JPS5851889B2 - Ring-shaped fluorescent lamp heating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the production of annular fluorescent lamps, the present invention is directed to a process in which a linear fluorescent lamp coated with a phosphor and provided with electrodes, etc. is wrapped around a cylindrical drum to form an annular shape. It relates to heating furnaces.

As a process before forming a linear fluorescent lamp into an annular shape,
The linear fluorescent lamp is intermittently transferred to heat and soften the lamp circumferentially uniformly in an electric heating furnace, and then the softened fluorescent lamp is stretched vertically, and the stem section at the lower end of the fluorescent lamp is heated and softened. It is necessary to insert it securely into the lower end positioning rod of the light lamp.

Conventionally, a cylindrical two-part electric furnace has been used as this heating furnace, and when the fluorescent lamp is heated, the two-part furnace is closed, and after a certain period of time, the furnace is opened and the fluorescent lamp is moved to the next process. It was a so-called movable (opening/closing type) electric furnace.

Of course, in practice, depending on whether the process of winding the fluorescent lamps one by one around the cylindrical drum or the process of winding two fluorescent lamps around the cylindrical drum at the same time is adopted, the above-mentioned electric furnaces are used in the process as many times as necessary. It is set up in

Furthermore, movable cylindrical two-part electric furnaces include furnaces that heat one fluorescent lamp at a time and so-called spectacle-shaped furnaces that can heat two fluorescent lamps at the same time.

These electric furnaces are combined to uniformly heat the fluorescent lamp.

However, in these conventional movable cylindrical two-part electric furnaces, strong shocks and vibrations are naturally applied, resulting in (1) frequent disconnection of the heater, and (2) failure of wiring other than the heater. (3) Refractory materials that make up the furnace are likely to fall off and be damaged;
There are certain disadvantages due to the fact that the furnace is movable, which significantly lowers the operating rate and becomes a bottleneck to improving productivity.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a new annular fluorescent lamp furnace which eliminates the above-mentioned drawbacks.

In order to achieve the above object, in the present invention, one end is an entrance portion,
a heating passage with the other end serving as an exit port, through which the object to be heated travels from the entrance port to the exit port, and a connecting portion connecting at least two opposing arcuate portions and the arcuate portions; an annular fluorescent light comprising: an inner wall surface of the heating passage; a heating element provided on the inner wall surface; and a closing body that freely opens and closes at least one of the entrance and exit ports. It has a lamp heating furnace configuration.

By making the heating furnace a fixed heating furnace with the above configuration, it was possible to eliminate all the drawbacks of the conventional movable heating furnace, and furthermore, the effect of reducing heat loss due to opening and closing of the furnace by about 20% was obtained.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a plan view for explaining the outline of a heating furnace according to the present invention, and FIG. 2 is a sectional view taken along the line xx'.

In Figs. 1 and 2, a heat insulating refractory 2 is attached to the heating furnace body 1, and the heat insulating refractory 2' on the inner wall of the heating passage has a shape consisting of an arcuate portion and a connecting portion connecting the arcuate portions. ing.

Heat generating elements 3 and 4 are arranged along this inner wall.

Closure bodies 5 that open and close at regular intervals are provided at the entrance and exit ports.
．． 5' is provided.

A linear fluorescent lamp 6 is installed in the heating furnace constructed in this manner.
is uniformly heated and softened, and the stem portion 8 at the lower end of the fluorescent lamp is inserted into the receiving rod 7, and then transferred to the next process.

Here, the heating elements 3 and 4 may be arranged continuously along the inner wall, but in order to facilitate maintenance and make it possible to finely adjust the temperature depending on the location, the heating elements 3 and 4 are arranged separately along the heating passage. The linear fluorescent lamp 6 is also divided and arranged along the longitudinal direction.

The optimal dividing arrangement is to divide the inner wall into an arcuate portion and a connecting portion, as shown in FIG.

By doing this, the area around the fluorescent lamp 6 can be uniformly heated by changing the amount of heat generated by the arc-shaped part heating element and the connecting part heating element (by changing the amount of electricity supplied).

In particular, in order to prevent a drop in temperature near the entry and exit ports due to opening and closing of the closing bodies 5, 5', the heat generation amount of the heating element 4 in the vicinity is adjusted to be higher than that in other parts.

Furthermore, almost the same effect can be obtained by dividing the heating elements 9 to 12 as shown in FIG.

The trajectory of the heating passage does not need to be an arc and may be a straight line, but when actually building manufacturing equipment, it is desirable to be able to install it with a minimum floor space, and in that case, it is optimal to use a heating passage whose trajectory traces an arc. Become.

Furthermore, the closing body 5 at the entrance port is usually directly connected when a preheating step using gas (a step of heating the fluorescent lamp very roughly) is performed as a preceding step, so it is not necessary.

Moreover, in practice it is necessary to pass the fluorescent lamp through a similar furnace twice in order to uniformly heat it.

Therefore, when adopting the process of winding two fluorescent lamps around a cylindrical drum, a heating furnace with at least four arc-shaped parts is required as shown in Figure 1; A heating furnace with two arcuate sections is required.

After being heated for a certain period of time, the fluorescent lamp 6 that enters from the entrance part moves intermittently to the next position, and in synchronization with this, the closing body 5' at the exit part opens, and the next winding starts. Move to process.

Experimental Example In the heating path shown in FIG. 1, we measured how the temperature distribution around the fluorescent lamp changes depending on the conditions.

In the case of the process of winding two cylindrical drums at the same time, a preheating furnace (
A fluorescent lamp heated to about 550° C. (not shown) passes through the entry port side closing body 5 and occupies a position P1.

In the next movement, it moves to position P2, and in the next movement, the next process of winding becomes a process.

The period of intermittent movement is approximately 12 seconds. Now, the temperature distribution measurement results are at position P and a.

The temperature was approximately uniform at 650° C. on the b, c, and d surfaces, and when the connecting portion heating element 4 was removed, the temperature was approximately 650° C. on the a, b surfaces, and approximately 610° C. on the d surface.

Next, at position P2, the temperature is almost uniform at 750°C on the a*b*c*d plane, and when the connecting heating element 4 is removed, the temperature is approximately 750°C on the a and b planes, about 730°C on the c plane, and about 730°C on the d plane. The temperature was about 710° C., and a bend of about 30 itt occurred at the lower end of the fluorescent lamp.

This is considered to be due to the influence of the closing body 5'.

Furthermore, at this time, if the exit port side closing body 5' is removed, a, b.

Although there was almost no change in the C-plane, the temperature distribution in the D-plane was about 650°C, which was not suitable for practical use.

As described above, by using the fixed beam intermittent continuous heating furnace according to the present invention, the occurrence of wire breakage accidents and refractory falling damage accidents that have occurred in the past has been significantly reduced, thereby improving operation and yield. The power consumption is about 2
It has become possible to dramatically increase productivity, such as by reducing waste by 0%.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the general configuration of a heating furnace for an annular fluorescent lamp according to the present invention, FIG. 2 is a sectional view taken along the line xx', and FIG. 3 is a plan view showing the divided arrangement of heating elements. 3.4...Heating element, 5,5'...Entry/exit port closing body.

Claims (1)

[Scope of Claims] 1. A heating passage having one end as an entrance port and the other end as an exit port, through which the object to be heated runs from the entrance port toward the exit port, and at least two opposing an inner wall surface of the heating passage consisting of a circular arc portion and a connecting portion connecting the circular arc portions; a heating element provided on the inner wall surface; and at least the exit port of the entry and exit ports. 1. A heating furnace for an annular fluorescent lamp, characterized in that it is equipped with a freely closed closing body. 2. The heating furnace for an annular fluorescent lamp according to claim 1, wherein the heating element is arranged in segments along the heating passage. 3. The heating furnace for an annular fluorescent lamp according to claim 2, wherein the heating element is divided into the arc portion and the connecting portion. 4. The heating furnace for an annular fluorescent lamp according to claim 2, wherein the heating element is divided so as to span a part of the arcuate portion and a part of the connecting portion. 5. A heating furnace for an annular fluorescent lamp according to any one of claims 1 to 4, characterized in that the calorific value of the heating element is varied depending on the location of the heating passage. 6. The heating furnace for an annular fluorescent lamp according to any one of claims 1 to 5, wherein the locus of the heating passage is a circular arc.