Device for protecting a connection member of a motor vehicle catalyst

Abstract

The invention relates to a protection device (10) for an electrical connection member of a motor vehicle catalytic converter to an electrical connector (26). It comprises: - a first part (14) defining a channel for inserting an electrode of the catalytic converter, - a second part (20) fixed to a free end (14A) of the first part, comprising a housing for receiving the electrical connection member, said housing being provided with a connection opening opening into the insertion channel, - a third part (30) intended to be assembled to the second part (20) so that once assembled, the second (20) and the third part (30) form a protective casing around the electrical member housed in the housing. Figure for the abstract: figure 1

Description

Title of the invention: Device for protecting a connection member of a motor vehicle catalyst

[0001] The invention relates to an electrical connection device, in particular an electrical connection device used in the automotive field.

[0002] A motor vehicle has several electrical components which are powered by a battery connected to them by electrical conductors, most often cables or cable harnesses.

[0003] In particular, it is known to electrically connect the electrode of a catalyst of a motor vehicle to an electronic component of the vehicle by means of a conductor.

[0004] It is known to electrically connect the conductor to the electrode by means of an electrical connection member made of electrically conductive material. Such an electrical connection member comprises, on the one hand, a first branch forming a connection lug to which is welded a socket in which the electrode is inserted and, on the other hand, a second branch, intended to be connected to the core of a conductor, often a cable whose core is made of copper.

[0005] In order to ensure electrical insulation of the electrode, the latter is equipped with a ring generally comprising a ceramic coating. However, this insulation can be compromised if water manages to infiltrate at the connection between the electrical connection member and the electrode. It is therefore necessary to provide a protective device around the connection member connecting the electrode to the conductor to ensure protection of the connection member from water, and which preferably ensures watertightness during immersion.

[0006] It is known from the prior art to provide a protection device comprising a first bent part fixed on the external catalyst surface around the socket and a second part welded to the first extending perpendicular to the axis of the electrode. Such a protection device makes it difficult to put in place seals making it possible to improve the sealing of the electrical connection. In addition, such a protection device requires the connection member to be inserted into the first part in a direction perpendicular to the axis of the socket, which limits the assembly possibilities. Finally, the two parts of the device are no longer removable once assembled, which prevents a visual inspection of the electrical connection, and makes it very difficult to replace.

[0007] The invention aims in particular to provide a protection device whose installation makes it possible to make the connection between the connection member and the electrode and thus avoid current leakage, which allows the connection member to be inserted in different directions, including a direction parallel to the longitudinal axis of the electrode, and which is removable in order to maintain access to the connection junction between the electrode and the conductor.

[0008] To this end, the invention relates to a device for protecting an electrical connection member of a motor vehicle catalyst to an electrical connector, characterized in that it comprises: - a first part defining a channel intended for the insertion of a catalyst electrode, - a second part fixed to a free end of the first part, comprising a housing intended to accommodate the electrical connection member, said housing being provided with a connection opening opening into the insertion channel,

[0009] - a third part intended to be assembled to the second part so that a Once assembled, the second and third parts form a protective casing around the electrical component housed in the receiving housing.

[0010] Thanks to the fact that the protection device is made in three parts according to the configuration indicated above, it is easy to insert between the second and third parts a seal to protect the connection member from the intrusion of liquid. In addition, it is possible to insert the connection member into the second part in different directions, including parallel to the longitudinal axis of the electrode, it is possible to provide assembly methods other than welding which do not risk damaging the connection member and / or the electrical conductor, and Finally it is possible to provide assembly methods which allow a subsequent separation of the second and third parts so as to check the connection and possibly replace some of the elements constituting it.

[0011] According to a preferred embodiment of the invention, the second part and the third part each comprise at one of their free ends a passage notch communicating with the receiving housing, so that the meeting of the receiving notches forms a passage orifice in the protective housing formed by the assembly of the second and third parts. In this way, the housing formed by the assembly of the second and third parts can accommodate one end of the electrical connector and in particular that connected to the connection member. Thus the junction between the connection member and an electrical connector also benefits from the protection of the protection device.

[0012] In order to avoid damage to the organ, a current leakage between the organ of connection and the electrical conductor, the three parts of the protection device are made of a material mainly comprising stainless steel. Indeed, due to the temperature prevailing inside the catalyst, the temperature of the electrode can reach 600°C. However, the core of the electrical conductor is generally made of a material mainly composed of copper, which is a good heat conductor. It is therefore preferable for the protection device to be made of a material which limits the heat flow transferred, via the electrical connection device, to the electrical conductor.

[0013] Preferably, in order to match the shape of the electrode and also protect it, the first part is substantially cylindrical in revolution.

[0014] Advantageously, in order to guarantee protection against high-pressure, high-temperature cleaning from several directions, in particular required by the IP (Protection Index) X9 standard, the second part is welded to the first part, preferably by an annular weld bead arranged around the connection opening.

[0015] In order to facilitate the connection of the electrode to the electrical conductor, the first part extends substantially along a first longitudinal axis and the second part extends substantially along a second longitudinal axis transverse to the first longitudinal axis, so that the first part and the second part form an elbow.

[0016] According to a preferred embodiment of the invention, the second part and the third part are connected to each other by snap-fastening means. This means of assembling the second and third parts is simple and quick for an operator, who only has to snap the third part onto the second part once the connecting member is arranged in the second part. It also allows the subsequent separation of the second and third parts easily.

[0017] According to a particular embodiment of the invention, the snap-fastening means comprise a plurality of snap-fastening windows provided in the third part and a plurality of corresponding snap-fastening tabs arranged on the second part, so that the assembly of the third part to the second part is obtained by snap-fastening the snap-fastening tabs of the second part into the windows. The insertion of tabs into windows is a simple means of snap-fastening assembly. In addition, their number makes it possible to distribute the snap-fastening forces and ensure a robust assembly.

[0018] In order to avoid untimely separation of the second and third parts after their assembly, the snap-fastening means are provided with non-return means.

[0019] In order to improve the sealing in the receiving housing and in particular to prevent water from infiltrating between the second and third parts, the protection device further comprises a peripheral seal intended to be arranged in the second part around the receiving housing, said peripheral seal matching the peripheral contours of the receiving housing and preferably being made of polytetrafluoroethylene. This material can in fact withstand high temperatures, which is advantageous near the catalyst which can reach 400°C.

[0020] To prevent the connection member from moving unexpectedly when it is connected to the electrode, which would impair its correct positioning, the receiving housing extends along a longitudinal axis, the protection device further comprising radial locking means intended to be arranged on either side of the receiving housing between a wall delimiting the receiving housing and a connection member arranged in said receiving housing so as to prevent movement of the connection member transverse to a longitudinal axis of the receiving housing. This may in particular be an addition during assembly of the connection member in the second part.

[0021] Advantageously, in order to limit the number of parts of the protection device and therefore simplify logistics and avoid the loss of elements, the radial locking means are carried by the peripheral seal.

[0022] In order to improve the sealing in the receiving housing and in particular to prevent water from infiltrating between the housing formed by the second and third parts and the connection member introduced into its passage orifice, the protection device further comprises an annular seal intended to enclose an electrical conductor introduced into the passage orifice, the annular seal preferably being made of silicone.

[0023] The invention also relates to an assembly comprising: - a connection member comprising a connection head intended to be connected to an electrode of a catalyst and a second branch intended to be connected to the core of a conductor, and - a device for protecting said connection member, characterized in that it is according to the invention.

[0024] The invention also relates to a motor vehicle catalyst comprising an electrode connected to an electrical connection assembly according to the invention. Brief description of the figures

[0025] The invention will be better understood on reading the following description given solely by way of example and with reference to the appended drawings in which:

[0026] [Fig-1] [Fig.l] is a perspective view of a connection assembly according to a first embodiment of the invention connected to an electrical connector,

[0027] [Fig.2] [Fig.2] is a perspective view of the electrical connection assembly of [Fig.l] mounted on a motor vehicle catalyst electrode, without the first and third parts of the protection device,

[0028] [Fig.3] [Fig.3] is a perspective view of the protection device of [Fig.l], without its third part,

[0029] [Fig.4] [Fig.4] is a perspective view of the second part of the device protection of the [Fig.l],

[0030] [Fig.5] [Fig.5] is a perspective view of the peripheral seal of the protective device of [Fig.3]. Detailed description

[0031] [Fig.l] shows a protection device 10 of a connection member 12 (visible in [Fig.2]) according to a first embodiment of the invention.

[0032] The protection device 10 comprises a first part 14 defining an insertion channel 16 for an electrode 18 of a motor vehicle catalyst (only a part of its external wall is visible in [Fig.2]). Conventionally, the electrode 18 extends in projection, normal to the external wall of the catalyst.

[0033] The electrode 18 is generally, as can be seen in particular in [Fig. 2], a cylindrical part of revolution extending along a first longitudinal axis, which corresponds to a vertical axis in the figures. The electrode comprises in particular an insulating ring 18B covered with an insulating coating, for example made of ceramic. It is sought to prevent water from infiltrating from the connection member 12 towards this ring 18B and causing the passage of current between the electrode 18 and the wall of the catalyst. Therefore, in the example shown in the figures, and as can be seen in figures 1 and 3 in particular, the first part 14 is also a part of revolution, more particularly cylindrical so as to match the shape of the electrode 18, the body of which is generally cylindrical. More particularly, the first part 14 forms a hollow tube, the insertion channel 16 extending over the entire length of the first 14.

[0034] The first part 14 is made of a material essentially comprising stainless steel in order to benefit from its low thermal conductivity for a metal. An element is said to essentially comprise a material when it comprises more than 50% by mass of this material.

[0035] The protection device 10 further comprises a second part 20 fixed to a free end 14A of the first part, here the free end 14A opposite the electrode 18. The second part 20 comprises a housing 22 for receiving the electrical connection member 12 which is provided with a connection opening 24 opening into the insertion channel 16. In the embodiment shown in the figures, the connection opening 24 is a circular opening, and preferably the same diameter than that of the insertion channel 16.

[0036] The second part 20 is welded to the first part 14, preferably by an annular weld bead (not visible in the figures) arranged around the connection opening 24. The weld bead is also located on the contour of the opening of the insertion channel 16 on the side of the free end 14A of the first part. The second part 20 is in fact here preferably also made of metal, and more particularly of a material essentially comprising stainless steel in order to benefit from its low thermal conductivity for a metal.

[0037] The second part 20 extends along a second longitudinal axis transverse to the first longitudinal axis of the first part, so that the first part 14 and the second part 20 form an elbow. In the example shown in the figures, the first longitudinal axis and the second longitudinal axis are substantially perpendicular.

[0038] The electrical protection device 10 further comprises a third part 30 intended to be assembled on the second part 20 so that once assembled, the second part 20 and the third part 30 form a protective housing around the electrical member 12 housed in the receiving housing 22. In [Fig.l] where the third part 30 is visible, the second part 20 and the third part 30 are assembled. Just like the first part 14 and the second part 20, the third part 30 is preferably also made of metal, and more particularly of a material essentially comprising stainless steel in order to benefit from its low thermal conductivity for a metal.

[0039] The second part 20 will now be described in more detail with reference to FIGS. 2 to 4.

[0040] The receiving housing 22 of the electrical connection member is delimited by a side wall 22L and a bottom 22F. In the example shown in the figures, it extends substantially over the entire length of the second part 20 of the protection device.

[0041] At one end of the receiving housing 22, called the connection end 22A, is the connection opening 24 which is made in the bottom of the housing 22F. At the connection end 22A, the side wall 22L surrounds the connection opening 24 while being of substantially annular shape except for a portion connecting it with a central section of the receiving housing 22 which is substantially elongated. In other words, the section of the connection end 22A of the housing is locally circular. The bottom 22F is, at this connection end 22A, substantially flat.

[0042] Such a shape is suitable for accommodating the 12T connection head of the connection member, which is conventionally substantially flat and circular. It will be noted that the 12T connection head is provided with a connection orifice (not visible in the figures), the outline of which is generally circular, through which the connecting member will be connected to the electrode 18 via the connection opening 24 via a nut E.

[0043] Optionally, the connection end 22A further comprises two protrusions 27 projecting from the side wall 22L, diametrically opposite relative to the connection opening 24. The protrusions 27 ensure the correct positioning of a peripheral seal 32 which will be described later.

[0044] The receiving housing further comprises, in the extension of the connection end 22A and communicating with the connection end 22A, a substantially longitudinal central portion 22C. The central portion 22C is delimited by two substantially planar and parallel side walls. The bottom 22F is in this central portion 22C substantially planar. The central portion 22C is thus adapted to a connecting branch 12B of the connection member 12, which is here substantially planar and of rectangular cross-section, intended to be connected to the core of an electrical conductor 26, which is here an electrical cable, by means of crimping wings 12A which grip the core of the conductor 26.

[0045] Optionally, two flanges 22R extending along the second longitudinal axis project from the side walls 22L of the central portion 22C substantially perpendicular to the second longitudinal axis. The two flanges 22R make it possible in particular to block the movement of the electrical conductor 26 which is received at the end opposite the connection end 22A of the receiving housing, or connection end 22C. The two flanges 22R extend over almost the entire length of the central portion 22C. However, in a variant not shown, the two flanges 22R may each be divided into a plurality of separate and spaced flanges.

[0046] The end opposite the connection end 22A, or connection end 22B, extends and communicates with the central portion 22C. Optionally, it comprises a rib 22S projecting from the side walls 22L and the bottom 22F perpendicularly thereto so as to locally create a radial narrowing of the receiving housing 22. More precisely, the rib 22S is semi-circular so as to accommodate the electrical conductor 26, possibly provided with an annular seal 40 which encloses the electrical conductor 26, matching its shape. The annular seal 40, or single-wire seal, is preferably made of silicone. Also optionally and for the same reasons, a second rib 22S is provided, arranged closer to the end of the second part 20.

[0047] In the area of ​​the connection end 22B, the bottom 22F of the receiving housing is no longer flat but forms a groove of preferably semi-circular cross-section in order to accommodate the electrical conductor 26, possibly equipped with the seal annular 40. More precisely, conductor is here an electric cable comprising a core of copper wires or comprising essentially copper. An insulating sheath, the only element of the conductor visible in the figures, surrounds the core over practically its entire length.

[0048] Finally, the connection end 22C, which is a free end of the second part 20, is provided with a passage notch 22E, the outline of which is also semi-circular in order to allow the passage of the electrical conductor 26. Here, the passage notch 22E is made in the second rib 22S but this is only an option.

[0049] Preferably, the protection device 10 further comprises a peripheral seal 32, shown alone in [Fig. 5], intended to be arranged in which the second part 20 around the receiving housing 22, as can be seen in Figures 2 and 3. The peripheral seal 32 follows the peripheral contours of the receiving housing 22. It makes it possible to protect the interior volume defined by the two parts 20, 30 from immersion by being placed at the junction between these two parts. Here, it is a substantially flat seal, resting at the top of the side wall 22L of the receiving housing.

[0050] In order to ensure its correct positioning in the receiving housing 22, the peripheral seal 32 is provided with notches 32E, here of rectangular outline, matching the protuberances 27 on three sides. Of course, the shape of the notches 32E can vary and the shape of the protuberances 27 will be adapted accordingly, and vice versa.

[0051] The peripheral seal 32 is preferably made of polytetrafluoroethylene (PTFE). This material can in fact withstand high temperatures, which is advantageous near the catalyst which can reach 400°C.

[0052] The peripheral seal 32 further comprises radial locking means 34 intended to be arranged on either side of the receiving housing 22 between the side wall 22L of the receiving housing and the connection member 12 once the latter is arranged in said receiving housing so as to prevent movement of the connection member 12 transverse to the longitudinal axis of the receiving housing 22. More precisely, as can be seen in FIGS. 2 and 3, the radial locking means 34 are arranged at the junction between the connection end 22A and the central part 22C of the receiving housing.

[0053] The radial locking means 34 consist of radial projections 36 of the peripheral seal 32 constituting a radial narrowing, that is to say in a direction transverse to the longitudinal axis of the second part 20, of the receiving housing 22. The radial projections 36 here extend perpendicularly to the longitudinal axis of the second part 20 and are of substantially rectangular cross-section. Other shapes could naturally be envisaged.

[0054] In a variant not shown, the radial locking means 34 are not part of the peripheral seal 32 and constitute separate elements. It may in particular be a wedge of substantially rectangular section intended to be arranged on either side of the receiving housing 22 between the side wall 22L of the receiving housing and the connection member 12 once the latter is arranged in said receiving housing, always so as to prevent a displacement of the connection member 12 transverse to the longitudinal axis of the receiving housing 22.

[0055] The third part 30 of the protection device will now be described. The second part 20 and the third part 30 form a protective housing around the connection member 12 housed in the receiving housing 22. Thus, the second part and the third part 30 have a similar outline.

[0056] More particularly, in the embodiment shown in the figures, they are almost entirely symmetrical with respect to a plane. The second part 20 and the third part 30 differ only in two aspects: the second part 20 is provided with a collar 28 over almost its entire contour in order to protect the joint between the second part 20 and the third part 30 from spraying. Furthermore, the third part 30 does not include a connection opening.

[0057] Thus, the third part 30 also comprises, at its free connection end 30C, opposite the passage notch 22E of the second part 20, a passage notch 30E so that the meeting of the receiving notches 22E, 30E forms a passage orifice 35 in the protective housing formed by the assembly of the second part 20 and the third part 30. The passage orifice 35 makes it possible to receive the electrical conductor 26, possibly provided with the annular seal 40, which therefore passes through the housing formed by the two parts 20, 30.

[0058] To assemble them easily, the second part 20 and the third part 30 are connected to each other by snap-fastening means 42.

[0059] In the embodiment shown in the figures, the snap-fastening means 42 comprise a plurality of snap-fastening windows 44 provided in the third part 30 and a plurality of corresponding snap-fastening tabs 46 arranged on the second part 20. The assembly of the third part 30 to the second part 20 is obtained by snap-fastening the snap-fastening tabs 46 into the snap-fastening windows 44.

[0060] The snap-in windows 44 are arranged around the perimeter of the third part 30 so as to be opposite the snap-in tabs 46 distributed symmetrically on the second part 42. More particularly, the snap-in tabs 46 are formed by cutouts in the collar 28 of the second part 20.

[0061] In the example shown in the figures, five snap-in windows 44 and as many snap-in tabs 46 are provided, which are distributed in the most homogeneous manner. possible around the perimeter of the housing formed by the two parts 20, 30. Thus, for example, a snap-in window 44 and a snap-in tab 46 are provided at the connection end 22A and two on each side of the receiving housing 22. Other configurations are naturally possible and the number of snap-in windows 44 and snap-in tabs 46 can vary. For example, seven could be provided rather than five.

[0062] Optionally, the snap-fastening means windows of the second part 20 to the third part 30 are provided with non-return means 48. The non-return means here consist of two lateral tabs 48 arranged on either side of each of the snap-fastening tabs 46 and the lower edge of each window 44B. The snap-fastening tabs 46 form an angle with the snap-fastening tab 46 so that when assembling the second part 20 to the third part 30, the lower edge 44B of the windows slides along the snap-fastening tab 46 until it passes under the lateral tabs 48. Thus, a reverse movement of the snap-fastening tab 46 does not allow the separation of the second 20 and the third part 30.

[0063] The non-return means 48 therefore make it possible to avoid an impromptu separation of the two parts 20, 30, but also make it possible to maintain pressure on the peripheral seal 32, which improves the sealing of the protection device 10. To unlock them, it is necessary to exert pressure on the snap-fastening tab 46 and the lateral tabs 48, which an operator can do using a screwdriver for example.

[0064] The invention is not limited to the embodiments presented and other embodiments will become clear to those skilled in the art. It is in particular possible to combine the embodiments presented. The invention can also be used to be mounted on elements other than a motor vehicle catalyst electrode, and in particular any heat-accumulating element. List of references

[0065] 10: Protective device 12: Connection organ 12A: Wings of the connecting member 12B: Branch of the connecting organ 12T: Head of the connecting member 14: First part of the protection device 14A: Free end of the first part 16: Insert channel of the first part 18: Catalyst electrode 20: Second part of the protection device 22: Accommodation for the first part 22A: Connection end of the reception accommodation 22B: Connection end of the reception accommodation 22C: Central part of the reception accommodation 22E: Passage notch of the second part 22F: Reception accommodation fund 22L: Side wall of the reception area 22R: Edges of the reception area 22S: Ribs projecting from the receiving housing 24: Opening of connection to the host accommodation 26: Electrical conductor 27: Protuberances 28: Collar of the second part 30: Third part of the protection device 30E: Passage notch of the third part 32: Peripheral seal 32E: Notches of the peripheral seal 34: Radial locking means 36: Radial projections of the peripheral seal 38: Passageway 40: Ring seal 42: Snap-in means 44: Snap-in window 46: Snap-in tabs 48: Anti-return means E: Nut

Claims

Claims

1. Protective device (10) for an electrical connection member (12) of a motor vehicle catalyst to an electrical connector (26), characterized in that it comprises: - a first part (14) defining a channel (16) intended for the insertion of an electrode of the catalyst, - a second part (20) fixed to a free end (14A) of the first part, comprising a housing (22) intended to receive the electrical connection member (12), said receiving housing (22) being provided with a connection opening (24) opening into the insertion channel (16), - a third part (30) intended to be assembled to the second part (20) so that once assembled, the second (20) and the third part (30) form a protective casing around the electrical member (12) housed in the receiving housing (22).

2. Protective device (10) according to claim 1, in which the second part (20) and the third part (30) each comprise at one of their free ends a passage notch (22E) communicating with the receiving housing (22), so that the meeting of the receiving notches (22E) forms a passage orifice (38) in the protective housing formed by the assembly of the second (20) and the third part (30).

3. A protective device (10) according to claim 1 or 2, wherein the three parts of the protective device (10) are made of a material essentially comprising stainless steel.

4. Protective device (10) according to any one of the preceding claims, in which the first part (14) is substantially cylindrical of revolution.

5. A protective device (10) according to any preceding claim, wherein the second part (20) is welded to the first part (14), preferably by an annular weld bead arranged around the connection opening (24).

6. A protective device (10) according to any preceding claim, wherein the first portion (14) extends substantially along a first longitudinal axis and the second portion (20) extends substantially along a second longitudinal axis transverse to the first longitudinal axis, such that the first portion (10) and the second part (20) form an elbow.

7. A protective device (10) according to any preceding claim, wherein the second part (20) and the third part (30) are connected to each other by snap-fastening means (42).

8. Protective device (10) according to claim 7, wherein the snap-fastening means (42) comprise a plurality of snap-fastening windows (44) provided in the third part and a plurality of corresponding snap-fastening tabs (46) arranged on the second part (20), so that the assembly of the third part (30) to the second part (20) is obtained by snap-fastening the snap-fastening tabs (44) of the second part (20) into the corresponding snap-fastening windows (46) of the third part (30).

9. Protective device (10) according to claim 7 or 8, in which the latching means (42) are provided with non-return means (48).

10. Protective device (10) according to any one of the preceding claims, further comprising a peripheral seal (32) intended to be arranged in the second part (20) around the receiving housing (22), said peripheral seal (32) matching the peripheral contours of the receiving housing (22) and preferably being made of polytetrafluoroethylene.

11. Protective device (10) according to any one of the preceding claims in which the receiving housing (22) extends along a longitudinal axis, the protective device further comprising radial locking means (34) intended to be arranged on either side of the receiving housing (22) between a wall (22L) delimiting the receiving housing and a connection member (12) arranged in said receiving housing (22) so as to prevent movement of the connection member (12) transverse to a longitudinal axis of the receiving housing (22).

12. Protective device (10) according to claims 10 and 11 taken in combination, in which the radial locking means (34) are carried by the peripheral seal (32).

13. Protective device (10) according to claim 2, further comprising an annular seal (40) intended to enclose an electrical conductor (26) introduced into the passage orifice (38), the annular seal (40) preferably being made of silicone.

14. Electrical connection assembly comprising: - a connection member (12) comprising a connecting head (12T) connection intended to be connected to an electrode of a catalyst and a branch (12B) intended to be connected to the core of a conductor, and - a protection device (10) for said connection member (12), characterized in that it is according to any one of the preceding claims.

15. A motor vehicle catalyst comprising an electrode (18) connected to an electrical connection assembly (10) according to claim 14.

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