CN112729479A

CN112729479A - Coil type magnetostrictive sensor

Info

Publication number: CN112729479A
Application number: CN202011537448.9A
Authority: CN
Inventors: 张廷彬; 张祖文
Original assignee: Beijing Swisa Instrument Co ltd
Current assignee: Beijing Swisa Instrument Co ltd
Priority date: 2020-12-23
Filing date: 2020-12-23
Publication date: 2021-04-30

Abstract

The application discloses a coil type magnetostrictive sensor, which comprises a shielding shell, wherein a control system is arranged in the shielding shell, the control system comprises an excitation module and a signal amplification module, the excitation module and the signal amplification module are electrically connected with a controller, and the excitation module is used for generating pulse excitation signals for a waveguide wire; the signal amplification module is used for amplifying the echo signal generated by the induction coil; the controller is used for controlling the excitation module to generate excitation current, receiving the digital signal generated by the signal amplification module, converting the digital signal into an analog signal and outputting the signal. According to the coil-type magnetostrictive sensor provided by the embodiment of the application, the measuring system is integrated into the sensor, so that the coil-type magnetostrictive sensor can be formed into an independent module product, the signal processing and amplifying function is realized in a highly integrated manner, and the loss and interference of external processing of signal lead-out are avoided; meanwhile, the copper sleeve shell is adopted outside the sensor to effectively shield interference.

Description

Coil type magnetostrictive sensor

Technical Field

The present application relates generally to the field of magnetostrictive sensor technology, and more particularly to a coil-type magnetostrictive sensor.

Background

The magnetostrictive liquid level meter is one of important measuring instruments in industrial process control, is widely used for medium liquid level measurement of various towers, tanks, troughs, spherical containers, boilers and other equipment, and can remotely transmit liquid level signals to monitor the containers in real time. It is suitable for liquid level indication in petroleum, chemical, electric, paper, metallurgy, water treatment, light industry and other industrial fields.

The high-end magnetostrictive products in the current market adopt piezoelectric ceramic sensors, and the magnetostrictive materials adopting the piezoelectric ceramic sensors have the defect of poor vibration resistance. The middle-low end magnetostrictive product generally adopts an inductance coil mode to measure the liquid level, but the inductance coil structure of the product cannot be made into a module integrated product, the volume is large, and the signal processing amplifying part is led out from the inductance coil through a wire, so that signal attenuation and signal interference are easily caused.

Disclosure of Invention

In view of the above-mentioned defects or shortcomings in the prior art, it is desirable to provide a coil-type magnetostrictive sensor that can realize an integrated sensor and complete data acquisition, processing and display.

A coil type magnetostrictive sensor comprises a shielding shell, a control system is arranged in the shielding shell, the control system comprises an excitation module and a signal amplification module which are electrically connected with a controller, wherein,

the excitation module is used for generating pulse excitation signals for the waveguide wire;

the signal amplification module is used for amplifying the echo signal generated by the induction coil;

the controller is used for controlling the excitation module to generate excitation current, receiving the digital signal generated by the signal amplification module, converting the digital signal into an analog signal and outputting the signal.

Furthermore, the controller comprises a signal processing unit for controlling the excitation module to generate the excitation current and a signal conversion unit for receiving and converting the data of the signal amplification module.

Furthermore, a supporting piece is fixedly arranged in the shielding shell, and a first through hole for the waveguide wire to pass through is formed in the supporting piece.

Further, the induction coil and the waveguide wire are coaxially arranged, the induction coil is fixed on the supporting piece through the coil framework, and the first hole position used for fixing the coil framework is arranged on the supporting piece.

Furthermore, a vibration absorbing rubber rod is fixedly arranged on the supporting piece through a second hole, and the second hole is positioned above the first hole.

Furthermore, a control circuit board and a signal amplification board are fixedly arranged on the outer side of the supporting piece, and the controller and the excitation module are arranged on the control circuit board; the signal amplification board is provided with the signal amplification module.

Furthermore, the waveguide wire penetrates out of the upper portion of the supporting piece and is fixed through a fixing bolt, a second through hole used for the waveguide wire to penetrate through is formed in the fixing bolt, a threaded hole is formed in the fixing bolt, and the threaded hole is perpendicular to the second through hole.

Further, the fixing bolt is fixed on the supporting piece through a second screw, and the waveguide wire is electrically connected with the control circuit board through the second screw.

Further, the fixing bolt is fixed on the supporting piece through a first screw, and the electric connection between the waveguide wire and the signal amplification board is realized through the first screw.

Further, the shielding shell and the supporting piece are fixedly connected at the positions of the control circuit board and the signal amplification board through potting.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

according to the coil-type magnetostrictive sensor provided by the embodiment of the application, the measuring system is integrated into the sensor, so that the coil-type magnetostrictive sensor can be formed into an independent module product, the signal processing and amplifying function is realized in a highly integrated manner, and the loss and interference of external processing of signal lead-out are avoided; meanwhile, the copper sleeve shell is adopted outside the sensor to effectively shield interference. The sensor has the characteristics of high vibration resistance of an inductance coil type measuring method and small volume of the piezoelectric ceramic sensor, and simultaneously has the signal processing function and lower cost which are not possessed by the piezoelectric ceramic sensor.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

fig. 1 is a schematic structural diagram of a coil-type magnetostrictive sensor according to an embodiment of the present application;

FIG. 2 is a block diagram of a control system provided by an embodiment of the present application;

fig. 3 is a cross-sectional view of a coil-type magnetostrictive sensor provided by an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a support provided in an embodiment of the present application;

FIG. 5 is a side view of a support provided by an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a fixing bolt provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a bobbin according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a bottom insulator according to an embodiment of the present application.

1. A shielding housing; 100. a control system; 200. an excitation module; 300. a signal amplification module; 400. a controller; 500. a signal processing unit; 600. a signal conversion unit; 2. a control circuit board; 3. a signal amplification board; 4. fixing the bolt; 5. a waveguide wire; 6. a first through hole; 7. a threaded hole; 8. a second through hole; 9. a first screw; 10. a second screw; 11. a support member; 12. a coil bobbin; 13. an induction coil; 14. positioning a groove; 15. a vibration absorbing rubber rod; 16. a bottom insulator; 17. encapsulating; 18. a display device.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The magnetostrictive liquid level meter based on the waveguide wire is mainly used for exciting and receiving ultrasonic guided waves in a first-order torsional mode. The magnetostrictive liquid level meter mainly adopts a waveguide wire with excellent magnetostrictive performance and an annular magnetic floater, wherein the magnetization direction of the magnetic floater is along the axial direction, and when a current signal is introduced into the waveguide wire, the magnetostrictive liquid level meter can excite the position of the magnetic floater of the waveguide wire to generate torsional mode guided waves based on the magnetostrictive effect. The generated torsional guided wave is transmitted to a guided wave receiving device on the end surface along the waveguide wire, and the calculation of the liquid level is completed by algorithm programming.

Referring to fig. 1 in detail, a coil-type magnetostrictive sensor includes a shielding housing 1, a control system 100 is disposed in the shielding housing 1, the control system 100 includes an excitation module 200 and a signal amplification module 300, which are electrically connected to a controller 400, as shown in fig. 2, wherein,

the excitation module 200 is configured to generate a pulse excitation signal for the waveguide wire 5;

the signal amplification module 300 is configured to amplify an echo signal generated by the induction coil 13;

the controller 400 is configured to control the excitation module 200 to generate an excitation current, receive a digital signal generated by the signal amplification module 300, convert the digital signal into an analog signal, and output the analog signal.

The controller 400 includes a signal processing unit 500 for controlling the excitation module 200 to generate the excitation current, and a signal conversion unit 600 for receiving and converting the data of the signal amplification module 300.

The signal processing unit 500 outputs the excitation signal and transmits the excitation signal to the excitation module 200; the controller 400 is further provided with a timer, which can respectively receive the start timing signal output by the excitation module 200 and the stop timing signal output by the signal amplification module 300, and calculate the time difference between the two signals; the excitation module 200 is a power amplification circuit, outputs a periodic narrow pulse signal, transmits the periodic narrow pulse signal to two ends of the waveguide wire 5, and sends a start timing signal to the controller 400; the signal amplification module 300 is used for amplifying, filtering and shaping the echo signal, and sends a stop timing signal to the controller 400.

During specific work, the induction coil 13 and the waveguide wire 5 are coaxially arranged, one end of the excitation module 200 is connected with the controller 400, and the other end is connected with the waveguide wire 5; the excitation module 200 excites a pulse current on the waveguide wire 5, and the current propagates along the waveguide wire 5 and generates a pulse current magnetic field around the waveguide wire 5. A group of permanent magnetic rings are arranged in a floater of the sensor, when a pulse current magnetic field meets a magnetic ring magnetic field generated by the floater, the magnetic field around the floater changes, so that a wave guide wire 5 made of magnetostrictive materials generates a torsional wave pulse at the position of the floater, and the pulse is transmitted back along the wave guide wire 5 at a fixed speed and is detected by an induction coil 13; the sensing coil 13 receives the detected signal from the signal amplifying module 300, and transmits the received signal to the signal converting unit 600 of the controller 400, and converts the received analog signal into a digital signal. The controller 400 can measure the liquid level of the measured liquid according to the time difference between the sending of the initial pulse and the receiving of the voltage signal.

In addition, during specific setting, a display device 18 can be arranged on the outer wall of the shielding shell 1, and the measured liquid level height can be directly displayed; of course, the communication device of the sensor can be connected with external equipment to transmit data to other external devices. The embodiments disclosed in the present application do not limit the display method of the sensor, and any display method is within the scope of the present application.

As shown in fig. 3-5, a control circuit board 2 and a signal amplification board 3 are fixedly disposed outside the supporting member 11, and the controller 400 and the excitation module 200 are disposed on the control circuit board 2; the signal amplification board 3 is provided with the signal amplification module 300.

The waveguide wire 5 penetrates out of the upper portion of the support 11 and is fixed through the fixing bolt 4, as shown in fig. 6, a second through hole 8 for the waveguide wire 5 to penetrate through is formed in the fixing bolt 4, a threaded hole 7 is formed in the fixing bolt 4, and the threaded hole 7 is perpendicular to the second through hole 8. The fixing bolt 4 is fixedly provided with a first screw 9 and a second screw 10 through the threaded hole 7, and the first screw 9 and the second screw 10 are positioned at two ends of the fixing bolt 4 and tightly press the waveguide wire 5. Further, the fixing bolt 4 is fixed on the supporting member 11 by a second screw 10, and the waveguide wire 5 is electrically connected to the control circuit board 2 by the second screw 10.

It should be noted that the fixing bolt 4 may be a hexagonal bolt, a circular bolt, or a bolt with other shapes, and the cross-sectional shape of the fixing bolt 4 is not limited in the embodiments of the present application. A channel for the waveguide wire 5 to pass through is arranged inside the fixing bolt 4, a threaded hole 7 is arranged inside the fixing bolt 4 in order to realize the fixed connection between the fixing bolt 4 and the supporting piece 11, and the fixing function is realized through the matching of a first screw 9 penetrating through the supporting piece 11 and the threaded hole 7; the other end of the threaded hole 7 is provided with a second screw 10, the second screw 10 can realize connection with the control circuit board 2, and in addition, the first screw 9 and the second screw 10 can realize fixation and tensioning of the waveguide wire 5.

A support member 11 is fixedly arranged in the shielding shell 1, and a first through hole 6 for the waveguide wire 5 to pass through is arranged in the support member 11. Induction coil 13 with wave guide 5 coaxial arrangement, induction coil 13 passes through coil skeleton 12 to be fixed support 11 is last, be provided with on support 11 and be used for fixing the first hole site of coil skeleton 12. The induction coil 13 is wound on the coil framework 12 by taking the coil framework 12 as a reference, and the waveguide wire 5 penetrates through the center of the coil framework 12 along the axis of the coil framework 12, so that the waveguide wire 5 and the induction coil 13 are ensured to have better concentricity, and the magnetostrictive liquid level meter has better output signals.

In a specific arrangement, as shown in fig. 7, the bobbin 12 is dumbbell-shaped, the middle of the bobbin is used for winding the induction coil 13, and a positioning groove 14 is provided on at least one end of the bobbin for positioning and fixing the bobbin 12 inside the supporting member 11. First hole site sets up the lower extreme position at shielding shell 1, is the echelonment, and the up end through first hole site is compressed tightly to the upper end, and the lower extreme compresses tightly through the bottom insulator 16 that is located shielding shell 1 below, and simultaneously, still be provided with around the inner wall of first hole site with constant head tank 14 matched with fastener for fix a position coil skeleton 12, prevent influence measurement accuracy such as induction coil 13's rotation in the measurement process.

In addition, a vibration absorbing rubber rod 15 is fixedly arranged on the support 11 through a second hole, and the second hole is positioned above the first hole. The vibration absorption rubber rod 15 is used for absorbing reflection echo, the material of the vibration absorption rubber rod can be silica gel or other rubber materials, the length of the vibration absorption rubber rod is shortened as far as possible under the requirement of meeting the wave absorption performance, the vibration absorption rubber rod 15 is fixed in the supporting piece 11, the sensor structure is more compact, the blind area of the upper end of the magnetostrictive liquid level meter is reduced, and the measurement precision is improved.

As shown in fig. 8, the lower end of the shield case 1 is also provided with a bottom insulator 16. The bottom insulating part 16 and the shielding shell 1 are fixedly connected in a threaded manner, a plug of the shielding shell 1 can be arranged in the shielding shell 1, and the coil framework 12 in the middle of the shielding shell 1 is further compressed.

The shielding shell 1 and the supporting member 11 are fixedly connected at the positions of the control circuit board 2 and the signal amplification board 3 through potting 17. The encapsulation is to pour the liquid compound into the device with electronic components and circuits mechanically or manually, and cure the liquid compound into the thermosetting polymer insulating material with excellent performance under normal temperature or heating condition. The encapsulation can strengthen the integrity of the electronic device and improve the resistance to external impact and vibration; the insulation between internal elements and circuits is improved, and the miniaturization and the light weight of devices are facilitated; the direct exposure of elements and circuits is avoided, the waterproof and moistureproof performances of the device are improved, and the service performance and stable parameters are improved. For example, when the organic silicon gel is used for encapsulation, low molecules are not released, no stress shrinkage exists, deep vulcanization can be carried out, no corrosion exists, the transparent silica gel becomes a transparent elastomer after vulcanization, components packaged in the gel layer are clearly visible, the component parameters can be measured one by needling the transparent silica gel into the gel layer, and the detection and the repair are convenient.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and is therefore not to be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Terms such as "disposed" and the like, as used herein, may refer to one element being directly attached to another element or one element being attached to another element through intervening elements. Features described herein in one embodiment may be applied to another embodiment, either alone or in combination with other features, unless the feature is otherwise inapplicable or otherwise stated in the other embodiment.

The present invention has been described in terms of the above embodiments, but it should be understood that the above embodiments are for purposes of illustration and description only and are not intended to limit the invention to the scope of the described embodiments. It will be appreciated by those skilled in the art that many variations and modifications may be made to the teachings of the invention, which fall within the scope of the invention as claimed.

Claims

1. A coil type magnetostrictive transducer comprises a shielding shell, and is characterized in that a control system is arranged in the shielding shell, the control system comprises an excitation module and a signal amplification module which are electrically connected with a controller, wherein,

2. The coil-type magnetostrictive sensor according to claim 1, wherein the controller comprises a signal processing unit for controlling the excitation module to generate an excitation current and a signal conversion unit for receiving and converting data of the signal amplification module.

3. The coil-type magnetostrictive sensor according to claim 1, characterized in that a support member is fixedly arranged in the shielding case, and a first through hole for the waveguide wire to pass through is arranged in the support member.

4. The coil-type magnetostrictive sensor according to claim 3, wherein the induction coil is arranged coaxially with the waveguide wire, the induction coil is fixed on the support member by a coil bobbin, and the support member is provided with a first hole for fixing the coil bobbin.

5. The coil-type magnetostrictive sensor according to claim 4, characterized in that a shock-absorbing rubber rod is fixedly arranged on the support via a second hole, which is located above the first hole.

6. The coil-type magnetostrictive sensor according to claim 3, wherein a control circuit board and a signal amplification board are fixedly arranged outside the supporting member, and the controller and the excitation module are arranged on the control circuit board; the signal amplification board is provided with the signal amplification module.

7. The coil-type magnetostrictive sensor according to claim 6, wherein the waveguide wire is extended from the upper part of the support and fixed by a fixing bolt, a second through hole for the waveguide wire to pass through is provided in the fixing bolt, and a threaded hole is provided in the fixing bolt, and the threaded hole is perpendicular to the second through hole.

8. The coil-type magnetostrictive sensor according to claim 7, wherein the fixing bolt is fixedly provided with a first screw and a second screw through the threaded hole, the first screw and the second screw being located at both ends of the fixing bolt and pressing the waveguide wire.

9. The coil-type magnetostrictive sensor according to claim 8, wherein the fixing bolt is fixed to the support by a second screw, and the electrical connection of the waveguide wire to the control circuit board is made by the second screw.

10. The coil-type magnetostrictive sensor according to claim 6, characterized in that the shield case and the support are fixedly connected by potting at the positions of the control circuit board and the signal amplification board.