Magnet module for a vibration tube, vibration tube device and method for producing a vibration tube device

Abstract

The invention relates to a magnet module for a vibration tube, comprising: - a magnet and a magnet holder (20), wherein the magnet holder (20) has a magnet holding region (21), a tube holding region (22) and a counterweight region (23), wherein the magnet holder (20) extends along a first axis (A1) and has a first end (24) and a second end (25) opposite the first end (24), wherein the magnet holding region (21) is arranged on the first end (24), and a magnet cavity (26) which is arranged axially with respect to the first axis (A1) and in which the magnet (10) is arranged, wherein the tube holding region (22) extends between the first end (24) and the second end (25) and has a tube cavity (27) which extends axially along a second axis (A2) for receiving the vibration tube (2), wherein the second axis (A2) is arranged orthogonally with respect to the first axis (A1).

Description

[0001] Magnetic module for a vibrating tube, vibrating tube device and method for manufacturing a vibrating tube device

[0002] The invention relates to a magnetic module for a vibrating tube, a vibrating tube device and a method for manufacturing a vibrating tube device.

[0003] Such vibrating tube devices are also called Coriolis meters. To measure the density of a medium, it is passed through a vibrating tube of the instrument while the tube is set into vibration by an exciter, and the resulting vibration of the tube is measured. The resulting vibration depends on the density of the medium flowing through the vibrating tube. By comparing the exciter vibration and the resulting vibration, the density of the medium can be determined. This comparison uses, for example, a phase shift or a change in amplitude between the exciter vibration and the resulting vibration of the vibrating tube.

[0004] To measure the vibration of the vibrating tube, magnets are usually attached to the tube. These magnets move relative to an electrical coil, inducing and measuring an electric current in the coil. These magnets have a certain weight and therefore influence the vibration behavior of the vibrating tube.

[0005] It is therefore an object of the invention to provide a magnetic module which enables the highest precision in measuring the vibration of a vibration tube.

[0006] This problem is solved according to the invention by a magnetic module for a vibrating tube according to claim 1.

[0007] The magnetic module according to the invention comprises: a magnet and a magnet holder, wherein the magnet holder has a magnet holding area, a tube holding area and a counterweight area, wherein the magnet holder extends along a first axis and has a first end and a second end opposite the first end, wherein the magnet holding area is arranged at the first end and has a magnetic cavity arranged axially to the first axis in which the magnet is arranged, wherein the tube holding area extends between the first end and the second end and has a tube cavity extending axially along a second axis for receiving the vibrating tube, wherein the second axis is arranged orthogonally to the first axis, wherein the tube cavity has a domed area extending radially about the second axis and axially along the second axis with a predetermined domed radius for contacting the vibrating tube.wherein the counterweight area is arranged at the second end and is dimensioned such that the center of mass of the magnet module lies essentially at the intersection of the first axis and the second axis.

[0008] The magnetic module according to the invention, in particular the counterweight section, enables the center of mass of the magnetic module to lie essentially on the central axis of the vibrating tube on which the magnetic module is mounted. This allows for optimal vibration behavior of the vibrating tube. Likewise, thanks to the arched section of the magnetic module, precise positioning and secure mounting of the magnetic module on the vibrating tube are possible.

[0009] According to one embodiment of the invention, the counterweight area has two legs which are spaced apart from each other by a leg spacing, wherein the leg spacing is greater than or equal to twice the arch radius.

[0010] According to a further embodiment of the invention, the two legs are symmetrical to each other, with the first axis and the second axis forming a plane of symmetry for the two legs.

[0011] According to one embodiment of the invention, the magnet holder is cylindrical and the magnet holding area has a first outer diameter and the counterweight area a second outer diameter, wherein the first outer diameter is smaller than the second outer diameter.

[0012] According to one embodiment of the invention, the magnet holding area has an annular magnetic mounting surface in the magnetic cavity.

[0013] According to one embodiment of the invention, the arched area is annular and has a radial gap. The aforementioned problem is also solved by a vibrating tube device according to claim 7.

[0014] The vibrating tube device according to the invention comprises: a first vibrating tube and at least one magnetic module, wherein the magnetic module is attached to the first vibrating tube in such a way that the tube holding area of ​​the magnetic module is in contact with the first vibrating tube.

[0015] According to one embodiment of the invention, the first vibrating tube has a first vibrating tube diameter and the arch radius corresponds to half the first vibrating tube diameter.

[0016] According to one embodiment of the invention, the vibrating tube and the magnetic module are made of the same material.

[0017] According to one embodiment of the invention, the vibrating tube device further comprises a second vibrating tube, wherein the first vibrating tube and the second vibrating tube are U-shaped, with three magnetic modules attached to each of the first vibrating tube and the second vibrating tube.

[0018] The above-mentioned problem is also solved by a method for manufacturing a vibrating tube device according to claim 11.

[0019] The method according to the invention comprises:

[0020] Providing a vibrating tube, a magnet and a magnet holder; attaching the magnet holder to the vibrating tube so that the tube holding area of ​​the magnet module is in contact with the vibrating tube;

[0021] Securing the magnet in the magnetic cavity of the magnet holder.

[0022] According to one embodiment of the invention, a soldering process is used to attach the magnet.

[0023] The invention is explained in more detail with reference to the following description of figures. The figures show:

[0024] Fig. 1 : a magnet holder of the magnetic module according to the invention,

[0025] Fig. 2: a vibrating tube device with the magnetic module according to the invention, a vibrating tube and the magnet holder from Figure 1, Fig. 3: the vibrating tube device from Figure 2 from a different viewing perspective, Fig. 4: an alternative embodiment of a magnet holder.

[0026] The magnet holder 20 shown in Figure 1 has a magnet holding area 21, a pipe holding area 22 and a counterweight area 23.

[0027] The magnet holding area 21 is a magnet holder for holding a magnet 10 (see Figure 2), the tube holding area 22 is a tube holder for attaching the magnet holder 20 to a vibrating tube 2 (see Figure 2), and the counterweight area 23 is a counterweight for balancing the weight. The magnet holder 20 is preferably formed in one piece with the aforementioned various areas. For example, the magnet holder 20 is made of stainless steel. However, it is also possible for the magnet holder to be assembled from different parts.

[0028] The magnetic holder 20 extends along a first axis A1 and has a first end 24 and a second end 25 opposite the first end 24.

[0029] The magnet holding area 21 is arranged at the first end 24 and has a magnetic cavity 26 arranged axially to the first axis A1, in which the magnet 10 is arranged (see Figures 2 and 3). "Arranged axially" here means that the magnetic cavity 26 has an inlet that is orthogonal to the first axis A1. The magnetic cavity 26 has a first inner diameter ID1, which preferably corresponds substantially to an outer diameter of the magnet 10. The magnet holding area 21 has a first outer diameter AD1, and the counterweight area 23 has a second outer diameter AD2. The first outer diameter AD1 is preferably smaller than the second outer diameter AD2 (see Figure 1).

[0030] Magnet 10 is a permanent magnet. Preferably, both the magnetic cavity 26 and the magnet 10 are cylindrical. The magnetic cavity 26 has a magnetic mounting surface 30 for attaching the magnet 10. The magnet 10 is, for example, inserted into the magnetic cavity 26 and bonded to the magnetic mounting surface 30. The magnetic mounting surface 30 is preferably annular.

[0031] The magnet holder 20 is preferably essentially cylindrical. For example, the magnet holder 20 is designed as a sleeve, with the magnetic cavity 26 preferably passing through the magnet holder 20 as a through-hole. Of course, it is also possible to have the magnetic cavity 26 merely as a depression on one end face, i.e., the first end 24, of the

[0032] to form the magnetic holder 20 so that the magnet 10 can be securely positioned in the magnetic holder 20.

[0033] The tube holding area 22 extends between the first end 24 and the second end 25 and has a tube cavity 27 extending axially along a second axis A2 for receiving the vibrating tube 2. The second axis A2 is arranged orthogonally to the first axis A1. The tube cavity 27 is a through-hole through the magnet holder 20. According to one embodiment, the magnet cavity 26 and the tube cavity 27 merge into one another. The magnet holding area 21 and the tube holding area 22 together have a first height H1 along the first axis A1.

[0034] The tube cavity 27 has a domed region 28 extending radially around the second axis A2 and axially along the second axis A2, with a predetermined domed radius R1 for contacting the vibrating tube 2. The domed region 28 forms a tube mounting surface. The domed region 28 preferably has a radial gap 31.

[0035] According to the embodiment shown in Figure 4, the arched area 28 is preferably annular. In this embodiment as well, the arched area 28 preferably has a radial gap 31. Thanks to the 31, it is possible to dimension the arched radius R1 slightly smaller than a radius, or half a vibration tube diameter SD1, of the vibration tube 2, so that the magnet holder 20 sits under tension on the vibration tube 2.

[0036] The counterweight section 23 is arranged at the second end 25 and is dimensioned such that the center of mass of the magnet module 1 lies essentially at the intersection of the first axis A1 and the second axis A2. The counterweight section 23 has a second height H2 along the first axis A1. Preferably, the first height H1 and the second height H2 are identical.

[0037] Preferably, the counterweight section 23 has two legs 29 spaced apart from each other by a leg spacing AB. The leg spacing AB is preferably greater than or equal to twice the arch radius R1. This allows for easy positioning of the magnet holder 20 on the vibrating tube 2. Preferably, the two legs 29 are symmetrical to each other, with the first axis A1 and the second axis A2 forming a first plane of symmetry E1 for the two legs 29 (see Figure 2).

[0038] Preferably, the two legs 29 are also symmetrical about a second plane of symmetry E2, which is spanned by the first axis A1 and a third axis A3, which is arranged orthogonally to the first axis A1 and to the second axis A2 (see Figure 3).

[0039] Figure 2 shows the vibrating tube device 100 according to the invention, comprising a first vibrating tube 2 and at least one magnetic module 1. The magnetic module 1 is mounted on the first vibrating tube 2 such that the tube holding area 22 of the magnetic module 1 is in contact with the first vibrating tube 2. The magnet 10 is mounted in the magnetic cavity 26.

[0040] The first vibrating tube 2 has a first vibrating tube diameter SD1. The arch radius R1 preferably corresponds substantially to half the first vibrating tube diameter SD1. In other words, one radius of the vibrating tube 2 corresponds to the arch radius R1.

[0041] The vibrating tube 2 is preferably made of the same material as the magnetic module 1. For example, the vibrating tube 2 is made of stainless steel.

[0042] According to one embodiment, the vibrating tube device 100 further comprises a second vibrating tube 2'. The first vibrating tube 2 and the second vibrating tube 2' are preferably U-shaped. A first magnetic module 1 is attached to the first vibrating tube 2, and a second magnetic module 1' is attached to the second vibrating tube 2'. The two magnetic modules 1, 1' of each vibrating tube 2, 2' are arranged along the first axis A1. The first magnetic module 1 and the second magnetic module 1' are arranged with their magnets 10, 10' relative to each other such that the magnets 10, 10' point away from each other (see Figures 2 and 3 together). According to this embodiment, the magnetic modules 1, T of the two vibrating tubes 2, 2' are connected to each other by a link before the magnetic modules 1, T are attached to the vibrating tubes 2, 2'. For example, this link is realized by one or two rods.Preferably, the rods are connected at one end to the counterweight section 23 of the first magnetic module 1 and at the other end to the counterweight section 23' of the second magnetic module T. This ensures that the magnetic modules 1, 1' are precisely aligned axially with each other. This allows the two magnetic modules 1, 1' to be slid onto the first vibrating tube 2 and second vibrating tube 2' without compromising their precise alignment. Likewise, the connection between the first magnetic module 1 and the second magnetic module T maintains the axial alignment of the magnetic modules 1, 1' when connecting them to the vibrating tubes 2, 2'. After the magnetic modules 1, 1' are attached to the vibrating tubes 2, 2', the connection between them is removed.The connection between the magnetic modules 1, 1' preferably has a predetermined breaking point, so that the connection can be easily removed after the magnetic modules 1, T have been attached.

[0043] According to an alternative embodiment, the connection is at least partially part of the counterweight section 23. This means that the connection is partially removed, for example, only a section of the connection marked by two predetermined breaking points. The part remaining on the magnetic modules thus constitutes part of the counterweight. For example, additional counterweights are attached to the remaining part. The additional counterweights thus also serve as balancing mass.

[0044] The following describes a method according to the invention for manufacturing the vibrating tube device 100.

[0045] First, the vibrating tube 2, the magnet 10 and the magnet holder 20 are provided.

[0046] Next, the magnetic holder 20 is attached to the vibrating tube 2 so that the tube-holding area 22 of the magnetic module 1 is in contact with the vibrating tube 2. Preferably, the magnetic holder 20 is first positioned on the vibrating tube 2 and then connected to it by soldering or welding. Alternatively, the magnetic holder can also be glued to the vibrating tube 2. According to an embodiment not shown, the vibrating tube 2 has a thread, and the magnetic module 1 has a thread complementary to the thread of the vibrating tube. In this embodiment, the magnetic holder 20 is screwed onto the vibrating tube 2.In the embodiment shown in Figure 4, when positioning the magnet holder 20 on the vibrating tube 2, the magnet holder 20 is preferably spread at the gap 31 in the elastic material area, so that the magnet holder 20 can be easily placed onto the vibrating tube 2. Naturally, the radius of curvature R1 is selected depending on the vibrating tube diameter SD1, so that an optimal fit of the magnet holder 20 on the vibrating tube 2 is guaranteed. The magnet 10 is then attached in the magnetic cavity 26 of the magnet holder 20. Here, the magnet 10 is preferably bonded to the magnetic mounting surface 30.

[0047] According to the embodiment shown in Figure 4, preferably two magnets 10 are attached to the magnet mounting surface 30 such that the two magnets 10 are opposite each other.

[0048] Reference symbol list

[0049] 1 magnetic module

[0050] 2 vibration tube

[0051] 10 Magnet

[0052] 20 magnetic holders

[0053] 21 Magnetic holding area

[0054] 22 Pipe holding area

[0055] 23 Counterweight area

[0056] 24 first end

[0057] 25 second end

[0058] 26 Magnetic cavity

[0059] 27 Tube cavity

[0060] 28 vaulted area

[0061] 29 thighs

[0062] 30 magnetic mounting surfaces

[0063] 31 gap

[0064] A1 first axis

[0065] A2 second axis

[0066] A3 third axis

[0067] AB leg spacing

[0068] E1 Plane of symmetry

[0069] R1 arch radius

[0070] SD1 vibration tube diameter

[0071] AD1 first outer diameter

[0072] AD2 second outer diameter

[0073] H1 first height

[0074] H2 second height

[0075] 100 vibrating tube device

Claims

Patent claims 1. A magnetic module (1) for a vibrating tube (2), comprising: a magnet (10) and a magnet holder (20), wherein the magnet holder (20) has a magnet holding area (21), a tube holding area (22), and a counterweight area (23), wherein the magnet holder (20) extends along a first axis (A1) and has a first end (24) and a second end (25) opposite the first end (24), wherein the magnet holding area (21) is arranged at the first end (24) and has a magnetic cavity (26) arranged axially to the first axis (A1) in which the magnet (10) is arranged, wherein the tube holding area (22) extends between the first end (24) and the second end (25) and has a tube cavity (27) extending axially along a second axis (A2) for receiving the vibrating tube (2), wherein the second axis (A2) is orthogonal to the first axis (A1) is arrangedo wherein the tube cavity (27) has a domed region (28) extending radially around the second axis (A2) and axially along the second axis (A2) with a predetermined domed radius (R1) for contacting the vibrating tube (2), o wherein the counterweight region (23) is arranged at the second end (25) and is dimensioned such that the center of mass of the magnet module (1) lies substantially at the intersection of the first axis (A1) and the second axis (A2).

2. Magnetic module (1) according to claim 1, wherein the counterweight area (23) has two legs (29) which are spaced apart from each other by a leg distance (AB), wherein the leg distance (AB) is greater than or equal to twice the arch radius (R1).

3. Magnetic module (1) according to claim 2, wherein the two legs (29) are symmetrical to each other, wherein the first axis (A1) and the second axis (A2) form a plane of symmetry (E1) for the two legs (29).

4. Magnetic module (1) according to claim 2, wherein the magnet holder (20) is cylindrical and the magnet holding area (21) has a first outer diameter (AD1) and the counterweight area (23) has a second outer diameter (AD2), wherein the first outer diameter (AD1) is smaller than the second outer diameter (AD2).

5. Magnetic module (1) according to one of the preceding claims, wherein the magnetic holding area (21) has an annular magnetic mounting surface (30) in the magnetic cavity (26).

6. Magnetic module (1) according to one of the preceding claims, wherein the arched area (28) is annular and has a radial gap (31).

7. Vibration tube device (100) comprising: a first vibration tube (2) and at least one magnet module (1), - wherein the magnetic module (1) is attached to the first vibrating tube (2) such that the tube holding area (22) of the magnetic module (1) is in contact with the first vibrating tube (2).

8. Vibration tube device (100) according to claim 7, wherein the first vibration tube (2) has a first vibration tube diameter (SD1) and the arch radius (R1) corresponds to half of the first vibration tube diameter (SD1).

9. Vibration tube device (100) according to claim 7 or 8, wherein the vibration tube (2) and the magnet module (1) are made of the same material.

10. Vibration tube device (100) according to claims 7 to 9, wherein the vibration tube device (100) further comprises a second vibration tube (2'), wherein the first vibration tube (2) and the second vibration tube (2') are U-shaped, and wherein three magnet modules (1) are attached to each of the first vibration tube (2) and the second vibration tube (2').

11. Method for manufacturing a vibrating tube device (100), comprising: providing a vibrating tube (2), a magnet (10) and a magnet holder (20), Attaching the magnet holder (20) to the vibrating tube (2) so that the tube holding area (22) of the magnet module (1) is in contact with the vibrating tube (2), attaching the magnet (10) in the magnetic cavity (26) of the magnet holder (20).

12. Method according to claim 11, wherein a soldering method is used when attaching the magnet (10).

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