Coil mounting structure

Abstract

The coil mounting structure (1) is provided with: a core (15, 17) which is wound with a primary side winding (16) and a secondary side winding (18) and can share magnetic flux; and a shell (2) which fixes the primary side winding (16), the secondary side winding (18) and the core (15, 17), wherein the core (15, 17) is provided with: a first core (15) which is wound with the primary side winding (16) and is fixed to the shell (2) side; and a second core (17) which is wound with the secondary side winding (18) and has one end fixed to the shell side, the inner diameter of one core (15) is formed to be greater than the outer diameter of the other core (17), and the primary side winding, the secondary side winding, the first core and the second core are fixed in a state that the other core (17) enters the inside of one core (15).

Description

Technical Field

[0001] This utility model relates to a structure for mounting a coil having windings and an iron core. Background Technology

[0002] Patent Document 1 discloses an inductor comprising an iron core, a coil having connecting terminals, and a molded portion covering at least a portion of the iron core and the coil. The inductor of Patent Document 1 has a winding coil disposed inside an iron core assembly having a first iron core and a second iron core. The winding coil has lead-out portions and connecting terminals at both ends, which are led out from an opening in the iron core assembly to the outside. In the inductor of Patent Document 1, the iron core assembly is covered by a molded portion formed by molding. Furthermore, mounting portions are provided on both sides of the molded portion, embedding the lead-out portions and connecting terminals, and are integrally formed during the molding process. In addition, a through hole is formed in the connecting terminal portion along the thickness direction, and a machined portion is formed in the mounting portion, communicating with the hole and having internal threads. By fastening screws or the like in the hole and the machined portion, the entire device is securely fixed.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2009-218532

[0004] In the inductor of Patent Document 1, the mounting portion is integrally formed within the molding portion, resulting in a robust overall structure that improves vibration resistance. However, in the inductor of Patent Document 1, the molding portion and mounting portion are arranged as a single unit covering the core assembly, lead-out portions, etc., potentially leading to an overall larger device size. Furthermore, holes are formed in the lead-out portions and connecting terminals to secure them, and a machined portion is formed in the mounting portion that extends through these holes. Therefore, the overall volume occupied by the device increases, potentially reducing the flexibility of its mounting. Utility Model Content

[0005] This utility model was developed in response to the aforementioned technical issues, and its purpose is to provide a coil mounting structure that can improve vibration resistance while ensuring the overall mounting performance of the device.

[0006] To achieve the above objectives, the coil mounting structure of this utility model comprises: a primary winding as the input side; a secondary winding as the output side; an iron core wound with the primary winding and the secondary winding, capable of sharing magnetic flux in the primary winding and the secondary winding; and a housing for fixing the primary winding, the secondary winding, and the iron core. The coil mounting structure is characterized in that the iron core comprises: a first iron core wound with the primary winding, one end of which is fixed to the housing side in the length direction; and a second iron core separately formed from the first iron core and wound with the secondary winding, one end of which is fixed to the housing side in the length direction. The inner diameter of the cylindrical iron core wound with the primary winding and the outer diameter of the cylindrical iron core wound with the secondary winding are larger than the outer diameter of the other cylindrical iron core. The other iron core is fixed to the housing while inside the first iron core.

[0007] In the coil mounting structure of this embodiment, the first coil with a primary winding wound on a first iron core and the second coil with a secondary winding wound on a second iron core are each configured as separate units. Therefore, the mass of each of the first and second coils is smaller than that of an integral coil with two windings wound on a single iron core. That is, the weight (load) generated by the portion holding the first or second coil in the housing is smaller than the weight generated by the portion holding the integral coil in the housing. Alternatively, the inertial force generated in the first and second coils due to vehicle vibrations can be reduced. Furthermore, compared to an integral coil, the center of gravity positions of the first and second coils can be shifted closer to the housing. That is, the distance from the fixed portion to the housing to the center of gravity position is shorter for the first and second coils than for an integral coil. Therefore, for example, in the event of vehicle vibrations, the stress generated at the root of each iron core and at the junction of each lead with the substrate can be reduced. Therefore, in the event of vehicle vibrations or impacts, the reduction in the durability of each coil and each substrate can be suppressed. Furthermore, the iron core of the other coil is inserted into the interior of the iron core of the first coil, thus preventing the coils from being too far apart. Therefore, it is possible to suppress the decrease in the effective value of the induced electromotive force generated on the output side, thereby preventing or suppressing the degradation of the device's performance. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view of a first embodiment of the coil mounting structure used to illustrate an embodiment of the present invention.

[0009] Figure 2 This is a cross-sectional view of a second embodiment of the coil mounting structure used to illustrate an embodiment of the present invention.

[0010] Figure 3 The figure shows another example of the coil mounting structure for illustrating an embodiment of the present invention, wherein, Figure 3 (a) is a cross-sectional view illustrating a third embodiment of the coil mounting structure. Figure 3 (b) is a cross-sectional view illustrating the fourth embodiment of the coil mounting structure. Detailed Implementation

[0011] Next, the present invention will be described based on the illustrated embodiments. Furthermore, the embodiments described below are merely one example of how the present invention is embodied and do not limit the scope of the present invention.

[0012] The coil mounting structure 1 of this invention is used when mounting common-mode chokes, transformers, or other components used for power conversion in a vehicle. That is, the coil mounting structure 1 is used when the common-mode choke or transformer is installed in the engine compartment, battery pack, or other parts of the vehicle via a metal or resin housing. The coil mounting structure 1 in the first embodiment of this invention mainly consists of a housing (outer shell) 2, a first substrate 3, a second substrate 4, and an inductor 5.

[0013] Housing 2 is used in an electronic control unit mounted in a vehicle, housing multiple electronic components such as a circuit board. Housing 2 is made of metal materials such as aluminum or copper, or resin materials such as plastic or epoxy resin. Furthermore, housing 2 is configured for efficient heat dissipation and for securing the internally mounted circuit board, coils, etc. By securing the internal electronic components, the durability of these components is prevented from decreasing due to vehicle vibrations, impacts, etc. A seal (not shown) is applied to housing 2, improving its waterproof and dustproof performance. Housing 2, thus configured, is securely fastened to the vehicle via a bracket or similar means.

[0014] In addition, such as Figure 1 As shown, the housing 2 has a first support portion 6 and a second support portion 7 extending opposite each other in the direction of their short sides. The first support portion 6 and the second support portion 7 extend opposite each other like beams, each having two first fastening portions 8 and two second fastening portions 9 protruding toward their opposing surfaces. By fastening the first substrate 3 to its first fastening surface and the second substrate 4 to its second fastening surface, the first substrate 3 and the second substrate 4 are arranged in an opposing state. Furthermore, the housing 2 has a fixing portion 10 for integrating the separately formed first support portion 6 and the second support portion 7, configured such that the first support portion 6 and the second support portion 7 can be integrated using a fixing member (not shown) at the fixing portion 10.

[0015] like Figure 1As shown, the first substrate 3 and the second substrate 4 are fixed inside the housing 2 by the first fastening member 11 and the second fastening member 12, respectively. Furthermore, inside the housing 2, the first substrate 3 and the second substrate 4 are arranged opposite each other. The first substrate 3 and the second substrate 4 are so-called printed circuit boards (PCBs) or printed wiring boards on insulating layers, with the main wiring disposed thereon. The first substrate 3 and the second substrate 4 electrically connect and mechanically support electronic components. The first coil and the second coil of the inductor 5, described later, are respectively bonded to the first substrate 3 and the second substrate 4 as such electronic components. Additionally, the printed circuit board is provided with pads or through-holes (not shown) for bonding the windings of the inductor 5, described later.

[0016] The inductor 5, also known as a coil, is an electronic component that uses a magnetic field to convert electrical energy, such as a common-mode choke or transformer. The inductor 5 is used in vehicle DC-DC converters, filter circuits, and charging systems. In the inductor 5, a magnetic field is generated by allowing current to flow from a power source such as a battery. In the inductor 5, an electromotive force (EMF) is generated in the direction that opposes the change in current, through a self-induced EMF caused by the change in the generated magnetic field, thus suppressing current fluctuations (pulsations) and stabilizing the current supply. The inductor 5 includes a first coil 13 and a second coil 14.

[0017] The first coil 13 and the second coil 14 are formed by windings and an iron core, respectively. That is, as shown... Figure 1 As shown, the first coil 13 is formed by spirally winding the primary-side winding 16 around the primary-side core 15. The second coil 14 is formed by winding the secondary-side winding 18 around the secondary-side core 17. Furthermore, the first coil 13 and the second coil 14 are arranged relative to each other in a manner that aligns with the left-right or vertical direction of the vehicle along their length.

[0018] The primary winding 16 and secondary winding 18 of the first coil 13 and the second coil 14 are identically constructed, each having an insulated metal wire. The primary winding 16 and secondary winding 18 are formed by a conductor (not shown) through which current flows during operation and an insulating film (not shown) covering the conductor with an insulating material. The primary winding 16 and secondary winding 18 may include, for example, enameled wire insulated by coating copper wire with enamel paint. Furthermore, the primary winding 16 and secondary winding 18 are not limited to enameled wire as described above; they may also be constructed using metal wire made from copper, aluminum, or other raw materials as conductors and using insulating materials such as mica or varnish as the insulating film. By increasing the number of turns, cross-sectional area, and length of the primary winding 16 and secondary winding 18, the inductance can be increased. Furthermore, the winding ratio of the primary winding 16 to the secondary winding 18 can be set according to the application. In the case of a common coil or transformer as described above, the number of turns of the secondary winding 18 can be set to be greater than the number of turns of the primary winding 16.

[0019] The primary-side core 15 and secondary-side core 17 of the first coil 13 and the second coil 14 are cores made of magnetic materials. For example... Figure 1 As shown, the primary side core 15 is formed in a cylindrical shape, and the secondary side core 17 is formed in a cylindrical shape with an outer diameter smaller than the inner diameter of the primary side core 15. By using magnetic materials such as metallic magnetic materials and ferrites in the primary side core 15 and the secondary side core 17, the inductance of the inductor section 5 can be increased. In addition, the magnitude of the inductance can be adjusted according to the permeability of the magnetic materials used as the primary side core 15 and the secondary side core 17.

[0020] The first coil 13 and the second coil 14, configured as described above, are connected to the first substrate 3 and the second substrate 4, respectively. Specifically, a first bracket 19, integrated with the primary-side core 15 of the first coil 13, is joined to the first substrate 3. The first bracket 19 is integrated with the end of the primary-side core 15 on the side opposite to the second substrate 4. The first bracket 19 is fixed to the first substrate 3 by adhesive or the like. Furthermore, the first lead 20 of the primary-side winding 16 is soldered together while inserted into the aforementioned through-hole of the first substrate 3. Thus, the first coil 13 is fixed to the first substrate 3.

[0021] The second coil 14 is also fixed to the second substrate 4 in the same manner as the first coil 13. That is, the second bracket 21, which is integrated with the secondary-side iron core 17 of the second coil 14, is joined to the second substrate 4. The second bracket 21 is integrated with the end of the secondary-side iron core 17 on the side opposite to the first substrate 3. The second bracket 21 is fixed to the second substrate 4 by means of adhesive or the like.

[0022] Furthermore, the second lead 22 of the secondary winding 18 is soldered together while inserted into the aforementioned through hole in the second substrate 4. Thus, the second coil 14 is fixed to the second substrate 4.

[0023] The second coil 14 is disposed on the outer side of the first coil 13 in the radial direction. That is, the inner diameter of the second coil 14 is larger than the outer diameter of the first coil 13. Furthermore, as described above, the first substrate 3 and the second substrate 4 are arranged opposite each other, thereby... Figure 1 As shown, the first coil 13 enters the interior of the second coil 14. Thus, as... Figure 1 As shown, the first coil 13 and the second coil 14 are arranged on concentric circles. Furthermore, the first coil 13 and the second coil 14 are mounted on the housing 2 or each of the substrates 3 and 4 in a manner that prevents them from contacting each other.

[0024] In the inductor section 5 configured as described above, current flows through the first coil 13 via a power source such as a battery. That is, the first coil 13 is located on the input side, and a magnetic field is generated by causing current to flow from the power source to the primary winding 16, thus producing magnetic flux. This magnetic flux is transmitted to the second coil 14 side.

[0025] In the second coil 14, an electromotive force (EMF) is generated due to the change in magnetic flux on the side of the first coil 13. That is, the voltage induced in the second coil 14 changes according to the change in the current flowing in the first coil 13. As a result, a current flows in the secondary winding 18 of the second coil 14. In other words, the second coil 14 is the output side, supplying a current corresponding to its self-induced EMF to the load such as the connected device. The EMF at this time is determined based on the inductance in the inductor section 5 and the rate of change of the flowing current. Therefore, in the inductor section 5, the number of turns of each winding 16, 18 in each coil 13, 14, the cross-sectional area of ​​each coil 13, 14, and the length of each coil 13, 14, or the material used for each iron core 15, 17, etc., are set according to the desired EMF.

[0026] In the coil mounting structure 1 configured in this way, after the first coil 13 and the second coil 14 in the inductor section 5 are integrated, the first support section 6 and the second support section 7 are connected and integrated, thereby completing the assembly. For example, the first coil 13 and the second coil 14 are formed by winding the primary side winding 16 around the primary side core 15 and the secondary side winding 18 around the secondary side core 17. The first coil 13 and the second coil 14 are respectively joined to the first substrate 3 and the second substrate 4 by welding. Then, the first substrate 3 with the first coil 13 joined is fastened to the first support section 6, and the second substrate 4 with the second coil 14 joined is fastened to the second support section 7. That is, the first substrate 3 is fastened by fastening the first fastening member 11 of each of the first fastening parts 8 of the first support section 6, and the second substrate 4 is fastened by fastening the second fastening member 12 of each of the second fastening parts 9 of the second support section 7. Then, by using the fixing part 10 to integrate the first support part 6 and the second support part 7, the installation of the inductor part 5 relative to the housing 2 is completed.

[0027] As described above, in the coil mounting structure 1 of this embodiment, the first coil 13 and the second coil 14 are each configured as separate units. Therefore, the mass of each of the first coil 13 and the second coil 14 can be less than the mass of an integral coil when a coil with two windings wound on a single iron core is joined to a substrate. That is, the weight (load) generated by the portion holding the integral coil in the housing 2 is smaller than the weight generated by the portion of the first substrate 3 that holds the first coil 13 or the portion of the second substrate 4 that holds the second coil 14. Furthermore, compared to the center of gravity position of the integral coil, the center of gravity positions of the first coil 13 and the second coil 14 can be shifted closer to their respective substrates 3 and 4. That is, compared to the center of gravity position of the integral coil, the center of gravity position of the first coil 13 is closer to the first substrate 3, and the center of gravity position of the second coil 14 is closer to the second substrate 4.

[0028] This reduces the weight (load) generated in the portion of the first substrate 3 supporting the first coil 13 and the portion of the second substrate 4 supporting the second coil 14, thus reducing the inertial force generated in the first coil 13 and the second coil 14 due to vehicle vibrations. Furthermore, compared to a one-piece coil, the distance from the center of gravity of each of the first coil 13 and the second coil 14 to each substrate 3 and 4 can be reduced. That is, the distance from the root portion of each coil 13 and 14, such as the root portion of each core 15 and 17, and the joint of each lead 20 and 22 in each winding 16 and 18 to the center of gravity can also be reduced. Therefore, in the event of vehicle vibrations, bending stress generated at the root of each core 15 and 17 and at the joint of each lead 20 and 22 can be reduced. Therefore, in the event of vehicle vibrations or impacts, the reduction in the durability of each coil 13 and 14 and each substrate 3 and 4 can be suppressed.

[0029] Furthermore, the separate construction of the first coil 13 and the second coil 14 ensures high insulation. Also, the cores 15 and 17 in the first coil 13 and the second coil 14 can be made of different materials. Additionally, by arranging the second coil 14 inside the first coil 13, the large distance between the coils 13 and 14 can be prevented. That is, the effective value of the induced electromotive force generated in the second coil 14 can be suppressed, thus preventing or suppressing a decrease in the performance of the inductor 5.

[0030] Next, the second embodiment of this utility model will be described. In the coil mounting structure 31 of the second embodiment of this utility model, the first substrate 3 and the second substrate 4 in the housing 2 are integrated by a spacer 32. Furthermore, in Figure 2 In this drawing, only the parts necessary for explanation are labeled with reference numerals, and for those parts that are not related to the illustrations... Figure 1 The same structures are labeled with the same reference numerals, and their descriptions are omitted or simplified.

[0031] like Figure 2 As shown, in the second embodiment, the housing 2 is positioned adjacent to the first substrate 3 and the second substrate 4 along their length. Furthermore, the housing 2 extends in a direction orthogonal to the length directions of the first substrate 3 and the second substrate 4. The housing 2 has a first holding portion 33 and a second holding portion 34, configured to clamp each of the first substrate 3 and the second substrate 4. For the first holding portion 33 and the first substrate 3, by fastening a third fastening member 35 while the first substrate 3 is clamped into the first holding portion 33, the housing 2 is integrated with the first substrate 3. Furthermore, for the second holding portion 34 and the second substrate 4, by fastening a fourth fastening member 36 while the second substrate 4 is clamped into the second holding portion 34, the housing 2 is integrated with the second substrate 4.

[0032] like Figure 2 As shown, in the coil mounting structure 31 of the second embodiment, a fifth fastening member 37 is provided, which clamps the first coil 13 of the first substrate 3, is fastened to both sides, and penetrates through the first substrate 3 in the thickness direction. Additionally, a sixth fastening member 38 is provided, which clamps the second coil 14 of the second substrate 4, is fastened to both sides, and penetrates through the second substrate 4 in the thickness direction. Furthermore, a spacer 32 is provided to integrate the opposing fifth fastening member 37 and the sixth fastening member 38.

[0033] The spacer 32 is made of materials such as metal or plastic. Threaded grooves (not shown) are formed at both ends of the spacer 32 along its axial direction. The fifth fastening member 37 or the sixth fastening member 38 described above can be screwed into the threaded grooves formed at both ends of the spacer 32. Thus, the spacer 32 can be fixed to the first substrate 3 and the second substrate 4.

[0034] An example of integrating the housing 2 with each of the substrates 3 and 4 by installing spacers 32 configured in this way will be described. First, through holes for inserting each fastening member 37, 38 are formed in each of the first substrate 3, in which the first coil 13 is integrated, and in each of the second substrate 4, in which the second coil 14 is integrated. The fifth fastening member 37 is positioned and fastened by aligning each of the two spacers 32 with the through holes from the side of the first substrate 3 in which the first coil 13 is integrated. The fifth fastening member 37 is inserted through the first substrate 3 and screwed into a threaded groove formed along the axial direction inside the spacer 32, thereby fastening the fifth fastening member 37 and the two spacers 32 to the first substrate 3.

[0035] Next, the through hole of the second substrate 4 is aligned with the position of the spacer 32 fixed to the first substrate 3 by the fifth fastening member 37 for positioning. In this state, the sixth fastening member 38 is inserted through the second substrate 4 and screwed into the threaded groove formed along the axial direction inside the spacer 32, thereby fastening the sixth fastening member 38 and the spacer 32 to the second substrate 4. Thus, the first substrate 3 and the second substrate 4 are integrated via the spacer 32.

[0036] The integrated first substrate 3 and second substrate 4 are thus fastened to the housing 2. As described above, the housing 2 has a first holding portion 33 and a second holding portion 34, which can respectively fasten a third fastening member 35 and a fourth fastening member 36 when each of the first substrate 3 and the second substrate 4 is clamped in. Therefore, when the first substrate 3 is clamped in the first holding portion 33 and the through hole of the first substrate 3 is aligned with the threaded hole of the first holding portion 33, the third fastening member 35 is fastened, and when the second holding portion 34 is clamped in the second substrate 4, the fourth fastening member 36 is fastened. Thus, the first substrate 3 and the second substrate 4 can be fixed to the housing 2.

[0037] With this structure, the first substrate 3 and the second substrate 4 are integrated, thus increasing the freedom of position for fastening each substrate 3, 4 to the housing 2 and reducing the number of fastening points. That is, as in... Figure 1 Compared to the case where each of the first substrate 3 and the second substrate 4 is fixed to the housing 2 in a separate state, as shown in the coil mounting structure 1 of the first embodiment, the mounting performance of the inductor 5 and each substrate 3, 4 can be improved.

[0038] In this way, the mounting capability is improved, allowing it to be configured such that only one of the first substrate 3 and the second substrate 4 is fastened to the housing 2. Based on Figure 3 The third embodiment shown in (a) and Figure 3 The fourth embodiment shown in (b) will be used to illustrate such an example.

[0039] In the coil mounting structure 41 of the third embodiment, as Figure 3 As shown in (a), only the first substrate 3 is fastened to the housing 2. Specifically, both ends of the first substrate 3 are longer than the second substrate 4 in the longitudinal direction, and a seventh fastening member 42 is fastened to each of its extended portions. The housing 2 is disposed on the side of the first substrate 3 facing the second substrate 4, and the seventh fastening member 42 is fastened from the side of the first substrate 3 opposite to the second substrate 4. Thus, the inductor 5 and each substrate 3, 4 can be fixed to the housing 2.

[0040] In the coil mounting structure 51 of the fourth embodiment, as Figure 3 As shown in (b), only the second substrate 4 is fastened to the housing 2. Specifically, the two ends of the second substrate 4 are longer than those of the first substrate 3 in the longitudinal direction, and an eighth fastening member 52 is fastened to each of its extended portions. The housing 2 is disposed on the side of the second substrate 4 facing the first substrate 3, and the eighth fastening member 52 is fastened from the side of the second substrate 4 opposite to the first substrate 3. Thus, the inductor 5 and each substrate 3, 4 can be fixed to the housing 2.

[0041] In the coil mounting structures 41 and 51 configured as shown in the third and fourth embodiments, only one of the first substrate 3 and the second substrate 4 is fixed to the housing 2. Therefore, in addition to the effects described above, each substrate 3 and 4 can be fixed according to the shape of the housing 2, etc., which can further improve the mounting performance.

[0042] The embodiments of this utility model have been described above, but this utility model is not limited to the examples described above, and appropriate modifications can be made within the scope of achieving the purpose of this utility model. For example, the housing 2 can also be constructed separately. In this case, it can also be configured such that the first substrate 3 is fixed to one housing 2 and the second substrate 4 is fixed to another housing 2. That is, the first coil 13 and the second coil 14 can be constructed separately, and the shapes of the housing 2 and each substrate 3 and 4 can be formed as either an integral part or separate parts.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1, 31, 41, 51… Mounting structure; 2… Housing; 3… First substrate; 4… Second substrate; 5… Inductor section; 6… First support section; 7… Second support section; 8… First fastening section; 9… Second fastening section; 10… Fixing section; 11… First fastening component; 12… Second fastening component; 13… First coil; 14… Second coil; 15… Primary side core; 16… Primary side winding; 17… Secondary side core; 18… Secondary side winding; 19… First bracket; 20… First lead; 21… Second bracket; 22… Second lead; 32… Spacer; 33… First holding section; 34… Second holding section; 35… Third fastening component; 36… Fourth fastening component; 37… Fifth fastening component; 38… Sixth fastening component; 42… Seventh fastening component; 52… Eighth fastening component.

Claims

1. A coil mounting structure, comprising: As the primary winding on the input side; As the secondary winding on the output side; The iron core is wound with the primary side winding and the secondary side winding, and can share magnetic flux in the primary side winding and the secondary side winding. as well as The housing is used to fix the primary winding, the secondary winding, and the iron core. The coil mounting structure is characterized in that, The iron core has: The first iron core has the primary side winding wound on it, and one end of it in the length direction is fixed to the housing side; and The second core is separately formed from the first core and has the secondary side winding wound around it, with one end in the length direction fixed to the housing side. In the first iron core with the primary side winding wound on it and the second iron core with the secondary side winding wound on it, the inner diameter of the cylindrical iron core is larger than the outer diameter of the cylindrical iron core. The other iron core is fixed to the housing while it is inside the first iron core.

Images