Power supply unit

Abstract

The invention discloses a power supply unit capable of reducing the number of components, reducing cost, reducing size, and suppressing vibration of a capacitor. A power supply unit (10) is provided with a printed circuit board (14) housed in a case (12) and a capacitor (16) mounted on the printed circuit board (14), the capacitor (16) has a pair of electrodes (66a, 66b) on both axial end surfaces of a cylindrical body (62), metal plates (90a, 90b) are fixed to the electrodes (66a, 66b) so as to be electrically conductive, each metal plate (90a, 90b) has a connection part (108), and the connection part (108) is inserted and brazed into a through hole (48) of the printed circuit board (14). At least one of the metal flat plates (90a, 90b) has a press-fit portion (104), the press-fit portion (104) is press-fitted into a press-fit hole (50) of the printed circuit board (14), and the capacitor (16) is fixedly held on the printed circuit board (14) by the press-fit portion (104) being press-fitted into the press-fit hole (50).

Description

Technical Field

[0001] The present invention relates to a power supply unit. Background Art

[0002] Conventionally, as an auxiliary power supply used in vehicles such as electric vehicles and hybrid vehicles when the battery voltage temporarily drops, a power supply unit using capacitors is known. For example, Patent Document 1 discloses a power supply unit having a structure in which a plurality of capacitors are mounted on a printed circuit board while being held by a synthetic resin holding member. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-81795 Summary of the Invention Problems to be Solved by the Invention

[0004] However, in the structure of Patent Document 1, since a synthetic resin holding member for holding a plurality of capacitors is required, there are problems of a large number of components and an inevitable increase in the size of the power supply unit itself. In addition, in order not to apply an external force to the wires (connection parts) of the capacitors soldered into the through holes of the printed circuit board due to the vibration of the capacitors, the locking structure of the capacitors provided on the holding member requires strict dimensional setting to avoid loosening. As a result, an increase in the mold cost of the holding member and the like is inevitably brought about, and the manufacturing cost soars. In addition, since a so-called radial capacitor in which a pair of wires (connection parts) protrude from one end face in the axial direction of the cylindrical body of the capacitor is used, the other side in the axial direction of the cylindrical body is likely to vibrate, resulting in a structure in which the vibration of the capacitor is likely to occur.

[0005] Here, the present invention provides a power supply unit that can reduce the number of components, reduce costs, and miniaturize, and can suppress the vibration of the capacitor. Means for Solving the Problems

[0006] The power supply unit of the present invention includes a printed circuit board housed in a housing and a capacitor mounted on the printed circuit board. The capacitor has a pair of electrodes at both axial end faces of a cylindrical body, and metal plates are fixedly mounted on each of the electrodes so as to be electrically conductive. Each of the metal plates has a connection part, and the connection part is inserted into and soldered to a through hole of the printed circuit board. At least one of the metal plates has a press-in part, and the press-in part is pressed into a press-in hole of the printed circuit board. By pressing the press-in part into the press-in hole, the capacitor is fixedly held on the printed circuit board. Advantages of the Invention

[0007] According to the power supply unit of the present invention, it is possible to reduce the number of components, reduce costs, and miniaturize, and can suppress the vibration of the capacitor. Description of the Drawings

[0008] Figure 1 is a perspective view showing the power supply unit according to Embodiment 1. Figure 2 is Figure 1 a top view of the power supply unit shown. Figure 3 is a right view showing a main part of a state in which the housing is removed from the power supply unit shown in Figure 1 an enlarged manner. Figure 4 is an enlarged view showing Figure 2 a longitudinal sectional view of a main part of the IV-IV cross section of Figure 5 is an enlarged view showing Figure 2 a longitudinal sectional view of a main part of the V-V cross section of Figure 6 is an enlarged view showing Figure 2 a longitudinal sectional view of a main part of the VI-VI cross section of Figure 7 is Figure 1 an exploded perspective view of the power supply unit shown. Figure 8 is a perspective view showing the upper housing of the housing constituting the power supply unit shown in Figure 1 from the bottom side. Figure 9 is an enlarged top view showing a main part of the printed circuit board constituting the power supply unit shown in Figure 1 an enlarged manner. Figure 10 is a perspective view showing the capacitor constituting the power supply unit shown in Figure 1 from one end face side in the axial direction. Figure 11 is a perspective view showing the capacitor constituting the power supply unit shown in Figure 1 from the other end face side in the axial direction. Figure 12 is a perspective view showing the electrolyte container constituting the power supply unit shown in Figure 1 an enlarged manner. Detailed Embodiments

[0009] <Description of Embodiments of the Present Invention> First, embodiments of the present invention will be enumerated and described. (1) The power supply unit of the present invention includes a printed circuit board housed in a housing and a capacitor mounted on the printed circuit board. The capacitor has a pair of electrodes on the axial end faces of a cylindrical body, and metal plates are electrically conductively fixed to each of the electrodes. Each of the metal plates has a connecting portion, and the connecting portion is inserted into and soldered to a through hole of the printed circuit board. At least one of the metal plates has a press-fitting portion, and the press-fitting portion is press-fitted into a press-fitting hole of the printed circuit board. By pressing the press-fitting portion into the press-fitting hole, the capacitor is fixedly held on the printed circuit board.

[0010] In the power supply unit according to the present invention, the capacitor is a so-called axial capacitor having a pair of electrodes provided on the axial end faces of a cylindrical body. Metal plates are electrically conductively fixed to the pair of electrodes on the axial end faces of the capacitor, and the metal plates are provided with connecting portions that are inserted into and soldered to the through holes of the printed circuit board. Further, by pressing the press-fitting portion provided on at least one of the metal plates into the press-fitting hole of the printed circuit board, the capacitor is fixedly held on the printed circuit board. That is, by skillfully utilizing the rigidity of the metal plate fixed to the electrode of the capacitor and the press-fitting force of the press-fitting portion of the metal plate into the press-fitting hole of the printed circuit board, the capacitor can be fixedly held on the printed circuit board. As a result, a power supply unit can be provided in which it is possible to reduce the number of components, and thus the cost and size reduction, without the need for a synthetic resin capacitor holder required in the past.

[0011] In addition, a pair of electrodes of the capacitor are provided at both axial ends of the cylindrical body, and the connecting portions of the metal plates fixed to them are soldered to the through holes of the printed circuit board. Therefore, it is also possible to solve the structural problem that, as in the case of a radial capacitor in which the wire (connecting portion) is only on one axial side in the past, the other axial side of the capacitor without an electrode is likely to vibrate. As a result, the vibration of the capacitor can be suppressed, and the possibility of cracks or the like occurring in the solder connecting the connecting portion and the through hole can be suppressed.

[0012] In addition, the press-fitting portion only needs to be provided on at least one metal plate, but it is also possible to realize more stable fixing of the capacitor to the printed circuit board by providing press-fitting portions on each of the metal plates.

[0013] In addition, regarding the method of fixing the metal plate to the pair of electrodes of the capacitor, any method can be adopted as long as it can be fixed in an electrically conductive state. For example, welding or riveting can be appropriately adopted.

[0014] (2) In the above (1), preferably, each of the metal plates has the press-fitting portion. Since the press-fitting portions are respectively provided on a pair of metal plates fixed to the axial end faces of the capacitor, by press-fitting the press-fitting portions into the press-fitting holes at both axial end portions of the capacitor, the capacitor can be fixed to the printed circuit board more stably. Moreover, the press-fitting portions can be respectively provided near each connection portion, which can advantageously suppress the influence of external force on the solder connecting the connection portion and the through hole, and can also improve the connection stability between the capacitor and the printed circuit board.

[0015] (3) In the above (1) or (2), preferably, each of the metal plates has a stopper portion, the stopper portion is placed on the printed circuit board, and the insertion amount of the connection portion into the through hole is defined. In a state where the stopper portion is placed on the printed circuit board, a gap extending upward is formed around the connection portion. Just by placing the stopper portion provided on the metal plate on the printed circuit board, the connection portion can be inserted into the through hole by a necessary amount, which can improve the assembly workability. In addition, since a gap extending upward is formed around the connection portion in a state where the stopper portion is placed on the printed circuit board, the completion of soldering when soldering the connection portion to the through hole can be promoted, and good soldering can be achieved. Moreover, it is easy to confirm the completion of soldering from the outside through the gap, and the product inspection work can also be carried out well.

[0016] (4) In the above (3), preferably, the press-fitting portion press-fitted into the press-fitting hole is soldered, and in a state where the stopper portion is placed on the printed circuit board, a gap extending upward is formed around the press-fitting portion. By soldering the press-fitting portion to the press-fitting hole, more stable fixation of the capacitor to the printed circuit board can be achieved. Moreover, since a gap extending upward is formed around the press-fitting portion in a state where the stopper portion is placed on the printed circuit board, the completion of soldering when soldering the press-fitting portion to the press-fitting hole can be promoted, and good soldering can be achieved. Moreover, it is easy to confirm the completion of soldering from the outside through the gap, and the product inspection work can also be carried out well.

[0017] (5) In any one of the above (1) to (4), preferably, in the metal plate having the press-fitting portion, the central portion in the length direction constitutes a welding portion welded overlapping with the electrode, and both side portions in the length direction constitute a pair of protruding plate portions bent in the plate thickness direction and protruding outward in the axial direction of the cylindrical body. The press-fitting portions are respectively provided to protrude from the lower end portions of the pair of protruding plate portions toward the printed circuit board, and each of the press-fitting portions is press-fitted into the press-fitting hole.

[0018] A welding part for welding with an electrode is provided at the central part in the length direction of the metal flat plate, and both sides in the length direction of the metal flat plate constitute a pair of protruding plate parts protruding outward in the axial direction. And, press-in parts are provided at the lower end parts of the respective protruding plate parts and are respectively press-fitted into press-fit holes. Thereby, the press-in parts can be dispersedly arranged at two positions separated in the direction perpendicular to the axis of the cylindrical main body of the capacitor and at positions separated outward in the axial direction from the electrode. Thereby, the capacitor can be fixed to the printed circuit board more stably. In particular, when combined with the above (2), at least four or more fixing points of the capacitor relative to the printed circuit board can be ensured at both axial ends of the capacitor and on both sides in the direction perpendicular to the axis, and a more stable fixing state can be achieved. In addition, only one press-in part may be provided at the lower end part of each protruding plate part, but a plurality of press-in parts may also be provided.

[0019] (6) In any one of the above (1) to (5), preferably, each of the metal flat plates has a stopper part, the stopper part is placed on the printed circuit board, defines the insertion amount of the connecting part into the through hole, and the central part in the length direction of each of the metal flat plates constitutes a welding part welded overlapping with the electrode, and both side parts in the length direction of each of the metal flat plates constitute a pair of protruding plate parts bent in the plate thickness direction and protruding outward in the axial direction of the cylindrical main body, and the stopper parts are respectively provided to protrude from the lower end parts of the pair of protruding plate parts toward the printed circuit board. The stopper parts can be arranged at a total of four positions on both axial sides at two positions separated in the direction perpendicular to the axis of the cylindrical main body of the capacitor and at positions separated outward in the axial direction from the electrode. Thereby, tilting of the capacitor relative to the printed circuit board can be prevented, and positioning of the capacitor relative to the printed circuit board can be realized more stably.

[0020] (7) In the above (5) or (6), preferably, the connecting part is provided to protrude from the lower end part of the central part in the length direction of the metal flat plate toward the printed circuit board. The connecting part can be provided near the welding part for welding with the electrode, and the conduction stability between the capacitor and the printed circuit board can be advantageously ensured.

[0021] (8) In any one of the above (5) to (7), preferably, a gas discharge valve is provided on one of the two end faces of the capacitor, the gas discharge valve discharges the gas generated in case of abnormality, the welding part of the metal flat plate is arranged around the gas discharge valve, and by connecting a pair of concave bending parts connecting the welding part of the metal flat plate and the pair of protruding plate parts, a guiding groove extending toward the printed circuit board side and guiding the electrolytic solution is formed, and the connecting part and a cutout part are provided on each of the protruding plate parts, and the guiding groove and the connecting part are separated in the axial direction through the cutout part.

[0022] A metal flat plate welded to the negative electrode provided with a gas discharge valve may cause conduction failure or the like if the electrolyte oozing out when gas is discharged from the gas discharge valve adheres to the connection part during capacitor abnormality. In this method, a pair of concave bending parts connecting the welding part of the metal flat plate and a pair of protruding plate parts form a guiding groove extending toward the printed circuit board side. Therefore, even when the electrolyte oozes out from the gas discharge valve, the electrolyte diffuses from the welding part to the guiding groove and is guided toward the printed circuit board side. As a result, the diffusion of the electrolyte to the protruding plate part side can be prevented or suppressed, and the bad condition that the electrolyte diffuses to the connection part provided on the protruding plate part can be advantageously prevented or suppressed. Moreover, in the protruding plate part, since the guiding groove and the connection part are separated by the cutout part, even if the electrolyte sometimes diffuses across the guiding groove, the cutout part can prevent or suppress the bad condition that the electrolyte diffuses to the connection part.

[0023] (9) In the above (8), it is preferable that an electrolyte receiver is arranged on the printed circuit board. The electrolyte receiver is located below the gas discharge valve and the guiding groove and receives the electrolyte oozing out from the gas discharge valve. By the electrolyte receiver, the diffusion of the electrolyte flowing down toward the printed circuit board side to the printed circuit board can be prevented or suppressed. Thus, the occurrence of conduction failure or the like in the power supply unit can be prevented, and the improvement of safety can be achieved.

[0024] (10) In any one of the above (1) to (9), it is preferable that a gas discharge valve is arranged on one of the two end faces of the capacitor. The gas discharge valve discharges the gas generated during abnormality. An electrolyte receiver is arranged on the printed circuit board. The electrolyte receiver is located below the gas discharge valve and receives the electrolyte discharged from the gas discharge valve. Even if the electrolyte sometimes oozes out from the gas discharge valve of the capacitor, the oozed electrolyte is received by the electrolyte receiver, and the diffusion to the printed circuit board can be prevented or suppressed. Thus, the occurrence of conduction failure or the like in the power supply unit can be prevented, and the improvement of safety can be achieved.

[0025] <Details of the embodiment of the present invention> The following describes specific examples of the power supply unit of the present invention with reference to the drawings. In addition, the present invention is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0026] <Embodiment 1> The following, use Figures 1 to 12A description will be given of the power supply unit 10 according to Embodiment 1 of the present invention. The power supply unit 10 of the present embodiment is, for example, used as a multifunctional backup power supply unit for systems such as steer-by-wire (SBW), braking, electric power steering (EPS), and autonomous driving when the power supply fails in an electric vehicle, a hybrid vehicle, etc., and is a high-capacity power supply unit. In addition, the power supply unit 10 can be arranged in any orientation. Hereinafter, the upper side will be set as Figure 3 the upper side in Figure 3 the lower side in Figure 2 the upper side in Figure 2 the lower side in Figure 2 the left side in Figure 2 the right side in

[0027] <Power supply unit 10> The power supply unit 10 includes a printed circuit board 14 housed in a housing 12 and capacitors 16 mounted on the printed circuit board 14. In Embodiment 1, three capacitors 16 are provided. In a state where the central axis directions of the substantially cylindrical capacitors 16 extend in the left-right direction, the capacitors 16 are arranged in parallel in the front-rear direction. In addition, among the three capacitors 16, the middle capacitor 16 is arranged in a state of being reversed in the left-right direction with respect to the capacitors 16 on both sides. That is, the middle capacitor 16 arranges the negative electrode side electrode 66a and the positive electrode side electrode 66b, which will be described later, in the opposite direction with respect to the capacitors 16 on both sides.

[0028] <Housing 12> In Embodiment 1, the housing 12 is composed of a substantially box-shaped lower housing 18 that opens upward and a substantially box-shaped upper housing 20 that covers the upper opening of the lower housing 18 and opens downward. These lower housing 18 and upper housing 20 can be formed of any material containing synthetic resin, metal, etc. In Embodiment 1, the lower housing 18 and the upper housing 20 are formed of synthetic resin.

[0029] The lower housing 18 includes a substantially rectangular bottom wall portion 22 that is substantially rectangular in plan view and a lower peripheral wall portion 24 that protrudes upward from the outer peripheral edge portion of the bottom wall portion 22. At multiple locations on the left and right sides of the lower peripheral wall portion 24, there are provided engaging frames 26 that protrude upward and can be elastically deformed in the left-right direction. In addition, at multiple locations on the circumference of the lower end portion of the lower peripheral wall portion 24, the thickness dimension of the lower peripheral wall portion 24 becomes larger, so that a lower abutting portion 28 that abuts against and supports the printed circuit board 14 from below when the printed circuit board 14 is fixed in the housing 12 is provided.

[0030] The upper housing 20 includes an upper bottom wall portion 30 that is substantially rectangular in plan view and an upper peripheral wall portion 32 that projects downward from the outer peripheral edge portion of the upper bottom wall portion 30. As the upper peripheral wall portion 32 becomes the inner peripheral side, the depth dimension (the vertical dimension from the lower opening) gradually increases. In short, as it becomes lower, it gradually expands toward the outer peripheral side. Thus, in the upper housing 20, the upper bottom wall portion 30 is located at the uppermost position in the central portion of the upper peripheral wall portion 32. In addition, an upper abutting portion 34 is provided on the outer peripheral portion of the upper peripheral wall portion 32. The upper abutting portion 34 projects downward and abuts and supports the printed circuit board 14 from above when the printed circuit board 14 is fixed within the housing 12. The upper abutting portion 34 is provided in a substantially annular shape over the entire circumference in the circumferential direction, and as shown in Figure 8 , threaded holes 36 are formed at multiple locations on the upper abutting portion 34, and screws 56 (described later) for fixing the printed circuit board 14 are screwed into the threaded holes 36. Further, positioning pins 37 that project downward are provided at positions on the upper abutting portion 34 that are offset from the threaded holes 36 in the circumferential direction. When the printed circuit board 14 is fixed, the upper housing 20 and the printed circuit board 14 are mutually positioned using the positioning pins 37.

[0031] Also, as shown in Figures 4 to 6 and Figure 8 , an upper supporting portion 38 that supports each capacitor 16 from above is provided on the lower surface of the upper bottom wall portion 30. The upper supporting portion 38 has recesses 40 at positions corresponding to the respective capacitors 16. The recesses 40 have curved surfaces corresponding to the outer peripheral surfaces of the respective capacitors 16. In Embodiment 1, the three downward-opening recesses 40 are provided separately from each other in the front-rear direction. The curvature of each recess 40 is substantially equal to the curvature of the cylindrical main body 62 of each capacitor 16 described later. In the assembled state of the power supply unit 10, the inner peripheral surfaces of the respective recesses 40 abut against the outer peripheral surfaces of the respective cylindrical main bodies 62 over substantially the entire surface. The upper supporting portion 38 is a component whose number of recesses 40 changes according to the number of capacitors 16, is formed separately from the upper housing 20, and can be fixedly attached later to the lower surface of the upper bottom wall portion 30. The upper supporting portion 38 is made of, for example, synthetic resin, and insulation between the upper housing 20 and each capacitor 16 can be achieved even when the upper housing 20 is made of metal.

[0032] In addition, engaging protrusions 42 that project outward in the left-right direction are provided at positions on the left and right sides of the upper peripheral wall portion 32 corresponding to the respective engaging frames 26 of the lower peripheral wall portion 24.

[0033] <Printed Circuit Board 14> The printed circuit board 14 is formed by printing a conductor such as metal on a rigid rectangular plate made of synthetic resin or the like. In a state of being fixed within the housing 12, a circuit (not shown) composed of a conductor is printed and formed on the upper surface and / or the lower surface. A connector 44 is fixed to the front of the printed circuit board 14, and the connector 44 is electrically connected to the circuit on the printed circuit board 14. In addition, an opening 46 penetrating in the thickness direction (front-back direction) is formed in the front portion of the housing 12 (the lower housing 18 and the upper housing 20). When assembling the power supply unit 10, the connector 44 is exposed forward through the opening 46 of the housing 12.

[0034] In addition, as also Figure 4 , Figure 9 shown, in a state where the printed circuit board 14 is fixed to the housing 12, through holes 48 are formed to penetrate in the plate thickness direction on both left and right sides of the printed circuit board 14 in the lateral direction, and connection portions 108 (described later) of each capacitor 16 are inserted into the through holes 48. Further, in a state where the printed circuit board 14 is fixed to the housing 12, press-fit holes 50 are formed to penetrate in the plate thickness direction on both left and right sides of the printed circuit board 14 in the lateral direction, and press-fit portions 104 (described later) of each capacitor 16 are press-fitted into the press-fit holes 50. Each of the through holes 48 is, for example, a substantially circular through hole formed in a size such that the inner peripheral surface of each through hole 48 and the outer peripheral surface of each connection portion 108 do not contact each other when each connection portion 108 is inserted. Each of the press-fit holes 50 is, for example, a substantially oblong through hole. When each press-fit portion 104 is press-fitted, the outer peripheral surface of each press-fit portion 104 is inserted while sliding along the inner peripheral surface of each press-fit hole 50. In Embodiment 1, for each press-fit hole 50 with respect to each press-fit portion 104, either the front-back direction dimension or the left-right direction dimension is slightly smaller, and the other is slightly larger, enabling the above-described press-fit and enabling welding (described later) to be completed.

[0035] These through holes 48 and press-fit holes 50 are respectively formed at positions corresponding to the connection portions 108 and press-fit portions 104 of each capacitor 16. Specifically, as also Figure 9 shown, at a portion of the printed circuit board 14 that holds the negative electrode side electrode 66a of each capacitor 16 (described later), a pair of press-fit holes 50, 50 are provided to be separated from each other in the front-back direction, and a pair of through holes 48, 48 are provided to be separated from each other in the front-back direction. These through holes 48 and press-fit holes 50 are provided to be separated from each other in the left-right direction, and each through hole 48 is provided on the outer side in the left-right direction of each press-fit hole 50. In addition, at a portion of the printed circuit board 14 that holds the positive electrode side electrode 66b of each capacitor 16 (described later), three press-fit holes 50 are provided to be separated from each other in the front-back direction, and a pair of through holes 48, 48 are provided to be separated from each other in the front-back direction. This pair of through holes 48, 48 is provided on both front-back sides and on the outer side in the left-right direction with respect to the three press-fit holes 50.

[0036] Further, as described later, an electrolyte reservoir 118 is disposed at a portion of the printed circuit board 14 that holds the negative electrode side electrodes 66a of the respective capacitors 16. That is, in the printed circuit board 14, a press-fitting hole 52 and a fitting hole 54 are formed to penetrate in the plate thickness direction. The press-fitting leg 130 of the electrolyte reservoir 118 is press-fitted into the press-fitting hole 52, and the fitting legs 132, 132 of the electrolyte reservoir 118 are inserted and fitted into the fitting holes 54. In the first embodiment, one press-fitting leg 130 and a pair of fitting legs 132, 132 are formed in one electrolyte reservoir 118, and one press-fitting hole 52 and a pair of fitting holes 54, 54 are formed at corresponding positions on the printed circuit board 14. Specifically, the press-fitting hole 52 is provided at the center in the front-rear direction of the pair of press-fitting holes 50, 50, and the pair of fitting holes 54, 54 are provided inside the pair of press-fitting holes 50, 50 in the left-right direction.

[0037] In addition, in the first embodiment, the printed circuit board 14 is fixed to the upper housing 20 by screws 56. At multiple locations on the outer peripheral portion of the printed circuit board 14, threaded holes 58 through which the respective screws 56 are inserted are formed to penetrate in the plate thickness direction. Further, at positions on the printed circuit board 14 corresponding to the respective positioning pins 37 of the upper housing 20, positioning holes 60 through which the respective positioning pins 37 are inserted are formed to penetrate in the plate thickness direction. In addition, the respective positioning pins 37 may be press-fitted into the respective positioning holes 60 or may be inserted with a clearance.

[0038] <Capacitor 16> As also Figure 10 , 11 shown, the capacitor 16 is a so-called axial capacitor and has a pair of electrodes 66, 66 (negative electrode side electrode 66a and positive electrode side electrode 66b) on the axial end faces 64, 64 (one end face 64a and the other end face 64b) of the cylindrical body 62. In addition, Figure 4 , 5 shows the side of one end face 64a (negative electrode side electrode 66a) of the capacitor 16. The specific structure inside the capacitor 16 is not limited, but in the first embodiment, the capacitor 16 is an electric double layer capacitor (EDLC) in which an electrolyte 68 is sealed inside.

[0039] More specifically, as Figures 4 to 6As shown, the capacitor 16 includes a substantially cylindrical capacitor housing 70. The capacitor housing 70 is made of metal, and both axial end portions are bent inwardly toward the inner circumferential side. As a result, at both axial end portions of the capacitor housing 70, circular through-holes 72 penetrating in the thickness direction (the central axis direction of the capacitor 16 and the left-right direction) are formed at the central portion. And, the through-holes 72 are covered from the inside by a metal terminal plate 74. The terminal plate 74 is generally circular plate-shaped as a whole, and the inner circumferential portion protrudes toward one side in the plate thickness direction with respect to the outer circumferential portion. That is, the terminal plate 74 has a substantially annular flange-shaped portion 76 at the outer circumferential portion, and a protruding portion 78 that protrudes toward one side in the plate thickness direction with respect to the flange-shaped portion 76 at the inner circumferential portion.

[0040] The terminal plate 74 overlaps with the axial end portion of the capacitor housing 70 from the axial inside. As a result, the portion where the axial end portion of the capacitor housing 70 is bent inwardly toward the inner circumferential side overlaps with the flange-shaped portion 76 which is the outer circumferential portion of the terminal plate 74, and the protruding portion 78 protrudes to the axial outside of the capacitor housing 70 through the through-hole 72. Further, the overlapping portion between the portion where the axial end portion of the capacitor housing 70 is bent inwardly toward the inner circumferential side and the flange-shaped portion 76 of the terminal plate 74 overlaps liquid-tightly with a substantially annular insulating layer 80 made of rubber, synthetic resin, etc. Thereby, electrical insulation between the capacitor housing 70 and the terminal plate 74 can be achieved, and leakage of the electrolytic solution 68 between the capacitor housing 70 and the terminal plate 74 can be prevented.

[0041] In addition, in the capacitor housing 70, at least both axial end faces are covered with a rubber-coated layer 82, and the axial one end face 64a and the other end face 64b of the capacitor 16 are constituted by the rubber-coated layer 82. Further, the rubber-coated layer 82 may be provided, for example, so as to cover substantially the entire outer surface of the capacitor housing 70 including both axial end faces. At the central portions of the axial one end face 64a and the other end face 64b of the rubber-coated layer 82, insertion through-holes 84 penetrating in the thickness direction (the central axis direction of the capacitor 16 and the left-right direction) are formed. And, the protruding portion 78 protruding to the axial outside from the capacitor housing 70 is inserted through the insertion through-hole 84, and the protruding portion 78 protrudes to the axial outside of the rubber-coated layer 82. In short, the through-holes 72 at both axial end portions of the capacitor housing 70 and the insertion through-holes 84 of the rubber-coated layer 82 are aligned and communicated, and through these through-holes 72 and the insertion through-holes 84, the protruding portions 78 of the respective terminal plates 74 protrude to the axial outside and are exposed to the outside.

[0042] Here, although not shown in the figure, inside the capacitor 16, the activated carbon electrode constituting the positive electrode and the activated carbon electrode constituting the negative electrode overlap with a separator, and the activated carbon electrodes and separators constituting these positive and negative electrodes are wound in a spiral shape. In addition, a wire 85 extends from the activated carbon electrode constituting the negative electrode, which is connected to the terminal plate 74 on the side of the axial end face 64a of the capacitor 16. As a result, the terminal plate 74 has a negative charge, and on the axial end face 64a of the capacitor 16, the negative electrode side electrode 66a is formed by the protrusion 78 exposed to the outside. In addition, a wire not shown in the figure extends from the activated carbon electrode constituting the positive electrode, which is connected to the terminal plate 74 on the side of the axial end face 64b of the capacitor 16. As a result, the terminal plate 74 has a positive charge, and on the axial end face 64b of the capacitor 16, the positive electrode side electrode 66b is formed by the protrusion 78 exposed to the outside.

[0043] These negative electrode 66a and positive electrode 66b (in short, the protrusions 78 of the two terminal plates 74) are both circular in the axial direction (left-right direction) of the capacitor 16. The sizes of the negative electrode 66a and the positive electrode 66b are not limited, but in the first embodiment, the negative electrode 66a is a circle larger than the positive electrode 66b in the axial direction (left-right direction) of the capacitor 16. Also, as shown in FIG. Figure 3 , Figure 5 As shown in FIG. 1 , a groove 86 extending elongatedly is provided in the central portion of the negative electrode 66a. The groove 86 has a depth dimension less than the full length of the thickness dimension of the protrusion 78 of the terminal plate 74, and the negative electrode 66a is formed to be thin-walled at the position where the groove 86 is formed. That is, the groove 86 does not penetrate the negative electrode 66a (protrusion 78), and when the capacitor 16 is normal, the electrolyte 68 is prevented from leaking through the groove 86.

[0044] In Embodiment 1, a plurality (three) of groove portions 86 are provided, and each groove portion 86 extends from the center of the negative electrode side electrode 66a toward the outer peripheral side. In particular, in Embodiment 1, the three groove portions 86 are provided at substantially equal intervals (every 120°) in the circumferential direction. Thereby, the strength of the negative electrode side electrode 66a is weakened particularly in the central portion, and when gas is generated inside and the internal pressure rises when the capacitor 16 is abnormal, the central portion of the negative electrode side electrode 66a preferentially breaks. As a result, the internal space and the external space of the capacitor 16 communicate with each other, and the internal gas is released. A gas discharge valve 88 for discharging the gas generated during abnormality is provided in the negative electrode side electrode 66a. Therefore, the gas discharge valve 88 is configured to include each groove portion 86. In addition, the thickness dimensions of the respective protruding portions 78 constituting the negative electrode side electrode 66a and the positive electrode side electrode 66b are not limited. For example, by forming the negative electrode side electrode 66a to be thinner than the positive electrode side electrode 66b, when the capacitor 16 is abnormal, the central portion of the negative electrode side electrode 66a further preferentially breaks, and the gas discharge valve 88 becomes an open state.

[0045] <Metal flat plate 90> A metal flat plate 90 is electrically conductively fixed to each electrode 66. That is, as Figure 10 shown, a negative electrode side flat plate 90a constituting the metal flat plate 90 is fixed to the negative electrode side electrode 66a, and, as Figure 11 shown, a positive electrode side flat plate 90b constituting the metal flat plate 90 is fixed to the positive electrode side electrode 66b. These negative electrode side flat plate 90a and positive electrode side flat plate 90b are formed of, for example, aluminum (including aluminum alloy) or copper (including copper alloy) having excellent conductivity. In Embodiment 1, the negative electrode side flat plate 90a and the positive electrode side flat plate 90b are formed by bending a substantially rectangular metal blank into a predetermined shape. The length direction of these negative electrode side flat plate 90a and positive electrode side flat plate 90b refers to the long side direction of the metal blank before bending, and in the state where the negative electrode side flat plate 90a and the positive electrode side flat plate 90b are respectively fixed to the negative electrode side electrode 66a and the positive electrode side electrode 66b, it is the front-rear direction which is one of the directions orthogonal to the central axis direction (left-right direction) of the capacitor 16.

[0046] <Negative electrode side flat plate 90a> In the negative electrode side flat plate 90a, the central portion in the length direction (front-rear direction) constitutes a welding portion 92a that is welded to the electrode 66 (negative electrode side electrode 66a) so as to overlap the electrode 66. In addition, in the negative electrode side flat plate 90a, both side portions in the length direction constitute a pair of protruding plate portions 94a, 94a that are bent in the plate thickness direction (left-right direction) and protrude outward in the axial direction of the cylindrical body 62. Therefore, the pair of protruding plate portions 94a, 94a extend in the left-right direction and are provided separately from each other in the front-rear direction.

[0047] Specifically, asFigure 3 , Figure 10 As shown in Figure 10 , the welded portion 92a of the negative electrode side flat plate 90a is substantially circular ring-shaped, and is inserted into the negative electrode side electrode 66a that protrudes outward in the axial direction in the capacitor 16. That is, a circular through-hole 96 penetrating in the plate thickness direction (left-right direction) is formed in the central portion of the welded portion 92a, and the outer peripheral surface of the negative electrode side electrode 66a and the inner peripheral surface of the through-hole 96 overlap in the radial direction. And, by welding these overlapping surfaces in the radial direction, the negative electrode side flat plate 90a and the negative electrode side electrode 66a are fixedly attached to each other. In addition, the welded portion 92a of the negative electrode side flat plate 90a may overlap with the rubber coating layer 82 located on the inner side in the axial direction in the axial direction, or may replace the welding of the negative electrode side electrode 66a, or on this basis, the negative electrode side flat plate 90a and the rubber coating layer 82 may be bonded. In Embodiment 1, the welded portion 92a of the negative electrode side flat plate 90a is disposed around the gas discharge valve 88 provided in the negative electrode side electrode 66a.

[0048] In addition, in the metal base plate constituting the negative electrode side flat plate 90a, each protruding plate portion 94a is formed by bending the portions on both sides in the length direction of the substantially circular ring-shaped welded portion 92a outward in the axial direction. That is, each protruding plate portion 94a is connected to the front and rear end portions of the welded portion 92a via a concave bending portion, and this concave bending portion extends in the up-down direction, and in short, extends toward the lower printed circuit board 14 side. And, as will be described later, the concave bending portion extending toward the printed circuit board 14 side constitutes a guiding groove 98 for guiding the electrolytic solution 68 when the electrolytic solution 68 leaks from the gas discharge valve 88 when the capacitor 16 is abnormal. In other words, the pair of concave bending portions connecting the metal flat plate 90 (negative electrode side flat plate 90a) and the pair of protruding plate portions 94a, 94a constitute the guiding grooves 98, 98 extending toward the printed circuit board 14 side.

[0049] In Embodiment 1, each protruding plate portion 94a of the negative electrode side flat plate 90a has the same shape as each other, and is substantially rectangular. Specifically, each protruding plate portion 94a of the negative electrode side flat plate 90a includes: an extending portion 100 that extends outward in the axial direction from the front and rear end portions of the welded portion 92a via a concave bending portion (each guiding groove 98); and a downward protruding portion 102 that protrudes downward from the extending end portion (outer end portion in the axial direction) of each extending portion 100. Therefore, each guiding groove 98 is formed in the portion of each extending portion 100 that is connected to the front and rear end portions of the welded portion 92a.

[0050] That is, each of the lower protruding portions 102 is not directly connected to the front and rear ends of the welding portion 92a in the front-rear direction, but is connected via each extension portion 100. The front and rear ends of each lower protruding portion 102 and the welding portion 92a are separated from each other in the axial direction (left-right direction) of the capacitor 16. In other words, in the case of assuming a protruding plate portion in which the lower protruding portion is directly connected to the front and rear ends of the welding portion 92a, by providing a cutout portion 103 that opens downward in the inner portion in the front-rear direction of the protruding plate portion, a lower protruding portion 102 separated from the extension portion 100 and the welding portion 92a is formed in each protruding plate portion 94a. In addition, as will be described later, a connecting portion 108 is provided in each lower protruding portion 102. Therefore, the connecting portion 108 and the cutout portion 103 are provided in each protruding plate portion 94a, and the cutout portion 103 separates each guide groove 98 and the connecting portion 108 in the axial direction (left-right direction).

[0051] At the lower end of each lower protruding portion 102, there are provided: a press-fitting portion 104 that is press-fitted into the press-fitting hole 50 of the printed circuit board 14; and a connecting portion 108 that is inserted through the through-hole 48 of the printed circuit board 14 and is electrically connected by solder 106 (illustrated by a double-dashed line in Figures 4 to 6 ). In addition, a stopper portion 110 is provided at the lower end of each lower protruding portion 102. The stopper portion 110 is placed on the printed circuit board 14 and defines the insertion amount of each connecting portion 108 into the through-hole 48. And by press-fitting each press-fitting portion 104 into each press-fitting hole 50, each capacitor 16 is fixedly held on the printed circuit board 14. In addition, in Embodiment 1, each press-fitting portion 104 press-fitted into each press-fitting hole 50 is also brazed, and each capacitor 16 is held on the printed circuit board 14 more firmly. The cross-sectional shapes of these press-fitting portions 104, connecting portions 108, and stopper portions 110 are not limited, but in Embodiment 1, the cross-sectional shapes of the press-fitting portions 104, connecting portions 108, and stopper portions 110 are all substantially rectangular.

[0052] In addition, in Embodiment 1, each of the press-fitting portions 104, connecting portions 108, and stopper portions 110 is provided in each of the protruding plate portions 94a that are separated from each other in the front-rear direction. Therefore, in the negative electrode side flat plate 90a, a pair of press-fitting portions 104, 104 are provided so as to be separated from each other in the front-rear direction, and a pair of connecting portions 108, 108 are provided so as to be separated from each other in the front-rear direction. Both the pair of press-fitting portions 104, 104 and the pair of connecting portions 108, 108 protrude downward toward the printed circuit board 14 side. In addition, in the negative electrode side flat plate 90a, a pair of stopper portions 110, 110 are provided so as to be separated from each other in the front-rear direction and protrude downward toward the printed circuit board 14 side.

[0053] At the lower end of each lower protrusion 102, the press-in portion 104, the connection portion 108, and the stopper portion 110 are separated from each other in the plate width direction (left - right direction) of the lower protrusion 102. The arrangement of the press-in portion 104, the connection portion 108, and the stopper portion 110 at the lower end of each lower protrusion 102 is not limited. However, in Embodiment 1, the press-in portion 104 is provided at the inner end in the left - right direction of each lower protrusion 102. In addition, the stopper portion 110 is provided at the outer end in the left - right direction of each lower protrusion 102, and the connection portion 108 is provided separately from the press-in portion 104 and the stopper portion 110 at the middle portion in the left - right direction of each lower protrusion 102.

[0054] And, as Figure 4 , 5 shown, in the state where each stopper portion 110 is placed on the printed circuit board 14, the portion between the stopper portion 110 and the connection portion 108 at the lower end of each lower protrusion 102 is separated upward with respect to the printed circuit board 14. In addition, in the state where each stopper portion 110 is placed on the printed circuit board 14, the portion between the connection portion 108 and the press-in portion 104 at the lower end of each lower protrusion 102 is separated upward with respect to the printed circuit board 14. That is, in the state where each stopper portion 110 is placed on the printed circuit board 14, a gap 112 that expands upward is formed around each connection portion 108. The gap 112 is, for example, a gap between the connection portions 108 and the stopper portions 110 arranged in the left - right direction. In addition, in the state where each stopper portion 110 is placed on the printed circuit board 14, a gap 114 that expands upward is formed around each press-in portion 104. The gap 114 is, for example, a gap between the connection portions 108 and the press-in portions 104 arranged in the left - right direction.

[0055] <Positive - side flat plate 90b> The structure of the positive - side flat plate 90b is basically the same as that of the negative - side flat plate 90a. The central portion in the length direction (front - rear direction) constitutes a welding portion 92b that is welded to the electrode 66 (positive - side electrode 66b) so as to overlap with the electrode 66. In addition, in the positive - side flat plate 90b, the two side portions in the length direction constitute a pair of protruding plate portions 94b, 94b that are bent in the plate thickness direction (left - right direction) and protrude outward in the axial direction of the cylindrical body 62. Therefore, the pair of protruding plate portions 94b, 94b expand in the left - right direction and are provided separately from each other in the front - rear direction.

[0056] Specifically, as Figure 3 , Figure 11As shown, the welded portion 92b of the positive electrode side flat plate 90b is also substantially circular-ring-shaped, similar to the negative electrode side flat plate 90a, and is externally inserted into the positive electrode side electrode 66b that protrudes outward in the axial direction of the capacitor 16. That is, a circular through-hole 96 that penetrates in the plate thickness direction (left-right direction) is also formed in the central portion of the welded portion 92b, and the outer peripheral surface of the positive electrode side electrode 66b and the inner peripheral surface of the through-hole 96 overlap in the radial direction. And by welding these overlapping surfaces in the radial direction to each other, the positive electrode side flat plate 90b and the positive electrode side electrode 66b are fixedly installed to each other. In addition, in the welded portion 92b of the positive electrode side flat plate 90b, it can overlap with the covering rubber layer 82 located on the inner side in the axial direction in the axial direction, or instead of welding the positive electrode side electrode 66b, or on this basis, the positive electrode side flat plate 90b and the covering rubber layer 82 can be bonded.

[0057] In addition, in the metal base plate constituting the positive electrode side flat plate 90b, a substantially rectangular portion is continuously provided in the substantially circular-ring-shaped welded portion 92b, and each protruding plate portion 94b is formed by bending both end portions in the length direction of the substantially rectangular portion outward in the axial direction. That is, the middle portion in the length direction of the substantially rectangular portion is not bent but continuously extends from the welded portion 92b to form the middle plate portion 116. In a state where the positive electrode side flat plate 90b is fixedly installed on the positive electrode side electrode 66b, the middle plate portion 116 is provided to protrude downward from the welded portion 92b, and each protruding plate portion 94b is connected to both end portions in the front-rear direction of the middle plate portion 116 via a concave bending portion.

[0058] A press-fitting portion 104 is provided at the lower end portion of the middle plate portion 116, and the press-fitting portion 104 is press-fitted into the press-fitting hole 50 of the printed circuit board 14. In Embodiment 1, three press-fitting portions 104 are provided at the lower end portion of the middle plate portion 116, and the respective press-fitting portions 104 are separated from each other in the plate width direction (front-rear direction) of the middle plate portion 116 and are provided to protrude downward toward the printed circuit board 14 side.

[0059] In addition, in Embodiment 1, the respective protruding plate portions 94b of the positive electrode side flat plate 90b also have the same shape as each other and are each substantially rectangular. In addition, the respective protruding plate portions 94b of the positive electrode side flat plate 90b do not have the extension portion 100 (notch portion 103) like the respective protruding plate portions 94a of the negative electrode side flat plate 90a, and lower protruding portions 102 are connected to both end portions in the front-rear direction of the middle plate portion 116 via a concave bending portion. That is, in the positive electrode side flat plate 90b, each protruding plate portion 94b is constituted by each lower protruding portion 102.

[0060] And a connection part 108 is provided at the lower end of the lower protruding part 102 below the positive electrode side flat plate 90b. The connection part 108 is inserted into the through hole 48 of the printed circuit board 14 and electrically connected by solder 106. In addition, a stopper part 110 is provided at the lower end of each lower protruding part 102. The stopper part 110 is placed on the printed circuit board 14 to define the insertion amount of each connection part 108 into the through hole 48. In the positive electrode side flat plate 90b, the cross-sectional shapes of each press-in part 104, each connection part 108, and each stopper part 110 are also substantially rectangular. Since the protruding plate parts 94b are separated from each other in the front-rear direction, the connection parts 108 and the stopper parts 110 provided on the protruding plate parts 94b are also separated from each other in the front-rear direction and are provided to protrude downward toward the printed circuit board 14 side.

[0061] The arrangement of the connection part 108 and the stopper part 110 at the lower end of each lower protruding part 102 is not limited. However, in Embodiment 1, the stopper parts 110 are provided at both ends in the left-right direction of each lower protruding part 102. In addition, in the middle part in the left-right direction of each lower protruding part 102, the connection part 108 is provided separately from the stopper parts 110 on both sides.

[0062] And in the positive electrode side flat plate 90b, similar to the negative electrode side flat plate 90a, when each stopper part 110 is placed on the printed circuit board 14, the part between the press-in parts 104 at the lower end of the intermediate plate part 116 is separated upward with respect to the printed circuit board 14. In addition, when each stopper part 110 is placed on the printed circuit board 14, the part between each stopper part 110 and each connection part 108 at the lower end of each lower protruding part 102 is separated upward with respect to the printed circuit board 14. That is, even in the positive electrode side flat plate 90b, when each stopper part 110 is placed on the printed circuit board 14, a gap 112 that expands upward is also formed around each connection part 108. The gap 112 is, for example, a gap between the connection parts 108 and the stopper parts 110 arranged in the left-right direction. In addition, when each stopper part 110 is placed on the printed circuit board 14, a gap 114 that expands upward is formed around each press-in part 104. The gap 114 is, for example, a gap between the press-in parts 104 arranged in the front-rear direction.

[0063] <Electrolyte container 118> An electrolyte reservoir 118 is disposed on the printed circuit board 14. The electrolyte reservoir 118 is located below the gas discharge valve 88 and each guiding groove 98, and stores the electrolyte 68 that oozes out from the gas discharge valve 88. That is, the electrolyte reservoir 118 is provided on one end face 64a (negative electrode side electrode 66a) side of the capacitor 16 on the printed circuit board 14. In the first embodiment, since three capacitors 16 are provided, three electrolyte reservoirs 118 are provided. In particular, in the first embodiment, as described above, among the three capacitors 16, the middle capacitor 16 has the negative electrode side electrode 66a and the positive electrode side electrode 66b arranged in the reverse direction with respect to the capacitors 16 on both sides. Therefore, the middle electrolyte reservoir 118 is arranged on the opposite side in the left-right direction with respect to the electrolyte reservoirs 118 on both sides. Thus, for example, even when the electrolyte reservoir has a horizontally long shape in which the dimension in the front-rear direction is larger than the dimension in the left-right direction, interference between adjacent electrolyte reservoirs can be avoided.

[0064] As Figure 12 shown, the electrolyte reservoir 118 is generally in the shape of a substantially rectangular box that opens upward, and is formed of, for example, synthetic resin. The electrolyte reservoir 118 includes a bottom wall 120 and a peripheral wall 122 that projects upward from the outer peripheral edge portion of the bottom wall 120. The peripheral wall 122 is configured to include an outer side wall portion 124 that is located outside the axial direction (left-right direction) of the capacitor 16 in a state where the capacitor 16 and the electrolyte reservoir 118 are assembled to the printed circuit board 14, an inner side wall portion 126 that is located inside the axial direction of the capacitor 16, and a pair of side wall portions 128, 128 that connect the outer side wall portion 124 and the inner side wall portion 126. That is, the pair of side wall portions 128, 128 face each other at a predetermined distance in the front-rear direction.

[0065] In addition, a recess 129 is formed at the upper end portion of the inner side wall portion 126. The recess 129 is used to avoid interference with the cylindrical main body 62 of the capacitor 16. In the first embodiment, the recess 129 has a curved shape corresponding to the outer peripheral surface of the cylindrical main body 62, but may be, for example, a rectangular recess. In addition, in the first embodiment, the curvature of the inner peripheral surface (upper end surface) of the recess 129 is substantially equal to the curvature of the outer peripheral surface of the cylindrical main body 62. As will be described later, when each capacitor 16 and each electrolyte reservoir 118 are assembled to the printed circuit board 14, the inner peripheral surfaces of the respective recesses 129 are in contact with the outer peripheral surfaces of the respective cylindrical main bodies 62 over substantially the entire surface. In addition, the curvature of the inner peripheral surface of the recess may be less than the curvature of the outer peripheral surface of the cylindrical main body 62, for example. In addition, when each capacitor 16 and each electrolyte reservoir 118 are assembled to the printed circuit board 14, the inner peripheral surfaces of the respective recesses 129 may not be in contact with the outer peripheral surfaces of the respective cylindrical main bodies 62, or such recesses 129 may not be provided.

[0066] Further, press-in legs 130 are provided at the center in the front-rear direction and the outer end portions in the left-right direction on the lower surface of the bottom wall 120, and the press-in legs 130 are press-fitted into the press-in holes 52 of the printed circuit board 14. Further, fitting legs 132 are provided at both end portions in the front-rear direction and the inner end portions in the left-right direction on the lower surface of the bottom wall 120, and the fitting legs 132 are inserted and fitted into the fitting holes 54 of the printed circuit board 14.

[0067] Specifically, the lower portion of the press-in leg 130 is an insertion portion 134 that is inserted into the press-in hole 52 in a press-fitted state, and the upper portion of the press-in leg 130 is a large-diameter portion 136 whose shape is larger than that of the press-in hole 52. When the press-in leg 130 is press-fitted into the press-in hole 52, the insertion portion 134 is inserted into the press-in hole 52 in a press-fitted state, and the large-diameter portion 136 abuts against the peripheral portion of the press-in hole 52 on the upper surface of the printed circuit board 14, thereby restricting further press-fitting of the press-in leg 130 into the press-in hole 52.

[0068] In addition, each fitting leg 132 is configured to include an outer portion 138 and an inner portion 140 that are opposed to each other at a predetermined distance in the front-rear direction, and the outer portion 138 and the inner portion 140 can be elastically deformed in directions approaching or separating from each other. A locking claw 142 protruding outward in the front-rear direction is provided at the lower end portion of each outer portion 138. Each fitting leg 132 can be inserted into each fitting hole 54 in a state where each outer portion 138 and each inner portion 140 are close to each other. In addition, when the locking claw 142 of each outer portion 138 passes through each fitting hole 54, each outer portion 138 and each inner portion 140 are elastically restored to the initial state, and the locking claw 142 is locked to the peripheral portion of each fitting hole 54 on the lower surface of the printed circuit board 14, thereby preventing each fitting leg 132 from falling off from each fitting hole 54.

[0069] <Assembly process of the power supply unit 10> Next, a specific example of the assembly process of the power supply unit 10 will be described. In addition, the assembly process of the power supply unit 10 is not limited to the following description.

[0070] First, the connector 44 is arranged on the printed circuit board 14, and the circuit on the printed circuit board 14 and the connector 44 are electrically connected. In addition, each press-in leg 130 of each electrolyte container 118 is press-fitted into each press-in hole 52 of the printed circuit board 14, and each fitting leg 132 is inserted and fitted into each fitting hole 54. Thus, the three electrolyte containers 118 are fixed to the printed circuit board 14.

[0071] Then, each press-fitting portion 104 of each capacitor 16 is press-fitted into each press-fitting hole 50 of the printed circuit board 14, and each connecting portion 108 is inserted into each through hole 48. The press-fitting of each press-fitting portion 104 and the insertion of each connecting portion 108 are performed until each stopper portion 110 of each capacitor 16 abuts against and is placed on the upper surface of the printed circuit board 14. By press-fitting each press-fitting portion 104 into each press-fitting hole 50, each capacitor 16 is fixedly held on the printed circuit board 14. Next, solder 106 is injected between each press-fitting hole 50 and each press-fitting portion 104 and between each through hole 48 and each connecting portion 108 to solder each press-fitting hole 50 and each press-fitting portion 104, and to solder each through hole 48 and each connecting portion 108. In addition, as this soldering process, a conventionally well-known soldering process such as reflow soldering can be adopted.

[0072] Next, as described above, the printed circuit board 14 equipped with the connector 44, each electrolyte container 118, and each capacitor 16 is fixed to the upper housing 20 by the screw 56. At this time, the printed circuit board 14 that is also turned upside down can be overlapped with the opening portion of the upper housing 20 that is turned upside down and opened upward, and can be screw-fixed from above.

[0073] Then, the lower housing 18 is brought close to the upper housing 20 to which the printed circuit board 14 is fixed, and each engaging projection 42 of the upper housing 20 is engaged with each engaging frame 26 in the lower housing 18, thereby fixing the upper housing 20 and the lower housing 18. Thus, the power supply unit 10 is completed.

[0074] In the power supply unit 10 assembled through the above-described process, as Figure 4 , 5 shown, the outer peripheral portion of the printed circuit board 14 is clamped and supported in the vertical direction by the upper abutting portion 34 of the upper housing 20 and the lower abutting portion 28 of the lower housing 18. In addition, as Figure 5 , 6 shown, the end portion on the side of the axial one end face 64a (negative electrode side electrode 66a) of each capacitor 16 is inserted into the recess 129 provided in the inner side wall portion 126 of each electrolyte container 118, and the inner peripheral surface of each recess 129 and the outer peripheral surface of each cylindrical main body 62 abut against each other with a predetermined circumferential dimension. Thus, each capacitor 16 is also clamped in the vertical direction between each recess 129 of each electrolyte container 118 and each recess 40 of the upper supporting portion 38 provided in the upper housing 20. Therefore, each capacitor 16 can also be fixedly held on the printed circuit board 14 by the housing 12 (upper housing 20 and lower housing 18).

[0075] According to the power supply unit 10 related to Embodiment 1, a negative-side flat plate 90a and a positive-side flat plate 90b are fixedly mounted on the negative-side electrode 66a and the positive-side electrode 66b of each capacitor 16, respectively, and these negative-side flat plates 90a and positive-side flat plates 90b each have a press-fitting portion 104. Further, by press-fitting each press-fitting portion 104 into each press-fitting hole 50 of the printed circuit board 14, each capacitor 16 is fixedly held on the printed circuit board 14. In particular, the negative-side flat plate 90a has a downward protruding portion 102 protruding downward, and the positive-side flat plate 90b has an intermediate plate portion 116 protruding downward, and each press-fitting portion 104 is provided at the lower ends of these downward protruding portion 102 and intermediate plate portion 116. Thus, each capacitor 16 is held in a state of being separated upward from the printed circuit board 14, and each capacitor 16 can be fixed to the printed circuit board 14 without a holding member made of synthetic resin or the like, and electrical insulation between each capacitor case 70 and the printed circuit board 14 can also be achieved.

[0076] In particular, in Embodiment 1, since the negative-side flat plate 90a and the positive-side flat plate 90b each have a press-fitting portion 104, each capacitor 16 can be fixed to the printed circuit board 14 by each press-fitting portion 104 on both axial sides. Thus, for example, when only one axial side of the capacitor is fixed to the printed circuit board, the end portion on the unfixed side of the capacitor may vibrate due to vehicle vibration or the like. However, the structure of Embodiment 1 can reduce the possibility of such a situation occurring and can stably fix each capacitor 16 to the printed circuit board 14.

[0077] The negative-side flat plate 90a and the positive-side flat plate 90b each have a stopper portion 110, and a gap 112 expanding upward is formed around each connection portion 108 in a state where each stopper portion 110 is placed on the printed circuit board 14. Similarly, a gap 114 expanding upward is formed around each press-fitting portion 104 in a state where each stopper portion 110 is placed on the printed circuit board 14. Thus, when brazing each connection portion 108 and each press-fitting portion 104 to the printed circuit board 14, the completion of brazing can be promoted, and after the brazing process, the completion of brazing can be visually confirmed from the outside.

[0078] The negative-side flat plate 90a has a welding portion 92a at the central portion in the longitudinal direction, and has projecting plate portions 94a, 94a projecting outward in the axial direction of the cylindrical body 62 at both side portions in the longitudinal direction. That is, the negative-side flat plate 90a has a pair of projecting plate portions 94a, 94a separated from each other in the front-rear direction, and each projecting plate portion 94a has a press-fitting portion 104. Therefore, on the negative-side electrode 66a side of each capacitor 16, it is supported by the printed circuit board 14 at two points separated in the front-rear direction through the respective press-fitting portions 104, so that the holding force of each capacitor 16 on the printed circuit board 14 can be improved. In particular, the positive-side flat plate 90b has the respective press-fitting portions 104 at the central portion in the longitudinal direction. Thus, in the projection in the up-down direction, each capacitor 16 is held on the printed circuit board 14 at three points separated from each other in the front-rear direction and the left-right direction, and a further improvement in the holding force can be achieved.

[0079] In addition, the positive-side flat plate 90b also has a welding portion 92b at the central portion in the longitudinal direction, and has projecting plate portions 94b, 94b projecting outward in the axial direction of the cylindrical body 62 at both side portions in the longitudinal direction. And, in both the negative-side flat plate 90a and the positive-side flat plate 90b, the respective projecting plate portions 94a, 94b each have a stopper portion 110. Thus, at four locations separated in the left-right direction and the front-rear direction, the respective stopper portions 110 are placed on the printed circuit board 14, so that the possibility that each capacitor 16 is held on the printed circuit board 14 in an inclined manner can be reduced. In particular, in Embodiment 1, in both the negative-side flat plate 90a and the positive-side flat plate 90b, connection portions 108 are provided near the respective stopper portions 110. Thus, it is possible to prevent the respective connection portions 108 from being inserted into the respective through holes 48 in an inclined manner, and the respective connection portions 108 and the printed circuit board 14 can be stably electrically connected.

[0080] A gas discharge valve 88 is provided at one axial end face 64a (negative-side electrode 66a) of each capacitor 16, and the gas discharge valve 88 discharges the gas generated when each capacitor 16 is abnormal. Thus, it is possible to prevent each capacitor 16 from being damaged by the gas generated during an abnormality. Here, when the gas is discharged, the gas discharge valve 88 is in an open state, so there is a possibility that the electrolytic solution 68 oozes out through the gas discharge valve 88. The electrolytic solution 68 oozing out through the gas discharge valve 88 leaks along the negative-side flat plate 90a, but by providing a guide groove 98 for guiding the electrolytic solution 68 in the negative-side flat plate 90a and providing a cutout portion 103 in each projecting plate portion 94a, the guide groove 98 is provided separately from the connection portion 108 in the axial direction (left-right direction) of the capacitor 16. Therefore, the electrolytic solution 68 is guided along the respective guide grooves 98 of the negative-side flat plate 90a to a position different from the connection portion 108, so that it is possible to avoid a malfunction such as poor conduction of the electrical connection portion (connection portion 108) between the negative-side flat plate 90a and the printed circuit board 14 due to the leaked electrolytic solution 68.

[0081] In particular, in Embodiment 1, an electrolyte reservoir 118 is provided on the printed circuit board 14. The electrolyte reservoir 118 is located below the gas discharge valve 88 and each guiding groove 98, and stores the electrolyte 68 that leaks from the gas discharge valve 88. Therefore, as Figure 3 、 Figure 5 indicated by the hollow arrows in the figure, the electrolyte 68 that leaks vertically downward from the gas discharge valve 88 and the electrolyte 68 that flows along each guiding groove 98 are received by the electrolyte reservoir 118, preventing it from flowing out onto the printed circuit board 14. As a result, it is also possible to avoid the leaked electrolyte 68 flowing on the printed circuit board 14 and reaching the connection portion 108, which may cause problems such as conduction failure.

[0082] <Modification Example> As described above, as a specific example of the present invention, Embodiment 1 has been described in detail. However, the present invention is not limited to this specific description. Modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention. For example, the modification examples of the following embodiments are also included in the technical scope of the present invention.

[0083] (1) In the above embodiment, each press-fitting portion 104 is provided on the negative electrode side flat plate 90a, and each press-fitting portion 104 is also provided on the positive electrode side flat plate 90b. However, the present invention is not limited to this configuration. For example, when one end face (negative electrode side electrode) side of the capacitor is supported by the electrolyte reservoir or other components support one end in the axial direction, or when sufficient fixing force is obtained by press-fitting in one axial direction, etc., the press-fitting portion may be provided only on either the negative electrode side flat plate or the positive electrode side flat plate.

[0084] (2) In the above-described embodiment, a pair of protruding plate portions 94a, 94a protruding axially outward are provided on the negative electrode side flat plate 90a, and a pair of protruding plate portions 94b, 94b protruding axially outward are provided on the positive electrode side flat plate 90b. However, the protruding plate portions may not be provided on the metal flat plate. For example, a metal flat plate extending straight in the front-rear direction may be provided, and press-in portions, connection portions, and stopper portions protruding downward may be provided at both end portions in the length direction and the central portion in the length direction of the metal flat plate. Even when the protruding plate portions are provided on the metal flat plate, the protruding plate portions may be provided only on one side in the length direction of the metal flat plate. Moreover, even when the press-in portions are provided on the protruding plate portions, the number of the press-in portions is not limited, and one or more press-in portions may be provided. That is, there is no limitation on the shape of the metal flat plate and the arrangement manner of the connection portions, press-in portions, and stopper portions provided on the metal flat plate, as long as at least one connection portion is provided on the metal flat plates provided on both sides of each electrode, and at least one press-in portion is provided on at least one of the metal flat plates provided on both sides of each electrode. In addition, the metal flat plate is not limited to a manner having through holes inserted into each electrode, and a plurality of metal flat plates may be conductively fixed to each electrode respectively.

[0085] (3) In the above-described embodiment, an intermediate plate portion 116 is provided at the central portion in the length direction of the positive electrode side flat plate 90b, and each press-in portion 104 protruding downward is provided on the intermediate plate portion 116. In addition, each protruding plate portion 94b is provided at both end portions in the length direction of the positive electrode side flat plate 90b, and a connection portion 108 protruding downward is provided on each of these protruding plate portions 94b. However, the press-in portions and the connection portions may be provided conversely. That is, the connection portion may protrude downward from the lower end portion of the intermediate plate portion, which is the central portion in the length direction of the positive electrode side flat plate, toward the printed circuit board, and the press-in portion may protrude downward from the lower end portion of each protruding plate portion toward the printed circuit board. In this way, the connection portion may be provided to protrude from the lower end portion of the central portion in the length direction of the metal flat plate (for example, the positive electrode side flat plate 90b) toward the printed circuit board. Thereby, the connection portion can be provided at a position closer to the electrode (for example, the positive electrode side electrode 66b), and an improvement in conduction efficiency can be achieved. In addition, by adopting the same shape for the positive electrode side flat plate and the negative electrode side flat plate, protruding plate portions are provided on both side portions in the length direction of the positive electrode side flat plate, and press-in portions are provided on each of the protruding plate portions, so that the capacitors can be held at four positions separated from each other in the length direction (left-right direction) and the direction orthogonal to the length direction (front-rear direction) on the printed circuit board. Thereby, the capacitors can be held on the printed circuit board more stably. In addition, similar to the positive electrode side flat plate, at least one of the press-in portion, the connection portion, and the stopper portion may protrude downward from the lower end portion of the welding portion, which is the central portion in the length direction of the negative electrode side flat plate, toward the printed circuit board.

[0086] (4) In the described embodiment, a plurality (three) of capacitors 16 are provided, but at least one capacitor may be provided. Even when a plurality of capacitors are provided, not all of the capacitors need to be axial type, as long as at least one is axial type and the structure of the present invention is applicable.

[0087] (5) The capacitor is not limited to the electric double layer capacitor (EDLC) as in the described embodiment, and known capacitors such as aluminum electrolytic capacitors, thin film capacitors, and tantalum electrolytic capacitors can be used. The capacitor is not limited to the type enclosing an electrolytic solution, and may also be a solid electrolytic capacitor using a solid electrolyte.

[0088] (6) In the described embodiment, a gas discharge valve 88 is provided on the negative electrode side electrode 66a, but the gas discharge valve may also be provided on the positive electrode side electrode. In this case, the electrolytic solution container can be provided on the positive electrode side electrode side. In addition, the structure of the gas discharge valve is not limited. In the described embodiment, the groove portion 86 constituting the gas discharge valve 88 is configured in a three-pronged shape, but the configuration of the groove portion is not limited. For example, it may be in a linear shape or a cross shape, or may extend radially from the center in five or more directions toward the periphery. Further, in the described embodiment, one electrolytic solution container 118 is provided for one capacitor 16, but for example, the negative electrode side electrodes of three capacitors may be aligned in one direction of the left-right direction, and one electrolytic solution container covering the end portions on the negative electrode side electrode side of the three capacitors may be provided. In addition, in the power supply unit of the present invention, the electrolytic solution container is not essential.

[0089] (7) In the described embodiment, the housing 12 (the upper housing 20 and the lower housing 18) is made of synthetic resin, and the upper housing 20 and the lower housing 18 are fixed by the engagement of the engagement protrusion 42 and the engagement frame 26, but it is not limited to this method. That is, the upper housing and the lower housing may be made of metal, and in this case, the upper housing and the lower housing can be fixed by bolts, for example. Description of Reference Numerals

[0090] 10 Power supply unit 12 Housing 14 Printed circuit board 16 Capacitor 18 Lower housing 20 Upper housing 22 Bottom wall portion 24 Lower peripheral wall portion 26 Engagement frame 28 Lower abutting portion 30 Upper bottom wall portion 32 Upper peripheral wall portion 34 Upper abutting portion 36 Threaded hole 37 Positioning pin 38 Upper support part 40 Recess 42 Engaging projection 44 Connector 46 Opening 48 Through hole 50 Press-fitting hole 52 Hole for press-fitting 54 Fitting hole 56 Screw 58 Threaded hole 58 60 Positioning hole 62 Cylindrical body 64 Axial end face 64a One end face 64b The other end face 66 Electrode 66a Negative electrode side electrode 66b Positive electrode side electrode 68 Electrolyte 70 Capacitor housing 72 Through hole 74 Terminal board 76 Flange-like part 78 Protrusion 80 Insulation layer 82 Rubber coating layer 84 Insertion through hole 85 Lead wire 86 Groove part 88 Gas discharge valve 90 Metal flat plate 90a Negative electrode side flat plate 90b Positive electrode side flat plate 92a, 92b Welding part 94a, 94b Protruding plate part 96 Through hole 98 Guide groove (concave bent part) 100 Extension part 102 Lower protrusion 103 Notch part 104 Press-fitting part 106 Solder 108 Connection part 110 Stopping part 112, 114 Gap 116 Intermediate plate part 118 Electrolyte container 120 Bottom wall 122 Peripheral wall 124 Outer wall portion 126 Inner wall portion 128 Lateral wall portion 129 Recess 130 Pressing leg 132 Fitting leg 134 Insertion portion 136 Large-diameter portion 138 Outer portion 140 Inner portion 142 Locking claw

Claims

1. A power supply unit includes a printed circuit board housed in a housing and a capacitor mounted on the printed circuit board. Among them, the capacitor has a pair of electrodes on axially opposite end faces of a cylindrical body, metal plates are fixedly mounted on each of the electrodes in a conductively connected manner, each of the metal plates has a connecting portion, and the connecting portion is inserted into and brazed to a through hole of the printed circuit board, at least one of the metal plates has a press-fitting portion, and the press-fitting portion is press-fitted into a press-fitting hole of the printed circuit board, by press-fitting the press-fitting portion into the press-fitting hole, the capacitor is fixedly held on the printed circuit board.

2. The power supply unit according to claim 1, wherein, Each of the metal plates has the press-fitting portion respectively.

3. The power supply unit according to claim 1 or claim 2, wherein Each of the metal plates has a stopper portion, the stopper portion is placed on the printed circuit board, and the insertion amount of the connecting portion into the through hole is defined. In a state where the stopper portion is placed on the printed circuit board, a gap extending upward is formed around the connecting portion.

4. The power supply unit according to claim 3, wherein The press-fitting portion press-fitted into the press-fitting hole is brazed, and in a state where the stopper portion is placed on the printed circuit board, a gap extending upward is formed around the press-fitting portion.

5. The power supply unit according to any one of claims 1 to 4, wherein, In the metal plate having the press-fitting portion, a central portion in the length direction forms a welding portion that is welded overlapping the electrode, and both side portions in the length direction form a pair of protruding plate portions that are bent in the plate thickness direction and protrude outward in the axial direction of the cylindrical body. The press-fitting portions are respectively provided to protrude from lower end portions of the pair of protruding plate portions toward the printed circuit board, and each of the press-fitting portions is press-fitted into the press-fitting hole.

6. The power supply unit according to any one of claims 1 to 5, wherein, Each of the metal plates has a stopper portion, the stopper portion is placed on the printed circuit board, and the insertion amount of the connecting portion into the through hole is defined. And a central portion in the length direction of each of the metal plates forms a welding portion that is welded overlapping the electrode, both side portions in the length direction of each of the metal plates form a pair of protruding plate portions that are bent in the plate thickness direction and protrude outward in the axial direction of the cylindrical body, and the stopper portions are respectively provided to protrude from lower end portions of the pair of protruding plate portions toward the printed circuit board.

7. The power supply unit according to claim 5 or claim 6, wherein, The connecting portion is provided to protrude from a lower end portion of a central portion in the length direction of the metal plate toward the printed circuit board.

8. The power supply unit according to any one of claims 5 to 7, wherein, a gas discharge valve is provided on one of the two end faces of the capacitor, and the gas discharge valve discharges gas generated during an abnormality, the welding portion of the metal plate is disposed around the gas discharge valve, by connecting a pair of concave bending portions connecting the welding portion of the metal plate and the pair of protruding plate portions, a guiding groove extending toward the printed circuit board side and guiding electrolyte is formed, a connecting portion and a cutout portion are provided on each of the protruding plate portions, and through the cutout portion, the guiding groove and the connecting portion are separated in the axial direction.

9. The power supply unit according to claim 8, wherein, An electrolyte reservoir is disposed on the printed circuit board, and the electrolyte reservoir is located below the gas discharge valve and the guiding groove and stores electrolyte that oozes out from the gas discharge valve.

10. The power supply unit according to any one of claims 1 to 9, wherein a gas discharge valve is provided on one of the two end faces of the capacitor, and the gas discharge valve discharges the gas generated during an abnormality. an electrolyte container is disposed on the printed circuit board, and the electrolyte container is located below the gas discharge valve and stores the electrolyte discharged from the gas discharge valve.

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