JPS6212239Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a roller hearth kiln used for firing small and lightweight ceramic products such as tiles.

(Conventional technology) Conventional roller hearth kilns for firing small and lightweight ceramic products such as tiles, for example,
Inside the furnace body maintained at 1200℃, there are many rollers with a small diameter of about 20 to 25φ for transferring the fired products.
Each roller is rotated by a drive chain at a constant speed such that the surface speed is, for example, about 20 mm/sec, and the product to be fired is transported from the entrance to the exit of the furnace body by friction between the roller surface and the product to be fired. It was used for firing. (For example, Publication of Utility Model Publication No. 57-44315) (Problem to be solved by the invention) However, in the conventional roller hearth kiln using such small diameter rollers, the weight of the roller and the product to be fired are reduced at high temperatures. Since the load acts on the roller 30, the central part of the roller 30 bends downward as shown in FIG. The following phenomenon occurs, which makes it difficult to automatically carry out the fired product 20 at the furnace outlet, and when directly firing tiles, etc., the intervals between tiles, etc. in the firing zone become uneven, and the flow of combustion gas becomes difficult. There were various problems such as irregularities, warping of the tiles, pecking, and other quality variations.
Such a phenomenon is considered to be unavoidable in roller hearth kilns using small diameter rollers, and an effective solution to this essential drawback of roller hearth kilns has been strongly sought after.

(Means for Solving the Problems) The present invention was completed in order to solve these conventional problems, and it includes drive rollers that rotate at a constant speed arranged in parallel inside the furnace body, and drive rollers that rotate at a constant speed. It is characterized in that free roller groups consisting of a plurality of continuous free rollers that can rotate freely are arranged at required locations between the rollers.

(Embodiment) Next, the present invention will be explained in detail with reference to an embodiment shown in FIGS. Drive rollers for transporting the fired products are arranged in parallel inside the oven.
Each drive roller 2 is rotated at a constant speed by a drive chain 5, and is used to transport tiles and other objects to be fired placed on its upper surface from the inlet to the outlet of the furnace body 1. A free roller group 7 consisting of a plurality of continuous free rollers 6 that can rotate freely is disposed at required locations between the drive rollers 2. The number of free rollers 6 constituting the free roller group 7 varies depending on the longitudinal size of the product to be fired, but
It is preferable that the number is slightly smaller than the number supported by the chisel, for example, the pitch between the free rollers 6 is 30 mm and the length of the product to be fired is 100 mm.
In the case of 2 to 3 pieces, the length of the product to be fired is
In the case of 150 mm, it is appropriate to use about 3 to 5 pieces. Moreover, it is preferable to arrange the free roller group 7 after about 10 driving rollers 2 are successively arranged in parallel (for example, every 7 to 10 m), and it is not preferable to arrange the free roller group 7 in a concentrated manner. Normally, the free roller 6 is in a state where the rotational speed is zero, and the bearing 3 is
4 and is supported at any speed.

(Function) In the device configured in this way, the article 20 to be fired, such as a tile, is placed on the upper surface of the drive rollers 2 which are arranged in parallel inside the furnace body 1 and rotate at a constant speed, and the product 20 is transferred inside the furnace body 1. This kiln is similar to the conventional roller hearth kiln in that the progress of the product to be fired in the center is inevitably delayed due to the bending of the drive roller 2. However, in the present invention, a free roller group 7 consisting of a plurality of continuous free rollers 6 that can freely rotate is provided at required locations between the drive rollers 2, so that the preceding baked products 20 on both sides are When the free roller group 7 is reached, the advancing speed decreases, and during this time, the products to be fired 20 that are lagging in the center move forward at a normal speed, catch up with the products to be fired 20 that are ahead, and are aligned. Such an alignment effect has been confirmed in the roller hearth kiln of the applicant company,
The reason is presumed to be as follows.

That is, it is assumed that the free roller 6 is initially in a stationary state, and considering that the preceding products 20 on both sides are approaching the free roller 6, the products 20 on both sides are stationary. The free roller 6 keeps the product mostly stationary, but as the number of products to be baked increases to reach the free roller, the rotation of the drive roller is transmitted to the free roller, and as a result, the product to be baked 20 gradually rotates the free roller. The moving speed of both ends is greatly attenuated in order to impart rotation to the free roller 6. However, later than this, free roller 6
As for the product 20 in the center that reaches the center, it will ride on the free roller 6 which is already rotating, so there will be almost no attenuation in speed as described above and it will move at a nearly constant speed. It is thought that in group 7, a phenomenon occurs in which the products 20 to be fired in the center catch up with the preceding products 20 to be fired on both sides and are aligned. When the tips of the products 20 to be fired, which are arranged in a substantially straight line in this manner, ride on the drive roller 2 in front of the free roller group 7, they are transported by the drive roller 2 at a predetermined speed almost simultaneously. becomes. Thus, according to the present invention, although the difference in progress of the fired product between both ends and the center cannot be completely eliminated, it is significantly reduced compared to the case where the free roller group 7 is not provided.

When we actually measured the effect of correcting the difference in progress between both ends and the center in a roller hearth kiln with a total length of 40 m and free rollers placed every 8 m, we found that There was a difference of 250 mm between the products to be fired, but in the roller hearth kiln of this example, the difference was 50 mm.
mm or less, making automatic unloading easier and preventing variations such as warping and pecking of tiles.

(Effects of the invention) As is clear from the above explanation, the present invention can prevent delays in the progress of the fired products in the center caused by the deflection of the rollers, and can automatically carry out the fired products at the furnace exit. It has succeeded in making the process easier and preventing variations in the quality of the fired products, so it has extremely great practical value as it eliminates the problems of conventional roller hearth kilns.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main parts of an embodiment of the present invention;
FIG. 2 is a sectional view showing a conventional roller hearth kiln, and FIG. 3 is a plan view of the main parts thereof. 1: Furnace body, 2: Drive roller, 6: Free roller, 7: Free roller group.

Claims (1)

[Scope of utility model registration request] Drive rollers 2 that rotate at a constant speed are arranged in parallel inside the furnace body 1, and free roller groups 7 consisting of a plurality of consecutive free rollers 6 that can rotate freely are arranged at required locations between the drive rollers 2. A roller hearth kiln characterized by: