EP3911502B1 - Crimping device and method for monitoring the state of its pressing elements - Google Patents

Description

The invention relates to a method for monitoring the condition of a crimping device and a crimping apparatus suitable for carrying out the method. The invention particularly relates to a method using a sensor system for measuring the travel of pressing elements of a crimping device.

Crimping involves using a forming tool to join two components together through plastic deformation using a pressing force. This creates a crimp, i.e., a mechanical connection that is difficult to break between a conductor and a connecting element, such as a plug or sleeve.

When crimping, high-quality crimping is desirable to ensure a durable, mechanically and electrically stable connection between the crimped components. A poor crimp quality can be caused, in particular, by a faulty crimp blank, by operating errors in a crimping device, such as an incorrectly set crimp height, and, in particular, by wear of the pressing elements.

Quality assurance of a crimp connection is usually carried out by measuring the crimp depth, by visually assessing a micrograph and/or by force/displacement monitoring during crimping.

State of the art

The WO 2012/110310 A1 proposes the aforementioned force/displacement monitoring during crimping. A crimp blank is plastically deformed by a forming tool. Specifically, when the forming tool retracts, both the force exerted by the forming tool on the crimp blank and the distance the forming tool moves are measured using a sensor. A change in displacement between a position at maximum force and a position initially free of force is used as an indicator of elastic recovery of the crimp blank. This indicator is proposed as a measure of the quality of the produced crimp.

The WO 2012/110310 A1 The proposed method is not suitable for determining a possible cause of crimping with undesirable quality.

The EP 2 313 235 B1 proposes a method for monitoring the wear of a hand-held pliers in which pressing elements can be pressed onto a workpiece and a pressing dimension to be achieved by actuating the hand-held pliers can be set using a presetting device. The method records a reference position and a wear position of the presetting device when the pressing elements are unworn or in use. When the hand-held pliers are actuated, the pressing elements are brought into a position corresponding to the reference pressing dimension by adjusting the presetting device. Comparing the wear position with the reference position provides a wear measurement.

The presetting device is adjusted using a knurled screw, the rotation of which is measured by an incremental encoder.

From the US 4,916,810 A A method and apparatus for terminating a plurality of wires to a plurality of terminals in an automated machine system is known, in which a high-quality crimp is to be maintained by monitoring the quality of a crimp and automatically adjusting machine elements. In the method, coded information indicating a predetermined crimp height is manually entered into the machine. In response to this input, the machine automatically adjusts the height of an anvil above a base. During a subsequently performed crimp, force and ram position data elements are collected and recorded for various incremental values. The crimp height of the current terminal is determined and compared to the set crimp height.

If the crimp height is outside a tolerance threshold, a reject signal is generated, and the machine is automatically reset. If the tolerance threshold is not exceeded, an acceptance signal is generated, and a comparison is made between the predetermined crimp height and the crimp height of some actual crimps. This determines whether a trend of approaching the tolerance threshold and exceeding it can be detected. If such a trend is present, the machine is automatically reset.

From the EP 3 396 796 A1 A pressing, crimping, or cutting tool with two components arranged in the force flow of the pressing, crimping, or cutting tool is known. An elastic support element and a sensor are arranged in mechanical parallel connection between the components, so that the sensor and the elastic support element experience correlated deflections as a result of an acting working force, and the stiffness of the elastic support element is dimensioned such that, at the maximum acting working force of the pressing, crimping, or cutting tool, the sensor experiences a maximum deflection of at least 0.05 mm or at least 1°. For this purpose, the pressing, crimping, or cutting tool can have an electronic control unit equipped with control logic for evaluating a measurement signal from the sensor, which enables calibration of the pressing, crimping, or cutting tool for machining operations. In this process, one or more calibration strokes are initiated, and the measurement signal from the sensor is recorded during at least one calibration stroke. From this, representative data, a calibration factor, a calibration curve, a characteristic map, or an offset are determined from at least one sensor measurement signal and/or representative fluctuations from several sensor measurement signals recorded during several calibration strokes. The representative data, the calibration factor, the calibration curve, the characteristic map, and/or the representative fluctuations are used to assess the quality of machining operations with the pressing, crimping, or cutting tool after calibration has been completed.

The EP 1071173 A2 relates to a terminal crimping quality evaluation device for determining the quality of a terminal crimped to a core of an electric wire by means of a terminal crimping device. The device uses a reference value envelope of characteristic values obtained when a terminal is correctly crimped to the core and a characteristic value envelope obtained when the terminal is crimped to the core.

Task

The object of the invention is to provide a method for monitoring the condition of a crimping device and a device suitable for carrying out the method. The object of the invention is to provide a method for monitoring the condition of pressing elements of an indent crimping device, and in particular of a four-mandrel crimping device.

The problem is solved with the features of the independent claims.

Advantageous embodiments of the invention are specified in the subclaims and/or the following description.

The present invention particularly relates to a method for monitoring the condition of pressing elements of a crimping device of a crimping apparatus, in which a crimping height of the crimping device is set up which is suitable for crimping a predetermined cable with a predetermined contact sleeve, in which a crimping height is set up in a first step and in a second step a path from a defined rest position to a working position of the pressing elements is measured which corresponds to the set crimping height.

In a crimping device, when crimping, in particular, a predetermined cable with a predetermined contact sleeve, the pressing elements of the crimping device are moved toward each other under pressure. The contact sleeve, which is provided with the cable, is arranged between the pressing elements and is pressed onto the cable under the pressure of the pressing elements. For a desirable mechanically and electrically stable connection, a predetermined suitable crimping height is provided, up to which the pressing elements act on the contact sleeve and the cable.

A cable mentioned throughout the context of the application may in particular comprise an electrical conductor, e.g. "stranded conductor", The electrical conductor can be a core of a cable, in particular a multi-core cable, which can be a stranded wire with a plurality of individual wires. In this context, it should be noted with regard to the term "cable" that, when reference is made here and throughout the application to a cable that is to be crimped, this always refers to a stripped core of a single- or multi-core cable that is to be crimped, the stranded wire of which can in particular also have a plurality of individual wires.

Particularly in indent crimping devices such as two-mandrel crimping devices and four-mandrel crimping devices, the pressing elements can be designed as opposing, tapered mandrels. The crimp height is the minimum distance between two opposing mandrels to which the mandrels are moved toward each other during crimping.

Setting a suitable crimp height for a predetermined contact sleeve and a predetermined cable can be achieved using adjusting mandrels of a suitable diameter with a suitable adjustment mechanism. A predetermined adjusting mandrel is positioned between the pressing elements of the crimping device, and the pressing elements are moved from their defined rest position toward the adjusting mandrel until the tips of the pressing elements touch the adjusting mandrel. The crimp height is set when the adjusting mandrel can be moved between the contacting pressing elements and corresponds to the diameter of the adjusting mandrel.

When adjusting the crimp height, the adjusting mandrel is not positioned between the pressing elements of the crimping device during the compression process, in order to protect the adjusting mandrel from damage if the crimp height is set too small for its diameter. Instead, the adjusting mandrel is positioned after the crimping When the crimping elements are brought together, the adjusting mandrel is inserted into the hole remaining between the crimping elements. The diameter of the adjusting mandrel corresponds approximately to the set crimp height when the adjusting mandrel can be inserted into the protruding hole with difficulty and a predetermined friction with the crimping elements.

By measuring the travel of the pressing elements from their rest position to their working position, and in particular to their position corresponding to the set crimping height, a comparable reference travel is easily and advantageously provided. Using a sensor system described below, the travel is measured when the crimping device is idle and also routinely when a crimping height is set as described above.

In a third step, the measured travel is compared with a recorded travel of a measurement of a travel of a crimp height previously set using the method. If the pressing elements are worn, their tips, in particular, are worn. Accordingly, the tips of opposing pressing elements of worn pressing elements can be further apart from each other during a crimp than the tips of new and/or unworn pressing elements. Consequently, the travel of worn pressing elements from their rest position to the working position corresponding to the set crimp height is greater than the travel of new and/or unused pressing elements.

By means of the above advantageous comparison of the path of the pressing elements from their rest position to their position corresponding to the set crimp height, the degree of wear of the pressing elements between the two measurements can be easily determined. The comparison can, for example, be made from the The ratio of the two measured paths and/or, particularly advantageously, can be determined by their difference.

In a fourth step, data is recorded, wherein the recorded data comprise at least the measured path and/or a result of the comparison. The method can be suitably carried out using suitable software provided on the evaluation electronics of a crimping device. The data are suitably stored on the evaluation electronics and are thus advantageously available for further implementations of the method and for corresponding further comparisons.

In a fifth step of the method according to the invention, the comparison carried out in the third step is checked for the presence of a predetermined criterion, after which a signal is output in a sixth step if the predetermined criterion is met. In this way, it is also advantageously possible to routinely check and recognize whether maintenance of the crimping device is desirable or whether replacement of worn pressing elements is necessary for crimps with a desirable quality. The signal can be a visual and/or acoustic indication and/or trigger a predetermined measure, such as switching a crimping device to a predetermined operating mode, which can be a maintenance mode, for example.

The above method according to the invention can be carried out routinely after a predetermined number of crimping operations have been carried out and/or particularly advantageously when setting up a batch of a predetermined number of contacts to be crimped with a predetermined crimp height. As described below, the method is advantageously suitable for providing an estimate from the comparison as to the extent to which the Pressing elements are suitable for a predetermined number of crimps.

When the method is carried out repeatedly, the comparison of the path with the recorded path can be carried out in the third step, suitably taking into account the set crimp height and the crimp height of the crimp height previously set up using the method. In the fourth step, the set crimp height and/or a result of a comparison of the set crimp height with the crimp height of the crimp height previously set up using the method are also recorded. In this way, the condition of the pressing elements can advantageously be routinely checked when setting up different crimp heights. Otherwise, only a device whose crimp height corresponds to the crimp height of a previously set crimp height can be checked for a deviation.

In step one of the above method according to the invention, a device E(n) of a crimping height H(n) can be carried out, where n is the number of devices E(n) of a crimping height H(n) carried out with the pressing elements of the crimping device, and where a reference dimension of a reference crimping height H(n) is used for the crimping height H(n), which can suitably correspond to half the actually set crimping height. If here above and below and in particular also with reference to Fig. 4A, Fig. 4B and Fig. 5 and when the claims refer to a crimp height H(n), for the sake of simplicity this always means the reference crimp height H(n), which corresponds to half the actual crimp height set using an adjusting mandrel with a predetermined diameter of the actual crimp height.

In step two, a path X(n) of the pressing elements of the crimping device is measured from a first position PO(n) to a second position P1(n), wherein the pressing elements are in their rest position in the first position PO(n) and in the second position P1(n) are in a working position which corresponds to the set crimping height H(n).

In the step three described above, a comparison of the path X(n) of the device E(n) with a path X(n-1) of a device E(n-1) of a crimping height H(n-1) carried out before the device E(n) of the crimping height H(n) can be carried out by considering the ratio of the measured path X(n) to the path X(n-1), namely X(n) / X(n-1) and in particular by considering the difference of the measured path, namely ΔX(n) = X(n) - X(n-1).

In step four described above, the recorded data can include at least the path X(n) and/or the above difference ΔX(n) of a device E(n). When recording the difference ΔX(n), it is advantageously possible to sum all recorded differences ΔX(n) of all performed devices E(n) in step three, namely to form the sum Σ ΔX(n), summing from 1 to n.

In the step five described above, a comparison of the difference ΔX(n) with a predetermined deviation can be performed, after which a signal is output in the above step six if the comparison meets a predetermined criterion. The above comparison performed in step five can be determined from the ratio and/or the difference of the deviation to/with the difference ΔX(n).

Suitably, the preceding device E(n-1) is the last device (E) performed before the device E(n), the path X(n-1) of the device E(n-1) being read in the third step from data recorded at the device E(n-1) in step four.

The data read out in step three and/or the data recorded in step four may further include, in addition to the path X(n) and/or the difference ΔX(n), the number n and/or the first crimp height H(n).

It is also advantageous in the third step to compare the crimp height H(n) with the second crimp height H(n-1), wherein the comparison can be derived from their ratio and/or in particular their difference, namely ΔH(n) = H(n) - H(n-1), wherein the data read out in step three and/or the data recorded in step four can also include the difference ΔH(n). In this way, the possibility is advantageously created of carrying out and comparing a plurality of devices E(n) with different crimp heights H(n) and of checking each device E(n) for a deviation of the path X(n). Otherwise, only a device E(n) whose crimp height H(n) corresponds to the crimp height H(n) of a previously set crimp height H(n) can be checked for a deviation.

In this way, it is advantageously possible to sum, in addition to the sum Σ ΔX(n) described above, all recorded differences ΔH(n) of all devices E(n) carried out, namely to form the sum Σ ΔH(n), summing from 1 to n.

In addition, the data read out in step three and/or the data recorded in step four may suitably include the Sum Σ ΔX(n) and Σ ΔH(n), which advantageously provides the possibility of also taking into account ΔX(n) and ΔH(n) of all devices in step three by means of their ratio and/or sum. Suitably, the sum Σ ΔH(n) and Σ ΔX(n), namely Σ [ΔH(n) + ΔX(n)], can be formed.

The sum Σ[ΔH(n) + ΔX(n)] can be compared with the predetermined deviation in the fifth step described above, and a signal can be output in the sixth step if this comparison meets a predetermined criterion. Suitably, the data read out in the third step and/or the data recorded in step four can comprise the sum Σ[ΔH(n) + ΔX(n)].

The sum Σ [ΔH(n) + ΔX(n)] is particularly advantageous for checking for the existence of a predetermined criterion of a comparison with the predetermined deviation, since in this way any number of devices E(n) with any number of crimping heights H(n) can also be routinely used for the method according to the invention.

The data recorded in step four can be suitably recorded and assigned to a device E(n). For example, the recorded data of a device E(n), namely n, X(n), H(n) and/or ΔX(n) and/or ΔH(n) and/or Σ ΔX(n) and/or Σ ΔH(n) and/or Σ [ΔH(n) + ΔX(n)], can be stored in tabular form in corresponding rows and columns. When recording the sum Σ [ΔH(n) + ΔX(n)], all data of a device E(n) that are assigned to previously performed devices E(n) can also be deleted. In this way, it is advantageously possible to keep the storage space required for the recorded data to a minimum.

A method according to the invention may further suitably comprise a further step in which the crimps C carried out after device E(n) of a crimping height H(n), namely the number #C(n), are counted, and the number #C(n) is recorded together with the recorded data, after which the data read out in step three may further comprise the number #C(n) of a device E(n).

In this way, the possibility is advantageously created that the signal output in step six can comprise, in addition to a message about the presence of a predetermined criterion of a deviation and/or the sum Σ [ΔH(n) + ΔX(n)], the number #C(n) and/or the sum of all crimping operations carried out Σ #C(n) of all devices E(n), according to which, for a device E(n) of a crimping height (n), a forecast can be made about the expected suitability of the pressing elements for a number of crimping operations to be carried out.

In the fourth step, the sum of the crimps performed Σ #C(n) is recorded together with the recorded data, and in step three the sum Σ #C(n) is read out.

The method according to the invention is particularly suitable for monitoring the operating state of a crimping device of a crimping apparatus described below, whose pressing elements are designed as conically tapered mandrels. The tip of the mandrel can be suitably rounded and/or have comparatively small elevations.

Suitably, the method involves a relative path measurement of the path X(n) using a position transmitter with a This is done using a Hall sensor, which can be installed on a device for applying pressure to the crimping device. Position transmitters with Hall sensors offer desirable measurement accuracy and are relatively inexpensive to purchase.

The invention therefore also relates in particular to a crimping device for checking the quality of a crimp of a predetermined cable with a predetermined contact sleeve and with a predetermined crimp height using a sensor system described above for measuring a path of a device for actuating a crimping device and an evaluation electronics.

The crimping device is an indent crimping device and is therefore particularly suitable and advantageous for crimping the cable with a particularly turned contact sleeve, and can be, for example, a two-mandrel crimping device and particularly preferably a four-mandrel crimping device.

As a device for actuating the crimping device, the crimping apparatus suitably has a pneumatic pressure device with a cylinder and a piston, which is operatively connected to the crimping device via a lever. For this purpose, the crimping device can have a cylindrical guide in which the pressing elements are mounted for radial movement. The lever is arranged so as to be pivotable about the axis of the guide and has an inner contour that interacts with the pressing elements. A protruding position transmitter comprising a Hall sensor can be easily provided on the cylinder for the relative measurement of the displacement of the pressing elements. The lever is preferably designed and arranged such that the displacement is measured linearly to the displacement of the pressing elements.

In the above-described crimping device, when crimping, in particular, a predetermined cable with a predetermined contact sleeve, the pressing elements of the crimping device are moved toward each other under pressure. The contact sleeve, which is provided with the cable, is arranged between the pressing elements and is pressed onto the cable under the pressure of the pressing elements. For a desirable mechanically and electrically stable connection, a predetermined suitable crimping height is provided, up to which the pressing elements act on the contact sleeve and the cable.

An adjustment mechanism is provided for setting a predetermined crimp height, which makes the crimping device suitable for various applications. In particular, in an indent crimping device such as a two-mandrel crimping device and a four-mandrel crimping device, the pressing elements are designed as opposing, tapered mandrels. The projecting crimp height is the minimum distance between two opposing mandrels up to which the mandrels are moved towards each other during crimping. The adjustment mechanism can, for example, and suitably, comprise an adjustable stop for the lever. In addition, the crimping device can comprise a stripping device that strips a predetermined cable or a wire of a predetermined cable and prepares it for crimping with a predetermined contact sleeve.

As described at the beginning of the method according to the invention, a suitable crimp height can be set, in particular with an adjustment mechanism using adjusting mandrels with a diameter suitable for a predetermined contact sleeve and a predetermined cable. A predetermined adjusting mandrel is arranged between the pressing elements of the crimping device, and the Crimping elements are moved from their defined rest position toward the adjusting mandrel until the tips of the crimping elements touch the adjusting mandrel. The crimp height is set as described above when the adjusting mandrel can be moved between the contacting crimping elements under a predetermined friction and corresponds to the diameter of the adjusting mandrel.

A crimping device according to the invention is thus suitable for carrying out a method according to the invention, wherein a software program suitable for carrying out the method can be suitably provided on the evaluation electronics of the crimping device. It is clear that the evaluation electronics have suitable means for this purpose, such as a memory option for recording data.

A crimping device particularly suitable for carrying out a method according to the invention can, in addition to a displacement sensor, also suitably comprise a force sensor suitable for measuring a force when pressure is applied to a crimping device, which force sensor can suitably be a piezo sensor.

A crimping device with a displacement and force sensor is designed to record a force/displacement curve when its crimping device is actuated. By comparing a force/displacement curve of a crimp with a reference model, a statement about the quality of the crimp can be made.

A suitable crimping device may furthermore have interfaces to cable-based and/or wireless signal and/or data connections. The crimping device may be networked in this way, after which, in step six of the method according to the invention, a predetermined message may be sent to an external device. For example, such a message may be sent to a mobile phone of a service technician, which provides the possibility of advantageously timely maintenance of the pressing elements of a crimping device.

In particular, a crimping device suitable for detecting a force/displacement curve of a crimping process comprises evaluation electronics and a suitable displacement sensor. The crimping device can therefore be retrofitted particularly easily and cost-effectively by installing a software program suitable for implementing the method without requiring additional hardware.

Examples of implementation

Fig. 1A

eine schematische Darstellung einer Crimpvorrichtung nach einer Ausführung der Erfindung mit einer Crimpeinrichtung;

Fig. 1B

die Crimpeinrichtung von Fig. 1A in einer vergrößerten Darstellung;

Fig. 1C

einen Dorn der Crimpeinrichtung von Fig. 1A und 1B in vergrößerter Darstellung;

Fig. 1D

ein Kabel mit einer Kontakthülse, lose und miteinander vercrimpt;

Fig. 2A

eine mit der Crimpvorrichtung aufgezeichnete Kraft/Weg-Kurve einer Crimpung nach einer Ausführung der Erfindung;

Fig. 2B

eine vergrößerte Darstellung der Crimpeinrichtung von Fig. 1A in einer ersten Position, zusammen mit einer bestimmungsgemäß zum Vercrimpen angeordneten Kontakthülse und einem Kabel;

Fig. 2C

die Crimpeinrichtung mit der Kontakthülse und dem Kabel von Fig. 3B in einer zweiten Position mit einer vorbestimmten Crimphöhe der Crimpung;

Fig. 3A

weitere Kraft/Weg-Kurven einer Crimpung zusammen mit zwei Hüllkurven eines Referenzmodells nach einer Ausführung der Erfindung;

Fig. 3B

einen vergrößerten Schnitt durch die bestimmungsgemäß zur Crimpung mit einem Kabel versehene Kontakthülse von Fig. 2B; und

Fig. 3C

ein Schliffbild eines Schnitts durch die Crimpung der Kontakthülse mit dem Kabel von Fig. 2C;

Fig. 4A

eine vergrößerte Darstellung eines Presselements einer Crimpeinrichtung in dessen Ruheposition in einem ersten und zweiten Betriebszustand mit einer ersten und zweiten eingerichteten Crimphöhe;

Fig. 4B

eine tabellarische Aufstellung von bei einer Einrichtung einer Crimphöhe gemessenen und/oder ermittelten und/oder aufgezeichneten Daten; und

Fig. 5

ein Flußdiagramm eines Verfahrens zur Überwachung des Zustands einer Crimpeinrichtung nach einer Ausführung der Erfindung.

Embodiments of the invention are illustrated in the drawings and explained in more detail below. They show:

Fig. 1A

a schematic representation of a crimping device according to an embodiment of the invention with a crimping device;

Fig. 1B

the crimping device of Fig. 1A in an enlarged view;

Fig. 1C

a mandrel of the crimping device from Fig. 1A and 1B in enlarged view;

Fig. 1D

a cable with a contact sleeve, loose and crimped together;

Fig. 2A

a force/displacement curve of a crimp recorded with the crimping device according to an embodiment of the invention;

Fig. 2B

an enlarged view of the crimping device of Fig. 1A in a first position, together with a contact sleeve arranged for crimping and a cable;

Fig. 2C

the crimping device with the contact sleeve and the cable from Fig. 3B in a second position with a predetermined crimp height of the crimp;

Fig. 3A

further force/displacement curves of a crimp together with two envelope curves of a reference model according to an embodiment of the invention;

Fig. 3B

an enlarged section through the contact sleeve intended for crimping with a cable of Fig. 2B ; and

Fig. 3C

a micrograph of a section through the crimping of the contact sleeve with the cable of Fig. 2C ;

Fig. 4A

an enlarged view of a pressing element of a crimping device in its rest position in a first and second operating state with a first and second set crimping height;

Fig. 4B

a tabular list of data measured and/or determined and/or recorded when setting up a crimp height; and

Fig. 5

a flowchart of a method for monitoring the condition of a crimping device according to an embodiment of the invention.

The figures contain partially simplified, schematic representations. In some cases, identical reference symbols are used for identical, but possibly not identical, elements. Different views of identical elements may be scaled differently. For the sake of simplicity and clarity, only one identical or similar element is provided with a reference symbol in the drawings.

Fig. 1A shows a schematic representation of a crimping device 1 according to an embodiment of the invention, and Fig. 1D shows a cable 4 with a contact sleeve 3, each loose and crimped together. Contact sleeve 3 is a turned contact sleeve 3.

The crimping device 1 is an indent crimping device and, in particular, a four-mandrel crimping device with a crimping device 2 comprising four pressing elements 20, which is particularly suitable for crimping a stripped cable or a strand of a stripped single-core cable 4 with a turned contact sleeve 3. The pressing elements 20 are suitably designed as pointed mandrels 20.

To actuate the crimping device 2, the crimping apparatus 1 comprises a pneumatic pressure device with a cylinder 10 and a piston 11, which is operatively connected to the crimping device 2 via a lever 130. For the initially described setting of a predetermined crimping height by means of adjusting mandrels, a suitable adjustment mechanism 12 is provided, which may have an adjustable stop for the lever 130.

During crimping by pressing a particularly turned contact sleeve 3 with a cable 4, the contact sleeve 3 with the strand of the cable 4 located therein is inserted into the crimping device 2 as intended, and the crimping device 2 is actuated and subjected to pressure by means of the pressure device. By means of a vertical movement and a vertically acting force F of the pressure device, the lever 130 coupled to the crimping device 2 is pivoted. The crimping device 2 and the lever 130 are designed and arranged such that the mandrels 20 move towards one another from their rest position P0 during pivoting or are brought into their rest position P0, which will be described below with reference to Fig. 1B The tips 21 of the mandrels 20 each lie on concentric circles, which will be described below with reference to Fig. 2B and 2C described.

The crimping device 1 is suitably configured to check the quality of a crimp of a predetermined cable 4 with a predetermined contact sleeve 3 and, for this purpose, comprises a displacement sensor 13 and at least one force sensor 14. The displacement sensor 13 can suitably be a position transmitter with a Hall sensor and can be provided on the cylinder 10 of the pressure device. The force sensor 14 can suitably be a piezo sensor 14 and can be arranged on the lever 130 and/or at least one piezo sensor provided on a fastening of the cylinder 10. The piezo sensors each measure an extension or tension upon actuation of the lever 130 or the counterforce acting on the cylinder 10 of a pressure acting on the piston 11.

The sensors 13, 14 are connected to an evaluation electronics 5 for signal and/or data transmission. The evaluation electronics 5 can control a screen and display a force/displacement curve G of a crimp, recorded using the signals from the sensors 13, 14, along with further information on the screen. Examples of a force/displacement curve G are described below with reference to Fig. 2A and 3A described.

Fig. 1B shows an enlarged, more detailed view of the crimping device 2 and Fig. 1C shows an enlarged mandrel 20 of the crimping device 2 of Fig. 1A and 1B For the sake of clarity, the force sensor 14 on the lever 130 is Fig. 1B not shown.

The crimping device 2 has a cylindrical guide with the cylinder axis A, in which four mandrels 20 are mounted for radial movement. The tips of the mandrels 10 are aligned towards each other. The lever 130 is mounted on the cylindrical guide so as to be axially pivotable or rotatable and has an inner contour which is formed by the cylindrical guide. outstanding minds of the Dorne 20.

When the lever 130 is pivoted, the tips 21 of the mandrels 20 are moved toward or away from each other in the direction of the axis A of the cylindrical guide or the pivot axis of the lever 130. The tips 21 of the mandrels 20 are each located on concentric circles. During crimping, a contact sleeve 3 provided with a cable 4 is pressed onto the cable 4 by actuating the lever 130 on the axis A of the cylindrical guide.

The crimping device 2 with its mandrels 20 is also described below with reference to Fig. 2B, 2C and 4A described.

A crimping device 1 with the features described above is intended for carrying out an initial and subsequently with reference to in particular also Fig. 4, Fig. 4B and Fig. 5 described procedure.

Fig. 2A shows a force/displacement curve G of a crimping device 1 of Fig. 1A crimping of a contact sleeve 3 with a cable 4 of Fig. 1D according to an embodiment of the invention.

During crimping, the mandrels 20 of the crimping device 2 are moved from their rest position P0 into further positions P to P1, with the tips of the mandrels 20 moving towards each other and being arranged on concentric circles. In this process, the sensors 13, 14 measure a distance X and a force F, which are represented by the force/displacement curve G. The positions P0, P, P1 each correspond to particularly characteristic values for the course of the force/displacement curve G and its analysis for evaluating the quality of a crimp. Positions P of the mandrels 20 and each correspond to a measured path X of the sensor 13.

Fig. 2B shows an enlarged view of the crimping device 2 of Fig. 1A in the rest position P0, together with a contact sleeve 3 arranged in the crimping device 2 as intended for crimping and a cable 4. The tips of the mandrels 20 of the crimping device 2 are arranged concentrically with the contact sleeve 3 and the cylindrical guide of the crimping device 2, which has the axis A.

A displacement of the mandrels 20 from the position P0 to the Fig. 2A to the position P adjacent to the position P0 is carried out using a constant force F. Accordingly, the course of the force/displacement curve G is also constant in a first area P0-P between the position P0 and the position P of the mandrels 20, in which the mandrels 20 of the crimping device 2 touch the surface of the contact sleeve 3.

Fig. 3B shows a opposite Fig. 2B Enlarged and more detailed representation of a section through a contact sleeve 3 intended for crimping with a cable 4. The interior of the contact sleeve 30 has, in addition to individual wires 40 of the stranded wire of the cable 4, a hollow space not occupied by the individual wires 40 of the stranded wire. The contact sleeve 3 is undamaged and its condition corresponds to the contact sleeve 3 of Fig. 2B in the area P0-P of the crimping with the force/displacement curve G.

Fig. 2C shows the mandrels 20 of the crimping device 2 at the position P1 of the mandrels 20 corresponding to the position P1 of the force/displacement curve G, wherein the tips of the mandrels 20 are arranged on a circle with a diameter H that corresponds to the set crimping height H. With the mandrels 20 arranged at the position P1, the stranded wire completely fills the space available in the contact sleeve 3. This condition of the contact sleeve 3 and the strand is shown in a micrograph of the contact sleeve 3 for the area P1 of Fig. 3C shown in which no individual wires 40 of the strand are visible and there is no cavity next to the strand. Fig. 3C shows a micrograph of a crimp with a desirable predetermined quality, in which no individual wires 40 or cracks in the contact sleeve 3 due to, for example, undesirable material defects are visible.

Fig. 3A shows further force/displacement curves G, G3 and G4 of a crimp together with two envelope curves GH of a reference model that is suitable for testing the quality of a crimp.

The two envelopes GH are in Fig. 4A are each shown with dotted lines and limit a tolerance range T. The force/displacement curve G of Fig. 4A is shown with a solid line and lies in its entire course from the position P0 to the position P1 of the mandrels 20 between the envelopes GH and corresponds to a crimping of a contact sleeve 3 with a cable 4 with a predetermined desirable quality, with a as described above with reference to Fig. 3C described micrograph. Crimping with such desirable quality is achieved in particular with intact, undamaged pressing elements 20, after which monitoring of the condition of the pressing elements 20 is desirable.

Fig. 5 shows a flowchart of a method for monitoring the state of a crimping device 1 according to an embodiment of the invention. To clarify the method, reference is also made to Fig. 4A and the table of Fig. 4B referred to.

Fig. 4A shows an enlarged view of a pressing element 20 of a crimping device 2 in its rest position P0 in a first operating state with a first set crimping height H(1) and in a second operating state with a second configured crimping height H(2). In the first operating state, the pressing element 20, designed as a tapered mandrel, is undamaged and/or new, and in the second operating state, the tip of the pressing element 20 is worn. The positions of the tips of the pressing element 20 define the positions P0(1) and P0(2).

Fig. 4B shows a tabular list of data measured and/or determined and/or calculated and/or recorded when setting up a crimp height.

As stated at the beginning, for the sake of simplicity, a reference crimp height H(1) of an actual crimp height H1 and a reference crimp height H(2) of an actual crimp height H2 are used as crimp heights H(1) and H(2), which correspond to half the crimp heights H1 and H2, respectively. For the sake of simplicity and clarity, the reference crimp heights H(1) and H(2) are referred to as crimp heights H(1) and H(2). Also for the crimp heights H(3) and H(n) of Table 3 of Fig. 4B For the sake of simplicity and clarity, this is a reference crimp height H(3) and H(n) of this type.

The pressing elements 20 of Fig. 4A are designed as pointed mandrels 20 and for a crimping device 1 of Fig. 1A suitable.

In a first step S1 of the method of executing Fig. 5 For a device E(n), a device E(1), E(2), H(3), E(n) of a crimping height H(1), H(2), H(3), H(n) is carried out. The pressing elements 20 of the device E(1) can be in a new and unused state, which is shown on the left side of Fig. 4A The pressing elements 20 of the further devices E(2), E(3), E(n) can be used and/or worn condition, wherein the further device E(2) of a comparatively worn pressing element 20 on the right side of Fig. 4A is shown.

In a device E(n) of the devices E(1), E(2), E(3), E(n), in a second step S2 a path X(1), X(2), X(3), X(n) of the pressing elements 20 of the crimping device 1 from a first position PO(n) to a second position P1(n) is measured, wherein the pressing elements 20 are in their rest position P0 in the first position PO(n) and in a working position P1 in the second position P1(n) which corresponds to the set crimping height H(n).

For a device E(n), in a third step S3, the comparison of the path X(n) of the device E(n) with a path X(n-1) of a device E(n-1) of a crimping height H(n-1) performed before the device E(n) of the crimping height H(n) is carried out in a suitable manner by subtracting the measured path, namely ΔX(n) = X(n) - X(n-1). For the first device E(1) of a crimping device with new pressing elements 20, this difference is ΔX(n) = 0. For the second device E(2) of the crimping device 2 with used pressing elements 20, which differ accordingly from the pressing elements 20 of the device E(1), this difference is ΔX(2) = X(2) - X(1).

The device E(n-1) is in this case the last device carried out before the device E(n), wherein the path X(n-1) of the device E(n-1) is read in the third step S3 of the method from data recorded at the device E(n-1) in a fourth step S4.

In the fourth step S4, data for further devices E(n) are recorded. The data may include at least the path X(n) and/or the above path difference ΔX(n) of a device E(n). Recording the path difference ΔX(n) advantageously creates the possibility of summing all recorded differences ΔX(n) of all performed devices E(n) in the third step S3, namely, forming the sum Σ ΔX(n), summing from 1 to n. For the first device E(1), Σ ΔX(1) = 0 and ΔX(1) = 0.

In a fifth step S5, a comparison of the difference ΔX(n) with a predetermined deviation is performed, and in a sixth step S6, a signal is output if the comparison meets a predetermined criterion. The above comparison performed in the fifth step S5 can be determined, for example, from the ratio and/or the difference of the deviation to/with the difference ΔX(n). The predetermined criterion can be a predetermined difference and/or a predetermined ratio.

The data read out in the third step S3 and/or the data of a device E(n) recorded in the fourth step S4 can furthermore comprise, in addition to the path X(n) and/or the difference ΔX(n), also the number n of the devices E(n) carried out and/or the respectively set crimping height H(n).

It is also advantageous in the third step S3 to compare the crimping height H(n) with the second crimping height H(n-1), wherein the comparison can be derived from their ratio and/or in particular their difference, namely ΔH(n) = H(n) - H(n-1), wherein the data read out in step three and/or the data recorded in step S4 can also include the difference ΔH(n). In this way, the possibility is advantageously created to implement a plurality of devices E(n) with different crimping heights H(n). Monitoring the operating state of the Press elements 20 are therefore often advantageously also routinely possible when setting up different crimping heights H(n).

Otherwise, only one device E(n) with a crimping height H(n) can be used to carry out the method according to the invention, the crimping height of which corresponds to the crimping height H(1) of the first device (1). For the first device E(1), ΔH(1) = 0 and ΔX(1) = 0.

In this way, it is also advantageously possible to sum, in addition to the sum Σ ΔX(n) described above, all recorded differences ΔH(n) of all performed setups E(n), namely to form the sum Σ ΔH(n), summing from 1 to n. For the first setup E(1), Σ ΔH(1) = 0 and ΔH(1) = 0.

Furthermore, the data read out in step S3 and/or the data recorded in step S4 may suitably include the sums Σ ΔX(n) and Σ ΔH(n), which advantageously provides the possibility of also taking into account ΔX(n) and ΔH(n) of all devices in step S3 by forming their ratio and/or their sum. Suitably, the sum Σ ΔH(n) and Σ ΔX(n), namely Σ [ΔH(n) + ΔX(n)], may be formed, wherein E(n) can be summed over all devices performed.

The sum Σ [ΔH(n) + ΔX(n)] can be compared with a predetermined deviation in the fifth step S5, wherein a signal is output in the sixth step S6 if this comparison meets a predetermined criterion. In a suitable manner, the data read out in the third step S3 and/or the data read out in the fourth step S4 recorded data also include the sum Σ [ΔH(n) + ΔX(n)].

The sum Σ [ΔH(n) + ΔX(n)] is particularly advantageous for testing for the existence of a criterion of the comparison V with the predetermined deviation, since in this way any number of devices E(n) with any number of crimping heights H(n) can be used for the method according to the invention.

The data recorded in step S4 can be suitably recorded with each device E(n) assigned. For example, the recorded data of a device E(n), namely n, X(n), H(n) and/or ΔX(n) and/or ΔH(n) and/or Σ ΔX(n) and/or Σ ΔH(n) and/or Σ [ΔH(n) + ΔX(n)], can be stored in tabular form in corresponding rows and columns. Fig. 4B shows an example of data stored in a table.

Furthermore, when recording the sum Σ [ΔH(n) + ΔX(n)] of a device E(n), all data associated with other devices E(n) can be deleted. This advantageously minimizes the storage space required for the recorded data.

A method according to the invention may further suitably comprise a further step in which the crimping operations C carried out after setting E(n) of a crimping height H(n), namely the number #C(n), are counted, and the number #C(n) is recorded together with the above recorded data, after which the data read out in step S3 may further comprise the number #C(n).

In this way, the possibility is advantageously created for the signal output in step S6 to include, in addition to a predetermined criterion and/or the sum Σ [ΔH(n) + ΔX(n)], the number #C(n) and/or their sum Σ#C(n), according to which, for a device E(n) of a crimping height (n), an estimate of the expected suitability of the pressing elements for a number of crimps to be performed can be made. It is clear that for a device E(n), the sum Σ#C(n) can also be recorded in step S4 of the method.

List of reference symbols

1

Crimping device

10

cylinder

11

Pistons

12

Adjustment mechanism

13

displacement sensor

130

lever

14

force sensor

2

Crimping device

20

Pressing element, mandrel

21

Great

3

Contact sleeve

4

Cable

40

Single wire

5

Evaluation electronics

A

axis

C

Crimping

E, E(n)

Furnishings

F

Power

X, X(n)

Away

G, G3, G4, GH

curve

H, H1, H2, H(n)

Crimp height, reference crimp height

n

Number

P0, P, P1

position

S1, S2, S3, S4, S5, S6

Step

Claims (15)

1. Method for monitoring the state of pressing elements (20), namely the degree of the wear of the pressing elements (20), of a crimping device (2) of a crimping apparatus (1) formed as an indent crimping apparatus during a configuration (E) of a crimping height (H) of the crimping apparatus (1) suitable for a crimping of a predetermined cable (4) with a predetermined contact sleeve (3), having the following steps:

   step (S1) :
   configuring (E) a crimping height (H);

   step (S2):
   measuring a travel (X) in an idle state of the crimping device (2) and during the configuration (E) of the crimping height (H), namely a travel (X) from a rest position (P0) to a working position (P1) of the pressing elements (20), which corresponds to the set crimping height (H);

   step (S3):
   comparing the travel (X) measured in step (S2) during the configuration (E) of the crimping height (H) with a recorded travel (X) of a measurement of a travel (X) of a configuration (E) of a crimping height (H) previously carried out using the method;

   step (S4):
   recording data, wherein the recorded data comprise at least the travel (X) measured in step (S2) during the configuration (E) of the crimping height (H) and/or comprise at least one result of the comparison carried out in step (S3) of the travel (X) with the recorded travel (X);

   step (S5):
   checking the comparison carried out in step (S3) for the presence of a predetermined criterion;

   step (S6):
   outputting a signal when the predetermined criterion is fulfilled.
2. Method according to Claim 1, wherein

   in step (S3) the travel (X) is compared with a recorded travel (X) of a measurement of a travel (X) of the last configuration (E) of the same crimping height (H) carried out using the method; and/or

   in step (S3) the comparison of the travel (X) with the recorded travel (X) is carried out in consideration of the configured crimping height (H) and the crimping height (H) of a configuration (E) of a crimping height (H) previously carried out using the method; and/or

   the data recorded in step (S4) also comprise the set crimping height (H) and/or a result of a comparison of the set crimping height (H) with the crimping height (H) of a configuration (E) of a crimping height (H) previously carried out using the method.
3. Method according to Claim 1 or 2, having the following steps:

   step (S1):
   configuring (E) a crimping height (H), namely configuring E(n) a crimping height H(n), wherein n is the number of the configurations (E) of a crimping height (H) carried out using the pressing elements (20) of the crimping device (2);

   step (S2):
   measuring a travel (X) in an idle state of the crimping device (2) and during the configuration E(n) of the crimping height H(n), namely a travel X(n) of the pressing elements (20) of the crimping device (2) from a first position PO(n) to a second position P1(n), wherein the pressing elements (20) are in the rest position (P0) thereof in the first position PO(n) and are in a working position (P1) in the second position P1(n), which corresponds to the set crimping height H(n);

   step (S3):
   comparing the travel X(n) measured in step (S2) of the configuration E(n) with a travel X(n-1) of a configuration E(n-1) of a crimping height H(n-1) carried out before the configuration E(n) of the crimping height H(n) by means of forming the difference of the measured travel (X), namely ΔX(n) = X(n) - X(n-1);

   step (S4):
   recording data, wherein the recorded data comprise at least the travel X(n) measured in step (S2) and/or the difference ΔX(n);

   step (S5):
   comparing the difference ΔX(n) formed in step (S3) with a predetermined deviation;

   step (S6):
   outputting a signal when the comparison fulfills a predetermined criterion.
4. Method according to Claim 3, wherein

   the configuration E(n-1) is the configuration (E) carried out last before the configuration E(n), and

   in step (S3) the travel X(n-1) of the configuration E(n-1) is read out from data recorded during the configuration E(n-1); and/or

   the data recorded in step (S4) and/or

   the data read out in step (S3)

   comprise in addition to the travel X(n) and/or the difference ΔX(n) also the number n and/or the crimping height H(n).
5. Method according to Claim 4, wherein

   in step (S3) also the crimping height H(n) is compared with the crimping height H(n-1) by means of forming the difference, namely $$\mathrm{\Delta H}\left(\mathrm{n}\right)=\mathrm{H}\left(\mathrm{n}\right)-\mathrm{H}\left(\mathrm{n}-1\right),$$

   

   and wherein

   the data recorded in step (S4) and/or

   the data read out in step (S3) also comprise

   the difference ΔH(n).
6. Method according to Claim 5, wherein

   in step (S3) also a sum of all recorded differences ΔH(n) of all configurations E(n) carried out is calculated, namely

   the sum Σ ΔH(n), wherein summing is carried out from 1 to n,

   and wherein

   the data recorded in step (S4) and/or

   the data read out in step (S3) also

   comprise the sum Σ ΔH(n).
7. Method according to one of Claims 3 to 6, wherein in step (S3) also a sum of all recorded differences ΔX(n) of all configurations E(n) carried out is calculated, namely

   the sum Σ ΔX(n), wherein summing is carried out from 1 to n,

   and wherein

   the data recorded in step (S4) and/or

   the data read out in step (S3) also

   comprise the sum Σ ΔX(n).
8. Method according to Claims 6 and 7, wherein

   in step (S3) also the sum of Σ ΔH(n) and Σ ΔX(n), namely the sum Σ [ΔH(n) + ΔX(n)], is formed,

   and wherein

   in step (S5) a comparison of the sum Σ [ΔH(n) + ΔX(n)] with the predetermined deviation is carried out, and

   in step (S6) a signal is output if

   the comparison fulfills a predetermined criterion,

   and wherein

   the data recorded in step (S4) and/or

   the data read out in step (S3) also

   comprise the sum Σ [ΔH(n) + ΔX(n)].
9. Method according to Claim 8, wherein

   the recorded data are respectively recorded under association with a configuration E(n),

   wherein

   upon recording of the sum Σ [ΔH(n) + ΔX(n)] of one configuration E(n) all data which are associated with another configuration E(n) are erased.
10. Method according to one of Claims 3 to 9, having a further step, in which the crimps (C) carried out after configuration E(n) of a crimping height H(n), namely the number #C(n), are counted, and

    the number #C(n) and/or the sum Σ#C(n) thereof of all configurations E(n) are recorded together with the data recorded in step (S4), and wherein

    the data read out in step (S3) also comprise the number #C(n) and/or the sum Σ#C(n) thereof of all configurations E(n).
11. Method according to Claim 8 or 9 and Claim 10, wherein
    the signal output in step (S6) comprises the predetermined criterion and/or the sum Σ [ΔH(n) + ΔX(n)] and/or the number #C(n) and/or the sum Σ#C(n) thereof.
12. Method according to one of Claims 1 to 11, wherein a travel measurement of the travel (X), X(n) is carried out using a position transmitter having a Hall sensor (13), and wherein preferably the method is used for monitoring the wear of the pressing elements (20) of a four-indent crimping apparatus, the pressing elements (20) of which are respectively formed as conically pointed mandrels (20).
13. Crimping apparatus (1) for crimping a predetermined cable (4) with a predetermined contact sleeve (3) using a sensor (13) for measuring a travel (X) of a device for actuating and/or applying pressure to a crimping device (2) and an evaluation electronics unit (5) having the following features:

    the crimping device (2) is suitable for compressing the cable (4) with the contact sleeve (3);

    the device for actuating the crimping device (2) has a pneumatic pressure device having a cylinder (10) and a piston (11), which are operationally connected to the crimping device (2) via a lever;

    a setting mechanism (12) is provided for setting a predetermined crimping height (H);

    the crimping apparatus (1) is an indent crimping apparatus and is configured suitably for carrying out a method according to one of Claims 1 to 12.
14. Crimping apparatus (1) according to Claim 13, having at least one Hall sensor (13) for travel measurement (X) and having a force sensor (14), whereupon the crimping apparatus (1) is designed suitably for acquiring a force/travel curve (G, G3, G4).
15. Crimping apparatus (1) according to Claim 13 or 14, wherein the crimping apparatus (1) is a two-indent crimping apparatus and preferably a four-indent crimping apparatus, the crimping device (2) of which has pressing elements (20) which are formed as conically pointed mandrels (20), and wherein the crimping apparatus (1) is suitable for compressing the cable (4) with a turned contact sleeve (3).

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