power electronics enclosure and device

Abstract

The invention relates to a housing (10) for a power electronics device (1) of an electric powertrain, for example for an inverter, the housing (1) comprising: - a base (11), - a set of peripheral walls (12) defining with the base a housing (15) suitable for receiving the components (20) of the power electronics device, - a cover (14) covering this housing (15), the housing (10) being characterized in that the set of peripheral walls (12) comprises a first part (121) fixed to the base (11) and a second part (122) attached or attachable to the cover (14), the cover (14) and the second part (122) of the set of peripheral walls (12) together forming a mass elastically connected to the first part of the set of peripheral walls. (Fig. 1)

Description

Title of the invention: Power electronic housing and device Technical field of the invention

[0001] The invention relates, in general, to the technical field of power electronic devices for electric powertrains, for example for motor vehicles. It relates more specifically, although not exclusively, to voltage inverter housings. Prior art

[0002] The emergence of electric motor vehicles as an alternative to or complement to internal combustion engines requires the use of an increasing number of electronic components. In particular, the use of inverters is necessary for electric motor vehicles using electric batteries. Indeed, the electric motors used in electric or hybrid vehicles generally consist of electromechanical converters, synchronous or asynchronous, whose operation most often requires the use of three-phase alternating current. However, the electric batteries of these vehicles deliver direct current, which must then be converted into alternating current.An inverter positioned near an electric motor within an electric powertrain allows, among other things, the transformation of direct current into alternating current.

[0003] Since an inverter is made up of fragile sub-components poorly adapted to the external conditions of a motor vehicle engine, these components are generally protected by a housing located in a dedicated space within the powertrain. Such a housing typically comprises a rigid body covered by a lid to isolate the electrical components inside.

[0004] When an electric or hybrid motor vehicle is in operation, vibrations, originating for example from the vehicle's mechanical gearboxes or from electromagnetic forces acting within the electric motor of the powertrain, are transmitted to the housing, and the cover is then likely to vibrate like a loudspeaker. When these vibrations have a frequency that matches the natural frequency of the cover, the vibrational energy of such movement generates noise pollution in the vicinity of the vehicle or for users located inside the vehicle's passenger compartment.

[0005] In the absence of corrective action, it is observed that in certain phases of vehicle use, the cover of an inverter of an electric powertrain is too often excited at its natural frequency.

[0006] To solve such a problem, it is known to decouple the cover and the body of the housing by inserting an elastic material between the body and the cover of the housing. Such a solution is described, for example, in document JP2020169572.

[0007] This solution makes it possible to lower the resonance frequency of the cover, but it turns out that on inverter housings of electric powertrains, this resonance frequency is still too high and the nuisances related to the vibrations of the cover are still annoying. Description of the invention

[0008] The invention aims to remedy all or part of the disadvantages of the prior art by proposing in particular a solution to avoid the phenomena of amplification of vibrations transmitted by a part of an electric vehicle powertrain (reducer, electric machine, etc.) to the housing of a power electronics device of this electric powertrain.

[0009] To this end, according to a first aspect of the invention, a housing for a power electronics device of an electric powertrain, for example for an inverter, is proposed, the housing comprising: - a base, - a set of peripheral walls defining with the base a housing suitable for receiving the components of the power electronics device, - a cover covering this housing, the housing being characterized in that the set of peripheral walls comprises a first part fixed to the base and a second part attached or attachable to the cover, the cover and the second part of the set of peripheral walls together forming a mass elastically connected to the first part of the set of peripheral walls.

[0010] The term "solidarisable" means the ability to be joined together while being, for example, removable.

[0011] Thus, compared with the known prior art solution, it is possible to further limit the vibration amplification phenomena, in particular during low-speed operation phases and lower the vibration level for higher speeds.

[0012] As this is a device intended for means of transport such as automobiles, it is also advantageous that the proposed solution does not add mass and that it has a small footprint. Here, the oscillating mass used for Vibration filtering is achieved through the inherent properties of the casing walls themselves, rather than relying on an external component solely for filtering. Therefore, the proposed solution adds no extra weight or bulk.

[0013] The invention may further include one or more of the following features:

[0014] According to one embodiment, the cover and the second part of the peripheral wall assembly are formed as a single unit, in particular in the same piece.

[0015] According to one embodiment, the cover and the second part of the peripheral wall assembly are formed on two separate pieces.

[0016] According to one embodiment, the cover and the second part of the peripheral wall assembly are mounted on top of each other in a removable manner.

[0017] Where appropriate, when the first part and the second part are not removable, the cover can form a movable cover.

[0018] According to one embodiment, fasteners such as screws can be used to assemble the cover and the second part of the peripheral wall assembly.

[0019] According to other embodiments, a thread can be provided on one of the cover and the second part of the peripheral wall assembly, and a complementary tapping can be provided on the other of the cover and the second part of the peripheral wall assembly.

[0020] Alternatively, a snap-on connection tab can be associated with one of the cover and the second part of the peripheral wall assembly and an additional snap-on connection housing can be provided on the other of the cover and the second part of the peripheral wall assembly.

[0021] According to one embodiment, the first part and the second part of the peripheral wall assembly are assembled one on top of the other in a removable manner.

[0022] Where appropriate, the cover and the second part of the peripheral wall assembly can jointly form a movable cover.

[0023] According to one embodiment, fasteners such as screws can be used to assemble the first and second parts of the perimeter wall assembly. The same fasteners can assemble the cover to the second part and the first part to the second part.

[0024] According to one embodiment, the housing comprises a first elastic connection linking the first part and the second part of the peripheral wall assembly. The first part and the second part are thus elastically connected.

[0025] According to one embodiment, the first part and the second part of the peripheral wall assembly are held together by means of at least one fastening element.

[0026] According to one embodiment, each fastening member includes a retaining portion directly or indirectly pressing the second part and the first part against each other when the fastening member is installed, and the housing includes a second elastic connection arranged between the retaining portion of said at least one fastening member and the second part of the peripheral wall assembly, or between the retaining portion of said at least one fastening member and the cover, or between the retaining portion of said at least one fastening member and the first part of the peripheral wall assembly.

[0027]

[0028] According to one embodiment, the second elastic connection is formed by a layer of elastic material fixed on the retaining portion of the fixing member so as to cooperate with the cover, the first or second part of the wall assembly.

[0029] According to one embodiment, each fastening member has a thread or tapped hole that can be screwed or is screwed into one of the first and second parts of the peripheral wall assembly, and the other of the first and second parts of the peripheral wall assembly is separated from the fastening member by the second elastic connection.

[0030] According to one embodiment, said at least one fastening member is a screw, the screw comprising a head and a shank having a threaded portion, the second part of the peripheral wall assembly comprising a through hole through which the shank passes; the head of the screw being pressed against one between the cover and the second part and the other between the cover and the first part comprising a tapping cooperating with the threaded portion of the shank of the screw.

[0031] According to one embodiment, said at least one fastening member comprises a stud and a nut, the stud having a shank comprising a threaded portion and being integral with the first part of the peripheral wall assembly, the second part of the peripheral wall assembly comprising a through hole through which the stud passes, the nut cooperating with the threaded portion of the stud.

[0032] According to one embodiment, the wall of the opening hole in the second part is distant from the rod. Thus, no vibration is transmitted by the rod to the second part of the peripheral wall assembly.

[0033] According to one embodiment, the second elastic connection extends over a face of the nut or the head of the screw which is pressed against the second part of the peripheral wall assembly, and is arranged around the rod.

[0034] In other words, when the screw is screwed into the first part, there is no rigid contact between the screw and the assembly consisting of the cover and the second part of the peripheral wall assembly.

[0035] According to one embodiment, the first elastic bond is formed by a layer of elastic material sandwiched between the first part and the second part of the peripheral wall assembly.

[0036] According to one embodiment, the first elastic connection surmounts the first part of the wall assembly around the components.

[0037] The first elastic connection provides a watertight link between the first part and the second part. The first elastic connection is, for example, an elastic material that runs along the entire perimeter of the walls.

[0038] According to one embodiment, the first part and the second part of the peripheral wall assembly are assembled to each other in a non-removable manner by means of the first elastic connection which is fixed on one side to the first part of the peripheral wall assembly and on the other side to the second part of the peripheral wall assembly.

[0039] Where appropriate, the first elastic connection can be glued, overmolded or clipped to both the first part and the second part of the peripheral wall assembly.

[0040] According to one embodiment, the housing comprises a plurality of fastening members, for example four, five or six. They can be arranged, for example, in the corners of the housing.

[0041] The invention also relates to a power electronics device comprising a housing as described above.

[0042] According to one embodiment, the components of the power electronics device are arranged at least partly in the volume defined by the second part of the peripheral wall assembly.

[0043] According to one embodiment, the second part of the wall assembly and the cover together represent, by mass, at least 20% of the mass of the casing, in particular at least 35%, in particular at least 50%.

[0044] According to one embodiment, all components are supported by the first part of the peripheral wall assembly and / or the bottom of the housing.

[0045] According to one embodiment, the elastic stiffness "k" between the first part and the second part of the peripheral wall assembly, and the mass "m" of the second part of the peripheral wall assembly and the cover combined, are such that: f (Res) ~ 200Hz

[0046] For a resonant frequency of 200 Hz, the frequency range for which vibration amplification is observed at the level of the inverter cover is approximately 140 Hz - 280 Hz. The threshold of 200 Hz is therefore retained because it has been observed by the inventors that the frequency content of the noises observed on the powertrain groups is located beyond.

[0047] According to this configuration, the solution makes it possible to lower the resonance frequency of the lid below the critical excitation frequencies at low speed (in particular 200Hz), and to filter the vibrations transmitted to the lid over a higher frequency range, in particular between 250 Hz to 1000 Hz for example).

[0048] According to another aspect, the invention also relates to a powertrain comprising a housing as defined above.

[0049] Other features and advantages of the invention are highlighted by the following description of non-limiting examples of implementation of the various aspects of the invention. brief description of the figures

[0050] Other features and advantages of the invention will become apparent from the following description, with reference to the accompanying figures, which illustrate:

[0051] [Fig-1]: a schematic diagram of a first embodiment of the invention,

[0052] [Fig.2]: a schematic diagram of a second embodiment of the invention,

[0053] [Fig.3]: a schematic diagram of a third embodiment of the invention,

[0054] [Fig.4]: a schematic diagram of a fourth embodiment of the invention,

[0055] [Fig.5]: a schematic diagram in perspective and exploded view of the fourth embodiment of the invention,

[0056] [Fig.6]: a schematic diagram of a fifth embodiment of the invention,

[0057] [Fig.7]: a schematic diagram of a sixth embodiment of the invention,

[0058] [Fig.8]: a schematic diagram of a seventh embodiment of the invention,

[0059] For clarity, identical or similar elements are identified by symbols identical reference points across all figures. DETAILED description of a method of implementation

[0060] With reference to figures 1 ([Fig.1]) to 8 ([Fig.8]) are illustrated partial schematic views of a power electronics device 1 of an electric powertrain, such as an inverter of a motor vehicle.

[0061] Under normal conditions, all vibrations related to the gears, electromagnetic forces, and the operation of the inverter are transmitted to the inverter housing 10. The cover 14 of the inverter housing 10 has a significant surface area and therefore acts like a loudspeaker to diffuse the noise.

[0062] [Fig. 1] schematically illustrates a housing 10 of such an inverter, the housing 10 comprising: - a base 11, - a set of peripheral walls 12 defining with the base a housing 15 inside which the components 20 of the power electronics device are housed, - a cover 14 covering this dwelling 15.

[0063] The peripheral wall assembly 12 comprises a first part 121 fixed to the bottom 11 and a second part 122 attached to the cover 14.

[0064] When the device is viewed with the bottom at the bottom, the first part of the peripheral wall assembly 12 corresponds to the lower part and the second part of the peripheral wall assembly 12 corresponds to the upper part.

[0065] The cover 14 and the second part 122 of the peripheral wall assembly 12 together form a mass elastically connected to the first part 121 of the peripheral wall assembly 12. The resonance frequency of this association is such that:

[0066] Res

[0067] with k: the stiffness of the elastic connection between the first part and the second part of the peripheral wall assembly; and m: the mass corresponding to the second part of the wall assembly and the cover.

[0068] In the context of an inverter for a powertrain, the casing will be sized and the casing materials, in particular the elastic connection, will be chosen so that f ( Res ) < 200 Hz.

[0069] It is observed that the components 20 of the power electronics device are arranged partly within the volume defined by the second part 122 of the peripheral wall assembly 12. Thus, part of the peripheral walls of the housing 10 is used to increase the mass of the mass / spring damper in order to lower the resonance frequency and filter the vibrations transmitted to the cover 14.

[0070] The second part of the wall assembly and the cover together represent, by mass, at least 20% of the mass of the housing, in particular at least 35%, in particular at least 50%. The greater the mass allocated to the cover 14 and to the second part 122 of the peripheral wall assembly 12, the lower their resonant frequency can be.

[0071] All components are preferably carried by the first part 121 of the peripheral wall assembly 12 and / or the bottom 11 of the housing 10. Thus, the electrical / electronic components are not likely to oscillate with the cover and the second part 122 of the peripheral wall assembly 12 and can be easily put in place.

[0072] In the first embodiment, the cover 14 and the second part 122 of the peripheral wall assembly 12 are formed as a single unit, in particular in the same piece.

[0073] The electrical device 20 can be received in the housing in a given direction, here vertically with respect to the figures.

[0074] The cover 14 extends along a reference plane P and is configured to cover and protect the components 20 of the power electronics device.

[0075] The first elastic bond 30 is formed by a layer of elastic material sandwiched between the first part 121 and the second part 122 of the peripheral wall assembly 12.

[0076] The first elastic connection 30 arranged between the first part 121 and the second part 122 of the peripheral wall assembly 12 can be fixed or removable.

[0077] When the first elastic connection is inmovable, the elastic material can be glued, clipped or overmolded both on the first part 121 and on the second part 122 of the peripheral wall assembly 12. The clipping can be done by complementary shape between the elastic material and a groove of the first and / or the second part, for example with a dovetail shape.

[0078] To facilitate maintenance of the components of the power electronics device 1 of [Fig. 1], a removable elastic connection is preferred in the first embodiment. In this case, the cover 14 and the second part 122 of the peripheral wall assembly 12 then form a movable cover. The first elastic connection is fixed, for example, by gluing it to one or the other of the first and second parts, or by clamping it without being previously fixed to either of the first and second parts.

[0079] It can be seen in the second embodiment of [Fig.2] that the first part 121 and the second part 122 of the peripheral wall assembly 12 can also be assembled to each other in an indestructible manner by means of the first elastic connection 30 which is fixed on one side to the first part 121 of the peripheral wall assembly 12 and on the other side to the second part 122 of the peripheral wall assembly.

[0080] Where appropriate, the first elastic connection 30 can be glued, clipped or overmolded both on the first part 121 and on the second part 122 of the peripheral wall assembly 12.

[0081] Therefore, in this second embodiment, the cover 14 and the second part 122 of the peripheral wall assembly 12 are advantageously formed on two separate pieces, the cover 14 being movable and attachable to the second part 122 of the peripheral wall assembly 12. These two pieces are therefore mounted one on top of the other in a removable manner, the cover 14 thus forms a movable cover. Fastening devices 70 such as screws can be used to assemble the cover 14 and the second part 122 of the peripheral wall assembly 12.

[0082] The embodiment of [Fig. 3] is feasible when the cover, forming a removable lid, has a circular shape. The screw device 70 is replaced by a thread formed on the cover 14 and a complementary tapped hole formed on the second part 122 of the peripheral wall assembly 12, or vice versa.

[0083] Alternatively, a snap-on connection tab can be associated with one of the cover and the second part of the peripheral wall assembly and an additional snap-on connection housing can be provided on the other of the cover and the second part of the peripheral wall assembly.

[0084] According to other embodiments, the first part 121 and the second part 122 of the peripheral wall assembly 12 can also be assembled one on top of the other in a removable manner.

[0085] Where appropriate, the cover 14 and the second part 122 of the peripheral wall assembly 12 can jointly form a movable cover.

[0086] In the example of [Fig.4], screws are used to assemble the first part 121 and the second part 122 of the peripheral wall assembly 12.

[0087] The first part 121 and the second part 122 of the peripheral wall assembly 12 are held together by means of screws 60, each comprising a shank 65 having a threaded portion 651 anchored in a thread in the first part 121, and a head 63 pressing the second part 122 directly or indirectly against the first part 121 of the peripheral wall assembly 12. If the cover 14 and the second part 122 of the peripheral wall assembly 12 are formed on two separate pieces (in particular to simplify their manufacture), the screws 60 allow both the cover 14 and the second part 122 of the peripheral wall assembly 12 to be joined together and the second part 122 and the first part 121 of the peripheral wall assembly 12 to be assembled with the housing 12.

[0088] A second elastic link 40 is arranged between the screw head 63 and the cover 14.

[0089] This second elastic link 40 is formed by a layer of elastic material fixed on the head 63 of the screw 60 so as to be pressed between the screw head 63 and the cover 14. The second elastic link can also be a separate washer interposed during assembly between the cover 14 and the screw head 63. This embodiment is schematically shown in [Fig. 5].

[0090] As can be seen in [Fig. 5], the first elastic bond 30 surmounts the first part of the peripheral wall assembly around the electrical and / or electronic components. In other words, it is arranged continuously between the first part and the second part of the peripheral wall assembly 12 around the components.

[0091] The elastic materials used for the first and second elastic bonds can be elastomeric materials, for example of the HNBR type which exhibit very good resistance to thermal stresses.

[0092] The second part 122 of the peripheral wall assembly 12 includes a through hole 1221 through which the shank 65 of the screw 60 passes, while another hole, such as a blind hole with a threaded hole, is provided in the first part 121. To prevent vibrations from being transmitted by the shank to the second part of the peripheral wall assembly, the wall of the through hole 1221 of the second part 122 is separated from the shank 65. Thus, there is no direct contact between the screw 60 and the assembly consisting of the cover 14 and the second part 122 of the peripheral wall assembly 12. In this configuration, the screws are associated with the first part, i.e., upstream of the mass-spring system.

[0093] In the example of [Fig.6], the screw is mounted in the opposite direction.

[0094] The shank 65 of the screw 60 having the threaded portion 651 is anchored in a tapped hole of the second part 122 of the peripheral wall assembly 12. The head 63 of the screw 60 presses directly or indirectly the first part 121 against the second part 122 of the peripheral wall assembly 12. In this example, the cover 14 and the second part 122 of the peripheral wall assembly 12 are formed on the same piece.

[0095] A second elastic link 40 which can have the same characteristics as before is arranged between the screw head 63 and the first part 121 of the peripheral wall assembly 12.

[0096] This second elastic link 40 can for example be formed by a layer of elastic material fixed on the head 63 of the screw 60 so as to be pressed between the screw head 63 and the first part 121.

[0097] The fastening elements are associated here with the second part and therefore contribute to the mass of the mass-spring system.

[0098] In the embodiment of [Fig.7], each fastening member 60 comprises a stud 66 and a nut 67, the stud 66 having a shank 662 comprising a threaded portion 661 and being integral with the first part 121 of the peripheral wall assembly 12. The second part 122 of the peripheral wall assembly 12 comprises a through hole 1221 through which the stud 66 passes, the nut 67 cooperating with the threaded portion 661 of the stud 67 projecting out of the peripheral wall assembly 12. In the mass-spring system, each nut is associated here with the first part 121 of the peripheral wall assembly 12, i.e. upstream of the mass-spring system.

[0099] The second elastic link 40 extends over an underside face of the nut 67.

[0100] In the last figure, the fastening member is a removable hook 60. A second elastic connection 40 is required between the head of the hook and the second part 122 of the peripheral wall assembly 12.

[0101] Each time, the housing 10 of the inverter I may have a generally parallelepiped shape, it being understood that it may have any other geometric shape.

[0102] Given the nature of the power electronics device 2 and to protect it from any residual dust, the housing is preferably sealed.

[0103] Naturally, the invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different embodiments of the invention without departing from the scope of the invention.

[0104] It is emphasized that all features, as they are apparent to a person skilled in the art from the present description, drawings and attached claims, even if in practice they have only been described in relation to other specific features, both individually and in any combinations, can be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances make such combinations impossible or meaningless.

Claims

Demands

1. Housing (10) for a power electronics device (1) of an electric powertrain, for example for an inverter, the housing (1) comprising: - a base (11), - a set of peripheral walls (12) defining with the base a housing (15) suitable for receiving the components (20) of the power electronics device, - a cover (14) covering this housing (15), the housing (10) being characterized in that the set of peripheral walls (12) comprises a first part (121) fixed to the base (11) and a second part (122) attached or attachable to the cover (14), the cover (14) and the second part (122) of the set of peripheral walls (12) together forming a mass elastically connected to the first part of the set of peripheral walls.

2. Housing (10) according to claim 1 in which the cover (14) and the second part (122) of the peripheral wall assembly (12) are formed in one piece, in particular in the same piece.

3. Housing (10) according to claim 1 in which the cover (14) and the second part (122) of the peripheral wall assembly (12) are formed on two separate pieces.

4. Housing (10) according to claim 3 in which the cover (14) and the second part (122) of the peripheral wall assembly (12) are mounted removably on top of each other.

5. Housing (10) according to any one of claims 1 to 4 in which the first part (121) and the second part (122) of the peripheral wall assembly (12) are removably assembled one on top of the other.

6. Housing (10) according to any one of claims 1 to 5 comprising a first elastic link (30) connecting the first part (11) and the second part (12) of the peripheral wall assembly (12).

7. Housing (10) according to any one of claims 1 to 6 in which the first part (121) and the second part (122) of the peripheral wall assembly (12) are held together by means of at least one fastening member (60).

8. Housing according to claim 7 in which each fastening member comprises a retaining portion (32) directly or indirectly pressing the second part and the first part against each other when the fastening member is installed, and the housing comprises a second elastic connection (40) arranged between the retaining portion (32) of said at least one fastening member (30) and the second part (122) of the peripheral wall assembly (12) or between the retaining portion (32) of said at least one fastening member (30) and the cover (14), or between the retaining portion (32) of said at least one fastening member (30) and the first part (122) of the peripheral wall assembly (12).

9. Housing according to claim 7 or 8 in which each fastener (60) has a thread or tapping that can be screwed or is screwed into one of the first part (121) and the second part (122) of the peripheral wall assembly (12), and the other of the first part (121) and the second part (122) of the peripheral wall assembly (12) is separated from the fastener by the second elastic link (40).

10. Housing (10) according to any one of claims 7 to 9 in which said at least one fastener (60) is a screw (60), the screw (60) comprising a head (63) and a shank (65) having a threaded portion (651), the second part (122) of the peripheral wall assembly (12) comprising a through hole (1221) through which the shank (65) passes; the head of the screw being pressed against one between the cover (14) and the second part (122) and the other between the cover (14) and the first part (121) comprises a tapped hole (1211) cooperating with the threaded portion (651) of the shank (65) of the screw (60).

11. Housing (10) according to claim 10 in which the wall of the through hole of the second part is distant from the rod 65.

12. Housing (10) according to claim 8 combined with claim 10 or 11 in which the second elastic link (40) is arranged on one face of the head (63) of the screw (60) which is pressed against the second part (122) of the peripheral wall assembly (12), and is arranged around the rod.

13. Housing (10) according to claim 6 in which the first elastic bond (30) is formed by a layer of elastic material sandwiched between the first part (121) and the second part (122) of the peripheral wall assembly (12).

14.

15.

16.

17. Housing (10) according to any one of the preceding claims wherein the second part (122) of the wall assembly and the cover (14) together represent, by mass, at least 20% of the mass of the housing, in particular at least 35%, in particular at least 50%. Power electronics device comprising a housing according to one of the preceding claims. Power electronics device according to the preceding claim comprising components carried by the first part 121 of the peripheral wall assembly and / or the bottom of the housing 10. Power electronics device according to any one of claims 15 or 16 in which the components of the power electronics device are arranged at least partly in the volume defined by the second part of the peripheral wall assembly.

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