DE10212993A1 - Electrical cable shoe crimping method has cable filaments held together by insulation ring during crimping procedure - Google Patents

Abstract

The crimping method has the insulation stripped from a cable end (12) by axial displacement of a cut insulation section before separation so that an insulation ring remains attached to the cable outer end, for holding the cable filaments together during the crimping of the cable shoe, after which the insulation ring is moved back towards the cable insulation. Also included are Independent claims for the following: (a) a crimping machine; (b) a method for removing the insulation from the end of a cable

Description

The invention relates to a method for crimping an electrical Connecting element according to the preamble of claim 1, a intended crimping machine and stripping process.

Such a crimping machine is, for example, in the patents DE 35 08 354 C1 and DE 43 18 326 C1 of the applicant. These machines are in the Production used to wire ends with electrical connectors, For example, to connect ferrules. The cable end is in one Feed opening inserted, fixed by a holding device and then cut the insulation of the cable end by means of a stripping device and subtracted. Then a wire end sleeve is stripped on the stripped Cable end put on and crimped by means of a crimping device.

With these known crimping machines - also called sling machines - crimping for wire end ferrules with an extremely high Produce clock frequency and thus with high productivity. However, it turned out that the processing of certain connecting elements, such as. Cable lugs cause considerable difficulties. Such cable lugs are punched and bent from a sheet metal part, the contact area approximately has rectangular cross-section, while with the cable end too crimping, tubular end portion, usually of an insulation is covered, is produced by bending the sheet metal jacket and thus on it Inner peripheral wall has interfering edges, which are caused by the peripheral edges of the bent sheet metal jacket are formed. Instead of the open one described above End section, the connecting elements can also be soldered or be sleeve-shaped closed pipe sections. Because of the open tubular end sections existing interfering edges it is very important that the connecting element in a precisely defined position Crimp head is fed so that the stripped cable end into the pipe section can be used without individual strands of the cable on the interference edges run up and be bent over and thus complicate the insertion or even prevent the crimping machine from malfunctioning. This exact  Positioning is used with cable lugs or similar asymmetrical Components further complicated because the central axis of the rectangular Contact area is offset from the central axis of the pipe section, so that it must be ensured that the connecting elements only in one Position are fed to the crimping head. With a twist opposite the predetermined position is an insertion of the cable end in the Pipe section practically impossible.

The invention has for its object a crimping method and one for it to create suitable crimping machine that can also be complex designed connecting elements, such as cable lugs in a simple manner machine processed.

This task is accomplished by a method of crimping an electrical Connecting element with the features of claim 1 and a Crimping machine with the features of claim 3 and a Stripping method according to claim 10 or 11 solved.

According to the invention, the cable end is stripped Insulation ring on the stripped part of the individual strands of the cable end holds together. This prevents the stripped when inserting the stripped Individual strands are bent into the crimp head. At the Attaching the electrical connection element to be crimped, for example the Cable lug, the insulation ring is pushed back so that an exact Insert the cable end without bending the cable strands and at the same time Secure contacting is guaranteed because the insulation ring from the Crimp area is pushed out. This is an extremely simple measure trouble-free automated crimping of even complex electrical components Fasteners guaranteed.

In principle, the prescribed procedure can be performed with the separation an insulation ring to secure the cable end even with stripping machines use that are only intended for stripping cable ends, whereby the crimping process in a separate step with your own machine is carried out. Such a stripping process is the subject of subsidiary claims 10 and 11.  

The isolation ring is preferably produced by the Insulation cut in a first step, then the corresponding one Part of the insulation is removed from the end of the cable until only one is left Insulation ring corresponding part sits on the strands and then in one final operation of this insulation ring from the rest of the peeled insulation is cut off.

Alternatively, part of the insulation can be removed completely first and then the insulation ring separated from the remaining insulation at the front to the end of the cable cross section.

The crimping machine according to the invention must accordingly be such be designed so that they cut the two stages - cutting the Isolation and cutting the isolation ring - as well as the special Pull-off process, in which an insulation ring remains on the cable end can lead, so that the control must be designed accordingly. For the two-stage insulation cutting is preferably a Cutting depth limitation used, which is a first incision limitation for Cutting the insulation and a cut limit to cut the Isolation ring has. The cut-off limit leaves a larger one Depth of cut as the incision limit.

The stripping device is designed so that in the axial direction of the cable different positions can be reached with the cutting blades, so that several variants for producing the insulation ring can be realized.

In a preferred embodiment, the stripping device has two diametrically arranged, mutually movable cutting knives, which are mounted on a common transverse guide via cutting jaws. As Incision limitation is effective in this embodiment cutting stop on which the cutting jaws when cutting the insulation and that when the insulation ring is separated from the movement path the cutting jaw is moved out. With this separation the Clipping limitation effective, through which the further movement of the Cutting jaws to limit the depth of cut is limited.  

As mentioned at the beginning, the exact position positioning of the electrical Fasteners are extremely important. In an advantageous variant of the The invention uses a feed device for the connecting elements which are fed via a feed path. The geometry of the track is like this chosen that the connecting elements have a transfer point only in the correct position reachable. Then the positionally positioned connecting element by means of a transfer device to the crimping head for further processing fed. In this way, the device requires minimal technical effort ensures that even highly complex fasteners with asymmetrical profiles can be fed to the crimping head in the correct position.

The flexibility of the crimping machine according to the invention can be further increased improve if this with a sensor for detecting the cable diameter is executed. The incision depth of the Stripping device to be changed.

Other advantageous developments of the invention are the subject of further subclaims.

The following is an advantageous embodiment of the invention explained in more detail using schematic drawings. Show it

Figure 1 is a schematic plan view of a stripping device of a crimping machine according to the invention.

FIG. 2 shows a pneumatic cylinder arrangement for actuating a slide of the stripping device from FIG. 1;

Fig. 3 shows a device for limiting the cutting depth of the insulation-stripping;

Fig. 4 is a schematic illustration of possible process variants that are feasible with the inventive crimping machine;

FIG. 5 shows a feed device of the crimping machine;

. Fig. 6 is a transfer device for transferring a component to be crimped of the feeding device according to FIG 5 to a crimper of FIG. 7;

Fig. 7 is a crimp with the crimp tool and its actuation means;

Figure 8 is a means for adjusting the crimp height of a crimping tool with a plurality of matrices.

Fig. 9 shows a device for adjusting the size of the connecting element to be crimped.

Details of a crimping machine according to the invention are explained below, which are usually designed with a feed device, a stripping device and a crimping device. The crimping machine contains suitable guiding devices in order to bring the crimping device or the stripping device into the working position with reference to a central insertion device for a cable end 12 . The guide devices can be linear guides, or - as in DE 35 08 354 C1 - a pivotable block which carries a crimping head or the stripping device on the end face, or it can be a swivel plate according to DE 43 18 326 C1 on which the mentioned Units are stored. Since such guide devices are known from the prior art, only the components essential to the invention, ie the stripping device 1 according to FIG. 1 and a feed device 2 for feeding electrical components, in the present case of cable lugs 74 according to FIG. 5 are explained below.

Fig. 1 shows a highly simplified top view of a stripping device 1 of the crimping machine. The stripping device 1 has a longitudinal guide 20 , on which a slide 26 which is displaceable in the axial direction 8 is guided. The slide 26 is displaced via pneumatic cylinders, which are described below with reference to FIG. 2.

A transverse guide 22 is arranged on the chute 26 , on which two cutting jaws 28 , 30 are mounted, each of which carries a cutting knife 32 or 34 . These are provided with V-shaped cutting edges which, when the cutting jaws 28 , 30 move together, practically completely encompass the outer circumference of a cable end 12 to be stripped, the two cutting knives 32 , 34 overlapping one another in sections.

The actuation of the cutting jaws 28 , 30 takes place via two pivoting levers 36 , 38 mounted on the aforementioned slide 26 , one end section of which is connected to the cutting jaws 28 and 30 in an articulated manner. The other end section of the pivot levers 36 , 38 is each provided with an obliquely set control groove 40 , 42 . In the control grooves 40, 42 are two control body 44 out 46, which are formed on a the two pivot levers 36, 38 through executing control Traverse 45th This is mounted on the end section of a feed spindle, not shown, or an actuating cylinder. By means of a feed movement in the axial direction 8, the control bodies 44 , 46 slide in the control grooves 40 , 42 and, accordingly, the pivot levers 36 , 38 are pivoted to close or open the cutting jaws 28 , 30 .

The carriage 26 also carries a stop device 50 . This is provided with an end stop 52 which limits the insertion depth of the cable end 12 to be stripped. This end stop 52 can be designed to be manually or automatically adjustable in order to allow easy adaptation to different cable diameters.

The stop device 50 is axially displaceably mounted on a longitudinal guide 24 . This stop device 50 is actuated via a pneumatic cylinder 48 , the stroke of which is selected such that the stop device 50 can be moved out of a region between the two cutting jaws 28 , 30 .

In Fig. 1, a holding clamp is indicated 54, through which the cable end introduced into the crimping machine 12 is fixed during the peeling of the insulation and during the crimping in the axial direction. 8

FIG. 2 shows a schematic illustration of a pneumatic cylinder arrangement 56 , via which the slide 26 can be axially displaced along the longitudinal guide 20 . That is, The axial position of the slide 26 and thus the effective position of the cutting knives 32 , 34 can be adjusted by suitable control of this pneumatic cylinder arrangement 56 . The pneumatic cylinder arrangement 56 has three cylinders 57 , 58 , 59 , the cylinder 57 having the largest stroke, the cylinder 58 having a substantially shorter stroke and the cylinder 59 the shortest stroke. In the arrangement shown, the cylinder 57 is attached to a bracket 98 of the crimping machine which is fixed to the housing. A piston rod 100 of the cylinder 57 is connected to the cylinder 58 , the piston rod 102 of which is in turn connected to the short-stroke cylinder 59 . A piston rod 104 of this cylinder engages on an end plate 106 fastened to the slide 26 . A series connection is thus formed by the three cylinders 57 , 58 and 59 , the maximum adjustable stroke being adjustable by extending the three cylinders 57 , 58 , 59 , while suitable intermediate positions can be reached by suitable control of one or more of the cylinders.

The retracted position of the three cylinders 57 , 58 , 59 is limited by stops 108 , 110 and 112 , respectively, the stop 108 being arranged on the cylinder 58 , the stop 110 on the cylinder 59 and the stop 112 on the end plate 106 . When the piston rods 100 , 102 , 104 are retracted , these stops 108 , 110 and 112 run onto the adjacent cylinders 57 , 58 , 59 , so that the retracted position is correspondingly limited. The stops 108 , 110 , 112 are designed to be adjustable so that the aforementioned retracted position can be adjusted. The connection between the piston rods 100 , 102 , 104 and the adjacent cylinders 58 , 59 or the face plate 106 can also be adjusted accordingly.

Another feature of the crimping machine according to the invention is that that these are automatically different on the machine control Can adjust sizes of fasteners and cable cross-sections.

I.e. no modifications are necessary to the effective positions and Operating parameters of the stripping device and the crimping device adjust.

FIG. 3 shows a schematic illustration of a cutting depth limitation 114 , by means of which the cutting depth of the cutting knives 32 , 34 ( FIG. 1) can be adjusted.

This cutting depth limitation 114 can be integrated, for example, in the stop device 50 according to FIG. 1. The depth of cut limitation 114 has two stop jaws 116 , 118 which are displaceable in the transverse direction and which are displaceably guided, for example, parallel or coaxially to the transverse guide 22 . Each stop jaw 116 has a pin 120 , 122 , which projects toward the viewer in accordance with FIG. 3 and which interacts in each case with a prism 124 or 126 which can also be displaced in the transverse direction. On the end sections of the prisms 124 , 126 which are removed from the bolts 120 , 122 , an inclined surface is formed in each case, on which the side surfaces of a wedge 128 bear. This is guided in the axial depth 8 in the cutting depth limit 114 and actuated by means of a servomotor, not shown. The prisms 124 , 126 are biased against the wedge surfaces of the wedge 128 by means of springs or similar devices.

The cutting jaws 28 , 30 described with reference to FIG. 1 run onto the stop jaws 116 , 118 when the stripping device is actuated, so that these limit the cutting depth. The distance between the prisms 124 , 126 and thus the stop position of the stop jaws 116 , 118 can be adjusted by axially displacing the wedge 128 . That is, the depth of cut of the stripping device is determined by the axial position of the wedge 128 .

The stripping method shown schematically in FIG. 4 can be implemented by the above-described stripping device according to the invention.

Variant 1 represents a preferred method.

The cable end is inserted into the position shown in Fig. 1 basic position of the stripping device 1 in the crimping machine, until it runs with its end face on the stop means 50. The cable diameter can be detected via a sensor or the like, so that, for example, the insertion length and other control parameters of the crimping device can be adapted. In the area of the stop device, a proximity switch is also provided, which detects the complete insertion of the cable end 12 . Furthermore, depending on the cable diameter detected, a control signal is sent to the cutting depth limiter 114 , so that the wedge 128 is brought into a corresponding position, by means of which the movement of the cutting jaws 28 , 30 is limited. The cable end 12 is fixed in its predetermined relative position by the holding pliers 54 . The pneumatic cylinder unit is brought into the state shown in FIG. 2, in which the piston rods 100 , 102 , 104 are completely retracted. In this position, the carriage 26 is moved completely forward, towards the cable end 12 , so that the cutting knives 32 , 34 are in a plane labeled A in FIG. 4. The stripping device is then actuated by pivoting the pivot levers 36 , 38 and the insulation is cut up to the strands 18 . This depth of cut is predetermined by the position of the wedge 128 .

In the next step, the piston rod 102 of the cylinder 58 is extended, while the other two cylinders 57 , 59 remain retracted. Accordingly, the carriage 26 feeds backwards into the position marked B, the cutting knives 32 , 34 remaining in their engagement position with the insulation of the cable end 12 . Accordingly, the cut part of the insulation is partially stripped from the strands 18 .

The cutting knives 32 , 34 are then moved apart and the piston rod 104 of the cylinder 59 is extended, so that the slide 26 performs a smaller, comparatively short stroke. The opened cutting knives 32 , 34 are then in the plane marked C in FIG. 4. In the next step, the stop device 50 is retracted to such an extent that the cutting depth limitation enables the cable end 12 to be severed completely. The two cutting jaws 28 , 30 are then closed again and a reference cut is carried out, by means of which the part of the insulation and the strand protruding above level C ( FIG. 4) are separated - this part which is separated off is referred to below as waste 16 .

In the final step, the largest cylinder 57 is actuated so that its piston rod 100 extends and the entire slide 26 is moved away from the cable with the cutting blades 32 , 34 .

An insulation ring 14 remains on the cable end 12 , which surrounds the strands so that they are positioned relative to one another. When the connecting element 74 is subsequently put on, this insulation ring 14 is then moved forward again towards the plane labeled A.

With variant 3, a further optimized stripping method is shown in FIG. 4.

After the axial positioning of the cable end 12 via the stop device 50 and the fixing using the holding pliers 54 , the two piston rods 102 , 104 of the cylinders 58 and 59 are first extended, while the cylinder 57 remains in the retracted state. The carriage 26 is displaced in such a way that the two cutting knives 32 , 34 are located in the plane labeled D. The stop device 50 has been extended so far that the cutting knives 32 , 34 can be closed to completely separate the cable end, so that a reference cut is carried out, by means of which the cable end is cut to length along the plane D.

Then the piston rod 102 of the central cylinder 58 is retracted and the slide is moved into the position marked with E. At the same time, the stop device 50 is retracted, so that the stop jaws 116 , 118 are brought into a position in which the depth of cut is limited so that only the insulation is cut. The insulation is then separated by the subsequent moving together of the cutting knives 32 , 34 and the insulation is pulled off when the cutting knives 32 , 34 are engaged by extending the piston rod 102 of the cylinder 58 .

In the next operation, the cutting knives 32 , 34 are opened and the pneumatic cylinder arrangement 56 is brought into the position shown in FIG. 2 (retracted piston rods), so that the cutting knives 32 , 34 are located in the plane labeled F. The position of the cutting depth limiter 114 remains unchanged. The stripping device 1 is then actuated again and the insulation ring 14 is cut off. In the next step, this insulation ring 14 is then moved by extending the piston rod 102 until its front ring surface lies in plane D and the rear ring surface lies in plane G.

The sequence shown in variant 3 has the advantage that the strands are only loaded in tension by moving the insulation ring 14 from position E to position D, while the strands in variant 1 can be compressed into position C by cutting. The disadvantage of variant 3 , however, is that one more activation step is required. In principle, one could also separate the insulation ring 14 beforehand, for example before or after the insulation that has been removed, and then finally move it forward.

The sequences shown as variants 2 and 4 correspond in principle to variants 1 and 3, however the reference cut is omitted in each case. In other words, these variants assume that the end face of the cable end 12 has been cut to length and positioned beforehand with comparatively high precision, so that no reference cut is required. The actuation of the cylinders 57 , 58 , 59 for moving the cutting knives into the planes A, B, C or F, E, D is exactly the same as in the previously described exemplary embodiments, so that the individual steps of variants 2 and 4 do not have to be explained. The strokes of the cylinders 57 , 58 , 59 can be adjusted to a certain extent to change the thickness of the insulation ring 14 and the length of the stripped part.

As already stated above, the stripping device 1 is disengaged by extending all three cylinders 57 , 58 , 59 , so that space is created for engaging the crimping head.

In the next step, a connecting element 74 is then placed on the stripped cable end 12 . The separation and position-oriented feeding of the connecting elements takes place via a feed pot 60 , shown schematically in FIG. 5, in which the connecting elements 74 are accommodated in an unordered manner. The connecting elements 74 are conveyed from this feed pot 60 into a feed path 62 , for example by vibration or the like, and are oriented in a position-oriented manner. This positional orientation takes place in a known manner by means of suitable guide links which are designed such that the connecting elements 74 can only reach a separating block 64 in a predetermined positional orientation. In this separating block 64 , the connecting elements 74 are individually brought into a transfer position in which they are taken over by a feed gripper 66 shown schematically in FIG. 5 and transferred to a transfer gripper 70 shown in FIG. 6. The connecting element 74 is taken over by a transfer gripper 70 with a clamping lever 72 which can be actuated by means of a pneumatic cylinder 76 . The transfer gripper 70 holding the connecting element 74 is designed as a swivel lever which is rotatably mounted in a slide 78 about a swivel joint 77 . This slide 78 can be moved along a longitudinal guide 80 . The slide 78 is displaced and the transfer gripper 70 is pivoted by means of a transfer cylinder 82 , which acts at a distance from the swivel joint 77 on a sliding joint 83 of the transfer gripper 70 .

The connecting element 74 located in the feed gripper 66 is clamped and accepted in the pivot position of the transfer gripper 70 shown by closing the lever 72 . The transfer cylinder 82 is then actuated so that the transfer gripper 70 is pivoted about the swivel joint 77 and is displaced in the axial direction 8 ( FIG. 1) along the longitudinal guide 80 , so that the connecting element 74 with its insulation part is inserted into the tool 92 . Then the tool 92 is moved to the left and to the front and thereby the connecting element 74 is shifted onto the stripped cable end 12 . The insulation ring 14 is shifted forward so that it is moved back into the position marked A or F and the strands 18 are held together during the entire placement process of the connecting element 74 in such a way that bending over is practically impossible. The insulation ring 14 thus remains on the cable end 12 .

After the above-described placement of the connecting element 74 on the stripped cable end 12 , the crimping device 6 of the crimping machine, shown schematically in FIG. 7, is moved into its working position. This crimping device 6 has a crimping head 94 , in which a crimping tool 92 is inserted. In Fig. 7 of the crimping tool 92 is shown in the open state. The tool has a fixed die or tool half 93 and a movable tool half 95 which can be brought into its closed position by means of a toggle lever 90 for crimping. That is, this toggle lever 90 is brought out of its angular position shown by extending a pneumatic toggle cylinder 96 into its extended position, so that the movable tool half 95 moves downward from its position shown in FIG. 7.

Fig. 8 is a front view of essential parts showing the crimping head 94th This has a block 130 on which the fixed tool half (die) 93 is fastened. The movable tool half 95 is fastened to a movable tool clamping plate 132 , which is displaceable along guides 134 . The upper end surface in FIG. 8 is designed as a wedge surface 136 which bears against a sliding wedge 138 which can be displaced in the transverse direction Q. This can be moved in the transverse direction Q by means of a servomotor or cylinder, not shown, so that the closing stroke of the tool 92 is changed accordingly (stroke of the toggle lever 90 remains constant). This means that the crimping depth of the tool can be adjusted by suitable adjustment of the sliding wedge 138 .

According to Fig. 8, the tool 92 has three differently shaped mold cavities 140, 142, 144, so that, depending on the orientation of the tool 92 with respect to the stripped cable end, three different sizes of fasteners 74 can crimp. The tool cavities 140 , 142 , 144 can optionally be brought into their predetermined crimping position with a device shown in FIG. 9.

As already mentioned above, the crimping head 94 after stripping the cable end 12 and the retraction of the stripping device 1 is shifted from its waiting position to the crimping position. In the exemplary embodiment shown, this displacement takes place from a position offset laterally with respect to the cable end 12 along a transverse guide (not shown), the stroke in this transverse direction being adjustable by the sliding stop 146 shown in FIG. 9. This has a rotatably mounted cam roller 148 , the outer circumference of which, according to the side view of the sliding stop 146, has three stop cams 150 , 152 , 154 offset in the axial direction. These each have a front and rear stop surface 156 , 158 , the stop surfaces 156 , 158 of the stop cams 150 , 152 , 154 being offset in this order from right to left (view according to FIG. 9).

By rotating the cam roller 148 , one of the stop cams, for example the stop cam 152, can be brought into an operative position between two stops 160 , 162 of a stop rod 164 , via which the transverse stroke of a sliding flange carrying the crimping head 94 can be limited. In other words, when the crimping head 94 is moved transversely into the crimping position, the stop 160 runs onto the stop surface 156 , while when the crimping head 94 is moved out after the crimping, the end position is predetermined by the stop 162 striking the stop surface 158 . The two stop surfaces 156, 158 are located with respect to the corresponding stop faces of the other stop cams 150, 154 placed in an intermediate position, that is, by this stop cam 152, the cavity 142 in its operative position. In the event that the other two tool cavities 140 , 144 are to be brought into engagement, the cam roller 148 is controlled such that the corresponding stop cam 150 or 154 is brought into the operative position between the stops 160 , 162 .

As already stated above, the drives of the cam roller 148 , the sliding wedge 138 and the wedge 128 can be controlled via the machine control depending on the diameter of the cable end 12 and the size of the connecting element 74 to be crimped, so that the desired parameters are set automatically without that manual intervention is required.

A crimping method and a crimping machine for pressing are disclosed an electrical connecting element, in particular a cable lug and a stripping method by means of which a cable end is stripped in such a way that an insulation ring remains on the stripped part. This isolation ring will when putting the cable lug back out of the contact area pushed.  

LIST OF REFERENCE NUMBERS

1

stripping device

2

feeding

4

Transfer device

6

crimper

8th

axially

12

cable end

14

insulation ring

16

waste

18

strands

20

longitudinal guide

22

width guide

24

longitudinal guide

26

carriage

28

dies

30

dies

32

cutting blade

34

cutting blade

36

pivoting lever

38

pivoting lever

40

control groove

42

control groove

44

control body

45

Traverse control

46

control body

48

pneumatic cylinder

50

stop device

52

end stop

54

holding forceps

56

Pneumatic cylinder arrangement

57

cylinder

58

cylinder

59

cylinder

60

feeder bowl

62

feed

64

singling unit

66

feed gripper

70

Transfer gripper

72

clamping lever

74

connecting element

76

pneumatic cylinder

77

pivot

78

carriage

80

longitudinal guide

82

Transfer cylinder

83

sliding joint

90

toggle

92

Tool

93

fixed tool half

94

crimphead

95

movable tool half

96

Toggle cylinder

98

console

100

piston rod

102

piston rod

104

piston rod

106

faceplate

108

attack

110

attack

112

attack

114

Cutting depth limit

116

stop jaws

118

stop jaws

120

bolt

122

bolt

124

prism

126

prism

128

wedge

130

block

132

movable tool clamping plate

134

guide

136

wedge surface

138

spline

140

mold cavities

142

mold cavities

144

mold cavities

146

sliding stop

148

Nockenwalze

150

stop cam

152

stop cam

154

stop cam

156

front stop surface

158

rear stop surface

160

attack

162

attack

164

stop rod

166

sliding flange

Claims (12)

1. A method for pressing an electrical connecting element, in particular a non-rotationally symmetrical one with a cable end ( 12 ), comprising the steps:

• - cutting and peeling insulation of the cable end ( 12 ),
• - pressing the connecting element ( 74 ) with the cable end ( 12 ),

characterized in that an insulation ring ( 14 ) is separated which, after the insulation has been removed, is arranged in the region of the cable end ( 12 ) in such a way that its strands ( 18 ) are held together and that when the connecting element ( 74 ) is placed on the cable end ( 12 ) the insulation ring ( 14 ) is pushed back towards the remaining insulation. 2. The method according to claim 1, wherein after cutting the insulation, a separated insulation part is moved until only one of the insulation ring ( 14 ) remains on the cable end ( 12 ). 3. crimping machine, in particular for performing the method according to claim 1 and 2, with a crimping head for pressing a cable end ( 12 ) with an electrical connecting element ( 74 ) and with a stripping device ( 1 ) for stripping the cable end ( 12 ), which is a cutting device ( 32 , 34 ) for cutting the insulation and a pulling device for pulling off a cut insulation part of the insulation, characterized by a control for driving the pulling device in such a way that the insulation part is not completely pulled off the cable end ( 12 ), and for driving the cutting device ( 32 , 34 ) for cutting the insulation and for separating the insulation ring ( 14 ) remaining on the cable end ( 12 ). 4. Crimping machine according to claim 3, wherein the stripping device ( 1 ) has an adjustable depth of cut limitation. 5. Crimping machine according to claim 4, wherein two diametrically arranged cutting knives ( 32 , 34 ) are fastened on two coaxially guided cutting jaws ( 28 , 30 ), which are movable towards or away from each other, and with a cutting stop ( 50 ) as a cutting limitation , on which the cutting jaws ( 28 , 30 ) run when cutting and which can be moved to separate the insulation ring ( 14 ). 6. Crimping machine according to one of claims 3 to 5, wherein the stripping device ( 1 ) for carrying out the pulling movement is mounted on a longitudinal guide ( 20 ) extending parallel to the cable axis. 7. Crimping machine according to one of the claims 3 to 6, wherein the crimping head ( 94 ) is assigned a feed device ( 2 ) with which the connecting elements ( 74 ), in particular not rotationally symmetrical in the correct position, can be transferred to the transfer device ( 4 ). 8. Crimping machine according to one of the claims 7, with a transfer device ( 4 ), via which the connecting element ( 74 ) located in the defined transfer position can be transferred to the crimping head ( 92 ). 9. crimping machine according to one of the preceding claims 3 to 8, wherein a sensor for detecting the cable diameter and a Has device for adjusting the cutting depth. 10. A method for stripping a cable end ( 12 ), comprising the steps:
Cutting the insulation, pulling off the insulation such that a portion of the cut insulation remains on the cable end and cutting off the insulation ring ( 14 ) remaining on the cable end ( 12 ) from the removed insulation. 11. Method for stripping a cable end ( 12 ) with the steps:
Cutting the insulation, pulling off the cut off part of the insulation, separating an insulation ring ( 14 ) from the remaining insulation and moving the insulation ring ( 14 ) towards the end of the cable end ( 12 ). 12. The method according to claim 10 or 11, wherein a reference cut is carried out through which a part of the insulation and the cable strands ( 18 ) is separated from the cable end ( 12 ).