A method for winding a linear displacement sensor

Abstract

This invention relates to the field of sensor technology, specifically to a winding method for a linear displacement sensor. It employs a lead-terminal structure, making lead soldering relatively easy, and all six lead terminals are located on the same side of the frame, facilitating operation by automated equipment. All coils of the sensor winding start from the same end of the frame, eliminating the need for flying wires and unnecessary overlapping of enameled wire during sensor binding, resulting in high shaping efficiency and coil reliability. All coils, except for the last two layers, have the same wire spacing, reducing complex programming patterns, simplifying implementation, and minimizing errors. Because the outermost layer of the coil uses a multi-segment winding method with varying wire spacing, the local accuracy of the sensor can be adjusted, improving the overall performance of the sensor.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and specifically to a method for winding a linear displacement sensor. Background Technology

[0002] A linear variable differential transformer (LVDT) is an electromagnetic displacement sensor that operates on a non-contact principle and is widely used in aerospace and defense industries, nuclear industries, and general industrial applications. Currently, there are two main problems in the prototype and production of LVDT sensors: first, the manual soldering of enameled wires to the leads is time-consuming and unsuitable for mass production or automated manufacturing; second, the coil binding and shaping process is lengthy, and the binding process can easily lead to cross-over and overlapping of the enameled wires, causing potential quality issues. Summary of the Invention

[0003] Purpose of the invention

[0004] The purpose of this invention is to provide a winding method for a linear displacement sensor. This method is suitable for automated winding production of the sensor, and the sensor has fewer transition enameled wires, reducing disordered stacking of enameled wires and improving the reliability of the sensor.

[0005] Technical solution

[0006] A method for winding a linear displacement sensor includes the following steps:

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

[0008] Step 2. The end of the primary coil is wound in a circle on the first lead terminal of the lead frame by the winding machine. The number of layers of the primary coil is even. 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 ending end. The end of the primary coil is wound in a circle on the second lead terminal of the lead frame by the winding machine.

[0009] Step 3. The end of the secondary A1 coil is wound in a circle on the third lead terminal of the lead frame using a winding machine. The winding length decreases in an arithmetic progression every two layers. Each two layers of winding means winding from the starting point to the end point and then back to the starting point, with the wire spacing being the same throughout. The last two layers are divided into several segments, with the wire spacing of each segment determined according to the sensor and voltage. The winding direction of the last two layers may be the same as or opposite to that of the previous coils. The end of the secondary A1 coil is wound in a circle on the fourth lead terminal of the lead frame using a winding machine.

[0010] Step 4. The end of the secondary B coil is wound in a circle on the sixth lead terminal of the lead frame using a winding machine. The wire spacing of the enameled wire is half that of the secondary A1 and secondary A2 coils. The first layer of winding starts from the starting point and ends at the ending point. Subsequent windings start from the ending point, with the length of each two layers decreasing in an arithmetic progression, returning from the ending point to the ending point. The third to last layer has the same length as the first layer and returns from the ending point to the starting point. The last two layers are divided into several segments, each with a different wire spacing, which is half that of the corresponding positions of the A1 and secondary A2 coils. The end of the secondary B coil is wound in a circle on the fifth lead terminal of the lead frame using 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 end is wound around the fourth lead terminal of the lead frame, and the wire end is wound around the fifth lead terminal of the lead frame.

[0012] Step 6. After the secondary A2 coil is wound, tie glass fiber wire to the outer surface of the secondary A2 coil; tie enameled wire to prevent the winding from unraveling.

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

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

[0015] Furthermore, the winding directions of the last two layers of the primary coil, secondary coil A1, secondary coil B, and secondary coil A2 are determined based on the sensor and the sum-value voltage. To obtain the specified difference ratio and sum-value voltage, the magnitude of the sum-value voltage needs to be adjusted.

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

[0017] Furthermore, the winding device wraps the enameled wire ends around the lead terminals in a "circular" manner.

[0018] The beneficial effects of this application are as follows:

[0019] The advantages of the linear displacement sensor winding method of this invention are as follows: It employs a lead terminal structure, making lead wire soldering relatively easy, and all six lead terminals are located on the same side of the frame, facilitating operation of automated equipment. All coils of the sensor winding start from the same end of the frame, eliminating the need for flying wires and unnecessary overlapping of enameled wires during sensor binding, resulting in high shaping efficiency and high coil reliability. All coils, except for the last two layers, have the same wire spacing, reducing complex programming patterns, simplifying implementation, and minimizing errors. Because the outermost layer of the coil uses a multi-segment winding method with different wire spacings, the local accuracy of the sensor can be adjusted, improving the overall performance of the sensor. Attached Figure Description

[0020] Figure 1 This is a simplified diagram of the linear displacement sensor winding and its lead-out structure according to the present invention.

[0021] Figure 2 This is a simplified diagram of the secondary windings A1 and A2 of the linear displacement sensor of the present invention;

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

[0023] Figure 4 This is a comparison chart showing the accuracy of the presence or absence of the last two layers of coils. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0025] Example 1

[0026] The method for winding a linear displacement sensor includes the following steps:

[0027] 1. Install the sensor frame (6) onto the winding machine. The coils on the winding (1) are soldered to the lead terminals (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 starts from the same end of the coil frame (6) and finally returns to the starting end.

[0028] 2. The end of the primary coil (2) is wound in a circle by the winding machine onto the first lead terminal (7) of the lead frame (8). The number of layers of the primary coil (2) is even. 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 end of the primary coil (2) is wound in a circle by the winding machine onto the second lead terminal (7) of the lead frame (8).

[0029] 3. The end of the secondary A1 coil (3) is wound in a circle by a winding machine onto the third lead terminal (7) of the lead frame (8). The winding length of each two layers decreases in an arithmetic progression. Each two layers of winding means winding from the starting point to the end point and then back to the starting point, with the wire spacing being the same throughout. The last two layers are divided into several segments, and the wire spacing of each segment is determined according to the sensor and voltage. The winding direction of the last two layers may be the same as or opposite to that of the previous coils. The end of the secondary A1 coil (3) is wound in a circle by a winding machine onto the fourth lead terminal (7) of the lead frame (8).

[0030] 4. The end of the secondary B coil (4) is wound in a circle by the winding machine onto the sixth lead terminal (7) of the lead frame (8). The wire spacing of the enameled wire is half that of the secondary A1 coil (3) and the secondary A2 coil (5). The first layer of winding starts from the starting point and ends at the end point. The subsequent winding starts from the end point and the length of each two layers decreases in an arithmetic progression, returning from the end point to the end point. The third layer from the end point 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 segments with different wire spacing. The wire spacing is half that of the corresponding positions of the A1 coil (3) and the secondary A2 coil (5). The end of the secondary B coil (4) is wound in a circle by the winding machine onto the fifth lead terminal (7) of the lead frame (8).

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

[0032] 6. After the secondary A2 coil (5) is wound, fiberglass wire is tied to the outer surface of the secondary A2 coil (5); enameled wire is tied to prevent the winding (1) from unraveling.

[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 primary coil (2), secondary A1 coil (3), secondary B coil (4) and secondary A2 coil (5) are made of the same enameled wire diameter; thus, the enameled wire does not need to be replaced during the winding process, and the winding efficiency will be maximized.

[0035] 9. Further, 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 and the sum voltage. In order to obtain the specified difference ratio and sum voltage, it is necessary to adjust the magnitude of the sum voltage; 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 and the more turns, the sum increases. The advantage of the same change in the number of turns of the last two layers of secondary A1 (3), secondary A2 (5), and secondary B at the same position is that the sum increases or decreases, while the difference remains unchanged; 10. Further, the lead terminal (7) and the lead wire (9) are injection molded into a whole to form a lead frame (8); the advantage of this is that the lead wire has extremely high tensile strength, while the lead terminal has considerable rigidity, which facilitates automatic binding of enameled wire and automatic welding of wire;

[0036] 11. Furthermore, the winding equipment wraps the enameled wire ends and tails around the lead terminal (7) by “drawing circles”, which is efficient and simple.

[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 frame length is 100mm.

[0040] 2. Begin winding primary coil 2. The primary coil has 6 layers and a total of 4000 turns. The spacing between layers 1 to 4 is the same at 0.125mm, so there are a total of 3200 turns. The spacing between layers 5 and 6 is 0.25mm. Then the winding machine returns to the starting point and draws a circle to tie the end of the wire.

[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 the following wire spacings: 100mm for the first and second layers, 66.7mm for the third and fourth layers, and 33.3mm for the fifth and sixth layers, with a wire spacing of 0.2mm. The seventh and eighth layers are the same, each 100mm, divided into 10 segments of 10mm each. Considering the general difference in linearity at both ends, the wire spacing is 0.28mm for the first segment, 0.15mm for the second to ninth segments, and 0.28mm for the tenth segment. The winding direction is opposite to that of the first to eighth layers, which will increase the sensitivity. 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 wire spacing of all the above layers is 0.1mm.

[0043] The 7th and 8th layers are the same, each 100mm is divided into 10 segments, each segment is 10mm. The line spacing in step 4 is half of that, so the line spacing is 0.14 for the first segment, 0.075 for the second to ninth segments, and 0.14 for the tenth segment. The winding direction is opposite to that of the 1st to 8th layers, which will increase the sensitivity. 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 once more as in step 3. Connect the ends of secondary A1 and secondary A2 at the lead terminals, and the total number of turns is the same as that of secondary B.

[0045] 6. After the winding is complete, a simple binding is all that's needed to finish the product.

[0046] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. 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 should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the disclosed technical content to make changes or modifications to create equivalent embodiments applicable to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A method for winding a linear displacement sensor, characterized in that, Includes the following steps: Step 1. Install the sensor frame onto the winding machine. The coils on the winding are soldered to the lead terminals of the frame. The winding is divided into 4 coils, namely the primary coil, secondary A1 coil, secondary B coil and secondary A2 coil. Each coil starts from the same end of the coil frame and finally returns to the starting end. Step 2. The end of the primary coil is wound in a circle on the first lead terminal of the lead frame by the winding machine. The number of layers of the primary coil is even. 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 ending end. The end of the primary coil is wound in a circle on the second lead terminal of the lead frame by the winding machine. Step 3. The end of the secondary A1 coil is wound in a circle on the third lead terminal of the lead frame using a winding machine. The winding length decreases in an arithmetic progression every two layers. Each two layers of winding means winding from the starting point to the end point and then back to the starting point, with the wire spacing being the same throughout. The last two layers are divided into several segments, with the wire spacing of each segment determined according to the sensor and voltage. The winding direction of the last two layers may be the same as or opposite to that of the previous coils. The end of the secondary A1 coil is wound in a circle on the fourth lead terminal of the lead frame using a winding machine. Step 4. The end of the secondary B coil is wound in a circle on the sixth lead terminal of the lead frame using a winding machine. The wire spacing of the enameled wire is half that of the secondary A1 and secondary A2 coils. The first layer of winding starts from the starting point and ends at the ending point. Subsequent windings start from the ending point, with the length of each two layers decreasing in an arithmetic progression, returning from the ending point to the ending point. The third to last layer has the same length as the first layer and returns from the ending point to the starting point. The last two layers are divided into several segments, each with a different wire spacing, which is half that of the corresponding positions of the A1 and secondary A2 coils. The end of the secondary B coil is wound in a circle on the fifth lead terminal of the lead frame using a winding machine. Step 5. The winding method of the secondary A2 coil is the same as that of the secondary A1 coil. The end of the wire is wound around the fourth lead terminal of the lead frame, and the end of the wire is wound around the fifth lead terminal of the lead frame.

2. The method as described in claim 1, characterized in that, It also includes step 6. After the secondary A2 coil is wound, fiberglass wire is tied to the outer surface of the secondary A2 coil; enameled wire is tied to prevent the winding from unraveling.

3. The method as described in claim 2, characterized in that, The frame is made of austenitic stainless steel, titanium alloy, or plastic.

4. The method as described in claim 3, characterized in that, The framework must meet the requirements of poor magnetic permeability and poor electrical permeability.

5. The method as described in claim 4, characterized in that, The primary coil, secondary coil A1, secondary coil B, and secondary coil A2 all have the same enameled wire diameter.

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

7. The method as described in claim 6, characterized in that, The lead terminals and leads are injection molded together to form a lead frame.

8. The method as described in claim 7, characterized in that, The winding equipment wraps the enameled wire ends around the lead terminals by "drawing circles".

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