Patent Application
20140283382
The invention relates to a wire positioning device for positioning an electrical wire in a processing device. The invention further relates to a processing device, comprising a processing station and a wire positioning device of this type. The invention further relates to a method for lowering thin wires and for positioning them in an oscillation-damped manner.
A device of this type and a method for lowering and positioning wires in a processing station, formed as a crimping station, of a processing device is described in prior WO 2009/017653A1.
In the conventional prior art:
A pivoting gripper mounted movably on a carriage grasps the wire at the insulation close to a bared wire end and moves in front of the crimping station, where it positions the bared wire end, for example a conductive wire or a stranded wire, approximately 8 to 10 mm above the lower punch and above a contact element to be crimped. The crimping tool is then started. The plunger moves downward with momentum by a stroke of approximately 30 to 60 mm, contacts the upright gripper head in the manner of a hammer during the last 8 to 10 mm and presses downward the spring-loaded gripper with the wire. The wire is thus introduced into the crimping claw, without significant deflection, provided it has a sufficiently large wire cross-section, and the sheathed part of the wire and/or the bared part is/are crimped synchronously on the lower punch by the upper punch of the crimping tool via an insulation and/or strand claw. At the same time, the carrier strip is separated by a separating punch.
Once crimping is complete, the crimping tool moves back up into its upper dead centre and the gripper likewise springs back. The spring travel of conventional grippers is approximately 16 mm.
Conventional wires fitted in cars (0.35 to 6 mm2) are relatively easy to handle, even though they deflect slightly and vibrate slightly when pressed downward with momentum. However, no considerable difficulties are encountered during the crimping process.
Very thin wires, for example measuring 0.13 mm2 are being increasingly installed in cars, however. Even wires having a wire cross-section of 0.05 mm2 are being considered. However, such thin wires can no longer be processed using conventional techniques.
Thin wires have additional insulation, which has high tensile strength because the insulation also has to withstand some of the tensile force. The thin conductive wire or the stranded wires of the thin wires continue to oscillate for a long time once introduced into the crimping claw when they are positioned using conventional grippers. The conductive wire or the stranded wire cannot be controlled and introduced reliably into the crimping claw of a contact element during the stroke motion of the crimping tool, and the conductive wire or stranded wire may become bent or buckled.
WO 2009/017653A1 discloses a wire positioning device intended to overcome such a drawback. The wire positioning device is arranged on a base frame. The wire positioning device according to WO 2009/017653A1 has a gripper and is mounted rotatably on a rotating plate. This moves the wire in the planes A, B and C. For vertical positioning, the gripper has cylindrical guide rods with teeth, which are connected to a gearwheel of a horizontally arranged driveshaft of a servomotor and convert the rotary motion into a vertical motion. The height and spacings can also be controlled, however, by a hydraulic or other drive means.
The crimping tool comprises a stationary anvil and movable crimp upper punch, which is moved vertically by a stroke of the crimping station. The servomotor of the wire positioning device moves the end of the wire, once it has been positioned above an electrical contact element arranged on the anvil, into the open insulation and/or strand claw of the contact element by lowering. The contact element is then crimped to the wire.
With a wire positioning device of this type, the wire can be lowered more slowly. However, synchronisation is extremely difficult because it cannot be easily controlled. In addition, an additional servomotor increases the cost of the wire positioning device considerably. A reduction in the lowering speed may then also have a negative effect on productivity.
To overcome these drawbacks, a device for lowering and positioning thin wires in a crimping station is known from WO 2011/004272A1, said device having a press base frame having a drive, which moves a press carriage along a central axis with a speed variation similar to a sine curve from an upper dead centre to a lower dead centre and back, a central plunger which is arranged parallel to the central axis and is fixed at one end to a holder, via which the plunger is connected rigidly to the press carriage of the crimping station so that the press carriage and plunger move synchronously in a downward stroke, a separate gripper with a gripper head and at least one pair of gripper jaws, by means of which the gripper positions at least one wire end of a conductor in a crimping zone of a crimping tool arranged on the press carriage and having a crimping tool upper part and a crimping tool lower part in a defined pivot-in position for crimping with crimping claws of a contact element, wherein at least one leading lowering device, which actuates the gripper head in a leading position in relation to the downward stroke of the plunger and lowers it in a leading position with reduced speed and thus moves the wire end from the pivot-in position into a defined crimping position, is assigned to or coordinated with the central plunger.
A drawback of the wire positioning device described in WO 2011/004272A1 is the high level of structural complexity and the associated high production costs.
GB 2021988A, referred to hereinafter as D1, describes a processing device comprising a processing station and a wire positioning device, as shown in particular in its FIG. 30. The processing station comprises a head 606, which is movable vertically in relation to the longitudinal axis of a wire and has a cutting knife 630 and a crimping element 631 inter alia. The wire positioning device comprises upper and lower positioning elements 408, 409 (“wire gathering heads”), which are movable vertically in relation to the longitudinal axis of the wire. The positioning elements 408, 409 can be transferred into an open position and into a closed position, as is shown in FIGS. 30 and 31 of D1, wherein, in the closed position, the positioning elements 408, 409 engage in one another in such a way that they surround the wire so as to hold it in its position as it is cut and stripped (in particular see page 10, lines 55 to 124).
In contrast to the invention, the movable head 606 described in D1 and comprising the element 640 is part of the processing station. It is therefore not part of the wire positioning device, as is provided in the invention, since the movable head 606 has tools, such as the cutting knife 630 and the crimping element 631, which process the wire for further use. The wire positioning device of D1 is, by contrast, formed by the positioning elements 408, 409 inter alia, which are then also to be compared to the lowering device according to the invention. If the positioning elements 408, 409 are compared to the lowering device according to the invention, the difference between D1 and the invention lies in the fact that the positioning elements 408, 409 are not designed in the form of a press piece within the meaning of the invention and also do not have a spring element arranged in a tube. By contrast, the positioning elements 408, 409 of D1 are moved into a closed position and into an open position in an unsprung manner.
U.S. Pat. No. 4,521,946A—referred to hereinafter as D2—describes a conveying system for wires 116 that have already been cut, wherein the cut wires 116 are transported between two mutually opposed belts 52, 54. In an embodiment of D2, as shown in FIGS. 15, 16 and 17 of D2, the upper belt 52 is connected to a conveying means 112 and the lower belt 54 is connected to a separator 68. The wires 116 are split by means of the separator 68 and are forwarded to different processing stations (in particular see D2, column 6, lines 27 to 38). The separator 68 has a pneumatic cylinder 172 to move the separator 68 accordingly so that it can split the wires and separate them from one another (in particular see D2, column 6, lines 44 to 47).
By contrast, a wire positioning device according to an embodiment of the invention comprises a lowering device with a press piece and a spring element arranged in a tube. This is not disclosed in D2.
FIGS. 15, 16 and 17 of D2 do not describe a wire positioning device within the meaning of the invention. By contrast, a completely different object compared to that to be achieved by the present invention, namely the separation of wires so that the separated wires can be fed to different processing stations, is pursued with the conveying system described in reference D2, and therefore the disclosure of D2 is in not believed comparable with the present subject matter.
EP 0813271A2—referred to hereinafter as D3—describes a device for producing a cable harness, in which connection elements 13a, 13b are arranged in a clamping and shifting unit 14 at the two ends 8, 10 of a wire 1. The wire 1 is clamped in two clamps 24a, 24b for this purpose, said clamps being driven by piston cylinders 25a, 25b (in particular see D3, column 5, lines 18 to 32). A wire positioning device comprising an embodiment of the invention is also not disclosed in D3, since D3 does not disclose a press piece and a lowering device having a spring element arranged in a tube.
An object of the present invention is therefore to create a solution by means of which the structural complexity of a wire positioning device and therefore of a processing device for an electrical wire can be reduced and by means of which selective positioning of an electrical wire in a processing station of a processing device can also be achieved.
A further object of the invention is to create a method which can be carried out in a cost effective manner and which, in particular, is suitable for the positioning of thin electrical wires.
Advantageous developments are illustrated in the figures and the present disclosure.
In accordance with the invention, the wire positioning device is characterised in that the lowering device has a press piece, which is spring-loaded by at least one spring element and is provided so as to be contacted against the wire guide, the at least one spring element being arranged in a tube.
When a wire is supplied for the wire positioning device, the wire guide and the free end of the wire protruding from the wire guide are oscillated both in a direction horizontal to the longitudinal axis of the wire and in a direction vertical to the longitudinal axis of the wire due to the filigree structure of a thin wire and the resultant likewise relatively thin design of the wire guide, which may be embodied for example in the form of a thin guide tube, from which a free end of the wire, preferably a partially bared end of the wire, protrudes. This oscillatory movement of the wire guide together with the wire introduced therein can be interrupted by a lowering of the lowering device and by the resultant contact of the press piece of the lowering device against the wire guide. The press piece is applied directly to the wire guide as a result of a movement of the lowering device vertically in relation to the longitudinal axis of the wire received in the wire guide, in such a way that the press piece comes to rest against an upper face of the wire guide.
The press piece preferably has a block or a plate, on which a flat contact surface is formed, by means of which the press piece is brought to rest against the wire guide when the lowering device is lowered. The press piece can also be formed as a hard rubber buffer, however, with a flat or slightly crowned contact surface. The press piece is mounted in the lowering device in a spring-loaded manner via at least one spring element, which is preferably embodied in the form of one or more compression springs, in such a way that the press piece can carry out a vertical movement in relation to the longitudinal axis of the electrical wire, guided by the spring element. The press piece can be connected to the spring element either directly or via an intermediate element, such as a pin. The press piece is therefore guided movably within the lowering device via the spring element, which is arranged in a tube, whereby, when the wire guide is positioned by contacting the press piece with the wire guide, the wire guide can initially be accelerated as smoothly as possible and, once a height of insertion desired for the processing, in the processing station, of the free end of the wire protruding from the wire guide has been reached, the oscillation of the wire guide and therefore of the free end, protruding from the wire guide, of the electrical wire received therein may be stopped. If the wire guide and the free end of the wire protruding from the wire guide is substantially free from oscillation, the free end of the wire is positioned in a highly accurate manner in the processing station, for example a crimping station, due to the fact that there is now no inherent movement of the free end of the wire. Due to the arrangement of the spring element in a tube, it is possible to position and guide the spring element within the lowering device in a precise manner. In particular, lateral tilting of the spring element, which is preferably embodied in the form of a spiral spring, is thus prevented. Due to the wire positioning device according to the invention, the wire may be positioned in a processing station of a processing device with a high level of repetition accuracy. By means of the spring-loaded press piece, the oscillations of the wire guide of the free end of the wire protruding from the wire guide may be reduced within a short period of time, and therefore the overall processing time of an electrical wire in a processing station of a processing device can be reduced, whereby processing can be carried out more economically.
The spring-loaded press piece thus replaces the servomotor or central plunger, with the highly complex leading lowering device, known from the prior art and has a substantially simpler design than these. Due to the relatively simple structural design of the device according to the invention, the production costs of a wire positioning device can also be reduced considerably compared to conventional wire positioning devices.
In accordance with a preferred embodiment of the wire positioning device, a stop element is arranged opposite the press piece, it being possible for the wire guide to be clamped in an oscillation-damped manner between the press piece and the stop element. The stop element is preferably positioned below the wire guide when the electrical wire is introduced into the processing station of the processing device, whereas the press piece of the lowering device is positioned above the wire guide so that the press piece and the stop element are basically opposite one another. When the press piece rests on an upper face of the wire guide, the wire guide, which is still oscillating, can be pressed downward by means of the press piece in the direction of the stop element until the wire guide lies directly or indirectly via its lower face on the stop element arranged below the press piece so that the wire guide is clamped between the press piece and the stop element in an oscillation-damped manner, whereby the oscillation of the wire guide and therefore also of the free end of the electrical wire protruding from the wire guide can be minimised or stopped particularly quickly and effectively. The repetition accuracy and the precision of the processing of the electrical wire received in the wire guide in the processing station of the processing device can thus be further improved.
Furthermore, the press piece of the lowering device is preferably arranged with a second longitudinal axis above the wire guide, and the stop element is preferably arranged with a third longitudinal axis below the wire guide, the press piece being arranged with the second longitudinal axis vertically in relation to the first longitudinal axis, and the stop element being arranged with the third longitudinal axis vertically in relation to the first longitudinal axis. It can thus be ensured that the press piece and the stop element each lie with the contact surfaces against the wire guide in a flat or slightly crowned manner to damp the oscillation of the wire guide, whereby oscillation of the wire guide is damped particularly quickly and effectively.
It is further preferable for the second longitudinal axis of the press piece to be arranged offset in relation to the third longitudinal axis of the stop element along the first longitudinal axis of the electrical wire.
In accordance with a further advantageous embodiment of the wire positioning device, the tube has an outer thread, which engages in a holding element having an inner thread. An outer thread can be formed on the outer peripheral surface of the tube, in which a holding element provided with an inner thread can engage. The tube in which the spring element is arranged can thus be positioned and fixed on the holding element. In addition, the tube and therefore the spring element can be easily fixed to the holding element by hand and adjusted at the same time via the outer thread and the inner thread engaging therein, without the need for further tools for this purpose. The effort required to form the wire positioning device can thus be reduced further. For example, the holding element may have a flange and a sleeve, wherein the sleeve can be fixed at a through-opening formed in the flange, and an inner thread, in which the outer thread of the tube can engage, can be formed on the inner wall of the sleeve so that the tube can be guided through the sleeve and the through-opening formed in the flange. The holding element can then be fixed via the flange to the processing station of the processing device.
Furthermore, the wire positioning device preferably has a pivotably mounted pivoting conveyor, the wire guide being fixed to the pivotably mounted pivoting conveyor. The wire to be processed can be held and transported in the pivotably mounted pivoting conveyor for example, since the wire is clamped between conveyor belts or pressure rollers formed on the pivoting conveyor. Starting from the fixing of the electrical wire on the pivoting conveyor, the wire and in particular the free end of the wire can be guided through the wire guide, which is arranged on the pivoting conveyor. The pivoting conveyor enables lateral pivoting of the wire fixed in the pivoting conveyor and guided in the wire guide, in the direction of the processing station of the processing device in which the free end of the wire protruding from the wire guide is crimped for example.
Furthermore, the invention is characterised by a processing device, in particular a crimping device, for an electrical wire, said processing device having a processing station and a wire positioning device. A processing device which has a wire positioning device according to the invention is characterised by a high level of positioning accuracy of the wire to be processed in the processing station of the processing device, wherein this can be achieved with a low level of structural complexity of the overall processing device. For example, if the processing device is a crimping device, a free end of the wire to be processed can be positioned with as little oscillation as possible in the processing station in crimping claws of a contact part provided in a crimping tool. The quality of the processing operation, in particular of the crimping operation, of a wire can thus be improved considerably, wherein the wire can also be processed within a relatively short period of time so that the wire can be processed in a highly economical manner.
The processing station preferably has a movable carriage, the lowering device of the wire positioning device preferably being arranged on the movable carriage. The movable carriage is preferably used so that part of the processing station of the processing device can be moved back and forth in a vertical direction. If the lowering device of the wire positioning device is arranged on the movable carriage, the movement of the lowering device vertical to the longitudinal axis of the wire received in the wire guide may be ensured by the movable carriage, and therefore additional aids, such as an additional drive on the lowering device itself, are not required to move the lowering device. The structural complexity of the processing device may thus be reduced further.
Furthermore, the stop element of the wire positioning device is fixed to a rigidly positioned carrier element of the processing station. In this case, ‘rigidly positioned’ means that the carrier element is arranged in the processing station in a non-displaceable or immobile manner. The stop element is preferably likewise arranged rigidly on the carrier element so that there can preferably be no relative displacement between the carrier element and the stop element. The stop element can thus form a secure, fixedly positioned counter pressure element for the press piece when the wire guide is pushed against the stop element by means of the press piece. Alternatively it is also possible, however, for the stop element to be movable vertically to the longitudinal axis of the wire received in the wire guide, similarly to the lowering device, so that the press piece and the stop element can be moved toward one another.
In accordance with the invention, the method is characterised in that a wire positioning device and a processing device according to the present disclosure are used.
In accordance with the method according to the invention, the lowering device is moved with the press piece from a first position into a second position. In the first position, the press piece is located above the upper face of the wire guide and distanced therefrom. The press piece has reached the second position as soon as it contacts the upper face of the wire guide, which leads to a first damping of the oscillation of the wire guide and of the wire. As the lowering device is lowered further, the press piece is moved vertically in the direction of the tube in accordance with the spring force of the spring element or of the individual spring elements, whilst the wire guide is moved with reduced acceleration by the press piece in the form of a pitch movement from the second position into a third position. The third position is reached as soon as the vertical movement of the lowering device and the pitch movement of the wire guide are concluded by contact with the stop element.
Further advantages, features and details of the invention will emerge from the following description, in which an exemplary embodiment of the invention is described with reference to the drawings. The features disclosed in the claims and in the description may be essential to the invention either individually or in any combination.
The list of reference signs forms part of the disclosure. The figures are described contiguously and comprehensively. Like reference signs denote like component parts, and reference signs having different indices denote functionally like or similar component parts.
In the figures:
The processing station 3 shown in this case is formed as a crimping station, and therefore the processing device shown in this case is also a crimping device. The crimping station shown in this case has a crimping tool with an upper punch unit 39 and a lower punch unit 40. The invention is not limited to a crimping device having a crimping station, however. For example, it may also be used for soldering or welding devices.
The wire positioning device 1 has a wire guide 4, in which the electrical wire 2 is received so as to be processed in the processing station 3. The wire guide 4 is embodied in this case in the form of a guide sleeve, through which the wire 2 is guided, wherein a free end 44 of the wire 2 protrudes from the wire guide 4.
The wire positioning device 1 further has a lowering device 5, which is arranged movably vertically in relation to a first longitudinal axis 45 of the electrical wire 3 received in the wire guide 4.
The lowering device 5 has a spring-mounted press piece 6 at one end, which, in a second position as shown in
The pin 13 is connected to a spring element 15 at a second end portion 14 of the pin 13 opposite the first end portion 12, in such a way that the press piece 6 is spring-loaded via the pin 13. The spring element 15 is embodied in this case in the form of a plurality of compression springs arranged in succession. Alternatively, the spring element 15 may also be formed from a single mechanical compression spring. A small, pressurised pneumatic cylinder is also conceivable, as is a design with a press plunger guided in the tube and, for example, two outer tension springs mounted between the press plunger head and the assembly flange. The spring element 15 and the second end portion 14 of the pin 13 are arranged in a tube 16, wherein the longitudinal axis of the tube 16 extends vertically in relation to the longitudinal axis of the electrical wire 2.
The tube 16 is closed via a first cap-shaped end piece 17 and via a second cap-shaped end piece 18, wherein a through-opening 19 is formed in the second cap-shaped end piece 18, the first end portion 12 of the pin 13 being guided through said through-opening.
An outer thread 20 is formed on the outer peripheral surface of the tube 16. The tube 16 is fixed to a holding element 21 via the outer thread 20. The holding element 21 has an L-shaped, curved flange 22 and a cylindrical sleeve 23, for example for adjusting the height of introduction of the wire, wherein an inner thread 24 is formed on an inner wall of the sleeve 23 and the outer thread 20 of the tube 16 engages in said inner thread. The tube 16 is guided through a through-opening 25 formed in the flange 22. The sleeve 23, which can also be formed as a nut, is fitted on the flange 22 in the region of the through-opening 25 and is preferably fixed to the flange 22 so that the tube 16 is guided through the sleeve 23 and the through-opening 25 formed in the flange 22 and is screwed via its outer thread 20 into the inner thread 24 of the sleeve 23 so as to be fixed to the holding element 21.
The flange 22 and/or the holding element 21 preferably have at least two adjacent through-openings 25 so that the tube 16 can be installed at different locations.
The lowering device 5 is arranged via the flange 22 of the holding element 21 on a movable carriage 26 of the processing station 3 of the processing device and is fixed thereto via a screw 27. The movable carriage 26, which for example may be a press carriage, is movable in a direction 28 vertically in relation to the first longitudinal axis 45 of the wire 2 received in the wire guide 4. Since the lowering device 5 is fixed rigidly to the movable carriage 26, the lowering device 5 follows the movement of the movable carriage 26 so that the lowering device 5 is guided vertically by means of the movable carriage 26. It is therefore not necessary to provide separate drive means for the lowering device 5. The movable carriage 26 is moved via a crankshaft 29 arranged in the processing station 3 and via a crank pin 30 connecting the movable carriage 26 to the crankshaft 29.
A stop element 31 is arranged opposite the press piece 6, wherein the press piece 6 and the stop element 31 are arranged opposite one another in such a way that a second longitudinal axis 46 of the press piece 6 is oriented so as to be slightly offset in relation to a third longitudinal axis 47 of the stop element 31. The stop element 31 has a plate 32, which can be formed as a hard rubber buffer with a flat or slightly crowned surface, a dowel 33 screwed into the plate 32, and a flange 34, to which the dowel 33 is fixed by means of a fixing element 37. The stop element 31 has a planar contact surface 35 on its plate 32, the lower face 36 of the wire guide 4 coming to rest directly or indirectly against said contact surface when the wire guide 4 is pressed downward in the direction of the stop element 31 by means of the press piece 6, as shown in
The wire guide 4 is also fixed to a horizontally pivotably mounted pivoting conveyor 41, via which the wire guide 4 is pivoted in the direction of the processing station 3, together with the wire 2 introduced into the wire guide 4, before the wire 2 is processed. The pivoting conveyor 41 has a pitch axis 42, about which the oscillation-damped pivoting conveyor 41 according to
Once the wire guide 4 has been pivoted in the direction of the processing station 3 together with the wire 2, the wire positioning device 1 is located in a first position, as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 11187480 | Nov 2011 | EP | regional |
This application is a 35 U.S.C. 371 national-phase entry of PCT International application no. PCT/IB2012/054137 filed on Aug. 14, 2012 and also claims benefit of priority to prior European application no. EP11187480 filed on Nov. 2, 2011, and also claims priority as a non-provisional of U.S. provisional application Ser. No. 61/554,765 filed on Nov. 2, 2011, and both European application no. EP11187480 and U.S. provisional application Ser. No. 61/554,765, as well as parent PCT International application no. PCT/IB2012/054137, are all incorporated herein by reference in their entireties for all intents and purposes, as if identically set forth in full herein.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB2012/054137 | 8/14/2012 | WO | 00 | 4/30/2014 |
| Number | Date | Country | |
|---|---|---|---|
| 61554765 | Nov 2011 | US |
