DE102022117760B3 - Electrical contact element - Google Patents

Abstract

The invention relates to an electrical contact element (1) having a thermally torn pin (2) and a stranded conductor (3), the stranded conductor (3) being stripped of insulation at the front end, so that the strands (4) form a free end and the thermally torn pin (2) has an embossed area (P) at the end, the strands (4) of the stranded conductor (3) being introduced into the embossed area (P) and being firmly connected to the thermally torn pin (2) by an embossing process. are connected and a method for producing such a contact element (1).

Description

The invention relates to an electrical contact element according to the preamble of claim 1 and a method for producing such a contact element.

Electrical contact elements such as crimp contact pins are used to create an electrical and mechanical connection between two electrical lines or an electrical line and a device. Electrical contact elements are often used in connectors for electrical coupling. Electrical contact elements are required in order to establish an electrical connection between an electrical conductor, in particular a stranded conductor, and a connection end of a pin or socket contact.

Crimping is often the connection technique used to connect stranded conductors to an electrical contact element. To do this, stranded conductors are fed into a crimp contact pin and pressed with a positive fit, i.e. crimped. The crimp contact pin can take the form of a sleeve, or is formed into a crimp contact pin during the crimping process from sheet metal and pressed with the conductor. In cable assembly, the manufacturing steps are automated. This includes cutting the conductor to length and stripping it, joining the crimp contact pin to the conductor or producing a contact pin by stamping and sheet metal forming, and applying the crimp to the conductor. Automatic machines are used for this. Pressing tools that are operated by hand to produce crimp connections are well known from the prior art.

Also known is the use of tapes stored in magazines in machines. For this purpose, a sheet metal strip and a conductor end are fed into the machine. In addition to stripping the conductor, punching and bending processes then take place in the machine in order to reshape the tape to produce a crimp contact pin, which is then pressed with the end of the conductor in the machine.

High-quality and secure crimp wire connections must be gas-tight, i.e. the crimp encloses the wires in such a way that the wires are gas-tight after crimping. When crimping, if done correctly, a gas-tight connection should be created that protects against corrosion.

Crimp contact pins which are made from sheet metal by stamping or bending processes are complex and expensive. Crimp contact pins made of sheet metal are not cast-proof, since the rolled sheet metal is not filled on the inside due to the roll forming and has a cavity, which means that further processing steps such as additional welding or soldering of such elements have to be carried out in order to use these contact elements in electronic assemblies safe to use, which is cumbersome and expensive when a potting system is required.

It is also known to use thermally cracked pins in connection technology for detachable connections. Thermally cracked pins are used, for example, in electronics production for the electrical connection of circuit boards, electronic components or switch groups in order to create a secure and at the same time detachable connection.

Thermally cracked pins are made from an endless solid material, for example from a wire. The wire can be in the form of rods or coils. The wire is split into individual pins by thermal tearing. At the separation points, there is a seamless taper, without burring, which forms a convex tip shape at the ends of the pin. The shape created by thermal cracking leads to improved contacting as the ends have a smooth surface. This leads to lower insertion forces and less pin wear.

Compared to conventionally manufactured crimp contact pins or pins, which are rolled or manufactured by sheet metal forming, thermally cracked pins are 10 to 20 times cheaper to manufacture per piece.

Furthermore, thermally cracked pins are of a higher quality than stamped, rolled or metal-formed contact pins. Rolled pins have a continuous cavity inside. This cavity inside the pin is formed when flat steel strip is rolled. As a result, rolled pins are not suitable for potting, since rolled pins are not tight and potting compound can penetrate this cavity or gap and from there get into the mating area, which has a negative effect on the connection and causes failures.

Stamping thermally cracked pins at one end and connecting them to stranded conductors is not known from the prior art.

Furthermore, no application is known from the prior art for further processing thermally cracked pins and embossing them at one end in order to use the thermally cracked pin at one end as a crimp contact pin. Usually In electronics production, thermally cracked pins are used at both ends as plug contacts and are not connected to stranded conductors.

One object of the invention is to provide an improved and at the same time inexpensive contact element for electronics production, which is cast-resistant. The contact element should produce a secure mechanical and electrical connection to a conductor or to a stranded conductor by simple reshaping, be gas-tight and have a compact design. Furthermore, the contact element should be suitable for use in industrially used end devices whose electronics are encapsulated to protect against external influences without air inclusions.

The object is achieved according to claim 1 by a permanent connection of a thermally cracked pin with a stranded conductor. Advantageous refinements of the invention are specified in the dependent claims.

According to the invention, the contact element has a thermally cracked pin and a stranded wire, the stranded conductor being stripped of insulation at the front end, so that the strands form a free end and the thermally cracked pin has an embossed area at the end. It is also proposed that the strands of the stranded conductor be introduced into the embossing area and connected to the thermally torn pin by means of an embossing process and in a gas-tight manner by means of a crimp connection.

• Schritt 1: Einbringen der Litzen des Litzenleiters in den Prägebereich
• Schritt 2: verschließen des Prägebereichs durch ein Crimp-Werkzeug
• Schritt 3: Entnahme des elektrischen Kontaktelements aus dem Crimp-Werkzeug.

The electrical contact element according to the invention is advantageously produced by the following steps:

• Step 1: Inserting the strands of the stranded conductor into the embossing area
• Step 2: sealing the embossing area with a crimping tool
• Step 3: Removal of the electrical contact element from the crimping tool.

• - Erstellen von thermisch gerissenen Pins mit einer endseitigen Umformung, so dass die Pins an einem Ende eine U-förmige Prägung aufweisen
• - Magazinieren der umgeformten thermisch gerissenen Pins auf einem Trägerband zur Weiterverarbeitung in einem Crimp-Automaten
• - Einbringen der magazinierten Pins in den Crimp-Automaten
• - Einbringen von Litzenleiter in den Automaten und Erstellen einer CrimpVerbindung durch Verformung der U-förmigen Prägung zu einer geschlossenen Form, in welcher der Litzenleiter mit den freien Litzenenden eingebracht ist
• - Entnahme der elektrischen Kontaktelemente aus dem Automaten.

A method for producing electrical contact elements of the above type is also shown. The procedure has the following steps:

• - Creation of thermally cracked pins with an end deformation so that the pins have a U-shaped embossing on one end
• - Magazine storage of the formed, thermally cracked pins on a carrier tape for further processing in a crimping machine
• - Inserting the magazined pins into the crimping machine
• - Insertion of stranded conductors into the machine and creation of a crimp connection by deforming the U-shaped embossing into a closed shape, in which the stranded conductor is inserted with the free stranded ends
• - Removal of the electrical contact elements from the machine.

Experiments have shown that the use of a thermally cracked pin for the electrical connection of a stranded conductor is extremely advantageous, since thermally cracked pins can be used in comparison to conventional crimp contact pins or pins, which are produced using more complex manufacturing processes, e.g. by rolling or by sheet metal Forming are made, can be made much cheaper. This results in cost advantages. Furthermore, thermally cracked pins have a seamless taper, which leads to improved contact with lower insertion forces. Advantageously, the thermally cracked pin has a U-shaped embossing at the end, into which the stranded conductor is inserted with the free, stripped stranded strand ends. The embossing is then closed by a crimping tool, so that the pin and the conductor are mechanically and electrically connected to one another and the pin and conductor together form an electrical contact element.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings.

• 1 zeigt einen Fügeschritt eines thermisch gerissenen Pins mit einem Litzenleiter;
• 2 zeigt ein erfindungsgemäßes Kontaktelement bestehend aus einem thermisch gerissenen Pin und einem Litzenleiter;
• 3a zeigt ein Schnittbild gemäß 1 durch den Prägebereich;
• 3b zeigt ein Schnittbild gemäß 2 durch den Prägebereich;
• 4 zeigt ein Schliffbild eines erfindungsgemäßen Kontaktelements.

They show schematically:

• 1 shows a joining step of a thermally cracked pin with a stranded conductor;
• 2 shows a contact element according to the invention consisting of a thermally cracked pin and a stranded conductor;
• 3a shows a sectional view according to 1 through the embossing area;
• 3b shows a sectional view according to 2 through the embossing area;
• 4 shows a micrograph of a contact element according to the invention.

In the following description of the preferred embodiments, the same reference symbols designate the same or comparable components.

1 shows the contact element 1 according to the invention consisting of a thermally cracked pin 2 and a stranded conductor 3 during a joining step. For this purpose, the thermally cracked pin 2 has an embossed area P at the end. interior Half of this embossed area P, the pin has a recess into which all the strands 4 of a stranded conductor 3 are introduced. Advantageously, the recess describes a U-shape. The indentation or the U-shaped embossing 10 was introduced into the contact element by an upstream embossing step with an embossing die. The indentation is to be designed in such a way that the strands can be fully inserted.

2 shows the contact element 1 according to the invention according to FIG 1 after crimping. The indentation, ie the U-shaped embossing, was closed by an embossing step with a crimping tool, so that the stranded wire 4 or the stranded wires 4 are pressed completely into the thermally torn pin 2 and connected firmly and gas-tight to the pin 2 by the embossing process is/are.

3a and 3b show sectional images through the embossing area according to 1 in the open state and according to 2 in the closed state.

3a shows the U-shaped preformed crimp jaw of the thermally cracked pin 2 with inserted stranded wire 4. The U-shape forms a depression in the middle, in which the stranded wire 4 is inserted and two vertically upward-pointing tabs are formed on the side, which are connected by means of a Embossing steps are folded inward, so that the strand 4 or the strands 4 is / are radially firmly enclosed after forming, see 3b .

3b shows the formed crimp jaw and the strand 4 pressed in the thermally cracked pin 2. The crimp jaw was radially closed by the crimping, so that the strand 4 or the strands 4 is/are completely surrounded by the pin 2.

4 shows the embossing area in cross-section in a micrograph for assessing the quality of the crimping. The gas-tight encapsulation of the strands 4 in the thermally cracked pin 2 can be clearly seen. A high-quality crimp connection exists when the round stranded wires 4 are completely pressed into a package and the individual stranded wires 4 can no longer be recognized or distinguished from one another. This is the case here. Such a connection is permanent, gas-tight and cast-resistant.

The advantages of the invention are, in particular, that it is shown that thermally cracked pins 2 can also be used as crimp contact pins. The invention shows that thermally cracked pins 2, which can be produced more cost-effectively and with higher quality than conventional contact pins made of sheet metal (which have been rolled, stamped and formed), can be shaped in such a way that they have a crimp tab at the end. This means that stranded conductors 3 can be crimped with thermally cracked pins 2 in order to produce a cost-effective, strong and gas-tight connection.

Reference List

1

electrical contact element

2

thermally cracked pin

3

stranded wire

4

strand

10

U-shaped embossing

P

embossing area

Claims (4)

Electrical contact element (1) having a thermally cracked pin (2) and a stranded conductor (3), the stranded conductor (3) being stripped of insulation at the front end, so that the strands (4) form a free end and the thermally cracked pin (2 ) has an embossed area (P) at the end, characterized in that the strands (4) of the stranded conductor (3) are introduced into the embossed area (P) and are firmly connected to the thermally cracked pin (2) by an embossing process. Electrical contact element after claim 1 the electrical contact element (1) being produced by the following steps: Step 1: introducing the strands (4) of the stranded conductor (3) into the embossed area (P); Step 2: closing the embossing area (P) with a crimping tool; Step 3: Removal of the electrical contact element (1) from the crimping tool. Process for the production of electrical contact elements claim 1 having the following steps: - creating thermally cracked pins (2) with an end deformation, so that the pins (2) have a U-shaped embossing (10) at one end; - Magazine storage of the formed thermally cracked pins (2) on a carrier tape for further processing in a crimping machine; - Introduction of the magazined pins (2) in the crimping machine; - Introduction of stranded conductor (3) in the machine and creating a crimp connection by deforming the U-shaped embossing 10 to form a closed shape, in which the stranded conductor (3) is introduced with the free stranded ends - removal of the electrical contact elements (1). Use of a thermally torn pin (2) for the electrical connection of a stranded conductor (3), the thermally torn pin (2) having a U-shaped embossing (10) at the end, characterized in that the stranded conductor (3 ) is inserted with the free wire ends and then the embossing (10) is closed with a crimping tool so that the pin (2) and the conductor (3) are mechanically and electrically connected to each other and the pin (2) and conductor (3 ) together form an electrical contact element (1).

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