Device and method for crimping connection elements, and crimping connection

Abstract

A device (1) for crimping connection elements (2). The device (1) comprises a machine frame (5), at least one punch, a drive assembly, at least one anvil (17), and a working chamber (31). The punch (3) is preferably arranged in a movable manner in relation to the machine frame (5). The punch (3) contains at least one working surface (4) for deforming a connection element (2). The drive assembly for moving the punch (3) is connected to the punch. The anvil (17) is connected to the machine frame (5) and has a receiving surface (8) for the connection element (2). The working chamber is located between the punch and the anvil and is opened and closed by a relative movement between the punch and the anvil. The device has at least one sonotrode, by which the receiving surface (8) of the anvil (17) is supplied with ultrasound.

Claims

1. A device for crimping of connection elements with electrical conductors, wherein the device comprises: at least one die, having a recess for deforming crimping tabs, with at least one working surface for deforming a connection element, a drive assembly for moving the at least one die, at least two anvils, wherein each of the at least two anvils has a receiving surface for the connection element, a working area between the at least one die and the at least two anvils is openable and closeable by a relative movement between the at least one die and the at least two anvils, wherein the device has at least one sonotrode, by which ultrasound is introducible into the receiving surface of only a first one of the at least two anvils such that an electrical conductor is ultrasonically welded to the connection element, the at least two anvils are decoupled from each other with regard to vibration.

2. The device according to claim 1, wherein the first anvil of the at least two anvils is releasably connectable to the at least one sonotrode.

3. The device according to claim 1, wherein the at least one sonotrode forms at least part of the first anvil.

4. The device according to claim 1, wherein torsional vibrations about an axis perpendicular to the receiving surface of at least the first anvil or longitudinal vibrations along an axis parallel or transverse to the receiving surface of at least the first anvil are introducible into the receiving surface of the first anvil, and the at least one sonotrode vibrates with a frequency greater than or equal to 20 kHz.

5. The device according to claim 1, wherein the device further comprises a machine frame and wherein at least a portion of the first anvil is decoupled from the machine frame with regard to vibration and the first anvil is not moveable relative to the machine frame during a crimping process.

6. The device according to claim 1, wherein the working surface is curved such that a contact surface between the at least one die and the at least two anvils is minimized.

7. A use of a device according to claim 1, for compressing a stranded conductor.

8. A method for producing a connection between an electrical conductor and a connection element involving the following steps: introducing the connection element into an opened working area, which is defined by at least two anvils and a movable die, wherein the at least two anvils are decoupled from each other with regard to vibration and wherein each of the at least two anvils has a respective receiving surface; inserting one end of an electrical conductor into the connection element; closing the working area with the movable die, wherein during the closing, at least one working surface of the die and at least one of the at least two receiving surfaces of the anvils deform the connection element so that a force-locking contact is created between the electrical conductor and the connection element; and introducing ultrasound by a sonotrode into only one of the at least two receiving surfaces of the anvil during and/or said deforming of the connection element such that the electrical conductor is ultrasonically welded to the connection element.

9. The method according to claim 8, wherein, upon closing the working area, a first segment of the connection element is connected to a portion of the electrical conductor by a first receiving surface of the anvil and a first one of the at least working surfaces of the die, and upon closing of the working area a second segment of the connection element is connected to the electrical conductor by a second one of the receiving surfaces of the anvil or a receiving surface of a second anvil and a second working surface of the die or a working surface of a second die.

10. The method according to claim 9, wherein the ultrasound is introduced only into the first receiving surface.

11. The method according to claim 8, further comprising introducing torsional ultrasound vibrations into the connection element.

12. The method according to claim 8, further comprising transmitting an ultrasound pulse into the connection element at least upon maximum force application between the die and the connection element.

13. The device according to claim 1, wherein the at least two anvils are decoupled from each other with regard to vibration by a spacing.

14. The method according to claim 8, wherein the at least two anvils are decoupled from each other with regard to vibration by a spacing.

15. The method according to claim 8, wherein the anvils are decoupled with regard to vibration by a dampening material which is arranged between the anvils.

16. The method as according to claim 15, wherein the dampening material is a foil.

Description

(1) The invention shall be explained more closely below with the aid of figures, which show only exemplary embodiments. There are shown schematically:

(2) FIG. 1: a perspective view of a device for crimping.

(3) FIG. 2: a cross section of a die and an anvil of a device for crimping.

(4) FIG. 3: a perspective detailed view of the device for crimping.

(5) FIG. 4: a perspective view of the device for crimping.

(6) FIG. 5: a perspective view of a lower machine portion of the device for crimping.

(7) FIG. 6: a side view of the device for crimping.

(8) The perspective view in FIG. 1 shows a device for crimping 1. In FIG. 1, the device 2 is shown in an open position. An upper machine portion 26 (see FIG. 2) has been pushed upward in the direction 30.

(9) FIG. 1 shows the lower machine portion 25 of the device. A plurality of connection elements 2 is conveyed in the lower machine portion 25. The connection elements 2 are each connected to a carrier strip 9 for the connection elements 2. A contact is provided between the connection element 2 and the carrier strip 9. The connection elements 2 themselves contain a first pair of crimping tabs 10 for a crimp around an electrical conductor (not shown) and a second pair of crimping tabs 11 for a tension relief crimp around an insulation of the conductor. Furthermore, each connection element 2 contains a terminal part 12, by which the conductor can then be connected to a terminal. The carrier strip 9 transports the connection elements 2 along a transport direction 21 into the crimping device 1.

(10) The device 1 contains a machine frame 5, by which all the machine portions are connected. The connection elements are crimped at a lower tool 7 and a die 3 (see FIG. 2). The tool 7 and the die 3 are located at a holding surface 23 for the carrier strip 9 of the connection elements 2 and a bearing surface 29 for the terminal part. The tool 7 with two anvils 17, 18 is located between these two surfaces.

(11) When the die 3 (see FIG. 2) moves against the tool 7, the holding surface 28 with the carrier strip 9 is forced downward. The contact between carrier strip 9 and connection element 2 is severed by a spring-loaded blade. In this way, the contact between the carrier strip 9 and the connection element 2 is interrupted. After the crimping process, the die 3 moves away from the tool 7 and the conductor with the connection element is removed from the working area 31. After this, a new connection element 2 is supplied into the working area 31 in that the carrier strip 9 pushes the connection elements 9 in the direction 21.

(12) FIG. 2 shows a cross section of a cutout of the device 1 in a plane formed by the transport direction of the connection elements 21 and a perpendicular direction 30. In FIG. 2, a crimping process at the first pair of crimping tabs 10 is illustrated. Prior to the process, an electrical conductor is stripped of its insulation at one end. This frees up single conductors 23 of a stranded conductor. In the first step of the process, the connection element 2 is placed in a working area 31. The working area 31 is formed by the die 3 and the anvil 7. The connection element 2 is introduced by the carrier strip 9 into the working area 31. The free end of the stranded conductor is introduced by a pit 32 (see FIG. 5) into the connection element 2, so that the free single conductors 23 lie between the first pair of crimping tabs 10 and the insulation of the conductor lies between the second pair of crimping tabs 11 (not shown). The die 3 of the upper machine portion 26 then moves in the direction ox the tool 7. The die 3 is driven with an eccentric press. The die 3 has a working surface 4. The working surface 4 deforms the connection element 2. The working surface 4 shown produces a so-called B-crimp. Furthermore, the working surface 4 has a curvature 20, against which the first pair of crimping tabs 10 slides and is deformed. By the working surface 4, the crimping tabs are at first bent inward and then downward. The deformation of the crimping tabs is plastic. During the deformation, the single conductors 23 are pressed against each other by the crimping tabs 10. The single conductors 22 are pressed against each other such that little or no free gaps are present between the individual single conductors 22. Moreover, the connection element 2 is pressed against a receiving surface 6 of the anvil by the pressure of the die 3.

(13) While the connection element 2 is being plastically deformed by the die 3, at the same time ultrasound is introduced into the connection element 2 and into the single conductors 22 via the receiving surface 8. The tool 7 vibrates about an axis 27 in a direction of vibration 22. The vibration is transmitted from the anvil 18 to the receiving surface 8 and from the receiving surface 8 to the connection element 2 and the single conductors 22. This vibration at ultrasound frequency produces friction between the individual single conductors 22 and between the crimping tabs 10 and the single conductors 22. The friction brings about a welding and breaks up an oxide layer on the outside of the conductor. In this way, the single conductors 23 are welded and an electrical resistance at the junction between single conductors 23 to the connection element 2 is reduced.

(14) FIG. 3 shows a detailed view of the crimping device 1. In FIG. 3, the holding surface 28, the bearing surface 23 and the receiving surface 8 can be seen in detail. The tool 7 contains a first anvil 17 for an insulation crimp and a second anvil 18 for the conductor crimp. The anvil 11 for the insulation or crimp crimps the second pair of crimping tabs 12. The anvil 16 for the conductor crimp crimps the first pair of crimping tabs 10. The die 3 accordingly has two anvils 17, 16, with which the crimping tabs 10, 11 are deformed.

(15) FIG. 4 shows schematically a system for producing torsional ultrasound vibrations. The system contains two ultrasound converters 13. The ultrasound converters 13 are connected to a torsional oscillator 14. The torsional oscillator 14 is a cylindrical body to whose shell surface the converters 13 are connected on opposite sides. The converters 23 vibrate in push-pull fashion. In this way, a torsional movement is generated about the axis 27 of the converter itself.

(16) The torsional oscillator 14 is held by a zero-point mounting with a flange 35. The flange 35 is shrink-fitted on the torsional oscillator at an oscillatory node of the torsional oscillator 14. The flange 35 holds the torsional oscillator 14 by resting against beams 36. At the same time, the flange 35 is pressed from above against the beams 36 by clamping devices 37.

(17) The torsional oscillator is connected to a transformation piece 24, configured according to the desired amplitude of vibration. The transformation piece 24 is adjoined by a sonotrode 19, forming the anvil 28 for the crimping.

(18) FIG. 5 shows a further schematic view of the crimping device 1. In FIG. 5, one conceivable height adjustment for the anvil 18 is shown. By activating, that is, by turning the wheel 15, the anvil 17 is displaced in the direction of the axis 27.

(19) FIG. 6 shows a side view of the crimping device 1. In the device 1, the anvils 17, 18 are separated by a gap 33 and do not touch. The gap is broader than the amplitude of vibration with which the anvil 18 vibrates. The anvil 28 is likewise decoupled in vibration from the machine frame 5 by a second gap 34. In addition, the anvil is connected by the zero-point mounting with flanges to the machine frame (see FIG. 4).