JP2000018994A - Coriolis mass flowmeter - Google Patents

Abstract

(57) [Problem] To provide a Coriolis mass flowmeter having improved stability, accuracy, and vibration resistance by improving insulation of internal vibration. In a Coriolis mass flowmeter for deforming and vibrating a vibrating tube by a Coriolis force generated by a flow of the measuring fluid and an angular vibration of the vibrating tube, an upstream side of the vibrating tube is provided. With the straight line connecting the fixed end and the downstream fixed end as a reference axis, the vibration axis is orthogonal to the reference axis or the central axis of the vibrating tube and one end is fixed to the vibrating tube so that vibration does not leak outside from the fixed end. A Coriolis mass flowmeter comprising a plate-shaped vibrator configured to be operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Coriolis mass flowmeter having improved stability, accuracy and vibration resistance by improving the insulation of internal vibration.

[0002]

2. Description of the Related Art FIG. 45 is an explanatory view of the structure of a conventional example generally used in the prior art.
No. 12 shows a conventional example. In the figure, both ends of a vibration tube 1 are attached to a flange 2. The flange 2 is for attaching the vibration tube 1 to a pipeline.

[0003] The exciter 3 is provided at the center of the vibration tube 1. The vibration detection sensors 4 and 5 are provided on both sides of the vibration tube 1 respectively. Both ends of the vibration tube 1 are fixed to the housing 6.

In the above configuration, the measurement fluid is flowed through the vibration tube 1 and the exciter 3 is driven. Assuming that the angular velocity “ω” in the vibration direction of the exciter 3 and the flow velocity “V” of the measurement fluid (hereinafter, a symbol surrounded by “” represents a vector amount),

The mass flow rate can be measured by measuring the amplitude of the vibration proportional to the Coriolis force in which the Coriolis force of Fc = −2 m “ω” × “V” acts.

FIG. 46 is an explanatory view of the structure of another conventional example generally used conventionally. In this conventional example, the vibration tube 1 is a two-tube type.

[0007]

In a general single-tube straight Coriolis mass flow meter as shown in FIG.
Are fixed at both ends. However, with a flow meter of a limited size, the end points cannot be completely fixed, and the end point slightly vibrates.

The following causes can be considered as the reason why the vibration occurs. When the vibrating tube 1 in which a fluid flows is deformed (approximately in a first-order mode resonance state) as shown in FIG. 47, the length of the tube becomes longer due to the deformation, and a tensile stress is generated in the axial direction of the vibrating tube. I do.

For example, φ9.6 × 0.91 of stainless steel
When the center portion of the 400 L vibrating tube 1 is deformed by 1 mm, a tensile force of 7.5 kgf is generated in the axial direction as shown in FIG.

When the vibrating tube 1 is excited in the primary resonance mode, the tensile force is maximized when the plus and minus deformations are maximum, and the tensile force is minimum and zero when the basic shape has no deformation. .

In one cycle of the excitation vibration, the tensile force repeats maximum and minimum twice. That is, the axial pulling force of the vibration tube 1 is generated at twice the frequency of the excitation frequency. The following problems occur when there is vibration due to this pulling force.

If the vibration isolation is insufficient, (1) the Q value becomes low, so that the internal vibration becomes unstable, and it becomes susceptible to extra vibration noise other than the excitation vibration. (2) Large energy is required for excitation, and power consumption increases.

(3) The degree of vibration leakage greatly changes, the vibration state of the vibrating tube also changes, and the zero point and span tend to change due to the installation method, environmental changes such as pipe stress and temperature, and external factors.

That is, Coriolis flowmeters that are unstable, have poor vibration resistance, and have poor accuracy with respect to these environmental changes and external factors tend to be used.

On the other hand, in the conventional example shown in FIG. 46, the two vibrating tubes 1 vibrate in opposite directions, so that the forces cancel each other out at the branch portion, and as shown in FIGS. It has a structure that is hard to leak outside. However, the structure of one vibration tube without a branch point cannot be obtained.

The present invention solves this problem. An object of the present invention is to provide a Coriolis mass flowmeter in which stability, accuracy and vibration resistance are improved by improving insulation of internal vibration.

[0017]

In order to achieve the above object, the present invention provides: (1) a measuring fluid flowing in a vibrating tube, and a flow of the measuring fluid and a Coriolis force generated by angular vibration of the vibrating tube; In a Coriolis mass flowmeter that deforms and vibrates the vibrating tube, one end is orthogonal to the center axis of the vibrating tube or the reference axis with a straight line connecting an upstream fixed end and a downstream fixed end of the vibrating tube as a reference axis. A Coriolis mass flowmeter comprising a plate-shaped vibrator fixed to the vibrating tube and configured to be vibration-insulated so that vibration does not leak outside from the fixed end. (2) The mass distribution and the shape of the vibrating tube and the mass distribution and the shape of the vibrating body are adjusted so that the center of gravity of the whole vibration system is arranged on the reference axis. 2. The Coriolis mass flow meter according to 1. (3) The mass distribution, shape, and rigidity of the vibrating tube, and the mass distribution, shape, rigidity, and spacing of the vibrating body are adjusted so that the center of gravity of the entire vibration system is located at the position of the vibration node of the excitation vibration. The Coriolis mass flowmeter according to claim 1 or 2, wherein (4) By adjusting the mass distribution, shape, and rigidity of the vibrating tube, and the mass distribution, shape, rigidity, and spacing of the vibrating body, the force generated at both ends fixed portions of the vibrating tube in the steady excitation state is determined by the reference. 3. The method according to claim 1, wherein only a torsional component around the axis is used, so that a component orthogonal to the reference axis due to an exciting force by the exciter does not occur.
Or the Coriolis mass flowmeter according to claim 3. (5) The upstream fixed end and the downstream fixed end are line-symmetric with respect to a midline equidistant from the downstream fixed end and have at least one gentle curved portion. The vibration tube according to any one of claims 1 to 4, further comprising a single vibrating tube that makes a simple vibration on a circumferential line having a predetermined distance from each point of the reference axis, with the straight line connecting the reference axes as the reference axis. Coriolis mass flowmeter. (6) A plate-shaped vibrator having one end orthogonal to the reference axis or the vibrating tube, and a vibration detection sensor provided at the other end of the vibrator. A Coriolis mass flowmeter according to any one of claims 5 to 5. (7) The Coriolis mass flowmeter according to any one of claims 1 to 6, further comprising an exciter for exciting the vibrating tube in a second-order mode or higher order vibration mode. (8) A compensator provided parallel to the reference axis and having both ends fixedly supported at both ends of the vibrating tube, and an exciter and a detector provided between the compensator and the vibrating tube. The Coriolis mass flow meter according to claim 1, wherein the mass flow meter is provided. (9) a flexible structure portion provided on the vibration tube between the upstream fixed end, the downstream fixed end, and the compensator for absorbing expansion and contraction in the direction of the reference axis and rotational vibration around the reference axis; 9. The Coriolis mass flowmeter according to claim 8, wherein the mass flowmeter is provided. It is what constituted.

[0018]

In the above construction, when the measuring fluid is flowed through the vibrating tube and the exciter is driven, Coriolis force acts.
By measuring the amplitude of the vibration proportional to the Coriolis force, the mass flow rate can be measured.

Thus, a plate-shaped vibrating body fixed to the vibrating tube and insulated from vibration so that vibration does not leak outside from the fixed end was provided. Hereinafter, a detailed description will be given based on embodiments.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of a main part of an embodiment of the present invention, which is one embodiment of the present invention.
In the figure, the configuration of the same symbol as in FIG. 45 represents the same function. Hereinafter, only differences from FIG. 45 will be described.

The plate-shaped vibrating bodies 11 and 12 are arranged such that a straight line connecting the upstream fixed end 13 and the downstream fixed end 14 of the vibration tube 1 is used as a reference axis 15, or the reference axis 15 or the central axis of the vibration tube 1. And one end of this vibration tube 1
, And is configured to be vibration-insulated so that vibration does not leak from the fixed ends 13 and 14 to the outside of the housing 6.

In this case, the mass distribution and shape of the vibrating tube 1 and the mass distribution and shape of the vibrating body are adjusted so that the center of gravity of the entire vibration system is arranged on the reference shaft 15. I have.

As shown in FIG. 1, the vibration system has a shape that is line-symmetric with respect to the X-axis direction. With respect to the middle line 16 (reference axis of line symmetry) of the upstream fixed end 13 and the downstream fixed end 14, the vibration tube 1, the vibration detection sensors 4, 5, and the vibration bodies 11, 12
Present at symmetrical positions.

At this time, the mass and the mass distribution of the vibrating bodies 11 and 12 are adjusted so that the entire vibrating system (vibrating tube 1, vibration detecting sensors 4 and 5, exciter 3, vibrating bodies 11 and 12)
Is arranged on the reference axis 15.

As a result, the plate-like vibrators 11, 12 fixed to the vibrating tube 1 and insulated so as to prevent vibration from leaking from the fixed ends 13, 14 to the outside are provided. The following advantages result.

(1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with a small amount of energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside is added to the inside again,
If the balance of the amount of dissipation is lost in the upstream and downstream, a change will occur in the internal vibration system, and the zero point and span will fluctuate.

In the present invention, the vibration is easily confined inside, so that there is no need to worry about this, and a highly accurate Coriolis mass flowmeter can be obtained.

Further, since the center of gravity of the entire vibration system is on the reference axis 15, (1) even if vibration noise is applied from the outside or a shock is applied, a portion distant from the center of gravity vibrates abnormally. It is possible to obtain a Coriolis mass flowmeter in which abnormal operation hardly occurs.

(2) Even if it is affected, it is symmetrical to the whole vibration system, and the influence is likely to occur relatively uniformly. Even if the vibration is not normal, it is necessary to detect the vibrations at two points upstream and downstream. Thus, a Coriolis mass flowmeter capable of canceling noise is obtained.

As a result, from the above, a stable and accurate Coriolis mass flowmeter which is hardly affected by external vibration or impact can be realized.

FIG. 2 is an explanatory view of a main part of another embodiment of the present invention, which is another embodiment of the present invention. In the present embodiment, the vibration tube 17 is
And at least one gently curved portion 19 which is symmetrical about the midline 16 equidistant from the downstream fixed end 14.
In this case, it has one gentle curved portion 19.

The plate-shaped vibrating body 18 has a straight line connecting the upstream fixed end 13 and the downstream fixed end 14 of the vibration tube 17 as a reference axis 15. At right angles, one end of this vibration tube 1
7, and is configured to be vibration-insulated so that vibration does not leak from the fixed ends 13 and 14 to the outside of the housing 6.

In this case, the mass distribution and shape of the vibrating tube 17 and the mass distribution and shape of the vibrating body 18 are adjusted.
The center of gravity of the entire vibration system is arranged on the reference axis 15. Also, the vibrating body 18 is
Are arranged.

As a result, in this embodiment, (1) the measurement fluid flow path is provided at the inlet (inlet) of the flow meter.
There is no branch or gap from the outlet to the outlet
Because of the single penetrating structure, a Coriolis mass flowmeter with low flow velocity loss, less clogging, and easy cleaning can be obtained.

(2) Not a complete straight tube, but a vibrating tube 1
If the curve 7 is previously bent 19 into a predetermined shape in a non-excited state, it can be easily absorbed by the curved portion 19 with respect to a change in ambient temperature, and a Coriolis mass flowmeter having good temperature characteristics can be obtained.

A Coriolis mass flowmeter which is not a general curved tube nor a perfect straight tube but has a moderate curvature 19 can realize the advantages of a curved tube and a straight tube at the same time.

FIG. 3 is an explanatory view of a main part of another embodiment of the present invention. FIG. 4 is a diagram illustrating the operation of FIG.

The plate-shaped vibrating bodies 21 and 22 are formed by using a straight line connecting the upstream fixed end 13 and the downstream fixed end 14 of the vibration tube 1 as a reference axis 15 or the reference axis 15 or the central axis of the vibration tube 1. And one end of this vibration tube 1
, And is configured to be vibration-insulated so that vibration does not leak from the fixed ends 13 and 14 to the outside of the housing 6.

The exciters 23 and 24 are provided on one end side of the vibrators 21 and 22, respectively. In this case, as shown in FIG.
By adjusting the mass distribution, the shape, the rigidity, and the interval of the vibrators 21 and 22, the center of gravity of the entire vibration system is arranged at the position of the node G of the vibration of the excitation vibration. Here, D indicates the initial position of the vibration tube, and E indicates the maximum deformation.

As a result, since the center of gravity of the entire vibration system is arranged at the position of the node of the vibration of the excitation vibration,
The center of gravity of the entire vibration system does not move, eliminating unnecessary vibration,
Vibration insulation is further enhanced. By enhancing the vibration isolation in this way, the following advantages are exhibited.

(1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with a small amount of energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation in the upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and the span fluctuate.

In the present invention, the vibration is easily trapped in the inside, so that there is no concern about the vibration, and a highly accurate Coriolis mass flowmeter can be obtained.

(4) In addition, even if a translational noise or impact which is normally received from the outside is added and the center of gravity performs a translational motion, the motion is different from a normal excitation vibration. Vibration can be distinguished. Therefore, a stable and highly accurate Coriolis mass flowmeter which is hardly affected by external vibration or impact can be obtained.

FIG. 5 is an explanatory view of a main part of another embodiment of the present invention, which is another embodiment of the present invention. 6, 7, 8, and 9 are explanatory diagrams of the operation of FIG.

The plate-shaped vibrating members 31 and 32 are arranged such that a straight line connecting the upstream fixed end 13 and the downstream fixed end 14 of the vibration tube 17 serves as a reference axis 15, or the center of the reference axis 15 or the center of the vibration tube 17. One end is fixed to the vibration tube 17 at right angles to the axis, and is configured to be vibration-insulated so that the vibration does not leak from the fixed ends 13 and 14 to the outside of the housing 6.

In this case, as shown in FIG. 5, the mass distribution, shape and rigidity of the vibrating tube 17 and the mass distribution, shape, rigidity and spacing of the vibrating bodies 31 and 32 are adjusted to adjust the center of gravity of the entire vibration system. Is arranged at the position of the node G of the vibration of the excitation vibration.

That is, the vibration system has a shape which is line-symmetric with respect to the X-axis direction. The vibration tube 17, the vibration detection sensors 4 and 5, and the vibration bodies 31 and 32 are located at symmetric positions with respect to the middle line 16 (reference axis of line symmetry) of the upstream fixed end 13 and the downstream fixed end 14.

FIGS. 6, 7, 8, and 9 are explanatory diagrams of the vibration in FIG. 5, and show the results of performing the finite element method modal analysis on the model in FIG. 5 using beam elements. 6 is a perspective view, FIG. 7 is a projection view from the X direction, FIG. 8 is a projection view from the Y direction,
FIG. 9 is a projection view from the Z direction, and shows the shape D in the initial state.
And the shape E at the time of the maximum deformation are plotted.

The vibrating tube 17 and the vibrating bodies 31 and 32
As shown by an arrow F in the drawing, the initial deformed position D is deformed to the maximum positive deformation position E, and then returned to the initial position D, and the maximum positive deformation E and the negative maximum deformation symmetric with respect to the XY plane. And returns to the initial position D. The vibration system repeats such simple vibration.

This analysis is a linear analysis when the amount of deformation is small. In FIGS. 6, 7, 8 and 9, the actual amount of deformation is shown in an enlarged manner for easy understanding. .

In the invention shown in FIG.
By adjusting the interval between the two vibrating bodies 31 and 32, the shapes and the mass distribution of the vibrating bodies 31 and 32, the entire vibration system (the vibration tube 17, the vibration detection sensors 4 and 5, the exciter 3,
The position of the center of gravity of the vibrators 31, 32 is set on the node G of vibration (see FIG. 7).

At the position of the vibration node G, the vibration system generates a rotation component about the X axis, but the position does not move (X, Y,
Z coordinate does not change). When the shape of the vibrating tube 17 is determined in advance, the center of gravity of the entire vibrating system can be arranged on the node G of vibration by adjusting the weight of the vibrating bodies 31 and 32.

The position of the vibration node G is determined by the vibrating body 31,
32 greatly depends on the mounting position. Generally, according to the center (or if it is centralized into one center), FIG.
0, FIG. 11, FIG. 12, and FIG.
Positive direction of axis.

As shown in FIG. 14, FIG. 15, FIG. 16, and FIG. 17, if the value is adjusted to an appropriate value, the vibration node G can be arranged on the reference axis.

This is because the vibrating tube 17 and the vibrating body 31,
In addition to the large Y coordinate of the connecting point 32, the vibrating tube 17 has a large deformation angle around the tube axis near the center, and the vibrating bodies 31, 32 connected thereto also have a large angle. It is conceivable that the intersection of 32 with the Y axis is in the plus direction of the Y axis.

For this reason, in order to set the center of gravity on the reference axis 15 and on the node G of vibration, one vibrator at the center cannot satisfy the purpose. Two oscillating bodies 31, 32 symmetrical in the upstream and downstream directions are required.

FIG. 18 is an explanatory view of a main part of another embodiment of the present invention.

By adjusting the mass distribution, shape and rigidity of the vibrating tube 17 and the mass distribution, shape, rigidity and spacing of the vibrating bodies 41 and 42, the fixed portions 13 and 14 at both ends of the vibrating tube 17 in the steady excitation state are adjusted. The generated force is only the torsional component ROTX around the reference axis 15 so that the components FY and FZ orthogonal to the reference axis 15 due to the excitation force by the exciter 3 are not generated.

The vibrating tube 17 and the vibrating bodies 41 and 42 are
As shown by the arrow F in the figure, the simple vibration is repeated around the initial position to the maximum positive and negative deformation positions.

The rigidity of the vibration tube 17 and the two vibrators 4
If the distance between the tube ends 1 and 42, the shape and the mass distribution of the vibrating bodies 41 and 42 are adjusted, the both ends fixed portion 1 in the steady vibration state is obtained.
With respect to the forces generated at 3 and 14, a torsional component around the reference axis 15 (ROTX in the figure) is generated, but a translational direction component (FY, FZ in the figure) due to the excitation vibration can be prevented. Yes, confirmed by FEM analysis.

As a result, in the steady excitation state, no force of the translational component other than the torsional component around the reference axis 15 is generated in the fixed portions 13 and 14 at both ends of the vibrating tube 17, so that the vibration hardly leaks out. .

[0066] For the reference axis 15 around the rotational force, compared to the vibration tube, torsional much greater rigidity (torsional rigidity = GI _P = Gπd ^4/32 rigidity effective with the fourth power of diameter)
The presence of the housing 6 of the Coriolis mass flow meter having

By increasing the vibration isolation as described above, the following advantages are exhibited. (1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with small energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of dissipation of vibration energy to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation in the upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and the span fluctuate.

In the present invention, since vibration is easily confined inside, a Coriolis mass flowmeter with high accuracy can be obtained without concern.

(4) Even when the noise or impact in the translation direction normally received from the outside is applied and the position of the center of gravity moves, the vibration is not a normal excitation vibration. Therefore, the vibration due to the noise is classified based on the mode shape and the frequency. Can be removed.

A stable and accurate Coriolis mass flowmeter which is hardly affected by external vibrations and shocks can be obtained.

FIG. 19 is an explanatory view of a main part of another embodiment of the present invention. FIG. 20 shows FIG.
21, FIG. 22, FIG. 23 are operation explanatory diagrams of FIG.

The vibrating tube 17 is symmetrical about the midline 16 equidistant from the upstream fixed end 13 and the downstream fixed end 14 and has at least one gentle curved portion 19. The reference axis 1 is a straight line connecting
5 is a single tube that makes a simple vibration on a circumferential line at a predetermined distance from each point of the reference shaft 15.

In this case, if the distance between the upstream fixed end 13 and the downstream fixed end 14 is L and the distance between the reference shaft 15 and the vibrating tube 17 is h, then approximately h ≦ 0.2.
It is desirable that the shape satisfy L.

The exciter 3 is provided at the center of the vibration tube 17. In this case, the vibrating body 51 has one end connected to the center of the vibrating tube 17 and the other end located on the opposite side of the reference shaft 15 from the vibrating tube 17.
The vibration detection sensors 4 and 5 are provided on both sides of the vibration tube 17,
Each is provided.

FIG. 21 is a sectional view taken along line bb of the vibrating tube 17 shown in FIG. 19, FIG. 22 is a sectional view taken along line aa, cc of the vibrating tube 17 shown in FIG. 19, and FIG. It is a perspective view which shows the mode of 17 vibration. FIG.
In FIG. 22, the vibration tube 1 is in the non-excited state.
7 is near the position of A.

In the excited state, the center of the vibration tube 17 moves on the circumference separated from the reference axis 15 by a radius R (x).

At the position of the cross section bb, on the circumference separated from the reference axis 15 by a radius R (b), at the position of the cross section aa or cc, the radius R (a) or R (c) Vibrates on the distant circle as A → B → A → C → A → B → (repeat).

In FIG. 23, A, B and C correspond to the respective positions of the vibration tube 17 in FIGS. 21 and 22. In addition, 1
Reference numerals 3 and 14 denote fixed ends, and 15 denotes a reference axis.

As for the vibration detection and signal processing, the same processing as that of a normal Coriolis mass flow meter may be performed. For example, the vibration detection sensors 4 and 5 may detect the Y component of the vibration, determine the phase difference between the outputs of the two sensors, perform frequency correction, temperature correction, and the like, and determine the mass flow rate flowing inside the tube 17. I can do it.

Since the vibration tube 17 vibrates only in a circumferential plane equidistant from the reference shaft 15, the vibration tube 1
No matter where the position 7 is, the length of the vibration tube 17 does not change.

Therefore, the pulling force in the axial direction is always constant. That is, due to the change in the axial force,
Vibration leakage can be eliminated. By increasing the vibration isolation, the vibration inside the flowmeter becomes stable, and a highly accurate and stable Coriolis mass flowmeter can be realized.

More specifically, since the Q value of the internal vibration is increased, the influence of vibration noise is reduced, the power consumption is reduced, and the zero point and the span change due to the change in the amount of vibration leakage can be reduced. A mass flow meter is obtained. By increasing the vibration isolation in this way, the following advantages are exhibited.

As a result, (1) the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, so that a Coriolis mass flowmeter resistant to external vibration noise can be obtained. Can be

(2) Since stable excitation can be realized with a small amount of energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation in the upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and the span fluctuate.

In the present invention, since vibration is easily confined inside, a Coriolis mass flowmeter with high accuracy can be obtained without concern.

[0089] Also, (4) measurement fluid FL _o flow path from the inlet flow meter (inlet) to the outlet (outlets), branched, or no gaps, since a single penetrating structure, the flow rate of loss less ,
A Coriolis mass flowmeter that is hard to clog and easy to clean is obtained.

(5) Vibration tube 1
7 is previously curved 52 in a predetermined shape in a non-excited state, so that a curved portion 52 can easily absorb a change in ambient temperature with respect to a change in ambient temperature, and a Coriolis mass flowmeter having good temperature characteristics can be obtained.

A Coriolis mass flowmeter which is not a general curved pipe nor a perfect straight pipe, but has an appropriate curve, and can realize the advantages of a curved pipe and a straight pipe simultaneously.

FIG. 24 shows an FEM analysis model according to the sixth embodiment of the present invention. A stainless steel material was used as a constituent material, and analysis was performed using a shell element with dimensions shown in FIG.

The vibrating tube 17 is symmetrical about the midline 16 equidistant from the upstream fixed end 13 and the downstream fixed end 14 and has at least one gentle curved portion 19. The reference axis 1 is a straight line connecting
5 is a single tube that makes a simple vibration on a circumferential line at a predetermined distance from each point of the reference shaft 15.

In the vibrators 41 and 42, the vibration detection sensors 4 and 5 are provided in the direction opposite to the vibrating tube 17 (near the tip of the vibrator in the figure) across the reference axis 15. .

The total sum of the Z-direction forces applied to the fixed portions 13 and 14 at both ends varies as follows depending on the mass M of the vibration detection sensors 4 and 5. ＝ FZΣ-0.82 kgf at M = 14.5 g MΣ15.8 g ΣFZ ≒ 0.04 kgf M = 16.3 g, ΣFZ ≒ 0.39 kgf When the vibration detection sensors 4 and 5 are installed, both ends fixed ends 13 and 1
The force applied to the four parts has almost disappeared.

The vibrating body 41, which is opposite to the vibrating tube 17 across the reference axis 15
By installing near the tip of 42, vibration can be detected at an optimal position.

That is, by being located at the tip of the vibrating bodies 41 and 42, the vibration can be measured at the place where the amplitude is the largest in the vibration system. Also, the phase difference generated by the Coriolis force becomes very large.

Actually, as a result of comparing the embodiment of FIG. 5 with the embodiment of FIG. 24 (corresponding to claim 6) by experiment, the following was obtained as an example.

The ratio of the sensor amplitude / drive amplitude is 0.8 in the embodiment of FIG. 5 and 3.5 in the embodiment of FIG. 25, which is 4.4 times. The generated phase difference <m rad> is 8.8 in the embodiment of FIG. 5 and 37.5 in the embodiment of FIG. 25, which is 4.3 times. Becomes

As described above, in both the amplitude ratio and the generated phase difference, values that are slightly more than four times larger than those in the embodiment of FIG. 5 were observed.

As a result, (1) If the measured amplitude is large, the S / N is improved. Conversely, if the measurement amplitude is the same as the conventional one, the excitation force can be reduced, and a Coriolis mass flowmeter with low power consumption can be obtained.

If the maximum amplitude is small, vibration energy is small, leakage to the outside is small, vibration isolation is easy, and a highly accurate and stable Coriolis mass flowmeter can be obtained.

(2) If the generated phase difference is large, the signal processing of the signal conversion part becomes easy. That is, a Coriolis mass flowmeter capable of realizing stable and highly accurate performance even with a simple and inexpensive signal processing circuit can be obtained.

On the other hand, if the signal processing performance is equivalent to the conventional one, it is possible to measure stably up to a low flow rate region where the generated phase difference is small, or to measure the mass flow rate of the gas originally generated with a small phase difference. A possible Coriolis mass flow meter is obtained.

As a result, since both the amplitude and the phase difference are larger than 4 times, it is very advantageous and a dramatic improvement effect can be obtained.

FIG. 25, FIG. 26, FIG. 27, and FIG. 28 are views for explaining the operation of the main part of another embodiment of the present invention. Excitation is performed in a higher-order vibration mode than the second-order mode. FIG. 5 shows the results of performing modal analysis on the embodiment in FIG. 5 by the finite element method using shell elements.

FIG. 25 is a perspective view, FIG. 26 is a projection view from the X direction in FIG. 25, FIG. 27 is a projection view from the Y direction in FIG.
FIG. 28 is a projection view from the Z direction in FIG. 25, and shows both the shape D in the initial state and the shape E at the time of maximum deformation.

In the third mode resonance state of the embodiment of FIG. 5, the resonance frequency is 228 Hz. Normally, when self-excited, the lowest vibration mode is likely to be excited.
The exciter 3 is adjusted so as to excite the next mode and self-excited.

The primary mode resonance frequency in the embodiment of FIG. 5 is 127 Hz, and FIGS. 29, 30, 31, and
This is a vibration mode shape as shown in FIG.

FIG. 29 is a perspective view, FIG. 30 is a projection view from the X direction in FIG. 29, FIG. 31 is a projection view from the Y direction in FIG.
FIG. 32 is a projection view from the Z direction in FIG. 29, and shows both the shape D in the initial state and the shape E at the time of maximum deformation.

29, 30, 31, and 32, the entire vibration system is deformed in the + Z direction. Excitation force is applied to the end rather than the circumferential vibration, so that a large force in the X and Z directions is applied to the end.

In the embodiment shown in FIG. 5, the resonance frequency of the second mode is 204 Hz, and the vibration mode shape is as shown in FIGS. 33, 34, 35 and 36.

FIG. 33 is a perspective view, FIG. 34 is a projection view from the X direction in FIG. 33, FIG. 35 is a projection view from the Y direction in FIG.
FIG. 36 is a projection view from the Z direction in FIG. 33, and shows both the shape D in the initial state and the shape E in the maximum deformation.

33, 34, 35, and 36, the deformation of the vibration tube 17 in the Z direction is reversed in the vicinity of the center in the plus and minus directions. Since the amount of deformation of the tube 17 itself is small, the generation of Coriolis force is also small, which is not a very practical vibration mode.

The fourth mode resonance frequency in the embodiment of FIG. 5 is 294 Hz, and has the vibration mode shapes as shown in FIGS. 37, 38, 39 and 40.

FIG. 37 is a perspective view, FIG. 38 is a projection view from the X direction in FIG. 37, FIG. 39 is a projection view from the Y direction in FIG.
FIG. 40 is a projection view from the Z direction in FIG. 37, and shows both the shape D in the initial state and the shape E in the maximum deformation.

In FIGS. 37, 38, 39, and 40, the entire vibrating tube 17 moves up and down in the Y direction on the YZ plane, and the generated Coriolis force is also in the Y direction. Excitation force is exerted not on the circumferential vibration but on the ends 13 and 14, so that large forces in the X and Y directions are applied to the ends 13 and 14.

[0118] Thus, when is excited by the third mode, the Coriolis force generated by measuring fluid FL _o flows, occurs approximately deformation similar secondary mode shape. That is, the mass flow rate can be obtained by detecting the Coriolis deformation in the second mode by the third mode excitation.

As a result, the following advantages can be obtained by exciting in the second, third, or higher order mode. (1) It is easy to set the excitation frequency higher. Vibration at low frequency is susceptible to vibration noise in the field, whereas high frequency excitation provides a Coriolis mass flowmeter that is less susceptible to vibration noise.

(2) The resonance frequencies of the excitation mode and the vibration mode generated by the Coriolis force can be made close to each other. In the embodiment of FIG. 5, the driving frequency is close to 228 Hz and the Coriolis approximation mode is close to 204 Hz.

From the following equation, when P = 1.117 and Q = 1000, the dynamic magnification G = 4.0 and the generated phase difference is large. However, the dynamic magnification G = (1−P ² ) / ((1−P ² ) ² +
(P / Q)) P = (drive frequency) / (resonance frequency of Coriolis approximation mode)

(3) If the generated phase difference is large, the signal processing of the signal conversion unit becomes easy. That is, a Coriolis mass flowmeter capable of realizing stable and highly accurate performance even with a simple and inexpensive signal processing circuit can be obtained.

Conversely, if the signal processing performance is equivalent to the conventional one, stable measurement can be performed up to the low flow rate region where the generated phase difference is small. A possible Coriolis mass flow meter is obtained.

FIG. 41, FIG. 42 and FIG. 43 are explanatory diagrams of the main parts of another embodiment of the present invention. 41 is a front view, FIG. 42 is a plan view of FIG.
42 is a side view of FIG. 41.

The compensator 63 is provided inside the housing 6. In the compensator 63, the vibration tube 17 is provided.
, An exciter 3 and vibration detection sensors 4 and 5 are provided.

In this case, an example is shown in which coils 301, 401, 501 and magnets 302, 402, 502 are used as the exciter 3 and the vibration detection sensors 4, 5. The compensator 63 is provided in parallel with the reference axis 15,
It is long in the parallel direction, and both ends are fixedly supported at both ends of the vibration tube 17.

In the above configuration, as shown in FIG.
When the exciter 3 is operated, a force of F ₁ and F _2, the coil 3
01 and the magnet 302 repel. By the force, the vibrator 61 and the vibration tube 17, around the reference axis 15 near as T _1, T _3, rotates in the clockwise direction in FIG. 43.

On the other hand, the compensator 63 generates T ₂ , T ₄
As shown in the figure, the vibrating tube 17 and the vibrating bodies 61 and 62 rotate counterclockwise.

Since the vibrating tube 17 and the compensator 63 are connected to each other, the fixed ends 13 and 14, which are the connecting portions thereof,
The right-handed force and the left-handed force cancel each other, which has the effect of reducing such components around the axis. Outside the compensator 63,
The rotation component around the reference axis 15 can be prevented from leaking.

As a result, the compensator 63 is
Is installed, the vibration tube 17 and the vibration bodies 61 and 6
2. The vibration detection sensors 4 and 5 and the compensator 63 are
, Forces are exerted in opposite directions to each other, and reverse rotation vibration about the reference axis 15 is generated.

At the fixed ends 13 and 14 where the vibration tube 17 and the compensator 63 are connected, forces act in opposite directions and cancel each other to form a node of vibration. Since not only the translational component but also the rotational component about the reference axis 15 can be suppressed, the vibration insulation can be further enhanced.

By increasing the vibration isolation as described above, the following advantages are exhibited. (1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with small energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) If the amount of vibration energy dissipated to the outside changes, or if the balance of the amount dissipated upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and span fluctuate. In the present invention, the vibration is easily confined inside, so that there is no worry and a highly accurate Coriolis mass flowmeter can be obtained.

(4) Even if a stress is applied from the outside, the internal vibration can be maintained in a stable excitation by supporting it with the compensator 63. That is, the vibration is hardly affected by the pipe stress and the thermal stress and is stable. A highly accurate Coriolis mass flowmeter can be obtained.

FIG. 44 is an explanatory view of a main part of another embodiment of the present invention. In the present embodiment, the flexible structure 71 that absorbs expansion and contraction in the direction of the reference shaft 15 and rotational vibration around the reference shaft 15 is connected to the upstream fixed end 13.
The vibration tube 17 is provided between the compensator 63 and the downstream fixed end 14.

As a result, since the flexible structure 71 is provided in the vibration tube 17 between the upstream fixed end 13, the downstream fixed end 14, and the compensator 63, (1) thermal expansion is absorbed. This makes it possible to obtain a Coriolis mass flowmeter capable of performing stable and accurate measurement over a wide temperature range.

(2) Even when a pipe stress is applied, the flexible structure 71 can absorb the stress and does not affect the inside, so that a stable and accurate Coriolis mass flowmeter can be obtained.

[0139]

As described above, according to the first aspect of the present invention,
According to this, the plate-shaped vibrating body fixed to the vibrating tube and insulated so that vibration does not leak to the outside from the fixed end is provided.

(1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even when external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with small energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
If the balance of the amount of dissipation is lost in the upstream and downstream, a change will occur in the internal vibration system, and the zero point and span will fluctuate.

According to the present invention, since vibration is easily confined inside, a Coriolis mass flowmeter with high accuracy can be obtained without concern.

According to the second aspect of the present invention, since the center of gravity of the entire vibration system is on the reference axis, (1) even if vibration noise is applied from the outside or an impact is received, a place distant from the reference axis If the vibration system has a center of gravity, abnormal vibration is likely to occur. However, since the center of gravity of the entire vibration system is on the reference axis, abnormal operation hardly occurs and a Coriolis mass flowmeter can be obtained.

(2) Even if it is affected, it is symmetrical to the whole vibration system, and the influence is likely to occur relatively uniformly. Even if the vibration is not normal, it is necessary to detect vibrations at two points upstream and downstream. Thus, a Coriolis mass flowmeter capable of canceling noise is obtained.

As a result, from the above, a stable and accurate Coriolis mass flowmeter which is hardly affected by external vibration or impact can be realized.

According to the third aspect of the present invention, the center of gravity of the entire vibration system does not move, so that useless vibration is eliminated and vibration isolation is further enhanced. By increasing the vibration isolation in this way, the following advantages can be obtained.

(1) The internal vibration system can realize a high Q value, and even if external noise is applied, the influence thereof is relatively small and the vibration is stable, so that a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with a small amount of energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation in the upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and the span fluctuate.

According to the present invention, the vibration is easily confined inside, so that there is no concern about this, and a high-precision Coriolis mass flowmeter can be obtained.

(4) Even if a translational noise or impact which is normally received from the outside is applied and the center of gravity performs a translational motion, it is a motion different from a normal excitation vibration. Can be distinguished and removed.

Accordingly, a stable and accurate Coriolis mass flowmeter which is hardly affected by external vibration and impact can be obtained.

According to the fourth aspect of the present invention, in the steady excitation state, no force of the translational direction component other than the torsion component around the reference axis is generated at the fixed portions at both ends of the vibrating tube. Hard to leak.

With respect to the rotational force about the reference axis, the torsional rigidity (torsional rigidity =
GI _P = Gπd ^4/32, the stiffness has effective against) the fourth power of the diameter, the presence of the housing of the Coriolis mass flow meter,
It is possible to suppress firmly.

By increasing the vibration isolation as described above, the following advantages are exhibited. (1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with small energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation is lost between the upstream and downstream of the vibrating tube, the internal vibration system is affected, and the zero point and the span fluctuate. In the present invention, the vibration is easily confined inside, so that there is no worry and a highly accurate Coriolis mass flowmeter can be obtained.

According to the fifth aspect of the present invention, since the vibration tube vibrates only in the circumferential surface equidistant from the reference axis, the vibration tube has a length no matter where the vibration tube is located. It will not change.

Therefore, the pulling force in the axial direction is always constant. That is, due to the change in the axial force,
Vibration leakage can be eliminated. By increasing the vibration isolation, the vibration inside the flowmeter becomes stable, and a highly accurate and stable Coriolis mass flowmeter can be realized.

More specifically, since the Q value of the internal vibration is increased, the influence of the vibration noise is reduced, the power consumption is reduced, and the zero point and the span change due to the change in the amount of vibration leakage can be reduced. A mass flow meter is obtained. By increasing the vibration isolation in this way, the following advantages are exhibited.

As a result, (1) the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, so that a Coriolis mass flowmeter resistant to external vibration noise can be obtained. Can be

(2) Since stable excitation can be realized with a small amount of energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation in the upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and the span fluctuate.

According to the present invention, since vibration is easily confined inside, a Coriolis mass flowmeter with high accuracy can be obtained without concern.

(4) The measurement fluid channel is provided at the inlet (inlet) of the flow meter.
There is no branch or gap from the outlet to the outlet
Because of the single penetrating structure, a Coriolis mass flowmeter with low flow velocity loss, less clogging, and easy cleaning can be obtained.

(5) Since the vibrating tube is not a complete straight tube but is curved in a predetermined shape in a non-excited state, it can easily absorb changes in ambient temperature at the curved portion, and has a temperature characteristic. , A good Coriolis mass flowmeter can be obtained.

A Coriolis mass flowmeter which is not a general curved tube nor a perfect straight tube but has an appropriate curve and can realize the advantages of a curved tube and a straight tube at the same time is obtained.

According to the sixth aspect of the present invention, the vibration detecting sensor is installed near the tip of the vibrating body in the direction opposite to the vibrating tube across the reference axis, so that the vibration can be detected at the optimum position. Becomes possible.

That is, by being located at the tip of the vibrating body, vibration can be measured at the place where the amplitude is the largest in the vibration system.

Actually, as a result of comparing the embodiment of FIG. 5 with the embodiment of FIG. 24 (corresponding to claim 6) by experiment, the following results were obtained as an example.

The ratio of the sensor amplitude / drive amplitude is 0.8 in the embodiment of FIG. 5 and 3.5 in the embodiment of FIG. 25, which is 4.4 times. The generated phase difference <m rad> is 8.8 in the embodiment of FIG. 5 and 37.5 in the embodiment of FIG. 25, which is 4.3 times. Becomes

As described above, in both the amplitude ratio and the generated phase difference, values that are slightly more than four times as large as those in the embodiment of FIG. 5 were observed.

As a result, the following advantages are exhibited by increasing the vibration isolation.

(1) If the measured amplitude is large, the S / N is improved. Conversely, if the same measurement amplitude as before is sufficient,
Excitation force can be reduced, and a Coriolis mass flowmeter with low power consumption can be obtained.

If the maximum amplitude is small, the vibration energy is small, the leakage to the outside is small, the vibration isolation is easy, and a highly accurate and stable Coriolis mass flowmeter can be obtained.

(2) If the generated phase difference is large, the signal processing in the signal conversion portion becomes easy. That is, a Coriolis mass flowmeter capable of realizing stable and highly accurate performance even with a simple and inexpensive signal processing circuit can be obtained.

Conversely, if the signal processing performance is equivalent to the conventional one, stable measurement can be performed up to the low flow rate region where the generated phase difference is small, and the mass flow rate measurement of gas originally having a small generated phase difference can be performed. A possible Coriolis mass flow meter is obtained.

As a result, since both the amplitude and the phase difference are larger than 4 times, it is very advantageous and a dramatic improvement effect can be obtained.

According to the seventh aspect of the present invention, the following advantages are obtained by exciting in the second, third, or higher order mode.

(1) It is easy to set the excitation frequency higher.
Vibration at low frequency is susceptible to vibration noise in the field, whereas high frequency excitation provides a Coriolis mass flowmeter that is less susceptible to vibration noise.

(2) The resonance frequencies of the excitation mode and the vibration mode generated by the Coriolis force can be made close to each other. The generated phase difference is also large.

(3) If the generated phase difference is large, the signal processing of the signal conversion unit becomes easy. That is, a Coriolis mass flowmeter capable of realizing stable and highly accurate performance even with a simple and inexpensive signal processing circuit can be obtained.

Conversely, if the signal processing performance is equivalent to the conventional one, it is possible to measure stably up to the low flow rate region where the generated phase difference is small, or to measure the mass flow rate of the gas originally generated with the small phase difference. A possible Coriolis mass flow meter is obtained.

According to the eighth aspect of the present invention, since the compensator is provided in the housing, the vibrating tube, the vibrator, the vibration detection sensor and the compensator are forced in opposite directions via the exciter. Works to generate reverse rotation vibration about the reference axis.

At the fixed end where the vibration tube and the compensator are connected, forces act in opposite directions and cancel each other to form a node of vibration. Since not only the translational component but also the rotational component about the reference axis can be suppressed, the vibration insulation can be further enhanced.

By increasing the vibration isolation as described above, the following advantages are exhibited. (1) Since the internal vibration system can realize a high Q value, the influence of external noise is relatively small even if external noise is applied, and the vibration is stable, a Coriolis mass flowmeter resistant to external vibration noise can be obtained.

(2) Since stable excitation can be realized with small energy, a Coriolis mass flowmeter with low current consumption can be obtained.

(3) The amount of vibration energy dissipated to the outside changes, or the vibration escaping to the outside reappears inside,
When the balance of the amount of dissipation in the upstream and downstream is disturbed, the internal vibration system is affected, and the zero point and the span fluctuate.

According to the present invention, since vibration is easily confined inside, there is no need to worry about this, and a highly accurate Coriolis mass flowmeter can be obtained.

(4) Even if stress is applied from the outside, the internal vibration can be kept stable by supporting it with the compensator. That is, stable and high precision is hardly affected by piping stress and thermal stress. A Coriolis mass flowmeter is obtained.

According to claim 9 of the present invention, the flexible structure portion is
Since it was provided in the vibration tube between the upstream fixed end and the downstream fixed end, and the compensator,

(1) A Coriolis mass flowmeter capable of absorbing thermal expansion and capable of performing stable and accurate measurement over a wide temperature range is obtained.

(2) Even when pipe stress is applied, the flexible structure can absorb the stress and does not affect the inside, so that a stable and accurate Coriolis mass flowmeter can be obtained.

Therefore, according to the present invention, it is possible to realize a Coriolis mass flowmeter having improved stability, accuracy and vibration resistance by improving the insulation of internal vibration.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 3 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of FIG. 3;

FIG. 5 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 6 is a perspective view illustrating the operation of FIG. 5;

FIG. 7 is an operation explanatory view of FIG. 5 and is a projection view from an X direction.

8 is an operation explanatory view of FIG. 5 and is a projection view from a Y direction.

FIG. 9 is an operation explanatory view of FIG. 5, and is a projection view from the Z direction.

FIG. 10 is a perspective view for explaining the operation of FIG. 5;

11 is an operation explanatory view of FIG. 5 and is a projection view from an X direction.

FIG. 12 is an operation explanatory view of FIG. 5 and is a projection view from a Y direction.

FIG. 13 is an operation explanatory view of FIG. 5 and is a projection view from the Z direction.

FIG. 14 is a perspective view illustrating the operation of FIG. 5;

FIG. 15 is an operation explanatory view of FIG. 5, and is a projection view from the X direction.

FIG. 16 is an operation explanatory view of FIG. 5 and is a projection view from the Y direction.

FIG. 17 is an operation explanatory view of FIG. 5 and is a projection view from the Z direction.

FIG. 18 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 19 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 20 is a side view of FIG. 19;

FIG. 21 is an explanatory diagram of the operation in FIG. 19;

FIG. 22 is an operation explanatory diagram of FIG. 19;

FIG. 23 is an operation explanatory diagram of FIG. 19;

FIG. 24 is an FEM analysis model according to another embodiment of the present invention.

FIG. 25 is an operation explanatory perspective view of another embodiment of the present invention.

FIG. 26 is a projection view from the X direction in FIG. 25;

FIG. 27 is a projection view from the Y direction in FIG. 25;

FIG. 28 is a projection view from the Z direction in FIG. 25.

FIG. 29 is a perspective view for explaining the operation in the primary mode of FIG. 5;

FIG. 30 is a projection view from the X direction in FIG. 29;

FIG. 31 is a projection view from the Y direction in FIG. 29;

32 is a projection view from the Z direction in FIG. 29.

FIG. 33 is a perspective view for explaining the operation in the secondary mode of FIG. 5;

FIG. 34 is a projection view from the X direction in FIG. 33.

FIG. 35 is a projection view from the Y direction in FIG. 33;

FIG. 36 is a projection view from the Z direction in FIG. 33;

FIG. 37 is a perspective view for explaining the operation of the fourth mode in FIG. 5;

FIG. 38 is a projection view from the X direction in FIG. 37.

39 is a projection view from the Y direction in FIG. 37.

40 is a projection view from the Z direction in FIG. 37.

FIG. 41 is an explanatory view of a main part configuration of another embodiment of the present invention.

FIG. 42 is a plan view of FIG. 41.

FIG. 43 is a side view of FIG. 41.

FIG. 44 is an explanatory view of a main part configuration of another embodiment of the present invention.

FIG. 45 is an explanatory diagram of a configuration of a conventional example generally used in the related art.

FIG. 46 is an explanatory view of the configuration of another conventional example generally used in the prior art.

FIG. 47 is an explanatory diagram of the operation in FIG. 45.

FIG. 48 is an explanatory diagram of the operation in FIG. 46.

FIG. 49 is an explanatory diagram of the operation in FIG. 46.

[Description of Signs] 1 Vibration tube 2 Flange 3 Exciter 4 Vibration detection sensor 5 Vibration detection sensor 501 Coil 502 Magnet 6 Housing 11 Vibrating body 12 Vibrating body 13 Upstream fixed end 14 Downstream fixed end 15 Reference axis 16 Middle line 17 Vibrating tube 18 Vibrating body 19 Gentle curved part 21 Vibrating body 22 Vibrating body 23 Exciter 24 Exciter 31 Vibrating body 32 Vibrating body 41 Vibrating body 42 Vibrating body 51 Vibrating body 61 Vibrating body 62 Vibrating body 63 Compensating body 71 Flexible structure section 301 coil 302 magnet 401 coil 402 magnet 501 coil 502 magnet

Claims (9)

[Claims] 1. A Coriolis mass flowmeter for deforming and vibrating a vibrating tube by a flow of a measuring fluid flowing in the vibrating tube and a Coriolis force generated by the flow of the measuring fluid and angular vibration of the vibrating tube; With the straight line connecting the side fixed end and the downstream fixed end as a reference axis, one end is fixed to the vibrating tube orthogonal to the reference axis or the central axis of the vibrating tube so that vibration does not leak outside from the fixed end. A Coriolis mass flowmeter comprising a plate-shaped vibrator configured to be insulated. 2. The method according to claim 1, wherein the mass distribution and shape of the vibrating tube and the mass distribution and shape of the vibrating body are adjusted so that the center of gravity of the entire vibration system is arranged on the reference axis. The Coriolis mass flow meter according to claim 1. 3. The mass distribution, shape and rigidity of the vibrating tube and the mass distribution, shape, rigidity and spacing of the vibrating body are adjusted so that the center of gravity of the entire vibration system is located at a node of the vibration of the excitation vibration. The Coriolis mass flowmeter according to claim 1, wherein the mass flowmeter is configured to be configured as follows. 4. The force generated at the fixed portions at both ends of the vibrating tube in a steady excitation state by adjusting the mass distribution, shape, and rigidity of the vibrating tube, and the mass distribution, shape, rigidity, and interval of the vibrating body. 4. The method according to claim 1, wherein only a torsional component around the reference axis is prevented from generating a component orthogonal to the reference axis due to an exciting force by an exciter. 5. Coriolis mass flowmeter. 5. The upstream fixed end and the downstream fixed end are symmetrical with respect to a midline equidistant from the upstream fixed end and the downstream fixed end and have at least one gentle curved portion. 5. A vibration tube, which makes a single vibration on a circumferential line at a predetermined distance from each point of the reference axis, using a straight line connecting the reference axis and the reference axis as a reference axis, is provided. 2. A Coriolis mass flowmeter according to 1. 6. A vibrating body having a plate-like shape, one end of which is orthogonal to the reference axis or the vibrating tube, and a vibration detecting sensor provided at the other end of the vibrating body. A Coriolis mass flowmeter according to any one of claims 1 to 5. 7. The Coriolis mass flowmeter according to claim 1, further comprising an exciter for exciting the vibrating tube in a higher-order vibration mode than a second-order vibration mode. 8. A compensator provided parallel to the reference axis and having both ends fixedly supported at both ends of the vibrating tube, an exciter and a detector provided between the compensator and the vibrating tube. The Coriolis mass flowmeter according to any one of claims 1 to 7, comprising: 9. A flexible structure provided on the vibrating tube between the upstream fixed end, the downstream fixed end, and the compensator for absorbing expansion and contraction in the direction of the reference axis and rotational vibration about the reference axis. 9. The Coriolis mass flow meter according to claim 8, further comprising a part.