JPH0498757A - Manufacture of tubular incandescent bulb - Google Patents

Abstract

PURPOSE:To enable the welding process of a straight lead section extended from a coil-shape luminous section and a metal foil to be easily automated by forming a coil-shape extra winding section at the tip of the aforesaid straight lead section. CONSTITUTION:Upon completion of a coiling process, a mandrel 9 wound with a coil is set to a ring anchor mounting machine, and the mandrel 9 is rotated to coil the predetermined positions of a luminous section 1 with the predetermined quantity of ring anchors 4, as shown in Fig. A. In this case, an extra winding section 3 is coiled about the mandrel 9 and, therefore, a straight lead section 2 is not separated from the mandrel 9, even if subjected to a centrifugal force. Consequently, a member for retaining the lead section 2 can be eliminated. When the tip of the lead section 2 is welded to a metal foil 5 having a welded external lead 6, it is easy to align the lead section 2 with the metal foil 5 and a welding work can be undertaken in a constant condition, as the lead section 2 is straight. As a result, the welding process can be easily automated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a tubular incandescent light bulb with both ends sealed.

[Prior art and its problems]

Tubular incandescent light bulbs with pinch seals formed at both ends of the tube bulb are widely used as light sources for document exposure in electrophotographic copying machines and as heat sources for fixing devices. An incandescent light bulb has a light-emitting part made of a coiled tungsten wire, which is held by a ring anchor and placed along the tube axis of the bulb, and a metal foil welded to the tip of a lead extending from both ends of the light-emitting part is attached to the bulb. It is buried in the pinch seals on both ends. That is, the mount consists of a coiled light emitting part, lead parts extending from both sides of the light emitting part, a ring anchor attached to the light emitting part, and a metal foil welded to the tip of the lead part. Therefore, when manufacturing the mount, lead parts are formed on both sides of the light emitting part in the coiling process that forms the light emitting part.First, one lead part is formed by winding a tungsten wire around a mandrel at a loose pitch, and then a predetermined shape is formed. The light emitting part is wound for a predetermined length at a tight pitch, and then wound again at a loose pitch to form the other lead part. Then, wrap the ring anchor around the light emitting part and remove the coil from the mandrel (however, since the lead part was wound at a loose pitch, it will not be straight but curled. Therefore,
When welding the tip of the lead part to the gold gC foil, the curved line and the flat surface will come into contact. In other words, the convexly curled portion of the lead portion or the concavely curled portion may come into contact with the flat metal foil, making it difficult to determine the contact position. Therefore, this welding process is difficult to automate and is performed manually, resulting in low productivity. In addition, the lead part and the metal foil are in point contact, and the contact area is extremely small.
There is a problem that makes it difficult to weld firmly.

For this reason, attempts have been made to make the lead part linear, but if the lead part is formed by running a tungsten wire in a straight line along the surface of the mandrel, a ring anchor is attached to the light emitting part after the coiling process. Sometimes the reed part separates from the rotating mandrel due to centrifugal force,
There is a problem where it hits other adjacent mandrels. Therefore.

When forming a linear lead portion using such a method, a member is required to hold the lead portion so that it does not separate from the mandrel.

[Purpose of the invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a tubular incandescent light bulb in which the lead portion can be made straight in a simple manner and the process of welding the lead portion and metal foil can be easily automated.

[Structure of the invention and its effects]

The structure of the present invention is such that a coiled light emitting part held by a ring anchor is arranged along the tube axis of the bulb, and metal foil connected to lead parts extending from both ends of the light emitting part is attached to pinch seal parts at both ends of the bulb. A method for manufacturing a buried tubular incandescent light bulb, the coiling comprising a straight lead part continuing on both sides of a coil-shaped light emitting part, and a fill-like winding part on both sides of the lead part. The method is characterized in that it includes a step of attaching a ring anchor to a coiled light emitting portion, and a step of cutting a linear lead portion and welding metal foil to the tip side thereof.

Further, between the process of attaching the ring anchor to the light emitting part and the process of welding the lead part and the metal foil, an energization process is provided in which the winding part is chucked and the coil is formed.

In other words, in the coiling process, a linear reed part is formed between the coiled light emitting part and the coiled discarded part, so one positioning is required when cutting the lead part and welding its tip to the metal foil. It is easy to weld and can be welded under certain conditions, making it easy to automate. and.

Since the leat part and the metal foil come into line contact and the contact area becomes large, welding can be performed reliably. Further, when attaching the ring anchor to the light emitting part, since the coiled winding part is wound around the mandrel, the lead part does not separate from the mandrel, and there is no need to provide a lead part holding mechanism in the ring anchor attaching machine.

Furthermore, by providing an energization process in which the coiled part is chucked to form the coil, it becomes easy to energize even if the lead part is straight, and the tungsten crystals deformed during the coiling process are recrystallize.

〔Example〕

Embodiments of the present invention will be specifically described below based on the drawings.

FIG. 2 shows a tubular incandescent light bulb with a rated power consumption in the range of 350 to 1150 W, which is used, for example, as a heat source in a fixing device of a copying machine. Tube-shaped bulb 7 made of quartz glass
A pinch seal portion 8 is provided at both ends of the metal foil 5, and a metal foil 5 made of molybdenum foil is embedded in each pinch seal portion 8.

A light emitting part 1 made of a tungsten wire wound into a coil is held by a ring anchor 4 and arranged along the tube axis of the bulb 1. Lead parts 2 extending from both ends of the light emitting part 1 are welded to the metal foil 5, and external leads 6 are also welded to the metal foil 5 and extend from the pinch seal part 8.

Next, a method for manufacturing such a tubular incandescent light bulb will be described. First, a coiled part 3, a linear lead part 2, and a coiled light emitting part 1 are manufactured in a coiling process. In other words, as shown in Figure 1 (a), the outer diameter is 0.5 to 1,
Rotate the mandrel 9 of 1 mmφ, and the wire diameter is 0.12.
A nozzle (not shown) for feeding out a tungsten wire of ~0.41 mmφ is sent in the axial direction of the mandrel 9, and first, the tungsten wire is wound around the mandrel 9 in a dense coil shape to form one winding part 3. The rotation of the mandrel 9 is then stopped and the nozzle is run axially along the surface of the mandrel 9. As a result, a linear lead portion 2 is formed. Then, by rotating the mandrel 9 and sending the nozzle at a predetermined speed, a dense coiled light emitting section 1 is formed. When the light emitting part 1 of a predetermined length is formed, the rotation of the mandrel 9 is stopped again and the nozzle is run to form the linear lead part 2. Finally, the mandrel 9 is rotated to form the other winding portion 3. As a result, a coil in which the light emitting part 1, the lead part 2, and the discarded winding part 3 are integrated is completed.

When the coiling process is completed, the mandrel 9 with the coil wound around it is set in the ring anchor installation machine, and as shown in Fig. 1 (
As shown in b), the mandrel 9 is rotated and a predetermined number of ring anchors 4 are wound around and attached to a predetermined portion of the light emitting part 1. This ring anchor 4 has a wire diameter of 0.25
It consists of a tungsten wire with a diameter of ~0.26 mm. At this time, since the winding part 3 is wrapped around the mandrel 9,
Even if centrifugal force acts, the linear lead portion 2 does not separate from the mandrel 9. Therefore, a member for holding the lead portion 2 is not necessary.

Next, the coil is pulled out from the mandrel 9, the lead part 2 is cut to a predetermined length, and the winding part 3 is separated. However, when performing a forming process, the winding part 3 is separated before cutting the lead part 2. Chuck it and apply electricity for a few seconds while applying tension. As a result, the tungsten crystals deformed in the coiling process are recrystallized, but the first coiled portion 3 is chucked, so that even if the lead portion is linear, energization can be easily carried out.

The lead part 2 is cut, and in the welding process, the external lead 6 is
When the tip of the lead part 2 is welded to the metal foil 5 to which the metal foil 5 has been welded, the mount is completed as shown in FIG. 1(C). At this time, since the lead portion 2 is linear, positioning with respect to the metal foil 5 is easy and welding can be performed under constant conditions, so this welding process can be easily automated. Furthermore, since the leat portion 2 and the metal foil 5 are in line contact and the contact area is increased, welding can be performed reliably.

Such a mount is placed inside a glass tube for a bulb, both ends of the glass tube are sealed by pressure, and the metal foil 5 is buried in the pinch seal portion 8, and the bulb 7 is filled with an inert gas along with a small amount of halogen gas. The tubular incandescent light bulb shown in Figure 2 is completed.

〔Effect of the invention〕

As explained above, in the method for manufacturing a tubular incandescent light bulb of the present invention, in the coiling process, a coiled discarded portion is formed at the tip of a linear lead extending from a coiled light emitting portion. When attaching a ring anchor to a mandrel, the lead part does not separate from the mandrel, and there is no need to provide a lead part holding mechanism in the ring anchor attaching machine. In addition, since the lead part is straight, the welding process between the lead part and the metal foil can be easily automated, greatly improving productivity, and the contact area between the lead part and the metal foil is large, allowing for reliable welding. There are also advantages.

[Brief explanation of the drawing]

Figures 1 (a), (b), and (c) are process explanatory diagrams. is an explanatory diagram of a tube-shaped incandescent light bulb. 1... Light emitting part 2... Lead part 3... Winding gore part 4... Ring anchor 5... Metal foil 6... External lead 7... Bulb 8.
...Pinch seal part 9...Mandrel Fig. 2

Claims (1)

[Claims] 1) A coiled light emitting part held by a ring anchor is arranged along the tube axis of the bulb, and a metal foil connected to a lead part extending from both ends of the light emitting part serves as a pinch seal at both ends of the bulb. A method for manufacturing a tubular incandescent light bulb embedded in a coiled part, the method comprising: a straight lead part continuing on both sides of the coiled light emitting part; and a coiling part forming further coiled ends on both sides of the lead part. a step of attaching a ring anchor to the coiled light emitting portion; and a step of cutting the linear lead portion and welding metal foil to the tip side thereof. manufacturing method. 2) A tube in which a coiled light emitting part held by a ring anchor is arranged along the tube axis of the bulb, and metal foil connected to lead parts extending from both ends of the light emitting part is embedded in the pinch seal parts at both ends of the bulb. A method for manufacturing a shaped incandescent light bulb, comprising: a coiling step of forming a linear lead part continuing on both sides of the coiled light emitting part, and further forming coiled winding parts on both sides of the lead part; a step of attaching a ring anchor to the light emitting part of the coil, an energizing step of chucking the winding part and forming a coil, a step of cutting the linear lead part and welding a metal foil to the tip side thereof, A method for manufacturing a tubular incandescent light bulb, comprising: