CN116337166A - Coriolis mass flow meter - Google Patents

Abstract

The invention provides a Coriolis mass flowmeter, which comprises a main body (1), a transmitter connector (2), an inner joint (3) and a measuring tube assembly (4), wherein the side wall of the main body (1) is welded with the transmitter connector (2) and is provided with a first welding part (5), the end part of the main body (1) is welded with the inner joint (3) and is provided with a second welding part (6), the measuring tube assembly (4) is arranged on the main body (1) and extends out of the end part of the main body (1) to be welded with the inner joint (3) and form a third welding part (7), and at least one stress groove (81, 82, 83 and 84) is respectively arranged near the first welding part (5), the second welding part (6) and/or the third welding part (7). The invention obviously reduces the influence of welding stress on the double measuring tubes of the sensor, and obviously improves the stability of resonance; the production qualification rate can be improved, and the precision is ensured; the influence of the installation stress on the precision is reduced.

Description

Coriolis mass flow meter

technical field

The invention relates to the field of instruments and meters, in particular to a Coriolis mass flowmeter.

Background technique

The Coriolis mass flowmeter is a more accurate instrument for measuring the mass flow of the medium. It works on the principle of Coriolis mechanics and directly measures the mass flow. It is basically not affected by the pressure and temperature of the medium. The medium flow path is smooth and there are no blocking elements, and its reliability is very good. Coriolis mass flow meters are becoming more and more common in the metering industry.

The core of the sensor is the resonant measuring tube, and the stability of its resonance depends on the symmetry, consistency and stability of the two sets of measuring tubes. In order to ensure sufficient strength and pressure bearing capacity, the measuring tube and its connection with the outside are all realized by argon arc welding. The welding current density is high, the heat is concentrated, and the stress generated by welding is large and not easy to eliminate. Especially the stainless steel material is more obvious, and this stress breaks the symmetry and stability of the two sets of measuring tubes, which leads to the deterioration of the performance of the sensor. Due to the uncontrollable stress, the pass rate of mass production of the sensor is difficult. improve.

During the installation process of the mass flowmeter, bolts, clips or threads are used to clamp the joints between the corresponding user site and the mass flowmeter, which will cause the sensor to be stressed, which will adversely affect the resonance of the measuring tube, causing the mass flowmeter accuracy deteriorates.

Contents of the invention

Aiming at the shortcomings in the prior art, the invention provides a Coriolis mass flowmeter.

In order to solve the above technical problems, the present invention is solved through the following technical solutions:

A Coriolis mass flowmeter, including a main body, a transmitter connector, an inner joint and a measuring tube assembly, the side wall of the main body is welded to the transmitter connector and is provided with a first welding portion, and the end of the main body is connected to the The inner joint is welded and has a second welding part. The measuring tube assembly is installed on the main body and extends out of the end of the main body to be welded with the inner joint. The welding part between the measuring tube assembly and the inner joint is the third welding part, which is close to the first welding part , the second welding portion and/or the third welding portion are respectively provided with at least one stress groove.

In some embodiments, the Coriolis mass flowmeter proposed by the present invention further includes a housing, the housing and the main body are both long arc-shaped pieces, and the housing and the main body are coaxially fixed to form a tube with openings at the left and right ends. body, the inner joint is welded to the openings at both ends of the pipe body to form a sealed pipe body, the inner joint (3) is coaxially arranged with the sealed pipe body, and the measuring tube assembly is fixed in the sealed pipe body.

In some embodiments, the Coriolis mass flowmeter proposed by the present invention further includes an outer joint welded to the inner joint; a side of the inner joint facing the outer joint is provided with a joint inclined surface, and the outer joint cooperates with the joint inclined surface.

In some embodiments, the central part of the main body of the Coriolis mass flowmeter proposed by the present invention is provided with a connection port, and the transmitter connector is welded at the connection port of the main body and arranged coaxially with the connection port.

In some embodiments, the stress groove disposed close to the first welding portion is a first stress groove, and the first stress groove is located on the side wall of the main body.

In some embodiments, the cross-section of the first stress groove is trapezoidal.

In some embodiments, the inner wall of the first stress groove close to the transmitter connector is an inner slope, the inner wall of the first stress groove away from the transmitter connector is an outer slope, and the inner slope is in line with the transmitter. The included angle of the axis of the connecting head is 25-35°, and the included angle between the outer slope and the axis of the transmitter connecting head is 40-50°.

In some embodiments, the first stress groove is an annular groove and is arranged coaxially with the transmitter connector.

In some embodiments, the depth of the first stress groove is 0.04-0.06 times the diameter of the transmitter connector; the width of the first stress groove is 0.09-0.11 times the diameter of the transmitter connector.

In some embodiments, the stress groove arranged near the second welding portion is a second stress groove, and there are two second stress grooves, both of which are annular grooves, and the two second stress grooves are respectively located at the second welding On the side wall of the main body and the side wall of the inner joint on both sides of the head.

In some embodiments, the second stress groove has an inverted triangular cross-section.

In some embodiments, the distance between the two second stress grooves is 0.09-0.11 times the diameter of the inner joint, and the depth of the second stress groove is 1.8-2.2mm; the two sides of the second stress groove The angle formed between the walls is 85-95°.

In some embodiments, chamfers are provided at the edge of the notch and the bottom of the second stress groove.

In some embodiments, the stress groove disposed near the third welding portion includes a third stress groove and a fourth stress groove, the third stress groove is an annular groove and is located on the outer wall of the measuring tube assembly, the fourth stress groove The groove is an annular groove and is located on the nipple.

In some embodiments, the cross-sections of the third stress groove and the fourth stress groove are rectangular.

In some embodiments, the depth of the third stress groove is greater than the depth of the fourth stress groove.

In some embodiments, there are a plurality of third stress grooves, which are sequentially and equidistantly arranged along the axial direction of the measuring tube assembly.

In some embodiments, the spacing between the third stress grooves is 1-2mm, and the distance between the third stress grooves and the inner joint is 0.45-0.55 times the diameter of the measuring tube assembly; the width of the third stress grooves is 0.15-0.25 times the pipe diameter of the measuring tube assembly; the depth of the third stress groove is 0.35-0.45 times the wall thickness of the measuring tube assembly.

In some embodiments, the fourth stress groove is located on the end surface of the nipple facing the main body.

In some embodiments, the width of the fourth stress groove is 0.15-0.25 times the diameter of the measuring tube assembly; the depth of the third stress groove is 0.35-0.45 times the diameter of the measuring tube assembly.

The present invention has remarkable technical effect owing to adopted above technical scheme: advantage of the present invention is as follows:

1) The welding deformation of the sensor is significantly reduced, the influence of the welding stress on the dual measuring tubes of the sensor is significantly reduced, and the stability of its resonance is significantly improved;

2) Through the control of welding stress, the qualification rate of the mass flowmeter in the production process can be improved, and the accuracy of the mass flowmeter can be guaranteed;

3) Reduce the influence of the installation stress of the mass flowmeter installed on the customer site on the accuracy of the flowmeter.

Description of drawings

The technical solutions of the present application will be further described in detail below in conjunction with the drawings and embodiments. In the drawings, the same reference numerals are used to denote the same parts unless otherwise stated. in:

Fig. 1 is a schematic structural view of a Coriolis mass flowmeter according to the present invention.

FIG. 2 is an enlarged structural schematic diagram of part A in FIG. 1 .

FIG. 3 is an enlarged structural schematic diagram of part B in FIG. 1 .

FIG. 4 is an enlarged structural schematic diagram of part C in FIG. 1 .

List of reference signs

1 Body 9 Housing

2 Transmitter connector 10 Male connector

3 Nipple 81 First stress groove

4 Measuring tube assembly 82 Second stress groove

5 First weld 83 Third stress groove

6 Second weld 84 Fourth stress groove

7 The third welding part

Detailed ways

The following description serves to disclose the present application to enable those skilled in the art to carry out the present application. The preferred embodiments described below are only examples, and those skilled in the art can devise other obvious variations. The basic principles of the application defined in the following description can be applied to other embodiments, variations, improvements, equivalents and other technical solutions without departing from the spirit and scope of the application.

Those skilled in the art should understand that, in the disclosure of the present application, the terms "vertical", "transverse", "upper", "lower", "front", "rear", "left", "right", " The orientation or positional relationship indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings or the optical axis direction of incident light imaging, which The above terms are only for the purpose of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, so the above terms should not be construed as limiting the present application.

In this application, the term "a" in the claims and the specification should be understood as "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element Can be multiple. Unless it is clearly stated in the disclosure of the present application that there is only one element, the term "a" or "an" cannot be understood as unique or singular, and the term "a" or "an" cannot be understood as a limitation on the number.

In the description of the present application, it should be understood that belonging to "first", "second" and so on are only for descriptive purposes, and should not be understood as indicating or implying relative importance. In the description of this application, it should be noted that, unless otherwise specified and limited, "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Generally, a Coriolis mass flow meter can be divided into two parts according to the functional logic, namely the sensor part and the transmitter part. The sensor part is a component that resonates and realizes the Coriolis mechanical structure, for example, it is used to sense the Coriolis force or vibration of the fluid flowing in the measuring tube, convert it into an electrical signal, and send it to Transmitter section. The transmitter can be an electronic component based on a high-performance microprocessor. For example, the processor of the transmitter part combines the measurement results obtained by the sensor part with other parameters, calculates the flow rate of the fluid, and outputs the calculation results. For the sake of simplicity, the transmitter part of the Coriolis mass flowmeter is not shown in FIG. 1 , but only the transmitter connector 2 is used to represent the structure for connecting the transmitter part.

Fig. 1 is a schematic structural view of a Coriolis mass flowmeter according to the present invention, in which the main body 1 connects the various parts of the sensor together and is welded with the housing 9 to form a closed space, thereby ensuring the Coriolis mass flowmeter The normal operation of the measuring tube assembly 4 of the flowmeter in this closed space is not affected and damaged by the external environment.

The transmitter connector 2 is welded on the main body 1 for connecting the sensor part with the transmitter part.

The measuring tube assembly 4 generates Coriolis force through resonance when the fluid flows through, and it is welded together with the inner joint 3 and the outer joint 10 as a channel for medium circulation. For example, the measuring tube assembly 4 is installed on the main body 1 and protrudes from the end of the main body 1 to be welded with the inner joint 3 .

The resonant part of the sensor part is the measuring tube assembly 4 in the middle of the main body 1 . The stress and deformation generated during the welding process of the sensor components must minimize the adverse effects on the measuring tube assembly 4, so as to ensure the stability of the sensor resonance, so that the accuracy of the mass flowmeter will not be affected.

Due to the large heat-affected range after argon arc welding of stainless steel materials, the product is easily deformed. Figure 4 schematically shows the heat-affected stress and deformation after welding with fillet welds. After testing and testing, when the total length of the product is, for example, 400mm, the deformation of the left and right sides of the diagram after welding can reach 1mm .

As shown in FIG. 2 , the transmitter connector 2 is welded on the side wall of the main body 1 and has a first welding portion 5 . The transmitter connector 2 is connected to the main body 1 through the first welding portion 5 . The end of the main body 1 is welded with the inner joint 3 and has a second welded portion 6 . The inner joint 3 is connected to the main body 1 by a second weld 6 . The welding between the measuring tube assembly 4 and the inner joint 3 is provided with a third welding portion 7 . The nipple 3 is connected to the measuring tube assembly 4 via a third weld 7 . Here, at least one stress groove may be provided adjacent to the first welding portion 5 , the second welding portion 6 and/or the third welding portion 7 respectively.

The Coriolis mass flowmeter according to the present invention also includes a housing 9, the housing 9 and the main body 1 are both long arc-shaped pieces, the housing 9 and the main body 1 are fixed coaxially and form a pipe body with openings at both left and right ends , the inner joint 3 is welded with the openings at both ends of the pipe body to form a sealed pipe body, the inner joint 3 is coaxially arranged with the sealed pipe body, and the measuring tube assembly 4 is fixed in the sealed pipe body.

The Coriolis mass flowmeter according to the present invention also includes an outer joint 10 welded to the inner joint 3; the side of the inner joint 3 facing the outer joint 10 is provided with a joint slope, and the outer joint 10 matches the joint slope. The middle part of the main body 1 is provided with a connecting port, and the transmitter connecting head 2 is welded at the connecting port of the main body 1 and arranged coaxially with the connecting port. The main body 1 is an approximate semicircular structure, which plays the role of support and fixation. All parts are welded together to work. The transmitter connector 2 is welded in the middle of the main body 1 and is perpendicular to its axis, so as to facilitate the transmitter Part of the installation. The inner joint 3 coincides with the central axis of the main body 1 and the outer circle is equal. It is precisely positioned and welded together by positioning pins. The outer joint 10 and the inner joint 03 are welded coaxially. It is mainly used for connection with the customer's on-site pipeline. The inner joint 3 is provided with a joint The slope is used to ensure that the medium is evenly distributed from one hole of the outer joint 10 to the inside of the two measuring tubes, so as to ensure the balance of the resonance of the two measuring tubes. The housing 9 is another approximately semicircular structure, which is consistent with the outer circle of the main body, and welded together to form a closed space that is completely circular and independent from the outside. It is used to fill inert gas and prevent the magnets and coils assembled by the measuring tube assembly 4 from And other parts are not oxidized while preventing the measuring tube from being damaged by external force.

In the working state, the medium flows into the pipeline of the vibrating measuring tube assembly 4 through the outer joint 10 and the inner joint 3, and then flows out through the inner joint 3 and the outer joint 10. The middle part of the pipeline of the measuring tube assembly 4 is equipped with an electromagnetic vibration device. This makes the measuring tube vibrate perpendicular to the pipeline at its natural frequency. Detectors are respectively arranged at both ends of the measuring tube assembly 4. The detectors can detect the displacement of the measuring tube end and monitor the vibration of the driver. The transmitter performs signal processing to obtain the mass flow rate of the medium.

FIG. 2 is an enlarged structural schematic diagram of part A in FIG. 1 . As shown in FIG. 2 , a first stress groove 81 is provided near the first welding portion 5 , and the first stress groove 81 is located on the side wall of the main body 1 .

The cross section of the first stress groove 81 is trapezoidal, one of the bases is located on the outer circumference of the main body 1 , and the other base is parallel to the first base. The inner wall of the first stress groove 81 close to the transmitter connector 2 is an inner slope, the inner wall of the first stress groove 81 away from the transmitter connector 2 is an outer slope, and the inner slope is in contact with the transmitter connector. The angle between the 2 axes is 30°, and the angle between the outer slope and the 2 axes of the transmitter connector is 45°.

In some embodiments, the first stress groove 81 is an annular groove and is arranged coaxially with the transmitter connector 2 . The depth of the first stress groove 81 is 0.05 times the diameter of the transmitter connector 2 ; the width of the first stress groove 81 is 0.1 times the diameter of the transmitter connector 2 .

Optionally, a plurality of first stress grooves 81 may be provided near the first welding portion 5 . The plurality of first stress grooves 81 may be arranged in parallel on the main body 1 and/or the transmitter connector 2 at equal intervals. Of course, the plurality of first stress grooves 81 can also be grouped, and each group is arranged on the main body 1 and/or the transmitter connector 2 with different intervals. Through this different arrangement, the stress concentration and deformation of the main body 1 and the transmitter connector 2 caused by welding can be eliminated more effectively, especially for specific areas of parts that are easily affected by adverse effects. deformation protection.

The stress relief structure of the present invention includes a first stress groove 81, as shown in FIG. 2, which eliminates the welding stress and bending deformation of longer parts after the fillet weld is welded. For example, a first stress groove 81 is provided in the circumferential direction around the weld seam, and the depth and width of the first stress groove 81 can be determined according to requirements, for example, according to the aperture diameter of the transmitter connector 2 . In some embodiments, two slopes may be provided on both sides of the first stress groove 81 , one slope may have an angle of 60 degrees, and the other slope may have an angle of 90 degrees.

FIG. 3 is an enlarged structural schematic diagram of part B in FIG. 1 . As shown in Figure 3, the stress groove 8 that is arranged near the second welding part 6 is a second stress groove 82, and the second stress groove 82 has two and both are annular grooves, and the two second stress grooves 82 They are respectively located on the side walls of the main body 1 and the inner joint 3 on both sides of the second welding portion 6 .

The second stress groove 82 has an inverted triangular cross-section, and the bottom edge is located on the outer circle of the main body or the inner joint.

The distance between the two second stress grooves 82 is 0.1 times the pipe diameter of the inner joint 3, and the depth of the second stress grooves 82 is 2mm; the clamp formed between the two side walls of the second stress grooves 82 The angle is 90°.

The edge of the notch and the bottom of the second stress groove 82 are provided with chamfers.

The stress relief structure of the present invention may also include a second stress groove 82, as shown in FIG. 3, which eliminates the stress concentration and deformation of the main body 1 and the inner joint 3 after the circumferential fillet welding of the two parts. At both ends of the welding seam, a second stress groove 82 is respectively provided on both sides of the butt seam between the main body 1 and the inner joint 3 . The distances from the two second stress grooves 82 to the butt joint between the main body 1 and the inner joint 3 may be equal.

Optionally, on the side where the stress concentration and deformation are greatly affected, or on both sides of the butt joint between the main body 1 and the inner joint 3, a plurality of first Two stress grooves 82 . For example, the plurality of second stress grooves 82 may be arranged in parallel on the main body 1 and/or the inner joint 3 at equal intervals. Of course, the plurality of second stress grooves 82 can also be grouped, and each group is arranged on the main body 1 and/or the inner joint 3 with different intervals. Through this different arrangement, the stress concentration and deformation of the main body 1 and the inner joint 3 caused by welding can be eliminated more effectively, and the protection against stress concentration and deformation can be improved especially for specific areas of parts that are easily affected by adverse effects. ability.

The depth of the second stress groove 82 can be determined as required, for example, determined according to the aperture size of the main body 1 . The second stress groove 82 may be chamfered at three edges.

FIG. 4 is an enlarged structural schematic diagram of part C in FIG. 1 . As shown in FIG. 4 , the stress groove 8 arranged near the third welding portion 7 includes a third stress groove 83 and a fourth stress groove 84 , the third stress groove 83 is an annular groove and is located at the bottom of the measuring tube assembly 4 On the outer wall, the fourth stress groove 84 is an annular groove and is located on the inner joint 3 .

Sections of the third stress groove 83 and the fourth stress groove 84 are rectangular.

The depth of the third stress groove 83 is greater than the depth of the fourth stress groove 84 .

There are multiple third stress grooves 83 arranged equidistantly along the axial direction of the measuring tube assembly 4 .

The spacing between the third stress grooves 83 is 1-2mm, and the distance between the third stress grooves 83 and the inner joint 3 is 0.5 times of the pipe diameter of the measuring tube assembly 4; the width of the third stress grooves 83 is the measuring tube assembly 0.2 times the pipe diameter; the depth of the third stress groove 83 is 0.4 times the wall thickness of the measuring tube assembly 4.

The fourth stress groove 84 is located on the end face of the inner joint 3 facing the main body 1 .

The width of the fourth stress groove 84 is 0.2 times the diameter of the measuring tube assembly 4 ; the depth of the third stress groove 83 is 0.4 times the diameter of the measuring tube assembly 4 .

The stress relief structure of the present invention may further include a third stress groove 83 and/or a fourth stress groove 84 . As shown in FIG. 4 , the stress concentration and deformation of the core part of the sensor, that is, the measuring tube assembly 4 , are eliminated after the end face is welded. At least one equidistant third stress groove 83 , especially three third stress grooves 83 , may be provided at a position away from the inner joint 3 in the outer circumferential direction of the measuring tube assembly 4 . The width and depth of the third stress groove 83 can be determined according to needs, especially according to the diameter of the main body 1 or the inner joint 3 . Furthermore, at least one fourth stress groove 84 may be provided in the direction of the end surface of the nipple 3 . The width and depth of the fourth stress groove 84 can be determined according to needs, especially according to the diameter of the main body 1 or the inner joint 3 .

Optionally, the stress grooves can have different cross-sectional shapes, especially rectangular, triangular, circular, trapezoidal, etc. Stress grooves of different cross-sectional shapes can be used in combination. These conventional shapes not only make the processing of stress grooves easier, but also provide different customized effects under different combinations, so as to achieve targeted resistance to stress concentration and deformation of parts.

It should be pointed out that the Coriolis mass flowmeter according to the present invention may also include transmitter components in addition to the sensor components described above. Here, a sensor refers to an element that resonates and implements a Coriolis mechanics structure. Transmitter components refer to electronic components based on high-performance microprocessors. The transmitter provides power to the sensor and processes and outputs signals. The Coriolis mass flowmeter according to the present invention may include a transmitter as an integral part of the whole, or the transmitter may be considered as an optional part manufactured and processed separately, which passes through the transmitter connector 2 Connect with mass flow meter. The Coriolis mass flowmeters of these two structural forms are all within the protection scope of the present invention.

Finally, it should be pointed out that the above description and the embodiments of the application shown in the drawings are only examples and do not limit the application. The functions and structural principles of this application have been shown and explained in the examples. Without departing from the principles, the technical features and implementation methods of this application can be combined or replaced arbitrarily, and the deformation or modification schemes formed thereby are also included in this application. within the scope of the description and disclosure of the application.

Claims (20)

1. The utility model provides a coriolis mass flowmeter, including main part (1), changer connector (2), nipple (3) and survey pipe assembly (4), the lateral wall and the changer connector (2) welding of main part (1) are equipped with first welded part (5), the tip and the nipple (3) welding of main part (1) are equipped with second welded part (6), survey pipe assembly (4) are installed on main part (1) and are stretched out main part (1) tip and nipple (3) welding, survey pipe assembly (4) and nipple (3) welded part is third welded part (7), wherein be close to first welded part (5), second welded part (6) and/or third welded part (7) are equipped with at least one stress groove (81, 82, 83, 84) respectively.

2. The coriolis mass flowmeter of claim 1 characterized in that it further comprises a housing (9), the housing (9) and the main body (1) are elongated arcuate pieces, the housing (9) is fixedly connected coaxially with the main body (1) and forms a tube body with left and right ends open, the nipple (3) is welded to the openings at the two ends of the tube body and forms a sealed tube body, the nipple (3) is coaxially disposed with the sealed tube body, and the measuring tube assembly (4) is fixedly mounted in the sealed tube body.

3. The coriolis mass flowmeter of claim 1 characterized in that the inner joint (3) is coaxial and further comprises an outer joint (10), the outer joint (10) being welded to the inner joint (3); one side of the inner joint (3) facing the outer joint (10) is provided with a joint inclined plane, and the outer joint (10) is matched with the joint inclined plane.

4. The coriolis mass flowmeter of claim 1 characterized in that the middle of the body (1) is provided with a connection port and the transmitter connection port (2) is welded at the connection port of the body (1) and coaxially arranged with the connection port.

5. The coriolis mass flowmeter of claim 1 characterized in that the stress groove disposed proximate the first weld (5) is a first stress groove (81), the first stress groove (81) being located on a sidewall of the body (1).

6. The coriolis mass flowmeter of claim 5 characterized in that the first stress groove (81) is trapezoidal in cross-section.

7. The coriolis mass flowmeter of claim 6 characterized in that the inner wall of the first stress groove (81) on the side near the transducer connector (2) is an inner slope and the inner wall of the first stress groove (81) on the side far from the transducer connector (2) is an outer slope, the angle between the inner slope and the axis of the transducer connector (2) is 25-35 ° and the angle between the outer slope and the axis of the transducer connector (2) is 40-50 °.

8. The coriolis mass flowmeter of claim 5 characterized in that the first stress groove (81) is an annular groove and is disposed coaxially with the transmitter connection head (2).

9. The coriolis mass flowmeter of claim 5 characterized in that the depth of the first stress groove (81) is 0.04-0.06 times the tube diameter of the transmitter connection head (2); the width of the first stress groove (81) is 0.09-0.11 times of the pipe diameter of the transmitter connector (2).

10. The coriolis mass flowmeter of claim 1 characterized in that the stress grooves disposed near the second weld (6) are second stress grooves (82), the second stress grooves (82) are two and each are annular grooves, and the two second stress grooves (82) are located on the side walls of the body (1) and the side walls of the nipple (3) on both sides of the second weld (6), respectively.

11. The coriolis mass flowmeter of claim 10 characterized in that the second stress groove (82) has an inverted triangular cross-section.

12. The coriolis mass flowmeter of claim 10 characterized in that the distance between two second stress grooves (82) is 0.09-0.11 times the diameter of the nipple (3) and the depth of the second stress grooves (82) is 1.8-2.2mm; an included angle formed between two side wall surfaces of the second stress groove (82) is 85-95 degrees.

13. The coriolis mass flowmeter of claim 10 characterized in that the notched edges and the notches bottoms of the second stress grooves (82) are chamfered.

14. The coriolis mass flowmeter of claim 1 characterized in that the stress grooves disposed near the third weld (7) comprise a third stress groove (83) and a fourth stress groove (84), the third stress groove (83) being an annular groove and located on the outer wall of the measurement tube assembly (4), the fourth stress groove (84) being an annular groove and located on the nipple (3).

15. The coriolis mass flowmeter of claim 14 characterized in that the third stress groove (83) and the fourth stress groove (84) are rectangular in cross-section.

16. The coriolis mass flowmeter of claim 14 characterized in that the third stress groove (83) has a depth that is greater than the depth of the fourth stress groove (84).

17. The coriolis mass flowmeter of claim 14 characterized in that the third stress grooves (83) are plural and are disposed equidistant in sequence along the axis of the measuring tube assembly (4).

18. The coriolis mass flowmeter of claim 14 characterized in that the spacing between the third stress grooves (83) is 1-2mm and the distance of the third stress grooves (83) from the nipple (3) is 0.45-0.55 times the tube diameter of the measuring tube assembly (4); the width of the third stress groove (83) is 0.15-0.25 times of the pipe diameter of the measuring pipe assembly (4); the depth of the third stress groove (83) is 0.35-0.45 times of the wall thickness of the measuring tube assembly (4).

19. The coriolis mass flowmeter of claim 14 characterized in that the fourth stress groove (84) is located on the end face of the nipple (3) that faces the body (1).

20. The coriolis mass flowmeter of claim 14 characterized in that the fourth stress groove (84) has a width that is 0.15-0.25 times the tube diameter of the measurement tube means (4); the depth of the third stress groove (83) is 0.35-0.45 times of the pipe diameter of the measuring pipe assembly (4).

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