High-sensitivity magnetic suspension sensor

Abstract

The utility model provides a high-sensitivity magnetic suspension sensor, and belongs to the technical field of sensors. The device comprises an outer shell, the bottom end of which is provided with a measuring cone; the inner shell is fixed in the outer shell, and two groups of electromagnetic induction coils are wound on the inner shell in series reversely; the vertical shaft is arranged in the inner shell and is restrained by an upper shaft sleeve and a lower shaft sleeve; the counterweight module is fixed on the vertical shaft; the static magnetic core is arranged on the vertical shaft in a sleeving manner and is arranged above the lower shaft sleeve; the movable magnetic core is arranged in the inner shell and is fixed on the vertical shaft; and the permanent magnets in the static magnetic core and the movable magnetic core are arranged in a homopolar opposite manner and are used for forming magnetic suspension support for the movable magnetic core. By adjusting the weight of the counterweight module, the weight of the suspension movable magnetic core body can be changed, and the torque difference generated by the magnetic levitation force and the gravity can be reduced, so that the pressure of the vertical shaft on the shaft sleeve is reduced to be close to zero, the static friction force between the vertical shaft and the shaft sleeve can be obviously reduced, and the sensing capability of extremely weak vibration signals can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a high-sensitivity magnetic suspension sensor, and specifically to a moving magnetic core type eddy current sensor using the magnetic suspension principle. Background Art

[0002] As a signal receiving device, the sensor is widely used in geological exploration, geological disease detection, engineering disease detection, earthquake and geological disaster monitoring, and can also be used as an acoustic wave communication transducer. According to different structural forms and principles, the vibration sensors currently used mainly include eddy current, capacitive, photoelectric and electrochemical types, among which eddy current sensors are one of the commonly used sensors. The eddy current sensors commonly used in the market mostly adopt moving coil or moving magnetic core structures, and the elastic fixed structure is realized by springs or shrapnel. However, the above-mentioned types of detectors all have the problem of overcoming the internal energy of the connection structure at the moment of vibration, resulting in low sensitivity and inability to identify extremely weak vibration signals. Utility Model Content

[0003] In view of this, in order to solve the problem that the existing sensors have low sensitivity and cannot identify extremely weak vibration signals, the utility model provides a high-sensitivity magnetic levitation sensor, which provides a suspension support force for the moving magnetic core through a static magnetic core and a moving magnetic core arranged opposite to each other with the same poles. The weight of the suspended moving magnetic core can be changed by adjusting the weight of the counterweight module, thereby reducing the torque difference generated by the magnetic buoyancy force and the gravity, thereby reducing the pressure of the vertical shaft on the shaft sleeve to near zero, thereby significantly reducing the static friction between the vertical shaft and the shaft sleeve, and improving the perception ability of extremely weak vibration signals.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A high-sensitivity magnetic suspension sensor, comprising:

[0006] An outer shell, the bottom end of which is provided with a measuring cone;

[0007] An inner shell is fixed inside the outer shell and has two sets of electromagnetic induction coils wound in reverse series, and the inner shell is in a vacuum state;

[0008] An upper sealing cap and a lower sealing cap are respectively arranged at the top end and the bottom end of the inner shell;

[0009] A vertical shaft, which is disposed in the inner shell and is constrained by an upper sleeve and a lower sleeve respectively close to the top and bottom ends of the inner shell;

[0010] A counterweight module, which is fixed on the vertical shaft and located between the lower sleeve and the lower sealing cap;

[0011] A static magnetic core, which is sleeved on the vertical shaft and arranged above the lower shaft sleeve;

[0012] A moving magnetic core, which is disposed in the inner shell and fixed on the vertical shaft;

[0013] The static magnetic core and the permanent magnets in the dynamic magnetic core are arranged opposite to each other with the same poles, so as to form a magnetic suspension support for the dynamic magnetic core.

[0014] Preferably, the lower sleeve is fixed to one end of a first retaining spring, and the other end of the first retaining spring is fixed to the inner bottom end of the outer shell.

[0015] Preferably, the upper sleeve is fastened by an upper sealing cap.

[0016] Preferably, the vertical shaft is made of non-magnetic austenitic stainless steel.

[0017] Preferably, the counterweight module is made of ceramic material.

[0018] Preferably, the outer shell is made of solid metal.

[0019] Preferably, the solid metal is 7 series aluminum alloy.

[0020] Preferably, the inner shell is made of a non-magnetic and non-conductive polymer material.

[0021] Preferably, the polymer material is PEEK.

[0022] Preferably, a waterproof polymer material is filled between the outer shell and the inner shell.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] The high-sensitivity magnetic suspension sensor provided by the utility model comprises a weight module and a static magnetic core to form a suspended dynamic magnetic core body, and a static magnetic core and a dynamic magnetic core arranged opposite to each other with the same poles provide a suspension support force for the dynamic magnetic core. By adjusting the weight of the weight module, the weight of the suspended dynamic magnetic core body can be changed, the suspension support force can be changed, and the resonant frequency of the sensor can be pre-adjusted. At the same time, the torque difference generated by the magnetic buoyancy force and the gravity can be reduced, thereby reducing the pressure of the vertical shaft on the shaft sleeve to near zero, which can significantly reduce the static friction between the vertical shaft and the shaft sleeve, and improve the perception ability of extremely weak vibration signals.

[0025] The utility model can flexibly adjust the weight of the suspended moving magnetic core by adjusting the weight of the counterweight module, change the suspension support force, and then pre-adjust the resonant frequency of the sensor to produce a product suitable for different application scenarios.

[0026] The utility model can change the center of gravity position of the suspended moving magnetic core body and reduce the torque difference generated by the magnetic buoyancy and gravity through the setting and adjustment of the counterweight module, thereby reducing the pressure of the vertical shaft on the straightening sleeve to close to 0. According to the friction formula f=μN (μ is the friction coefficient), the static friction between the vertical shaft and the sleeve can be significantly reduced.

[0027] Compared with a structure without a counterweight module to adjust the center of gravity of the moving magnetic core, the vibration threshold of the sensor can be reduced by more than 80%. Therefore, the utility model has the ability to perceive extremely weak vibration signals and can be applied to communication and monitoring in underground space or deep sea.

[0028] The utility model can be applied to various extremely weak mechanical wave signal receiving scenarios, such as earthquake exploration, detection and monitoring of hydraulic structure defects, underground and underwater acoustic wave communication transduction, etc.

[0029] In summary, the magnetic levitation sensor provided by the utility model is a moving magnetic core eddy current sensor using the magnetic levitation principle, which is gradually recognized and used by the market due to its simple structure, high sensitivity and good low-frequency effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the utility model;

[0031] 1. Upper sealing cap; 2. Upper shaft sleeve; 3. Vertical shaft; 4. Moving magnetic core; 5. Inner housing; 6. First retaining spring; 7. Outer housing; 8. Coil assembly; 9. Static magnetic core; 10. Lower shaft sleeve; 11. Counterweight module; 12. Lower sealing cap; 13. Measuring cone. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model without making creative work are within the scope of protection of the utility model.

[0033] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the term "first" is only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0035] like Figure 1 As shown, the utility model provides a high-sensitivity magnetic suspension sensor, comprising:

[0036] The outer shell 7 has a measuring cone 13 at its bottom, wherein the material of the outer shell 7 is preferably solid metal, such as 7 series aluminum alloy, etc., which can be selected according to actual needs. The outer shell 7 made of solid metal not only has the function of system sealing, but also provides damping for the vibration of the moving magnetic core 4. The measuring cone 13 transmits the vibration of the detected object to the outer shell 7, and further to the inner shell 5. The permanent magnet in the static magnetic core 9 in the inner shell 5 pushes the permanent magnet in the moving magnetic core 4 to produce relative movement relative to the electromagnetic induction coil through magnetic repulsion, thereby generating an induced voltage in the electromagnetic induction coil, and useful information is interpreted by reading the change in voltage.

[0037] The inner housing 5 is fixed in the outer housing 7 and has two sets of electromagnetic induction coils wound in reverse series;

[0038] The material of the inner shell 5 is preferably a non-magnetic and non-conductive polymer material, and specifically PEEK can be selected.

[0039] The upper sealing cap 1 and the lower sealing cap 12 are respectively arranged at the top and bottom ends of the inner shell 5, and are used to form a closed state between the outer shell 7 and the inner shell 5;

[0040] A vertical shaft 3, which is disposed in the inner housing 5 and is constrained by an upper shaft sleeve 2 and a lower shaft sleeve 10 located at the top and bottom ends of the inner housing 5 respectively;

[0041] The material of the vertical shaft 3 is preferably non-magnetic austenitic stainless steel.

[0042] A counterweight module 11, which is fixed on the vertical shaft 3 and is located between the lower sleeve 10 and the lower sealing cap 12;

[0043] The material of the weight module 11 is preferably ceramic material, which is used to adjust the weight and the position of the structural center of gravity of the moving magnetic core 4 .

[0044] A static magnetic core 9, which is sleeved on the vertical shaft 3 and arranged above the lower shaft sleeve 10;

[0045] A moving magnetic core 4, which is disposed in the inner shell 5 and fixed on the vertical shaft 3;

[0046] The static magnetic core 9 is disposed opposite to the permanent magnet in the dynamic magnetic core 4 with the same poles, so as to form a magnetic suspension support for the dynamic magnetic core 4 .

[0047] In the present invention, the system consisting of the moving magnetic core 4, the static magnetic core 9, the inner shell 5 and the electromagnetic induction coil group 8 is installed in the outer shell 7 and is sealed.

[0048] In the utility model, the permanent magnet of the moving magnetic core 4 is constrained by an upper sleeve and a lower sleeve 10, wherein the upper sleeve is installed on the inner shell 5 at the upper position of the vertical shaft 3, and the lower sleeve 10 is installed on the inner shell 5 between the moving magnetic core 4 and the counterweight module 11.

[0049] In the present invention, the counterweight module 11 and the permanent magnet of the moving magnetic core 4 are connected in series and fixed via a vertical shaft 3 made of non-magnetic austenitic stainless steel material, and together form a suspended moving magnetic core 4 body.

[0050] In the present invention, the lower sleeve 10 is fixed to one end of the first retaining spring 6 , and the other end of the first retaining spring 6 is fixed to the inner bottom end of the outer shell 7 .

[0051] In the present invention, the upper sleeve 2 is fixed to the inner top end of the outer shell 7 and is fastened by the upper sealing cap 1 .

[0052] In the utility model, waterproof polymer material is filled between the outer shell 7 and the inner shell 5, that is, the inner shell 5 and the outer shell 7 are sealed with waterproof polymer material, the protection level is improved, and it is convenient for permanent use underground and deep sea.

[0053] The working principle of the utility model is as follows:

[0054] The vibration of the detected object is transmitted to the outer shell 7 through the measuring cone 13, and further to the inner shell 5. The permanent magnet in the static magnetic core 9 in the inner shell 5 drives the permanent magnet in the moving magnetic core 4 to produce relative movement relative to the electromagnetic induction coil through magnetic repulsion. According to Faraday's law of electromagnetic induction, an induced voltage is generated in the electromagnetic induction coil, and useful information is interpreted by reading the change in voltage.

[0055] The utility model replaces the spring or shrapnel of the traditional sensor with the magnetic repulsion of the static magnetic core on the dynamic magnetic core, and offsets the torque of the dynamic magnetic core and the magnetic buoyancy force by adjusting the center of gravity position of the dynamic magnetic core assembly, thereby reducing the friction resistance of the vibration system to almost zero, greatly improving the sensor's perception ability of extremely weak signals.

[0056] Application scenario 1: Seabed fixed-position monitoring sonar. Compared with similar products, this sensor, when used as a sonar, is tens to hundreds of times more sensitive than the most advanced sonars on the market.

[0057] Application scenario 2: Infrasonic communication, the encoded infrasonic waves are sent underground or underwater in the form of mechanical energy. This sensor can receive the infrasonic signal at a long distance and obtain the original information by decoding it again. Compared with traditional sensors, the high-sensitivity magnetic levitation sensor provided by the utility model eliminates the springs and shrapnel in traditional sensors and optimizes the structure and material design to greatly reduce the sum of the torque of magnetic repulsion and gravity, greatly reduce the system's vibration resistance, and improve the perception of extremely weak vibration signals.

[0058] The above are only preferred specific implementations of the utility model; however, the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and improved ideas of the utility model within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model.

Claims

1. A high-sensitivity magnetic suspension sensor, characterized in that: include: An outer shell, the bottom end of which is provided with a measuring cone; An inner shell, which is fixed inside the outer shell and has two sets of electromagnetic induction coils wound in reverse series; An upper sealing cap and a lower sealing cap are respectively arranged at the top end and the bottom end of the inner shell; A vertical shaft, which is disposed in the inner shell and is constrained by an upper sleeve and a lower sleeve respectively close to the top and bottom ends of the inner shell; A counterweight module, which is fixed on the vertical shaft and located between the lower sleeve and the lower sealing cap; A static magnetic core, which is sleeved on the vertical shaft and arranged above the lower shaft sleeve; A moving magnetic core, which is disposed in the inner shell and fixed on the vertical shaft; The static magnetic core and the permanent magnets in the dynamic magnetic core are arranged opposite to each other with the same poles, so as to form a magnetic suspension support for the dynamic magnetic core.

2. A high-sensitivity magnetic levitation sensor according to claim 1, characterized in that: The lower sleeve is fixed to one end of a first clamping spring, and the other end of the first clamping spring is fixed to the inner bottom end of the outer shell.

3. A high-sensitivity magnetic levitation sensor according to claim 1, characterized in that: The upper shaft sleeve is fastened by an upper sealing cap.

4. A high-sensitivity magnetic levitation sensor according to claim 1, characterized in that: The material of the vertical shaft is non-magnetic austenitic stainless steel.

5. A high-sensitivity magnetic levitation sensor according to claim 1, characterized in that: The material of the counterweight module is ceramic material.

6. A high-sensitivity magnetic levitation sensor according to claim 1, characterized in that: The outer shell is made of solid metal.

7. A high-sensitivity magnetic levitation sensor according to claim 6, characterized in that: The solid metal is 7 series aluminum alloy.

8. The high-sensitivity magnetic levitation sensor according to claim 1, characterized in that: The inner shell is made of a non-magnetic and non-conductive polymer material.

9. A high-sensitivity magnetic levitation sensor according to claim 8, characterized in that: The polymer material is PEEK.

10. A high-sensitivity magnetic levitation sensor according to any one of claims 1 to 9, characterized in that: The outer shell and the inner shell are filled with waterproof polymer material.

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