EP2006963B1 - Attachment method for a cable lug and cable bending device - Google Patents

Abstract

The method involves detaching an insulation of an end section of a cable (10). An end side section (20) is bended of the stripped end section of the cable. The stripped end section is inserted into the crimping section of a cable lug. The cable is attached in the cable lug by deforming the crimping section. Independent claims are also included for the following: (1) a cable with a cable lug (2) a cable bending device for bending an end side section of a stripped end section of an electrical cable.

Description

The invention relates to a method for fastening an electrical cable to a cable lug with at least one deformable crimping section. The invention further relates to a cable bending device.

In the cabling of electrical systems, especially in the automotive sector, cable lugs are often used, which are attached by means of a crimp on the cable. In the automotive field, a variety of cables are assembled into harnesses or harnesses. Due to the increasing number of electrical consumers installed in a motor vehicle, the amount of cables required also increases. In view of the associated cost increase and the increase in vehicle weight, the aim is to reduce the cable cross-section of the individual cables. Nevertheless, even a cable with a small cable cross-section should be reliably attached to a cable lug. However, it should be avoided to provide special cable lugs for cables with a small cross section. Nevertheless, the criteria of good processability and secure contacting must be met, in particular in the case of automated production.

Out US 3,871,932 A For example, a method for connecting two insulated electrical conductors is known. Accordingly, the two ends of the conductor are stripped and bent back over their entire length. Then, the ends of the two conductors are folded together so that the stripped and bent back end portions are aligned side by side. Finally, the two ends are connected to each other by means of a metallic crimp barrel.

Out EP 0 485 963 A1 a cable bending apparatus is known in which the exposed end portion of a cable core is first bent vertically by means of a vertically acting heating press. The portion bent over by 90 ° is then bent by a further 90 ° by means of a further, horizontally acting heating press, so that the cable core finally has a U-shape.

The object of the present invention is therefore to provide a method for fastening an electrical cable to a cable lug with at least one deformable crimp section, which also provides a reliable mechanical and electrical connection for cables with a small cross-section. It is another object of the present invention to provide a cable bending apparatus for preparing an electrical cable for a crimped connection.

• ein Entfernen der Isolierung von einem Endabschnitt des Kabels;
• ein Umbiegen eines endseitigen Teilabschnitts des abisolierten Endabschnitts des Kabels;
• ein Einlegen des abisolierten Endabschnitts in den Crimpabschnitt des Kabelschuhs; und
• ein Befestigen des Kabels und Kabelschuh durch Verformen des Crimpabschnitts.

The object is achieved by a method having the features of claim 1 and by a cable made by this method. The method according to the invention for fastening an electrical cable having conductors surrounded by insulation to a cable lug with at least one deformable crimp section comprises:

• removing the insulation from an end portion of the cable;
• bending over an end portion of the stripped end portion of the cable;
• inserting the stripped end section into the crimp section of the cable lug; and
• attaching the cable and cable lug by deforming the crimping section.

In the method according to the invention, the conductor cross-section of the fastening region of the cable to be inserted into the crimp section of the cable lug is doubled by the bending over of the end-side section of the stripped end section. As a result, a sufficient number of wires in the region of the crimp section of the cable lug is available in order to produce a mechanically durable connection between cable lug and cable. Since the circumference of the cable in the fastening area and thus the electrical contact area is increased by bending, a reduction of the contact resistance between the cable and cable lug and therefore an improvement of the electrical conductivity is achieved.

Furthermore, for such a connection cable lugs can be used, which were originally intended for a larger nominal line cross-section. This reduces the manufacturing costs, since no special cable lugs for the cable with a smaller cable cross-section must be developed, manufactured and kept available. Thus, for example, a cable lug, which is released for cable cross-sections of 0.22 to 0.35 mm ² , are also connected to a cable with a cable cross section of originally 0.13 mm ² , since by applying the method according to the invention, its line cross-section in the crimp increased to 0.26 mm ² and thus lies within the release range.

Furthermore, the tools provided for crimping cable lugs for a specific nominal cross section can continue to be used.

In a preferred variant of the method, the length of the bent portion is substantially equal to half the length of the stripped end portion. This means that the wire ends of the bent section are bent back to the vicinity of the insulation of the cable. This avoids that the wires partially cover the insulation with too long dimensioned part of the insulation and thus impair an additionally provided crimp fastening of the insulation on the cable lug or ensure too short bent section no consistent cross-section within the crimp.

The length of the stripped end section is preferably at least equal to twice the length of a stripping length predetermined for the crimping section, in particular equal to twice the length of the crimping section.

This ensures that the entire crimp section can be filled with cable cores with the same overall cross-section. But it is also possible to strip the end portion to a length which is shorter than twice the length of the crimping, in which case the crimping is depending on the aspect ratio of the bent and remaining portions only partially filled with wires or at least only partially wires with double cross-section while in another part the cross section corresponds only to the simple cross section of the cable.

It is advantageous if the section is bent over to a bending angle of about 180 °. Characterized the cores of the section are parallel to the cores of the non-bent portion of the stripped end portion, whereby the insertion of the stripped end portion is facilitated in the crimping portion of the cable lug. It is prevented that individual wires protrude from the crimping section of the cable lug and are not covered by the crimping elements.

In an advantageous variant of the method, the bending of the section comprises a first turn and a subsequent second turn each at an angle of about 90 °. This also achieves a parallel alignment of all wires in the crimping section. However, the bending process is simplified by the two-stage bending, since the portion to be bent does not need to be grasped and bent by a rotational movement of about 180 °, but also by two translational movements of suitable means each can be bent perpendicular to the section.

Preferably, the bent over to about 180 ° portion is pressed together by a pressing means with the remaining end portion. hereby the end portion is brought into a compact form, so that a particular in the insertion of the stripped end portion in the crimping section disturbing protruding individual cable cores is avoided from the crimping.

It is also advantageous if the cable is cut off before removing the insulation at a different angle of inclination of 90 ° to the longitudinal axis of the cable to provide an inclined end face of the end portion, wherein the inclination angle is chosen so that the end face of the bent portion in the Substantially perpendicular to the longitudinal axis of the cable. Since the inner strands are bent with a smaller radius than the outer strands when the section is bent over, the strands in the region of the section move longitudinally relative to one another. As a result, with a cable cut vertically, the ends of the inner wires would be closer to the insulation than the ends of the outer wires. Since it is to be avoided that individual wires protrude from the crimping portion of the cable lug, or the cross-section decreases to the insulation-side end of the crimping portion, therefore, the cable is cut off before the bending operation at a corresponding inclination angle, which compensates for the displacement of the wires to each other.

The object of the invention is further achieved by a cable bending device with the features of claim 9. The cable bending device according to the invention for bending an end portion of a stripped end portion of an electric cable comprises a guide in which the cable is slidably guided in its longitudinal direction, a bending element adjacent to an end portion of the guide, which is displaceable for a first turn of the portion perpendicular to the guide is and arranged adjacent to the bending element Gate element, which has an opening provided for a following on the first turning second turning of the section opening, which is tapered in a direction away from the guide direction.

Such a cable bending device makes it possible to perform the bending of the section largely automated. The bending element causes by a displacement movement perpendicular to the guide the first turn, while by a relative movement of the cable and the link element, the second turn of the section takes place in a bent position.

The cable bending apparatus may be operated according to a method having the features of claims 13 to 15.

According to a preferred embodiment, the bending element has a recess which is in particular curved in the form of a dished to receive the bent section. This ensures compliance with a predetermined bending radius and prevents shearing of the section between the guide and the bending element, since the recess ensures successive bending and picking up of the section.

The partial section is preferably bendable by a displacement of the cable in the longitudinal direction following the first turning and a cooperation therewith with the sliding element on the bending angle of approximately 180 °. This simplifies the construction of the cable bending device, since the link element can be arranged rigidly with respect to the guide and the relative movement required for the second turn can be effected solely by an already provided displacement of the cable.

According to an advantageous embodiment of the invention, a pressing means for compressing the bent portion is arranged with the remaining end portion adjacent to the tapered side of the opening of the link element. Thus, the cable bending device can additionally make the compression of the bent portion with the end portion. Furthermore, it is avoided that get caught in a retraction of the cable from the cable bending device individual wires with the link element.

Preferably, electrical and / or mechanical funding for moving the cable are provided. As a result, the bending process can be further automated.

In an advantageous embodiment, the opening of the link element allows the cable to pass through the link element. The opening in the link element is therefore chosen so large that the cable can be passed together with its insulation through this opening. This allows a continuous operation of the cable bending device and avoids a time-consuming retraction of the cable.

In an advantageous development, the pressing means comprises at least one roller. As a result, a continuous compression of the bent portion is achieved together with the passage of the cable through the gate element.

Preferably, the roller has a groove. As a result, the compressed end portion of a certain, preferably round cross-sectional shape be given to make subsequent insertion into the cable lug and the crimping reliable.

Fig. 1A bis 1C

Seitenansichten eines Endabschnitts eines elektrischen Kabels in verschiedenen Biegezuständen;

Fig. 2A und 2B

perspektivische Ansichten eines Kabelschuhs und eines elektrischen Kabels vor und nach der Befestigung des Kabels von Fig. 1C an dem Kabelschuh;

Fig. 3A bis 3D

Schnittansichten einer erfindungsgemäßen Kabelbiegevorrichtung und eines elektrischen Kabels in verschiedenen Zuständen;

Fig. 3E

eine perspektivische Ansicht eines Biegeelements der Kabelbiegevorrichtung von Fig. 3A bis 3D; und

Fig. 3F

Schnittansicht einer Presswalze der Kabelbiegevorrichtung von Fig. 3A bis 3D.

The invention will be explained below with reference to an embodiment with reference to the drawing; in this show:

Fig. 1A to 1C

Side views of an end portion of an electric cable in different bending states;

FIGS. 2A and 2B

perspective views of a cable lug and an electric cable before and after the attachment of the cable Fig. 1C on the cable lug;

Fig. 3A to 3D

Sectional views of a cable bending device according to the invention and an electrical cable in different states;

Fig. 3E

a perspective view of a bending element of the cable bending device of Fig. 3A to 3D ; and

Fig. 3F

Section view of a press roll of the cable bending device of Fig. 3A to 3D ,

Fig. 1A shows a cable 10 having a plurality of cores 14 sheathed with an insulation 12. The insulation 12 has been removed in the region of an end section 16. The end face 18 of the cable 10 is inclined to the longitudinal axis, wherein the inclination angle is about 45 °.

Fig. 1B shows the cable 10 of Fig. 1A after a first turn. A portion 20 of the stripped end portion 16 is at an angle bent from about 90 °. The length of the section 20 is about half the length of the stripped end portion 16.

Fig. 1C shows the cable 10 of Fig. 1B after making a second turn. As a result, the portion 20 has been bent by a further 90 °, so that its wires 14 are parallel to the wires 14 of the non-bent end portion 16 and the end face 18 is adjacent to the insulation 12.

In Fig. 2A a lug 22 is shown having a contact portion 24 at one end. This contact portion 24 is executed in the example shown as a pin, with basically cable lugs can be used with other types of contact portions.

At the other end of the cable lug 22 there is an insulation crimping section 28 for attachment to the insulation 12. Adjacent thereto is a wire crimping section 26 for receiving the end section 16 including the partial section 20 bent over by 180 ° Fig. 1C intended.

The cable 10 is in Fig. 2A Already aligned in the longitudinal direction of the cable lug 22 and is inserted in this orientation in the crimping sections 26, 28.

The invention can be used both in the open lugs 22 shown here, in which the end portion 16 of the cable 10 in the claw-shaped crimping sections 26, 28 is inserted, as well as in closed lugs, not shown here, in which the cable in the axial direction is inserted into sleeve-shaped crimping sections, apply.

Fig. 2B Now shows the cable 10 in a state connected to the cable lug 22, wherein the crimping portions 26, 28 are deformed such that they embrace the wires 14 and the insulation 12 frictionally. As can be seen, the insulation 12 terminates immediately before the end of the wire crimping portion 26. At the other end, the wires 14 protrude slightly beyond the opposite end of the wire crimping portion 26. As a result, a complete filling of the wire crimping section 26 is always ensured, ie the line cross section in the region of the end section 16 including the bent section 20 is over the entire length of the wire crimping section 26 twice the original line cross section of the cable 10.

According to a variant of the method, a remaining portion of the insulation 12 may remain immediately at the front end of the end portion 16, i. the insulation is not completely removed from the end portion 16. The end section 16 is bent in such a way that this residual section comes to lie next to the insulation 12 in the region of the insulation crimp section 28. By the associated increase in the degree of filling of the insulation crimping section 28, the fastening of the insulation 12 on the cable lug 22 can be improved.

The Fig. 3A to 3D show a schematic representation of a cable bending device 30, which is suitable for carrying out the method according to the invention. It comprises a cuboid base body 32, in which a guide 34 is provided for the cable 10. The guide 34 is designed as a cylindrical bore whose diameter is slightly greater than the outer diameter of the cable 10 including the insulation 12 is.

On a side surface of the base body 32 a displaceable perpendicular to the guide 34 bending element 36 is provided, which releases the opening of the guide 34 in a basic position, but this sweeps over in the course of a sliding movement.

As in Fig. 3E can be seen, in the bending element 36 in the region of an end face 40 and a longitudinal surface 42, an approximately semi-cylindrical recess 38 is introduced. In the end face 40 opposite end portion, the recess 38 is rounded like a backdrop.

Adjacent to the bending element 36, a funnel-shaped gate element 44 is arranged, which tapers from its side facing the base body 32 in the longitudinal direction of the guide 34 to an outlet opening 46. Behind the outlet opening 46, a pair of opposing pressure rollers 48 is provided, which according to the longitudinal section of Fig. 3F are provided with a circumferential groove 50.

With reference to the Fig. 3A to 3D Hereinafter, a method of bending the subsection 20 will be described.

As in Fig. 3A can be seen, the cable 10 is inserted into the guide 34 so far that the portion 20 of the stripped end portion 16 protrudes from the guide 34 at the other end.

According to Fig. 3B Now, the bending element 36 is moved out of its basic position. It captures with its end face 40 the subsection 20 and bends it by an angle of about 90 °. The backdrop-shaped recess 38 causes a guide of the section 20 and finally takes this completely, so that a shearing of the section 20 is prevented by the bending element 36.

Subsequently, according to Fig. 3C the bending element 36 is pushed back into its normal position and the cable 10 is displaced in the direction of the link element 44. In this case, the portion 20 is detected by the link element 44 and further bent in the course of the sliding movement of the cable 10 until the end of the cable 10 reaches the outlet opening 46.

If according to Fig. 3D the cable 10 is pushed further through the link element 44 passes, the end portion 16 passes between the pressure rollers 48. These cause on the one hand a reduction of the bending radius and on the other a compression or compaction of the wires 14 in the region of the end portion 16, whereby the end portion 16 due the contour of the circumferential grooves 50 receives an approximately circular cross-section.

The cable bending device described above can be provided in particular as an additional module for a cutting machine for the assembly of cables.

LIST OF REFERENCE NUMBERS

10

electric wire

12

insulation

14

veins

16

end

18

face

20

part Of

22

lug

24

Contact section

26

Aderncrimpabschnitt

28

Isolierungscrimpabschnitt

30

Cable bending device

32

body

34

guide

36

flexure

38

recess

40

face

42

longitudinal surface

44

link element

46

outlet opening

48

press roll

50

circumferential groove

Claims (15)

1. Method for fastening of an electrical cable (10), comprising leads (14) enclosed by insulation (12), to a lug (22) with at least one deformable crimping section (26, 28), comprising:

   removing the insulation (12) from an end portion (16) of the cable (10);

   bending an end-side section (20) of the stripped end portion (16) of the cable (10);

   inserting the stripped end portion (16) into the crimping section (26) of the lug; and

   fastening the cable (10) in the lug (22) by deforming the crimping section (26, 28).
2. Method according to claim 1,
   thus characterized,
   that the length of the bent section (20) is essentially equal to half of the length of the stripped end portion (16).
3. Method according to claim 1 or 2,
   thus characterized,
   that the length of the stripped end portion (16) is at least equal to the double length of a predetermined stripping length for the crimping section (26), in particular equal to the double length of the crimping section (26).
4. Method according to one of the preceding claims,
   thus characterized,
   that the section (20) is bent to a bending angle of approximately 180°.
5. Method according to one of the preceding claims,
   thus characterized,
   that bending the section (20) includes a first bending and a subsequent second bending respectively about an angle of approximately 90°.
6. Method according to claim 4 or 5,
   thus characterized,
   that the approximately 180° bent section (20) is pressed together with the remaining end portion by pressing means (48).
7. Method according to one of the preceding claims,
   thus characterized,
   that the cable (10), prior to removal of the insulation (12), is cut off in an inclination angle other than 90° to the longitudinal axis of the cable (10), to create an inclined front surface (18) of the end portion (16), wherein the inclination angle is selected so that the front surface (18) of the bent section (20) runs essentially vertical to the longitudinal axis of the cable (10).
8. Cable (10) with at least one lug (22), manufactured by a method according to one of claims 1 to 7.
9. Cable bending device (30) for bending an end-side section (20) of a stripped end portion (16) of an electrical cable (10), with a guide (34), in which the cable (10) is movable provided in its longitudinal direction, a bending element (36) adjacent to an end area of the guide (34), which is movable vertical to the guide (34) for a first bending of the section (20), and a link element (44) disposed adjacent to the bending element (36), comprising an opening for a second bending of the section (20) subsequent to the first bending, which is tapered in a direction away from the guide (34).
10. Cable bending device according to claim 9,
    thus characterized,
    that the bending element comprises a recess (38), in particular link-curved, for reception of the bent section (20).
11. Cable bending device according to claim 9 or 10,
    thus characterized,
    that the section (20) is bendable by moving the cable (10) in longitudinal direction, subsequent to the first bending, and thereby cooperating with the link element (44), to the bending angle of approximately 180°.
12. Cable bending device according to one of the claims 9 to 11,
    thus characterized,
    that a pressing means (48) is disposed adjacent to the tapered side of the opening (46) of the link element (44) for pressing together the bent section (20) with the remaining end portion.
13. Method for operation of the cable bending device (30) according to claim 9 to 12, comprising:

    inserting the cable (10) into the guide (34), so that the section (20) protrudes from the guide (34);

    shifting the bending element (36) to bend the section (20) of a bending angle of approximately 90°; and

    shifting the cable (10) into the opening of the link element (44) to bend the bent section (20) further to approximately 180°.
14. Method according to claim 13,
    characterized by
    shifting the cable (10) through the pressing means (48), to thereby press together the bent section (20) with the remaining end portion (16).
15. Method according to claim 14,
    characterized by
    shifting back the bending element (36), subsequent to shifting the bending element (36), to release the guide (34).

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