Charging connectors for electric and hybrid vehicles
Patent Information
- Application Number
- EP2023772763
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-23
- Filing Date
- 2023-09-01
- Publication Date
- 2025-07-30
AI Technical Summary
Charging connectors for electric and hybrid vehicles face limitations in handling high charging currents due to temperature constraints, as they heat up beyond the allowed limit when high currents are required for rapid charging, and standard connector geometries restrict the use of larger conductive materials.
Incorporating a heat-conducting element within the charging connector that extends from the plug-in area to the connection area, enhancing thermal conductivity and allowing effective heat dissipation to an active cooling system, even when the connector is not equipped with one, by using materials like copper or aluminum, and optimizing the geometric arrangement for improved heat transfer.
This solution enables increased short-term current carrying capacity with limited heating, effectively managing heat dissipation and supporting both passive and active cooling methods, thereby enabling higher charging currents without exceeding temperature limits.
Smart Images
Figure 1.1
Abstract
Description
[0001] Charging connectors for electric and hybrid vehicles
[0002] The invention relates to a charging connector for electric and hybrid vehicles, with charging contacts for contacting corresponding charging contacts of a corresponding charging connector, a plug-in area in which the charging connector, when plugged into the corresponding charging connector, overlaps with the corresponding charging connector in the plug-in direction and the charging contacts of the two connectors are in galvanically conductive contact with one another, and a connection area in which the charging contacts are galvanically conductively connected to electrical lines that lead away from the charging connector.
[0003] Electric and hybrid vehicles have a rechargeable energy storage device, usually a high-voltage battery, which supplies energy to an electric drive motor during operation. The storage capacity of these high-voltage batteries is limited, so they must be recharged regularly at a charging station. The battery is charged using a charging cable provided between the charging station and the vehicle. The charging cable, for example, in accordance with European standard IEC 62196 Type 2, is equipped with a charging plug on one end that can be plugged into a charging socket provided on the charging station, and with a charging coupling on the other end that can be connected to a charging plug installed in the electric or hybrid vehicle. For the purposes of this article, charging sockets, charging plugs, charging couplings and charging plugs are all referred to as “charging connectors”.Charging sockets and charging couplings have contact sleeves as charging contacts and charging plugs as well as charging plugs that can be installed in electric and hybrid vehicles have contact pins as charging contacts that can be inserted into the contact sleeves.
[0004] As explained, for example, in EP 3 043 421 A1, a charging current flowing through the charging connector causes it to heat up due to ohmic current heat losses. However, the heating of the charging connector is limited to a limit temperature increase. For example, according to the IEC 62196-3 standard, the limit temperature increase is limited to 50 K. This in turn leads to a maximum charging current for largely standardized connector geometries that generally cannot exceed 200 A in continuous load operation. However, with intermittent charging of the battery of an electric or hybrid vehicle, higher charging currents over limited periods of time are necessary in order to charge the battery in the desired short time. This can lead to temporary heating of the charging connectors which exceeds the limit temperature increase.The cable cross-section of the electrical connection bodies cannot be increased arbitrarily, since the connector geometries are standardized and, in addition, the smallest possible amount of conductive material, usually copper, should be used for the electrical connection bodies.
[0005] In this respect, according to EP 3 043 421 A1, the object is to be achieved by providing an electrical connection body which enables increased charging currents with limited heating and therefore has an increased short-time current carrying capacity. This object is to be achieved by providing an electrical connection body for a charging plug or a charging socket, wherein the electrical connection body has a first connection region for the galvanic connection to an electrical energy receiver and a second connection region for the galvanic connection to an electrical energy source, wherein the electrical connection body is designed such that it has a cooling fluid channel formed in the electrical connection body, wherein the cooling fluid channel of the electrical connection body is fluidly connected to a cooling fluid source which is arranged in a charging station.
[0006] Cooling of a charging plug connector for electric and hybrid vehicles, which cooling starts at the side of the charging station, is also well known from the prior art. DE 10 2015 119 338 A1 describes, for example, two connection points for coolant lines being arranged on a contact sleeve element of a charging plug. Coolant is guided in a circle around the contact sleeve element by means of a spiral-shaped plug-in element. The two connection points serve as inlets and outlets for the coolant, which is guided from the charging station to the charging plug. EP 3 433 902 B1 likewise describes a plug connector part with cooled contact elements. Here, too, the supply of coolant via coolant lines to the contact elements of the charging coupling connected to the charging cable is provided on the charging station side.A fluid is provided as the coolant, which is directed perpendicular to the contact element into the hollowed-out contact element and flows back within the contact element. Finally, 10 2016 105 361 B4 also describes a connector part with a cooled contact element, whereby here, too, the charging station side provides for the supply of a coolant via coolant lines to the contact elements of a charging socket connected to the charging cable. Guide elements are arranged on the contact elements to ensure that the coolant, in the form of compressed air, flows around the contact elements.
[0007] Based on this, the object of the present invention is to achieve improved heat dissipation in a charging connector which is not itself equipped with a cooling system on the part of a charging station.
[0008] This object is achieved by the subject matter of the independent claims. Preferred developments of the invention are described in the subclaims.
[0009] According to the invention, a charging connector for electric and hybrid vehicles is provided, with
[0010] Charging contacts for contacting corresponding charging contacts of a corresponding charging plug connector, a plug-in area in which the charging plug connector, when plugged into the corresponding charging plug connector, overlaps with the corresponding charging plug connector in the plug-in direction and the charging contacts of the two plug connectors are in galvanically conductive contact with one another, a connection area in which the charging contacts are galvanically conductively connected to electrical lines that lead away from the charging plug connector, and a heat-conducting element that is different from the charging contacts and extends from the plug-in area into the connection area.
[0011] When reference is made here to a corresponding charging plug connector, this means, on the one hand, a charging plug connector which has the same plug face as the charging plug connector according to the invention, whereby one plug face has contact pins while the other plug face has contact sleeves, and vice versa. The set comprising the charging plug connector according to the invention and the corresponding charging plug connector can therefore be plugged together. On the other hand, the term corresponding charging plug connector is also used here when the plug faces in the aforementioned sense only partially correspond, i.e. the corresponding charging plug connector, for example.does not have all the contacts that are present in the charging plug connector according to the invention, but the existing contacts of the corresponding charging plug connector correspond to the charging plug connector according to the invention in terms of the plug face, so that the charging plug connector according to the invention and the corresponding charging plug connector can also be plugged together in this case.
[0012] One such case is a charging connector connected to a charging cable for direct current charging in accordance with the European standard IEC 62196 Type 2. Such a charging connector can be plugged into a charging plug installed in the body of an electric or hybrid vehicle and suitable for both alternating current and direct current charging. The alternating current plug face of the direct current charging connector only contains the communication contacts and the protective contact, but no contacts for the outer conductor and a center conductor for alternating current charging.
[0013] In the present case, a heat-conducting element is understood to be an element that results in the thermal conductivity of the charging connector according to the invention being greater in the plug-in direction than without the heat-conducting element. The installation of the heat-conducting element thus improves the ability of the charging connector to dissipate heat generated in the charging connector when plugged into the corresponding charging connector toward the corresponding charging connector.
[0014] In the present case, reference is made to a plug-in area of the charging connector according to the invention in which the charging connector, when plugged into the corresponding charging connector, overlaps with the corresponding charging connector in the plug-in direction and the charging contacts of the two connectors are in galvanically conductive contact with one another. Such a plug-in area of a charging connector is generally also defined and geometrically limited in that the charging connector has a device which ensures that the two charging connectors, in the plugged-in state, overlap with one another over a certain maximum length, which corresponds to the fully plugged-in state of one charging connector into the other charging connector.
[0015] It is therefore a key aspect of the invention to support passive cooling on the part of the charging plug connector and to use the thermal coupling between the charging plug connector and a corresponding charging plug connector plugged into it, so that heat can be effectively transferred from the charging plug connector to the corresponding charging plug connector. This is of particular use if the corresponding charging plug connector is equipped with an active cooling system, as described above with reference to the prior art. By means of the heat-conducting element provided according to the invention, heat generated in the charging plug connector according to the invention can be dissipated in the direction of the active cooling system of the corresponding charging plug connector, so that this active cooling system can practically also be used for the plug connector according to the invention.
[0016] In principle, the charging contacts can have a wide variety of shapes. However, according to a preferred embodiment of the invention, the charging contacts are circular in cross-section. They are preferably designed as contact sleeves or as contact pins that can be inserted into contact sleeves.
[0017] As already explained above, the only requirement for the heat-conducting element is that it results in the thermal conductivity of the charging plug connector according to the invention being greater in the plug-in direction than without the heat-conducting element. The installation of the heat-conducting element is therefore intended to improve the ability of the charging plug connector to dissipate heat generated in the charging plug connector when plugged in with the corresponding charging plug connector in the direction of the corresponding charging plug connector. According to a preferred development of the invention, the heat-conducting element is made of metal, preferably copper or aluminum. Furthermore, other materials and material mixtures with good thermal conductivity are of course also possible for the heat-conducting element, which lead to the improved heat dissipation from the charging plug connector according to the invention.
[0018] The invention initially only requires that the heat-conducting element extend from the plug-in area of the charging connector into the connection area of the charging connector. However, it is preferably provided that the heat-conducting element extends in the plug-in direction. This provides the shortest path for heat dissipation from the charging connector, which promotes effective heat dissipation.
[0019] In this case, it is preferably the case that the heat-conducting element runs parallel to a charging contact and ends in the plug-in area at the same length as the parallel charging contact. Within the scope of this preferred development, however, it is also possible for the heat-conducting element to end before the parallel charging contact, in particular in an area between 1 and 3 mm before the end of the parallel charging contact. In both cases, it can be achieved that the heat-conducting element does not cause interference during plugging and yet reaches very close to the corresponding charging connector in the plugged-in state, which supports heat dissipation.
[0020] It is also advantageous if the heat-conducting element in the connection area ends at the same length as the parallel charging contact or only after the parallel charging contact. This allows heat to be absorbed from a large area within the charging connector and transferred to the corresponding charging connector when plugged in.
[0021] There are a variety of different geometric arrangement options for the heat-conducting element in the charging connector. However, the heat-conducting element is preferably arranged so that it runs in an area between two direct current charging contacts. During direct current charging, particularly high temperatures arise in the area of the direct current contacts. Due to the higher currents, the temperatures are also significantly higher than in the area of the alternating current charging contacts during alternating current charging.
[0022] In this case, contacts such as these are referred to as DC charging contacts and are intended exclusively for charging with direct current. In contrast, there are AC charging contacts. This refers to the outer conductors and the neutral conductor (center conductor), which are also intended for charging with alternating current. An outer conductor (also colloquially referred to as a phase) is a conductor that is live during normal operation and can contribute to the transmission or distribution of electrical energy, but is not a neutral conductor. A neutral conductor is a conductor that is electrically connected to the neutral point and is able to contribute to the distribution of electrical energy. In the European standard IEC 62196 Type 2, the contacts, which are referred to here as AC charging contacts, are designated LI, L2 and L3 (outer conductors) and N (neutral conductor), and the DC charging contacts are designated DC+ and DC-.This understanding should not be contradicted by the fact that the European standard IEC 62196 Type 2 also provides for an operating mode according to which direct current charging takes place via the contacts LI, L2, L3 and N.
[0023] It is now particularly preferred if two heat-conducting elements running parallel to one another are provided. If these heat-conducting elements are arranged in the region of two DC charging contacts running parallel to one another, it is particularly advantageous if the plane in which the longitudinal axes of the two DC charging contacts lie is parallel to the plane in which the longitudinal axes of the two heat-conducting elements lie. An arrangement in which the two heat-conducting elements run between the two DC charging contacts in regions slightly above and slightly below the DC charging contacts is therefore particularly preferred.
[0024] The heat-conducting elements can basically have different shapes. However, according to a preferred development of the invention, the heat-conducting elements both have a triangular shape in cross-section and each have a corner of the triangle pointing towards the axis that runs parallel to the middle between the two DC charging contacts. It is particularly preferred that the two sides of the triangle that lead to the corner pointing towards the axis that runs parallel to the middle between the two DC charging contacts are concave. It is advantageous in this case if the concave sides in cross-section each follow a shape that is given by a circle whose center lies on the longitudinal axis of the respective charging contact.This results in a shape and position of the two heat conducting elements which allow the heat conducting elements to reach very close to the direct current charging contacts over a relatively large area.
[0025] The invention also relates to the use of a charging connector according to one of the preceding claims on the vehicle body of an electric or hybrid vehicle. It is particularly preferred that the charging connector is a built-in charging connector, in particular according to the European standard IEC 62196 Type 2.
[0026] The invention also relates to a system comprising a charging plug connector as described above and a charging plug connector corresponding thereto, wherein the corresponding charging plug connector is provided with a cooling element that can be supplied with a cooling fluid. This system is preferably designed such that it also has a charging station and a charging cable connected to the charging station and carrying the corresponding charging plug connector, wherein the charging station has a cooling fluid source and the charging cable is provided with cooling fluid lines in order to transport the cooling fluid from the cooling fluid source to the cooling element of the corresponding charging plug connector and back again. The cooling fluid source of the charging station is designed such that heated cooling fluid returned from the charging plug connector is cooled again so that it is available again for cooling.
[0027] The invention is described in more detail below with reference to the drawings using preferred embodiments.
[0028] The drawings show
[0029] Fig. 1 shows a perspective view of a charging connector according to a preferred embodiment of the invention,
[0030] Fig. 2 shows a perspective view of a charging connector corresponding to the connector in Fig. 1,
[0031] Fig. 3a shows schematically the charging connector from Fig. 1 in a side view, Fig. 3b shows a section of the charging connector from Fig. 3a along the line AA,
[0032] Fig. 4 shows the heat conducting element shown in Fig. 3b in a perspective view,
[0033] Fig . 5a the heat conducting element shown in Fig . 3b in
[0034] cross-section,
[0035] Fig . 5b a heat conducting element with a triangular
[0036] cross-section,
[0037] Fig . 5c a heat conducting element with a circular
[0038] Cross-section and
[0039] Fig. 6 schematically shows a system with a charging connector, a corresponding charging connector, a charging cable, a charging station and a cooling system according to a preferred embodiment of the invention.
[0040] Fig. 1 shows a perspective view of a charging connector 1 according to a preferred embodiment of the invention. This is a charging plug for installation in the vehicle body 17 of an electric or hybrid vehicle 18, as shown schematically in Fig. 6. The present charging connector 1 is essentially and in terms of its plug face a charging plug according to the European standard IEC 62196 Type 2. In addition to AC charging contacts (not further provided with reference symbols), a protective contact and communication contacts, the charging connector 1 has two DC charging contacts 2 for DC charging.
[0041] The charging connector 1 is composed of a front housing part 24 and a rear housing part 25. The front housing part 24 is connected to the rear housing part 25 by laser welding. The front housing part 24 is the housing part that faces outward when installed in a vehicle body 17 and is intended to receive a corresponding charging connector 4.
[0042] Such a corresponding charging connector 4 can be seen in a perspective view in Fig. 2. This is a charging coupling for direct current charging, which essentially corresponds to the European standard IEC 62196 Type 2 in terms of its plug-in face. Two direct current charging contacts 14 are provided for direct current charging, which interact with the direct current charging contacts 2 of the charging connector 1 during charging. Specifically, the direct current charging contacts 2 of the charging connector 1 are designed as contact pins and the direct current charging contacts 14 of the corresponding charging connector 4 are designed as contact sleeves into which the contact pins can be inserted. In addition, the corresponding charging connector 4 has two communication contacts 16 and a protective contact 15.
[0043] As can be seen in particular from Fig. 3a, the charging plug connector 1 has a plug-in area 5 in the front housing part 24 and a connection area 6 in the rear housing part 25. The plug-in area 5 is defined as an area in which the charging plug connector 1, when plugged into the corresponding charging plug connector 4, overlaps with the corresponding charging plug connector 4 in the plug-in direction and the DC charging contacts 2, 14 of the two plug connectors 1, 4 are in galvanically conductive contact with one another. The connection area 6 is defined as an area in which the charging contacts 2 of the charging plug connector are galvanically conductively connected to electrical lines 7 which lead from the charging plug connector 1 to a battery (not shown in more detail).
[0044] What is crucial in the preferred embodiment of the invention described here is that two metallic heat-conducting elements 8 made of aluminum are provided, which extend parallel to the DC charging contacts 2 in the plug-in direction of the charging connector 1, specifically from the plug-in area 5 into the connection area 6. The heat-conducting elements 8 both end in the plug-in area 5 at approximately the same length as the parallel DC charging contacts 2. Furthermore, the heat-conducting elements 8 also extend far into the connection area 6, where they end only behind the mutually parallel DC charging contacts 2.
[0045] From Fig. 3a and 3b it can be seen that the heat conducting elements 8 run in an area between the two DC charging contacts 2, wherein the plane in which the longitudinal axes 9 of the two DC charging contacts 2 lie is parallel to the plane in which the longitudinal axes 10 of the two heat conducting elements lie. The heat conducting elements 8 each have a triangular shape in cross section and each point with a corner 11 of the
[0046] Triangle to the axis 12 , which runs parallel to the two DC charging contacts 2 in the middle.
[0047] The shape of the heat-conducting elements 8 is further adapted to the shape of the DC charging contacts 2 in that the two sides of the triangle leading to the corner 11, which points to the axis 12, which runs parallel to the center between the two DC charging contacts 2, are concave. Specifically, the concave sides in cross-section each follow a shape defined by a circle 13 whose center lies on the longitudinal axis 9 of the respective DC charging contact 2. This is indicated schematically in Fig. 5a.
[0048] Overall, this results in a shape for the two heat-conducting elements 8, as can be seen in the perspective view in Fig. 4. In this context, however, it should be noted that the shapes of the heat-conducting elements 8 shown in Figs. 4 and 5a are very favorable for heat dissipation from the DC charging contacts 2, since their shape essentially corresponds to the outer shape of the DC charging contacts 2 in their regions facing the DC charging contacts 2, so that the heat-conducting elements 8 can be moved close to the DC charging contacts 2. However, other cross-sectional shapes for the heat-conducting elements 8 are possible, namely, for example, a triangular shape with straight sides, as shown in Fig. 5b, or, in principle, a circular shape, as shown in Fig. 5c.
[0049] It has already been mentioned above that the charging connector 1 in the form of a built-in plug is used on the vehicle body 17 of an electric or hybrid vehicle 18. In this context, reference may be made to Fig. 6, which schematically shows a system according to a preferred exemplary embodiment of the invention, which system comprises a charging connector 1 installed in a vehicle body 17 of an electric or hybrid vehicle 18, a charging connector 4 corresponding to it, a charging station 20 and a charging cable 21 connected to the charging station 20 and carrying the corresponding charging connector 4. What is essential in this preferred exemplary embodiment of the invention is that the corresponding charging connector 4 is provided with a cooling element 19 to which a cooling fluid can be applied for cooling the corresponding charging contacts 4.In order to achieve cooling of the corresponding charging contacts 4 via the cooling elements 19, the charging station 20 is provided with a cooling fluid source 23 and the charging cable 21 has cooling fluid lines 22 in order to transport the cooling fluid from the cooling fluid source 23 to the cooling element 19 of the corresponding charging connector 4 and back again.
[0050] Because the charging plug connector 1 installed in the vehicle body 17 of the electric or hybrid vehicle 18 is now provided with the two heat-conducting elements 8, the thermal coupling between the charging plug connector 1 installed in the vehicle body 17 of the electric or hybrid vehicle 18 and the corresponding charging plug connector 4 attached to the charging cable 21 is significantly improved when the two charging plug connectors 1, 4 are plugged in, so that the active cooling in the corresponding charging plug connector 4 with the cooling fluid originating from the cooling fluid source can also be used indirectly for cooling the charging plug connector 1 installed in the vehicle body 17 of the electric or hybrid vehicle 18.
[0051] Reference symbol list
[0052] 1 charging connector
[0053] 2 charging contacts / DC charging contacts
[0054] 3 corresponding charging contacts
[0055] 4 corresponding charging connectors
[0056] 5 Plug-in area
[0057] 6 Connection area
[0058] 7 electrical cables
[0059] 8 Heat conducting element
[0060] 9 Longitudinal axes of the DC charging contacts
[0061] 10 Longitudinal axes of the heat conducting elements
[0062] 11 corner of the triangle
[0063] 12 Axis in the middle between the DC charging contacts
[0064] 13 Circle
[0065] 14 DC contacts
[0066] 15 Protective contact
[0067] 16 communication contacts
[0068] 17 Vehicle body
[0069] 18 Electric or hybrid vehicle
[0070] 19 Cooling element
[0071] 20 charging stations
[0072] 21 charging cables
[0073] 22 cooling fluid lines
[0074] 23 Cooling fluid source
[0075] 24 front housing part
[0076] 25 rear housing part
Claims
Patent claims 1. Charging connector (1) for electric and hybrid vehicles (18), with Charging contacts (2) for contacting corresponding charging contacts (3) of a corresponding charging plug connector (4), a plug-in area (5) in which the charging plug connector (1), when plugged into the corresponding charging plug connector (4), overlaps with the corresponding charging plug connector (4) in the plug-in direction and the charging contacts (2, 3) of the two plug connectors (1, 4) are in galvanically conductive contact with one another, a connection area (6) in which the charging contacts (2) are galvanically conductively connected to electrical lines (7) which lead away from the charging plug connector (1), and a heat-conducting element (8) which is different from the charging contacts (2) and extends from the plug-in area (5) to the connection area (6).
2. Charging connector (1) according to claim 1, wherein the heat-conducting element (8) is made of metal, preferably of copper or aluminum.
3. Charging connector (1) according to claim 1 or 2, where — the heat conducting element (8) is in the plugging direction of the charging connector (1).
4. Charging connector (1) according to claim 3, wherein the Heat conducting element (8) parallel to a charging contact (2) runs and ends in the plug-in area (5) at the same length as the parallel charging contact (2) or in front of the parallel charging contact (2).
5. Charging connector (1) according to claim 3 or 4, wherein the heat-conducting element (8) ends in the connection area (6) at the same length as the parallel charging contact (2) or only behind the parallel charging contact (2).
6. Charging connector (1) according to one of the preceding claims, wherein the charging contacts (2) are direct current charging contacts (2) and the heat-conducting element (8) runs in a region between the two direct current charging contacts (2).
7. Charging connector (1) according to one of the preceding claims, wherein two heat conducting elements (8) running parallel to one another are provided.
8. Charging connector (1) according to claim 7, wherein the DC charging contacts (2) run parallel to one another and the plane in which the longitudinal axes (9) of the two DC charging contacts (2) lie is parallel to the plane in which the longitudinal axes (10) of the two heat-conducting elements lie.
9. Charging connector (1) according to claim 8, wherein the heat conducting elements (8) each have a triangular shape in cross section and are each connected to a corner (11) of the triangle to the axis (12) which runs parallel to the two DC charging contacts (2) in the middle.
10. Charging connector (1) according to claim 9, wherein the two sides of the triangle leading to the corner (11) pointing to the axis (12) running parallel to the two DC charging contacts (2) in the middle between them are concave.
11. Charging connector (1) according to claim 10, wherein the concave sides in cross section each follow a shape defined by a circle (13) whose center lies on the longitudinal axis (9) of the respective DC charging contact (2).
12. Use of a charging connector (1) according to one of the preceding claims on the vehicle body (17) of an electric or hybrid vehicle (18).
13. System comprising a charging connector (1) according to one of claims 1 to 11 and a charging connector (4) corresponding thereto, wherein the corresponding charging connector (4) is provided with a cooling element (19) which can be supplied with a cooling fluid.
14. System according to claim 13, further comprising a charging station (20) and a charging cable (21) connected to the charging station (20) and carrying the corresponding charging connector (4), wherein the charging station (20) has a cooling fluid source (23) and the charging cable (21) is provided with Cooling fluid lines (22) are provided to transport the cooling fluid from the cooling fluid source (23) to the cooling element (19) of the corresponding charging connector (4) and back again.