Capacitor block including spacer

Abstract

The present invention relates to a capacitor block (1), in particular a capacitor block for an electrical device, comprising: a recess; at least one capacitor element (5), which has a first end arranged in the recess and a second end (9) opposite to the first end (7) and extending out of the recess; a stopper (11), which is attached to the second end (9) of the capacitor element (5); and at least one spacer (13), which bears against the stopper (11) so as to determine the distance between the second end (9) of the capacitor element (5) and an end wall of the recess.

Description

Technical Field

[0001] The present invention relates to a capacitor block, in particular a capacitor block for an electrical device, the electrical device being carried on a motor vehicle, for example, such as an inverter, a voltage converter or a battery charger. Background Art

[0002] As is known, in a capacitor block, a capacitor element can be placed in a housing and embedded in a potting material, which mainly has the function of holding the capacitor element and protecting it from moisture. This potting material is usually in the form of a resin. The capacitor element consists of, for example, a film wrapped around the capacitor terminals. Usually, the capacitor element is completely embedded in the resin, so that the outside of the capacitor block is formed by the outer wall of the housing and a face formed by the resin. Only the electrical terminals extend out of the resin from the face. However, in some applications, in particular in electric vehicles, it is desirable to reduce the size of the electronic components. Now, in this capacitor block structure, the housing and the resin occupy a considerable amount of space. In addition, in order to allow the resin to flow, it is necessary to leave space between the capacitor element and the side walls of the housing.

[0003] A capacitor block is known in which the housing extends a height less than the height of the capacitor element. The housing then forms a plate just large enough to contain the resin at one end of the capacitor block, which end comprises the electrical connection between the electrical terminals of the capacitor block and the electrodes of the capacitor element.

[0004] However, capacitor elements of the same model may have different heights because there is inherent uncertainty in the way they are manufactured. Therefore, within the same capacitor block, capacitor elements may have different heights. In addition, in the industrial manufacturing process, the capacitor elements of each capacitor block may have different heights, which has an impact on the repeatability of the size of the manufactured capacitor block. This is particularly important in electrical equipment, where the capacitor block must be cooled to dissipate the heat emitted when the capacitor block is powered by electrical energy. For this reason, electrical equipment is usually provided with a cooling circuit. In order to optimize heat dissipation, the entire face of the capacitor block must be tightly pressed against the cooling circuit. Now, the height difference between the capacitor elements of the capacitor block may not allow the face of the capacitor block to be uniformly and tightly pressed against the cooling circuit. In any case, if measures are taken to ensure that the height within a capacitor block is consistent, the differences between the capacitor blocks of the same model may cause interference in the size string of the electrical equipment including the capacitor block. The specific height of each capacitor module is not suitable for industrial-scale manufacturing.

[0005] Therefore, there is still a need for a capacitor block of limited volume, but which maintains a certain degree of flexibility with respect to the uncertainty of capacitor element manufacturing. Summary of the invention

[0006] To this end, the present invention relates to a capacitor block, in particular a capacitor block for an electrical device, comprising: a housing; at least one capacitor element having a first end accommodated in the housing and a second end opposite to the first end and extending out of the housing; an end stopper, the end stopper being fixed to the second end of the capacitor element; and at least one spacer, which abuts against the end stopper so as to determine the distance between the second end of the capacitor element and the bottom of the housing.

[0007] Thus, the spacer supports the capacitor element relative to the bottom of the housing. The height of the capacitor block between the bottom of the housing and the second end of the capacitor element is set by the spacer, which means that the height of the capacitor block is controlled, although there is uncertainty in the height of the capacitor element. The bottom is, for example, a wall of the housing, in particular a peripheral wall facing the first end of the capacitor element.

[0008] According to an embodiment of the invention, a potting material, in particular a resin, at least partially fills the housing so as to seal the capacitive element at its first end. According to a variant, the potting material is an electrical insulator and thus provides electrical insulation of the first end relative to the housing receiving the first end.

[0009] The resin exhibits many properties that are advantageous for its use in capacitor blocks. In particular, the resin is fluid during filling of the housing. The fluidity allows the resin to be evenly distributed in the housing, between the capacitor elements, and at the connections of the capacitor elements. The resin is cured (hardened) by heating and effectively polymerized. Therefore, after the polymerization step, the resin becomes solid. This polymerization can be achieved by heating in an oven. In this way, the resin surrounds one end of the capacitor element and seals the end. In addition, the polymerized resin makes the bottom of the housing rigid and strong, which allows effective abutment via the outer face of the bottom when the capacitor block is tightly pressed against the heat sink.

[0010] In one variation, the second end of the capacitor element extends out of the potting material.Only a portion of the capacitor element is located in the housing.

[0011] According to an embodiment of the invention, the housing is formed by a bottom and a side wall extending from the bottom, defining the internal volume of the housing. The bottom of the housing includes the end of the capacitor element and acts as an electrical insulator between the capacitor element and the elastic member. In particular, the side wall extends toward the second end of the capacitor element.

[0012] In a variant, the side wall stops near the second end of the capacitor element. Thus, the housing only includes the first end of the capacitor element. In particular, the side wall stops at a height less than half, or even less than one-third or one-quarter of the height of the capacitor element. The size of the housing is thus reduced, and the volume of the capacitor block is thus also reduced.

[0013] In a variant, in order to facilitate rapid and uniform filling of industrial-scale manufacturing processes, the side walls of the housing can be inclined outwards. This means that the area defined by the edge of the side wall, in particular in a plane parallel to the bottom of the housing, is larger than the area of ​​the bottom of the housing. The space occupied by the capacitor block depends at least in part on the extent of the side walls of the housing. The smaller the extent to which the side walls extend, the smaller the space occupied by the capacitor block. However, in this variant, it is preferred to ensure at least a minimum extent in order to allow sealing of the first end of the capacitor element, which end is embedded in the potting material.

[0014] In a variant, the potting material extends to a height that is less than the height of the side walls. In particular, this makes the capacitor block easier to handle before polymerisation, since the risk of overflow is reduced.

[0015] According to an embodiment of the present invention, the spacer extends from the bottom of the housing.

[0016] In one embodiment of the present invention, the capacitor block includes at least two spacers, which are evenly distributed at the bottom of the housing. This ensures that the points where the spacers and the end stops abut against each other are evenly distributed. This avoids the capacitor element being unbalanced relative to the spacers. This imbalance can cause the capacitor element to tilt, and therefore cause the outer face of the capacitor block to be non-parallel to the bottom of the housing at the second end of the capacitor element. This will be particularly harmful when the capacitor block is tightly pressed against the heat sink. This tight pressing is achieved, for example, by pressing the stressed elastic member against the outer face of the bottom of the housing so as to abut the relative outer face of the capacitor block against the heat sink. When the plane of the tightly pressed surface is parallel to the surface pushed by the elastic member, the heat dissipation generated by the capacitor block tightly pressed against the heat sink is optimal. At least two spacers determine the equal distance between the end stop and the bottom of the housing at each point on the end stop. Therefore, they help to keep the end stop parallel to the bottom of the housing. The spacer can promote the uniform distribution of the tight pressing force applied by the elastic member.

[0017] According to an embodiment of the present invention, the spacer has a cylindrical or conical shape.

[0018] In one embodiment of the present invention, the first end of the capacitor element comprises a first electrode of the capacitor element, and the capacitor block comprises a first electrical terminal pressed against the first electrode to be electrically connected to the first electrode, the first electrical terminal comprising at least one opening through which the spacer passes. The opening in the first electrical terminal allows for space saving. Specifically, there is no need to provide an overhang around the first electrical terminal at the bottom of the housing. This overhang will accommodate the spacer so that it passes beside the first electrical terminal and extends toward the end stop. Due to the opening in the first electrical terminal, this overhang can be omitted, thereby reducing the volume of the capacitor block. The opening can have various shapes. It can be composed of a hole of any possible shape. The opening can be a notch formed by an edge of the first electrical terminal. The opening can be obtained by cutting or any other means. The opening allows the spacer to pass through so that it can abut against the end stop.

[0019] According to an embodiment of the invention, the end stop comprises a second electrical connection terminal of the capacitor block, said second electrical terminal being pressed against the second electrode of the capacitor element so as to be electrically connected to said second electrode of the capacitor element. In a variant, said second electrode is included in the second end of the capacitor element.

[0020] According to a variant, the electrical connection between the second electrical terminal and the second electrode of the capacitive element is obtained by metallization. The metallization operation notably comprises obtaining a mechanical connection and an electrical contact between the electrode of the capacitive element and the corresponding electrical terminal by metallization.

[0021] In a variant, the electrical connection between the second electrical terminal and the second electrode of the capacitive element, in particular the electrical connection obtained by metal spraying, is covered with a lacquer so as to seal the electrical connection. In particular, the lacquer is spread over the entire second end of the capacitive element. The lacquer provides a seal at the second end without being bulky. The lacquer is, for example, a silicone lacquer.

[0022] In particular, the first or second electrical terminal may be a conductive plate or sheet.In particular, the first or second electrical terminal provides a connection of the capacitive element to an element external to the capacitive block.

[0023] The invention also relates to a method for assembling a capacitor block, comprising the following steps:

[0024] - providing a capacitive element having a first end and a second end as opposite ends, the end stop being fixed to the second end,

[0025] - mounting the capacitive element in a housing by means of a first end of the capacitive element so that a second end is outside the housing,

[0026] The mounting step comprises abutting at least one spacer against the end stop so as to determine the distance between the second end of the capacitive element and the bottom of the housing.Thus, the manufacture and use of expensive, complex or cumbersome tools is avoided.

[0027] According to one embodiment, the method comprises the following steps:

[0028] - at least partially filling the housing with a fluid potting material so as to at least partially, if not completely, fill the space between the capacitive element and the peripheral wall of the housing;

[0029] - Curing the potting material, in particular by heating, in particular in order to fix the capacitive element in the housing.

[0030] In this way, the capacitor element is fixed in the housing, and the first end of the capacitor block is sealed, and the capacitor block has a limited volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be better understood according to the following description:

[0032] - Figure 1 shows a capacitor block according to an exemplary embodiment of the present invention;

[0033] - Figure 2 Shows the formation Figure 1 The housing of the capacitor block;

[0034] - Figure 3 Shows Figure 1 electrical terminals of the capacitor block;

[0035] - Figure 4 Shown without housing Figure 1 Capacitor block;

[0036] - Figure 5 The capacitive elements of the capacitive block are shown. DETAILED DESCRIPTION

[0037] Figure 1 A capacitor block 1 according to an exemplary embodiment of the invention is shown. The capacitor block 1 is provided with a housing 14. The housing 14 forms a housing 3. The housing 14 comprises in particular a bottom 15 and a side wall 17 extending from the bottom 15. The bottom 15 and the side wall 17 delimit an inner volume of the housing 3. The housing 14 receives a first end 7 of a capacitor element 5 into the housing 3. The first end 7 is in particular embedded in a potting material 12, such as a resin, contained in the inner volume.

[0038] In the example shown, four capacitive elements 5 are arranged side by side in the housing 3. In the following, the example will be described with reference to only one 5a of the capacitive elements 5, the description of course applying to the other capacitive elements 5. An example of a capacitive element 5 is shown in FIG. Figure 5 As shown. The capacitive element 5 is particularly provided with a first electrode formed by its first end 7, and a second electrode of opposite polarity formed by a second end 9 opposite to the first end 7. Alternatively, the capacitive element 5 can have its electrodes together at a single end 7, 9. The capacitive element 5 is, for example, a film capacitor. The outer curvature of the capacitive element 5 then results from the manufacturing method of the capacitive element: the capacitive element 5 is particularly composed of a film wound in the form of a flat cylinder, the ends of which form the electrodes of the capacitor, in particular after a metallization step.

[0039] The first end 7 of the capacitive element 5 is embedded in a potting material 12 contained in the housing 3. The second end 9 of the capacitive element 5 extends out of the housing 3. The end stop 11 is fixed to the capacitive element 5 at the second end 9 of the capacitive element 5. The spacer 13 extends from the bottom 15 of the housing 3 to abut against the end stop 11, thereby determining the distance between the second end 9 of the capacitive element 5 and the bottom 15 of the housing 3. The illustrated example includes four spacers 13, but in the following, the example will be described with reference to two spacers 13a, 13b associated with the capacitive element 5a, the description of course being applicable to other capacitive elements 5 and their corresponding spacers 13.

[0040] In particular, the capacitor block 1 comprises a first electrical terminal 23 configured to connect the capacitor element 5 to an external element. In particular, the first electrical terminal 23 abuts against the first end 7 for electrical contact with the first electrode of the capacitor element 5. For this purpose, the first electrical terminal 23 particularly comprises a tongue 23L soldered to the first electrode of the capacitor element 5. The first electrical terminal 23 also comprises an opening 25 through which the spacer 13 passes so as to abut against the end stop 11.

[0041] The capacitor element 5 is provided with a first electrical terminal 23 and an end stop 11 to form a bare capacitor block 1N, ie a capacitor block 1 without a housing 14, such as Figure 4As shown. The bare capacitor block 1N is then installed in the housing 3 of the casing 14. During this installation, the first end 7 of the capacitor block 5 is introduced into the housing 14 so that the spacer 13 enters the opening 25 of the first electrical terminal 23. The introduction of the capacitor element 5 into the housing 14 is stopped by the contact between the top of the spacer 13 and the end stop 11. The positioning of the spacer 13 in the housing 14 is designed to correspond to the position of the opening 25. However, the spacer 13 is located in the empty space between the capacitor element 5 and the edge of the bottom 15 of the housing 3, that is, in particular, between the capacitor element 5 and the side wall 17. Therefore, once installed in the housing 3, the bare capacitor block 1N is supported by the spacer 13. In particular, a space is retained between the bottom 15 of the housing 3 and the first electrical terminal 23. In other words, the capacitor element 5 equipped with the first electrical terminal 23 is kept suspended by the spacer 13.

[0042] In particular, the side wall 17 of the housing 14 extends to a height that allows the potting material 12 to encapsulate the first end 7 of the capacitive element 5 and the first electrical terminal 23 .

[0043] The end stop 11 comprises in particular a second electrical connection terminal 27 of the capacitive block 5. Like the first electrical connection terminal 23, the second electrical connection terminal 27 is in particular configured to connect the capacitive element 5 to an external element. To this end, the second electrical connection terminal 27 abuts against a second electrode of the capacitive element 5 at the second end 9 of the capacitive element 5, which electrode is in particular formed by the second end 9. In particular, the lacquer is spread over the entire second end 9 of the capacitive element 5 to establish a seal at the second end 9.

[0044] In particular, the first electrical connection terminal 23 comprises an end 31 for providing a connection to a power electronics module. In particular, the second electrical connection terminal 27 comprises an end 33 intended to provide a connection to an electrical power source, in particular a battery.

[0045] like Figure 2 As shown, the spacers 13 are evenly distributed over the bottom 15 in order to provide a stable hold of the end stop 11 and thus of the capacitive element 5 .

[0046] The spacers 13 have in particular a conical shape with a polygonal cross section. However, they may have a different shape, for example the shape of a rod with a cylindrical, conical or circular cross section. The shape which tapers towards the end stop 11 combines the advantages of a firm base with an easy passage during installation.

[0047] The described example of a capacitor block 1 is otherwise similar to the example described in the publication of European patent application EP3197035, the description of which is incorporated into the present application.

Claims

1. A capacitor block (1) for an electrical device, comprising: - a housing (3), - at least one capacitive element (5) having a first end (7) housed in the housing (3) and a second end (9) opposite the first end (7) and extending out of the housing (3), - an end stop (11) fixed to the second end (9) of the capacitive element (5), at least one spacer (13) abutting against said end stop (11) so as to determine the distance between the second end (9) of the capacitive element (5) and the bottom (15) of said housing (3), The housing (3) is at least partially filled with a potting material (12) of resin so as to seal the capacitor element (5) at the first end (7) of the capacitor element (5), and the second end (9) of the capacitor element (5) extends out of the potting material (12).

2. The capacitor block (1) according to claim 1, wherein: The spacer (13) extends from a bottom (15) of the housing (3).

3. A capacitor block (1) as claimed in claim 1 or 2, comprising at least two spacers (13), and wherein: The spacers (13) are evenly distributed on the bottom (15) of the housing (3).

4. The capacitor block (1) according to claim 1 or 2, wherein: The spacer (13) has a cylindrical or conical shape.

5. The capacitor block (1) according to claim 1 or 2, wherein: The first end (7) of the capacitive element (5) comprises a first electrode of the capacitive element (5), and the capacitive block (1) comprises a first electrical connection terminal (23) pressed against the first electrode so as to be electrically connected to the first electrode, the first electrical connection terminal (23) comprising at least one opening (25) through which the spacer (13) passes.

6. The capacitor block (1) according to claim 1 or 2, wherein: The housing (3) is formed by the bottom and a side wall (17) extending from the bottom (15), defining an inner volume of the housing (3).

7. The capacitor block (1) according to claim 1 or 2, wherein: The end stop (11) comprises a second electrical connection terminal (27) of the capacitor block (1), the second electrical connection terminal (27) being pressed against a second electrode of the capacitor element (5) to be electrically connected to the second electrode of the capacitor element (5).

8. A method for assembling a capacitor block (1), comprising the following steps: - providing a capacitive element (5) having a first end (7) and a second end (9) as opposite ends, an end stop (11) being fixed to the second end (9); - mounting the capacitive element (5) in the housing (3) via the first end (7) of the capacitive element so that the second end (9) is outside the housing (3); The step of mounting the capacitive element (5) in the housing (3) via the first end (7) of the capacitive element comprises bringing at least one spacer (13) into abutment against the end stop (11) to determine the distance between the second end (9) of the capacitive element (5) and the bottom (15) of the housing (3).

9. The assembly method according to claim 8, comprising the following steps: - connecting a first electrical connection terminal (23) of the capacitor block (1) to a first electrode of the capacitor element (5), which electrode is contained in the first end (7), and connecting a second electrical connection terminal (27) of the capacitor block (1) to a second electrode of the capacitor element (5), which electrode is contained in the second end (9), said second electrical connection terminal (27) being contained in said end stop (11); and The step of mounting the capacitor element (5) in the housing (3) via the first end (7) of the capacitor element comprises passing a spacer (13) through an opening (25) in a first electrical connection terminal (23) so that it abuts against the end stop (11).

10. The assembly method according to claim 9, comprising the following steps: - at least partially filling the housing (3) with a fluid potting material (12) so as to at least partially fill, if not completely, the space between the capacitive element (5) and the peripheral wall of the housing (3); - Curing the potting material (12).

11. The assembly method according to claim 10, wherein: The curing of the potting material (12) is achieved by heating.

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