CN114485367A - A probe of an inductive displacement sensor, a probe coil excitation method and an inductive displacement sensor - Google Patents

Abstract

The invention discloses a probe of an inductive displacement sensor, a probe coil exciting method and the inductive displacement sensor, wherein the probe comprises: the detection coil comprises a plurality of detection coils and a mesh shielding cover arranged between the detection coils, wherein an insulation distance d is arranged between the detection coils and the mesh shielding cover. The probe of the inductance type displacement sensor is internally provided with the plurality of detection coils, each detection coil is isolated by the mesh shield cover, the distance between the detection coils can be effectively reduced, the signal interference between the detection coils is eliminated, the insulation distance d is arranged between the detection coils and the mesh shield cover, and the mesh shield cover is prevented from influencing the measurement range of the detection coils.

Description

A probe of an inductive displacement sensor, a probe coil excitation method and an inductive displacement sensor

technical field

The invention relates to the field of sensors, in particular to a probe of an inductive displacement sensor, a probe coil excitation method and an inductive displacement sensor.

Background technique

Most of the existing inductive displacement sensor probes use a single-coil structure. When the probe fails or the controller circuit is aging, temperature drifted, or soldered, the sensor output signal will all fail or the signal will be distorted, which will affect the authenticity of the signal, and It may make the monitored equipment unable to start normally, or unable to operate normally, or unable to judge the real equipment failure.

The most effective and direct method to improve the measurement reliability is to use multiple coils to measure a measurement point in parallel. When the signals detected by multiple coils are the same, the measurement signal of the measurement point is considered to be authentic and credible. . However, when the ordinary inductive displacement sensor performs vibration and displacement measurement, the target surface size of the metal object to be measured is required to be more than 3 times the diameter of the probe coil. more than 3 times the diameter, otherwise, due to the high-frequency characteristics of the self-resonant frequency of the probe coil or the excitation frequency, mutual coupling interference will occur between the probe coils. The use of the same frequency synchronous drive eddy current displacement sensor can shorten the center distance between the two probes to about 1.5 times the diameter of the probe, but it still cannot be used redundantly in places where the size of the target surface to be measured is severely limited.

SUMMARY OF THE INVENTION

The invention provides a probe of an inductive displacement sensor, a probe coil excitation method and an inductive displacement sensor, which are used to solve the technology that the redundant probe coil cannot be used when the current inductive displacement sensor is severely limited to the size of the target surface of the measured object. question.

In order to solve the above technical problems, in the first aspect, the present invention proposes a probe of an inductive displacement sensor, which includes: a plurality of detection coils, and a mesh shielding cover arranged between each detection coil, the detection coils are connected to all the detection coils. An insulating distance d is set between the mesh shields.

As a further improvement of the above technical solution: the detection coils are specifically three, which are a first detection coil, a second detection coil and a third detection coil.

As a further improvement of the above technical solution: there are two mesh shields, which are a first mesh shield and a second mesh shield, and the first mesh shield is arranged on the first detection Between the coil and the second detection coil, the second mesh shield is provided between the second detection coil and the third detection coil.

As a further improvement of the above technical solution: the first detection coil, the second detection coil, the third detection coil, the first mesh shield and the second mesh shield are concentrically nested, and the diameters are in order from small to large. It is a first detection coil, a first mesh shield, a second detection coil, a second mesh shield, and a third detection coil.

As a further improvement of the above technical solution: the first detection coil, the second detection coil, the third detection coil, the first mesh shield and the second mesh shield are arranged side by side, and the first detection coil, the third The diameters of the second detection coil and the third detection coil are the same.

As a further improvement of the above technical solution: the mesh shield includes a radial surface with a plurality of through holes, an axial bottom surface and an axial sensitive surface, and an insulation is provided between the detection coil and the radial surface. The distance d, the distance between the detection coil and the axial sensitive surface is smaller than the distance between the detection coil and the axial bottom surface.

As a further improvement of the above technical solution: the diameter of the radial surface is the same as the diameter of the axial bottom surface, and the diameter of the axial sensitive surface is larger than the diameter of the axial bottom surface.

Beneficial effects: The probe of the inductive displacement sensor of the present invention is provided with a plurality of detection coils inside, and each detection coil is isolated by a mesh shield, which can effectively reduce the distance between the detection coils and eliminate the need for The signal interference between the detection coils, and the insulation distance d is set between the detection coil and the mesh shield, so as to prevent the mesh shield from affecting the measurement range of the detection coil, the probe of the inductive displacement sensor of the present invention can reduce The small probe detection surface area realizes the redundancy of multiple detection coils at the same time, and does not affect the measurement range of the detection coil, which greatly improves the reliability and stability of the probe of the inductive displacement sensor.

In a second aspect, the present invention further provides an inductive displacement sensor, which includes a signal processing circuit, and also includes the probe described in the first aspect,

Each of the detection coils is electrically connected to a signal processing circuit and an excitation source through an extension cable, the signal processing circuit includes a detection circuit that is electrically connected to the detection coil and a normalization circuit that is electrically connected to the detection circuit. circuit.

Beneficial effects: The inductive displacement sensor of the present invention provides an independent excitation source and a signal processing circuit for each detection coil, and at the same time enables all detection coils to detect the same target point, and the monitoring coils do not affect each other. It can realize redundant detection of the same target by multiple detection coils, which can not only avoid data measurement due to damage to detection coils, but also improve data reliability through mutual verification of multiple sets of data.

In a third aspect, the present invention also provides a probe coil excitation method for an inductive displacement sensor, the method is applied to the inductive displacement sensor described in the second aspect, and specifically includes the following steps:

S1: Input high-frequency excitation signal to each detection coil;

S2: Obtain the detection signal output by each of the detection coils through each detector corresponding to the detection coil;

S3: The detector outputs the detection signal to the normalization circuit;

S4: When more than 2/3 of the detection signals are the same or within the preset fluctuation threshold range, output the detection signals to the external judgment circuit.

As a further improvement of the above technical solution: the step S1 is specifically:

After frequency division by the same excitation source, a high-frequency excitation signal is provided for all the detection coils at the same time, or a high-frequency excitation signal is provided for each corresponding detection coil respectively through a plurality of excitation sources.

Beneficial effect: The probe coil excitation method of an inductive displacement sensor of the present invention enables all detection coils to detect the same target point, and by acquiring the detection signal of each detection coil, when more than 2/3 of the detection signals are When the detection signal is the same or within the preset fluctuation threshold range, the detection signal is output, which greatly improves the authenticity and stability of the detection signal.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The present invention will be described in further detail below with reference to the accompanying drawings.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a schematic cross-sectional structure diagram of a probe of an inductive displacement sensor according to a preferred embodiment of the present invention;

2 is a schematic cross-sectional structure diagram of an inductive displacement sensor probe according to another preferred embodiment of the present invention;

3 is a schematic cross-sectional structure diagram of an inductive displacement sensor probe according to another preferred embodiment of the present invention;

4 is a schematic structural diagram of a mesh shielding cover of an inductive displacement sensor probe according to a preferred embodiment of the present invention;

5 is a schematic structural diagram of a radial surface of a mesh shielding cover according to a preferred embodiment of the present invention;

6 is a schematic structural diagram of the axial bottom surface of the mesh shielding cover according to the preferred embodiment of the present invention;

7 is a schematic structural diagram of an axially sensitive surface of a mesh shielding cover according to a preferred embodiment of the invention;

FIG. 8 is a schematic diagram of signal transmission of the inductive displacement sensor of the present invention.

The symbols in the figure represent:

1, detection coil; 11, first detection coil; 12, second detection coil; 13, third detection coil; 2, mesh shield; 21, first mesh shield; 22, second mesh shield ; 23, radial surface; 24, axial bottom surface; 25, axial sensitive surface.

Detailed ways

The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

Also, unless otherwise defined, technical or scientific terms used in the description of this application shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer", etc. used in the description of this application to indicate orientation are only used To indicate the relative direction or positional relationship, rather than implying that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and when the absolute position of the described object changes, its relative positional relationship may also change accordingly , so it cannot be construed as a limitation on this application. The terms "first", "second", "third" and similar terms used in the description of this application are only used for the purpose of description, to distinguish different components, and cannot be construed as indicating or implying relative importance. Words like "a," "an," or "the" and the like used in the description of this application should not be construed as an absolute limitation on the quantity, but should be construed as the presence of at least one. The use of "comprising" or "comprising" and similar words in the description of this application means that the elements or things appearing before the word encompass the elements or things listed after the word and their equivalents, but do not exclude other elements or things.

It should also be noted that, unless otherwise expressly specified and limited, the words "installed", "connected", "connected" and the like used in the description of this application should be understood in a broad sense, for example, the connection may be a fixed connection, It can also be a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of the two components. Those skilled in the art Its specific meaning in this application can be understood according to specific circumstances.

Embodiment 1, a probe of an inductive displacement sensor.

The probe of the inductive displacement sensor in this embodiment includes: a plurality of detection coils 1 and a mesh shield 2 arranged between each detection coil 1 , and an insulation is provided between the detection coil 1 and the mesh shield 2 distance d.

According to design requirements, the number of detection coils 1 in this embodiment can be any number. Specifically, in this embodiment, there are three detection coils, which are a first detection coil 11 , a second detection coil 12 and a third detection coil respectively. 13. In other embodiments, as shown in FIG. 3 , there may be six detection coils 1 , and the six detection coils 1 are all separated by a “well”-shaped mesh shield 2 .

Since the mesh shield 2 is provided between each detection coil 1 to separate the detection coils 1, since the number of detection coils 1 in this embodiment is three, in this embodiment, the mesh Specifically, there are two shielding covers 2 , namely, a first mesh shielding cover 21 and a second meshing shielding cover 22 . The first meshing shielding cover 21 is arranged between the first detection coil 11 and the second detection coil 12 . The two mesh shields 22 are arranged between the second detection coil 12 and the third detection coil 13 .

The first mesh shield 21 is located between the first detection coil 11 and the second detection coil 12, and is used to shield and isolate the high-frequency coupling interference of the first detection coil 11 and the second detection coil 12. The second mesh shield 22 Located between the second detection coil 12 and the third detection coil 13 , it is used to shield and isolate the high-frequency mutual coupling interference between the second detection coil 12 and the third detection coil 13 .

In the probe of the inductive displacement sensor of this embodiment, the first detection coil 11 , the second detection coil 12 , the third detection coil 13 , the first mesh shield 21 and the second mesh shield 22 are concentrically nested, and The diameters from small to large are the first detection coil 11 , the first mesh shield 21 , the second detection coil 12 , the second mesh shield 22 , and the third detection coil 13 .

The first detection coil 11 , the second detection coil 12 , the third detection coil 13 , the first mesh shield 21 and the second mesh shield 22 are concentrically nested. All have an insulation distance d, therefore, the first detection coil 11, the second detection coil 12, the third detection coil 13, the first mesh shield 21 and the second mesh shield 22 have the same shape, which can be circular In this embodiment, the first detection coil 11 , the second detection coil 12 , the third detection coil 13 , the first mesh shield 21 and the second mesh shield 22 are all circular The shape is illustrated as an example. Therefore, as shown in FIG. 1, the cross sections of the first detection coil 11, the second detection coil 12, the third detection coil 13, the first mesh shield 21 and the second mesh shield 22 as a concentric circle.

As shown in Figures 4-7, in the probe of the inductive displacement sensor in this embodiment, the mesh shield 2 includes a radial surface 23, an axial bottom surface 24 and an axial sensitive surface 25. Since the detection coil 1 is made of metal, it will The measurement range of the coil is affected. Therefore, an insulation distance d is required between the detection coil 1 and the radial surface 23 . The distance between the detection coil 1 and the axial sensitive surface 25 is smaller than the distance between the detection coil 1 and the axial bottom surface 24 .

The diameter of the radial surface 23 is the same as the diameter of the axial bottom surface 24 , and the diameter of the axial sensitive surface 25 is larger than that of the axial bottom surface 24 .

The mesh shield 2 adopts an omnidirectional three-dimensional shielding structure through the radial surface 23 , the axial bottom surface 24 and the axial sensitive surface 25 , and the protected detection coil 1 is located near the axial sensitive surface 25 .

As shown in FIG. 5 , the radial surface 23 of the mesh shield 2 is used to shield the lateral electromagnetic interference of the protected detection coil 1. Tests have shown that the mutual interference of adjacent detection coils 1 mainly comes from the radial surface 23. This direction has less eddy current loss on the protected detection coil 1 or can be set farther from the edge of the detection coil 1, which has little effect on the range of the sensor, the aperture is set relatively tight, the mesh opening is relatively small, and the wall thickness is relatively thick. .

As shown in FIG. 6 , the axial bottom surface 24 of the mesh shield 2 is used to shield and isolate the electromagnetic waves from the rear end of the adjacent detection coil 1. Since these two directions can be set far from the edge of the detection coil 1 than the range of the sensor, therefore The aperture setting is very dense, the mesh opening is relatively small, and the wall thickness is relatively thick, which can achieve better shielding effect.

As shown in Figure 7, the axial sensitive surface 25 of the mesh shield 2 is the working sensitive surface and eddy current detection surface of the protected detection coil 1. In order to reduce the eddy current loss of the metal mesh in this direction, the mesh aperture It can be set to be sparser and the wall thickness as thin as possible. The size of the mesh opening can be adjusted according to the actual excitation frequency of the probe, or the opening can be in the shape of vertical or horizontal strips to ensure the measurement range.

Since the detection coil 1 cannot contact the radial surface 23 , the axial bottom surface 24 and the axial sensitive surface 25 of the mesh shield 2 , an insulating material needs to be filled between the mesh shield 2 and the detection coil 1 to make the detection coil 1 Fix, such as polyester resin and other materials.

In this embodiment, the first detection coil 11 , the second detection coil 12 and the third detection coil 13 use high-frequency excitation signals of different frequencies. Due to the eddy current penetration depth of the measured metal target surface due to the high-frequency excitation signals of different frequencies It increases as the frequency decreases. When cracks appear on the surface or inside of the metal target surface to be measured, the signal values output by the three coils will be different. Therefore, the structure and parallel work excitation method can also monitor the surface cracks of the metal to be measured. or internal cracks.

The probe of the inductive displacement sensor in this embodiment is shielded and isolated from the high-frequency coupling interference of the first detection coil 11 and the second detection coil 12 through the first mesh shield 21, and the second mesh shield 22 shields and isolates the second detection coil. The high-frequency coupling and interference between the coil 12 and the third detection coil 13 interfere with each other, and an insulation distance d is set between the detection coil 1 and the mesh shield 2 to prevent the mesh shield 2 from affecting the measurement range of the detection coil 1. The first detection coil 11 , the second detection coil 12 , the third detection coil 13 , the first mesh shield 21 and the second mesh shield 22 are concentrically nested and are all circular, which greatly reduces the The detection surface area of the probe reduces the detection surface area of the probe while realizing the redundancy of multiple detection coils 1 without affecting the measurement range of the detection coil 1, which greatly improves the probe performance of the inductive displacement sensor. reliability and stability.

Embodiment 2, a probe of an inductive displacement sensor.

The difference between this embodiment and Embodiment 1 is that the first detection coil 11 , the second detection coil 12 , the third detection coil 13 , the first mesh shield 2 and the second mesh shield 22 of this embodiment are from the left Arranged sequentially to the right, the cross section is shown in FIG. 2 , the first detection coil 11 , the second detection coil 12 , the third detection coil 13 , the first mesh shield 2 and the second mesh shield 22 are arranged side by side. To meet the requirements of some special places.

The probe of the inductive displacement sensor in this embodiment can make the probe of the inductive displacement sensor realize the redundancy of multiple detection coils 1 while reducing the detection surface area of the probe, and will not affect the measurement range of the detection coil 1. The reliability and stability of the probe of the inductive displacement sensor are improved.

Embodiment 3, an inductive displacement sensor.

As shown in FIG. 8 , the inductive displacement sensor of this embodiment includes a signal processing circuit, and also includes the probe of Embodiment 1,

Each detection coil 1 is electrically connected to a signal processing circuit and an excitation source through an extension cable, respectively. The signal processing circuit includes a detection circuit electrically connected to the detection coil and a normalization circuit electrically connected to the detection circuit.

Each detection coil 1 of the inductive displacement sensor in this embodiment forms a channel independently with its high-frequency excitation signal, detection circuit, and normalization circuit, and each channel measures the same target independently and in parallel without affecting each other. The structure of adding mesh shields 2 between the detection coils 1 of each layer can effectively shield the high electromagnetic wave interference from the side, rear and sensitive ends of the protected detection coils 1 in all directions. There is a certain insulation distance d between the detection coil 1 of each channel and the mesh shield 2, which will not affect the measurement range. When the signals monitored by multiple coils or more than 2/3 of the coils are all the same or within the specified fluctuation threshold range, the external judgment circuit considers it to be the real signal of the measurement point, making the measurement result true, reliable and credible. It is suitable for special application places with high frequency response requirements, strong real-time requirements and complex electromagnetic environment.

Embodiment 4, a probe coil excitation method of an inductive displacement sensor.

As shown in FIG. 8 , the probe coil excitation method of the inductive displacement sensor of this embodiment is applied to the inductive displacement sensor of Embodiment 3, and specifically includes the following steps:

S1: Input a high-frequency excitation signal to each detection coil 1;

After frequency division by the same excitation source, a high-frequency excitation signal is provided for all the detection coils 1 at the same time, or a high-frequency excitation signal is provided for each corresponding detection coil 1 through a plurality of excitation sources respectively.

When a high-frequency excitation signal is provided for all the detection coils 1 after frequency division by the same excitation source, the reliability of the excitation source is very high, and a high-quality excitation source must be used. Therefore, this embodiment uses multiple excitation sources. A method of providing a high-frequency excitation signal for each corresponding detection coil 1 respectively.

S2: Obtain the detection signal output by each detection coil 1 through each detector corresponding to the detection coil 1;

S3: The detector outputs the detection signal to the normalization circuit;

S4: When more than 2/3 of the detection signals are the same or within the preset fluctuation threshold range, output the detection signals to the external judgment circuit.

The probe coil excitation method of the inductive displacement sensor in this embodiment enables all the detection coils 1 to detect the same target point, and by collecting the detection signals of each detection coil 1, when more than 2/3 of the detection signals are the same or When it is within the preset fluctuation threshold range, the detection signal is output, which greatly improves the authenticity and stability of the detection signal.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A probe of an inductive displacement sensor, characterized in that it comprises: a plurality of detection coils (1) and a mesh shield (2) arranged between each detection coil (1), the detection coils An insulating distance d is set between (1) and the mesh shielding cover (2). 2 . The probe of an inductive displacement sensor according to claim 1 , wherein the detection coils are specifically three, which are a first detection coil ( 11 ), a second detection coil ( 12 ) and a first detection coil ( 12 ) respectively. 3 . Three detection coils (13). 3. The probe of an inductive displacement sensor according to claim 2, characterized in that, the mesh shielding cover (2) is specifically two, which are a first mesh shielding cover (21) and a second mesh shielding cover (21) respectively. A mesh shield (22), the first mesh shield (21) is provided between the first detection coil (11) and the second detection coil (12), the second mesh shield A cover (22) is provided between the second detection coil (12) and the third detection coil (13). 4 . The probe of an inductive displacement sensor according to claim 3 , wherein the first detection coil ( 11 ), the second detection coil ( 12 ), the third detection coil ( 13 ), the first detection coil ( 13 ), the first detection coil ( 12 ), the The mesh shield (21) and the second mesh shield (22) are concentrically nested, and the diameters from small to large are the first detection coil (11), the first mesh shield (21), the second A detection coil (12), a second mesh shield (22), and a third detection coil (13). 5 . The probe of an inductive displacement sensor according to claim 3 , wherein the first detection coil ( 11 ), the second detection coil ( 12 ), the third detection coil ( 13 ), the first detection coil ( 11 ), the first detection coil ( 12 ), the The mesh shield (2) and the second mesh shield (22) are arranged side by side, and the diameters of the first detection coil (11), the second detection coil (12) and the third detection coil (13) are the same. 6 . The probe of an inductive displacement sensor according to claim 1 , wherein the mesh shield ( 2 ) comprises a radial surface ( 23 ) provided with a plurality of through holes, an axial bottom surface ( 24) and the axial sensitive surface (25), an insulating distance d is set between the detection coil (1) and the radial surface (23), the detection coil (1) and the axial sensitive surface ( The distance between 25) is smaller than the distance between the detection coil (1) and the axial bottom surface (24). 7 . The probe of an inductive displacement sensor according to claim 6 , wherein the diameter of the radial surface ( 23 ) is the same as the diameter of the axial bottom surface ( 24 ), and the axial sensitive The hole diameter of the surface (25) is larger than the hole diameter of the axial bottom surface (24). 8. An inductive displacement sensor, comprising a signal processing circuit, characterized in that, further comprising the probe according to any one of claims 1 to 7, Each of the detection coils (1) is electrically connected to one of the signal processing circuits and an excitation source respectively through an extension cable, and the signal processing circuit includes a detection circuit that is electrically connected to the detection coil (1) and a detection circuit that is electrically connected to the detection coil (1). A normalized circuit of electrical connections. 9. A probe coil excitation method of an inductive displacement sensor, wherein the method is applied to the inductive displacement sensor of claim 8, and specifically comprises the following steps: S1: input a high-frequency excitation signal to each detection coil (1); S2: Obtain the detection signal output by each of the detection coils (1) through each detector corresponding to the detection coil (1); S3: The detector outputs the detection signal to the normalization circuit; S4: When more than 2/3 of the detection signals are the same or within the preset fluctuation threshold range, output the detection signals to the external judgment circuit. 10. The probe coil excitation method of an inductive displacement sensor according to claim 9, wherein the step S1 is specifically: After frequency division by the same excitation source, high-frequency excitation signals are simultaneously provided for all detection coils (1), or high-frequency excitation signals are provided for each corresponding detection coil (1) through multiple excitation sources respectively.

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