阅读说明：本技术 制造热流量计的探针的方法、热流量计的探针和热流量计 (Method for manufacturing probe of thermal flowmeter, and thermal flowmeter ) 是由 阿纳斯塔西奥斯·巴达利斯 斯特凡·加布苏埃尔 亚历山大·格林 汉诺·舒尔特海斯 托比亚斯·波 于 2020-03-31 设计创作，主要内容包括：本发明涉及一种用于制造热流量计(1)的探针(10)的方法(100),该热流量计用于测量测量管(2)中的介质的质量流量,具有纵向轴线的探针套筒(11)和宽松地布置在探针套筒中的探针芯(12)被提供。在至少第一方法步骤(101)中,探针套筒借助于高能率成形相对于纵向轴线在探针芯的方向上在其整个周长上径向地变形,一体地结合的连接在探针套筒与探针芯之间产生,因此形成杆(13),杆构成基体(14),或者基体(14)与杆分离,基体被用于探针制造,变形速度达到大于100m/s,尤其大于200m/s的值,高能率成形尤其通过爆炸成形或电磁成形被实现。(The invention relates to a method (100) for producing a probe (10) of a thermal flow meter (1) for measuring a mass flow of a medium in a measuring tube (2), a probe sleeve (11) having a longitudinal axis and a probe core (12) loosely arranged in the probe sleeve being provided. In at least a first method step (101), the probe sleeve is deformed radially over its entire circumference in the direction of the probe core relative to the longitudinal axis by means of high-energy-rate forming, an integrally bonded connection being produced between the probe sleeve and the probe core, whereby a shank (13) is formed, which constitutes a base body (14), or the base body (14) is separated from the shank, which is used for probe manufacture, the deformation speed reaching values greater than 100m/s, in particular greater than 200m/s, the high-energy-rate forming being effected in particular by explosion forming or electromagnetic forming.)

1. A method for manufacturing a probe (10) for a thermal flow meter (1), which thermal flow meter (1) is intended for measuring a mass flow of a medium in a measuring tube (2),

wherein the probe core (12) is arranged loosely in a probe sleeve (11) having a longitudinal axis (11.2),

wherein, in at least a first method step, the probe sleeve is deformed radially by means of high-energy rate shaping in the direction of the probe core entirely around the longitudinal axis, wherein a material-bonded connection occurs between the probe sleeve and the probe core and a rod is thereby formed,

wherein the rod represents a matrix (14) or wherein the matrix (14) is separate from the rod, wherein the matrix is applied for probe manufacturing,

wherein the radial deformation speed reaches a value of more than 100m/s, in particular more than 200m/s, wherein the high-energy rate forming is achieved in particular by means of explosion forming or magnetic forming.

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein, in a further method step, the base body is stretched, by means of which a reduction of the outer diameter (14.1) of the base body and a smoothing of the side surface (14.2) of the base body is obtained.

3. The method according to claim 1 or 2,

wherein in a further method step the first end (14.3) of the base body is tightly sealed by a medium,

wherein the sealing of the first end comprises removing the probe core in an end region (14.31), wherein a probe head (15) is introduced into the end region and is fixed to the probe sleeve, in particular by laser welding,

wherein the outer side (15.1) of the probe head has in particular a circular shape, for example a hemispherical shape or a semi-elliptical shape.

4. The method according to any one of the preceding claims,

wherein in a further method step the probe core (12) is at least partially exposed in sections on the side facing the second end (14.4) of the base body,

wherein contact areas (12.1) for mounting thermoelectric elements on the probe core are prepared on the probe core,

wherein the contact area has an internal angle of less than 30 degrees, in particular less than 20 degrees, preferably less than 10 degrees, with respect to the longitudinal axis.

5. The method of claim 4, wherein the first and second light sources are selected from the group consisting of,

wherein, in a further method step, after the thermoelectric element (16) is mounted, for example by means of soldering, gluing or sintering, a connection sleeve (17) is provided on the base body, which completely covers the previously at least partially exposed region, wherein the connection sleeve is connected to the probe sleeve medium in a tight manner, in particular by means of circumferential laser welding.

6. The method of claim 5, wherein the first and second light sources are selected from the group consisting of,

wherein the probe sleeve comprises a reduced outer diameter section in a contact region (11.1) for connection with the connection sleeve, wherein in a further method step the connection sleeve is inserted onto the reduced outer diameter section.

7. The method according to any one of the preceding claims,

wherein the probe sleeve (11) is made of a first material comprising stainless steel, and wherein the probe core (12) is made of a second material comprising, for example, silver or copper,

wherein the second material has a thermal conductivity of at least 100W/(mK), in particular at least 200W/(mK), preferably at least 300W/(mK),

wherein the connecting sleeve (17) is made in particular of the first material.

8. The method according to any one of the preceding claims,

wherein the probe core (12.2) has a diameter of less than 5mm, in particular less than 4mm, and preferably less than 3mm and greater than 0.5mm, in particular greater than 1mm, and preferably greater than 1.5mm, and after high energy rate forming

Wherein the probe sleeve has an unreduced outer diameter which is at least 0.1mm, in particular at least 0.2mm, preferably at least 0.5mm, and at most 1.5mm, in particular at most 1.2mm, preferably at most 1mm larger than the diameter of the probe core.

9. A probe (10) of a thermal flow meter (1) manufactured according to the method of any of the preceding claims, the thermal flow meter (1) being for measuring a mass flow of a medium in a measuring tube (2), comprising:

a base body (14) having a probe core (12) and a probe sleeve (11), the probe sleeve (11) at least partially surrounding the probe core and being connected to the probe core by a material bond;

a probe tip (15), said probe tip (15) being media tightly connected with and sealing said probe sleeve at a first end of said base;

a thermoelectric element (16), which thermoelectric element (16) is fixed to a contact region of the probe core, for example by soldering, gluing or sintering, in a region previously at least partially exposed, wherein the thermoelectric element has, in particular, an electrical connection line (16.1), by means of which the thermoelectric element can be operated;

a connection sleeve (17), the connection sleeve (17) completely covering the previously at least partially exposed region, wherein the connection sleeve is medium-tightly connected with the probe sleeve, in particular by means of circumferential laser welding.

10. The probe as set forth in claim 9, wherein,

wherein the probe core comprises a bulge (12.3) protruding from the base region in the previously at least partially exposed region,

wherein the contact region is arranged on the protrusion and has an internal angle of less than 30 degrees, in particular less than 20 degrees, preferably less than 10 degrees, with respect to the longitudinal axis.

11. The probe as set forth in claim 10, wherein,

wherein the protrusion comprises a rear surface connected to the probe sleeve by a material bond, wherein the probe sleeve is adapted to mechanically stabilize the protrusion in the region of the rear surface.

12. The probe according to any one of claims 9 to 11,

wherein the thermoelectric element is adapted to determine the temperature of the medium and/or to heat the medium.

13. A heat flow measurement device (1) comprising:

a measuring tube (2) for conveying a medium;

at least one probe (10) according to any of claims 9 to 12, wherein the probe is arranged in the measurement tube;

an electronic measurement/operation circuit (3) for operating the at least one probe and providing a flow measurement,

a housing (4) for housing the electronic measuring/operating circuit.

Technical Field

The present invention relates to a method of manufacturing a probe for a thermal flow meter for measuring a mass flow of a medium in a measuring tube, such a probe and a thermal flow meter with such a probe.

Background

A typical thermal flow meter comprises a probe which extends into the measuring tube of such a flow meter and is surrounded by a medium during operation. Typically, at least one probe is adapted to record the medium temperature and at least one probe is adapted to heat the medium. For example, the mass flow can be derived from the heating current required to maintain the temperature difference between the heating probe and the thermographic probe.

In order to be able to quickly record temperature or flow changes of the medium, a low thermal mass of the probe and a good thermal transition between the probe and the medium is important.

DE102016121110a1 proposes to manufacture the probe by melting silver in a sleeve. In this way, in principle, a good thermal conversion between the probe and the medium can be provided. However, this method is prone to bubble formation in the silver melt, making probes often not useful. This results in undesirable waste which must pass through the test probe to be discovered, and results in high costs.

Disclosure of Invention

It is therefore an object of the present invention to provide a better method with less waste, to provide a probe manufactured by the better method, and to provide a thermal flow meter with such a probe.

This object is achieved by the method defined in independent claim 1, the probe defined in independent claim 9 and the thermal flow meter defined in independent claim 13.

In the inventive method for manufacturing a probe for a thermal flow meter for measuring the mass flow of a medium in a measuring tube, a probe core is provided loosely arranged in a probe sleeve having a longitudinal axis,

wherein, in at least a first method step, the probe sleeve is deformed radially by means of high-energy rate shaping in the direction of the probe core entirely around the longitudinal axis, wherein a material-bonded connection occurs between the probe sleeve and the probe core, and the rod is thus formed,

wherein the shaft represents the substrate, or wherein the substrate is separate from the shaft, wherein the substrate is used in probe fabrication,

wherein the radial deformation speed reaches a value of more than 100m/s, and in particular more than 200m/s, wherein the high-energy rate forming is achieved in particular by means of explosion forming or magnetic forming.

In this case, the spacing between the outer surface of the probe core and the inner surface of the probe sleeve should ideally not exceed 0.5mm before the high energy rate shaping is applied, so that there is a loose fit.

Explosion forming is a forming method developed by explosion covering. The probe sleeve is surrounded by an explosive material, which has a fast detonation velocity. After ignition of the explosive substance, a material-bonded connection occurs when the sleeve wall strikes against the probe core, so that a mechanically stable connection is produced, whereby a good heat transfer between the probe core and the probe sleeve is ensured.

Magnetic forming exploits the phenomenon that a time-varying magnetic field induces eddy currents in an electrically conductive material, and the eddy currents on a portion thereof generate a force on the material, which force is directed radially inwards. Under strong magnetic fields and fast rates of change, sleeve-shaped conductive objects can undergo rapid deformation.

In an embodiment, in a further method step, the base body is stretched, by means of which a reduction of the outer diameter of the base body and a smoothing of the side surfaces of the base body is obtained.

For example, the substrate is drawn through an opening in the tool having a diameter slightly smaller than the outer diameter of the substrate. In this way, the side surface of the base can be smoothed. Also in this way, the outer diameter of the substrate can be brought to the desired size. Multiple stretching steps using sequential smaller openings can be required.

In an embodiment, in a further method step, the first end of the basic body is tightly sealed by a medium,

wherein the sealing of the first end comprises removing the probe core in the end region, wherein the probe head is introduced into the vacated end region and is fixed to the probe sleeve, in particular by laser welding,

wherein the outer side of the probe head has in particular a circular shape, such as for example a hemispherical shape or a semi-elliptical shape.

In an embodiment, in a further method step, the probe core is at least partially exposed in sections on the side facing the second end of the base body,

wherein contact areas for mounting a pyroelectric element on a probe core are prepared on the probe core,

wherein the contact area has an internal angle with respect to the longitudinal axis of less than 30 degrees, and in particular less than 20 degrees, and preferably less than 10 degrees.

In this case, the thermoelectric element may be, for example, a PT100 thermoelectric element.

In an embodiment, in a further method step, after the installation of the thermoelectric element, for example by means of soldering, gluing or sintering, a connection sleeve is provided on the base body, which completely covers the previously at least partially exposed region, wherein the connection sleeve is connected to the probe sleeve medium in a tight manner, in particular by means of circumferential laser welding.

In an embodiment, the probe sleeve comprises a reduced outer diameter portion in the contact region for connection with the connection sleeve, wherein in a further method step the connection sleeve is inserted onto the reduced outer diameter portion.

In an embodiment, the probe sleeve is made of a first material comprising stainless steel, and wherein the probe core is made of a second material comprising silver or copper for example,

wherein the second material has a thermal conductivity of at least 100W/(mK), in particular at least 200W/(mK), preferably at least 300W/(mK),

wherein the connecting sleeve is made in particular of a first material.

In an embodiment, the diameter of the probe core after high energy rate forming is less than 5mm, in particular less than 4mm, preferably less than 3mm, and greater than 0.5mm, in particular greater than 1mm, preferably greater than 1.5mm, and

wherein the probe sleeve has an outer diameter in the region of the unreduced outer diameter which is at least 0.1mm larger, in particular at least 0.2mm larger, preferably at least 0.5mm larger, and at most 1.5mm larger, in particular at most 1.2mm larger, preferably at most 1mm larger than the diameter of the probe core.

A probe of the invention for a thermal flow meter for measuring the mass flow of a medium in a measuring tube, manufactured according to the method of any one of the preceding claims, the probe comprising:

a base body having a probe core and a probe sleeve, the probe sleeve at least partially surrounding the probe core and connected to the probe core by a material bond;

a probe head media tightly connected to and sealing the probe sleeve at the first end of the base;

a thermoelectric element fixed to the contact area of the probe core in an at least partially exposed area, for example due to soldering, bonding or sintering;

a connection sleeve which completely covers the previously at least partially exposed region, wherein the connection sleeve is connected to the probe sleeve in a medium-tight manner, in particular by means of circumferential laser welding.

In an embodiment, the probe core includes a protrusion from the base region in a previously at least partially exposed region,

wherein the contact area is arranged on the protrusion and has an internal angle with respect to the longitudinal axis of less than 30 degrees, in particular less than 20 degrees, preferably less than 10 degrees.

In an embodiment, the protrusion comprises a rear surface connected to the probe sleeve by a material bond, wherein the probe sleeve is adapted to mechanically stabilize the protrusion in the area of the rear face.

In an embodiment, the thermoelectric element is adapted to determine the temperature of the medium and/or to heat the medium.

The thermal flowmeter of the present invention comprises:

a measuring tube for conveying a medium;

at least one probe according to any of claims 9 to 12, wherein the probe is arranged in a measurement tube;

electronic measurement/operation circuitry for operating the at least one probe and providing a flow measurement.

Drawings

The invention will now be described on the basis of examples of embodiments presented in the accompanying drawings, in which:

fig. 1a) to 1d) are views of examples of different stages in the manufacture of the probe of the invention;

FIGS. 2a) to 2c) are views of different embodiments of a probe core with contact areas for attaching thermoelectric elements; and

fig. 3 is a schematic front view of an example of a thermal flow meter.

Detailed Description

Fig. 1a) shows a part of a probe sleeve 11 with a longitudinal axis 11.2, a probe core 12 being loosely arranged in the probe sleeve 11. In a first method step for producing the probe according to the invention, the probe sleeve is deformed radially in the direction of the probe core, completely around the longitudinal axis, so that a material-bonded connection with the probe core occurs. In this case, the deformation is effected by means of high-energy rate shaping, wherein the radial deformation speed reaches values greater than 100m/s, in particular greater than 200 m/s. The high energy forming can be, for example, explosion forming or magnetic forming. The explosive forming results from the explosive covering. An explosive material is placed on the outside of the probe sleeve and ignited. During the impact of the probe sleeve against the probe core, the high deformation speed causes the interface of the probe sleeve material and the probe core material to mix. In this way, a rod consisting of a probe core fixed in a probe sleeve is obtained.

Fig. 1b) shows a cross section through a substrate 14, the substrate 14 being applied for probe manufacturing. In this case, after the high-energy rate forming, the base body is manufactured by separating the stem portion from the remaining portion of the stem.

In a further method step, the base body can be subjected to a stretching, by means of which a reduction or adjustment of the outer diameter 14.1 of the base body and a smoothing of the side surface 14.2 of the base body is obtained. In this case, the base is drawn through an opening having a diameter slightly smaller than the outer diameter of the base. This step can be repeated a number of times, in each case with smaller openings. The base body has a first end 14.3 and a second end 14.4.

Fig. 1c) shows a further stage of the production of the probe according to the invention, in which, in a further method step, in the end region 14.31 of the first end a, the probe tip 15 is then introduced into the end region, in which a portion of the probe core is removed and subsequently fixed to the probe sleeve, in particular by laser welding. In this way, the first end of the basic body is tightly sealed by the medium. For example, the outer side 15.1 of the probe head has, as shown in this case, for example a circular shape, such as a hemispherical shape or a semi-elliptical shape, which is beneficial for the flow resistance of the probe.

In a further method step, the probe core is exposed at the second end of the base body and a contact region is formed for arranging the thermoelectric element 16 on the probe core. The contact region can extend parallel to the longitudinal axis of the probe sleeve, such as shown in this case. For example, FIG. 2 shows other views of the contact region. The thermoelectric elements 16 are fixed, for example, by means of soldering, gluing or sintering.

In this case, the pyroelectric element 16 comprises an electrical connection line 16.1 by means of which the pyroelectric element is connectable to the electronic measuring/operating circuit 3; see fig. 3.

The probe sleeve 11 can be provided with a reduced outer diameter in the contact region 11.1 for receiving a connecting sleeve 17, such as is shown in fig. 1d) in this case, so that a stop is formed for the connecting sleeve.

The order of the method steps described herein can be varied.

Fig. 1d) shows an end stage of the manufacture of a probe of the invention, in which, after the thermoelectric element 12 has been arranged on the probe core 12, a connection sleeve 17 is inserted over the exposed area of the substrate, so that the previously exposed area is now completely covered. After fixing the connection sleeve, the connection sleeve is then brought into a medium-tight connection with the probe sleeve, for example by means of circumferential laser welding.

The probe sleeve 11 shown in fig. 1a) to 1d) is made of a first material comprising stainless steel, while the probe core 12 is made of a second material, for example comprising silver or copper, wherein the second material has a thermal conductivity of at least 100W/(m K), in particular at least 200W/(m K), preferably at least 300W/(m K). The connecting sleeve 17 is made in particular of a first material.

Since stainless steel has a lower thermal conductivity than the second material, for example, a temperature change of the probe sleeve caused by a change in the temperature of the medium causes the temperature distribution in the sensor core to be uniform or almost constant, and thus causes the temperature distribution in the thermoelectric element to be uniform or almost constant.

Fig. 2a) to 2c) show by way of example a cross section through a basic body 14 of the invention with a probe core 12 and a probe sleeve 11. In the case of fig. 2a) and 2b), in each case a projection 12.3 with a contact area is formed by the probe core in the exposed area and a thermoelectric element 16 is mounted on the contact area. In the case of fig. 2c), the diameter of the base body is large enough to arrange the thermoelectric elements perpendicular to the longitudinal axis 11.2 of the probe sleeve. The example of embodiment shown in fig. 2a) and 2b) enables the manufacture of small diameter probes. In this way, the thermal mass of the probe can be optimized, and thus the response behavior can be optimized.

Fig. 3 shows a schematic front view of a thermal flow meter 1 by way of example, the thermal flow meter 1 having a measuring tube 2, two probes 10 according to the invention arranged in the interior of the measuring tube 2, and a housing 4 with an electronic operating circuit 3. The electronic operating circuitry is adapted to operate the probe 10 and provide a flow measurement.

For measuring the mass flow of the medium through the measuring tube 2, for example, the first probe is heated in the medium flowing through the measuring tube 40, so that the temperature difference with respect to the temperature of the medium remains constant. In this case, the second probe can be used to measure the temperature of the medium. Assuming that the media properties (such as density and composition) remain unchanged, the mass flow of the media can be ascertained via the heating current required to maintain the temperature. The thermal flow meter shown here is exemplary and purely for illustrative purposes. The person skilled in the art will be able to group together any number of probes according to the given requirements of the application and arrange these probes in the measuring tube in the desired manner. Methods of operating such probes are known in the art.

REFERENCE SIGNS LIST

1 thermal flowmeter

2 measuring tube

3 electronic measuring/operating circuit

4 casing

10 Probe

11 Probe sleeve

11.1 contact area

11.2 longitudinal axis

12 probe core

12.1 contact area

12.2 Probe core diameter

12.3 projection

13 rod/rod portion

14 base body

14.1 outer diameter of substrate

14.2 side surface

14.3 first end of base body

14.31 end region

14.4 second end of base body

15 Probe head

15.1 outside of the Probe head

16 thermoelectric element

16.1 Electrical connection wire

17 connecting sleeve