A differential displacement sensor that is easy to implement with high precision

Abstract

The application discloses a differential displacement sensor easy to realize high-precision installation and a zero adjustment method thereof, and belongs to the technical field of sensor zero adjustment. The differential displacement sensor comprises an A probe, a B probe and a controller, the A probe and the B probe are electrically connected with the controller; and further comprises a zero adjustment probe, the zero adjustment probe can replace the A probe or the B probe and is connected with the controller. The application utilizes high-precision and high-resolution output of the sensor, provides quantitative guidance for installation of the first probe, provides high-precision and high-resolution data feedback for installation quality, improves installation precision of the first probe, and further guarantees the repeatability of the sensor sensitivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, and more particularly to a differential displacement sensor easy to install with high precision and a zero adjustment method thereof. BACKGROUND

[0002] A differential sensor is a common form of sensor, which can reduce the influence of environmental changes on the sensor to a certain extent. The differential displacement sensor has two probes. When the measured object moves, the distance from the target plate to the two probes changes in opposite directions, so the characteristics (resistance, capacitance, inductance, etc.) of the two probes change in opposite directions. The displacement change can be demodulated according to the change of these characteristics. When the temperature or other environmental factors change, since the environmental factors act on the two probes at the same time, the characteristics of the two probes change in the same direction, which can be offset in the circuit to reduce the influence of environmental changes on the sensor.

[0003] The differential displacement sensor requires that the sum of the distances from the two probes to the target plate is a constant d when installed, so as to ensure that the sensor sensitivity and the calibration results remain consistent and output accurate displacement. The installation process of the differential displacement sensor is generally as follows: (1) adjust the target plate 2 to the appropriate position; (2) install one of the A probes 1 and adjust the distance from the A probe 1 to the target plate 2 to L=d / 2 (as shown in Figure 1 ); (3) install the other B probe 3 and adjust the distance from the B probe 3 to the target plate 2 so that the sensor output is zero (as shown in Figure 2 ). Among them, the distance from the A probe 1 to the target plate 2 in the second step can be measured by using a ruler, a caliper, etc. However, these measurement methods are greatly affected by human factors and it is difficult to achieve high precision.

[0004] After searching, there are many disclosures about the zero adjustment of the differential sensor output. For example, the application number 201020243744.3 discloses a differential capacitance type acceleration sensor plate zero adjustment device. A magnetic steel is fixed in the central part of the shell, a sensor magnetic circuit frame is arranged in the cavity of the shell, the top of the sensor magnetic circuit frame has upper and lower movable plates, a driving plate with a groove at the lower end is arranged on the right side of the shell, an adjustable eccentric wheel is installed in the groove and is installed on the magnetic circuit frame of the sensor through a fixed pressing plate, and an adjustment center shaft is arranged on the upper part of the driving plate. When adjusting the zero point, the sensor elastic spring sheet is not damaged, and the sensor zero output voltage can be accurately adjusted. However, the structure of this application is relatively complex, the implementation cost is relatively high, and it is not convenient for popularization and application. SUMMARY

[0005] 1. Technical problems to be solved by the present application

[0006] In order to overcome the above deficiencies of the prior art, the present application provides a differential displacement sensor and a zero adjustment method thereof, which can be easily installed with high precision.

[0007] 2. Technical solutions

[0008] In order to achieve the above-mentioned purpose, the technical solutions provided by the present application are as follows:

[0009] The differential displacement sensor of the present application comprises an A probe, a B probe and a controller, the A probe and the B probe are electrically connected with the controller; and further comprises a zero adjustment probe, which can replace the A probe or the B probe and is connected with the controller.

[0010] As a further improvement of the present application, the zero adjustment probe comprises an inductor and a resistor connected in series, the inductor and the resistor are arranged on a first circuit board, the first circuit board is arranged in a first shell, one end of the first shell is provided with a first connector, and the inductor and the resistor are connected to the inner core and the shielding layer of the first connector respectively.

[0011] As a further improvement of the present application, the inductance of the inductor and the resistance of the resistor are equal to the inductance of the probe to be replaced by the zero adjustment probe.

[0012] As a further improvement of the present application, the zero adjustment probe comprises a coil and a metal plate, the coil and the metal plate are respectively adhered to the two sides of a first barrier sheet, the coil, the first barrier sheet and the metal plate are arranged in a second shell, one end of the second shell is provided with a second connector, and the two connectors of the coil are connected to the inner core and the shielding layer of the second connector via a first lead wire.

[0013] As a further improvement of the present application, the coil of the zero adjustment probe is the same as the coil of the probe to be replaced; the first barrier sheet is made of ceramic or glass sheet, and the thickness of the first barrier sheet is d / 2.

[0014] As a further improvement of the present application, the zero adjustment probe comprises a capacitor, the capacitor is arranged on a second circuit board, the second circuit board is arranged in a third shell, one end of the third shell is provided with a third connector; one end of the capacitor is connected to the inner core of the third connector, and the other end is connected to the outer shielding layer of the third connector, the capacitor and the inner core of the third connector are covered by a shielding cover, and the shielding cover is connected to the inner shielding layer of the third connector.

[0015] As a further improvement of the present application, the zeroing probe comprises a capacitive probe arranged in a fourth shell, one end of the fourth shell is provided with a fourth connector, and the other end of the fourth shell is provided with a second barrier sheet for blocking the fourth shell and the capacitive probe; the capacitive probe is connected to the fourth connector through a coaxial line.

[0016] As a further improvement of the present application, the second barrier sheet is made of ceramic or glass, and the thickness of the second barrier sheet is d / 2.

[0017] As a further improvement of the present application, the first shell, the second shell, the third shell and the fourth shell are metal shells, the first connector and the second connector are coaxial connectors, and the third connector and the fourth connector are triaxial connectors.

[0018] The present application also provides a zeroing method of the differential displacement sensor, in the calibration process, the target plate of the sensor is adjusted to zero point, the B probe is removed, the zeroing probe is replaced, and the output value x0 of the controller of the sensor at this time is recorded; in the installation process of the sensor probe, the A probe and the zeroing probe are first installed, the distance between the A probe and the target plate is adjusted, the output of the controller of the sensor is x0, the zeroing probe is removed, the B probe is replaced, and the distance between the B probe and the target plate is adjusted, so that the output of the controller of the sensor is zero.

[0019] 3. Beneficial effects

[0020] Compared with the prior art, the technical scheme provided by the present application has the following remarkable effects:

[0021] (1) The differential displacement sensor of the present application is easy to install with high precision, a zeroing probe is designed, the zeroing probe is used to replace one of the probes (such as the B probe) of the sensor in the calibration process, the output x0 of the sensor when the target plate of the sensor is adjusted to zero point is recorded, and the user is informed; in the installation process of the sensor probe, the A probe and the zeroing probe are first installed, the distance between the A probe and the target plate is adjusted, the output of the controller of the sensor is x0, at this time, the state of the sensor is consistent with that in the calibration process, and the distance between the A probe and the target plate is d / 2. The zeroing probe is removed, the B probe is replaced, and the distance between the B probe and the target plate is adjusted, so that the output of the controller of the sensor is zero, at this time, the distance between the two probes of the sensor and the target plate is d / 2. The scheme uses the high precision and high resolution output of the sensor to provide quantitative guidance for the installation of the first probe, provides high-precision and high-resolution data feedback for the installation quality, improves the installation precision of the first probe, and further ensures the repeatability of the sensitivity of the sensor.

[0022] (2) The differential displacement sensor of the present application is easy to install with high precision, the overall design idea is simple and easy to implement, the structure of the zeroing probe is simple, the manufacturing cost is low, and the application is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 and Figure 2 is a measurement schematic diagram of a conventional differential displacement sensor;

[0024] Figure 3 and Figure 4 is a measurement schematic diagram of a differential displacement sensor of the present application;

[0025] Figure 5 is a schematic diagram of a zeroing probe structure of one embodiment of a differential eddy current sensor;

[0026] Figure 6 is a schematic diagram of a zeroing probe structure of another embodiment of a differential eddy current sensor;

[0027] Figure 7 is a schematic diagram of a zeroing probe structure of one embodiment of a differential capacitance sensor;

[0028] Figure 8 is a schematic diagram of a zeroing probe structure of another embodiment of a differential capacitance sensor.

[0029] Explanation of reference numerals in the schematic diagrams:

[0030] 1, A probe; 2, a target plate; 3, B probe; 4, a controller; 5, a zeroing probe;

[0031] 61, a first connector; 62, a first housing; 63, an inductor; 64, a resistor; 65, a first circuit board;

[0032] 71, a second connector; 72, a second housing; 73, a first lead wire; 74, a coil; 75, a first barrier sheet; 76, a metal plate;

[0033] 81, a third connector; 82, a third housing; 83, a shield; 84, a capacitor; 85, a second circuit board; 86, a second lead wire; 87, a third lead wire;

[0034] 91, a fourth connector; 92, a fourth housing; 93, a coaxial line; 94, a capacitance probe; 95, a second barrier sheet. DETAILED DESCRIPTION

[0035] For a further understanding of the present application, reference will be made to the following detailed description taken in conjunction with the accompanying drawings and examples.

[0036] Example 1

[0037] In conjunction with Figure 3 and Figure 4The differential displacement sensor of the embodiment is easy to implement high-precision installation, and the overall design idea is as follows: a zero-adjusting probe 5 is made, and the parameters of the zero-adjusting probe 5 are equal to (or similar to) the parameters of one of the probes (for example, the B probe 3) at the zero point of the sensor.

[0038] During the calibration process, the sensor target plate 2 is adjusted to the zero point, the B probe 3 is removed, the zero-adjusting probe 5 is replaced, the output value x0 of the sensor controller 4 at this time is recorded, and the user is informed.

[0039] When the sensor probe is installed, the A probe 1 and the zero-adjusting probe 5 are first installed, the distance between the A probe 1 and the target plate 2 is adjusted, so that the output of the sensor controller 4 is x0, at this time, the state of the sensor is consistent with the state during the calibration, and the distance between the A probe 1 and the target plate 2 is d / 2. The zero-adjusting probe 5 is removed, and the B probe 3 is replaced. The distance between the B probe 3 and the target plate 2 is adjusted, so that the output of the sensor controller 4 is zero, at this time, the distance between the two probes of the sensor and the target plate is d / 2.

[0040] The embodiment utilizes the high precision and high resolution output of the sensor to provide quantitative guidance for the installation of the first probe, provides high-precision and high-resolution data feedback for the installation quality, improves the installation precision of the first probe, and further ensures the repeatability of the sensor sensitivity.

[0041] Embodiment 2

[0042] In combination Figure 5 For the differential eddy current sensor, the zero-adjusting probe 5 can be in the following form: an inductor 63 and a resistor 64 are connected in series, the inductance of the inductor 63 and the resistance of the resistor 64 are equal to (or similar to) the inductance of one of the probes and the resistance of one of the probes at the zero point of the target plate 2. The inductor 63 and the resistor 64 are arranged on a first circuit board 65, the first circuit board 65 is arranged in a metal shell, one end of the metal shell is provided with a coaxial connector, and the inductor 63 and the resistor 64 are connected in series, and the two ends are respectively connected to the inner core and the shielding layer of the coaxial connector.

[0043] Embodiment 3

[0044] In combination Figure 6 For the differential eddy current sensor, the zero-adjusting probe 5 can be in the following form: including a coil 74 and a metal plate 76, the coil 74 and the metal plate 76 are respectively pasted on both sides of a first blocking sheet 75, the first blocking sheet 75 is a ceramic sheet with a thickness of d / 2, the coil 74, the first blocking sheet 75 and the metal plate 76 are arranged in a metal shell, one end of the metal shell is provided with a coaxial connector, and the two connectors of the coil 74 are respectively connected to the inner core and the shielding layer of the coaxial connector through a first lead 73. The coil 74 is the same as the coil of the probe replaced by the zero-adjusting probe 5.

[0045] Example 4

[0046] In combination Figure 7 For the differential capacitance sensor, the zeroing probe 5 can be in the following form: a standard capacitor 84 is used to simulate a probe at zero point of the target plate. The capacitor 84 is arranged on a second circuit board 85, which is arranged in a metal shell. A triax connector is arranged at one end of the metal shell. One end of the capacitor 84 is connected to the inner core of the triax connector (connected to the measuring electrode) through a second lead wire 86, and the other end is connected to the outer shield (connected to the ground) through a third lead wire 87. A metal shield 83 is additionally used to completely cover the capacitor 84 and the inner core of the third connector 81, and the shield 83 is connected to the inner shield of the triax connector (connected to the guard electrode).

[0047] Example 5

[0048] In combination Figure 8 For the differential capacitance sensor, the zeroing probe 5 can be in the following form: a standard capacitor probe 94 is installed in a grounded metal shell, so that the surface of the capacitor probe 94 is about d / 2 away from the metal shell to simulate a probe at zero point of the target plate. Specifically, a glass sheet with a thickness of d / 2 is arranged as a second barrier sheet 95, and the second barrier sheet 95 is used to make the surface of the capacitor probe 94 about d / 2 away from the metal shell. A triax connector is arranged at one end of the metal shell, and the capacitor probe 94 is connected to the triax connector through a coaxial line 93. Specifically, the measuring electrode of the standard capacitor probe 94 is connected to the inner core of the triax connector, the guard electrode is connected to the inner shield of the triax connector, and the shell of the zeroing probe is connected to the outer shield of the triax connector to be grounded.

[0049] As can be seen from the above description, the four differential displacement sensors described in Examples 2-5 have simple structure, are easy to implement, have low manufacturing cost, and are convenient for popularization and application.

[0050] The above description of the present application and its embodiments is illustrative and not restrictive, and the embodiments shown in the drawings are only one of the embodiments of the present application, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it, without departing from the purpose of the present application, similar structural forms and embodiments can be designed without creativity, which should belong to the protection scope of the present application.

Claims

1. A differential displacement sensor that is easy to install with high precision, comprising a probe A (1), a probe B (3) and a controller (4), wherein the probe A (1), the probe B (3) and the controller (4) are electrically connected; and characterized in that: It also includes a zero adjustment probe (5), which can replace the A probe (1) or the B probe (3) and is connected to the controller (4); During the calibration process, the sensor target plate (2) is adjusted to zero point, the B probe (3) is removed, and the zeroing probe (5) is replaced, and the output value x0 of the sensor controller (4) at this time is recorded; when installing the sensor probe, first install the A probe (1) and the zeroing probe (5), adjust the distance between the A probe (1) and the target plate (2) so that the output of the sensor controller (4) is x0, remove the zeroing probe (5), replace it with the B probe (3), adjust the distance between the B probe (3) and the target plate (2) so that the output of the sensor controller (4) is zero; The zero-adjusting probe (5) includes an inductor (63) and a resistor (64) connected in series, wherein the inductor (63) and the resistor (64) are arranged on a first circuit board (65), the first circuit board (65) is arranged in a first housing (62), a first connector (61) is arranged at one end of the first housing (62), and the inductor (63) and the resistor (64) are connected in series, and the two ends are respectively connected to the inner core and the shielding layer of the first connector (61); The inductance of the inductor (63) and the resistance of the resistor (64) are equal to the inductance and resistance of the probe replaced by the zero-adjusting probe (5).

2. A differential displacement sensor that is easy to install with high precision according to claim 1, characterized in that: As a replacement structure for the zero-adjusting probe (5), the zero-adjusting probe (5) includes a coil (74) and a metal plate (76), the coil (74) and the metal plate (76) being respectively adhered to both sides of a first barrier sheet (75), the coil (74), the first barrier sheet (75) and the metal plate (76) being all arranged in a second housing (72), a second connector (71) being provided at one end of the second housing (72), and the two connectors of the coil (74) being respectively connected to the inner core and the shielding layer of the second connector (71) via a first wire (73).

3. The differential displacement sensor that is easy to install with high precision according to claim 2, characterized in that: The coil (74) is the same as the coil of the probe replaced by the zeroing probe (5); the first barrier (75) is made of ceramic or glass, and the thickness of the first barrier (75) is d / 2.

4. The differential displacement sensor that is easy to install with high precision according to claim 1, characterized in that: As a replacement structure for the zero-adjusting probe (5), the zero-adjusting probe (5) includes a capacitor (84), the capacitor (84) is arranged on a second circuit board (85), the second circuit board (85) is arranged in a third shell (82), and a third connector (81) is arranged at one end of the third shell (82); one end of the capacitor (84) is connected to the inner core of the third connector (81), and the other end is connected to the outer shielding layer of the third connector (81); the inner core of the capacitor (84) and the third connector (81) are covered with a shielding cover (83), and the shielding cover (83) is connected to the inner shielding layer of the third connector (81).

5. The differential displacement sensor that is easy to install with high precision according to claim 1, characterized in that: As a replacement structure for the zeroing probe (5), the zeroing probe (5) includes a capacitance probe (94), which is arranged in a fourth housing (92), a fourth connector (91) is arranged at one end of the fourth housing (92), and a second barrier (95) is arranged at the other end of the fourth housing (92), the second barrier (95) blocking the fourth housing (92) and the capacitance probe (94); the capacitance probe (94) is connected to the fourth connector (91) via a coaxial line (93).

6. The differential displacement sensor that is easy to install with high precision according to claim 5, characterized in that: The second barrier sheet (95) is made of ceramic or glass, and the thickness of the second barrier sheet (95) is d / 2.

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