System having a charging plug-in connector for electric and hybrid vehcles and having a heat store

Abstract

The invention relates to a system having a charging plug-in connector (1) for electric and hybrid vehicles (18) and having a heat store (6), wherein the charging plug-in connector (1) has a housing (7), charging contacts (2) arranged in the housing, and a heat-conducting element (5), the heat-conducting element (5) makes thermally conductive contact with at least one charging contact (2), the heat store (6) is arranged outside the housing (7) and the heat-conducting element (2) is guided out of the housing (7) and makes thermally conductive contact with the heat store (6) arranged outside the housing (7), so that heat dissipation from the charging contact (2) in the direction of the heat store (6) is possible. In this way, heat dissipation is improved for a charging plug-in connector (1) that is not itself equipped with a cooling system from a charging station.

Description

[0001] System with a charging connector for electric and hybrid vehicles and a heat storage unit

[0002] The invention relates to a system with a charging connector for electric and hybrid vehicles and a heat accumulator, wherein the charging connector has a housing, charging contacts arranged in the housing and a heat conducting element.

[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 and 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. As explained, for example, in EP 3 043 421 A1, a charging current flowing through the charging connector heats up due to ohmic current heat losses. However, the heating of the charging connector is legally limited to a limit temperature increase. For example, according to standard IEC 62196-3, the limit temperature increase is limited to 50 K. This in turn leads to a maximum charging current for largely standardized connector geometries that cannot generally exceed 200 A in continuous load operation.However, with intermittent charging of the battery of an electric or hybrid vehicle, higher charging currents are required over limited periods of time to charge the battery in the desired short time. This leads to temporary heating of the charging connectors, which exceeds the limit temperature increase. However, the cable cross-section of the electrical connector bodies cannot be increased indefinitely, since the connector geometries are standardized and, in addition, the smallest possible amount of conductive material, usually copper, should be used for the electrical connector bodies.

[0004] According to EP 3 043 421 A1, an electrical connection body is provided which enables increased charging currents with limited heating and therefore has an increased short-time current carrying capacity. For this purpose, an electrical connection body for a charging plug or a charging socket is proposed, 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.

[0005] 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 socket connected to the charging cable is provided on the charging station side.A fluid is provided as a coolant, which is guided perpendicular to the contact element into the hollowed contact element and flows back within the contact element.

[0006] Finally, 10 2016 105 361 B4 also describes a connector part with a cooled contact element. Here, too, a coolant is supplied via coolant lines to the contact elements of a charging socket connected to the charging cable on the charging station side. 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] However, solutions are also known from the state of the art which can also be used with a charging connector which is not cooled directly by the charging station, such as a charging connector built into the vehicle body of an electric or hybrid vehicle, such as a built-in charging connector in accordance with the European standard IEC 62196 Type 2.

[0008] For example, DE 10 2016 107 409 A1 describes a plug connector part for connecting to a mating connector part, which comprises a housing which has a plug-in section for plugging into the mating connector part and a contact element arranged on the plug-in section for making electrical contact with an associated mating contact element of the mating connector part. In addition, a heat pipe connected to the contact element and a heat sink arranged in the housing are provided, which heat sink is in thermally conductive connection with the contact element for dissipating heat from the contact element via the heat pipe. In this way, a plug connector part with a contact element is provided which can have a high current-carrying capacity, for example for use in a charging system for charging an electric vehicle.

[0009] Furthermore, DE 20 2019 102 461 U1 describes a plug connector part for connecting to a mating connector part, comprising a housing, a plug-in section arranged on the housing for plugging into the mating connector part, an electrical contact element arranged on the plug-in section for transmitting a current between the plug connector part and the mating connector part, and a cooling element arranged on the contact element for cooling the contact element, wherein a fan device is provided for generating an air flow at the cooling element. However, this system and the system described in DE 10 2016 107 409 A1 are very complex.

[0010] 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.

[0011] This object is achieved by the subject matter of the independent claims. Preferred developments of the invention are described in the subclaims.

[0012] According to the invention, a system is thus provided with a charging connector for electric and hybrid vehicles and a heat accumulator, wherein the charging connector has a housing, charging contacts arranged in the housing and a heat conducting element, the heat conducting element makes thermally conductive contact with at least one charging contact, the heat accumulator is arranged outside the housing and the heat conducting element is led out of the housing and makes thermally conductive contact with the heat accumulator arranged outside the housing, so that heat can be dissipated from the charging contact to the heat accumulator.

[0013] In this case, a heat-conducting element is understood to be an element that results in the thermal conductivity between the charging contact, to which the heat-conducting element is connected, and the heat accumulator, to which the heat-conducting element is also connected, being better than without the heat-conducting element. The installation of the heat-conducting element therefore improves the ability to dissipate heat generated at or in the charging contact to the heat accumulator. The heat-conducting element can then contact the heat accumulator through an opening or recess in the housing of the charging connector.

[0014] In this case, a heat storage device is used if the system is equipped with this heat storage device as an element whose function is to absorb and store the heat generated during the charging process. This can delay the heating of the charging connector's components.

[0015] The heat accumulator is arranged outside the housing of the charging contact in such a way that the heat generated during the charging process can be carried away by the charging contact and absorbed in the heat accumulator without the heat absorbed in the heat accumulator additionally heating the charging connector. In principle, the heat accumulator can be formed from various materials. However, according to a preferred development of the invention, provision is made for the heat accumulator to comprise water or a mixture of water and glycol or an oil. The oil can be, for example, a mineral oil, a vegetable oil or a silicone oil. It can also be provided that the heat accumulator is a latent heat accumulator in which a phase change material is arranged.

[0016] Since the heat accumulator is not housed in the charging contact housing, there are hardly any restrictions regarding its size or positioning. However, the heat accumulator must be thermally conductively connected to the heat-conducting element. Furthermore, the heat generated during the charging process is stored outside the charging contact, which further delays the heating of the charging contact. A key aspect of the invention is therefore to support the passive cooling of the charging connector with a heat accumulator arranged outside the charging connector housing.

[0017] In principle, it is possible for the heat-conducting element to be galvanically non-conductive. However, according to a preferred development of the invention, a part of the heat-conducting element that contacts the charging contact has a coating formed from a heat-conducting, electrically insulating material, so that a galvanically conductive connection between the heat-conducting element and the charging contact is prevented, and the heat-conducting element (5) has a thermal conductivity that is above 30 W / (m K), preferably above 100 W / (m K).

[0018] This coating can be applied to the heat-conducting element, for example, by overmolding or casting. The fact that the coating prevents a galvanically conductive connection between the charging contact and the heat-conducting element makes it possible to use materials for the heat-conducting element that have high thermal conductivities. Suitable materials are, for example, silver or copper. At the same time, however, these materials are also galvanically conductive. The galvanic insulation of the heat-conducting element allows the heat to be dissipated from the charging contacts into a common heat storage device without causing a short circuit in the charging contacts. This also makes it possible to bring several heat-conducting elements together before the thermal connection to the heat storage device, thus enabling a thermal equilibrium between the charging contacts.

[0019] According to a preferred development of the invention, it is provided that the coating has a thermal conductivity which is greater than 0.3 W / (m K), preferably greater than 1 W / (m K). For this purpose, the coating can advantageously be a heat-conducting plastic such as silicone. In order to further increase the heat conduction between the heat-conducting element and the charging contact, it can be provided that ceramic particles are contained in the plastic. In addition, the plastic is plastically deformable in such a way that direct contact is made possible and air pockets, which are not advantageous for heat transfer, can be avoided. For this purpose, it can be provided that the charging connector additionally has heat-conducting paste which is arranged between the charging contact and the coating of the heat-conducting element. The heat-conducting paste can also contain ceramic particles.

[0020] The invention also relates to the use of a system comprising a charging connector for electric and hybrid vehicles and a heat accumulator, as described above, on the vehicle body of an electric or hybrid vehicle.

[0021] In principle, the heat accumulator can be designed in various ways. However, according to a preferred development of the invention, the heat accumulator is designed using the vehicle body. The vehicle body advantageously offers a large thermal mass which can absorb the heat dissipation from the charging process. Likewise, the heat accumulator designed in this way can be cooled via convection since the vehicle body, despite its mass, also has a high surface to volume ratio. Furthermore, the invention relates to an electric or hybrid vehicle with a system having a charging connector for electric and hybrid vehicles and a heat accumulator, as described above, wherein the heat accumulator is formed using a metallic structure of the electric or hybrid vehicle.In the present case, a metallic structure means a structure comprising metal which is located on the vehicle body and / or is surrounded by it and / or is a part of it.

[0022] Since the structure is metallic, it usually has good thermal conductivity and can therefore be advantageously contacted with the heat-conducting element in a thermally conductive manner. Likewise, metallic structures in the electric or hybrid vehicle usually have a high volume so that the heat dissipation from the charging contacts can be absorbed in the metallic structure. For this purpose, it is particularly preferred that the heat accumulator is formed using the vehicle body of the electric or hybrid vehicle. However, it may also be preferred that the heat accumulator is formed using the chassis of the electric or hybrid vehicle.

[0023] The invention also relates to a system with the charging connector and the heat accumulator and a charging connector corresponding thereto, wherein the corresponding charging connector is provided with a cooling element that can be supplied with a cooling fluid and the corresponding charging contacts of the corresponding charging connector are designed as contact sleeves into which the charging contacts of the charging connector designed as contact pins can be inserted.

[0024] When we talk about a corresponding charging connector in this case, we mean, on the one hand, a charging connector that has the same mating face as the charging connector, but one mating face has contact pins while the other mating face has contact sleeves, and vice versa. The set of charging connector and corresponding charging connector can therefore be plugged together. On the other hand, we also talk about a corresponding charging connector in this case if the mating faces only partially correspond in the aforementioned sense, i.e., the corresponding charging connector, for example, does not have all the contacts that are present in the charging connector, but the existing contacts of the corresponding charging connector correspond to the mating face of the charging connector, so that the charging connector and the corresponding charging connector can also be plugged together in this case.

[0025] 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.

[0026] An outer conductor (also known colloquially as a phase conductor) is a conductor which 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 which 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 conductor) 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 recognises an operating mode according to which direct current charging takes place via the contacts LI, L2, L3 and N.

[0027] The system is preferably designed such that it further comprises a charging station and a charging cable connected to the charging station and carrying the corresponding charging 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 connector and back again. The cooling fluid source of the charging station is designed such that heated cooling fluid returned from the charging connector is cooled again so that it is available again for cooling.

[0028] The invention is described in more detail below with reference to the drawings using preferred embodiments.

[0029] The drawings show

[0030] Fig. 1 schematically shows a system with a charging connector and a heat storage device according to a preferred embodiment of the invention,

[0031] Fig. 2 shows a connector corresponding to the connector shown in Fig. 1,

[0032] Fig. 3 shows schematically the system with the charging connector and the heat storage device from Fig. 1 in an electric or hybrid vehicle in a sectional view and

[0033] Fig. 4 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.

[0034] Fig. 1 schematically shows a system with a charging connector 1 for electric and hybrid vehicles 18 and a heat accumulator 6 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 schematically shown in Fig. 4.

[0035] The present charging connector 1 is essentially, and in terms of its mating face, a built-in charging connector 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 charging contacts 2 for direct current charging. The heat accumulator is arranged outside a housing 7 of the charging connector and is thermally conductively connected to the charging contacts 2 of the charging connector 1 via a heat-conducting element 5. For this purpose, the charging contacts 2 can each be contacted with a heat-conducting element 5.

[0036] Alternatively, a heat-conducting element 5 can be provided with a branch and thus contact both charging contacts 2 . As a result, the heat generated during the charging process is carried away to the heat accumulator 6 and does not heat up the housing 7 of the charging connector 1 . The charging connector 1 can be coupled to a corresponding charging connector 4, which is shown in Fig. 2 . This is a charging coupling that can be attached to a charging cable and plugged together with the charging plug. The charging coupling shown here as an example is one for direct current charging and therefore has corresponding direct current charging contacts 3 , a protective contact and communication contacts . Both the charging plug shown here and the coupling shown here correspond to the European standard IEC 62196 in terms of their plug face.

[0037] Finally, Fig. 3 shows a sectional view of part of an electric or hybrid vehicle 18 with a system having the charging connector 1 and the heat accumulator 6. The charging connector 1 is inserted into a metallic structure 12 in the form of a vehicle body 17 of the electric or hybrid vehicle 18. The charging contacts 2 are thermally conductively connected to a heat-conducting element 5 via a coating 8. The coating 8 is galvanically insulating and is applied to the heat-conducting element 5. The heat-conducting element 5 is in turn thermally conductively connected to the vehicle body 17, which in this case is used as a heat accumulator 6. The heat generated during the charging process is thus conducted away to the vehicle body 17 and absorbed by it. This heat can then be dissipated by convection on the surface of the vehicle body 17.It has already been mentioned above that the charging connector 1 is used in the form of a built-in plug on the vehicle body 17 of an electric or hybrid vehicle 18. In this context, reference is made to Fig. 4, 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 3.In order to achieve cooling of the corresponding charging contacts 3 via the cooling elements 19, the charging station 20 is provided with a cooling fluid source 14 and the charging cable 21 has cooling fluid lines 22 in order to transport the cooling fluid from the cooling fluid source 14 to the cooling element 19 of the corresponding charging connector 4 and back again.

[0038] Because the charging connector 1 installed in the vehicle body 17 of the electric or hybrid vehicle 18 is brought into engagement with the corresponding charging contacts 3 on the charging station side during the charging process, the heat generated during the charging process is, on the one hand, absorbed in the heat accumulator 6 and, on the other hand, subjected to the charging station-side cooling through the thermal coupling between the charging connector 1 installed in the vehicle body 17 of the electric or hybrid vehicle 18 and the corresponding charging connector 4 attached to the charging cable 21 when the two charging connectors 1, 4 are plugged in. In this way, the active cooling in the corresponding charging connector 4 with the cooling fluid originating from the cooling fluid source can also be used indirectly for cooling the charging connector 1 installed in the vehicle body 17 of the electric or hybrid vehicle 18.

[0039] Reference symbol list

[0040] 1 charging connector

[0041] 2 charging contacts

[0042] 3 corresponding charging contact

[0043] 4 corresponding charging connectors

[0044] 5 Heat conducting element

[0045] 6 heat storage

[0046] 7 housings

[0047] 8 Coating

[0048] 12 metallic structure

[0049] 14 Cooling fluid source

[0050] 17 Vehicle body

[0051] 18 Electric or hybrid vehicle

[0052] 19 Cooling element

[0053] 20 charging stations

[0054] 21 charging cables

[0055] 22 cooling fluid lines

Claims

Patent claims 1. System with a charging connector (1) for electric and hybrid vehicles (18) and a heat accumulator (6), wherein the charging connector (1) has a housing (7), charging contacts (2) arranged in the housing and a heat conducting element (5), the heat conducting element (5) makes thermally conductive contact with at least one charging contact (2), the heat accumulator (6) is arranged outside the housing (7) and the heat conducting element (2) is led out of the housing (7) and makes thermally conductive contact with the heat accumulator (6) arranged outside the housing (7), so that heat can be dissipated from the charging contact (2) to the heat accumulator (6).

2. System according to claim 1, wherein a part of the heat-conducting element (5) which contacts the charging contact (2) has a coating (8) which is formed with a heat-conducting, electrically insulating material, so that a galvanically conductive connection between the heat-conducting element (5) and the charging contact (2) is prevented, and the heat-conducting element (5) has a thermal conductivity which is above 30 W / (m K), preferably above 100 W / (m K).

3. System according to claim 2, wherein the coating (8) has a thermal conductivity which is above 0.3 W / (m K), preferably above 1 W / (m K).

4. Use of a system comprising a charging connector (1) for electric and hybrid vehicles (18) and a heat accumulator (6) according to one of the preceding claims on the vehicle body (17) of an electric or hybrid vehicle (18).

5. Use of the system according to claim 4, wherein the heat accumulator (6) is formed using the vehicle body (17) is formed.

6. Electric or hybrid vehicle (18) with a system with a charging connector (1) for electric and hybrid vehicles (18) and a heat accumulator (6) according to one of claims 1 to 3, wherein the heat accumulator (6) is formed using a metallic structure (12) of the electric or hybrid vehicle (18) is formed.

7. Electric or hybrid vehicle (18) according to claim 6, wherein the heat accumulator (6) is formed using the vehicle body (17) of the electric or hybrid vehicle (18).

8. Electric or hybrid vehicle (18) according to claim 6 or 7, wherein the heat accumulator (6) is formed using the chassis of the electric or hybrid vehicle (18).

9. System with the charging connector (1) and the heat accumulator (6) according to one of claims 1 to 3 and a charging connector (4) corresponding thereto, wherein the corresponding charging connector (4) is provided with a cooling element (19) which can be acted upon by a cooling fluid and the corresponding charging contacts (3) of the corresponding charging connector (4) are designed as contact sleeves into which the charging contacts (2) of the charging connector (1), designed as contact pins, can be inserted.

10. System according to claim 9, 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 (14) and the charging cable (28) is provided with cooling fluid lines (22) in order to transport the cooling fluid from the cooling fluid source (14) to the cooling element (19) of the corresponding charging connector (4) and back again.

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