Magnetic Induction Flowmeter

Abstract

The invention relates to a magnetic induction flowmeter (1) for insertion into a pipe (2) through which a medium flows and for determining a flow rate-dependent measurement variable induced in the medium, the magnetic induction flowmeter (1) comprising: a housing (3), a front body (5) which is arranged on an end face (4) of the housing (3) and seals the end face of the housing (3); a measurement electrode arrangement (6) for making electrical contact with the medium and for tapping an induced voltage in the flowing medium; a field system (7) for generating a magnetic field through the end face (4) of the housing (3), the field system (7) being arranged in the housing (3), the field system (7) comprising a coil arrangement (8) which comprises a coil arrangement carrier (9) for winding a coil wire (10), and the coil arrangement carrier (9) and the front body (5) being integrally formed. The invention also relates to a method for producing a front body (5) for a flowmeter according to the invention.

Description

Field of the Invention

[0001] The present invention relates to a magnetic induction flowmeter and a method for producing a precursor of a magnetic induction flowmeter. Background Art

[0002] Magnetic induction flowmeters are used to determine the flow rate and volume flow of a medium flowing in a pipe. A magnetic induction flowmeter has a magnet system that generates a magnetic field perpendicular to the flow direction of the flowing medium. A single coil is usually used for this purpose. To achieve a significantly uniform magnetic field, the pole shoes are additionally formed and attached in such a way that the magnetic field lines extend across the entire pipe cross-section essentially perpendicular to the transverse axis of the measuring tube or parallel to the vertical axis of the measuring tube. Measuring electrode pairs attached to the lateral surface of the measuring tube tap an electrical measurement voltage or potential difference that is applied perpendicular to the flow direction and perpendicular to the magnetic field and that is generated when a conductive medium flows along the flow direction upon application of the magnetic field. Since, according to Faraday's induction law, the tapped measurement voltage depends on the velocity of the flowing medium, the flow rate u, and the externally known cross-section of the tube, the volume flow can be determined from the induced measurement voltage U.

[0003] Compared to magnetic induction flowmeters for conducting media, which include a measuring tube with an attached field system and measuring electrodes, magnetic induction flowmeters with a generally cylindrical housing are introduced into a lateral opening in a pipe and fastened in a liquid-tight manner. A special measuring tube is no longer required. The measuring electrode arrangement and the coil arrangement on the lateral surface of the measuring tube mentioned at the beginning are omitted and replaced by a field system arranged inside the housing and directly adjacent to the measuring electrodes, which is designed such that the axis of symmetry of the magnetic field lines of the generated magnetic field intersects the front surface or region between the measuring electrodes perpendicularly. In the prior art, there are already a large number of magnetic induction flowmeters with different field systems.

[0004] For example, EP 0 892 251 A1 teaches a magnetic induction flowmeter having a front plate in the form of a spherical cap and a coil that is pushed onto a cylindrical coil core serving as a coil carrier. When assembling the individual components of the magnetic induction flowmeter, the arrangement and fastening of the field system in the housing and the attachment of the front plate are carried out in separate assembly steps. Summary of the Invention

[0005] Starting from the prior art, it is an object of the present invention to provide a magnetic induction flowmeter having a compact and easily installable field system.

[0006] It is an object of the present invention to provide a corresponding method for producing a field system of a magnetic induction flowmeter with reduced assembly steps.

[0007] This object is achieved by the magnetic induction flowmeter according to the invention and a method for generating a field system.

[0008] A magnetic induction flowmeter for insertion into a pipe through which a medium flows and for determining a measured variable depending on the flow rate induced in the medium comprises:

[0009] - a housing,

[0010] wherein a front body is arranged on an end face of the housing, and the front body closes the housing at the end face;

[0011] - a measurement electrode arrangement for making electrical contact with the medium and tapping an induced voltage in the flowing medium;

[0012] - a field system for generating a magnetic field through the end face of the housing,

[0013] wherein the field system is arranged in the housing,

[0014] wherein the field system comprises a coil arrangement,

[0015] wherein the coil arrangement comprises a coil arrangement carrier for winding a coil wire,

[0016] wherein the coil arrangement carrier and the front body are integrally formed.

[0017] The housing of the magnetic induction flowmeter generally has a cavity, in which the field system, electrical conductors are also arranged, and depending on the application, an operating circuit, a measurement circuit and / or an evaluation circuit are also arranged in the cavity. However, the housing can also be formed as a casting or be completely encapsulated, wherein the electrical conductors, measurement electrodes and field system are also encapsulated. The housing is generally cylindrical or hollow cylindrical, but can also be cuboid, depending on the application. The medium contact shell of the housing is usually designed to be conductive, for example made of metal or metallized, and serves as a reference electrode.

[0018] On the end face in contact with the medium, the housing is provided with a front body that seals the interior of the housing. The front body is preferably disc-shaped. The front body seals the interior of the housing to prevent the flowing medium in the pipe.

[0019] The magnetic induction flowmeter is inserted into an opening of a pipe such that a front section of the housing is in direct contact with the medium to be conducted.

[0020] In order to detect a measured variable depending on the flow rate induced in a medium, a measuring electrode arrangement is required, in particular at least one measuring electrode in combination with a reference electrode, which measuring electrode arrangement is electrically connected to a reference potential, in particular the ground potential. For example, the reference electrode can be embodied as a needle electrode, a ring electrode, or can also be realized by a partial metal housing connected to the reference potential - such as a grounding system. However, commercially available magnetic induction flow meters have two measuring electrodes, which are arranged on the measuring electrode axis and on the medium contact end face of the front body, where the magnetic induction flow meter is to be arranged in an opening of a pipe such that the measuring electrode axis preferably extends perpendicular to the flow direction of the medium.

[0021] The measuring electrode arrangement consisting of at least two measuring electrodes can already be pre-assembled for the production of a magnetic induction flow meter, i.e., the at least two measuring electrodes are interconnected via a connecting body. Then, such a measuring electrode arrangement is inserted into a mold of an injection molding system and encapsulated together with the front body. Alternatively, through holes can be provided in the front body and the measuring electrodes, which are usually designed as tip electrodes, are pressed into these through holes. Magnetic induction flow meters with more than three measuring electrodes are known.

[0022] The coil arrangement can include exactly one coil or several coils. The coil generally includes a coil arrangement carrier having an opening and at least one coil wire wound around the coil arrangement carrier. The opening in the coil arrangement carrier is preferably designed such that a field conductor, for example in the form of a coil core and / or a field loop, can be inserted in a form-fitting manner. The magnetic induction flow meter according to the invention preferably includes exactly one coil.

[0023] According to the invention, the front body and the coil arrangement carrier are designed as one piece. That is to say, the front body and the coil arrangement carrier are integrally formed and have no connection points, i.e., the two components are seamlessly connected to each other. This is usually achieved by an injection molding process. Thus, the field system is installed in the housing, and the housing is closed with the front body in a single assembly step.

[0024] One embodiment provides that the coil arrangement has a first contact body arrangement,

[0025] wherein the contact body arrangement includes a first contact body and a second contact body,

[0026] wherein a first coil wire end of the coil wire is connected to a first section of the first contact body,

[0027] wherein a second coil wire end of the coil wire is connected to a first section of the second contact body.

[0028] The contact body arrangement can be achieved by pre-assembled contact bodies which are connected by connecting bodies. Such a contact body arrangement simplifies the installation of the contact bodies in the mold of the injection molding system. The contact body arrangement can also include individual, non-pre-assembled contact bodies.

[0029] The contact bodies are used to easily connect the precision coil wire to the operating circuit. For this purpose, the coil wire ends are connected to the first section or wound around the first section of the respective contact bodies. The contact device electrically connects the contact bodies to the operating circuit. Thus, the coil wire is not directly connected to the operating circuit, but is inserted through the contact bodies, which results in a simplification of the contacts during the assembly of the various components of the magnetic induction flowmeter.

[0030] The contact bodies are preferably metal sheet parts designed to be bent. Additionally, the first contact body and the second contact body are preferably identical parts.

[0031] One embodiment provides that the first sections of the first contact body and the second contact body each have a longitudinal axis which, in each case, lies in the cross-section of the coil arrangement carrier.

[0032] In the case where the coil arrangement and the coil arrangement carrier have a common longitudinal axis, it is particularly advantageous if the longitudinal axes of the first sections of the contact bodies lie substantially in the common cross-section of the coil arrangement carrier. When automatically winding the coil wire onto the coil arrangement carrier, first the coil wire end is attached to the first section of the first contact body, and then the coil wire is wound. This is achieved by moving the winding device in the longitudinal direction of the coil arrangement carrier or by moving the coil arrangement carrier in the longitudinal direction. After the winding has ended, the coil wire is attached to the first section of the second contact body. The production method ends with dipping the first section into a solder bath. Such a production method can be easily automated.

[0033] The first sections of the contact bodies can be arranged on the end face of the coil arrangement carrier. According to a preferred embodiment, the contact bodies are arranged parallel to each other. According to another embodiment, the first sections of the contact bodies are arranged in a central part which connects the coil arrangement carrier and the precursor to each other.

[0034] The first sections of the two contact bodies can also be arranged offset longitudinally with respect to the coil arrangement carrier.

[0035] One embodiment provides that the first contact body and the second contact body each have a second section which is in form-fitting connection with the coil arrangement carrier and is preferably surrounded by the coil arrangement carrier, in particular embedded in the polymer matrix forming the coil arrangement carrier.

[0036] Advantageously, the contact body can be connected to the coil arrangement carrier in a form - fitting manner, for example, by being attached in a recess in the coil arrangement carrier.

[0037] Particularly advantageously, the contact body has a second section which extends into the interior of the coil arrangement carrier or which is surrounded by the body of the coil arrangement carrier, so that the form - fitting connection fastens the contact body to the coil arrangement carrier. This connection can preferably be achieved by encapsulating the contact body arrangement during the injection molding of the precursor and the coil arrangement carrier.

[0038] The coil arrangement carrier can also include a central part, in which the second section is arranged.

[0039] One embodiment provides that the first contact body and the second contact body each have a longitudinal axis in the second section, which longitudinal axis is inclined relative to the longitudinal axis of the first section and / or relative to the longitudinal axis of the coil arrangement carrier.

[0040] Thus, the second section extends spatially away from the first section, thereby achieving a more stable fastening of the contact body arrangement or the individual contact elements to the coil arrangement carrier.

[0041] One embodiment provides that the first contact body and the second contact body each have a third section for contacting the coil wire with an operating circuit.

[0042] In this case, the second section is located between the first section and the third section. The first section is for attaching and fastening the coil wire. The third section is for this purpose and is designed such that the operating circuit can be electrically connected via a contact device. The intermediate third section serves to spatially offset the third section from the first section.

[0043] Measurement circuits in the field of flow measurement technology are well - known. The purpose of a measurement circuit is to detect very small absolute values and changes of the corresponding measured variable. There are a variety of different embodiments, each having its advantages and disadvantages.

[0044] Accordingly, the measurement circuit includes an analog / digital converter which converts an input signal - in this case a potential difference which currently exists between respective pairs of measurement electrodes or a potential which exists at respective measurement electrodes - into digital data, which digital data is then further processed or stored by an evaluation circuit. However, other measurement converters or measurement transducers from the field of digital measurement technology are also known and suitable for detecting a measurement voltage or potential.

[0045] The evaluation circuit is configured to process the measured values of the individual measured variables measured by the measuring circuit and to determine the measured variable sought. Therefore, the evaluation circuit generally comprises a microprocessor, an amplifier and a noise filter. The measuring circuit and the evaluation circuit can have a modular design and can communicate by means of a wireless connection, or can be part of a single electronic measuring and evaluation unit arranged in the housing of the flow meter.

[0046] One embodiment provides that the measuring electrode arrangement is arranged in the precursor.

[0047] wherein the measuring electrode arrangement has two measuring electrodes, each measuring electrode having an end section for connecting the measuring electrode to a measuring circuit,

[0048] The end section is arranged in the housing.

[0049] The contact body here extends all the way to the end face of the front body located inside the housing, at which the end section of the measuring electrode is located. According to this embodiment, the end section of the measuring electrode and the third section of the contact element are located in a common cross section. This not only simplifies the attachment of the contact device (via which the electrical connection to the operating circuit is established), but also opens up the possibility of connecting the end section and the third section to the measuring circuit and / or the operating circuit via a single contact device.

[0050] One exemplary embodiment provides that a longitudinal axis of the third section of the first contact body and the second contact body respectively extends substantially parallel to the longitudinal axis of the coil arrangement carrier and / or parallel to an end section of the measuring electrode.

[0051] One exemplary embodiment provides that the contact device is designed to connect the measuring electrode to a measuring circuit and to connect the contact body to an operating circuit.

[0052] One embodiment provides that the contact device is designed as a printed circuit board with contact terminals.

[0053] wherein the two contact terminals are formed to be complementary to the end sections of the two measuring electrodes and are configured to electrically connect the end sections of the measuring electrodes to the measuring circuit,

[0054] wherein the two contact terminals are formed to be complementary to the third sections of the two contact bodies and are configured to electrically connect the third sections of the two contact bodies to the operating circuit,

[0055] Therein, the contact device is arranged on the front element in a form-fitting manner.

[0056] The circuit board may have electronic components of the measurement circuit and / or the operating circuit. So far, the coil and the measurement electrodes have been individually wired and soldered to the measurement circuit and / or the operating circuit.

[0057] One embodiment provides that the precursor has at least one bulge for fastening the precursor when winding the coil wire.

[0058] For automatically winding the coil wire onto the coil arrangement carrier, a fastening surface is required to hold the coil arrangement carrier during winding. Advantageously, the precursor has bulges serving as fastening surfaces, and the coil arrangement carrier can be fastened to the holder of the winding system via the bulges.

[0059] A method according to the invention for producing a magnetic induction flowmeter, in particular a field system of a magnetic induction flowmeter according to the invention, comprises the following production steps:

[0060] - Providing a core and a mold cavity,

[0061] wherein the mold cavity has a receiving portion for each of the contact bodies,

[0062] - Arranging the contact bodies in their respective receiving portions;

[0063] - Forming a cavity between the core and the mold cavity by joining the core and the mold cavity together;

[0064] - Filling the cavity with a casting material forming the precursor and the coil arrangement carrier and encapsulating the contact bodies; and

[0065] - Curing the casting material.

[0066] During the production of the precursor and the coil arrangement carrier, casting a section of the contact bodies together will reduce the number of assembly steps and provide sufficient fastening of the contact bodies or the contact body arrangement in the coil arrangement carrier.

[0067] The injection molding process is suitable as a particularly advantageous method for filling the cavity.

[0068] One embodiment provides the following method steps:

[0069] - Winding the coil wire around a first section of the first contact body;

[0070] - Winding the coil wire around the coil arrangement carrier along a first direction substantially parallel to the longitudinal axis of the coil arrangement carrier;

[0071] - Winding the coil wire around the coil arrangement carrier along a second direction opposite to the first direction;

[0072] - Wind the coil wire around the first section of the second contact body.

[0073] One embodiment provides that when the core and the cavity are combined, the first contact body and / or the second contact body are formed into their final state by means of bending.

[0074] Wherein, in the final state, the longitudinal axis in the first section of the first contact body extends substantially perpendicular to the longitudinal axis of the coil arrangement carrier in the cross-section of the coil arrangement carrier, while the longitudinal axis of the third section of the first contact body extends substantially parallel to the longitudinal axis of the coil arrangement carrier.

[0075] When the casting mold is combined, especially when the core is introduced into the cavity, there is sufficient kinetic energy to deform the contact body. Therefore, it is advantageous that the contact body is not pre-bent or only partially pre-bent and is not reshaped, especially bent, until the core has been introduced into the cavity. Description of the Drawings

[0076] The present invention is explained in more detail with reference to the following drawings. Shown are:

[0077] Figure 1 : Two views of an embodiment of a precursor and a coil arrangement carrier according to the present invention,

[0078] Figure 2 : Side view of the structure of the precursor, in which the coil core, the field circuit and the contact body are installed,

[0079] Figure 3 : Two views of an embodiment of a precursor mounted on a housing according to the present invention,

[0080] Figure 4 : A magnetic induction flowmeter installed in a pipeline according to the present invention, and

[0081] Figure 5 : Flowchart of an embodiment of a method for producing a precursor according to the present invention. Detailed Description of the Invention

[0082] Figure 1Shows two views of an embodiment of a precursor and a coil arrangement carrier according to the present invention. The precursor 5 has a cylindrical base body. In addition, the precursor 5 has two end faces, where the first end face is in contact with the medium, and the second end face is located inside the housing 3. The measuring electrode arrangement 6 is arranged in the precursor 5. The measuring electrodes 23, 24 extend from the first end face through the precursor 5 to the second end face. The measuring electrodes 23, 24 each have a front section in contact with the medium and an end section 25 extending into the interior of the housing 3. The measuring electrodes 23, 24 each have a longitudinal axis 33, which extends parallel to the longitudinal axis of the coil arrangement carrier 9 and intersects the second end face perpendicularly. According to the illustrated embodiment, the measuring electrodes 23, 24 are each designed as needle electrodes.

[0083] The precursor 5 is integrally formed with the coil arrangement carrier 9. According to the illustrated embodiment, a central member 32 integrally connected to the precursor 5 and the coil arrangement carrier 9 is arranged between the precursor 5 and the coil arrangement carrier 9. The coil arrangement carrier 9 has a hollow cylindrical basic shape. The winding surface wound with the coil wire 10 is bounded by two disks in two longitudinal directions of the coil arrangement carrier 9. The coil arrangement 8 is attached to the coil arrangement carrier 9. According to the illustrated embodiment, the coil arrangement 8 exactly contains one coil.

[0084] The coil wire ends of the coil wire 10 are connected to two contact bodies 11, 12, in particular to the first sections 15 of the contact bodies 11, 12. The contact bodies 11, 12 are shaped such that the longitudinal axes of the first sections 15 of the contact bodies 11, 12 are located in a common cross-section of the coil arrangement carrier 9. In addition, the contact bodies 11, 12 are shaped such that the second sections 19 are inclined with respect to the longitudinal axis of the coil arrangement carrier 9, while the longitudinal axis 28 of the third section 21 extends parallel to the longitudinal axis 18 of the coil arrangement carrier 9. The contact bodies 11, 12, in particular the third sections 21 of the contact bodies 11, 12, are partially encapsulated by the polymer matrix of the coil arrangement carrier 9. In the illustrated embodiment, the second section extends into the central member 32. The third section 21 extends from the second end face of the precursor 5 in the direction of the interior of the housing 3.

[0085] The three sections 15, 19, 21 of the separately illustrated contact body have their own longitudinal axes 16, 20, 28 marked by dotted lines.

[0086] Figure 2 A side view showing the structure of the precursor 5 and the coil arrangement carrier 9, in which the coil core 30, the field circuit 29 and the contact device 27 are installed. The illustrated precursor 5 has Figure 1 all the necessary features. In addition to the coil arrangement carrier 9 and the precursor 5, the field circuit 29, the coil core 30 extending through the cross-sectional area of the coil and the contact device 27 are also shown.

[0087] In addition,Figure 2 Shows the coil core 30 together with the field circuit 29 and the contact device 27, wherein the contact device 27 has contact terminals 31 for the measuring electrodes and the contact bodies, for precisely connecting them to the measuring circuit 22 and / or the operating circuit 26. The coil core 30 is cylindrical, and the field circuit 29 has the basic shape of a double-bent strip. The field circuit 29 and the coil core 30 can be integrally formed or consist of at least two assembled individual components. The contact device 27 is formed by a circuit board and includes the measuring circuit 22 and / or the operating circuit 26.

[0088] Figure 3 Shows two views of an embodiment of the precursor 5 mounted on the end face 4 of the housing 3 according to the invention. The housing 3 has a cylindrical basic shape. The housing 3 can be cast with a casting material for attaching the field system. The precursor 5 of the shown embodiment has a measuring electrode arrangement 6, which has two measuring electrodes 23, 24 arranged along the diameter of the precursor 5. The precursor 5 is pressed into the housing 3 in a medium-sealed manner, or arranged in a medium-sealed manner with a seal, in particular by extrusion.

[0089] Figure 4 Shows the magnetic induction flowmeter 1 installed in the pipeline 2 according to the invention. A transmitter with an evaluation circuit 34 and a transmitting unit 35 is connected to the magnetic induction flowmeter 1. Optionally, the transmitter can have a display 36.

[0090] Figure 5 Shows a flowchart of an embodiment of a method for producing a field system according to the invention, having the following method steps:

[0091] Provide a core part and a mold cavity, wherein the mold cavity has a receiving part for each of the contact bodies.

[0092] - Arrange the contact bodies in their respective receiving parts, wherein the contact bodies are either preformed, or partially preformed, or bent into their final shape when the core part is inserted into the mold cavity.

[0093] - By combining the core part and the mold cavity, form a cavity between the core part and the mold cavity;

[0094] - Fill the cavity and in particular encapsulate the contact bodies in a casting material forming the precursor and the carrier of the coil arrangement by an injection molding process;

[0095] - Cure the casting material;

[0096] - Wind the coil wire around the first section of the first contact body;

[0097] - Wrap the coil wire around the coil by arranging the carrier along a first direction that is substantially parallel to the longitudinal axis of the carrier arranged around the coil;

[0098] - Wrap the coil wire around the coil by arranging the carrier along a second direction that is opposite in orientation to the first direction;

[0099] - Wind the coil wire around the first section of the second contact body.

[0100] According to a further embodiment, when the core and the cavity are combined, the first contact body and / or the second contact body are formed into a final state by means of bending, wherein, in the final state, the longitudinal axis extends substantially perpendicular to the longitudinal axis of the carrier arranged around the coil in the cross-section of the carrier arranged around the coil in the first section of the first contact body, while the longitudinal axis of the third section of the first contact body extends substantially parallel to the longitudinal axis of the carrier arranged around the coil.

[0101] List of reference numerals

[0102] 1 Magnetic flowmeter

[0103] 2 Pipeline

[0104] 3 Housing

[0105] 4 Front side

[0106] 5 Precursor

[0107] 6 Measuring electrode arrangement

[0108] 7 Field system

[0109] 8 Coil arrangement

[0110] 9 Coil arrangement carrier

[0111] 10 Coil wire

[0112] 11 First contact body

[0113] 12 Second contact body

[0114] 15 First section

[0115] 16 Longitudinal axis of the first section

[0116] 18 Longitudinal axis of the carrier arranged around the coil

[0117] 19 Second section

[0118] 20 Longitudinal axis of the second section

[0119] 21 Third section

[0120] 22 Operating circuit

[0121] 23 Measuring electrode

[0122] 24 Measuring electrode

[0123] 25 End section of the measuring electrode

[0124] 26 Measuring circuit

[0125] 27 Contact device

[0126] 28 Longitudinal axis of the third section

[0127] 29 Field circuit

[0128] 30 Coil core

[0129] 31 Contact terminal

[0130] 32 Central member

[0131] 33 Longitudinal axis of the measuring electrode

[0132] 34 Evaluation circuit

[0133] 35 Transmitting unit

[0134] 36 Display

Claims

1. A magnetic induction flowmeter (1) for insertion into a pipe (2) through which a medium flows and for determining a measured variable that is induced in the medium and depends on the flow rate, the magnetic induction flowmeter (1) comprising: - a housing (3), wherein a front body (5) is arranged on an end face (4) of the housing (3), and the front body (5) seals the housing (3) at the end face; - a measurement electrode arrangement (6) for making electrical contact with the medium and for tapping an induced voltage in the flowing medium; - a field system (7) for generating a magnetic field through the end face (4) of the housing (3), wherein the field system (7) is arranged in the housing (3), wherein the field system (7) comprises a coil arrangement (8), wherein the coil arrangement (8) comprises a coil arrangement carrier (9) for winding a coil wire (10), wherein the coil arrangement carrier (9) and the front body (5) are integrally formed, wherein the coil arrangement (8) has a contact body arrangement, wherein the contact body arrangement comprises a first contact body (11) and a second contact body (12), wherein a first coil wire end of the coil wire (10) is connected to a first section (15) of the first contact body (11), wherein a second coil wire end of the coil wire (10) is connected to a first section (15) of the second contact body (12), wherein each of the first contact body (11) and the second contact body (12) has a second section (19) that is connected to the coil arrangement carrier (9) in a form-fitting manner.

2. The magnetic induction flowmeter (1) according to claim 1, Among them, wherein the first sections (15) of the first contact body (11) and the second contact body (12) each have a longitudinal axis (16) that lies in a cross-section of the coil arrangement carrier (9).

3. The magnetic induction flowmeter (1) according to claim 1, Among them, wherein the second section (19) is surrounded by the coil arrangement carrier (9).

4. The magnetic induction flowmeter (1) according to claim 1, Among them, wherein the second section (19) is in a polymer matrix forming the coil arrangement carrier (9).

5. The magnetic induction flowmeter (1) according to claim 1, Among them, wherein each of the first contact body (11) and the second contact body (12) has a longitudinal axis (20) that is inclined with respect to the longitudinal axis (16) of the first section (15) in the second section (19).

6. The magnetic induction flowmeter (1) according to claim 1, Among them, wherein each of the first contact body (11) and the second contact body (12) has a third section (21) for bringing the coil wire (10) into contact with an operating circuit (22).

7. The magnetic induction flowmeter (1) according to claim 6, Among them, wherein the measurement electrode arrangement (6) is arranged in the front body (5), Wherein, the measurement electrode arrangement (6) has two measurement electrodes (23, 24), and each measurement electrode has an end section (25) for connecting the measurement electrode (23, 24) to a measurement circuit (26). Wherein, the end section (25) is arranged in the housing (3).

8. The magnetic induction flowmeter (1) according to claim 7, Among them, The longitudinal axes (28) of the third sections (21) of the first contact body (11) and the second contact body (12) extend parallel to the longitudinal axis (18) of the coil arrangement carrier (9), and / or parallel to the end sections (25) of the measurement electrodes (23, 24).

9. The magnetic induction flowmeter (1) according to claim 8, Among them, The contact device (27) is configured to connect the measurement electrodes (23, 24) to the measurement circuit (26), and connect the contact bodies (11, 12) to the operating circuit (22).

10. The magnetic induction flowmeter (1) according to claim 9, Among them, The contact device (27) is designed as a printed circuit board with contact terminals, Wherein, two contact terminals are formed to be complementary to the end sections (25) of the two measurement electrodes (23, 24), and the two contact terminals are configured to electrically connect the end sections (25) of the measurement electrodes (23, 24) to the measurement circuit (26), Wherein, two contact terminals are formed to be complementary to the third sections (21) of the two contact bodies (11, 12), and the two contact terminals are configured to electrically connect the third sections (21) of the two contact bodies (11, 12) to the operating circuit (22), Wherein, the contact device (27) is arranged on the front body (5) in a form - fitting manner.

11. The magnetic induction flowmeter (1) according to one of the preceding claims, Among them, The front body (5) has at least one bulge for fastening the front body (5) when winding the coil wire (10).

12. A method for producing a field system (7) of a magnetic induction flowmeter (1) according to one of the preceding claims, the method comprising the following production steps: - Providing a core and a mold cavity, Wherein the mold cavity has a receiving portion for each of the contact bodies (11, 12), - Arranging the contact bodies (11, 12) in the respective receiving portions; - Forming a cavity between the core and the mold cavity by combining the core and the mold cavity together; - Filling the cavity with a casting material for forming the front body (5) and the coil arrangement carrier (9) and encapsulating the contact bodies; - Curing the casting material; - Winding the coil wire (10) around the first section (15) of the first contact body (11); - Winding the coil wire (10) around the coil arrangement carrier (9) along a first direction parallel to the longitudinal axis (18) of the coil arrangement carrier (9); - Wrap the coil wire (10) around the carrier (9) arranged around the coil in a second direction opposite to the first direction; and - Wrap the coil wire (10) around the first section (15) of the second contact (12).

13. The method according to claim 12, Among them, wherein the first contact (11) and / or the second contact (12) is formed into a final state by bending when the core and the cavity are joined together, wherein, in the final state, the longitudinal axis (16) in the first section (15) of the first contact (11) extends perpendicular to the longitudinal axis (18) of the coil arrangement carrier (9) in the cross-section of the coil arrangement carrier (9), and the longitudinal axis (28) of the third section (21) of the first contact (11) extends parallel to the longitudinal axis (18) of the coil arrangement carrier (9).

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