Linear displacement sensor winding method

Abstract

The invention relates to the technical field of sensors, in particular to a linear displacement sensor winding method. A lead terminal structure is adopted, leads are relatively easy to weld, and all the six lead terminals are arranged on the same side of the framework, so that operation of automatic equipment is facilitated. All the coils of the sensor winding are wound from the same end of the framework, so that the advantages of no fly wire, no need of laminating enameled wires when the sensor is bound, high shaping efficiency and high reliability of the coils are achieved. The line distances of all coils except the last two layers are the same, complex programming modes are reduced, implementation is convenient, and errors are not prone to occurring. As the outermost layer of the coil adopts a multi-section winding mode with different wire distances, the local precision of the sensor can be adjusted, and the comprehensive performance of the sensor is improved.

Description

Technical Field

[0001] The invention relates to the technical field of sensors, and in particular to a winding method for a linear displacement sensor. Background Art

[0002] The linear variable differential transformer (LVDT) is an electromagnetic displacement sensor that uses a non-contact principle and is widely used in the aerospace and defense industry, the nuclear industry, and general industrial applications. There are two main problems with the current LVDT sensor during trial production and production: First, the welding of the enameled wire to the lead wire is a manual operation, which is time-consuming and not conducive to mass or automated production; second, the coil binding and shaping time is long, and the enameled wire is prone to cross-over and overlap during the binding process, causing quality risks. Summary of the invention

[0003] Purpose of the Invention

[0004] The object of the present invention is to provide a linear displacement sensor winding method, which is suitable for the automated winding production of the sensor, and the sensor has less transition enameled wires, reduces disordered stacking of the enameled wires, and improves the reliability of the sensor.

[0005] Technical Solution

[0006] A linear displacement sensor winding method comprises the following steps:

[0007] Step 1. Install the sensor frame on the winding machine, and weld the coil on the winding to the lead terminal of the frame. The winding is divided into 4 coils, namely the primary coil, the secondary A1 coil, the secondary B coil and the secondary A2 coil. Each coil is wound from the same end of the coil frame and finally returns to the starting end;

[0008] Step 2. The wire end of the primary coil is wound around the first lead terminal of the lead frame by a winding machine. The number of layers of the primary coil is an even number. The number of layers or the wire spacing of the last layer is adjusted by setting the total number of turns to realize the winding of the coil from the starting end to the starting end; the wire end of the primary coil is wound around the second lead terminal of the lead frame by a winding machine;

[0009] Step 3. The end of the secondary A1 coil is wound around the third lead terminal of the lead frame by a winding machine, and the length of every two layers of winding decreases according to an arithmetic progression. Every two layers of winding refer to winding from the starting point, reaching the end point and then winding back to the starting point, and the wire spacing is the same during this period; the last two layers are divided into several sections, and the wire spacing of each section is determined according to the sensor and value voltage. The winding starts from the starting point, reaches the end point and then winds back to the starting point. The winding direction of the last two layers may be the same as or opposite to the previous coil; the end of the secondary A1 coil is wound around the fourth lead terminal of the lead frame by a winding machine;

[0010] Step 4. The wire end of the secondary B coil is wound on the sixth lead terminal of the lead frame by a winding machine, and the wire pitch of the enameled wire is half of that of the secondary A1 coil and the secondary A2 coil. The first layer of winding is wound from the starting point to the end point; the subsequent windings are wound from the end point, and the length of every two layers of winding decreases according to an arithmetic progression, from the end point back to the end point; the third to last layer has the same length as the first layer, and returns from the end point back to the starting point; the last two layers are divided into several sections, and the wire pitch of each section is different, which is half of the corresponding position of the A1 coil and the secondary A2 coil; the wire end of the secondary B coil is wound on the fifth lead terminal of the lead frame by a winding machine;

[0011] Step 5. The winding method of the secondary A2 coil is the same as that of the secondary A1 coil. The wire head is wound around the fourth lead terminal of the lead frame, and the wire tail is wound around the fifth lead terminal of the lead frame.

[0012] Step 6. After winding the secondary A2 coil, tie the glass fiber wire on the outer surface of the secondary A2 coil; tie the enameled wire so that the winding will not spread out.

[0013] Furthermore, the skeleton is made of austenitic stainless steel, titanium alloy or plastic, and must meet the requirements of poor magnetic conductivity and poor electrical conductivity.

[0014] Furthermore, the enameled wires of the primary coil, the secondary A1 coil, the secondary B coil and the secondary A2 coil have the same wire diameter.

[0015] Further, the winding directions of the last two layers of the primary coil, the secondary A1 coil, the secondary B coil and the secondary A2 coil are determined according to the sensor sum voltage. In order to obtain the specified difference ratio sum voltage, the magnitude of the sum voltage needs to be adjusted.

[0016] Furthermore, the lead terminals and the leads are injection molded as a whole to form a lead frame.

[0017] Furthermore, the winding equipment winds the enameled wire head and tail around the lead terminal in a "circle-drawing" manner.

[0018] The beneficial effects of this application are:

[0019] The advantage of a linear displacement sensor winding method of the present invention is that it adopts a lead terminal structure, welding leads is relatively easy, and all six lead terminals are on the same side of the skeleton, which is convenient for the operation of automated equipment. All coils of the sensor winding are wound from the same end of the skeleton, which has the advantage of no flying wires, unnecessary overlapping of the enameled wires when the sensor is tied, high shaping efficiency, and high coil reliability. All coils have the same wire spacing except the last two layers, which reduces complex programming modes, is easy to implement, and is not prone to errors. Since the outermost layer of the coil adopts a winding method with multiple sections of different wire spacing, the local accuracy of the sensor can be adjusted to improve the overall performance of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the winding and the outgoing wire structure of the linear displacement sensor of the present invention.

[0021] Figure 2 It is a schematic diagram of the secondary A1 coil and A2 coil of the linear displacement sensor winding of the present invention;

[0022] Figure 3 It is a schematic diagram of the secondary B coil of the linear displacement sensor winding of the present invention;

[0023] Figure 4 This is a comparison chart of accuracy with and without the last two layers of coils. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar originals or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0025] Example 1

[0026] A linear displacement sensor winding method comprises the following steps:

[0027] 1. Install the sensor frame (6) on the winding machine, and weld the coil on the winding (1) to the lead terminal (7) of the frame (6). The winding (1) is divided into 4 coils, namely the primary coil (2), the secondary A1 coil (3), the secondary B coil (4) and the secondary A2 coil (5). Each coil is wound from the same end of the coil frame (6) and finally returns to the starting end;

[0028] 2. The wire end of the primary coil (2) is wound around the first lead terminal (7) of the lead frame (8) by a winding machine, the number of layers of the primary coil (2) is an even number, and the number of layers or the wire spacing of the last layer is adjusted by setting the total number of turns to achieve the winding of the coil from the starting end to the starting end; the wire end of the primary coil (2) is wound around the second lead terminal (7) of the lead frame (8) by a winding machine;

[0029] 3. The end of the secondary A1 coil (3) is wound around the third lead terminal (7) of the lead frame (8) by a winding machine, and the length of each two layers of winding decreases according to an arithmetic progression. Each two layers of winding refer to winding from the starting point, reaching the end point and then winding back to the starting point, and the wire spacing is the same during the process; the last two layers are divided into a number of sections, and the wire spacing of each section is determined according to the sensor and the value voltage. The winding is from the starting point, reaching the end point and then winding back to the starting point. The winding direction of the last two layers may be the same as or opposite to that of the previous coil; the end of the secondary A1 coil (3) is wound around the fourth lead terminal (7) of the lead frame (8) by a winding machine;

[0030] 4. The wire end of the secondary B coil (4) is wound in a circle on the sixth lead terminal (7) of the lead frame (8) by a winding machine, and the wire pitch of the enameled wire is half of that of the secondary A1 coil (3) and the secondary A2 coil (5). The first layer of winding is wound from the starting point to the end point; the subsequent windings are wound from the end point, and the length of each two layers of winding decreases according to an arithmetic progression, and returns from the end point to the end point; the third to last layer has the same length as the first layer, and returns from the end point to the starting point; the last two layers are divided into several sections, and the wire pitch of each section is different, and the wire pitch is half of the corresponding position of the A1 coil (3) and the secondary A2 coil (5); the wire end of the secondary B coil (4) is wound in a circle on the fifth lead terminal (7) of the lead frame (8) by a winding machine;

[0031] 5. The winding method of the secondary A2 coil (5) is the same as that of the secondary A1 coil (3), the wire head is wound around the fourth lead terminal (7) of the lead frame (8), and the wire tail is wound around the fifth lead terminal (7) of the lead frame (8);

[0032] 6. After the secondary A2 coil (5) is wound, a glass fiber wire is tied to the outer surface of the secondary A2 coil (5); the enameled wire is tied so that the winding (1) will not fall apart.

[0033] 7. Furthermore, the frame (6) is made of austenitic stainless steel, titanium alloy or plastic; it must meet the requirements of poor magnetic permeability and poor electrical conductivity; in this way, the utilization rate of the magnetic field generated by the coil will be maximized; the eddy current effect generated in the frame is minimized, and the accuracy of the sensor will be improved;

[0034] 7. Furthermore, the enameled wires of the primary coil (2), the secondary A1 coil (3), the secondary B coil (4) and the secondary A2 coil (5) have the same diameter; thus, the enameled wires do not need to be replaced during the winding process, and the winding efficiency will be maximized;

[0035] 9. Furthermore, the winding directions of the last two layers of the primary coil (2), secondary A1 coil (3), secondary B coil (4) and secondary A2 coil (5) are determined according to the sensor sum voltage. In order to obtain the specified difference ratio sum voltage, the size of the sum voltage needs to be adjusted; the smaller the line spacing, the larger the sum voltage; the larger the line spacing, the smaller the sum voltage; because when the magnetic lines remain unchanged, the smaller the line spacing, the more turns, so the sum increases. The last two layers of turns of secondary A1 (3) and secondary A2 (5) and secondary B at the same position change in the same way, the advantage is that the sum increases or decreases, while the difference remains unchanged; 10. Furthermore, the lead terminal (7) and the lead (9) are injection molded as a whole to form a lead frame (8); the advantage brought about by this is that the lead has extremely high tensile strength, and the lead terminal has considerable rigidity, which is convenient for automatic binding of enameled wire and automatic welding wire;

[0036] 11. Furthermore, the winding device winds the enameled wire head and tail around the lead terminal (7) in a "circle-drawing" manner, which is highly efficient and simple in process.

[0037] Example 2

[0038] The present invention is implemented as follows:

[0039] 1. The winding machine draws a circle and ties the wire end to the lead terminal 7 of the lead frame 8. The length of the frame is 100mm;

[0040] 2. Start winding the primary coil 2. The primary coil has 6 layers and 4000 turns. The spacing between the 1st to 4th layers is the same, which is 0.125mm, so there are 3200 turns in total. The spacing between the 5th and 6th layers is 0.25mm. The winding machine returns to the starting point and draws a circle to tie the wire tail.

[0041] 3. The winding machine draws a circle and ties the wire end to the lead terminal 7 of the lead frame 8. The secondary coil A1 has 100mm for the first and second layers, 66.7mm for the third and fourth layers, and 33.3mm for the fifth and sixth layers. The wire spacing is 0.2mm. The seventh and eighth layers are the same, both 100mm divided into 10 sections, each section is 10mm. Considering the general linearity difference at both ends, the wire spacing is 0.28 for the first section, 0.15 for the second to ninth sections, and 0.28 for the tenth section. The winding direction is opposite to that of the first to eighth layers, so that the sensitivity will increase. Finally, the winding machine draws a circle and ties the wire end to the lead terminal 7 of the lead frame 8.

[0042] 4. The winding machine draws a circle and ties the wire end to the lead terminal 7 of the lead frame 8. The first layer of the secondary coil B is 100mm long; the second and third layers are 66.7mm long, the fourth and fifth layers are 33.3mm long, and the sixth layer is 100mm long. The above wire spacing is 0.1mm;

[0043] The 7th and 8th layers are the same, both are 100mm divided into 10 sections, each section is 10mm, and the line spacing is half of that in step 4, so the line spacing is 0.14 for the first section, 0.075 for the 2nd to 9th sections, and 0.14 for the 10th section. The winding direction is opposite to the 1st to 8th layers, so the sensitivity will increase. Finally, the winding machine draws a circle and ties the wire end to the lead terminal 7 of the lead frame 8;

[0044] 5. Continue winding according to step 3. The secondary A1 and secondary A2 are connected at the lead terminals. The total number of turns is the same as that of secondary B.

[0045] 6. After winding, the finished product can be completed by simple binding.

[0046] It is understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and unless defined as here, will not be interpreted with idealized or overly formal meanings. The specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Within the spirit and principle of the present invention, any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment of equivalent changes for application in other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution content of the present invention, any modification, equivalent replacement, improvement, etc., made according to the technical essence of the present invention, should be included in the protection scope of the present invention.

Claims

1. A linear displacement sensor winding method, characterized in that: The steps include: Step 1. Install the sensor frame on the winding machine, and weld the coil on the winding to the lead terminal of the frame. The winding is divided into 4 coils, namely the primary coil, the secondary A1 coil, the secondary B coil and the secondary A2 coil. Each coil is wound from the same end of the coil frame and finally returns to the starting end; Step 2. The wire end of the primary coil is wound around the first lead terminal of the lead frame by a winding machine. The number of layers of the primary coil is an even number. The number of layers or the wire spacing of the last layer is adjusted by setting the total number of turns to realize the winding of the coil from the starting end to the starting end; the wire end of the primary coil is wound around the second lead terminal of the lead frame by a winding machine; Step 3. The end of the secondary A1 coil is wound around the third lead terminal of the lead frame by a winding machine, and the length of every two layers of winding decreases according to an arithmetic progression. Every two layers of winding refer to winding from the starting point, reaching the end point and then winding back to the starting point, and the wire spacing is the same during this period; the last two layers are divided into several sections, and the wire spacing of each section is determined according to the sensor and value voltage. The winding starts from the starting point, reaches the end point and then winds back to the starting point. The winding direction of the last two layers may be the same as or opposite to the previous coil; the end of the secondary A1 coil is wound around the fourth lead terminal of the lead frame by a winding machine; Step 4. The wire end of the secondary B coil is wound on the sixth lead terminal of the lead frame by a winding machine, and the wire pitch of the enameled wire is half of that of the secondary A1 coil and the secondary A2 coil. The first layer of winding is wound from the starting point to the end point; the subsequent windings are wound from the end point, and the length of every two layers of winding decreases according to an arithmetic progression, from the end point back to the end point; the third to last layer has the same length as the first layer, and returns from the end point back to the starting point; the last two layers are divided into several sections, and the wire pitch of each section is different, which is half of the corresponding position of the A1 coil and the secondary A2 coil; the wire end of the secondary B coil is wound on the fifth lead terminal of the lead frame by a winding machine; Step 5. The winding method of the secondary A2 coil is the same as that of the secondary A1 coil. The wire head is wound around the fourth lead terminal of the lead frame, and the wire tail is wound around the fifth lead terminal of the lead frame.

2. The method according to claim 1, characterized in that The method also includes step 6. After the secondary A2 coil is wound, a glass fiber wire is tied to the outer surface of the secondary A2 coil; and the enameled wire is tied so that the winding will not spread out.

3. The method according to claim 2, characterized in that The skeleton is made of austenitic stainless steel, titanium alloy or plastic.

4. The method according to claim 3, characterized in that The skeleton needs to meet the requirements of poor magnetic conductivity and poor electrical conductivity.

5. The method according to claim 4, characterized in that The enameled wires of the primary coil, the secondary A1 coil, the secondary B coil and the secondary A2 coil have the same wire diameter.

6. The method according to claim 5, characterized in that The winding directions of the last two layers of the primary coil, the secondary A1 coil, the secondary B coil and the secondary A2 coil are determined according to the sensor sum voltage; in order to obtain a specified difference ratio sum voltage, the sum voltage needs to be adjusted.

7. The method according to claim 6, characterized in that The lead terminals and the leads are integrally molded to form a lead frame.

8. The method according to claim 7, characterized in that The winding equipment wraps the enameled wire head and tail around the lead terminal in a "circle" manner.

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