EP0676910B1 - Method for manufacturing curved radiators, especially incandescent halogen lamps - Google Patents

Abstract

The mfr. is effected in 3 successive stages, in which a linear lamp tube containing a glow resistance is filled with a gas at a cold pressure of not higher than 1.5 bar, before it is locally heated and then bent into the required shape, with a working filling pressure of about 1 bar maintained during the localised heating and bending. Pref. the cold filling pressure is between 600 and 800 mbar, with part of the lamp tube cooled during the localised heating and bending steps, for maintaining the required working filling pressure. <IMAGE>

Description

The invention relates to a method for producing curved or angled spotlight, especially from Halogen bulbs.

Such spotlights, in particular lamps with halogen filling, are suitable for use in hobs, e.g. as a radiator heating element. For example, you are in DE-GM 88 02 062, in EP-OS 434 373 and 438 254 as well in GB-PA 2 250 669.

The previously used manufacturing processes for such radiators according to GB-PA 1 237 023 and DE-OS 38 26 669 provide that the tube is first in the bent Shaped, the glow resistor placed in the bent tube and the ends of the tube are closed. Only in the end is that Evacuated, filled and socketed pipe via a pump connection. This is usually a filling pressure of 2 - 3 bar is used.

JP 1227377 describes a production process, the following process steps includes: making a rod-shaped emitter and local Heating the tube. A special spiral holder is used which is initially spaced (0.8-2.2 mm) from the piston wall. At the local When heated, the bulb wall is oval because the lamp is cold Condition there is a negative pressure of 0.45 to 0.75 atm. In DE-C 12 62 469, the overpressure is produced according to a Operating pressure of approx. 3 atm.

It is an object of the present invention to produce such radiators make it more economical and simplify the procedure.

This object is achieved by the method steps of claim 1 solved. Particularly advantageous configurations can be found in the dependent claims.

The advantage of the method according to the invention is that it has a minimum on manufacturing steps and especially complex steps such as complicated threading of the filament or squeezing the deformed one Kolbens saves. Ultimately, the simplified procedure makes it significant less waste caused.

Surprisingly, it has been shown that it is possible to change the filling pressure of a To dimension the emitter so that the emitter is not just a good operating behavior shows, but also for subsequent processing under Deformation of the piston tube is suitable. For this it is necessary to have one Filling gas pressure to be used with the necessary for the deformation When the pipe is heated, the processing pressure then increases to about 1 bar can be set. The suitable pressure range is between approximately 200 mbar and 1.5 bar.

The filling pressure should preferably be selected between 300 and 900 mbar. A filling pressure of 600 to 800 mbar is particularly suitable, regardless of the type of filling gas and possibly small additions of halogen-like additives. Argon or another noble gas or a mixture is usually used different noble gases used, possibly can, as previously known, other inert gases, e.g. Nitrogen. The right choice of Filling pressure causes the piston to neither move during the bending process inflates still that he collapses. The general rule is that with short lamps (100 to 200 mm long) the filling pressure more in the lower half of the above Range, with long lamps (more than 300 mm in length) more in the upper Half of the above range should be set. An additional fine adjustment can be achieved by cooling the tube during processing become. If a noticeable excess pressure is selected, the lamp is cooled Basically necessary during the bending process, especially with a cold filling pressure of more than 1.1 bar.

Because of this gimmick, which was previously not considered feasible, this can be done Simplify the manufacturing process of curved radiators considerably.

According to the invention, a baseless radiator with a cylindrical one is now first used Piston, as has been known for a long time, but the one discussed above Filling pressure used. It has a linear lamp, e.g. is loosely fixed in the piston by means of retaining rings. Preferably the two ends of the tube are closed with a press seal.

Only then is the tube of the finished lamp emitted in a kind of zone melting process locally heated and then deformed in one or more substeps. This process is not only for glass tubes, mainly quartz glass, but also suitable from quartz.

The deformation may consist of angling one or more sections of the tube. Sections on one or both pipe ends can preferably be angled so that, for example, a U-shaped pipe is formed.
For this purpose, the tube is locally heated, preferably by means of a heating source surrounding the tube in a ring, for example a gas burner.

On the other hand, the method can in principle also be used for the continuous bending of the tube. In particular, it is a matter of producing a partial circle or full circle, but also a spiral or a full circle with overlapping ends bent out of the circle plane or other shapes similar to the prior art described at the outset.
In this case, the still rod-shaped radiator is mounted in an apparatus which comprises a pincer-like holding means and a feed means generating drive means. The holding means can be moved on a circular path, preferably via a drive shaft or axis. It is connected to it via a swivel arm.
The feed-generating drive means (for example in the form of a linkage or in the form of a band, in particular a steel band) is arranged approximately tangentially to the circular path of the rotating arm. The easiest way to do this is by means of a tape that is wound onto a disc that is mounted on the shaft next to the rotating arm and has approximately the same diameter as the circular path of the rotating arm. The tube is attached to the drive means so that it can be moved like a conveyor belt. At least one end of the lamp, preferably both ends, are fixed by holding means. One end is held by the holding means movable on a circular path.
The two moving parts can be set in motion in a timed manner (preferably simultaneously or almost simultaneously). The disk for the drive means is preferably attached to the drive shaft directly or via a transmission.

First, near the tangent point, where the drive means approximately touches the circular path of the rotating arm, a local section of the The tube is heated in a ring, for example a ring is used as the heat source Gas burner used. The gas burner is preferably two Divide (half rings) together to insert the tube To facilitate opening of the half rings.

Then both the drive means and the movable Holding device put into operation. In this way, any one can Create a pitch circle or a (more or less complete) full circle. Also an S-shaped or differently arranged series of partial circle sections is by repeatedly reassembling the partially bent pipe possible. In particular, the above-mentioned bending process is also with this Equipment can be implemented by moving only a very small pitch circle. In particular, the processes of angling and continuous Turning can be combined, e.g. to create an Ω-like full circle, the pipe ends are parallel.

After bending, the radiator can be finished in a known manner, e.g. the ends can be sandblasted and socketed.

Figur 1

eine stabförmige Halogenglühlampe

Figur 2

dieselbe Lampe nach dem Abwinkeln der Enden

Figur 3

dieselbe Lampe nach dem Biegen eines Vollkreises

Figur 4

eine Prinzipdarstellung des Biegevorganges.

Figur 5

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Halogenglühlampe

The invention is explained below using an exemplary embodiment. It shows

Figure 1

a rod-shaped halogen lamp

Figure 2

the same lamp after bending the ends

Figure 3

the same lamp after bending a full circle

Figure 4

a schematic diagram of the bending process.

Figure 5

a further embodiment of a halogen incandescent lamp according to the invention

FIG. 1 shows a rod-shaped 800 W halogen incandescent lamp (festoon), known per se, with a filling of argon (700 mbar) and a halogen additive. The two ends 2 are crimped. The axially arranged filament 3 is loosely fixed by retaining rings 19 in the tube 4 made of quartz glass. In the vicinity of the pipe end 2, the pipe 4, the length of which is approximately 350 mm, is first heated with an annular gas burner 5 and an end section 2 'is bent by approximately 30 ° (arrow in FIG. 2). The same procedure is followed with the second end section 2 '. The tube 4 is then bent into a full circle (FIG. 3), the two end sections 2 'again being parallel.
The apparatus required for this is shown in FIG. 4. The already angled spotlight 1 is indirectly attached to a vertically movable steel band 6, in that the lower end section 2a is fixed by a rigid holding forceps 7, which is connected to the steel band via a table 18. The end of the straight section of the tube is fixed in the region of the transition to the upper end section 2b by a similar holding pliers 8, which is, however, movably mounted on a drive shaft 11 via a rotating arm 15. An annular gas burner 10 surrounds the radiator 1 directly in front of the holding tongs 8. The steel band 6 is fastened on the shaft 11 by means of a circular disk 9 which sits next to the rotating arm 15 (not visible in the top view).
When the apparatus is started up by turning (arrow) the drive shaft, the radiator is forced into a circular shape, the desired bending radius being determined by the distance between the holding pliers 8 and the drive shaft 11.

Zum Abwinkeln der Endabschnitte wird die noch gerade Lampe in eine Aufnahme mit Ringbrenner montiert. Oberhalb des Ringbrenners befindet sich eine zangenartige Haltevorrichtung, die sich auf einer Kreisbahn bewegen kann.

Nach dem Anwärmen wird das Rohr über einen kurzen Teilkreis bewegt und somit oberhalb des Ringbrenners abgebogen, wobei es über ein Antriebsmittel nachgeschoben wird. Der Vorteil dieses Vorgehens ist, daß so eine Falte auf der Innenseite der Abwinkelung, wo das Glas zusammengeschoben wird, vermieden wird.

The sequence of the combined bending and bending process can be summarized as follows:

To bend the end sections, the still straight lamp is mounted in a holder with a ring burner. Above the ring burner is a pincer-like holding device that can move on a circular path.

After heating, the tube is moved over a short pitch circle and is thus bent above the ring burner, whereby it is pushed by a drive means. The advantage of this procedure is that such a crease on the inside of the bend where the glass is pushed together is avoided.

Both end sections are bent in the manner described.

The tube, which is angled on both sides, is then rotated through 180 ° and mounted again in the receptacle, so that the bent end sections protrude from the drive shaft (FIG. 4). Just before the upper end section bends, the lamp is gripped by holding tongs and, after passing through a ring torch, is bent by the tongs describing a circular path. The diameter of this circular path is identical to the diameter of the ring-shaped lamp.
The process is ended via a limit switch after approximately a full circle has been run through, if and only if both angled end sections are parallel. The finished bent lamp has, for example, a tube diameter of 8 mm and a diameter of the full circle of approximately 9 cm.

In general, the choice of filling pressure depends on the volume of the lamp, since this the amount of pressure change (generally an increase) during processing. Since the tube diameter leaves little scope (typical values are 8 - 12 mm), the main criterion for the volume is the Lamp length. Depending on the desired lamp output, it is approx. 50 to 1000 mm. Accordingly, a filling pressure of approximately 300 to 900 mbar used. It is set in a rough approximation proportional to the lamp length. With a length of approx. 300 to 450 mm, for example, a Use filling pressure from 650 to 750 mbar. But it is also possible for this Length range a constant filling pressure (in this case at the upper limit, 750 mbar) and the working pressure of 1 bar through more or less intensive cooling of the unheated pipe sections maintain. The cooling can e.g. (Figure 4) by liquid nitrogen 20 take place as described in DE-OS 34 43 384.

The lamp 21, shown in a highly simplified form in FIG. 5, forms a pitch circle 22 curved, but has no angled ends. Rather, they are tangential Extensions 23 of the pitch circle. This means that there is no need for the first embodiment, the necessary step of the angling.

Claims (13)

1. Method for producing a bent or angled-off electric radiator lamp (1) having an incandescent resistor (3) contained in a tube (4), the tube (4) being bent and/or angled-off and containing a filling gas at a given cold filling pressure and being sealed at two ends (2), in particular a halogen incandescent lamp suitable as a high-intensity radiator lamp heating element, the production comprising at least the following method steps:

   a) production of a tubular electric radiator lamp;

   b) local heating of the tube (4);

   characterized in that the method step a) proceeds as follows:

   a) production of the tubular radiator - lamp, the cold filling pressure of the filling gas being measured in a range from 200 mbar to 1500 mbar; and in that a further method step c) is run through after the method step b) :

   c) subsequent deformation of the tube into the desired shape, a working filling pressure of approximately 1 bar being maintained during the heating and deformation.
2. Method according to Claim 1, characterized in that the cold filling pressure is selected between 300 and 900 mbar, preferably between 600 and 800 mbar, in particular from 700 + 50 mbar.
3. Method according to Claim 1, characterized in that a part of the tube is cooled (20) during steps b) and/or c) in order to maintain the working filling pressure.
4. Method according to Claim 1, characterized in that the method steps b) and c) are applied for the purpose of angling off tube sections (2').
5. Method according to Claim 4, characterized in that method step b) proceeds as follows:

   heating of a tube region by means of a local heat source annularly surrounding the tube.
6. Method according to Claim 4, characterized in that method step c) proceeds as follows:

   bending the tube region off at the desired angle.
7. Method according to Claim 1, characterized in that the method steps b) and c) are applied for the purpose of continuously bending the tube, in particular, to form a partial circle or complete circle.
8. Method according to Claim 4 or 7, characterized in that method step b) proceeds as follows:

   mounting of the at least still substantially tubular radiator lamp in a receptacle in such a way that an end section (2b) of the tube is held in a holding device, preferably a clamp (8) of the receptacle, which holding device can be moved on a circular track, while at least a substantial part of the tube (4) is connected to a feed-generating drive means (6) arranged approximately tangentially to the circular track, and

   heating a tube region by means of a local heat source (5; 10) annularly surrounding the tube.
9. Method according to Claim 4 or 7, characterized in that method step c) proceeds as follows:

   operation of the feed-generating drive means (6),

   commissioning of the movable holding device (8).
10. Method according to Claim 9, characterized in that the two partial steps are tuned to one another in time, in particular by mechanical coupling of the two devices.
11. Method according to Claims 4 and 7, characterized in that the method according to Claim 4 is carried out before the method according to Claim 7, in particular the angling-off being implemented by moving along a very small partial circle, and the lamp being subsequently used rotated by 180° for the continuous bending.
12. Method according to Claim 11, characterized in that in order to achieve a full circle the bending process in accordance with Claim 7 is terminated precisely when the angled-off end sections are parallel to one another.
13. Method according to one of the preceding claims,
    characterized in that the tube (4) consists of quartz glass or fused quartz.

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