Component of field device

Abstract

An assembly (3) of a field device comprises a first component (32) and a second component (34), where the first component (32) has a cylindrical bore (328), where the second component (34) has a mounting sleeve (343) having at least one cylindrical portion (344) with a clearance fit with respect to the cylindrical bore (328) of the first component (32), where the first component (32) has a cylindrical bore (328) and the second component (34) has at least one cylindrical portion (344) with a clearance fit with respect to the cylindrical bore (328) of the first component (32). The mounting sleeve (343) has an annularly encircling flange (348) around the at least one first cylindrical portion (344), which is integrally formed with the at least one first cylindrical portion (344) and has an interference fit with respect to the cylindrical bore (328), the encircling flange (348) of the at least one first cylindrical portion (344) being introduced into the cylindrical bore (328), and the encircling flange (348) of the at least one first cylindrical portion (344) being inserted into the cylindrical bore (328). The mounting sleeve (343) has a cylindrical bore (328) such that at least one first cylindrical portion (344) of the mounting sleeve (343) is radially clamped in the cylindrical bore (328), as a result of which an annularly encircling radial seal is formed between the first component (32) and the second component (34).

Description

Technical Field

[0001] The invention relates to an assembly of a field device. Background Art

[0002] Because field devices are produced in assemblies that are combined to form complete devices, it is necessary to provide pressure-bearing and media-resistant seals that are effective over a wide temperature range. Metal-to-metal seals in which two metal sealing surfaces abut against each other with a suitable surface pressure are particularly suitable for this purpose. Published patent application DE 2011 264 discloses a sealing device in which a cylindrical sleeve with a conical profile on the front side is axially compressed with a complementary cone to generate a radial surface pressure against a cylindrical tube guided through the sleeve. The above document is only one example among many in which the goal is always to achieve radial sealing by axial clamping. Although this works in principle, it is very complicated because multiple parts with small manufacturing tolerances are required to achieve a defined radial sealing effect. Therefore, the purpose of the present invention is to find a remedy. Summary of the invention

[0003] The invention achieves the object by an assembly according to independent claim 1 and a vortex flow meter according to independent claim 7 .

[0004] SUMMARY OF THE INVENTION An assembly of a field device according to the invention comprises a first component and a second component, wherein the first component has a cylindrical bore, wherein the second component has a mounting sleeve having at least one first cylindrical portion with a clearance fit relative to the cylindrical bore of the first component, wherein the mounting sleeve has an annularly circumferential flange around the at least one first cylindrical portion, the annularly circumferential flange being formed integrally with the at least one first cylindrical portion and having an interference fit relative to the cylindrical bore, wherein the circumferential flange of the at least one first cylindrical portion is introduced into the cylindrical bore such that the at least one first cylindrical portion of the mounting sleeve is radially clamped in the cylindrical bore, as a result of which an annularly circumferential radial seal is formed between the first component and the second component, wherein the interference fit is achieved by at least local deformation of the at least one first cylindrical portion, in particular in the vicinity of the flange.

[0005] The vicinity of the flange includes, in particular, the region of the sleeve which adjoins the flange on both sides in the axial direction.

[0006] A field device for the purposes of the invention, in particular a measuring device for industrial process measurement technology, is used to record process measurement variables such as flow rate, flow velocity, filling level, pressure, temperature, density, viscosity, pH value or other process measurement variables. The measuring device for measuring the flow rate can include, for example, a vortex flowmeter, a magnetic induction flowmeter, an ultrasonic flowmeter, a thermal flowmeter or a Coriolis flowmeter. The filling level measuring device includes in particular a TDR measuring device with free radiation or guided microwave or ultrasonic measuring device. The pressure measuring device includes a pressure transducer, whose measuring diaphragm can be subjected to the medium pressure directly or via a pressure transmitter. These measuring devices and other devices mentioned as examples may include components according to the invention.

[0007] In a further development of the invention, the first component has a first axial stop surface, wherein the second component has a second axial stop surface which cooperates with the first axial stop surface to define the axial position of the second component relative to the first component.

[0008] In a further development of the invention, at least one first cylindrical portion is arranged in the cylindrical bore with a coupling length in the axial direction, wherein the coupling length is not less than half the diameter of the cylindrical bore, for example not less than three quarters of the diameter of the cylindrical bore, and in particular not less than twice the diameter of the cylindrical bore.

[0009] In a further development of the invention, the average radial deformation of the mounting sleeve on the contact surface of the interference fit between the mounting sleeve and the borehole is at least twice as large as the radial deformation of the borehole, in particular at least four times as large as the radial deformation of the borehole, and / or

[0010] The maximum radial deformation of the mounting sleeve, in particular in the vicinity of the flange, is at least four times, in particular at least eight times, greater than the radial deformation of the borehole.

[0011] The average radial deformation may in particular be determined by integrating the radial deformation over the volume of the body under consideration, over the axial area of ​​the first cylindrical portion, divided by the integrated volume.

[0012] In a further development of the invention, the mounting sleeve has a plastic deformation in the region of the contact surface of the interference fit between mounting sleeve and bore and / or near the flange, wherein, in particular, the bore has no plastic deformation in the region of the contact surface.

[0013] In a further development of the invention, the axial length of the contact surface in the interference fit is not more than one fifth, in particular not more than one tenth, of the axial length of the at least one first cylindrical portion.

[0014] A vortex flowmeter according to the present invention comprises:

[0015] a measuring tube having a measuring tube sheath which defines a lumen for conducting a medium;

[0016] a disturbance body in the lumen of the measuring tube for generating an eddy flow path; and

[0017] An assembly according to any one of the preceding claims,

[0018] Wherein, the second component also includes a propeller sensor,

[0019] wherein the mounting sleeve has a first end face, wherein the mounting sleeve is at least partially arranged in a portion of the first end face facing forward in the borehole,

[0020] The mounting sleeve has a second end face facing away from the first end face,

[0021] Wherein, the paddle sensor is arranged on the second end surface;

[0022] The measuring tube jacket has an opening in the flow direction behind the disturbance body, through which the paddle sensor protrudes into the tube cavity.

[0023] Therein, the first component is connected to the measuring tube jacket in a medium-tight manner along a contact surface which annularly surrounds the mounting sleeve.

[0024] In a further development of the vortex flowmeter according to the invention, the mounting sleeve has a second cylindrical part adjacent to the first cylindrical part in the direction of the second end face, wherein the second cylindrical part has a greater wall thickness than the first cylindrical part, and wherein the second cylindrical part has an elastic membrane supporting the paddle sensor on its end face facing away from the first end face.

[0025] In a further development of the vortex flow meter according to the invention, the first component has a first axial stop surface, wherein the second component has a second axial stop surface, the second axial stop surface cooperating with the first axial stop surface to define the axial position of the second component relative to the first component, wherein a radial step facing the first end face between the first cylindrical part and the second cylindrical part forms the second axial stop surface.

[0026] In a further development of the vortex flowmeter according to the invention, a sealing ring, in particular a graphite sealing ring, is clamped between a sealing surface of the measuring tube sheath, which annularly surrounds the opening in the measuring tube sheath, and a sealing surface of the mounting sleeve, which faces away from the first end face of the mounting sleeve and separates the tube cavity of the measuring tube from the first component.

[0027] In a further development, the vortex flow meter according to the invention further comprises an electromechanical transducer for detecting a deflection of the paddle sensor and for providing the deflection-dependent electrical primary signal, wherein the electromechanical transducer is arranged in the mounting sleeve.

[0028] In a further development, the vortex flow meter according to the invention further comprises an electronics housing and a measuring and operating circuit for operating the electromechanical transducer and for detecting the electrical primary signal, wherein the electronics housing is held at a distance from the measuring tube by a first component, wherein the measuring and operating circuit is arranged in the electronics housing, and wherein the electrical connection passes through the first component, via which the measuring and operating circuit is connected to the electromechanical transducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention will now be explained in more detail based on the exemplary embodiments shown in the drawings.

[0030] In the attached picture:

[0031] Figure 1 : is a view of an exemplary embodiment of a vortex flowmeter according to the present invention;

[0032] Figure 2a : is a longitudinal section through an exemplary embodiment of an assembly according to the invention in a vortex flow meter; and

[0033] Figure 2b : is an enlarged detailed longitudinal section through an exemplary embodiment of an assembly according to the invention. DETAILED DESCRIPTION

[0034] Figure 1 The embodiment of the vortex flowmeter 1 shown comprises a measuring tube 2 with a substantially cylindrical measuring tube jacket 21, which surrounds a lumen 23 for conducting the medium. A disturbance body 24, in particular a prismatic disturbance body, extends through the lumen 23 of the measuring tube 2 in order to narrow the transparent cross section of the measuring tube. Due to this narrowing of the cross section, an eddy path is created in the flowing medium, the frequency of the eddy detachment from the disturbance body 24 being substantially proportional to the velocity.

[0035] The paddle sensor 340 protrudes through the opening 25 in the jacket body 21 of the measuring tube 2 in the flow direction into the lumen 23 downstream of the disturbance body 24 in order to detect eddy currents.

[0036] Now refer to Figure 2a and Figure 2bFurther details of the vortex flowmeter and assembly for producing a vortex flowmeter according to the present invention are explained. The vortex flowmeter also includes an assembly 3 attached to the measuring tube 2 and including a first component 32 and a second component 34, in which case each component is integral. The first component 32 includes a flange 322 and a support tube 324 for supporting the electronics housing 40. The flange 322 rests against a mounting surface 326 of the measuring tube jacket 21 and is secured by means of bolts 329 (only in the case of Figure 1 A cylindrical bore 328 extends through the first component 32 along the longitudinal axis of the support tube 324.

[0037] The second component 34 includes the aforementioned paddle sensor 340, an elastic ring membrane 342 and a mounting sleeve 343. The paddle sensor 340 includes a shaft 341, which is connected to the inner edge of the ring membrane 342 and to the outer edge to which the mounting sleeve 343 is connected. The mounting sleeve 343 includes a first portion 344 and a second portion 345, wherein the second portion is arranged between the ring membrane 342 and the first portion 344. The second portion 345 is designed as a rigid hollow cylinder adjacent to the ring membrane 342, and its cylinder axis extends perpendicular to the plane spanned by the ring membrane 342, and extends in a direction away from the paddle sensor 340 relative to the ring membrane. The first part 344 of the mounting sleeve 343 has a significantly smaller wall thickness than the second part 345 having substantially the same inner diameter, whereby the mounting sleeve 343 has a radial step on its jacket surface at the transition between the first part 344 and the second part 345, which forms an annularly surrounding axial stop surface 346, which faces the first end face of the mounting sleeve 343 and faces away from the annular membrane 342 on the second end face of the mounting sleeve. The first part 344 of the mounting sleeve 34 is inserted into the borehole 328 through which the first component 32 extends over the length L, wherein the cylindrical jacket surface of the first part 344 of the mounting sleeve 343 has a clearance fit with the borehole 328. An annular flange 348 extends around the jacket surface of the first part 344 of the mounting sleeve 343 and has an interference fit with the borehole 328. The profile of the flange 348 can be, for example, annular or spherical. By inserting the first part 344 of the mounting sleeve 343 into the bore 328, a metal-metal seal, which is particularly pressure-bearing, is formed between the first component 32 and the second component 34. In this case, the mounting sleeve 343 is elastically and optionally partially plastically deformed in the region of the first part 344, particularly near the flange.

[0038] The axial stop surface 346 between the first part 344 and the second part 345 of the mounting sleeve 343 rests against the mounting surface 326 of the flange 322 of the first component 32, whereby the second component is axially clamped in the blind bore 28 in the measuring tube jacket 21, wherein the opening 25 in the measuring tube jacket leads to the bottom of the blind bore 28. The sealing ring 27, in particular a graphite sealing ring, is axially clamped between the bottom of the blind bore 28 and the second end face of the mounting sleeve 343. Thus, the second component including the paddle sensor 340 is connected to the measuring tube jacket in a defined position and is therefore temperature-resistant, medium-resistant, vibration-resistant and pressure-resistant. In the event of failure of the sealing ring 27, the metal-to-metal seal between the first component 32 and the second component 34 also reliably prevents the medium from the lumen 23 of the measuring tube 2 from entering the electronics housing 40 through the bore 328 of the support tube 324.

[0039] A measuring and operating circuit 42 for operating the vortex flowmeter 1 is arranged in the electronics housing, the measuring and operating circuit being designed to evaluate the signal of an electromechanical transducer 44 arranged in the second component 34 and for detecting the movement of the paddle sensor. The electromechanical transducer 44 can in particular be a capacitive, inductive or resistive transducer which is connected to the operating and evaluation circuit via a cable passing through a bore 328 of the support tube 324.

[0040] Although the invention has been explained using a vortex flow meter and is particularly relevant here, it is also of interest for other field devices in which two components must be reliably connected to one another.

Claims

1. A component (3) of a field device, the component (3) comprising a first component (32) and a second component (34), wherein: The first component (32) has a cylindrical bore (328), wherein the second component (34) has a mounting sleeve (343), the mounting sleeve (343) having at least one cylindrical portion (344), the at least one cylindrical portion (344) having a clearance fit relative to the cylindrical bore (328) of the first component (32), wherein the mounting sleeve (343) has an annularly surrounding flange (348) surrounding the at least one first cylindrical portion (344), the flange (348) being integrally formed with the at least one first cylindrical portion (344) and having An interference fit relative to the cylindrical bore (328), wherein the circumferential flange (348) of the at least one first cylindrical portion (344) is introduced into the cylindrical bore (328) so that the at least one first cylindrical portion (344) of the mounting sleeve (343) is radially clamped in the cylindrical bore (328), as a result of which an annularly circumferential radial seal is formed between the first component (32) and the second component (34), wherein the interference fit is achieved by at least local deformation of the at least one cylindrical portion, in particular in the vicinity of the flange.

2. The assembly (3) according to claim 1, wherein The first component (32) has a first axial stop surface (326), and wherein the second component (34) has a second axial stop surface (346) which cooperates with the first axial stop surface to define an axial position of the second component (34) relative to the first component (32).

3. The assembly (3) according to any one of claims 1 or 2, wherein: The at least one first cylindrical portion (344) is arranged in the cylindrical bore (328) with a coupling length (L) in the axial direction, wherein the coupling length (L) is not less than half the diameter of the cylindrical bore (328), for example not less than three quarters of the diameter of the cylindrical bore (328), and in particular not less than one times the diameter of the cylindrical bore (328).

4. The assembly (3) according to any one of claims 1 to 3, wherein: On the contact surface of the interference fit between the mounting sleeve (343) and the bore (328), the average radial deformation of the mounting sleeve (343) is at least twice the radial deformation of the bore (328), in particular at least four times the radial deformation of the bore (328), and / or Therein, the maximum radial deformation of the mounting sleeve (343), in particular near the flange, is at least four times, in particular at least eight times, the radial deformation of the bore (328).

5. Assembly (3) according to any one of the preceding claims, wherein The mounting sleeve (343) has plastic deformation in the region of the contact surface of the interference fit between the mounting sleeve (343) and the bore hole (328) and / or in the vicinity of the flange, and wherein, in particular, the bore hole (328) has no plastic deformation in the region of the contact surface.

6. Assembly (3) according to claim 4 or 5, wherein: The axial length of the contact surface in the interference fit is not greater than one fifth of the axial length of the at least one first cylindrical portion, in particular not greater than one tenth of the axial length of the at least one first cylindrical portion.

7. A vortex flowmeter (1), comprising: A measuring tube (2), the measuring tube (2) having a measuring tube sheath (21) defining a lumen (23) for guiding a medium; a disturbance body (24), the disturbance body (24) being in the tube cavity (23) of the measuring tube (2) for generating an eddy current path; and The assembly (3) according to any one of the preceding claims, Wherein, the second component (34) further comprises a paddle sensor (340), The mounting sleeve (343) has a first end surface, wherein the mounting sleeve (343) is at least partially arranged in a portion of the first end surface facing forward in the borehole (328), Wherein, the mounting sleeve (343) has a second end surface facing away from the first end surface, Wherein, the paddle sensor (340) is arranged on the second end surface; The measuring tube sheath (21) has an opening in the flow direction behind the disturbance body (24), and the paddle sensor (340) protrudes into the tube cavity through the opening. Therein, the first component (32) is connected to the measuring tube sheath (31) along a contact surface (326) annularly surrounding the mounting sleeve (343).

8. The vortex flow meter (1) according to claim 7, wherein: The mounting sleeve (343) has a second cylindrical portion (345) adjacent to the first cylindrical portion (344) in the direction of the second end face, wherein the second cylindrical portion (345) has a greater wall thickness than the first cylindrical portion (344), and wherein the second cylindrical portion (345) has an elastic membrane (342) supporting the paddle sensor (340) on its end face facing away from the first end face.

9. A vortex flow meter (1) according to claim 7 having an assembly according to claim 2, wherein: A radial step facing the first end surface between the first cylindrical portion (344) and the second cylindrical portion (345) forms a second axial stop surface (346).

10. The vortex flow meter (1) according to any one of claims 7 to 9, wherein: A sealing ring (27) is clamped between a sealing surface of the measuring tube sheath (21) and a sealing surface of the mounting sleeve, the sealing ring being in particular a graphite sealing ring, the sealing surface of the measuring tube sheath (21) annularly surrounding the opening (25) in the measuring tube sheath, the sealing surface of the mounting sleeve facing away from the first end face of the mounting sleeve (343), and separating the tube cavity (23) of the measuring tube (2) from the first component (32).

11. The vortex flow meter (1) according to any of the preceding claims, further comprising an electromechanical transducer (44) for detecting a deflection of the paddle sensor and for providing an electrical primary signal which is dependent on the deflection, wherein The electromechanical transducer (44) is arranged in the mounting sleeve (343).

12. The vortex flow meter (1) of claim 10, further comprising an electronics housing (40); and a measurement and operating circuit (42) for operating the electromechanical transducer (44) and for detecting the electrical primary signal, wherein: The electronics housing (40) is held at a distance from the measuring tube (2) by the first component (32), wherein the measuring and operating circuit (42) is arranged in the electronic device housing (40), and Therein, electrical connections pass through the first component (32) through which the measuring and operating circuit is connected to the electromechanical transducer.

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