WO2011004272A1

WO2011004272A1 - Device and method for lowering and positioning thin wires

Info

Publication number: WO2011004272A1
Application number: PCT/IB2010/052648
Authority: WO
Inventors: Willi Blickenstorfer
Original assignee: Schleuniger Holding Ag
Priority date: 2009-07-08
Filing date: 2010-06-14
Publication date: 2011-01-13

Abstract

The invention relates to an image generation system for generating an image of a region of interest. The image generation system comprises a measured data providing unit for providing measured data of the region of interest, a reconstruction unit (12) for reconstructing a first and a second image of the region of interest from the measured data using a first and a second reconstruction method, a noise determination unit (13) for determining first and second noise values for first and second image elements of the first and second image, and an image element combining unit (14) for combining corresponding first and second image elements into combined image elements forming a combined image based on the first and second noise values. By combining corresponding image elements of two differently reconstructed images based on determined noise values, a combined image of a region of interest can be generated with an improved quality.

Description

Device and method for lowering and positioning thin wires

Description

1. Technical field of the invention

The invention relates to a device and to a method for lowering and positioning thin wires in a crimping station, the device having at least a press base frame with 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 bottom dead centre and back. The device also has 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 rigidly connected to the press carriage of the crimping station so that press carriage and plunger move synchronously in a downward stroke. Furthermore, the device has 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.

In the method for lowering and positioning thin wires, the stroke of a press carriage and hence of an upper plunger is carried out synchronously with the stroke of a central plunger arranged on a holder and belonging to a crimping station by a common drive, the upper plunger being lowered from a first position at an upper dead centre to a sixth position at a bottom dead centre with a sinusoidal speed variation, and the stripped wire end being positioned in a defined swivel-in position by a gripper head when the upper plunger is in the first position at the upper dead centre.

2. Prior art

Such a device and a method for lowering and positioning wires in a crimping station are described in the prior art of WO 2009/017653 Al. A pivoting gripper which is displaceably mounted on a carriage grips the wire not far from a stripped wire end on the insulation and travels therewith before the crimping station, where it positions the stripped wire end, for example a conductive wire or a stranded wire, about 8 to 10 mm above the lower plunger and above a contact element to be crimped. Thereafter, the crimping tool is started. The press plunger travels with a stroke of about 40 to 60 mm with momentum in a downward direction, strikes the stationary gripper head like a hammer during the last 8 to 10 mm and presses the spring-loaded gripper with the wire in a downward direction. As a result, the wire is inserted into the crimping jaw without major bending if it has a sufficiently large wire cross-section, and the sheathed part of the wire and/or the stripped part with an insulated and/or conductor claw is crimped synchronously by the upper plunger of the crimping tool. At the same time, the support strip is also separated from a separating plunger.

After crimping, the crimping tool travels upwards again to its upper dead centre and the gripper also springs back. The spring deflection of commercially available grippers is about 16 mm.

The customary wires which are installed in an automobile (0.35 - 6 mm²) are relatively compliant even if they bend somewhat and tremble somewhat when they are forced with momentum downwards. In the crimping process, however, there are no significant problems. Increasingly, however, very thin wires, e.g. 0.13 mm², are also being installed in an automobile. Even wires having a wire cross-section of 0.5 mm² are being considered. Such thin wires can, however, no longer be processed by conventional technology.

Thin wires have an additional insulation which has a very high tensile strength because the insulation must also take up part of the tensile force. The thin conductor wire or the strands of the thin wires continue to vibrate for a long time on insertion into the crimping jaw when they are being positioned by conventional grippers. The conductor wire or the stranded wire cannot be controlled during the stroke of the crimping tool and inserted by a reliable process into the clamping jaw of a contact element, and conductor wire or stranded wire may be curved or bent.

WO 2009/017653 Al discloses a positioning device which is intended to eliminate such a disadvantage. The positioning device is arranged on a base frame. However, it should be mentioned that it can also be arranged directly on the crimping tool in order to control the vertical position of the stripped wire end within the crimping zone of the crimping tool . Such a solution is, however, not disclosed.

The positioning device according to WO 2009/017653 Al has a gripper and is rotatably mounted on a turntable. It moves the wire in the planes A, B and C. For the vertical positioning, the gripper has cylindrical guide rods with teeth, which are connected to a toothed wheel of a horizontally arranged drive shaft of a servo motor and convert the rotational movement into a vertical movement. However, the height and the spacings can also be controlled by a hydraulic or other drive means. The crimping tool comprises a stationary anvil and moveable upper crimping plunger, which are moved vertically by a stroke of the crimping station. The servo motor of the positioning device moves the wire end, after it has been positioned above an electrical contact element lying on the anvil, by lowering into the open insulation and/or conductor jaw of the contact element. The contact element is then crimped with the wire .

With such a positioning device, it is true that the wire can be lowered more slowly. However, synchronization is extremely difficult because it is difficult to control. Moreover, an additional servo motor makes a positioning device considerably more expensive. A reduction in the lowering speed may then also adversely affect the productivity.

Object of the invention It is an object of the invention to provide an economical device and a low-vibration method having process reliability for lowering and positioning very thin wires, and nevertheless to ensure the wire processing of thin wires in the same quantity at constant processing speed and with constant quality.

Achievement of the object

This object is achieved by the features of Claims 1 and 14. Further developments of the invention are given in the drawings and in the dependent claims.

According to the invention, the at least one leading lowering device which actuates the gripper head of a gripper in a leading position relative 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 to a defined crimping position is assigned to or coordinated with the central plunger .

The lowering device according to the invention at least has

• at least one angle lever,

• at least one lifting flank having a ramp function for at least one roller,

• at least one transmission lever and

• at least one leading lowering means which is connected to the transmission lever via a joint with the angle lever and via a link to the leading lowering means.

In addition, the drive of the crimping station for the press carriage and the plunger is, according to the invention, simultaneously the drive for the lowering device .

The leading lowering means may be either sleeve-shaped or rod-shaped or may have another expedient shape. According to the invention, one or more leading lowering means are coordinated with the plunger or the leading lowering means is a lowering sleeve which is superposed on the central plunger.

The leading lowering means preferably has, on its underside or bottom opening, a damping ring, for example in the form of an 0-ring, a plastic ring, a plastic sleeve or another shock-absorbing material, with which the leading lowering means makes contact with the gripper head of the gripper and, after a calming phase for the wire end, lowers the gripper with reduced speed relative to the plunger in a leading position. The leading lowering means moves the wire end in a leading position to a crimping position as close as possible to the crimping claws with a defined acceleration and little vibration. After the wire end has reached the crimping position, the plunger is guided to a set-down position in which both the leading lowering means and the plunger make contact with the gripper head. From the set-down position, the plunger either passes through the bottom opening of the lowering sleeve or performs in another manner the further lowering of the gripper and of the wire end. In an fifth downward stroke to a sixth position, the plunger ends the crimping process synchronously with the crimping tool upper part in a manner known per se. The lowering sleeve according to the invention may also be in the form of a multi-part lowering sleeve and may have a height adjustment device which is easy to operate .

In the method according to the invention, the gripper head is lowered by at least one leading lowering means of a lowering device, which is coordinated with or superposed on the plunger, in a leading position, from the swivel-in position of the stripped wire end to a crimping position with reduced speed relative to the plunger, and the wire end is moved in a leading position up to an optimized punch for the carrier strip to a crimping position as close as possible to the crimping claws with little vibration, the optimized punch simultaneously centring the conductor. Thereafter, the wire end is crimped in a continuous process .

The leading lowering movement of the wire end with inclusion of a plurality of rest phases results in the leading lowering means being caused to move over a defined lifting flank with reduced vibration and prevents the plunger from striking the gripper with impact. Thus, a moderate, harmonious, vertical movement and an enormous reduction of the impact speed of the central plunger results, especially since the plunger encounters the gripper head of the gripper only right at the end, shortly before reaching the bottom dead centre of a sinusoidal curve of the speed as a function of time. The synchronous lowering speed of the upper punch in this region is just sufficient to roll in the conductor claws and to complete the crimping process.

Also advantageous in the case of this solution according to the invention is that no separate drive, e.g. a servo drive, is required, which would make such a crimping station considerably more expensive and which would have to be synchronized in a time-critical manner with the press speed.

Brief description of the drawings

The invention is illustrated in more detail schematically and by way of example with reference to the drawings .

The figures show the following:

Fig. 1 - A front view of a crimping station in a first working example of a device according to the invention in the form of a lowering device having a lowering sleeve as a leading lowering means in a first position at an upper dead centre, with a partial region of a crimping tool being shown.

Fig. 2 - A partial cross-section A - A through the crimping station according to fig. 1, with the lowering device according to the invention and a gripper, still in the first position of the lowering device. Fig. 3 - The crimping station according to fig. 2 in a second position, according to the invention, of the lowering device.

Fig. 4 - The crimping station according to figures 2 and 3 in a third position, according to the invention, of the lowering device.

Fig. 5 - The crimping station according to figures 2 to 4 in a sixth position, according to the invention, of the lowering device; crimping tool and lowering device are at the bottom dead centre.

Fig. 6 - A movement sequence in a front view of an upper punch and a lower punch of a crimping tool (not shown) and of a wire end, shown from a first to a third position, according to the invention, of the method according to the invention.

Fig. 7 - The continuation of the movement sequence according to fig. 6, shown from a third to a fourth position, according to the invention, of the method according to the invention.

Fig. 8 - The continuation of the movement sequence according to fig. 7, shown from a fourth to a sixth position, according to the invention, of the method according to the invention.

Fig. 9 - A partial enlarged diagram of the fourth position according to the invention as shown in fig. 8 after a press stroke of 33 mm with simultaneous lowering of the wire end by 6 mm by the method according to the invention.

Fig. 10 - A cut-out of the partial cross-section A - A through the crimping station according to fig. 1 in a second working example with a two-part lowering sleeve according to the invention.

Working example

The device for lowering and positioning thin wires in a crimping station 22 has, in the drawings according to figures 1 to 5, a press base frame 16 in a first embodiment, comprising a drive shaft 10 and a crankpin 11 which, via a connecting rod 21, moves a press carriage 12 along a central axis 14 with a speed variation similar to a sine curve from an upper dead centre to a bottom dead centre and back. In addition, the device has a central plunger 8 which is arranged parallel to the central axis 14 and is fixed at one end to a holder 9 via which the plunger 8 is rigidly connected to the press carriage 12 of the crimping station 22 so that press carriage 12 and plunger 8 move synchronously in a downward stroke. Moreover, the device has a separate gripper 23 having a gripper head 25 and a pair 2 of gripper jaws, by means of which the gripper 23 positions a wire end 3 of a conductor 39 in a crimping zone 33 of a crimping tool arranged on the press carriage 12 and having a crimping tool upper part 36 and a crimping tool lower part 38, in a defined swivel-in position 32 as close as possible (about 1.5 to 2 mm) to the gripper head 25 for crimping with crimping claws of a contact element.

According to the invention, at least one leading lowering device 1 is assigned to or coordinated with the central plunger 8, which lowering device 1 makes contact with the gripper head 25 in a leading position with respect to the downward stroke of the plunger 8 and lowers said gripper head 25 with reduced speed in a leading position and thereby moves the wire end 3 from the swivel-in position 32 (fig. 3) to a defined crimping position 41 (fig. 4) .

According to the invention, the lowering device 1 at least has

• at least one angle lever 6,

• at least one lifting flank 7 having a ramp function for at least one roller 20,

• at least one transmission lever 30 and

• at least one leading lowering means 5 which is connected to the transmission lever 30 via a joint 4 with the angle lever 6 and via a link 31 with the leading lowering means 5.

The drive of the crimping station 22 for the press carriage 12 and the plunger 8 simultaneously forms the drive for the lowering device 1.

The leading lowering means 5 may be sleeve-shaped or rod-shaped. If it is rod-shaped (not shown) , one or more leading lowering means 5 are assigned to or coordinated with the plunger 8. Assigned or coordinated leading lowering means 5 can, however, also be sleeve-shaped (not shown) . The leading lowering means 5 can, however, also be a lowering sleeve 5a which is superposed on the central plunger 8, as shown in figures 1 to 5. The invention is to be illustrated in more detail with reference to this working example.

The lowering device 1 according to the invention as shown in figures 1 to 5 and 10 has

• two angle levers 6 on the right and left of the lowering sleeve 5a,

• a lifting flank 7 having a ramp function for a roller 20,

• two transmission levers 30 and

• the lowering sleeve 5a which is connected to the transmission levers 30 via in each case a joint 4 with in each case an angle lever 6 and via one link 31 each with the lowering sleeve 5a on the right and left.

This working example comprises a symmetrical construction of the lowering device one with two angle levers 6. However, constructions having only one angle lever 6 or more than two angle levers 6 can be implemented. Such constructions are likewise within the scope of protection of the invention.

According to the invention, the lowering sleeve 5a is superposed at the other end of the central plunger, in the direction towards the gripper 23, in partial regions such that the lowering sleeve 5a encompasses the plunger 8 by a defined length which corresponds approximately to the downward stroke of the press carriage 12 to a fifth position 51. The lowering sleeve 5a is guided in a vertically displaceable manner on the central plunger 8 and is part of the lowering device 1 for the gripper 23, which lowering device 1 is ahead of the plunger 8.

The lowering sleeve 5a has, on its underside or bottom opening 42, a damping ring 59, for example in the form of an 0-ring. The lower region 5'' of a two-part lowering sleeve 5a, as shown in fig. 10, can, however, also be formed from a plastic ring, a plastic sleeve or another resilient material, with or without 0-ring, in order to make contact with the gripper head 25 of the gripper 23 with shock absorption and to lower the gripper 23 with reduced speed relative to the plunger 8. The wire end 3 moves in a leading position up to an optimized punch 27, to a crimping position 41 as close as possible to the crimping claws 28 with little vibration and with a defined acceleration in a downward stroke. After the wire end 3 has reached the crimping position 41, the plunger 8 is guided to a set-down position 60 in which both the leading lowering sleeve 5a and the plunger 8 make contact with the gripper head 25.

From the set-down position 60 and after reaching the optimized punch 27, the plunger 8 passes through the bottom opening 42 of the lowering sleeve 5a and performs the further lowering of the gripper 23 and of the wire end 3 and, in a fifth downward stroke 52 up to a sixth position 53, the plunger 8 ends the crimping process synchronously with the crimping tool upper part 36 in a manner known per se.

The angle levers 6 are arranged on one bracket 17 each which is rigidly connected to the press base frame 16 and to a base plate 55 of the lowering device 1, whereby the bracket 17 may have a U-shape and is welded, screwed or otherwise connected to the base plate 55 of the lowering device 1. In the working examples according to figures 1 to 5 and 10, two brackets 17 are arranged at right angles from the press base frame in the direction of the lowering sleeve 5a. The lifting flank 7 of the lowering device 1 is arranged in a strip 56 on which the roller 27 mounted on the angle levers runs. The strip 56 is arranged on the press carriage 12 and concomitantly executes the downward stroke of the press carriage. During this procedure, the angle of gradient of the positively controlled lifting flank 7 controls the lowering speed and the lowering acceleration of the lowering sleeve 5. The angle of gradient of the lifting flank and the transition radii 63, 64 can be designed to be variable. The height of the lifting flank 7 determines the stroke of the lowering sleeve 5a. It is therefore important for the strip 56 to be exchangeable.

One or more sliding bushes 24 which slide over the plunger 8 are arranged on the inner surface of the lowering sleeve 5a, and the plunger 8 is simultaneously guided so as to be vertically moveable along the inner surface of the sliding bushes 24 in the lowering sleeve 5a. The two angle levers 6 which encompass the outer wall of the lowering sleeve 5a on two opposite sides and are hinged to one transmission lever 30 each via one joint 4 each are particularly clearly evident in fig. 1. Either the two angle levers 6 may have one roller 20 each or the angle levers 6 are connected to one another via a common roller 20, as shown in this working example. However, it is also within the scope of the invention for the strip 56 to have at least one groove and for a roller 20 to be displaceably guided in each groove.

Fig. 2 to 5 and 10 show that the angle levers 6 are triangular. However, they may also be rectangular or curved or may have another expedient form. Moreover, the angle levers 6 have at least one axle 18 which is mounted on the bracket 17 arranged on the press base frame 16 and causes the angle levers 6 to execute a tilting movement as soon as the roller 20 of the lowering device 1, while it is running up the lifting flank 7 moving downwards with the press carriage 12, guides the angle levers 6 via the axle 18 to a slightly skew position, with the result that the lowering sleeve 5a experiences a lowering in the direction of the gripper head 25 via the two transmission levers 30 and lowers said gripper head 25 in a leading position relative to the central plunger 8.

Moreover, the lowering device 1 has at least one spring 19 which is connected at one end to the angle levers 6 and at the other end to the bracket 17. The springs 9 press the roller 20 of the angle lever 6 against the lifting flank 7.

The lowering device 1 moves the lowering sleeve 5a and hence the gripper 23 with the wire end 3 from a first downward stroke 44 to a fourth downward stroke 50 in a leading position, with reduced speed, with a defined acceleration and with reduced vibration from a first position 43 continuously to a fifth position 51, and the plunger 8 performs the further lowering of the gripper 23 and of the wire end 3 in a fifth downward stroke 52 to a sixth position 53 (fig. 5) in order to complete the crimping process, shown in figures 6 to 8. The device according to the invention moreover has an optimized punch 27 having at least one wire guide lug 54 for preliminary centring of the wire end 3 in the crimping position 41, not more than 2 mm above the opened crimping claws 28 of the contact element positioned on a lower punch 26 of the crimping tool lower part 38.

According to the invention, the lowering sleeve 5a may also be multi-part. Fig. 10 shows such a working example of a device according to the invention, on which the lowering sleeve 5a is in two parts and has an upper region 5' and a lower region 5'' . The joints 4 of the lowering device 1 are arranged in the upper region 5' of the lowering sleeve 5 in this working example. The lower region 5'' of the lowering sleeve 5a is preferably made of plastic or another suitable shock-absorbing material. Moreover, the lowering sleeve 5 has a height adjustment device 58.

In this working example, the height adjustment device 58 is formed by fine threads corresponding to one another, in such a way that the upper region 5' of the lowering sleeve 5a has a fine thread below the joints 4 on its outer surface and the lower region 5' ' of the lowering sleeve 5 has a fine thread on its inner surface. The height adjustment device 58 can be manually operated. In the method for lowering and positioning thin wires, the stroke of the press carriage 12 and hence that of the upper punch 29 are carried out synchronously with the stroke of the central plunger 8 arranged on the holder 9 by the common drive unit, the upper punch 29 being lowered from a first position 43 at an upper dead centre via a second position 45, a third position 47, a fourth position 49, a fifth position 51 to a sixth position 53 at the bottom dead centre with a sinusoidal speed variation and the stripped wire end 3 being positioned by a gripper head 25 in a defined swivel-in position 32 when the upper punch 29 is in the first position 43 at the upper dead centre.

According to the invention, the gripper head 25 is lowered by at least one leading lowering means 5a of a lowering device 1, which lowering means is coordinated with or superposed on the plunger 8, in a leading position from the swivel-in position 32 of the stripped wire end 3 to a crimping position 41 with reduced speed relative to the plunger 8. The wire end 3 is moved in a leading position up to an optimized punch 27 to a crimping position 41 as close as possible to the crimping claws 28 with little vibration and the wire end 3 is then crimped in a continuous process.

In this working example, the total downward stroke of the press carriage 12 is 40 mm altogether according to figures 6 to 8. However, the stripped wire end 3 in the meantime covers altogether only 8 mm of a lowering movement .

The downward stroke of the upper punch 29 begins with a first downward stroke 44 (fig. 6), in which a roller 20 of the lowering device 1 moves on a flat surface 61 of a strip 56 mounted on the press carriage 12, before a lifting flank 7, up to a knee point 57 of the lifting flank 7, while the upper punch 27 is moved from the first position 43 to the second position 45 and, in this working example, thereby covers a distance of 15 mm. The gripper 23 in the meantime remains in the rest position and the wire end 3 in the swivel-in position 32, so that conductor wire or strand 34 of the wire end 3 have sufficient time from the preceding swivel-in movement of the gripper 23 to come to rest.

The first downward stroke 44 of the upper punch 49 is further performed continuously with a second downward stroke 46 in which the upper punch 29 is moved from the second position 45 to the third position 47, at the same time at least one roller 20 of the lowering device 1 running up at least one lifting flank 7, and one or more angle levers 6 connected to the roller 20 being moved via at least one axle 18 to a further tilted position, with the result that one or more leading lowering means 5 connected to the angle levers 6 and to one articulated transmission lever 30 each are moved from the second position 45 to the third position 47 until the leading lowering means 5, in this working example a lowering sleeve 5a superposed on the plunger 8, touches, or the leading lowering means 5 touch, the gripper head 25 with their lower opening 42 but do not as yet move. This is shown in figures 3 and 6. In the working example according to fig. 6, the upper punch 29 covers a distance of 4 mm thereby. The stripped wire end 3 continues to remain in the swivel-in position 32 and meanwhile also still has time to eliminate possible residual vibrations which were caused during the swivel-in process of the gripper 23.

The second downward stroke 46 is followed by a third downward stroke 48, shown in fig. 7, in which the upper punch 29 is moved from the third position 47 to the fourth position 49, at the same time the roller 20 of the lowering device 1 being guided via the lifting flank 7 to the end thereof and the wire end 3 being moved by the lowering movement of the gripper 23, which is triggered by the leading lowering means 5, from the swivel-in position 32 to the crimping position 41 according to fig. 4 in a leading position.

During the third downward stroke, the upper punch 29, in this working example according to fig. 7, moves altogether 24 mm downwards. In the same period, the lowering sleeve 5a descending in a leading position moves the gripper 23 and hence the stripped wire end 3 with reduced speed by only 6 mm downwards. The movement of the lowering sleeve 5a is therewith complete .

The third downward stroke 48 is followed by a fourth downward stroke 50 according to fig. 8, in which the upper punch 29 is moved from the fourth position 49 to the fifth position 51, at the same time at least one roller 20 of the lowering device 1 moving on a flat surface behind the lifting flank 7, the lowering sleeve 5a therefore remaining in its position and moreover no lowering movement being executed by the wire end 3 and the gripper 23, and the wire end 3 continuing to remain in the crimping position 41 for further reduction of vibration. The length of stroke of the upper punch 29 in this working example is 5 mm.

The fourth downward stroke 50 is followed by a fifth downward stroke 52, in which the upper punch 29 is moved from the fifth position 51 to the sixth position 53, at the same time the roller 20 of the lowering device 1 continuing to move on the flat surface 62 behind the lifting flank 7, the leading lowering means 5 therefore remaining in a position, the plunger head 54 of the central plunger 8 passing, at the bottom opening 42, through the leading lowering means 5, in this working example the lowering sleeve 5a according to fig. 5, making contact with the gripper head 52 and in this way the wire end 3 being inserted into the open end of a crimping claw 28, while at the same time the actual crimping process is carried out in a known manner by the upper punch 29. In this working example, this lowering movement is only 2 mm both for the upper punch 29 and for the stripped wire end 3.

In principle, the speed curve and the acceleration curve of the leading lowering movement of the wire end 3 are controlled by the angle of gradient and by the transition radii 63, 64 of the lifting flank 7, while the stroke of the leading lowering means 5 is determined by the height of the lifting flank 7. The lifting flank 7 having a defined angle of gradient is exchanged for a lifting flank 7 having a steep or shallower angle of gradient if the leading lowering movement of the leading lowering means 5 is to take place more rapidly or more slowly than shown in this working example.

According to the invention, the wire end 3 is positioned with preliminary centring in an optimized punch 27 in the crimping position 41 as close as possible (about 1.5 to 2 mm) in the opened crimping claws 28 of the contact element positioned on a lower punch 26 of the crimping tool lower part 38. The punch 27 thus performs wire guidance and positioning right to the front at the tip, close to the conductor wire or the strand 34.

The optimized punch 27 has a slot 35 which is arranged about 0.3 to 0.4 mm above the lower punch 26 and through which the contact elements arranged in series run as strip material. Simultaneously with the fifth downward stroke 52, the carrier material is separated from the contact element by the punch 27 in a manner known per se.

The lowering movement of the wire end 3 is effected by the lowering device 1 upstream of the first to fourth downward strokes 44, 46, 48, 50 of the upper punch 29 in a leading position, with reduced speed and with reduced vibration. Only the fifth downward stroke 52, which, owing to the sinusoidal speed variation of press carriage 12 and plunger 8, within the fifth downward stroke 52, takes place with reduced speed but with sufficient speed for the crimping process, is carried out synchronously by the upper punch 29 and gripper 23. In the case of a leading lowering means 5, which is in the form of a two-part lowering sleeve 5a according to fig. 10, the height of the lowering sleeve 5a can be adjusted via a height adjustment means 58, the height of the lowering sleeve 5a being tailored to the optimized punch 27 of the lower punch 26 of the crimping tool.

The lowering device 1 for the lowering process for exact positioning of the wire end 3 with reduced vibration in the crimping position 41 has no drive device of its own, but the drive device of the crimping station 22 is concomitantly used.

The particular advantage of this lowering movement of the wire end 3 in two (or more) steps is that the movement required for the first leading lowering movement of the leading lowering means 5 is fed in via the angle lever 6 with the roller 20 from the lifting flank 7, this lifting flank 7 together with the press carriage 12 being moved vertically downwards. The wire end 3 has time, after the first leading lowering movement "to come to rest", i.e. to eliminate vibrations which have been caused by the lowering movement. Because of this leading lowering movement and the calming phases of the wire end 3, the subsequent crimping process takes place substantially more uniformly and reproducibly than in the case of the customary, pulse-like lowering movement of the plunger 8 in only one step. In all working examples, the design of the lifting flank 7 in the strip 56, which specifies the leading stroke dimension of the lowering sleeve 5a and the speed and acceleration profile, is variable. The strip 56 can be exchanged within a short changeover time for a strip 56 having a changed angle of gradient of the lifting flank 7.

The adjustability of the plunger 8 is also variable. The setting is chosen so that the wire end 3 remains straight in the crimping process.

Because no separate drive is required, the production of the lowering device 1 according to the invention is also very economical. Moreover, the ongoing operating costs are lower than in the case of solutions which are already known.

A further advantage is that the centring of the wire no longer takes place via the upper punch 29, as customary to date in the prior art, but takes place via the optimized punch 27 which additionally centres the wire. The result of this is that there are no longer any strands 34 at the top and that the strands 34 are distributed uniformly in the crimping claw 28 of the contact element.

It is self evident that, instead of the connecting rod 21, a drive having a spindle, a crankshaft, a toggle lever or another type of drive can also be used without departing from the scope of the invention. List of reference numerals

Lowering device

Pair of gripper jaws

Wire end, stripped

Joint

Leading lowering means

a Lowering sleeve

' Upper region of the lowering sleeve 5

' ' Lower region of the lowering sleeve 5

Angle lever

Lifting flank

Plunger

Holder

0 Drive shaft

1 Crankpin

2 Press carriage

3 Receiving groove for crimping tool upper part4 Central axis of crimping tool

5 Fixing surface for crimping tool base plate6 Press base frame

7 Bracket

8 Axle

9 Spring

0 Roller

1 Connecting rod

2 Crimping station

3 Gripper

4 Sliding bush

5 Gripper head

6 Lower punch

7 Optimized punch Crimping claw of the contact element Upper punch

Transmission lever

Link

Swivel-in position

Crimping zone

Conductor wire or strand

Slot

Crimping tool upper part

Crimping tool base plate

Crimping tool lower part

Conductor

Insulation

Crimping position

Bottom opening of the lowering sleeve First position of the lowering sleeve First downward stroke

Second position of the lowering sleeve Second downward stroke

Third position of the lowering sleeve Third downward stroke

Fourth position of the lowering sleeve Fourth downward stroke

Fifth position

Fifth downward stroke

Sixth position

Wire guide lug

Base plate of the lowering device Strip

Knee point of the lifting flank 7 Height adjustment device

Damping ring 60 Set-down position

61 Flat surface

62 Flat surface

63 Transition radius

64 Transition radius

The list of reference numerals is part of the disclosure .

Claims

1. Device for lowering and positioning thin wires in a crimping station (22), having at least

• a press base frame (16) having a drive which moves a press carriage (12) along a central axis (14) with a speed variation similar to a sine curve from an upper dead centre to a bottom dead centre and back,

• a central plunger (8) which is arranged parallel to the central axis (14) and is fixed at one end to a holder (9) via which the plunger (8) is rigidly connected to the press carriage (12) of the crimping station (22) so that the press carriage (12) and plunger (8) move synchronously in a downward stroke,

• a separate gripper (23) having a gripper head (25) and at least one pair (2) of gripper jaws, by means of which the gripper (23) positions at least one wire end (3) of a conductor (39) in a crimping zone (33) of a crimping tool arranged on the press carriage (12) and having a crimping tool upper part (36) and a crimping tool lower part (38), in a defined swivel-in position (32) for crimping with crimping claws (28) of a contact element,

characterized in

• that at least one leading lowering device (1) which actuates the gripper head (25) in a leading position relative to the downward stroke of the plunger (8) and lowers it with reduced speed in a leading position and thus moves the wire end (3) from the swivel-in position (32) to a defined crimping position (41) is assigned to or coordinated with the central plunger (8) .

2. Device according to Claim 1, characterized in

that the lowering device (1) at least has

• at least one angle lever (6),

• at least one lifting flank (7) having a ramp function for at least one roller (20),

• at least one transmission lever (30) and

• at least one leading lowering means (5) which is connected to the transmission lever (30) via a joint (4) with the angle lever (6) and via a link (31) with the leading lowering means (5), and/or

that the drive of the crimping station (22) for the press carriage (12) and the plunger (8) is simultaneously the drive for the lowering device (D•

3. Device according to either of the preceding claims, characterized in

that the leading lowering means (5) is sleeve- shaped or rod-shaped,

that one or more leading lowering means (5) are coordinated with the plunger (8) or

that the leading lowering means (5) is a lowering sleeve (5a) which is superposed on the central plunger (8) .

4. Device according to any of the preceding claims, characterized in

• that the leading lowering means (5) has, on its underside or bottom opening (42), a damping ring (59), for example in the form of an 0- ring, a plastic ring, a plastic sleeve or another shock-absorbing material, by means of which the leading lowering means (5) makes contact with the gripper head (25) of the gripper (23) and lowers the gripper (23) with reduced speed relative to the plunger (8) in a leading position and thus moves the wire end (3) in a leading position up to the crimping position (41) as close as possible to the crimping claws (28) with little vibration and with a defined acceleration and

• that, after the wire end (3) has reached the crimping position (41), the plunger (8) is guided to a set-down position (60) in which both the leading lowering means (5) and the plunger (8) make contact with the gripper head

(25) and

• that the plunger (8), from the set-down position (60), either passes through the bottom opening (42) of the lowering sleeve (5a) or performs a further lowering of the gripper (23) and of the wire end (3) in another manner and ends the crimping process in a manner known per se in a fifth downward stroke (52) to a sixth position (53) synchronously with the crimping tool upper part (36) .

5. Device according to any of the preceding claims, characterized in that the angle lever (6) is arranged on a bracket (17) rigidly connected to the press base frame (16) and/or to a base plate (55) of the lowering device (1), whereby the bracket may have a U-shape and is welded, screwed or otherwise connected to the base plate (55) of the lowering device (1), and in that the angle lever (6) may be triangular, rectangular or curved or has another expedient form.

6. Device according to any of the preceding claims, characterized in

that the lifting flank (7) of the lowering device (1) is arranged in a strip (56) on which the roller (20) of the angle lever (6) is guided and in that the strip (56) is arranged on the press carriage (12) and concomitantly performs the downward stroke of the press carriage (12) and in that the angle of gradient and the transition radii (63, 64) of the lifting flank (7) control the lowering speed and the lowering acceleration of the leading lowering means (5) and

that the height of the lifting flank (7) determines the stroke of the leading lowering means (5) and in that the strip (56) may be exchangeable.

7. Device according to Claim 6, characterized in

that the angle lever (6) has at least one axle (18) which is mounted on the bracket (17) and

that the roller (20) of the lowering device (1), while it is running up the lifting flank (7) moving downwards with the press carriage (12), guides the angle lever (6) via the axle (18) in a tilting movement, with the result that the leading lowering means (5) experiences a lowering in the direction of the gripper head (55) via the transmission lever (30) and lowers said gripper head in a leading position relative to the central plunger (8).

8. Device according to any of the preceding claims, characterized in

that the lowering device (1) has two angle levers (6) and two transmission levers (30) which are connected via in each case one joint (4) to in each case an angle lever (6) and via one link (31) each to the lowering sleeve (5a) on the right and left and

that the lowering device (1) has at least one spring (19) which is connected at one end to the angle levers (6) and at the other end to the bracket (17), and the springs (19) press the roller (20) between the angle levers (6) against the lifting flank (7) .

9. Device according to any of the preceding claims, characterized in that an optimized punch (27) has at least one wire guide lug (54) for preliminary centring of the wire end (3) in the crimping position (41), not more than 2 mm above the opened crimping claws (28) of the contact element positioned on the lower punch (26) of the crimping tool lower part (38) .

10. Device according to any of the preceding claims, characterized in

that the lowering sleeve (5a) is superposed on the central plunger (8) at the other end in the direction of the gripper (23) in partial regions in such a way that the lowering sleeve (5a) encompasses the plunger (8) by a defined length which corresponds approximately to the downward stroke of the press carriage (12) to a fifth position (51) and

that the lowering sleeve (5a) is guided in a vertically displaceable manner on the central plunger (8) .

11. Device according to any of the preceding claims, characterized in

that one or more sliding bushes (24) which slide over the plunger (8) are arranged on the inner surfaces of the lowering sleeve (5a) and

that the plunger (8) is simultaneously guided in a vertically displaceable manner along the inner surfaces of the sliding bushes (24) in the lowering sleeve (5a) .

12. Device according to any of the preceding claims, characterized in

that the lowering sleeve (5a) is multi-part and has at least one upper region (5' ) and a lower region I 5' ' )

that the joints (4) of the lowering device (1) are arranged in the upper region (5' ) of the lowering sleeve (5a) , that optionally the lower region (5' ' ) of the lowering sleeve (5a) is made of plastic or another suitable shock-absorbing material and

that the lowering sleeve (5a) has a height adjustment device (58).

13. Device according to Claim 12, characterized in

that the upper region (5' ) of the lowering sleeve (5a) has a fine thread below the joints (4) on its outer surface, in

that the lower region (5'') of the lowering sleeve (5a) has a corresponding fine thread on its inner surface and

that the fine threads form the height adjustment device (58) .

14. Method for lowering and positioning thin wires, in which the stroke of a press carriage (12) and hence of an upper punch (29) is carried out synchronously with the stroke of a central plunger (8) of a crimping station (22), which plunger (8) is arranged on a holder (9), by a common drive, the upper punch (29) being lowered from a first position (43) at an upper dead centre via a second position (45), a third position (47), a fourth position (49), a fifth position (51) to a sixth position (53) at the bottom dead centre with a sinusoidal speed variation and the stripped wire end being positioned in a defined swivel-in position (32) by a gripper head (25) when the upper punch (29) is in the first position (43) at the upper dead centre, characterized in

that the gripper head (25) is lowered, by at least one leading lowering means (5) of a lowering device

(1), coordinated with or superposed on the plunger

(8), in a leading position from the swivel-in position (32) of the stripped wire end (3) to a crimping position (41) with reduced speed relative to the plunger (8) and

that the wire end (3) is moved thereby in a leading position up to an optimized punch (27) in a crimping position (41) as close as possible to the crimping claws (28) with little vibration and in that the wire end (3) is then crimped in a continuous process.

15. Method according to Claim 14, characterized in that the downward stroke of the upper punch (29) begins with a first downward stroke (44) in which a roller

(20) of the lowering device (1) moves on a flat surface (61) of a strip (56) mounted on the press carriage (12), before a lifting flank (7), while the upper punch (29) is moved from the first position (43) to the second position (45) but the gripper (23) remains in the rest position and the wire end (3) remains in the swivel-in position

(32), so that conductor wire or strand (34) of the wire end (3) are calmed following the preceding swivel-in movement of the gripper (23) .

16. Method according to Claims 14 and 15, characterized in that the downward stroke of the upper punch (29) is further carried out continuously with a second downward stroke (46) by moving the upper punch (29) from the second position (45) to the third position

(47), at the same time at least one roller (20) of the lowering device (1) running up at least one lifting flank (7) and one or more angle levers (6) connected to the roller (20) being moved thereby via at least one axle (18) to a more advanced tilting position, with the result that one or more leading lowering means (5) connected to the angle levers (6) and to one articulated transmission lever (30) each are moved from the second position

(45) to the third position (47) until the leading lowering means (5) touches, or the leading lowering means (5) touch, the gripper head (25) with their bottom opening (42) but do not as yet move.

17. Method according to Claims 14 to 16, characterized in that the second downward stroke (46) is followed by a third downward stroke (48) in which the upper punch (29) is moved from the third position (47) to the fourth position (49), at the same time the roller (20) of the lowering device (1) being guided over the lifting flank (7) to the end thereof, and the wire end (3) being moved, by the lowering movement of the gripper (23) triggered by the leading lowering means (5), from the swivel-in position (32) to the crimping position (41) in a leading position, it being possible for the leading lowering means (5) to be, for example, a lowering sleeve (5a) which is superposed on the central plunger (8) .

18. Method according to Claims 14 to 17, characterized in that the third downward stroke (48) is followed by a fourth downward stroke (50) in which the upper punch (29) is moved from the fourth position (49) to the fifth position (51), at the same time the roller (20) of the lowering device (1) moving on a flat surface (62) behind the lifting flank (7), the leading lowering means (5) therefore remaining in its position and no lowering movement being executed even by the wire end (3) and the gripper

(23), and the wire end (3) continuing to remain in the crimping position (41) for further calming of vibration .

19. Method according to Claims 14 to 18, characterized in that the fourth downward stroke (50) is followed by a fifth downward stroke (52) in which the upper punch (29) is moved from the fifth position (51) to the sixth position (53) , at the same time the roller (20) of the lowering device (1) moving further on the flat surface (62) behind the lifting flank (7), the leading lowering means (5) therefore remaining in its position, the plunger head (54) of the central plunger (8) making contact with the gripper head (52) by, for example, passing through the lowering sleeve (5a) at a bottom opening (42), and in this way the wire end (3) being inserted into the opened end of a crimping claw (28) while at the same time the actual crimping process is carried out in a known manner by the upper punch (29) .

20. Method according to Claims 14 to 19, characterized in

that the speed curve and acceleration curve of the leading lowering movement of the wire end (3) is controlled by the angle of gradient and the transition radii (63, 64) of the lifting flank (7) and

that the stroke of the leading lowering means (5) is determined by the height of the lifting flank (7) .

21. Method according to Claims 14 to 20, characterized in that the wire end (3) is positioned with preliminary centring in an optimized punch (27) in the crimping position (41) as close as possible in the opened crimping claws (28) of a contact element positioned on a lower punch (26) of the crimping tool lower part (38) .

22. Method according to Claims 14 to 21, characterized in that the lowering movement of the wire end (3) by the lowering device (1) takes place upstream of the first to fourth downward strokes (44, 46, 48, 50) of the upper punch (29) in a leading position, with reduced speed and with reduced vibration, and only the fifth downward stroke (52), which, owing to the sinusoidal speed variation of press carriage (12) and plunger (8), takes place with reduced speed but with sufficient speed for the crimping process, is carried out synchronously by the upper punch (29) and gripper (23) .

23. Method according to Claims 14 to 22, characterized in that the height of the lowering sleeve (5a) is adjusted via a height adjustment device (58), the height being tailored to the optimized punch (27) of the lower punch (26) of the crimping tool.

24. Method according to Claims 14 to 23, characterized in that a lowering device (1) according to Claims 1 to 13 is used and in that the lowering device (1) for the lowering process has no separate drive device for exact positioning of the wire end (3) with reduced vibration in the crimping position

(41), but the drive device of the crimping station (22) is concomitantly used.