JPH08240460A - Flowmeter and its manufacture - Google Patents

Abstract

PURPOSE: To obtain a steady flow in a short passage without requiring an ordinary straight line passage part by arranging a straightening body having plural divided passages almost over the whole of a passage cross section, and respectively measuring a flow rate in the respective divided passages by flow rate sensors. CONSTITUTION: Thin plastic vertical sheets 21 and horizontal sheets 22 are respectively combined with each other in the mutually orthogonal direction, and a straightening body 20 having plural divided passages 23 is inserted into a case 10. Small flow rate sensors are respectively arranged in the respective divided passages 23, and are connected to a power source and a processing circuit through printed wiring 25 and a wiring aggregate plate 26. Therefore, since a steady flow can be immediately obtained in the respective divided passages 23 even by a flow just after passing through a bent pipe, the whole flow rate in the divided passages 23 can be accurately calculated from a prescribed calculative expression on the basis of a flow rate measured at a point in the divided passages. Therefore, a flow rate of the whole passages can be easily and accurately obtained by calculating the flow rate in the respective divided passages 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow meter, and more particularly to a flow meter having a rectifying function capable of obtaining a steady flow without requiring a linear flow path having a normal length and a method for manufacturing the same.

[0002]

2. Description of the Related Art In order to accurately measure the flow rate of a fluid flowing through a flow path such as a conduit using a single flow meter, the flow should be sufficiently developed to have a stable flow velocity distribution type. In addition, a straight flow path portion (runway) having a length of 20 times or more the inner diameter of the flow path is provided on the upstream side of the flowmeter, and a straight flow path portion having substantially the same length is also provided on the downstream side. It is necessary to provide. (Refer to "Flow Measurement Handbook" published by Nikkan Kogyo Shimbun Co., Ltd.) A fluid flow with a stable flow velocity distribution in a steady flow is called "Hagen-Poiseuille flow", with the center of the flow path as the apex. , Has a parabolic flow velocity distribution in which the flow velocity decreases toward the inner peripheral surfaces on both sides in the radial direction. Therefore, if the flow rate (flow rate) measured at one place in the flow channel is applied to this flow velocity distribution, the flow rate in the entire flow channel can be easily calculated.

However, it is generally difficult to secure a space for providing the straight flow passage portion including the above-mentioned runway. For example, when a flow meter is installed in the piping of the device, ensuring a straight flow path portion hinders downsizing and cost reduction of the device. Further, when a flow meter is installed in a gas pressure regulating facility in a city, there is a restriction that an installation space cannot be taken, or even if the installation space is taken, land cost is expensive.

A volumetric flow meter shown in FIG. 9 is conventionally known as a means for measuring the flow rate without providing a linear flow path section in a state where the flow rate distribution is not steady.

Furthermore, when this volumetric flow meter cannot be used, a simple flow rate measurement is performed in which the flow rate is measured at multiple points and the average flow rate is obtained. Japanese Patent Examination Sho 60-72
Japanese Patent Publication No. 07 discloses a Pitot tube flowmeter having a plurality of measurement holes as shown in FIG.

[0006]

In the conventional flow rate measurement using an ordinary flow meter, in order to create a steady flow, a straight line having a diameter of 20 times or more of the diameter of the flow path is provided before and after the place where the flow meter is installed. A flow path is required, and the flow rate of a fluid in a turbulent state cannot be measured accurately. Also,
The volumetric flow meter has a problem that the response speed is slow and a special space for installing the flow meter is required. Furthermore, in the case of the Pitot tube type flow meter, the flow rate measurement range is narrower than 2 digits, the response speed is slow, and an expensive differential pressure converter is required to obtain an electric output signal. There is.

The present invention has been made in order to solve the above-mentioned problems in the prior art, and an object of the present invention is to obtain a steady flow in a short flow path without the need for a normal straight flow path section. It is to provide a flow meter having a rectifying function capable of performing the above and a manufacturing method thereof.

[0008]

In order to achieve the above object, according to a first basic aspect of the present invention, a channel is installed in a case over substantially the entire cross section of the flow path and with a predetermined length. A rectifying body having a plurality of divided flow paths, sealing means for filling a gap between the inner peripheral surface of the case and the divided flow paths and / or between the divided flow paths, and each of the divided flow paths of the rectifying body. A flow meter is provided that includes a plurality of installed flow sensors and wiring equipment for connecting the flow sensors to a power supply and a processing circuit, respectively.

The rectifying body in the first basic mode has a frame for covering the outer periphery thereof, and the sealing means has an outer peripheral shape conforming to the inner peripheral shape of the case and a hole conforming to the outer peripheral shape of the rectifying body. And a seal plate mounted on at least one side end portion of the rectifying body in the axial direction and / or a sealing material packed between the rectifying body and the frame and between the divided flow paths.

Each of the flow rate sensors is attached to a central portion of the inner wall surface on one side of each of the divided flow passages, and to a sensor sheet provided orthogonal to the flow so as to pass through the center of each divided flow passage. By doing so, it may be installed at the center of each of the divided channels.

The cross-sectional shape of each of the divided flow passages can be appropriately selected from polygons including quadrilaterals and circles.

Further, the wiring facility includes a printed wiring formed on a divided flow channel wall for forming a divided flow channel, a wiring assembly board for collecting these printed wirings, the wiring assembly board, a power source and a processing circuit. And a wiring sheet provided so as to connect the two.

Further, in addition to the flow rate sensor, a pressure sensor and a temperature sensor may be installed in each divided channel.

According to a second basic aspect of the present invention, a printed wiring is provided, and a plurality of flow rate sensors are arranged at equal intervals in the vertical direction and substantially in the center in the longitudinal direction so as to be respectively connected to the printed wiring. A plurality of vertical sheets with a predetermined length that are fixed in position and that have a plurality of slits that are cut at equal intervals so as to extend from one end side to almost the center position along the longitudinal direction are arranged in rows at equal intervals. And, having a plurality of slits cut at equal intervals so as to extend from one end side to the substantially central position along the longitudinal direction, and a plurality of horizontal sheets having the same length as the vertical sheet, each slit While meshing with each other, a plurality of vertical sheets arranged in a row are respectively mounted in the horizontal direction to form a rectifying body having a large number of rectangular divided flow paths, and each printed wiring of the rectifying body is covered. A wiring aggregate plate for fixing the rectifying body in an appropriate place, providing a wiring sheet on the wiring aggregate plate so as to connect each of the flow rate sensors to a power supply and a processing circuit, and the rectifying body also serves as a support. A method of manufacturing a flowmeter is provided, which includes the steps of inserting the case through a seal plate into a case having substantially the same length.

According to the third basic aspect of the present invention, a plurality of divided flow passage tubes each having a half length of a predetermined length are arranged in a line in the longitudinal direction with their respective opening end faces aligned. The outer surfaces of the plurality of divided flow passage tubes are fixed to each other so as to form a flow passage unit, and a pipe is formed from the end surface at the central portion along the longitudinal direction of one end face of the first divided flow passage unit. A slit is cut along the axial direction, and a plurality of flow rate sensors are fixed in a row in the vertical direction at the same intervals as the opening width of each divided flow channel of the first divided flow channel unit, and a printed wiring connected to each flow rate sensor. To form a half-divided sensor unit by inserting and fixing a sensor sheet having slits in the slit, and a second split in which the same number of split flow channel pipes as the first split flow channel unit are fixed in a line in the vertical direction. Forming a flow path unit And the one end face of the second divided flow channel unit and the end face having the sensor sheet of the first divided flow channel unit are abutted and fixed to each other to form the tandem sensor unit, and the same number and / or different A plurality of columnar sensor units each having a number of divided flow channel tubes are arranged in the horizontal direction until a predetermined width is formed, and these columnar sensor units are connected to each other to form a rectifying body having a large number of divided flow channels. That is, a wiring aggregate plate for collecting the printed wiring of the rectifying body is provided at an appropriate place of the rectifying body, and a wiring sheet is provided on the wiring aggregate plate so as to connect each of the flow rate sensors to the power supply and the processing circuit. And a method for manufacturing a flowmeter, which includes the steps of inserting the rectifying body into a case having substantially the same length through a seal plate that also serves as a support. .

In the manufacturing method according to the third basic aspect, each of the divided flow channel pipes is a circular pipe or a pipe having a polygonal shape in cross section, and the circular pipe or the pipe having the polygonal shape is the most preferable. They are in close contact with each other in a closely packed form.

[0017]

[Function] By flowing through the divided flow passages having a rectifying function, for example, a steady flow can be immediately obtained in each divided flow passage even immediately after passing through the curved pipe. Based on the calculated flow rate, the flow rate in the entire divided channel can be accurately calculated from a predetermined calculation formula. Therefore, the flow rate in the entire flow path can be easily and almost accurately calculated by integrating the flow rates in the respective divided flow paths.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail below with reference to several preferred embodiments shown in the accompanying drawings.

First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic perspective view of a first embodiment, in which a plurality of vertical sheets 21 and horizontal sheets 22 made of, for example, thin plastic are combined in directions orthogonal to each other to form a plurality of quadrangles. The rectifying body 20 including the divided flow path 23 is inserted into the case 10. Printed wirings 25 are provided at appropriate places on each sheet, and these printed wirings 25 are connected to the wiring assembly board 26.
And is connected from there via a wiring sheet 27 to a power supply and a processing circuit (not shown).

Inside each of the divided flow passages 23 in the rectifying body 20, for example, as shown in the cross-sectional view of FIG. 2, a small-sized member fixed to an inner wall surface of one side of the vertical sheet 21 with an adhesive, for example. A flow sensor 24 is installed. These flow rate sensors 24 are connected to the printed wiring 25, respectively, as shown in FIG.

FIG. 3 is a perspective view showing a seal plate 28 which also functions as a support for inserting the rectifying body 20 into the case 10 and fixing the rectifying body 20 therein. The seal plate 28 has an outer diameter that matches the inner diameter of the case 10, and a hole 28a that matches the outer peripheral shape of the rectifying body 20 is formed inside the seal plate 28.

Although not shown, flanges are formed at both ends of the case 10 so as to be suitable for connection to piping or the like.

Next, the manufacturing method of the first embodiment will be described with reference to FIG.

Printed wirings 25 are provided at appropriate places, and a plurality of flow rate sensors 24 are fixed at equal intervals in the longitudinal direction and substantially in the central position in the longitudinal direction so as to be connected to the printed wirings 25, respectively, with an adhesive. Further, a plurality of vertical sheets 21 each having a predetermined length and having a plurality of slits cut at equal intervals so as to extend from one end side to a substantially central position along the longitudinal direction are first arranged at equal intervals in the vertical direction. It

A plurality of vertical sheets 21 arranged vertically are provided with a plurality of slits cut at equal intervals so as to extend from one end side to a substantially central position along the longitudinal direction. Multiple horizontal sheets 22 of the same length
Are mounted in the lateral direction so that the respective slits mesh with each other and are orthogonal to each other. As a result, the rectifying body 20 having the plurality of rectangular divided flow paths 23 is formed.

Subsequently, a wiring assembly board 26 for collecting the printed wirings 25 is provided at an appropriate position of the rectifying body 20, and the wiring assembly board 26 is connected to each of the flow rate sensors 24 for connecting to a power source and a processing circuit. A wiring sheet 27 is provided.

Finally, at least one end of the rectifying body 20,
Preferably, seal plates 28 also serving as supports are provided at both ends, and the assembly 1 has a substantially same length.
0 is inserted into the flowmeter as the first embodiment of the present invention.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the above-described first embodiment in that it has a divided channel 23 having a circular cross section. That is, inside the frame 20a having the same shape as the outer peripheral shape of the rectifying body 20 of the first embodiment, a predetermined number of the divided flow passage pipes 29 each having a circular cross section are arranged in a line in a vertical direction to sequentially form a flow passage unit. The rectifying body 20 is formed by inserting. Frame 20a and each divided flow channel tube 2
The space is filled with the sealing material 20b between the sealing material 20b and the space between the adjacent flow passage tubes 29. This sealing material 20b
Need only be packed into at least one end face in the longitudinal direction of the rectifying body.

Further, as shown in detail in FIG. 8, the flow rate sensor 24 installed in each divided flow path 23 is a thin strip-shaped sensor provided with printed wiring, for example, made of plastic or glass. It is installed at the center of the cross section of the divided flow path 23 via the sheet 24a.

By making the divided flow passage 23 circular in cross section as in the second embodiment, the flow state in the divided flow passage 23 is a steady flow having a known flow velocity distribution, and therefore more accurate. It is possible to perform various flow rate measurements.

Here, the manufacturing method of the second embodiment will be described with reference to FIG.

First, a plurality of divided flow passage pipes 29 having a half length are arranged so that the opening end faces of the divided flow passage pipes 29 are aligned in the vertical direction to form a first divided flow passage unit 29a.
The outer surface of each of the plurality of divided flow channel tubes 29 is fixed to each other via an adhesive, and the one end surface of the first divided flow channel unit 29a is located at the central portion along the longitudinal direction from the end surface. The slit 29c is cut along the tube axis direction.

Subsequently, a plurality of flow rate sensors 24 have the same width as the opening width of each divided flow channel tube 29 of the first divided flow channel unit 29a on the strip-shaped sensor sheet 24a having a printed wiring connected to each flow rate sensor. It is fixed in a line in the longitudinal direction at intervals with an adhesive. This sensor sheet 24a is inserted into the slit so that each flow sensor 24 is located at the center of the cross section of each divided channel, and is fixed with an adhesive that also serves as a seal. This forms a halved column sensor unit.

Further, a second divided flow passage unit 29b is formed in which the same number of divided flow passage tubes 29 as the first divided flow passage units 29a are fixed in a line in the vertical direction with an adhesive, and the second divided flow passage unit 29b is formed. One tandem sensor unit is formed by abutting one end surface of the divided flow path unit 29b and the end surface of the first divided flow path unit 29a having the sensor sheet 24a and joining them with an adhesive.

Subsequently, a plurality of column sensor units each having the same number and / or a different number of divided flow channel pipes 29 are arranged in the horizontal direction until a predetermined width is obtained, and these column sensor units are bonded with an adhesive. The rectifying body 20 having a large number of divided flow paths 23 is formed by connecting them to each other.

A wiring assembly plate 26 for collecting the printed wirings is put in place on the rectifying body 20 thus formed.
And a wiring sheet 27 for connecting each of the flow rate sensors to a power source and a processing circuit, respectively.

Finally, the seal plate 28 which also serves as a support is attached to at least one end side of the rectifying body 20, and then this assembly is inserted into the case 10 having substantially the same length, whereby the flow rate of the second embodiment is increased. The gauge is manufactured.

Preferably, the rectifying body 20 is inserted into the frame 20a, and the space between the frame 20a and the rectifying body 20 and the spaces between the adjacent divided flow channel tubes 29 are not provided. The sealing material 20b is packed.

FIGS. 6 and 7 show the third and fourth aspects of the present invention.
Each example is shown in cross-section.

In the third embodiment shown in FIG. 6, as apparent from the drawing, the divided flow passage pipes 29 having a circular cross section described in the second embodiment are arranged in a close packing form, By adopting such an arrangement form, it is possible to improve the flow state and reduce the pressure loss in the case 10 due to the formation of the divided flow paths 23.

In the fourth embodiment shown in FIG. 7, divided channel tubes 29 having a hexagonal cross section are arranged in a honeycomb shape, and a polygon other than the hexagonal cross section is formed. It is also possible to arrange an array of divided flow channels with.

The configurations and manufacturing methods of the third and fourth embodiments are almost the same as those of the second embodiment, and therefore detailed description thereof will be omitted to avoid duplication.

In Embodiments 2 to 4 shown in FIGS. 5 to 7, the frame 20a is not always necessary, and the side faces of the flow path units may be laterally arranged while being fixed to each other with an adhesive. In this case, the inner peripheral surface of the hole 29 a of the seal plate 29 provided at at least one end of the rectifying body 20 is formed in a corrugated or toothed shape so as to match the outer peripheral surface of each divided flow channel tube 29.

What can be said in common to the flowmeters of the first to fourth embodiments is that, when the number of the divided flow passages 23 is N, the flow state in each divided flow passage becomes a steady flow. The run-up distance of the divided flow path is approximately 1 / of the run-up distance of the entire flow path.
It can be (N) ^1/2 . Then, the divided channel 23
Is twice or more than the approach distance, and the flow rate sensor 24 is installed at a position away from both ends of the divided flow path 23 by the approach distance or more. For example, for a 100 mm diameter conduit, the traditional run-up distance would need to be at least 2 meters (100 mm x 20 times) and the length of the straight conduit required to install the flow meter would be at least 4 meters. But in this straight conduit 100
When the rectifying body having the individual divided flow paths is provided, the run-up distance of each divided flow path may be 0.2 meters (2 m × 1/10). Therefore, the required conduit length is 0.4 meters, which can be shortened to 1/10 of the conventional length.

Further, it is common that all the flow rate sensors 24 are installed on the same cross section in the direction perpendicular to the flow, and particularly preferably, all the flow rate sensors 24 are at the center of the cross section of each divided flow path. Is installed in.

Further, a filter may be installed on the upstream side of the rectifying body 20 if necessary.

As the flow rate sensor used in the present invention, the hot wire type semiconductor flow rate sensor, which is small in size, excellent in response performance, easy to obtain electric signal output, and capable of being manufactured at a low cost, is most suitable. A heat wire made of polysilicon, which can have a wide measurement range, is preferably used for the. On the other hand, separately from this, it is possible to insert the vortex generator of the Karman vortex flowmeter as a flow sensor into each divided flow path.

When using a hot wire type semiconductor flow rate sensor to measure a flow whose temperature and pressure are non-uniform,
Accurate flow rate measurement cannot be performed by measuring only the flow rate sensor 24. This is because, in a flow having nonuniform temperature and pressure, it is highly possible that the temperature and pressure in each divided flow path are also different. Therefore, in such a case, the output of each flow rate sensor 24 needs to be corrected according to the temperature and pressure in each divided flow path. for that reason,
In addition to the flow rate sensor 24, it is necessary to install a temperature sensor 31 and a pressure sensor 32 in each divided channel as shown in FIG. A semiconductor temperature sensor is used as the temperature sensor 31,
A semiconductor diaphragm type pressure sensor can be preferably used as the pressure sensor 32. Each of these sensors can be individually manufactured and individually installed, but it is also possible to integrally install the sensors on the same substrate as one chip.

The above description is merely illustrative of the preferred embodiments of the present invention and the scope of the present invention is not limited thereto. Many more variations and modifications of the present invention will readily suggest themselves to those skilled in the art without departing from the scope of the invention.

[0050]

According to the flow meter of the present invention, the effects described below can be obtained. 1. 1. A long straight flow path (runway) for obtaining a laminar flow having a known flow velocity distribution is not required, which can contribute to downsizing of various devices. The flow rate of the fluid in the turbulent state can be accurately measured. 3. Since a flow meter can be built in the flow path of various devices, a space for exclusive use of the flow meter is not required, and downsizing and cost reduction of the device are realized. 4. Since each of the divided flow passages having the built-in flow meter has a function as a rectifier, it is possible to exert a rectifying effect. 5. By using the heat wire type small flow rate sensor as the flow rate sensor, a quick response speed can be obtained and the flow rate fluctuation can be accurately measured. 6. By using a hot wire made of polysilicon as the hot wire of the hot wire type small flow sensor, a wide range of flow rate measurement over three digits can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the first embodiment shown in FIG.

FIG. 3 is a perspective view showing a seal plate used in the first embodiment shown in FIG.

FIG. 4 is an explanatory diagram showing a mounting process of a vertical sheet and a horizontal sheet that constitute the straightening member used in the first embodiment shown in FIG.

FIG. 5 is a sectional view showing a main part of a second embodiment of the present invention.

FIG. 6 is a sectional view showing an essential part of a third embodiment of the present invention.

FIG. 7 is a sectional view showing a main part of a fourth embodiment of the present invention.

FIG. 8 is an explanatory view showing a manufacturing process of a column sensor unit which constitutes a rectifying body used in the second to fourth embodiments shown in FIGS. 5 to 7 respectively.

FIG. 9 is a schematic sectional view showing an example of a conventional volumetric flow meter.

FIG. 10 is an explanatory diagram of flow rate measurement using an example of a conventional Pitot tube flow meter.

[Explanation of symbols]

 10 Case 10a Inner Surface of Case 20 Rectifier 20a Frame 20b Sealing Material 21 Vertical Sheet 22 Horizontal Sheet 23 Divided Flow Path 24 Flow Sensor 24a Sensor Sheet 25 Printed Wiring 26 Wiring Assembly Board 27 Wiring Sheet 28 Seal Plate 28a Hole 29 Divided Flow Path Pipe 29a First split flow channel unit 29b Second split flow channel unit 29c Slit 30 Column sensor unit 31 Temperature sensor 32 Pressure sensor

Claims (13)

[Claims] 1. A rectifying body having a plurality of divided flow passages installed in a case over a substantially entire cross section of the flow passage and having a predetermined length, and an inner peripheral surface of the case and the divided flow passages. Means and / or a plurality of flow rate sensors respectively installed in each of the divided flow paths of the rectifying body, and these flow rate sensors are connected to a power supply and a processing circuit, respectively. A flow meter including a wiring facility for operating the flow meter. 2. The flow meter according to claim 1, wherein the rectifying body has a frame that covers an outer periphery of the rectifying body. 3. The flow meter according to claim 1, wherein a pressure sensor and a temperature sensor are further installed in each of the divided flow paths, in addition to the flow rate sensor. 4. The sealing means has an outer peripheral shape matching the inner peripheral shape of the case and a hole having a shape matching the outer peripheral shape of the rectifying body, and at least one side end in the axial direction of the rectifying body. 3. A seal plate mounted on a portion and / or a seal material packed between the rectifying body and the frame and between the outer peripheral surfaces of the divided flow paths.
Flowmeter as described. 5. The flow rate sensor according to claim 1, wherein each of the flow rate sensors is attached to a central portion of an inner wall surface on one side of each of the divided flow paths. Flow meter. 6. The flow rate sensor is installed in a central portion of each of the divided flow passages by being attached to a sensor sheet provided so as to pass through the center of each divided flow passage and orthogonal to the flow. The flowmeter according to any one of claims 1 to 3, wherein the flowmeter is provided. 7. The flow meter according to claim 1, wherein each of the divided channels has a polygonal cross-sectional shape. 8. The flowmeter according to claim 1, wherein each of the divided channels has a circular cross-sectional shape. 9. The flowmeter according to claim 7, wherein the cross-sectional shape of each of the divided flow paths is a quadrangle. 10. The printed wiring, wherein the wiring facility is formed on a divided flow channel wall for forming the divided flow channel, a wiring assembly board that collects these printed wirings, the wiring assembly board, the power supply, and The flow meter according to any one of claims 1 to 9, further comprising: a wiring sheet provided so as to be connected to the processing circuit. 11. A printed wiring is provided, and a plurality of flow rate sensors are fixed at equal intervals in the vertical direction and at substantially central positions in the longitudinal direction so as to be respectively connected to the printed wiring, and further from one end side in the longitudinal direction. A plurality of vertical sheets of a predetermined length having a plurality of slits that are cut at equal intervals so as to extend to approximately the center position along the Having a plurality of slits cut at equal intervals so as to extend to the center position, a plurality of horizontal sheets having the same length as the vertical sheet, while engaging each slit with each other, arranged in the column Forming a rectifying body having a large number of quadrangular divided flow paths by laterally mounting it on a plurality of vertical sheets, and a wiring group for collecting each printed wiring of the rectifying body. A plate is provided at an appropriate position on the rectifying body, a wiring sheet is provided on the wiring collecting plate so as to connect each of the flow rate sensors to a power supply and a processing circuit, and a sealing plate that also serves as a support for the rectifying body is provided. A method of manufacturing a flowmeter, which comprises the steps of inserting the case into a case having substantially the same length. 12. A plurality of divided flow passage tubes each having a length half of a predetermined length are arranged so as to form a first divided flow passage unit arranged in a line in the longitudinal direction with their respective opening end faces aligned. Fixing the outer surfaces of the divided flow channel pipes to each other, and cutting a slit from the end face along the pipe axis direction in the central portion along the longitudinal direction of the one end face of the first divided flow channel unit. A plurality of flow rate sensors are fixed in a line in the vertical direction at the same intervals as the opening widths of the respective divided flow paths of the first divided flow path unit, and a sensor sheet having a printed wiring connected to each flow rate sensor is provided in the slit. Forming a half-divided flow path unit by inserting and fixing the divided flow path pipes in the vertical direction to form a second split flow path unit. That Forming a tandem sensor unit by abutting and fixing one side end surface of the second divided channel unit and the end surface having the sensor sheet of the first divided channel unit, and dividing the same number and / or a different number of units Forming a rectifying body having a large number of divided flow paths by arranging a plurality of the column sensor units each having a flow path tube in a horizontal direction until a predetermined width is formed and connecting the column sensor units to each other. Providing a wiring aggregate plate for collecting the printed wirings of the rectifying body at appropriate places on the rectifying body, and providing a wiring sheet on the wiring aggregate plate so as to connect each of the flow rate sensors to a power supply and a processing circuit. Of the flowmeter, including the steps of inserting the rectifying body into a case having substantially the same length through a seal plate that also serves as a support body. Production method. 13. Each of the divided flow channel pipes is a circular pipe or a pipe having a polygonal shape in a cross section, and the circular pipes or the pipes having a polygonal shape are in close contact with each other in a closest packing form. The method for manufacturing a flowmeter according to claim 12, wherein.