Multi-part contact element

Abstract

The invention relates to a multi-part contact element for liquid-cooled charging plugs, having a contact plug with copper conductors attached thereon and a hose connection, wherein a coolant flow body is arranged between the contact plug and the hose connection, wherein the coolant flow body fixes and connects the contact plug and the hose connector axially spaced apart from one another, wherein a coolant chamber is formed within the coolant flow body between the contact plug and the copper conductor guided through the interior of the coolant flow body. The invention also relates to a liquid-cooled charging plug having at least two multi-part contact elements.

Description

[0001] Description

[0002] Multi-part contact element

[0003] The invention relates to a multi-part contact element for liquid-cooled charging plugs, comprising a contact plug with a copper conductor attached thereto and a hose connection. Furthermore, the invention relates to a liquid-cooled charging plug with at least two multi-part contact elements.

[0004] Contacts generally have at least one electrically conductive contact section for detachable, temporary or plug-in connection with a corresponding

[0005] A mating contact element and a shaft section adjoining the contact section for attaching an electrical cable to the contact. Such a contact, plug-in contact, or high-current contact can be used on a charging plug or charging socket, for example, for charging an electrically powered vehicle. In this case, a cable is connected to a charging station on the one hand and carries a

[0006] Connector part in the form of a charging plug, which can be plugged into an associated mating connector part in the form of a charging socket on a vehicle in order to establish an electrical connection between the charging station and the vehicle.

[0007] During a charging process of electrical energy storage devices, accumulators, heat is generated as a result of the high electrical power and electrical currents transmitted, not only on the cable with which a charging plug is connected, for example, to a charging station, but also on the charging plug and in particular within the charging plug, for example on high-current contacts, via which electrical contact is made with associated mating contacts, for example on the side of a charging socket on an electric vehicle, when the charging plug is plugged into the charging socket and the electrical power is transmitted.

[0008] Such high-current contacts, which are made of an electrically conductive material, for example copper, heat up when a charging current flows through the contacts, plug contacts, or high-current contacts. The contacts must generally be dimensioned depending on the charging current to be transmitted so that the contacts have sufficient current-carrying capacity and heating of the contact elements is limited. The rule here is that the larger the charging current to be transmitted, the larger the contact must be. However, scaling the contact element size with increasing charging current is limited due to the associated space requirements, weight, and costs. Therefore, there is a need to transmit a high charging current with a comparatively small contact.

[0009] High charging currents are particularly important in the context of the envisioned electromobility. Only in this way can electric vehicles and their energy storage systems be "refueled" in a short time.

[0010] A solution approach that is generally known in the state of the art is to cool contacts and high-current contacts passively or actively in order to realize the transmission of electrical power with limited heating of the power-transmitting components even in smaller-sized components.

[0011] This fundamental relationship in connection with electrically detachable contacting of electrically powered vehicles with a charging station is shown in DE 10 2018 112 746 A1. Presented here is a charging station for an electric vehicle with a base, a plug with plug contacts for plugging into a compatible socket on the electric vehicle, and a flexible cable which is attached to the base with a first end and to the plug with a second end of the cable opposite the first end. The plug can be moved back and forth between a parking position and a charging position. The plug contacts of the plug point in the same spatial direction in the parking position and in the charging position. The cable and / or the plug have an internal cooling system which is operatively connected to the base and is supplied with a cooling medium from the base. The cooling system comprises at least one internal cooling circuit.

[0012] When cooling such charging plugs and charging cables, it is particularly challenging to make the cooling performance as effective as possible while simultaneously keeping the installation space required for the cooling devices as small as possible. The document US 2015 / 0217654 A1 shows a charging system for an electric vehicle, comprising a power supply, a cable with a first and a second end, wherein the first end is attached to the power supply, wherein the cable comprises a charging wire and a cooling line, each of which extends from the first end to the second end; and a connector which is attached to the second end of the cable, wherein the connector has a form factor which corresponds to a charging station of the electric vehicle; wherein the cooling line is suitable for transporting a fluid which cools the charging wire or line. The cooling line and the current-carrying charging wire or line are practically arranged as a line package.

[0013] WO 2017 / 133893A1 shows another approach to cooling, in particular the charging plug, by flushing the contact elements with cooling fluid and cooling the charging cable by forming cable-hose packages. A cable arrangement is presented, comprising a cable with a cable hose and an arranged conductor. The cable hose is arranged at a distance from the conductor and forms a first intermediate space between the at least one conductor and the cable hose. At least one pipe for conveying a cooling fluid and a connecting piece which comprises at least one contact element which is connected to the at least one conductor, and a chamber. The chamber comprises a first connection which is connected to the first monitoring space between the at least one conductor and the cable hose and a second connection which is connected to the at least one pipe.

[0014] The teaching of DE 10 2019 132 390 A1 comprises a charging plug with a cooling device for improving cooling through direct contact of the cooling medium with the current-conducting components of the charging plug and the cable. It is proposed that, in addition to cooling the high-current contact to increase the current to be transmitted while maintaining a constant cable cross-section, a direct connection of the conductor and cooling hose to the high-current contact is suitable for achieving cooling improvements. The direct connection integrally supports both the conduction of electrical energy and the direct, improved heat transfer from the heating cable components to the cooling medium as a result of the direct physical contact.

[0015] Many of the cooling devices available in the prior art are designed in such a way that only partial areas of the high-current contacts are subjected to cooling. Often, only sections of the contact elements or the contact areas with the mating connector are cooled. In solutions that cool both the charging connector or contact elements and the current-carrying cables, the cooling medium flows are turbulent, reducing the cooling effect, or the flow velocity is too low. This is often also due to large cross-sectional changes or kinks in the flow channel. The object of the invention is to further develop existing cooling solutions for contact elements for liquid-cooled charging connectors so that the aforementioned disadvantages of the prior art are at least partially reduced and the cooling reliability is improved.

[0016] To solve this problem, the invention proposes a multi-part contact element for liquid-cooled charging plugs, comprising a contact plug with a connected copper conductor, a hose connection and a coolant flow body.

[0017] The coolant flow body is formed from a first flow body shell and at least one second flow body shell and accommodates the contact plug and the copper conductor within its interior. The axial fixation and connection of the contact plug and the hose connection is accomplished and sealed by the coolant flow body, such that a space for the coolant is formed within the coolant flow body between the contact plug and the copper conductor passing through the interior of the coolant body and the hose connection. The hose connection is designed to be concentric with both the contact connection and the copper conductor and encloses a copper conductor section such that a concentric annular cross-section for the flow of coolant is created between the hose connection and the copper conductor. Coolant can flow into or out of the coolant space via this annular cross-section.

[0018] The coolant chamber is also largely formed by a concentric ring cross-section between the copper conductor, contact plug, and coolant flow body. This ensures that the contact plug and the copper conductor are almost completely surrounded by the coolant, and the coolant flow is largely laminar and uniform. This achieves particularly high cooling performance while simultaneously reducing the size.

[0019] In order to allow flow through the coolant chamber of the coolant flow body, at least one recess is provided in the wall of the coolant flow body, through which the coolant can flow in or out. If two multi-part contact elements are installed in a liquid-cooled charging plug and enclosed by a charging plug housing, then the at least one recess can be used as an inflow opening for the coolant that has flowed out of the recess of the first multi-part contact element. After flowing through the coolant chamber of the second multi-part contact element, the coolant can flow into the hose connection of the second multi-part contact element and flow out through the hose, so that a coolant flow is present throughout the liquid-cooled charging plug.

[0020] The invention is explained in more detail below using an exemplary embodiment in conjunction with the figures. In the figures:

[0021] Fig. 1 is a perspective exploded view of the multi-part contact element;

[0022] Fig. 2 a side view of the multi-part contact element;

[0023] Fig. 3 a sectional side view of the multi-part contact element;

[0024] Fig. 4 is a three-dimensional representation of two multi-part contact elements in a possible relative position to each other within a liquid-cooled charging plug;

[0025] Fig. 5 a three-dimensional representation of two multi-part contact elements inserted into a charging plug connection plate;

[0026] Fig. 6 is a perspective view of a liquid-cooled charging connector with charging connector connection plate and charging connector housing.

[0027] Figure 1 shows a perspective exploded view of the multi-part contact element 1. The multi-part contact element 1 has a contact plug 10, which is arranged axially at the end and is connected to a copper conductor 40 in an electrically conductive and mechanically resilient manner. The copper conductor 40 is connected to a power source, so that a charging current is applied to the contact plug 10 of the multi-part contact element 1, which can be used to charge a vehicle's electrical energy storage device. The contact plug 10 and the copper conductor 40 are arranged concentrically to one another and lie on a common center axis of the multi-part contact element 1. A hose connector 30 is pushed over the copper conductor 40, the hose connector piece 32 of which is designed to receive and secure a hose (not shown).The hose and the hose connection 30 have larger inner diameters than the outer diameter of the copper conductor 40, so that a concentric annular gap is formed for the passage of coolant and introduction into the contact plug 10.

[0028] The coolant flow body 20 of this exemplary embodiment is formed by at least two flow body shells 21, which contact the contact plug 10 and the hose connection 30 and fix them axially spaced from one another. Alternatively, it is possible to construct the coolant flow body 20 as a single piece, i.e., with a sleeve-like structure.

[0029] Figure 2 illustrates a side view of the multi-part contact element 1. The flow body shells 21 forming the coolant flow body 20 are fixed in the folded position by a preferably detachable connection, in the exemplary embodiment shown by two screws screwed into a threaded blind hole each or by self-tapping screws into a bore each.

[0030] Due to the recognition of the invention that, in addition to the direct physical contact of the coolant with the components to be cooled, contact plug 10 and copper conductor 40, the uniform and laminar flow behavior of the coolant also improves the cooling performance, the coolant flow body 20 is structurally designed in such a way that the flow through the coolant flow body 20 with coolant is supported. This is achieved in that the coolant flow body 20 guides the coolant from the inlet or outlet point through the concentric ring cross-section formed by the hose connection 30 and copper conductor 40 through the coolant flow body 20 and thus along the components to be cooled, contact plug 10 and copper conductor 40, and introduces or discharges it from the coolant flow body 20 through at least one recess 23.The position of the at least one recess 23 within the flow body shells 21 forming the coolant flow body 20 is selected such that the longest possible flow path is formed within the coolant flow body 20 in the flow direction along the components to be cooled, namely the contact plug 10 and the copper conductor 40. In the illustrated embodiment, the at least one recess 23 is therefore arranged at the end of the coolant flow body 20 opposite the hose connection 30, preferably in a region of approximately one-third of the total length of the coolant flow body 20.

[0031] The contact plug 10 has a contact plug seal 11, and the hose connection 30 has a hose connection seal 31. These seals 11, 31 serve to seal the liquid-cooled charging plug 100, into which the multi-part contact element 1 can be inserted. The contact plug seal 11 of the contact plug 10 seals against a charging plug connection plate 110, and the hose connection seal 31 of the hose connection 30 seals against a charging plug housing 120.

[0032] Figure 3 shows a sectional side view of the multi-part contact element 1. The contact plug 10 and the hose connection 30 are contacted and mechanically secured by means of fixings 24, which are designed as circumferential, annular, and concentric collars at the end of the coolant flow body 20 and engage in compatible groove areas of the contact plug 10 and the hose connection 30. The fixings 24 can have a sealing effect through suitable dimensional tolerances of the fixing partners or separate seals, so that the coolant chamber 22 of the coolant flow body 20 is sealed at these points.

[0033] The coolant chamber 22 is formed in the flow direction of the coolant by concentric ring cross-sections, so that the coolant flow between the hose connection 30 and the at least one recess 23 is uniform.

[0034] The copper conductor 40 is attached to the contact plug 10 through an axial blind hole in the contact plug 10, into which the copper conductor 40 is inserted and pressed. In order to achieve both good electrically conductive contact and stable mechanical connection and at the same time to achieve good heat conduction through solid-state contact, the blind hole extends over approximately half the longitudinal extent of the contact plug 10. Figure 4 illustrates a three-dimensional representation of two multi-part contact elements 1 in a possible relative position to one another within a liquid-cooled charging plug 100. The orientation of the at least one recess 23 can be adjusted independently of the relative position and orientation of the multi-part contact elements 1 in that the coolant flow bodies 20 are rotationally symmetrical and can be aligned in their orientation during assembly.

[0035] Figure 5 comprises a three-dimensional representation of two multi-part contact elements 1 introduced into a charging plug connection plate 110. The multi-part contact elements 1 are fixed, for example, via a snap ring engaging in a snap ring groove.

[0036] Figure 6 shows a perspective illustration of a liquid-cooled charging plug 100 with charging plug connection plate 110 and charging plug housing 120. The multi-part contact elements 1 introduced into the charging plug connection plate 110 are accommodated in the interior of the charging plug housing 120 and, together with the contact plug seals 11 and hose connection seals 31, seal the liquid-cooled charging plug 100, so that a tightly sealed space for the coolant is provided in its interior.

[0037] By using two multi-part contact elements 1 in a liquid-cooled charging plug 100, a total coolant flow can be generated. Initially, the coolant flows via a hose connected to the hose connection 30 of the first multi-part contact element 1 into the coolant chamber 22 and then through the at least one recess 23 out of the coolant chamber and into the sealed charging plug housing 120. Subsequently, the coolant flows through the at least one recess 23 into the coolant chamber 22 of the second multi-part contact element 1 and then out of the coolant chamber 22 via the hose connection 30 into the hose of the second multi-part contact element 1. List of Reference Symbols

[0038] 1 multi-part contact element

[0039] 10 contact plugs

[0040] 11 Contact plug seal

[0041] 20 coolant flow bodies

[0042] 21 Flow body shell

[0043] 22 Coolant chamber

[0044] 23 Recess

[0045] 24 Fixation

[0046] 30 hose connection

[0047] 31 Hose connection seal

[0048] 32 hose connectors

[0049] 40 copper conductors

[0050] 100 liquid-cooled charging plugs

[0051] 110 Charging plug connection plate

[0052] 120 charging plug housings

Claims

Claims 1. Multi-part contact element (1) for liquid-cooled charging plugs (100), comprising a contact plug (10) with a copper conductor (40) attached thereto and a hose connection (30), characterized in that a coolant flow body (20) is arranged between the contact plug (10) and the hose connection (30), wherein the coolant flow body (20) fixes and connects the contact plug (10) and the hose connection (30) at an axial distance from one another, wherein a coolant chamber (22) is formed within the coolant flow body (20) between the contact plug (10) and the copper conductor (40) passing through the interior of the coolant flow body (20).

2. Multi-part contact element (1) according to claim 1, characterized in that the coolant space (22) of the coolant flow body (20) has at least one concentric ring cross-section.

3. Multi-part contact element (1) according to claim 1, characterized in that the coolant flows through the coolant flow body (20) between an inflow point and an outflow point.

4. Multi-part contact element (1) according to claim 3, characterized in that an inflow or outflow point is formed by a concentric ring cross-section between the hose connection (30) and the copper conductor (40).

5. Multi-part contact element (1) according to claim 3, characterized in that an inflow or outflow point is formed by at least one recess (23) in the coolant flow body (20).

6. Multi-part contact element (1) according to claim 5, characterized in that the at least one recess (23) is arranged at the end of the coolant flow body (20) opposite the hose connection (30).

7. Multi-part contact element (1) according to claim 1, characterized in that the coolant flow body (20) is formed by at least two flow body shells (21).

8. Multi-part contact element (1) according to claim 1, characterized in that the coolant flow body (20) fixes and connects the contact plug (10) and the hose connection (30) by means of a respective fixation (24) axially spaced from one another, wherein the fixations (24) seal.

9. Multi-part contact element (1) according to claim 1, characterized in that the contact plug (10) has a contact plug seal (11).

10. Multi-part contact element (1) according to claim 1, characterized in that the hose connection (30) has a hose connection seal (31).

11. Liquid-cooled charging plug (100), comprising a charging plug connection plate (110) and a charging plug housing (120) and at least two multi-part contact elements (1) according to one of the preceding claims.

12. Liquid-cooled charging plug (100) according to claim 11, characterized in that a total coolant flow is generated in that the coolant first flows into the coolant chamber (22) of the first multi-part contact element (1) via a hose connected to the hose connection (30) of the first multi-part contact element (1) and then flows out of the coolant chamber via the at least one recess (23) into the sealed charging plug housing (120) and flows in through the at least one recess (23) into the coolant chamber (22) of the second multi-part contact element (1) and then flows out of the coolant chamber (22) via the hose connection (30) into the hose of the second multi-part contact element (1).

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