Charging connector part for a charging system for charging an electric vehicle

Abstract

A charging connector part (5) for a charging system for charging an electric vehicle (4) comprises a plug section (500) for plugging in and connecting to a mating connector part (3), at least one electrical plug contact (51A, 51B) arranged on the plug section (500) for transmitting a charging current, and a heat pipe (57A, 57B) which has an encapsulated volume (576) in which a working medium (577) is enclosed, wherein the at least one plug contact (51A, 51B) has a receiving channel (513) into which the heat pipe (57A, 57B) projects and in which at least one heat transfer medium (58) is received for thermal contacting the heat pipe (57A, 57B) with the at least one plug contact (51A, 51B).

Description

[0001] The invention relates to a charging connector part for a charging system for charging an electric vehicle according to the preamble of claim 1 and a charging system for charging an electric vehicle.

[0002] Such a charging connector part comprises a plug-in section for plugging into a mating connector part and at least one plug contact arranged on the plug-in section for transmitting a charging current.

[0003] Such a charging connector part can be designed as a charging plug or charging socket and can be arranged on a charging cable at a charging station or on an electric vehicle. A charging plug arranged on a charging cable can be connected to a charging socket to establish an electrical connection between a charging station and the electric vehicle and to electrically charge the electric vehicle. A charging connector part within the meaning of this text should therefore be understood as a charging socket or a charging plug.

[0004] In the field of electromobility, it is desirable to charge electric vehicles quickly and efficiently to reduce charging times and the associated downtime. To enable rapid charging of an electric vehicle during a fast charging process, high charging powers are used, combined with large charging currents, for example, with a current of 700 A or even higher. Currents of up to 3000 A are even conceivable for charging commercial vehicles.

[0005] When high charging currents are transmitted, the contact elements and other components of the charging connector become heated. For example, regulations stipulate that no component of the charging connector may heat up to temperatures exceeding 90°C. Therefore, when high charging currents are used, care must be taken to prevent excessive heating of the charging connector.

[0006] The arrangement and dimensioning of electrical contact elements on charging connectors for electric vehicles is typically prescribed by standards. Contact geometries on such charging connectors cannot therefore be easily scaled to potentially achieve a greater current-carrying capacity at the contact elements. One challenge, therefore, is to enable the greatest possible power transmission with existing contact geometries.

[0007] In principle, it is possible to increase the current-carrying capacity of, for example, a charging cable and a charging plug connected to the charging cable by increasing the cross-section of the current-carrying load lines. However, because a charging cable must be handled manually by a user, there are limits to increasing the cross-section of the load lines and the associated increase in weight of the charging cable.

[0008] One way to improve the current-carrying capacity of the charging cable, charging plug, and charging socket is to provide active cooling for the current-carrying components, particularly the charging cable and the charging plug connected to the charging cable. The coolant used can be water or a water mixture (e.g., using antifreeze components) or an oil-based coolant. Care must be taken to ensure that heat can be efficiently transferred to the cooling medium to dissipate heat from the component to be cooled.

[0009] In a charging connector known from EP 3 103 173 B1, a cooling unit through which a coolant can flow is arranged between busbar components. A flow channel is defined in a housing of the cooling unit, which is designed to guide the coolant flow tangentially along the busbar components.

[0010] In a charging connector part known from DE 10 2016 107 409 A1, a coolant flow flows through heat sinks. The heat sinks are connected to associated contact elements via heat pipes, which absorb heat from the contact elements via the heat pipes.

[0011] CN 207116763 U describes a contact on which a cooling sleeve is arranged for conducting a coolant flow.

[0012] The object of the present invention is to provide a charging connector part that enables cooling or heat distribution on current-carrying components in a cost-effective manner.

[0013] This object is achieved by an article having the features of claim 1.

[0014] Accordingly, the charging connector part has a heat pipe which has an encapsulated volume in which a working medium is enclosed, wherein the at least one plug contact has a receiving channel into which the heat pipe projects and in which a heat transfer medium which at least partially surrounds the heat pipe is received for thermally contacting the heat pipe with the at least one plug contact.

[0015] The charging connector part has a plug-in section with one or more plug contacts arranged thereon. For example, two plug contacts are arranged on the plug-in section, which can be used to transmit a charging current in the form of a direct current and, when plugged in, are connected to associated mating contact elements of the mating connector part.

[0016] The at least one plug contact can be designed, for example, as a contact socket or a contact pin. The charging connector part can be electrically connected to an associated mating contact of a mating connector part via the at least one plug contact, so that an electrical connection can be established between the charging connector part and the mating connector part.

[0017] The charging connector part can, for example, be a charging plug connected to a charging cable. The mating connector part can accordingly be a charging socket (also referred to as a charging receptacle or inlet), for example, on a vehicle. Conversely, the charging connector part can also be a charging socket on a vehicle and plug into a mating connector part in the form of a charging plug on a charging cable.

[0018] The at least one plug contact has a receiving channel into which a heat pipe extends. Thus, a receiving channel is formed in the at least one plug contact, for example, in the form of a bore, into which the heat pipe extends.

[0019] A heat pipe is a heat exchanger that utilizes the evaporation enthalpy of a working fluid to achieve a high heat flux density for heat transfer. This allows large amounts of heat to be transferred over a small cross-sectional area. Generally, a distinction can be made between two designs: the heat pipe and the two-phase thermosiphon, although the basic operating principle is the same for both designs.

[0020] The energy transfer capacity of a heat pipe is largely determined by the specific enthalpy of vaporization (in kJ / mol or kJ / kg) of the working fluid. The heat pipe, for example, consists of a metal, tubular vessel enclosing a hermetically sealed volume. This volume is filled with a working fluid, such as water or ammonia, which generally fills the volume partly in a liquid state and partly in a gaseous state.

[0021] The heat pipe generally absorbs heat with one section and releases heat with another. The section of the heat pipe that absorbs energy is called the evaporator. The section of the heat pipe that releases energy is called the condenser.

[0022] The heat pipe conducts heat by evaporating the working fluid at the point of heat input. As a result, the temperature does not rise any further and the supplied energy is instead converted into enthalpy of vaporization. This locally increases the pressure in the heat pipe, resulting in a (slight) pressure gradient within the heat pipe, allowing the evaporated working fluid to disperse throughout the volume. Where the temperature is lower, the working fluid condenses, and energy is released from the heat pipe to the environment.

[0023] The part of the working medium, which is now liquefied at the heat release point, returns to the heat absorption point by gravity (thermosiphon) or by capillary forces (heat pipe).

[0024] Because the vapor and liquid of the working medium are located in the same volume, the system operates in a wet vapor region. This results in a predetermined temperature at a certain pressure in the heat pipe. Since the pressure differences in heat pipes are very small, usually just a few Pascals, the resulting temperature difference between the heat-absorbing point (evaporator) and the heat-dissipating point (condenser) is small. A heat pipe therefore has a low thermal resistance.

[0025] In a gravity-driven heat pipe (two-phase thermosiphon or gravity heat pipe), the medium circulates due to gravity. As a result, the working fluid flows independently back to the heat-absorbing location (evaporator) after condensing due to heat loss. Heat pipes, on the other hand, utilize the capillary effect to transport the condensed working fluid back to the heat-absorbing location (evaporator). Heat transfer in the heat pipe, designed as a heat pipe, is therefore position-independent.

[0026] In a heat pipe designed as a heat pipe, a vessel encapsulating the volume is made of copper or a heat-resistant steel such as 1.4841 or nickel-based alloys, for example.

[0027] To thermally couple the heat pipe to the at least one plug contact, a heat transfer medium is arranged in the receiving channel, via which the heat pipe thermally contacts the plug contact. The heat transfer medium surrounds at least a portion of the heat pipe and, on the other hand, rests against the plug contact, so that the heat pipe is thermally coupled to the plug contact via the heat transfer medium.

[0028] The heat pipe is housed in the receiving channel. The receiving channel can generally have a clear width that is only slightly larger than the diameter of the heat pipe, ensuring a precise fit for the heat pipe. A gap between the heat pipe and an inner surface circumferentially bounding the receiving channel is filled with the heat transfer medium, enabling efficient heat transfer from the plug contact to the heat pipe via the heat transfer medium.

[0029] The heat transfer medium is accommodated in the space between the heat pipe and the inner wall of the plug contact defining the receiving channel, and at least partially fills the space between the heat pipe and the plug contact in the region of the receiving channel. In one embodiment, the heat transfer medium is liquid in a (normal) operating state of the charging connector part, so that the heat transfer medium can fill the space at least approximately completely and adapt to the shape of the heat pipe on the one hand and the receiving channel on the other. If a liquid is used as the transfer medium (i.e., the heat transfer medium is in liquid form at least in the operating state of the charging connector part), a gap between the heat pipe and the plug contact in the region of the receiving channel is at least approximately completely filled, thus thermally bridging the gap.

[0030] In general, the heat transfer medium should sufficiently fill a gap between the heat pipe and an inner wall of the associated plug contact surrounding the receiving channel so that a large area of ​​the heat pipe within the receiving channel is covered by the heat transfer medium. However, the fill level should be such that, upon heating and, if necessary, a phase change, the volume expansion of the heat transfer medium does not exceed the fillable volume in the receiving channel.

[0031] In one embodiment, the heat transfer medium has a melting point that is lower than a temperature at the at least one plug contact in the operating state. During operation of the charging connector part, when a charging current is transmitted via the at least one plug contact, heating occurs at the plug contact. In a normal operating state, the temperature at the plug contact is thus preferably greater than the melting point of the heat transfer medium. This results in the heat transfer medium being in liquid form in the operating state and thus filling a transition between the heat pipe and the plug contact in a gap-free manner.

[0032] The temperature of the plug contact in the operating state can be adjusted to a predetermined operating temperature, for example a predetermined temperature range, by heat dissipation and cooling.

[0033] The temperature at the at least one plug contact in the operating state can, for example, be in a range around 90°C. For example, the heat transfer medium has a melting point that lies in a range between 50°C and 90°C.

[0034] In one embodiment, the heat transfer medium contains a metal alloy that preferably has a comparatively low melting point. In particular, the heat transfer medium has low thermal resistance and thus good thermal conductivity.

[0035] For example, the heat transfer medium can be a so-called Fields metal, which is accommodated in the receiving channel and at least partially surrounds the heat pipe. A Fields metal is composed of 51% indium, 32.5% bismuth, and 16.5% tin (each by mass) and has a melting point of approximately 61°C to 62°C.

[0036] In another embodiment, a so-called Wood's metal can be used, which has a melting point between 73°C and 77°C and consists of 50% bismuth, 25% lead, 12.5% ​​cadmium and 12.5% ​​tin (each by mass).

[0037] In one embodiment, the heat pipe extends out of the receiving channel at one end of the receiving channel. To prevent the heat transfer medium, which may be in liquid form during the operating state of the charging connector part, from flowing out of the receiving channel, the receiving channel is preferably closed at that end by a closure element. The closure element can be formed, for example, by an adhesive or a sealant that closes a transition between the heat pipe and the plug contact in the region of the open end of the receiving channel. The closure element is chemically resistant, particularly relative to the heat transfer medium.

[0038] The heat pipe can, in particular, be cylindrically shaped and extend along a longitudinal axis. The receiving channel can, accordingly, be cylindrically shaped and extend along the longitudinal axis.

[0039] In one embodiment, the at least one plug contact extends longitudinally along the longitudinal axis. The heat pipe is arranged, for example, coaxially to the longitudinal axis and thus coaxially to the plug contact. The longitudinal axis can, in particular, extend along a plug-in direction along which the charging connector part can be plugged into an associated mating connector part in order to establish an electrical connection between the at least one plug contact of the charging connector part and an associated mating contact of the mating connector part.

[0040] For example, the at least one plug contact has a preferably cylindrical shaft section that extends along the longitudinal axis and can be plugged into the mating connector part. The receiving channel is formed, for example, coaxially to the longitudinal axis. The at least one plug contact is formed, for example, as a contact pin made of a solid material, for example, as a turned part made of a metal material, for example, a copper material, and the receiving channel is formed as a bore in the shaft section such that the receiving channel extends longitudinally within the shaft section to accommodate the heat pipe.

[0041] The heat pipe can provide cooling or heat distribution at the plug contact by thermally coupling the heat pipe to the plug contact over a large area via the heat transfer medium. In this way, heat distribution at the plug contact can be provided via the heat pipe, preventing localized overheating at the plug contact and allowing heat to be transported, for example, from a location of high heating to an area of ​​the plug contact where heating is lower, so that heat is evenly distributed across the plug contact. The heat pipe can therefore be used (solely) for heat distribution at the associated plug contact, independent of active cooling.

[0042] In one embodiment, the heat pipe serves to thermally couple the associated plug contact and a cooling device. For this purpose, the charging connector part has a cooling unit for cooling the at least one plug contact, wherein the cooling unit is operatively connected to the heat pipe. The cooling unit serves as a heat sink and can absorb heat, allowing heat to be dissipated from the at least one plug contact via the heat pipe and transported to the cooling unit.

[0043] The cooling unit can provide active cooling or passive cooling. For passive cooling, the cooling unit can be designed as a heat sink, where heat can be absorbed and stored, for example, to increase the thermal inertia of the charging connector part. For active cooling, the cooling unit can, for example, have a coolant flowing through it, so that heat can be absorbed by the cooling unit during operation and dissipated via the coolant.

[0044] The cooling unit is generally arranged in relation to the at least one plug contact such that heat can be absorbed at the one or more plug contacts via the cooling unit and dissipated from the one or more plug contacts in order to cool the one or more plug contacts in this way. Within the receiving channel of the associated plug contact, the heat pipe is operatively connected to the at least one plug contact such that heat from the at least one plug contact can be absorbed by the heat pipe. The heat pipe extends out of the receiving channel in the direction of the cooling unit and is operatively connected to the cooling unit such that heat can be transported to the cooling unit via the heat pipe and introduced into the cooling unit.

[0045] In one embodiment, the cooling unit has a flow chamber through which a coolant flows. The heat pipe extends into the flow chamber and is surrounded by the coolant. The heat pipe is thus received in the receiving channel of the plug contact and extends into the flow chamber of the cooling unit with a section remote from the plug contact, allowing heat absorbed by the plug contact to be dissipated within the cooling unit.

[0046] Because the heat pipe is operatively connected to the at least one plug contact on the one hand and extends into the flow space and is surrounded by coolant in the flow space on the other, efficient heat conduction between the plug contact and the cooling unit can take place via the heat pipe. Heat conduction takes place with low thermal resistance, so that efficient heat transfer between the plug contact and the cooling unit takes place despite the spatial separation of the cooling unit from the at least one plug contact. The cooling unit can therefore be installed in the charging connector part wherever space is available and does not necessarily have to be arranged in the immediate vicinity of the at least one plug contact, but can be spatially separated from the at least one plug contact and is thermally coupled to the at least one plug contact via the heat pipe.

[0047] During operation, a coolant flows through the flow chamber. The coolant, for example, a liquid, water- or oil-based coolant, is intended to absorb and dissipate heat at the heat pipe, so that heating at the at least one plug contact is at least reduced. Coolant is supplied to the cooling unit via at least one coolant line and flows through the flow chamber of the cooling unit, thus ensuring a coolant flow through the cooling unit during operation.

[0048] In order to thermally couple the cooling unit and the at least one plug contact to one another, the heat pipe is provided, which on the one hand is operatively connected to the at least one plug contact and on the other hand extends into the flow space of the cooling unit in such a way that the coolant flows around the heat pipe in the flow space, so that heat can be absorbed by the heat pipe via the coolant and dissipated by the heat pipe.

[0049] In one embodiment, the heat pipe is operatively connected to the at least one plug contact with a first section for absorbing heat, and extends into the flow space with a second section for dissipating heat. The first section and the second section of the heat pipe are spatially spaced from one another. At the first section, via which the heat pipe is connected to the at least one plug contact, heat is absorbed at the associated plug contact. In contrast, heat is dissipated via the second section, which extends into the flow space of the cooling unit. The first section can therefore also be referred to as an evaporator, the second section as a condenser.

[0050] In one embodiment, the second section of the heat pipe extends through the flow chamber. The heat pipe thus enters the flow chamber of the cooling unit at one wall of the cooling unit, extends through the flow chamber with the second section, and exits the flow chamber again at another wall of the cooling unit. The second section extends freely within the flow chamber and is thus surrounded by the coolant flowing through the flow chamber.

[0051] In one embodiment, the heat pipe has a tube wall enclosing the encapsulated volume and an insulating layer arranged on the outside of the tube wall for electrically insulating the tube wall from the coolant flowing through the flow space. The tube wall can be made of a metal material, for example, a copper material or a steel material. To electrically insulate the tube wall from the coolant—particularly when the coolant is water-based—the tube wall is coated with an insulating layer on an outer side facing the flow space, so that the tube wall does not come into direct contact with the coolant flowing through the flow space.

[0052] The insulating layer can be made, for example, by a coating on the pipe wall or by a tubular insulating element made of an electrically insulating material that surrounds the pipe wall.

[0053] In one embodiment, the cooling unit has at least one connection point for connecting to a coolant line. For example, the cooling unit can have two connection points for connecting two cooling lines. A coolant flow can, for example, be introduced into the cooling unit via one connection point and discharged again via the other connection point.

[0054] In one embodiment, the cooling unit has a housing part that partially delimits the flow space. The heat pipe extends through a wall of the housing part into the flow space, so that coolant flows around the heat pipe within the cooling unit and heat can thus be dissipated into the coolant. In order to seal a transition between the wall of the housing part and the heat pipe in a moisture-tight manner, a sealing element is provided, which is arranged between the heat pipe and the wall of the housing part, for example by the heat pipe extending through the plug-shaped sealing element. The sealing element thus creates a seal so that coolant cannot escape from the flow space of the cooling unit.

[0055] In one embodiment, the at least one plug contact has a busbar, via which the at least one plug contact is connected to a load line for carrying a charging current. The load line is connected to the busbar. The busbar is connected to the at least one plug contact, in particular to a shaft section of the plug contact, so that a current can be conducted between the shaft section and the load line via the busbar.

[0056] In one embodiment, the cooling unit has a connecting element that defines sections of the flow space and is connected to the busbar. The connecting element, which can be made of a metal material with good thermal conductivity, is attached, for example, to the housing part of the cooling unit and, together with the housing part, defines the flow space inside the cooling unit. Because the connecting element is a good thermal conductor, heat can be absorbed at the busbar via the connecting element and transferred to the coolant inside the flow space via the connecting element.

[0057] The busbar is preferably mechanically connected to the connection element, for example, via fastening elements such as screws. The busbar is thus thermally coupled to the connection element, allowing heat to be conducted from the busbar into the connection element.

[0058] Because the connecting element is preferably made of a metal material for good thermal conductivity, the connecting element is also electrically conductive. Through the connection to the busbar, the connecting element is thus also electrically connected to the busbar. To ensure electrical insulation between the busbar and the coolant inside the cooling unit, the connecting element is electrically insulated from the flow space by an insulating element. The insulating element is arranged, for example, between the connecting element and the housing part of the cooling unit, so that the insulating element forms an intermediate layer between the connecting element and the flow space inside the cooling unit.The insulating element is formed, for example, by a plastic film, preferably made of a high-performance plastic with a thin wall thickness, which has an electrically insulating effect but has a low thermal resistance for heat conduction between the connecting element and the coolant inside the cooling unit.

[0059] The charging connector part has, for example, two electrical plug contacts and two heat pipes, each connected to one of the plug contacts. The plug contacts can serve as load contacts, for example, for transmitting a charging current in the form of a direct current. A heat pipe is assigned to each plug contact. The respective heat pipe is operatively connected to the respective plug contact, so that heat can be absorbed at the respective plug contact via the associated heat pipe and introduced into the cooling unit via the heat pipe. Each heat pipe extends into the flow chamber inside the cooling unit and, during operation, is surrounded by coolant in the flow chamber.

[0060] A charging system for charging an electric vehicle comprises a charging connector part of the type described above. Such a charging system also comprises a mating connector part that can be plugged into the charging connector part. The charging connector part can, for example, implement a charging plug arranged on a charging cable. The mating connector part, in contrast, can be arranged on the electric vehicle, for example, as a charging socket, and can be connected to the charging connector part in the form of the charging plug. The charging plug can, for example, be connected to a charging station via the charging cable, so that when the charging connector part and the mating connector part are connected, charging currents can be transmitted from the charging station to the electric vehicle.

[0061] It is also conceivable that the charging connector part implements a charging socket on the side of an electric vehicle.

[0062] A charging connector part of the type described here can be used in particular for transmitting charging currents in the form of direct currents. However, such a charging connector part can also be used for transmitting charging currents in the form of alternating currents.

[0063] The concept underlying the invention will be explained in more detail below with reference to the exemplary embodiments illustrated in the figures. They show: Fig. 1 a view of a charging station with a charging cable arranged thereon for connecting to an electric vehicle; Fig. 2 a view of an embodiment of a charging connector part in the form of a charging socket; Fig. 3 a view of a contact assembly comprising two plug contacts and an associated cooling unit; Fig. 4 a view of the arrangement according to Fig. 3, without a plate-shaped connecting element and a busbar arranged thereon; Fig. 5 an exploded view of the arrangement according to Fig. 3; Fig. 6 an exploded view of a plug contact with an associated heat pipe; Fig. 7A is a sectional view along the line AA according to Fig. 5; Fig. 7B is a partially enlarged view of the sectional view according to Fig. 7A; Fig. 8A is a longitudinal sectional view through a plug contact with a heat pipe accommodated therein; Fig. 8B is a partially enlarged view of the arrangement according to Fig. 8A; Fig. 9 is a view of another embodiment of a charging connector part in the form of a charging socket; Fig. 10 a view of a contact assembly of the charging connector part according to Fig. 9, comprising two plug contacts and an associated cooling unit; Fig. 11 a cross-sectional view along the line AA according to Fig. 10; and Fig. 12 a longitudinal section view along the line BB according to Fig. 10.

[0064] Fig. Figure 1 shows a charging system comprising a charging station 1, which serves to charge an electrically powered vehicle 4, also referred to as an electric vehicle. The charging station 1 is designed to provide a charging current in the form of an alternating current or a direct current and has a cable 2, which is connected at one end to the charging station 1 and at the other end to a charging connector part 3 in the form of a charging plug.

[0065] The charging connector part 3 in the form of the charging plug arranged on the charging cable 2 can be plugged into an associated charging connector part 5 in the form of a charging socket arranged on the vehicle 4 in order to transmit charging currents between the charging station 1 and the vehicle 4.

[0066] To enable rapid charging of the electric vehicle 4, e.g., during a so-called rapid charging process, the transmitted charging currents have a high current intensity, e.g., greater than 500 A, possibly even in the order of 700 A or more (for commercial vehicles, for example, even in the range of 3000 A). Such high charging currents result in thermal losses at the cable 2 and also at the charging plug 3 and the charging socket 5, which can lead to heating of the cable 2, the charging plug 3, and the charging socket 5.

[0067] The permissible heating of components of the charging system is limited by standards, for example, to a maximum value of 50 K or to an absolute temperature value of 90 °C for individual components. This means that measures must be taken to prevent excessive heating during charging, especially when high currents, for example in the order of 700 A or more, are used.

[0068] In one embodiment of a Fig. On the charging connector part 5 shown in Figure 2 in the form of a vehicle-mounted charging socket, plug contacts 52 are arranged on an upper plug section 501, which serve, for example, to transmit a charging current in the form of an alternating current or to transmit control signals or as a grounding contact. In contrast, plug contacts 51A, 51B are arranged on a lower plug section 500, which serve as load contacts for transmitting a charging current in the form of a direct current. When plugged into the associated mating connector part 3 in the form of the charging plug on the charging cable 2, the plug contacts 51A, 51B come into electrical contact with associated mating contact elements on the charging plug 3 side, so that a charging current can be transmitted from the charging station 1 to the electric vehicle 4.

[0069] In the illustrated charging connector part 5 in the form of the charging socket, active cooling is provided in order to absorb and dissipate heat, particularly in the area of ​​the plug contacts 51A, 51B carrying the charging current, and in this way to limit the heating at the charging connector part 5.

[0070] For this purpose, the charging connector part 5 in the illustrated embodiment, as can be seen from the views according to Fig. 3 to 5, a cooling unit 56 has a flow chamber 564 within a housing part 560, through which coolant flows during operation of the charging connector part 5. The flow chamber 564 is closed by plate-shaped connecting elements 561, 562, which are attached to the housing part 560 on opposite sides and are firmly connected to the housing part 560, so that the housing part 560 and the connecting elements 561, 562 together define the flow chamber 564.

[0071] Cooling lines 55 are connected to the cooling unit 56, through which coolant is introduced into the flow space 564 and is also discharged from the flow space 564. Within the flow space 564, the coolant is deflected so that during operation a coolant flow F is generated through the flow space 564, as can be seen from the sectional view according to Fig. 7A can be seen.

[0072] The plug contacts 51A, 51B each extend longitudinally along a longitudinal axis L and are each designed as contact pins for plugging into associated mating contact elements in the form of contact sockets on the side of the mating connector part 3. Each plug contact 51A, 51B has a cylindrical shaft section 511 and an insulating cap 512 attached to one end of the shaft section 511. Each shaft section 511 is connected to an associated busbar 510, to which a pair of load lines 53A, 53B are connected for conducting a charging current, as shown in Fig. 3 is evident.

[0073] The plug contacts 51A, 51B can be connected along a plug direction E with the associated mating contacts of the mating connector part 3 in order to establish an electrical connection between the charging connector part 5 and the mating connector part 3 and thus to transmit a charging current between the charging station 1 and the electric vehicle 4.

[0074] In the illustrated embodiment, each plug contact 51A, 51B is assigned a heat pipe 57A, 57B, which extends longitudinally along the longitudinal axis L of the respective plug contact 51A, 51B and establishes a thermal coupling of the plug contact 51A, 51B with the cooling unit 56. Each heat pipe 57A, 57B extends into a receiving channel 513 in the interior of the respectively assigned plug contact 51A, 51B, as can be seen from Fig. 6 in conjunction with the sectional view according to Fig. 7A, and is thus arranged coaxially to the longitudinal axis L of the respective associated plug contact 51A, 51B.

[0075] Within the receiving channel 513, the respective heat pipe 57A, 57B is thermally coupled to the associated plug contact 51A, 51B, so that heat can be absorbed at the heat pipe 57A, 57B and dissipated by the plug contact 51A, 51B. The section of the heat pipe 57A, 57B extending within the receiving channel 513 represents a heat-absorbing section of the heat pipe 57A, 57B and can also be referred to as an evaporator.

[0076] As can be seen from the sectional views according to Fig. 8A and Fig. As can be seen in Figure 8B, a heat transfer medium 58 is provided for thermal coupling between the heat pipe 57A, 57B and the associated plug contact 51A, 51B, which heat transfer medium is accommodated in the receiving channel 513. The heat transfer medium 58 fills a gap between the respective heat pipe 57A, 57B and an inner wall of the associated plug contact 51A, 51B surrounding the respective receiving channel 513 such that the gap between the heat pipe 57A, 57B and the plug contact 51A, 51B is substantially filled and thus thermally bridged.

[0077] The heat transfer medium 58 is inserted into the receiving channel 513. The receiving channel 513 is cylindrical, for example. The heat pipe 57A, 57B is inserted into the receiving channel 513 of the respective associated plug contact 51A, 51B with a precise fit, but with a (small) gap. Within the receiving channel 513, the heat transfer medium 58 surrounds the heat pipe 57A, 57B and, on the one hand, covers the heat pipe 57A, 57B and, on the other hand, rests against the plug contact 51A, 51B, so that the gap between the heat pipe 57A, 57B and the plug contact 51A, 51B is bridged by the heat transfer medium 58.

[0078] The heat transfer medium 58 has good thermal conductivity. In particular, the heat transfer medium 58 can be in a liquid phase when the charging connector part 5 is in an operating state. For example, the heat transfer medium 58 consists of a material, for example a metallic material, that has a melting point below the operating temperature at the associated plug contact 51A, 51B in a normal operating state of the charging connector part 5. For example, the heat transfer medium 58 can consist of a metal alloy that has a melting point in a range between 50°C and 90°C, wherein an operating temperature at the plug contact 51A, 51B can be, for example, 90°C and can be adjusted by heat dissipation at the plug contact 51A, 51B.

[0079] In one embodiment, the heat transfer medium 58 consists of a so-called Field metal, which has a melting point of 61°C to 62°C.

[0080] In a resting state, in which no charging currents are transferred via the plug contacts 51A, 51B, the heat transfer medium 58 can be in a solid state within the gap between the heat pipe 57A, 57B and the associated plug contact 51A, 51B, for example. If heat is transferred via the plug contacts 51A, 51B during operation, the plug contacts 51A, 51B heat up and the heat transfer medium 58 liquefies as soon as the temperature at the plug contacts 51A, 51B exceeds the melting point of the heat transfer medium 58. In the liquid phase, the heat transfer medium 58 wets the heat pipe 57A, 57B and establishes a substantially gap-free thermal coupling between the heat pipe 57A, 57B and the associated plug contact 51A, 51B.

[0081] As can be seen from the enlarged view according to Fig. 8B, a free end of the receiving channel 513 of each plug contact 51A, 51B is closed by a closure element 580, which can be formed, for example, by an adhesive or sealant, which closes a transition between the heat pipe 57A, 57B and the plug contact 51A, 51B in the region of the outlet of the receiving channel 513, so that the heat transfer medium 58 in the liquid state cannot escape from the receiving channel 513.

[0082] As can be seen particularly from the sectional views according to Fig. 7A and Fig. As can be seen in Figure 7B, the respective heat pipe 57A, 57B extends through a cap element 570 and a sealing element 571 into the flow space 564 within the cooling unit 56. The heat pipe 57A, 57B extends through the flow space 564 and, with an end remote from the associated plug contact 51A, 51B, out of the flow space 564. The remote end engages a sealing element 572 and is supported relative to the housing part 560 via a cap element 573.

[0083] The sealing elements 571, 572 seal a passage of the heat pipe 57A, 57B through walls of the housing part 560 so that coolant cannot escape from the flow space 564 inside the cooling unit 56.

[0084] The respective associated plug contact 51A, 51B is mechanically supported relative to the cooling unit 56 via the cap element 570 in that a section of the busbar 510 carrying the shaft section 511 or a riveted end of the shaft section 511 rests against the cap element 570.

[0085] The respective associated plug contact 51A, 51B is thermally coupled to the cooling unit 56 via the respective heat pipe 57A, 57B. During operation, the section of the heat pipe 57A, 57B extending freely through the flow space 564 is surrounded by the coolant flow F within the flow space 564, so that heat can be absorbed by the heat pipe 57A, 57B and dissipated by the heat pipe 57A, 57B. The section of the heat pipe 57A, 57B extending freely through the flow space 564 can also be referred to as a condenser.

[0086] The heat pipes 57A, 57B are each formed as longitudinally extending tubular elements. Encapsulated within each heat pipe 57A, 57B is a volume 576 in which a working medium, for example, water or ammonia, is contained. The volume 576 is hermetically sealed by a tube wall 574, which is made, for example, of a metal material, preferably a copper material or a steel material.

[0087] In order to electrically insulate the respective heat pipe 57A, 57B from the coolant flowing through the flow space 564 and thus ensure electrical separation of the respective plug contact 51A, 51B from the cooling unit 56, the pipe wall 574 is covered on the outside by an insulating layer 575 and is thus electrically insulated from the flow space 564 and the coolant flowing therein.

[0088] The busbars 510 of the plug contacts 51A, 51B are each connected to an associated connection element 561, 562 of the cooling unit 56. The connection elements 561, 562 are preferably made of a metal material with good thermal conductivity and, in addition to mechanically securing the busbars 510, also serve to absorb heat at the busbars 510 and transfer it to the coolant within the flow chamber 564. The busbars 510 are mechanically connected to the connection elements 561, 562, for example, via fastening means in the form of screws, and are thus thermally (and also electrically) connected to the connection elements 561, 562.

[0089] In order to create an electrical separation of the busbars 510 from the flow space 564 inside the cooling unit 56, the connection elements 561, 562 are each separated from the flow space 564 by an insulating element 563, for example in the form of an electrically insulating plastic film, and are thus electrically insulated from the flow space 564.

[0090] The housing part 560 is preferably made of an electrically non-conductive material, for example a plastic material.

[0091] In the case of Fig. 2 to 8A, 8B, the cooling unit 56 is connected to cooling lines 55 to provide active cooling and is flowed through by a coolant during operation, so that heat can be actively dissipated from the cooling unit 56. In an embodiment shown in Fig. In contrast, in the embodiment shown in Figures 9 to 12, a cooling unit 56 is designed as a heat sink for passive heat absorption, without active cooling being provided by a coolant flow.

[0092] The cooling unit 56 can increase the thermal inertia of the charging connector part 5 by absorbing and temporarily storing heat at the cooling unit 56. The cooling unit 56 is coupled to the plug contacts 51A, 51B via the heat pipes 57A, 57B, in that the heat pipes 57A, 57B extend into bores 565A, 565B of the cooling unit 56, which is manufactured, for example, as a solid block made of a metal material. The heat pipes 57A, 57B are preferably electrically insulated from the cooling unit 56 by coating the heat pipes 57A, 57B with an electrically insulating layer in the area of ​​the bores 565A, 565B.

[0093] Heat can be dissipated from the plug contacts 51A, 51B via the heat pipes 57A, 57B and introduced into the cooling unit 56, which temporarily stores the heat and, if necessary, dissipates it to the outside via its outer surface. Heating at the plug contacts 51A, 51B is thus reduced by heat transfer to the cooling unit 56.

[0094] Furthermore, the embodiment according to Fig. 9 to 12, in particular with regard to the plug contacts 51A, 51B and the thermal coupling of the plug contacts 51A, 51B with the heat pipes 57A, 57B, functionally identical to the embodiment according to Fig. 2 to 8A, 8B.

[0095] The idea underlying the invention is not limited to the preceding embodiments, but can also be implemented in other ways.

[0096] A charging connector part of the type in question here can implement a charging plug, for example on a charging cable, or a charging socket, for example on the side of an electric vehicle.

[0097] Such a charging connector part can be used, in particular, to transmit a charging current in the form of a direct current. However, it is also conceivable for the charging connector part to be designed to transmit a charging current in the form of an alternating current.

[0098] Active cooling can be provided on one (single) plug contact or on several plug contacts.

[0099] In the illustrated embodiment, each plug contact is assigned a (single) heat pipe. It is also conceivable to assign more than one heat pipe to a plug contact, so that heat dissipation and / or heat distribution occurs via multiple heat pipes at an assigned plug contact. List of reference symbols 1 charging station 2 charging cables 3 Charging connector part (charging plug) 4 vehicle 5 Charging socket 50 housings 500, 501 plug-in section 51A, 51B plug contact 510 busbar 511 Contact section (shaft) 512 Insulating cap 52 plug contact 53A, 53B load line 54 Line 55 coolant line 56 Cooling unit 560 housing part 561, 562 connecting element 563 Insulating element (insulating layer) 564 Flow space 565A, 565B bore 57A, 57B heat pipe 570 cap element 571 sealing element 572 sealing element 573 cap element 574 Pipe wall 575 Insulating layer 576 Encapsulated Volume 577 Working medium 58 Heat transfer medium 580 locking element E Plug-in direction F Coolant flow L Longitudinal axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 103 173 B1

[0009] DE 10 2016 107 409 A1

[0010] CN 207116763 U

[0011]

Claims

[1] Charging connector part (5) for a charging system for charging an electric vehicle (4), with a plug-in section (500) for plugging into a mating connector part (3) and at least one electrical plug contact (51A, 51B) arranged on the plug-in section (500) for transmitting a charging current, characterized by a heat pipe (57A, 57B) having an encapsulated volume (576) in which a working medium (577) is enclosed, wherein the at least one plug contact (51A, 51B) has a receiving channel (513) into which the heat pipe (57A, 57B) projects and in which at least one heat transfer medium (58) at least partially surrounding the heat pipe (57A, 57B) is received for thermally contacting the heat pipe (57A, 57B) with the at least one plug contact (51A, 51B). [2] Charging connector part (5) according to claim 1, characterized bythat the heat transfer medium (58) is liquid at least in one operating state of the charging connector part (5). [3] Charging connector part (5) according to claim 1 or 2, characterized by that the heat transfer medium (58) has a melting point which is lower than a temperature at the at least one plug contact (51A, 51B) in the operating state. [4] Charging connector part (5) according to claim 3, characterized by that the melting point is in a range between 50°C and 90°C. [5] Charging connector part (5) according to one of the preceding claims, characterized by that the heat transfer medium (58) contains a metal alloy. [6] Charging connector part (5) according to one of the preceding claims, characterized by that the heat transfer medium (58) contains a Field metal. [7] Charging connector part (5) according to one of the preceding claims, characterized bythat the heat pipe (57A, 57B) extends out of the receiving channel (513) at one end of the receiving channel (513), wherein the receiving channel (513) is closed at the end by a closure element (580) for preventing the heat transfer medium (58) from escaping from the receiving channel (513). [8] Charging connector part (5) according to one of the preceding claims, characterized by that the receiving channel (513) extends longitudinally along a longitudinal axis (L) and the heat pipe (57a, 57B) extends longitudinally along the longitudinal axis (L) in the receiving channel (513). [9] Charging connector part (5) according to claim 8, characterized by that the at least one plug contact (51A, 51B) extends longitudinally along the longitudinal axis (L). [10] Charging connector part (5) according to claim 8 or 9, characterized byin that the at least one plug contact (51A, 51B) has a shaft section (511) which can be plugged into the mating connector part (3) and extends along the longitudinal axis (L), wherein the receiving channel (513) is formed in the shaft section (511). [11] Charging connector part (5) according to one of the preceding claims, characterized by a cooling unit (56) for cooling the at least one plug contact (51A, 51B), wherein the cooling unit (56) is operatively connected to the heat pipe (57A, 57B). [12] Charging connector part (5) according to claim 11, characterized by that the cooling unit (56) has a flow space (564) through which a coolant is to flow, wherein the heat pipe (57A, 57B) extends into the flow space (564) and is surrounded by the coolant in the flow space (564). [13] Charging connector part (5) according to claim 12, characterized bythat the heat pipe (57A, 57B) is operatively connected to the at least one plug contact (51A, 51B) with a first section for absorbing heat and extends into the flow space (564) with a second section for dissipating heat. [14] Charging connector part (5) according to claim 13, characterized by that the second section of the heat pipe (57A, 57B) extends through the flow space (564). [15] Charging connector part (5) according to one of claims 12 to 14, characterized by that the heat pipe (57A, 57B) has a pipe wall (574) enclosing the encapsulated volume (576) and an insulating layer (575) arranged on the outside of the pipe wall (574) for electrically insulating the pipe wall (574) from the coolant flowing through the flow space (564). [16] Charging connector part (5) according to one of claims 12 to 15, characterized bythat the cooling unit (56) has a housing part (560) which partially delimits the flow space (564), wherein the heat pipe (57A, 57B) extends through a wall of the housing part (560) and a transition between the wall and the heat pipe (57A, 57B) is sealed by a sealing element (571, 572). [17] Charging connector part (5) according to one of claims 12 to 16, characterized by in that the at least one plug contact (51A, 51B) has a busbar (510) via which the at least one plug contact (51A, 51B) is connected to a load line (53A, 53B) for carrying a charging current, wherein the cooling unit (56) has a connection element (561, 562) which delimits the flow space (564) in sections and is connected to the busbar (510). [18] Charging connector part (5) according to claim 17, characterized bythat the connection element (561, 562) is electrically insulated relative to the flow space (564) via an insulating element (563). [19] Charging connector part (5) according to one of the preceding claims, characterized by that the charging connector part (3) has two electrical plug contacts (31A, 31B) and two heat pipes (57A, 57B) each connected to one of the plug contacts (31A, 31B). [20] Charging system for charging an electric vehicle (4), comprising a charging connector part (5) according to one of the preceding claims and a charging station (1) which can be electrically connected to the electric vehicle (4) via the charging connector part (5) for transmitting a charging current.

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