Crimping device, method for producing a crimp connection and combination of an electric conductor and an electric connector

Abstract

The invention relates to a crimping device (1) for crimping a crimping sleeve (2) onto an electric conductor (3), wherein the crimping device (1) comprises a first die (4) and a second die (5) such that the crimping device (1) is designed for one-axis pressing, wherein the first die (4) has a first cross-sectional die profile (6) and the second die (5) has a second cross-sectional die profile (7), wherein the first cross-sectional die profile (6) and the second cross-sectional die profile (7) together form a crimping profile (8). The problem of specifying a crimping device which is both mechanically simple in design and ensures advantageous pressing is essentially solved in that the first cross-sectional die profile (6) has at least one mandrel (9) and the second cross-sectional die profile (7) has at least one mandrel (9), wherein the crimping profile has at least three mandrels (9).

Description

[0001] Crimping device, method for producing a crimp connection and composite of an electrical conductor and electrical connector

[0002] The invention is based on a crimping device for crimping a crimp sleeve onto an electrical conductor, wherein the crimping device comprises a first die and a second die, so that the crimping device is designed for uniaxial pressing, wherein the first die has a first cross-sectional die profile and wherein the second die has a second cross-sectional die profile, wherein the first cross-sectional die profile and the second cross-sectional die profile together form a crimping profile.

[0003] In the sense of the invention, the crimp profile is thus a cross-sectional profile resulting from the first cross-sectional die profile and the second cross-sectional die profile when the first die and the second die are closed. A cross-sectional die profile is the side of the cross section through the crimping device facing the crimp sleeve, which is in contact with the crimp sleeve during pressing.

[0004] The crimping device according to the invention can be part of a hand-operated crimping pliers or a toggle press or also part of an electrically operated crimping machine, whereby the electrically operated crimping machine can be either a semi-automatic or a fully automatic machine.

[0005] The electrical conductor to which the crimp sleeve is attached or crimped using the crimping device can comprise one or more wires. A conductor comprising several thin wires is also referred to as a stranded conductor, while a conductor with only one wire is also referred to as a solid conductor. Within the scope of the present invention, the electrical conductor can be either a stranded conductor or a solid conductor.

[0006] Furthermore, the invention relates to a method for producing a crimp connection between an electrical conductor and an electrical connector, wherein the electrical connector comprises a crimp sleeve.

[0007] Furthermore, the invention relates to a composite of an electrical conductor and an electrical connector, wherein the electrical connector comprises a crimp sleeve.

[0008] Crimp connections, by means of which electrical conductors are crimped to electrical connectors at the ends to create a solid unit, are well known in the art. Different crimp geometries are particularly well known, e.g., four-prong crimp geometries, B-crimp geometries, hexagonal crimp geometries, or WM-crimp geometries. The disadvantage of these crimp geometries is that the area of ​​the crimp sleeve, which is located at the end toward the conductor next to the crimp area, also exhibits a "roundness" due to uneven crimping. This can be disadvantageous, as it generally requires more space both longitudinally and radially. Furthermore, the resulting deformation can be detrimental to the subsequent use of this connection.

[0009] Crimp contacts and crimp geometries, which particularly concern multi-axial pressings, are known from the documents WO 2022 / 073743 A1, DE 102018 199440 A1, EP 2685573 A2 and EP 3 984 702 A1.

[0010] Based on the prior art described above, the object of the present invention is to provide a crimping device that is both mechanically simple and ensures advantageous compression. Furthermore, the object of the invention is to provide a method for producing a crimp connection between an electrical conductor and an electrical connector, as well as a composite comprising an electrical conductor and an electrical connector.

[0011] According to a first teaching of the present invention, the aforementioned object is achieved by a crimping device as described above with the features of patent claim 1 in that the first cross-sectional die profile has at least one mandrel and the second cross-sectional die profile has at least one mandrel, wherein the crimping profile has at least three mandrels. According to the invention, at least one of the two cross-sectional profiles has at least two mandrels.

[0012] According to the invention, it was recognized that a crimp profile having at least three mandrels, preferably at least four mandrels, can be realized using two dies, so that the crimping occurs along one axis. The crimping device can thus be designed particularly simply. Furthermore, the mechanically simple design can be combined with a deformation of the conductor that is advantageous for the connection, resulting in a particularly advantageous connection overall.

[0013] In particular, the crimp sleeve can be designed to be shorter than usual, ensuring a secure crimp connection. Crimping at multiple points is not necessary, even with large conductor cross-sections, resulting in shorter processing times for the user. Since multiple crimping steps are not required, process reliability is also increased. The crimping device according to the invention is particularly suitable for crimping crimp sleeves onto electrical conductors with large conductor cross-sections. Since the assembly according to the invention is a mass product, a shorter design of the crimp sleeve ensures a significant cost advantage through material savings.

[0014] According to an advantageous embodiment, the first cross-sectional die profile has at least two mandrels, and the second cross-sectional die profile has at least two mandrels, so that the crimp profile has at least four mandrels. Such a profile ensures sufficient deformation of the electrical conductor, thus ensuring secure contact between the conductor and the crimp sleeve. Particularly preferably, the four mandrels of the crimp profile are each arranged at an angle of approximately 45° to the pressing direction.

[0015] According to a further advantageous embodiment, the crimping profile is designed symmetrically with respect to the separation axis, which is formed at the junction of the first die and the second die when the second die rests on the first die. A symmetrical design of the crimping profile requires an even number of mandrels, for example, four mandrels or six mandrels. At the same time, the number of mandrels on the first die corresponds to the number of mandrels on the second die.

[0016] It is also conceivable for the crimping profile to be asymmetrical with respect to the separation axis, which is formed at the junction of the first die and the second die when the second die rests on the first die. According to this configuration, the number of mandrels on the first die is unequal to the number of mandrels on the second die. In particular, the total number of mandrels present is odd.

[0017] According to a further advantageous embodiment of the crimping device, the first die and the second die have a longitudinal axis, wherein the shape of the first cross-sectional die profile and / or the shape of the second cross-sectional die profile changes along the longitudinal axis. At least one die has a cross-sectional die profile at its end that exerts less force on the crimp sleeve during crimping than a cross-sectional die profile arranged centrally in the die, preferably one that does not cause the crimp sleeve to be crimped.

[0018] Particularly preferably, the first die and the second die have a cross-sectional die profile at the end facing the electrical conductor that exerts less force on the crimp sleeve during crimping than a cross-sectional die profile arranged centrally in the die, preferably one that does not cause the crimp sleeve to be compressed. This configuration has the advantage that an area is already present at the end of the crimping device that exerts little or no force on the crimp sleeve, thus preserving the round shape of the crimp sleeve. Particularly preferably, the crimp profile arranged at the end corresponds to the outer shape of the crimp sleeve.

[0019] The orientation of the longitudinal axis corresponds to the orientation of the longitudinal axis of the crimp sleeve when the crimp sleeve is arranged in the first die.

[0020] According to a preferred embodiment, the crimping device has a crimping area in which the crimp sleeve is pressed onto the electrical conductor, and a run-out area in which the force on the crimp sleeve is reduced or in which no force acts on the crimp sleeve even when the dies are closed.

[0021] According to a further preferred embodiment, in at least one die, the transition from the crimping area to the end-side cross-sectional die profile of the crimp sleeve is continuous, i.e., not stepped. This embodiment has the advantage that the stress on the wires of the electrical conductor increases continuously and that there are no steps or edges, thus significantly reducing the risk of individual wires being sheared off or otherwise damaged.

[0022] According to a further embodiment of the crimping device, the first die and the second die have a longitudinal axis, wherein the first die and / or the second die have a run-out zone with a ramp in the direction of the longitudinal axis and at least in the direction of the electrical conductor. The presence of the run-out zone increases the cross-section of the crimp profile in the direction of the electrical conductor. Particularly preferably, the crimp profile arranged at the end essentially corresponds to the outer shape of the crimp sleeve.

[0023] It is particularly preferred if the run-out zone occupies at most 1 / 3 of the length of the die in the longitudinal direction or at most 1 / 4 of the length of the die in the longitudinal direction or at most 1 / 5 of the length of the die in the longitudinal direction.

[0024] According to one embodiment, only the at least one mandrel of the first die and / or the at least one mandrel of the second die have a run-on bevel. According to this embodiment, the radius of the respective end-side cross-sectional die profile or the radius of the end-side crimp profile can be smaller than the radius of the outer crimp sleeve. In this case, a force also acts on the crimp sleeve at the end.

[0025] Alternatively, the radius of the respective end-side cross-sectional die profile or the radius of the end-side crimp profile can correspond to the radius of the outer crimp sleeve.

[0026] It is also advantageous if the crimping area is performed by the entire crimp profile, not just by the mandrels. In this case, the radius of the crimp profile is smaller than the radius of the outer crimp sleeve at the points where no mandrel is located. According to this configuration, the first cross-sectional die profile and / or the second cross-sectional die profile can have a run-on bevel that extends completely across the respective cross-sectional die profile.

[0027] It is particularly advantageous if the crimp profile is essentially circular on the side facing the electrical conductor. This design ensures that the area of ​​the crimp sleeve facing the conductor, which also encloses the conductor, is circular and therefore not deformed.

[0028] According to a next advantageous embodiment, the first die and / or the second die has / have two run-out zones, wherein the two run-out zones are each arranged at the end in the direction of the electrical conductor and in the direction of the electrical connecting element on the first die and / or on the second die.

[0029] This design has the advantage that, on the one hand, the transition of the electrical conductor into the crimping area can be continuous, and, on the other hand, burr formation can be avoided at the end facing the electrical connecting element. Furthermore, in both end areas, it is ensured that the crimp sleeve retains its round shape adjacent to the crimping area, which is particularly advantageous for subsequent use, for example, when connecting to other components.

[0030] According to a second teaching of the present invention, the object set out at the outset is achieved by a method mentioned at the outset for producing a crimp connection between an electrical conductor and an electrical connector, in that the method is carried out with one of the crimping devices described above and in that the method comprises the following steps:

[0031] - in one preparatory step: inserting one end of the electrical conductor into the crimp sleeve and inserting the crimp sleeve into the first die,

[0032] - in one connection step: closing the second die and the first die so that the crimp sleeve and the stripped end of the conductor are pressed together in the crimping area,

[0033] - in one opening step: opening the first die and the second die.

[0034] The preparation step does not involve a fixed sequence of defined steps. It is therefore irrelevant whether the stripped end of the electrical conductor is inserted into the crimp sleeve first, or whether the crimp sleeve is first inserted into the first die. The method has the advantage that it can be carried out particularly easily due to uniaxial crimping, i.e. crimping in one pressing direction. At the same time, the geometry of the crimp profile allows for an advantageous connection between the electrical conductor and the electrical connector via the crimp sleeve. The uniaxial crimping is achieved by moving the two dies towards each other, whereby the direction of movement of the dies can be perpendicular to the longitudinal axis of the crimp sleeve, but does not have to be.Uniaxial crimping can also be achieved, for example, by a pincer movement in which the two dies are moved toward each other in a circular arc. This process can be performed manually using crimping pliers or a toggle press, for example, or with an electric crimping machine.

[0035] According to a third teaching of the present invention, the object set out at the outset is achieved by a composite of an electrical conductor and electrical connector as described at the outset, in that the crimp sleeve is pressed onto one end of the electrical conductor using a crimping device described above and a method described above.

[0036] According to an advantageous embodiment, the electrical connector is designed as a cable lug or as a plug connector or as a wire end sleeve.

[0037] Furthermore, it is advantageous if the electrical conductor has a plurality of wires, wherein the wires are pressed onto the crimp sleeve in the crimping area and wherein an inclined transition area is present at least on one side between the pressed area and the non-pressed area. This design of the assembly ensures that, on the one hand, the load on the wires of the conductor only increases continuously and that there are no steps or edges where the wires could be damaged. On the other hand, the shape of the crimp sleeve can be retained in the non-pressed area, so that uneven deformation of the sleeve outside the crimping area can be avoided. A roundness of the crimp sleeve in the non-pressed area has advantages, for example, in guaranteeing certain protection classes (IP protection classes).

[0038] With regard to the individual designs of the assembly, particular reference is made to the description of the different designs of the crimping device.

[0039] There are numerous possibilities for designing and developing the crimping device according to the invention, the method according to the invention, and the composite according to the invention. Reference is made to the claims subordinate to the independent patent claims, as well as to the following exemplary embodiments in combination with the drawings. The drawing shows Fig. 1, an exemplary embodiment of an open crimping device,

[0040] Fig. 2 an embodiment of a closed crimping device,

[0041] Fig. 3 an embodiment of the crimping device in longitudinal section,

[0042] Fig. 4 an embodiment of a crimping device with inserted crimp sleeve,

[0043] Fig. 5 the embodiment from Fig. 4 in longitudinal section,

[0044] Fig. 6 an embodiment of a first and second die,

[0045] Fig. 7 shows another embodiment of a crimping device,

[0046] Fig. 8 shows a further embodiment of a crimping device along the section plane CC from Fig. 7,

[0047] Fig. 9 shows an embodiment of a composite comprising an electrical conductor and an electrical connector,

[0048] Fig. 10 shows an embodiment of a method for producing a crimp connection.

[0049] Fig. 1 shows a front view of an embodiment of a crimping device 1 for crimping a crimp sleeve 2 onto an electrical conductor 3, comprising a first die 4 and a second die 5. The two dies 4, 5 are open in the illustrated embodiment.

[0050] For crimping, the conductor 3 is inserted with a stripped end into the crimp sleeve 2, and the crimp sleeve 2 is inserted into the first die 4. The electrical conductor 3 preferably has a plurality of wires that are stripped in the area of ​​the crimp sleeve 2. Subsequently, the second die 5 is moved toward the first die 4 in the direction of the arrow until the dies 4, 5 lie directly on top of one another.

[0051] The first die 4 has a first cross-sectional die profile 6 and the second die has a second cross-sectional die profile 7, so that the first cross-sectional die profile 6 and the second cross-sectional die profile 7 together form a crimping profile 8.

[0052] During crimping, the individual wires of conductor 3 are squeezed and deformed in such a way that insulating surfaces tear open, allowing electrical contact to be established with the crimp sleeve 2. Furthermore, the crimp sleeve 2 and the wires of conductor 3—or the individual wire of a solid conductor—are plastically deformed together in such a way that they form a solid bond when crimped.

[0053] In the illustrated embodiment, the first cross-sectional die profile 6 has two mandrels 9, and the second cross-sectional die profile 7 also has two mandrels 9. Thus, the crimp profile 8 has a total of four mandrels 9, which plastically deform the electrical conductor 3 together with the crimp sleeve 2.

[0054] The illustrated embodiment is advantageous in that a four-mandrel crimping profile with a two-part die can act on the conductor. The crimping process thus takes place along one axis, i.e., in one pressing direction. This has the advantage that the crimping device 1 can be designed to be particularly simple and cost-effective mechanically. Furthermore, the crimping process is also simpler, i.e., when more than one axis is used. The illustrated geometry eliminates the need for crimping in more than one crimping area, even with large conductor cross-sections.

[0055] Fig. 2 shows another illustration of a crimping device 1 with a first die 4 and a second die 5, wherein the dies 4, 5 are arranged in a closed position relative to one another. In this embodiment, the crimping profile 8 also has a total of four mandrels 9.

[0056] Fig. 3 shows the embodiment illustrated in Fig. 2 as a longitudinal section along the defined section plane AA. It can be seen from the illustration that the dies 4, 5 have a run-out zone 10 at the end, in which a continuous transition from a crimping profile comprising the four mandrels 9 to a circular crimping profile is formed. The wires crimped in practice using the mandrels 9 can thus be slowly and continuously relieved of the high stress. Furthermore, damage to the wires at an edge—not present here—is avoided.

[0057] Fig. 4 and 5 show a crimping device 1 together with a crimping sleeve 2, but without the electrical conductor, once in front view (Fig. 4) and once in longitudinal section along the defined cutting plane BB (Fig. 5) with the longitudinal axis 20 of the crimping device 1. The cutting plane BB lies exactly between two mandrels.

[0058] The longitudinal section in Fig. 5 shows this less deformed region of the crimp sleeve 2; the mandrels 9 are each arranged on the dies 4 and 5 offset by approximately 45° from the intersection points of the axis BB and the crimp sleeve 2. It can be seen from the end of the dies 4, 5 facing the conductor that the dies 4, 5 have a run-out zone 10, via which the crimp profile 8 is continuously transformed into a circular cross-section. In the illustrated embodiment, the run-out zone 10 is also arranged in the region of the crimp profile 8 in which no mandrel 9 is present.

[0059] Fig. 6 shows a separate representation of a first die 4 and a second die 5. Both the first die 4 and the second die 5 have two mandrels 9, which merge into a run-out zone 10 at their ends. In the illustrated embodiment, the run-out zone 10 has a continuous reduction in the height of the respective mandrel 9. In addition to the reduction in the height of the mandrels 9, the radius of the remaining area of ​​the crimp profile 8 also increases, so that the essentially circular cross-section of the crimp profile at the end facing the conductor essentially corresponds to the external shape of the crimp sleeve 2. This arrangement has the advantage that there are no edges or steps in the run-out zone that could otherwise lead to damage to the wires, for example, shearing or kinking of the wires. Furthermore, no uneven deformation of the crimp sleeve 2 occurs in the area next to the crimping device 1.

[0060] Fig. 7 shows a further embodiment of a crimping device 1 comprising a first die 4 and a second die 5 in a closed position.

[0061] Furthermore, Fig. 8 shows the crimping device 1 along the sectional plane CC defined in Fig. 7. This illustration shows in particular the outlet zone 10, which is arranged at the end in the area of ​​the mandrels 9.

[0062] Fig. 9 shows an embodiment of a composite 19 comprising an electrical conductor 3 and electrical connector 11. The electrical connector 11 has a crimp sleeve 2 and a plug connector terminal 12. The crimp sleeve 2 is pressed together with the wires 13 of the electrical conductor 3 to form a single unit. At each end of the crimping region 14, a run-out zone 10 is arranged, over which the crimp profile 8 continuously transitions into a circular cross-section, so that there are no edges where the wires 13 could be damaged. Furthermore, the run-out zone 10 prevents uneven deformation of the crimp sleeve 2 next to the crimping region 14. In the illustrated embodiment, a run-out zone 10 is present both in the direction of the electrical conductor 3 and in the direction of the plug connector terminal 12.The figure also shows the end of a sheath 15 which has been removed from the end of the conductor 3 which is inserted into the crimp sleeve 2.

[0063] Fig. 10 shows an embodiment of a method for producing a crimp connection between an electrical conductor 3 and an electrical connector 11, wherein the electrical conductor 3 may comprise one or more wires 13. The electrical connector 11 comprises, in particular, the crimp sleeve 2. If the electrical conductor 3 has a sheath 15, this must be removed from the end of the conductor 3 or the cable before the crimping process, so that only the stripped end of the cable, i.e., the actual conductor 3, is inserted into the crimp sleeve 2.

[0064] The method is carried out using a crimping device 1 shown in Fig. 1 and comprises the following steps: In a preparatory step 16, one end of the electrical conductor 3 is inserted into the crimp sleeve 2, and the crimp sleeve 2 is placed into the first crimping die 4. Whether the conductor 3 is inserted into the crimp sleeve 2 first or whether the crimp sleeve 2 is placed into the first die 4 first is irrelevant for the method. In a connecting step 17, the second die 5 and the first die 4 are closed or moved toward one another, such that the crimp sleeve 2 and the stripped end of the conductor 3 are crimped together in the crimping area 14.

[0065] In an opening step 18, the first die 4 and the second die 5 are opened again.

[0066] The method shown has the advantage that it is particularly easy to carry out due to the use of only two dies 4, 5 and that due to the geometry of the

[0067] Crimp profile 8 can further provide an advantageous connection between the electrical conductor and the electrical connector. The method described is particularly advantageous for conductors with large cross-sections.

[0068] Reference symbol

[0069] 1 crimping device

[0070] 2 crimp sleeves

[0071] 3 electrical conductors

[0072] 4 first die

[0073] 5 second die

[0074] 6 first cross-sectional die profile

[0075] 7 second cross-sectional die profile

[0076] 8 Crimp profile

[0077] 9 Thorn

[0078] 10 Run-off area

[0079] 11 electrical connector

[0080] 12 connector connection

[0081] 13 wires

[0082] 14 Crimping area

[0083] 15 Sheathing

[0084] 16 Preparation step

[0085] 17 Connection step

[0086] 18 Opening step

[0087] 19 Composite of an electrical conductor and an electrical connector

[0088] 20 Longitudinal axis

Claims

Patent claims 1. Crimping device (1) for crimping a crimp sleeve (2) onto an electrical conductor (3), the crimping device (1) comprising a first die (4) and a second die (5), such that the crimping device (1) is designed for uniaxial pressing, the first die (4) having a first cross-sectional die profile (6) and the second die (5) having a second cross-sectional die profile (7), the first cross-sectional die profile (6) and the second cross-sectional die profile (7) together forming a crimping profile (8), characterized in that the first cross-sectional die profile (6) has at least one mandrel (9) and that the second cross-sectional die profile (7) has at least one mandrel (9), the crimping profile (8) having at least three mandrels (9).

2. Crimping device (1) according to claim 1, characterized in that the first cross-sectional die profile (6) has at least two mandrels (9) and that the second cross-sectional die profile (7) has at least two mandrels (9), so that the crimp profile (8) has at least four mandrels (9).

3. Crimping device (1) according to claim 1 or 2, characterized in that the crimping profile (8) is formed symmetrically with respect to the separation axis which is formed at the connection of the first die (4) and the second die (5) when the second die (5) rests on the first die (4).

4. Crimping device (1) according to one of claims 1 to 3, characterized in that the first die (4) and the second die (5) have a longitudinal axis (20), and that the shape of the first cross-sectional die profile (6) and / or the shape of the second cross-sectional die profile (7) changes in the course of the longitudinal axis (20), wherein at least one die (4, 5) has a cross-sectional die profile (6, 7) at its end which exerts less force on the crimp sleeve (2) during pressing than a cross-sectional die profile arranged centrally in the die (4, 5), preferably which does not cause any pressing of the crimp sleeve (2).

5. Crimping device according to claim 4, characterized in that in at least one die (4, 5) the transition from the crimping area (14) into the end-side cross-sectional die profile (6, 7) of the crimp sleeve (2) is continuous, i.e. not step-like.

6. Crimping device (1) according to one of claims 1 to 5, characterized in that the first die (4) and the second die (5) have a longitudinal axis (20), and that the first die (4) and / or the second die (5) has or have at least one run-out zone (10) with a run-on bevel in the direction of the longitudinal axis (20) at least in the direction of the electrical conductor (3).

7. Crimping device (1) according to one of claims 1 to 6, characterized in that the crimping profile (8) is substantially circular on the side facing the electrical conductor (3).

8. Crimping device (1) according to one of claims 1 to 7, characterized in that the first die (4) and / or the second die (5) has or have two run-out zones (10), wherein the two run-out zones (10) are each arranged at the end in the direction of the electrical conductor (3) and in the direction of an electrical connector (11) on the first die (4) and / or on the second die (5).

9. A method for producing a crimp connection between an electrical conductor (3) and an electrical connector (11), wherein the electrical connector (11) comprises a crimp sleeve (2), characterized in that the method is carried out with a device (1) according to one of claims 1 to 8 and that the method comprises the following steps: - in a preparatory step (16): inserting one end of the electrical conductor (3) into the crimp sleeve (2) and inserting the crimp sleeve (2) into the first die (4), - in a connecting step (17): closing the second die (5) and the first die (4) so ​​that the crimp sleeve (2) and the stripped end of the conductor (3) are crimped together in the crimping area (14), - in one opening step (18): opening the first die (4) and the second die (5).

10. Composite (19) comprising an electrical conductor (3) and an electrical connector (11), wherein the electrical connector (11) comprises a crimp sleeve (2), characterized in that the crimp sleeve (2) is pressed onto one end of the electrical conductor (3) using a crimping device (1) according to one of claims 1 to 8 and a method according to claim 9.

11. The assembly (19) according to claim 10, characterized in that the electrical connector (11) is designed as a cable lug or as a plug connector (12) or as a wire end sleeve.

12. Composite (19) according to claim 10 or 11, characterized in that the electrical conductor (3) has a plurality of wires (13), wherein the wires (13) are pressed with the crimp sleeve (2) in the crimping area (14) and wherein an oblique transition area is present at least on one side between the pressed area and the non-pressed area.

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