Coil assembly for an electromechanical relay, electromechanical relay comprising the coil assembly, and method for manufacturing the coil assembly

Abstract

To provide a coil assembly for producing an electromagnetic driving force in an electromechanical relay, and a production method thereof.SOLUTION: A coil assembly (1) comprises a core (2), an energizing coil (14) wound about the core (2), and a separate distancing member (24) positioned between the core (2) and the energizing coil (14) for radially distancing the energizing coil (14) from the core (2). The distancing member (24) includes at least one layer (26) of separation windings (28) that are formed of a strand material (30). Due to the use of the strand material (30), the distancing member (24) can be manufactured much thinner than conventionally molded distancing members, so that the energizing coil (14) can have a smaller mean inner diameter, saving the installation space and improving the coil efficiency.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a coil assembly for generating an electromagnetic driving force in an electromechanical relay or other types of switching devices, such as contactors. Further, the present invention relates to an electromechanical relay comprising the coil assembly. Further, the present invention relates to a method of manufacturing the coil assembly.

Background Art

[0002] Electromechanical relays and other switching devices often rely on the electromagnetic driving force generated by a coil assembly. The coil assembly generally comprises an energized coil wound around a core, with a spacing member positioned between the core and the coil. Usually, the spacing member is an insulating tube or cage formed by injection molding. Using an injection molded tube or cage results in relatively large dimensions. Thereby, the spacing member has an adverse effect on space efficiency and energy efficiency during its operation.

[0003] Therefore, it is desirable to provide a coil assembly that is small and does not adversely affect energy efficiency.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide means for improving the performance of an electromechanical relay, generally means for improving the coil assembly of an electromechanical relay, particularly with respect to space and energy consumption.

Means for Solving the Problems

[0005] This object is achieved by a coil assembly for generating an electromagnetic driving force, comprising a core, an energized coil wound around the core, and a separate spacer member located between the core and the energized coil for radially spacing the energized coil from the core, the spacer member including at least one layer of separated windings formed from a stranded wire material.

[0006] The technical effects and advantages achieved by the above solution are as follows. In the coil assembly of the present invention, the energized coil is spaced from the core by a spacer member as a means of mechanical and / or electrical separation. That is, the spacer member can perform an insulating function, but its purpose may be limited to a mere mechanical function, for example, performed during the manufacture of the coil assembly, as will be described in more detail later. By using a stranded wire material, a spacer member in the form of at least one layer of separated windings can be manufactured much thinner than a spacer member formed by a conventional method that often has to comply with certain minimum material thickness requirements defined by manufacturability, fire resistance, etc.

[0007] The coil assembly of the present invention uses its thin spacer member to save installation space and improve coil efficiency considering smaller dimensions. This is because the energized coil can be wound closer to the core, resulting in a smaller average inner diameter of the energized coil.

[0008] Therefore, the coil assembly of the present invention solves the above problems.

[0009] The above solution can be further improved by adding one or more of the following optional mechanisms. Each of the following optional mechanisms is advantageous in itself and can be combined independently of the other optional mechanisms.

[0010] According to one possible embodiment, the core may be a substantially elongated element extending along the longitudinal axis. For example, the core can have a cylindrical shape with a circular, oval, or elliptical cross-section that is at least partially perpendicular to the longitudinal axis. At least one layer of separated windings can be arranged in the cylindrical shape. In this embodiment, it is advantageous that there are no sharp edges on the core that could damage the twisted wire material.

[0011] According to another possible embodiment, the core can exhibit a T-shape. In other words, the core can include straight ends and a T-shaped end that are located opposite each other along the longitudinal axis. A cuboid portion can extend between the straight end and the T-shaped end. Such cores are already often used in coil assemblies with formed spacer members and are commercially available.

[0012] However, in the present invention, since the formed spacer member is omitted, there is no immediate need for the core to have straight ends that would allow the formed spacer member to slide onto the core. Therefore, the present invention is not limited to a T-shaped core and can also be used in combination with an H-shaped core. That is, the core can include two T-shaped ends that are located opposite each other along the longitudinal axis, and a cuboid portion may extend between them. In this embodiment, as will be described in more detail later, a spacer member composed of at least one layer of separated windings can be obtained by winding the twisted wire material around the cuboid portion.

[0013] Furthermore, the core can be formed from iron or any other ferromagnetic material having a relative permeability greater than 1, preferably greater than 10, more preferably greater than 100, and most preferably greater than 1000. In particular, the core can be an iron core. This amplifies the electromagnetic driving force.

[0014] According to another possible embodiment, at least one layer of the separated winding has a thickness of 10 to 150 micrometers. The thickness is preferably measured in the radial direction perpendicular to the longitudinal axis. Compared with a conventional coil assembly with a formed spacer member, this embodiment is advantageous in terms of its compact structure.

[0015] Depending on the required thickness and function of the spacer member, at least two layers of the separated winding may be provided. That is, when the spacer member serves as electrical insulation between the energized coil and the core, two or more layers of the separated winding may be required to achieve the dielectric strength necessary to prevent electrical breakdown at the operating voltage of the coil assembly. However, if the only purpose of the spacer member is merely mechanical separation between the energized coil and the core, one layer of the separated winding may be sufficient. The latter case will be described later.

[0016] The energized coil itself can include at least one layer of energized coil windings spirally wound around the longitudinal axis at the portion of the spacer member. These energized coil windings can include enameled metal wires, particularly enameled copper wires. As will be described later, due to the electrical insulation lacquer inherent in the enameled metal wires of the energized coil windings, the spacer member itself does not necessarily need to provide insulation properties and can operate according to only mechanical principles. Depending on the desired electromagnetic driving force that the coil assembly should be able to generate, the energized coil can include more than 5, preferably more than 10, more preferably more than 20, and most preferably more than 50 layers of energized coil windings.

[0017] The maximum number of layers is determined by each application, but should not exceed 100 layers. Otherwise, the efficiency improvement effect of the coil assembly of the present invention will become less prominent or negligibly small.

[0018] According to another possible embodiment, the winding material may be flexible so as to be wound around the core, particularly around the rectangular parallelepiped portion of the core, without forming sharp corners. That is, the winding material forms only rounded bends when wound around the core. Thus, the winding material is particularly suitable for performing only the above-mentioned mechanical separation between the energized coil and the core. That is, the winding material can function to cover the sharp edges of the core, particularly the sharp edges of its rectangular parallelepiped portion. Otherwise, when the energized coil is wound around the core, such edges would damage the lacquer of the energized coil winding.

[0019] When the above-mentioned mere mechanical separation is the main function, the winding material used for the separated winding can include a metal wire, particularly an enameled copper wire, but the winding material is not interconnected to the energized coil winding. For example, the metal wire may be a coil wire having a diameter of 10 to 100 micrometers. This embodiment is advantageous because the same raw material or at least the same type of raw material as that used for an energized coil that can use a coil wire having the same or larger diameter can be used.

[0020] Alternatively or in addition, the winding material can include a flat ribbon cable and / or an insulating tape. Further, the winding material can include a plastic wire having a circular cross-section. The winding material may be braided or twisted. Thus, the coil assembly of the present invention provides a wide range of choices of raw materials that can be freely selected based on aspects such as price, performance, and availability.

[0021] As described above, at least one layer of the separated winding can be obtained by winding the winding material around the rectangular parallelepiped portion of the core. In particular, the winding material can be wound spirally around the rectangular parallelepiped portion of the core. Advantageous for this embodiment is that at least one layer of the separated winding can be formed with the same winding machine as the energized coil that is also wound spirally (later). In particular, one mounting step and one removal step can be omitted in this way.

[0022] Alternatively, the stranded wire material can be formed as a plurality of ring-shaped components arranged coaxially with the core. The ring-shaped components are closed in the circumferential direction and can be slid onto the core from the above-mentioned straight end when using a T-shaped core. Otherwise, the ring-shaped components are open in the lateral direction and can be snap-fastened to the core or bent around the core. For the manufacture of the present embodiment, especially when supplied as a coil with a pre-wound energizing coil, a winding machine is unnecessary.

[0023] According to another possible embodiment, the separated winding and the energizing coil can have the same winding pitch. The advantage of this embodiment is that during manufacturing, when the separated winding is completed and then the energizing coil is wound, there is no need to change the pitch. Alternatively, the separated winding and the energizing coil may each have a different winding pitch. This reduces the possibility of the coil wire of the energizing coil entering between adjacent separated windings as in the case where the winding pitches are the same, resulting in a more reliable separation between the core and the energizing coil.

[0024] According to another possible embodiment, the stranded wire material surrounds the core without a gap between the core and the energizing coil. This embodiment is particularly advantageous when the winding pitches of the separated winding and the energizing coil are the same. The absence of a gap prevents the coil wire of the energizing coil from entering between adjacent separated windings. Alternatively, if the gap is sufficiently smaller than the diameter of the energizing coil wire, there may be a gap between individual separated windings.

[0025] According to another possible embodiment, the coil assembly can comprise at least one positioning member arranged at an end of the core, said end extending from at least one layer of the separated windings. The at least one positioning member can be, for example, a spool collar formed from an insulating material. The spool collar can have a collar portion which is substantially disc-shaped and extends circumferentially around the longitudinal axis. Further, the collar portion can include a front face arranged to face an axial direction parallel to the longitudinal axis. The energized coil and the spacer member can each abut axially against the front face of the collar portion. Preferably, the coil assembly comprises two such positioning members respectively arranged at both ends of the core with respect to the longitudinal axis. Providing the positioning member is advantageous for preventing the energized coil and the spacer member from sliding on the core axially or even slipping off the core.

[0026] Optionally, the at least one positioning member includes at least one fixing pin. The at least one fixing pin can be integrally formed by a pin-shaped portion of the at least one positioning member. Further, at least one end of the stranded wire material is fixed to the at least one fixing pin. The fixing of the end of the stranded wire material can be achieved by tying, winding, adhesion, etc. Thus, the unwinding of the stranded wire material wound around the core can be prevented at least on one side.

[0027] To prevent the unwinding of the stranded wire material on both sides, both ends of the stranded wire material can be commonly fixed to the same fixing pin. This is particularly advantageous when an even number of separated winding layers are provided, since both ends of the stranded wire material are then relatively close to each other. Alternatively, the at least one positioning member can also include two fixing pins, and both ends of the stranded wire material are fixed to different fixing pins.

[0028] Instead of fixing both ends of the twisted wire material to one or more fixed pins, both ends of the twisted wire material can be joined to each other, for example, by binding them together. Thereby, the structure of at least one positioning member can be simplified.

[0029] In an embodiment including an odd number of separated winding layers and provided with two positioning members, each of the two positioning members can include at least one fixed pin for each end of the twisted wire material. Thereafter, both ends of the twisted wire material can be respectively fixed to the nearest fixed pins.

[0030] According to another possible embodiment, at least one positioning member can reach a corner between the core and at least one layer of the separated winding. By having at least one positioning member occupy the corner, it prevents the winding of the energized coil from slipping off the separated winding and entering the corner.

[0031] It is preferable that at least one positioning member and the spacing member are separate components. In particular, the spacing member does not include a molded part. That is, potentially flammable injection - molded resins or plastics that must meet certain requirements regarding a certain minimum material thickness according to any technical standard (for example, the so - called UL yellow card) are not arranged between the core and the energized coil.

[0032] The first object is achieved by an electromechanical relay comprising a coil assembly according to any one of the above - mentioned embodiments and two conductive coil terminal pins, wherein the ends of the energized coil are fixed to different coil terminal pins respectively.

[0033] The electromechanical relay benefits from the advantages of the coil assembly that bring high electrical efficiency, compact arrangement, low manufacturing cost, and short manufacturing time. Therefore, the electromechanical relay of the present invention achieves the first object.

[0034] The end of the twisted wire material and the entire separated winding are preferably potential-free even when they contain a conductive material (e.g., copper). That is, the end of the twisted wire material is not fixed to the coil terminal pin at all. This can omit the corresponding fixing step, thus simplifying the manufacturing process.

[0035] Alternatively, both ends of the twisted wire material are fixed to the same coil terminal pin. Therefore, the existing pins that must be provided for the energized coil can prevent the unwinding of the twisted wire material in any case.

[0036] The first object is further achieved by a method of manufacturing a coil assembly, which includes the steps of providing a core extending along a longitudinal axis, winding a twisted wire material around the core portion in the longitudinal axis to form at least one layer of separated windings of a separating member, and helically winding an enamelled metal wire around the separating member portion in the longitudinal axis to form an energized coil separated from the core by the separating member. The twisted wire material is preferably wound helically. The twisted wire material can be an enamelled metal wire such as a copper wire, a flat ribbon cable, or an insulating tape.

[0037] The method of the present invention achieves the first object in order to enable the manufacture of the coil assembly of the present invention showing the aforementioned advantages.

[0038] According to one possible embodiment of the method, at least one layer of the separated winding is formed by starting the winding of the twisted wire material at or near the center of the core. In addition, the winding of the twisted wire material can also be stopped at or near the center of the core. That is, the winding can be started and / or ended exactly at the center of the core or at a position closer to the center of the core than at least the end of any core.

[0039] From said position, the twisted wire material is spirally wound around the core towards one end of the core to form the first half of the first layer of the separated winding. After reaching a certain outermost position (for example, where one positioning member is arranged), the twisted wire material is then wound towards the starting position on top of the first half of the first layer of the separated winding. Thereby, the first half of the second layer of the separated winding is formed. After passing through the starting position, in order to complete the second half of the first layer of the separated winding, the twisted wire material is again wound directly around the core towards the opposite outermost position. This process can be repeated until the desired number of separated winding layers are obtained in halves. Thereby, the method of the present invention is advantageous in that the starting end and / or the ending end of the twisted wire material is held so as to be self-retained by the upper separated winding and / or later by the energized coil, resulting in a coil assembly with few loose ends.

[0040] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. The illustrated and described embodiments are for illustrative purposes only. The combination of mechanisms shown in the embodiments can be changed according to the above description. For example, if the technical effects related to the mechanisms not shown in the embodiments but described above are advantageous for a specific application, those mechanisms can be added. Conversely, if the technical effects related to the mechanisms shown as part of the embodiments are unnecessary for a specific application, those mechanisms can be omitted as described above.

[0041] In the figures, elements corresponding to each other with respect to function and / or structure are denoted by the same reference numerals.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0043] First, with reference to the exemplary embodiments shown in FIGS. 1-5, the structure of a possible embodiment of the coil assembly 1 according to the present invention will be described. Further below, FIG. 2 is used to explain a method of manufacturing the coil assembly 1 according to the present invention.

[0044] FIG. 1 is a top view of a coil assembly 1 according to one possible embodiment of the present disclosure. The coil assembly 1 functions to be used in an electromechanical relay or another type of switching device (not shown) that requires electromagnetic driving force. As can be seen, the coil assembly 1 includes a core 2. The core 2 may be a substantially elongated element 4 that extends along the longitudinal axis 6 and has an H-shape. That is, the core 2 can include two T-shaped ends 8 that are located opposite to each other along the longitudinal axis 6. Between the T-shaped ends 8, a rectangular parallelepiped portion 10 can extend (see FIG. 2).

[0045] According to another embodiment shown in FIG. 5, the core 2 can instead have a T-shape. In other words, the core 2 can include only one T-shaped end 8 and a straight end 34 that are located opposite to each other along the longitudinal axis 6 instead of two T-shaped ends 8. This embodiment is advantageous because when the energized coil is supplied as a pre-wound coil, the entire energized coil can be slid onto the core 2 from the straight end 34.

[0046] Furthermore, the core 2 can be formed from iron or any other ferromagnetic material having a relative permeability greater than 1, preferably greater than 10, more preferably greater than 100, and most preferably greater than 1000. The maximum number of optional layers should not exceed 100. In particular, the core 2 can be the iron core 12. This amplifies the electromagnetic driving force generated by the coil assembly.

[0047] Furthermore, as shown in FIG. 1, the coil assembly 1 includes an energized coil 14 wound around the core 2. The energized coil 14 can include at least one layer 16 of energized coil windings 18. These energized coil windings 18 can include an enameled metal wire 20, particularly an enameled copper wire 22. Due to the electrical insulation lacquer of the enameled metal wire 20, the energized coil windings 18 are essentially insulated from each other and from the core 2. Depending on the desired electromagnetic driving force that the coil assembly 1 should be able to generate, the energized coil 14 can include more than 10, more preferably more than 50, more preferably more than 100, and most preferably more than 200 layers 16 of energized coil windings 18.

[0048] As best seen in FIG. 3, the coil assembly 1 further includes a separate spacer member 24, located between the core 2 and the energized coil 14, as a means of mechanical and / or electrical separation for radially spacing the energized coil 14 from the core 2. That is, the spacer member 24 can perform an insulating function, but its purpose may be limited to a mere mechanical function, for example, performed during the manufacture of the coil assembly, as will be described in more detail later.

[0049] The spacer member 24 includes at least one layer 26 of separation windings 28 formed from a stranded wire material 30. By using the stranded wire material 30, the spacer member 24 in the form of at least one layer 26 of separation windings 28 can be manufactured much thinner than a conventional spacer member (not shown) that often has to comply with certain minimum material thickness requirements defined by manufacturability, fire resistance, etc.

[0050] The coil assembly 1 of the present invention uses its thin spacer member 24 to save installation space and improve coil efficiency. This is because the energized coil 14 can be wound closer to the core 2, so that the average inner diameter 32 of the energized coil 14 becomes smaller (see FIG. 4). Furthermore, since it is not necessary to perform a costly and time-consuming forming process to manufacture the spacer member 24 in the form of at least one layer 26 of the separated winding 28, the manufacturing cost is reduced and the productivity is improved.

[0051] At least one layer 26 of the separated winding 28 can be obtained by winding the stranded wire material 30 around the rectangular parallelepiped portion 10 of the core 2. In particular, the stranded wire material 30 can be wound spirally around the rectangular parallelepiped portion 10 of the core 2. Alternatively, the stranded wire material 30 can be formed as a plurality of ring-shaped parts (not shown) arranged coaxially with the core 2. The ring-shaped parts are closed in the circumferential direction and can be slid onto the core from the above-mentioned straight end 34 when using the T-shaped core 2. Otherwise, the ring-shaped parts are open in the lateral direction and can be snap-fastened to the core 2 or bent around the core 2.

[0052] Therefore, the enameled metal wire 20 of the energized coil winding 18 is wound spirally around the longitudinal axis 6 at the portion 36 of the spacer member 24. Therefore, the separated winding 28 and the energized coil winding 18 can have the same winding pitch. Thereby, during manufacturing, when the separated winding 28 is completed and then the energized coil winding 18 is wound, it is not necessary to change the pitch. Alternatively, the separated winding 28 and the energized coil winding 18 may each have a different winding pitch. Thereby, since the possibility that the coil wire of the energized coil winding 18 enters between the adjacent separated windings 28 is reduced as in the case where the winding pitches are the same, more reliable separation between the core 2 and the energized coil 14 occurs.

[0053] Even when the winding pitch is the same, in order to ensure a reliable separation between the core 2 and the energized coil 14, the stranded wire material 30 can surround the core 2 without a gap between the core 2 and the energized coil 14. Alternatively, if the gap (not shown) is sufficiently smaller than the diameter of the coil wire of the energized coil, there may be a gap between the individual separated windings 28.

[0054] As shown in FIG. 2, the coil assembly 1 can include at least one positioning member 38 disposed at the ends 8, 34 of the core 2, and the ends 8, 34 extend from at least one layer 26 of the separated windings 28. The at least one positioning member 38 can be, for example, a spool collar 40 formed of an insulating material. The spool collar 40 can have a collar portion 42, and this collar portion 42 is substantially disc-shaped and extends in the circumferential direction 44 around the longitudinal axis 6. Further, the collar portion 42 can include a front surface 46 arranged to face an axial direction 84 parallel to the longitudinal axis 6. The energized coil 14 and the spacer member 24 can each abut against the front surface 46 of the collar portion 42 in the axial direction 84.

[0055] In order to maintain the above-mentioned absence of a gap, it is preferable that the coil assembly 1 includes two such positioning members 38 respectively disposed at both ends 8, 34 of the core 2 with respect to the longitudinal axis 6. Thus, it is possible to prevent the energized coil 14 and the spacer member 24 from sliding on the core 2 in the axial direction 84 or even slipping off the core 2.

[0056] As shown in FIG. 3, depending on the required thickness 48 and function of the spacer member 24, at least two layers 26 of the separated windings 28 may be provided. That is, when the spacer member 24 serves as electrical insulation between the energized coil 14 and the core 2, two or more layers of separated windings may be required to achieve the breakdown voltage resistance necessary to prevent electrical breakdown at the operating voltage of the coil assembly. However, if the only purpose of the spacer member 24 is merely mechanical separation between the energized coil 14 and the core 2, a single layer 26 of the separated windings 28 may be sufficient.

[0057] In order to establish merely a mechanical separation between the energized coil 14 and the core 2, the stranded wire material 30 is preferably flexible so as to be wound around the core 2, particularly around the cuboid portion 10 of the core 2, without forming sharp corners. That is, the stranded wire material 30 should form only rounded bends when wound around the core 2. Thus, the stranded wire material 30 can function to cover the sharp edges of the core 2, particularly the sharp edges of its cuboid portion 10. Otherwise, such edges would damage the lacquer of the energized coil winding 18 when the energized coil 14 is wound around the core 2.

[0058] In the illustrated embodiment, the stranded wire material 30 used for the separated winding 28 includes a metal wire 50, particularly an enameled copper wire 52, similar to the energized coil winding 18, but the stranded wire material 30 is not interconnected to the energized coil winding 18. That is, the energized coil winding 18 and the separated winding 28 are different components. For example, the stranded wire material may be a coil wire having a diameter of 21 to 90 micrometers, while the energized coil can include a separate coil wire having the same or a larger diameter. This is advantageous because the same raw material or at least the same type of raw material can be used for both the energized coil winding 18 and the separated winding 28.

[0059] Alternatively or in addition, the stranded wire material 30 can include a flat ribbon cable and / or an insulating tape (not shown). Thus, the coil assembly 1 provides a wide range of choices of raw materials that can be freely selected based on aspects such as price, performance, and availability.

[0060] According to an embodiment not shown, at least one positioning member 1 can include at least one fixing pin (not shown). At least one fixing pin can be integrally formed by a pin-shaped portion of at least one positioning member 38. Further, in order to prevent the rewinding of the twisted wire material 30 on at least one side, at least one end portion 54 of the twisted wire material 30 can be fixed to at least one fixing pin. The fixing of the end portion 54 of the twisted wire material can be realized by bundling, winding, adhesion, etc.

[0061] When an even number of separated winding layers 26 are provided and both end portions 54 of the twisted wire material 30 are relatively close to each other, by commonly fixing both end portions 54 of the twisted wire material 30 to the same fixing pin, the rewinding of the twisted wire material 30 can be prevented on both sides. Since no current flows through the twisted wire material 30, there is no risk of short circuit even if the end portions 54 of the twisted wire material are in direct contact. Nevertheless, at least one positioning member 38 can also include two fixing pins, and both end portions 54 of the twisted wire material 30 are fixed to different fixing pins. Instead of fixing both end portions 54 of the twisted wire material 30 to one or more fixing pins, both end portions 54 of the twisted wire material 30 can be joined to each other, for example, by bundling them together.

[0062] When an odd number of separated winding layers 26 and two positioning members 38 are provided, each of the two positioning members 38 can include its own fixing pin for each end portion 54 of the twisted wire material 30. Thereafter, both end portions 54 of the twisted wire material 30 can be respectively fixed to the nearest fixing pins.

[0063] As seen in FIG. 3, at least one positioning member 38 can reach a corner portion 56 between the core 2 and at least one layer 26 of the separated winding 28. By at least one positioning member 38 occupying the corner portion 56, it is prevented that the winding of the energized coil 14 slides off from the separated winding 28 and enters the corner portion 56.

[0064] It is preferable that at least one positioning member 38 and the spacer member 24 are separate components. In particular, the spacer member does not include a molded part. In particular, FIG. 3 shows only the stranded wire material 30, and the injection molded resin or plastic parts are not arranged between the core 2 and the energized coil 14. Such parts are potentially flammable and thus must meet certain requirements regarding the minimum material thickness to comply with technical standards (e.g., the so-called UL Yellow Card) that are not necessary when using the stranded wire material.

[0065] Accordingly, at least one layer 26 of the separated winding 28 can have a thickness 58 of 50 micrometers or less. Here, the thickness 58 is measured in the radial direction 60 perpendicular to the longitudinal axis 6. In contrast, a conventional coil assembly with a molded spacer member (not shown) typically has a thickness of at least 0.25 - 0.40 millimeters.

[0066] An electromechanical relay (not shown) according to the present invention comprises a coil assembly 1 according to any one of the above embodiments and two conductive coil terminal pins, with the ends of the energized coil fixed to different coil terminal pins respectively. The ends 54 of the stranded wire material 30 and the entire separated winding 28 are preferably potential-free even when they contain a conductive material (e.g., copper). That is, it is not necessary to fix the ends 54 of the stranded wire material 30 to the coil terminal pins at all. However, instead, the ends 54 of the stranded wire material 30 may both be fixed to the same coil terminal pin.

[0067] Next, a method for manufacturing the coil assembly 1 according to the present invention will be described with reference to FIGS. 2 and 3.

[0068] The method includes providing a core 2 extending along a longitudinal axis 6, winding a stranded material 30 around the longitudinal axis 6 at a portion 62 of the core 2 to form at least one layer 26 of a separated winding 28 of a spacer member 24, and helically winding an enameled metal wire 20 around the longitudinal axis 6 at a portion 36 of the spacer member 24 to form an energized coil 14. In the resulting coil assembly 1, the energized coil 14 is spaced from the core 2 by the spacer member 24. The stranded material 30 is also preferably wound helically. For example, the stranded material 30 may be an enameled metal wire 50 such as a copper wire 52, a flat ribbon cable, or an insulating tape.

[0069] At least one layer 26 of the separated winding 28 can be formed by starting the winding of the stranded material 30 at or near the center 64 of the core 2. Additionally, the winding of the stranded material 30 can also be stopped at or near the center 64 of the core 2. That is, the winding can be started and / or ended exactly at the center 66 of the core 2 or at least at a position 68 closer to the center 66 of the core 2 than the ends 8, 34 of the core 2.

[0070] From the position 68, the stranded material 30 is helically wound around the core 2 towards one end 8 of the core 2 to form a first half 70 of a first layer 72 of the separated winding 28 (see FIG. 3). After reaching a certain outermost position 74 (for example, where one positioning member 38 is arranged), the stranded material 30 is then wound towards the starting position 68 on the first half 70 of the first layer 72 of the separated winding 28. Thereby, a first half 76 of a second layer 78 of the separated winding 28 is formed. After passing through the starting position 68, the stranded material 30 is again directly wound around the core 2 towards the opposite outermost position 80 to complete a second half 82 of the first layer 72 of the separated winding 28.

[0071] This process can be repeated until the desired number of separated winding layers 26 are obtained in half portions. Thereby, the method of the present invention provides an advantageous coil assembly 1 with few loose ends because the starting end and / or the ending end of the stranded material 30 are held so as to be self-held by the upper separated winding 28 and / or later by the energized coil 14.

Explanation of Signs

[0072] 1 Coil assembly 2 Core 4 Element 6 Axis 8 End 10 Portion 12 Core 14 Energized coil 16 Layer 18 Energized coil winding 20 Enameled metal wire 22 Enameled copper wire 24 Spacer 26 Layer 28 Separated winding 30 Stranded material 32 Mean inner diameter 34 Straight end 36 Portion 38 Positioning member 40 Spool collar 42 Collar portion 44 Circumferential direction 46 Front face 48 Thickness 50 Metal wire 52 Enameled copper wire 54 End 56 Corner 58 Thickness 60 Radial direction 62 Portion 64 Center 66 Center 68 Position 70 First half 72 First layer 74 Position 76 First half 78 Second layer 80 Position 82 Second half 84 Axial direction

Claims

1. A coil assembly (1) for generating an electromagnetic driving force, comprising: - core (2), - a current-carrying coil (14) wound around said core (2); - a separate spacing member (24) located between the core (2) and the current carrying coil (14) for radially spacing the current carrying coil (14) from the core (2); The spacing member (24) includes at least one layer (26) of a separation winding (28) formed from stranded wire material (30); The coil assembly (1) comprises at least one positioning member (38) disposed at an end (8, 34) of the core (2); The at least one positioning member (38) includes at least one fixed pin, and at least one end (54) of the stranded wire material (30) is fixed to the at least one fixed pin.

2. The coil assembly (1) of claim 1, wherein the at least one layer (26) of the isolated winding (28) has a thickness of 50 micrometers or less.

3. The coil assembly (1) of claim 1, wherein the stranded material (30) comprises at least one of a metal wire (50), a flat ribbon cable, and an insulating tape.

4. 2. The coil assembly (1) of claim 1, wherein the stranded wire material (30) is formed as a plurality of ring-shaped components arranged coaxially with the core (2), or the stranded wire material (30) is spirally wound around the core (2).

5. The coil assembly (1) of claim 1, wherein the separated winding (28) and the energized coil (14) have different winding pitches or the same winding pitch.

6. The coil assembly (1) of claim 1, wherein the stranded wire material (30) tightly surrounds the core (2) between the core (2) and the current carrying coil (14).

7. A coil assembly (1) as described in claim 1, wherein the ends (8, 34) of the core (2) extend from at least one layer (26) of a separate winding (28).

8. 2. The coil assembly (1) of claim 1, wherein the at least one positioning member (38) extends to a corner (56) between the core (2) and the at least one layer (26) of isolated windings (28).

9. The coil assembly (1) of claim 1, wherein the spacer (24) does not include a molded part.

10. The coil assembly (1) of claim 1, wherein ends (54) of the stranded wire material (30) are joined together.

11. A coil assembly (1) for generating an electromagnetic driving force, comprising: - core (2), - a current-carrying coil (14) wound around said core (2); - a separate spacing member (24) located between the core (2) and the current carrying coil (14) for radially spacing the current carrying coil (14) from the core (2); The spacing member (24) includes at least one layer (26) of a separation winding (28) formed from stranded wire material (30); The ends (54) of the stranded wire material (30) are joined together, forming a coil assembly (1).

12. 1. An electromechanical relay, comprising: A coil assembly (1) according to any one of claims 1 to 11, two conductive coil terminal pins; An electromechanical relay, wherein the ends of the energized coil (14) are secured to different coil terminal pins.

13. 13. The electromechanical relay of claim 12, wherein no ends (54) of the stranded wire material (30) are secured to a coil terminal pin or both ends (54) of the stranded wire material (30) are secured to the same coil terminal pin.

14. 1. An electromechanical relay, comprising: A coil assembly (1) for generating an electromagnetic driving force; two conductive coil terminal pins; The coil assembly (1) comprises: - core (2), - a current-carrying coil (14) wound around said core (2); - a separate spacing member (24) located between the core (2) and the current carrying coil (14) for radially spacing the current carrying coil (14) from the core (2); The spacing member (24) includes at least one layer (26) of a separation winding (28) formed from stranded wire material (30); The ends of the current-carrying coil (14) are fixed to different coil terminal pins, An electromechanical relay, wherein the ends (54) of the stranded wire material (30) are not secured to a coil terminal pin or both ends (54) of the stranded wire material (30) are secured to the same coil terminal pin.

15. A method for manufacturing a coil assembly (1) according to any one of claims 1 to 11, comprising the steps of: - providing a core (2) extending along a longitudinal axis (6); - winding a stranded material (30) on a portion (62) of said core (2) around said longitudinal axis (6) to form at least one layer (26) of a separation winding (28) of a spacing member (24); - helically winding an enamelled metal wire (20) about said longitudinal axis (6) at a portion (36) of said spacer (24) to form a current carrying coil (14) spaced from said core (2) by said spacer (24).

16. 16. The method of claim 15, wherein the at least one layer (26) of the isolation winding (28) is formed by starting winding near a center (64) of the core (2).

17. A coil assembly (1) for generating an electromagnetic driving force, comprising: - core (2), - a current-carrying coil (14) wound around said core (2); - a separate spacing member (24) located between the core (2) and the current carrying coil (14) for radially spacing the current carrying coil (14) from the core (2); The coil assembly (1), wherein the spacing member (24) includes at least one layer (26) of separate windings (28) formed from stranded wire material (30), the stranded wire material (30) being formed as a plurality of ring-shaped components arranged coaxially with the core (2), the plurality of ring-shaped components being circumferentially closed or laterally open.

18. 1. An electromechanical relay, comprising: A coil assembly (1) according to claim 17, two conductive coil terminal pins; An electromechanical relay, wherein the ends of the energized coil (14) are secured to different coil terminal pins.

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