DE102018105507A1 - Device for testing a contact force of an electromechanical connection and charging device for an electric vehicle - Google Patents

Abstract

Device for testing a contact force of an electromechanical connection,
with at least one test contact (4, 6),
- With at least one force measuring device (8, 10) for measuring axial forces and
with at least one support structure (16),
- wherein the force measuring device (8, 10) is fixed to the support structure (16) and
- Wherein the test contact (4,6) to the force measuring device (8, 10) is attached.

Description

The present invention relates to a device for testing a contact force of an electromechanical connection and a charging device for an electric vehicle with such a device.

In the field of electromobility there are highest requirements for charging connectors in terms of their stability and safety, with current charging currents of up to 500A being transmitted. This assumes that e.g. a permanently installed charging plug of a public charging station retains its efficiency even after several years of use with thousands of charging cycles.

The contact systems of charging connectors usually consist of one or more pairs of contacts, which are nested and circumferentially resiliently braced against each other. Thus, a contact pair e.g. be formed as round pins and slotted socket, the pin is in the inserted state in the socket and rest spring elements of the socket on an outer circumferential surface of the pin. Due to the resilient elastic tension of the pin within the socket, a normal contact force between the pin and the socket is formed, which makes it possible to conduct electrical current through the contact parts. A wear-related reduction of the contact normal force leads to the fact that the contact resistance of the electromechanical plug connection is increased. A shortfall of a critical normal force should therefore be avoided to ensure the electrical function.

In general, any defect in the electrical power contacts, be it due to wear, contamination or willful damage to such a charging connector, the risk that the contact resistance of the electromechanical connector is increased during charging. An increase in the contact resistance leads to an increased voltage drop across the load contacts, which entails an increased power loss. The associated heat development can be so high in extreme cases that the load contacts set the surrounding plastic material of the connector and / or the cables on fire.

In order to monitor a charging process, it is known, for example, to use a shutdown device with temperature sensors which monitor the temperature of the load contacts and terminate a charging process when a limit temperature is exceeded. In this case, it is disadvantageous for the end customer that he does not complete the charging process in a timely manner at the relevant charging station and, moreover, that the vehicle can be damaged. Furthermore, such a temperature monitoring does not exclude that a faulty charging plug, which may be responsible for the temperature overrun, is reused after cooling in a subsequent charging process until the temperature limit is reached.

Against this background, the present invention is based on the technical problem to provide an apparatus and a charging device for an electric vehicle, which do not have the disadvantages mentioned above or at least to a lesser extent, and in particular to enable a reliable, permanently reliable transmission of charging power to electric vehicles, wherein a defective charging plug is detectable in particular before its use.

The technical problem described above is achieved by a device according to claim 1 and a charging device according to claim 9. Further embodiments of the invention will become apparent from the dependent claims and the description below.

In the present case, when talking about an electric vehicle, it is a motor vehicle that is at least partially or completely electrically driven and has at least one traction battery or traction battery.

According to a first aspect, the invention relates to a device for testing a contact force of an electromechanical connection, with at least one test contact, with at least one force measuring device for measuring axial forces and at least one support structure, wherein the force measuring device is attached to the support structure and wherein the test contact on the Force measuring device is attached.

It has been found that by measuring axial forces during the manufacture and / or release of a plug connection along a plugging direction, it is possible to conclude the contact normal force of a charging plug connection. Thus, the contact normal force results e.g. from a measured during release of the connector, axial pulling force multiplied by a coefficient of friction of the material pairing of the connector. The contact normal force is oriented in particular perpendicular to the measured, axial pulling force.

The device may e.g. be used to check the mechanical contactability of socket contacts of a charging plug attached to the charging column between charging operations at a charging station, in which the test contact of the device is inserted into an associated socket contact of the charging plug and an axial pulling force when releasing the connector is measured.

Falling below a required minimum pulling force indicates the presence of a low contact normal force during a charging process. The charging plug or a socket contact of the charging plug can therefore be checked between the charging processes for its mechanical contactability. If a minimum pulling force is exceeded, the relevant charging station can be disabled and report a defect in the charging plug.

The device can therefore in particular be a test device for checking an axial pulling force when releasing a plug connection. From the axial pulling force can be concluded that the normal force between the contacts of an electromechanical charging connector.

The plug connection, which can be formed between the test contact and a contact of a charging plug, can be a purely mechanical plug connection. Thus, the test contact may be formed of a non-conductive or poorly conductive material, or be coated with a non-conductive or poorly conductive material. The plug connection, which can be formed between the test contact and a contact of a charging plug, can be an electromechanical plug connection. Thus, the test contact may be formed of a conductive material, or be coated with a conductive material. Regardless of whether the test contact is conductive or non-conductive, device is used to check the mechanical contactability of a contact to be tested, in particular its ability to form a Mindestkontaktnormalkraft to a corresponding contact partner of a contact pairing a charging connector.

According to a further embodiment of the invention, the test contact is a test pin, which is set up for insertion into a sleeve-shaped load contact of an electric vehicle charging connector. Accordingly, the test pin may be shaped in the manner of a load contact pin, which forms the counterpart to the sleeve or socket-shaped load contact of the electric vehicle charging plug on a charging socket of a motor vehicle.
It can be provided that the test pin has the same or a smaller diameter than the standard diameter of the test to be tested, sleeve-shaped load contact associated load contact pin of an electric vehicle. Alternatively or additionally, the test pin may have a friction-reducing coating at least in sections. Thus, the wear of a load contact to be tested can be reduced by the test procedures.

The test pin can have a diameter which corresponds to the standard diameter of the test to be tested, sleeve-shaped load contact associated load contact pin of an electric vehicle. Such a test pin may be coated or uncoated.
The test contact may be a sleeve or socket intended to test the mechanical contactability of a contact pin. Such a sleeve-shaped or bush-shaped test contact may have a larger receiving diameter to reduce the wear caused by the test procedures, as the Normaufnahmedurchmesser one of the test to be tested, pin-shaped load contact associated load contact sleeve. Alternatively or additionally, the sleeve-shaped or bush-shaped test contact can have, at least in sections, a friction-reducing coating. Thus, the wear of a load contact to be tested can be reduced by the test procedures.

According to a further embodiment of the device, the support structure has at least one linear unit for moving the test contact between at least one first position and at least one second position. The device may therefore be adapted to perform a plug and release movement of the test contact relative to a contact to be tested a charging plug. Thus, the linear unit may in particular be adapted to perform a lifting movement between the first position and the second position.

The linear unit may have an electromechanical drive, with a spindle, a reciprocating piston, a chain, a belt or the like.

It can be provided that the force measuring device is attached to a support plate of the support structure, a drive of the linear unit is mounted on a base plate of the support structure and between the support plate and the base plate, a linear guide is formed. Thus, a reliable and repeatable linear movement of the test contact can be achieved.

The force measuring device can be fixed by means of an elastic compensation element, such as a plastic buffer or the like, to the support structure to compensate for misalignment or the like in the manufacture of a connector to a contact to be tested and to avoid resulting from misalignment, mechanical tension.

Alternatively or additionally, it can be provided that the test contact is fastened by means of a holder in a form-fitting and releasable manner to the force-measuring device. Thus, the test contact, for example, have an end arranged, circular circumferential collar which is inserted into a holder formed as a slotted pocket. Alternatively or additionally, the test contact with the force measuring device and / or the holder can be screwed, pinned or jammed.

Alternatively, it may be provided that the force-measuring device is not indirectly attached to the support plate or the supporting structure by means of an elastic compensating element, but without compensating element. Similarly, the test contact according to alternative embodiments not indirectly via a holder, but directly without the provision of the holder, be attached directly to the force measuring device.

A further embodiment of the device is characterized in that at least two test contacts are provided, each test contact is assigned in each case a force measuring device. Thus, the device may have a plurality of test contacts, wherein, depending on the contact layout to be tested, a corresponding test contact is provided for each contact of a charging plug. In particular, test contacts may be provided for testing each load contact and each data or control contact of a charging plug.

Alternatively, the device may have exactly two test contacts, wherein each of the two test contacts is assigned in each case one force measuring device. In particular, the two test contacts can be set up for testing load contacts of a charging plug which, during charging operation, transmit the electrical charging power to an electric vehicle to be charged.

In particular, the test contacts may have mutually spaced, parallel longitudinal axes, wherein the distance of the longitudinal axes of the standard spacing of the load contacts of a charging plug according to one of the standards SAEJ1772, IEC62196-2, GB / T20234.2-2015, IEC 62196-3, GB / T20234. 3-2015 corresponds.

According to a further embodiment of the device is provided that the force measuring means of the at least two test contacts or the exact two test contacts are attached to the support plate. Thus, the force measuring devices can be displaced together with the associated test contacts.

A test contact may include sensors such as a temperature sensor, a current sensor, a voltage sensor, or a humidity sensor to detect further readings.

According to a second aspect, the invention relates to a charging device for charging an electric vehicle, with a housing, with a charging cable, with a charging plug, which is arranged on the end of the charging cable and having at least one contact with a housing formed on the housing for holding the Charging plug, with a device according to the invention for testing a contact force of an electromechanical connection, wherein the device according to the invention is associated with the receptacle, wherein the test contact with the contact of the charging plug is mechanically connectable, and wherein the force measuring device for measuring a pulling force when releasing a between the test contact and the contact of the charging plug formed, mechanical connection is established, and / or a plug-in force in establishing a formed between the Prüfkontakt and the contact of the charging plug, mechanical connection is established.

The device according to the invention is used as part of the charging device according to the present invention to check the mechanical contactability of the contact of the charging plug between charging processes at the charging station, in which the test contact of the device according to the invention is connected to the contact of the charging plug and e.g. an axial pulling force when loosening the connector is measured.

Falling below, e.g. a required minimum pulling force, suggests the presence of a low contact normal force during a charging process. The charging plug or a socket contact of the charging plug can therefore be checked between the charging processes for its mechanical contactability. If a minimum pulling force is exceeded, the relevant charging station can be disabled and report a defect in the charging plug and / or display.

The manufacture and release of the plug connection between the test contact and the contact of the charging plug and the measurement and evaluation of the axial forces measured by the force measuring device can be automated.

It can be provided that the test contact and the contact of the charging plug along a plug-in axis are arranged coaxially or aligned.

The device according to the invention can therefore be, in particular, a testing device integrated in a charging device for checking an axial pulling force when releasing a plug connection. From the measured, axial pulling force can be concluded that the normal force between the contacts of an electromechanical charging connector.

A further embodiment of the loading device is characterized in that the Charging device has a locking device with at least one locking element, such as a bolt or the like, wherein the locking device is adapted to lock the charging plug electromechanically in the receptacle, as far as a predetermined minimum force is exceeded when checking the contact force between the test contact and the contact of the charging plug. The charging plug can not be removed from the receptacle in the locked state, so that a defective charging plug can be detected prior to its use and blocked for further use.

It is envisaged that the charging plug is automatically locked immediately after insertion into the receptacle and release of the lock takes place only after a positive test result by the device for checking the contact force.

It can be provided that the measurement results of the test apparatus are stored and transmitted to a central database in order to document the long-term wear behavior of the contacts of a charging plug. For this purpose, the charging device can have a data interface for the transmission of measured data.

It can be provided that the test contact, as far as the charging plug is held in the receptacle, in particular is locked, from a first position in which the test contact is spaced from the contact of the charging plug, in the direction of contact of the charging plug in a second position is movable to form a mechanical connection to the contact of the charging plug, and that the test contact from the second position in which the test contact is mechanically connected to the contact of the charging plug, is movable to the first position. According to alternative embodiments of the invention, it is likewise conceivable that the charging plug is drawn into the housing in the direction of a stationary testing device and is disengaged again in order to carry out the checking procedure.

The charging cable can be a charging cable permanently installed on the charging device, in particular for DC charging.

• 1 eine erfindungsgemäße Vorrichtung zum Prüfen einer Kontaktkraft in einer perspektivischen Ansicht von oben;
• 2 die Vorrichtung aus 1 in einer Seitenansicht;
• 3 die Vorrichtung aus 1 in einer Draufsicht;
• 4 Prüfkontakte mit hülsenförmigen Lastkontakten in einer perspektivischen Ansicht von oben;
• 5 die Prüfkontakte und Lastkontakte aus 4 in einem Längsschnitt in einer ersten Position;
• 6 die Prüfkontakte und Lastkontakte aus 4 in einem Längsschnitt in einer zweiten Position;
• 7 eine erfindungsgemäße Ladevorrichtung zum Laden eines Elektrofahrzeugs in einer perspektivischen Ansicht;
• 8 eine vergrößerte Darstellung des Ladesteckers der Ladevorrichtung aus 7;
• 9 die erfindungsgemäße Vorrichtung aus 1 in einem in die Ladevorrichtung aus 7 montierten Zustand;
• 10 die Anordnung aus 9 in einem Längsschnitt in einer ersten Position;
• 11 die Anordnung aus 9 in einem Längsschnitt in einer zweiten Position.

The invention will be described in detail with reference to an exemplary embodiments illustrative drawing. Each show schematically:

• 1 an inventive device for testing a contact force in a perspective view from above;
• 2 the device off 1 in a side view;
• 3 the device off 1 in a plan view;
• 4 Test contacts with sleeve-shaped load contacts in a perspective view from above;
• 5 the test contacts and load contacts 4 in a longitudinal section in a first position;
• 6 the test contacts and load contacts 4 in a longitudinal section in a second position;
• 7 a charging device according to the invention for charging an electric vehicle in a perspective view;
• 8th an enlarged view of the charging plug of the charging device 7 ;
• 9 the device of the invention 1 in one in the loader 7 assembled state;
• 10 the arrangement 9 in a longitudinal section in a first position;
• 11 the arrangement 9 in a longitudinal section in a second position.

In 1 is a device 2 for testing a contact force of an electromechanical connection. The device 2 has two test contacts 4 . 6 , which each have a force measuring device 8th . 10 for measuring axial forces along the axes 12 . 14 assigned.

The device 2 has a support structure 16 , wherein the force measuring device 8th and the force measuring device 10 each on the support structure 16 are attached. The test contact 4 is at the force measuring device 8th attached. The test contact 6 is at the force measuring device 10 attached, in particular the 2 and 3 can be seen.

The supporting structure 16 has a linear unit 18 to move the test contact 4 and the test contact 6 from a first position ( 10 ) into a second position ( 11 ).

Like that 1 . 2 and 3 can be further seen, are the force measuring device 8th and the force measuring device 10 on a support plate 20 the supporting structure 16 attached. A drive 22 the linear unit 16 is on a base plate 24 the supporting structure 16 assembled. Between the support plate 20 and the base plate 24 is a linear guide 26 educated.

The force measuring device 8th is by means of an elastic compensating element 28 on the support plate 20 attached. The force measuring device 10 is by means of an elastic compensating element 30 on the support plate 20 attached.

The test contact 4 is by means of a holder 32 positive locking and releasable on the force measuring device 8th attached. The test pin 6 is by means of a holder 34 positive locking and releasable on the force measuring device 10 attached. At the brackets 32 . 34 each is a slotted bag 32 . 34 into which a respective assigned test contact 4 . 6 is inserted.

According to further embodiments of the invention can be provided that the force measuring devices 8th . 10 not, as shown in this example, indirectly, by means of the elastic compensating element 28 . 30 on the support plate 20 are attached, but without the compensation elements 28 . 30 directly on the support plate 20 or the supporting structure 16 are attached. Likewise, the test pins 4.6 according to alternative embodiments directly without the provision of the brackets 32 . 34 , directly at the force measuring equipment 8th . 10 be attached.

In the present case, the test contacts 4.6 around test pins 4.6 for insertion into sleeve-shaped load contacts 36 . 38 an electric vehicle charging plug 46 are set up (see 4-6 . 10 . 11 ).

The test pins 4 . 6 in the present case have a smaller diameter than the standard diameter of the sleeve-shaped load contacts 36 . 38 associated load contact pin of an electric vehicle. Next point the test pins 4 . 6 in the present case a friction-reducing coating in the region of its outer lateral surfaces.

7 shows a loading device according to the invention 40 , The loading device 40 has a housing 42 and a charging cable 44 , On the charging cable 44 At the end is a charging plug 46 arranged.

In the 4 shown load contacts 36 . 38 form the load contacts 36 . 38 of the charging plug 46 (see. 10 . 11 ).

The housing 42 has a recording 48 to hold the charging plug. After completing a charge, the charging plug becomes 46 therefore in the recording 48 plugged in and is held there.

The loading device 40 has a device according to the invention 2 , which is arranged inside the housing. The device 2 is the recording 48 assigned, so the test pins 4 . 6 the device 2 to the load contacts 36 . 38 of the charging plug 46 are arranged axially aligned. The test contacts 4 . 6 are therefore by means of a linear movement from a first position ( 10 ) into a second position ( 11 movable to a plug connection to the load contacts 36 . 38 train.

The test contacts 4 . 6 are therefore with the load contacts 36 . 38 of the charging plug 46 mechanically connectable, wherein the force measuring devices 8th . 10 the device 2 for measuring a pulling force when releasing the between the test contacts 4.6 and the load contacts 36 , 38 of the charging plug 46 formed, mechanical connector is set, so in the event that the load contacts 4.6 using the linear unit 18 from the second position ( 11 ) to the first position ( 10 ) be withdrawn.

The loading device 40 also has a locking device 50 , with a locking element 52 , wherein the locking device 50 to set up the charging plug 48 electromechanical in the receptacle 48 to lock, as far as a predetermined minimum force when checking the contact force between the test contacts 4 . 6 and the load contacts 36 . 38 of the charging plug 46 is fallen short of.

LIST OF REFERENCE NUMBERS

2

device

4

test contact

6

test contact

8th

Force measuring device

10

Force measuring device

12

axis

14

axis

16

supporting structure

18

linear unit

20

support plate

22

drive

24

baseplate

26

linear guide

28

compensation element

30

compensation element

32

holder

34

holder

36

load contact

38

load contact

40

loader

42

casing

44

charge cable

46

charging plug

48

admission

50

locking device

52

locking element

Claims (11)

Device for testing a contact force of an electromechanical connection, with at least one test contact (4, 6), - With at least one force measuring device (8, 10) for measuring axial forces and with at least one support structure (16), - wherein the force measuring device (8, 10) is fixed to the support structure (16) and - The test contact (4, 6) is attached to the force measuring device (8, 10). Device after Claim 1 , characterized in that the test contact (4, 6) is a test pin (4, 6) which is adapted for insertion into a sleeve-shaped load contact (36, 38) of an electric vehicle charging connector (46). Device after Claim 2 , characterized in that - the test pin (4, 6) has the same or a smaller diameter than the standard diameter of the sleeve-shaped load contact (36, 38) associated load contact pin of an electric vehicle and / or - the test pin (4, 6) at least in sections has a friction-reducing coating. Device according to one of Claims 1 to 3 , characterized in that the support structure (16) has at least one linear unit (18) for moving the test contact (4, 6) between at least one first position and at least one second position. Device after Claim 4 , characterized in that - the force measuring device (8, 10) on a support plate (20) of the support structure (16) is fixed, - a drive (22) of the linear unit (18) mounted on a base plate (24) of the support structure (16) and - between the support plate (20) and the base plate (24) is a linear guide (26) is formed. Device according to one of Claims 1 to 5 characterized in that - the force measuring means (8, 10) by means of an elastic compensating element (28, 30), such as a plastic buffer or the like, to the support structure (16) is attached and / or - the test contact (4, 6) by means of a Holder (32, 34) is positively and releasably attached to the force measuring device (8, 10). Device according to one of Claims 1 to 6 , characterized in that - at least two test contacts (4, 6) or exactly two test contacts (4, 6) are provided, - each test contact (4, 6) each having a force measuring device (8, 10) is associated. Device after Claim 5 and Claim 7 , characterized in that the force measuring means (8, 10) of the at least two test contacts (4, 6) or the exactly two test contacts (4, 6) are fastened to the support plate (20). Charging device for charging an electric vehicle, - with a housing (42), - with a charging cable (44), - with a charging plug (46) which is arranged on the end of the charging cable (44) and the at least one contact (36, 38) with a receptacle (48) formed on the housing (42) for holding the charging plug (46), with a device (2) for testing a contact force of an electromechanical connection according to any one of Claims 1 to 8th - wherein the device is associated with the receptacle (48), - wherein the test contact (4, 6) with the contact (36, 38) of the charging plug (46) is mechanically connectable, and - wherein the force measuring device for measuring - a pulling force during Releasing a mechanical connection formed between the test contact (4, 6) and the contact (36, 38) of the charging plug (46), and / or - an insertion force when establishing a between the test contact (4, 6) and the contact (36, 38) of the charging plug (46) formed, mechanical connection is established. Charger after Claim 9 , characterized in that - the loading device (40) has a locking device (50) with at least one locking element (50), such as a bolt or the like, - wherein the locking device (50) is adapted to the electromechanical charging plug (46) in the To lock recording (48), as far as a predetermined minimum force when checking the contact force between the test contact (4, 6) and the contact (36, 38) of the charging plug (46) is reached. Charger according to one of Claims 9 or 10 , characterized in that - that the test contact (4, 6), as far as the charging plug (46) is held in the receptacle (48), from a first position in which the test contact (4, 6) a distance to the contact ( 36, 38) of the charging plug (46), in the direction of the contact (36, 38) of the Charging plug (46) is movable to a second position to form a mechanical connection to the contact (36, 38) of the charging plug (46) and that the test contact (4, 6) from the second position in which the test contact ( 4, 6) is mechanically connected to the contact (36, 38) of the charging plug (46), is movable in the first position.

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