JPH04115124A - Laminar flow element - Google Patents

Abstract

PURPOSE:To obtain an element wherein mirror-surface finishing is easy, impurities are not attached and convection does not occur by bringing the planar parts of a plurality of block pieces wherein grooves are formed into close contact so that the grooves agree to each other, and forming flow paths. CONSTITUTION:A plurality of parallel grooves 12 are formed in divided planar parts 11 of block pieces 10 made of stainless steel or the like. At the outer part of each block piece 10, a part 13 whose diameter is slightly smaller, a part 14 whose diameter is slightly larger and tapered parts 15 and 16 are formed. A tapered part 18 which agrees with the tapered part 15 is formed on a cylindrical ring body 17 for fixation. Both block pieces 10 constituted in this way are externally coupled so that the grooves 12 agree. Under the state wherein the divided planar parts 11 of the block pieces 10 are put together so that the grooves 12 agree, the ring body 17 is coupled on the outer part of the part 13 having the slightly smaller diameter. Then, a plurality of flow paths 19 whose cross section is circular are formed in the parallel state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminar flow element used in a laminar flow meter that measures the flow rate of fluid such as gas.

[Conventional technology]

Conventionally, the laminar flow element has two types: (1) many thin tubes inserted inside an outer tube, and (2) a through hole in the center and a communication path that communicates this hole with the outer periphery of the disk. A method in which a large number of discs with a plurality of discs arranged in a direction are stacked so that fluid flows from the outer periphery of the disc through a communication path to a hole in the center (for example, Japanese Patent Application Laid-Open No. 50-2968), Laminated many thin plates with many holes (for example, Japanese Patent Publication No. 1)
-40300).

[Problem to be Solved by the Invention] However, in the method (2) above, since a thin tube with an extremely small inner diameter (for example, about 0.2 ml and a length of about 20 m) is used, a large number of these tubes are inserted into the main outer tube. In addition, it is difficult to polish the inside of each capillary to a mirror-like finish, resulting in problems such as particles and impurities in the fluid adhering to the inside of the capillary. .

In addition, in the above measures (1) and (2), since a large number of plate-like members such as disks or thin plates are laminated, a large number of fluids accumulate in the contact area between the plate-like members other than the groove or hole. This poses a problem in that particles and impurities tend to accumulate.

The present invention has been made with the above-mentioned considerations in mind, and its purpose is to easily achieve a mirror finish while maintaining good laminar flow characteristics as a laminar flow element.
It is an object of the present invention to provide a clean laminar flow element that does not attract or retain impurities.

[Means for Solving the Problem] In order to achieve the above-mentioned object, the laminar flow element according to the present invention has the following features:
The present invention is characterized in that one or more flow channels are formed by making a plurality of block pieces each having one or more grooves formed in the plane portions and bringing the plane portions into close contact with each other so that the grooves match each other.

[Effect]

In the laminar flow element having the above-mentioned configuration, before the block pieces are brought together, the surfaces of the concave grooves that will become the flow paths can be easily and sufficiently polished.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, FIG. 3 shows the main parts of a laminar flow meter in which the laminar flow element S according to the present invention is inserted. In this figure, 1 is a flow meter block, and its fluid inlet 2 and fluid guide A bypass channel 4 between the outlet 3 and the outlet 3 is provided with an N flow element S, which will be described later. Reference numeral 5 denotes a measurement flow path provided in parallel with the bypass flow path 4, and is provided so as to connect openings 6 and 7 opened on the upstream and downstream sides of the laminar flow element S, respectively. Sensor coils 8.9, which are connected to a bridge circuit (not shown) and serve as a component thereof, are wound around the outer periphery of the sensor coil 5a at appropriate intervals.

Next, an example of the configuration of the laminar flow element S will be explained with reference to FIG. 1 and FIG. The block piece is made of a metal with excellent properties, and a plurality of mutually parallel grooves 12 are formed in each dividing plane part 11 of the block piece 10. In this embodiment, the cross section of each groove 12 is The visual shape is a semicircle.

A slightly smaller diameter portion 1 is provided on the outside of each block piece 10.
3, a slightly larger diameter portion 14 and tapered portions 15 and 16 are formed.

The formation of each of these portions 13 to 16 is performed before dividing the cylinder into two.

Reference numeral 17 refers to fitting the two block pieces 10 configured as described above so that their concave grooves 12 match each other so that the split plane parts 11 are aligned, so that they do not separate. This is a cylindrical ring body for fixing, made of stainless steel, for example, and has a tapered portion 18 that matches the tapered portion 15 on the inner periphery of one end thereof.

Therefore, in order to form the laminar flow element S, the block piece 1
2 and 4 by fitting the ring body 17 to the outside of the slightly smaller diameter portion 13 with the split plane parts 11 aligned so that the grooves 12 match each other. As shown, a plurality of flow channels 1 having a circular cross-sectional view
9 are formed parallel to each other. and,
This laminar flow element S is incorporated into the bypass channel 4 within the flowmeter block 1, as shown in FIG.

In the laminar flow element S having the above configuration, the surface of the groove 12 in the block piece lO can be sufficiently polished in advance or subjected to a surface modification treatment, so that the inside of the flow path 19 in contact with the fluid to be measured can be adjusted as desired. It can be finished to a mirror-like finish. Therefore, even if impurities are mixed into the fluid to be measured, they will not adhere to the inside of the flow path 19.

In the illustrated laminar flow element S, the block piece l
Since the tapered portions 15 and 16 are formed on the outer periphery of O, all flow paths 19 are open in the direction of fluid flow, and no fluid stagnation occurs, so impurities in the fluid are quickly removed from the system. be excluded. Further, due to the tapered portion 15 formed on the outer periphery of the block piece 10 and the taper 18 formed on the inner periphery of the ring body 17, the tightening force by the ring body 17 acts strongly on the block piece 10. Furthermore, since the tapered part 16 is formed on the outer periphery of the block piece 10, when the laminar flow element S is incorporated into the bypass channel 4 in the flow meter block 1, there is an advantage that an O-ring for sealing is not required. be.

The present invention is not limited to the embodiments described above, but can be implemented with various modifications, which will be described with reference to FIGS. 5 to 8.

First, in the example shown in FIG. 5, no tapered portion is formed on the outer periphery of the block piece IO, and no tapered portion is formed on the inner periphery of the ring body 17.
Needless to say, the block pieces 10 are butted against each other.

In the example shown in FIG. 6, the cylinder is divided into four parts along a line passing through the center, and a plurality of grooves 22 parallel to each other are formed in the divided plane parts 21 of each of the four block pieces 20. In addition, 23 is a ring body for fixation.

Furthermore, in the examples shown in FIGS. 7 and 8, rectangular grooves 24 are formed in the dividing plane portions of the flock pieces 10 and 20, respectively. In this case, the flow path formed by the groove 24 can be enlarged, and the flow rate of the laminar flow element S can be increased while maintaining a good laminar flow state.

As understood from both embodiments, the shape of the groove can be any shape other than circular.

Incidentally, in the embodiment illustrated above, the flock piece 10.20 is constructed by dividing the cylinder into two or four parts, but the number of divisions is not limited to this, and any division may be made. good. Furthermore, it is not always necessary to divide the area equally. It goes without saying that a square column may be used instead of a cylinder and divided in the same manner.

Furthermore, the grooves 12, 22, 24 can be formed not only by divided flat parts formed by dividing a cylinder or a square pillar, but also by a member having a flat part, such as a surface part in the longitudinal direction of a square pillar or a pillar having a semicircular cross section. It may be formed on a flat part in the length direction. That is,
A predetermined concave groove 12.22 is formed in the flat part of these prisms and pillars.
．． 24, the prisms, columns, etc. are placed in the concave groove 12.2.
2. The laminar flow element S may be formed by bringing the 2.24 pieces into close contact with each other.

Furthermore, a concave groove 12.2224 formed in the plane part
does not need to be plural, and may be one.

That is, the plurality of block pieces 10.20 are inserted into the groove 122.
When the flat parts 2 and 24 are brought into close contact with each other, only one flow path 19 may be formed.

[Effects of the Invention] Since the present invention is configured as described above, it is possible to easily achieve a mirror finish while maintaining good laminar flow characteristics as a laminar flow element, and to prevent the adhesion and accumulation of impurities. It is possible to obtain a clean laminar flow element that does not cause turbidity. In addition, it is easy to form grooves and finish them to a mirror finish.
Accordingly, a high-performance laminar flow element can be obtained at a low cost.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, FIG. 1 is an exploded perspective view of a laminar flow element according to the present invention, FIG. 2 is a vertical cross-sectional view in an assembled state, and FIG. FIG. 4 is a vertical cross-sectional view showing the essential parts of a laminar flow type flowmeter incorporating a flow element, and FIG. 4 is an enlarged cross-sectional view of the laminar flow element portion. 5 to 8 show laminar flow elements according to other embodiments, FIG. 5 is an exploded perspective view of a laminar flow element made up of two block pieces, and FIG. 6 is an exploded perspective view of a laminar flow element made up of two block pieces. FIG. 7 is a perspective view of a laminar flow element made up of two block pieces, and FIG. 8 is a perspective view of a laminar flow element made of four block pieces. 10, 20...Block piece, 11...Plane part, 12
．． 22.24... Concave groove, 19... Channel, S... Laminar flow element.

Claims (1)

[Claims] A layer characterized in that one or more flow passages are formed by a plurality of block pieces each having one or more grooves formed in the plane parts, and the plane parts are brought into close contact with each other so that the grooves match each other. Ryu element.