring device 1.

In the flow rate measuring apparatus 1 described above, the case where the magnet 5 performs the orbiting motion and the direction sensor 6 is provided at the center position of the orbiting motion has been described. The same applies to the position.
Further, as shown in FIG. 7, even when the magnet 5 is placed on the small elbow 18 of the link mechanism L, the magnet 5 draws a closed curve and can be detected. In this case, since the magnet 5 circulates while performing parallel movement, the magnetic pole located on the direction sensor 6 side changes along with the lap. That is, as shown in FIG. 8 (A), for example, when the N pole of the magnet 5 is turned upward in FIG. Is located below the direction sensor 6, the N pole is on the direction sensor 6 side. In this case, the azimuth sensor 6 detects the direction of the magnetic flux as shown in FIG.
Furthermore, it is also possible to arrange the orientation sensor 6 outside the magnet 5 that makes a circular motion.
Furthermore, it is possible to arrange the magnet 5 at the center of the circular motion and rotate the azimuth sensor 6.

  As described above, in the flow rate measuring device according to the present invention, the magnet or the azimuth sensor is provided in the orbiting portion. Therefore, the magnet or the azimuth sensor also circulates, and the azimuth sensor detects this orbiting motion. The position of the film can be detected by obtaining the relative position between the two. This has the effect of improving the measurement resolution and enabling accurate measurement, and is useful as a flow rate measuring device that measures the flow rate of fluid, particularly a membrane-type flow rate measuring device.

It is a perspective view showing the whole membrane gas meter which is a flow measuring device concerning an embodiment of the invention. It is a longitudinal cross-sectional view of the principal part of a membrane type gas meter. It is a disassembled perspective view of the principal part of a membrane type gas meter. It is a top view of the principal part of a membrane type gas meter. It is a disassembled perspective view which shows the relationship between the position of the magnet provided in the rotating plate, and the position of a direction sensor. (A) The top view which shows the state of the magnet which goes around the direction sensor, (B) It is a graph which shows the change of the direction of the magnetic flux detected by the direction sensor. It is a disassembled perspective view which shows the relationship between the position of the magnet provided in the link mechanism, and the position of a direction sensor. (A) The top view which shows the state of the magnet which goes around the direction sensor, (B) It is a graph which shows the change of the direction of the magnetic flux detected by the direction sensor. It is a principal part top view of the conventional film | membrane type gas meter.

Explanation of symbols

1 Membrane gas meter (flow rate measuring device)
4 Weighing chamber 5 Magnet 6 Direction sensor 11 Film R1 Circulation part

Claims (3)

A flow rate measuring device for measuring a flow rate of the fluid, comprising a membrane that reciprocates once in accordance with supply and discharge of a predetermined amount of fluid to and from a measuring chamber, and a revolving portion that revolves in response to the reciprocating movement of the membrane. ,
Having a magnet and an orientation sensor for detecting the orientation of the magnet;
One of the magnet and the azimuth sensor is provided in the circulating section, and the flow rate of the fluid is measured from the relative position of the magnet and the azimuth sensor.   The flow rate measuring device according to claim 1, wherein the magnet is arranged in the circulation section, and the azimuth sensor is arranged in the center of the circulation movement of the magnet.   The flow rate measuring device according to claim 1, wherein the magnet always circulates with the same magnetic pole directed toward the azimuth sensor.

Images