CN214251192U

CN214251192U - Differential balance type liquid level sensing device

Info

Publication number: CN214251192U
Application number: CN202120018841.0U
Authority: CN
Inventors: 张光春
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-06
Filing date: 2021-01-06
Publication date: 2021-09-21
Anticipated expiration: 2031-01-06

Abstract

The utility model provides a differential balance type liquid level sensing device, which comprises a liquid level output component and a differential force detection component; the utility model discloses an innovative sensing device based on magnetic coupling and mechanical transmission's principle design, at the magnetic floating block along with the unsteady in-process of the liquid level that awaits measuring, also remove jointly thereupon with the drive coaster of magnetic floating block magnetic coupling, drive the haulage rope and remove, and then drive rim plate and transmission shaft and take place pivoted mechanical displacement, potentiometric sensor can convert mechanical displacement into continuous resistance output signal, further converts the digital signal into again and instructs the liquid level. The utility model discloses can carry out linear monitoring to the liquid level that awaits measuring, it can accurate reaction and measure the position of magnetism floater in the liquid level cabin, and then carries out accurate control and calculation to the liquid level, has realized high linearity and high accuracy measurement. Furthermore, the utility model discloses a differential balance formula level sensing device does not rely on the density of the liquid medium that awaits measuring to survey, and the suitability is strong.

Description

Differential balance type liquid level sensing device

Technical Field

The utility model belongs to the technical field of the level sensor technique and specifically relates to a differential balance formula liquid level sensing device is related to.

Background

The liquid level sensor is an important instrument for monitoring the liquid level of a liquid medium in a container, has very wide application in the fields of petrochemical industry, pharmacy, electric power and the like, and is particularly important in the field of petroleum transportation such as oil tankers and the liquid level monitoring of oil tanks on the oil tankers. At present, the liquid level sensors commonly used in the prior art mainly comprise a floating ball liquid level sensor and a piezoelectric type liquid level sensor.

The floating ball liquid level sensor is a liquid level sensor designed based on the Archimedes buoyancy principle, and the sensor generally comprises a detection tube, a slidable magnetic floating ball is sleeved outside the detection tube, a plurality of reed pipes are arranged inside the detection tube, and when the floating ball floats along the detection tube along the liquid level, the reed pipes at different positions can be attracted by magnetism to act, so that the resistance value is changed. However, in the float level sensor, a reed switch action generates a corresponding resistance value, but the change of the resistance value is nonlinear, that is, the liquid level is also nonlinear. Although a plurality of reed switches are densely arranged in the detection tube in order to improve the liquid level detection linearity of the floating ball liquid level sensor in the prior art, the action of the reed switches is realized through the magnetic field induction of the magnetic floating ball and the reed switches, and the magnetic field induction has dispersibility. Therefore, the liquid level of the prior art float level sensor is displayed to be nonlinear and has low accuracy.

The piezoelectric liquid level sensor generates a linearly changing current signal by detecting the pressure at different liquid levels, however, the measurement of the pressure is related to the density of the liquid medium to be measured, and when the density of the liquid medium to be measured is greatly different from the density of the liquid medium designed by the piezoelectric liquid level sensor, the error of the measured liquid level value is also very large. Therefore, in order to accurately measure the liquid levels of different liquid media, different piezoelectric liquid level sensors are required to be replaced, so that the applicability is poor, and the cost is high.

Therefore, how to design a liquid level sensor which can linearly reflect liquid level change, has high precision and is not influenced by the density of a liquid medium is a technical problem which needs to be solved urgently in the industry at present.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome above-mentioned problem, the utility model provides a differential balance formula liquid level sensing device, its innovative level sensor for designing based on magnetic coupling and mechanical transmission principle has realized having had extensive suitability to the high linearity and the high accuracy measurement of liquid level simultaneously.

The technical scheme of the utility model as follows: a differential balance type liquid level sensing device comprises a liquid level output assembly and a differential force detection assembly; the liquid level output assembly comprises a potential sensor, a transmission shaft, a signal conversion box and a liquid level display; an output shaft of the potential sensor is fixedly connected with the transmission shaft; the signal conversion box converts the electric signal of the potential sensor into a current signal and inputs the current signal to the liquid level display; the differential force detection assembly comprises a driving wheel disc, a traction rope, a driving unit and a balance unit, the driving wheel disc is fixedly sleeved on the transmission shaft, and the traction rope is wound on the driving wheel disc; the driving unit comprises a first detection pipe, a magnetic floating block, a driving pulley and a guide wheel, the first detection pipe is a hollow pipeline, and the magnetic floating block is slidably sleeved outside the first detection pipe; the driving pulley is magnetically coupled with the magnetic floating block, and the driving pulley is arranged inside the first detection pipe and can slide along the inner wall of the first detection pipe; the guide wheel is fixedly arranged below the driving pulley; the balance unit comprises a second detection pipe and a balance pulley, and the second detection pipe is arranged in parallel with the first detection pipe and is a hollow pipeline; the balance pulley is arranged inside the second detection pipe and can slide along the inner wall of the second detection pipe; two ends of the traction rope are respectively arranged in the first detection tube and the second detection tube in a penetrating mode, one end of the traction rope bypasses the guide wheel to be connected with the driving pulley, and the other end of the traction rope is connected with the balance pulley.

Compared with the prior art, the utility model provides a differential balance formula liquid level sensing device, its innovative sensing device for based on magnetic coupling and mechanical transmission's principle design, at the unsteady in-process of magnetic floater along with the liquid level that awaits measuring, also remove jointly thereupon with magnetic floater magnetic coupling's drive coaster, it removes to drive the haulage rope, and then drive driving wheel dish and transmission shaft take place pivoted mechanical displacement, potentiometric sensor can convert mechanical displacement into continuous resistance output signal, further convert the digital signal into again and instruct the liquid level. The utility model discloses can carry out linear monitoring to the liquid level that awaits measuring, it can accurate reaction and measure the position of magnetic floater in the liquid level cabin, and then has realized the accurate control and the calculation of liquid level. Furthermore, the utility model discloses a differential balance formula level sensing device does not rely on the density of the liquid medium that awaits measuring to survey, and the suitability is strong.

Further, the bottom end and the top end of the first detection tube and the second detection tube are respectively provided with a bottom end sealing plate and a top end sealing plate. The utility model discloses an there is not the liquid that awaits measuring in first detecting tube and the second detecting tube, but realizes the transmission and then monitor the liquid level through the magnetic coupling of magnetism floater and drive coaster.

Further, the liquid level output assembly further comprises a box body, the potential sensor, the transmission shaft and the signal conversion box are arranged in the box body, and the driving wheel disc is arranged in the box body. The utility model discloses an each spare part setting among the liquid level output subassembly can fix the outside at the liquid storage cabin with the box when the installation in the box, easy to assemble, use and the maintenance in later stage. Meanwhile, electronic elements and electrical equipment do not exist in the oil storage cabin, so that the inside and the outside of the oil storage cabin are electrically isolated, and the safety factor is greatly improved.

The device further comprises a communication pipeline, one end of the communication pipeline is connected with the box body, the other end of the communication pipeline is connected with the top end sealing plate, and the traction rope penetrates through the communication pipeline and the top end sealing plate and is arranged in the first detection pipe/the second detection pipe. The utility model discloses a intercommunication pipeline is the important part of connecting liquid level output subassembly and differential power detection subassembly for two big parts relatively independent sets up and can make up the use again, provide convenience for transportation, installation and the maintenance in later stage.

Further, the liquid level output subassembly still includes support frame and bearing, the support frame is fixed to be set up in the box, the bearing is fixed to be set up on the support frame, potentiometric sensor is fixed to be set up on the support frame, the transmission shaft rotationally sets up on the bearing.

Furthermore, the top and the bottom of the first detection tube are respectively provided with an upper limit block and a lower limit block, and the magnetic floating block is positioned between the upper limit block and the lower limit block. The utility model discloses a go up the setting of spacing piece and spacing piece down and can prevent droing of magnetic floating block, improved the security of using.

Furthermore, the magnetic floating block is a magnetic floating ball. The utility model discloses set up the magnetism floating block into spherical structure, spherical structure has bigger specific surface area, can float along with the liquid level sensitively more.

Further, the guide wheel is fixedly arranged on the bottom end sealing plate of the first detection pipe. The utility model discloses the effect of leading wheel is for changing the direction of haulage rope.

Further, the output shaft of the potential sensor is fixedly connected with the transmission shaft through a connecting flange.

Further, the potential sensor is a multi-coil winding potentiometer. The utility model discloses use many circles of wire-wound potentiometers, many circles of wire-wound potentiometers are that a resistance wire coiling becomes on cyclic annular skeleton, can make the potentiometers that the resistance changes through many circles pivoted mechanical angle, and in addition, many circles of wire-wound potentiometers have high accuracy, advantage that stability is good.

For a better understanding and an implementation, the present invention is described in detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic view of a partial structure of the differential balanced liquid level sensing device of the present invention;

fig. 2 is a schematic view of the working principle of the differential balanced liquid level sensing device of the present invention.

Reference numerals:

10-oil storage cabin, 21-box, 22-first support frame, 23-second support frame, 24-potential sensor, 25-transmission shaft, 26-connecting flange, 27-bearing, 28-signal conversion box, 31-driving wheel disc, 32-hauling rope, 331-first detecting tube, 332-magnetic floating block, 333-driving pulley, 334-guide wheel, 335-bottom end sealing plate, 336-top end sealing plate, 337-upper limiting block, 338-lower limiting block, 341-second detecting tube, 342-balance pulley, 41-first communicating pipeline and 42-second communicating pipeline.

Detailed Description

The utility model provides a differential balance formula level sensing device please refer to simultaneously and show fig. 1 and fig. 2, including liquid level output subassembly, differential power detection subassembly and intercommunication pipeline. In this embodiment, for the convenience of explanation the utility model discloses a method of use sets up the utility model discloses an use the scene to be the oil storage tank 10 on the oil tanker, but need explain, the utility model discloses a differential balance type liquid level sensing device is applicable to in the environment of various needs monitoring liquid levels.

The liquid level output assembly comprises a box body 21, a support frame arranged in the box body 21, a potential sensor 24, a transmission shaft 25, a signal conversion box 28 and a liquid level display (not shown); the tank body 21 is a main carrier and a mounting part of the liquid level output assembly, and the tank body 21 is fixedly arranged outside the oil storage chamber 10; the two support frames are fixedly arranged at the bottom of the box body 21, specifically, the two support frames are respectively a first support frame 22 and a second support frame 23, and the first support frame 22 and the second support frame 23 are arranged at intervals; the potential sensor 24 is fixedly arranged on the first support frame 22, the potential sensor 24 is preferably a multi-turn wire-wound potentiometer, and when an output shaft of the multi-turn wire-wound potentiometer rotates mechanically, a mechanical displacement signal can be converted into an output resistance signal; the transmission shaft 25 is fixedly connected with the output shaft of the potential sensor 24 through a connecting flange 26, in this embodiment, the transmission shaft 25 is fixed on the support frame through two bearings 27, specifically, two bearings 27 are provided, the two bearings 27 are respectively provided on the first support frame 22 and the second support frame 23, and the transmission shaft 25 is rotatably provided on the two bearings 27; the signal conversion box 28 is electrically connected with the electric potential sensor 24, the signal conversion box 28 can convert the resistance signal of the electric potential sensor 24 into a linear stable current signal of 4-20mA, and the linear stable current signal is input into the liquid level display, and the liquid level display can finally present a digital signal which is convenient for a worker to read the liquid level height.

The differential force detecting assembly includes a driving wheel 31, a traction rope 32, a driving unit and a balancing unit; the driving wheel disc 31 is fixedly sleeved on the transmission shaft 25, and the driving wheel disc 31 is positioned in the interval between the first support frame 22 and the second support frame 23; the haulage rope 32 is orderly wound and is arranged in the recess of drive rim plate 31, just the both ends of haulage rope 32 expose in drive rim plate 31, the setting standard of haulage rope 32 is: when one end of the pulling rope 32 is not subjected to an external force, a pulling force is applied to the other end of the pulling rope 32, so that the pulling rope 32 does not slip and the driving wheel 31 can smoothly rotate, and in this embodiment, the material of the pulling rope 32 is preferably an inelastic and wear-resistant material.

The driving unit includes a first detecting tube 331, a magnetic floater 332, a driving pulley 333, and a guide wheel 334. The first detection pipe 331 is a hollow pipe, preferably a seamless stainless steel pipe; further, a bottom end sealing plate 335 and a top end sealing plate 336 are respectively disposed at the bottom end and the top end of the first detecting tube 331, and preferably, the bottom end sealing plate and the top end sealing plate are both sealing flanges, specifically, stainless steel sealing flanges, which are required to prevent gas in the oil storage tank 10 from entering the first detecting tube 331/the second detecting tube 341 and further prevent the gas from leaking to the outside of the oil storage tank 10; the top and the bottom of the first detecting tube 331 are respectively provided with an upper limit block 337 and a lower limit block 338. The magnetic floating block 332 is slidably sleeved outside the first detection tube 331 and is located between the upper limiting block 337 and the lower limiting block 338; preferably, the magnetic floating block 332 is a magnetic floating ball. The driving pulley 333 is disposed inside the first detecting tube 331 and is slidable along an inner wall thereof; specifically, the driving pulley 333 is magnetically coupled to the magnetic floating block 332, that is, the driving pulley 333 is powered by the magnetic floating block 332, and when the magnetic floating block 332 floats with the liquid level outside the first detection tube 331, the driving pulley 333 moves with the magnetic floating block 332 inside the first detection tube 331, and the driving pulley 333 and the magnetic floating block 332 realize non-contact synchronous movement in the same direction by means of magnetic coupling; preferably, the drive block 333 has four metal wheels. The guide wheel 334 is fixedly disposed on the bottom end sealing plate 335 and located below the driving pulley 333, and the guide wheel 334 is specifically a fixed pulley.

The balance unit comprises a second detection tube 341 and a balance pulley 342, the second detection tube 341 is a hollow pipeline, the top end and the bottom end of the second detection tube 341 are respectively provided with a top end sealing plate 336 and a bottom end sealing plate 335, the length of the second detection tube 341 is the same as that of the first detection tube 331, and the second detection tube 341 is arranged in parallel with the first detection tube 331; the balance block 342 is disposed inside the second detecting tube 341 and is slidable along an inner wall thereof, and preferably, the balance block 342 has four metal wheels.

Further, the communication ducts are hollow ducts, specifically, a first communication duct 41 and a second communication duct 42, one end of the first communication duct 41 is communicated with the bottom of the box 21, and the other end is communicated with the top end sealing plate 336 of the first detection pipe 331; one end of the second communication channel 42 communicates with the bottom of the case 21, and the other end communicates with the top end sealing plate 336 of the second sensing tube 341. Both ends of the pulling rope 32 respectively pass through the first communicating pipe 41 and the second communicating pipe 42 and are inserted into the first detecting pipe 331 and the second detecting pipe 341, wherein the pulling rope 32 inserted into the first detecting pipe 331 bypasses the guide wheel 334 to be connected with the driving pulley 333, and the pulling rope 32 inserted into the second detecting pipe 341 is connected with the balance pulley 342. In this embodiment, the tank 21 is fixedly installed outside the oil storage tank 10, the communication pipe is installed outside the oil storage tank 10, and the first detection pipe 331 and the second detection pipe 341 are installed inside the oil storage tank 10.

Further, in the present embodiment, in order to ensure the differential force detecting assembly to operate accurately, the following steps are required:

1. the diameter of the driving wheel disc and the number of turns of the potential sensor (namely, a multi-turn wire-wound potentiometer) are selected and determined according to the measuring range, and the specific calculation is as follows: h_m=π*D*N，Wherein H_mThe height of the liquid level required to be measured in the oil storage chamber is pi which is a constant, D which is the diameter of the driving wheel disc, and N which is the number of turns required to rotate the driving wheel disc.

2. When the potential sensor (i.e. the multi-coil winding potentiometer) determines that the starting torque of the transmission shaft is constant, the weight of the driving tackle is selected to be 1-2 times of the starting torque of the transmission shaft, the weight of the balancing tackle is equal to 3-5 times of the starting torque of the transmission shaft, and the traction rope can be in a tension state.

3. The buoyancy of the magnetic floating block should be greater than the gravity of the driving tackle + the gravity of the balancing tackle + the torque force for overcoming the transmission shaft, wherein when the magnetic floating ball is adopted, the buoyancy calculation formula is as follows: g = ρ × G × V, where ρ is the density of the liquid cargo to be measured, G is the gravity coefficient, and V is the volume of the magnetic float immersed in the liquid (V ≈ 1/2 volume of the magnetic float).

4. The magnetic coupling force between the magnetic floating block and the driving pulley is larger than the buoyancy of the magnetic floating block.

The working principle of the differential balanced level sensing device of the present invention is explained below, please refer to fig. 2:

when the liquid level in the oil storage cabin rises to the point that the magnetic floating ball floats, the magnetic floating ball moves upwards along the outer part of the first detection pipe along with the continuous rising of the liquid level, meanwhile, the driving pulley is driven to move upwards together through magnetic coupling, the driving pulley drives the driving wheel disc to rotate along the anticlockwise direction (looking towards the driving wheel disc) through the traction rope and the guide wheel, the balance pulley also moves upwards, at the moment, the transmission shaft rotates together with the driving wheel disc, thereby driving the output shaft of the potential sensor (i.e. the multi-turn wire-wound potentiometer) to rotate with the driving wheel disc in the same direction and angle, further generating the linear change of the resistance value, converting the resistance signal of the potential sensor into a current signal by the signal conversion box, and linear and stable 4-20mA current signals are input into the liquid level display, and finally digital signals which are convenient for workers to read the height of the liquid level are displayed in the liquid level display. Similarly, when the liquid level descends, the magnetic floating ball drives the driving pulley to move downwards together through magnetic coupling, at the moment, because the driving pulley moves downwards, the tension of the traction rope connected with the driving pulley is instantaneously reduced, the balance of the tension of the traction ropes on two sides of the original driving wheel disc is broken, the balance pulley overcomes the torque of the transmission shaft to move downwards, during the period, the driving wheel disc is in a dynamic balance state, the transmission shaft is also in a smooth rotation state, but the rotation direction of the driving wheel disc is always clockwise (looking towards the driving wheel disc), the driving wheel disc and the transmission shaft rotate together, and then the output shaft of the driving potential sensor rotates in the same direction and at the same angle with the driving wheel disc, and the linear change of the resistance value is further generated.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention.

Claims

1. The utility model provides a differential balance formula liquid level sensing device which characterized in that: comprises a liquid level output assembly and a differential force detection assembly; the liquid level output assembly comprises a potential sensor, a transmission shaft, a signal conversion box and a liquid level display; an output shaft of the potential sensor is fixedly connected with the transmission shaft; the signal conversion box converts the electric signal of the potential sensor into a current signal and inputs the current signal to the liquid level display; the differential force detection assembly comprises a driving wheel disc, a traction rope, a driving unit and a balance unit, the driving wheel disc is fixedly sleeved on the transmission shaft, and the traction rope is wound on the driving wheel disc; the driving unit comprises a first detection pipe, a magnetic floating block, a driving pulley and a guide wheel, the first detection pipe is a hollow pipeline, and the magnetic floating block is slidably sleeved outside the first detection pipe; the driving pulley is magnetically coupled with the magnetic floating block, and the driving pulley is arranged inside the first detection pipe and can slide along the inner wall of the first detection pipe; the guide wheel is fixedly arranged below the driving pulley; the balance unit comprises a second detection pipe and a balance pulley, and the second detection pipe is arranged in parallel with the first detection pipe and is a hollow pipeline; the balance pulley is arranged inside the second detection pipe and can slide along the inner wall of the second detection pipe; two ends of the traction rope are respectively arranged in the first detection tube and the second detection tube in a penetrating mode, one end of the traction rope bypasses the guide wheel to be connected with the driving pulley, and the other end of the traction rope is connected with the balance pulley.

2. The differential balanced level sensing apparatus of claim 1, wherein: and the bottom end and the top end of the first detection tube and the second detection tube are respectively provided with a bottom end sealing plate and a top end sealing plate.

3. The differential balanced level sensing apparatus of claim 2, wherein: the liquid level output assembly further comprises a box body, the potential sensor, the transmission shaft and the signal conversion box are arranged in the box body, and the driving wheel disc is arranged in the box body.

4. The differential balanced level sensing apparatus of claim 3, wherein: the detection box further comprises a communication pipeline, one end of the communication pipeline is connected with the box body, the other end of the communication pipeline is connected with the top end sealing plate, and the traction rope penetrates through the communication pipeline and the top end sealing plate to be arranged inside the first detection pipe/the second detection pipe.

5. The differential balanced level sensing apparatus of claim 3, wherein: the liquid level output assembly further comprises a support frame and a bearing, the support frame is fixedly arranged in the box body, the bearing is fixedly arranged on the support frame, the potential sensor is fixedly arranged on the support frame, and the transmission shaft is rotatably arranged on the bearing.

6. The differential balanced level sensing apparatus of claim 1, wherein: the top and the bottom of the first detection tube are respectively provided with an upper limiting block and a lower limiting block, and the magnetic floating block is positioned between the upper limiting block and the lower limiting block.

7. The differential balanced level sensing apparatus of claim 1, wherein: the magnetic floating block is a magnetic floating ball.

8. The differential balanced level sensing apparatus of claim 2, wherein: the guide wheel is fixedly arranged on the bottom end sealing plate of the first detection pipe.

9. The differential balanced level sensing apparatus of claim 1, wherein: and the output shaft of the potential sensor is fixedly connected with the transmission shaft through a connecting flange.

10. The differential balanced level sensing apparatus of any one of claims 1 to 9, wherein: the potential sensor is a multi-coil wire-wound potentiometer.