CN111696827B

CN111696827B - Liquid level switch

Info

Publication number: CN111696827B
Application number: CN202010694847.XA
Authority: CN
Inventors: 姜夏旭; 孙连锡; 孟祥琦
Original assignee: Weifang Yafeng Chemical Instrument Co ltd
Current assignee: Weifang Yafeng Chemical Instrument Co ltd
Priority date: 2020-07-18
Filing date: 2020-07-18
Publication date: 2023-06-23
Anticipated expiration: 2040-07-18
Also published as: CN111696827A

Abstract

The invention relates to a liquid level switch, which comprises a mounting seat arranged on a storage tank, wherein a guide hole is formed in the mounting seat, an inner guide rod is movably arranged in the guide hole, a micro switch is fixedly arranged on the mounting seat, an inner magnetic steel is fixedly arranged at the upper end of the inner guide rod, an upper driving magnetic steel capable of triggering the micro switch when moving upwards is arranged between the inner magnetic steel and the micro switch, and the magnetic pole at the lower end of the upper driving magnetic steel is the same as the magnetic pole at the upper end of the inner magnetic steel; the floating mechanism is used for driving the inner guide rod to move upwards when the liquid level in the storage tank rises; the floating mechanism comprises a sinking barrel and a tension compensation mechanism, so that false alarm caused by inaccurate density can be avoided; the control precision can be effectively improved, and the on-line self-checking and disassembly-free maintenance of the liquid level can be realized.

Description

Liquid level switch

Technical Field

The invention relates to a liquid level switch.

Background

At present, aiming at a large crude oil or viscosity medium storage tank or reaction tank, most float type liquid level meters cannot be used because of high viscosity, the application environment is a float type liquid level meter displayed by a field mechanical pointer, the storage is too high, potential safety hazards of overflow irrigation can be caused, the liquid level is observed and judged through the scale of a human eye pointer, a pump valve is manually cut off to achieve the purpose of controlling the liquid level of raw materials in the storage tank, the operation mode brings great labor cost, and the storage tank is generally high, is unfavorable for observation, is low in safety coefficient, and is mostly dependent on the responsibility of field personnel.

At present, a liquid level switch can drive a set of magnetic steel to move up and down through the change of the buoyancy of an inner floater, drive a set of lever bracket at the side to act, and drive a reed switch or a micro switch contact to be closed so as to achieve the purpose of liquid level control. However, this structure has a number of disadvantages, including:

most of liquid level switches in the prior art only depend on the buoyancy change of a floater to cause the action of the inner magnetic steel to be used as a driving element for the switching action. The wall of the floating ball is generally thinner and is not resistant to high temperature and high pressure; the weight is lighter, if not spacing, easy off tracking, but if spacing is carried out to the float directly, can cause the viscosity too big, the floater sticks and can't move. For example, chinese patent CN208432911 and CN201320486088.3, which both use hollow floating balls as measuring elements, and set a guide rod, the floating balls move up and down on the guide rod, and have the advantage of limiting the moving position of the floating balls, but if the viscosity of the measuring medium is too high, the inner hole of the floating ball and the guide rod cannot act due to viscosity problem. The inner hole hollow floating ball structure is only suitable for normal pressure low viscosity measurement liquid.

In the prior art, the floating ball in the liquid level switch mostly cannot be regulated in a counterweight, for example, although a detachable counterweight chamber with an elastic sealing ring is designed on the floating ball in Chinese patent CN 206740215U, the elastic sealing ring is mostly not high-temperature resistant or corrosion resistant, and is easy to corrode and fail, and meanwhile, the threaded seal is easy to leak, after the liquid permeates into the interior of the counterweight chamber of the floating ball, the mass of the floating ball is increased, and the buoyancy of the floating ball is less than that of gravity and fails.

The prior art liquid level switch adopts linkage switch side structural design more, like chinese patent CN 203415493U, side magnet steel linkage switch, though reached adjustable switch action position's purpose, but the common problem of this type of structure lies in that interior magnet steel is along with the rising of liquid level, after reaching alarm position, outer magnet steel linkage switch can appear the action, but, along with the continuation of liquid level rising, when the position of interior magnet steel exceeds outer magnet steel linkage switch's magnetic induction position, outer magnet steel linkage switch can become invalid, should continue full liquid level warning when, will report to the police and stop, continue to annotate the fluid, can cause the potential safety hazard of overflow filling. The inability to memorize self-hold is a common problem with such side-mounted ganged switches.

The liquid level switch in the prior art is integrally connected with the hard guide rod of the inner magnetic steel component by adopting the floating ball, the liquid level control position is not well regulated, meanwhile, because the inner diameter of the connecting rod sleeve at the upper end of the inner magnetic steel component is smaller, the hard guide rod is generally longer in length, so that the condition of left and right shaking of the floating ball is probably caused, the inner magnetic steel component at the upper end is frequently blocked and dead faults caused by eccentricity or overlarge viscosity, the cleaning and maintenance are required to be regularly disassembled, and the online self-checking and the disassembly-free maintenance cannot be realized. Although a self-checking structure is designed in Chinese patent CN 206039306, the self-checking device is driven to move upwards by pulling a handle to drive a floating ball to link by the design, the actual operability is not considered, if the handle rod is too tight, the sealing effect is achieved, but the handle rod is also held tightly and is difficult to operate to move up and down, if the compression nut is too loose, the leakage of liquid or volatile gas in a storage tank is caused to cause the potential safety hazard, the structure has larger technical defects, and meanwhile, the self-checking device has the defects that the floating ball is easy to adhere to an inner guide rod due to high viscosity, a side part is provided with a sensing switch, the volume of a pontoon outside the self-checking device is increased, the cost is increased and the like.

In the liquid level switch in the prior art, because the connecting rod is longer, the requirement on the centering of the field installation is higher, if the connecting rod is blocked by the inclined installation, the controllable length of the liquid level switch is usually smaller, the control position is mostly not adjustable, the material cost is higher, the failure rate is higher, and the control precision is poorer.

In the liquid level switch in the prior art, because the floating ball is light in weight and the floating ball and connecting rod are integrated, in order to limit the action range of the floating ball, an outer pontoon arranged at the side part is usually matched, and the switch is arranged above the outer pontoon at the side part. For example, CN208432911U adds significant cost and many crude oil tanks cannot be fire welded in situ, so the uniformity of installation also limits the implementation of control functions. Meanwhile, the floating ball is too light, is easy to float due to the fluctuation of the liquid level in the storage tank, and is easy to cause false alarm caused by misoperation of the switch.

Disclosure of Invention

The invention aims to solve the technical problem of providing the liquid level switch which can effectively improve the control precision, is applicable to lower density liquid measurement, has the self-holding memory function, and can realize the on-line self-checking and the disassembly-free maintenance of the liquid level.

In order to solve the technical problems, the technical scheme of the invention is as follows: the liquid level switch comprises a mounting seat arranged on a storage tank, wherein a guide hole is formed in the mounting seat, an inner guide rod is movably arranged in the guide hole, a micro switch is fixedly arranged on the mounting seat, an inner magnetic steel is fixedly arranged at the upper end of the inner guide rod, an upper driving magnetic steel capable of triggering the micro switch when moving upwards is arranged between the inner magnetic steel and the micro switch, and the magnetic pole at the lower end of the upper driving magnetic steel is the same as the magnetic pole at the upper end of the inner magnetic steel; the floating mechanism is used for driving the inner guide rod to move upwards when the liquid level in the storage tank rises.

As the preferable technical scheme, the floating mechanism comprises a sinking piece, a flexible connecting rope is arranged between the sinking piece and the inner guide rod, the liquid level in the storage tank reaches a certain height, the sinking piece floats upwards, and the tension compensation mechanism drives the guide rod to move upwards.

As an optimal technical scheme, the sinking piece is a sinking barrel.

As the preferable technical scheme, the tension compensation mechanism comprises a spring sleeved outside the inner guide rod, the lower end of the spring is connected to a spring baffle, the upper end of the spring is connected to the lower surface of the mounting seat, and an adjusting mechanism is arranged between the spring baffle and the inner guide rod.

As the preferable technical scheme, the adjusting mechanism comprises a threaded hole arranged on the spring baffle plate, an external thread is arranged at the lower end of the inner guide rod, and the external thread of the inner guide rod is screwed on the threaded hole on the spring baffle plate.

As an optimal technical scheme, the mounting seat is provided with a sealing cover for covering the upper end of the inner guide rod.

As the preferable technical scheme, the external thread is also screwed with a nut propped against the lower surface of the spring baffle plate.

As the preferable technical scheme, the lower surface of mount pad is equipped with the cover and is in the outer spring protection tube of spring, spring protection tube includes the body and shutoff is in the lower mouth of pipe department of body, be equipped with on the lower extreme cover and supply interior guide bar is worn out the via hole, spring baffle are located in the spring protection tube, interior guide bar is followed the last mouth of pipe of body is penetrated the body and is followed the via hole is worn out the body. The nut is also located within the spring protection tube,

as the preferable technical scheme, the lower surface of mount pad is equipped with mount pad external screw thread, the upper end of spring protection tube be equipped with mount pad external screw thread complex protection tube internal screw thread.

As the preferred technical scheme, still include self-checking mechanism, self-checking mechanism includes the self-checking pole, be equipped with the seal shell on the mount pad, the self-checking pole cover be in the seal shell and with seal shell clearance fit, the self-checking pole can be in reciprocate in the seal shell, self-checking pole magnet steel is installed to the lower extreme of self-checking pole, fixed mounting has the cover to be in on the spring baffle the outer guide bar self-checking magnet steel of interior guide bar, the one side magnetic pole that the self-checking pole magnet steel is close to the spring protection tube and the outside magnetic pole of guide bar self-checking magnet steel repel each other.

As an optimal technical scheme, the sinking barrel is provided with a counterweight adjusting mechanism.

Due to the adoption of the technical scheme, the liquid level switch comprises a mounting seat arranged on a storage tank, wherein a guide hole is formed in the mounting seat, an inner guide rod is movably arranged in the guide hole, a micro switch is fixedly arranged on the mounting seat, an inner magnetic steel is fixedly arranged at the upper end of the inner guide rod, an upper driving magnetic steel capable of triggering the micro switch when moving upwards is arranged between the inner magnetic steel and the micro switch, and the magnetic pole at the lower end of the upper driving magnetic steel is identical with the magnetic pole at the upper end of the inner magnetic steel; the floating mechanism is used for driving the inner guide rod to move upwards when the liquid level in the storage tank rises; the floating mechanism comprises a sinking barrel and a tension compensation mechanism, so that false alarm caused by inaccurate density can be avoided; the control precision can be effectively improved, and the on-line self-checking and disassembly-free maintenance of the liquid level can be realized.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic diagram of an embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 at I;

FIG. 4 is an enlarged view of a portion of FIG. 2 at II;

fig. 5 is a partial enlarged view at III in fig. 2.

Detailed Description

As shown in fig. 1 to 5, a liquid level switch comprises a mounting seat 1 mounted on a storage tank, wherein a guide hole is formed in the mounting seat 1, an inner guide rod 3 is movably mounted in the guide hole, a micro switch 4 is fixedly mounted on the mounting seat, an inner magnetic steel 5 is fixedly mounted at the upper end of the inner guide rod 1, an upper driving magnetic steel 6 capable of triggering the micro switch when moving upwards is arranged between the inner magnetic steel 5 and the micro switch 4, and the magnetic pole at the lower end of the upper driving magnetic steel 6 is the same as the magnetic pole at the upper end of the inner magnetic steel 5; the floating mechanism is used for driving the inner guide rod to move upwards when the liquid level in the storage tank rises. The internal magnetic steel and the upper driving magnetic steel adopt a magnetic coupling driving principle, the internal magnetic steel is completely isolated from the micro-switch cavity, the internal magnetic steel and the upper driving magnetic steel are structurally designed up and down, the upper driving magnetic steel directly acts on the micro-switch contact position, the driving assembly is reduced, the self-holding memory function is achieved, and the safety and reliability are higher.

The floating mechanism comprises a sinking piece, the sinking piece is a sinking barrel 7, a flexible connecting rope 11 is arranged between the sinking barrel 7 and the inner guide rod 3, the liquid level in the storage tank reaches a certain height, the sinking barrel floats upwards, and the tension compensation mechanism drives the guide rod to move upwards. The inner guide rod tube is flexibly connected with the sinking barrel, the sinking barrel can realize self-centering, and the upper end of the inner guide rod is not easy to be blocked eccentrically to cause faults. The flexible connecting rope can prevent the dead lock caused by the connection of the hard rods, and the alarm position can be adjusted by adjusting the length of the flexible connecting rope.

The flexible connecting rope connecting structure is not only suitable for a side additional outer pontoon mounting mode, but also can be in a form of being directly mounted at the top of the measuring storage tank, and meanwhile, the requirement on neutrality of the mounting is far lower than that of a hard connecting rod structural form, so that the application range of the technical scheme is effectively expanded.

The tension compensation mechanism comprises a spring 12 sleeved outside the inner guide rod, the lower end of the spring 12 is connected to a spring baffle 13, the upper end of the spring 12 is connected to the lower surface of the mounting seat 1, and an adjusting mechanism is arranged between the spring baffle 13 and the inner guide rod.

The micro switch and the inner magnetic steel adopt the vertical through magnetic coupling principle, when the liquid level rises, the buoyancy of the sinking barrel is increased, the inner guide rod pipe moves upwards under the action of downward tension of the sinking barrel and upward tension of the spring, the upper driving magnetic steel at the lower end of the homopolar magnetic pole repulsive micro switch closes the micro switch contact to act and keep all the time until the liquid level falls below an alarm position point, and the upper driving magnetic steel breaks the micro switch contact under the action of gravity, so that the self-holding function can be realized.

The tension compensation mechanism can prevent the micro switch from being inactive caused by too small buoyancy.

The adjusting mechanism comprises a threaded hole formed in the spring baffle plate 13, an external thread is arranged at the lower end of the inner guide rod 3, and the external thread of the inner guide rod 13 is screwed on the threaded hole formed in the spring baffle plate. The compensation force can be conveniently adjusted through the adjusting mechanism, the device can be suitable for more density change or accurate adjustment of alarm positions, and the compensation force provided by the spring can be applied to adapt to larger viscosity requirements.

The floating mechanism comprises a sinking barrel 7, and a counterweight adjusting mechanism is arranged on the sinking barrel 7. The sinking barrel 7 comprises an upper sealing head 8, a lower sealing head 9 and a sinking barrel pipe 10 arranged between the upper sealing head and the lower sealing head.

The sinking barrel replaces the traditional hollow floating ball, the sinking barrel adopts a solid or thick-wall pipe, and the counterweight adjusting mechanism can adopt a solid piece, so that the increase of gravity caused by leakage in the cavity of the hollow structure is avoided. The sinking barrel is heavy in mass and thick in wall thickness or directly adopts a solid structure, the pressure resistance and self-finding performance of the sinking barrel are superior to those of the hollow floating ball, an internal guide rod is not needed, the failure that the floating ball cannot act due to viscosity can be reduced, and the structure can be more suitable for high-viscosity high-temperature high-pressure measuring media.

The weight adjusting mechanism comprises a weight threaded rod 22 welded at the lower end of the lower seal head 9, and a plurality of solid weight blocks 23 can be assembled on the weight threaded tube 22. The device can realize the adjustment of the quality of the sinking bucket and the fine adjustment of the alarm action position, is suitable for measuring different density media or correcting the alarm position deviation of the sinking bucket immersed in the measured liquid depth caused by the density change, and improves the alarm control precision.

The upper end of the flexible connecting rope is connected with one end of the inner guide rod penetrating through the pipe body downwards, and the lower end of the flexible connecting rope is connected to the sinking barrel.

Therefore, the purpose of adjusting the relative position of the lower end of the spring and the inner guide rod can be achieved by adjusting the position of the spring baffle plate, and the tension compensation mechanism can compensate the tension of the sinking barrel in real time, so that the implementation condition is provided for the sinking barrel by adopting a thick-wall pipe or a solid design. The spring can carry out pulling force compensation to the increase of the gravity of the sinking barrel, and the spring can be suitable for measuring liquid with smaller density. The design is adjustable to adapt to different qualities of the sinking barrel.

The external thread is also screwed with a nut 14 which abuts against the lower surface of the spring baffle.

The mounting seat is provided with a sealing cover 15 covering the upper end of the inner guide rod. The liquid level switch adopts a non-contact magnetic coupling measurement principle, so that the liquid for measurement control and the electronic control switch are completely isolated, the purposes of high pressure resistance and high temperature resistance are achieved, and meanwhile, the safety performance of the switch is improved.

The invention is mainly applied to the field of automatic alarm control of high-temperature high-pressure or more viscous liquid level storage tank measurement, and can realize a liquid level switch with the function of automatic alarm or control of liquid level. The switch is based on a non-contact magnetic coupling principle, and can realize high-temperature and high-pressure resistant application occasions. The design comprises a sinking barrel and a tension compensation mechanism, so that false alarm caused by inaccurate density can be avoided; the spring protection tube is arranged, so that the problem that the failure cannot be reported due to the fact that the original design is easy to be blocked can be solved; the sinking barrel and the inner guide rod are arranged to be of a steel wire rope flexible connection structure, so that the liquid level alarm position can be conveniently adjusted, the adjustment of the liquid level alarm position can be realized, and the blocking caused by the connection of the hard rods can be prevented; the force transmission structure of the micro switch and the thrust magnetic steel is optimized, the self-holding memory function of liquid level alarm is realized, the control stability is effectively improved, and the safety performance of linkage control is improved; a set of self-checking device capable of realizing self-checking maintenance without disassembly is added, so that the daily production and maintenance efficiency cost is facilitated.

The lower surface of mount pad is equipped with the cover and is in the outer spring protection pipe 16 of spring, spring protection pipe includes the body and shutoff is in the lower end cover 17 of the lower mouth of pipe department of body, be equipped with on the lower end cover 17 and supply interior guide bar is worn out the via hole 18, spring baffle are located in the spring protection pipe, interior guide bar 3 follow the upper mouth of pipe of body penetrates the body and follow the via hole is worn out the body. The nut 14 is also located within the spring protection tube.

The lower surface of mount pad is equipped with the mount pad external screw thread, the upper end of spring protection tube 16 be equipped with mount pad external screw thread complex protection tube internal screw thread.

In order to prevent spring 3 deformation excessively causes elasticity inefficacy, the design has increased spring protection pipe 16, and the upper end of spring protection pipe 16 is equipped with the protection pipe internal thread, can direct threaded connection on the mount pad external screw thread, has the lower extreme design of spring protection pipe and takes the lower extreme cover 17 of hole, when spring 3's elastic deformation excessively, can carry out spacing protection through the lower extreme cover, the screwed connection structure of this spring protection pipe design simultaneously also conveniently dismantles.

When the liquid level in the measuring storage tank rises, the volume of immersing in the immersed liquid of the immersed barrel in the liquid will increase, the buoyancy of the immersed barrel will increase, the spring of the tension compensation mechanism will drive the inner guide rod to move upwards, the inner magnetic steel at the upper end of the inner guide rod moves upwards, after the inner magnetic steel moves upwards to a certain distance, the upper driving magnetic steel will close the micro switch contact because of homopolar magnetic repulsion, the upper driving magnetic steel always keeps in a state of closing the micro switch along with the continuous rising of the liquid level, after the liquid level descends, the upper driving magnetic steel falls under the action of self gravity, thereby breaking the contact of the micro switch, and in order to prevent damage failure caused by overlarge deformation of the spring in the tension compensation mechanism due to overlarge mass of the immersed barrel or overlarge liquid level descending, the spring protection tube has a lower end cover, the purpose of protecting the spring can be achieved, the centering performance of the spring and the inner guide rod can be ensured, the threaded dismounting structure of the spring protection tube is convenient to install and maintain.

Still include self-checking mechanism, self-checking mechanism includes self-checking pole 21, be equipped with seal shell 18 on the mount pad, self-checking pole 21 cover be in the seal shell and with seal shell clearance fit, self-checking pole 21 can be in reciprocate in the seal shell 18, self-checking pole magnet steel 19 is installed to self-checking pole's lower extreme, fixed mounting has the cover to be in on the spring baffle the outer guide bar self-checking magnet steel 20 of interior guide bar, the one side magnetic pole that self-checking pole magnet steel 20 is close to the spring protection tube and the outside magnetic pole of guide bar self-checking magnet steel repel each other. The self-checking pole is located the seal shell, and purpose is sealed shell inner chamber and is kept apart in the storage tank completely, when needs self-checking or maintenance operation for self-checking pole 17 reciprocates in the seal shell, notice observe micro-gap switch's break-make and realize the effect of self-checking, avoided scene to dismantle mount pad 1 wholly and examine and repair the condition, if interior guide bar 3 has slight card to have simultaneously, also can realize the purpose of maintaining through self-checking pole non-contact magnetic coupling repulsion, because wholly adopt the mode of non-contact complete isolation, avoided the complete hidden danger of revealing.

And a self-checking rod locking mechanism is arranged between the self-checking rod and the sealing shell. The self-checking rod locking mechanism can lock the position of the self-checking rod, so that the self-checking rod magnetic steel is far away from the guide rod self-checking magnetic steel when self-checking is not performed, and the movement of the inner guide rod is prevented from being influenced. The self-checking rod locking mechanism can adopt a limiting nut which is rotatably arranged on the opening of the sealing shell, the self-checking rod is provided with an external thread matched with the limiting nut, and the relative position of the self-checking rod and the limiting nut is adjusted by rotating the limiting nut.

The foregoing has shown and described the basic principles, main features and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The liquid level switch is characterized by comprising a mounting seat arranged on a storage tank, wherein a guide hole is formed in the mounting seat, an inner guide rod is movably arranged in the guide hole, a micro switch is fixedly arranged on the mounting seat, an inner magnetic steel is fixedly arranged at the upper end of the inner guide rod, an upper driving magnetic steel capable of triggering the micro switch when moving upwards is arranged between the inner magnetic steel and the micro switch, and the magnetic pole at the lower end of the upper driving magnetic steel is the same as the magnetic pole at the upper end of the inner magnetic steel; the floating mechanism is used for driving the inner guide rod to move upwards when the liquid level in the storage tank rises; the mounting seat is provided with a sealing cover for covering the upper end of the inner guide rod; the floating mechanism comprises a sinking piece, a flexible connecting rope is arranged between the sinking piece and the inner guide rod, the liquid level in the storage tank reaches a certain height, the sinking piece floats upwards, and the guide rod is driven by the tension compensation mechanism to move upwards; the sinking piece is a sinking barrel; the tension compensation mechanism comprises a spring sleeved outside the inner guide rod, the lower end of the spring is connected to a spring baffle, the upper end of the spring is connected to the lower surface of the mounting seat, and an adjusting mechanism is arranged between the spring baffle and the inner guide rod; the adjusting mechanism comprises a threaded hole arranged on the spring baffle plate, an external thread is arranged at the lower end of the inner guide rod, and the external thread of the inner guide rod is screwed on the threaded hole on the spring baffle plate; the lower surface of the mounting seat is provided with a spring protection pipe sleeved outside the spring, the spring protection pipe comprises a pipe body and a lower end cover which is blocked at the lower pipe orifice of the pipe body, the lower end cover is provided with a through hole for the inner guide rod to penetrate out, the spring and the spring baffle are positioned in the spring protection pipe, and the inner guide rod penetrates into the pipe body from the upper pipe orifice of the pipe body and penetrates out of the pipe body from the through hole; the self-checking device comprises a mounting seat, and is characterized by further comprising a self-checking mechanism, wherein the self-checking mechanism comprises a self-checking rod, a sealing shell is arranged on the mounting seat, the self-checking rod is sleeved in the sealing shell and in clearance fit with the sealing shell, the self-checking rod can move up and down in the sealing shell, self-checking rod magnetic steel is mounted at the lower end of the self-checking rod, guide rod self-checking magnetic steel sleeved outside the inner guide rod is fixedly mounted on a spring baffle, and one side magnetic pole of the self-checking rod magnetic steel close to a spring protection tube is repelled with the outer magnetic pole of the guide rod self-checking magnetic steel.

2. The liquid level switch of claim 1, wherein the lower surface of the mounting seat is provided with mounting seat external threads, and the upper end of the spring protection tube is provided with protection tube internal threads matched with the mounting seat external threads.

3. The fluid level switch of claim 1, wherein the sinking basket is provided with a weight adjustment mechanism.