JPH0490492A - Tunnel furnace - Google Patents

Abstract

PURPOSE:To eliminate a warping of a burned member and to get a flat burned member having a high degree of flatness by a method wherein a bogie within a tunnel furnace is moved to perform a burning operation and the burned member is held between a table and a loading weight plate near a burning region by lifting up the table. CONSTITUTION:A tunnel-like furnace 14 is mounted on a floor 1 through a furnace supporting frame 12. A bogie passed through a preheating zone approaches a burning zone, where a caster 30 is rotated along an ascending slope 36 to cause a stem 24 to be pushed up and a table 28 is also gradually pushed up. As the caster 30 approaches a raised portion 40, a burned member is pushed against a lower surface of a loading weight plate 34. Then, under a condition in which the table 28 is lifted up to its upper lifting limit position, the loading weight plate 34 is floated up from a weighting plate mounting table 32, resulting in that a weight of the loading weight plate 34 is fully applied to a flat plate-like burned member on the table 28. Due to this fact, the burned member is burned while being press held between the loading weight plate 34 and the table 28.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tunnel furnace suitable for firing ceramics, and in particular to a tunnel furnace suitable for firing ceramics, and particularly for firing a flat green body into a flat sintered plate. Regarding the tunnel furnace that can be used.

[Prior Art] As is well known, a tunnel furnace has a material to be fired mounted on a trolley.
It is configured so that the object to be fired is fired by passing it through the tunnel-shaped furnace body.

Inside the tunnel-shaped furnace body, from the population side to the exit side, there are a pre-heating zone, a firing zone, and a cooling zone.

When producing ceramic fired bodies, usually, an organic binder is added to ceramic raw material powder and kneaded.
It is molded into the desired shape to form a green body. Next, this green body is calcined to oxidize and eliminate the binder, and then main firing is performed.

Note that this calcination is sometimes referred to as degreasing firing.

Conventionally, when firing a ceramic flat plate in a tunnel furnace, it was necessary to calcinate the green body in a firing device separate from the tunnel furnace for main firing, and then introduce this calcined product into the tunnel furnace for main firing. Ta.

The reason for firing in two stages in this way is that during the calcination of the flat green body, the flat body curls like a "surume", so in the main firing, a weight plate for loading is placed on top of the calcined body, This is because it is necessary to turn the calcined product upside down and fire it to remove curl distortion and flatten it.

[Problems to be solved by the invention] When firing flat ceramics in a tunnel furnace,
As mentioned above, after the green body is calcined in a furnace different from the tunnel furnace, the temperature is lowered once and then the calcined material is introduced into the tunnel furnace, so there are 8 rows from the calciner to the tunnel furnace. A large amount of thermal energy was lost during the opening.

[Means for Solving the Problems] The tunnel furnace according to claim (1) of the present invention includes a tunnel-shaped furnace body, a rail laid through the inside of the furnace body, and 8! In a tunnel furnace, a table for loading a material to be fired is provided on the trolley so as to be movable up and down, and the table is gradually raised as the trolley moves, and then a filling table is provided. A table lifting mechanism that gradually lowers the table, and a loading weight plate that is arranged above the table and presses the object to be fired on the table against the lower surface of the table when the table is raised. This is a characteristic feature.

The tunnel furnace according to claim (2) is characterized in that according to claim (1),
The table lifting mechanism includes a guide slope that extends between the rails and is raised near the firing zone of the tunnel-shaped furnace body and is lower in the preheating zone and the cooling zone; The system includes a vertically movable stem extending vertically through the cart, and wheels such as casters that are pivotally connected to the lower end of the stem and roll on the guide slope. It is characterized in that the table is provided at the upper end of the table.

[Function] In the tunnel furnace of claim (1), when the trolley is moved in the tunnel furnace to carry out firing, the object to be fired is pushed up near the firing zone, causing the table and the loading weight plate to collide with each other. be caught between. As a result, even if the object to be fired is warped, the warp is removed, and a flat fired object with high flatness is obtained.

In the tunnel furnace according to claim (2), when the cart approaches the vicinity of the firing zone, the stem rises along the slope;
This pushes the table up. Such a table lifting/lowering mechanism has a simple mechanism and can forcefully push up the table toward the load weight plate.

E example] Examples will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a tunnel furnace according to an embodiment of the present invention in a direction perpendicular to the cart feeding direction, and FIG.
A vertical sectional view taken along line I, FIG. 3 is an overall layout of the tunnel furnace, and FIG. 4 is a side view showing the firing mechanism inside the tunnel furnace.
FIG. 5 is an explanatory diagram of the truck drive mechanism, and FIG. 6 is a plan view of the vicinity of the tunnel furnace.

In Figure 1.2, a furnace support frame 12 is placed on the floor 1o.
A tunnel-shaped furnace body 14 is installed through the tunnel. 14
a is a heater. Furthermore, a pair of rails 16 are laid on the floor 10.

The truck 18 is movable along the rail 16 by wheels 2° rolling on the rail 16.

A through hole 22 passing through the truck 18 in the vertical direction is bored, and a stem 24 is inserted into the through hole 22 in the stem guide 2.
6, it is inserted so that it can move freely in the vertical direction.

A table 28 on which a green body is mounted is attached to the upper end of the stem 24. Further, casters 30 are pivotally attached to the lower end of the stem 24.

A frame-shaped weight plate mounting base 32 is placed on the top surface of the table 18, and a load weight plate 34 is placed on this weight plate mounting base 32.

In the floor 10 between the rails 16.16, grooves 35 are dug along the rails 16.

The artificial side of the tunnel-shaped furnace body 14 is a preparatory zone, the vicinity of the center is a firing zone, and the vicinity of the exit is a cooling zone. From the preheating zone to the firing zone, the bottom surface of the groove 35 has an upward slope 36, and from the firing zone to the cooling zone, the bottom surface of the groove 35 has a downward slope 38. A portion between the upward and downward slopes 36 and 38 forms a raised surface 40 that is more elevated than the other portions.

Note that the side portion of the cart 18 is a recess 42 , and a protrusion 44 projecting laterally from the inner surface of the furnace body 14 is located in the recess 42 .
By entering, heat is prevented from escaping from the baking chamber 46 above the carriage 18.

Further, as shown in FIG. 2, a recess 42 is also provided at the front part of the cart 18 in the traveling direction, and a convex part 46 of an adjacent cart provided at the rear in the traveling direction enters the recess 42, thereby allowing the adjacent cart 18. The structure is designed to provide insulation between 18 and 18 degrees.

As shown in FIG. 3, in this embodiment, the rails 16 are installed in the form of a circuit, and two tunnel-shaped furnace bodies 14 are installed. A cart drive device 50 is installed at the entrance side of each furnace body 14. In this embodiment, as shown in FIG. 5, this truck driving device includes a driving pulley 52 and a driven pulley 5.
4, and the claws 58 of the claw belt 56 engage with the bottom surface of the truck 18 to move the truck 18 forward.

A green body handling section 60 is provided on the artificial side of the tunnel furnace 14 for placing the object to be fired on the trolley 14.
A fired product handling section 62 is provided on the exit side of the furnace body 14 to take out the fired product.

As shown in FIG. 6, a heat shielding gate 64 is provided on the artificial side of the furnace body 14.

In the tunnel furnace configured in this manner, a flat green body is placed on the table 28 of the cart 18 and introduced into the furnace body 14. Then, it is preheated in a preheating zone, and at this time, the organic binder component contained in the green body is oxidized and lost. After passing through the preheating zone, the cart reaches the firing zone and moves along the ascending slope 36 onto the casters 3.
0 is rolled, the stem 24 is pushed up, and the table 28 is also gradually pushed up. When the caster 30 reaches the raised portion 40, the object to be fired is pressed against the lower surface of the weight plate 34 for loading. When the table 28 is raised to its upper limit, the load weight plate 34 is lifted up from the weight plate mounting base 32, and the weight of the load weight plate 34 is transferred to the flat plate on the table 28. The object to be fired is fully covered. Therefore, the object to be fired is the weight plate 3 for loading.
4 and the table 28 and is pressed under pressure, and even if any warpage has occurred up to that point, this warp is smoothed out and a fired product with high flatness is obtained.

After being cooled in the cooling zone, the fired product fired into a flat plate shape in this way is carried out of the furnace body 14 and placed on a trolley.
It is taken out from 8.

In this way, according to the tunnel furnace of this embodiment, the flat green body can be directly introduced into the tunnel furnace and calcining and main firing can be performed in a consistent manner. Therefore, the heat energy consumption is significantly lower than in the conventional firing apparatus which performs calcination and main firing separately. Of course, the firing time is also extremely short.

In the tunnel furnace according to the above embodiment, the table 28, weight plate mount 32, loading weight plate 34, etc. are made of a highly heat-resistant material that can sufficiently withstand even the maximum firing temperature of the firing zone.

In the above embodiment, the caster 30 moves over the raised portion 40, which has slopes 36.38 with upward and downward slopes at the front and rear.
The table 28 is raised and lowered by the rolling of the table 28. However, according to a structure similar to the cam mechanism, the table 28 is pushed up strongly and the fired object is moved between the table 28 and the weight plate 34 for loading. Can grip objects strongly.

In addition, since the loading weight plate 34 is configured to be placed on the weight plate mounting base 32, the loading weight plate 34 is
A compressive force equal to the weight of 4 is applied. Therefore, it is possible to reliably apply an equal pressing force to each fired product. Of course, the mechanism for raising and lowering the table 28 is simple in structure and has excellent durability.

In the above embodiment, one table 28 is provided on one cart, but a plurality of tables may be provided on one cart.

[Effects] As described above, according to the tunnel furnace of the present invention, a flat green body can be fired consistently from calcination to main firing, and the consumed thermal energy is small, making it extremely economical. Furthermore, the firing time is also shortened.

In particular, when configured as in claim (2), a predetermined pressing force can be reliably applied to the flat object to be fired, and the table lifting mechanism is simple and has excellent durability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a tunnel furnace according to an embodiment of the present invention;
Figure 2 is a sectional view taken along line II-II in Figure 1, Figure 3 is a tunnel furnace layout, Figure 4 is a side view showing the flat plate firing mechanism inside the furnace, and Figure 5 is a cart drive mechanism. The side view shown in FIG. 6 is a plan view of the vicinity of the entrance of the tunnel furnace. 14...Furnace body, 14a...Heater, 16.
...Rail, 18...Dolly, 24...Stem, 28...Table, 30...Casters,
34... Weight plate for loading, 36.38-... Slope, 40... Protuberance.

Claims (2)

[Claims] (1) In a tunnel furnace that has a tunnel-shaped furnace body, a rail that is laid through the inside of the furnace body, and a truck that is moved on the rail, the truck is provided with a mechanism that is movable up and down. a table for loading objects to be fired; a table lifting mechanism that gradually raises the table as the cart moves and then gradually lowers the table; the table is disposed above the table; A tunnel furnace characterized by comprising: a weight plate for pressing a material to be fired on a table against the lower surface thereof when the table is raised; (2) In claim (1), the table elevating mechanism extends between rails along the rails, is raised near the firing zone of the tunnel-shaped furnace body, and is raised in the pre-heating zone and cooling zone. a guide slope that is lower than the guide slope; a vertically movable stem that extends vertically through the cart; and wheels that are pivotally connected to the lower end of the stem and roll on the guide slope; A tunnel furnace, characterized in that the table is provided at the upper end of the stem.