WO2022034167A1

WO2022034167A1 - Method and device for the contactless continuity check of a cable

Info

Publication number: WO2022034167A1
Application number: PCT/EP2021/072468
Authority: WO
Inventors: Peter Khu
Original assignee: Peter Khu
Priority date: 2020-08-13
Filing date: 2021-08-12
Publication date: 2022-02-17
Also published as: AT524105A1; EP4196801A1

Abstract

The aim of the invention is to provide a continuity check of a cable (1) comprising a conductor (3) and a plug connection (2) located at a first cable end (11) and having a plug recess (21) and a plug contact (22) located in the plug recess (21), the continuity check causing only low or no wear of the plug connection (2). The aim is achieved in that a test electrode (4) is positioned at the plug recess (21), and a highly exciting test signal (S) is generated at the test electrode (4), which test signal is transmitted contactlessly to the plug contact (22) in order to check the continuity of the cable (1).

Description

METHOD AND DEVICE FOR NON-CONTACT CONTINUITY TESTING OF A CABLE

The present invention relates to a method for testing the continuity of a cable with a conductor and a plug connection arranged at a first cable end of the cable, the plug connection comprising a plug recess and a plug contact arranged in the plug recess, which is electrically connected to the conductor. Furthermore, the present invention relates to a device for testing the continuity of a cable with a plug connection arranged at a first cable end of the cable with a plug recess in which a plug contact electrically connected to the conductor is arranged, and the use of the device for testing the continuity of at least one cable of a cable harness.

If two points are electrically connected with negligible electrical resistance, this is referred to as electrical continuity. It is often necessary to check the continuity of a cable having a conductor and an insulating jacket surrounding the conductor. One way of checking the continuity of a cable is to make electrical contact with the conductor at the first and second end of the cable and to measure the resistance between these points. For example, a voltage can be applied and it can be checked whether an electric current is flowing. However, cable ends are usually provided with plug-in connections, with which the conductor at the cable end cannot simply be contacted. Although the plug connections have plug contacts, which are each connected to the conductor, these plug contacts are located in a plug recess of the respective plug connection. In order to contact the conductor via the plug connection, the plug connection can be connected to a suitable socket, i.e. a complementary plug connection. The socket has socket contacts which are in physical contact with the plug connections and thus make electrical contact. When the connector is connected to the socket, however, wear occurs on the connector, which is to be avoided. Plug connections are often only designed for one-off connection with a socket. This connection must not be broken afterwards.

In particular when several cables are connected to form a cable harness, it is often not clear which cable end belongs to which cable end. Connected cable ends can thus be determined using a continuity test. If the continuity test between two cable ends is positive, it can be assumed that the two cable ends belong to the same cable. However, if the plug-in connections provided at the respective cable end are contacted by means of a complementary socket, wear also occurs on the plug-in connection. It is therefore an object of the present invention to specify a method and a device for testing the continuity of a cable, which causes little or no wear on the plug connections.

This object is achieved according to the invention by positioning a test electrode on the plug recess, a high-voltage test signal being generated at the test electrode, which is transmitted without contact to the plug contact in order to check the continuity of the cable. The object is also achieved by a device in which a test electrode that can be positioned on the plug recess is provided, with a signal generator connected to the test electrode also being provided, which is designed to generate a high-voltage test signal on the test electrode in order to a positioning of the test electrode on the plug recess to transmit the test signal without contact to the plug contact in order to check the continuity of the cable. It is therefore not necessary to insert the plug connection into a socket for the continuity test of the cable, which prevents the plug connection from closing. Furthermore, it is fundamentally not necessary for the plug contact to be physically contacted, e.g. by a test electrode.

In the context of the present invention, a high-voltage test signal is to be understood as meaning test signals with a voltage of at least 300V, or at least 1 kV, or at least 10 kV.

The test electrode can be spring-loaded. For this purpose, a base element can be provided, to which the test electrode is spring-connected. So that the test electrode can be positioned in the plug recess in a spring-loaded manner. However, the test electrode can also be connected to a base element in an unsprung manner.

The test signal is preferably high-frequency. Such a test signal can be transmitted particularly well without contact.

An arc is preferably ignited between the test electrode and the plug contact, which arc transmits the high-voltage test signal from the test electrode to the plug contact without contact. However, the arc ignited in this way does not cause any corrosion or other wear or other type of impairment on the plug connection. Accordingly, the signal generator can be designed, for example, to generate a high-frequency and high-voltage test signal.

Strong field strengths between the test electrode and the plug contact are primarily required for the stated ignition of an arc between the test electrode and the plug contact. It should be noted that with small distances between the test electrode and the plug contact, for example in the range of less than 10mm, or less than 5mm, or less than 1mm, even a low voltage of the test signal can cause an arc to ignite. For example, with a distance of 1mm between the test electrode and the plug contact, a voltage of 300V can be sufficient to ignite an arc.

In the context of the invention, a high-frequency test signal is to be understood, for example, as a test signal with a test frequency in the range from 3 kHz to 100 GHz, preferably 10 kHz to 100 MHz, particularly preferably 30 kHz to 300 kHz.

In principle, however, the test signal can also have a low frequency. In the context of the invention, a low-frequency test signal is to be understood, for example, as a test signal with a test frequency of 3 Hz to 3 kHz, preferably 30 Hz to 3 kHz.

However, the test signal can also have a test frequency in the range from 3 Hz to 30 kHz, for example.

It is also conceivable for the test signal to be in the form of a pulsating, preferably periodically pulsating, DC voltage.

The test signal can be applied between the plug contact and another point of the cable, it being checked whether the test signal flows between the plug contact and the further point of the cable. If so, the continuity test is positive. If it is determined that the test signal does not flow from the plug contact to the further point of the cable, the continuity test is negative.

The test signal is preferably applied between the plug contact and a second cable end of the cable, it being particularly advantageous if a further test electrode is positioned in a further plug recess of a further plug connection arranged at the second cable end, with the test signal on the further test electrode being transmitted without contact to an in the second plug recess arranged plug contact, which is electrically connected to the conductor, is transferred to check the continuity of the cable. A further test electrode can thus be provided, which can be positioned in a further plug recess of a second plug-in connection arranged on a second cable end of the cable. Correspondingly, the signal generator is connected to the further test electrode in order to transmit the test signal at the further test electrode without contact to a further plug contact arranged in the further plug recess in order to check the continuity of the cable.

The test signal is therefore applied between the test electrode and the additional test electrode and is transmitted without contact from the test electrode to the plug contact and from the additional test electrode to the additional plug contact - provided the components mentioned are electrically connected to one another. This will be the test signal So also transferred between the plug contact and the other plug contact - if they are electrically connected to each other. The continuity test of the cable thus determines whether the plug contact is electrically connected to the other plug contact via the conductor. If the signal flows after application, the continuity test is positive. If the signal does not flow after application, the continuity test is negative.

The test electrode preferably has a radial electrode diameter at at least one point which is larger than a minimum cutout diameter of the plug cutout. In this way it can be prevented that the test electrode penetrates completely into the plug recess, with which it can be ensured that the test electrode touches the plug contact - which is undesirable.

The device according to the invention and the method according to the invention can be used to check the continuity of at least one cable of a cable harness. In a wiring harness, it is often not clear which cable ends belong to which cable. A cable can, for example, also have several cable ends, e.g. if the cable branches in a Y-shape or X-shape. The cable ends of a cable harness (or at least a majority of the cable ends of a cable harness) are each provided with plug connections, which each include plug contacts in plug recesses. In order to determine which cable ends belong to one another, it is possible to check which plug contacts are electrically connected to one another. For this purpose, a test electrode can be arranged on each of the plug recesses. Furthermore, a test signal can be applied in each case between two or more test electrodes, for example via a switching matrix, in order to determine the respective passage. If it is determined that the test signal flows between two or more test electrodes, the continuity test of the cable ends on which the test electrodes are arranged is positive. This can be used to determine which cable ends belong to which cable. The respective test signals can be applied between two or more cable ends simultaneously or alternately.

The present invention is explained in more detail below with reference to FIGS. 1 to 3, which show advantageous configurations of the invention by way of example, schematically and not restrictively. while showing

1 shows a cable with a plug connection

2 shows a test electrode arranged on a plug recess 3 shows a cable with two plug connections and test electrodes arranged on the respective plug recesses.

1 shows a longitudinal section through a cable 1 with a conductor s and a plug connection 2 , the conductor 3 being surrounded by an insulating jacket 30 . The plug connection 2 has a plug recess 21 and is connected to a first cable end 11 of the cable 1 . The plug recess 21 is arranged pointing away from the cable 1 so that it can be connected to a socket 8 . A plug contact 22 is provided in the plug recess 21 and is electrically connected to the conductor 3 . The plug contact 22 can also be formed by a part of the conductor 3, e.g. a first end of the conductor 3.

1 shows a socket 8 that fits the plug connection 2 , the socket having a socket recess 81 and a socket contact 82 arranged in the socket recess 81 . The socket recess 81 is designed to accommodate at least part of the plug connection 2 . If the plug connection 2 is inserted into the socket recess 81, the socket contact 81 is also inserted into the plug recess 21 and the socket contact 81 makes electrical contact with the plug contact 22 of the plug connection 2 and thus also with the conductor 3. Connection elements 83 are often provided on the socket 8, which connect the plug connection 2 firmly to the socket 8 when the plug connection 2 is inserted into the socket 8, for example by latching onto the plug connection 2, as is shown by way of example in FIG.

In order to check the passage of a cable 1, the plug contact 22 has hitherto been contacted directly with a test contact. A socket 8, as described above, is often used for this purpose, with the socket contact 82 serving as a test contact. In the case of a direct, physical contact with a test contact and in particular when the socket 8 is separated from the plug connection 2, however, the plug connection 2 is heavily used and experiences a certain amount of wear. If connecting elements 83 are provided, which snap into place when the plug-in connection 2 is connected to the socket 8, these connecting elements 83 must be released from the socket 8 when the plug-in connection 2 is disconnected. Many plug connections 2 are only designed for a one-off connection with a socket 8, which must not be released afterwards. Thus, a continuity test by connecting the plug connection 2 to a socket 8 is not advantageous.

Therefore, according to the invention, as shown in FIG. 2, a test electrode 4 is provided, which is positioned on the plug recess 21. A signal generator 5 generates at the Test electrode 4 a high-voltage test signal S, which is transmitted without contact to the plug contact 22 to check the passage of the cable 1. In contrast to the prior art, there is no direct, physical contact between the plug contact 22 and a test contact in order to transmit a test signal S via the plug contact 22 to the conductor s, but rather a non-contact transmission of the test signal S from a test electrode 4 to the plug contact 22 .

The test electrode 4 can be spring-mounted on a base element (not shown). The base element can also include the signal generator 5

The test electrode 4 preferably has a radial electrode diameter at least at one point, which is larger than the minimum opening diameter of the plug opening 21 . This can prevent the test electrode 4 from penetrating too far into the plug recess 21 and, in the worst case, touching the plug contact 22 . The test electrode 4 can have a round electrode end, as shown in FIG. 2, but test electrodes 4 that have a pointed electrode end, for example, are also conceivable. It is only important that the test electrode 4 is suitable for transmitting the test signal S to the plug contact 22 without contact.

It is particularly advantageous if the test signal S is high-frequency and high-voltage. According to a particularly advantageous embodiment of the method according to the invention, an arc 6 is ignited between the test electrode 4 and the plug contact 22, with the arc 6 ensuring the contactless transmission of the test signal S from the test electrode 4 to the plug contact 22. It has been shown that an arc 6 does not cause any significant corrosion or other damage to the plug contact 22 or impair the function of the plug contact 22 .

Although voltages of 1kV or more are often used to ignite an arc 6, with small distances between test electrode 4 and plug contact 22, for example in the range of less than 10mm, or less than 5mm, or less than 1mm, lower voltages of the Test signal S, for example 500V, or 300V, bring about an ignition of an arc 6. With a distance of 1 mm between the test electrode 4 and the plug contact 22, a voltage of 300 V can already be sufficient to ignite an arc 6 under suitable conditions.

The test signal S can be applied between the plug contact 22 and another point of the cable 1. For this purpose, only at this further point of the cable 1 the conductor 3 must be electrically contacted (directly or without contact). If it is determined that the test signal S flows between the plug contact 22 and the further point of the cable after it has been applied, the continuity test is positive. The test signal S preferably represents an alternating voltage, which is particularly preferably high-voltage and high-frequency. Applying the test signal S thus means applying the AC voltage. The flow or transmission of the test signal S correspondingly means a flow of an alternating current. As part of the continuity test, the test signal S (an alternating voltage) is applied and it is checked whether the test signal S (an alternating current) is flowing.

For example, the test signal S can be applied between the plug contact 22 and a second cable end 12 of the cable 1 . If the second cable end 12, as shown in FIG. 3, is provided with a further plug connection 2', a further test electrode 4' can be positioned in a further plug recess 21' of the further plug connection 2'. A further plug contact 22', which is electrically connected to the conductor 3, is arranged in the further plug recess 21'. The further plug contact 22 can also be formed by a part of the conductor 3, for example a second end of the conductor 3.

The further test electrode 4' can be spring-mounted on a base element (not shown). The test electrode 4 and the further test electrode 4' are preferably spring-mounted on the same base element. The base element can include the signal generator 5 .

The test signal S can thus be applied by the signal generator 5 between the test electrode 4 and the further test electrode 4'. In this case (if there is continuity), the test signal S is transmitted without contact not only from the test electrode 4 to the plug contact 22, but also to the further test electrode 4' to the further plug contact 22'. A further arc 6' can form between the further test electrode 4' and the further plug contact 22'. The circuit of the test signal S is thus from the signal generator 6 via the test electrode 4 (possibly the arc 6), the plug contact 22, the conductor 3, the further plug contact 22' (possibly the further arc 6'), the further test electrode 4' and again the signal generator 5 is closed - in this case the continuity test is positive.

A use of the method according to the invention and the device according to the invention for continuity testing of cables 1 of a cable harness is particularly advantageous. In a cable harness, it is often not clear which cable ends 11 , 12 belong to which cable 1 . To determine which cable ends 11, 12 are electrically connected to one another, a respective test electrode 4 can be arranged on plug recesses 21, 2T of the associated plug connections 2, 2'. Furthermore, a respective test signal S can be applied, for example via a switching matrix, between two or more test electrodes 4, 4' in order to determine the continuity between two cable ends 11, 12. this can be done simultaneously or alternately. The respective test signals S for different cables 1 can be encoded differently in order to be able to assign the cable ends 11, 12 of the cable 1 in question that are connected to one another.

Claims

patent claims

1. Method for testing the continuity of a cable (1) with a conductor (3) and a plug connection (2) arranged at a first cable end (11) of the cable (1), the plug connection (2) having a plug recess (21) and an in plug contact (22) which is arranged in the plug recess (21) and is electrically connected to the conductor (3), characterized in that a test electrode (4) is positioned on the plug recess (21), and in that on the test electrode (4) a high-voltage test signal (S) is generated, which is transmitted without contact to the plug contact (22) in order to check the continuity of the cable (1).

2. The method according to claim 1, characterized in that the high-voltage test signal (S) is high-frequency.

3. The method according to claim 1 or 2, characterized in that an arc (6) is ignited between the test electrode (4) and the plug contact (22), the arc (6) being used for the non-contact transmission of the high-voltage test signal (S) from the test electrode (4) on the plug contact (22).

4. The method according to any one of claims I to 3, characterized in that the high-voltage test signal (S) is applied between the plug contact (22) and another point of the cable (1) and it is checked whether the test signal (S) is between the plug contact (22) and the further point of the cable (1) flows.

5. The method according to claim 4, characterized in that the high voltage test signal (S) between the plug contact (22) and a second cable end (12) of the cable (1) is applied.

6. The method according to claim 5, characterized in that a further test electrode (4') is positioned in a further plug recess (21') of a further plug connection (2') arranged on the second cable end (12), and that the high-voltage test signal (S ) is transmitted via the further test electrode (4') to a plug contact (22) which is arranged in the second plug recess (21) and is electrically connected to the conductor (1), in order to check the continuity of the cable (1).

7. Device for testing the continuity of a cable (1) with a plug connection (2) arranged at a first cable end (11) of the cable (1) and having a plug recess (21), in which a plug contact (22 ) is arranged, characterized in that a test electrode (4) which can be positioned on the connector recess (21) is provided, and that a with

-9- a signal generator (5) connected to the test contact (4) is provided, which is designed to generate a high-voltage test signal (S) at the test electrode (4) in order to generate the high-voltage test signal when the test electrode (4) is positioned on the plug recess (21). (S) to be transferred without contact to the plug contact (22) in order to check the continuity of the cable (1).

8. The device according to claim 7, characterized in that the signal generator (5) is designed to generate a high-frequency, high-voltage test signal (S).

9. Device according to claim 7 or 8, characterized in that the signal generator (5) is designed to ignite an arc (6) between the test electrode (4) and the plug contact (22), the arc (6) for the non-contact Transmission of the test signal (S) from the test electrode (4) to the plug contact (22) ensures.

10. Device according to one of claims 7 to 9, characterized in that the test electrode (4) has at least one point a radial electrode diameter which is greater than a minimum recess diameter of the plug recess (21).

11. Device according to one of Claims 7 to 10, characterized in that a further test electrode (4'), which is connected to a further plug recess (21') of a second plug-in connection (2 ') can be positioned, is provided, and that the signal generator (5) is connected to the further test electrode (4') in order to transmit the high-voltage test signal (S) at the further test electrode (4') without contact to a plug recess (22 ') Arranged to transfer further plug contact (22') to check the passage of the cable (1).

12. Use of the device according to one of claims 7 to 11 for continuity testing at least one cable (1) of a cable harness.