JPS63161151A - Method for conveying material to be heated in blackening treatment - Google Patents

Abstract

PURPOSE:To form dense blackening films on the surfaces of shadow masks for cathode ray tubes by stacking the shadow masks spaced from each other on a metal frame and passing the masks through the inside of a blackening furnace having opening/ closing doors on inlet and outlet sides. CONSTITUTION:The many shadow masks A parted from each other at specified intervals are stack on the metal frame 81 and after the frame is placed on a charging table 25, the frame is put into a front chamber 23. After the atmospheric gas for blackening from a gas generator 61 is introduced into the chamber 23 by opening a valve 52, the door 41 is opened and the frame is introduced into a heating and holding furnace 21. The atmospheric gas for blackening is filled by a valve 51 in the chamber 21 and the masks are heated to about 580 deg.C in the atmosphere, by which the blackening films essentially consisting of Fe3O4 are formed on the surfaces. The masks are in succession thereof cooled down to about 100 deg.C in a cooling zone 22. The masks are passed through a rear chamber 24 in which the atmospheric gas for blackening is filled through a valve 63 and thereafter, the frame 81 is taken to the outside of the blackening furnace. The blackening treatment of the many shadow masks at one time is thus permitted.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention uses a blackening furnace to blacken heat-receiving materials such as a shadow mask for a cathode ray tube, its support frame, and even an inch shield while conveying them through the furnace. The present invention relates to a method for transporting the heated material during processing.

A shadow mask type color television or a cathode ray tube of an OAIa display has a shadow mask welded to a support frame between the panel and the funnel. This type of shadow mask has a blackened film (an oxide film mainly made of Fe30a) on its surface, including the support frame and inner shield, for the purpose of preventing diffuse reflection of the electron beam, doming of the shadow mask, and occurrence of red rust. is used.

By the way, in a continuous blackening furnace used to form a blackening film on the surface of a heat target material such as a shadow mask or its support frame, CO and CO2 are removed while the heat target material is transported through the furnace.
The shadow mask and its support frame are heated and soaked at around 580°C under an atmospheric gas containing It is required that a dense blackened film of a predetermined thickness can be formed on the surface of a heated material with good workability and economical stability.

The present invention relates to a method for conveying a heated material to meet such demands.

<Conventional technology and its problems> Conventionally, in a continuous blackening furnace used to form a blackening film on the surface of a heat target material such as a shadow mask or its support frame, the method of conveying the heat target material is , transportation is carried out by a meshbelt conveyor. This is a method in which the material to be heated is placed on a mesh belt that rotates endlessly between the inside and outside of the furnace. The material is heated and soaked at about 580° C. in an exothermic gas atmosphere containing about 0% CO, and then cooled to about 100° C. to form a blackened film on the surface of the heated material.

However, the above conventional method has various problems as follows.

1) For example, shadow masks must be placed one by one on the mesh belt so that they do not overlap, and then taken out one by one after the blackening process, resulting in poor workability and productivity. When shadow masks are stacked on top of each other on the mesh belt, it is difficult to form a black film on the overlapping parts, which causes problems such as red rust, and conversely, a sufficient black film is formed on the overlapping parts. If you try to do so, the thickness of the blackened film formed on the non-overlapping parts will become too thick, and such a blackened film will easily peel off. This causes welding defects when assembling between the Therefore, the reality is that shadow masks are handled one by one as described above, putting up with the poor workability.

Such poor workability also poses a problem when the shadow mask is cleaned prior to the blackening process.

2) Since a mesh belt that rotates endlessly between the inside and outside of the furnace is used, the mesh belt is repeatedly heated inside the furnace and cooled outside the furnace, resulting in a large waste of thermal energy.

3) Due to the use of mesh belts as described above, the charging and discharging sides of the blackening furnace are open, and even if they are placed horizontally and narrowed into a flue, there will be leakage from the open parts. Requires a large amount of atmospheric gas.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention solves the conventional problems as described above and provides an improved conveyance method that meets the above-mentioned demands.

However, the Ming Dynasty was born on wood.

When using a blackening furnace to form a blackening film on the surface of materials to be heated, such as cathode ray tube shadow masks and their support frames, while transporting them through the furnace, the inside of the blackening furnace is where the atmosphere inside the furnace can be shut off by a door that can be opened and closed. The present invention relates to a method for transporting heat-target materials in a blackening film forming process, characterized in that a metal frame loaded with heat-target materials in multiple stages at predetermined intervals above and below is transported while being supported by a roller conveyor.

An important point in the present invention is that in order to form a dense blackened film of a predetermined thickness on the surface of heat-receiving materials such as a shadow mask and its support frame with good workability and economically, The metal frames are stacked in multiple stages at predetermined intervals above and below, and the metal frames are conveyed by a roller conveyor in the furnace atmosphere, which is shut off by a door that can be opened and closed.

The configuration of the present invention will be explained in more detail below based on one drawing.

<Embodiment> FIG. 1 is an overall front view showing one embodiment of the present invention, and FIG. 2 is a partially enlarged side view thereof. The blackening furnace body 11, which includes a heating/soaking zone 21 and a cooling zone 22, has a door 41 on its charging side that can be opened and closed by a drive device 31, and a door that can be opened and closed by a drive device 32 on its discharge side. 42 are each equipped. A gas generator 6 is connected to the blackening furnace body 11 via a valve 51.
The exothermic gas from No. 1 is introduced, and the atmosphere inside the furnace due to this is shut off by doors 41 and 42. A front chamber 23 is connected to the charging side of the blackening furnace body 11 through a door 41, and a rear chamber 24 is connected to the charging side through a door 42. The atmosphere in each room is controlled by valve 52.
．． 53, and a drive device 33 is provided on the charging side of the front chamber 23.
A loading table 25 is attached to the rear chamber 24 via a door 43 which can be opened and closed by a drive device 34, and a loading table 26 is attached to the loading side of the rear chamber 24 via a door 44 which can be opened and closed by a drive device 34. A roller conveyor 71 is provided extending from the charging table 25 to the front chamber 23 to the blackening furnace main body 11 (heating/soaking zone 21 to cooling zone 22) to the rear chamber 24 to the loading table 26.

In the drawing, a short receiving piece 8 protrudes toward the inner side of the metal frame 81.
2, the shadow masks A to be processed are stacked vertically at predetermined intervals in multiple stages, and the metal frame 81 is transferred to the roller conveyor 7.
1, charging table 25 → front chamber 23 → blackening furnace main body 11 (heating/soaking zone 21 → cooling zone 22) → rear chamber 24 →
Although the state is shown in which the loading table 26 is being transported in this order, this implementation state will be explained in more detail using the case of a shadow mask whose material is aluminum guild steel as an example. be.

First, as illustrated in FIG. 2, the shadow masks A are stacked in multiple stages on the metal frame 81 with predetermined intervals above and below. Then, the metal frame 81 is placed on the roller conveyor 71, loaded from the loading table 25 into the front chamber 23, and the door 43 is closed. After replacing the inside of the front chamber 23 with exothermic gas introduced through the valve 52, the door 41 is opened and the metal frame 81 is inserted into the blackening furnace main body 1.
1 and close the door 41. In the blackening furnace main body 11, the shadow mask A loaded on the metal frame 81 is transported inside the furnace by the roller conveyor 71, and is heated in the heating/soaking zone 21 under an exothermic gas atmosphere introduced through the valve 51.
Heat treated to around 80℃, then heated to 100℃ in cooling zone 22
Cool to a certain degree. After cooling, the inside of the rear chamber 24 is sealed with the valve 5.
After replacing the gas with exothermic gas introduced through 3,
The door 42 is opened, the metal frame 81 is inserted into the rear chamber 24, and the door 42 is closed. Finally, the door 44 is opened, the metal frame 81 is extracted to the loading table 26, and the door 44 is closed. Hereinafter, the above-mentioned operation is continuously repeated. Although the explanation will be omitted, depending on the material of the shadow mask, it is also possible to introduce steam, for example, in addition to the exothermic gas into the heating/soaking zone, and to introduce air, in addition to the exothermic gas, into the cooling zone. .

Advantageous Effects> As is already clear, the present invention described above has the following excellent effects.

(1) In order to load the heated materials into the metal frame and handle them all at once,
Workability and productivity are good, and such good workability is similarly exhibited in the cleaning treatment performed prior to the blackening treatment.

(2) The materials to be heated are handled together in a metal frame, and the roller conveyor that conveys the metal frame is always kept under the same temperature conditions inside the furnace, so it endlessly rotates inside and outside the furnace to heat it. Compared to the case where heated materials are conveyed one by one using a mesh belt that repeatedly performs cooling and cooling, there is less waste of thermal energy per unit processing amount.

(3) The metal frame that handles the materials to be heated is transported by a roller conveyor, and the inside of the blackening furnace is isolated by doors installed on the charging and unloading sides, so less atmospheric gas is required. It's fine.

(4) The materials to be heated loaded in the metal frame are spaced apart from each other by a predetermined distance above and below, and the atmosphere inside the furnace is blocked and there is no disturbance, so the entire surface of each material to be heated is covered. A dense blackened film with a predetermined thickness can be formed.

[Brief explanation of the drawing]

FIG. 1 is an overall front view showing one embodiment of the present invention, and FIG. 2 is a partially enlarged side view thereof. 11. Blackening furnace main body, 21. Heating/soaking zone 22. Cooling zone, 23. O front chamber, 24. Rear chamber 25. Charging table, 26. Loading table 31-34. Drive device, 4
1-44... Doors 51-53 - Valve, 61 - Gas generator 71... Roller conveyor, 81 - Metal frame A 11
11 Shadow mask patent applicant Daido Steel Co., Ltd. Toshiba Corporation

Claims (1)

[Claims] 1. When using a blackening furnace to form a blackening film on the surface of heated materials such as cathode ray tube shadow masks and their support frames while transporting them through the furnace, the atmosphere inside the furnace may be blocked by a door that can be opened and closed. A method for transporting materials to be heated in blackening treatment, which comprises transporting a metal frame loaded with materials to be heated in multiple stages at predetermined intervals above and below in a furnace while being supported by a roller conveyor.