CN103872525B - Plug connection unit for connecting the cable circuit to the sensor module - Google Patents

Abstract

The present invention relates to a kind of plug connection unit for cable circuit to be connected with sensor assembly, is particularly used for cable circuit shell（23）In cable circuit and sensor assembly housing（17）In the plug connection unit that is connected of sensor assembly, it includes being used in cable circuit（3,14）And sensor assembly（1,15）Between carry out the wave point of energy and/or data transfer（2）, the wherein wave point（2）First segmentation be arranged on cable circuit（3,14）In and the wave point（2）Second segmentation be arranged on sensor assembly（1,15）In, the wherein wave point（2）By magnetic screen（10）Surround and the magnetic screen（10）It is arranged on cable circuit shell（23）And/or sensor assembly housing（17）In.

Description

Plug connection unit for connecting the cable circuit to the sensor module

technical field

The invention relates to a plug connection unit for connecting a cable circuit to a sensor module, comprising a wireless interface for energy and/or data transmission between the cable circuit and the sensor module. A first section of the interface is located in the cable circuit and a second section of the interface is located in the sensor module.

Background technique

In process automation technology, a large number of different sensors are used for recording process variables. Examples of such sensors include pH sensors, gas sensors, flow sensors, mass flow sensors, and the like. In modern industrial plants, such sensors are often operated under different environmental conditions. For example, sensors are exposed to corrosive chemicals, heat, vibration, etc.

In such cases, the sensor is arranged at the measuring point consisting of the sensor element and the sensor cable, which connects the sensor to the measuring transducer. In some applications, the sensor is housed in a retractable assembly of stainless steel or a durable synthetic material such as plastic to enable insertion and withdrawal of the sensor into the process.

A cable circuit with digital signal conditioning is known from DE 10 2007 048 812 A1. The cable circuit is used to connect the sensor module to the measuring transducer. The cable circuit includes a contactless interface for signal transmission between a circuit formed in the cable and a sensor module, wherein the sensor module is galvanically isolated from the cable circuit and The signal transmission between them is carried out by optical, inductive or capacitive means. Furthermore, the sensor module is also supplied with energy via the wireless interface. In this case, the wireless interface is located partly in the cable circuit and partly in the sensor module, wherein the two parts of the wireless interface are arranged opposite each other by introducing the cable circuit into the sensor module. The housing of the sensor module and the cable has a relatively small diameter, for example 12mm. The sensor can be implemented in a stretchable assembly (see below) whereby the maximum outer dimension is predetermined. As already mentioned, part of the signal conditioning takes place in the sensor and/or in the circuit in the cable. Components required for adjustment, such as microprocessors, other active components, and passive components must be adapted to predetermined spatial conditions. Due to the relatively small housing diameter, the thickness of the cable housing is very small and is, for example, 1-2 mm, and accordingly the thickness of the sensor housing is very small and is, for example, 1-2 mm.

In particular, when the wireless interface is realized as a stray field transformer whose primary winding is arranged in the cable circuit and whose secondary winding is arranged in the sensor module, stray magnetic fields for energy and data transmission occur, which are also in the cable and outside the sensor housing. For example, by installing such a plug connection unit in a tubular stainless steel component for inserting the sensor module into the medium to be examined, the stainless steel component has an influence on stray fields. On the other hand, the stainless steel component acts like a second secondary winding which is electrically shorted. On the other hand, eddy current losses of stainless steel components occur. As a result, the effective inductance and the effective mass of the primary winding change in such a way that the operating point of the primary winding changes and the efficiency of the cable including the sensor decreases. As a result, both energy and data transmission are negatively affected.

Contents of the invention

It is therefore an object of the present invention to provide a plug connection unit which, given the space requirements, in particular with the smallest possible space requirements, ensures a reliable energy and/or data transmission between the cable circuit and the sensor module.

According to the invention, this object is achieved by the feature comprising a wireless interface surrounded by a magnetic shield, which is arranged in the cable circuit housing and/or the sensor module housing. Thus, secure transmission is enabled with given space requirements. This magnetic shielding has the advantage that the magnetic circuit of the plug connection unit is altered such that it exists only within the cable circuit and the sensor module. In this case, the stray fields outside the cable circuit and the sensor module are small, so that the influence on the energy and data transmission is eliminated.

Advantageously, the wireless interface is realized as an inductive or capacitive interface. Especially in the case of such physical principles, it is necessary to use shielding in order to suppress the influence of external stray fields on the function of the interface.

In a variant, the magnetic shield consists of a film or sheet arranged inside the cable circuit housing and/or the sensor module housing. In this way, the magnetic shield can be structurally simple and its production cost-effective.

Alternatively, the magnetic shield is placed in a plastic cable housing and/or a plastic sensor module housing. Therefore, no adjustment of the two layers consisting of housing and shielding with respect to one another is required when, for example, ferromagnetic material is injection molded around plastic.

In one form of embodiment, the cable circuit housing and/or the sensor module housing are completely or partially made of plastic bonded ferrite. Thus, the cable circuit housing and the sensor module housing are materials that simultaneously serve as magnetic shielding.

In a further variant, the magnetic shielding is realized in at least one region of the cable circuit housing surrounding the first section of the wireless interface and/or at least in a second section of the sensor module housing surrounding the wireless interface. implemented in the region. In this form, a minimum degree of shielding is provided with respect to external stray fields. The more the magnetic field generated by the inductive or capacitive interface extends inside the cable circuit, the more complete the magnetic shielding of the cable circuit housing is, and accordingly the more the magnetic field generated by the inductive or capacitive interface extends inside the sensor module , the more complete the magnetic shielding of the sensor module housing.

In one embodiment, the magnetic shield is composed of a material with a relative magnetic permeability >1. Selecting a material with such a magnetic permeability ensures shielding against stray fields outside the plug connection unit.

The magnetic shield can be made from a variety of materials. Especially in the case of the magnetic shield consisting of a ferromagnetic material, a particularly high relative permeability is achieved.

Advantageously, the magnetic shield of electrically conductive material is realized in the shape of a tube and includes a longitudinal slot. This longitudinal gap suppresses the occurrence of secondary short-circuit windings.

In a preferred embodiment, the cable circuit housing and the sensor module housing are realized tubular and have a diameter of approximately 12 mm. In particular, the housings should be realized in such a way that they can be used in telescoping assemblies.

Description of drawings

The present invention allows various forms of embodiment. The selection thereof will now be explained in more detail on the basis of the accompanying drawings, which are shown below, in which equivalent features are provided with equivalent reference numerals:

Figure 1 shows the data exchange between the measuring transmitter, the cable circuit and the sensor module;

Figure 2 is an example of an embodiment of a cable circuit and a sensor module; and

FIG. 3 is an example of an embodiment of the shielding of the inductive interface according to FIG. 2 .

detailed description

FIG. 1 shows a plug connection unit for recording and forwarding measured values. The plug connection unit comprises a sensor module 1 which communicates with a cable circuit 3 via a wireless interface 2 . In such a case, the wireless interface 2 is realized as an inductive interface. In order to be able to forward the data recorded in the sensor module 1 to a superordinate system, the cable circuit 3 is connected to the measuring transducer 5 via a cable 4 . Part of the tasks of the measuring transducer 5 can be taken over by the cable circuit 3 . Thus, for example, it is also possible to directly connect the sensor module 1 to the bus.

The sensor module 1 comprises a sensor 6, which is applied in the field of process automation, thus eg a flow sensor, a mass flow sensor, a pH sensor, a gas sensor or the like. Within the sensor module 1 , the sensor 6 is connected to an electronic circuit 7 , which in turn is coupled to the wireless inductive interface 2 . The inductance interface 2 includes a primary winding 8 arranged on one side of the cable circuit and a secondary winding 9 arranged on one side of the sensor module. The secondary winding 9 is connected to the electronic circuit 7 . When the sensor module 1 is plugged onto the cable circuit 3 by means of a pluggable connector coupling, the primary winding 8 and the secondary winding 9 are brought into a defined spatial orientation relative to each other, enabling a connection between the cable circuit 3 and the sensor module 1 High-frequency signals are transmitted in both directions. In this way, data exchange between the cable circuit 3 and the sensor module 1 is enabled.

Furthermore, energy supply to the sensor module 1 can also take place via the inductive interface 2 . In this respect, the high-frequency signal of the cable circuit 3 generated in the circuit 12 is received by the secondary winding 9 of the sensor module 1 in order to serve as an operating voltage for the electronic circuit 7 and the sensor 6 . In addition to the wireless interface 2 , the cable circuit 3 includes an interface 11 to the cable 4 via which data exchange with the measuring transducer 5 takes place.

FIG. 2 shows an example of an embodiment of a cable circuit 14 arranged at the end of a cable 13 . Furthermore, a sensor module 15 is shown, which can be connected via a pluggable connector coupling to the cable circuit 14 to enable data and energy transmission via the inductive interface 2 . The sensor module 15 comprises a sensor 16 for recording measured values. The sensor module housing 17 includes threads 18 to enable the sensor module 15 to be mounted in a stainless steel telescoping assembly (not shown). At the end of the sensor module 15 remote from the sensor 16 there is provided a cylindrical end portion 19 in which the secondary winding 20 of the inductive interface 2 is arranged. A cutout of the bayonet connector 21 is located in the side of the cylindrical end portion 19 .

The cylindrical end portion 19 of the sensor module 15 includes a front cavity 22 for receiving a cylindrical protrusion 24 formed on a cable circuit housing 23 . The ferrite core of the primary winding equipped with the inductive interface 2 is located within the cylindrical protrusion 24 . During insertion of the cable circuit 14 into the sensor module 15 , the primary winding arranged in the protrusion 24 enters a defined spatial position relative to the secondary winding 20 to enable data and power transfer between the cable circuit 14 and the sensor module 15 . transmission. The radially inwardly extending lugs on the sleeve-shaped side 25 of the cable circuit 14 then engage the cutouts of the bayonet connector 21 and secure the plug connection. The cable circuit housing 23 and the sensor module housing 17 are realized in a tubular shape and have a diameter of 12 mm. The wall thickness of the housing 23 is about 1 mm, so that the cable circuit 14 must be placed inside the remaining 10 mm, correspondingly, the wall thickness of the housing 17 is about 1 mm, and the sensor module 15 must be placed inside within the remaining 10 mm.

FIG. 3 shows a magnetic shield 10 for enclosing the primary winding 8 and the secondary winding 9 . The magnetic shield 10 is made of a ferromagnetic material and, in the first embodiment, is preferably formed into a tubular shape with a film or sheet. The cable circuit housing 23 as well as the sensor module housing 17 are formed of plastic and, as explained with reference to FIG. 2 , likewise realized in a tubular shape. In the installed state, the magnetic shield 10 surrounds at least the inductive connection 2 of the plug connection unit and thus the primary winding 8 and the secondary winding 9 . In such cases, there are different options for arranging the magnetic shield 10 on the plug connection unit. The magnetic shield 10 may be placed internally on the cable circuit housing 23 as well as on the sensor module housing 17 . A particularly perfect solution is that in which the sensor module housing 17 and the cable circuit housing 23 are plastic, into which the magnetic shield 10 is introduced. In a further alternative, the shield 10 may be affixed to the primary winding 8 and, correspondingly, the shield 10 may be affixed to the secondary winding 9 . In such a case, the magnetic shield 10 can be realized as a closed body or also as a gapped body. A slotted body is advantageous when the material of the magnetic shield 10 is conductive, so as to inhibit the formation of secondary short circuit windings.

The explained plug connection unit has the advantage that energy and data transmission between the sensor module 1 , 15 and the cable circuit 3 , 14 takes place independently of external magnetic fields. In such a case also external environmental conditions such as magnetically active from the stainless steel telescoping assembly housing the sensor module are eliminated. Furthermore, due to the presence of the magnetic shield 10 , adjacent sensor modules realized in the same way with the inductive interface 2 do not interfere with each other.

Claims (9)

1. one kind is used for the sensor die in the cable circuit in cable circuit shell (23) and sensor assembly housing (17) The plug connection unit that block is connected, it includes being used to carry out energy between cable circuit (3,14) and sensor assembly (1,15) Amount and/or data transfer wave point (2), wherein the wave point (2) first segmentation positioned at the cable circuit (3, 14) in and the wave point (2) second segmentation be located at the sensor assembly (1,15) in, wherein the wave point (2) surrounded by magnetic screen (10), it is characterised in that the magnetic screen (10) be arranged on the cable circuit shell (23) and/ Or in the sensor assembly housing (17),

Wherein described magnetic screen (10) is set to first segmentation of the wave point (2) and/or second segmentation, And it is implemented as closing main body,

Wherein described cable circuit shell (23) and the sensor assembly housing (17) are embodied as tubulose and with about 12mm diameter, and

The wall thickness of wherein described cable circuit shell (23) and the wall thickness of the sensor assembly housing (17) are about 1mm。

2. plug connection unit according to claim 1, it is characterised in that the wave point (2) is implemented as inductance or electric capacity Interface.

3. plug connection unit according to claim 1, it is characterised in that the magnetic screen (10) is by being arranged on the cable electricity The film or thin slice of road housing (23) and/or sensor assembly housing (17) inside are formed.

4. plug connection unit according to claim 1, it is characterised in that the magnetic screen (10) is placed in the cable electricity of plastics In the sensor assembly housing (17) of road housing (23) and/or plastics.

5. plug connection unit according to claim 4, it is characterised in that the cable circuit shell (23) and/or the sensing Device module housing (17) is completely or partially as made by plastics bonded ferrite.

6. plug connection unit according to claim 4, it is characterised in that the magnetic screen (10) is surrounding the wave point (2) realized at least one region of the first segmentation, described cable circuit shell (23), and/or at least described in encirclement Realized in region that the second of wave point (2) is segmented, sensor assembly housing (17).

7. the plug connection unit of one in claim 1-6, it is characterised in that the magnetic screen (10) by with>1 The material of relative permeability formed.

8. plug connection unit according to claim 7, it is characterised in that the magnetic screen (10) is ferromagnet.

9. the plug connection unit of one in claim 1-6, it is characterised in that the magnetic screen of conductive material (10) it is embodied as tubulose and including longitudinal slot.