Retaining device within a power electronics device.

Abstract

Title of the invention: Retaining device within a power electronics device. The present invention relates to a power electronics device (2) comprising a housing (4) in which at least one electronic component is housed, the power electronics device (2) comprising a printed circuit board to which signal transmission pins (16) are connected, capable of transmitting information relating to the current flowing in the power electronics device (2), the housing (4) comprising a retaining device (28) extending from a wall (22) of the housing (4) contributing to the delimitation of the internal housing (8), the retaining device (28) being configured to hold the signal transmission pins (16) in position. (Figure 1)

Description

Title of the invention: Retaining device within a power electronics device.

[0001] The present invention relates to the field of electronics and electrical engineering, and more particularly to the field of power electronic devices.

[0002] Power electronics devices are electrical devices integrated into many types of equipment, particularly motor vehicles such as electric or hybrid vehicles. These power electronics devices typically comprise a housing delimiting an internal space within which at least one electrical component is housed, and a printed circuit board on which other components such as integrated circuits, capacitors, or inductors are installed.

[0003] These power electronic devices may include voltage converters designed to perform a conversion between direct current and alternating current. In electric or hybrid vehicles, these voltage converters are typically interposed between an electrical energy storage device and an electric machine designed to generate the vehicle's drive torque to enable its movement.

[0004] For this purpose, the power electronics device is electrically connected by a first set of electrical connections to the means of electrical energy storage and by a second set of electrical connections to the electrical machine and includes a plurality of electronic components capable of generating a conversion of the electrical current between the two sets of connections.

[0005] In this context, it may be useful to retrieve information relating to the electrical current flowing between the electrical energy storage device and the power electronics device, for example, to control the operation of the electronic components and provide them with appropriate control instructions. To retrieve this information, it is known to implement signal pins extending from connection buses of the first electrical connection set to the printed circuit board, the signal pins being connected to the printed circuit board via their free end opposite the first electrical connection set. In particular, it is known to pass the ends of the signal pins through the printed circuit board to allow this end to cooperate with a mounting device on the printed circuit board.

[0006] Although functional, this solution is not optimal because the positioning of the signal pin ends in the mounting device must be precise, and the fact that these pins are supported by the connection buses of the first electrical connection assembly introduces a large number of manufacturing and assembly tolerances. Furthermore, signal pins are typically made as thin strips, which are susceptible to deflection, and their cantilevered positioning on the connection buses promotes such deflection. This can result in the signal pin ends being pressed into the mounting devices, which generates material particles from the pins due to friction against the mounting means. Moreover, this arrangement necessitates positioning the signal pins in close proximity to the connection buses of the first electrical connection assembly.

[0007] The present invention falls within this context and aims to overcome at least some of the drawbacks of the prior art.

[0008] Thus, the present invention relates to a power electronics device comprising a housing defining an internal compartment in which at least one electronic component is housed, the at least one electronic component being electrically connected to a positive polarity branch and a negative polarity branch, the polarity branches being configured to connect the power electronics device to an electrical energy storage means, the power electronics device comprising a printed circuit board on which are connected signal transmission pins capable of transmitting information relating to the current flowing in the positive and negative polarity branches, the housing comprising a retaining device extending from a wall of the housing participating in delimiting the internal compartment, the retaining device being configured to hold the signal transmission pins in position.

[0009] The power electronics device can form a voltage converter configured to perform, in particular, a conversion between a direct current and an alternating current. For this purpose, the power electronics device is placed between an electrical energy storage device and an electrical machine. By way of example, at least one electrical component forms a capacitor that smooths voltage peaks during the conversion.

[0010] The positive and negative polarity branches ensure the circulation of a high-voltage electric current, i.e., of at least 800 V. These polarity branches are electrically connected to at least one electronic component and to the electrical energy storage means, if applicable, via other complementary polarity branches.

[0011] The signal transmission pins are separate from the polarity branches. The signal transmission pins carry an electric current of lower voltage than that flowing in the polarity branches, and for this purpose, the signal transmission pins are thinner than the connecting buses forming the polarity branches. The signal transmission pins are connected to the printed circuit board and, in particular, allow the transmission of information relating to the electric current flowing in the polarity branches. It should be noted that the signal transmission pins are not directly electrically connected to the polarity branches.

[0012] In addition, the signal transmission pins extend substantially from the bottom of the housing, near at least one electronic component, towards the printed circuit board in a main extension direction substantially perpendicular to the plane of a bottom wall of the housing.

[0013] The retaining device maintains the perpendicularity of the signal transmission pins to the back wall, that is, maintains their theoretical position for mounting on the printed circuit board. Indeed, due to their thinness and considerable length, the signal transmission pins can be subject to bending deformations, which are mitigated by the retaining device. It is understood that the retaining device forms a support element that maintains the position of the signal transmission pins, both relative to each other and to the back wall of the enclosure, and therefore to the mounting points on the printed circuit board designed to receive them.

[0014] According to one feature of the invention, the signal transmission pins are connected to the printed circuit board via a free end of a substantially straight main portion, the retaining device extending at least in part along said main portion.

[0015] The retaining device acts as a support, preventing deformation of the signal pins in all possible directions. Thus, the retaining device ensures that the position of the signal transmission pins is fixed and cannot change. Such a change in the position of the signal transmission pins would lead to a defect during the assembly of the power electronics device and the risk of generating particles through friction of the signal transmission pins in their designated mounting device. By extending along the main portion of the signal transmission pins, the retaining device is sufficiently close to the main portion to be able to support the stresses exerted on the signal transmission pins, particularly during the assembly of these pins on the printed circuit board, without risk of breakage of these pins.

[0016] According to one feature of the invention, the signal transmission pins include a recess, the retaining device extending within the recess of the signal transmission pins.

[0017] The recess allows the corresponding pin to be positioned overlapping the retaining device, thus improving, simply by sliding the retaining device within the recess, the cooperation between the retaining device and the signal transmission pins. In this way, the stresses exerted on the signal transmission pins are better absorbed by the retaining device in all conceivable directions of deformation.

[0018] According to one feature of the invention, the signal transmission pins comprise the main portion and a base portion substantially perpendicular to said main portion and linking the latter to the electronic component, the recess extending along the main portion up to the junction between the main portion and the base portion.

[0019] The fact that the recess also extends over the base portion allows the retaining device to be inserted into the signal transmission pins without it coming into contact with the base portion. In other words, a notch is made in the base portion of the signal transmission pins which allows the retaining device to slide along the recess in an insertion movement that is parallel to the direction of extension of the main portion and the retaining device.

[0020] According to one feature of the invention, the retaining device has a principal part substantially straight and parallel to the principal portion of one of the corresponding signal transmission pins, the thickness of the principal part being greater than the thickness of the principal portion.

[0021] Thus, the retaining device has a rigidity greater than that of the signal transmission pins, which allows it to respond effectively to the stresses, and in particular to the bending stresses, exerted against the signal transmission pins.

[0022] According to one feature of the invention, a free edge of the signal transmission pins extends beyond the retaining device in a main elongation direction along which the retaining device and the signal transmission pins extend.

[0023] Thus, it is possible to connect the signal transmission pins to the printed circuit board without the retaining device interfering with this connection.

[0024] According to one feature of the invention, the internal housing is filled with a filling material, the retaining device and the signal transmission pins forming respectively protrusions from the filling material.

[0025] According to a feature of the invention, the retaining device extends over at least 50% of the main dimension of at least one of the signal transmission pins.

[0026] This length ensures that the contact between the retaining device and the signal transmission pins is sufficient to limit the risk of bending of the signal transmission pins.

[0027] According to one feature of the invention, the retaining device includes at least one groove disposed at a free end of the retaining device and in which is housed an edge of the recess formed in at least one of the signal transmission pins.

[0028] This groove makes it possible to effectively retain said signal transmission pin with the retaining device.

[0029] According to one feature of the invention, the groove forms a groove fitted to the dimensions of the part of at least one signal transmission pin housed in the groove.

[0030] This adjustment limits the movement of the signal transmission pins relative to the retaining device.

[0031] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and the illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0032] [Fig-1] partially represents a power electronics device, showing in particular a housing suitable for housing an electronic component not shown here, polarity branches through which a high voltage current flows, signal transmission pins for transmitting information relating to an electric current flowing within the power electronics device and a device for retaining the signal transmission pins;

[0033] [Fig.2] schematically represents a more detailed view of the housing and device of visible retention on the [Fig.l];

[0034] [Fig.3] schematically represents a cross-sectional view of the retaining device making visible the main parts extending along a stacking direction and at the end of which a groove is made;

[0035] [Fig.4] schematically represents a cross-sectional view, in perspective and rendering The cooperation between the retaining device and the signal transmission pins is visible. one edge of a recess made in the signal transmission pins being housed in the groove visible on the [Fig.3];

[0036] [Fig.5] schematically represents a more detailed view of the pins of signal transmission making visible the recess made within said signal transmission pins;

[0037] [Fig.6] schematically represents a cross-sectional view of the electronic device of power making visible a filling material present in an internal housing defined by the housing, the signal transmission pins and the retaining device forming protrusions of said filling material.

[0038] The features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0039] In the figures, the elements common to several figures retain the same reference.

[0040] Figure 1 schematically illustrates part of a power electronics device 2 comprising a housing 4 defining an internal compartment 6 in which at least one electronic component is housed, not shown here. In the embodiment shown, the power electronics device 2 is a voltage converter intended to perform a conversion between a direct current and an alternating current.

[0041] Also, in the embodiment shown, the power electronics device 2 is intended to equip an electric or hybrid vehicle. Within this electric or hybrid vehicle, the power electronics device 2 is interposed between an energy storage means and an electric machine. The electrical energy storage means forms, for example, a vehicle battery intended at least to store electrical energy and transmit it to the electric machine to ensure its operation. The electric machine is, for example, part of a powertrain and is intended to generate drive torque to enable the electric or hybrid vehicle to move.

[0042] To this end, at least one electronic component may, as in the embodiment shown, be a coupling capacitor intended to filter the electric current flowing through the power electronics device 2 between the battery and the electric machine. The at least one electronic component is arranged on a plate of The cooling element 8 is connected, on the one hand, to a positive polarity branch 10 and a negative polarity pin 12 for connection to the electrical energy storage system, and on the other hand, to power modules via two positive and negative connection branches 14, which are partially overlapped. The polarity branches 10 and 12 are designed to carry a high-voltage electric current, in particular on the order of 800 V, which allows the power electronics device to supply electrical energy to the electric machine at its output to ensure its operation and, in particular, to generate the driving torque of the motor vehicle.

[0043] The polarity branches 10, 12 visible in [Fig. 1] are electrically connected to other branches of their respective polarities joining the electrical energy storage means. Optionally, the polarity branches 10, 12 may extend through a printed circuit board 5, shown schematically in [Fig. 4]. More specifically, the power electronics device 2 comprises this printed circuit board 5, which is positioned opposite the internal housing 6 of the enclosure 4. Furthermore, the power electronics device 2 may include a housing that is attached to the enclosure 4 or that encloses the enclosure 4 so as to protect the various elements of the power electronics device 2, such as the printed circuit board.

[0044] In addition, the power electronics device 2 includes signal transmission pins 16 and in particular a positive signal transmission pin 18 and a negative signal transmission pin 20. The signal transmission pins 16 are electrically connected at one end to the electronic component and at the opposite end to the printed circuit board 5. It should be noted that the signal transmission pins 16 are not directly connected to the polarity branches 10, 12 but rather to the electronic component.

[0045] These signal transmission pins 16 enable the transfer of electrical data, and in particular instructions or operating data of the electronic component. It is understood that the signal transmission pins 16 are intended to ensure the flow of an electric current at a relatively low voltage compared to the voltage of the electric current flowing in the positive and negative polarity branches 10, 12.

[0046] As can be seen in [Fig. 1], the signal transmission pins 16 extend mainly along a principal elongation direction, having a first end connected to the electronic component which is located near a bottom wall 22 of the housing 4 on which at least one electronic component is located, and a second end which is connected to the printed circuit board 5. This principal elongation direction is thus parallel to a stacking direction D of the printed circuit board in relation to the internal housing 6 of the housing 4. Indeed, during the assembly of the power electronics device 2, the positive and negative polarity branches 10, 12 as well as the signal transmission pins 16 are first secured to at least one electronic component then the printed circuit board 5 is brought into relation to the internal housing 6 so that the positive and negative polarity branches 10, 12 extend through an opening made in the printed circuit board 5 and the signal transmission pins 16 are electrically connected to electrical traces made on the printed circuit board 5.

[0047] By way of illustrative and non-limiting example of the invention, the signal transmission pins 16 can be electrically connected to the printed circuit board via a fastening system 17 disposed on the printed circuit board and configured to clamp a free edge 24 of the signal transmission pins 16 as they pass through the printed circuit board during its assembly onto the housing. For this purpose, the free edge 24 of the signal transmission pins 16 forms the end of a main portion 26 of each signal transmission pin 18, 20 which extends substantially straight along the main elongation direction of the signal transmission pins 16.

[0048] The fact that the signal transmission pins 16 include this substantially straight main portion 26 makes it easy to assemble the printed circuit board onto the housing 4, in which at least one electronic component electrically connected to the signal transmission pins 16 is previously placed. Indeed, to ensure this assembly easily, it is sufficient to place the printed circuit board opposite the internal housing 6 of the housing 4 and then bring the housing 4 closer to the printed circuit board along the main elongation direction, ensuring that the free edge 24 of the signal transmission pins 16 and an opening, formed in the printed circuit board and associated with the fastening system, are aligned along said main elongation direction.

[0049] In addition, the power electronics device 2, and more specifically the housing 4, includes a retaining device 28. This retaining device 28 is more easily visible in figures 2 to 4.

[0050] The retaining device 28 is configured to hold the signal transmission pins 16 in position. Indeed, the signal transmission pins 16 have a thickness, measured perpendicular to the principal elongation direction and forming the smallest dimension of the signal transmission pins 16, which is thin compared to the dimension of these signal transmission pins along the principal elongation direction. It is understood that without an associated retaining device, and particularly under the effect of their own weight, the signal transmission pins signal 16 could be caused to bend so that the straight portion could tilt relative to the stacking direction D, which would degrade the quality as well as the ease of assembly of the free edge 24 of the signal transmission pins 16 with the printed circuit board.

[0051] The retention of the signal transmission pins 16 by the retaining device 28 thus makes it possible to ensure that the main elongation direction, in particular of the main straight portion 26, is parallel to the stacking direction of the printed circuit board 5 with respect to the housing 4.

[0052] The retaining device 28 extends from at least one wall of the housing 4 which helps to define the internal housing 6. In the embodiment shown in particular in [Fig.2], the retaining device 28 extends in particular from the bottom wall 22. Alternatively or in addition, the retaining device 28 may extend from a peripheral wall 30 extending here in a plane perpendicular to the bottom wall 22.

[0053] Furthermore, and as can be seen in [Fig. 3], the retaining device 28 comprises a body 32, here integral with the bottom wall 22, and a return wall 34 integral with the peripheral wall 30. The body 32 forms a solid surface from which extends a main part 36 of the retaining device 28. Here, the retaining device 28 comprises two main parts 36, each main part 36 being associated with a separate signal transmission pin 18, 20.

[0054] Like the main portions 26 of the signal transmission pins 16, the main parts 36 of the retaining device 28 extend in a straight line parallel to the stacking direction previously mentioned and therefore parallel to the main elongation direction of the main portions 36. Also, these main parts 36 extend from the body 32 of the retaining device 28 with a gap between the main parts 36 equal to the gap between the main portions 26 of the signal transmission pins 16.

[0055] The main parts 36 of the retaining device 28 have a thickness, measured parallel to the thickness of the signal transmission pins 16, greater than the thickness of the straight main portion 26 of the signal transmission pins 16. This greater thickness of the main parts 36 compared to the main portions 26 gives the main parts 36 of the retaining device greater rigidity than the signal transmission pins and makes the retaining device less sensitive to possible deflections, which allows it to play its role as a support for the signal transmission pins 16.

[0056] Each main portion 26 of the signal transmission pins 26 is housed in a main portion 36 of the retaining device 28. For this purpose, the main portions 36 of the retaining device 28 have at a free end 38, opposite the bottom wall of the housing, a groove 40 made in the thickness of the main parts 36. This groove 40 is intended, as seen in [Fig.4], to house a part of the main portion 26 of the signal transmission pins 16. It should be noted that in order to allow the electrical connection of the signal transmission pins 16 to the printed circuit board, the free edge 24 of each signal transmission pin 18, 20 extends along the main elongation direction beyond the retaining device 28 and the free ends 38 of the main parts 36 of this retaining device.

[0057] Figure 5 illustrates more specifically the signal transmission pins 16. As can be seen in Figure 5, each of the signal transmission pins 16 comprises a recess 42 formed in the main portion 26, this recess 42 extending along the elongation direction of the main portion 26. As can be seen in Figure 4, this recess 42 is formed in a signal transmission pin 16 to allow the cooperation of this pin with a corresponding main portion 36 of the retaining device 28 and more particularly to allow the signal transmission pin to be threaded around the retaining device 28 dedicated to it until an edge 44 of the recess 42 matches the groove 40.It is understood that in order to accommodate the edge 44 of the recess 42 in the groove 40 while minimizing the possible movement of the signal transmission pin, the groove 40 forms a groove fitted to the dimensions of the edge 44 of the recess 42 housed in the groove 40. It is noteworthy in [Fig.3] that the groove 40 is delimited by two elongated portions 48, each having a chamfer 50 oriented opposite the groove 40 and facilitating the insertion of the edge 44 of the recess 42 in a context where the dimensions of the bottom of the groove 40 and of the signal transmission pins, in a given cutting plane, are fitted.

[0058] Furthermore, each signal transmission pin 18, 20 comprises a base portion 46 extending intersecting the main portion 26, and here substantially perpendicular to said main portion 26. This base portion 46 is specifically intended to allow electrical connection to the associated electronic component. The recess 42 extends into this base portion 46, forming a clearance zone at the junction of the base portion 46 and the main portion 26, so that this base portion 46 does not interfere with the central part 36 of the retaining device 28 when the latter and the signal transmission pin slide relative to each other to reach their final position in which the groove 40 cooperates with the edge 44 of the recess 42.

[0059] It should be noted that it is understood from the foregoing that the retaining device 28 is made of an electrically insulating material, such as a material plastic, so that contact between the signal transmission pins 16 and the retaining device 28 is not likely to generate a short circuit.

[0060] Furthermore, the internal housing 6 is filled with a filler material 52, such as resin, which is injected once the electronic components, the positive and negative polarity branches, and the associated signal transmission pins are correctly positioned in the internal housing. Such a filler material is notably visible in [Fig. 6], and this [Fig. 6] shows a feature whereby at least a portion of the main parts 36 of the retaining device 28 protrudes from the filler material 52.Of course, to allow the connection of the signal transmission pins to the printed circuit board, the free edges 24 of the signal transmission pins must protrude from the filler material, and it is advantageous here that part of the retaining device also extends beyond the level of the filler material to extend the guiding dimension of the signal transmission pins and ensure that they do not bend.

[0061] Furthermore, to ensure that the signal transmission pins 16 have sufficient resistance to deformation, conferred by the retaining device 28, the retaining device 28 extends over at least 50% of the main dimension, measured parallel to the main elongation direction, of at least one of the signal transmission pins 16.

[0062] The present invention as just described achieves the goal it set for itself by proposing a power electronics device in which signal transmission pins, separate from high-voltage polarity branches and intended to ensure the flow of information relating to an electric current flowing within the power electronics device, are held along a stacking direction by a retaining device to allow in particular a simple assembly of the power electronics device without risk of particle generation.

[0063] The present invention is not limited to the means and configurations described and illustrated herein and also extends to any equivalent means and configuration as well as to any technically operative combination of such means.

Claims

Demands

1. Power electronics device (2) comprising a housing (4) defining an internal compartment (6) in which at least one electronic component is housed, the at least one electronic component being electrically connected to a positive polarity branch (10) and a negative polarity branch (12), the polarity branches (10, 12) being configured to connect the power electronics device (2) to an electrical energy storage means, the power electronics device (2) comprising a printed circuit board (5) on which signal transmission pins (16) are connected, capable of transmitting information relating to the current flowing in the positive and negative polarity branches (10, 12), the housing (4) comprising a retaining device (28) extending from a wall (22) of the housing (4) participating in delimiting the internal compartment (6),the retaining device (28) being configured to hold the signal transmission pins (16) in position.

2. Power electronics device (2) according to claim 1, wherein the signal transmission pins (16) are connected to the printed circuit board (5) via a free edge (24) of a substantially straight main portion (26), the retaining device (28) extending at least in part along said main portion (26).

3. Power electronics device (2) according to any one of claims 1 and 2, wherein the signal transmission pins (16) comprise a recess (42), the retaining device (28) extending within the recess (42) of the signal transmission pins (16).

4. Power electronics device (2) according to claims 2 and 3, wherein the signal transmission pins (16) comprise the main portion (26) and a base portion (46) substantially perpendicular to said main portion (26) and linking the latter to the electronic component, the recess (42) extending along the main portion (26) to the junction between the main portion (26) and the base portion (46).

5. Power electronics device (2) according to any one of claims 2 to 4, wherein the retaining device (28) presents a main part (36) substantially straight and parallel to the main portion (26) of one of the corresponding signal transmission pins (16), the thickness of the main part (36) being greater than the thickness of the main portion (26).

6. Power electronics device (2) according to claim 2, wherein the free edge (24) of the signal transmission pins (16) extends beyond the retaining device (28) in a principal elongation direction along which the retaining device (28) and the signal transmission pins (16) extend.

7. Power electronics device (2) according to any one of claims 1 to 6, wherein the internal housing (6) is filled with a filling material (52), the retaining device (28) and the signal transmission pins (16) forming respective projections of the filling material (52).

8. Power electronics device (2) according to any one of claims 1 to 7, wherein the retaining device (28) extends over at least 50% of the main dimension of at least one of the signal transmission pins (16).

9. Power electronics device (2) according to claim 4, wherein the retaining device (28) comprises at least one groove (40) disposed at a free end (38) of the retaining device (28) and in which is housed an edge (44) of the recess (42) formed in at least one of the signal transmission pins (16).

10. Power electronics device (2) according to claim 9, wherein the groove (40) forms a groove fitted to the dimensions of the portion of at least one signal transmission pin (16) housed in the groove (40).

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