EP3551887B1

EP3551887B1 - Compressor for an air-conditioning installation of a motor vehicle equipped with a cover having improved sealing

Info

Publication number: EP3551887B1
Application number: EP17829048.2A
Authority: EP
Inventors: Augustin Bellet; Mohamed Khanchoul
Original assignee: Valeo Japan Co Ltd
Current assignee: Valeo Japan Co Ltd
Priority date: 2016-12-08
Filing date: 2017-12-05
Publication date: 2020-11-04
Anticipated expiration: 2037-12-05
Also published as: CN110062847A; CN110062847B; WO2018105603A1; EP3551887A1; FR3060064A1

Description

Technical Field

The field of the present invention is that of compressors fitted to air-conditioning installations for motor vehicles. The invention relates more specifically to methods for sealing an electric compressor, particularly with regard to the electric connectors that supply it.

Background Art

Air-conditioning installations of motor vehicles comprise a closed air-conditioner circuit inside which a coolant fluid flows. In succession, and in the direction of flow of the coolant fluid through it, the air-conditioner circuit essentially comprises a compressor, a condenser, an expansion chamber and an evaporator.
The compressor comprises an axially extending casing of general cylindrical shape. The casing is equipped with an inlet opening through which the fluid enters at low pressures to the inside of the casing. The fluid then flows through the casing from the inlet opening towards a mechanism for compression of the coolant fluid. An outlet opening is in communication with the compression mechanism for the evacuation of the high-pressure fluid to the outside of the casing, after it has been compressed.
The compression mechanism is driven in rotation by a drive unit, the operation of which is regulated by a control module. The drive unit and the control module are fitted inside the casing. The compressor is powered electrically from an electrical wiring set coming from the vehicle receiving the compressor. In this context, the control module is of necessity powered by at least one electric connector connected to the electrical wiring set located outside the casing. Furthermore, this control module is covered by a cover affixed to the casing.
With a view to solving problems of making the compressor lighter in terms of weight whilst still retaining a degree of mechanical strength for it, a compressor has been proposed that comprises a cover formed by a part made from synthetic materials and another part made from metallic materials. This is, in particular, the case of the compressor cover illustrated in document EP2500516A2 .
Compressors featuring a cover made of a metallic and a synthetic portion are for example disclosed in documents US2014/294628 A1 and US2013/323097 A1 .
A first drawback of the technology presented in the above-mentioned document lies in the methods for manufacturing the cover. In fact, the synthetic part is poured into the metallic part, including at the location of the electric connector. Such operations for manufacturing the cover are complex to implement because they require precise management and positioning of the mould impressions.
A further drawback of this technology lies in the lack of sealing upon closure of the casing using the cover. Indeed, the control module is very sensitive to corrosion. Poor sealing of the cover may lead to damage that may be terminal for the compressor itself. In point of fact, cooling of the synthetic part involves a removal of material that significantly adversely affects the seal between the synthetic part and the metallic part.
The object of the present invention is thus to resolve the above-described drawbacks by designing an electric compressor that has a good level of sealing vis-à-vis the exterior environment, and is capable of preventing the ingress of foreign bodies into the casing and into a space arranged between the metallic part and the plastic part.
The subject of the present invention is a compressor for an air-conditioning installation of a motor vehicle, the compressor extending along a longitudinal axis and comprising at least one casing which houses at least:

a mechanism for compression of a coolant fluid,
a drive unit, particularly an electric motor, arranged inside the casing and that drives the compression mechanism,
a module for control of the drive unit,
at least one electric connector intended to connect the control module electrically to an energy source outside the compressor, and
a cover comprising a metallic part and a synthetic part arranged one against the other along the longitudinal axis and traversed by the electric connector. According to the invention, at least one sealing device is arranged between the metallic part and the synthetic part, the sealing device extending around an electric connector.

Irrespective of the illustrative embodiment selected, the invention has at least one of the following features, considered in isolation or in combination:

the metallic part has at least a first groove in which the sealing device is arranged,
the synthetic part has at least a second groove in which the sealing device is arranged,
the first groove and/or the second groove thus form a receiving zone that holds the sealing device in place,
the first groove and the second groove face one another,
the metallic part comprises at least one orifice traversed by a portion of the electric connector,
the portion of the electric connector forms, together with the synthetic part, a single monobloc component. In such a case, the electric connector is a single monobloc component with the synthetic part,
the portion of the electric connector is attached onto the synthetic part. It is understood, here, that the connector and the synthetic part are made independently and then secured to one another,
the compressor according to the invention may comprise at least two distinct electric connectors, each surrounded by a dedicated sealing device. One of these electric connectors is a power electric connector, whilst the other connector is a control electric connector,
the sealing device is formed by a bead of adhesive, by an O-ring or by a combination of these elements,
the metallic part is a pressed plate. The first groove, the folded edge or the orifice are the result of an operation performed using a press,
the synthetic part comprises a plate equipped with a reinforcement. This synthetic part is obtained by moulding, particularly by injection-moulding,
the metallic part and the synthetic part are pieces that can be separated structurally without one or other of these pieces being destroyed.

The invention also covers a method for assembling a compressor cover as defined above. According to the method for assembling the cover, the metallic part and the synthetic part are formed separately. Then, subsequently, at least one sealing device is placed on the synthetic part and/or on the metallic part around the electric connector. Lastly, the metallic part is attached onto the synthetic part.
Complementarily, prior to the synthetic part and the metallic part being brought together, the sealing device is arranged in the liquid state in a first groove preformed in the metallic part or in a second groove preformed in the synthetic part.
When the metallic part and the synthetic part are brought together, a portion of the electric connector passes through at least one orifice pre-made in the metallic part.
The invention also relates to a compressor, particularly an electric compressor, comprising a cover as defined above or as obtained by means of the method presented above.
Further features, details and advantages of the present invention will become more clearly apparent from reading the detailed description given below by way of indication and with reference to the various illustrative embodiments of the invention depicted in the following figures:

Brief Description of Drawings

[Fig. 1] Figure 1 is a schematic representation of an illustrative embodiment of a compressor organised for equipping an air-conditioning installation of a motor vehicle,
[Fig. 2] Figure 2 is a perspective view of a first embodiment of a cover equipping the compressor according to the invention,
[Fig. 3] Figure 3 is a view according to another perspective of a cover equipping the compressor according to the invention,
[Fig. 4] Figure 4 is a perspective view of a synthetic part that is a component of the cover illustrated in Figure 3,
[Fig. 5] Figure 5 is a perspective view of a metallic part that is a component of the cover illustrated in Figure 3, attached onto the synthetic part shown in Figure 4.

Detailed Description

The embodiments that are described in the following text are not limiting in any way; it will be possible, in particular, to imagine variants of the invention that comprise only a selection of the features described below, in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to distinguish the invention from the state of the art.
Figure 1 illustrates a compressor 1 organised for equipping an air-conditioning installation equipping a motor vehicle. The compressor 1 comprises a casing 2 that has a general cylindrical shape, extending along a principal axis X.
The casing 2 comprises an inlet opening 3 and an outlet opening 4 for a coolant fluid, the latter flowing in the casing 2 from the inlet opening 3 towards the outlet opening 4 along and/or in components installed inside the casing 2.
This casing 2 delimits at least one housing 11 in which extends a compression mechanism 5 that compresses the coolant fluid. The compression mechanism 5 is implemented, via a drive shaft 6, by a drive unit 7 received in the housing 11, inside the casing 2. According to an illustrative embodiment, a drive unit 7 of this type is an electric motor, in particular a three-phase electric motor. The compression mechanism 5 has, for example, spiral compression mechanisms, one of the spirals being fixed whilst the other spiral oscillates, or, in other words, orbits.
This drive unit 7 is powered electrically and regulated by a control module 8 via an electric link 9. The control module 8 is arranged in a cavity 10 of the casing 2 or of a body attached onto the casing 2. In any event, the cavity 10 is separated from the housing 11 by at least one wall 12 traversed by the electric link 9. The cavity 10 is, here, for example, provided in the extension of the compression mechanism 5 and of the drive unit 7 along the longitudinal axis X of the casing 2, the drive unit 7 being arranged longitudinally between the compression mechanism 5 and the control module 8. The control module 8 is an electronic device configured at least in order to transform a continuous current from a vehicle into an alternating current adapted to activate the drive unit 7.
The cavity 10 comprising the control module 8 must of necessity contain a controlled atmosphere devoid of any body or element likely to damage the control module 8, in particular the control electronics and/or the power electronics forming it. The control module 8 thus comprises first electronic components dedicated to the management of the power supplied to the drive unit 7 and second electronic components dedicated to the management of the control, signal and/or diagnostic information 14 relating to the compressor 1.
The casing 2, in particular the cavity 10, is closed by a cover 13. The latter is a means for closing off the cavity 10. Along the longitudinal axis X of the casing 2, the control module 8 is installed in the cavity 10 and is connected electrically to the environment outside the compressor 1 by passing through the cover 13. This arrangement facilitates the electric connection of the control module 8 to the exterior of the casing 2, that is to say to an electrical supply wiring set 15 belonging to the vehicle. An electric connection of this type is implemented by means of at least one electric connector 16, the function of which is to convey electric energy from the wiring set 15 towards the control module 8.
This electric connector 16 comprises at least one portion 17 extending between a first end located inside the cavity 10 and a second end located outside the compressor 1. This portion 17 forms, for example, a peripheral skirt of the electric connector.
This electric connector 16 also comprises at least one electrically conducting pin 18, in particular two pins 18. The pin 18 comprises a first end that extends inside the compressor 1 and a second end located outside the compressor 1. The first end of the pin 18 is arranged in order that it can be welded onto the control module 8 or embedded therein. The second end of the pin 18 is designed to be embedded in a socket 19 generally connecting the control module 8 to the electrical supply wiring set 15 of the vehicle. Figure 1 illustrates a situation in which the electric connector 16 forms a male end piece, whilst the socket 19 forms a female end piece, but the invention naturally covers a reverse arrangement of the electric connector 16 and the socket 19.
According to one of the embodiments of the cover, the electric connector 16 may optionally also comprise a base configured in order to attach the electric connector 16 onto the cover 13. According to an embodiment that is an alternative to the above embodiment, the electric connector 16 is incorporated into the cover 13, in particular by being co-moulded therewith.
The electric compressor 1 illustrated in Figure 1 comprises two electric connectors organised and installed as described above. The electric connector referenced 16 is, here, a power electric connector, whilst a control electric connector 20 likewise traverses the cover 13.
As illustrated in Figure 1, the cover 13 is affixed to the casing 2 of the compressor 1, preferably directly on the casing 2, with the aid of fastening means, such as screws, for example. To that end, the cover 13 comprises a series of holes 21 distributed over the external periphery of the cover 13. It will be noted that the cover 13 covers all the longitudinal end of the casing 2, thereby entirely closing the cavity 10.
Figures 2 and 3 show two illustrative embodiments of the cover 13, that of Figure 2 comprising a single electric connector 16, whereas the cover of Figure 3 comprises two distinct electric connectors referenced 16 and 20, in particular the power electric connector 16 and the control electric connector 20, as set forth above.
The cover 13 illustrated in these two figures comprises at least one metallic part 22 and one synthetic part 23 arranged one against the other along the longitudinal axis X of the compressor 1. These two parts are superposed, the synthetic part 23 being covered by the metallic part 22. The metallic part 22 forms a barrier against the electromagnetic waves generated by the control module 8 so as to confine those waves to the cavity 10. The synthetic part 23, meanwhile, reinforces the mechanical structure of the cover 13. It also carries at least one of the electric connectors 16, 20 described above.
Advantageously, the metallic part 22 and the synthetic part 23 are formed independently of one another then attached one against the other, as will be explained in detail below. The synthetic part 23 is, for example, produced in accordance with a moulding, for example an injection-moulding, process. The metallic part 22 is, meanwhile, produced, for example, from a pressed metal sheet.
The metallic part 22 is formed from a plate 24 surrounded by a folded edge 25, thereby delimiting a hollow that receives the synthetic part 23. At least one orifice 26 traverses the plate 24, one edge of the orifice 26 forming a closed perimeter that surrounds the electric connector 16, 20, more particularly the portion 17. It will be noted that the latter extends along an axis perpendicular to a plane in which the plate 24 extends, this axis advantageously being parallel to the longitudinal axis X of the casing 2.
Figure 3 shows more precisely the synthetic part 23 that extends in the hollow of the metallic part 22. The synthetic part 23 is formed from a panel 27 on which are provided reinforcements 35, in a honeycomb design. The panel 27 is traversed by the pins 18 of the two electric connectors 16, 20 shown in this illustrative embodiment. The panel 27 further comprises an increased thickness around the pins 18 of the electric connectors.
According to a first embodiment illustrated in Figure 3, the electric connector 16 is a single monobloc component with the synthetic part 23. "Single monobloc component" is understood to mean that these two pieces form a single assembly that cannot be separated without causing damage to at least one of the two pieces. These two pieces are thus moulded simultaneously, inside one and the same mould. The portion 17 of the electric connector 16, 20 is thus an extension of the material of the panel 27.
According to a further embodiment, illustrated in Figure 4, the electric connector 16, 20 may comprise a base that is attached and secured onto the panel 27 of the synthetic part 23. In such a case, the panel 27 has an opening with a form that complements the portion 17, the base of the electric connector 16, 20 coming to bear against the panel 27.
According to the invention, provision is made for a sealing device 28 that extends between the synthetic plate 23 and the metallic plate 22 and surrounds the opening of the power electric connector 16 or the opening of the control electric connector 20. A sealing device 28 of this type may be a flexible component capable of deforming in order to press against the metallic part 22 and the synthetic part 23. By way of example, this sealing device is a joint, in particular a flat joint or an O-ring. The sealing device 28 may also have the form of a bead of adhesive deposited on the metallic part 22 and/or on the synthetic part 23, around the portion 17 of the electric connector 16, 20.
Figure 2 shows an example of a member adapted to receive the sealing device 28. According to this example, the metallic part 22 is provided with a first groove 29 that delimits a zone for receiving the sealing device, be this previously manufactured or deposited in the liquid state in the first groove 29. The latter is produced by deformation of the plate 24 of the metallic part 22, particularly using a press. The first groove 29 surrounds the electric connector and when the sealing device 28 is housed therein the foreign bodies and impurities that migrate into the space separating the metallic part 22 from the synthetic part 23 via the orifice 26 are blocked by the sealing device 28.
Figure 4 shows a first face of the synthetic part 23 that is turned towards the metallic part 22 when these two pieces are brought together. The base of each of the electric connectors 16, 20 is secured on the panel 27 by four fastening devices, for example screws. The base of each electric connector 16, 20 bears against a second face of the synthetic part, this second face facing the control module 8. The synthetic part 23 also comprises perforations 31 made in its periphery. These perforations 31 form cutouts allowing the passage of the systems for fastening the cover 13 on the casing 2.
According to the illustration in Figure 4, the panel 27 has a sector without a reinforcement, against which the sealing device 28 bears. The synthetic part 23 may comprise a second groove 32 formed at the time as the synthetic part 23 is moulded. This second groove 32 thus delimits a channel of parallelepipedal profile in which the sealing device 28 may be received, poured or deposited in a semi-liquid manner. Figure 4, lastly, shows two sealing devices 28, each surrounding a dedicated electric connector.
Figure 5 illustrates the metallic part 22 seen from the standpoint of the hollow that receives the synthetic part illustrated in Figure 4. The first groove 29 here, also, forms a channel that follows a square profile and surrounds the orifice 26 made through the plate 24 of the metallic part 22. A third groove 33 is made in the plate 24 to receive a sealing device 28 dedicated to the control electric connector 20.
According to the invention, only one or a plurality of first grooves 29 may be produced in order to receive the one or more sealing devices 28, a bearing zone 34 of the sealing device on the synthetic part 23 in such a case being flat. Similarly, the cover 13 may be provided with only one or with a plurality of second grooves 32 provided in the synthetic part 23 to receive the one or more sealing devices, a bearing zone of the sealing device 28 on the metallic part 22 in such a case being flat. According to a combination of these solutions, the invention makes provision for the metallic part 22 and the synthetic part 23 to each comprise at least one groove 29, 32 for receiving a sealing device 28. In such a case, it will be advantageous, in order to reduce the overall size of the cover 13 along the longitudinal axis X, to arrange the first groove 29 and the second groove 32 facing one another. The sealing device 28 is thus interposed between the first groove 29 and the second groove 32.
The cover 13 just described is assembled in accordance with a particular method. It will be noted that this method may be implemented to produce the cover 13 independently of the compressor 1, or implemented in the course of mounting the compressor 1.
This method comprises a first step consisting in separately manufacturing the metallic part 22 and the synthetic part 23. This results in two pieces ready to be assembled. According to a second step, at least one sealing device 28 is placed on the synthetic part 22 and/or on the metallic part 22 around the electric connector 16, 20. When the sealing device 28 is a joint, it is positioned against the synthetic part 23 or against the metallic part 22, for example by being received in the first or second groove 29, 32. When the sealing device 28 is a bead of adhesive or of a liquid elastomeric product, it may be deposited either on the metallic part 22 or on the synthetic part 23 or on both these parts. More specifically, this bead of adhesive may be deposited in the first groove 29 and/or in the second groove 32 produced during the step of manufacturing the metallic part 22 and the synthetic part 23. According to a third step, the metallic part 22 is attached onto the synthetic part 23, the latter being housed in the hollow of the metallic part 22 delimited by the plate 24 and the folded edge 25. When the synthetic part 23 is brought together against the metallic part 22, the portion 17 of the electric connector 16 traverses the metallic part, passing through the orifice 26.
Upon assembly of the compressor 1, the cover 13 thus pre-assembled may be secured to the casing 2 of the compressor 1, thus generating a pressure that crushes the sealing device 28 between the metallic part 22 and the synthetic part 23. Alternatively, it is possible to first position the synthetic part 23 against the casing 2 of the compressor 1, then install the sealing device, and then attach the metallic part 22 against the casing 2, sandwiching the synthetic part and the sealing device.
The sealing of an electric compressor is improved on account of the cover thus produced.

Claims

Compressor (1) for an air-conditioning installation of a motor vehicle, the compressor (1) extending along a longitudinal axis (X) and comprising at least one casing (2) which houses at least:
- a mechanism (5) for compression of a coolant fluid,

- a drive unit (7) arranged inside the casing (2) and that drives the compression mechanism (5),

- a module (8) for control of the drive unit (7),

- at least one electric connector (16, 20) intended to connect the control module (8) electrically to an energy source outside the compressor (1), and

- a cover (13) comprising a metallic part (22) and a synthetic part (23) arranged one against the other along the longitudinal axis (X) and traversed by the electric connector (16, 20),
characterised in that at least one sealing device (28) is arranged between the metallic part (22) and the synthetic part (23), the sealing device (28) extending around the at least one electric connector (16, 20).
Compressor (1) according to Claim 1, wherein the metallic part (22) has at least a first groove (29) in which the sealing device (28) is arranged.
Compressor (1) according to Claim 1 or 2, wherein the synthetic part (23) has at least a second groove (32) in which the sealing device (28) is arranged.
Compressor (1) according to Claims 2 and 3, wherein the at least one first groove (29) and the at least one second groove (32) face one another.
Compressor (1) according to any one of the preceding claims, characterised in that the metallic part (22) comprises at least one orifice (26) traversed by a portion (17) of the at least one electric connector (16, 20).
Compressor (1) according to Claim 5, wherein the portion (17) of the at least one electric connector (16, 20) forms, together with the synthetic part (23), a single monobloc component.
Compressor (1) according to Claim 5, wherein the portion (17) of the at least one electric connector (16, 20) is attached onto the synthetic part (23).
Compressor (1) according to any one of the preceding claims, comprising at least two distinct electric connectors (16, 20), each surrounded by a dedicated sealing device (28).
Compressor (1) according to any one of the preceding claims, wherein the sealing device (28) is formed by a bead of adhesive.
Compressor (1) according to any one of Claims 1 to 8, wherein the sealing device (28) comprises at least one O-ring.
Compressor (1) according to any one of the preceding claims, characterised in that the metallic part (22) is a pressed plate.
Compressor (1) according to any one of the preceding claims, characterised in that the synthetic part (23) comprises a plate (27) equipped with a reinforcement (35).
Method for assembling a cover (13) of a compressor (1) for an air-conditioning installation of a motor vehicle, the cover (13) comprising at least one metallic part (22) and one synthetic part (23) carrying at least one electric connector (16, 20), in the course of which:
- the metallic part (22) and the synthetic part (23) are formed separately,

- subsequently, at least one sealing device (28) is placed on the synthetic part (23) and/or on the metallic part (22) around the electric connector (16, 20),

- the metallic part (22) is attached onto the synthetic part (23), and characterized in that the at least one sealing device (28) is placed between the synthetic part (23) and the metallic part (22).
Assembly method according to the preceding claim, in the course of which the at least one sealing device (28) is arranged in the liquid state in a first groove (29) preformed in the metallic part (22) or in a second groove (32) preformed in the synthetic part (23).
Assembly method according to Claim 13 or 14, wherein the at least one electric connector (16, 20) comprises a portion (17) that passes through at least one orifice (26) pre-made in the metallic part (22).
Vehicle comprising a compressor (1) according to any one of Claims 1 to 12.