DE102022122292A1 - Charging connector for an electric or hybrid vehicle - Google Patents

Abstract

The subject of the invention is a charging connector (1) for an electric or hybrid vehicle, with a contact sleeve (2) that can be reversibly compressed radially inwards for receiving a contact pin (2) of a charging plug and an actuator arrangement with which the contact sleeve can be compressed radially inwards, so that in the case that a contact pin (3) is inserted into the contact sleeve (2), the normal force between the contact sleeve (2) and the contact pin (3) received in the contact sleeve is increased. This makes it possible to improve the connection between two charging connectors that are 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.

Description

The invention relates to a charging connector for an electric or hybrid vehicle, with a contact sleeve that can be reversibly compressed radially inwards for receiving a contact pin of a charging plug.

Electric and hybrid vehicles have a rechargeable energy storage device, usually a high-voltage battery, which provides energy to an electric drive motor while driving. The storage capacities of these high-voltage batteries are limited, so they have to be recharged regularly at a charging station. The battery is charged via a charging cable provided between the charging station and the vehicle, whereby the charging cable, for example in accordance with the European standard IEC 62196 Type 2, has a charging plug on one side that can be plugged into a charging socket provided on the charging station, and on the other side is provided with a charging coupling that can be connected to a charging plug installed in the electric and hybrid vehicle. In the present case, charging sockets, charging plugs, charging couplings and charging plugs are subsumed under the term “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 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 current-carrying parts increases, especially when charging with direct current with very high currents, which can be over 500 A. Charging connectors for electric and hybrid vehicles are therefore subject to legal and user-specific requirements regarding the temperature monitoring of AC and DC charging contacts. For DC charging, a temperature measurement is usually required on both DC charging contacts. For this purpose, a component suitable for temperature measurement, usually an NTC resistor, is brought as close as possible to the heat source, i.e. the charging contact, in order 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 switched off. However, the goal is to avoid such a temperature increase above the critical temperature in order to enable an efficient charging process that can be completed in the shortest possible time.

The DE 10 2019 113 591 A1 describes a connector part with a sensor device arranged on contact lamellas of a contact element. For this purpose, it is provided that a sensor device is arranged on a contact element of a charging plug of a DC charging station and is designed to detect a temperature on the contact lamellae. For appropriate contacting in the coupling or on the side of the vehicle, a counter-contact element is provided for inclusion in the contact elements. So that a defined normal contact force can be provided between the contact lamellae and the mating contact element when plugged in, a spring element is arranged in a groove of the contact lamellae. The spring element provides a radially inwardly directed pretensioning force on the contact lamellae and thereby counteracts any expansion of the contact lamellae in an elastically resilient manner, so that the contact lamellae rest against an inserted mating contact element with sufficient pretensioning force and reduce the contact resistance accordingly.

Proceeding from this, the object of the invention is to improve the connection between two charging connectors that are 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.

This task is solved by the subject matter of the independent claims. Preferred developments of the invention are described in the subclaims.

According to the invention, a charging connector for an electric or hybrid vehicle is thus provided, with a contact sleeve that can be reversibly compressed radially inwards for receiving a contact pin of a charging plug and an actuator arrangement with which the contact sleeve can be compressed radially inwards, so that in the case that in the Contact sleeve a contact pin is inserted, the normal force between the contact sleeve and the contact pin received in the contact sleeve is increased.

The invention is therefore based on the knowledge that the heat development at charging contacts is largely due to the power loss that occurs there during charging. This power loss in turn can be reduced if the contact resistance between the contact sleeve and the contact pin is reduced. Such a reduction is achieved in the present case by reversibly compressing the contact sleeve radially inwards during the charging process, so that it presses against the contact pin that is inserted into the contact sleeve, which increases the normal force between the contact sleeve and the contact pin received in the contact sleeve elevated.

The basic idea of the invention is that the contact resistance is inversely proportional to the normal force, which, in the case of contact pins with a circular cross section, is applied as a discrete surface load on the cylindrical surface forming the outside of a contact pin. This relationship follows the equation R = C / F _n . Here R is the contact resistance, C is a quantity that is representative of all relevant physical quantities (modulus of elasticity, etc.) and is independent of the normal force F _n . An increase in the normal force therefore leads directly to a reduction in the contact resistance. For this increase in the normal force, according to the invention, force is introduced onto the contact sleeve, namely by means of the actuator arrangement, with which the contact sleeve can be compressed radially inwards.

It is a prerequisite of the invention that the contact sleeve can be reversibly compressed radially inwards to accommodate a contact pin of a charging plug. Such compressibility can be achieved in various ways. According to a preferred development of the invention, however, it is provided that the contact sleeve has a plurality of contact lamellae which circumferentially limit the insertion area for the contact pin to the outside. In the relaxed state, these contact lamellae are separated from one another along at least part of the insertion length of the contact pin, and are therefore at a distance from one another. Viewed further back in the insertion direction of the contact pin, the slats are then preferably connected to one another, so that from an electrical point of view they represent a common charging contact.

There are now a variety of options for actually implementing the invention. According to a preferred development of the invention, it is provided that the actuator arrangement has a flexible compression element and an actuator for mechanically acting on the flexible compression element, the flexible compression element circumferentially encompassing the contact sleeve and the actuator is functionally connected to the flexible compression element in such a way that By activating the actuator, the flexible compression element can be contracted, so that in the case that a contact pin is inserted into the contact sleeve, the contact sleeve is pressed radially inwards against the contact pin.

The flexible compression element is preferably a flexible band, which is particularly preferably made of metal or plastic. Furthermore, according to a preferred development of the invention, it is provided that the actuator has an adjusting screw with which the flexible band can be tightened and loosened again.

The mechanism of action of the preferred exemplary embodiment of the invention described here is similar in terms of its functionality to the function of a brake band on an automatic transmission or the function of a hose clamp with which a hose is fixed on a connecting piece.

The actuator acts on the adjusting screw so that the diameter of the band can be reduced and increased again, so that the contact sleeve is compressed or can move back to its basic state after loosening the flexible band.

According to another preferred embodiment of the invention, the actuator arrangement has at least two compression elements that are rigid during operation and an actuator for mechanically acting on the rigid compression elements, the rigid compression elements circumferentially encompassing the contact sleeve in such a way and the actuator is functionally connected to the rigid compression elements in such a way that By activating the actuator, the rigid compression elements can be moved towards each other, so that in the event that a contact pin is inserted into the contact sleeve, the contact sleeve is pressed radially inwards against the contact pin.

The fact that the compression elements are rigid during operation means that they are designed to be so stable that they are not deformed due to the mechanical action by the actuator during the intended operation for compressing the contact sleeve.

According to a preferred development of the invention, in this preferred exemplary embodiment it is provided that the actuator has an adjusting screw or an eccentric for moving the rigid compression elements towards and away from each other. According to one embodiment of the preferred exemplary embodiment described here, two opposing compression elements are provided, which partially surround the contact sleeve circumferentially. If these compression elements are now moved towards each other by means of the actuator, which, as mentioned above, can be an adjusting screw or an eccentric, they are pressed radially against the outside of the contact sleeve, so that it also happens that the contact sleeve is inserted into the contact sleeve Contact pin presses, so that the normal force between the contact sleeve and the contact pin received in the contact sleeve is increased.

According to a third preferred embodiment of the invention, the actuator arrangement has a compression element that is rigid during operation an actuator for mechanically acting on the rigid compression element, wherein the contact sleeve has a control contour on its outside, the rigid compression element has a control contour on its inside that interacts with the control contour, the rigid compression element circumferentially surrounds the contact sleeve and the rigid compression element relative to the actuator can be rotated to the contact sleeve, so that by rotating the compression element relative to the contact sleeve, the control contour of the rigid compression element interacts with the control contour of the contact sleeve in such a way that the flexible compression element is pulled together, so that in the case that a contact pin is inserted into the contact sleeve, the Contact sleeve is pressed radially inwards against the contact pin.

It is preferably the case that the control contour of the contact sleeve is an outwardly projecting starting slope and the control contour of the rigid compression element is an inwardly pointing projection. If the rigid compression element is now rotated relative to the contact sleeve and the control contour of the rigid compression element with its inward-pointing projection comes into contact with the outwardly protruding starting slope of the contact sleeve, the rigid compression element exerts an ever greater pressure on the contact sleeve, the further it goes the projection of the rigid compression element moves along the starting slope of the contact sleeve. By turning back the rigid compression element, this pressure can be reduced again and finally completely eliminated, so that the contact pin can finally be removed from the contact sleeve again without the increased normal force desired for the charging process according to the invention prevailing.

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, however, the charging connector has two contact sleeves that can be reversibly compressed radially inwards for receiving a respective contact pin of a charging plug and an actuator arrangement with which both contact sleeves can be compressed radially inwards, so that the normal force between the respective contact sleeve and a respective one The contact pin received in the contact sleeve is increased, the contact sleeves and the contact pins being DC charging contacts. Especially with DC charging contacts, the advantages provided by the invention can be significant, since in DC charging, due to the high charging currents, there is a particular risk that a DC charging contact will be heated above a critical temperature.

In this context, it should also be noted that the transition from a compression element to the contact sleeve on which it acts is preferably electrically insulating. In this way, such a compression element can also be used together for two DC charging contacts, since the compression element does not lead to an electrical short circuit between the DC charging contacts.

• reversibles Stauchen der Kontakthülse nach Einstecken des Kontaktstiftes in die Kontakthülse und vor dem Starten des Ladevorgangs,
• Laden der Batterie und
• Beenden des reversiblen Stauchens der Kontakthülse nach Beendigung des Ladevorgangs und vor dem Ausstecken des Kontaktstiftes aus der Kontakthülse.

It is a significant aspect of the invention that the charging 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. In this way it is avoided that there is strong friction between the contact sleeve and the contact pin when plugging or unplugging the contact pin. According to the invention, the normal force can be selectively increased so that it 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 the battery of an electric or hybrid vehicle using a previously described charging connector is provided, which has the following method steps:

• reversible compression of the contact sleeve after inserting the contact pin into the contact sleeve and before starting the charging process,
• Charging the battery and
• End the reversible compression of the contact sleeve after the charging process has ended and before unplugging the contact pin from the contact sleeve.

The invention is explained in further detail below using preferred exemplary embodiments with reference to the drawings.

• 1 schematisch einen Ladesteckverbinder in Form einer Ladekupplung gemäß einem bevorzugten Ausführungsbeispiel der Erfindung in einer perspektivischen Ansicht,
• 2a eine Kontakthülse und einen Kontaktstift gemäß einem bevorzugten Ausführungsbeispiel der Erfindung in ungestecktem Zustand,
• 2b die Kontakthülse und den Kontaktstift aus 2a in gestecktem Zustand,
• 3a schematisch einen Schnitt durch Kontakthülse und Kontaktstift gemäß 2b,
• 3b schematisch die auf die Innenseite der Kontakthülse in 3a wirkenden Normalkräfte,
• 3c die auf die Außenseite des Kontaktstifts aus 3a wirkenden Normalkräfte,
• 3d die erfindungsgemäß auf die Außenseite der Kontakthülse aufgebrachten zusätzlichen Normalkräfte,
• 4 schematisch im Querschnitt eine Kontakthülse und einen Kontaktstift zusammen mit einer Aktoranordnung und einem flexiblen Stauchelement gemäß einem bevorzugten Ausführungsbeispiel der Erfindung,
• 5 schematisch im Schnitt zwei Kontakthülsen und in diese eingesteckte Kontaktstifte zusammen mit einer Aktoranordnung und zwei starren Stauchelementen gemäß einem bevorzugten Ausführungsbeispiel der Erfindung und
• 6 schematisch im Teilschnitt eine Kontakthülse und einen darin eingesteckten Kontaktstift zusammen mit einem starren Stauchelement gemäß einem bevorzugten Ausführungsbeispiel der Erfindung.

Show in the drawings

• 1 schematically a charging connector in the form of a charging coupling according to a preferred embodiment of the invention in a perspective view,
• 2a a contact sleeve and a contact pin according to a preferred embodiment of the invention in the unplugged state,
• 2 B the contact sleeve and the contact pin 2a in plugged state,
• 3a schematically a section through the contact sleeve and contact pin 2 B ,
• 3b schematically on the inside of the contact sleeve in 3a acting normal forces,
• 3c which is on the outside of the contact pin 3a acting normal forces,
• 3d the additional normal forces applied according to the invention to the outside of the contact sleeve,
• 4 schematically in cross section a contact sleeve and a contact pin together with an actuator arrangement and a flexible compression element according to a preferred embodiment of the invention,
• 5 schematically in section two contact sleeves and contact pins inserted into them together with an actuator arrangement and two rigid compression elements according to a preferred exemplary embodiment of the invention and
• 6 schematically in partial section a contact sleeve and a contact pin inserted therein together with a rigid compression element according to a preferred embodiment of the invention.

Out of 1 A charging connector 1 according to a preferred embodiment of the invention can be seen schematically in a perspective view. 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. Two direct current contacts 14 are provided and, above them, a protective contact 15 and two communication contacts 16 for controlling the charging process.

The DC charging contacts 14 each have a contact sleeve 2, as in the 2a and 2 B shown. The contact sleeve 2 is provided with contact lamellae 5, between which slots 17 are provided. In this way, a contact sleeve 2 that can be reversibly compressed radially inwards is also used to accommodate a contact sleeve 2 2a and 2 B Contact pin shown provided.

2a now shows the contact sleeve 2 and the contact pin 3 in the unplugged state, and the plugged state is in 2 B recognizable. Conventionally, it is the case that the contact sleeve 2 is stretched slightly outwards when the contact pin 3 is inserted, which is made possible by the flexible metal material from which the contact sleeve 2 and the contact pin 3 are formed. In this respect, there is already a fundamentally sufficient electrical contact between the contact sleeve 2 and the contact pin 3 inserted into it, as shown in 2 B is shown.

This state, in which the contact pin 3 is inserted into the contact sleeve 2, is also shown schematically in section 3a shown. Out of 3b It can now be seen how normal forces shown with arrows act outwards on the interior of the contact sleeve 2 when the contact pin 3 is inserted into the contact sleeve 2. By analogy, in 3c shown which normal forces act from the outside on the peripheral surface of the contact pin 3. It should be noted that for the sake of clarity 3c The representation of the contact sleeve 2, into which the contact pin 3 is inserted, has been omitted. Out of 3d The principle underlying the invention can now be seen, according to which the contact sleeve 2 is reversibly compressed radially inwards in order to reduce the contact resistance between the contact sleeve 2 and the contact pin 3, which is indicated by arrows pointing radially inwards. In order to concretely implement this functional principle, there are various options, for which three different preferred embodiments for the invention are explained below.

Out of 4 is shown, again schematically in section, how a contact pin 3 is inserted into a contact sleeve 2. Here, an actuator arrangement with an actuator 7, an adjusting screw 10 and a flexible compression element 6 is provided in the form of a flexible band, which surrounds the contact sleeve 2 circumferentially in such a way that when the flexible band 6 is contracted, the contact sleeve 2 is compressed inwards. In this respect, the procedure in this preferred embodiment of the invention is such that after the charging coupling 1 has been plugged onto a charging plug in an electric or hybrid vehicle, the actuator 7 is actuated so that the flexible band 6 is pulled together by means of the adjusting screw 10. This increases the normal forces acting on the outside of the contact sleeve 2, so that there is also an increase in the normal forces that act on the outside of the contact pin 3 due to the contact sleeve 2 surrounding the contact pin 3. This is associated with a reduction in the contact resistance between the contact sleeve 2 and the contact pin 3, which leads to lower power loss and thereby less heating of the contact sleeve 2 and contact pin 3 during the charging process.

In contrast to that in 4 shown preferred embodiment of the invention are in the preferred embodiment of the invention, which 5 It can be seen that no flexible compression element but rather two compression elements 9 that are rigid during operation are provided. The fact that the compression elements 9 are rigid during operation means that they cannot be deformed by means of the actuator 7 provided here and the adjusting screw 10 provided here. Rather, it is the case that the adjusting screw 10 driven by the actuator 7 moves the two rigid compression elements 9 towards each other, so that the two contact sleeves 2, which are enclosed by the rigid compression elements 9, are compressed radially inwards. In this way, too, the desired effect is achieved, according to which the normal force that acts between the contact sleeves 2 and the contact pin 3 inserted therein is increased.

Finally it's in 6 a preferred embodiment of the invention can be seen, wherein a single rigid compression element 11 is provided. This rigid compression element 11 is provided with a control contact 13 in the form of an inward-pointing projection.

This projection interacts with a starting slope, which is provided by means of a control contour 12 provided on the outside of the contact sleeve 2. The further the projection of the control contour 13 moves along the increasingly outward starting slope of the control contour 12, the stronger the force with which the rigid compression element compresses the contact sleeve 2, which also results in an increased normal force between the contact sleeve 2 and the in this inserted contact pin 3 is achieved.

Turning the rigid compression element 11 clockwise here is a tightening, with which the contact sleeve 2 becomes increasingly compressed, while turning the rigid compression element 11 counterclockwise corresponds to a loosening, in which the normal force between the contact sleeve 2 and the contact pin 3 is reduced again. This tightening or loosening is also effected here by means of a schematically indicated actuator 7.

Reference symbol list

1

Charging connector

2

contact sleeve

3

Contact pin

4

Actuator arrangement

5

Contact lamellas

6

flexible compression element

7

Actor

8th

adjusting screw

9

rigid compression elements

10

adjusting screw

11

rigid compression element

12

Tax contour

13

Control contour

14

DC contacts

15

Protective contact

16

Communication contacts

17

slots

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102019113591 A1 [0004]

Claims (12)

Charging connector (1) for an electric or hybrid vehicle, with a contact sleeve (2) that can be reversibly compressed radially inwards for receiving a contact pin (2) of a charging plug and an actuator arrangement with which the contact sleeve can be compressed radially inwards, so that in the event that a contact pin (3) is inserted into the contact sleeve (2), the normal force between the contact sleeve (2) and the contact pin received in the contact sleeve ( 3) is increased. charging connector (1). Claim 1 , wherein the contact sleeve (2) has a plurality of contact lamellae (5) which circumferentially limit the insertion area for the contact pin (3) to the outside. charging connector (1). Claim 1 or 2 , wherein the actuator arrangement has a flexible compression element (6) and an actuator (7) for mechanically acting on the flexible compression element (6), the flexible compression element (6) circumferentially encompassing the contact sleeve (2) and the actuator (7) functionally is connected to the flexible compression element (6) in such a way that the flexible compression element (6) can be pulled together by activating the actuator (7), so that in the event that a contact pin (3) is inserted into the contact sleeve (2), the contact sleeve (2) is pressed radially inwards against the contact pin (3). charging connector (1). Claim 3 , wherein the flexible compression element (6) is a flexible band. charging connector (1). Claim 4 , where the band is made of metal or plastic. charging connector (1). Claim 4 or 5 , wherein the actuator arrangement has an adjusting screw (8) with which the flexible band can be tightened and loosened again. charging connector (1). Claim 1 or 2 , wherein the actuator arrangement has at least two compression elements (9) which are rigid during operation and an actuator (7) for mechanically acting on the rigid compression elements (9), wherein the rigid compression elements (9) surround the contact sleeve (2) circumferentially in such a way and the actuator ( 7) is functionally connected to the rigid compression elements (9) in such a way that by activating the actuator (7), the rigid compression elements (9) can be moved towards one another, so that in the case that a contact pin (2) is inserted into the contact sleeve (2). 3) is inserted, the contact sleeve (2) is pressed radially inwards against the contact pin (3). charging connector (1). Claim 7 , wherein the actuator arrangement has an adjusting screw (10) for moving the rigid compression elements (9) towards one another and away from one another. charging connector (1). Claim 1 or 2 , wherein the actuator arrangement has a compression element (11) that is rigid during operation and an actuator (7) for mechanically acting on the rigid compression element (11), the rigid compression element (11) circumferentially encompasses the contact sleeve (2), the contact sleeve (2). has a control contour (12) on its outside, the rigid compression element (11) has on its inside a control contour (13) which interacts with the control contour (12), and with the actuator (7) the rigid compression element (11) relative to the contact sleeve (2) is rotatable, so that by rotating the rigid compression element (11) relative to the contact sleeve (2), the control contour (13) of the rigid compression element (11) interacts with the control contour (12) of the contact sleeve (2) in such a way that the rigid compression element (11 ) is pulled together, so that in the case that a contact pin (3) is inserted into the contact sleeve (2), the contact sleeve (2) is pressed radially inwards against the contact pin (3). charging connector (1). Claim 9 , wherein the control contour (12) of the contact sleeve (2) is an outwardly protruding connecting bevel and the control contour (13) of the rigid compression element (11) is an inward-pointing projection. Charging connector (1) according to one of the preceding claims, with two contact sleeves (2) which can be reversibly compressed radially inwards for receiving a respective contact pin (3) of a charging plug and an actuator arrangement with which both contact sleeves (2) can be compressed radially inwards, so that in the event that a contact pin (3) is inserted into the contact sleeve (2), the normal force between the respective contact sleeve (2) and a respective contact pin (3) received in the contact sleeve (2) is increased, the contact sleeves (2 ) DC charging contacts are. Method for charging the battery of an electric or hybrid vehicle using a charging connector (1) according to one of the preceding claims, with the following method steps: reversible compression of the contact sleeve (2) after inserting the contact pin (3) into the contact sleeve (2) and before starting the charging process, charging the battery and ending the reversible compression of the contact sleeve (2) after the charging process has ended and before unplugging the contact pin (3) from the contact sleeve (2).

Images