Capacitor unit

Abstract

To provide a capacitor unit capable of suitably cooling a capacitor.SOLUTION: A capacitor unit includes a plurality of capacitors 30 arranged in a row and having a metallikon electrode 32A at one axial end, and a housing case in which the plurality of capacitors 30 are housed, the plurality of capacitors 30 are arranged in a direction intersecting the axial direction of the capacitors 30 with the metallikon electrode 32A facing in one direction, the housing case includes a rib interposed between two adjacent capacitors 30, and a bottom wall portion 61 of the housing case facing the metallikon electrode 32A forms a part of a refrigerant flow path R1.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a capacitor unit in which a plurality of capacitors are integrated.

Background Art

[0002] Patent Document 1 describes a structure in which a plurality of capacitors (capacitance elements) are commonly packaged, and such a common package is attached to a housing. Such a common package includes a slit portion and a fixing portion for connecting and fixing to the inner wall of the housing in the slit portion. Further, the housing has a cooling portion formed in a wall portion separated from the common package. In such a structure, heat generated by the capacitor is transmitted to the cooling portion through the fixing portion and the housing, and heat exchange occurs in the cooling portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-described structure prioritizes the cooling of the converter and inverter accommodated in the vicinity of the cooling portion in the housing portion rather than the cooling of the capacitor.

[0005] In view of the above points, the present invention has been made, and an object thereof is to provide a capacitor unit capable of suitably cooling a capacitor.

Means for Solving the Problems

[0006] In order to solve the above-described problems, the capacitor unit of the present invention is arranged in a row and in the axial direction Each of the two endsThe device comprises a plurality of capacitors having metallicon electrodes, and a housing case that houses the plurality of capacitors, and the plurality of capacitors are One end in the axial direction They are arranged in a direction intersecting the axial direction of the capacitor, and the housing case is A first wall portion facing one axial end of a plurality of capacitors, A second wall portion facing the other axial end of the plurality of capacitors, Ribs interposed between two adjacent capacitors and, Equipped with, The first wall portion It constitutes part of the refrigerant flow path, The rib is connected to the first wall portion and the second wall portion. It is characterized by the following: [Effects of the Invention]

[0007] According to the present invention, the capacitor can be suitably cooled in the capacitor unit. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view showing a booster to which an electrical component cooling structure according to an embodiment of the present invention is applied. [Figure 2] This is a schematic perspective view showing a capacitor unit according to an embodiment of the present invention. [Figure 3] This is a schematic plan view showing a capacitor unit according to an embodiment of the present invention. [Figure 4] This is a schematic side view showing a capacitor unit according to an embodiment of the present invention. [Figure 5] This is a schematic bottom view showing a capacitor unit according to an embodiment of the present invention. [Figure 6] This is a schematic perspective view showing an assembly of a capacitor, a retaining member, and a busbar according to an embodiment of the present invention. [Figure 7] This is a schematic perspective view showing a storage case according to an embodiment of the present invention. [Figure 8] This is a schematic front view showing a housing case according to an embodiment of the present invention. [Figure 9] This is a schematic perspective view showing the capacitor unit according to an embodiment of the present invention with the resin part removed. [Figure 10] This is a schematic front view showing the capacitor unit according to an embodiment of the present invention with the resin part removed. [Figure 11] Figure 1 is a cross-sectional view taken along line XI-XI, schematically showing an electrical component cooling structure according to an embodiment of the present invention. [Figure 12] This is a magnified section of Figure 11. [Modes for carrying out the invention]

[0009] Next, embodiments of the present invention will be described in detail, with reference to the drawings as appropriate, using the case where the electrical component cooling structure of the present invention is used to cool electrical components constituting a voltage control unit (VCU) in a vehicle as an example. Vehicles to which the electrical component cooling structure of the present invention is applied include electric vehicles (electric cars, etc.) that use a motor as a power source. Examples of electrical components include capacitors, etc.

[0010] In the following description, the vertical direction is based on the state in which the boost converter is installed in the vehicle. The longitudinal and lateral directions, which are perpendicular to the vertical direction, are based on the housing case in which the capacitor is housed, with the longitudinal direction being the depth direction of the housing case and the lateral direction being the width direction of the housing case. In other words, the longitudinal and lateral directions used in this embodiment do not necessarily coincide with the longitudinal and lateral directions of the vehicle.

[0011] As shown in Figure 1, the electrical component cooling structure 1 according to an embodiment of the present invention is a structure for cooling a capacitor 30 (see Figure 6), which is an electrical component constituting the circuit of a booster 2 mounted on a vehicle. In Figure 1, the illustration of electrical components (electrical component units) other than the capacitor unit 3 is omitted. The booster 2 is positioned between the vehicle's battery and motor, and boosts the battery voltage to the voltage required by the motor, supplying the boosted battery power to the motor. The booster 2 to which the electrical component cooling structure 1 is applied comprises a housing 10, a first sealing member 20A (see Figure 5), a second sealing member 20B (see Figure 5), and a capacitor unit 3.

[0012] <Housing> The housing 10 is a metal member for accommodating electrical components and the like that constitute the booster 2. Examples of the electrical components accommodated in the housing 10 include a capacitor 30 (see FIG. 6), a reactor, an inverter, a converter, and the like.

[0013] The housing 10 has a shape with an open upper part, and integrally includes a bottom wall portion 11, a peripheral wall portion 12 erected from the peripheral edge of the bottom wall portion 11, and an annular (rectangular frame-shaped) flange portion 13 extending outward from the upper end of the peripheral wall portion 12 of the housing 10.

[0014] A refrigerant flow portion 14 (see FIG. 11) that is recessed outward (downward in this embodiment) of the housing 10 is formed in the bottom wall portion 11. The refrigerant flow portion 14 will be described in detail later.

[0015] The flange portion 13 is fixed to the lower end portion of another device (for example, a power module) of the vehicle via bolts or the like.

[0016] <First Sealing Member and Second Sealing Member> The first sealing member 20A and the second sealing member 20B (see FIG. 5) are annular (substantially rectangular frame-shaped) resin members (gaskets) that seal between the housing 10 and the housing case 60 of the capacitor unit 3. The assembled state of the first sealing member 20A and the second sealing member 20B will be described in detail later.

[0017] <Capacitor Unit> As shown in FIGS. 2 to 5, the capacitor unit 3 includes a plurality of capacitors 30 (see FIG. 6), a holding member 40 (see FIG. 6), bus bars 50A, 50B, a housing case 60, and a resin portion 70.

[0018] <Capacitor> As shown in Figure 6, the capacitor 30 is an electrical component (electrical element) that generates heat when energized, and comprises two metallized films 31A and 31B on which electrodes are formed on a dielectric film, and two metallicon electrodes 32A and 32B as external electrodes. The two metallized films 31A and 31B are wound around the axis of the capacitor 30 (around the vertical axis in this embodiment) in a state of being superimposed on each other. The metallicon electrode 32A is an external electrode (N-side electrode in this embodiment) formed at one axial end (lower end in this embodiment) of the wound metallized films 31A and 31B, and is connected to the metallized films 31A and 31B and is electrically connected to the electrode of metallized film 31A. The metallicon electrode 32B is an external electrode (P-side electrode in this embodiment) formed at the other axial end (upper end in this embodiment) of the wound metallized film 31A, 31B, and is connected to the metallized film 31A, 31B and electrically connected to the electrode of the metallized film 31B.

[0019] <Retaining member> The holding member 40 is a metal (or resin) member that holds a plurality (three in this embodiment) of capacitors 30. In this embodiment, the holding member 40 comprises a lower holding member 41 that holds the lower parts of the plurality of capacitors 30 and an upper holding member 42 that holds the upper parts of the plurality of capacitors 30.

[0020] <Busba> The busbar 50A is a metal component that electrically connects the metallic electrodes 32A of multiple capacitors 30 to other electrical components of the boost converter 2. One end of the busbar 50A connects the metallic electrodes 32A of multiple (9 in this embodiment) capacitors 30 in parallel via lead terminals (not shown). The other end of the busbar 50A is exposed from the housing case 60 and resin part 70, which will be described later, and is electrically connected to other electrical components of the boost converter 2.

[0021] The busbar 50B is a metal component that electrically connects the metallic electrode 32B of the capacitor 30 to other electrical components of the boost converter 2. One end of the busbar 50B connects the metallic electrode 32B of multiple (9 in this embodiment) capacitors 30 in parallel via lead terminals (not shown). The other end of the busbar 50B is exposed from the housing case 60 and resin part 70, which will be described later, and is electrically connected to other electrical components of the boost converter 2.

[0022] <Capacitor arrangement> Multiple capacitors 30 are aligned in a position where the metallic electrode 32A formed at one axial end of each capacitor 30 is oriented in one direction (downward in this embodiment), and are arranged in a line in a direction that intersects (orthogonal to) the axial direction of the capacitor 30 (a direction parallel to the surface of the metallic electrode 32A, in this embodiment, the left-right direction). Adjacent capacitors 30, 30 are spaced apart by a predetermined interval.

[0023] <Storage Case> As shown in Figures 2 to 5, the housing case 60 is a metal (e.g., aluminum) component that houses a plurality of capacitors 30. As shown in Figures 7 and 8, the housing case 60 integrally comprises a bottom wall portion 61, an upper wall portion 62 facing the bottom wall portion 61, a back wall portion 63 connecting the peripheral edges of the bottom wall portion 61 and the upper wall portion 62, and a pair of side wall portions 64, 64. The housing case 60 also integrally comprises a pair of flange portions 65, 65 extending from both ends of the bottom wall portion 61 so as to protrude beyond the side wall portions 64. The housing case 60 also integrally comprises a plurality of ribs 66 that partition the internal space of the housing case 60. An opening 60a is formed at the front end of the housing case 60.

[0024] The flange portion 65 is part of the bottom wall portion 61. Both ends of the flange portion 65 in the front-rear direction constitute fixing portions 65a, 65a which are fixed to the bottom wall portion 11 of the housing 10 by bolts or the like. The fixing portions 65a are formed outside the refrigerant discharge groove portion 61b, which will be described later.

[0025] Multiple ribs (six in this embodiment) 66 are arranged at equal intervals between a pair of side walls 64, 64, dividing the internal space of the housing case 60 into multiple sections in the left-right direction. The lower end of each rib 66 is connected to the bottom wall 61. The upper end of each rib 66 is connected to the top wall 62. The rear end of each rib 66 is connected to the back wall 63. The front-to-back dimension of each rib 66 is smaller than the front-to-back dimensions of the bottom wall 61 and the top wall 62. These ribs 66 are interposed between adjacent capacitors 30, 30. That is, each capacitor 30 is housed in a space partitioned by the ribs 66 within the housing case 60.

[0026] As shown in Figure 5, an annular projection 61a and a refrigerant discharge groove 61b are formed on the outer surface (in this embodiment, the bottom surface) of the bottom wall portion 61.

[0027] The annular projection 61a protrudes downward from the lower surface of the bottom wall portion 61. The portion of the bottom wall portion 61 surrounded by the annular projection 61a constitutes the refrigerant flow portion 61c.

[0028] The refrigerant discharge groove 61b is formed outside the annular projection 61a and inside the fixing portion 65a, and is recessed upward from the lower surface of the bottom wall portion 61. The refrigerant discharge groove 61b is formed to be continuous with the pair of side walls 64, 64 side and the opening 60a side of the annular projection 61a.

[0029] As shown in Figures 11 and 12, the annular protrusion 61a and the pair of flange portions 65, 65 of the bottom wall portion 61 have an annular first groove portion 60b and an annular second groove portion 60c formed therein.

[0030] The first groove 60b is formed on the outer circumferential surface of the annular projection 61a.

[0031] The second groove 60c is formed on the lower surface of the bottom wall 61 and the pair of flange portions 65, 65. The second groove 60c is formed in an annular shape so as to surround the annular projection 61a and the refrigerant discharge groove 61b from the axial outer side of the housing case 60.

[0032] <Resin part> The resin part 70 is a resin (for example, epoxy resin) that is filled and solidified inside the housing case 60 so as to cover the multiple condensers 30, holding members 40, and busbars 50A and 50B housed in the housing case 60. This resin part 70 prevents the condensers 30 from coming into contact with the refrigerant 4 (see Figures 11 and 12).

[0033] <Refrigerant distribution structure> The refrigerant flow section 14 formed in the bottom wall 11 of the housing 10 integrally comprises a peripheral wall 14a extending outward from the bottom wall 11 to the housing 10 (downward in this embodiment) and an end wall 14b that closes the tip (lower end in this embodiment) of the peripheral wall 14a. Holes 14c, 14c, which are inlets and outlets for the refrigerant 4, are formed at both the left and right ends of the peripheral wall 14a, respectively.

[0034] The housing case 60 is fixed to the casing 10 by being bolted to the bottom wall portion 11 at the fixing portion 65a. In this fixed state, the annular projection 61a is fitted (internally fitted) into the peripheral wall portion 14a of the refrigerant flow portion 14. That is, the annular projection 61a and the refrigerant flow portion 61c cooperate with the refrigerant flow portion 14 (peripheral wall portion 14a and end wall portion 14b) to constitute a refrigerant flow path R1 through which the refrigerant 4 flows. Furthermore, this fitted portion is sealed so that the refrigerant 4 cannot flow through by the first sealing member 20A housed in the first groove portion 60b.

[0035] Before the housing 10 and the housing case 60 are assembled, the first sealing member 20A is housed in the first groove 60b with a portion of it protruding from the first groove 60b. The first sealing member 20A is press-fitted between the bottom surface of the first groove 60b and the peripheral wall 14a, thereby acting as an axial seal that provides an axial sealing function between the annular projection 61a and the peripheral wall 14a of the housing case 60.

[0036] Outside the refrigerant flow path R1, the refrigerant discharge groove 61b faces the bottom wall 11 and communicates with a hole 11a formed in the bottom wall 11. The hole 11a is for discharging the refrigerant 4 that has entered the housing 10 to the outside of the housing 10. In other words, the refrigerant discharge groove 61b works in cooperation with the bottom wall 11 to form a refrigerant discharge path R2 through which the refrigerant 4 is discharged.

[0037] Outside the refrigerant discharge passage R2, the bottom wall portion 61 and the flange portion 65 are in contact with the bottom wall portion 11. This contact area is sealed off, preventing the flow of refrigerant 4, by the second sealing member 20B housed in the second groove portion 60c.

[0038] Before the housing 10 and the housing case 60 are assembled, the second sealing member 20B is housed in the second groove 60c with a portion of it protruding from the second groove 60c. The second sealing member 20B is press-fitted between the bottom surface of the second groove 60c and the bottom wall 11, thereby providing a surface seal that performs a sealing function in the plane direction perpendicular to the axial direction between the bottom wall 61 and the bottom wall 11.

[0039] The electrical component cooling structure 1 employs a first sealing member 20A as an axial seal and a second sealing member 20B as a surface seal. Compared to the case where two surface seals are used, this reduces the number of fixing points of the electrical components (capacitor 30, capacitor unit 3) to the housing 10, thereby simplifying the structure. Furthermore, compared to the case where two axial seals are used, the electrical component cooling structure 1 can shorten the distance between the capacitor 30 and external devices (e.g., power modules), thereby reducing parasitic inductance.

[0040] In this structure, the refrigerant 4 flowing through the refrigerant channel R1 exchanges heat with the metallicon electrode 32A via the bottom wall portion 61, thereby absorbing and dissipating heat generated inside the capacitor 30 and cooling the capacitor 30. The heat conduction efficiency of the metallized films 31A and 31B of the capacitor 30 is better in the axial direction (up and down in this embodiment) in which the metallized films 31A and 31B are wound than in the direction perpendicular to that axis.

[0041] The heat generated in the metallized films 31A and 31B is transferred to the metallicon electrode 32A, and then transferred to the refrigerant 4 via the bottom wall portion 61, which is located near the metallicon electrode 32A and faces it through the resin portion 70. In other words, since the condenser 30 has the metallicon electrode 32A located close to the bottom wall portion 61, it is effectively cooled by the refrigerant 4.

[0042] Furthermore, some of the heat generated by the metallized films 31A and 31B is transferred to the metallicon electrode 32B, and from the upper wall portion 62 located near the metallicon electrode 32B and facing it via the resin portion 70, it is transferred to the bottom wall portion 61 via either the rear wall portion 63, the side wall portion 64, or the rib 66, and then transferred to the refrigerant 4 via the bottom wall portion 61. In other words, since the condenser 30 is provided close to the upper wall portion 62 where the metallicon electrode 32B is connected to the bottom wall portion 61 via the rib 66, etc., it is effectively cooled by the refrigerant 4. Note that some of the heat transferred to the metallicon electrode 32B is transferred to the outside air outside the housing case 60 via the upper wall portion 62, the rear wall portion 63, and the side wall portion 64.

[0043] Here, adjacent capacitors 30, 30 are arranged so that their metallic electrodes 32A, 32B intersect with the arrangement direction. With this structure, the temperature rise due to thermal interference between adjacent capacitors 30, 30 can be suppressed compared to the case where the metallic electrodes 32A, 32B of adjacent capacitors 30, 30 face each other. Furthermore, with this configuration, the distance between adjacent capacitors 30, 30 can be shortened.

[0044] Furthermore, the ribs 66 suppress temperature rise due to thermal interference between adjacent capacitors 30, 30, contributing to a reduction in the maximum temperature of the capacitors 30. In addition, the ribs 66 improve the strength of the housing case 60, and the thinning of the bottom wall 61 improves the cooling performance of the capacitors 30.

[0045] <Structure to prevent refrigerant from entering the housing> Here, we will explain the case where the refrigerant 4 leaks beyond the first sealing member 20A to the outside of the refrigerant flow path R1 (in the direction toward the area inside the housing 10 that is outside the refrigerant flow path R1 and where electrical components other than the capacitor 30 are housed). In this case, the refrigerant 4 is discharged to the outside of the housing 10 via the refrigerant discharge passage R2 and the hole 11a before it can enter the inside of the housing 10 (in the inside of the housing 10 that is outside the refrigerant flow path R1 and where electrical components other than the capacitor 30 are housed). Furthermore, the refrigerant 4 that has leaked to the outside of the refrigerant flow path R1 is prevented from entering the inside of the housing 10 (in the inside of the housing 10 that is outside the refrigerant flow path R1 and where electrical components other than the capacitor 30 are housed) by the second sealing member 20B.

[0046] A capacitor unit 3 according to an embodiment of the present invention comprises a plurality of capacitors 30 arranged in a row, each having a metallic electrode 32A at one end in the axial direction, and a housing case 60 that houses the plurality of capacitors 30. The plurality of capacitors 30 are arranged in a direction intersecting the axial direction of the capacitors 30, with the metallic electrode 32A facing one side. The housing case 60 includes ribs 66 interposed between two adjacent capacitors 30. The wall portion (bottom wall portion 61) of the housing case 60 facing the metallic electrode 32A constitutes a part of the flow path (refrigerant flow path R1) for the refrigerant 4. Therefore, the capacitor unit 3 can achieve optimal cooling of the capacitor 30.

[0047] In the capacitor unit 3, the rib 66 is connected to the wall portion. Therefore, the capacitor unit 3 can achieve optimal cooling of the capacitor 30 via the ribs 66.

[0048] In the capacitor unit 3, the rib 66 is connected to another wall (upper wall 62) of the housing case 60 that faces the other axial end of the capacitor 30. Therefore, by thinning the wall portion of the capacitor unit 3, even more favorable cooling of the capacitor 30 can be achieved.

[0049] An embodiment of the present invention provides an electrical component cooling structure 1 comprising an electrical component (capacitor 30) that generates heat when energized, a housing case 60 that houses the electrical component, and a casing 10 to which the housing case 60 is attached. One wall portion (bottom wall portion 11) of the casing 10 is recessed outward from the one wall portion and includes a refrigerant flow portion 14 through which refrigerant 4 flows, and a hole portion 11a for discharging the refrigerant 4 that has entered the casing 10. One wall portion (bottom wall portion 61) of the housing case 60 is front The refrigerant flow section 14 includes an annular projection 61a fitted inside, a refrigerant discharge groove 61b formed outside the annular projection 61a so as to communicate with the hole 11a, and a fixing portion 65a fixed to the housing 10 outside the refrigerant discharge groove 61b, wherein a first groove 60b is formed on at least one of the inner circumferential surface of the refrigerant flow section 14 and the outer circumferential surface of the annular projection 61a, and a first sealing member 20A that seals the space between the refrigerant flow section 14 and the annular projection 61a is housed in the groove 60b. Therefore, the electrical component cooling structure 1 improves the cooling efficiency of the electrical components, effectively prevents the refrigerant 4 from entering the housing 10 (leaking from the refrigerant flow path R1), and effectively discharges the refrigerant 4 that has entered the housing 10 (leaked from the refrigerant flow path R1) to the outside of the housing 10.

[0050] In the electrical component cooling structure 1, a second groove 60c is formed between the refrigerant discharge groove 61b and the fixing portion 65a, in at least one of the walls of the housing 10 and the housing case 60, to accommodate a second sealing member 20B that seals the space between the housing 10 and the housing case 60. Therefore, the electrical component cooling structure 1 improves the cooling efficiency of the electrical components, more effectively prevents the refrigerant 4 from entering the housing 10 (leaking from the refrigerant flow path R1), and more effectively discharges the refrigerant 4 that has entered the housing 10 (leaked from the refrigerant flow path R1) to the outside of the housing 10.

[0051] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified as appropriate without departing from the spirit of the invention. For example, the electrical component cooling structure 1 and / or condenser unit 3 of the present invention can be applied not only to electric vehicles but also to heavy machinery, ships, etc. Furthermore, the first groove 60b in which the first sealing member 20A is housed may be formed in the peripheral wall portion 14a of the refrigerant flow portion 14 of the housing 10, or it may be formed in both the peripheral wall portion 14a and the annular protrusion 61a. Similarly, the second groove 60c in which the second sealing member 20B is housed may be formed in the bottom wall portion 11 of the housing 10, or it may be formed in both the bottom wall portion 11 and the bottom wall portion 61 and the flange portion 65. [Explanation of Symbols]

[0052] 1. Cooling structure for electrical components 2. Step-up transformer 3. Capacitor Unit (Electrical Component Unit) 4 Refrigerant 10 cabinets 11 Bottom wall (one wall) 11a Hole 12 Peripheral wall section 13 Flange section 14 Refrigerant flow section 20A First sealing member 20B Second sealing member 30 Capacitors (electrical components) 31A, 31B Metallized film 32A, 32B Metallicon electrodes 40 Retaining member 41 Lower retaining member 42 Upper retaining member 50A, 50B Busbar 60 storage cases 60a opening 60b First groove 60c Second groove 61 Bottom wall section (wall section, single wall section) 61a Annular protrusion 61b Refrigerant discharge channel 62 Upper wall section (other wall sections) 63 Back wall 64 Side wall section 65 Flange section (single wall section) 65a Fixed part 66 Ribs 70 Resin part R1 Refrigerant flow path (flow path) R2 Refrigerant discharge path

Claims

[Claim 1] The device comprises a plurality of capacitors arranged in a row, each having a metallic electrode at both ends in the axial direction, and a housing case that accommodates the plurality of capacitors. The multiple capacitors are arranged in a direction intersecting the axial direction of the capacitor, with one end of each capacitor facing in one direction. The aforementioned storage case is A first wall portion facing one axial end of a plurality of capacitors, A second wall portion facing the other axial end of the plurality of capacitors, A rib interposed between two adjacent capacitors, Equipped with, The first wall portion constitutes part of the refrigerant flow path, The rib is connected to the first wall portion and the second wall portion. A capacitor unit characterized by the following features.

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