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 into a mating connector part (3) and at least one electrical plug contact (51A, 51B) arranged on the plug section (500) for transmitting a charging current. A heat pipe (57A, 57B) is operatively connected to the at least one plug contact (51A, 51B), the heat pipe having an encapsulated volume (576) in which a working medium (577) is enclosed, the at least one plug contact (51A, 51B) having a receiving channel (513) in which the heat pipe (57A, 57B) is arranged at least with one section, the heat pipe (57A, 57B) being configured to conduct heat to 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 to a charging system for charging an electric vehicle.

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

[0003] Such a charging connector component can be designed as a charging plug or charging socket and is located on a charging cable at a charging station or on an electric vehicle. A charging plug on a charging cable can be connected to a charging socket to establish an electrical connection between the charging station and the electric vehicle, thus enabling the electric vehicle to be charged. Therefore, for the purposes of this text, a charging connector component is understood to mean either a charging socket or a charging plug.

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

[0005] When transmitting high charging currents, the contact elements and other components of the charging connector heat up. It is stipulated, for example, that no component of the charging connector may heat up to a temperature exceeding 90°C. Therefore, when using high charging currents, care must be taken to prevent excessive heating of the charging connector.

[0006] The arrangement and dimensioning of electrical contact elements on charging connector components for electric vehicle charging are usually prescribed by standards. Contact geometries on such charging connector components therefore cannot be readily scaled to potentially achieve a higher current-carrying capacity at the contact elements. A challenge thus lies in enabling the highest possible power transmission with existing contact geometries.

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

[0008] The object of the present invention is to provide a charging connector part that reduces the risk of locally excessive heating at a plug contact in a cost-effective manner.

[0009] This problem is solved by an object having the features of claim 1.

[0010] Accordingly, the charging connector part has a heat pipe operatively connected to the at least one plug contact, which has an encapsulated volume in which a working medium is enclosed. The at least one plug contact has a receiving channel in which the heat pipe is arranged, at least with a section, wherein the heat pipe is configured to conduct heat to the at least one plug contact.

[0011] The charging connector part has a plug section with one or more plug contacts arranged on it. For example, two plug contacts are arranged on the plug section, which can serve to transmit a charging current in the form of a direct current and, when plugged in, are connected to corresponding mating contact elements of the mating connector part.

[0012] The at least one plug contact can be designed, for example, as a socket or a pin. The charging connector part can be electrically connected to a corresponding mating contact of a mating connector part via this at least one plug contact, thus establishing an electrical connection between the charging connector part and the mating connector part.

[0013] The charging connector part can be, for example, a charging plug connected to a charging cable. The mating connector part can be a charging socket (also called a charging port or inlet), for example, on a vehicle. Conversely, the charging connector part can also be a charging socket on a vehicle and be plugged into a mating connector part in the form of a charging plug on a charging cable.

[0014] The at least one plug connector has a receiving channel in which at least a section of the heat pipe is arranged. The receiving channel is thus formed within the at least one plug connector, for example in the form of a bore, into which the heat pipe extends. Within the receiving channel, the heat pipe is operatively connected to the at least one plug connector, so that heat can be absorbed by the heat pipe from the at least one plug connector and also transferred back into the at least one plug connector.

[0015] The heat pipe allows heat to be conducted to at least one of the plug contacts, thus distributing heat across the plug contact during operation. The heat pipe increases the thermal conductivity at the plug contact, automatically compensating for temperature differences and ensuring a more uniform temperature distribution, particularly along its axial length.

[0016] The heat pipe is designed to distribute heat along the plug contact by absorbing heat at a first location and releasing it at a second location. Heat can thus be absorbed via the heat pipe at the plug contact where, during operation, excessive heating occurs (compared to other sections of the plug contact). The heat pipe can then transport heat away from a location of localized heating to other locations on the plug contact, thereby reducing the temperature at the site of localized heating. This heat distribution via the heat pipe allows the temperature of the plug contact to be more uniform by reducing localized heating through heat transfer to other sections of the plug contact.

[0017] A heat pipe is a heat exchanger that utilizes the enthalpy of vaporization of a working medium 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, two designs can be distinguished: the heat pipe and the two-phase thermosiphon, although the basic operating principle is the same for both.

[0018] The energy-transporting capacity of a heat pipe is primarily determined by the specific enthalpy of vaporization (in kJ / mol or kJ / kg) of the working medium. The heat pipe consists, for example, of a metal, tubular vessel that encloses a hermetically sealed volume. This volume is filled with a working medium, such as water or ammonia, which generally occupies part of the volume in a liquid state and part in a gaseous state.

[0019] A heat pipe generally absorbs heat in one section and releases it in another. The section of the heat pipe that absorbs heat is called the evaporator. The section that releases heat, on the other hand, is called the condenser.

[0020] The heat pipe conducts heat by causing the working fluid to evaporate at the point of heat input. As a result, the temperature does not rise further, and the supplied energy is instead converted into the enthalpy of vaporization. This locally increases the pressure within the heat pipe, creating a (slight) pressure gradient, which causes 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 surroundings.

[0021] The portion of the working medium, which has now liquefied again at the heat emission point, returns to the point of heat absorption by gravity (thermosiphon) or by capillary forces (heat pipe).

[0022] Since the steam and liquid working fluid are in the same volume, the system operates in a wet steam region. This means that a predetermined temperature is present at a specific pressure in the heat pipe. Because the pressure differences in heat pipes are usually very small, typically only a few Pascals, the resulting temperature difference between the heat-absorbing point (evaporator) and the heat-emitting point (condenser) is also small. Consequently, a heat pipe has a low thermal resistance.

[0023] In a gravity-driven heat pipe (two-phase thermosiphon or gravity heat pipe), the medium circulates due to gravity. As a result, the working medium flows back to the heat-absorbing point (evaporator) on its own after condensing due to heat release. Heat pipes, on the other hand, utilize the capillary effect to guide the condensed working medium back to the heat-absorbing point (evaporator). Therefore, heat transfer in a heat pipe is independent of its orientation.

[0024] In a heat pipe designed as a heat pipe, a volume-enclosing vessel is made, for example, of copper or a heat-resistant steel such as 1.4841 or nickel-based alloys.

[0025] Because the heat pipe incorporates at least one plug contact, efficient heat conduction to the plug contact can occur via the heat pipe. This heat conduction has low thermal resistance, resulting in efficient heat transfer between different points on the plug contact.

[0026] In one embodiment, the heat pipe has a pipe wall that encloses the encapsulated volume. The pipe wall can be made of a metal material, for example, copper or steel.

[0027] In one embodiment, at least one plug contact extends longitudinally along a longitudinal axis. The plug contact can, for example, be cylindrical in at least one section, with the cylinder axis corresponding to the longitudinal axis of the plug contact along which it extends. At one end, the plug contact can be connected to an associated load line. The other end is free and can be plugged in along a direction pointing along the longitudinal axis to an associated mating contact of the mating connector part. The receiving channel is preferably straight and extends longitudinally within the plug contact, and can be formed coaxially with or radially offset from the longitudinal axis of the plug contact.

[0028] At least one plug contact can be equipped with one or more heat pipes for heat conduction. In one embodiment, for example, each plug contact is assigned exactly one heat pipe, which is received, for instance, in a receiving channel extending coaxially to the longitudinal axis of the plug contact. In another embodiment, each plug contact is assigned a plurality of heat pipes, each of which is received in a receiving channel on the plug contact. For this purpose, several receiving channels can be formed on the plug contact, which are distributed, for example, around the longitudinal axis of the plug contact, such that each receiving channel is formed radially outside the longitudinal axis and extends longitudinally within the plug contact.

[0029] The receiving channel is arranged coaxially to the longitudinal axis and thus coaxially to the plug contact. The heat pipe is housed within the receiving channel and therefore extends coaxially to the longitudinal axis within the plug contact, allowing heat to be distributed axially along the plug contact. This is achieved by conducting heat from one axial location to another via the heat pipe, thus removing heat from areas of excessive local heating and distributing it to other sections of the plug contact during operation.

[0030] For example, the at least one plug contact has a preferably cylindrical shaft section extending along the longitudinal axis, which can be plugged into the mating connector part and in which 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 from a solid material, for example, as a turned or milled part from 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.

[0031] In one embodiment, the heat pipe extends between a first end of the at least one plug contact and a second end of the at least one plug contact inside the plug contact. The first end can, for example, correspond to an end of the plug contact through which the plug contact can be connected to an associated mating contact and which is thus exposed in such a way that contact with the mating contact can be established. At the second end, the plug contact can, for example, be connected to an associated load line. The receiving channel extends between the first end and the second end, for example, by being formed into the plug contact from the second end and extending to the first end or almost to the first end within the plug contact.The heat pipe thus extends axially along (at least almost) the entire length of the plug contact, so that heat can be distributed along the axial length of the plug contact via the heat pipe.

[0032] 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.

[0033] The charging connector part, for example, has two electrical contacts and two heat pipes, each connected to one of the contacts. The contacts can serve as load contacts, for example, to transmit a charging current in the form of direct current. One or more heat pipes are assigned to each contact. The respective heat pipe is operatively connected to its assigned contact, so that heat can be absorbed at the respective contact via the associated heat pipe and conducted through the heat pipe to the respective contact.

[0034] A charging system for charging an electric vehicle comprises a charging connector of the type described above. Such a charging system also includes a mating connector that can be plugged into the charging connector. The charging connector can, for example, be a charging plug attached to a charging cable. The mating connector, on the other hand, can, for example, be a charging socket on the electric vehicle and be connected to the charging connector in the form of a charging plug. The charging plug can then be connected to a charging station via the charging cable, so that, when the charging connector and mating connector are connected, charging currents can be transferred from the charging station to the electric vehicle.

[0035] It is also conceivable and possible that the charging connector part implements a charging socket on the side of an electric vehicle.

[0036] A charging connector 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 can also be used for transmitting charging currents in the form of alternating currents.

[0037] The underlying concept of the invention will be explained in more detail below with reference to the exemplary embodiments shown in the figures. The figures show: Fig. 1. A view of a charging station with a charging cable attached to it 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 Another view of the charging connector part, without a rear housing part; Fig. 4 a view of the arrangement according to Fig. 3, with separately shown plug contacts for transmitting a charging current in the form of a direct current; Fig. 5 a separate view of the plug contacts for transmitting a charging current in the form of a direct current; Fig. 6 a view of the plug contacts, with separately shown, associated heat pipes; Fig. 7A a longitudinal section view through a plug connector; and Fig. 7B a view of a temperature curve at the plug contact according to Fig. 7A in operation.

[0038] 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 alternating current or 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 3 in the form of a charging plug.

[0039] 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 transfer charging currents between the charging station 1 and the vehicle 4.

[0040] To enable rapid charging of the electric vehicle 4, e.g., during a so-called fast-charging process, the transmitted charging currents have a high current intensity, e.g., greater than 500 A, possibly even on the order of 700 A or more (for commercial vehicles, for example, even in the range of 3000 A). Due to such high charging currents, thermal losses occur at the cable 2, as well as 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.

[0041] The permissible temperature rise of components in the charging system is limited by standards, for example to a maximum value of 50 K or to an absolute temperature 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 on the order of 700 A or more, are used.

[0042] In one embodiment of a Fig. 2 and Fig. In the charging connector part 5 shown in Figure 3, which is in the form of a vehicle-side charging socket, plug contacts 52 are arranged on an upper plug section 501. These serve, for example, to transmit a charging current in the form of alternating current, to transmit control signals, or as a grounding contact. In contrast, plug contacts 51A and 51B are arranged on a lower plug section 500. These serve as load contacts for transmitting a charging current in the form of direct current. When plugged into the corresponding mating connector part 3, in the form of the charging plug on the charging cable 2, the plug contacts 51A and 51B make electrical contact with the corresponding mating contact elements on the side of the charging plug 3, so that a charging current can be transmitted from the charging station 1 to the electric vehicle 4.

[0043] The in Fig. 4 and also in separate views in Fig. 5 and Fig. The six illustrated plug contacts 51A, 51B each extend longitudinally along a longitudinal axis L and are each designed as contact pins for plugging into corresponding mating contact elements in the form of contact sockets on 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 for conducting a charging current is connected.

[0044] 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.

[0045] In the illustrated embodiment, each plug contact 51A, 51B is associated with a heat pipe 57A, 57B, which extends longitudinally along the longitudinal axis L of the respective plug contact 51A, 51B and is thermally coupled to the plug contact 51A, 51B either continuously along its axial length or at defined, distributed locations. Each heat pipe 57A, 57B extends into a receiving channel 513 inside the respective associated plug contact 51A, 51B, as shown in the figure. Fig. 5 and Fig. 6 in conjunction with the sectional view according to Fig. 7A can be seen, and in the illustrated embodiment, is arranged coaxially to the longitudinal axis L of the respective associated plug contact 51A, 51B.

[0046] 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, conducted at the plug contact 51A, 51B and also released again at the plug contact 51A, 51B.

[0047] The heat pipes 57A, 57B are each designed as longitudinally extended pipe elements. Within each heat pipe 57A, 57B, a volume 576 is encapsulated, containing a working medium 577, for example, water or ammonia. The volume 576 is hermetically sealed by a pipe wall 574, which is made, for example, of a metallic material, preferably copper or steel.

[0048] Heat can be absorbed at each of the corresponding plug contacts 51A and 51B via the heat pipe 57A, 57B, and also transferred back to the corresponding plug contact 51A, 51B (at a different location). The heat pipe 57A, 57B thus distributes the heat generated at the corresponding plug contact 51A, 51B during operation, allowing heat to be transported away from a point on the plug contact 51A, 51B where significant heat may occur during operation and dissipated to other sections of the plug contact 51A, 51B. The heat pipes 57A, 57B thus ensure heat distribution at the plug contacts 51A, 51B, so that local heating, in particular overheating, is avoided by distributing heat with low thermal resistance along the length of the respective plug contact 51A, 51B.

[0049] As can be seen from the sectional view according to Fig. As can be seen in Figure 7A, the receiving channel 513 is formed into the plug contact 51A, 51B almost along its entire length. In particular, the receiving channel 513, in which the associated heat pipe 57A is received, extends from an end 515 of the plug contact 51A, 51B, to which the busbar 510 is connected for connection to the associated load line 53A, 53B, to a free end 514 of the plug contact 51A, 51B, via which the plug contact 51A, 51B can be plugged into an associated mating contact of a mating connector part.The heat pipe 57A, 57B, which is incorporated in the receiving channel 513, extends along the length of the receiving channel 513 within the associated plug contact 51A, 51B and can thus absorb heat at an axial location of the plug contact 51A, 51B where heating occurs during operation, in order to transport the heat from this axial location to other locations and thus distribute it along the length of the plug contact 51A, 51B.

[0050] During operation, for example, local heating can occur at a point where the plug contact 51A, 51B is in contact with the corresponding mating contact of the mating connector part. From such a point, heat can be dissipated via the heat pipe 57A, 57B incorporated within the plug contact 51A, 51B in order to distribute thermal energy axially along the length of the plug contact 51A, 51B.

[0051] Fig.Figure 7B shows a temperature curve T over length l for a plug connector 51A, 51B with a heat pipe 57A, 57B inserted within it during operation, compared to a temperature curve T' for a plug connector without a heat pipe. It is evident that the temperature difference between a point of highest heating and a point of lowest heating is significantly smaller for the plug connector 51A, 51B with the heat pipe 57A, 57B inserted within it than for the plug connector without a heat pipe. The risk of local overheating can thus be reduced.

[0052] In the illustrated embodiment, a receiving channel 513 is formed in each plug contact 51A, 51B coaxially to the longitudinal axis L of the respective plug contact 51A, 51B, in which exactly one heat tube 57A, 57B is received.

[0053] In other embodiments, it is also conceivable that each plug contact 51A, 51B has several receiving channels 513, each with a heat pipe 57A, 57B, which are arranged, for example, radially outside the longitudinal axis L and thus eccentrically to the longitudinal axis L within the plug contact 51A, 51B. For example, such receiving channels 513 can be distributed around the longitudinal axis L at the same radial position or at radially different positions, each receiving an associated heat pipe 57A, 57B.

[0054] In the illustrated embodiment, the plug contact 51A, 51B is formed by a contact pin made of solid material, for example using a turning or milling process. However, the plug contact 51A, 51B can also be formed by a contact socket.

[0055] The idea underlying the invention is not limited to the preceding embodiments, but can also be implemented in other ways.

[0056] A charging connector component of the type under discussion can implement a charging plug, for example on a charging cable, or a charging socket, for example on the side of an electric vehicle.

[0057] Such a charging connector component can be used, in particular, to transmit a charging current in the form of direct current. However, it is also conceivable that the charging connector component is designed to transmit a charging current in the form of alternating current. Reference symbol list 1 charging station 2 charging cables 3 Charging connector part (charging plug) 4 vehicles 5 charging sockets 50 cases 500, 501 plug section 51A, 51B Plug connector 510 busbar 511 Contact section (shaft) 512 Insulating cap 513 Intake channel (bore) 514, 515 ends 52 Plug contact 53A, 53B Load line 54 Management 57A, 57B Heat pipe 574 Pipe wall 576 Encapsulated volume 577 Working medium E Plug direction L Longitudinal axis

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) operatively connected to the at least one plug contact (51A, 51B), 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) in which the heat pipe (57A, 57B) is arranged with at least a portion, wherein the heat pipe (57A, 57B) is designed to conduct heat to the at least one plug contact (51A, 51B). [2] Charging connector part (5) according to claim 1, characterized bythat the heat pipe (57A, 57B) is designed to distribute heat to the plug contact (51A, 51B) by absorbing heat at a first location of the at least one plug contact (51A, 51B) and dissipating heat at a second location of the at least one plug contact (51A, 51B). [3] Charging connector part (5) according to claim 1 or 2, characterized by that the at least one plug contact (51A, 51B) extends longitudinally along a longitudinal axis (L), wherein the receiving channel (513) extends longitudinally in the at least one plug contact (51A, 51B). [4] Charging connector part (5) according to claim 3, characterized by that the receiving channel (513) is formed coaxially to the longitudinal axis (L) in the plug contact (51A, 51B). [5] Charging connector part (5) according to claim 3 or 4, 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). [6] Charging connector part (5) according to one of the preceding claims, characterized by that the heat pipe (57A, 57B) extends between a first end (514) of the at least one plug contact (51A, 51B) and a second end (515) of the at least one plug contact (51A, 51B) in the interior of the plug contact (51A, 51B). [7] Charging connector part (5) according to one of the preceding claims, characterized by 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. [8] Charging connector part (5) according to one of the preceding claims, characterized bythat 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). [9] 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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