An electromagnetic flowmeter

Abstract

The present invention relates to the technical field of electromagnetic flowmeters, and specifically to an electromagnetic flowmeter, whose technical solution is: comprising a flowmeter housing and a switchable inductive inner core, the flowmeter housing comprising an outer sleeve, the switchable inductive inner core comprising a measuring inner tube, the measuring inner tube being mounted on the inner side of the outer sleeve, the outer sleeve being fixedly mounted on the outer wall of the measuring inner tube, a pair of telescopic inductive electrodes being respectively provided at both ends of the outer wall of the outer sleeve, and a rotating excitation coil being slidably mounted on the outer wall of the outer sleeve. The present invention uses a rotating excitation coil that can slide between the two ends of the outer sleeve to press and trigger the corresponding telescopic inductive electrode. When encountering the situation of detection fluid stratification, electrode surface scaling or detection fluid turbulence, it is only necessary to control the rotating excitation coil to slide to the other end of the outer sleeve, and at the same time press and trigger the telescopic inductive electrode at the other end, thereby changing the detection position of the excitation coil and the inductive electrode, so as to achieve the effect of cleaning the inductive electrode.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic flowmeters, and in particular to an electromagnetic flowmeter. Background Art

[0002] An electromagnetic flowmeter is a flow measurement instrument based on Faraday's law of electromagnetic induction. It is used to measure the flow of conductive liquids or slurries. Its working principle is to convert the flow velocity of the conductive liquid flowing through the pipe into an electrical signal through the principle of electromagnetic induction, thereby measuring the flow rate.

[0003] Existing electromagnetic flowmeters are usually equipped with a pair of excitation coils and a pair of induction electrodes, and the positions of the excitation coils and electrodes are fixed. Based on this structural characteristic, the following problems may arise during the use of existing electromagnetic flowmeters:

[0004] 1. The installation angle of the electrodes in the electromagnetic flowmeter has a certain influence on the flow measurement. If the bubbles, impurities or stratification in the measured fluid are serious, and the installation direction of the two electrodes happens to be perpendicular to the stratified fluid, this will cause the two electrodes to be in different layers. The conductivity of the fluid in different layers is different, which may increase the measurement error of the electrodes and greatly affect the measurement accuracy of the electromagnetic flowmeter.

[0005] 2. Under certain working conditions, the fluid may contain solid particles, sediments or other chemical components, which may deposit or scale on the electrode surface. Since the position of the electrode is fixed, pollutants or scale may accumulate on the electrode surface after long-term operation. The accumulated pollutants or scale may reduce the contact quality between the electrode and the fluid, thereby causing measurement errors or signal attenuation.

[0006] 3. When the fluid flow state in the electromagnetic flowmeter fluctuates violently or is turbulent, the fixed-position electrodes and excitation coils may not be able to adapt to such changes. If the turbulent position happens to overlap with the position of the electrodes and excitation coils, this may cause the induced voltage signal to be unstable or distorted, and the accuracy of the measurement signal may be affected;

[0007] Therefore, it is necessary to invent an electromagnetic flowmeter. Summary of the Invention

[0008] In order to achieve the above-mentioned object, the present invention provides the following technical solutions: an electromagnetic flowmeter, comprising a flowmeter housing and a switchable inductive inner core;

[0009] The flow meter housing includes an outer shell, connecting pipes are installed at both ends of the outer shell, a flange is installed at the end of the connecting pipe away from the outer shell, a processor housing is installed on the top surface of the outer shell, an electrical interface is provided on the processor housing, a signal processor is installed in the processor housing, and bolts are installed between the outer shell and the processor housing;

[0010] The switchable sensing core includes a measuring inner tube, which is installed on the inner side of the outer shell and the inner side of the connecting tube. The outer wall of the measuring inner tube fits the inner wall of the connecting tube. A sliding component is installed on the outer wall of the measuring inner tube. The sliding component includes an outer sleeve, which is fixedly installed on the outer wall of the measuring inner tube. A pair of telescopic sensing electrodes are respectively provided at both ends of the outer wall of the outer sleeve. A rotary excitation coil is slidably installed on the outer wall of the outer sleeve. The rotary excitation coil is used to slide at both ends of the outer sleeve and press to trigger the corresponding telescopic sensing electrodes.

[0011] Preferably, the sliding assembly includes a fixing ring, which is fixedly mounted at both ends of the outer sleeve, and deflection grooves are provided on opposite sides of the outer sleeve, and the deflection grooves are obliquely deflected 90° along the outer wall of the measuring inner tube. A pair of beveled protrusions are provided on the side of the fixing ring close to the outer sleeve, and the beveled protrusions on the fixing ring are mounted at both ends of the deflection groove on the outer sleeve.

[0012] Preferably, the rotary excitation coil includes a coil seat, and the two coil seats are relatively arranged on both sides of the outer sleeve. A deflection slider is fixedly installed on the side of the coil seat close to the outer sleeve, and oblique cuts are provided at both ends of the deflection slider. The deflection slider is slidably installed in the deflection slot, and the deflection slider slides along the deflection slot.

[0013] Preferably, the rotary excitation coil includes a rotating clamp, which is fixedly mounted on one side of the coil seat, and a propulsion ring is installed on the side of the rotating clamp away from the coil seat, and openings are provided on the upper and lower opposite sides of the propulsion ring. A hydraulic rod is fixedly mounted on the outer wall of the connecting tube of the propulsion ring away from the rotating clamp, and the output end of the hydraulic rod passes through the outer shell and is fixedly connected to the propulsion ring.

[0014] Preferably, the rotary excitation coil includes an electromagnetic wire, which is wound on a coil seat. A coil connector is provided on the side of the coil seat away from the outer sleeve. One end of the coil connector passes through the coil seat and is electrically connected to the electromagnetic wire, and the other end of the coil connector is connected to the coil wire. The end of the coil wire away from the coil connector extends upward into the processor housing and is electrically connected to the electrical interface.

[0015] Preferably, the rotary excitation coil includes a pressing slider, which is fixedly installed between the adjacent ends of the two coil seats. The pressing slider and the coil seat form an annular structure. The pressing slider is provided with convex plates on both sides close to the connecting tube, and the convex plates on both sides of the pressing slider are tilted away from the outer sleeve.

[0016] Preferably, an induction connector is fixedly installed in the middle of the pressing slider, the induction connector passes through the pressing slider, the end of the induction connector away from the surface of the outer sleeve is electrically connected to the induction wire, and a processor interface is provided at the bottom of the signal processor, the end of the induction wire away from the induction connector extends upward into the processor housing and is electrically connected to the processor interface.

[0017] Preferably, the outer shell is provided with outer tube openings on the upper and lower sides close to one end of the hydraulic rod, the outer shell is also provided with outer tube openings on the lateral sides away from one end of the hydraulic rod, and the inner wall of the measuring inner tube is provided with inner tube openings near the outer tube openings.

[0018] Preferably, the telescopic sensing electrode includes electrodes, and the four electrodes are respectively slidably inserted into the outer tube openings on the surface of the outer shell. An airtight ring is provided on the side of the outer tube opening close to the surface of the outer shell. The airtight ring is sleeved and installed on the outside of the electrode. A gas injection port is provided on one side of the airtight ring, and pressurized gas is injected into the interior of the airtight ring. Granular protrusions are provided on the surface of the airtight ring.

[0019] Preferably, the telescopic induction electrode includes an air ring bracket, which is sleeved on the side surface of the airtight ring away from the outer shell, and the air ring bracket is fixedly connected to the outer shell. An electrode cap is fixedly installed on the end of the electrode away from the outer shell, and a spring is arranged between the electrode cap and the air ring bracket, and the spring is installed on the outer wall of the electrode.

[0020] The beneficial effects of the present invention are as follows: by pressing and triggering the corresponding telescopic induction electrode through the rotary excitation coil that can slide between the two ends of the outer sleeve, when the rotary excitation coil is located at one end of the outer sleeve, the telescopic induction electrode at that end is pressed and triggered, and the telescopic induction electrode extends into the inner wall of the measuring inner tube and performs measurement. When encountering the situation of detecting fluid stratification, scaling on the electrode surface or detecting fluid turbulence, it is only necessary to control the rotary excitation coil to slide to the other end of the outer sleeve and press and trigger the telescopic induction electrode at the other end. At the same time, the surface dirt of the scaling electrode is automatically peeled off during the retraction process, so as to achieve the effect of changing the detection position of the excitation coil and the induction electrode, and cleaning the induction electrode, so that it can flexibly deal with situations such as fluid stratification, scaling on the electrode surface or detecting fluid turbulence, thereby effectively improving the measurement accuracy of the electromagnetic flowmeter. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The appearance diagram provided by the present invention;

[0022] Figure 2 A schematic diagram of the internal structure of the outer shell provided by the present invention;

[0023] Figure 3 A schematic diagram of the internal structure provided by the present invention;

[0024] Figure 4 A schematic diagram of the sliding of the rotary excitation coil provided by the present invention;

[0025] Figure 5 A side cross-sectional view provided for the present invention;

[0026] Figure 6 This is a schematic diagram of the telescopic sensing electrode provided by the present invention before triggering;

[0027] Figure 7 This is a schematic diagram of the telescopic sensing electrode provided by the present invention after being triggered;

[0028] Figure 8 A schematic diagram of the inner wall of the measuring inner tube provided by the present invention;

[0029] Figure 9 A detailed view of the interior of the outer shell provided by the present invention;

[0030] Figure 10 A schematic diagram of the installation of the coil base provided by the present invention;

[0031] Figure 11 An exploded view of the coil base provided by the present invention;

[0032] Figure 12 An exploded view of the telescopic sensing electrode provided by the present invention;

[0033] Figure 13 A schematic diagram of electrode pressing provided by the present invention;

[0034] Figure 14 A cross-sectional view of the airtight ring provided by the present invention in a state where the electrode is pressed downward;

[0035] Figure 15 A schematic diagram of electrode lifting provided by the present invention;

[0036] Figure 16 This is a cross-sectional view of the airtight ring provided by the present invention in the electrode raised state.

[0037] In the figure: 111, outer shell; 112, connecting pipe; 113, flange; 114, processor housing; 115, electrical interface; 116, bolt; 121, measuring inner tube; 122, inner tube opening; 131, outer sleeve; 132, fixing ring; 133, deflection slide; 134, outer tube opening; 141, propulsion ring; 142, hydraulic rod; 151, coil seat; 152, rotating clamp; 153, electromagnetic wire; 154, coil connector; 155, coil wire; 156, deflection slider; 161, airtight ring; 162, air ring bracket; 163, electrode; 164, electrode cap; 165, spring; 171, pressing slider; 172, sensing connector; 173, sensing wire; 174, processor interface; 175, signal processor. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0039] Example 1, as Figure 1 - Figure 7 As shown, an electromagnetic flowmeter in an embodiment of the first aspect of the present invention includes a flowmeter housing and a switchable inductive inner core;

[0040] The flowmeter housing includes an outer shell 111, with connecting pipes 112 installed at both ends of the outer shell 111, and a flange 113 installed at the end of the connecting pipe 112 away from the outer shell 111. A processor housing 114 is installed on the top surface of the outer shell 111, and an electrical interface 115 is provided on the processor housing 114. A signal processor 175 is installed in the processor housing 114, and bolts 116 are installed between the outer shell 111 and the processor housing 114;

[0041] The switchable sensing core includes a measuring inner tube 121, which is installed on the inner side of the outer shell 111. The measuring inner tube 121 is installed on the inner side of the connecting tube 112. The outer wall of the measuring inner tube 121 fits with the inner wall of the connecting tube 112. A sliding component is installed on the outer wall of the measuring inner tube 121. The sliding component includes an outer sleeve 131. The outer sleeve 131 is fixedly installed on the outer wall of the measuring inner tube 121. A pair of telescopic sensing electrodes are respectively provided at both ends of the outer wall of the outer sleeve 131. A rotary excitation coil is slidably installed on the outer wall of the outer sleeve 131. The rotary excitation coil is used to slide at both ends of the outer sleeve 131 and press to trigger the corresponding telescopic sensing electrodes.

[0042] In the above embodiment, it should be noted that threaded holes are provided on both the outer shell 111 and the processor housing 114, and bolts 116 are threaded into the threaded holes of the outer shell 111 and the processor housing 114. The flange 113 is used to connect the fluid pipeline. The flange 113 on the upper end of the connecting tube 112 at both ends of the outer shell 111 is connected to the fluid pipeline to achieve the effect of connecting to the fluid pipeline; the processor housing 114 is used to protect the signal processor 175. The signal processor 175 is externally connected to a power supply. The signal processor 175 has a built-in remote signal transmission module for interlocking with a remote display device. After receiving the voltage signal from the electrode, the signal processor 175 undergoes amplification, filtering, conversion, and other processing to ultimately output an electrical signal proportional to the flow rate. This electrical signal can be converted into a flow rate value, and the flow rate data can be displayed on a display or remote device; the electrical interface 115 is externally connected to a power supply and connected to the rotating excitation coil. The excitation coil is powered by the electrical interface 115. The current flowing in the excitation coil generates a magnetic field, causing the conductive particles in the fluid in the measuring inner tube 121 to cut the magnetic lines of force, thereby inducing a voltage between the electrodes;

[0043] By pressing a rotating excitation coil that can slide between the two ends of the outer sleeve 131, the corresponding telescopic induction electrode is triggered. When the rotating excitation coil is located at one end of the outer sleeve 131, the telescopic induction electrode at that end is pressed to trigger the telescopic induction electrode, which extends into the inner wall of the measuring inner tube 121 and performs measurement. When encountering the situation of detecting fluid stratification, scaling on the electrode surface or detecting fluid turbulence, it is only necessary to control the rotating excitation coil to slide to the other end of the outer sleeve 131 and press and trigger the telescopic induction electrode at the other end. At the same time, the surface dirt of the scaling electrode is automatically peeled off during the retraction process, so as to achieve the effect of changing the detection position of the excitation coil and the induction electrode, and cleaning the induction electrode, so that it can flexibly deal with situations such as fluid stratification, scaling on the electrode surface or detecting fluid turbulence, thereby effectively improving the measurement accuracy of the electromagnetic flowmeter.

[0044] Example 2, as Figure 2 - Figure 7 and Figure 9 、 Figure 10 As shown, an electromagnetic flowmeter includes embodiment 1. In addition, the sliding assembly includes a fixed ring 132, which is fixedly mounted on both ends of an outer sleeve 131. Deflection grooves 133 are provided on opposite sides of the outer sleeve 131. The deflection grooves 133 are obliquely deflected 90° along the outer wall of the measuring inner tube 121. A pair of oblique cut protrusions are provided on the side of the fixed ring 132 close to the outer sleeve 131. The oblique cut protrusions on the fixed ring 132 are mounted on both ends of the deflection grooves 133 on the outer sleeve 131.

[0045] In the above embodiment, it should be noted that the beveled protrusions on the fixing ring 132 are inserted into the two ends of the deflection groove 133 and fixed in the deflection groove 133. The beveled protrusions on the fixing ring 132 play a role in limiting the sliding of the rotary excitation coil. The deflection groove 133 on the outer sleeve 131 is used to achieve the effect of limiting the sliding path of the rotary excitation coil. The deflection groove 133 with an oblique deflection of 90° can make the rotary excitation coil slide horizontally while deflecting 90° along the surface of the measuring inner tube 121.

[0046] Example 3, as Figure 2 - Figure 7 and Figure 9 - Figure 12As shown, an electromagnetic flowmeter includes embodiment 2. In addition, the rotary excitation coil includes a coil seat 151, and the two coil seats 151 are relatively arranged on both sides of the outer sleeve 131. A deflection slider 156 is fixedly installed on the side of the coil seat 151 close to the outer sleeve 131. The two ends of the deflection slider 156 are provided with oblique cuts. The deflection slider 156 is slidably installed in the deflection slot 133. The deflection slider 156 slides along the deflection slot 133. The rotary excitation coil includes a rotating clamp 152, and the rotating clamp 152 is fixedly installed on one side of the coil seat 151. A propulsion ring 141 is installed on the side of the rotating clamp 152 away from the coil seat 151. Openings are provided on the upper and lower opposite sides of the propulsion ring 141. A hydraulic rod 142 is fixedly installed on the outer wall of the connecting tube 112 on the side of the propulsion ring 141 away from the rotating clamp 152. The output end of the hydraulic rod 142 passes through the outer shell 111 and is fixedly connected to the propulsion ring 141. The rotary excitation coil includes an electromagnetic wire 153, which is wound on the coil seat 151. A coil connector 154 is provided on the side of the coil seat 151 away from the outer sleeve 131. One end of the coil connector 154 passes through the coil seat 151 and is electrically connected to the electromagnetic wire 153. The other end of the coil connector 154 is connected to the coil wire 155. The end of the coil wire 155 away from the coil connector 154 extends upward into the processor housing 114 and is electrically connected to the electrical interface 115.

[0047] In the above embodiment, it should be noted that the propulsion ring 141 is rotatably mounted on the rotating clamp 152, the deflection slider 156 is in a parallelogram structure, and a plurality of hydraulic rods 142 are provided on the outer wall of the connecting pipe 112. The hydraulic rods 142 are externally connected to a power supply and a control system. A technician observes the flow data output by the signal processor 175 through a display or a remote device. When the flow data shows abnormal conditions such as unstable flow, obvious decrease or increase, it can be determined that abnormal conditions such as fluid stratification, electrode surface scaling, or detection fluid turbulence may occur in the flow meter. At this time, the technician needs to control and start the hydraulic rod 142 to push the propulsion ring 141 to move. The propulsion ring 141 drives the rotating clamp 152 and the coil seat 151 to move, so as to achieve the effect of driving the coil seat 151 to slide along the surface of the outer sleeve 131. At the same time, the deflection slider 156 and the deflection groove 133 drive the coil seat 151 to deflect between the rotating clamp 152 and the propulsion ring 141, and the coil seat 151 deflects 90°.

[0048] The electrical interface 115 conducts current through the coil conductor 155 and the coil connector 154 into the electromagnetic conductor 153. The current flowing in the electromagnetic conductor 153 generates a magnetic field, thereby causing the conductive particles in the fluid in the measuring inner tube 121 to cut the magnetic lines of force.

[0049] The width of the openings provided on the upper and lower opposite sides of the propulsion ring 141 is greater than the total width of the telescopic sensing electrodes, so as to prevent the telescopic sensing electrodes from blocking the propulsion ring 141 from sliding.

[0050] Example 4, as Figure 2 - Figure 7 and Figure 9 - Figure 12 As shown, an electromagnetic flowmeter includes embodiment 3. In addition, the rotary excitation coil includes a pressing slider 171, which is fixedly installed between the adjacent ends of the two coil seats 151. The pressing slider 171 and the coil seats 151 form a ring structure. The pressing slider 171 is provided with convex plates on both sides close to the connecting tube 112. The convex plates on both sides of the pressing slider 171 are tilted away from the outer sleeve 131. An induction connector 172 is fixedly installed in the middle of the pressing slider 171. The induction connector 172 passes through the pressing slider 171. The end of the induction connector 172 away from the surface of the outer sleeve 131 is electrically connected to the induction wire 173. A processor interface 174 is provided at the bottom of the signal processor 175. The end of the induction wire 173 away from the induction connector 172 extends upward into the processor housing 114 and is electrically connected to the processor interface 174.

[0051] In the above embodiment, it should be noted that the pressing slider 171 is made of insulating material. When the coil base 151 moves and rotates, it will drive the pressing slider 171 to move and rotate. After the pressing slider 171 moves and rotates to a specified position, it can press down a specified telescopic sensing electrode. When the pressing slider 171 presses down the telescopic sensing electrode, the sensing connector 172 is connected to the telescopic sensing electrode. The voltage signal sensed by the telescopic sensing electrode is introduced into the processor interface 174 through the sensing connector 172 and the sensing wire 173, and then analyzed by the signal processor 175 to output an electrical signal proportional to the flow rate, so as to achieve the effect of measuring the flow data in the inner tube 121.

[0052] Example 5, as Figure 8 - Figure 16As shown, an electromagnetic flowmeter includes embodiment 4. In addition, outer tube openings 134 are provided on the upper and lower sides of the outer shell 111 near one end of the hydraulic rod 142, and outer tube openings 134 are also provided on the lateral sides of the outer shell 111 away from the end of the hydraulic rod 142. The inner wall of the measuring inner tube 121 near the outer tube openings 134 is provided with inner tube openings 122. The telescopic sensing electrode includes an electrode 163. The four electrodes 163 are respectively slidably inserted into each outer tube opening 134 on the surface of the outer shell 111. An airtight ring 161 is provided on one side of the outer tube opening 134 near the surface of the outer shell 111. The airtight ring 161 61 is sleeved and installed on the outside of the electrode 163, a gas injection port is provided on one side of the air-tight ring 161, pressurized gas is injected into the inside of the air-tight ring 161, and granular protrusions are provided on the surface of the air-tight ring 161. The telescopic sensing electrode includes an air-ring bracket 162, and the air-ring bracket 162 is sleeved and arranged on the side surface of the air-tight ring 161 away from the outer shell 111. The air-ring bracket 162 is fixedly connected to the outer shell 111, and an electrode cap 164 is fixedly installed on the end of the electrode 163 away from the outer shell 111, and a spring 165 is provided between the electrode cap 164 and the air-ring bracket 162, and the spring 165 is installed on the outer wall of the electrode 163.

[0053] In the above embodiment, it should be noted that the spring 165 is sleeved on the outer wall of the electrode 163. When the electrode cap 164 contacts the induction connector 172, the electrode cap 164 is electrically connected to the induction connector 172. The airtight ring 161 is a hollow annular structure with a certain degree of ductility. A large amount of gas is injected into the airtight ring 161 through the gas injection port in advance to form a high pressure in the airtight ring 161. In the initial state, the electrode cap 164 is pushed upward by the elastic force of the spring 165 itself to push the electrode 163 upward. At this time, the lower end of the electrode 163 is out of the center of the airtight ring 161. Under the limit of the air ring bracket 162, the high-pressure gas in the airtight ring 161 prompts the airtight ring 161 to squeeze into the outer tube opening 134, so as to achieve the effect of sealing the outer tube opening 134.

[0054] When the pressing slider 171 moves to above the electrode cap 164, the electrode cap 164 pushes the electrode 163 into the center of the airtight ring 161 and passes through the outer tube opening 134 and the inner tube opening 122. The lower end of the electrode 163 extends into the inner wall of the measuring inner tube 121. At the same time, the electrode cap 164 contacts and connects with the sensing connector 172, and the spring 165 contracts under the force. At this time, the airtight ring 161 still seals the electrode 163 and the inner tube opening 122.

[0055] When the slider 171 is pressed and moved away again, the spring 165 pushes the electrode cap 164 to drive the electrode 163 to retract again, and the granular protrusions on the surface of the airtight ring 161 are used to rub the end of the electrode 163 to remove the scale on its surface.

[0056] The usage process of the present invention is as follows: a person skilled in the art connects the electrical interface 115 to a power source, and the electrical interface 115 introduces current into the electromagnetic wire 153 through the coil wire 155 via the coil connector 154. The current flowing in the electromagnetic wire 153 generates a magnetic field, causing the conductive particles in the fluid in the measuring inner tube 121 to cut the magnetic lines of force. At this time, the electrode 163 on the inner wall of the measuring inner tube 121 senses the fluid voltage, and the voltage signal is introduced into the processor interface 174 through the electrode cap 164 via the sensing connector 172 and the sensing wire 173. The signal processor 175 analyzes and outputs an electrical signal proportional to the flow rate, and then the flow data is sent to the remote display device through the built-in remote signal sending module of the signal processor 175. The technician displays the observed flow data through the remote device. When the flow data shows abnormal conditions such as unstable flow, obvious decline or increase, it can be judged that fluid stratification, electrode surface scaling or detection may occur in the flow meter. In order to measure abnormal conditions such as fluid turbulence, technicians are required to control and start the hydraulic rod 142 to push the propulsion ring 141 to move. The propulsion ring 141 drives the rotating clamp 152 and the coil seat 151 to move, driving the coil seat 151 to slide along the surface of the outer sleeve 131. At the same time, the deflection slider 156 and the deflection slot 133, the coil seat 151 drives the rotating clamp 152 and the propulsion ring 141 to deflect. The coil seat 151 deflects 90° and drives the pressing slider 171 to deflect 90° to above the electrode 163 at the other end. When the pressing slider 171 moves to above the electrode cap 164, under the pressure of the electrode cap 164, the electrode cap 164 pushes the electrode 163 into the center of the airtight ring 161 and passes through the outer tube opening 134 and the inner tube opening 122. The lower end of the electrode 163 extends into the inner wall of the measuring inner tube 121. At the same time, the electrode cap 164 contacts and connects with the induction connector 172 to switch the detection position of the excitation coil and the induction electrode.

[0057] The above description is merely a preferred embodiment of the present invention. Anyone skilled in the art may utilize the above-described technical solutions to modify the present invention or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent replacement based on the technical solution of the present invention falls within the scope of protection claimed by the present invention.

Claims

1. An electromagnetic flowmeter, comprising a flowmeter housing and a switchable inductive core, characterized in that: The flow meter housing includes an outer shell, connecting pipes are installed at both ends of the outer shell, a flange is installed at the end of the connecting pipe away from the outer shell, a processor housing is installed on the top surface of the outer shell, an electrical interface is provided on the processor housing, a signal processor is installed in the processor housing, and bolts are installed between the outer shell and the processor housing; The switchable sensing inner core includes a measuring inner tube, which is installed on the inner side of the outer shell, and the measuring inner tube is installed on the inner side of the connecting tube. The outer wall of the measuring inner tube fits the inner wall of the connecting tube. A sliding component is installed on the outer wall of the measuring inner tube, and the sliding component includes an outer sleeve. The outer sleeve is fixedly installed on the outer wall of the measuring inner tube. A pair of telescopic sensing electrodes are respectively provided at both ends of the outer wall of the outer sleeve. The sliding component includes a fixing ring, which is fixedly installed at both ends of the outer sleeve. Deflection grooves are provided on opposite sides of the outer sleeve. The deflection grooves are obliquely deflected 90° along the outer wall of the measuring inner tube. A pair of oblique cut protrusions are provided on the side of the fixing ring close to the outer sleeve. The oblique cut protrusions on the fixing ring are installed on the outer sleeve. At both ends of the deflection slide groove on the outer wall of the outer sleeve, a rotary excitation coil is slidably installed, and the rotary excitation coil is used to slide at both ends of the outer sleeve and press to trigger the corresponding telescopic induction electrode. The rotary excitation coil includes a coil seat, and the two coil seats are relatively arranged on both sides of the outer sleeve. A deflection slider is fixedly installed on the side of the coil seat close to the outer sleeve, and oblique cuts are provided at both ends of the deflection slider. The deflection slider is slidably installed in the deflection slide groove, and the deflection slider slides along the deflection slide groove. The rotary excitation coil includes a rotating clamp, and the rotating clamp is fixedly installed on one side of the coil seat. A propulsion ring is installed on the side of the rotating clamp away from the coil seat. Openings are provided on the upper and lower opposite sides of the propulsion ring, and the propulsion ring is away from A hydraulic rod is fixedly installed on the outer wall of the connecting tube on one side of the rotating clamp, and the output end of the hydraulic rod passes through the outer shell and is fixedly connected to the propulsion ring. The rotary excitation coil includes a pressing slider, and the pressing slider is fixedly installed between the adjacent two ends of the two coil seats. The pressing slider and the coil seat form an annular structure. The pressing slider is provided with convex plates on both sides close to the connecting tube, and the convex plates on both sides of the pressing slider are tilted in the direction away from the outer shell. The telescopic induction electrode includes electrodes, and the four electrodes are respectively slid into each outer tube opening on the surface of the outer shell. An airtight ring is provided on the side of the outer tube opening close to the surface of the outer shell, and the airtight ring is sleeved and installed on the outside of the electrode. A gas injection port is provided on one side of the airtight ring, and an air injection port is injected inside the airtight ring. Pressurized gas is introduced, and granular protrusions are provided on the surface of the airtight ring. The telescopic sensing electrode includes an air ring bracket, which is sleeved on the side surface of the airtight ring away from the outer shell. The air ring bracket is fixedly connected to the outer shell. An electrode cap is fixedly installed on the end of the electrode away from the outer shell. A spring is provided between the electrode cap and the air ring bracket, and the spring is installed on the outer wall of the electrode. A sensing connector is fixedly installed in the middle of the pressing slider, and the sensing connector passes through the pressing slider. The end of the sensing connector away from the surface of the outer sleeve is electrically connected to the sensing wire. A processor interface is provided at the bottom of the signal processor, and the end of the sensing wire away from the sensing connector extends upward into the processor housing and is electrically connected to the processor interface.

2. The electromagnetic flowmeter according to claim 1, characterized in that: The rotary excitation coil includes an electromagnetic wire, which is wound on a coil seat. A coil connector is provided on the side of the coil seat away from the outer sleeve. One end of the coil connector passes through the coil seat and is electrically connected to the electromagnetic wire, and the other end of the coil connector is connected to the coil wire. The end of the coil wire away from the coil connector extends upward into the processor housing and is electrically connected to the electrical interface.

3. The electromagnetic flowmeter according to claim 1, characterized in that: The outer shell is provided with outer tube openings on the upper and lower sides near one end of the hydraulic rod, and the outer shell is also provided with outer tube openings on the lateral sides away from one end of the hydraulic rod. The inner wall of the measuring inner tube is provided with inner tube openings near the outer tube openings.

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