JPH0222648Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a laminar flow element suitable for use in a laminar flow meter.

BACKGROUND TECHNOLOGY When a fluid flows in a laminar flow through a channel with a constant cross section, the flow rate is proportional to the pressure loss between the channels and inversely proportional to the viscosity. A laminar flow meter calculates the pressure loss in the flow path and measures the flow rate proportional to this, and the laminar flow meter can measure the flow rate in linear proportion to the pressure.
Although it is possible to realize a cheap and simple flow meter,
In order to realize laminar flow, conventionally, thin tubes are bundled and inserted into a flow path so as to satisfy laminar flow conditions, and the pressure difference between the front and rear of the thin tube section is measured. However, with this method, it is difficult to obtain thin tubes with a uniform cross section due to burrs, scratches, bends, etc. that occur on the cut surface when cutting the thin tubes, and even when the tubes are bundled to form an integral structure, distortion occurs. This problem is likely to occur, and the cost of obtaining a highly accurate laminar flow element is high.
In order to solve this problem, Japanese Patent Publication No. 54-3743 discloses a through hole that has a front surface, a rear surface, and an outer circumferential surface that is connected to both surfaces, and that penetrates through the front and rear surfaces, and that connects the through hole and the outer circumferential surface. Suitable length for communicating and forming a laminar flow for the fluid flowing inside.
A laminar flow element has been proposed which has at least one disc member with at least one communicating passage having a diameter ratio. However, the fluid flow in this laminar flow element reaches from the outer circumferential surface of the disk member to the through hole in the center, and the distance between them is determined by the inner diameter of the flow path, so laminar flow conditions are required. In order to obtain the passage length, a spiral groove or the like was required. It is difficult to obtain such grooves with high precision, and there are disadvantages in that the combined flow in the through hole becomes a swirling flow.

Problems to be Solved by the Present Invention In the conventional example, in addition to the above-mentioned disadvantages, when creating a laminar flow element, when a plurality of disc members are laminated and fixed, one side of the disc member is Due to the groove processing, distortion occurs in the plane, which forms a passage other than the groove, which changes the flow path area and becomes a factor in instability.

Means for Solving Problems In order to solve the above-mentioned problems, the present invention stacks the grooves of the groove plates constituting the laminar flow element in a linear shape, and uses thick plates as the holding plates of the laminated groove plates. , make the inner surface of the presser plate convex, or
It is designed to be held between thin elastic plates.

Embodiment FIG. 1 is a perspective view showing an embodiment of the laminar flow element according to the present invention, in which 1 indicates an upper presser plate, 2
1 is a lower holding plate, in which a large number of grooved plates 3 are laminated between these holding plates and fixed integrally with screws 4.

FIG. 2 shows the upper presser plate 1, the lower presser plate 2,
And, in the perspective view of the groove plate 3, the upper holding plate 1 is provided with holes 1a and 1b for differential pressure detection, and the lower holding plate 2 is provided with an upstream opening 2a into which the fluid to be measured flows, and an opening 2a on the upstream side into which the fluid to be measured flows. A downstream opening 2b through which the fluid flows out is provided in the groove plate 3, and the openings 2a, 2 of the lower presser plate are provided in the groove plate 3.
Openings 3a and 3b having the same dimensions as those shown in FIG. In the present invention, a large number of groove plates 3 having the above-mentioned configuration are stacked together, and this is pressed by an upper presser plate 1 and a lower presser plate 2,
It is integrally fixed with screws 4.

FIG. 3 is a cross-sectional view taken along the line -- in FIG.
From there, it passes through the grooves 3c formed in each groove plate 3 to reach the lower opening 3b, and further flows through the downstream opening 2b of the lower holding plate. When the fluid to be measured flows through the groove plate, a laminar flow occurs in the groove plate, and a pressure difference is generated in this part, but this pressure difference P is proportional to the flow rate, so this pressure difference P can be measured. By doing so, the flow rate to be measured can be measured.

FIG. 4 is a diagram showing a modified example of the upper and lower presser plates 1 and 2, and FIG. A is an example in which the inner side of the presser plate, that is, the surface facing the groove plate portion, is formed into a convex surface 1' or 2', and FIG. 1 is a structure in which elastic plates 1'' or 2'' are joined to holding plates 1 and 2. By doing so, distortion or the like does not occur in the laminated portion of the groove plates, and stable laminar flow can be obtained.

Effects As is clear from the above description, according to the present invention, it is possible to provide a laminar flow element with a simple configuration, high precision, and low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the laminar flow element according to the present invention, FIG. 2 is a perspective view of an upper presser plate, a lower presser plate, and a groove plate used in implementing the present invention. FIG. 1 is a sectional view taken along the line 1 in FIG. 1, and FIG. 4 is a diagram showing a modification of the upper and lower press plates. 1... Upper holding plate, 1a, 1b... Differential pressure detection hole, 2... Lower holding plate, 2a... Inflow port, 2b...
... Outlet, 3... Groove plate, 3a... Inlet, 3b...
...outlet, 3c...groove, 4...screw.

Claims (1)

[Claims for Utility Model Registration] (1) A constant cross section that satisfies laminar flow conditions for fluid flow on one side of the thin plate between a pair of openings that are opened near opposite sides of the thin plate and parallel to the sides. A laminar flow element characterized by stacking a plurality of groove plates communicating with each other through a plurality of parallel grooves, and integrally sandwiching the stack plates with holding plates having openings that are opened at the same intervals as the groove plates. . (2) The laminar flow element according to claim (1), wherein the central portion of the surface of the presser plate facing the groove plate is formed into a convex surface. (3) The laminar flow element according to claim (1) of the utility model registration, characterized in that an elastic plate is integrally joined to the side of the holding plate opposite to the groove plate.