The present invention relates to an electrical plug type connector for electrically contacting a mating connector, as required in particular as a charging socket for an electric or hybrid vehicle.

For charging the batteries in electric or hybrid vehicles, there have now become established various systems which operate with comparatively high voltages and currents (for example, 400 Volt alternating current at 50 or 60 Hz) in order to keep the charging times for charging the vehicle battery as short as possible. These high voltages involve strict safety requirements with respect to the contact safety and breakdown strength and the creep currents which occur.

A complication when used on a motor vehicle is that the charging socket can also come into contact with moisture and in the case of winter use or coastal climates also with salt water. Accordingly, the relevant requirements for connectors, sockets, vehicle couplings and vehicle connectors during conductive charging of electric vehicles have to be complied with. The relevant provisions are set out in the standard IEC 62196-1 :2012 (Chapter 28), which refers to IEC 60664-1 :2007. According to IEC 62196-1 , the sizing of the creep paths is intended to be configured in accordance with a pollution degree 4 according to IEC 60664-1. Since the contact with water spray and moisture cannot be avoided in principle, means must further be provided in order to discharge water which has entered the charging socket in a defined manner from the plug type connector region again.

To this end, it is known to fit drains which direct water which has entered the contact chambers or the plug type collars of the charging socket via a corresponding drainage path out of the plug type connector region again.

Such drainage openings in the contact chambers and inside the plug type collar further have the advantage that, when the plug type connection is assembled and released, an exchange of air can take place, so that the insertion forces remain as small as possible. Examples of such drainage arrangements are described in US 8,257,101 B2 and EP 2525443 A1. US 5,066,252 A discloses a receiving member for metal contacts which is intended to prevent unintentional securing of the contact receiving member in a plug type connector by means of the provision of a two-step locking process.

Furthermore, WO 2012/169144 A1 makes reference to a sealed plug type connector for contacting a motor-vehicle-side mating connector having a lock for fixing the plug type connector in the inserted state.

However, since in these known arrangements, on the one hand, the drainage openings of the contact chambers open in common drainage channels and these are further formed by means of a cooperation of sealing elements and housing walls, the known arrangements are not suitable for complying with the requirements with respect to the long creep paths according to a pollution degree 4 of IEC 60664-1.

The object addressed by the present invention is therefore to provide an electrical plug type connector, for example, for the charging socket of an electric or hybrid vehicle, which also operates under harsh conditions of use in a correct and safe manner. This object is achieved by the subject-matter of the independent patent claims. Advantageous developments of the present invention are set out in the dependent patent claims.

In this instance, the present invention is based on the recognition that the water discharge paths in a plug type connector in the context of creep current resistance also constitute an electrically conductive connection. It has further been recognised that separation of the fluid paths from each other and from other current-carrying contacts using only pressed-on sealing elements in the context of the creep current resistance is not an adequately reliable separation.

According to the present invention, each of the contact chambers is therefore connected to a separate drainage channel which is formed in the housing integrally and in a state separated from the other drainage channels. In this manner, it is possible for the drained fluids from the various contact chambers no longer to be able to come into contact with each other to form a closed electrical connection in the context of a creep current path. Furthermore, although a housing with such drainage channels places higher demands on the mould removal technology, it is more cost-effective and easier to assemble in terms of the subsequent assembly and number of individual components. In particular by means of the provision of the drainage channels which are separated from each other for the high-voltage contact chambers, the compliance with the air and creep paths according to IEC 62196-1 :2012 can be complied with.

The drainage channels according to the present invention enable, owing to their spatial separation, air and creep paths having a length of, for example, 60 mm. A high level of insulation resistance can thereby be achieved, even after being subjected to salt water, whereby a high level of reliability can be ensured even during operation in contaminated environments.

In the plug type connector according to the invention, the at least two contact chambers which contain the power contact elements are generally arranged within a substantially tubular insertion socket. Since this insertion socket is arranged in a motor vehicle in most cases so that it is orientated in an oblique manner towards the rear, fluid can accumulate therein and a separate drainage opening for this region, which is also referred to below as an insertion face, has to be provided. According to the invention, this drainage opening is connected to precisely one of the drainage channels so that no connection to the remaining contacts can be produced. Preferably, this is the drainage channel which removes water from the contact chamber of a contact element which is connected to earth.

Alternatively, however, there may also be provision for the insertion socket to provide a separate drainage channel which is constructed integrally in the housing. The electrical plug type connector according to the invention may have, for mounting, for example, on a motor vehicle, an assembly plate, the insertion socket at least partially protruding from the assembly plate. Since, as already mentioned, the gradient of the insertion socket is conventionally directed towards the rear and towards the inner side, the drainage opening is advantageously arranged in an end region of the insertion socket, which end region faces the assembly plate and which is directed downwards during assembly so that no fluid can accumulate inside the insertion face.

In order to fix the power contact elements within their respective contact chambers, catch means for engaging the contact elements may advantageously be provided. In addition to catch hooks, which cooperate with the metal contact, there may also be provided catch openings in which projections of the contact engage. In a particularly elegant manner, there may be provision for the opening which leads to the drainage channel in this context to perform a dual function and to be constructed both for engagement and for discharging the fluids.

Owing to the fact that the catch elements for the power contacts are arranged in the drainage channel, they can be constructed in a particularly space-saving, resilient and flexible manner and their removal from the mould in the injection-moulding tool can be carried out in a relatively simple manner.

So that the arrangement is completely sealed at the inner side, in order to seal the transition between the power contacts and the respective associated contact chambers, a sealing means, such as, for example, an O-ring of a resilient material, may be provided. Owing to the fact that each of the contact chambers is in air exchange with the external space via the drainage channels, when the plug type connector and the mating connector thereof are joined together, no pressure loads can occur on these sealing means.

So that the assembled power contact elements remain securely fixed in a rattle-free manner, even with great temperature changes, there may advantageously be provided a secondary locking device for locking the power contact elements to the housing.

This locking device is actuated in a particularly reliable and efficient manner if it can be displaced in a direction transverse relative to the assembly direction of the plug type connector and mating connector.

So that the water discharged from the drainage channels can be supplied to a defined end position, there is preferably provided for collecting and discharging the fluid discharged from the drainage channels a discharge connection piece which may be able to be connected, for example, to a hose.

The power contact elements are connected at the side facing away from the connector face to lines which are in contact with the vehicle electric system. For this connection, it is possible to use, for example, crimp, solder or plug type connections. In order to protect such contacting arrangements, the plug type connector may have a cover which can further also be provided with a suitable tensile relief member. Adequate contact protection and mechanical protection of the cable contacts is thereby enabled.

In addition to the actual power contacts, at least one signal contact for transmitting signals between the electrical plug type connector and the mating connector may be provided on the plug type connector. The transmission can take place in a contacting or contact-free manner, such as, for example, an optically inductive or capacitive manner. Since these signal contacts do not guide any high voltages and currents, it is sufficient for the drainage thereof to be carried out into the insertion face. To this end, corresponding drainage openings may be provided in the contact chambers of the signal contact. The signal contact elements are also connected to the vehicle electronic system in the contact region thereof by means of corresponding lines.

The housing of the plug type connector according to the invention is produced from a suitable electrically insulating, mechanically stable and age-resistant plastics material, for example, using injection-moulding technology. As already mentioned, the advantages of the solution according to the invention are evident in particular when the plug type connector is used as a charging socket for an electric or hybrid vehicle. Of course, however, the solutions according to the invention may also be used for other plug type connectors in which adequate air and creep current resistance and removal of water even in moist or salt-containing atmospheres have to be ensured.

For better understanding of the present invention, it is explained in greater detail with reference to the embodiments illustrated in the following Figures. Components which are the same are given the same reference numerals and the same component names. Furthermore, some features or feature combinations from the different embodiments shown and described may also constitute solutions which are independent, inventive or in accordance with the invention per se.

In the drawings:

Figure 1 is a perspective sectioned illustration of an electrical plug type connector according to an advantageous embodiment of the present invention; Figure 2 is a perspective view of the housing, when viewed towards the insertion face;

Figure 3 is a perspective view of the housing, when viewed towards the cable connection side;

Figure 4 is a plan view of the housing, when viewed towards the insertion face; Figure 5 is a plan view of the housing, when viewed towards the connection side; Figure 6 is a first cross-section through the arrangement of Figure 4; Figure 7 is a second cross-section through the arrangement of Figure 4; Figure 8 is a third cross-section through the arrangement of Figure 4; Figure 9 is a first cross-section through the arrangement of Figure 5; Figure 10 is a second cross-section through the arrangement of Figure 5; Figure 1 1 is a detail from Figure 9; Figure 12 is a detail from Figure 8.

The present invention is described below with reference to the example of a charging socket for an electric or hybrid vehicle. For a person skilled in the art, however, it is clear that the ideas according to the invention can be used everywhere where electrical contacts with higher voltages are intended to be inserted in a safe manner under harsh environmental conditions.

In this instance, the embodiment of an AC charging socket in accordance with a GB/Chinese standard is always set out. In this standard, five power contact elements and two signal contacts are provided. However, the principles according to the invention may of course also be used with all other alternating current, direct current or combined AC/DC charging systems.

Figure 1 is firstly a sectioned, perspective view of the overall arrangement.

The charging socket 100, which is generally also referred to as a plug type connector, comprises a housing 102, which can be produced from an electrically insulating plastics material using injection-moulding technology. The housing 102 has an assembly plate 104, from which the actual insertion socket 106 partially protrudes. Inside the collar-like insertion socket 106, there are arranged in accordance with the GB/China Standard Part 2 five contact chambers 108 for the power contact elements and two contact chambers 1 10 for the signal contacts.

Electrically conductive power contact elements 1 12 which are generally produced from metal are received in each case in the contact chambers 108. In the embodiment shown, the power contact elements 1 12 are constructed as socket contacts. Of course, however, the present invention is not limited only to socket contacts. Pin contacts can naturally also be used for a plug type connector 100 according to the invention.

Each of the power contact elements 1 12 has a contact region 1 14 in which the electrical contact is closed with respect to the mating connector and a connection region 1 16 in which the lines which lead to the vehicle cabling and consequently to the vehicle electrical system are connected. In the embodiment shown, the connection region 1 16 is constructed as a socket contact, in the same manner as the contact region 1 14.

For reliable sealing between the housing 102 and the electrical power contact or signal contact, there is provision in the present embodiment for O-rings 1 18 to be fitted as a sealing means. The power contact elements 1 12 are, on the one hand, secured in the associated contact chambers 108 by way of catch means. On the other hand, there is provided a locking device 120 which can be displaced transversely relative to the insertion direction 122 in order to lock all seven contact elements in one operating step. A cable guide 124 and a cable cover 126 which can be connected thereto protect the outgoing cables (not illustrated in the drawings) in the assembled state.

According to the invention, each of the contact chambers 108 has a drainage opening 128, through which fluids (that is to say, gas or liquids) which have entered the contact chamber can be discharged. Of course, the metal contact element 1 12 must also have an opening 130 at this location.

According to the invention, the drainage opening 128 opens into a drainage channel 132, which is produced from the housing material in a state closed at all sides in the cross- section thereof and is constructed separately for each contact chamber 108. Each of the drainage channels 132 which extend in a substantially parallel manner leads into the discharge connection pieces 134 which can lead the fluid, for example, to a hose. Figures 2 to 12 are various views and cross-sections of the housing 102 of the charging socket 100 according to the invention in accordance with a GB/China Part 2 Standard.

Figure 2 is a perspective view of the insertion face with the five contact chambers 108a-e for power contact elements and two contact chambers 1 10 for signal contacts. All the contact chambers 108a-e, 1 10 are arranged within the insertion socket 106. A separate drainage channel 132a-e is correspondingly associated with each of the contact chambers 108a-e. In the cross-section thereof, the drainage channels 132a-e are produced from the material of the housing 102 in a state closed at all sides and in an integral manner. The fluids which are discharged from the drainage channels 132 can be discharged via a discharge connection piece, which is secured to two catch projections 136.

Owing to this specific closed production method, the creep path between two contact elements with different potential may be twice the contact chamber length at the front side and twice the drainage channel length at the rear side. Values in the region of 60 mm can be readily achieved.

In the assembly plate 104, there are further provided securing openings 138, through which the charging socket 100 can be connected to the vehicle chassis by means of riveting or screwing.

The slightly oblique position of the housing 102 shown in Figure 2, in which the opening of the insertion face 106 is higher than the rear base region, substantially corresponds to the installation location of the plug type connector in the motor vehicle. It is therefore clear that water also has to be removed from the insertion socket 106. This takes place via drains which are described in greater detail below.

Figure 3 is a perspective view of the side of the housing 102 facing the vehicle inner space. In this instance, all seven contact chambers 108, 1 10 are surrounded by a collar which is not completely peripheral. This collar 140 serves to fix the locking device 120 in the secured state. As can be seen from the plan view of Figure 4, another drainage opening 142 is provided to remove water from the insertion socket 106. As can be seen from the sectioned illustration in Figure 6, the drainage opening 142 opens in the central drainage channel 132c.

Water is removed from the signal contact chambers 1 10 via the drainage openings 144 into the insertion socket 106. Since the signal contact drainage openings 144 are arranged above the drainage opening 142 of the insertion socket under conventional installation conditions, the water which is discharged at this location flows down to the drainage opening 142, from where it can flow into the channel 132c and from there into the discharge connection piece. Figure 5 shows that the power contact elements are retained in the contact chambers 108 by means of compressing ribs 146. Furthermore, there is provided in each of the drainage openings 128 a catch device which cooperates with the power contact element in order to fix it in the contact chamber 108. In a similar manner, the drainage opening is also used on the signal contact chambers for forming a catch device.

As already mentioned, the drainage opening 142 shown in Figure 4 opens into the drainage channel 132c which is associated with the central contact chamber 108c. As can be seen from the contact designations of Figure 5, the contact which is arranged in the central contact chamber 108c is connected to earth and is therefore most suitable for connecting the drainage of the insertion socket 106 to the drainage channel 132c which is associated therewith. When the creep paths are taken into account, it can be seen that, as a result of the connection which is produced via the drainage opening 142, the spacing between the drainage opening 128c and the insertion-side inlet of the contact chamber 108b a sufficiently long distance is still also provided.

Figure 7 shows, as indicated in Figure 4, the cross-section through the contact chamber 108d and the signal contact chamber 1 10 which is located thereabove, and through the securing opening 138. In particular the position of the drainage opening 144 which leads outwards into the socket and which is further used as a catch device for the signal contact can be seen.

Figure 8 is a cross-section through the three upper power contact chambers 108a, 108c and 108e. Figure 9 is accordingly the cross-section through the two signal contact chambers 1 10. It can be seen that the drainage opening 144 is advantageously at the same time used to form a catch arm 146, by means of which a primary engagement of the signal contact element 1 13 is enabled.

According to Figure 8, a corresponding catch arm 150 in the drainage opening 128 is provided in order to secure the respective power contact elements.

Figure 10 is another cross-section, this time through the two lower power contact chambers 108b and 108d. In addition to the catch arms 150 used for the engagement, the rectangular closed cross-section of the three drainage channels 128a, 128c and 128e which extend from above can further be seen from this sectioned illustration. Figures 1 1 and 12 finally show the locking mechanism for the contact elements, again as detailed views from Figures 9 and 8, respectively. Using the solution according to the invention, it is possible to construct a charging socket for a motor vehicle in such a manner that all requirements with respect to creep current paths and air paths can be complied with even in the presence of significant occurrences of contamination or the influence of salt-containing water spray. The production is cost- effective with high batch numbers and the assembly and mounting are precise and simple.

LIST OF REFERENCE NUMERALS