JPH0221188A - Blackened film forming furnace for shadow mask structural body - Google Patents

Abstract

PURPOSE:To prevent the corrosion of materials for a chamber and eliminate the production of dust and/or foreign substance due to the corrosion to permit the stabilized use of a furnace for a long period of time by cooling the inside of the chamber of the furnace, which constitutes a cooling zone, with air. CONSTITUTION:The cooling zone of a blackened film forming furnace is constituted of three chambers 7, 8, 9 divided into three cooling zones while the peripheral walls of the furnace are provided with flow passages 10, 11, 12 permitting independent flows of cooling air. Respective zones of the chambers are cooled independently by the flow of the air whereby high-temperature shadow mask structural bodies 13, coming out of a heating zone, are transferred by a mesh-belt type conveyer 14 sequentially, then, the temperature of the bodies 13 becomes 100 deg.C and are carried out of the cooling zones. In this case, the opening degree of air flow rate regulating dampers 27, 28, 29 as well as the rotation of a motor for an air discharging device 23 are controlled in accordance with the outputs of temperature sensors 24, 25, 26 provided in respective chambers 7, 8, 9 whereby the amount of discharging air may be regulated and the temperatures of the cooling zones in respective chambers 7, 8, 9 may be controlled at a desired value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a blackening film forming furnace for a shadow mask structure for a shadow mask type color picture tube, and particularly to a cooling zone configuration.

[Conventional technology]

As is well known, a shadow mask for a color picture tube is fixed and reinforced to a bottom frame as a color selection electrode to form a shadow mask structure.

Normally, in order to manufacture this shadow mask structure, the shadow mask and the support frame are each press-molded into a predetermined shape from a mild steel plate, and after cleaning, a blackened film of Fe, O, etc. is applied in a blackened film forming step. In this blackening film forming process, the shadow mask structure is rapidly heated to about 550°C to 650°C in a mixed gas atmosphere of CO2°H, O, N, etc. in a blackening film forming furnace, and its surface is coated with Fe, O, etc. , forms a blackened film. The blackening film forming furnace in this step is called a heating zone of the blackening film forming furnace.

Next, the shadow mask structure heated to a high temperature to form a blackened film as described above is removed from the heating zone, and then
The material is gradually cooled and heat treated to more firmly adhere the blackened film formed as described above, and then taken out of the furnace at a temperature of about 100.degree. C. or less. The blackening film forming furnace in this step &C is called a cooling zone of the blackening film forming furnace.

FIG. 3 shows the cooling zone 1 of the blackening film forming furnace of the shadow mask structure, and the shadow mask is heated to a temperature of about 550° to 650° C. after exiting the heating zone 2 (not shown) of the blackening film forming furnace. The structure is conveyed to a mesh belt-shaped conveyor 3 and moved from the left side (7J) to the right side in the drawing, and is gradually cooled down to about 100° C. or less before being taken out of the furnace.

The cooling zone 1 of the blackening film forming furnace consists of a chamber 4 divided into a plurality of cooling zones (cooled temperature atmosphere).
5 and 6, cooling water is made to flow through the peripheral wall of each chamber 4, 5, and 6, and this cooling water lowers the temperature of each zone and sequentially cools the shadow mask structure. There is.

[Problem to be solved by the invention]

However, according to the cooling method in the cooling zone of the conventional blackening film forming furnace described above, since the chambers 4.5. This is likely to occur, leading to water leakage and shortening the lifespan of the furnace. In particular, depending on the quality of the industrial water used as cooling water, the chamber material may be severely corroded, resulting in Problem E.

In addition, as corrosion of the chamber material progresses, dust and foreign matter caused by the corrosion will be generated in the chamber, and this will adhere to the shadow mask structure passing through the furnace, causing clogging and corrosion of the shadow mask and causing color image reception. There was a possibility that it would have an unfavorable effect on the operation of the pipe.

For this reason, poor quality steel (e.g. 8US3) is used as a chamber material.
Although it has been proposed to use 04), it is not practical because it increases the cost and there is a risk that cracks may occur due to thermal strain f, resulting in water leakage.

In view of the above-mentioned conventional problems, it is an object of the invention to provide a blackening film forming furnace in which the chamber material is less corroded and water does not leak.

[Means to solve the problem]

The above purpose is to blacken the shadow mask structure by having a heating zone for heating the shadow mask structure to form a blackened film, and a cooling zone for cooling the shadow mask structure discharged from the heating zone. This is achieved by providing a passage for furnace cooling air in the peripheral wall of the furnace chamber constituting the cooling zone in the film forming furnace 1.

[Effect]

Since the above means uses air to cool the inside of the chamber, there is little corrosion of the chamber material, and therefore, the furnace can be used stably for a long period of time without the generation of dust or foreign matter due to corrosion.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows the cooling zone of the blackening film forming furnace, and this cooling zone is divided into three cooling zones: chamber 7, 8. 9
Consists of. To explain the second Sumiko chamber 7 as an example, there is a flow path 1 in which cooling air is independently passed through its peripheral wall.
0,11.12 are provided.

Through this air flow, each zone of the chamber is independently cooled, and the high-temperature shadow mask structure 13 discharged from the unillustrated heating zone 771 in FIG. It is cooled to a temperature of about 100°C, and then taken out of the cooling zone.

Each chamber 7.8.9 of the cooling zone is provided with an inlet 15, 16, 17 and an outlet 18, 19, 20 for cooling air, and the cooling air taken in from the duct 21 is provided with an inlet 15, 16, 17 and an outlet 18, 19, 20. .1771) are discharged from the exhaust ports 18, 19, 20 through the channels in the peripheral wall of each chamber half and 8.9, and are forcibly discharged by the exhaust device 23 installed in the exhaust duct 22, cooling each zone independently. Rub it until it becomes cloudy.

And each chamber 7, 8. 9 are provided with temperature sensors 24, 25, 26 for measuring the temperature of the zone, and air volume adjustment dampers 27, 28.2 are provided in response to the output of the sensor.
At the same time, by controlling the rotation of the electric motor of the exhaust device 23 using an inverter, the amount of exhaust gas is adjusted and the cooling zone of each chamber 7.degree. 8.9 is controlled to a desired temperature.

In addition, each chamber 7, 8. If fins 30 are attached to the cooling air flow path provided on the peripheral wall of 9, the cooling effect becomes even more effective.

With the above-described structure, the shadow mask structure is cooled to a desired temperature, taken out of the furnace, and then proceeded to the next step.

〔Effect of the invention〕

According to the invention mentioned above, the cooling zone of the blackening film forming furnace is cooled using air, so there is no water leakage or corrosion of the chamber material, and no dust or foreign matter is generated in the furnace FF3t. Therefore, the shadow mask is not clogged or corroded. It also has excellent economical effects, such as extending the life of the furnace and reducing maintenance.

[Brief explanation of the drawing]

Fig. 1 is a side view of the main part of an embodiment of the cooling zone of the blackening film forming furnace according to the present invention, Fig. 2 is a side view of the main part as seen from the arrow E in Fig. 1, and Fig. 3 is a conventional one. It is a side view of the main part of the blackening film forming furnace. 7, 8. 9...Chamber 10.11,1
2... Channel, 14... Conveyor, 15, 16
゜17... Inlet, 18, 19.20... Outlet, 21.22... Duct, 23... Exhaust device,
24.25,26...Temperature sensor →? ,27,28゜2
9...Air volume adjustment damper. Figure 1 Figure 2 A Otsu 8, 9: Changha 14: Combe 7 15.16.17: Inlet 8.19.20: Oval exit 27. 28, 29: Otori t5 round 67” nno 7: Chan t＼°− 101112=A way 14-conveyor 15 2nd fire inlet 18: 2nd non-exit 2+, 22: evening 24° filling sensor

Claims (1)

[Claims] 1. A blackening film forming furnace for a shadow mask structure having a heating zone for heating a shadow mask structure and forming a blackening film thereon, and a cooling zone for cooling the shadow mask structure taken out from the heating zone. A blackening film forming furnace with a shadow mask structure, characterized in that a flow path for furnace cooling air is provided on a peripheral wall of a chamber of the furnace constituting the cooling zone. 2. The furnace that makes up the cooling zone consists of multiple chambers,
2. A blackening film forming furnace for a shadow mask structure according to claim 1, wherein passages for furnace cooling air are provided independently of each other on the peripheral wall of each chamber. 3. Temperature sensors are provided in each of the plurality of chambers of the furnace constituting the cooling zone, and the temperature of each of the chambers is controlled to a predetermined temperature by adjusting the amount of ventilation in each of the chambers based on the output of the temperature sensor. A blackening film forming furnace for a shadow mask structure according to claim 2, characterized in that: