Induction coil assembly and linear variable differential transformer

Abstract

The utility model provides an induction coil assembly. The induction coil assembly includes a bobbin, a plurality of coils, a printed circuit board member, and a connector. The winding reel comprises a hollow channel, two end parts and a plurality of containing areas arranged outside the winding reel and located between the two end parts, wherein the containing areas are separated by separating flanges. A plurality of coils are respectively wound into the plurality of receiving regions to generate an inductive signal as a ferromagnetic core of the linearly variable differential transformer moves. The printed circuit board is fixed on the winding reel and is electrically connected with the coils so as to receive and process the induction signals. The connector is electrically connected to the printed circuit board through a wire so as to output signals from the printed circuit board. The utility model further provides a linear variable differential transformer with the induction coil assembly. According to the technical scheme, the manufacturing process is simplified, manual operation is avoided, manufacturability and reliability of products are improved, and cost is reduced.

Description

Technical Field

[0001] The utility model relates to electrical components and sensors including such electrical components. Specifically, the utility model relates to an induction coil assembly and a linear variable differential transformer including such an induction coil assembly. Background Art

[0002] As an electrical sensor based on the principle of electromagnetic induction, a linear variable differential transformer (abbreviated as LVDT sensor) is specifically designed to convert mechanical linear displacement into an electrical signal. Due to its non-contact operation, the LVDT sensor exhibits excellent accuracy and stability in various industrial applications. Especially in hydraulic systems, it plays a crucial role in monitoring the position of the spool of a hydraulic valve. The accurate displacement measurement ability of the LVDT sensor is essential for ensuring the performance of the valve operation. By converting the mechanical displacement of the valve into an easily processed electrical signal, the LVDT sensor provides key information for the precise control and feedback of the hydraulic system. Therefore, the accuracy and reliability of the LVDT sensor are directly related to the overall performance and efficiency of the valve.

[0003] The induction coil assembly is also a key component in the LVDT sensor. To ensure the required accuracy and reliability, the structure of the induction coil assembly in existing LVDT sensors is very complex, and there are also high requirements for manufacturing and assembly.

[0004] Therefore, there is a need in the art for an induction coil assembly that can simplify the manufacturing process and reduce costs, and also a need for a linear variable differential transformer (i.e., LVDT sensor) that can ensure accuracy and reliability. Summary of the Utility Model

[0005] One technical problem to be solved by the utility model is to provide an induction coil assembly that simplifies the assembly process and can ensure reliability, and another technical problem to be solved is to provide a linear variable differential transformer that reduces manual operation and can ensure accuracy.

[0006] To solve the above technical problems, the present utility model provides an induction coil assembly for a linear variable differential transformer. The induction coil assembly includes a winding cylinder, a plurality of coils, a printed circuit board member, and a connector. The winding cylinder includes a hollow channel, two end portions, and a plurality of receiving areas provided on the outside of the winding cylinder and located between the two end portions, wherein the plurality of receiving areas are separated by partition flanges. The plurality of coils are respectively wound into the plurality of receiving areas to generate induction signals as the ferromagnetic core of the linear variable differential transformer moves. The printed circuit board member is fixed to the winding cylinder and forms an electrical connection with the plurality of coils to receive and process the induction signals. The connector is electrically connected to the printed circuit board member through a wire to output signals from the printed circuit board member.

[0007] According to a preferred embodiment of the present utility model, the terminal ends of the coils are welded to the input ends of the printed circuit board member by means of through-hole welding to fix the printed circuit board member to the winding cylinder.

[0008] According to a preferred embodiment of the present utility model, the printed circuit board member is fixed to the winding cylinder by an adhesive.

[0009] According to a preferred embodiment of the present utility model, the plurality of coils include a primary power coil and at least two secondary induction coils. The two terminal ends of the primary power coil correspond to the two output ends of the printed circuit board member and are electrically connected to the two interfaces of the connector. The terminal ends of the at least two secondary induction coils are converted into two other output ends through the printed circuit board member and are electrically connected to the two other interfaces of the connector.

[0010] According to a preferred embodiment of the present utility model, the coil is a three-section induction coil or a five-section induction coil.

[0011] According to a preferred embodiment of the present utility model, the partition flange is integrally formed with the winding cylinder.

[0012] According to a preferred embodiment of the present utility model, the induction coil assembly further includes at least two extension members fixed to the winding cylinder, and the printed circuit board member is fixed to the winding cylinder through the extension members.

[0013] According to a preferred embodiment of the present utility model, the extension member is integrally formed with the partition flange, or the extension member is separately formed and fixedly connected to the partition flange.

[0014] According to a preferred embodiment of the present utility model, the number of the extension members corresponds to the number of the plurality of coils.

[0015] According to a preferred embodiment of the present utility model, a groove for accommodating the wire of the coil is provided on the extension member.

[0016] According to a preferred embodiment of the present utility model, the winding bobbin and / or the separating flange and / or the extension member are made of a rigid insulating material.

[0017] To solve the above technical problems, the present utility model also provides a linear variable differential transformer for a hydraulic valve. The linear variable differential transformer includes a housing, the above-mentioned induction coil assembly, and a ferromagnetic core. The ferromagnetic core is located inside the winding bobbin of the induction coil assembly, and the ferromagnetic core can be linked with the spool of the hydraulic valve to detect the displacement of the spool. The induction coil assembly is mounted on the hydraulic valve for sensing the mechanical displacement of the ferromagnetic core and generating an induction signal. The housing is mounted on the hydraulic valve, and a connector of the induction coil assembly (1) is installed inside the housing. The printed circuit board member of the induction coil assembly is fixed to the winding bobbin and forms an electrical connection with the wiring terminal of the coil, and the output end of the printed circuit board member is electrically connected to the connector through a wire.

[0018] By adopting the technical solution of the present utility model, the problems of manual wiring and the stability of related port connections are avoided, and the circuit of the printed circuit board member can be protected. The manufacturing process of the induction coil assembly is simplified and the manual operation of the linear variable differential transformer is reduced. Therefore, the manufacturability and reliability of the product are improved, and the cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To enable those skilled in the art to more fully understand the present utility model, the specific embodiments of the present utility model will be described in detail below with reference to the drawings. Among them:

[0020] Figure 1 is a perspective view of an embodiment of the induction coil assembly of the present utility model.

[0021] Figure 2 is a perspective view of an embodiment of the linear variable differential transformer of the present utility model, in which the housing of the linear variable differential transformer is removed for showing the internal structure.

[0022] DESCRIPTION OF THE REFERENCE NUMERALS

[0023] 1 Induction coil assembly

[0024] 11 Winding bobbin

[0025] 111, 112 Both ends

[0026] 113 Separating flange

[0027] 114 Extension member

[0028] 12 Coils

[0029] 13 Printed Circuit Board Assembly

[0030] 131 Connection Terminal

[0031] 14 Connector

[0032] 2 Linear Variable Differential Transformer

[0033] 3 Hydraulic Valve. Detailed Embodiment

[0034] To make the present utility model clearer, the following describes in detail a specific embodiment of the present utility model with reference to the accompanying drawings. However, the present utility model is not limited to this embodiment, and various variations can be made without departing from the inventive concept of the present utility model.

[0035] Figure 1 An induction coil assembly 1 of the present utility model is shown. The outer contour of the induction coil assembly 1 is shown as a generally cylindrical shape, but the present utility model is not limited thereto, and any suitable shape is not restricted according to design requirements. The induction coil assembly 1 can be used for a linear variable differential transformer 2 (i.e., an LVDT sensor) to convert linear displacement into an electrical signal. The induction coil assembly 1 shown in the figure is a three-section coil, but the present utility model is not limited thereto, and the induction coil assembly 1 can also be a five-section coil, etc., according to design requirements.

[0036] The induction coil assembly 1 includes a bobbin 11, a plurality of coils 12, a printed circuit board assembly (PCBA) 13, and a connector 14. The bobbin 11 provides shape retention for the induction coil assembly 1 and is made of a material with certain mechanical strength and good insulation performance. The bobbin 11 includes two end portions 111, 112 and a plurality of receiving areas provided between the two end portions and located outside the bobbin 11. The plurality of receiving areas are separated by partition flanges 113 to eliminate the mutual inductance between the coils. The plurality of coils 12 are respectively wound into the plurality of receiving areas, and these coils are generally divided into a primary coil and a secondary coil. Only the positions where the coils 12 are located are simply shown in the figure, and their details are not depicted.

[0037] According to an embodiment of the present utility model, a plurality of coils 12 include a primary power coil and at least two secondary induction coils. The secondary induction coils can be two or four. Two terminals of a primary power coil correspond to two output terminals of a printed circuit board member 13 and are electrically connected to two interfaces of a connector 14. Terminals of at least two secondary induction coils are converted into two other output terminals through the printed circuit board member 13 and are electrically connected to two other interfaces of the connector 14. That is, the PCBA converts the terminals of the coils into 4 output terminals according to the design requirements and electrically connects them to the connector. This design avoids manual wiring and related port problems and can protect the circuits and components.

[0038] The interior of the winding bobbin 11 is hollow to accommodate the ferromagnetic core of the LVDT sensor. The main body part of the winding bobbin 11 is constructed in a substantially cylindrical shape. The number of accommodation areas depends on the design requirements and can be three, five or other numbers. The partition flange 113 is generally a structure protruding from the surface of the main body of the winding bobbin 11. As shown in the figure, in this embodiment, the partition flange 113 is an annular flange. The partition flange 113 is generally integrally formed with the winding bobbin 11. The partition flange 113 can also be a separately manufactured independent component and be fixed to the winding bobbin 11.

[0039] One coil 12 is wound in each accommodation area. In the illustrated three-section induction coil assembly 1, generally, the primary coil (power coil) is located at the central position and serves as an input coil to receive an AC power supply voltage, thereby generating an alternating magnetic field. The two secondary coils (induction coils) are located on both sides of the primary coil. When the ferromagnetic core moves in the inner channel of the coil, it will change the magnetic flux passing through the secondary coils, thereby causing the two secondary coils to generate electromotive forces of different magnitudes, and thus judging the direction and magnitude of the movement of the ferromagnetic core. The terminals of the coil 12 are connected to the printed circuit board member 13. As shown in the figure, an electrical connection is formed between the terminals of the coil 12 and the input terminals of the printed circuit board member 13 at the connection terminal 131. According to a preferred embodiment, the two terminals of each coil respectively correspond to 2 input terminals on the printed circuit board member 13 for conveniently and reliably achieving electrical connection.

[0040] According to the present utility model, the printed circuit board member 13 is fixed to the winding bobbin 11. That is to say, according to the inventive concept of the present utility model, the printed circuit board member 13 and the winding bobbin 11 are fixed into an integral structure. Specifically, during production, the printed circuit board member 13 has been electrically connected and fixed to the winding bobbin 11. Thereby, problems that may be caused by manual assembly / wiring during subsequent use can be avoided, and the printed circuit board member 13 can be protected. For example, improper port configuration caused by manual wiring and poor contact caused by the technical level of the operator may lead to unstable reliability of the product. The existing printed circuit board member 13 is usually fixed to the housing of the linear variable differential transformer, and is also easily damaged due to factors such as vibration of the housing. Since the wiring process of the operator is eliminated, the cost is also reduced, and the uncertainty of personnel participation is eliminated. The output end of the printed circuit board member 13 is electrically connected to the connector 14 through a wire to transmit signals to the connector 14 and output through the connector 14. The output port of the connector 14 is usually a standardized port.

[0041] The printed circuit board member 13 can be fixed to the winding bobbin 11 in any way. For example, the printed circuit board member 13 can be directly fixed to any position on the outer periphery of the winding bobbin 11, preferably directly fixed to the partition flange 113 and / or the two end portions 111, 112 of the winding bobbin 11. According to another embodiment of the present utility model, in order to more firmly, effectively and conveniently fix the printed circuit board member 13 on the winding bobbin 11, extension members 114 can be provided on at least two of the two end portions 111, 112 and the partition flange 113 of the winding bobbin 11, and the printed circuit board member 13 is fixed to the winding bobbin 11 through the extension members 114. The height / length of the extension member 114 provides a suitable spacing between the printed circuit board member 13 and the coil 12, so as to facilitate the installation of the printed circuit board member 13, but at the same time does not significantly increase the volume of the induction coil assembly. Preferably, the extension member 114 extends from or is fixed to the partition flange 113, so that the extension member 114 extends parallel to the cross-section of the winding bobbin 11 / has the same length starting from the partition flange 113, so that the end face of the extension member 114 is substantially in a plane parallel to the axis of the winding bobbin 11. Such a setting will make the plane of the printed circuit board member 13 substantially parallel to the axis of the winding bobbin 11 after the printed circuit board member 13 is fixed to the extension member 114, thereby simplifying the manufacturing process and improving the structural stability.

[0042] Preferably, the extension member 114 can be a structure that is integral with the separating flange 113 and extends from the separating flange 113. In this case, the extension member 114 is integrally formed with the separating flange 113. Alternatively, the extension member 114 can be separately formed as an independent component, preferably separately formed as identical components to each other, and then fixedly connected to the separating flange 113 and / or fixedly connected to the ends 111, 112 of the bobbin 11 respectively. Preferably, the bobbin 11, the separating flange 113, and the extension member 114 can be integrally formed. The shape of the extension member 114 is not limited, but according to a preferred embodiment shown in the figure, the extension member 114 is in the form of a flat plate with the same thickness as the separating flange 113. The number of the extension members 114 is not limited, but considering the structural stability, the number of the extension members 114 can be at least two. Of course, the number of the extension members 114 can also be set to three or more. As a preferred embodiment, the number of the extension members 114 corresponds to the number of coils. Or in other words, for a three-segment coil, three extension members 114 can be provided, and each extension member 114 corresponds to one coil 12 respectively; while for a five-segment coil, five extension members 114 can be provided.

[0043] As a preferred embodiment, a groove 115 or a channel for accommodating the wire of the coil 12 is provided in the extension member 114. The end portion of the wire of the coil 12 can be placed in the groove 115 or the channel, and the connection terminal protrudes from the extension member 114, and then the connection terminal is electrically connected to the input end of the printed circuit board member 13. Preferably, the input end of the printed circuit board member 13 is a pad, and the connection terminal of the coil is directly soldered to the pad. As Figure 1 shown, in the three-segment coil assembly 1, each coil 12 corresponds to one extension member 114, and the connection terminals of each coil 12 are electrically connected to the input end of the printed circuit board member 13. Figure 1 It is shown that six connection terminals are respectively soldered to six input ends of the printed circuit board member 13, forming six connection terminals 113. Preferably, the connection terminal of the coil is soldered to the input end of the printed circuit board member 13 in a through-hole soldering manner, thereby fixing the printed circuit board member 13 to the bobbin 11 while achieving electrical connection.

[0044] Of course, the printed circuit board member 13 can be directly pasted onto the bobbin 11 or the extension member 114. In this case, the connection terminal of the coil 12 can be electrically connected to the printed circuit board member 13 by any suitable method. As an alternative, while the printed circuit board member 13 is through-hole soldered to the bobbin 11 or the extension member 114, pasting can also be assisted.

[0045] The interior of the bobbin 11 is hollow, that is, an inner channel is provided therein to accommodate a moving component, such as the ferromagnetic core of a sensor.

[0046] The bobbin 11 is made of a rigid insulating material. According to a preferred embodiment, the extension 114 is also made of a rigid insulating material. Preferably, the bobbin 11 and the extension 114 are integrally made of the same material.

[0047] According to the present utility model, since the printed circuit board component and the bobbin are fixed together and the terminal of the coil is electrically connected to the input terminal of the printed circuit board component, the induction coil and the printed circuit board component can maintain a stable mechanical and electrical connection, thus significantly improving the reliability of the induction coil assembly. In the prior art, the printed circuit board component is usually fixed to the housing of the linear variable differential transformer at a certain distance from the induction coil assembly. When connecting the induction coil and the printed circuit board component through wires, it is easy for the connection port to become disconnected. Moreover, manual wiring is not only prone to misoperation but also cannot ensure the reliability of the connection port. Therefore, the induction coil assembly of the present utility model has the advantages of simplifying the manufacturing process and avoiding manual operation, thereby reducing misoperation and cost, and improving both the manufacturability and reliability of the induction coil assembly of the present utility model while reducing the cost.

[0048] Figure 2 shows the adoption of Figure 1 the linear variable differential transformer 2 with the induction coil assembly 1 shown, in which the housing of the linear variable differential transformer 2 is removed to show the internal structure. As Figure 2 shown, the connector 14 of the induction coil assembly 1 is actually fixed to a housing (not shown). The illustrated linear variable differential transformer 2 is mounted on the hydraulic valve 3 to measure the displacement of the spool of the hydraulic valve. The linear variable differential transformer 2 includes a housing (not shown), Figure 1 the induction coil assembly 1 shown, and a ferromagnetic core. The ferromagnetic core of the linear variable differential transformer 2 is interlocked with the spool of the hydraulic valve to detect the displacement of the spool.

[0049] According to the present utility model, the induction coil assembly 1 is mounted on the hydraulic valve 3, and the ferromagnetic core for sensing the position change is placed in the hollow channel of the induction coil assembly 1.

[0050] As an alternative embodiment, the induction coil assembly 1 can be mounted through a pressure pipe already mounted on the hydraulic valve 3, such that the induction coil assembly 1 is sleeved outside the pressure pipe and the ferromagnetic core is placed in the inner channel of the pressure pipe.

[0051] According to the present utility model, since the printed circuit board component is fixed to the winding bobbin, the stability and precision of the linear variable differential transformer during operation can be ensured. Moreover, the assembly process can be simplified, assembly time can be saved, and costs can be reduced. Due to the improved manufacturability and reliability of the induction coil assembly, the assemblability and reliability of the linear variable differential transformer on which it is installed are also improved. Thereby, installation errors can be effectively reduced and the accuracy of the detection results can be improved.

[0052] The above specific embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Those skilled in the art can make various modifications and variations without departing from the inventive concept of the present utility model. Therefore, all equivalent technical solutions fall within the protection scope of the present utility model, and the protection scope of the present utility model is defined by the appended claims.

Claims

1. An induction coil assembly (1) for a linear variable differential transformer (2), characterized in that: The induction coil assembly (1) comprises a bobbin (11), a plurality of coils (12), a printed circuit board component (13) and a connector (14), wherein: The winding drum (11) comprises a hollow passage, two ends (111, 112), and a plurality of accommodating areas arranged outside the winding drum (11) and between the two ends (111, 112), wherein the plurality of accommodating areas are separated by a separation flange (113); The plurality of coils (12) are respectively wound into the plurality of accommodation areas to generate induction signals as the ferromagnetic core of the linear variable differential transformer (2) moves; The printed circuit board component (13) is fixed to the bobbin (11) and is electrically connected to the plurality of coils (12) to receive and process the induction signal; and The connector (14) is electrically connected to the printed circuit board component (13) via a wire to output a signal from the printed circuit board component (13).

2. The induction coil assembly (1) according to claim 1, characterized in that: The connection terminal of the coil (12) is welded to the input end of the printed circuit board component (13) by through-hole welding to fix the printed circuit board component (13) to the winding drum (11); or the printed circuit board component (13) is fixed to the winding drum (11) by an adhesive.

3. The induction coil assembly (1) according to claim 1, characterized in that: The plurality of coils (12) include a primary power supply coil and at least two secondary induction coils, wherein two connection terminals of the primary power supply coil correspond to two output terminals of the printed circuit board component (13) and are electrically connected to two interfaces of the connector (14), and the connection terminals of the at least two secondary induction coils are converted into two other output terminals through the printed circuit board component (13) and are electrically connected to two other interfaces of the connector (14).

4. The induction coil assembly (1) according to claim 1, characterized in that: The coil (12) is a three-segment induction coil or a five-segment induction coil.

5. The induction coil assembly (1) according to claim 1, characterized in that: The partition flange (113) is formed integrally with the bobbin (11).

6. The induction coil assembly (1) according to any one of claims 1 to 5, characterized in that: The induction coil assembly (1) further comprises at least two extension pieces (114) fixed to the winding drum (11), and the printed circuit board component (13) is fixed to the winding drum (11) via the extension pieces (114).

7. The induction coil assembly (1) according to claim 6, characterized in that: The extension piece (114) is formed integrally with the partition flange (113).

8. The induction coil assembly (1) according to claim 6, characterized in that: The extension piece (114) is provided with a groove (115) for accommodating the wire of the coil (12).

9. The induction coil assembly (1) according to claim 6, characterized in that: The bobbin (11) and / or the separation flange (113) and / or the extension piece (114) are made of a rigid insulating material.

10. A linear variable differential transformer (2) for a hydraulic valve (3), characterized in that: The linear variable differential transformer (2) comprises a housing, an induction coil assembly (1) according to any one of claims 1 to 9, and a ferromagnetic core, wherein: The ferromagnetic core is located inside the winding drum (11) of the induction coil assembly (1) and is capable of being linked with the valve core of the hydraulic valve (3) to detect the displacement of the valve core; The induction coil assembly (1) is mounted on the hydraulic valve (3) to sense the displacement of the ferromagnetic core and generate an induction signal; The housing is mounted on the hydraulic valve (3), and a connector (14) of the induction coil assembly (1) is mounted inside the housing; and The printed circuit board component (13) of the induction coil assembly (1) is fixed to the bobbin (11), and the input end of the printed circuit board component (13) is electrically connected to the terminal of the coil (12), and the output end is electrically connected to the connector (14) through a wire.

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