DE2318884A1 - WIRE FEEDING IN WINDING MACHINES - Google Patents

Description

WIRE FEEDING IN WINDING MACHINES The invention relates to a device which allows even very thin wires with a constant winding force like this to be withdrawn from a supply reel that when the winding machine is started repeatedly there is no risk of tearing.

It is known that thin wires have a low tensile strength that can let the supply reel stand still during the winding process. It will then the winding wire is drawn off axially from the supply reel.

When starting the winding machine, with this method it is then permissible to to accelerate very quickly to a high working speed. The supply spool must yes here not accelerated as with tangential unwinding. Still enough this method does not allow for particularly thin wires, such as those used for manufacturing of microphone voice coils are used to process.

It is also known that in winding machines a constant Winding force is tried to achieve that one of the tensile force of the winding wire dependent friction brake is controlled in their strength, mostly a band brake is used for this, which is more or less similar to Prony's bridle is pressed heavily on the circumference of a wheel. This wheel is then at the same time the guide role of the winding wire, which does not slip on it with that force which determines the band brake on this wheel. The winding force a movable pulley is measured, which is mechanically driven by their location can influence the strength of the band brake.

With this method there is a constant tensile force of the winding wire to be reached as long as the winding machine is working, but not at the moment in which the machine starts. Because between static and moving friction changes the coefficient of friction is generally doubled.

During the transition from static friction to dynamic friction, the Braking power about twice as much. Particularly thin wires then often tear when Starting the winding machine.

Another disadvantage is usually that the winding wire before it runs into the tension regulator, must be pre-braked. That happens in general by two strips of felt that lie on top of one another with a certain amount of pressure. Between This felt strip now runs the winding wire, which is so strong due to the frictional heat can be heated so that a wire insulation made of thermoplastic material melt can. When the winding machine is stopped, this winding wire then sticks in the Felt brake firmly. When it is restarted, it will tear every time.

The task of pulling the wire between the stationary and running winding machine to keep it really constant and with it a breaking of a wire, no matter how thin to prevent, was solved by the fact that, instead of a dormant resp. sliding friction a rolling friction was used, which is a practically constant Has a coefficient of friction. An exemplary embodiment is shown in FIG. Here is a axially tensioned high shoulder ball bearing (1) as a support for the guide roller (2) used for the thin winding wire (9). The strength of the axial tension pressure can be done by hand within fine limits using a knurled screw (3) and the compression spring (4) can be set. The counterpressure is absorbed by a disk groove bearing (5) which together with the shoulder bearing (1) pressed into the guide roller (2), the stronger the Ball bearing (1) is axially tensioned by the spring (4), the greater the Rolling resistance and the greater the necessary force exerted by the winding wire (9) needed to turn its guide roller (2). In no moment occurs Transition from the static friction to the smaller sliding friction. Constant is a similar unwinding process guaranteed with constant inhibition.

The advantage of a constant rolling resistance for the bearing of the The guide roller (2) can thus be fully transferred from the winding wire by this fully embraces the leadership role. With a wrap angle of ß- 560 ° and a coefficient of friction between winding wire (plastic-coated copper wire) and leadership role (e.g.

made of hard rubber) of g = 0.6, the driving ability of the guide roller is calculated according to the Eytelwein equation to S1 = 1.1165 x e c. # ß = 47.5 S2 here means S1 is the force with which the winding wire is pulled around the circumference of the guide roller (2) must, while he runs with a restrained force S2 on the guide roller. c is the groove factor, which depends on the shape of the groove in the guide roller the frictional force increases.

It is only 1 for a flat surface, otherwise it is always greater than 1. In the above calculation it was set equal to 1.

Now the pull-off force of the winding wire is around 50 times greater is the restraining force with which the wire runs onto the guide roller, this force is mainly from the rolling resistance, respectively. from the escapement of the ball bearing (1) determined. In such a case, you can route the wire between the Set two braking felt disks (6) so weak that the Wire does not occur when traversing. So that is the gluing one with thermoplastic Insulated winding wire material no longer when the winding machine is shut down to fear.

Should the restrained force between the two felt strips? still be too big, one could avoid too much frictional heat Increase the wrap angle ß or the groove factor c at this point.

Before the winding wire is finally fed into the winding machine, it still has to run over the pulley (7).

This pulley allows due to its spring-loaded mounting (8) at high Start-up acceleration of the winding machine gives way to the winding wire. Because of this The guide roller (2) with the ball bearings (1) and (5) is given sufficient yield Time to also get to the operating speed. This will decrease the necessary acceleration force that the moment of inertia of the guide roller when Start must overcome. It brings about a corresponding compensation when stopping the machine.

Claims (3)

Claims 1. Device for wire winding machines, which - between supply reel and the actual winding process in the machine itself for unwinding and guiding the Winding wire is used, with a constant tensile force of the winding wire at the same time is achievable during the winding process, characterized in that the constant tensile force is generated by axially bracing one or more ball bearings, the one Wire guide roller carries. 2. Apparatus according to claim 1, characterized in that by a sufficiently large angle of wrap of the winding wire around the claim 1 mentioned guide roller and / or a correspondingly shaped guide groove in a material with a high coefficient of friction, the tensile force of the winding wire during the winding process is only defined by the restraining force of the tensioned ball bearing. 3. Apparatus according to claim 1, characterized in that a Additional deflection roller of the type mentioned in claim 1, movably mounted with springs Leading role allows to reach its operating speed with a delay, if the winding machine has a high start-up acceleration or a stopping delay to grant if the winding machine stops quickly.