Excitation device for electromagnetic flow sensor of electromagnetic flowmeter
Technical Field
The invention belongs to the technical field of electromagnetic flowmeters, relates to an electromagnetic flow sensor, and particularly relates to an excitation device for the electromagnetic flow sensor of an electromagnetic flowmeter.
Background
For the electromagnetic flow sensor, the generation of an induced electrical signal depends on an electric field formed when fluid charged particles inside the measuring tube cut magnetic lines of force, and when the electric field force and the magnetic field force borne by the charged particles are balanced, a voltage signal can be generated at the signal electrode, so that the generation of the voltage signal depends on an included angle between the direction of a magnetic field inside the measuring tube and a connecting line of the signal electrode, which is generated by an excitation system, and the included angle is 90 degrees, namely the included angle is optimal when the direction of the magnetic field is perpendicular to the connecting line of the signal electrode.
The existing excitation device for the electromagnetic flow sensor of the electromagnetic flowmeter is mostly in a saddle-shaped structure in appearance, for example, in the Chinese utility model patent of an excitation winding induction module with the publication number of CN211978010U, when in use, the lower end surface of a saddle-shaped shell can lead the excitation module to be closely attached and installed on a measuring tube, and the saddle-shaped excitation winding, a magnetic core and a magnetic yoke in the shell act together to form an arc symmetrical magnetic field; the structure is relatively suitable for a large-caliber measuring tube, and when the structure is applied to a small-caliber measuring tube, the structure firstly needs to be tightly attached to the measuring tube during installation, so that a signal electrode almost has no installation space, and secondly, the direction of a magnetic field generated near the signal electrode is difficult to meet the requirement of being perpendicular to a signal electrode connecting line, and the measurement precision can be seriously influenced; in order to solve the above problems, it is necessary to develop an excitation device for an electromagnetic flow sensor of an electromagnetic flowmeter.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides the excitation device for the electromagnetic flow sensor of the electromagnetic flowmeter, which has high measurement precision, high waterproof grade and convenient and quick assembly and is suitable for a small-caliber measuring tube.
The purpose of the invention is realized as follows: an excitation device for an electromagnetic flow sensor of an electromagnetic flowmeter comprises a square shell, wherein a mounting sleeve A is arranged at the center of the bottom of the square shell, the lower end of the mounting sleeve A is arranged in an open mode, an I-shaped coil frame is arranged at the outer side of the mounting sleeve A at the bottom of the square shell, excitation coils are wound around the frame body of the I-shaped coil frame, a square hole which is communicated from top to bottom is formed in the center of the I-shaped coil frame, a magnetic core A and a magnetic core B which are arranged in a crossed mode are arranged between two side walls facing each other in the square hole in a pairwise mode, the cross sections of the magnetic core A and the magnetic core B are of a U-shaped structure, the top ends of two side edges of the U-shaped structure are provided with outward extending flanges perpendicular to the U-shaped structure, the flanges are arranged on the upper end face corresponding to the I-shaped coil frame, and the bottoms of the magnetic core A and the magnetic core B are provided with through holes A matched with the outer diameter of the mounting sleeve A, magnetic core A with magnetic core B's bottom is passed through wear to establish hole A wears to locate set up after range upon range of on the installation sleeve and from top to bottom square casing's bottom, I-shaped coil frame's up end is equipped with the shape of falling U-shaped yoke just the both sides limit of the shape of falling U-shaped yoke is hugged closely respectively square casing corresponding lateral surface sets up, the up end of the shape of falling U-shaped yoke is equipped with the card and locates square casing up end's apron.
Preferably, the lower terminal surface both sides of square casing are equipped with the mounting panel of two symmetric distributions respectively, the lateral surface of mounting panel with the lateral surface parallel and level of square casing sets up, the lower terminal surface of mounting panel is the arc structure.
Preferably, two glue filling holes which are symmetrically distributed are formed in one side of the square shell.
Preferably, the bottom of the square shell is positioned on the outer side of the mounting sleeve A, and a limiting groove matched with the shape of the I-shaped coil frame is formed in the outer side of the mounting sleeve A in an excavating mode.
Preferably, an annular structure which is inwards sunken is dug around the frame body of the I-shaped coil frame, and the excitation coil is wound around the frame body of the I-shaped coil frame through the annular structure.
Preferably, the position of the folded edge, which is lapped on the upper end face of the I-shaped coil frame, is dug to be provided with a clamping groove matched with the folded edge.
Preferably, the upper end both sides of square casing symmetry respectively dig and are equipped with two matches the bayonet socket that the apron set up, set up respectively on the base both sides of the shape of falling U yoke its both sides limit is hugged closely on the bayonet socket the lateral surface setting of square casing, the apron passes through the bayonet socket card is located behind the upper end of square casing the surface of apron respectively with the corresponding surface parallel and level setting of square casing.
Preferably, one side of the cover plate is provided with two symmetrically distributed wire passing holes, and the wire passing holes are matched with the outer diameters of the outgoing lines of the excitation coils.
Preferably, the lower end face of the cover plate is provided with a mounting sleeve B which is mutually sleeved with and connected with the mounting sleeve A and coaxially arranged, the upper end of the mounting sleeve B is arranged in an open mode, a penetrating hole B matched with the mounting sleeve B is formed in the bottom of the inverted U-shaped magnetic yoke, and the cover plate is arranged on the upper end face of the inverted U-shaped magnetic yoke after penetrating through the penetrating hole B.
Preferably, the outer ends of the two sides of the inverted U-shaped magnetic yoke are respectively provided with two long waist-shaped connecting holes which are symmetrically distributed, and the centers of the outer ends of the two sides of the inverted U-shaped magnetic yoke are dug to be provided with signal electrode wiring gaps.
Due to the adoption of the technical scheme, the invention has the beneficial effects that:
(1) the invention adopts a square structure, when in use, the coil, the magnetic core and the magnetic yoke of the square structure are symmetrically arranged at two sides of the measuring tube in parallel through the arc structure at the bottom of the square shell, the residual space between the square shells is very large and is enough for installing a signal electrode, the measuring tube is very suitable for being used for the measuring tube with a small caliber, and meanwhile, the coil, the magnetic core and the magnetic yoke which are symmetrically distributed at two sides of the measuring tube in parallel jointly act to form a parallel symmetrical magnetic field, so that the direction of the magnetic field in the measuring tube is vertical to the connecting line of the signal electrode, the measuring use requirement is met, the measuring precision is effectively ensured, the measuring precision is high, and compared with the arc symmetrical magnetic field formed by the original saddle-shaped structure, the magnetic field distribution is uniform and regular, the magnetic field symmetry is enhanced, and the measuring precision is further improved;
(2) the square shell and the cover plate clamped at the upper end of the square shell can form a relatively closed accommodating space, so that the coil, the magnetic core and the magnetic yoke accommodated in the accommodating space can realize IP68 grade water prevention through glue pouring, and the waterproof grade is high;
(3) when the square shell is assembled, the I-shaped coil frame wound with the excitation coil, the magnetic core A, the magnetic core B, the inverted U-shaped magnetic yoke and the cover plate are sequentially assembled in the square shell from bottom to top, wherein the I-shaped limiting ring is quickly positioned through the limiting groove, the magnetic core A and the magnetic core B are quickly positioned through the through hole A, the inverted U-shaped magnetic yoke is quickly positioned through the through hole B, the cover plate is quickly positioned through the sleeving connection of the installation sleeve A and the installation sleeve B, and the square shell is convenient and quick to assemble;
in summary, the invention has the advantages of high measurement precision, high waterproof grade and convenient and fast assembly, and is suitable for small-caliber measuring tubes.
Drawings
Fig. 1 is a schematic perspective view of the present invention.
Fig. 2 is a schematic perspective view of the present invention.
Fig. 3 is a schematic perspective view of the present invention with the cover removed.
Fig. 4 is a schematic perspective view of the present invention with the cover plate and the yoke removed.
Fig. 5 is a schematic perspective view of a square housing according to the present invention.
Fig. 6 is a schematic perspective view of a square housing according to the present invention.
Fig. 7 is a schematic perspective view of the assembled excitation coil and i-shaped bobbin of the present invention.
Fig. 8 is a schematic perspective view of an i-shaped coil frame according to the present invention.
Fig. 9 is a schematic perspective view of the exciting coil of the present invention.
Fig. 10 is a schematic perspective view of the assembled magnetic cores a and B according to the present invention.
Fig. 11 is a schematic perspective view of a magnetic core a and a magnetic core B according to the present invention.
Fig. 12 is a perspective view of the inverted U-shaped yoke according to the present invention.
Fig. 13 is a schematic perspective view of the cover plate of the present invention.
Fig. 14 is a perspective view of the present invention mounted on a measuring tube in use.
In the figure: 1. square casing 11, encapsulating hole 12, mounting panel 13, installation sleeve A14, bayonet 15, spacing groove 2, apron 21, cross line hole 22, installation sleeve B23, annular step 3, the shape of falling U yoke 31, long waist shape connecting hole 32, signal wire wiring breach 33, wear to establish hole B4, I-shaped coil frame 41, draw-in groove 42, quad slit 43, loop configuration 5, magnetic core A6, magnetic core B7, excitation coil 8, hem 9, wear to establish hole A100, survey buret.
Detailed Description
It should be understood that when the square excitation device is used under the condition that the caliber of the measuring tube is large, the overall size of the manufactured electromagnetic flowmeter is overlarge, and the electromagnetic flowmeter is not beneficial to storage, transportation and actual environment use, so that the square excitation device is more suitable for the measuring tube with a small caliber; the saddle-shaped excitation device can be tightly attached to the wall of the measuring pipe, so that the saddle-shaped excitation device can make the whole size of the electromagnetic flowmeter proper and is more suitable for the measuring pipe with large caliber.
The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings.
As shown in fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, fig. 7, fig. 8, fig. 9, fig. 10, fig. 11, fig. 12, and fig. 13, the present invention provides an excitation device for an electromagnetic flow sensor of an electromagnetic flowmeter, including a square housing 1, wherein a mounting sleeve a13 is provided at the bottom center of the square housing 1, the lower end of the mounting sleeve a13 is open, and the lower end surface of the mounting sleeve a13 is flush with the lower end surface of the square housing 1.
An I-shaped coil frame 4 is arranged at the bottom of the square shell 1 and positioned at the outer side of the mounting sleeve A13, and an excitation coil 7 is wound around the frame body of the I-shaped coil frame 4 and used for generating an alternating magnetic field. Specifically, the excitation coil 7 is a multi-turn coil formed by winding a complete wire coated with an insulating layer, and both ends of the wire are led out from both sides of the multi-turn coil after winding to form lead-out wires.
A square hole 42 which is through up and down is formed in the center of the I-shaped coil frame 4, and a magnetic core A5 and a magnetic core B6 which are arranged in a cross shape are respectively arranged between two opposite side walls in the square hole 42 in a pairwise mode and are used for enhancing the inductance of the excitation coil 7 and regulating and controlling the distribution of a magnetic field. The cross sections of the magnetic core A5 and the magnetic core B6 are of a U-shaped structure, the top ends of two side edges of the U-shaped structure are provided with flanges 8 which are perpendicular to the U-shaped structure and extend outwards, the flanges 8 are erected on the upper end face corresponding to the I-shaped coil frame 4, the bottoms of the magnetic core A5 and the magnetic core B6 are provided with through holes A9 matched with the outer diameter of the installation sleeve A13, and the bottoms of the magnetic core A5 and the magnetic core B6 are erected on the installation sleeve 13 through the through holes A9 and are erected at the bottom of the square shell 1 after being stacked up and down.
The upper end face of the I-shaped coil frame 4 is provided with an inverted U-shaped magnetic yoke 3 for regulating and controlling magnetic field distribution, realizing the electromagnetic shielding effect of an excitation structure and enabling magnetic lines of force to form a closed loop. Two side edges of the inverted U-shaped magnetic yoke 3 are respectively arranged closely to the corresponding outer side surfaces of the square shell 1, and the upper end surface of the inverted U-shaped magnetic yoke 3 is provided with a cover plate 2 clamped on the upper end surface of the square shell 1.
In specific implementation, the magnetic core a5, the magnetic core B6 and the inverted U-shaped magnetic yoke 3 are made of high-permeability sheet materials through stamping and folding by a die.
In specific implementation, the square shell 1, the I-shaped coil frame 4 and the cover plate 2 are made of plastics and are processed by die sinking and injection molding.
Preferably, two symmetrically-distributed mounting plates 12 are respectively arranged on two sides of the lower end face of the square shell 1, the outer side faces of the mounting plates 12 are flush with the outer side face of the square shell 1, and the lower end face of each mounting plate 12 is of an arc-shaped structure. Specifically, the arc-shaped structure of the lower end face of the mounting plate 12 is matched with the pipe wall of the measuring pipe 100, so as to facilitate the square casing 1 to be tightly attached to the measuring pipe 100, thereby facilitating the excitation device provided by the invention to be tightly attached to the measuring pipe 100.
Preferably, two glue filling holes 11 which are symmetrically distributed are formed in one side of the square shell 1 and used for filling glue into a relatively closed accommodating space formed by the square shell 1 and the cover plate 2.
Preferably, the bottom of the square shell 1 is provided with a limiting groove 15 dug out of the mounting sleeve a13 and matched with the shape of the i-shaped coil frame 4, so that the i-shaped coil frame 4 can be mounted in the square shell 1 more conveniently and quickly, and the excitation coil 7 can be mounted in place more conveniently and quickly.
Preferably, an annular structure 43 which is recessed inwards is dug around the frame body of the i-shaped coil frame 4 and used for accommodating and limiting the multi-turn coil, and the excitation coil 7 is wound around the frame body of the i-shaped coil frame 4 through the annular structure 43. During specific implementation, after the excitation coil 7 is wound in the annular structure 43 better than the I-shaped coil frame 4, the I-shaped coil frame 4 and the excitation coil 7 can be integrally combined through integral winding of an electrical tape outside the excitation coil 7, and assembly is facilitated. During specific implementation, glue can be applied to the bottom of the limiting groove 15, and then the integrated I-shaped coil frame 4 and the excitation coil 7 are installed in place at one time. Particularly, the I-shaped coil frame 4 and the excitation coil 7 can be more firmly and reliably installed in the square shell 1 by integral winding of the electrical tape and bottom gluing of the limiting groove 15, and the vibration prevention is realized in the use process, so that the stability of a magnetic field is facilitated, and the accuracy of measurement is further facilitated.
In specific implementation, the ring structure 43 may be a square, rectangle, circle, ellipse, etc.
Preferably, the slot 41 matched with the folded edge 8 is dug at the position where the folded edge 8 is overlapped on the upper end face of the i-shaped coil frame 4, so that the magnetic core A5 and the magnetic core B6 can be conveniently and rapidly installed in place. Specifically, the height of the slot 41 is equal to the thickness of the magnetic core a5 and the magnetic core B6, so that the upper end surface of the i-shaped coil frame 4 and the upper end surface of the magnetic core a5 and the upper end surface of the magnetic core B6 can be flush with each other and then integrally arranged close to the bottom of the inverted U-shaped magnetic yoke, and therefore the magnetic core a5 and the magnetic core B6 can be stably and reliably arranged between the excitation coil 7 and the inverted U-shaped magnetic yoke, and the magnetic core a 6 and the magnetic core B6 cannot shake randomly in the using process, and the magnetic field is also stable and accurate in measurement.
Preferably, two bayonets 14 matched with the cover plate 2 are symmetrically dug at two sides of the upper end of the square shell 1 respectively and used for clamping the inverted U-shaped magnetic yoke 3 and the cover plate 2. The two sides of the bottom edge of the inverted U-shaped magnetic yoke 3 are respectively arranged on the bayonet 14, the two side edges of the inverted U-shaped magnetic yoke are closely attached to the outer side surface of the square shell 1, and the cover plate 2 is clamped on the upper end of the square shell 1 through the bayonet 14, and the outer surface of the cover plate 2 is respectively arranged in parallel with the corresponding outer surface of the square shell 1. Particularly, the inverted-U-shaped magnetic yoke 3 and the cover plate 2 can be more stably and reliably mounted on the square shell 1 through the bayonet 14, and the square shell cannot shake randomly in the use process, is also favorable for the stability of a magnetic field and is further favorable for the accuracy of measurement.
Preferably, one side of the cover plate 2 is provided with two symmetrically distributed wire through holes 21 for leading out the outgoing wires of the excitation coil 7, and the wire through holes 21 are arranged in a manner of matching with the outer diameters of the outgoing wires of the excitation coil 7.
Preferably, the lower end surface of the cover plate 2 is provided with a mounting sleeve B22 and a mounting sleeve B22 which are mutually sleeved and connected with the mounting sleeve a13 and coaxially arranged, the upper end of the mounting sleeve B22 is open, the bottom of the inverted U-shaped magnetic yoke 3 is provided with a through hole B33 matched with the mounting sleeve B22, and the cover plate 2 is arranged on the upper end surface of the inverted U-shaped magnetic yoke 3 through the through hole B22. Particularly, the annular step 23 that the inside wall lower extreme of installation sleeve B22 dug to be equipped with the setting of matching installation sleeve A13 upper end, installation sleeve A13's upper end just overlaps and locates on annular step 23, installation sleeve A13's up end just near the step face setting of annular step 23 for take place the hourglass to glue when preventing the encapsulating, effectively guarantee that the relatively inclosed accommodation space of encapsulating back square shell 1 and apron 2 formation can provide better waterproof performance.
Preferably, the outer ends of two sides of the inverted U-shaped yoke 3 are respectively provided with two symmetrically distributed long kidney-shaped connecting holes 31 for connecting two excitation devices provided by the present invention symmetrically installed on two sides of the measuring tube 100. The outer end centers of two side edges of the inverted U-shaped magnetic yoke 3 are dug with signal electrode wiring gaps 32 for the installation of signal electrodes.
As shown in fig. 14, when the present invention is actually used, two excitation devices provided by the present invention are symmetrically installed and fixed on both sides of the measurement pipe 100 through screws and nuts, and two signal electrodes are symmetrically installed on both sides of the measurement pipe 100 perpendicular to the excitation devices provided by the present invention, so that the present invention can be used; when the electromagnetic flow meter is used, the two sets of excitation coils 7, the magnetic core A5, the magnetic core B6 and the inverted U-shaped magnetic yoke 3 which are symmetrically distributed on two sides of the measuring tube 100 in parallel act together to form a parallel symmetrical magnetic field with uniform and regular magnetic field distribution and symmetrically enhanced magnetic field, and even if the parallel symmetrical magnetic field is near a signal electrode, magnetic lines of force of the parallel symmetrical magnetic field are mutually perpendicular to and uniformly distributed with a signal electrode connecting line, namely the whole magnetic field inside the measuring tube 100 is uniformly distributed and the included angle between the magnetic field direction and the signal electrode connecting line is 90 degrees, so that fluid charged particles inside the measuring tube 100 can fully cut the magnetic lines of force to form a uniform and enhanced electric field, an uniform and enhanced induced electric signal is generated by the electromagnetic flow sensor, and the aim of improving the test precision of the electromagnetic flow meter is fulfilled; when the electromagnetic flowmeter is used, the excitation coil 7, the magnetic core A5, the magnetic core B6 and the inverted U-shaped magnetic yoke which are positioned in the relatively closed accommodating space formed by the square shell 1 and the cover plate 2 are well protected after glue pouring, and are prevented from being corroded by water and the like in the long-term working process, so that the electromagnetic flowmeter can be used in severe working environments and stably and reliably complete test work for a long time.
Finally, it should be noted that the above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and although the present invention is described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the specific embodiments of the present invention without departing from the spirit and scope of the present invention, and all the modifications or equivalent substitutions should be covered in the claims of the present invention.