Combined coil type displacement sensor for cooperatively measuring radial offset and axial displacement
By designing a combined coil displacement sensor including a built-in rod body, a coil frame, an excitation coil, a series circumferential induction coil and an independent radial induction coil group, the problem of difficult to measure radial eccentricity and axial displacement at the same time in the prior art is solved, and high-precision continuous measurement and structural simplification are achieved.
Patent Information
- Application Number
- CN202510043209.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-04-01
AI Technical Summary
The prior art is difficult to measure radial eccentricity and axial displacement simultaneously with high accuracy, resulting in low measurement accuracy and high system complexity.
A combined coil displacement sensor that coordinates the measurement of radial offset and axial displacement is designed, including a built-in rod body, a coil frame, an excitation coil, a series circumferential induction coil and an independent radial induction coil group, and continuous measurement is achieved through electromagnetic induction principles and differential voltage measurement technology.
High-precision continuous measurement of radial offset and axial displacement is achieved, the structure is simple and the winding complexity is low, which reduces manufacturing costs and improves measurement accuracy.
Smart Images
Figure CN119737849A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of linear displacement sensors, and in particular to a combined coil type displacement sensor for collaboratively measuring radial offset and axial displacement. Background Art
[0002] In the measurement process, position feedback is closely related to the subsequent actions of the actuator, and plays a vital role in industries such as aerospace, machinery, construction, and energy mining. With the continuous advancement of the upgrading and transformation of the global industrial manufacturing industry, the requirements for measurement technology are becoming increasingly stringent, and a number of new standards such as non-contact, integration, digitization, and modularization have been proposed.
[0003] Electromagnetic induction displacement sensors achieve accurate measurement of rod displacement by causing changes in coil impedance due to the movement of the built-in rod. This is a typical non-contact displacement sensor suitable for harsh environments such as water, oil and radiation. However, due to long stroke, assembly positioning error or execution error, rod eccentricity is inevitable, which not only affects the measurement accuracy of rod displacement, but also has a negative impact on the normal operation of the equipment.
[0004] At present, for the simultaneous measurement of eccentric displacement and linear displacement, two sets of sensors are usually installed: one set measures the eccentric displacement and the other measures the linear displacement. However, this installation method not only increases the complexity and cost of the system, but the two sets of sensors may generate signal interference, affecting the measurement accuracy.
[0005] Therefore, it is particularly urgent to develop a displacement sensor with a simple structure that can achieve high-precision measurement of radial eccentricity and axial displacement. Summary of the invention
[0006] The object of the present invention is to provide a combined coil displacement sensor for cooperatively measuring radial offset and axial displacement, so as to solve the problems existing in the prior art.
[0007] The technical solution adopted to achieve the purpose of the present invention is as follows: a combined coil displacement sensor for collaboratively measuring radial offset and axial displacement includes a built-in rod body, a coil frame, an excitation coil, a series-connected circular induction coil and an independent radial induction coil group arranged in a spatial rectangular coordinate system o-xyz.
[0008] The coil skeleton includes a circular tube body, and 4 annular baffles and 8 positioning bosses arranged on the outer wall of the circular tube body. The z-axis of the spatial rectangular coordinate system o-xyz is parallel to the axial direction of the circular tube body, and the x-axis and the y-axis are parallel to the radial direction of the circular tube body. The 4 annular baffles are arranged on the outer wall of the circular tube body at intervals. The 4 annular baffles are marked as the first annular baffle, the second annular baffle, the third annular baffle and the fourth annular baffle in sequence. The 4 annular baffles separate the tube body of the circular tube body into a starting section, a middle section and an ending section. The 8 positioning bosses are divided into 4 groups, marked as the first positioning boss group, the second positioning boss group, the third positioning boss group and the fourth positioning boss group in sequence. The first positioning boss group and the second positioning boss group are arranged at the starting section, and the third positioning boss group and the fourth positioning boss group are arranged at the ending section. The two positioning bosses in the same group of positioning boss groups are arranged symmetrically. The two adjacent groups of positioning boss groups are arranged 90 degrees apart. Two adjacent groups of positioning bosses are coordinated with each other in such a way that the lines connecting the projection points of the center points of the four positioning bosses on the xy plane form a square.
[0009] The excitation coil includes three units wound at intervals along the axial direction. The three units are marked as a starting unit, an intermediate unit and an ending unit in sequence. The starting unit is wound in the starting section, and the first positioning boss group and the second positioning boss group sandwich the starting unit. The intermediate unit is wound in the middle section. The ending unit is wound in the ending section, and the third positioning boss group and the fourth positioning boss group sandwich the ending unit.
[0010] The series circumferential induction coil includes four units wound at intervals along the axial direction. The four units are marked as the first unit, the second unit, the third unit and the fourth unit in sequence. The first unit and the second unit are wound in the starting section. The first annular baffle and the first positioning boss group clamp the first unit. The second positioning boss group and the second annular baffle clamp the second unit. The third unit and the fourth unit are wound in the ending section. The third annular baffle and the third positioning boss group clamp the third unit. The fourth positioning boss group and the fourth annular baffle clamp the fourth unit.
[0011] The independent radial induction coil group surrounds the periphery of the excitation coil. The independent radial induction coil group includes radial induction coil group I, radial induction coil group II, radial induction coil group III and radial induction coil group IV. The radial induction coil group I, radial induction coil group II, radial induction coil group III and radial induction coil group IV each include two circular arc hollow coils. The circular arc hollow coil of the radial induction coil group I is sleeved on the fourth positioning boss group through an inner hole. The circular arc hollow coil of the radial induction coil group II is sleeved on the third positioning boss group through an inner hole. The circular arc hollow coil of the radial induction coil group III is sleeved on the second positioning boss group through an inner hole. The circular arc hollow coil of the radial induction coil group IV is sleeved on the first positioning boss group through an inner hole.
[0012] The built-in rod is inserted into the inner cavity of the circular tube body. A sinusoidal excitation is applied to the excitation coil to generate a uniform and repeatedly distributed alternating magnetic field in the axial and radial directions. The response signals of the series-connected circular induction coil and the independent radial induction coil group are detected to determine the axial displacement and / or radial displacement of the built-in rod.
[0013] Furthermore, the built-in rod body is made of soft magnetic material and has good magnetic permeability, ensuring that an obvious induction signal can be generated in the excitation magnetic field.
[0014] Furthermore, the coil frame is made of non-magnetic material and has good mechanical strength and stability.
[0015] Furthermore, when the built-in rod body moves axially, the induced voltage of the series circumferential induction coil and the induced voltage of the independent radial induction coil group change linearly. When the built-in rod body deviates radially, the differential voltage of the two circular arc hollow coils in the same radial induction coil group changes linearly with the radial offset distance.
[0016] The technical effects of the present invention are unquestionable:
[0017] A. It can realize continuous measurement of radial offset and axial displacement, with simple structure and low winding complexity;
[0018] B. It includes a set of serially connected circular induction coils and a set of independent radial induction coils. Both sets of coils can continuously detect the axial displacement of the built-in rod body and have redundant measurement function in axial displacement detection.
[0019] C. A set of radial induction coils are arranged in a staggered manner along the circumference and axial direction to achieve simultaneous measurement of the radial offset and axial displacement of the built-in rod body. The induced voltages of the two radial induction coils at the same axial height are subtracted to measure the radial offset. The voltages of all radial induction coils are summed to achieve axial displacement measurement. The radial induction coils in this arrangement can not only reflect the distance of the built-in rod body from the axis, but also continuously detect the axial displacement of the rod body, improve measurement accuracy, reduce winding complexity, simplify sensor structure, and reduce manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 A schematic diagram of the cross-section of the structure of a combined coil displacement sensor for collaboratively measuring radial offset and axial displacement;
[0021] Figure 2 Schematic diagram of the excitation coil, the circumferential induction coil and the radial induction coil;
[0022] Figure 3 for Figure 1 AA surface section view;
[0023] Figure 4 for Figure 1 BB surface cross-sectional view.
[0024] Figure 5 Schematic diagram of radial position detection principle.
[0025] In the figure: built-in rod body 1, coil skeleton 2, round tube body 201, annular baffle 202, positioning boss 203, excitation coil 3, circumferential induction coil 4, radial induction coil group I5, radial induction coil group II6, radial induction coil group III7, radial induction coil group IV8. DETAILED DESCRIPTION
[0026] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.
[0027] Embodiment 1:
[0028] See also Figure 1 to Figure 5 The present embodiment provides a combined coil displacement sensor for collaboratively measuring radial offset and axial displacement, comprising a built-in rod body 1, a coil skeleton 2, an excitation coil 3, a series-connected circular induction coil 4 and an independent radial induction coil group arranged in a spatial rectangular coordinate system o-xyz.
[0029] The coil skeleton 2 includes a circular tube body 201, and four annular baffles 202 and eight positioning bosses 203 arranged on the outer wall of the circular tube body 201. The z-axis of the spatial rectangular coordinate system o-xyz is parallel to the axial direction of the circular tube body 201, and the x-axis and the y-axis are parallel to the radial direction of the circular tube body 201. The four annular baffles 202 are arranged on the outer wall of the circular tube body 201 at intervals. The four annular baffles 202 are marked as the first annular baffle, the second annular baffle, the third annular baffle and the fourth annular baffle in sequence. The four annular baffles 202 separate the tube body of the circular tube body 201 into a starting section, a middle section and an ending section. The eight positioning bosses 203 are divided into four groups, which are marked as the first positioning boss group, the second positioning boss group, the third positioning boss group and the fourth positioning boss group in sequence. The first positioning boss group and the second positioning boss group are arranged at the starting section, and the third positioning boss group and the fourth positioning boss group are arranged at the ending section. The two positioning bosses 203 in the same positioning boss group are arranged symmetrically. The two adjacent positioning boss groups are arranged 90 degrees apart. The two adjacent positioning boss groups are coordinated with each other in the following manner, that is, the line combination of the projection points of the center points of the four positioning bosses 203 on the xy plane forms a square.
[0030] The excitation coil 3 includes three units wound at intervals along the axial direction. The three units are marked as a starting unit, an intermediate unit and an ending unit in sequence. The starting unit is wound in the starting section, and the first positioning boss group and the second positioning boss group sandwich the starting unit. The intermediate unit is wound in the middle section. The ending unit is wound in the ending section, and the third positioning boss group and the fourth positioning boss group sandwich the ending unit.
[0031] The series circumferential induction coil 4 includes four units wound at intervals along the axial direction. The four units are marked as the first unit, the second unit, the third unit and the fourth unit in sequence. The first unit and the second unit are wound in the starting section. The first annular baffle and the first positioning boss group clamp the first unit. The second positioning boss group and the second annular baffle clamp the second unit. The third unit and the fourth unit are wound in the ending section. The third annular baffle and the third positioning boss group clamp the third unit. The fourth positioning boss group and the fourth annular baffle clamp the fourth unit.
[0032] The independent radial induction coil group surrounds the periphery of the excitation coil 3. The independent radial induction coil group includes radial induction coil group I5, radial induction coil group II6, radial induction coil group III7 and radial induction coil group IV8. The radial induction coil group I5, radial induction coil group II6, radial induction coil group III7 and radial induction coil group IV8 each include two circular arc hollow coils. The circular arc hollow coil of the radial induction coil group I5 is sleeved on the fourth positioning boss group through the inner hole. The circular arc hollow coil of the radial induction coil group II6 is sleeved on the third positioning boss group through the inner hole. The circular arc hollow coil of the radial induction coil group III7 is sleeved on the second positioning boss group through the inner hole. The circular arc hollow coil of the radial induction coil group IV8 is sleeved on the first positioning boss group through the inner hole.
[0033] The built-in rod body 1 is inserted into the inner cavity of the circular tube body 201. A sinusoidal excitation is applied to the excitation coil 3 to generate a uniform and repeatedly distributed alternating magnetic field in the axial and radial directions. The response signals of the series-connected circumferential induction coil 4 and the independent radial induction coil group are detected to determine the axial displacement and / or radial displacement of the built-in rod body 1.
[0034] A. Realization of continuous measurement of sensor axial displacement:
[0035] When the built-in rod body 1 moves axially, the induced voltage of the series-connected circular induction coil 4 and the induced voltage of the independent radial induction coil group change linearly with it. The series-connected circular induction coil 4 coaxial with the excitation coil 3 can capture the changes in the axial magnetic field generated by the built-in rod body 1 when it moves axially, and its induced voltage change is nearly linearly related to the axial displacement of the built-in rod body 1. The independent radial induction coil group is arranged orthogonally to the excitation coil 3, and can capture the changes in the radial magnetic field generated by the built-in rod body 1 when it moves axially, and its total induced voltage also has a certain approximate linear relationship with the axial displacement of the built-in rod body 1. Therefore, the induced voltages of the series-connected circular induction coil 4 and the independent radial induction coil group both change approximately linearly with the displacement of the built-in rod body 1, and can realize continuous axial displacement measurement, and the two sets of measuring coils are redundant structures in the detection of the axial displacement of the built-in rod body 1.
[0036] B. Implementation of continuous measurement of sensor radial offset:
[0037] When the built-in rod body 1 is radially offset, the differential voltage of the two circular arc hollow coils in the same radial induction coil group changes linearly with the radial offset distance. Figure 2 As shown, radial induction coil group I5 and radial induction coil group III7 are used to detect the offset in the x direction, and radial induction coil group II6 and radial induction coil group IV8 are used to detect the offset in the y direction.
[0038] See also Figure 5, (a) shows that the magnetic field is symmetrical when the built-in rod 1 is at the center, and (b) shows that the magnetic field is asymmetrical when the built-in rod 1 is offset. When the built-in rod 1 is radially offset along the x direction, the offset will cause the induced voltage of one circular arc hollow coil in the same group of radial induction coils to increase, while the induced voltage of the other circular arc hollow coil will decrease. When the built-in rod 1 is in the middle position, the two radial induction coils at the same axial height correspond to the following. Figure 2 As shown in 5 or Figure 2 The radial induction coil group A shown in Figure 7 is completely identical and symmetrical, so the mutual inductances M1 and M2 between the two radial induction coils are equal. According to the principle of electromagnetic induction, the induced electromotive force E of the two radial induction coils is 21 、E 22 are also equal, then U d =E 21 -E 22 =0, that is, the differential voltage is 0.
[0039] When the built-in rod body 1 is radially offset along the positive direction of the x-axis, the magnetic flux passing through the radial induction coil on the positive side of the x-axis is greater than that of the radial induction coil on the negative side of the x-axis, and the mutual inductance between the radial induction coil on the positive side of the x-axis and the excitation coil 3 increases, while the mutual inductance between the radial induction coil on the negative side of the x-axis and the excitation coil 3 decreases, that is, M1>M2. Therefore, the induced electromotive force E of the radial induction coil on the positive side of the x-axis is 21 Increase, the induced electromotive force E of the radial induction coil on the negative side of the x-axis 22 The corresponding decrease is U d =E 21 -E 22 >0; on the contrary, when the built-in rod 1 deviates radially along the negative x direction, the induced electromotive force E of the radial induction coil on the positive x-axis side 21 Less than the induced electromotive force E of the radial induction coil on the negative side of the x-axis 22 , that is U d =E 21 -E 22 <0.
[0040] Similarly, when the built-in rod body 1 deviates radially along the y-axis direction, the radial induction coil groups 6 and 8 measure the deflection in the y-direction based on the same principle.
[0041] According to the calculation and analysis based on the above principles, the radial induction coil can change the mutual inductance between the two radial induction coils in the corresponding radial induction coil group and the excitation coil 3 through the radial offset of the built-in rod body 1, so that the differential voltage changes accordingly with the change of the distance of the built-in rod body 1 offset from the axis, thereby realizing radial offset measurement.
[0042] The combined coil displacement sensor of the present invention adopts the efficient electromagnetic induction principle and differential voltage measurement technology in both axial displacement and radial offset measurement, which not only improves the measurement accuracy, but also simplifies the structure of the sensor, reduces the manufacturing cost, and has a good application prospect.
[0043] Embodiment 2:
[0044] The main contents of this embodiment are the same as those of the embodiment 1, wherein the built-in rod body 1 is made of soft magnetic material. The built-in rod body 1 has good magnetic permeability, ensuring that an obvious induction signal can be generated in the excitation magnetic field.
[0045] Embodiment 3:
[0046] The main contents of this embodiment are the same as those of embodiment 1 or 2, wherein the coil frame 2 is made of non-magnetic material. The coil frame 2 has good mechanical strength and stability.
Claims
1. A combined coil displacement sensor for collaboratively measuring radial offset and axial displacement, characterized in that: It comprises a built-in rod body (1), a coil frame (2), an excitation coil (3), a series-connected circular induction coil (4) and an independent radial induction coil group arranged in a spatial rectangular coordinate system o-xyz; The coil skeleton (2) comprises a circular tube body (201), and four annular baffles (202) and eight positioning bosses (203) arranged on the outer wall of the circular tube body (201); the z-axis of the spatial rectangular coordinate system o-xyz is parallel to the axial direction of the circular tube body (201), and the x-axis and the y-axis are parallel to the radial direction of the circular tube body (201); the four annular baffles (202) are arranged at intervals on the outer wall of the circular tube body (201); the four annular baffles (202) are marked in sequence as a first annular baffle, a second annular baffle, a third annular baffle and a fourth annular baffle. shaped baffle; four annular baffles (202) divide the tube body of the circular tube body (201) into a starting section, a middle section and an ending section; the eight positioning bosses (203) are divided into four groups, which are marked as a first positioning boss group, a second positioning boss group, a third positioning boss group and a fourth positioning boss group in sequence; the first positioning boss group and the second positioning boss group are arranged at the starting section, and the third positioning boss group and the fourth positioning boss group are arranged at the ending section; the two positioning bosses (203) in the same group of positioning boss groups are arranged symmetrically; and two adjacent groups of positioning boss groups are arranged with a 90-degree offset; The excitation coil (3) comprises three units wound at intervals along the axial direction; the three units are marked as a starting unit, a middle unit and an ending unit in sequence; the starting unit is wound in the starting section, and the first positioning boss group and the second positioning boss group sandwich the starting unit; the middle unit is wound in the middle section; the ending unit is wound in the ending section, and the third positioning boss group and the fourth positioning boss group sandwich the ending unit; The series-connected circular induction coil (4) comprises four units that are wound at intervals along the axial direction; the four units are marked as a first unit, a second unit, a third unit and a fourth unit in sequence; the first unit and the second unit are wound in the starting section; the first annular baffle and the first positioning boss group clamp the first unit; the second positioning boss group and the second annular baffle clamp the second unit; the third unit and the fourth unit are wound in the ending section; the third annular baffle and the third positioning boss group clamp the third unit; the fourth positioning boss group and the fourth annular baffle clamp the fourth unit; The independent radial induction coil group surrounds the periphery of the excitation coil (3); the independent radial induction coil group includes radial induction coil group I (5), radial induction coil group II (6), radial induction coil group III (7) and radial induction coil group IV (8); the radial induction coil group I (5), radial induction coil group II (6), radial induction coil group III (7) and radial induction coil group IV (8) each include two circular arc hollow coils; the circular arc hollow coil of the radial induction coil group I (5) is sleeved on the fourth positioning boss group through an inner hole; the circular arc hollow coil of the radial induction coil group II (6) is sleeved on the third positioning boss group through an inner hole; the circular arc hollow coil of the radial induction coil group III (7) is sleeved on the second positioning boss group through an inner hole; the circular arc hollow coil of the radial induction coil group IV (8) is sleeved on the first positioning boss group through an inner hole; The built-in rod body (1) is inserted into the inner cavity of the circular tube body (201); a sinusoidal excitation is introduced into the excitation coil (3) to generate a uniform and repeatedly distributed alternating magnetic field in the axial and radial directions; and response signals of the series-connected circular induction coil (4) and the independent radial induction coil group are detected to determine the axial displacement and / or radial displacement of the built-in rod body (1).
2. A combined coil displacement sensor for collaboratively measuring radial offset and axial displacement according to the method of claim 1, characterized in that: The built-in rod body (1) is made of soft magnetic material.
3. The combined coil displacement sensor for collaboratively measuring radial offset and axial displacement according to claim 1, characterized in that: The coil frame (2) is made of non-magnetic material.
4. The combined coil displacement sensor for collaboratively measuring radial offset and axial displacement according to claim 1, characterized in that: When the built-in rod body (1) moves axially, the induced voltage of the series-connected circular induction coil (4) and the induced voltage of the independent radial induction coil group change linearly accordingly; when the built-in rod body (1) deviates radially, the differential voltage of two circular arc-shaped hollow coils in the same radial induction coil group changes linearly with the radial offset distance.