JPH0453071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing flat columnar filaments used in automobile headlights and the like.

(Prior art) In order to manufacture a flat columnar filament, as shown in FIG. In this state, the wire is sandwiched between tungsten plates d, set in a hydrogen furnace, the molybdenum wire b and the rectangular mandrel c are melted, and finally legs e are formed at both ends.

(Problems to be Solved by the Invention) According to the conventional manufacturing method described above, the process is complicated and difficult to automate, and it requires the use of molybdenum wire and molybdenum mandrel, and a process of melting these afterwards. , When coiling with a rectangular mandrel, the back tension of the tungsten wire is not constant, which causes biting and irregular winding, and the current temperature of the hydrogen furnace is 1700
There were various problems, such as the temperature being limited to about 30°F, the setting being incomplete, and the leg molding after setting being easy to break.

This invention was made to technically solve these problems, and enables automation and simplification of the process.
The object of the present invention is to provide a method for manufacturing flat columnar filaments that can be set completely, have good coiling conditions, and are of excellent quality.

(Means for Solving the Problems) As a means for solving these problems, the present invention provides a method for rotating tungsten wires while rotating two parallel pin-shaped mandrels so that the centers of these mandrels serve as rotational axes. The gist of the manufacturing method is to form a filament having legs at both ends by winding the filament into a flat helical shape, set the filament by applying an electric current in an inert gas atmosphere, and then move one of the mandrels to extract the filament. It is something.

It also adjusts the tension of the tungsten wire when the tungsten wire is wound in a flat helical shape using two parallel pin-shaped mandrels.

(Example) Next, an example of the present invention will be described in more detail with reference to the drawings. In Fig. 2, 1 is motor 2
It is a rotating part driven by a mandrel moving lever 3 and a wire chuck lever 4.
They are provided so as to face the outer periphery. A pin-shaped mandrel 5 is attached to the tip of the mandrel moving lever 3, and is symmetrical with respect to the pin-shaped mandrel 6 fixed to the tip protrusion 1a of the rotating section 1 with the rotation axis When the lever 3 is pushed down slightly against the spring 3a, the mandrel 5 approaches the mandrel 6 and the gap between them narrows. The wire chuck lever 4 is provided with a presser piece 4a at its tip so that the tip of the tungsten wire 7 can be pressed and fixed against the notch 1b of the protrusion 1a, and the lever 4 is pressed against the spring 8. By pushing back 4, the tungsten wire 7 can be removed. Reference numeral 9 denotes a mandrel guide, and holes 9a and 9b are fitted into the parallel pin-shaped mandrels 5 and 6.
, and can be slid along the rotation axis X by a motor 10. Reference numeral 11 denotes a tungsten wire feeding device, which includes a lateral feed (horizontal feed) motor 12 and a foot-forming motor 13, and the tungsten wire 7 is fed out via a spool 14 and a nozzle 15. Reference numeral 16 denotes an electromagnetic magnet for tension adjustment provided in connection with the spool 14.

In order to manufacture the desired filament using such a device, first drive the traverse feed motor 12 to move the feed device 11, and then move the tip of the tungsten wire 7 to the rotating section using the chuck lever 4. 1 (Figure 1 A). Next, the leg forming motor 13 is driven to move the feeding device 11 in the direction A shown in the figure, thereby forming the leg on the winding start side. Thereafter, the motor 10 is driven to advance the mandrel guide 9 and fit the mandrels 5 and 6 into the holes 9a and 9b, respectively.

Then, the motor 2 is driven to rotate the rotary unit 1, and at the same time, the lateral feed motor 12 is used to rotate the feeding device 1.
While moving the tungsten wire 7, the tungsten wire 7 is sent out at a constant speed, and the mandrel guide 9 is also moved by the motor 10 in accordance with the tungsten wire, and the tungsten wire 7 is wound in a spiral shape by the mandrels 5 and 6. ).
In this coiling process, at the beginning of winding the tungsten wire 7, the speed is slowly changed and the tension of the tungsten wire 7 is weakened by the action of the magnet 16, and at the intermediate stage, the speed and tension are kept constant, and at the end of the winding. In the stage , the speed is slowed down and the tension is applied strongly. This is to maintain the back tension of the tungsten wire 7 at a constant level, to prevent excessive tension from being applied to the tungsten wire or from loosening the wire, and to prevent irregular winding. Also,
Due to the elasticity (spring back) of the tungsten wire 7, the number of turns is reduced compared to the actual number of turns, so extra winding is done to account for this amount of unwinding. The amount of unwinding depends on the product type, coiling conditions,
It varies depending on the wire material, etc., but for example, for a 65W car headlight, a wire with 20 turns will wind back about 1.5 turns.

After this coiling, the feeding device 11 is moved by the motor 13 in the direction B shown in the figure to form the leg at the end of the coiling (FIG. 1C). The filament is
In addition to springback during coiling, deformation occurs due to internal distortion of the coiling after coiling and before actual use, so the amount of deformation must be estimated in advance to ensure that the final filament foot will match the dimensions. Perform coiling and leg shaping. This amount of deformation is determined by the coiling conditions,
Appropriate adjustment is required since it varies depending on the material of the wire, etc.

After coiling, a setting process is performed to prevent the flat filament from twisting. In the case of the present invention, the tungsten wire 7 is cut at a predetermined point after forming the legs at the end of the winding, and then placed in an inert gas atmosphere. Setting is performed by passing current from a pulse power supply Q to the flat filament in P (FIG. 1D).

After this setting, the mandrel guide 9 is returned and removed from the mandrels 5 and 6, and the mandrel moving lever 3 is activated to move the mandrel 5 to the mandrel 6 side as shown in FIG. By opening the lever 4 against the spring 8, the flat filament can be extracted.

(Effects of the Invention) As explained above, according to the present invention, two parallel pin-shaped mandrels are used to spirally wind the filament, and then the filament can be pulled out by moving one of the mandrels. This eliminates the need for melting a molybdenum mandrel and primary winding of molybdenum as in the past, making it possible to simplify the manufacturing process and reduce costs.

In addition, the manufacturing process can be automated, the back tension during coiling can be controlled to be constant, and setting can be done completely at a temperature suitable for the tungsten wire, resulting in high dimensional accuracy and minimal deformation. It is possible to produce flat filaments of excellent quality.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the method of the present invention in the order of steps, FIG. 2 is a schematic perspective view of the main parts of the device,
FIG. 3 is an explanatory diagram showing the conventional method in the order of steps. DESCRIPTION OF SYMBOLS 1...Rotating part, 2...Motor, 3...Lever for mandrel movement, 4...Lever for wire chuck, 5, 6...Pin-shaped mandrel, 7...Tungsten wire, 8...Spring, 9... ...Mandrel guide, 10...Motor, 11...Tungsten wire feeding device, 12...Transverse feed motor, 13...
...Foot forming motor, 14...Spool, 15...
Nozzle, 16... Magnet for tension adjustment.

Claims (1)

[Claims] 1. While rotating two parallel pin-shaped mandrels with the centers of these mandrels serving as rotational axes, a tungsten wire is wound in an oblate spiral shape to form a filament having legs at both ends. . A method for producing a flat columnar filament, which comprises: setting the filament by passing a current through it in an inert gas atmosphere; and then moving the one mandrel and extracting the filament. 2. The method of manufacturing a flat columnar filament according to claim 1, wherein the tension of the tungsten wire is adjusted when the tungsten wire is wound in a flat helical shape around the two parallel pin-shaped mandrels.