JPS6042574B2 - Fluorescent coating baking equipment for fluorescent lamps - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement in a fluorescent coating firing apparatus for a fluorescent lamp.

When manufacturing fluorescent lamps, a phosphor suspension consisting of a phosphor, a solvent, and a binder is applied to the inner surface of a glass tube, the solvent is dried, and then the coated glass tube is heated in a heating oven. It is necessary to burn the binder by heating it through the glass tube and burn the phosphor onto the inner surface of the glass tube.

Conventionally, this kind of fluorescent coating baking apparatus is shown in Fig. 1a and b.
As shown in the figure, a glass tube 2 coated with a fluorescent suspension is placed on a number of rotating and moving cylindrical rollers 1, and a heat source (not shown) such as a radiant burner or an electric heater is placed on the glass tube 2 from above or below. ), which burns off the binder and burns off the fluorescent coating on the inner surface of the glass tube 2.

However, in the fluorescent coating firing apparatus configured as described above, the entire length of the glass tube 2 is always in contact with the cylindrical roller 1 for rotating and transporting the glass tube 2. Since the heat of the tube 2 is transmitted through the cylindrical roller 1 and escapes to the outside, there is a drawback that the thermal efficiency of heating and firing is not good. This invention was made in view of the above-mentioned drawbacks, and instead of using a large number of cylindrical rollers, a pair of chain conveyors installed in parallel in a heating furnace with pawls embedded therein, and a chain conveyor on the side of this chain conveyor are installed in parallel in a heating furnace. By making the device consist of a guide rail on which a glass tube whose inner surface is coated with a phosphor suspension is placed, the device itself can be simplified, maintenance and inspection can be facilitated, and thermal efficiency can be improved. The present invention provides a fluorescent coating firing device for a fluorescent lamp, which can improve labor efficiency and save energy.

An embodiment of the present invention will be described below based on FIG. 2. In the figure, reference numerals 3 and 3 indicate a pair of chains in which a plurality of heat-resistant materials or pawls 4 covered with heat-resistant materials are planted at a predetermined pitch. The conveyors are installed parallel to each other in a heating furnace (not shown) and are configured to operate synchronously in the same direction.

Reference numerals 5 and 5 designate two guide rails which are provided on the sides of the chain conveyor 3 with their upper surfaces higher than the chain conveyor 3, and are coated with a heat-resistant material or a heat-resistant material, and are coated with a phosphor suspension. The glass tube 2 is placed thereon.

In the fluorescent coating firing apparatus constructed in this way, first, the glass tube 2 coated with the fluorescent suspension is orthogonally crossed with the guide rail 5, and is supported between the pawls 4. After placing it on the guide rail 5, the chain conveyor 3
When the glass tubes 2 are rotated and conveyed by the pawls 4 on the guide rails 5 and passed through the heating furnace, the radiant burners or A heat source such as an electric heater (
(not shown) heats the glass tube 2, burns off the binder in the coating film applied to the inner surface of the glass tube 2, and burns a fluorescent coating on the inner surface of the glass tube 2. It is. Furthermore, in order to uniformly heat the glass tube 2 in the heating furnace, it is essential that the glass tube itself rotates while the glass tube 2 passes through the heating furnace. Depending on the contact resistance between the guide rail 5 and the glass tube 2, the glass tube 2 may slip on the guide rail 5 and not rotate properly. In order to achieve layer effect, the shape and material of the pawl 4 and the glass tube 2 should be adjusted so that the contact resistance between the pawl 4 and the glass tube 2 is smaller than the contact resistance between the guide rail 5 and the glass tube 2. Even more effects can be obtained by using a shape that reduces the contact area or by using a material for the pawl 4 that allows the glass tube 2 to easily slide.

Furthermore, as a means to improve the rotation of the glass tube itself,
As shown in FIG. 3, it has been found that it is even better to incline the chain conveyor 3 and the guide rail 5 so that the direction of movement of the glass tube 2 is lowered. In other words, by creating an inclination, the glass tube 2 is not pushed forward by the pawls 4, but rotates on the guide rail due to its own weight, so the influence of friction from the pawls is almost eliminated, and the glass tube The rotation is smooth and the risk of scratching the surface of the glass tube is extremely reduced. However, if the inclination angle is too large, the entire tunnel-shaped heating furnace that is installed to cover the chain conveyor will also need to be tilted, and as a result, the hot air inside the heating furnace will flow in the direction with the highest chimney effect, causing the entire heating furnace to Since the thermal efficiency of the inclination angle decreases, it has been practical to set the inclination angle to 200 degrees.
As described above, in this invention, both ends of a glass tube coated with a phosphor suspension are supported by a pair of guide rails, and the glass tube is conveyed while being supported between pawls. Since the device does not require a large number of cylindrical rollers unlike the conventional device shown in Fig. 1, the structure is simplified, maintenance and inspection are easier, and the contact area between the glass tube and the device is reduced. Since this is extremely small, the amount of heat escaping to the outside of the glass tube can be significantly reduced, resulting in an extremely high thermal efficiency.

[Brief explanation of the drawing]

1A and 1B are perspective views and side views of the main parts of a conventional fluorescent coating baking apparatus for fluorescent lamps, and FIGS. FIG. 3 is a side view of the main parts of the chain conveyor and the guide rail, which are also inclined.

Claims (1)

[Claims] 1. A pair of chain conveyors each having a plurality of pawls are installed in parallel in a heating furnace, and a phosphor suspension is applied to the inner surface of the sides of both chain conveyors. A guide rail is installed on which the glass tube is placed, the glass tube is placed on the guide rail perpendicularly to the guide rail, and the glass tube is conveyed by the pawl of the chain conveyor, A fluorescent coating baking device for a fluorescent lamp, characterized in that a fluorescent coating is baked on the inner surface of the glass tube using the heat source of the heating furnace. 2. A fluorescent coating baking device for a fluorescent lamp according to claim 1, wherein the contact resistance between the pawl of the chain conveyor and the glass tube is smaller than the contact resistance between the guide rail and the glass tube. 3. Claim 1, characterized in that the chain conveyor and the guide rail are inclined so that the direction of movement of the glass tube is lowered, and the angle of inclination is 20 degrees or less.
A fluorescent coating firing apparatus for a fluorescent lamp according to item 1 or 2.