Plug connector part having a temperature-monitoring device

A connector part for connecting to a mating connector part includes: a housing part; an electrical contact element arranged on the housing part for making electrical contact with the mating connector part; and a temperature monitoring device having a sensor device for detecting a heating on the contact element. The temperature monitoring device includes a carrier element which extends flatly along a plane, on which the sensor device is arranged, and which has two clip arms via which the carrier element is clippable onto the contact element.

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2018/059643, filed on Apr. 16, 2018, and claims benefit to Belgian Patent Application No. BE 20175284, filed on Apr. 24, 2017. The International Application was published in German on Nov. 1, 2018 as WO/2018/197247 under PCT Article 21(2).

FIELD

The invention relates to a connector part for connecting to a mating connector part.

BACKGROUND

Such a connector part comprises a housing part, an electrical contact element arranged on the housing part for establishing an electrical contact with the mating connector part, and a temperature monitoring device having a sensor device for detecting heating at the contact element.

Such a connector part can be a male as well as a female connector part. Such a connector part can be used in particular on a charging device for transmitting a charging current. The connector part can in particular be designed as a charging plug or charging socket for charging an electric motor-driven motor vehicle (also referred to as an electric vehicle) and can be used on the side of a charging station, e.g. as a charging plug on a charging cable, or on the side of a vehicle as a so-called inlet.

Charging plugs or charging sockets for charging electric vehicles are to be designed in such a way that charging currents can be transmitted. Since the thermal dissipation increases quadratically with the charging current and in addition it is prescribed that a temperature increase at a plug connector part must not exceed 50 K, it is necessary with such charging plugs or charging sockets to provide temperature monitoring in order to detect an overheating at components of the charging plug or charging socket at an early stage and, if necessary, to modify the charging current or even switch off the charging device.

In a charging plug known from EP 2 605 339 A1, a temperature sensor is arranged on an insulating body approximately in the center between contact elements of the contact plug. Via the temperature sensor, it can be detected whether there is any excessive heating somewhere on the contact elements in order to cause the charging process to be switched off, if necessary.

In a charging plug known from GB 2 489 988 A, a plurality of temperature sensors are provided which transmit temperature data via a line.

Depending on the temperature range in which the temperatures recorded at the temperature sensors are located, a charging process is controlled.

From U.S. Pat. No. 6,210,036 B1 a connector is known in which several temperature sensors are serially interlinked via a single-core cable. The temperature sensors are arranged on an insulating body and exhibit a significant change in resistance at a predetermined temperature which is such that a control circuit connected to the line can detect the change and adjust the current flow through the charging plug and, if necessary, switch it off.

U.S. Pat. No. 8,325,454 B2 discloses a plug in which thermistors are assigned to individual contacts, which are connected in parallel to one another and switch on a thyristor when a threshold temperature is exceeded, in order in this way to switch off a current flow through the contacts.

In charging plugs known from the prior art, temperature sensors are embedded in particular in an insulating body. This is necessary in order to electrically insulate the temperature sensors from the contact elements at which heating can occur. At the same time, this has the disadvantage that a temperature change at one of the contact elements is transmitted via the insulating body with a time delay and is thus perceived at the temperature sensors with a time delay. Especially with concepts which are supposed to enable a fast switch-off of a load circuit in the event of a fault, such arrangements of temperature sensors are therefore possibly unsuitable.

There is a need for a temperature monitoring device which can be simple and cost-effective in design and allows temperature monitoring on the contact elements with a fast response behavior for rapid initiation of countermeasures, such as a fast switch-off of a charging current.

In a connector part known from DE 10 2015 106 251 A1, contact elements are arranged in openings in a circuit board. One or more sensor devices are provided on the circuit board and serve to detect heating at one or more contact elements.

SUMMARY

In an embodiment, the present invention provides a connector part for connecting to a mating connector part, comprising: a housing part; an electrical contact element arranged on the housing part configured to make electrical contact with the mating connector part; and a temperature monitoring device comprising a sensor device configured to detect a heating on the contact element, wherein the temperature monitoring device further comprises a carrier element which extends flatly along a plane, on which the sensor device is arranged, and which has two clip arms via which the carrier element is clippable onto the contact element.

DETAILED DESCRIPTION

In an embodiment, the present invention provides a connector part which enables temperature monitoring with fast response behavior and simple construction in a simple and cost-effective manner.

Accordingly, the temperature monitoring device has a carrier element extending flatly along a plane, on which the sensor device is arranged and which has two clip arms via which the carrier element is clipped onto the contact element.

The carrier element can be embodied, for example, as a circuit board carrying electrical conductor tracks, for example on a carrier body consisting of an electrically insulating material. Alternatively, however, the carrier element can also be realized by a so-called metal core circuit board.

The fact that the carrier element is clipped onto the contact element makes it particularly easy to mount the temperature monitoring device on an assigned contact element. A separate temperature monitoring device can be assigned to each contact element of the connector part, the temperature monitoring device being clipped via its clip arms onto the respectively associated contact element and thereby fastened to the contact element.

The clip arms are preferably formed integrally with the carrier element. Thus, the clip arms are molded onto the carrier element and are sufficiently elastic, so that the carrier element can be clipped onto the associated contact element and held in the clipped-on position on the contact element.

The carrier element is designed symmetrically, for example, with an axis of symmetry located in the plane along which the carrier element extends.

The clip arms preferably form an opening between them, which has an edge region which extends along a circular arc and surrounds the contact element. Because the contact element extends through the opening of the carrier element formed between the clip arms and is in contacting contact with the edge area of the opening, the contact element is in planar contact with the carrier element and thus thermally coupled to the carrier element, so that the sensor device arranged on the carrier element can detect heating on the contact element.

Because a sensor device can thus be located close to an assigned contact element, the sensor device can detect a heating of the contact element without large temporal latency, i.e. with rapid response behavior, so that the information about the heating can be quickly evaluated in order to initiate a suitable countermeasure, e.g. switching off a transmitted charging current.

The contact element advantageously extends perpendicularly through the opening of the carrier element formed between the clip arms. The carrier element extends flatly in the plane assigned to it, while the contact element is perpendicular to this plane.

In an advantageous embodiment, the edge region of the opening is covered at least partially by a metalization layer. The edge region is thus metalized with a (highly thermally conductive) metal material (e.g. copper) and is in planar contact via the metalization layer with the contact element to which the carrier element is attached, so that the temperature monitoring device is thermally coupled to the contact element via it.

The sensor device of the temperature monitoring device is preferably arranged sufficiently far away from the contact element on the carrier element, so that the sensor device (while maintaining the air and creepage distance required for insulation) is electrically insulated from the contact element. In order to enable a detection of a heating at the contact element without substantial delay, the carrier element preferably has a thermally conductive (metal) layer, for example a copper layer, which is contacted to the metalization layer at the edge region. The thermally conductive layer can, for example, be embedded in the base body and extend as far as the sensor device, preferably underneath the sensor device, within the carrier element. When the contact element is heated, the thermally conductive layer also heats up due to the contact element contacting the metalization layer at the edge region and the connection of the thermally conductive layer to the metalization layer. Since the sensor device can be arranged in immediate spatial proximity to the thermally conductive layer—with electrical insulation via the base body—the sensor device can immediately detect a heating of the thermally conductive layer and thus detect heating at the contact element.

In one embodiment, a first thermally conductive layer is arranged on a surface of the base body, and a second thermally conductive layer is embedded in the base body. The first thermally conductive layer and the second thermally conductive layer, which are each preferably formed from a highly thermally conductive metal material, for example copper, are preferably thermally connected to one another via so-called thermal vias, so that there is a thermal coupling between the thermally conductive layers, and the thermally conductive layers, each of which is contacted with the metalization layer at the edge region of the opening, thus heat up uniformly.

While the first thermally conductive layer on the surface of the carrier element, on which the sensor device is also arranged, is spaced apart by a distance from the sensor device and is thereby electrically insulated from the sensor device, the second thermally conductive layer extends within the base body preferably as far as below the sensor device and is electrically insulated from the sensor device via the base body. Heat is thus conducted via the second thermally conductive layer to the sensor device and can be detected at the sensor device.

A carrier element with different thermally conductive (metal) layers is realized, for example, by a circuit board in which the base body is made of an insulating material, for example FR4.

In an alternative embodiment, the carrier element can be realized by a so-called metal core circuit board which has a metal core, for example made of aluminum, and at least one electrically insulating layer covering the metal core completely or partially. In this case, the metal core of the metal core circuit board is electrically and thermally contacted with the contact element to which the temperature monitoring device is attached. The sensor device is electrically insulated from the metal core via an insulating layer, but is arranged in close spatial positional relation to the metal core, so that heating at the contact element is transferred via the metal core to the sensor device by thermal conduction and can be detected at the sensor device.

A design of a metal core circuit board is known from DE 39 35 680 A1, for example.

The clip arms, via which the temperature monitoring device is attached to the associated contact element, are sufficiently elastic in such a way that the temperature monitoring device can be clipped onto the associated contact element, with reliable support in the clipped-on position. In order to improve the elasticity at the clip arms and in particular to reduce a risk of breakage at the clip arms during repeated insertion, at least one relief recess can be provided on the carrier element, which locally weakens the carrier element, so that the clip arms can be sufficiently elastically deformed and the opening formed between the clip arms can be elastically expanded during insertion.

The relief recess can be formed, for example, within the carrier element. However, the relief recess can also extend from the opening formed between the clip arms and extend into the carrier element starting from the opening. The relief recess can be produced, for example, by milling and extends perpendicularly to the plane along which the carrier element extends, through the carrier element.

In one embodiment, the connector part has a contact carrier on which one or more contact elements are held and which is fastened to the housing part. Via the contact carrier with the contact elements arranged thereon, a pre-assembled subassembly is created which can be arranged and fastened to the housing part of the connector part. A temperature monitoring device is arranged on at least one contact element—preferably such contact elements which serve as power contacts for transmitting large (charging) currents—and is held above it on the contact carrier.

The temperature monitoring device is preferably clipped onto the associated contact element via the clip arms of the carrier element, but is not additionally fixedly connected to the contact carrier or the housing part. The temperature monitoring device is thus fixed only to the contact element, but not to the contact carrier and the housing part, so that a force effect on the contact element, for example when the connector part is plugged into an associated mating connector part, does not lead to a load on the temperature monitoring device, and in particular no (appreciable) forces are transmitted between the contact element and the contact carrier or the housing part via the carrier element of the temperature monitoring device.

In order to ensure a secure hold of the temperature monitoring device on the associated contact element, especially when heating occurs at the contact element and thus at the carrier element of the temperature monitoring device, the carrier element of the temperature monitoring device can be elastically supported against the contact carrier by means of a spring element, for example. The carrier element is thus not fixed to the contact carrier in a stationary manner, but is elastically supported relative to the contact carrier and is preloaded above it in such a way that the carrier element is pressed into contact with the contact element. If, for example, a (slight) deformation of the carrier element occurs due to heating at the contact element and at the carrier element, the carrier element is pressed into contact with the associated contact element via the biasing spring element and is thus in advantageous contact with the contact element, so that a thermal coupling between the contact element and the carrier element and also a mechanical hold of the carrier element on the contact element is ensured.

In one embodiment, the spring element is designed as a leg spring and is supported with a first leg on the carrier element and with a second leg on the contact carrier. Via its spring legs, the spring element brings about a biasing spring force between the contact carrier and the carrier element in the direction of the contact element, preferably in the plane in which the carrier element extends in a planar manner.

The connector part can be used, for example, as a charging plug or as a charging socket of a charging system for charging an electric vehicle. For this purpose, the connector part has contact elements which serve as load contacts for transmitting a charging current, for example in the form of a direct current or in the form of an alternating current. Temperature monitoring devices are preferably arranged on these load contacts, wherein in an advantageous embodiment each contact element is assigned its own temperature monitoring device. The sensor device of each temperature monitoring device is connected to a control device, for example, so that signals recorded via the temperature monitoring device can be evaluated and used for controlling a charging current transmitted via the load contacts.

Sensor devices of the type described here can be designed, for example, as temperature sensors, e.g. in the form of temperature-dependent resistors. Such temperature sensors can be, for example, resistors with a positive temperature coefficient (so-called PTC resistors) whose resistance value rises with increasing temperature (also referred to as PTC thermistors which have good electrical conductivity at low temperature and have a reduced electrical conductivity at higher temperatures). Such temperature sensors can, for example, also have a non-linear temperature characteristic and can be produced, for example, from a ceramic material (so-called ceramic PTC thermistors).

However, for example, it is also possible to use electrical resistors with a negative temperature coefficient (so-called NTC resistors) as temperature sensors, the resistance value of which decreases with increasing temperature.

Alternatively or additionally, temperature sensors formed by semiconductor components can also be used.

FIG. 1shows in a schematic view a vehicle1in the form of an electric motor-driven vehicle (also referred to as an electric vehicle). The electric vehicle1has electrically chargeable batteries via which an electric motor for moving the vehicle1can be electrically supplied.

In order to charge the batteries of the vehicle1, the vehicle1can be connected to a charging station2via a charging cable3. For this purpose, the charging cable3can be plugged with a charging plug30at one end into an assigned mating connector part4in the form of a charging socket of vehicle1and is electrically connected at its other end via another charging plug31with a connector part4in the form of a charging socket at charging station2. Charging currents with comparatively high amperage are transmitted to vehicle1via the charging cable3.

In the case of a connector part4in the form of a vehicle inlet shown inFIG. 2in an overall view, a contact carrier41shown inFIGS. 3 to 6is arranged on a housing part40. The housing part40has plug sections400,401which can be plugged into an associated mating connector part, for example a charging plug.

The plug sections400,401have a number of axially extending contact elements402,403defining an insertion direction. By plugging in connectors with the associated mating connector part, the contact elements402,403are electrically contacted with associated mating contact elements of the mating connector part, so that electrical contacting between the connector part4and the mating connector part is established and, for example, charging currents can be transmitted for charging.

The contact carrier41illustrated inFIGS. 3 to 6has fastening points410,411to which the contact elements402,403are to be fastened and, when the contact carrier41is attached to the housing part40, are held relative to the plug sections400,401. The contact elements402assigned to the upper plug section400, which realize an earthing contact and signal contacts, are to be arranged at the upper fastening points410. In contrast, the contact elements403assigned to the lower plug section401are fastened at lower fastening points411and serve as load contacts for transmitting a charging current in the form of a direct current.

The contact carrier41provides a pre-assembled subassembly via which the contact elements402,403are combined and which can be fastened to the housing part40of the connector part4as a contact insert.

The contact elements403serving as load contacts are each assigned a temperature monitoring device5which serves to detect a heating on the associated contact element403and is attached to the contact element403for this purpose. The temperature monitoring device5has a carrier element50in the form of a circuit board extending flat along a plane E, on which a sensor device is arranged and which is mechanically held on the associated contact element403.

In the exemplary embodiment shown, each contact element403is assigned its own temperature monitoring device5. The temperature monitoring device5is fixed with its carrier element50to the associated contact element403, but not—with the exception of an elastic preload via a spring element42—on the contact carrier41and also not on the housing part40, so that the temperature monitoring device5is not in a power transmission line between the contact element403and the contact carrier41and the housing part40, and thus load forces acting on the contact element403or the housing part40do not lead to (appreciable) loading on the temperature monitoring device5.

Each temperature monitoring device5is elastically supported relative to the contact carrier41via a spring element42and is pressed via the spring element42within the plane E in the direction of the respectively associated contact element403. The spring element42thus effects an elastic preload on the carrier element50of the temperature monitoring device5which brings about a mechanically secure hold of the temperature monitoring device5on the associated contact element403along with favorable thermal coupling.

For mounting the contact elements403on the contact carrier41, as shown in the sequence ofFIGS. 7A to 7C, the temperature monitoring devices5are first attached to the contact elements403and the spring elements42are arranged on the contact carrier41as can be seen in the transition fromFIG. 7AtoFIG. 7B. Then, as depicted inFIG. 7C, the contact elements403with the temperature monitoring devices5arranged thereon are arranged at the fastening points411of the contact carrier41and are mechanically fastened the contact carrier41above them.

The spring elements42are formed by leg springs which are each supported by a first leg420on the carrier element50of the associated temperature monitoring device5and are held on the contact carrier41via a second leg421. Via the first spring legs420, the spring elements42act on head sections500on the upper side of the support elements50of the temperature monitoring devices5and thus press the temperature monitoring devices5in the direction of the contact elements403.

FIGS. 8 to 10show separate views of a contact element403with an associated temperature monitoring device5. The temperature monitoring device5has a support element50formed by a circuit board on which two clip arms501,502are formed, which form an opening51with a circular arc-shaped edge region510between them. For fastening the temperature monitoring device5to the contact element403, the carrier element50with the clip arms501,502is inserted into a circumferential fastening groove404of the contact element403, which is cylindrical in its basic shape, so that, as can be seen fromFIGS. 9 and 10, the temperature monitoring device5is held in clipping manner on the contact element403via the clip arms501,502.

The carrier element50has a relief recess511extending from the opening51and extending into the carrier element50. The relief recess511can, for example, be milled into the carrier element50and serves to adjust the elasticity at the clip arms501,502in such a way that in the assembled position the clip arms501,502engage around the contact element503and thereby rest against the contact element403in an elastically preloaded manner, so that firstly a fixed mechanical hold and secondly a good thermal coupling between the carrier element50and the contact element403is created.

The contact element403has a further fastening groove405which is offset axially relative to the fastening groove404and via which the contact element403is to be arranged at the associated fastening point411of the contact carrier41. A cylinder shaft406, via which an electrical load line can be connected to the contact element403, axially adjoins the fastening groove405. At the other opposite end, the contact element403forms a contact section407in the form of a contact jack formed by contact lamellae, into which an associated contact plug of a mating connector part can be inserted.

In a exemplary embodiment shown inFIGS. 11 to 13, the carrier element50of the temperature monitoring device5is formed by a multilayer circuit board, in which the edge region510of the opening51is covered by a metalization layer52and in which thermally conductive metal layers (e.g. copper layers) extend on a surface504of a base body503and inside the base body503. A sensor device56is arranged on the surface504and serves to detect heating at the contact element403, to which the temperature monitoring device5is attached.

A first thermally conductive layer53, depicted inFIG. 11, extends along the surface504of the carrier element50in this embodiment. The thermally conductive layer53is connected to the metalization layer52and is spaced apart from the sensor device56by a distance A and thereby electrically insulated from the sensor device56.

A second thermally conductive layer55extends inside the base body503, as depicted inFIG. 12and shown inFIG. 13, which is thermally coupled to the first thermally conductive layer53via a plurality of heat vias54and is also connected to the metalization layer52at the edge region510of opening51. The second thermally conductive layer55extends to below the sensor device56but is electrically insulated from the sensor device56via the base body503made of an electrically insulating material (for example FR4).

When the contact element403associated with the temperature monitoring device5heats up, the heat produced on the contact element403is directly absorbed via the metalization layer52and the thermally conductive (metal) layers53,55and leads to uniform heating of the thermally conductive layers53,55thermally coupled to one another via the heat vias54. In doing so, the heat is transported via the second thermally conductive layer55embedded in the base body503to below the sensor device56, so that the heating can be detected directly at the sensor device56and thus the heating at the contact element403can be detected without a large time delay.

The sensor device56is thus reliably electrically insulated from the contact element403, in particular via the distance A from the first heat-conducting layer53and via the base body503from the second heat-conducting layer55. In addition, the sensor device56is located so close to the second thermally conductive layer55that heating can be directly absorbed at the contact element403and thus at the second thermally conductive layer55.

The sensor device56is connected to metalization sections560on the surface504of the base body503. In particular, lines (see also e.g.FIG. 14for this purpose) can be connected to the sensor device56via the metalization sections560.

In the exemplary embodiment of the temperature monitoring device5shown inFIGS. 11 to 13, the relief recess511is formed into the carrier element50starting from the opening51. In contrast, in an exemplary embodiment depicted inFIG. 14, relief recesses511are arranged in the interior of the carrier elements50of the temperature monitoring devices5and are thus surrounded by the carrier element50when viewed along the plane E, so that a closed contour results around each relief recess511.FIG. 14additionally shows a connecting line57at each temperature monitoring device5which is connected to the sensor device56for transmitting sensor signals.

Apart from that, the exemplary embodiment ofFIG. 14is essentially functionally identical to the exemplary embodiment according toFIGS. 11 to 13, so that reference is made to the preceding embodiments.

In an exemplary embodiment illustrated inFIG. 15, the carrier element50of the temperature monitoring device5is formed by a so-called metal core circuit board which comprises a metal core58made of aluminum, for example, as schematically depicted inFIG. 16. The metal core58is completely or partially covered, on one side or on both sides, by insulating layers580,581so that the metal core58is in particular electrically insulated from a sensor device56arranged on the carrier element50. Via an electrically conductive (metal) layer582the sensor device56can be connected, for example, to lines and through them to a control device.

In this exemplary embodiment, the carrier element50is directly connected via the metal core58to the contact element403and is thus thermally coupled. The heat is conducted directly under the sensor device56via the (highly thermally conductive) metal core58, so that heating can be detected at the sensor device56without a large delay in time.

The clip arms501,502are formed by the metal core circuit board in this embodiment. A relief recess511extends from the opening51(viewed in plane E) into the metal core circuit board.

The idea underlying the invention is not limited to the exemplary embodiments described above, but can also be realized in a similar manner in conjunction with completely differently designed embodiments.

In principle, a connector part of the type described here can not only be used as a charging plug or charging socket in a charging device for charging an electric vehicle, but can also be used in a variety of ways on a wide variety of different devices wherever monitoring of heating on a contact element is required.

A connector part of the type described here can in principle have one or more contact elements. One or more sensor devices can be used to monitor heating.

LIST OF REFERENCE SIGNS