Coil device

Abstract

To improve a manufacturing cost by commonalizing components.SOLUTION: A transformer 20 includes: secondary-side coils 22A and 22B having ring-shaped winding units 22A1 and 22B1; and cases 24A and 24B as a pair of insulating members arranged across the winding units 22A1 and 22B1. The pair of cases 24A and 24B are made of the same molded product, and a plurality of engagement units 2415, 2416, and 2417 formed in each of the cases are engaged with the case 24 of the other side and are thus connected to each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a coil device. [Background technology]

[0002] The transformer module described in Patent Document 1 below includes a transformer that is a coil device. This transformer has a primary winding, a pair of secondary windings, and a transformer core. The primary winding is wound around a bobbin multiple times and housed in a case, and the pair of secondary windings are arranged to sandwich the case. The case is composed of a pair of cup-shaped members made of an insulating material. The pair of cup-shaped members are connected to each other by inserting a tip of a peripheral wall of one cup-shaped member into the inside of a tip of a peripheral wall of the other cup-shaped member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-26597 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above transformer, the pair of cup-shaped members that make up the case are molded into different shapes so that they can be joined together. When manufacturing this transformer, it is necessary to manage two types of cup-shaped members (insulating members) that have different shapes. For this reason, there is room for improvement in terms of standardizing parts.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In consideration of the above problems, an object of the present invention is to provide a coil device capable of improving manufacturing costs by standardizing parts. [Means for solving the problem]

[0006] The coil device of the present invention comprises a first coil having a ring-shaped winding portion, and a pair of insulating members arranged with the winding portion sandwiched therebetween, the pair of insulating members being made of the same molded product and being joined to each other by engaging multiple locking portions formed on each of the insulating members with the opposing insulating member. Effect of the Invention

[0007] In the present invention, a pair of insulating members are disposed with the annular winding portion of the first coil between them. The pair of insulating members are joined to each other by engaging a plurality of locking portions formed on each of the insulating members with the other insulating member. Since these insulating members are made of the same molded product, the manufacturing costs can be improved by sharing the same parts. [Brief description of the drawings]

[0008] [Figure 1] 1 is a side view showing a DC-DC converter device according to an embodiment. [Diagram 2] FIG. 2 is a circuit diagram showing a circuit configuration of the DC-DC converter device. [Diagram 3] 2 is a perspective view showing a transformer module included in the DC-DC converter device. FIG. [Figure 4] FIG. 2 is an exploded perspective view showing a transformer included in the transformer module. [Diagram 5] FIG. 4 is a first perspective view showing a case as an insulating member. [Figure 6] FIG. 2 is a second perspective view showing the case as the insulating member. [Figure 7] FIG. 13 is a third perspective view showing a case as an insulating member. [Figure 8] FIG. 4 is a fourth perspective view showing a case as an insulating member. [Figure 9] FIG. 13 is a perspective view for explaining a method of locking a pair of cases together. [Figure 10] FIG. 4 is a first perspective view showing a cover as an insulating cover. [Figure 11] FIG. 2 is a second perspective view showing the cover as an insulating cover. [Figure 12] 13 is a perspective view for explaining a method of locking the cover to the case. FIG. [Figure 13] FIG. 4 is a first perspective view showing the locked state between the case and the cover. [Figure 14] FIG. 11 is a second perspective view showing the locked state between the case and the cover. [Figure 15] FIG. 11 is a third perspective view showing the locked state between the case and the cover. [Figure 16] FIG. 13 is a fourth perspective view showing the locked state between the case and the cover. [Figure 17] FIG. 1 is a first perspective view showing a partial configuration of a transformer according to an embodiment. [Figure 18] FIG. 2 is a second perspective view showing a partial configuration of the transformer according to the embodiment. [Figure 19] FIG. 11 is a third perspective view showing a partial configuration of a transformer according to an embodiment. [Figure 20] FIG. 4 is a fourth perspective view showing a partial configuration of the transformer according to the embodiment. [Figure 21] FIG. 5 is a fifth perspective view showing a partial configuration of a transformer according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 21. In this embodiment, for convenience of explanation, the directions indicated by front-rear, left-right, and up-down arrows appropriately shown in each figure are defined as front-rear, left-right, and up-down directions, and the positions and orientations of the components will be described. Also, in each figure, some symbols may be omitted to make the drawings easier to see.

[0010] 1 and 2, a DC-DC converter device 1 as a power conversion device according to this embodiment is roughly configured to include a heat dissipation member 2, a switching circuit section 3, a transformer module 4, and a rectifier circuit section 5 mounted on a mounting surface 2a of the heat dissipation member 2, and a circuit board 6 arranged above the mounting surface 2a with a gap therebetween. The heat dissipation member 2 is configured by forming a conductive material with excellent thermal conductivity, such as aluminum, into a plate shape. Various wiring patterns required for the circuit of the DC-DC converter device 1 are formed on the circuit board 6. The circuit board 6 is fixed to the heat dissipation member 2 by screws or the like via protrusions (not shown), such as spacers or blocks, provided so as to protrude from the mounting surface 2a of the heat dissipation member 2.

[0011] The switching circuit section 3 converts an input DC voltage from a DC power supply 100 connected to an input terminal 10 into an AC voltage, and is composed of four switching elements 11. Since each switching element 11 generates heat during operation, by mounting the switching circuit section 3 on the heat dissipation member 2, the heat of the switching elements 11 can be dissipated to the heat dissipation member 2. An input capacitor 12 for stabilizing the input DC voltage is also provided between the DC power supply 100 and the switching circuit section 3. The input capacitor 12 may be mounted on either the heat dissipation member 2 or the circuit board 6. The DC power supply 100 is connected to the input capacitor 12 and the switching circuit section 3 directly or via a wiring pattern on the circuit board 6.

[0012] The rectifier circuit section 5 rectifies the output voltage of the transformer 20 included in the transformer module 4 described later, and is composed of a plurality of rectifier elements 13. Since each rectifier element 13 generates heat during operation, the rectifier circuit section 5 is mounted on the heat dissipation member 2, so that the heat of the rectifier element 13 can be dissipated to the heat dissipation member 2. The rectifier circuit section 5 does not need to be limited to a two-phase full-wave rectifier as shown in the figure. A smoothing circuit section 15 that smoothes the output voltage rectified by the rectifier circuit section 5 is also provided between the rectifier circuit section 5 and an output terminal 14 for connecting to a load device (not shown). In FIG. 2, the smoothing circuit section 15 is composed of a choke coil 15A and an output capacitor 15B, but is not limited thereto. Each component of the smoothing circuit section 15 may be mounted on either the heat dissipation member 2 or the circuit board 6.

[0013] 3, the transformer module 4 is roughly configured to include a transformer 20 for transforming the AC voltage converted in the switching circuit section 3 and outputting it to the rectifier circuit section 5, a current transformer 60 for measuring the AC current flowing through the windings of the transformer 20, and a terminal block 70 for supporting the current transformer 60. The transformer 20 corresponds to the "coil device" in the present invention. The terminal block 70 is fixed to the heat dissipation member 2 by means of screws or the like.

[0014] 4, the transformer 20 includes primary windings 21A and 21B connected to the switching circuit section 3, secondary windings 22A and 22B connected to the rectifier circuit section 5, a transformer core 23 to which the primary windings 21A and 21B and the secondary windings 22A and 22B are attached, and cases 24A and 24B, covers 25A and 25B, and a separator 26 for respectively arranging the primary windings 21A and 21B and the secondary windings 22A and 22B at predetermined positions. The primary windings 21A and 21B correspond to the "two second coils" of the present invention, the secondary windings 22A and 22B correspond to the "two first coils" of the present invention, the cases 24A and 24B correspond to the "pair of insulating members" of the present invention, the covers 25A and 25B correspond to the "two insulating covers" of the present invention, and the separator 26 corresponds to the "insulating plate" of the present invention.

[0015] The primary windings 21A and 21B are made of linear conductors. The primary winding 21A has a winding portion 21A1 wound in a substantially spiral shape with the vertical direction as the axial direction, and a pair of lead-out portions 21A2 and 21A3 drawn out from the winding portion 21A1 to the outside in the radial direction (here, the front side). Similarly, the primary winding 21B has a winding portion 21B1 wound in a substantially spiral shape, and a pair of lead-out portions 21B2 and 21B3 drawn out from the winding portion 21B1 to the outside in the radial direction. The winding portions 21A1 and 21B1 are arranged coaxially with each other. The pair of lead-out portions 21A2 and 21A3 are formed by both ends of the primary winding 21A, and the pair of lead-out portions 21B2 and 21B3 are formed by both ends of the primary winding 21B.

[0016] The lead-out portion 21A2 and the lead-out portion 21B2 are stacked on top of each other in the vertical direction and are connected to each other by means such as soldering. Similarly, the lead-out portion 21A3 and the lead-out portion 21B3 are stacked on top of each other in the vertical direction and are connected to each other by means such as soldering. These lead-out portions 21A2, 21B2, 21A3, and 21B3 are electrically connected to the switching circuit portion 3. In addition, one lead-out portion 21A2 and one lead-out portion 21B2 form a primary winding 61 of a current transformer 60. In this current transformer 60, an induced electromotive force (AC voltage) is generated in a secondary winding (not shown) based on an AC voltage applied to the primary winding 61. This induced electromotive force is detected by a current detection circuit 80 shown in FIG. 2, so that the AC current applied to the primary windings 21A and 21B of the transformer 20 is measured. This current detection circuit 80 is provided on a circuit board 6.

[0017] The secondary windings 22A and 22B are made of a conductive plate material (e.g., copper plate). The secondary winding 22A has a winding portion 22A1 formed in an annular plate shape with the vertical direction as the axis direction, and a pair of lead pull-out portions 22A2 and 22A3 extending from both ends of the circumferential direction of the winding portion 22A1 to the radially outward (here, rearward) side. Similarly, the secondary winding 22B has a winding portion 22B1 formed in an annular plate shape with the vertical direction as the axis direction, and a pair of lead pull-out portions 22B2 and 22B3 extending from both ends of the circumferential direction of the winding portion 22B1 to the radially outward (here, rearward) side. The winding portions 22A1 and 22B1 are arranged coaxially with each other. In addition, these winding portions 22A1 and 22B1 are also arranged coaxially with the winding portions 21A1 and 21B1 of the primary windings 21A and 21B.

[0018] The lead pull-out portions 22A2, 22A3, 22B2, and 22B3 are plate-shaped with the thickness direction being in the vertical direction, and extend parallel to each other from the winding portions 22A1 and 22B1. The lead pull-out portions 22A3 and 22B3 are stacked on each other in the vertical direction. The lead pull-out portions 22A2 and 22B2 are arranged on both the left and right sides of the lead pull-out portions 22A3 and 22B3 stacked on each other in the vertical direction. These lead pull-out portions 22A2, 22A3, 22B2, and 22B3 are fixed to a terminal block (not shown) fixed to the heat dissipation member 2 by means of screws or the like, and are electrically connected to the rectifier circuit portion 5 via the terminal block.

[0019] A fixing lead-out portion 22A4 extends rearward from the winding portion 22A1 of the secondary winding 22A. The fixing lead-out portion 22A4 is fixed to a terminal block 70 shown in FIG. 3 by using a screw 72. The portion of the terminal block 70 into which the screw 72 is screwed is made of a metal having high thermal conductivity, and this metal portion is in contact with the heat dissipation member 2. This allows the heat generated in the secondary winding 22A to be transferred to the heat dissipation member 2. A separator 26 is disposed between the winding portion 22A1 of the secondary winding 22A and the winding portion 22B1 of the secondary winding 22B.

[0020] The separator 26 is made of an insulating material such as resin and has an annular plate shape with the vertical axis as the axial direction. The separator 26 is coaxially disposed between the winding portion 22A1 and the winding portion 22B1 and is sandwiched between them. The separator 26 insulates the secondary windings 22A and 22B from each other. The resin constituting the separator 26 may contain, for example, a thermally conductive filler. This allows heat to be transferred between the secondary windings 22A and 22B via the separator 26.

[0021] The cases 24A and 24B are disposed on both the upper and lower outer sides of the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B and the separator 26. The cases 24A and 24B are made of an insulating material such as resin. The resin constituting the cases 24A and 24B may contain, for example, a thermally conductive filler. As shown in Figs. 5 to 9, the cases 24A and 24B are made of the same molded product and are disposed in opposite directions with the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B and the separator 26 sandwiched therebetween. The cases 24A and 24B are joined to each other by engaging a plurality of (three in this case) locking claws 2415, 2416, and 2417 formed on each of the cases with each other. The locking claws 2415, 2416, and 2417 correspond to the "locking parts" in the present invention.

[0022] Covers 25A and 25B are disposed on the opposite side of the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B with respect to the above-mentioned cases 24A and 24B, that is, on both the upper and lower outer sides of the cases 24A and 24B. The covers 25A and 25B are made of an insulating material such as resin. For example, a thermally conductive filler is added to the resin that constitutes these covers 25A and 25B. As shown in Figs. 10 to 12, these covers 25A and 25B are made of the same molded product and are disposed in the opposite direction to each other with the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B, the separator 26, and the cases 24A and 24B sandwiched therebetween. Each cover 25A and 25B is joined to each case 24A and 24B by engaging a plurality of (four in this case) cover locking parts 2508 formed on each cover with each case 24A and 24B.

[0023] Hereinafter, the cases 24A, 24B and the covers 25A, 25B will be described mainly with reference to Figs. 4 to 21. Figs. 13 to 16 are perspective views showing a state in which the case 24A (or case 24B) and the cover 25A (or cover 25B) are engaged, and Figs. 17 to 21 are perspective views showing a partial configuration of the transformer 20. In Figs. 17 to 21, illustrations of the primary windings 21A, 21B, the transformer core 23, the terminal block 70, etc. are omitted. In the following description, the cases 24A, 24B may be simply referred to as "case 24," and the covers 25A, 25B may be simply referred to as "cover 25."

[0024] As shown in Figs. 5 to 8, the case 24 is formed in a substantially rectangular box shape that is flat in the vertical direction. The dimension of the case 24 in the front-rear direction is set slightly longer than the dimension in the left-right direction. The case 24 has a bottom wall portion 2401 that is a substantially rectangular plate with the plate thickness direction being in the vertical direction, and a peripheral wall portion 2402 that protrudes from the outer periphery of the bottom wall portion 2401 to one side in the vertical direction. A circular through hole 2403 is formed in the center of the bottom wall portion 2401. A cylindrical boss portion 2404 that protrudes to one side in the vertical direction is formed on the hole edge of the through hole 2403. The inner peripheral surface of the peripheral wall portion 2402 is formed in a substantially cylindrical surface shape that is concentric with the boss portion 2404. An annular storage portion 2405 is formed between the peripheral wall portion 2402 and the boss portion 2404. The housing section 2405 of the case 24A houses the winding section 21A1 of the primary winding 21A (see FIG. 4), and the housing section 2405 of the case 24B houses the winding section 21B1 of the primary winding 21B. Each housing section 2405 houses the winding sections 21A1, 21B1 of the primary windings 21A, 21B on the side opposite to the side facing the winding sections 22A1, 22B1 of the secondary windings 22A, 22B in the cases 24A, 24B.

[0025] As shown in Figs. 6 to 8, a pair of left and right draw-out openings 2406 that open the above-mentioned housing portion 2405 to the front side are formed at the front end and both left and right ends of the case 24. At the locations where the left and right draw-out openings 2406 are formed, the peripheral wall portion 2402 is partially omitted. The primary winding 21A, whose winding portion 21A1 is housed in the housing portion 2405 of the case 24A, has a pair of draw-out portions 21A2 and 21A3 drawn out to the outside of the case 24A through the left and right draw-out openings 2406. Similarly, the primary winding 21B, whose winding portion 21B1 is housed in the housing portion 2405 of the case 24B, has a pair of draw-out portions 21A2 and 21A3 drawn out to the outside of the case 24B through the left and right draw-out openings 2406.

[0026] 5 to 8, extension walls 2407 are formed at both ends in the front-rear direction (both ends in the longitudinal direction) and both ends in the left-right direction (both ends in the width direction) of the case 24. These four extension walls 2407 each extend outward in the front-rear direction from the peripheral wall 2402. At the tip of each extension wall 2407, at the end opposite the bottom wall 2401, a claw C2 is formed protruding outward in the left-right direction.

[0027] As shown in Fig. 5 and Fig. 8, at the front end and both ends in the left-right direction of the case 24, the bottom wall portion 2401 is extended forward from the peripheral wall portion 2402 to form a pair of left and right hook portions 2412, 2413. At the front end and both ends in the left-right direction of the case 24, locking claws 2415, 2416 are formed as locking portions. The left and right locking claws 2415, 2416 protrude from the bottom wall portion 2401 toward the other side in the up-down direction, and are disposed adjacent to one side in the left-right direction of the left and right hook portions 2412, 2413. These locking claws 2415, 2416 are disposed side by side in the left-right direction. Each of these locking claws 2415, 2416 is formed in an elongated plate shape with the plate thickness direction being the front-rear direction and the longitudinal direction being the up-down direction. At the tip of each of the locking claws 2415, 2416, a claw portion C1 is formed which protrudes rearward.

[0028] As shown in Figs. 5 to 8, a frame-shaped portion 2408 is formed at the rear end of the case 24, protruding rearward from the peripheral wall portion 2402. This frame-shaped portion 2408 has a long rectangular frame shape with the longitudinal direction being the left-right direction when viewed from the front-rear direction. As shown in Figs. 5, 7 and 8, on one side in the left-right direction of the frame-shaped portion 2408, the bottom wall portion 2401 extends rearward beyond the peripheral wall portion 2402, thereby forming a hook portion 2414. This hook portion 2414 is retreated forward beyond the frame-shaped portion 2408.

[0029] As shown in Figs. 5 to 8, on the other side in the left-right direction with respect to the frame-shaped portion 2408, the bottom wall portion 2401 is extended rearward beyond the peripheral wall portion 2402 to form an extension portion 2410. This extension portion 2410 protrudes rearward beyond the frame-shaped portion 2408. The tip portion of this extension portion 2410 is bent toward the other side in the up-down direction. In addition, a positioning piece 2411 extends toward the other side in the up-down direction from an inner end portion in the left-right direction of this extension portion 2410. This positioning piece 2411 is in the form of a plate with its plate thickness direction being in the left-right direction.

[0030] Further, a locking claw 2417 is formed as a locking part on the base end side of the extension part 2410. This locking claw 2417 protrudes from the base end of the extension part 2410 toward the other side in the up-down direction. This locking claw 2417 is an elongated plate with the plate thickness direction being the front-rear direction and the longitudinal direction being the up-down direction. However, this locking claw 2417 is set to have a larger width dimension in the left-right direction than the two locking claws 2415 and 2416 described above. As a result, this locking claw 2417 is configured to be less likely to bend in the front-rear direction than the two locking claws 2415 and 2416 described above. A claw part C1 protruding forward is formed at the tip of this locking claw 2417. When viewed from the up-down direction, this locking claw 2417 is disposed on the opposite side to one of the two locking claws 2415 and 2416 described above, across the center of the through hole 2403.

[0031] As described above, the cases 24A and 24B are arranged in opposite directions with the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B and the separator 26 sandwiched therebetween. These cases 24A and 24B function as insulating members that insulate the secondary windings 22A and 22B from the primary windings 21A and 21B. These cases 24A and 24B are joined to each other by engaging the locking claws 2415, 2416, and 2417 formed on each case with the hook parts 2412, 2413, and 2414 of the other case. In other words, the cases 24A and 24B are joined to each other with the winding parts 22A1 and 22B1 and the separator 26 sandwiched therebetween. When these cases 24A, 24B are joined together, the cases 24A, 24B are arranged in a vertically opposite orientation so that the housing portions 2405 of the cases 24A, 24B are open to opposite sides (see FIG. 9). When the cases 24A, 24B are brought close to each other in this orientation, the locking claws 2415, 2416, 2417 formed on the cases 24A, 24B are locked to the hook portions 2412, 2413, 2414 formed on the other cases 24A, 24B. Note that the secondary windings 22A, 22B and the separator 26 are not shown in FIG. 9.

[0032] During the above-mentioned engagement, the claws C1 formed at the tip of each of the locking claws 2415, 2416, 2417 are in sliding contact with the hooking portions 2412, 2413, 2414, so that each of the locking claws 2415, 2416, 2417 is temporarily and elastically deflected in the front-rear direction. Then, each of the locking claws 2415, 2416, 2417 is elastically restored, so that the claws C1 of each of the locking claws 2415, 2416, 2417 are hooked on the hooking portions 2412, 2413, 2414. This allows the case 24A and the case 24B to be coupled to each other. During this coupling, the two locking claws 2415, 2416 are more easily deflected than the remaining one locking claw 2417, so these two locking claws 2415, 2416 are mainly deflected. This allows the above-mentioned coupling to be performed smoothly. In this connection, for example, after the locking claws 2417 of each case 24A, 24B are hooked onto the hooking portions 2414 of the other case, the locking claws 2415, 2416 (i.e., the easily flexible locking claws) of each case 24A, 24B may be locked onto the hooking portions 2412, 2413 of the other case. This makes the locking operation easier than when the three locking claws 2415, 2416, 2417 are simultaneously locked onto the three hooking portions 2412, 2413, 2414.

[0033] 17 to 21, when the connection of the cases 24A and 24B is completed, the housing portions 2405 of the cases 24A and 24B are opened on the opposite side to the winding portions 22A1 and 22B1 of the secondary windings 22A and 22B. In this connection completed state, the two locking claws 2415 and 2416 are arranged side by side in the tangential direction of the winding portions 22A1 and 22B1 of the secondary windings 22A and 22B, and one locking claw 2415 and the remaining locking claw 2417 of the two locking claws 2415 and 2416 are arranged on the opposite sides to each other with respect to the center of the winding portions 22A1 and 22B1 of the secondary windings 22A and 22B.

[0034] The cases 24A and 24B connected as described above are configured such that the locking claws 2415 and 2416 formed on each case interfere with each other in the left-right direction, thereby restricting the relative displacement of the cases 24A and 24B in the left-right direction. Furthermore, each of these cases 24A and 24B has a rotation stopper 2409 that, in the above-mentioned connected state, engages (here, faces closely to) a locking claw 2417 formed on the other case 24 from one circumferential side of the winding parts 22A1 and 22B1, thereby restricting the relative rotation of the winding parts 22A1 and 22B1 in one circumferential direction side. These rotation stopper parts 2409 are formed by one end surface in the left-right direction of the frame-shaped part 2408 of each case 24A and 24B. These rotation prevention portions 2409 interfere with each locking claw 2417, thereby limiting the relative displacement of cases 24A, 24B in the left-right direction and preventing relative rotation of cases 24A, 24B in the circumferential direction of winding portions 22A1, 22B1.

[0035] In the above-mentioned completed connection state, the positioning pieces 2411 of the cases 24A and 24B are arranged on both left and right outer sides of the lead pull-out portions 22A2 and 22B2 of the secondary windings 22A and 22B. The lead pull-out portions 22A3 and 22B3 are arranged between the lead pull-out portions 22A2 and 22B2, overlapping each other in the vertical direction. This allows the positioning pieces 2411 to restrict the left and right displacement of 22A3, 22B3, 22A2, and 22B2.

[0036] On the other hand, as shown in Figs. 10 and 11, the cover 25 (cover 25A and cover 25B) is formed in a substantially rectangular plate shape that is flat in the vertical direction. The cover 25 is set so that the left-right dimension is longer than the front-rear dimension. The cover 25 has a horizontal wall portion 2501 that is substantially rectangular plate-shaped with the vertical direction as the plate thickness direction, a pair of front and rear wall portions 2502 and 2503 that protrude from both front and rear ends of the horizontal wall portion 2501 to one side in the vertical direction, and a pair of left and right wall portions 2504 and 2505 that protrude from both left and right ends of the horizontal wall portion 2501 to the other side in the vertical direction. A circular through hole 2506 is formed in the center of the horizontal wall portion 2501. A cylindrical boss portion 2507 that protrudes to one side in the vertical direction is formed on the hole edge of the through hole 2506. At the front end of the cover 25 and at both left and right ends, a cover locking portion 2508 is formed, protruding outward in the front-rear direction.

[0037] When the covers 25A and 25B having the above configuration are coupled to the cases 24A and 24B, as shown in Fig. 12, the covers 25A and 25B are disposed on the sides facing the housing portions 2405 of the cases 24A and 24B. Then, the covers 25A and 25B and the cases 24A and 24B are brought closer to each other, so that the cover locking portions 2508 formed on the covers 25A and 25B are locked with the claw portions C2 formed on the extension wall portions 2407 of the cases 24A and 24B. As a result, the covers 25A and 25B are coupled to the cases 24A and 24B. These covers 25A and 25B are coupled to the cases 24A and 24B so as to cover the primary windings 21A and 21B accommodated in the housing portions 2405 of the cases 24A and 24B.

[0038] When the covers 25A, 25B are joined to the cases 24A, 24B as described above, the claws C2 of the extension wall portions 2407 slide against the cover locking portions 2508, causing the cover locking portions 2508 and the extension wall portions 2407 to temporarily and elastically bend in the left-right direction. Then, the cover locking portions 2508 and the extension wall portions 2407 elastically return to their original positions, causing the claws C2 of the extension wall portions 2407 to hook onto the cover locking portions 2508, and the covers 25A, 25B are restrained by the cases 24A, 24B.

[0039] The above-mentioned coupling (locking) is performed in a state where the winding parts 21A1, 21B1 of the primary windings 21A, 21B are accommodated in the accommodation parts 2405 of the cases 24A, 25B, and the lead-out parts 24A2, 24A3, 24B2, 24B3 of the primary windings 21A, 21B are inserted into the lead-out openings 2406 of the cases 24A, 25B. In a state where this coupling is completed, the primary windings 21A, 21B are prevented from falling off from the cases 24A, 24B by the covers 25A, 25B. As described above, the primary windings 21A, 21B are not shown in Figs. 17 to 21.

[0040] As described above, when the cases 24A, 24B are joined together and the covers 25A, 25B are joined to the cases 24A, 24B, the primary windings 21A, 21B, the secondary windings 22A, 22B, the cases 24A, 24B, the covers 25A, 25B, and the separator 26 are integrated together, which makes the subsequent assembly work easier.

[0041] That is, the transformer core 23 and the terminal block 70 are assembled to the primary windings 21A, 21B, secondary windings 22A, 22B, cases 24A, 24B, covers 25A, 25B, and separator 26 integrated as described above, and this assembly work becomes easier. The transformer core 23 is configured by combining a pair of E-shaped cores 23A, 23B, for example. The pair of E-shaped cores 23A, 23B are made of a magnetic material, are formed in an E shape when viewed from the front-rear direction, and are arranged opposite each other in the up-down direction.

[0042] Next, the operation and effects of this embodiment will be described. In the DC-DC converter device 1 according to this embodiment, a DC voltage input to an input terminal 10 is converted to an AC voltage in a switching circuit section 3 and output to a transformer module 4. In the transformer module 4, the AC voltage output from the switching circuit section 3 is transformed into an AC voltage of a different voltage in a transformer 20 and output to a rectifier circuit section 5. In the rectifier circuit section 5, the output voltage from the transformer 20 is rectified and output to a smoothing circuit section 15. In the smoothing circuit section 15, the output voltage from the rectifier circuit section 5 is smoothed and output from an output terminal 14 to the outside.

[0043] In the above transformer 20, a pair of cases 24A, 24B are arranged facing in opposite directions with the windings 22A1, 22B1 of the secondary windings 22A, 22B and the separator 26 sandwiched therebetween. These cases 24A, 24B are joined to each other by engaging a plurality of locking claws 2415, 2416, 2417 formed on each case with the mating case 24. These cases 24A, 24B function as insulating members that insulate the secondary windings 22A, 22B from the primary windings 21A, 21B. These cases 24A, 24B are made of the same molded product, and therefore the manufacturing cost can be improved by sharing parts.

[0044] The transformer 20 also includes a pair of primary windings 21A, 21B having annular winding portions 21A1, 21B1, and the above-mentioned cases 24A, 24B each have an annular housing portion 2405 that houses the above-mentioned respective winding portions 21A1, 21B1. That is, the cases 24A, 24B that insulate the primary windings 21A, 21B from the secondary windings 22A, 22B have the housing portion 2405 that houses the winding portions 21A1, 21B1 of the primary windings 21A, 21B. This allows the primary windings 21A, 21B to be easily arranged at predetermined positions.

[0045] Each of the cases 24A and 24B has a housing portion 2405 on the opposite side to the winding portions 22A1 and 22B1 of the secondary windings 22A and 22B and the separator 26. The covers 25A and 25B are connected to the cases 24A and 24B so as to cover the primary windings 21A and 21B housed in the housing portion 2405. The covers 25A and 25B are connected to the cases 24A and 24B by engaging a plurality of cover locking portions 2508 formed on each of the covers 25A and 25B with the cases 24A and 24B. This allows the primary windings 21A and 21B to be held in the cases 24A and 24B by the covers 25A and 25B. Moreover, the covers 25A and 25B function as insulating members that insulate the primary windings 21A and 21B. These covers 25A, 25B are made of the same molded product, and by standardizing these parts, the manufacturing cost can be further improved.

[0046] In the transformer 20, the winding portions 22A1 and 22B1 of the secondary windings 22A and 22B provided between the cases 24A and 24B are insulated from each other by the separator 26. In this manner, by having two secondary windings 22A and 22B, the design freedom of the number of turns of the secondary windings, etc. is improved.

[0047] In addition, the above-mentioned cases 24A and 24B are each formed with three locking claws 2415, 2416, and 2417 (all locking portions). This allows the configuration of each of the cases 24A and 24B to be simplified and the work of connecting the cases 24A and 24B to each other to be easier, compared to, for example, a case in which each of the cases 24A and 24B has four locking portions. In addition, for example, it is easier to stabilize the connection state between the cases 24A and 24B and ensure the connection strength, compared to, for example, a case in which each of the cases 24A and 24B has four locking portions.

[0048] In each of the cases 24A and 24B, two of the three locking claws 2415, 2416, and 2417 are arranged side by side in the tangential direction (here, the left-right direction) of the winding parts 22A1 and 22B1. The remaining locking claw 2417 is arranged on the opposite side of the center of the winding parts 22A1 and 22B1 to one of the two locking claws 2415 and 2416. By arranging the remaining one 2417 in this manner, it is possible to easily secure a space for drawing out the lead drawing parts 22A2, 22A3, 22B2, and 22B3 of the secondary windings 22A and 22B.

[0049] Each of the cases 24A and 24B has a rotation stopper 2409 that engages with the remaining one locking claw 2417 formed on the other case from one circumferential side of the winding portions 22A1 and 22B1. This makes it possible to restrict, with a simple configuration, the relative rotation of the mutually coupled cases 24A and 24B toward one circumferential side of the winding portions 22A1 and 22B1 in a configuration in which three locking claws 2415, 2416, and 2417 are formed on each of the cases 24A and 24B.

[0050] Furthermore, the three locking claws 2415, 2416, 2417 are formed to bend elastically when the cases 24A, 24B are joined together. Two of these locking claws 2415, 2416 are configured to bend more easily than the remaining locking claw 2417. As a result, when the cases 24A, 24B are joined together, the two locking claws 2415, 2416 are primarily bent, eliminating the need to apply equal force to the three locking claws 2415, 2416, 2417, making the joining operation easier.

[0051] In the above embodiment, the two locking claws 2415, 2416 are configured to bend more easily than the remaining locking claw 2417, but this is not limited to the above. The three locking claws 2415, 2416, 2417 may be configured to be equally flexible.

[0052] In the above embodiment, each of the cases 24A and 24B has a rotation stopper 2409 that engages with the locking claw 2417 of the other case, but this is not limited to the above. Each of the cases 24A and 24B may be configured to engage with a portion other than the locking claw 2417 of the other case.

[0053] In the above embodiment, the two locking claws 2415, 2416 are arranged side by side in the tangential direction of the winding parts 22A1, 22B1, and the remaining locking claw 2417 is arranged on the opposite side of the center of the winding parts 22A1, 22B1 from the locking claw 2415, but this is not limiting. For example, the three locking claws 2415, 2416, 2417 may be arranged at equal distances from each other. In that case, however, it is necessary to change the arrangement of the lead pull-out parts 22A2, 22A3, 22B2, 22B3 of the secondary windings 22A, 22B, etc.

[0054] In the above embodiment, each of the cases 24A and 24B has three locking claws 2415, 2416, and 2417, but the present invention is not limited to this. Each of the cases 24A and 24B may have four or more locking claws (locking portions). Alternatively, each of the cases 24A and 24B may have two locking portions and an engagement portion for preventing misalignment. In this case, for example, the two locking portions prevent the cases 24A and 24B from being separated from each other in the up-down direction Y, and the engagement portion for preventing misalignment prevents the cases 24A and 24B from being misaligned from each other in the front-rear direction and / or the left-right direction.

[0055] In the above embodiment, the locking claws 2415, 2416, and 2417 are configured as locking parts, but the present invention is not limited to this. For example, the cylindrical locking parts formed on the cases 24A and 24B may be locked (for example, press-fitted) into locking holes formed on the other cases, thereby connecting the cases 24A and 24B to each other.

[0056] In the above embodiment, the two secondary windings 22A, 22B (corresponding to the "first coil" in the present invention) are arranged between the pair of cases 24A, 24B, but the present invention is not limited to this. The "first coil" in the present invention may be configured with one secondary winding.

[0057] In addition, in the above embodiment, the cover 25A, 25B is provided as an insulating cover, but the present invention is not limited to this. Instead of the cover 25A, 25B, another insulating member may be provided.

[0058] In the above embodiment, the cases 24A, 24B and the covers 25A, 25B are molded separately and then joined together after molding, but this is not limiting. The cases 24A, 24B and the covers 25A, 25B may be molded integrally.

[0059] In the above embodiment, the primary winding and the secondary winding may be reversed in arrangement.

[0060] In the above embodiment, the present invention is applied to the transformer 20 of the DC-DC converter device 1, which is a power conversion device, but the present invention is not limited to this. For example, the present invention can also be applied to a choke coil. In that case, the configuration does not include windings corresponding to the primary windings 21A and 21B.

[0061] In addition, the present invention can be implemented in various modifications without departing from the spirit and scope of the present invention. Furthermore, the scope of the present invention is not limited to the above-described embodiment. [Explanation of symbols]

[0062] 20 Transformer (coil device) 21A, 21B Primary winding (second coil) 21A1, 21B1 Winding section (winding section) 22A, 22B Secondary winding (first coil) 22A1, 22B1 Winding section (winding section) 24A, 24B Case (insulating material) 2415, 2416, 2417 Locking claw (locking part) 25A, 25B Cover (insulating cover) 2508 Cover locking part 26 Separator (insulating plate)

Claims

1. A first coil having an annular winding portion; Two second coils each having an annular winding portion; a pair of insulating members disposed with the winding portion of the first coil therebetween, the insulating members having a housing portion for housing the winding portion of the second coil on the side opposite to the side facing the first coil, the insulating members each having a plurality of locking portions formed thereon disposed radially outward of the winding portion of the first coil; Two insulating covers covering the second coil housed in the housing portion; Equipped with the pair of insulating members are made of the same molded product, and are joined to each other by engaging the multiple locking portions formed on each of the insulating members with the insulating member on the other side; The two insulating covers are coupled to the pair of insulating members by engaging a plurality of cover engaging portions formed on each of the two insulating covers with the pair of insulating members, respectively.

2. Two of the first coils; an insulating plate disposed between the two winding portions of the first coil; The coil device according to claim 1 , wherein the pair of insulating members are joined to each other with the two winding portions of the first coil and the insulating plate sandwiched therebetween.

3. 3. The coil device according to claim 1, wherein each of the pair of insulating members has three of the locking portions formed thereon.

4. Two of the three locking portions are arranged side by side in a tangential direction of the winding portion of the first coil, The coil device according to claim 3 , wherein the remaining one of the three locking portions is disposed on the opposite side to one of the two locking portions across the center of the winding portion.

5. The coil device according to claim 4, wherein each of the pair of insulating members has a regulating portion that regulates relative rotation of the winding portion of the first coil in one circumferential direction by engaging with the remaining locking portion formed on the mating insulating member.

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