Charging plug connector for an electric or hybrid vehicle

Abstract

The invention relates to a charging plug connector (1) for an electric or hybrid vehicle, the charging plug connector comprising: a contact sleeve (2) which provides an opening (4) for receiving a contact pin (3) of a corresponding charging plug connector; a clamping ring (5) arranged on the outer periphery of the contact sleeve (2); and at least one spring element (6) that is in contact with the clamping ring (5), wherein the spring element (6) extends into the opening (4) through a through-hole (7) arranged radially in the contact sleeve (2), and the clamping ring (5) has a contour (8) that acts on the spring element (6) such that, by moving the clamping ring (5) relative to the spring element (6), the spring element (6) is moved further into the through-hole (7) counter to its spring force, or is moved in the opposite direction due to its spring force. This makes it possible to improve the connection between two charging plug connectors which are intended for charging an electric or hybrid vehicle, such that the charging contacts of the charging plug connectors exhibit as little temperature increase as possible.

Description

[0001] Charging connector for an electric or hybrid vehicle

[0002] The invention relates to a charging connector for an electric or hybrid vehicle, comprising a contact sleeve with which an opening is provided for receiving a contact pin of a corresponding 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 and charging plugs that can be installed in electric or hybrid vehicles have contact pins as charging contacts that can be inserted into the contact sleeves. When charging an electric or hybrid vehicle, the temperature of the live parts increases, particularly when charging with direct current at very high currents that can exceed 500 A. Charging connectors for electric and hybrid vehicles are therefore subject to legal and user-specific requirements regarding the temperature monitoring of alternating current and direct current charging contacts. For direct current charging, temperature measurement is generally required on both direct current charging contacts.For this purpose, a component suitable for temperature measurement, usually an NTC resistor, is placed as close as possible to the heat source, i.e., the charging contact, to enable real-time temperature monitoring for charging optimization and safety monitoring. If the temperature of a charging contact exceeds a predefined critical temperature, the charging process is shut down. The goal, however, is to prevent the temperature from rising above the critical temperature in order to enable an efficient charging process that can be completed in the shortest possible time.

[0004] DE 10 2019 113 591 A1 describes a plug connector part with a sensor device arranged on contact blades of a contact element. For this purpose, a sensor device is arranged on a contact element of a charging plug of a DC charging station, which sensor device is designed to detect a temperature at the contact blades. For the corresponding contact in the coupling or on the vehicle side, a mating contact element is provided for reception in the contact elements. So that a defined contact normal force can be provided between the contact blades and the mating contact element in the plugged-in state, a spring element is arranged in a groove in the contact blades.The spring element provides a radially inwardly directed pre-tensioning force on the contact blades and thus elastically counteracts any expansion of the contact blades, so that the contact blades rest against a plugged-in mating contact element with sufficient pre-tensioning force and reduce the contact resistance accordingly.

[0005] Based on this, the object of the invention is to improve the connection between two charging connectors intended for charging an electric or hybrid vehicle in such a way that the charging contacts of the charging connectors show the lowest possible temperature increases.

[0006] This object is achieved by the subject matter of the independent claims. Preferred developments of the invention are described in the subclaims.

[0007] According to the invention, a charging plug connector for an electric or hybrid vehicle is thus provided, with a contact sleeve with which an opening for receiving a contact pin of a corresponding charging plug connector is provided, a clamping ring arranged on the outer circumference of the contact sleeve and at least one spring element in contact with the clamping ring, wherein the spring element extends into the opening through a through-bore arranged radially in the contact sleeve and the clamping ring has a contour acting on the spring element such that by moving the clamping ring relative to the spring element, the spring element is moved further into the through-bore against its spring force or is moved in the opposite direction due to its spring force.

[0008] According to the invention, it is therefore provided that the contour can be used to act on the spring element in such a way that the spring element is moved further into the through-hole against its spring force. The opposite direction is a direction opposite the through-hole. If the clamping ring is moved further or backwards, the contour is designed such that the pressure on the spring element decreases and the spring element is moved in the opposite direction following its spring force. The clamping ring is located on the outer circumference of the contact sleeve. The movement of the clamping ring is therefore preferably a rotational movement about a central axis of the contact sleeve located in the opening, which coincides with a central axis of the contact pin in an assembled state in which the contact pin is received in the opening.

[0009] 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.

[0010] The invention is based on the finding that the heat development at charging contacts is significantly due to the power loss that occurs there during charging. This power loss can in turn be reduced if the contact resistance between the contact sleeve and contact pin is reduced. Such a reduction is achieved here by the spring element being pressed against the contact pin by the movement of the clamping ring during the charging process. The contact spring is galvanically conductively connected to the contact sleeve. The pressure exerted by the spring element on the contact pin increases the normal force between the spring element and the contact pin.

[0011] The basic idea of ​​the invention is that the contact resistance is inversely proportional to the normal force. This relationship follows the equation R = C / F n. Here R is the contact resistance, C is a quantity that represents all relevant physical quantities (Young's modulus, etc.) and is independent of the normal force F n is. An increase in the normal force thus leads directly to a reduction in the contact resistance. To increase the normal force, the invention provides for a force introduction to the spring element by means of movement of the clamping ring, with which the spring element is moved further into the through-bore and thus pressed against the contact pin arranged in the opening.

[0012] It is a prerequisite of the invention that the contour of the clamping ring is designed in such a way that the spring element is moved further into the through-bore when the clamping ring moves or in the opposite direction due to its spring force. Such movements can be achieved with different contours. However, according to a preferred development of the invention, the contour on the clamping ring is provided with a recess so that the spring element, in a position opposite the recess in the clamping ring, is moved in the opposite direction due to its spring force. The clamping ring therefore has a contour with a recess. If the recess is located in the immediate vicinity of the spring element, no more pressure is transferred to the spring element via the clamping ring and the spring element moves in the opposite direction according to its spring force.

[0013] In this context, according to a development of the invention, it is particularly preferred that a transition in the form of a starting contour is formed on the recess of the contour, with which transition the spring element is moved successively further into the through-bore or in the opposite direction by moving the clamping ring. The contour therefore has a pressure part and the recess. The pressure part exerts pressure on the spring element so that it is pressed further into the through-bore. If there is now a transition in the form of a starting contour from the pressure part to the recess and vice versa, the pressure on the spring element can be successively increased or reduced. This effectively prevents the clamping ring from tilting on the spring element and thus provides a failure safeguard.

[0014] In principle, it is possible to arrange the spring element on the contact sleeve in various ways. However, according to a preferred development of the invention, the spring element is attached to a spring holder ring and the spring holder ring is arranged on the outer circumference of the contact sleeve between the contact sleeve and the clamping ring. The spring holder ring surrounds the contact sleeve all around and thus ensures that the spring element is held securely so that it cannot fall out of the through-hole. The spring element is preferably fastened to the spring holder ring in such a way that it extends away from the spring holder ring essentially axially parallel to the central axis of the contact sleeve and under preload into the through-hole.The spring element rests largely against the contact sleeve, but is curved away from the contact sleeve immediately before entering the through-bore, so that a projection is formed in the spring element against which the pressure part of the clamping ring's contour presses. The bending length of the spring element is reduced by exerting pressure with the pressure part on the projection of the spring element, thus increasing the normal force. A 20% reduction in the bending length results in a 50% increase in the normal force.

[0015] In principle, the spring element can be shaped in various ways. However, according to a particularly preferred embodiment of the invention, the spring element extends, under pretension, through the through-bore into the opening so far that the diameter of the opening at this point is smaller than the diameter of the contact pin. As a result, the contact pin inserted into the opening is held by the clamping ring even without additional pressure. The spring element makes galvanic contact with the contact pin.

[0016] According to a further preferred development of the invention, the charging plug connector or the contact sleeve is provided with a plurality of spring elements and a plurality of through-bores, wherein each spring element extends into the opening through a through-bore arranged radially in the contact sleeve, and the clamping ring has a contour such that by moving the clamping ring relative to the spring elements, the spring elements are moved further into the through-bores against their spring force or are moved in the opposite direction due to their spring force. This increases the contact surface between the spring elements and the contact pin and, as a result, achieves better conductivity and reduces the contact resistance.

[0017] In principle, the spring elements and the through-holes can be arranged on the contact sleeve in any desired manner. However, according to a preferred embodiment of the invention, the spring elements and the through-holes are arranged equidistant from one another along the outer circumference of the contact sleeve. This holds the contact pin centered in the opening, and the normal force between the spring elements and the contact pin is evenly distributed. Each spring element exerts the same pressure on the contact pin, thereby achieving particularly advantageous contact, since local temperature differences due to locally varying contact resistances are effectively avoided.

[0018] According to a particularly preferred development of the invention, in this context, it is provided that recesses are formed in the contour of the clamping ring corresponding to the arrangement of the spring elements and that the clamping ring completely encloses the contact sleeve along the outer circumference. Each recess is therefore assigned to a spring element. The spacing of the recesses in the contour of the clamping ring corresponds to the spacing of the spring elements or through-holes along the outer circumference of the contact sleeve. In particular, if the spring elements with the through-holes are arranged equidistant from one another, the clamping ring does not necessarily have to be movable in two directions of movement, but only in one, in order to move the spring elements accordingly, which reduces the susceptibility to errors.

[0019] There are numerous possibilities for the concrete implementation of the movement of the clamping ring. According to a preferred development of the invention, the charging connector is provided with an actuator arrangement with which the clamping ring can be moved.

[0020] In this context, according to a preferred development of the invention, the actuator arrangement has a slide and an actuator for acting on the latter, and the slide is non-positively connected to the clamping ring in such a way that a translational movement of the slide is converted into a rotational movement of the clamping ring. For this purpose, the slide is attached to the clamping ring with a hinge joint. The translational movement of the slide takes place in two ways, so that the clamping ring can be rotated in two directions of movement, taking into account the degree of freedom provided by the hinge joint. This lever drive formed in this way enables particularly rapid actuation of the clamping ring and, with it, the spring elements.

[0021] According to another preferred development of the invention, the actuator arrangement has a worm shaft and an actuator for acting on the latter, the clamping ring being designed as a gear along its outer circumference and the worm shaft engaging the gear in a force-fitting manner in such a way that a rotational movement of the worm shaft brings about a rotational movement of the clamping ring. In contrast to the previous development of the invention, it is provided here in particular that the clamping ring is designed in such a way that when the worm shaft rotates in one direction of rotation, the spring elements can be moved further into the through-bore or can be moved in the opposite direction by the spring force. For this purpose, it is provided that the clamping ring is designed as a gear over its entire circumference.

[0022] If the clamping ring is designed as a gear on its outer circumference, the worm shaft is also designed to be rotatable in two directions. With this actuator arrangement, a particularly high pressure can be exerted on the spring elements or the contact pin, so that the normal force between the spring elements and the contact pin can be increased or increased to a particularly high degree.

[0023] The invention can basically be used for any charging contacts of a charging connector for charging an electric or hybrid vehicle. According to a preferred development of the invention, the contact sleeves and the contact pins accommodated in the contact sleeves are direct current charging contacts. The advantages provided by the invention can be considerable, especially with direct current charging contacts, since with direct current charging there is a particular risk, due to the high charging currents, that a direct current charging contact will be heated above a critical temperature. In this context, it should also be noted that one actuator arrangement can be used for both contact sleeves if at least the part of the clamping ring that is connected to the actuator drive is electrically insulating. This prevents an electrical short circuit between the direct current charging contacts.

[0024] A key aspect of the invention is that the charging plug connector provided according to the invention makes it possible to provide an increased normal force between the contact sleeve and a contact pin inserted into the contact sleeve only when the contact pin is already inserted into the contact sleeve. This avoids strong friction between the contact sleeve and the contact pin when the contact pin is inserted or removed. According to the invention, the normal force can therefore be selectively increased such that the increased normal force is only present when it is desired and not when it would lead to greater wear on the contact pin and the contact sleeve.In this respect, according to a preferred development of the invention, a method for charging a battery of an electric or hybrid vehicle by means of a charging connector as described above is provided, which method comprises the following steps:.

[0025] Rotating the clamping ring after inserting the contact pin into the contact sleeve and before starting a charging process, so that the spring element is moved further into the through-hole, charging the battery and

[0026] Rotate the clamping ring after the charging process has been completed and before the contact pin is removed from the contact sleeve so that the spring element is moved in the opposite direction due to its spring force.

[0027] The invention is explained in more detail below using preferred embodiments with reference to the drawings.

[0028] The drawings show

[0029] Fig. 1 shows a charging connector in the form of a charging coupling according to a preferred embodiment of the invention in a perspective view,

[0030] Fig. 2a shows a contact pin according to a preferred embodiment of the invention in a perspective view,

[0031] Fig. 2b shows a contact sleeve according to a preferred embodiment of the invention in a perspective view,

[0032] Fig. 3 shows a spring retainer ring with attached spring elements according to a preferred embodiment of the invention in a perspective view, Fig. 4a shows a perspective view of the contact sleeve from Fig. 2b with the attached spring retainer ring from Fig.

[0033] 3 ,

[0034] Fig. 4b the contact sleeve with the attached spring retainer ring from Fig. 4a in a sectional view,

[0035] Fig. 5 shows the contact sleeve with the attached spring retainer ring and a clamping ring according to a preferred embodiment of the invention,

[0036] Fig. 6a shows the contact sleeve with the attached spring retainer ring and the clamping ring according to Fig. 5 with an actuator arrangement according to a preferred embodiment of the invention and

[0037] Fig. 6b shows the contact sleeve with the attached spring retainer ring and the clamping ring according to Fig. 5 with an actuator arrangement according to an alternative embodiment of the invention.

[0038] Fig. 1 shows a schematic perspective view of a charging connector 1 according to a preferred embodiment of the invention. This charging connector 1 is a charging coupling that can be plugged onto a charging plug attached to an electric or hybrid vehicle. The plug face shown here corresponds to the European standard IEC 62196 Type 2. It features two direct current contacts 16, as well as a protective contact 17 and two communication contacts 18 for controlling the charging process.

[0039] The DC charging contacts 16 each have a contact sleeve 2, as shown in Fig. 2b. The contact sleeve 2 has an opening 4 for receiving a contact pin shown in Fig. 2a. Additionally, the contact sleeve 2 is formed with radially arranged through-bores 7, which create continuous connections from the surroundings to the opening 4 of the contact sleeve.

[0040] Fig. 3 shows a perspective view of a spring retainer ring 10 with three attached spring elements 6, which are arranged equidistant from one another along the circumference of the spring retainer ring. The spring elements 6 are spaced apart from one another by 120°. Fig. 4a shows the contact sleeve 2 with the spring retainer ring 10 attached. The spring retainer ring 10 is not completely closed here, so that it can be plugged onto the contact sleeve 2 in the form of a snap closure. The individual spring elements 6 are designed such that they protrude into the respective through-bore 7, as can be seen in a sectional view in Fig. 4b.

[0041] In Fig. 5, a clamping ring 5 is placed on the spring holder ring 10 with the spring elements 6. The clamping ring 5 has a contour 8 in which three pressure parts 19 are arranged alternating with three recesses 9. If a contact pin 3 is now inserted into the opening 4 of the contact sleeve 2, the clamping ring 5 is in a position in which the recesses 9 lie opposite the spring elements 6. If the contact pin 3 is plugged together with the contact sleeve 2, the pressure parts 19 exert pressure on the spring elements 6 by turning the clamping ring 5, whereby the spring elements are pressed further into the through-bores 7 against their spring force and press against the contact pin 3 with increased normal force.

[0042] Figs. 6a and 6b show two different variants for the actuated movement of the clamping ring 5 from Fig. 5. Both variants provide for the force-fitting connection of the clamping ring 5 to an actuator arrangement 11, which causes the clamping ring 5 to rotate.

[0043] Fig. 6a shows an actuator arrangement 11 with an actuator 13 and a slide 12 connected to the actuator for translational force transmission. The slide 12 is connected to the clamping ring 5 via a hinge-like joint, so that the translational movement of the slide 12 causes a rotational movement of the clamping ring 5. Fig. 6b shows an alternative worm drive. The actuator 13 is connected to a worm shaft 14. The clamping ring 5 is provided with teeth on a part or section of its outer circumference, so that a gear is formed along this section. This toothing is designed such that the teeth of the clamping ring 5 engage with the teeth of the worm shaft 14. The actuator-driven rotation of the worm shaft 14 thus causes a rotation of the clamping ring 5. List of reference symbols

[0044] 1 charging connector

[0045] 2 contact sleeves

[0046] 3 contact pins

[0047] 4 Opening

[0048] 5 clamping ring

[0049] 6 spring element

[0050] 7 Through hole

[0051] 8 Contour

[0052] 9 Recess

[0053] 10 feather shark ter ring

[0054] 11 Actuator arrangement

[0055] 12 sliders

[0056] 13 Actuator

[0057] 14 Worm shaft

[0058] 15 gear

[0059] 16 DC charging contacts

[0060] 17 Protective contact

[0061] 18 Communication contact

[0062] 19 Printing part

Claims

Patent claims 1. Charging plug connector (1) for an electric or hybrid vehicle, with a contact sleeve (2) with which an opening (4) for receiving a contact pin (3) of a corresponding charging plug connector is provided, a clamping ring (5) arranged on the outer circumference of the contact sleeve (2) and at least one spring element (6) in contact with the clamping ring (5), wherein the spring element (6) extends into the opening (4) through a through-bore (7) arranged radially in the contact sleeve (2) and the clamping ring (5) has a contour (8) acting on the spring element (6) such that by moving the clamping ring (5) relative to the spring element (6), the spring element (6) is moved further into the through-bore (7) against its spring force or is moved in the opposite direction due to its spring force.

2. Charging connector (1) according to claim 1, wherein the contour (8) on the clamping ring (5) has a recess (9) so that the spring element (6) is moved in the opposite direction due to its spring force in a position opposite the recess (9) of the clamping ring (5).

3. Charging connector (1) according to claim 2, wherein a transition in the form of a starting contour is formed on the recess (9) of the contour (8), with which the spring element (6) can be successively moved by the movement of the clamping ring (5). moved further into the through hole (7) or in the opposite direction.

4. Charging connector (1) according to one of the preceding claims, wherein the spring element (6) is attached to a spring retainer ring (10) and the spring retainer ring (10) is arranged on the outer circumference of the contact sleeve (2) between the contact sleeve (2) and the clamping ring (5).

5. Charging connector (1) according to one of the preceding claims, wherein the spring element (6) extends under prestress through the through-bore (7) into the opening (4) so far that the diameter of the opening (4) at this point is smaller than the diameter of the contact pin (3).

6. Charging plug connector (1) according to one of the preceding claims with a plurality of spring elements (6) and a plurality of through-bores (7), wherein a spring element (6) in each case extends into the opening (4) through a through-bore (7) arranged radially in the contact sleeve (2), and the clamping ring (5) has a contour (8) such that by moving the clamping ring (5) relative to the spring elements (6), the spring elements (6) are moved further into the through-bores (7) against their spring force or are moved in the opposite direction due to their spring force.

7. Charging connector (1) according to claim 6, wherein the spring elements (6) and the through-bores (7) are arranged equidistant from one another along the outer circumference of the contact sleeve (2).

8. Charging connector (1) according to claim 7, wherein recesses (9) are formed in the contour (8) of the clamping ring (5) corresponding to the arrangement of the spring elements (6) and the clamping ring (5) completely encloses the contact sleeve (2) along the outer circumference.

9. Charging connector (1) according to one of the preceding claims with an actuator arrangement (11) with which the clamping ring (5) is movable.

10. Charging connector (1) according to claim 9, wherein the actuator arrangement (11) comprises a slider (12) and an actuator (13) for acting on it and the slide (12) is connected to the clamping ring (5) in such a force-fitting manner that a translatory movement of the slide (12) is converted into a rotary movement of the clamping ring (5).

11. Charging connector (1) according to claim 9, wherein the actuator arrangement (11) comprises a worm shaft (14) and an actuator (13) for acting thereon, wherein the clamping ring (5) is designed as a gear (15) along its outer circumference and the worm shaft (14) engages forcefully in the gear (15) in such a way that with a rotary movement of the worm shaft (14) a rotational movement of the clamping ring (5) is effected.

12. Method for charging a battery of an electric or hybrid vehicle by means of a charging connector (1) according to one of the preceding claims, comprising the following method steps: Rotating the clamping ring (5) after inserting the contact pin (3) into the contact sleeve (2) and before starting a charging process, so that the spring element (6) is moved further into the through-bore (7), charging the battery and rotating the clamping ring (5) after completing the charging process and before unplugging the contact pin (3) from the contact sleeve (2) so that the spring element (6) is moved in the opposite direction due to its spring force.

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