JP2018078247A - Capacitor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor module improving mountability and vibration resistance.SOLUTION: In a capacitor module 10, fixing portions 14 and 15 respectively project in an outside direction of a case 11 from side wall portions 13 at both ends in a row direction of a plurality of capacitor element. A fixing portion 16 is provided in a space in a deep recessed portion 11c depressed to a position interposed between two groups from a bottom portion 12 toward an inside direction of the case 11 when dividing the plurality of capacitor elements into the two groups of one end side and the other end side in the row direction. Therefore, the capacitor module 10 has no fixing portion projecting from the bottom portion 12 in the outside direction of the case 11, so that a physique on the bottom portion 12 side becomes small. Consequently, an electric power conversion device hardly interfere with an engine and the like, so that mountability is improved. The fixing portions 14, 15, 16 are position so as to sandwich the plurality of capacitor elements in the row direction thereof, so that vibrations of the capacitor elements themselves are suppressed to improve vibration resistance.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in this specification has a fixing portion in which a surface of a filled potting material (hereinafter referred to as a potting surface) is exposed to the outside and extends in a direction perpendicular to the potting surface. The present invention relates to a capacitor module fixed to a fixed part.

  In a capacitor module having a plurality of capacitor elements, a potting material is filled in the case in order to improve the electrical insulation characteristics of the capacitor elements and to suppress mechanical vibration of the capacitor elements. The potting material hardens in the case to the same extent as gel or gel. For this reason, some capacitor modules are attached in a positional relationship in which the potting surface of the hardened potting material is perpendicular to the fixed part of the device due to the convenience of arrangement in the device on which the module is mounted. The capacitor device (2) disclosed in Patent Document 1 below is an example. The numbers in parentheses correspond to the symbols described in the same document.

  In the capacitor device (2) of Patent Document 1, as shown in FIGS. 1 and 2 of the same document, the capacitor case (20) is provided with a bottom surface fixing portion (24) and a side surface fixing portion (25). These are fastened and fixed in the protruding formation direction Y (the Y axis of the coordinate system shown in the same figure) with respect to the fixed portion by using fastening members such as bolts penetrating them. On the other hand, the semiconductor unit (5) that electrically connects the capacitor device (2) has a Z-axis orthogonal to the projecting direction Y of the power terminal (61) and the control terminal (62) of the semiconductor module (6). In the direction, the capacitor case (20) is disposed to face the potting surface (290).

JP 2014-68449 A

  By the way, such a capacitor module is typically used in a power conversion device mounted on a vehicle such as an electric vehicle or a hybrid vehicle, as disclosed in Patent Document 1 described above. In these vehicles, for example, the power converter is housed in an engine compartment. In addition to the power conversion device, the engine compartment houses a number of device devices such as an engine, a motor generator, a transaxle, and an engine accessory device (for example, EGR (Exhaust Gas Recirculation)). Therefore, it may be difficult to ensure sufficient space in the engine compartment to accommodate the power converter.

  In particular, when the capacitance of the capacitor element included in the capacitor module increases, the size of the module itself increases. Then, for example, as in the capacitor device (2) of Patent Document 1, when the bottom surface fixing portion (24) provided in the capacitor case (20) is in a positional relationship protruding to the mounting side of the engine or its auxiliary device, the capacitor The case of the power converter that houses the device (2) also protrudes to the engine side by the amount of protrusion of the bottom surface fixing portion (24). And when the power converter device which protruded to the engine side interferes with an engine etc., such a power converter device cannot be accommodated in an engine compartment. In other words, the fixing portion that protrudes from the case of the capacitor module may reduce the mountability of the power conversion device that houses the module.

  Further, for example, when a capacitor module is used as a filter capacitor or a smoothing capacitor in a voltage converter, an inverter, or the like that constitutes a power converter as in the capacitor device (2) of Patent Document 1, a ripple generated during the operation of the switching circuit. Current flows through the capacitor element. For this reason, when the capacitor element is a film capacitor or the like, a Coulomb force is generated between the metallized films wound by the ripple current flowing through the capacitor element. Then, the repeated expansion and contraction of the film due to the Coulomb force vibrates the capacitor element itself. Such vibration of the capacitor element is suppressed by the fixing portion of the case that fastens and fixes the capacitor module to the fixed portion.

  For example, in the capacitor device (2) of Patent Document 1, the bottom surface fixing portion (24) and the side surface fixing portion (25) provided in the capacitor case (20) are fastened and fixed to the fixed portion, and the capacitor device (2) or The vibration of the capacitor element (30) itself is suppressed. However, the bottom surface fixing portion (24) and the side surface fixing portion (25) are arranged toward the outside of the capacitor case (20) so as to surround the capacitor element (30). Therefore, it is difficult to sufficiently suppress the vibration of the capacitor element (30) located away from either the bottom surface fixing portion (24) or the side surface fixing portion (25). That is, the fixed portion protruding from the case of the capacitor module may make it difficult to improve the vibration resistance of the capacitor element. The present specification provides a technique for improving mountability and vibration resistance.

  The capacitor module disclosed in this specification includes a first fixing portion and a second fixing portion in a case provided in the capacitor module. The first fixing portions project from the both side walls of the case located at both ends in the column direction of the plurality of capacitor elements in the case outward direction and are perpendicular to the potting surface and both side walls of the case. The second fixing portion is perpendicular to the potting surface and both side walls of the case, and divides the plurality of capacitor elements into two groups on one end side and the other end side in the column direction, from the bottom portion facing the opening portion of the case. It is provided in a space in a recess that is recessed to a position interposed between two groups toward the inside of the case.

  Thereby, since the said capacitor module does not have the fixing | fixed part which protrudes in a case outer side direction from a bottom part, the physique of a bottom part side becomes small. Therefore, for example, even when the power conversion device that houses the capacitor module is mounted in the engine compartment alongside the engine or its auxiliary device, the engine due to the fixed portion on the bottom side of the capacitor module protruding. There is no overhang on the side. Therefore, the power conversion device hardly interferes with the engine or the like, and the mountability is improved.

  The first fixing portion protrudes from the both side walls of the case in the case outer direction, whereas the second fixing portion is provided in a space in a recess that is recessed from the bottom toward the case inner side. The recess divides the plurality of capacitor elements into two groups on one end side and the other end side in the column direction. Therefore, for example, even when vibrations due to the Coulomb force generated by the ripple current flowing in a plurality of capacitor elements may occur in the capacitor elements themselves, these capacitor elements are placed in the column direction near each capacitor element. The first fixing portion and the second fixing portion are positioned so as to be sandwiched between the first fixing portion and the second fixing portion. Accordingly, the vibration of the capacitor element itself is suppressed, so that the vibration resistance is improved.

  Details of the technology disclosed in this specification and further improvements will be described in the embodiments of the present invention.

It is a perspective view of the capacitor module of an example. It is a top view of the capacitor module of an example. It is sectional drawing of the capacitor | condenser module of an Example. It is explanatory drawing at the time of accommodating the power converter device which mounts the capacitor | condenser module of an Example in an engine compartment. It is explanatory drawing at the time of accommodating the power converter device which mounts the capacitor | condenser module of a comparative example in an engine compartment.

  A capacitor module according to an embodiment will be described with reference to the drawings. In FIG. 1, the perspective view of the capacitor | condenser module 10 of an Example is shown. FIG. 2 shows a plan view of the capacitor module 10. FIG. 3 shows a cross-sectional view of the capacitor module 10. This cross-sectional view is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is an explanatory diagram in the case where the power conversion device 40 on which the capacitor module 10 is mounted is accommodated in the engine compartment 2.

  The capacitor module 10 mainly includes four capacitor elements 31, 32, 33, 34, a bus bar (not shown), a case 11, a terminal plate 18, and a potting material 20. The capacitor module 10 is used in, for example, a power conversion device 40 mounted in the engine compartment 2 of an electric vehicle (hereinafter simply referred to as a vehicle). The capacitor elements 31, 32, 33, and 34 are hereinafter referred to as capacitor elements 31-34.

  The vehicle power conversion device 40 converts the DC power of the battery into AC power suitable for driving the travel motor. For example, the output voltage of the battery is DC 200V (volt), and the driving voltage of the traveling motor is AC 600V. For this reason, the power converter 40 for a vehicle uses a voltage converter that performs step-up / step-down between the output voltage (200V) of the battery and the drive voltage (600V) of the traveling motor, and DC power to drive the traveling motor. It has an inverter that converts it into suitable AC power. The capacitor module 10 of the embodiment is used as a smoothing capacitor or a filter capacitor in such a voltage converter or inverter of the power converter 40. Therefore, the capacitor module 10 includes, for example, four capacitor elements 31-34 having the same capacitance that are electrically connected in parallel because it is necessary to have a large capacitance of several F (farad).

  The case 11 that houses the capacitor elements 31-34 is, for example, a flat box made of resin with a shallow depth. One end of the case 11 is open without a lid (opening 11a), and the bottom 12 is provided on the other end. The capacitor elements 31 to 34 of the embodiment have a vertically long bar shape as will be described later. Therefore, these capacitor elements 31-34 are accommodated in the case 11 as if they were laid down sideways. The bottom 12 is formed with a shallow recess 11b that matches the rounded corner shape of the capacitor elements 31-34.

  On both sides of the width direction of the case 11 (X-axis direction of the coordinate system shown in the drawing), that is, on both side wall portions 13, a flat plate shape for fixing the capacitor module 10 in the power converter 40 in a vertically placed state. Fixing portions 14 and 15 are formed. That is, in this embodiment, as shown in FIG. 1 and FIG. 4, the capacitor module 10 has a power conversion device in such a positional relationship that the bottom 12 rises in the height direction (Z-axis direction of the coordinate system shown in the figure). It is mounted in 40 cases 41. In this case 41, for example, three fixed portions 43, 44, 45 protrude inward from the respective side walls positioned so as to surround the capacitor module 10 from three directions.

  Flat fixing portions 14 and 15 that can be inserted with bolts 70 that can be screw-fastened in the Z-axis direction are formed on the side wall portion 13 of the case 11 with respect to the two fixed portions 43 and 44. Specifically, the plate-like fixing portions 14 and 15 protrude perpendicularly to the bottom portion 12 (or a potting surface 21 described later) and the side wall portion 13 outward from the side wall portions 13 on both sides. In the embodiment, the fixing portions 14 and 15 are formed integrally with the side wall portion 13. Holes 14a and 15a are respectively formed in the fixing portions 14 and 15, and a metal sleeve 17 is insert-molded in these holes 14a and 15a. Bolts 70 penetrating these metal sleeves 17 are screwed into female thread portions formed on the fixed portions 43 and 44 of the case 41, for example.

  The capacitor element 31-34 of the example is a film capacitor in which a cross-sectional shape (or end face shape) in the radial direction around the winding axis is an oval or a rounded rectangle (hereinafter referred to as a rounded rectangle). is there. The capacitor elements 31-34 have the same capacity and the same shape. The film capacitor is typically a capacitor obtained by winding a metallized film into a flat shape. For example, the metallized film is formed by depositing a metal such as aluminum on one side of a strip-shaped insulating film, and functions as an electrode plate for accumulating charges. Two of these are overlapped and wound around the winding axis in a roll shape a predetermined number of times to form the main body of the capacitor element 31-34. The main body portion is provided with external electrode portions (not shown) that are electrically connected to each of the two metallized films, and these external electrode portions function as electrodes of the capacitor elements 31-34. . In the present embodiment, one of the external electrode portions is connected to the positive bus bar, and the other is connected to the negative bus bar. These bus bars are connected to connection leads 19 via positive and negative terminal plates 18, respectively.

  In the present embodiment, the capacitor elements 31 to 34 having the same capacity and the same shape are divided into two groups so that the side surface having the larger area is parallel to the bottom portion 12 of the case 11. And is accommodated in the case 11. That is, in this embodiment, the four capacitor elements 31-34 are divided into two groups of two capacitor elements 31, 32 and capacitor elements 33, 34, and are accommodated side by side in the case 11. . When viewed from the opening 11a of the case 11, the side surfaces (side surfaces having a larger area) of the four capacitor elements 31-34 are divided into two groups and aligned in the width direction. Yes.

  In the present embodiment, such two groups are divided by a deep concave portion 11c positioned substantially at the center in the width direction of the bottom portion 12 (X-axis direction of the coordinate system shown in the figure). That is, among the capacitor elements 31-34 aligned in a row, the capacitor elements 31, 32 positioned on the fixed portion 14 (one end) side and the capacitor elements 33, 34 positioned on the fixed portion 15 (other end) side A deep recess 11c that is recessed from the outside of the bottom 12 toward the inside of the case 11 (opening 11a side) is formed in the case 11 (bottom 12) so as to be interposed therebetween. Further, in the space formed by the deep recess 11c, the fixing portion 16 corresponding to the fixed portion 45 of the power conversion device 40 described above is formed.

  That is, in the space of the deep recess 11 c, the Z-axis with respect to the fixed portion 45 of the three fixed portions 43, 44, 45 protruding inward from the side wall of the case 41 of the power conversion device 40. A flat plate-like fixing portion 16 is formed through which a bolt 70 that can be screwed in the direction can be inserted. Specifically, the flat fixing part 16 projects perpendicularly to the side wall part 13 and the bottom part 12 (or the potting surface 21) on both sides. The fixing portions 16 are located at substantially the same distance from the fixing portions 14 and 15 provided on the side wall portions 13 on both sides. In the embodiment, the fixing portion 16 is formed integrally with the bottom portion 12, and a hole portion 16a is formed. A metal sleeve 17 is insert-molded in the hole 16a. For example, the bolt 70 penetrating the metal sleeve 17 is screwed into a female screw portion formed in the fixed portion 45 of the case 41.

  The potting material 20 is filled around the capacitor elements 31-34 aligned in the case 11 (the potting material 20 is colored gray in FIG. 3 for convenience in drawing notation). Note that). The potting material 20 is a fluid insulating resin material, for example, silicon resin. The potting material 20 may be cured by ultraviolet irradiation, heating, or chemical addition, in addition to those that cure with time. The potting material 20 is filled in the case 11 in which the capacitor elements 31-34 are accommodated in a flowing state, and then hardens to the same degree as a gel or a gel to seal the capacitor elements 31-34.

  In the present embodiment, for example, the potting material 20 is filled in the case 11 so as to cover each of the capacitor elements 31-34 and the positive and negative bus bars. The potting material 20 is filled in the case 11 and covers the periphery of each capacitor element 31-34, thereby improving the electrical insulation characteristics of each capacitor element 31-34. Further, mechanical vibration of the capacitor elements 31-34 due to Coulomb force generated between the metallized films due to the ripple current flowing is suppressed. The terminal plates 18 of the positive electrode and the negative electrode are exposed to the outside without being covered with the potting material 20. That is, the terminal plate 18 is substantially perpendicular to the surface (hereinafter referred to as a potting surface) 21 of the potting material 20 sealing the capacitor elements 31-34 (the tip direction of the Y axis in the coordinate system shown in the drawing). Protrusively toward.

  As shown in FIG. 4, the capacitor module 10 configured as described above includes, for example, a bolt 70 that passes through the metal sleeve 17 of each of the fixing portions 14, 15, and 16 formed in the case 11. By screwing the parts 43, 44, 45, the power converter 40 is attached and fixed to the case 41. The connection leads 19 connected to the bus bars of the capacitor elements 31-34 in the capacitor module 10 are electrically connected to, for example, a power card (for example, a semiconductor module including a switching element such as an IGBT) constituting the power card unit 50. As a result, the voltage converter and inverter of the power converter 40 can be used as a smoothing capacitor and a filter capacitor.

  The power conversion device 40 is accommodated in the engine compartment 2. In addition to the engine 3, the engine compartment 2 accommodates an EGR 4 and a transaxle 5. The power converter 40 is directly mounted on the transaxle 5, for example. Depending on the vehicle type, the surrounding space in the plane direction of the power conversion device 40 (the XY plane direction of the coordinate system shown in the figure) may be narrow. For example, as shown in the figure, when the EGR 4 provided adjacent to the engine 3 is taller than the transaxle 5 and is close to the space in which the power converter 40 is accommodated, the EGR 4 and the power converter 40 The gap Sa between the two is small. Therefore, for example, as shown in FIG. 5, in the power conversion device 140 in which the projecting portion 142 projecting to the EGR4 side exists, the projecting portion 142 can interfere with the EGR4. When there is not enough room, the power converter 140 cannot be accommodated. FIG. 5 is an explanatory diagram in the case where the power conversion device 140 on which the capacitor module 100 of the comparative example is mounted is accommodated in the engine compartment 2.

That is, in the capacitor module 100 mounted on the power converter 140, the fixing portion 116 corresponding to the fixed portion 145 of the case 141 protrudes from the bottom portion 112 toward the outside of the case 111. Therefore, the protruding portion 142 protrudes from the side wall of the case 141 toward the EGR 4 side by the protruding amount of the fixing portion 116 that protrudes outward from the bottom portion 112 (case 111). In order to prevent the interference between the power conversion device 140 and the EGR 4, it is necessary to enlarge the gap Sb between the EGR 4 and the projection amount. Even if the protruding portion 142 is configured not to protrude from the side wall of the case 111, the bottom 112 of the capacitor module 100, the side wall of the case 111, and the gap Sc need to be enlarged to the same size as the gap Sb. . Therefore, the width of the case 111 in the Y-axis direction is increased to approximately the same amount as the protruding amount of the protruding portion 142.
In other words, even if the protruding portion 142 is configured not to protrude from the side wall of the case 111, in order to prevent interference between the power conversion device 140 and the EGR4, it is necessary to enlarge the gap Sb between the EGR4 and the protruding amount. Therefore, it is the same as the case where the protrusion 142 protrudes from the side wall.

  As described above, the capacitor module 10 according to the present embodiment has the fixing portions 14 and 15 and the fixing portion 16 in the case 11. The fixing portions 14, 15 protrude from the side wall portions 13 of the case 11 located at both ends in the column direction of the plurality of capacitor elements 31-34 to the outer side of the case 11, respectively, and are perpendicular to the potting surface 21 and both the side wall portions 13. It is. The fixing part 16 is perpendicular to the potting surface 21 and both side wall parts 13, and the plurality of capacitor elements 31-34 are divided into two groups on one end side and the other end side in the column direction, and the opening part 11a of the case 11 is divided. Is provided in a space in the deep recess 11 c that is recessed from the bottom 12 facing the inner side of the case 11 to a position interposed between the two groups.

  As a result, the capacitor module 10 does not have a fixing portion that protrudes from the bottom 12 toward the outer side of the case 11, so that the physique on the bottom 12 side is reduced. Therefore, for example, even when the power conversion device 40 that accommodates the capacitor module 10 is mounted side by side in the engine compartment 2 or the EGR 4 in the engine compartment 2, the fixing portion on the bottom 12 side of the capacitor module 10 protrudes. As a result, the protrusion 142 toward the engine 3 is eliminated. Therefore, it becomes difficult for the power conversion device 40 to interfere with the engine 3 and the like, and the mountability is improved. Further, since the side wall shape of the opening of the case 41 of the power conversion device 40 in a plan view is a straight line, for example, a liquid gasket agent (FIPG) is compared with the case where the projecting portion 142 from the case 41 to the engine 3 side exists. ; Formed In Place Gasket) can be easily applied to the side wall.

  In addition, the fixing portions 14 and 15 protrude from both side wall portions 13 of the case 11 toward the outer side of the case 11, whereas the fixing portion 16 has a deep recess that is recessed from the bottom portion 12 toward the inner side of the case 11. 11c is provided in the space. The deep recess 11c divides the plurality of capacitor elements 31-34 into two groups on one end side and the other end side in the column direction. Therefore, for example, even when vibration due to the Coulomb force generated by the ripple current flowing through the plurality of capacitor elements 31-34 may occur in the capacitor elements 31-34 themselves, they are close to the capacitor elements 31-34. , The fixing portions 14, 15 and 16 are located so as to sandwich the capacitor elements 31-34 in the column direction. Therefore, the vibration of the capacitor elements 31-34 itself is suppressed, so that the vibration resistance is improved and the deterioration of the NV (Noise and Vibration) characteristics is suppressed.

  In particular, since the four capacitor elements 31-34 have the same capacity and the same shape, the weight balance between the capacitor elements 31, 32 and the capacitor elements 33, 34 is centered around the fixed portion 16 provided in the deep recess 11c of the case 11. It becomes equal on both sides (the fixed part 14 side and the fixed part 15 side). Further, the fixing portions 16 are positioned at substantially the same distance from the fixing portions 14 and 15 provided on the side wall portions 13 on both sides. Thereby, it is easy to balance the rigidity by the fixing portions 14 and 15 around the fixing portion 16. Further, the natural frequency value of the capacitor module 10 is increased as compared with the case where the fixed portion 16 is not present. Therefore, it is possible to suppress mechanical vibration of the capacitor element 31-34 caused by the ripple current flowing through the capacitor element 31-34, and, for example, the vertical direction generated in the transaxle 5 (the coordinates shown in the figure). Even when vibration in the Z-axis direction of the system is input to the capacitor module 10, it is possible to suppress such longitudinal vibration of external input. Further, it is possible to suppress a decrease in mechanical strength of each positive and negative bus bar to which the capacitor elements 31-34 are connected.

  In the above embodiment, the case where there are four capacitor elements having the same capacity and the same shape as the plurality of capacitor elements has been described. When a plurality of capacitor elements have the same capacity and the same shape, the weights of the capacitor elements are almost the same. Therefore, as long as the number is even, the number may be six or more, or two.

  Further, in the above-described embodiment, the capacitor elements 31 to 34 have been described by exemplifying the case where they have the same capacity and the same shape (that is, the case where they have the same weight). If the weight balance of both sides (the fixed portion 14 side and the fixed portion 15 side) of the case 11 with the deep concave portion 11c as the center is equal (same or substantially the same), each capacitor element on the fixed portion 14 side and the fixed portion 15 side The electrostatic capacity and shape of each may be different.

  Points to be noted regarding the example technology will be described. The fixing portions 14 and 15 correspond to an example of a first fixing portion. The fixing part 16 corresponds to an example of a second fixing part. The deep recess 11c corresponds to an example of a recess.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Moreover, the technique illustrated in this specification or the drawings achieves a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Engine compartment 3: Engine 4: EGR
5: Transaxle 10: Capacitor module 11: Case 11a: Opening portion 11b: Shallow concave portion 11c: Deep concave portion 12: Bottom portion 13: Side wall portions 14, 15, 16: Fixing portion 20: Potting material 21: Potting surfaces 31, 32, 33, 34: Capacitor element 40: Power conversion device 41: Cases 43, 44, 45: Fixed portion 50: Power card unit 70: Bolt Sa, Sb: Clearance

Claims (1)

A capacitor module that has a fixed portion that is exposed to the outside and the surface of the filled potting material is expanded in a direction perpendicular to the potting surface, and fixes the fixed portion to the fixed portion;
A case having an opening on one end side and a bottom on the other end side;
A plurality of capacitor elements arranged in a row in the case;
A potting material that fills the case and seals the plurality of capacitor elements to form the potting surface, and
The case is
A first fixing portion that protrudes from both side walls of the case located at both ends in the row direction of the plurality of capacitor elements in the case outer direction and is perpendicular to the potting surface and the both side walls;
A concave portion that divides the plurality of capacitor elements into two groups on one end side and the other end side in the column direction and is recessed from the outside of the bottom portion toward the inside of the case to a position interposed between the two groups; ,
A second fixing portion provided in a space in the recess and perpendicular to the potting surface and both side walls of the case;
A capacitor module comprising: