JP7504009B2 - Coil device - Google Patents

Description

The present invention relates to a coil device.

The surface mount coil described in Patent Document 1 below comprises an edgewise wound coil, a core portion of a core inserted into the coil, a flange formed integrally with one end of the core portion, a flange base core having a roughly rectangular shape to which the other end of the core portion is fixed, and a plastic cover attached to the flange base core. The edgewise wound coil has an electrode portion wound around the bottom surface of the flange base core, which is fixed to the bottom surface of the flange base core with an adhesive. The bottom surface of the flange base core is provided with an adhesive guide groove into which adhesive is poured.

JP 2003-347129 A

For example, in a coil device mounted on a power conversion device for a vehicle, there is a configuration in which coils and insulating members are stacked in multiple layers, and each member may be glued together with an adhesive at the surface or at the points as a vibration countermeasure. By gluing in this way, sliding between the members caused by vibration while the vehicle is running is prevented, and insulation failure caused by wear of the members and the outflow of wear powder can be prevented. However, in a configuration in which the members are glued together at the surface or at the points as described above, if the number of stacked members increases, the number of steps for gluing increases and the gluing work becomes complicated.

The present invention takes the above problems into consideration and aims to provide a coil device that is easy to glue.

The coil device according to the present invention comprises a coil having an annular winding portion and a pair of insulating members arranged with the winding portion sandwiched therebetween, and a concave groove portion is formed on the end faces of the coil and the pair of insulating members, the concave groove portion extending in the stacking direction of the coil and the pair of insulating members and communicating with each other, and an adhesive is filled in the groove portion.

The coil device according to the present invention comprises a coil having an annular winding portion and a pair of insulating members arranged with the winding portion sandwiched between them. A concave groove portion is formed on the end faces of the coil and the pair of insulating members, extending in the stacking direction of the coil and the pair of insulating members and communicating with each other, and the groove portion is filled with adhesive. This allows the coil and the pair of insulating members to be bonded simultaneously, making the bonding operation easier.

1 is a side view showing a DC-DC converter device according to an embodiment of the present invention; FIG. 2 is a circuit diagram showing the circuit configuration of the DC-DC converter device. 2 is a perspective view showing a transformer module provided in the DC-DC converter device. FIG. FIG. 2 is a perspective view showing a transformer included in the transformer module. FIG. 2 is a front view of the transformer, showing a state before adhesive is filled into grooves. FIG. 6 is an enlarged view showing a part of FIG. 5 . 6 is a front view corresponding to FIG. 5 and illustrating a state after the adhesive has been filled into the grooves. FIG. FIG. 2 is a cross-sectional plan view showing a partial configuration of the transformer. FIG. FIG. 4 is a first perspective view showing a case as an insulating member. FIG. 2 is a second perspective view showing a case as an insulating member. FIG. 11 is a third perspective view showing a case as an insulating member. FIG. 4 is a fourth perspective view showing a case as an insulating member. FIG. 13 is a perspective view for explaining a method of locking a pair of cases together. FIG. 4 is a first perspective view showing a cover as an insulating cover. FIG. 2 is a second perspective view showing the cover as an insulating cover. 13 is a perspective view for explaining a method of locking the cover to the case. FIG.

One embodiment of the present invention will be described below with reference to Figures 1 to 17. In this embodiment, for ease of explanation, the directions indicated by the front-back, left-right, and up-down arrows appropriately shown in each figure are defined as the front-back direction, left-right direction, and up-down direction, 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 read.

As shown in FIG. 13, the 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 the mounting surface 2a, and a circuit board 6 arranged above the mounting surface 2a at a distance. 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. This 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 that are provided to protrude from the mounting surface 2a of the heat dissipation member 2.

The switching circuit section 3 converts the input DC voltage from the DC power supply 100 connected to the 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 that stabilizes 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 the wiring pattern of the circuit board 6.

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 have to be limited to two-phase full-wave rectification as in the illustrated example. 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 the 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 to this. Each component of the smoothing circuit section 15 may be mounted on either the heat dissipation member 2 or the circuit board 6.

As shown in FIG. 3, the transformer module 4 is roughly composed of 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 this invention. The terminal block 70 is fixed to the heat dissipation member 2 by means of screws or the like.

As shown in Figures 4 to 9, the transformer 20 is configured to include primary windings 21A, 21B connected to the switching circuit section 3, secondary windings 22A, 22B connected to the rectifier circuit section 5, a transformer core 23 to which the primary windings 21A, 21B and secondary windings 22A, 22B are attached, and cases 24A, 24B, covers 25A, 25B, and a separator 26 for arranging the primary windings 21A, 21B and secondary windings 22A, 22B in predetermined positions, respectively. The secondary windings 22A, 22B correspond to the "coils" in the present invention, the cases 24A, 24B correspond to the "pair of insulating members" in the present invention, and the separator 26 corresponds to the "insulating plate" in the present invention.

The primary windings 21A and 21B are made of linear conductors. The primary winding 21A has a winding portion 21A1 wound in a generally spiral shape with the vertical axis as the axial direction, and a pair of lead-out portions 21A2 and 21A3 drawn out radially outward (here, to the front) from the winding portion 21A1. Similarly, the primary winding 21B has a winding portion 21B1 wound in a generally spiral shape, and a pair of lead-out portions 21B2 and 21B3 drawn out radially outward from the winding portion 21B1. 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.

The lead wire portion 21A2 and the lead wire 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 wire portion 21A3 and the lead wire 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 wire portions 21A2, 21B2, 21A3, and 21B3 are electrically connected to the switching circuit portion 3. In addition, one lead wire portion 21A2 and one lead wire portion 21B2 form the primary winding 61 of the current transformer 60. In this current transformer 60, an induced electromotive force (AC voltage) is generated in the secondary winding (not shown) based on the AC voltage applied to the primary winding 61. This induced electromotive force is detected by the 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 the circuit board 6.

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

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 top of 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 top of each other in the vertical direction. These lead pull-out portions 22A2, 22A3, 22B2, and 22B3 are fixed, for example, by means of screws or the like to a terminal block (not shown) fixed to the heat dissipation member 2, and are electrically connected to the rectifier circuit portion 5 via the terminal block.

A fixing lead-out portion 22A5 extends from the winding portion 22A1 of the secondary winding 22A toward the front, i.e., toward the opposite direction to the lead-out direction of the multiple lead-out portions 22A2, 22A3, 22B2, and 22B3. This fixing lead-out portion 22A5 is fixed to the terminal block 70 shown in FIG. 3 by using a screw 72. The portion of the terminal block 70 where the screw 72 is screwed is made of a metal with 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.

In addition, grooves 22A4, 22B4 are formed at the front end of each winding portion 22A1, 22B1 of the secondary windings 22A, 22B. These grooves 22A4, 22B4 are recessed radially inward of each winding portion 22A1, 22B1 when viewed from the top-bottom direction. These grooves 22A4, 22B4 are formed so that their positions in the front-back direction and the left-right direction match. The groove 22A4 formed in the winding portion 22A1 is formed adjacent to the fixing pull-out portion 22A5 in the left-right direction.

The separator 26 is made of an insulating material such as resin, and is in the shape of a circular plate with its axis extending in the vertical direction. A pair of left and right grooves 2601 are formed in the front end of the separator 26. The left and right grooves 2601 are recessed radially inward of the separator 26 when viewed from the vertical direction, and are formed symmetrically in the horizontal direction. One of these grooves 2601 is formed so that its position in the front-rear and horizontal directions coincides with that of the grooves 22A4, 22B4 formed in the winding parts 22A1, 22B1 of the secondary windings 22A, 22B.

The separator 26 is coaxially disposed between the winding portion 22A1 and the winding portion 22B1 and is sandwiched between them. The secondary windings 22A and 22B are insulated from each other by the separator 26. In addition, the resin that constitutes 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.

Cases 24A and 24B are arranged 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 that makes up these cases 24A and 24B may contain, for example, a thermally conductive filler. As shown in Figures 10 to 14, these cases 24A and 24B are made of the same molded product and are arranged in opposite directions with the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B and the separator 26 sandwiched between them. These cases 24A and 24B are joined to each other by engaging multiple (here, three) locking claws 2415, 2416, and 2417 formed on each case with the other case.

In addition, covers 25A and 25B are arranged on the opposite side of the windings 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 Figures 15 to 17, these covers 25A and 25B are made of the same molded product and are arranged in opposite directions with the windings 22A1 and 22B1 of the secondary windings 22A and 22B, the separator 26, and the cases 24A and 24B sandwiched between them. Each cover 25A and 25B is connected to each case 24A and 24B by engaging a plurality of (four in this case) cover engaging parts 2508 formed on each cover with each case 24A and 24B. Below, we will explain the cases 24A, 24B and covers 25A, 25B mainly using Figures 9 to 17.

As shown in Figures 10 to 13, the case 24 is formed in a generally 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 generally 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 at the hole edge of the through hole 2403. The inner circumferential surface of the peripheral wall portion 2402 is generally cylindrical and 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 storage section 2405 of the case 24A houses the winding section 21A1 of the primary winding 21A (see FIG. 9), and the storage section 2405 of the case 24B houses the winding section 21B1 of the primary winding 21B.

As shown in Figs. 11 to 13, a pair of left and right draw-out openings 2406 that open the above-mentioned storage section 2405 to the front 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 section 2402 is partially omitted. The primary winding 21A, whose winding section 21A1 is housed in the housing section 2405 of the case 24A, has a pair of draw-out sections 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 section 21B1 is housed in the housing section 2405 of the case 24B, has a pair of draw-out sections 21A2 and 21A3 drawn out to the outside of the case 24B through the left and right draw-out openings 2406.

As shown in Figures 10 to 13, 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 portion C2 is formed that protrudes outward in the left-right direction.

10 and 13, at the front end and both left and right ends 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. In addition, at the front end and both left and right ends of the case 24, locking claws 2415, 2416 are formed as locking portions. The left and right locking claws 2415, 2416 each protrude from the bottom wall portion 2401 toward the other side in the up-down direction, and are arranged adjacent to one side in the left-right direction of the left and right hook portions 2412, 2413. These locking claws 2415, 2416 are arranged side by side in the left-right direction. Each of these locking claws 2415, 2416 is an elongated plate 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 that protrudes to the other side in the front-rear direction.

As shown in Figures 10 to 13, a frame-shaped portion 2408 is formed at the rear end of the case 24, protruding from the peripheral wall portion 2402 to the other side in the front-to-rear direction. This frame-shaped portion 2408 has a long rectangular frame shape with the longitudinal direction being the left-to-right direction when viewed from the front-to-rear direction. As shown in Figures 10, 12 and 13, on one side in the left-to-right direction of the frame-shaped portion 2408, the bottom wall portion 2401 extends further toward the other side in the front-to-rear direction than the peripheral wall portion 2402, thereby forming a hook portion 2414. This hook portion 2414 is retracted forward of the frame-shaped portion 2408.

As shown in Figures 10 to 13, on the other left-right side of the frame-shaped portion 2408, the bottom wall portion 2401 is extended further in the front-rear direction than the peripheral wall portion 2402 to form an extension portion 2410. This extension portion 2410 protrudes rearward from 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 from the inner end portion in the left-right direction of this extension portion 2410 toward the other side in the up-down direction. This positioning piece 2411 is plate-shaped with the plate thickness direction being in the left-right direction.

In addition, a locking claw 2417 is formed as a locking portion on the base end side of the extension 2410. This locking claw 2417 protrudes from the base end of the extension 2410 toward the other side in the vertical direction. This locking claw 2417 is an elongated plate with the plate thickness direction being the front-to-rear direction and the longitudinal direction being the up-to-down direction. However, this locking claw 2417 is set to have a larger width dimension in the left-to-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-to-back direction than the two locking claws 2415 and 2416 described above. A claw portion C1 protruding forward is formed at the tip of this locking claw 2417. When viewed from the vertical direction, this locking claw 2417 is located on the opposite side of one of the two locking claws 2415 and 2416 described above, across the center of the through hole 2403.

As shown in FIG. 13, at the front end of the case 24, the central portion in the left-right direction of the peripheral wall portion 2402 is a thick portion 2418. In this thick portion 2418, the thickness of the peripheral wall portion 2402 is expanded in the front-rear direction. A groove portion 2419 is formed at each end of one side in the left-right direction of this thick portion 2418. The left and right groove portions 2419 are formed symmetrically in the left-right direction, and the front side and the other side in the up-down direction (the lower side in FIG. 13) are open. One of these groove portions 2419 is formed so that the positions in the front-rear direction and left-right direction match the groove portions 22A4, 22B4 formed in the winding portions 22A1, 22B1 of the secondary windings 22A, 22B, and one of the left and right groove portions 2601 formed in the separator 26.

As described above, the cases 24A and 24B of the above configuration are arranged in opposite directions with the windings 22A1 and 22B1 of the secondary windings 22A and 22B and the separator 26 sandwiched between them. 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 hooks 2412, 2413, and 2414 on the other case. When these cases 24A and 24B are joined to each other, the cases 24A and 24B are arranged in opposite directions in the vertical direction so that the storage sections 2405 of each case 24A and 24B are open to the opposite sides (see FIG. 14). In this position, the cases 24A and 24B are brought closer to each other, so that the locking claws 2415, 2416, and 2417 formed on each case 24A and 24B are locked to the hooks 2412, 2413, and 2414 formed on the other cases 24A and 24B. Note that the secondary windings 22A and 22B and the separator 26 are not shown in FIG. 14.

During the above-mentioned engagement, the claws C1 formed at the tip of each of the engagement claws 2415, 2416, 2417 are in sliding contact with the hooks 2412, 2413, 2414, so that each of the engagement claws 2415, 2416, 2417 is temporarily and elastically deflected in the front-rear direction. Then, each of the engagement claws 2415, 2416, 2417 elastically returns to its original state, so that the claws C1 of each of the engagement claws 2415, 2416, 2417 are hooked onto the hooks 2412, 2413, 2414. This allows the case 24A and the case 24B to be joined together. During this engagement, the two engagement claws 2415, 2416 are more easily deflected than the remaining engagement claw 2417, so these two engagement claws 2415, 2416 are primarily deflected. This allows the above-mentioned engagement to be performed smoothly. During this connection, for example, the locking claws 2417 of each case 24A, 24B may be hooked onto the hooking portion 2414 of the other case, and then 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.

As shown in Figures 3 to 7, when the connection of the cases 24A and 24B is complete, the housing section 2405 of each case 24A and 24B is open on the side opposite the winding sections 22A1 and 22B1 of the secondary windings 22A and 22B. In this connected state, the two locking claws 2415 and 2416 are arranged side by side in the tangential direction of the winding sections 22A1 and 22B1 of the secondary windings 22A and 22B, and one of the two locking claws 2415 and 2416, the locking claw 2415, and the remaining locking claw 2417, are arranged on opposite sides of the centers of the winding sections 22A1 and 22B1 of the secondary windings 22A and 22B.

In addition, the cases 24A and 24B connected as described above are configured so that the relative displacement of the cases 24A and 24B in the left-right direction is restricted by the engagement claws 2415 and 2416 formed on each case interfering with each other in the left-right direction. Furthermore, each of these cases 24A and 24B has a rotation stopper 2409 that, in the above-mentioned completed connection state, engages (here, faces closely) with the engagement claws 2417 formed on the other case from one circumferential side of the winding parts 22A1 and 22B1 of the secondary windings 22A and 22B, thereby restricting the relative rotation of the winding parts 22A and 22B1 to one circumferential side. These rotation stopper parts 2409 are formed by the end faces on one left-right side of the frame-shaped parts 2408 of each case 24A and 24B. These rotation stoppers 2409 interfere with each of the locking claws 2417, limiting the relative displacement of the cases 24A and 24B in the left-right direction, and preventing the cases 24A and 24B from rotating relative to each other in the circumferential direction of the winding parts 22A1 and 22B1.

In addition, in the above-mentioned completed connection state, the positioning pieces 2411 of the cases 24A and 24B are arranged on both the left and right outer sides of the lead pull-out portions 22A2 and 22B2 of the secondary windings 22A and 22B. Between the lead pull-out portions 22A2 and 22B2, the lead pull-out portions 22A3 and 22B3 are arranged, which are stacked in the vertical direction. This allows the left and right displacement of 22A3, 22B3, 22A2, and 22B2 to be limited by the positioning pieces 2411.

In addition, in the above-mentioned combined state, the cases 24A and 24B are stacked on both sides of the axial direction (vertical direction) of the windings 22A1 and 22B1 of the secondary windings 22A and 22B to form a stacked portion 29 (see Figures 3 to 5 and 7). A groove 291 extending in the vertical direction is formed on the front end surface of this stacked portion 29 (i.e., the front end surfaces of the windings 22A1 and 22B1 and the cases 24A and 24B). This groove 291 corresponds to the "groove" in this invention.

The groove 291 is formed in a concave shape by vertically connecting one of the left and right grooves 2419 formed in the cases 24A and 24B, the grooves 22A4 and 22B4 formed in the windings 22A1 and 22B1 of the secondary windings 22A and 22B, and one of the left and right grooves 2601 formed in the separator 26. The grooves 2419, 22A4, 22B4, and 2601 that are continuously arranged in the vertical direction have the same shape when viewed from the vertical direction. The groove 291 extends in the vertical direction (the stacking direction of the stacking section 29) across the cases 24A and 24B, the windings 22A1 and 22A2, and the separator 26. However, the groove 291 does not reach both ends of the cases 24A and 24B in the vertical direction, and both ends in the vertical direction are closed by parts of the cases 24A and 24B. The groove 291 has walls 2911 and 2912 (see FIG. 6) at both ends in the vertical direction. In addition to the walls 2911 and 2912, the groove 291 has left and right walls 2913 and 2914 that face each other in the circumferential direction (here, approximately left and right direction) of the winding parts 22A1 and 22B1, and a bottom 2915 that faces the radial outside (here, the front side) of the winding parts 22A1 and 22B1. The groove 291 is disposed adjacent to the fixing lead-out part 22A5 of the secondary winding 22A in the circumferential direction (here, left side) of the winding parts 22A1 and 22B1.

As shown in FIG. 7, the groove 291 is filled with adhesive AD. When the adhesive AD hardens, the cases 24A, 24B, the secondary windings 22A, 22B, and the separator 26 are bonded together and integrated. The adhesive AD is, for example, an epoxy resin-based adhesive.

On the other hand, as shown in FIG. 15 and FIG. 16, the cover 25 (cover 25A and cover 25B) is formed in a substantially rectangular plate shape that is flat in the vertical direction. The left-right dimension of this cover 25 is set to be longer than the front-rear dimension. This cover 25 has a horizontal wall portion 2501 that is a substantially rectangular plate shape with the vertical direction as the plate thickness direction, a pair of front and rear wall portions 2502, 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, 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 this 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 that protrudes outward in the front-rear direction.

When the covers 25A and 25B configured as described above are coupled to the cases 24A and 24B, as shown in FIG. 17, the covers 25A and 25B are disposed on the side facing the storage section 2405 of each case 24A and 24B. Then, as the covers 25A and 25B and the cases 24A and 24B are brought closer to each other, the cover locking section 2508 formed on each cover 25A and 25B is locked with the claw section C2 formed on the extension wall section 2407 of each case 24A and 24B. This allows the covers 25A and 25B to be coupled to the cases 24A and 24B.

When the covers 25A, 25B are joined to the cases 24A, 24B as described above, the claws C2 of the extension walls 2407 slide against the cover locking parts 2508, causing the cover locking parts 2508 and the extension walls 2407 to temporarily and elastically flex in the left-right direction. Then, the cover locking parts 2508 and the extension walls 2407 elastically return to their original position, causing the claws C2 of the extension walls 2407 to hook onto the cover locking parts 2508, and the covers 25A, 25B are restrained to the cases 24A, 24B.

The above-mentioned connection (locking) is performed when the winding parts 21A1, 21B1 of the primary windings 21A, 21B are housed in the housing 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. When this connection is complete, the covers 25A, 25B are configured to prevent the primary windings 21A, 21B from falling out of the cases 24A, 24B.

When the cases 24A and 24B are joined together as described above, and the covers 25A and 25B are joined to the cases 24A and 24B, the primary windings 21A and 21B, the secondary windings 22A and 22B, the cases 24A and 24B, the covers 25A and 25B, and the separator 26 are integrated. This makes the subsequent assembly work easier.

In other words, the transformer core 23 and 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 is facilitated. As an example, the transformer core 23 is configured by combining a pair of E-shaped cores 23A, 23B. 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-to-back direction, and are arranged opposite each other in the up-down direction.

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 unit 3 and output to a transformer module 4. In the transformer module 4, the AC voltage output from the switching circuit unit 3 is transformed into an AC voltage of a different voltage in a transformer 20 and output to a rectifier circuit unit 5. In the rectifier circuit unit 5, the output voltage from the transformer 20 is rectified and output to a smoothing circuit unit 15. In the smoothing circuit unit 15, the output voltage from the rectifier circuit unit 5 is smoothed and output to the outside from an output terminal 14.

The above-mentioned transformer 20 includes secondary windings 22A, 22B having annular windings 22A1, 22B, and a pair of cases 24A, 24B arranged with the windings 22A1, 22B sandwiched between them. A concave groove 291 is formed on the end faces of the windings 22A1, 22B and the cases 24A, 24B, extending in the stacking direction of the windings 22A1, 22B and the cases 24A, 24B, and the groove 291 is filled with adhesive AD. This allows the windings 22A1, 22B and the cases 24A, 24B to be bonded simultaneously. In other words, the windings 22A1, 22B and the cases 24A, 24B can be bonded to each other in a single bonding operation. This makes the bonding operation easier and reduces the time required for the bonding operation.

Moreover, this transformer 20 includes two secondary windings 22A, 22B, each of which has a winding portion 22A1, 22B1 disposed between the cases 24A, 24B, and a separator 26 disposed between the winding portions 22A1, 22B1 of the two secondary windings 22A, 22B. The grooves 291 are formed to communicate with the winding portions 22A1, 22B1 and the end faces of the separator 26. This allows the pair of cases 24A, 24B, the two secondary windings 22A, 22B, and the separator 26 to be bonded together in a single bonding operation. This makes the bonding operation extremely easy and significantly reduces the time required for the bonding operation. In addition, since the transformer has two secondary windings 22A, 22B, the design freedom of the number of turns of the secondary windings, etc. is improved.

Furthermore, because the pair of cases 24A, 24B, the two secondary windings 22A, 22B, and the separator 26 are bonded together, relative displacement of these components is prevented when vibration is applied to the transformer 20, i.e., the DC-DC converter device 1. As a result, sliding contact between the above-mentioned components that accompanies the relative displacement is prevented, and wear of the above-mentioned components that accompanies the sliding contact is prevented. This wear can cause insulation failure due to wear of the cases 24A, 24B and the separator 26, and can cause wear powder (i.e., conductor powder) to flow out due to wear of the secondary windings 22A, 22B, but this can be avoided in this embodiment.

The groove 291 is closed in the stacking direction (vertical direction) and has walls 2911, 2912 that face each other in the vertical direction, left and right walls 2913, 2914 that face each other in the approximately horizontal direction, and a bottom 2915. These walls 2911, 2912, 2913, 2914 and bottom 2915 come into contact with adhesive AD, so that the pair of cases 24A, 24B, the pair of secondary windings 22A, 22B, and the separator 26 are integrated in the front-back, left-right, and vertical directions. This allows the pair of cases 24A, 24B, the pair of secondary windings 22A, 22B, and the separator 26 to be firmly fixed to each other, and the relative displacement of each of the above members due to front-back, left-right, up-down vibrations can be effectively prevented. Moreover, the grooves 2419, 22A4, 22B4, and 2601 that communicate with each other in the vertical direction in the above-mentioned groove 291 have the same shape when viewed from the vertical direction. When assembling the pair of cases 24A and 24B, the two secondary windings 22A and 22B, and the separator 26, these members can be positioned using the grooves 2419, 22A4, 22B4, and 2601.

In addition, the secondary windings 22A and 22B have a plurality of lead pull-out portions 22A2, 22A3, 22B2, and 22B3 extending radially outward (here, the other side in the front-to-rear direction) from the winding portions 22A1 and 22B1 of the secondary windings 22A and 22B, respectively. These lead pull-out portions 22A2, 22A3, 22B2, and 22B3 are fixed to the heat dissipation member 2 via a terminal block (not shown). In addition, the secondary winding 22A has a fixing pull-out portion 22A5 extending from the winding portion 22A1 in the opposite direction (here, the front side) to the extending direction of the plurality of lead pull-out portions 22A2, 22A3, 22B2, and 22B3. This fixing pull-out portion 22A5 is fixed to the heat dissipation member 2 via a terminal block 70. The groove 291 is formed adjacent to one of the left and right sides of the fixed pull-out portion 22A5 (one of the circumferential directions of the winding portions 22A, 22B). The fixed pull-out portion 22A5 fixed to the heat dissipation member 2 is a portion that is relatively less affected by vibration. Therefore, by providing the groove 291, i.e., the adhesive portion between the pair of cases 24A, 24B and the two secondary windings 22A, 22B and the separator 26, adjacent to the fixed pull-out portion 22A5, the impact of vibration on the adhesive portion can be reduced. As a result, it becomes easier to maintain the aforementioned adhesive effect for a long period of time.

In the above embodiment, the groove 291 is formed only on one side of the left and right direction of the fixing drawer 22A5 (one side of the circumferential direction of the winding parts 22A and 22B), but this is not limited to the above. That is, the groove 291 may be formed on both sides of the circumferential direction of the winding parts 22A and 22B of the fixing drawer 22A5. In this case, a pair of left and right grooves may be formed on the winding parts 22A1 and 22B3, similar to the pair of left and right grooves 2601 of the separator 26. By forming the grooves 291 on both sides of the left and right direction of the fixing drawer 22A5, the pair of cases 24A and 24B, the two secondary windings 22A and 22B, and the separator 26 can be bonded more firmly.

In addition, in the above embodiment, the winding portions 22A1, 22B1 of the two secondary windings 22A, 22B (both of which correspond to the "coil" of the present invention) are arranged between the pair of cases 24A, 24B, but this is not limited to this. The "coil" of the present invention may be one.

In addition, in the above embodiment, the arrangement of the primary winding and the secondary winding may be reversed.

In the above embodiment, the present invention is applied to the transformer 20 of the DC-DC converter device 1, 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 equivalent to the primary windings 21A and 21B.

The present invention can be modified in various ways without departing from the spirit of the invention. It goes without saying that the scope of the invention is not limited to the above embodiment.

20 Transformer (coil device)
22A, 22B Secondary winding 22A1, 22B1 Winding portion 22A5 Fixing lead-out portion 24A, 24B Case (insulating member)
26 Separator (insulating plate)
27 Secondary winding (coil)
28 Winding portion 291 Groove portion 2911, 2912 Wall portion AD Adhesive

Claims (5)

A coil having an annular winding portion;
a pair of insulating members disposed with the winding portion therebetween;
a concave groove portion extending in a stacking direction of the coil and the pair of insulating members and communicating with each other is formed on end surfaces of the coil and the pair of insulating members;
The groove is filled with an adhesive. Two coils, each having the winding portion disposed between the pair of insulating members;
an insulating plate disposed between the two windings of the coil;
The coil device according to claim 1 , wherein the groove is formed so as to communicate with the two coils and the end faces of the insulating plate. The coil device according to claim 1 or 2, wherein the groove portion has a wall portion at each end in the stacking direction and is a groove that is closed in the stacking direction. The coil has a fixing lead portion extending from the winding portion,
4. The coil device according to claim 1, wherein the groove is formed at a position adjacent to the fixing lead-out portion. The coil device according to claim 4, wherein the grooves are formed on both sides adjacent to the fixing drawer.