cable coupling

Abstract

The invention relates to a line coupling (1) for electrical or fluidic lines (8), comprising at least two detachably connectable coupling parts (11, 12), which are designed to be attached to one end of a line (8) and which have mutually corresponding coupling elements (2) which can be brought into engagement with one another to establish a connection between the at least two lines (8), wherein the coupling parts (11, 12) enclose a test chamber (13) in the connected state, a displacement means (3) for the targeted reduction of the test chamber (13) is arranged on or in the test chamber (13), and a test means (4) for detecting a leak is arranged on or in the pressure chamber (13).The displacement means (3) comprises a screw (32) which is arranged on or in at least one coupling part (11, 12) in such a way that it reduces or enlarges the test space (13) depending on the direction of rotation when it is rotated.

Description

The invention relates to a line coupling for electrical or fluidic lines according to the preamble of claim 1.Electrical lines can comprise, for example, individual electrical conductors or electrical cables, i.e. a plurality of electrical conductors connected to one another in a conductor strand. Fluidic lines may comprise, for example, rigid tubes or flexible hoses configured to carry a fluid, i.e. a gas such as air or the like, or a liquid such as water or the like. For manufacturing reasons, electrical and fluidic lines are usually composed of two or more part lines, wherein the ends of the part lines are connected to one another by line couplings, which are designed, for example, as plug connectors. Similarly, electrical and fluidic conduits are connected to sources and sinks of the streams of energy transported through the conduits by conduit couplings. It is obvious that the line coupling must be tight for a reliable function against the ingress and egress of substances, in particular water.At present, electrical line couplings on high-voltage batteries, which are usually designed as releasable plug connections, can no longer be checked for tightness after contacting in the vehicle. This means that a tightness requirement can only be checked before installation on the individual part. The actual final connection can no longer be checked later. On the market, no plug concept is known which can be checked locally for tightness in the vehicle. A leak-tightness test of the final connection, especially for HV connectors, is not possible with any known concept.DE 10 2016 107 216 A1 discloses a device for checking the tightness of a component of a cable harness for a vehicle. The device has at least one fluid-tight test container for fluidic communication or at least partial accommodation of the component and / or of the cable harness, and at least one test adapter which is configured for closing the test container in a cover-like manner and for connecting or threading the component through it in such a way that the component is fluidically connected to the interior of the test container or a first part is arranged in the interior of the test container and a second part is arranged on an outer side of the test container. The device further comprises a pump which is configured to generate a negative test pressure within the test container, and a control device which is configured to actuate the pump and to monitor the negative test pressure within the test container.DE 10 2019, 219 220 A1 describes a device for carrying out a leak-tightness test of an electrical component, having at least one control unit, a gas sensor connected to the control unit, wherein gases emerging from the electrical component can be measured by the gas sensor. Furthermore, a method for carrying out a leak test, an electrical component, and a method for producing an electrical component are disclosed.DE 21 2013 000 072 U1 describes a plug connector element for connecting to a mating mating element in order to close contacts and mating contacts of a line, wherein the plug connector element has a housing with a sliding surface, wherein a clamping device is arranged on the housing, wherein the clamping device can be switched between a clamping position and a release position, wherein the clamping device comprises a clamping element arranged in the region of the sliding surface for pressing against a mating surface of the mating element that is mating with the sliding surface, wherein the clamping element is arranged completely within a depression of the housing in the release position, wherein the clamping element projects out of the depression in the clamping position, the clamping device comprises an actuating element for switching between the release position and the clamping position, wherein the clamping device comprises a shaft, the shaft is rigidly connected to the clamping element and the actuating element, and the clamping device is formed in one piece. CN 1 15 313 108 A relates to the technical field of communication links and discloses a self-testable communication link.WO 2008 / 092 783 A1 relates to a device for monitoring the tightness of a line, having a casing which encloses the line and a cavity which is at least partially guided around the line, and having a sensor for monitoring the cavity. In order to be able to monitor a plurality of lines cost-effectively and reliably, it is proposed that the sensor be arranged in the cavity and the cavity be surrounded in a pressure-tight manner by the casing.It is an object of the present invention to specify a line coupling for electrical or fluidic lines, the tightness of which can be checked at any time, i.e. in particular also in the installed state, for example at a poorly accessible location.The object is achieved according to the invention by a line coupling for electrical or fluidic lines, which comprises at least two coupling parts which can be detachably connected to one another and which are designed to be attached to one end of a line in each case and which have mutually corresponding coupling elements which can be brought into engagement with one another in order to produce a connection between the at least two lines. In such a line coupling, it is proposed according to the invention that the coupling parts are designed such that, in the connected state, they enclose a test chamber, that a displacement means for the targeted reduction in size of the test chamber is arranged on or in the test chamber, and that a test means for detecting a leak is arranged on or in the pressure chamber. The displacement means comprises a screw which is arranged on or in at least one coupling part in such a way that, depending on the direction of rotation, it reduces or increases the test space when it is rotated.Where the ends of two conduits are to be connected together, conduit couplings are used which comprise at least two coupling parts, each of which is attached to the end of one of the two conduits. The coupling parts have mutually corresponding coupling elements. Correspondingly, in this context, the coupling elements are designed such that they can be brought into engagement with one another in a manner such that they produce a permanent connection between the two lines to be connected. Here, permanently does not mean that the connection must be non-detachable. On the contrary, many line couplings are designed such that they can be opened if necessary, i.e. the two coupling parts can be detached from one another again without destruction. For this purpose, the coupling elements can be designed, for example, as latching noses of a coupling part, which latch behind corresponding latching noses or in latching recesses of the other coupling part and thus secure the connection of the coupling parts. In other embodiments, the coupling elements can be designed, for example, as an external thread of one coupling part and a corresponding internal thread of the other coupling part or of a union nut belonging to the other coupling part. In further embodiments, the coupling elements can be designed as a bayonet lock, the components of which are arranged on the two coupling parts in a manner known per se. Other possible designs of the line coupling are Storz couplings, Perrot couplings, Gardena couplings, etc., without the scope of application of the invention being limited to the designs mentioned.The solution to the problem underlying the invention consists in that a test space is created in the interior of the line coupling, i.e. when the coupling parts are connected to one another, in which test space a displacement means is provided in order to generate an internal pressure in the test space which is increased with respect to the surrounding air pressure. If the connection of the coupling parts of the line coupling is tight, this increased internal pressure remains above a defined limit value over a defined time. If, on the other hand, the connection of the coupling parts of the line coupling is tight, the internal pressure of the test chamber falls below a defined limit value over a defined time. This change in internal pressure by escape of air can be indicated or made measurable by a test means.The solution proposed according to the invention makes it possible for the first time to perform 100% testing of critical plug connections in the final state, i.e. for example in a vehicle. Leakage can be directly detected. This can be eliminated or the product can be discharged.Advantageous embodiments of the invention are the subject matter of the dependent claims.According to the invention, a displacement means for targeted reduction in size of the test space is arranged on or in the test space.According to the invention, it is provided that the displacement means comprises a screw which is arranged on or in at least one coupling part in such a way that it reduces or increases the test space as a function of the direction of rotation when it is rotated. This embodiment is particularly simple in construction, very inexpensive and robust.According to another embodiment, it can be provided that the displacement means comprises a piston which is arranged movably on or in at least one coupling part in such a way that it reduces or increases the test space as a function of the direction of movement when it is moved. With this embodiment, a greater increase in the internal pressure of the test chamber relative to the ambient pressure can be achieved. The piston advantageously has a sealing arrangement with which it sealingly abuts boundary walls of the test chamber.The piston can be arranged, for example, on or in a coupling part in such a way that, when the coupling parts are connected, for example by a relative movement of the coupling parts connected thereto and thus without further intervention by the engineer, apart from additional force exertion, it is displaced in the test space and thus reduces the test space and thereby increases the internal pressure of the test space.In a further embodiment, it can be provided that a carrier pin is arranged on or in a first coupling part. It can furthermore be provided that one or more pistons are arranged on one or more carrier pins and can be displaced back and forth thereon. The carrier pin can furthermore have a sealing arrangement with which it sealingly abuts boundary walls of the test space. The carrier pin can, for example, if it is a line coupling for electrical lines, carry at a free end electrical contacts which are electrically contacted when the coupling parts are connected to electrical contacts of the other coupling part.According to one embodiment, it can be provided that the test means comprises a pressure indicator which is designed to visually indicate a change in an internal pressure prevailing in the test space. In this way, it can be immediately detected by the assembler of the line coupling whether the connection is tight or whether a fault correction measure has to be initiated. This can also be checked by an external sensor system. In a simple embodiment, the pressure indicator can comprise an indicator element which is designed to be moved by the change in the internal pressure prevailing in the test space. Such a display element can be, for example, a resiliently mounted pin which is held in a first position counter to the force of a spring element by the increased internal pressure of the test chamber. If air, test gas or protective gas escapes from the test space and the internal pressure thus falls, the force of the spring element displaces the pin into a second position, which can be optically distinguished from the first position. Alternatively, such a display element can be, for example, a resiliently mounted disk with a marking which is held in a first position counter to the force of a spring by the increased internal pressure of the test chamber. When air escapes from the test chamber and the internal pressure thus falls, the force of the spring rotates the disk into a second position, which can be optically distinguished from the first position by the marking. Many other configurations for such pressure indicators are conceivable and can be used for carrying out the invention.In a further embodiment, it can alternatively or additionally be provided that the pressure indicator comprises a light element which is designed to be switched on or off by the change in the internal pressure prevailing in the test space. For example, a light emitting diode (LED) can be turned off or on by a pressure switch when the internal pressure in the test space rises or falls.Alternatively or additionally, it can be provided in various configurations that the test means comprises a pressure or flow sensor which is designed to generate a signal which can be evaluated by measurement if a change in the internal pressure prevailing in the test space or a volume or mass flow out of the test space is detected. The measurement signals generated by such sensors can be evaluated by an evaluation unit and lead to a dichotomic decision as to whether the line coupling is tight or leaky. Such an evaluation unit can be permanently arranged, for example, as a monitoring module and can be linked to one or more such sensors. Alternatively, the evaluation unit can be a diagnostic tool which is used only as required and is used in quality control or fault diagnosis and is then removed again.Exemplary embodiments of the invention are explained in more detail below with reference to drawings.The following are shown: FIG. 1 shows a first exemplary embodiment of a line coupling, and FIG. 2 shows a second exemplary embodiment of a line coupling according to the invention.FIG. 1 shows a first exemplary embodiment of a line coupling 1 having a first coupling part 11 and a second coupling part 12 which can be connected to one another in order to produce an electrical contact between electrical lines 8. For this purpose, both coupling parts 11, 12 have mutually corresponding coupling elements 2, which in the exemplary embodiment are designed as latching lugs 21 which engage one behind the other. The first coupling part 11 is mounted at the end of a line 8 which is to be electrically connected to another component, for example a vehicle battery. To the other component, which is not shown in the figure, the second coupling part 12 is fixedly attached. Both coupling parts 11, 12 have on their mutually facing sides electrical contacts 7 which are contacted with one another when the coupling parts 11, 12 are connected to one another. In this case, a test space 13 is formed in the interior of the line coupling 1, which test space is intended to serve according to the invention for the tightness test of the line coupling 1.The first coupling part 11 has a carrier pin 6, which has a piston-like thickening 61 at its free end facing the second coupling part 12, on the outer circumference of which a seal 5 is arranged. This seal 5 seals the piston-like thickening 61 of the carrier pin 6 against the outer wall of the test chamber 13 when the coupling parts 11, 12 are connected to one another. On the end face of the carrier pin 6, there are electrical contacts 7 which come into electrical contact with corresponding electrical contacts 7 of the second coupling part 12 when the line coupling 1 is closed.A displacement means 3, which is designed as a hollow cylindrical piston 31, is displaceably mounted on the cylindrical carrier pin 6. The piston 31 has a seal 5 both on its outer circumference and on its inner circumference, as a result of which the piston 31 is sealed against the outer wall of the test chamber 13 on the one hand and against the carrier pin 6 on the other hand.In the piston 31, a test means 4, which is designed as a pressure sensor 41 in the exemplary embodiment, is also arranged, which is exposed to the internal pressure of the test chamber 13 and thus makes any pressure change measurable. For this purpose, the pressure sensor 41 is connected to an evaluation unit arranged outside the test space 13.Due to the arrangement of the seals 5 integrated in the coupling region, a test space 13 is created when the coupling parts 11, 12 are connected. When connecting the coupling parts 11, 12, the test chamber 13 is reduced by the movable displacement means 3, i.e. by displacement of the piston 31 relative to the piston-like thickening 61 of the carrier pin 6, and a test pressure, i.e. an internal pressure increased with respect to the ambient pressure, is thus generated. The pressure sensor 41 is exposed to this increased internal pressure, which is capable of indicating a signal that can be evaluated by measurement in the event of a pressure change, or of transmitting it to an external evaluation unit, so that a decision can be made about the tightness of the line coupling 1.Alternatively, instead of a pressure sensor 41, a pressure measuring foil (not shown), a flow sensor (not shown) or a pressure indicator 42 (not shown) can also be used. A spring-mounted display element, such as a pin or a disk, an LED or another illuminant, can be used as the pressure indicator 42, for example. The display of an external evaluation unit can also be used as a pressure indicator 42.If the increased internal pressure of the test chamber 13 is kept long enough above a predefined limit value, the connection is to be evaluated as functionally tight. If, on the other hand, the pressure in the test space 13 falls more quickly than a defined limit value within a predefined period of time, it is possible to infer an leaking connection and to follow an n.i.o. strategy. When using a flow sensor, a volume or mass flow, optionally also an electrical voltage value, is defined as a limit value.FIG. 2 shows a second exemplary embodiment of a line coupling 1 having a first coupling part 11 and a second coupling part 12 which can be connected to one another in order to produce electrical contact between electrical lines 8. For this purpose, both coupling parts 11, 12 have mutually corresponding coupling elements 2, which in the exemplary embodiment are designed as latching lugs 21 which engage one behind the other. The first coupling part 11 is mounted at the end of a line 8 which is to be electrically connected to another component, for example a vehicle battery. To the other component, which is not shown in the figure, the second coupling part 12 is fixedly attached. Both coupling parts 11, 12 have on their mutually facing sides electrical contacts 7 which are contacted with one another when the coupling parts 11, 12 are connected to one another. In this case, a test space 13 is formed in the interior of the line coupling 1, which test space is intended to serve according to the invention for the tightness test of the line coupling 1.The first coupling part 11 has a carrier pin 6, which has a piston-like thickening 61 at its free end facing the second coupling part 12, on the outer circumference of which a seal 5 is arranged. This seal 5 seals the piston-like thickening 61 of the carrier pin 6 against the outer wall of the test chamber 13 when the coupling parts 11, 12 are connected to one another. On the end face of the carrier pin 6, there are electrical contacts 7 which come into electrical contact with corresponding electrical contacts 7 of the second coupling part 12 when the line coupling 1 is closed.The first coupling part 11 has, at its end facing the line 8, i.e. facing away from the second coupling part 12, a displacement means 3 which is designed as a screw 32 which can be screwed into the first coupling part 11 or out of the first coupling part 11. The screw 32 has a seal 5 on its outer periphery, whereby the screw 32 is sealed against the threaded bore 33 provided in the first coupling part 11.In the first coupling part 11 there is also arranged a test means 4, which in the embodiment is designed as a pressure indicator 42 in the form of a spring-mounted pin, which is exposed on the one hand to the internal pressure of the test chamber 13 and on the other hand to the ambient pressure and thus indicates any pressure change by a visible displacement in the first coupling part 11. However, a spring-mounted disk (not shown), an LED (not shown) or another lighting means (not shown) can also be used as the pressure indicator 42.Due to the arrangement of the seals 5 integrated in the coupling region, a test space 13 is created when the coupling parts 11, 12 are connected. After the coupling parts 11, 12 have been connected, the test space 13 is reduced by the movable displacement means 3, i.e. by turning the screw 32, and a test pressure, i.e. an internal pressure increased with respect to the ambient pressure, is thus generated. The pressure indicator 42 is exposed to this increased internal pressure, which changes its position in a visually visible manner when the differential pressure between the test chamber 13 and the environment changes, so that a decision can be made about the tightness of the line coupling 1.Alternatively, instead of a pressure indicator 42, a pressure sensor 41 (not shown), a pressure measuring foil (not shown) or a flow sensor (not shown) can also be used.If the increased internal pressure of the test chamber 13 is kept long enough above a predefined limit value, the connection is to be evaluated as functionally tight. If, on the other hand, the pressure in the test space 13 falls more quickly than a defined limit value within a predefined period of time, it is possible to infer an leaking connection and to follow an n.i.o. strategy. When using a flow sensor, a volume or mass flow, optionally also an electrical voltage value, is defined as a limit value.List of reference characters1 Line coupling 11 First coupling part 12 Second coupling part 13 Test chamber 2 Coupling element 21 Latching nose 3 Displacement means 31 Piston 32 Screw 33 Threaded bore 4 Test means 41 Pressure sensor 42 Pressure indicator 5 Seal 6 Carrier pin 61 Piston-like thickening 7 Electrical contact 8 Line

Claims

Line coupling (1) for electrical or fluidic lines (8), comprising at least two coupling parts (11, 12) which can be detachably connected to one another, - which are designed to be attached to one end each of a line (8) and - which have mutually corresponding coupling elements (2) which can be brought into engagement with one another in order to produce a connection between the at least two lines (8), wherein - the coupling parts (11, 12), in the connected state, enclose a test space (13), - a displacement means (3) for the targeted reduction in size of the test space (13) is arranged on or in the test space (13), and - a test means (4) for detecting a leak is arranged on or in the test space (13), characterized in that the displacement means (3) comprises a screw (32) which is arranged on or in at least one coupling part (11, 12) in such a way, that it reduces or increases the test space (13) as a function of the direction of rotation when it is rotated.Line coupling (1) according to Claim 1, characterized in that the test means (4) comprises a pressure indicator (42) which is designed to visually indicate a change in an internal pressure prevailing in the test space (13).Line coupling (1) according to Claim 2, characterized in that the pressure indicator (42) comprises an indicator element which is designed to be moved by the change in the internal pressure prevailing in the test space (13), and / or the pressure indicator (42) comprises a luminous element which is designed to be switched on or off by the change in the internal pressure prevailing in the test space (13).Line coupling (1) according to one of Claims 1 to 3, characterized in that the test means (4) comprises a pressure sensor (41) or a flow sensor which is designed to generate a signal which can be evaluated by measurement technology if a change in the internal pressure prevailing in the test space (13) or a volume or mass flow out of the test space (13) is detected.Line coupling (1) according to one of Claims 1 to 4, characterized in that the displacement means (3) comprises a piston (31) which is arranged movably on or in at least one coupling part (11, 12) in such a way that it reduces or increases the test space (13) as a function of the direction of movement when it is moved.Line coupling (1) according to Claim 5, characterized in that the piston (31) has at least one seal (5), with which it bears sealingly against boundary walls of the test space (13).Line coupling (1) according to claim 5 or 6, characterised in that a carrier pin (6) is arranged on or in a first coupling part (11), and the piston (31) is arranged on the carrier pin (6) and is displaceable back and forth thereon.Line coupling (1) according to claim 7, characterised in that the carrier pin (6) has at least one seal (5), with which it sealingly abuts boundary walls of the test space (13).Line coupling (1) according to claim 7 or 8, characterised in that the carrier pin (6) carries at a free end electrical contacts (7) which are electrically contacted when the coupling parts (11, 12) are connected to electrical contacts (7) of the second coupling part (12).

Images