Plug-in connector part

Abstract

The invention relates to a plug-in connector part for mechanical and electrical connection to a mating plug-in connector part, in particular relates to a charging socket (1) on a motor vehicle for coupling with a charging plug as constituent parts of an electric charging infrastructure for electric or hybrid motor vehicles, or vice versa, having a housing (2) composed of plastic and also having at least one electrical contact element (3), which is arranged in the housing (2). A cooling element (5), which is in thermal contact with the electrical contact element (3), is also realized. According to the invention, the contact element (3) and the cooling element (5) are electrically insulated from each other.

Description

[0001] Description

[0002] Connector part

[0003] The invention relates to a plug connector part for mechanically and electrically connecting to a mating plug connector part, in particular a motor vehicle-side charging socket for coupling to a charging plug as part of an electrical charging infrastructure for electric or hybrid motor vehicles, or vice versa, with a housing made of plastic and at least one electrical contact element arranged in the housing, and with a cooling element which is in thermal contact with the electrical contact element.

[0004] The connector part is generally a charging socket in a motor vehicle that can be coupled to an associated charging plug, for example, found at an electric charging station. The charging plug, like the charging socket, is part of an electrical charging infrastructure that can be used to charge the rechargeable energy storage devices or batteries of electric or hybrid vehicles. In principle, the connector part on the motor vehicle can also be a charging plug instead of a charging socket. In this case, the charging station is equipped with an associated charging socket. Typically, however, the electric or hybrid vehicle has a charging socket with several electrical contact elements arranged in the housing, into which the charging plug connected to the charging station is inserted to charge the respective motor vehicle.

[0005] In order to supply the high electrical power required by the electric motors in the vehicle in question and to provide sufficient range, high-voltage batteries or accumulators are used today, which are typically charged with high-voltage direct current. In addition to such DC charging processes (direct current), most electric or hybrid vehicles also allow the charging process to be carried out using an alternating voltage in the sense of an AC charging process (alternate current). In this case, however, low currents and long charging times are usually used, whereas the DC charging process described above involves high voltages and high currents and the resulting short charging times.

[0006] Particularly with DC charging processes, the high current intensity causes the electrical contact elements used at these points to become increasingly hot. This increases the resistance, which hinders the electrical charging process and the desired rapid charging. Furthermore, due to the heat generated at or in a charging station, the charging current must be controlled or regulated to accommodate the potentially rising temperature of the contact element.

[0007] For this reason, the prior art according to EP 3 616 270 B1 describes a connector part including a temperature monitoring device. The temperature monitoring device ensures that the current is shut off or at least reduced in the event of any overheating of the contact element.

[0008] The generic prior art according to EP 3 433 904 B1 involves equipping the contact element with a heat capacity element as a cooling element. This is intended to optimize and accelerate heat dissipation from the contact element to the environment. In this way, high currents can be transmitted in the best case scenario, without triggering a possible and additionally provided temperature monitoring device. This has proven to be fundamentally successful.

[0009] However, the prior art according to EP 3 433 904 B1 generally proceeds in such a way that the individual heat capacity elements or cooling elements are connected to a shaft section of the contact element via an attachment piece, either force-fitting or form-fitting. The cooling elements are solid, cuboid-shaped metallic bodies. As a result, on the one hand, the available installation space inside the connector part or the charging socket is reduced. On the other hand, an increased weight is observed, along with increased costs and the risk of electrical short circuits still occurring. For this purpose, the prior art proceeds in such a way that the cooling elements of different contact elements are electrically insulated from one another.

[0010] However, this still poses the problem that the cooling elements, due to their electrical connection to the contact elements, may be subject to high voltage. While the insulation between the individual cooling elements may provide electrical insulation from each other, it may not provide sufficient electrical insulation from other components inside the connector or from the outside. This is potentially problematic, particularly given the constantly increasing DC voltages or high voltages in this area. The invention aims to remedy this situation.

[0011] The invention is based on the technical problem of further developing such a connector part in such a way that both flawless heat dissipation and cooling as well as reliable electrical insulation are observed, even when high voltage is applied. To solve this technical problem, the invention proposes that the contact element and the cooling element be electrically insulated from each other in a generic connector part for mechanical and electrical connection to a mating connector part.

[0012] In contrast to the generic prior art according to EP 3 433 904 B1, the invention initially proceeds in such a way that the cooling element and the contact element cannot form an electrical connection with each other, but rather are electrically insulated from each other. In contrast, the known and generic teaching operates in such a way that at this point, the cooling elements are each connected to the shaft section of the contact element by means of an attachment piece, either force-fitting or form-fitting. This means that at this point, an electrical connection is deliberately promoted—contrary to the inventive teaching.

[0013] The electrical insulation between the contact element and the cooling element, while simultaneously creating a thermally conductive connection, can be implemented in different ways. According to a first variant, it is in principle possible for the cooling element to be both electrically insulating and thermally conductive. A variant has proven particularly advantageous in this case, in which the cooling element is made of, or is manufactured from, a thermally conductive plastic or polymer. This also allows the cooling element to be electrically insulating.

[0014] The thermally conductive polymer can be one in which individual fillers are embedded for heat conduction. The invention is based on the finding that thermoplastics typically used to manufacture the plastic housing for the connector part generally have thermal conductivities of a maximum of 0.5 W / m ■ K. This means that the plastics typically used in this context, such as polypropylene (PP), PA (polyamide), polyethylene terephthalate (PET), polyethylene (PE), etc., have the aforementioned typical values ​​for their thermal conductivity.

[0015] In order to provide a cooling element with increased thermal conductivity that is also electrically insulating, a suitable filler can be embedded in the plastic in question. Electrically insulating and thermally conductive fillers have proven particularly advantageous here. These include, for example, aluminum compounds or boron compounds, particularly preferably aluminum oxide or boron nitride. This can increase the thermal conductivity of the plastic in question by at least a factor of 3, so that a correspondingly constructed cooling element in this context has thermal conductivities of at least 1.5 W / m ■ K.

[0016] In this context, the relevant thermally conductive fillers in the plastic used to manufacture the cooling element can be provided in a grammage of up to 50 wt.% or more. Further details on the fillers and the associated plastics can be found in the relevant DE 10 2007 037 316 A1, which represents the relevant state of the art. This publication deals with thermally conductive and electrically insulating thermoplastic compounds, i.e., plastics with the aforementioned specific fillers incorporated. Reference is also made to DE 10 2013 208 605 A1.

[0017] In addition to the already described possibility of designing the cooling element to be both electrically insulating and thermally conductive, the invention opens up the further option of the contact element and the cooling element being thermally conductively coupled to one another via an electrically insulating heat transfer element. In this way, the cooling element itself can be designed to be both electrically conductive and thermally conductive, for example, it can be made from a metal. Metals such as steel, aluminum, or zinc have proven particularly advantageous in this case. In this case, the necessary electrical insulation is not provided by the cooling element itself, but rather by the electrically insulating heat transfer element, which is interposed between the electrically conductive contact element and the cooling element, which in this case is also electrically conductive.

[0018] In principle, even with an electrically non-conductive yet thermally conductive cooling element made of the described plastic with embedded fillers, the electrically insulating heat transfer element in question can be additionally incorporated if necessary. This ultimately depends on the degree of electrical conductivity of the cooling element, or how high it is set to be. This means that, depending on the fillers incorporated into the plastic in question to create the cooling element, the electrically insulating heat transfer element can be interposed between the contact element and the cooling element, if necessary, or not.

[0019] In connection with the electrically insulating heat transfer element, it has proven particularly advantageous if it is formed as a component of the plastic housing. This eliminates the need for additional manufacturing measures and special production methods. In this context, it is particularly advantageous if the heat transfer element encloses the contact element in a ring-shaped or cylindrical cross-section with a wall thickness of, in particular, a few millimeters. In this case, even wall thicknesses of less than 1 mm can be advantageously used.

[0020] The heat transfer element, which forms part of the housing, can again be defined by fillers incorporated into the plastic. These fillers are only introduced into the plastic in the area of ​​the heat transfer element. Here, electrically insulating fillers with increased thermal conductivity can be used, as already described in the introduction. Particularly suitable for this purpose are aluminum and drilled compounds, particularly aluminum oxide or boron nitride, which are incorporated into the plastic of the housing in the area of ​​the heat transfer element, thus defining the electrically insulating yet thermally conductive heat transfer element.

[0021] Alternatively or additionally, the heat transfer element can also be designed as a component independent of the housing. In this case, it is conceivable that the heat transfer element is a fill made of, for example, a ceramic or mineral material. Alternatively or additionally, the heat transfer element independent of the housing can also be designed as a hose clamp that at least largely encloses the electrical contact element. It is also possible for the heat transfer element to have such a hose clamp.

[0022] In the latter case, the heat transfer element is typically constructed in two parts and generally consists of an actual transfer element that surrounds the contact element in question in a ring-like manner, and an additional clamping sleeve. With the help of the clamping sleeve, the heat transfer element, including the electrical contact element, can be inserted into a hole in the housing. In this process, the clamping sleeve or hose clamp is compressed. The clamping sleeve or hose clamp has a high thermal conductivity because, at this point, the heat transfer element, which is located inside, primarily provides both electrical insulation and heat conduction. The result is a connector part characterized by particularly favorable thermal management. This can be attributed to the fact that a cooling element is used that is electrically insulated from the contact element.This prevents any high voltage present at the contact element from being transferred to the cooling element. To achieve this in detail, either a plastic or polymer-based cooling element with embedded fillers can be used, or an electrically insulating heat transfer element can be interposed between the contact element and the cooling element. Of course, the two basic measures described above can also be combined.

[0023] In any case, it is ensured that either the cooling element itself is electrically insulating and simultaneously thermally conductive, or, if the cooling element is electrically conductive, the intermediate heat transfer element ensures electrical insulation to the contact element. These are the key advantages.

[0024] The invention is explained in more detail below with reference to a drawing which merely represents an exemplary embodiment; in the drawings:

[0025] Fig. 1 shows the connector part according to the invention in the form of a motor vehicle charging socket in a front view,

[0026] Fig. 2 the corresponding rear view to Fig. 1 ,

[0027] Fig. 3 shows the object according to Figures 1 and 2 in a

[0028] Front view and

[0029] Fig. 4 shows the article according to Fig. 3 in a side view. Fig. 5A, B, C a modified embodiment and

[0030] Fig. 6A, B, C show a further embodiment of the invention.

[0031] The figures show a connector part for mechanically and electrically connecting to a mating connector part. In fact, the connector part according to the exemplary embodiment in Figures 1 and 2 is a motor vehicle-mounted charging socket 1. The charging socket 1 is designed for coupling to a charging plug, which is not shown in detail and represents a component of an electrical charging infrastructure for electric or hybrid motor vehicles.

[0032] For this purpose, the charging socket 1 is equipped with a plastic housing 2 and at least one electrical contact element 3 arranged within the housing 2. In the following, only the two contact elements 3 required for a DC charging process will be examined in more detail. The additional electrical contact elements 4, which are required for an AC charging process, will not be discussed in detail. According to the exemplary embodiment, the two electrical contact elements 3 inside the housing 2 are equipped with a cooling element 5. The cooling element 5 is in thermal contact with the electrical contact element 3.

[0033] The overall design is as shown in detail in the front view in Fig. 3 and the side view in Fig. 4. Within the scope of the invention, there are two different variants for implementation. In fact, according to a first variant, the cooling element 5 can be designed to be electrically insulating and at the same time thermally conductive. In this case, the cooling element 5 may be made of a plastic or polymer and thus a component of the housing, into which fillers are embedded that are designed to be electrically insulating and at the same time thermally conductive. Suitable fillers have already been described in the introduction and can be, for example, aluminum oxide and / or boron nitride. In this case, an additional electrically insulating heat transport element 6, indicated in Fig. 3, between the contact element 3 and the cooling element 5 is dispensable.

[0034] In the embodiment according to Figures 3 and 4, however, the electrically insulating heat transport element 6 is used overall. With the help of the electrically insulating heat transport element 6, the contact element 3 and the cooling element 5 are coupled to one another in a thermally conductive manner. In this case, the cooling element 5 is advantageously made of a metal such as steel, aluminum, or zinc. Combinations are of course also conceivable. In this context, so that the cooling element 5 made of metal is not exposed to the high voltage applied to the contact element 3, the electrically insulating heat transport element 6 ensures electrical decoupling between the contact element 3 and the cooling element 5. In contrast, the variant already described is characterized in that the heat transport element 6 is dispensable because the cooling element 5 itself provides the electrical insulation.

[0035] In the variant shown in Figures 3 and 4, the heat transfer element 6 can be made of a foreign material (i.e., not plastic). Ceramic or mineral materials have proven particularly suitable for this purpose, as they provide both electrical insulation and thermal conductivity. Suitable ceramic materials include zirconium, and mineral materials such as sand or the like can be used.

[0036] In addition, the overall design is such that the heat transfer element 6 surrounds the contact element 3 in a ring-shaped cross-section with a wall thickness S of, in particular, a few millimeters. In fact, the wall thickness S of the heat transfer element 6 can be a few millimeters or even less than 1 mm. In this way, a particularly favorable and rapid heat transfer from the contact element 3 to the cooling element 5 is realized and implemented, which corresponds to particularly effective cooling.

[0037] Based on the exemplary embodiment, it can be seen that the cooling element 5 is designed in a strip shape and has cooling fins 5a at the ends. These cooling fins 5a can protrude laterally beyond the housing 2 when viewed from the front. This depends on the installation and space conditions for the charging socket 1. Furthermore, it can be seen that the cooling element 5 is strip-shaped and only encloses the contact elements 3 for the DC charging process, whereas the other contact elements 4 for the AC charging process are not covered due to the lower currents there.

[0038] The previously described variant according to Figures 3 and 4 is designed such that the heat transfer element 6 is made of a foreign material (i.e., not plastic). In this case, the heat transfer element 6 is designed as a component independent of the housing 2 or the cooling element 5. Figures 5 and 6 also show a variant in which the heat transfer element 6 is designed as a component independent of the housing 2 or the cooling element 5.

[0039] In fact, it can be seen from Fig. 5A that in this case the heat transfer element 6 there is designed as a hose clamp that at least largely encloses the electrical contact element 3. This can be done in such a way that after pre-assembly of the electrical contact element 3 and the housing 2 or its cooling element 5, the heat transfer elements 6 shown, each designed as a two-ear hose clamp, are deformed in air gaps in the housing 2 or the cooling element 5, and largely eliminate or close them. A similar situation applies to the further variant also shown in Fig. 5B, according to which a screw 7 or another clamping device at this point ensures that any air gaps remaining after pre-assembly are eliminated, so that a continuous heat flow from the contact element 3 via the heat transfer element 6 to the housing 2 or its cooling element 5 is observed and present.

[0040] The further variant according to Fig. 6 is characterized by a two-part heat transfer element 61, 62, which in turn is designed as a component independent of the housing 2 or its cooling element 5. Firstly, a primary heat transfer element 61 is implemented, which completely encloses the electrical contact element 3 and ensures electrical decoupling between the contact element 3 and the housing 2 or cooling element 5. This primary heat transfer element 61 can be a coating of the electrical contact element 3 made of plastic or a polymer with embedded fillers that are designed to be electrically insulating and simultaneously thermally conductive.

[0041] In addition to this primary heat transfer element 61, a secondary heat transfer element 62 is provided, which is designed as a clamping sleeve. The clamping sleeve in question can be equipped with significantly improved thermal conductivity compared to the primary heat transfer element 61. This results in assembly advantages, as can be seen from the perspective view additionally shown in Fig. 6.

[0042] In this context, the clamping sleeve in question or the secondary heat transfer element 62 and the electrical contact element 3, including the primary heat transfer element 61, can actually be moved into a pre-assembled position in a corresponding bore or recess in the partially illustrated cooling element 5 without any assembly force. During this process, the clamping sleeve or the secondary heat transfer element 61 is compressed and pressed into the bore in the cooling element 5 with a slight transition fit. This can be done entirely without tools and thus results in a cost-effective and lightweight, yet functionally reliable variant.

[0043] List of reference symbols

[0044] 1 charging socket

[0045] 2 housings 3 contact elements

[0046] 4 additional contact elements

[0047] 5 Cooling element

[0048] 5a Cooling fins

[0049] 6 Heat transfer element 61,62 Heat transfer element

[0050] S wall thickness

Claims

Patent claims 1. Plug connector part for mechanically and electrically connecting to a mating plug connector part, in particular a motor vehicle-side charging socket (1) for coupling to a charging plug as components of an electrical charging infrastructure for electric or hybrid motor vehicles, or vice versa, with a housing (2) made of plastic and at least one electrical contact element (3) arranged in the housing (2), and with a cooling element (5) which is in thermal contact with the electrical contact element (3), characterized in that the contact element (3) and the cooling element (5) are electrically insulated from one another.

2. Connector part according to claim 1, characterized in that the cooling element (5) is electrically insulating and at the same time thermally conductive.

3. Connector part according to claim 2, characterized in that the cooling element (5) consists of a thermally conductive polymer.

4. Connector part according to one of claims 1 to 3, characterized in that the contact element (3) and the cooling element (5) are thermally conductively coupled to one another via an electrically insulating heat transport element (6).

5. Connector part according to claim 4, characterized in that the heat transport element (6) surrounds the contact element (3) in cross-section in a ring shape with a wall thickness (S) of in particular a few millimeters.

6. Connector part according to claim 5, characterized in that the wall thickness (S) is less than 1 mm.

7. Connector part according to one of claims 4 to 6, characterized in that the heat transfer element (6) is formed as a component of the housing (2).

8. Connector part according to claim 7, characterized in that the heat transfer element (6) has fillers made of, for example, aluminum oxide or boron nitride embedded in the plastic of the housing (2).

9. Connector part according to one of claims 4 to 8, characterized in that the heat transport element (6) is designed as a component independent of the housing.

10. Connector part according to claim 9, characterized in that the heat transport element (6) is designed as a bed of a ceramic or mineral material and / or the contact element (3) is at least largely enclosing a hose clamp or has such a clamp.

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