CN219589619U - LVDT sensor - Google Patents

Abstract

The utility model relates to an LVDT sensor comprising: iron core, skeleton, coil and outer casing; the framework is of a tubular structure, the iron core is slidably arranged in a cavity of the framework, the coil is sleeved on the outer side wall of the framework, two ends of the coil are electrically connected with wires, and the wires penetrate through the shell; the shell is of a tubular structure, the shell is sleeved on the outer side of the framework, the axis of the shell is in the same direction as the axis of the framework, the coil is positioned between the framework and the shell, and the opposite ends of the shell are respectively connected with the opposite ends of the framework; the lateral wall of shell is equipped with inlet port and oil outlet, and the inlet port is applicable to the cavity that lets in cooling oil between shell and the skeleton, and the oil outlet is applicable to the discharge with cooling oil. Compared with the existing LVDT sensor, the high-temperature environment causes unstable output and poor reliability of the sensor. The utility model dissipates heat of the LVDT sensor, always ensures that the LVDT sensor is at normal working temperature, and ensures normal use of the LVDT sensor in a high temperature environment.

Description

LVDT sensor

Technical Field

The utility model relates to the technical field of measuring tools, in particular to an LVDT sensor.

Background

The LVDT sensor is an abbreviation of Linear Variable Differential Transformer linear variable differential transformer, which is an electromagnetic induction type displacement sensor capable of converting a mechanical displacement signal into an electrical signal. Existing LVDT sensors typically have a housing, coil, wire, backbone, and core in order from the outside to the inside, such as CN208780117U. The coil is wound on the framework and is used for generating an induction magnetic field, and due to the electromagnetic induction principle, corresponding electric signals can be generated by the mechanical displacement of the iron cores arranged in the framework and transmitted to other controllers through wires arranged at two ends of the coil.

LVDT sensors have some high temperature applications, such as measuring rock deformation in oil exploitation. However, in the conventional LVDT sensor, the magnetic material performance of the coil is reduced, the nonmetallic material is aged and disabled due to the high-temperature environment, so that the output precision of the sensor is reduced, the linearity is deteriorated, the sensitivity is reduced, and finally the output of the LVDT sensor is unstable and the reliability is poor under the high-temperature environment.

Therefore, how to ensure the normal use of the LVDT sensor in a high temperature environment is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

In order to ensure the normal use of the LVDT sensor in a high temperature environment, the present utility model provides an LVDT sensor.

An LVDT sensor according to the present utility model comprises:

iron core, skeleton, coil and outer casing;

the framework is of a tubular structure, the iron core is slidably arranged in a cavity of the framework, the coil is sleeved on the outer side wall of the framework, two ends of the coil are electrically connected with wires, and the wires penetrate through the shell;

the shell is of a tubular structure, the shell is sleeved on the outer side of the framework, the axis of the shell and the axis of the framework face in the same direction, the coil is positioned between the framework and the shell, and the opposite ends of the shell are respectively connected with the opposite ends of the framework;

the side wall of shell is equipped with inlet port and oil outlet, the inlet port is applicable to with the cooling oil lets in the shell with cavity between the skeleton, the oil outlet is applicable to with the cooling oil discharge.

In one possible implementation, the skeleton is provided with a connection;

the two connecting parts are respectively positioned at two opposite ends of the framework, the connecting parts are annular, the inner side wall of the annular structure of the connecting parts is connected with the framework, and the outer side wall of the annular structure of the connecting parts is connected with the shell.

In one possible implementation manner, the shell is strip-shaped, and the oil inlet and the oil outlet are respectively located at two opposite ends of the shell body in the width direction.

In one possible implementation, the coil is provided with a thermal insulation layer.

In one possible implementation, a thermal insulation layer is provided on the outer side of the skeleton.

In one possible implementation, the housing inner side wall is provided with a heat insulating layer.

In one possible implementation, the housing is generally cylindrical.

In one possible implementation, the housing is provided with a signal hole therethrough;

the coil comprises a first secondary coil, a primary coil and a second secondary coil, wherein the first secondary coil, the primary coil and the second secondary coil are sequentially distributed on the framework, the two ends of the first secondary coil, the primary coil and the second secondary coil are respectively provided with a wire, the number of the wires is more than two, and the wires penetrate out of the shell through the signal holes.

In one possible implementation, the edge of the signal hole is provided with a seal.

The utility model is suitable for mechanical displacement detection in high temperature environment, the iron core can freely move in the framework, the iron core is connected with a workpiece to be detected through the detection rod, the iron core generates displacement along with the displacement change of the workpiece, electromagnetic induction generates an electric signal, and the electric signal is transmitted to the display through the lead to realize the detection function of the LVDT sensor. Through being provided with oil inlet and oil-out at the shell penetration, hydraulic oil passes through the oil inlet business turn over shell, directly carries out energy transfer with the coil contact, dispels the heat for the coil, realizes the high temperature resistant function of sensor. Compared with the existing LVDT sensor, the high-temperature environment causes unstable output and poor reliability of the sensor. The utility model dissipates heat of the LVDT sensor, always ensures that the LVDT sensor is at normal working temperature, and ensures normal use of the LVDT sensor in a high temperature environment.

In addition, the arrangement of the oil inlet and the oil outlet ensures that the cavity between the shell and the framework is always communicated with the outside, so that the pressure relief of the sealed space can be realized, the balance of internal pressure and external pressure is realized, and the high pressure resistance function of the sensor is realized. Compared with the existing LVDT sensor, in order to conduct electromagnetic shielding among a plurality of sensors, the shell covers the framework, a sealed space is formed between the shell and the framework, but potential safety hazards exist in the sealed space in a high-temperature high-pressure environment.

Drawings

FIG. 1 shows a schematic structural diagram of an LVDT sensor of an embodiment of the present utility model;

fig. 2 shows a schematic structural view of an iron core according to an embodiment of the present utility model.

Detailed Description

Various exemplary embodiments, features and aspects of the utility model will be described in detail below with reference to the drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

It should be understood, however, that the terms "center," "longitudinal," "transverse," "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," and the like indicate or are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the utility model or simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the utility model.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

In addition, numerous specific details are set forth in the following description in order to provide a better illustration of the utility model. It will be understood by those skilled in the art that the present utility model may be practiced without some of these specific details. In some instances, well known methods, procedures, components, and circuits have not been described in detail so as not to obscure the present utility model. The coil comprises a first secondary coil, a primary coil and a second secondary coil, and the first secondary coil, the primary coil and the second secondary coil are sequentially distributed on the framework. And leads are arranged at two ends of the first secondary coil, the primary coil and the second secondary coil, and are suitable for being electrically connected with a controller to transmit electric signals output by the LVDT sensor.

FIG. 1 shows a schematic structural diagram of an LVDT sensor according to an embodiment of the present utility model; fig. 2 shows a schematic structural view of an iron core according to an embodiment of the present utility model.

As shown in fig. 1, the LVDT sensor includes: iron core 100, bobbin 200, coil 300 and housing 400; the framework 200 is of a tubular structure, the iron core 100 is slidably arranged in a cavity of the framework 200, the coil 300 is sleeved on the outer side wall of the framework 200, two ends of the coil 300 are electrically connected with the wires 310, and the wires 310 penetrate through the shell 400; the two ends of the coil 300 are welded with wires 310, and the other ends of the wires 310 are arranged to penetrate out of the housing 400. The shell 400 is of a tubular structure, the shell 400 is sleeved on the outer side of the framework 200, the axis of the shell 400 and the axis of the framework 200 face in the same direction, the coil 300 is positioned between the framework 200 and the shell 400, the coil 300 is wound on the outer side of the framework 200, and the opposite ends of the shell 400 are respectively connected with the opposite ends of the framework 200; the side wall of the housing 400 is provided with an oil inlet hole and an oil outlet hole, the oil inlet hole is suitable for introducing cooling oil into a cavity between the housing 400 and the framework 200, and the oil outlet hole is suitable for discharging the cooling oil.

The utility model is suitable for mechanical displacement detection in high temperature environment, the iron core 100 can freely move in the framework 200, the iron core 100 is connected with a workpiece to be detected through the detection rod, the iron core 100 generates displacement along with the displacement change of the workpiece, electromagnetic induction generates an electric signal, and the electric signal is transmitted to a display through a lead 310, so that the detection function of the LVDT sensor is realized. Through the oil inlet 410 and the oil outlet 420 which are formed in the shell 400 in a penetrating manner, hydraulic oil directly contacts with the coil 300 to transfer energy through the oil inlet and the oil outlet in the shell 400, and the coil 300 is cooled, so that the high temperature resistant function of the sensor is realized. Compared with the existing LVDT sensor, the high-temperature environment causes unstable output and poor reliability of the sensor. The utility model dissipates heat of the LVDT sensor, always ensures that the LVDT sensor is at normal working temperature, and ensures normal use of the LVDT sensor in a high temperature environment.

In addition, the arrangement of the oil inlet 410 and the oil outlet 420 ensures that the cavity between the shell 400 and the framework 200 is always communicated with the outside, so that the pressure in the sealed space can be relieved, the balance of internal and external pressure is achieved, and the high pressure resistant function of the sensor is realized. Compared with the existing LVDT sensor, in order to conduct electromagnetic shielding among a plurality of sensors, the shell covers the framework, a sealed space is formed between the shell and the framework, but potential safety hazards exist in the sealed space in a high-temperature high-pressure environment.

The LVDT sensor operates on the principle of a core 100 movable transformer. The coils 300 are distributed on the bobbin 200, the primary coil 300 is located between two secondary coils 300, and a freely movable rod-shaped iron core 100 is arranged inside the bobbin 200. When the core 100 is at the intermediate position, the induced electromotive forces generated by the two secondary coils 300 are equal, so that the output voltage is zero; when the core 100 moves inside the coils 300 and is deviated from the center position, the induced electromotive forces generated by the two coils 300 are not equal, and there is a voltage output, the magnitude of which depends on the magnitude of the detected displacement. The method is used for measuring accurate data such as elongation, vibration frequency, amplitude, thickness and expansion of an object; the device can also be used for positioning machine tools and hydraulic cylinders, controlling roll gaps and valves, and the like.

An existing LVDT sensor suitable for a high temperature environment, for example, a high temperature LVDT displacement sensor disclosed in patent document CN110487161B, although an oil inlet 410 and an oil outlet 420 are provided to dissipate heat, a coil assembly is located in a sleeve, a heat exchange cavity is formed between the sleeve and a housing 400, circulating hydraulic oil always flows outside the sleeve, and is not in direct contact with the coil assembly, only heat exchange can be performed outside the sleeve, and heat dissipation is performed for the coil assembly indirectly through the sleeve and air replacement. The oil inlet 410 and the oil outlet 420 are directly arranged on the shell 400 in a penetrating way, hydraulic oil enters from the oil inlet 410 and directly flows between the shell 400 and the framework 200 to directly contact with the coil 300, and heat is directly dissipated from the shell 400, the framework 200 and the coil 300 in a short distance. The hydraulic oil insulates and dissipates heat, and is directly contacted with the coil 300 without affecting accuracy. Compared with the existing LVDT sensor, the LVDT sensor can directly and rapidly dissipate heat of the shell 400, the framework 200 and the coil 300, and is simple and efficient.

In one possible implementation manner, the opposite ends of the skeleton 200 along the axial direction of the tubular structure are provided with mounting holes, the iron core 100 is integrally columnar, the axial direction of the columnar structure of the iron core 100 is the same as that of the skeleton 200, the iron core 100 is matched with the inner cavity of the tubular structure of the skeleton 200, and the iron core 100 is slidably arranged in the inner cavity of the skeleton 200. The iron core 100 is suitable for being connected with a workpiece to be measured, the iron core 100 generates displacement along with the workpiece to be measured, the sensor generates an electric signal through electromagnetic induction, and signal conversion of the LVDT sensor is completed, so that mechanical displacement is accurately measured.

In one possible implementation, the housing 400 is made of a common material having an electromagnetic shielding effect, such as metal iron, and a relatively sealed accommodating space is formed between the housing 400 and the framework 200 to perform electromagnetic shielding, so as to prevent inaccurate measurement values caused by external discharge of an interfering electromagnetic field and external environmental interference.

In one possible implementation, there are more than two oil inlets, each of the LVDT sensors has a linear range, and during operation, the movement of the core 100 cannot exceed the linear range of the coil 300, otherwise non-linear values will be generated, and the measurement result is inaccurate. Depending on the range to be measured, LVDT sensors of different ranges are selected, the longer the range, the longer the coil 300 and the longer the housing 400. The number of oil inlets can be properly increased according to the length of the coil 300, the flow time of hydraulic oil is shortened, and heat dissipation is performed on the coil 300 and other parts as soon as possible. The oil outlet is one, and the oil outlet and the oil inlet are respectively distributed at two opposite ends of the long tube structure body of the shell in the width direction.

In one possible implementation, the device further comprises a partition board, wherein the partition board is arranged in an inner cavity between the shell and the framework, and the partition board is matched with the inner cavity; the number of the oil inlets is more than two, the number of the oil outlets is consistent with that of the oil inlets, and the oil inlets and the oil outlets are arranged oppositely. More than two oil inlets are adjacently arranged, one end of the partition plate is positioned between the two adjacent oil inlets, and the other end of the partition plate is positioned between the two adjacent oil outlets. And the heat dissipation is carried out in a partitioning way, so that the heat dissipation speed is increased.

In one possible implementation, the skeleton 200 is provided with a connection; the two connecting parts are respectively positioned at two opposite ends of the framework 200, the connecting parts are annular, the inner side wall of the annular structure of the connecting parts is connected with the framework 200, and the outer side wall of the annular structure of the connecting parts is connected with the shell 400. That is, the frame 200 and the housing 400 are fixedly connected by a connecting portion, and are hermetically provided. Simple structure, easy acquisition.

In one possible implementation manner, two ends of the tubular structure of the housing 400 are provided with abdicating holes, the skeleton 200 is matched with the abdicating holes, the skeleton 200 is sleeved in the housing 400 through the abdicating holes, and outer side walls of the two ends of the tubular structure of the skeleton 200 are respectively and hermetically connected with edges of the abdicating holes of the housing 400.

In one possible implementation manner, the casing 400 is a tubular structure with an opening at one end, the skeleton 200 is matched with the abdication hole, the skeleton 200 is sleeved in the casing 400 through the abdication hole, one end of the tubular structure of the skeleton 200 is in sealing connection with one side surface of the casing 400, which is away from the abdication hole, and the outer side wall of the other end of the tubular structure of the skeleton 200 is respectively in sealing connection with the edge of the abdication hole of the casing 400.

In one possible implementation manner, the casing 400 is a tubular structure with an opening at one end, the skeleton 200 is matched with the hole of stepping down, the skeleton 200 is sleeved in the casing 400 through the hole of stepping down, one end of the tubular structure of the skeleton 200 is in sealing connection with one side surface of the casing 400, which is away from the hole of stepping down, and the other end of the tubular structure of the skeleton 200 penetrates out of the casing 400 through the hole of stepping down, namely, the skeleton 200 protrudes out along the outer side wall of the opening end of the casing 400.

In one possible implementation, the housing 400 is elongated, the housing 400 is a long tube, and the oil inlet 410 and the oil outlet 420 are located at opposite ends of the housing 400 in the width direction. The direction of the LVDT sensor is reasonably placed, hydraulic oil enters from bottom to top, the contact area and the length of time between the hydraulic oil and the coil 300 are guaranteed, and heat dissipation is carried out.

In one possible implementation, the wire 310 is soldered to the coil 300.

It should be noted that, the coil 300 is located between the housing 400 and the framework 200, which is a key area for ensuring measurement accuracy, and heat insulation layers made of different materials are set according to functions, so that the high temperature resistant function of the LVDT sensor is finally ensured.

In one possible implementation, the coil 300 is provided with a thermal insulation layer, ensuring the high temperature resistant function of the coil 300. The heat insulating layer is made of polyimide, has strong high and low temperature resistance and can resist the ambient temperature of minus 196 ℃ to plus 200 ℃.

In one possible implementation, the wrapping wire of the coil 300 is made of polyimide, so as to form a heat insulation layer of the coil 300, and ensure the high temperature resistant function of the coil 300.

In one possible implementation, the wire 310 is provided with a protective layer, the protective layer is made of a heat-insulating material, the protective layer is arranged to cover the outer side of the wire 310, and the wire 310 is coated in the protective layer, so that the high temperature resistant function of the wire 310 is ensured.

Further, the lead 310 is made of silver-plated copper wire, and the outer coating is made of teflon insulating film to form a protective layer, so that the lead can resist high temperature of 200 ℃.

In one possible implementation, a thermal insulation layer is provided on the outside of the skeleton 200; the heat insulation layer is of a tubular structure, the heat insulation layer is matched with the framework 200, the framework 200 is sleeved in the heat insulation layer, and the coil 300 is wound and sleeved on the outer side of the heat insulation layer of the framework 200.

Further, the heat insulation layer is made of high-temperature-resistant carbon fiber, so that the high-temperature-resistant function of the framework 200 is ensured.

In one possible implementation manner, the coil 300 framework 200 is made of high-temperature-resistant carbon fiber materials, so that the coil 300 framework 200 has strong high-temperature-resistant insulating capability while being used as a coil 300 carrier.

In one possible implementation manner, the inner side wall of the shell 400 is provided with a heat-insulating layer, the heat-insulating layer is matched with the shell 400, the heat-insulating layer is fixed on the inner side wall of the shell 400, the heat-insulating layer is made of carbon fiber, the shell 400 is protected from being damaged by a high-temperature and high-pressure environment, and the high-temperature resistant function of the shell 400 is improved. The insulation layer maintains the same shape as the housing 400, and covers the inner sidewall of the housing 400.

Further, the heat preservation layer is of a tubular structure, and the structure is simple and easy to obtain.

In one possible implementation, the housing 400 is generally cylindrical and is simple and readily available in shape.

In one possible implementation, the housing 400 is provided with a signal hole therethrough; the coil 300 includes a first secondary coil 300, a primary coil 300 and a second secondary coil 300, wherein the first secondary coil 300, the primary coil 300 and the second secondary coil 300 are sequentially distributed on the framework 200, two ends of the first secondary coil 300, the primary coil 300 and the second secondary coil 300 are respectively provided with a wire 310, the number of the wires 310 is more than two, and more than two wires 310 penetrate out of the housing 400 through a signal hole. The wiring is simple, and confusion omission is prevented.

In one possible implementation, the edges of the signal holes are provided with seals that allow the wires 310 to pass through and ensure that the signal holes are oil tight. The sealing part is made of elastic materials such as rubber and has certain elasticity, so that the relative sealing between the shell 400 and the framework 200 except for an oil inlet and an oil outlet is ensured, the lead 310 is allowed to pass through, and the oil leakage is avoided at the position of the signal hole.

In one possible implementation, the edges of the signal holes are rounded, reducing wear of the wires 310.

The foregoing description of embodiments of the utility model has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (9)

1. An LVDT sensor comprising:

iron core, skeleton, coil and outer casing;

the framework is of a tubular structure, the iron core is slidably arranged in a cavity of the framework, the coil is sleeved on the outer side wall of the framework, two ends of the coil are electrically connected with wires, and the wires penetrate through the shell;

the shell is of a tubular structure, the shell is sleeved on the outer side of the framework, the axis of the shell and the axis of the framework face in the same direction, the coil is positioned between the framework and the shell, and the opposite ends of the shell are respectively connected with the opposite ends of the framework;

the side wall of shell is equipped with inlet port and oil outlet, the inlet port is applicable to with the cooling oil lets in the shell with cavity between the skeleton, the oil outlet is applicable to with the cooling oil discharge.

2. The LVDT sensor of claim 1, wherein the skeleton is provided with a connection;

the two connecting parts are respectively positioned at two opposite ends of the framework, the connecting parts are annular, the inner side wall of the annular structure of the connecting parts is connected with the framework, and the outer side wall of the annular structure of the connecting parts is connected with the shell.

3. The LVDT sensor of claim 1, wherein the housing is elongated, and the oil inlet and the oil outlet are located at opposite ends of the housing in a width direction, respectively.

4. The LVDT sensor of claim 1, wherein the coil is provided with an insulating layer.

5. The LVDT sensor of claim 1, wherein a thermal insulation layer is provided on the outside of the skeleton.

6. The LVDT sensor of claim 1 wherein the housing inner side wall is provided with a thermal insulation layer.

7. The LVDT sensor of claim 1, wherein the housing is generally cylindrical.

8. The LVDT sensor of claim 1, wherein the housing is provided with a signal aperture therethrough;

the coil comprises a first secondary coil, a primary coil and a second secondary coil, wherein the first secondary coil, the primary coil and the second secondary coil are sequentially distributed on the framework, the two ends of the first secondary coil, the primary coil and the second secondary coil are respectively provided with a wire, the number of the wires is more than two, and the wires penetrate out of the shell through the signal holes.

9. The LVDT sensor of claim 8, wherein the edge of the signal aperture is provided with a seal.