JPH0610622B2 - Flowmeter - Google Patents

Description

The present invention relates to a flow meter capable of instantaneously measuring a mass flow rate of a fluid.

<Prior Art> Conventionally, as a flow meter for measuring the flow rate of a fluid, there is a flow meter as shown in FIGS. 4 and 5 (US Pat. No. 3,953,81).
No. 9). The flowmeter 100 is roughly composed of a flange 101, a housing 102, a vane 103, a rotating shaft 105, a potentiometer 106 and a torsion spring 107. One end of the vane 103 has a rotating shaft 105.
The rotary shaft 105 is fixed to a slider of the potentiometer 106. The rotary shaft 105 is fixed to the slider of the potentiometer 106. Therefore, an electric signal corresponding to the rotation angle of the vane 103 can be taken out from the lead wire 108. As shown in FIG. 5, the flow meter 100 is inserted into the flow passage 109 so that the rotation axis 105 of the vane 103 is at a right angle to the axis of the fluid flow passage 109, and the center of the free tip of the vane 103 is inserted. The portion is located at the axial position of the flow path 109 and is installed so as to face the wall 111 provided in the flow path 109 at a right angle to the axis of the flow path 109, and the flange 101 is bolted to the main body 110. Fixed to.

The fluid flowing through the flow path 109 rotates the vanes 103 at an angle according to the flow velocity. Therefore, the flow meter 100 can measure the volume flow rate as a function of the rotation angle of the vane 103.

<Problems to be Solved by the Invention> However, in the above conventional flowmeter, the vane 1
The passage resistance when passing through 03 is measured by the pressure difference between the fluids on both sides of the vane 103 (rotation angle of the vane 103). The measured flow rate is a volume flow rate, and the mass flow rate cannot be measured. Therefore, there is a problem in that it is impossible to accurately measure the flow rate such as the flow in which cavitation occurs or the flow including bubbles. Further, since the passage resistance of the fluid is affected by the viscosity change due to the temperature change, there is a problem that an accurate flow rate measurement cannot be performed in an environment where the temperature is unstable.

Therefore, an object of the present invention is to obtain a mass flow rate by measuring a change in fluid momentum (momentum), so that it is not affected by a temperature change, and a flow causing cavitation, a flow including bubbles, etc. It is to provide a flow meter capable of accurately measuring the mass flow rate of

<Means for Solving the Problems> A main body having a cylindrical chamber 3a inside and a body slidably fitted in the chamber 3a and provided with passages 11a, 11 inside are provided from the outside. A detection body 5 in which the fluid flows into the passages 11a, 11 and flows out to the outside again, and the detection body 5 provided in the main body and obliquely inclined with respect to the axis of the detection body 5. , Which are for introducing the fluid to the internal passages 11a, 11 and the inside of the detection body 5, and which are provided inside the detection body 5 and through the inflow passages 17, 17 ,. The outflow passages 13, 13, ... Which guide the fluid flowing into the main body 11 into the main body at an angle inclined with respect to the axis of the detection body 5 in the same inclination direction as the inflow passages 17, 17 ,. A flow that flows into the detection body 5 through 17, 17, ... And then flows out through the outflow passages 13, 13 ,. An axial force acting on the detecting element 5 by the momentum of change in mass of the is characterized by having a load measuring means 6 for detecting the mass flow rate information of the fluid flowing through the detection body 5.

The principle of the present invention will be described below.

The equation of the momentum of the fluid in an arbitrary inspection plane is [external force] =
It can be expressed as [flow rate expressed by mass] × [speed change]. That is, for example, an inflow angle of a fluid flowing into a given inspection surface in a certain direction is θ ₁ , an outflow angle of a fluid flowing out from the inspection surface in the certain direction is θ ₂ , an inflow velocity of the fluid to the inspection surface is Is V ₁ , the outflow velocity of the fluid from the inspection surface is V ₂ , and the flow rate of the fluid flowing into and out of the inspection surface is Q, the equation of the momentum in a certain direction of the inspection surface is expressed as follows. be able to.

F = ρ · Q (V ₂ cosθ ₂ −V ₁ cosθ ₁ ) + ρ · L · + Fτ + α (1) where, ρ: Density of fluid L: Damping length (fluid inlet and outlet of inspection surface) The above-mentioned constant direction component of the distance between) and: dQ / dt F τ: Viscous frictional force generated between the fluid and the inner wall of the portion of the inspection surface through which the fluid passes α: The object surrounded by the inspection surface is the fluid It is a transient force required to accelerate the whole body when moving by the force received from.

Usually, the term of ρ · L · + Fτ + α in equation (1) is ρ
Since it is a sufficiently small amount compared with the term of Q (V ₂ cos θ ₂ −V ₁ cos θ ₁ ), it can be ignored and the above equation (1) becomes as follows.

F = ρ · Q (V ₂ cos θ ₂ −V ₁ cos θ ₁ ) ... (2) Here, the cross-sectional area of the inlet of the inflow passage for guiding the fluid to the detection body is A ₁ , and the fluid from the detection body is Assuming that the cross-sectional area of the outlet of the outflow passage provided in the detection body for outflow is A ₂ , the equation (2) is assumed to be V ₁ = Q / A ₁ and V ₂ = Q / A ₂ , Here, if θ ₁ = θ ₂ and A ₁ = A ₂ Becomes Therefore, the mass flow rate (ρ · Q) can be expressed by the relationship of the axial force of the detector with θ, A and ρ as constants. If this force F is detected by an appropriate means, the mass flow rate can be measured. You can

<Operation> The fluid supplied to the main body of the flowmeter is guided by the inflow passages 17, 17 provided in the main body to the passages 11a, 11 inside the detection body 5 at an inclined angle, and further, The outflow passages 13, 13, ... Are guided into the main body at the same inclination angle as the inflow passages 17, 17 ,. At that time, a force acts on the detection body 5 due to a change in the momentum of the mass of the fluid.

By detecting the force by the load measuring means 6, the momentum of the mass of the fluid that flows into the detection body 5 through the inflow passages 17, 17, ... And flows out through the outflow passages 13, 13 ,. Is measured to determine the mass flow rate. Therefore, the flow rate can be measured without being affected by the temperature, and the mass flow rate such as a flow including bubbles can also be measured.

<Examples> The present invention will be described in detail below with reference to illustrated examples.

FIG. 1 shows a first embodiment, which is a flow meter (hereinafter referred to as a momentum flow meter) for measuring a constant direction component of a force acting on an inspection surface by a load cell as a load measuring means.

As shown in FIG. 1, the momentum flowmeter 1 includes a main body 2 having an axially cylindrical hole 2a therein, a sleeve 3 fitted in the axial hole 2a, and a hole 3a of the sleeve 3. It is roughly configured by a cylindrical detection body 5 that is slidably fitted, a load cell 6 that detects the axial force of the detection body 5, and covers 7 and 8 that close the hole 3a of the sleeve 3. .

The detection body 5 is a main part of the present invention, and is a part for extracting a change in the momentum of the fluid as a force. A hole 5a is formed from one end surface 5b of the detection body 5 along the axis of the prefecture body 5, and a screw portion 10 is provided near the entrance of the hole 5a. At the same time, a hole 5d is provided on the other end surface 5c. In addition, four holes 1 are formed from the outer peripheral surface 5e of the detection body 5 at intervals of 90 ° from each other and penetrate the holes 5a toward the axis of the detection body 5.
.. are provided, and an annular groove 11a is provided on the outer peripheral surface 5e so that the holes 11, 11 ,. This annular groove 11a
The hole 11 constitutes a passage on the inflow side of the detection body 5. Further, the outer peripheral surface 5e is penetrated into the hole 5a of the detection body 5 on the end surface 5c side of the through-hole of the hole 11 at an angle θ toward the axis of the detection body 5 at intervals of 45 °. The eight fluid outflow passages 13, 13, ...

The threaded portion 14a of the detection body plug 14 is screwed into the threaded portion 10 of the detection body 5 to seal the hole 5a, and a chamber 15 is formed in the detection body 5.

The outer peripheral surface 3b of the sleeve 3 is separated from the outer peripheral surface 3b by an angle of 90 ° and penetrates the hole 3a at the same angle θ toward the axis of the detection body 5 as the outflow passages 13, 13 ,. Four fluid inflow passages 17, 17, ... Which have the same area A as the outflow passages 13, 13 ,. Furthermore, the outer peripheral surface 3
b are spaced at an angle of 45 ° from each other and face the axis of the detection body 5 and are closer to the end face 3c than the through hole of the inflow passage 17.
Eight holes 18, 18, ... That penetrate the hole 3a on the side are provided, and an annular groove 18, is provided on the inner peripheral surface 3a so as to connect the holes 18, 18 ,. At that time, the distance between the line connecting the centers of the openings of the inflow passages 17, 17, ... On the inner peripheral surface 3a of the sleeve 3 and the center line of the annular groove 18a is determined by the annular groove on the outer peripheral surface 5e of the detection body 5. 11 center line and outflow passage 13,1
It should be the same as the distance from the line connecting the centers of the openings.

The outer peripheral surface 2b of the main body 2 has a center intersecting with a line connecting the centers of the openings of the inflow passages 17, 17, ... In the outer peripheral surface 3b of the sleeve 3 fitted to the main body 2, and the inner peripheral surface 2a. An inlet port 19 communicating with the above is provided. Further, the outer peripheral surface 3b of the sleeve 3 fitted to the main body 2 has a center line intersecting with a line connecting the centers of the holes 18, 18, ... And an outlet port 21 communicating with the inner peripheral surface 2a is provided.
Further, the inner peripheral surface 2a of the main body 2 is provided with an annular groove 20 having its center at the center of the inlet port 19 so that the fluid flowing from the inlet port 19 can flow into all the inflow passages 17,1.
I try to run into 7, ... Similarly, an annular groove 24 having a center at the center position of the outlet port 21 is provided so that the flow flowing out from all the outflow passages 13, 13 is discharged from the outlet port 21 to the outside.

The cover 7 is provided with a threaded portion 22 by forming a through hole 7a. The cover 7 is fixed to the end surface 2c of the main body 2 by a bolt (not shown), the load cell 6 is inserted into the hole 7a, and the cover plug 23 is screwed and fixed to the screw portion 22. Further, the cover 7 is provided with a groove 25 in the radial direction from the hole 7a along the end face 7b, and the lead wire 26 of the load cell 6 is guided to the outside through the groove 25 to apply the force received by the detecting portion of the load cell 6 to the outside. Extracted as a change in voltage or current.

The cover 8 is provided with a threaded portion 27 by forming a through hole 8a. The cover 8 is fixed to the end surface 2d of the main body 2 by a bolt (not shown), and the suber plug 29 is screwed into the screw portion 27 and fixed to the hole 8a. Also,
The spring 30 is contracted between the cover plug 29 and the bottom of the hole 5d of the detection body 5, and the cover plug 23
The spring 30 and the cover plug 29 fix the detector 5 and the load cell 6 to each other. At this time, the centers of the openings of the inflow passages 17, 17, ... On the inner peripheral surface 3a are aligned with the centers of the annular grooves 11a on the outer peripheral surface 5e,
All of the fluid flowing in from the inflow passages 17, 17, ...
Be guided inside e.

Two annular grooves 31, 32 are formed on the outer peripheral surface 5e of the detection body 5.
Are provided at the positions of the sleeve 3 corresponding to the positions of the annular grooves 31, 32, and holes 34, 35; 37, 38 are provided respectively, and an annular groove 34a for communicating the holes 34, 35 with the outer peripheral surface 3b. And an annular groove 37a that connects the holes 37 and 38. The annular grooves 34a and 37a are opened to the outside through a hole 39 provided in the main body 2, and the drain generated in the momentum flowmeter 1 has annular grooves 31 and 32 and holes 35 and 38a. Then, they are collected in the drain port through the annular grooves 34a, 37a and the hole 39 in the main body 2 and are returned to the tank.

Further, the sleeve 3 is provided with holes 44 and 45 communicating with the chamber 41 formed by the detecting body 5, the detecting body plug 14, the sleeve 3 and the cover 7, and further, an annular groove communicating with the holes 44 and 45. 44a is provided on the outer peripheral surface 3b of the sleeve 3. Further, the sleeve 3 is provided with holes 46 and 47 communicating with a chamber 42 formed by the detection body 5, the sleeve 3 and the cover 8,
An annular groove 46a is provided on the outer peripheral surface 3b of the sleeve 3 so that the holes 46 and 47 communicate with each other. Further, the main body 2 is provided with a communication hole 49 that communicates the annular grooves 44a and 46a, and an atmosphere opening port 50 that opens the annular groove 44a to the atmosphere.

The momentum flowmeter 1 having the above structure measures a fluid as follows.

The fluid flowing in through the inlet port 19 has an annular groove 20 provided in the main body 2 and four inflow passages 1 provided in the sleeve 3.
, 17, through the annular groove 11a provided in the detection body 5 and the four holes 11, 11, ... into the chamber 15 of the detection body 5. Further, the fluid flowing into the chamber 15 is transferred to the eight outflow passages 13, 13, ... Provided in the detection body 5, the annular groove 18a provided in the sleeve 3, the eight holes 18, 18 ,. It passes through the provided annular groove 24 and flows out from the outlet port 21.

At this time, the closed curved surface surrounded by the outer peripheral surface 5e of the detection body 5 and both end surfaces 5b, 5c of the detection body 5 can be considered as an inspection surface. Therefore, the inflow passages 17
Change of the momentum in the inspection surface of the fluid flowing in at a constant angle to the axis of the detection body 5 from 7, ... And outflowing at a constant angle from the outflow passages 13, 13 ,. , Is equal to the force acting on the object (detection body 5) in the inspection plane, and the above equation (3) is obtained. As described above, in this embodiment, the angle θ ₁ of the inflow passage and the angle θ _{2 of the} outflow passage are equal (= θ), and the sectional area A ₁ of the inlet and the sectional area A _{2 of the} outlet are equal. Are set equal to (= A), so that they flow into the inspection surface including the outer peripheral surface 5e as represented by the equation (4),
Furthermore, the mass flow rate of the fluid flowing out from the inspection surface is
It can be measured by measuring the force acting on the detection body 5.

Here, as described above, the detection body 5 is in pressure contact with the load cell 6 via the detection body plug 14 by the spring 30. Therefore, the force acting on the detection body 5 is
It can be obtained by subtracting the spring force of the spring 30 from the force extracted as a change in voltage or current by the load cell 6, and the mass flow rate of the fluid flowing in the momentum flowmeter 1 can be measured.

In this embodiment, the detection body 5 is pressed against the load cell 6 by the spring 30, so that a change in momentum, that is, a change in the force acting on the detection body 5 is directly detected by the load cell 6, so that the response is good.

FIG. 2 shows a second embodiment, in which a constant direction component of the force acting on the inspection surface is converted into a displacement by a centering spring which is a load measuring means, and an operating transformer which is a load measuring means. It is a momentum flow meter that measures the displacement. Here, the means for converting the change in momentum due to the fluid into a force is the same as in the first embodiment, and in FIG. 2 the members having the same structure as in the first embodiment have the same parts as those in FIG. A number is given and the description is omitted.

As shown in FIG. 2, the momentum flowmeter 51 of this embodiment includes a main body 2, a sleeve 3 and a detecting body 5, centering springs 30 and 52 for converting the axial displacement acting on the detecting body 5, and the above-mentioned. The differential transformer 53 for electrically detecting the displacement and the covers 57, 58 for closing the hole 3a of the sleeve 3 are roughly configured.

On the outer peripheral surface 5e of the detection body 5, the detection body 5 is attached to the sleeve 3
Even if the fluid moves in the hole 3a, an annular groove 60 having a width sufficient to guide all the fluid flowing in from the inflow passages 17, 17, into the detection body 5 is provided. Further, a cylindrical protrusion 61 is provided at the center of the end surface 5c of the detection body 5, and a hole 63 is opened along the axis at the center of the end surface to provide a screw portion 64.

On the inner peripheral surface 3a of the sleeve 3, all the fluid flowing out from the outflow passages 13, 13, ...
Annular groove 6 having a width sufficient to guide 8 and 18
5 is provided. Here, the outflow passage 1 provided in the detection body 5
3 and 13, and the inflow passages 17, 17 provided in the sleeve 3
Similarly, the sectional area of and is A, and the inflow angle with respect to the axis of the detection body 5 is also θ.

The main body 2 is provided with a communication hole 65 which communicates the annular groove 46a with the outlet port 21, and a communication hole 66 which communicates the annular groove 44a with the outlet port 21 to generate in the momentum flowmeter 51. The drain is the hole 44,
45, 46, 47, annular grooves 44a, 46a, communication holes 65,
Through 66 into outlet port 21.

The differential transformer 53 includes a cartridge 54 and a coil 5.
5 and the movable iron core 56 and the like. The movable iron core 56 is fixed to the other end of a rod 70 having a threaded portion 69 at the tip, and the threaded portion 69 of the rod 70 is screwed onto the threaded portion 64 of the detection body 5 and a nut 71 is used to detect the detection body 5. It is fixed coaxially with.

The cover 57 is provided with a cylindrical protrusion 57b at the center of the end face 57a that abuts the main body 2, and three stepped holes 67 are provided along the axis at the center of the end face of the protrusion 57b.
The base end portion 54a of the cartridge 54 of the differential transformer 53 is fitted into the middle portion of the stepped hole 67 and fixed by the nut 73. The cover 57, to which the cartridge 54 is fixed in this way, allows the rod 70 and the movable iron core 56 to pass through the hole 54b provided along the axis of the cartridge 54, and fits the protrusion 57b into the hole 3a of the sleeve 3. do it,
The shaft of the detector 5 and the movable iron core 56 are mounted by a bolt (not shown).
It is sealed with an O-ring 78 and fixed to the main body 2 so as to be coaxial with the axis of. Further, the coil 55 of the differential transformer 53 is slidably provided on the cartridge 54,
A spring 74 compressed between the nut 73 and the coil 55 urges the spring outward, and is fixed by a nut 75 at the tip of the cartridge 54 via a collar 77. Therefore, by rotating the nut 75, the coil 5
5 can be moved along the axis of the cartridge 54, and the position of the coil 55 with respect to the movable iron core 56 can be corrected to the optimum position.

A hole 81 for enclosing an O-ring 79 at one end of the cover 58.
And a stepped hole 82 penetrating along the axis at the center of the end face. An O-ring 83 is fitted in the center of the stepped hole 82, and a cover plug 85 having a protruding portion 85a protruding into the chamber 42 facing the detector plug 14 is fitted and fixed with a nut 86. To do. The cover 58
Is fixed to the main body 2 by a bolt (not shown).

The centering springs 30 and 52 are contracted between the cover plug 85 and the detection body plug 14 and between the detection body 5 and the base end portion 54a of the cartridge 54.
The detection body 5 is fixed in the sleeve 3 substantially at the center.
Therefore, the detection body 5 can be moved along the axis by turning the cover plug 85, and the position of the detection body 5 can be corrected to the optimum position with respect to the sleeve 3.

The momentum flowmeter 51 having the above configuration measures the flow rate of the fluid as follows.

The fluid flowing in from the inlet port 19 passes through the inflow passages 17, 17, ... As in the first embodiment, and the chamber 1 of the detection body 5
5 and then outflow from the outlet port 21 through the outflow passages 13, 13, .... Therefore, similarly to the first embodiment, the mass of the fluid flowing in the momentum flowmeter 51 is measured by measuring the force acting on the object in the inspection surface including the outer peripheral surface 5e of the detection body 5, that is, the detection body 5. The flow rate can be measured.

As described above, the detection body 5 is supported by the centering springs 30 and 52 substantially in the center of the sleeve 3 with the centers of the openings of the inflow passages 17, 17, ... Aligned with the center of the annular groove 60. There is. Therefore, the detection body 5 is displaced against the spring force of the centering springs 30 and 52 according to the force received by the fluid flow. The displacement amount of the detection body 5, that is, the displacement amount of the movable iron core 56 of the differential transformer 51 is extracted from the lead wire 87 as an electric signal. That is, when the displacement amount of the detection body 5 electrically detected by the differential transformer 53 is x and the spring constants of the centering springs 30 and 52 are k ₁ and k ₂ , respectively, the detection body 5
Is changed by x, the force F ₁ received by the spring 30 is F ₁ = k ₁ x, and the force F ₂ received by the spring 52 is
F ₂ = k ₂ x, and the force F received by the detection body 5 is F = F ₁ + F ₂ = (k ₁ + k ₂ ) x. Therefore, in this embodiment, the mass flow rate can be obtained by obtaining the displacement amount x of the detection body 5.

In this embodiment, the chambers 41 and 42 facing both end faces of the detection body 5 are provided.
Since it is communicated with the outlet port 21, it is not necessary to seal the high pressure fluid on the outer peripheral surface 5e of the detection body 5, and the hydraulic lock phenomenon does not occur even when used for a long time. In this case, even if the communication holes 65 and 66 communicate with the inlet port 19, the same effect can be obtained.

In each of the above-mentioned first and second embodiments, the detection body 5 is provided with a flow path consisting of the annular grooves 11a and 60, the holes 11 and 11, the chambers 15 and 15, and the outflow passages 13 and 13. There is. However, the effect of the present invention can be obtained by inflowing the fluid at a constant angle to the inspection surface including the outer peripheral surface 5e of the detection body 5 and further flowing out from the inspection surface at a constant angle. It is not necessary to form a flow path inside.

FIG. 3 is a cross-sectional view of an essential part showing a third embodiment, which is an example in the case where a fluid passage is not formed inside the detection body 91.
It should be noted that, in FIG. 3, members having the same structure as those in FIGS. 1 and 2 are given the same part numbers as those in FIGS. Further, the detector, the sleeve, the spring, and the load measuring means, which are the main parts of this embodiment, are shown, and the other parts are omitted.

An annular groove 92 is provided substantially at the center of the outer peripheral surface 91a of the detection body 91, and its side wall 92a forms the same angle θ with the axis of the detection body 91 as the inflow angle θ of the inflow passages 17, 17 ,.
And the outer peripheral surface 91 of the detection body 91.
The area A of the fluid inlet to the inspection surface including a and the area A of the fluid outlet from the inspection surface are the same. Here, the outer peripheral surface of the detector 91 forming the inspection surface is a cylindrical surface (the inner peripheral surface 3a of the sleeve 3 including the surfaces 91a, 91a in contact with the inner peripheral surface 3a of the sleeve 3 in the detector 91).
And corresponding to the surfaces 92a, 92b, 92c of the detection body 91.
Is not included. In addition, the wall surface 92 of the annular groove 92.
The b and 92c allow the fluid flowing from the inflow passages 17, 17, ... to completely flow into the inspection surface including the outer peripheral surface 91a of the detection body 91, and have the outflow angle θ along the side wall 92a. Any shape may be used as long as it can flow out from the inspection surface.

The detection portion of the load cell 6, which is load measuring means for detecting the force exerted by the fluid on the detection body 91, is pressed against the end surface 91b of the detection body 91 by the spring 30, as in the first embodiment. Further, the load measuring means may be a device that converts into a displacement and measures it as in the second embodiment.

In each of the first, second, and third embodiments described above, the sleeve 3 is interposed between the detection body 5 or 91 and the main body 2, and the inflow passages 17, 17, ... There are provided annular grooves 18a and 65, holes 18 and the like for the purpose. However, the present invention is not limited to this, and the sleeve 3 is not used, and the DC inflow passage 1 is added to the main body 2.
.., annular grooves 18a, 65, etc. may be provided.

Further, in each of the above-described embodiments, each inflow θ ₁ into the inspection surface including the outer peripheral surface 5e or 91a of the detection body 5 or 91 and the outflow angle θ ₂ from the inspection surface, or the inflow port The cross-sectional area A ₁ and the cross-sectional area A _{2 of the} outlet are set to the same value, but the present invention is not limited to this.
However, in the case of θ ₁ ≠ θ ₂ or A ₁ ≠ A ₂ , the mass flow rate must be calculated by the equation (3).

Further, in each of the above-described embodiments, the detection body 5 or 91
Although the load cell 6 or the centering springs 30 and 52 and the differential transformer 53 are used as the load measuring means for detecting the force received by the above, they may be detected by other means.

As described above, according to the present invention, by measuring the force generated by the change in the momentum of the fluid on the object within the inspection plane, the mass flow rate can be obtained without being affected by the change in the viscosity due to the change in the fluid temperature. Can be measured, and the flow rate of a flow in which cavitation occurs or a flow including bubbles can also be measured.

<Effects of the Invention> As is clear from the above, the flowmeter of the present invention is
It passes through the inflow passage of the main body, which has a cylindrical chamber inside, into the passage inside the detector at an angle inclined to the axis, and flows out through the outflow passage at the angle inclined in the same inclination direction as the inflow passage. The force acting on the above-mentioned detection body is caused by the change in the momentum of the mass of the fluid, and the force acting on this detection body is detected by the load measuring means. Therefore, the change in the momentum of the mass of the fluid is measured as the force acting on the detection body. And the mass flow rate of the fluid can be determined by the change in the momentum of the mass of the fluid.

Therefore, according to the present invention, it is possible to accurately measure the mass flow rate of a fluid such as a gas containing cavitation or a fluid containing bubbles without being affected by a change in viscosity of the fluid due to a change in temperature. Also, the flowmeter of the present invention is very compact and has the advantage that it can be easily incorporated into other fluid devices.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the flow meter of the present invention,
FIG. 2 is a sectional view of an embodiment different from the above embodiment,
FIG. 3 is a cross-sectional view of a main part in an embodiment different from each of the above embodiments, FIG. 4 is a perspective view of a conventional flow meter, and FIG. 5 is a fourth view in a state where the above conventional flow meter is installed in a flow path. Figure A-A
FIG. 1 ... Load type flow meter, 2 ... Main body, 3 ... Sleeve, 5 ... Detecting body, 6 ... Load cell, 13 ... Outflow passage, 17 ... Inflow passage, 51 ... Displacement type flow meter 30 52 52 Centering spring 53 53 Differential transformer.

Claims (1)

[Claims] 1. A main body having a cylindrical chamber (3a) therein, and a main body fitted slidably in the chamber (3a) and provided with passages (11a, 11) inside, From which the fluid flows into the above passages (11a, 11) and again flows out to the outside
(5) and the passage (11a, 1a in the detection body (5) provided in the main body at an angle inclined with respect to the axis of the detection body (5).
1) for introducing a fluid into the inflow passage (17, 1, ...) and the detection body (5).
7, ...) through the passageway (11a, 1) in the detection body (5).
Outflow passages (13, 13) for guiding the fluid flowing into 1) into the main body at the same inclination angle as the inflow passages (17, 17, ...) With respect to the axis of the detection body (5). , ...) and the mass momentum of the fluid flowing into the detection body (5) through the inflow passages (17,17, ...) And flowing out through the outflow passages (13,13, ...). A flowmeter comprising a load measuring means (6) for detecting an axial force acting on the detection body (5) due to a change as mass flow rate information of a fluid flowing in the detection body (5). .