Plug-in connector part for a charging system for charging an electric vehicle
Patent Information
- Application Number
- EP2023702464
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-11
- Filing Date
- 2023-02-02
- Publication Date
- 2024-12-18
AI Technical Summary
Existing connector parts for electric vehicle charging systems face challenges in efficiently managing high charging currents without excessive heating, which limits their current-carrying capacity and poses electrical safety risks due to potential coolant contact with live components.
A connector part with a cooling unit featuring an open housing for coolant flow and an electrically insulating separating layer to prevent coolant contact with current-carrying components, using non-conductive fluids or insulating materials like polyimide films for efficient heat absorption and electrical insulation.
The solution effectively absorbs and dissipates heat from high-current busbars while ensuring reliable electrical insulation, allowing for increased current-carrying capacity without safety risks, even with conductive coolants, by using thin, thermally conductive separating layers.
Smart Images
Figure 1.1
Abstract
Description
[0001] Connector part for a charging system for charging an electric vehicle
[0002] The invention relates to a 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.
[0003] Such a connector part comprises a plug-in section for plugging into a mating connector part, at least one plug-in contact arranged on the plug-in section for transmitting a charging current, and at least one busbar electrically connected to the at least one plug-in contact and connectable to a load line, said busbar having a surface section extending flatly along a plane.
[0004] Such a 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.
[0005] 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.
[0006] When high charging currents are transmitted, the contact elements and other components of the connector part heat up. It is stipulated that heating of a connector part may not exceed 50 K. Therefore, when high charging currents are used, care must be taken to prevent excessive heating of the connector part.
[0007] The arrangement and dimensioning of electrical contact elements on connector components for charging electric vehicles is typically prescribed by standards. Contact geometries on such connector components 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.
[0008] 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.
[0009] 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. If water or a water mixture (e.g., using antifreeze components) is used as the cooling medium, care must be taken to ensure that the cooling medium does not come into contact with current-carrying components. Should water come into contact with DC-carrying components, there is a risk of electrolytic decomposition, which could lead to damage to the components. Furthermore, contact of water with current-carrying components must always be prevented to avoid an electrical safety risk.
[0010] 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.
[0011] In a connector component 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.
[0012] The object of the present invention is to provide a connector part that enables active cooling of current-carrying components in a cost-effective manner, while efficiently absorbing heat from the current-carrying components and reliably electrically isolating a coolant flow from the current-carrying components. This object is achieved by an object having the features of claim 1.
[0013] Accordingly, the connector part has a cooling unit which has a housing arranged on the surface section for conducting a coolant flow, wherein the housing is open on a side facing the surface section and an electrically insulating separating layer is arranged between the housing and the surface section, wherein the surface section is arranged on a first side of the separating layer and the coolant flow flows on a second side of the separating layer.
[0014] The housing is open on a side facing the surface section. An interior of the housing is thus openly facing the surface section, so that a coolant flowing through the housing is guided along the surface section without an intervening housing wall, thus allowing heat to be absorbed efficiently at the surface section.
[0015] If an electrically non-conductive fluid, such as an oil-based coolant, is used as the cooling medium, no special precautions are generally required to electrically insulate the coolant from the surface section. If, however, water or another electrically conductive fluid is used as the cooling medium, it must be ensured that the surface section is electrically insulated from the coolant.
[0016] This is achieved in the present case by arranging an electrically insulating separating layer on the surface section, which creates electrical insulation between the surface section and the cooling medium in the housing. The separating layer covers the surface section of the busbar in such a way that the surface section is arranged on a first side of the separating layer, while the coolant flow flows on a second side of the separating layer in the housing. The coolant flow is in contact with the separating layer, so that the separating layer acts as a (direct) intermediate layer, separating the coolant flow from the surface section.
[0017] The separating layer is in contact with the surface section on the first side. The coolant flows on the second side of the separating layer. Heat can thus be transferred from the surface section into the coolant flow via the separating layer and thus absorbed and dissipated by the coolant flow.
[0018] Because the separating layer can be made thin, the thermal resistance of the separating layer can be kept low, so that heat from the surface section of the busbar can be efficiently absorbed and dissipated by the coolant flow.
[0019] The separating layer can be formed, for example, by a plastic film, in particular a film made of a high-performance plastic, for example a material containing polyimide, in particular polysuccinimide (PSI), polybismaleimide (PBMI), polyimidesulfone (PISO), or polymethacrylimide (PMI), or a similarly high-performance plastic material. The plastic film is preferably non-meltable (at temperatures occurring during operation of the connector part during intended use) and provides electrical insulation with high dielectric strength even with a small film thickness.
[0020] For example, the plastic film can have a thickness of 0.1 mm or less, preferably 0.07 mm or less, and more preferably 0.03 mm or less. The small thickness (wall thickness) of the separating layer results in low thermal resistance at the separating layer, allowing heat to be efficiently absorbed at the busbar and dissipated via the cooling unit.
[0021] The plastic film, particularly when made of a polyimide material, should have a high, permanent dielectric strength with respect to the electrical potential between the power contact and the coolant flow. The area-normalized thermal resistance of the separating layer corresponds to the quotient of the thickness (wall thickness) of the separating layer and the specific thermal conductivity of the separating layer. Thus, to minimize thermal resistance, the wall thickness must be small and / or the thermal conductivity must be high. Because the thickness (wall thickness) can be very small when the separating layer is made of a plastic film, particularly when made of a polyimide material, the thermal resistance at the separating layer can be low even with only a medium specific thermal conductivity of the separating layer, for example in the range of 0.4 W / (mK).
[0022] The separating layer formed by a plastic film can, for example, be glued to the surface section of the busbar or connected in some other way in order to ensure a flat, tight coverage of the surface section by the separating layer.
[0023] The separating layer can have additional functional layers arranged on the plastic film, for example, vapor deposition, to adapt heat transfer and / or dielectric strength for the intended application. In one embodiment, the separating layer can be formed by a heat-conducting element made of a material different from the housing material. The housing can be made of a plastic material, for example. The heat-conducting element, in contrast, is made of a material different from the plastic material of the housing, for example, a material containing silicone rubber.
[0024] Silicone rubber refers to elastomers consisting of silicone polymer chains with alternating oxygen and silicon atoms, i.e., -Si-O-Si- bonds (siloxane bonds). They are therefore also called polyorganosiloxanes.
[0025] If the separating layer is formed by a (flatly extending) heat-conducting element, the heat-conducting element can, for example, have a thickness equal to or less than 1 mm, preferably equal to or less than 0.5 mm. Such a separating layer formed by a heat-conducting element can have a high specific thermal conductivity, for example, up to 5 W / (mK). Such a heat-conducting element can thus have a low thermal contact resistance despite a comparatively large wall thickness.
[0026] The heat conducting element covers the surface section of the busbar and is, for example, glued to the surface section.
[0027] In one embodiment, the separating layer can be formed, for example, by an electrically insulating coating on the surface section, for example by painting or flocking on the surface section.
[0028] The housing is arranged on the surface section of the busbar, for example, screwed to the housing. The separating layer occupies an intermediate position between the housing and the surface section. To create a fluid-tight transition between the housing and the separating layer, a seal can be arranged between the housing and the separating layer, for example, a seal running circumferentially on a side of the housing facing the surface section, which creates a fluid-tight transition between the housing and the separating layer to prevent the cooling medium from escaping.
[0029] If the surface section of the busbar is flat, the separating layer covering the surface section is also flat. If, however, the surface section is curved, the separating layer is also curved. If the surface section is cylindrical, the separating layer can extend, for example, as a tube section within the surface section or outside it around the surface section.
[0030] In one embodiment, the cooling unit has a chamber arrangement arranged in the housing for conducting a coolant flow. The chamber arrangement comprises a plurality of chambers in fluid communication with one another. At least some of the chambers are configured to conduct a coolant flow along a flow direction perpendicular to the plane.
[0031] According to this embodiment, the cooling unit comprises a housing in which chambers are formed through which, during operation, a coolant flow is conducted to absorb heat at the busbar connected to the plug contact. The housing of the cooling unit is arranged on the surface section of the busbar, so that the coolant flow is directed through the housing and thus along the surface section, allowing heat to be absorbed favorably at the surface section of the busbar. The coolant flow can dissipate the heat, actively cooling the busbar and thus the electrical contact connected to the busbar.
[0032] The housing is arranged on the surface section of the busbar. The housing is preferably attached to the surface section, for example, glued or screwed to the surface section.
[0033] The housing is preferably made of an electrically insulating material, in particular a plastic material. The busbar with the surface portion formed thereon, in contrast, consists of a material with good electrical conductivity, in particular a metal material, for example, copper.
[0034] The coolant flow is directed via the chamber arrangement such that it flows through at least some of the chambers along a flow direction perpendicular to the plane of the surface section. Through some of the chambers, the coolant flow is thus directed in the flow direction towards the surface section and thus strikes the surface section perpendicularly. Through other chambers, the coolant flow is directed away from the surface section against the flow direction. Because the coolant flow is directed perpendicular to the surface section, it can be achieved that heat is absorbed at the surface section with a good heat transfer coefficient and thus with great cooling effectiveness, particularly in comparison to a coolant flow directed tangentially (parallel) to the surface section. The plane can be flat.However, the plane can also be curved, so that the surface section of the busbar has a curved shape. For example, the busbar can be cylindrical, and the surface section can correspond to a wall section of the cylindrical busbar.
[0035] Advantageously, the chamber arrangement is designed to direct the coolant flow in a meandering manner in the direction of flow toward the surface section and away from the surface section, counter to the direction of flow. The coolant flow thus flows perpendicularly toward the surface section and also perpendicularly away from the surface section. Because the coolant flow is directed perpendicularly toward the surface section at several points, heat can be absorbed at the busbar in a distributed manner across the surface of the surface section and thus dissipated from the busbar in a cost-effective and efficient manner.
[0036] If the connector part, particularly for transmitting a charging current in the form of a direct current, has two plug contacts, each connected to a busbar, the housing can, for example, be arranged between the surface sections and guide the coolant flow back and forth between the surface sections. The coolant flow is thus directed perpendicularly to the surface sections of the busbars and can thus efficiently absorb heat at the surface sections.
[0037] In one embodiment, a first chamber of the chamber arrangement is designed to direct the coolant flow in the flow direction towards the surface section. The first chamber can, for example, have a first flow cross-section. A first inflow channel is connected to the first chamber, for example in the flow direction, and serves to direct the coolant flow from the first chamber in the flow direction towards the surface section. The first inflow channel preferably has a flow cross-section that is reduced compared to the flow cross-section of the first chamber, so that the coolant flow in the inflow channel is directed towards the surface section of the busbar with a reduced flow cross-section and thus an increased flow velocity and strikes the surface section of the busbar perpendicularly.
[0038] In one embodiment, a second chamber, which is in flow communication with the first chamber, is designed to direct the coolant flow away from the surface section in the opposite direction of flow. The second chamber is arranged downstream of the first chamber and thus receives the coolant flow from the first chamber. The second chamber directs the coolant flow away from the surface section of the busbar, for example, toward a surface section of an adjacent busbar associated with another plug contact.
[0039] A second inflow channel can be connected to the second chamber, which serves to direct the coolant flow from the second chamber against the flow direction, for example, perpendicularly toward the surface section of the adjacent busbar. The second inflow channel can also have a reduced flow cross-section. The flow cross-section of the second chamber can, for example, correspond to the flow cross-section of the first chamber. In contrast, the second inflow channel has a reduced flow cross-section, which, for example, corresponds to the flow cross-section of the first inflow channel.
[0040] A third chamber can be in flow communication with the second chamber in the downstream direction, which is designed to (again) direct the coolant flow in the flow direction toward the surface section of the busbar. A third inflow channel can be connected to the third chamber in the flow direction, which channel directs the coolant flow with a reduced flow cross-section perpendicularly along the flow direction toward the surface section.
[0041] Further chambers can be connected to the third chamber, which are arranged relative to one another and are in flow connection with one another in such a way that the coolant flow is directed in a meandering manner towards the surface section and away from the surface section, so that the coolant flow hits the surface section at several points perpendicularly and thus heat can be absorbed at the surface section in a favorable, efficient manner.
[0042] The surface section extends along a plane spanned by a longitudinal direction and a vertical direction. A transverse direction, which corresponds to a surface normal of the plane, is perpendicular to the longitudinal direction and the vertical direction. The chambers of the chamber arrangement can be offset from one another along the longitudinal direction and / or along the vertical direction and / or along the transverse direction, wherein the chambers together form a flow channel that guides the coolant flow, preferably in a meandering direction perpendicular to the surface section and also perpendicularly away from the surface section.
[0043] In one embodiment, the chambers are arranged at two height levels. A first arrangement of chambers can be arranged distributed along a first height level perpendicular to the height direction. A second arrangement of chambers, in contrast, can be arranged distributed along a second height level perpendicular to the height direction and spaced from the first height level. In the vertically offset arrangements of the chambers, the coolant flow is guided in a meandering manner. Once the coolant flow has flowed through the chambers of one height level, the coolant flow enters the chambers of the other height level and is guided through these chambers in a meandering manner.
[0044] Each arrangement of chambers can be assigned a connection for connecting a coolant line. In particular, the first arrangement of chambers can have a first connection for introducing the coolant flow, and the second arrangement of chambers can have a second connection for discharging the coolant flow.
[0045] The connectors can each be connected to a coolant hose, with the coolant hoses being routed, for example, in a charging cable connected to the connector part and also carrying the power lines. The connector part can be connected, for example, to a charging station via the charging cable.
[0046] In one embodiment, the connector part has two electrical plug contacts and two busbars, each connected to one of the plug contacts and each having a surface section. The cooling unit is arranged between the surface sections of the busbars. The housing of the cooling unit is connected to the surface sections, for example, glued or screwed to the surface sections. A coolant flow is guided in a meandering manner, preferably back and forth between the surface sections, via the chamber arrangement in the housing of the cooling unit, so that the coolant flow is alternately directed perpendicularly onto one surface section and the other surface section and flows back and forth between the surface sections. Heat can thus be efficiently absorbed at both surface sections and dissipated from the surface sections.
[0047] A charging system for charging an electric vehicle comprises a connector part of the type described above. Such a charging system also comprises a mating connector part that can be plugged into the connector part. The 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 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 connector part and the mating connector part are connected, charging currents can be transmitted from the charging station to the electric vehicle.
[0048] It is also conceivable that the connector part implements a charging socket on the side of an electric vehicle.
[0049] A 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 connector part can also be used for transmitting charging currents in the form of alternating currents.
[0050] The concept underlying the invention will be explained in more detail below with reference to the exemplary embodiments illustrated in the figures. They show:
[0051] Fig. 1 is a view of a charging station with a charging cable arranged thereon for connecting to an electric vehicle;
[0052] Fig. 2 is a view of an embodiment of a connector part in the form of a charging plug;
[0053] Fig. 3A is a view of the connector part without a housing;
[0054] Fig. 3B is another view of the arrangement according to Fig. 3A;
[0055] Fig. 4A shows an arrangement of plug contacts of the connector part, with a cooling unit arranged between busbars of the plug contacts;
[0056] Fig. 4B is another view of the arrangement according to Fig. 4A;
[0057] Fig. 5A is a side view of the arrangement according to Fig. 4A;
[0058] Fig. 5B is a plan view of the arrangement according to Fig. 4A;
[0059] Fig. 6A is an exploded view of the arrangement according to Fig. 4A;
[0060] Fig. 6B is an exploded view from a different perspective; Fig. 7A is a partially cutaway view of the arrangement according to Fig. 4A;
[0061] Fig. 7B is another view of the arrangement according to Fig. 7A;
[0062] Fig. 8A is a sectional view taken along the line 11 of Fig. 7B;
[0063] Fig. 8B is a sectional view taken along the line II-II of Fig. 7B;
[0064] Fig. 8C is an enlarged view in section A according to Fig. 8A;
[0065] Fig. 9 is a view of the arrangement according to Fig. 5B, illustrating a coolant flow through the cooling unit;
[0066] Fig. 10A is an enlarged fragmentary view of the sectional view of Fig. 8A, illustrating coolant flow through chambers of a chamber arrangement of the cooling unit;
[0067] Fig. 10B is an enlarged fragmentary view of the arrangement of Fig. 8B, illustrating coolant flow through chambers of the chamber arrangement of the cooling unit;
[0068] Fig. 11 is a partial exploded view of another embodiment of a contact assembly of a connector part;
[0069] Fig. 12 is a view of a cooling unit of the contact assembly;
[0070] Fig. 13 a side view of the cooling unit;
[0071] Fig. 14A is a sectional view taken along the line II of Fig. 13;
[0072] Fig. 14B is a sectional view taken along line II-II of Fig. 13;
[0073] Fig. 15 is a partially enlarged, sectional exploded view corresponding to section A in Fig. 14A;
[0074] Fig. 16 is another partially enlarged sectional view, corresponding to section B in Fig. 14A; and Fig. 17 is a partially enlarged sectional view, corresponding to the view in Fig. 15, but in the assembled position.
[0075] Fig. 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 201 to the charging station 1 and at another end 200 to a connector part 3 in the form of a charging plug.
[0076] As can be seen from the enlarged view of Fig. 2, the connector part 3 has plug-in sections 300, 301 on a housing 30, with which the connector part 3 can be plugged into an associated mating connector part 5 in the form of a charging socket on the vehicle 4. In this way, the charging station 1 can be electrically connected to the vehicle 4 in order to transmit charging currents from the charging station 1 to the vehicle 4.
[0077] 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. Such high charging currents result in thermal losses at the cable 2 and also at the charging plug 3 and charging socket 5, which can lead to heating of the cable 2, the charging plug 3, and the charging socket 5.
[0078] The permissible heating of components of the charging system is limited by standards, for example to a maximum value of 50 K. 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.
[0079] In the connector part 3 in the form of the charging plug according to Fig. 2, plug contacts are arranged on socket domes 302 on the upper plug section 300, which serve, for example, to transmit control signals or as a grounding contact (connected to a grounding line 22, see Fig. 3B). In contrast, plug contacts 31A, 31B are arranged on socket domes 303 on the lower plug section 301, 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 5 in the form of the charging socket on the electric vehicle 4 side, the plug contacts 31A, 31B come into electrical contact with associated mating contact elements on the charging socket 5 side, so that a charging current can be transmitted from the charging station 1 to the electric vehicle 4.
[0080] In the illustrated connector part 3 in the form of the charging plug, active cooling is provided to absorb and dissipate heat, particularly in the area of the plug contacts 31 A, 31 B carrying the charging current, in order to limit the heating of the connector part 3.
[0081] As can be seen from Fig. 3A, 3B to 6A, 6B, in the illustrated embodiment of the connector part 3, each plug contact 31 A, 31 B is assigned a busbar 32A, 32B, via which the respective plug contact 31 A, 31 B is connected to an arrangement of two load lines 21 A, 21 B each.
[0082] Each plug contact 31A, 31B has a contact section 310 in the form of a socket, via which a plug connection can be established with an associated mating contact element in the form of a contact pin of the mating connector part 5. At an end facing away from the contact section 310, the plug contact 31A, 31B is connected to an associated, flange-shaped end 321 of the associated busbar 32A, 32B, so that the respective plug contact 31A, 31B is mechanically fixed to the busbar 32A, 32B and electrically contacted with the busbar 32A, 32B.
[0083] At an end 320 facing away from the end 321, each busbar 32A, 32B is connected to an arrangement of load lines 21A, 21B. Each busbar 32A, 32B is connected to two load lines 21A, 21B, which are thus jointly connected to the respectively assigned plug contact 31A, 31B and carry a charging current in the form of a direct current via the plug contacts 31A, 31B.
[0084] The load lines 21 A, 21 B are guided together in the charging cable 2 connected to the connector part 3 and enclosed in a cable sheath 20 of the charging cable 2 (see, for example, Fig. 3A, 3B).
[0085] A cooling unit 33 is arranged between the busbars 32A, 32B, which serves to absorb and dissipate heat from the busbars 32A, 32B. Each busbar 32A, 32B has a flat surface section 322. The surface sections 322 of the busbars 32A, 32B extend parallel to one another and are each firmly connected to a housing 330 of the cooling unit 33 via screw connections, so that the busbars 32A, 32B are mechanically secured to one another via the cooling unit 33.
[0086] The housing 330 of the cooling unit 33 is made of an electrically insulating plastic material.
[0087] A chamber arrangement 332 is formed in the housing 330 to provide cooling, as can be seen from Fig. 6A, 6B in conjunction with Fig. 7A, 7B, via which a coolant flow can be directed through the housing 330 and along the surface portions 322 of the busbars 32A, 32B.
[0088] As can be seen from Fig. 6A, 6B, the housing 330 is open on the sides facing the surface sections 322 of the busbars 32A, 32B, so that the housing 330 does not close the chambers formed in the housing 30 towards the surface sections 322 of the busbars 32A, 32B.
[0089] However, between the housing 330 and the surface sections 322 of the busbars 32A, 32B, a separating layer 331A, 331B in the form of, for example, a plastic film made of a polyimide material is arranged on each side, which takes up an intermediate layer between the housing 330 and the surface section 322 on the respective side of the housing 330 and thus separates the chamber arrangement in the interior of the housing 330 from the surface section 322.
[0090] The separating layer 331A, 331B consists of an electrically insulating material. The separating layer 331A, 331B thus electrically separates the cooling medium inside the cooling unit 33 from the respective busbar 32A, 32B. A circumferential seal 333 on each side of the housing 330 ensures that coolant cannot escape from the interior of the housing 330 and come into electrical contact with the respective busbar 32A, 32B.
[0091] Coolant lines 23, 24 are connected to the cooling unit 33 and are routed together with the load lines 21A, 21B in the charging cable 2. A first coolant line 23 is connected to a first connection 334. A second coolant line 24 is connected to a vertically offset connection 338 on the same side of the housing 330 (see in particular Fig. 6B). The chamber arrangement 332 inside the housing 330 consists of a plurality of chambers in flow communication with one another, which direct a coolant flow through the cooling unit 33 between the connections 334, 338. The chambers of the chamber arrangement 332 are arranged relative to one another in such a way that a meandering coolant flow is set, which is guided back and forth in a meandering manner between the surface sections 322 of the busbars 32A, 32B and can thus absorb heat at the busbars 32A, 32B.
[0092] The surface sections 322 of the busbars 32A, 32B each extend along a plane P spanned by a longitudinal direction X and a height direction Z (see Fig. 10A, 10B), wherein the surface sections 322 of the busbars 32A, 32B extend parallel to one another and are spaced from one another along a transverse direction Y.
[0093] Two arrangements of chambers are formed in the housing 330. These arrangements are located at different heights (viewed along the height direction Z) and are each assigned to one of the connections 334, 338. Connection 334 serves as an inlet for introducing a coolant flow into the arrangement of chambers located at the height of connection 334 (in Fig. 6B corresponding to the upper arrangement of chambers within the housing 330). Connection 338, in contrast, serves as an outlet for diverting the coolant flow from the arrangement of chambers located at the height of connection 338 (in Fig. 6B corresponding to the lower arrangement of chambers within the housing 330).
[0094] Fig. 8A and 8B show cross-sectional views along the lines II and II-II of Fig. 7B. The cross-sectional views represent sections through the upper, first arrangement of chambers associated with the port 334, through which a coolant flow flows after being introduced via the port 334, to then enter the lower arrangement of chambers and flow through the lower arrangement of chambers to the port 338 and to be discharged via the port 338.
[0095] From the enlarged view according to Fig. 8C, it can be seen that the chambers of the chamber arrangement 332 are each open towards the surface sections 322 of the busbars 32A, 32B, but are separated from the surface section 322 of the busbar 32A, 32B by the respectively associated separating layer 331A, 331B and are thus electrically insulated. The housing 330 is sealed fluid-tight at the transition to the separating layer 331A, 331B by the circumferential seal 333, so that coolant cannot flow out of the interior of the housing 330 at the transition to the separating layer 331A, 331B. Fig. 9 shows the basic coolant flow F that occurs when the coolant is guided through the chamber arrangement 332 inside the housing 330 of the cooling unit 33.It is particularly evident that the coolant flow F is directed in a meandering manner between the surface sections 322 of the busbars 32A, 32B and is thus alternately directed perpendicularly to the surface section 322 of one busbar 32A and then perpendicularly to the surface section 322 of the other busbar 32B. The coolant flow F thus alternately strikes one busbar 32A and the other busbar 32B perpendicularly. By flowing against the busbars 32A, 32B in this way, good heat transfer can be achieved between the coolant flow F and the surface sections 322 of the busbars 32A, 32B, and thus heat can be efficiently absorbed at the busbars 32A, 32B.
[0096] The coolant flow F, as shown in principle in Fig. 9, is adjusted by the chambers of the chamber arrangement 332 inside the housing 330. The chambers are in flow communication with one another and are flowed through one after the other starting from the connection 334, wherein the chambers are connected to one another and arranged relative to one another in such a way that a meandering coolant flow F, as shown in Fig. 9, results.
[0097] Referring now to Fig. 10A and 10B, the coolant flow F, starting from the connection 334, first flows into a chamber 335-1 and is guided in the chamber 335-1 in a flow direction S towards the surface section 322 of the busbar 32A extending flatly along a plane P (Fig. 10A), in order to then pass through a flow opening 336-1 into an underlying chamber 335-2 and to flow through the chamber 335-2 in the opposite direction to the other busbar 32B (Fig. 10B). On the side of the other busbar 32A, the coolant flow F flows through a flow opening 336-2 into a chamber 335-3 located above the chamber 335-2 (Fig. 10A) in order to flow from this chamber 335-3 into a chamber 335-4 adjacent along the longitudinal direction X.
[0098] While the chambers 335-1 ... 335-3 serve to introduce the coolant flow F from the connection 334, a plurality of pairs of chambers 335-4, 335-5; 335-6, 335-7; 335-8, 335-9; 335-10, 335-11 are arranged in a row (along the longitudinal direction X), which are each arranged and formed mirror-inverted to one another (to a plane of symmetry located centrally between the surface sections 322 of the busbars 32A, 32B) and are in serial flow connection with one another. Starting from the chamber 335-3, the coolant flow F flows through a flow opening 336-3 (Fig. 10A) into the chamber 335-4 and is guided in the chamber 335-4 along the flow direction S towards the surface section 322 of the busbar 32A.At a central wall 339 of the housing 330, the coolant flow F flows into an inflow channel 337-1, which connects to the chamber 335-4 in the flow direction S and directs the coolant flow F with a reduced flow cross-section perpendicular to the surface section 322 of the busbar 32A, as can be seen from Fig. 10B.
[0099] In particular, the chamber 335-4 has a flow cross-section Q1, which is reduced to a flow cross-section Q2 in the inflow channel 337-1. This leads to an increase in the flow velocity in the inflow channel 337-1, so that the coolant flow F impinges perpendicularly on the surface section 322 of the busbar 32A at an increased flow velocity.
[0100] From the inflow channel 337-1, the coolant flow F flows into the chamber 335-5 and from the chamber 335-5 via a flow opening 336-4 (Fig. 10A) into the adjacent chamber 335-6 along the longitudinal direction X. In the chamber 335-6, the coolant flow F is now directed towards the other busbar 32B, wherein the coolant flow F flows at the central wall 339 into an inflow channel 337-2 adjoining the chamber 335-6 and is thus again directed via the inflow channel 337-2 with a reduced flow cross-section and thus with an increased flow velocity perpendicular to the surface section 322 of the busbar 32B.
[0101] From the inflow channel 337-2, the coolant flow F flows into the adjoining chamber 335-7 and through the flow opening 336-5 into the adjacent chamber 335-8 along the longitudinal direction X, in which the coolant flow F is again directed towards the busbar 32A and strikes the busbar 32A perpendicularly through the adjoining inflow channel 337-3. Via the adjoining chamber 335-9, the flow opening 336-6, the chamber 335-
[0102] 10 and the inflow channel 337-4, the coolant flow F is then directed back to the busbar 32B.
[0103] From the inflow channel 337-4 (Fig. 10A) the coolant flow F enters the last chamber 335-
[0104] 11 of the arrangement of chambers at this height level. At the bottom of this chamber 335-11, a flow opening 336-7 is formed, through which the coolant flow F is now directed into the arrangement of chambers below, to flow back through the chambers of this lower level, meandering, and to be discharged via connection 338.
[0105] The arrangement of the chambers 335-1 ... 335-11 creates a flow channel that directs the coolant flow F in a meandering manner back and forth between the surface sections 322 of the busbars 32A, 32B. Because the coolant flow F is alternately directed perpendicularly to one busbar 32A and the other busbar 32B, heat can be efficiently absorbed and dissipated at the busbars 32A, 32B with a good heat transfer coefficient.
[0106] The separating layers 331A, 331B between the housing 330 and the surface sections 322 of the busbars 32A, 32B also provide reliable electrical insulation between the cooling unit 33 and the busbars 32A, 32B. Because the separating layers 331A, 331B, formed, for example, by a thin plastic film each, can be thin, the separating layers 331A, 331B advantageously do not significantly impair the heat transfer at the busbars 32A, 32B.
[0107] Figs. 11 to 17 show another embodiment of a contact assembly of a connector part 3, which has plug contacts 31A, 31B and busbars 32A, 32B with a cooling unit 33 arranged therebetween and, in this respect, corresponds to the contact assembly according to Figs. 4A, 4B of the previously described embodiment. The embodiment according to Figs. 11 to 17 differs only in the design of the cooling unit 33, so that with regard to the remaining components of the connector part 3, reference should be made to the preceding explanations of the embodiment according to Figs. 3A, 3B to 10A, 10B.
[0108] 11 to 17, the cooling unit 33 has a housing 330 which forms a chamber arrangement 332 in an interior space. However, this chamber arrangement is simplified compared to the chamber arrangement 332 of the previously described embodiment and forms only two chambers separated by a central wall 339. A coolant flow is introduced, for example, via a coolant hose 23 at an inlet 334 into one of the chambers, flows inside the housing 330 through a flow opening 336 into the adjacent, other chamber, and is discharged via an outlet 338 and a coolant hose 24. This results in a coolant flow through the housing 330 of the cooling unit 33. As in the previously described embodiment, the housing 330 of the cooling unit 33 is arranged between the surface sections 322 of the busbars 32A, 32B and is open towards the surface sections 322.The housing 330 is formed, for example, from a plastic material.
[0109] To prevent contact with the busbars 32A, 32B when using an electrically conductive cooling medium, for example water, a separating layer 331A, 331B is arranged between the housing 330 and each surface section 322 of the busbars 32A, 32B, which electrically insulates and thus electrically separates the interior of the housing 330 of the cooling unit 33 from the respective busbar 32A, 32B. The separating layer 331A, 331B covers the surface section 322 of the respectively assigned busbar 32A, 32B and rests against the surface section 322. The separating layer 331A, 331B can, for example, be adhesively bonded to the assigned surface section 322.
[0110] In order to seal off a transition between the housing 330 and the separating layer 331A, 331B in a moisture-tight manner, a seal 333 is arranged on a peripheral edge of the housing 330, as can be seen, for example, from the enlarged views according to Figs. 15 to 17. The seal 333 is received on the housing 330 and circumferentially surrounds an opening formed in the housing 330, facing the respective busbar 32A, 32B, via which opening the housing 330 is open towards the respective busbar 32A, 32B. The seal 333 bears sealingly against the respectively assigned separating layer 331A, 331B and thus seals a transition between the housing 330 and the separating layer 331A, 331B in a fluid-tight manner.
[0111] Because the housing 330 is open towards the respectively assigned busbar 32A, 32B in both of the previously described embodiments, the cooling medium inside the housing 330 flows directly along the separating layer 331A, 331B. The cooling medium flows on one side of the separating layer 331A, 331B. On the other, opposite side of the separating layer 331A, 331B, the surface section 322 of the respectively assigned busbar 32A, 32B is arranged, wherein the separating layer 331A, 331B lies flat against the surface section 322 and covers it flatly, so that the cooling medium inside the housing 330 of the cooling unit 33 is only separated from the surface section 322 by the separating layer 331A, 331B.
[0112] The separating layer 331 A, 331 B can be thin and represents a low thermal resistance. Heat at the surface section 322 can thus be transferred into the coolant with low thermal resistance and thus be absorbed and dissipated by the coolant.
[0113] In both exemplary embodiments, the separating layer 331A, 331B can be made, for example, from a plastic film, for example made of a polyimide material. Such a plastic film can be very thin, for example, with a wall thickness equal to or less than 0.1 mm, preferably equal to or less than 0.07 mm. Such a plastic film can have a high dielectric strength for separating the electrical potential of the respectively assigned busbars 32A, 32B from the coolant. Due to the small thickness of the plastic film, heat can be transferred efficiently with low thermal resistance from the busbars 32A, 32B into the coolant.
[0114] In another embodiment, the separating layer 331A, 331B can be formed, for example, by a heat-conducting element made of silicone rubber. Such a heat-conducting element can have a greater thickness—compared, for example, to a plastic film made of a polyimide material—for example, equal to or less than 1 mm, preferably equal to or less than 0.5 mm. Such a heat-conducting element can have a high specific thermal conductivity and thus provide a low heat transfer resistance despite its increased wall thickness.
[0115] In yet another embodiment, the separating layer 331 A, 331 B can also be formed by an electrically insulating coating, for example in the form of a paint or flocking, on the surface section 322.
[0116] The idea underlying the invention is not limited to the preceding embodiments, but can also be implemented in other ways.
[0117] A 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.
[0118] Such a connector part can be used, in particular, to transmit a charging current in the form of a direct current. However, it is also conceivable that the connector part is designed to transmit a charging current in the form of an alternating current.
[0119] Active cooling can be provided on one or more plug contacts. A busbar can be designed as a separate component for a plug contact, but can also be formed integrally with the plug contact and thus implemented as a section of the plug contact.
[0120] The surface section of the busbar can be flat. However, the surface section can also be curved. The separating layer for insulation can be flat or curved, depending on the surface coverage of the surface section of the busbar.
[0121] List of reference symbols
[0122] Charging station
[0123] 2 charging cables
[0124] 20 cable sheath
[0125] 200, 201 end
[0126] 21A, 21B load line
[0127] 22 Earthing wire
[0128] 23, 24 Coolant hose
[0129] 3 charging plugs
[0130] 30 housings
[0131] 300, 301 plug-in section
[0132] 302, 303 socket dome
[0133] 31A, 31B plug contact
[0134] 310 Contact section
[0135] 311 End
[0136] 32A, 32B busbar
[0137] 320, 321 End
[0138] 322 area section
[0139] 33 Cooling unit
[0140] 330 housing
[0141] 331 A, 331 B separating layer (film)
[0142] 332 Chamber arrangement
[0143] 333 Seal
[0144] 334 inflow
[0145] 335-1...335-11 Chamber
[0146] 336, 336-1...336-7 Flow opening
[0147] 337-1...337-4 Inlet channel
[0148] 338 drain
[0149] 339 wall
[0150] 34 Fastening element
[0151] 4 vehicle
[0152] 5 Charging socket
[0153] E Insertion direction
[0154] F Coolant flow
[0155] P Level
[0156] Q1, Q2 Flow cross-section S Flow direction
[0157] X Longitudinal direction
[0158] Y transverse direction
[0159] Z Altitude direction
Claims
Patent claims 1. Connector part (3) for a charging system for charging an electric vehicle (4), comprising a plug section (301) for plugging into a mating connector part (5), at least one electrical plug contact (31 A, 31 B) arranged on the plug section (301) for transmitting a charging current, and at least one busbar (32 A, 32 B) electrically connected to the at least one plug contact (31 A, 31 B) and connectable to a load line (21 A, 21 B), which has a surface section (322) extending planarly along a plane (P), characterized by a cooling unit (33) which has a housing (33) arranged on the surface section (322) for conducting a coolant flow (F), wherein the housing (330) is open on a side facing the surface section (322) and an electrically insulating separating layer (331 A, 332 B) is located between the housing (330) and the surface section (322). 331 B) is ordered,wherein the surface section (322) is arranged on a first side of the separating layer (331 A, 331 B) and the coolant flow (F) flows on a second side of the separating layer (331 A, 331 B).
2. Connector part (3) according to claim 1 , characterized in that the separating layer (331 A, 331 B) is formed by a plastic film.
3. Connector part (3) according to claim 2, characterized in that the plastic film is made of a material containing polyimide.
4. Connector part (3) according to 2 or 3, characterized in that the plastic film has a thickness equal to or less than 0.1 mm, preferably equal to or less than 0.07 mm.
5. Connector part (3) according to claim 1 , characterized in that the separating layer (331 A, 331 B) is formed by a heat conducting element which is made of a material different from the material of the housing (33).
6. Connector part (3) according to claim 5, characterized in that the heat conducting element is made of a material containing silicone rubber.
7. Connector part (3) according to claim 5 or 6, characterized in that the heat conducting element has a thickness equal to or less than 1 mm, preferably equal to or less than 0.5 mm.
8. Connector part (3) according to one of the preceding claims, characterized in that the cooling unit (33) has a seal (333) arranged between the housing (330) and the separating layer (331 A, 331 B).
9. Connector part (3) according to one of the preceding claims, characterized in that the cooling unit has a chamber arrangement (332) arranged in the housing (33) for guiding the coolant flow (F), wherein the chamber arrangement (332) comprises a plurality of chambers (335-1...335-11) in flow communication with each other and at least some of the chambers (335-1...335-11) are configured to guide a coolant flow (F) along a flow direction (S) perpendicular to the plane (P).
10. Connector part (3) according to claim 9, characterized in that the chamber arrangement (332) is designed to direct the coolant flow (F) meandering in the flow direction (S) towards the surface section (322) and away from the surface section (322) against the flow direction (S).
11. Connector part (3) according to claim 9 or 10 characterized in that a first chamber (335-4) is formed to direct the coolant flow (F) in the flow direction (S) towards the surface section (322).
12. Connector part (3) according to claim 11, characterized in that a first inflow channel (337-1) for directing the coolant flow (F) from the first chamber (335-4) in the flow direction (S) towards the surface section (322) connects to the first chamber (335-4), wherein the first inflow channel (337-1) has a reduced flow cross-section (Q2) compared to a flow cross-section (Q1) of the first chamber (335-4).
13. Connector part (3) according to claim 11 or 12, characterized in that a second chamber (335-6) is formed in flow communication with the first chamber (335-4) to direct the coolant flow (F) away from the surface section (322) against the flow direction (S).
14. Connector part (3) according to claim 13, characterized in that a second inflow channel (337-2) for directing the coolant flow (F) from the second chamber (335-6) against the flow direction (S) connects to the second chamber (335-6), wherein the second inflow channel (337-2) has a reduced flow cross-section (Q2) compared to a flow cross-section (Q1) of the second chamber (335-6).
15. Connector part (3) according to claim 13 or 14, characterized in that a third chamber (335-8) is formed which is in flow communication with the second chamber (335-6) to direct the coolant flow (F) in the flow direction (S) towards the surface section (322).
16. Connector part (3) according to one of claims 9 to 15, characterized in that the plane is spanned by a longitudinal direction (X) and a vertical direction (Z) and extends perpendicular to a transverse direction (Y), wherein at least some of the chambers (335-1...335-11) are offset from each other along the longitudinal direction (X) and / or along the vertical direction (Z) and / or along the transverse direction (Y).
17. Connector part (3) according to claim 16, characterized in that a first arrangement of chambers (335-1...335-11) is arranged distributed to each other along a first height plane perpendicular to the height direction (Z) and a second arrangement of chambers (335-1...335-11) is arranged distributed to each other along a second height plane perpendicular to the height direction (Z) and spaced apart from the first height plane.
18. Connector part (3) according to claim 17, characterized in that the first arrangement of chambers (335-1...335-11) has a first connection (334) for introducing the coolant flow (F) and the second arrangement of chambers (335-1...335-11) has a second connection (338) for discharging the coolant flow (F).
19. Connector part (3) according to claim 18, characterized in that the first connection (334) and the second connection (338) can each be connected to a coolant hose (23, 24).
20. Connector part (3) according to one of the preceding claims, characterized in that the connector part (3) has two electrical plug contacts (31A, 31B) and two busbars (32A, 32B) each having a surface section (322) connected to one of the plug contacts (31A, 31B), wherein the A cooling unit (33) is arranged between the surface sections (322) of the busbars (32A, 32B). A charging system for charging an electric vehicle (4), comprising a connector part (3) according to one of the preceding claims.