阅读说明：本技术 具有变形体的管式传感器 (Tubular sensor with deformation body ) 是由 马库斯·迪纳 卢卡斯·施彼乐 霍夫·布洛切 托马斯·罗滕巴赫 于 2020-03-12 设计创作，主要内容包括：本发明涉及一种测量系统(1),尤其是用于测量压力,所述测量系统具有测量管(2)、变形体(3)、用于测量伸长和/或扩宽(AW)的分析单元以及壳体(7)。(The invention relates to a measuring system (1), in particular for measuring pressure, comprising a measuring tube (2), a deformation body (3), an evaluation unit for measuring elongation and/or expansion (AW), and a housing (7).)

1. Measuring system (1) for a physical quantity, in particular a pressure measuring system (1), comprising:

-a housing (7);

-a measurement pipe (2) comprising:

-at least one tubular deformation body (3) whose cross section is deformed at least partially in a defined manner deviating from an annular cross section and which is elastically widened under the effect of pressure;

-two input sections (4) each applied on an end section (3a) of the deformation body (3) and each having a circular cross section on an outer edge section (4a) thereof;

-two sealing sections (5) for sealingly interfacing the measuring system (1) to a process, wherein the sealing sections (5) are molded on the outer edge section (4a) of the input section (4); and

-two moulded support sections (6) supporting the housing (7);

-a measuring and sensing device (8) which measures elongation and/or widening (AW) at least at two points on a section of the deformation body (3); and

an evaluation unit which evaluates the measured values of the elongation and/or the expansion (AW) electronically and outputs them as measurement signals,

wherein the housing (7) encloses the measuring tube (2) in its direction of extension (32) at least partially on the outside and stabilizes the measuring tube.

2. The measuring system (1) according to claim 1, wherein the housing (7) sealingly encloses the measuring tube (2).

3. Measuring system (1) according to claim 1 or 2, wherein the measuring tube (2) is internally lined with a silicone or replaceable silicone cover (50).

4. The measuring system (1) according to any one of the preceding claims, wherein the deformation body (3) of the measuring tube (2) has a wall thickness of 0.1mm to 0.5mm or 0.2mm to 3.0 mm.

5. The measurement system (1) according to any of the preceding claims, wherein the connections of the measurement tube (2) have an inner diameter of 3mm to 40mm or 20mm to 60 mm.

6. The measuring system (1) according to any one of the preceding claims, wherein the input section (4) has a wall thickness corresponding to a wall thickness of the deformation body (3).

7. The measuring system (1) according to any one of the preceding claims, wherein the input section (4) is implemented solidly and/or has an inner contour transition from annular to elliptical.

8. The measuring system (1) according to any one of the preceding claims, wherein the input section (4) is implemented in one piece with the support section (6) and the sealing section (5).

9. The measuring system (1) according to any one of the preceding claims, wherein the housing (7) is materially bonded and sealingly abutted to the support section (6).

10. The measuring system (1) according to any one of the preceding claims, wherein the housing (7) is provided with a vacuum or with a negative pressure with respect to the external atmosphere.

11. The measuring system (1) according to claim 10, wherein the housing (7) has a service port for mounting or controlling a vacuum or negative pressure.

12. Measuring system (1) according to claim 10 or 11, wherein the housing (7) has internally a pressure or vacuum sensor (16) for monitoring the vacuum or the negative pressure.

13. The measuring system (1) according to any one of the preceding claims, wherein the measuring tube (2) has an applied temperature sensor (17) which is positioned inside the housing (7).

14. The measuring system (1) according to any one of the preceding claims, wherein the housing (7) is provided with a glass sleeve (34) open to the outside atmosphere or to a second part of the housing (7), through which glass sleeve contacts for signal transmission are guided.

15. The measuring system (1) as claimed in one of the preceding claims, comprising an interface which is accessible via a plug connection and/or a display for outputting measured values.

16. The measurement system (1) according to any one of the preceding claims, wherein the analysis unit is adapted to analyze the measurement signal according to:

-data detected by means of an optical measuring system;

-data detected by means of a laser-optical device (8B), wherein the laser-optical device (8B)

-performing a reference measurement from the laser beam directed via the mirror (10, 11, 12),

and/or

-performing direct measurements from laser beams directed via a beam splitter (35) or via a common optical path through at least three mirrors (10, 11, 12),

-data detected by means of at least one capacitive sensor (8A);

-data detected by means of at least one strain-sensitive optical fiber sensor (8D) wound around the measuring tube (2);

-data detected by means of two or four strain gauges (8C);

-data detected by means of a wheatstone bridge formed by strain gauges (8C), and/or

-data detected by means of at least one surface acoustic wave sensor (8E),

the elongation and/or widening (AW) of the deformation (3) of the measuring tube (2) is evaluated, in particular with the aid of a fast Fourier transform.

17. The measurement system (1) according to any one of the preceding claims, comprising a sensor for knowing the flow rate and at least one giving unit for giving signals comprising the flow rate, pressure and temperature.

18. The measurement system (1) according to any one of the preceding claims, wherein the housing (7) has a length of 100mm to 300mm or 50mm to 800 mm.

19. Measuring system (1) according to one of the preceding claims, wherein the measuring tube (2) and the input section (4) are joined by means of a weld seam (99), wherein the weld seam (99) is manufactured in a weld, a through-weld, an endless track automatic weld and/or a laser weld.

20. The measuring system (1) according to claim 19, wherein the roughness of the inner surfaces of the input section (4) and the measuring tube (2) in the region of the weld seam (99) has an Ra value of less than or equal to 3 μ ι η, in particular less than or equal to 2 μ ι η, in particular less than or equal to 0.8 μ ι η.

21. Measuring system (1) according to claim 19 or 20, wherein the transition between the measuring tube (2) and the inner surface of the input section (4) runs at least substantially flat and/or without edges, without steps and/or without an ejector of a height of maximum 2mm in the region of the weld seam (99).

22. The measuring system (1) according to any one of the preceding claims, wherein the deformation body (3) and/or the input section (4) has a larger diameter and/or cross section than the sealing section (5).

Technical Field

The invention relates to a measuring system for a physical variable, in particular a pressure.

Background

Generic measuring systems for physical variables, in particular pressure, are known from the prior art, for example from US 4,207,551 a, US 3,046,788A and EP 0074574 a 1. The measuring system comprises a tubular deformation body which has an annular cross section at its end for the sealed connection to a process. The tubular deformation body furthermore has a measuring section or deformation body which is shaped off-annularly, for example oval, elliptical, flat oval, or also non-axisymmetrically, for example "D-shaped". The elastic geometry of the tubular deformation body is changed by changing the process pressure relative to the external pressure of the tube. When the internal pressure is greater than the external pressure, the deformed tube cross section strives to be annular and there results different forms of elongation and compression, which also act on the tube outer surface. When the internal pressure is lower than the external pressure, the tube cross section increasingly strives for a geometry deviating from the circular shape, that is to say the degree of deformation is increased. In this case, it is possible to use "co-pressing" of the tube cross section. This likewise results in different forms of elongation and compression which also act on the tube outer surface. In the following, widening of the pipe section is also understood to mean a kind of joint compression, which depends on whether a high or negative pressure exists in the measuring pipe relative to the external pipe pressure. This effect should be used as a measuring effect for the parameter "pressure" when using a sufficiently strong spring-elastic material.

Disclosure of Invention

The object of the present invention is to provide a measuring system for a physical variable that is improved over the prior art.

The measuring system according to the invention for a physical parameter, in particular pressure, comprises a housing and a measuring tube. The measuring tube comprises at least one tubular deformation body, the cross section of which is deformed at least partially in a defined manner differing from a circular cross section and which widens elastically under pressure. Furthermore, the measurement pipe comprises: two input sections which are each arranged on an end section of the deformation body and each have a circular cross section on their outer edge sections; and two sealing sections for sealingly interfacing the measurement system to a process, wherein the sealing sections are molded on the outer edge section of the input section. Furthermore, the measurement pipe comprises: two molded support sections supporting the housing; a measuring sensor device which measures the elongation and/or the widening at least at two points of a section of the deformation body; and an evaluation unit which evaluates the measured values of the elongation and/or widening electronically and outputs them as measurement signals. The housing encloses the measuring tube at least partially on the outside in its direction of extension and stabilizes the measuring tube against mechanical and further influences.

The measuring system forms a cost-effective solution for tubular measuring systems for the main measurement variable "pressure". In addition, other measured variables, such as temperature and flow rate, and measured variables derived therefrom, such as density, may be integrated. The measuring system has a structure which can be flowed through with a free cross section. Furthermore, the structure is free of dead zones, i.e. there is no possibility of the medium of the flow-through measuring system getting caught in dead-end or undercut or forming deposits there. The measuring system can be designed to adequately compensate or prevent external pressure fluctuations, temperature effects, environmental influences and mechanical reactions. A particularly high measurement accuracy can be achieved in this case.

In one possible embodiment of the measuring system, the housing encloses the measuring tube in a sealed manner. The housing can thus be loaded with underpressure or vacuum.

In a further possible embodiment of the measuring system, the measuring tube is internally lined with a silicone or replaceable silicone cover, so that the flow resistance to the medium flowing through is minimal and/or the requirement for increased hygiene is met by the replaceability due to the possibility of single use.

In a further possible embodiment of the measuring system, the deformation body of the measuring tube has a wall thickness of 0.1mm to 0.5mm or 0.2mm to 3.0 mm.

In a further possible embodiment of the measuring system, the connecting piece of the measuring tube has an inner diameter of 3mm to 40mm or 20mm to 60 mm.

In a further possible embodiment of the measuring system, the input section has a wall thickness corresponding to the wall thickness of the deformation body. As a result, no step is produced between the inlet section and the deformation body, which in turn results in a small flow resistance and a free cross section for the medium flowing through.

In a further possible embodiment of the measuring system, the input section is embodied in a solid manner and/or has an annular to oval inner contour transition. In particular, the input section, which is embodied solid in relation to the deformable body, is characterized by a particularly low deformability. The robust design of the input section prevents deformation of the input section and measurement errors resulting therefrom. For example, the solidly embodied input section is produced by machining, for example drilling and/or milling, a body made of a solid material, in particular a metal or a metal alloy. Alternatively, the manufacturing may be performed by deformation of a solid material.

In a further possible embodiment of the measuring system, the input section is formed in one piece with the support section and the sealing section. This also results in a small flow resistance and a free cross section for the medium flowing through.

In a further possible embodiment of the measuring system, the housing material is bonded and sealingly bonded to the support section. The housing can thus be loaded with underpressure or vacuum.

In a further possible embodiment of the measuring system, the housing is provided with a vacuum or with a negative pressure relative to the external atmosphere.

In a further possible embodiment of the measuring system, the housing has a service port for installing or controlling the vacuum or underpressure in order to facilitate the installation of the vacuum or underpressure in an advantageous manner.

In a further possible embodiment of the measuring system, the housing has a pressure sensor or a vacuum sensor for monitoring the vacuum or the negative pressure inside it, in order to facilitate the monitoring of the vacuum or the negative pressure in an advantageous manner.

In a further possible embodiment of the measuring system, the measuring tube has an applied temperature sensor, which is positioned inside the housing or on the measuring tube. The temperature of the medium can thus additionally be detected and, if necessary, processed.

In a further possible embodiment of the measuring system, the housing is provided with a glass sleeve which is open to the outside atmosphere or to the second part of the housing, through which glass sleeve contacts for signal transmission are guided. This enables reliable signaling for outputting, storing and/or further processing of the detected data.

In a further possible embodiment of the measuring system, the measuring system comprises an interface which can be contacted via the plug connection and/or a display for outputting measured values, in order to be able to display the detected data in an advantageous manner.

In a further possible embodiment of the measuring system, the evaluation unit is designed to evaluate the measurement signal based on:

-data detected by means of an optical measuring system;

data detected by means of laser optics, wherein the laser optics

Performing a reference measurement from the laser beam directed via the mirror,

and/or

-performing direct measurements from laser beams directed via a beam splitter or via a common optical path through at least three mirrors,

-data detected by means of at least one capacitive sensor;

-data detected by means of at least one strain-sensitive optical fibre sensor wound around the measuring tube;

-data detected by means of two or four strain gauges;

data detected by means of a Wheatstone bridge formed by strain gauges, and/or

-data detected by means of at least one surface acoustic wave sensor,

in particular, the elongation and/or widening of the deformation of the measuring tube is evaluated with the aid of a fast fourier transformation. This evaluation is very reliable.

In a further possible embodiment of the measuring system, the measuring system comprises a sensor for ascertaining the flow rate and at least one determining unit for determining a signal comprising the flow rate, the pressure and the temperature.

In a further possible embodiment of the measuring system, the housing has a length of 100mm to 300mm or 50mm to 800 mm.

In a further possible embodiment of the measuring system, the measuring tube and the input section are joined by means of a weld seam, wherein the weld seam is produced by welding, through welding, automatic welding of the annular rail and/or laser welding. The weld seam can be produced relatively simply and enables a fluid-tight and particularly durable joint of the measuring tube and the input section and a low roughness of the inner surfaces of the input section and the measuring tube in the region of the weld seam. The measuring system is therefore particularly suitable for use in the pharmaceutical sector as well as in the food industry.

In a further possible embodiment of the measuring system, the roughness of the inner surface of the measuring tube and of the input section in the region of the weld seam has an Ra value of less than or equal to 3 μm, in particular less than or equal to 2 μm, in particular less than or equal to 0.8 μm. This results in a small flow resistance and a free cross section for the medium flowing through. In addition, this makes it possible to meet the demands for an increased purity of the process medium.

In a further possible embodiment of the measuring system, the transition between the inner surface of the measuring tube and the inner surface of the input section extends at least substantially flat and/or without edges, steps and/or projections of maximum height 2mm in the region of the weld seam. This also results in a small flow resistance and a free cross section for the medium flowing through.

In a further possible embodiment of the measuring system, the measuring section or the deformation body and/or the input section has a larger diameter and/or cross section than the sealing section.

Drawings

Embodiments of the present invention are explained in detail below with reference to the accompanying drawings.

Parts that correspond to each other are provided with the same reference numerals throughout the figures.

Here:

fig. 1 schematically shows a measurement system for a physical quantity;

fig. 2A to 2K schematically show different cross sections of tubular variants of the measuring tube.

Fig. 3 schematically shows a perspective view of a measuring tube;

FIGS. 4A and 4B schematically illustrate different views of a measurement tube; and

fig. 5 schematically shows a cross-sectional view of a measuring tube, which comprises an optical analysis device.

Parts that correspond to each other are provided with the same reference numerals throughout the figures.

Detailed Description

Fig. 1 schematically shows a possible exemplary embodiment of a measuring system 1 for a physical variable.

The measuring system 1 comprises a measuring tube 2.

The measuring tube 2 in turn comprises a deformation body 3 which is pressed or deformed flat at least partially in a defined manner deviating from the annular cross section and can be widened elastically under pressure.

Furthermore, the measuring tube 2 comprises two input sections 4, which are each arranged on an end section 3a of the deformation body 3 and have an annular cross section on their outer edge sections 4a facing outwards. The input section 4 has, on its ends, outwardly, molded sealing sections 5 which are provided for the sealed docking of the measuring system 1 to a process.

Support sections 6 are molded onto the input section 4 and/or the sealing section 5, which support the outer housing 7 of the measuring system 1.

A measuring technique or measuring sensor device 8 for measuring the value of the elongation and/or the expansion AW at a section of the deformation body 3 is realized with a capacitive sensor 8A and/or a laser optical device 8B and/or a strain-sensitive sensor or strain gauge 8C.

The laser optics 8B divert at least one laser beam 8F onto the mirrors 10, 11, which are oriented for reference measurement. On these mirrors 10, 11, the corresponding laser beam 8F is deflected onto a mirror 12 arranged on the deformation body 3, which, in connection with the above-described widening AW, has different positions relative to the mirrors 10, 11 and the laser optics 8B. By means of a detector, not shown in detail, which is arranged, for example, in the region of at least one of the mirrors 10, 11 or in the region of the laser optics 8B, the respective contact position of the laser beam reflected by the mirror 12 can be determined as a function of the position of the mirror 12 and the value of the spread AW can be derived therefrom. Alternatively, the mirror 12 itself is designed as a detector, for example as a CCD chip.

Further, the optical fiber sensor 8D can detect elongation. Alternatively, the temperature can be measured in addition to the elongation by means of the so-called fiber Bragg technique (Faser-Bragg-Technik). For this purpose, for example, the optical fiber of the optical fiber sensor 8D is wound around the relevant pipe section of the measuring tube 2 and optionally fixed with an elastic potting.

Alternatively, the elongation and/or widening AW is measured by means of a strain gauge 8C which is to be applied to the deformation body 3 and is also referred to as a strain-measuring resistor. For this purpose, in particular, the strain gauges 8C are considered which are glued to the deformation body 3 or else suitable strain measuring elements which are applied to the deformation body 3 by another suitable method.

Furthermore, a so-called surface acoustic wave sensor 8E, in short a SAW sensor, can sense the elongation and the flow rate inside the measuring tube 2.

For this purpose, the housing 7 is optionally evacuated or provided with a vacuum via a connection 15, which is welded in a sealed manner or is provided as a docking station for servicing purposes. In order to maintain the vacuum as long as possible inside the housing 7, a getter material 13 is applied inside the housing 7 in a possible embodiment for receiving moisture.

The vacuum inside the housing 7 is monitored by means of a vacuum sensor 16 in a possible embodiment.

The applied temperature sensor 17 detects the temperature on the measuring tube 2 for compensating temperature errors.

It is calculated by an evaluation unit, in particular evaluation electronics, which measures the values on a circuit board 20 in the housing 7 or a circuit board 21 in the second housing part 22. There, the detected measured values are evaluated, converted and output as measurement signals via the display and/or radio device 30 or the plug interface 31. For this purpose, a relative pressure sensor for detecting an external pressure relative to the negative pressure in the housing 7 or an ambient air pressure sensor for detecting an external pressure can also be used for providing a relative pressure signal.

The housing 7 encloses the measuring tube 2 in its direction of extent 32 on the outside at least partially, alternatively, of course completely, by welding on the support section 6. The housing encloses the measuring tube 2 and stabilizes the measuring tube against mechanical and further influences.

The housing 7 and the housing part 22 are separated by a sealed glass sleeve 34, which guides the measurement signals to the outside and/or the current and voltage supply to the inside. Alternatively to the glass sleeve 34, signals and energy can also be transmitted via radio, for example via RFID or by induction. The housing part 22 can also be completely cast, and the circuit boards 20, 21 are provided with recesses for this purpose, so that the casting material is distributed well and encloses all the structural components well. Alternatively, the circuit boards 20, 21 and the conductor tracks are also partially flexibly designed as flexible circuit boards (FPC).

In a further possible embodiment of the measuring system 1, the measuring section or deformation body 3 has one or more temperature sensors 17 and at least one heating element, so that the flow direction of the medium and/or the flow speed of the medium can be determined by evaluating the temperature measurements.

Fig. 2A to 2F and 2H to 2K show the cross section of the tubular deformation body 3 and thus the different measuring cross sections of the measuring tube 2, i.e. the flat oval 40 or the oval 41, and the arrangement of the sensors, in particular of the capacitive sensor 8A, the surface acoustic wave sensor 8E and/or the strain gauge 8C.

In this case, in particular, the measuring tube 2 is oriented such that it can be idle when the installation is emptied (see fig. 2C or fig. 2J for this purpose). In this case, a slightly inclined position may be advantageous.

The exemplary embodiments shown in fig. 2H to 2K are produced, for example, by widening by means of internal pressure in a so-called hydroforming process. In this case, it is particularly advantageous if the measuring section or deformation body 3 always has a larger diameter or cross section than the sealing section 5.

Fig. 3 shows a perspective view of a possible embodiment of a measuring tube 2 with a deformable body 3 and two inlet sections 4, which are connected to the deformable body 3 in a ring shape. The sealing section 5 may optionally be welded.

Fig. 4A shows another possible embodiment of the measuring tube 2.

In this case, it is possible for the measuring tube 2 to have an inner cover layer of the elastomer lining made of silicone, which can be removed, or an embodiment with a replaceable silicone cover 50 is also possible.

In the illustrated embodiment, a robust design of two input sections 4 is also shown, which on the one hand connect the deformation body 3 via welding and on the other hand mold the sealing section 5 and the support section 6 for the housing 7, which is not illustrated. These sections have in particular transitions from a circular cross section to an elliptical measuring section or deformation body 3.

Fig. 4B shows a further possible embodiment of a welding process, a measuring tube 2 with a deformation body 3 and an inlet section 4. In this case, the welding can be effected by welding, as shown, or by means of a through-welding process with the tubular deformation body 3 joined to a flange. In this case, it is possible to provide: without post-processing, a welding quality is achieved in which the weld seam 99 has an overhang on its inner face, which reaches a small overhang height AWH of only a few millimeters or less.

Fig. 5 shows a further embodiment with interferometric measurement of the measuring tube 2.

In which case possible errors are eliminated by the lateral offset. In this case, the reference length LR is detected by the beam splitter 35, on the one hand, and the widening AW due to the process pressure P of the deformable body 3 is detected by the operating time shift of the light, on the other hand.

The beam splitter 35 can optionally be switched on in a periodic manner in this case, and the laser optics 8B can optionally also be embodied as an LED laser, a laser diode or a photodiode.

The laser optics 8B can also be both an emitter and a detector, so that a detector, which is also configured, for example, in the form of a CCD sensor or as a photodiode, can be docked via a mirror or beam splitter 35 and thus also integrated into the structure of the laser optics 8B.

For example, the laser beam is directed by means of the laser optics 8B onto the mirror 36 and from there onto the beam splitter 35. From there, the laser beam is transmitted to the mirror 10 and from there, back to the mirror 11 through the beam splitter 35. On the mirror 11, a detector is arranged in a possible embodiment, wherein the signal received with the detector according to the previously described course of the laser beam can be used as a reference measurement with a reference length LR. Furthermore, the laser beam is reflected back from the mirror 11 to the beam splitter 35, which diverts the laser beam to the mirror 36 and the laser optics 8B. Thereby, a reference measurement with the reference length LR can also be performed by means of the laser optics 8B.

The laser beam directed from the laser optics 8B onto the mirror 36 and from said mirror onto the beam splitter 35 is additionally also deflected onto a mirror 12 arranged on the deformation body 3, which has different positions as a function of the expansion AW. From mirror 12, the laser beam is reflected back to beam splitter 35, which diverts the laser beam to mirror 11 and to mirror 36. By means of a detector, not shown in detail, which is arranged, for example, in the region of the mirror 11 or 12, the operating time of the laser beam can thus be determined and the widening AW determined therefrom. It is also possible to determine the operating time of the laser beam by means of the laser optics 8B and to determine the widening AW therefrom.

The invention is not limited to the foregoing detailed embodiments. The invention may be modified within the scope of the following claims. Likewise, the various aspects recited by the dependent claims may be combined with each other.

List of reference numerals

1 measuring system

2 measuring tube

3 variants

3a end section

4 input section

4a edge section

5 sealing section

6 support section

7 casing

8 measuring and sensing device

8A capacitance sensor

8B laser optical device

8C strain gauge

8D optical fiber sensor

8E surface acoustic wave sensor

8F laser beam

10 reflecting mirror

11 mirror

12 reflecting mirror

13 getter material

15 coupling part

16 vacuum sensor

17 temperature sensor

20 circuit board

21 circuit board

22 shell element

30 display and/or radio device

31 plug interface

32 direction of extension

34 glass sleeve

35-beam splitter

36 reflecting mirror

40 flat oval

41 oval shape

50 silica gel covering piece

60 ambient pressure sensor

99 welding seam

AW broadening

AWH ejector height

LR reference length

P course pressure