JPH066266B2 - Abrasive material projection area control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for controlling a projection area for efficiently projecting a polishing / cleaning material onto a workpiece, and particularly to hot rolling in which a plurality of strip widths are provided. It is suitable for removing scale from steel sheets.

<Prior Art> Scale is generated on the surface of a steel sheet produced by a hot rolling mill, and it is necessary to remove this scale in order to obtain a smooth steel sheet surface by subsequent cold rolling. The conventional hot-rolled steel sheet descaling method is to continuously introduce the rolled hot-rolled steel sheet into the pickling tank, and to pass through the pickling tank to dissolve and remove the scale of the rolled steel sheet with the acid solution. There is.

In recent years, along with the speeding up of the hot rolling process and the continuation of the pickling process and the cold rolling process, various continuous pickling methods described above have been investigated. If it is increased, the equipment inevitably becomes large in size, and more expensive waste acid treatment equipment is also necessary in order to avoid pollution by waste acid treatment.

Therefore, as disclosed in Japanese Patent Application No. 55-79088 and the like, a method of projecting a blasting material on a hot rolled steel sheet to mechanically remove the scale has been devised. As shown in FIG. 4 showing this principle, at least one set (two sets in the illustrated example) of the abrasive cleaning material projecting devices 2 and 3 are opposed to each other with the strip plate 1 interposed therebetween, and these abrasive cleaning material projecting devices 2 and 3 are arranged. From a particle diameter of 0.3 mm or less to the surface of the strip 1 at a high speed, and when the abrasive 1 collides with the strip 1, it adheres to the surface of the strip 1. The scale is peeled off.

According to such a mechanical method, it is possible to perform descaling with high efficiency without pollution. However, in the above-mentioned conventional method, the projection width of the cleaning material 4 is always constant regardless of the width of the strip 1. For the strip 1 having a narrow plate width, the polishing / cleaning material 4 is wastefully used to reduce the polishing / cleaning efficiency, and a large amount of the polishing / cleaning material 4 projected in vain collides with a cabinet (not shown). ,
This causes early wear of the cabinet.

Therefore, as shown in FIG. 5, a plurality of centrifugal type cleaning / blasting material projecting devices 5, 6 for projecting the cleaning / cleaning material 4 with a constant spread are arranged in the plate width direction of the strip 1 to obtain the strip width of the strip 1. In accordance with the above, there has been announced that the abrasive cleaning material projection devices 5 and 6 are moved toward and away from the strip plate 1.

<Problems to be Solved by the Invention> In the conventional one in which the entire polishing / cleaning material projection device is moved relative to the strip to change the polishing / cleaning area, the moving mechanism of the polishing / cleaning material projection device is large and complicated. Therefore, it has a drawback that the equipment cost increases. In addition, there is a high possibility that the abrasive cleaning material will be mixed in the moving mechanism of the abrasive cleaning material projection device, and there is a drawback that frequent failures are induced.

An object of the present invention is to provide a method capable of changing the scouring area of the scouring material by a very simple method based on such knowledge.

<Means for Solving Problems> A method for controlling a projection / cleaning material projection region according to the present invention is a combination of a plurality of polishing / cleaning material projection devices for projecting the cleaning / cleaning material with a constant spread,
The projection direction of the abrasive cleaning material by the abrasive cleaning material projecting device is changed according to the size of the work.

<Operation> By changing the projection direction of the abrasive cleaning material by each abrasive cleaning material projection device and setting the overlapping amount of the projection area large or small, the entire projection area is changed. For example, when the work is small, the overlap of the projection areas is increased, and when the work is large, the overlap of the projection areas is decreased.

<Example> As shown in FIG. 1 showing the structure of an example of the abrasive cleaning material projection apparatus for realizing the present invention, and FIG. 2 and FIG. 3 showing the working state thereof, the strip plate 11 is sandwiched and opposed to each other. The abrasive cleaning material projecting device 12 in which the strips 11 are arranged in the plate width direction has a distributor 14 integrated with a rotating shaft 13 that is driven and rotated, and a cylindrical member disposed so as to surround the distributor 14. It is composed of a control cage 15 and a projection disc 16 which rotates integrally with the rotary shaft 13. An impeller 17 is radially fixed to the projection disk 16 so as to surround the control cage 15, and a slit-like discharge port 19 for a polishing and cleaning material 18 is formed in the control cage 15. Although the control cage 15 is normally in a fixed state, it can be rotated as needed, and the direction of the discharge port 19 can be arbitrarily changed.

Therefore, the polishing agent 18 sent from the opening 20 of the distributor 14 into the control cage 15 is sent out from the discharge port 19 to the projection disk 16, and is accelerated by the centrifugal force accompanying the rotation of the projection disk 16. It is projected onto the strip plate 11.

Here, when the plate width of the strip 11 is long, the position of the discharge port 19 of the control cage 15 is corrected so that the projection direction of the polishing / cleaning material 18 is downward (see FIG. 2). The overlapping amount of the projection area of the polishing / cleaning material 18 by the projection device 12 is set to be small so that the polishing / cleaning material 18 is projected onto the entire strip 11.

On the other hand, on the contrary, when the strip plate 11 has a short strip width, the cleaning material 1
The position of the discharge port 19 of the control cage 15 is corrected so that the projection direction of 8 is oblique to the strip plate 11 (3rd
(See the drawing), the overlapping amount of the projection area of the polishing / cleaning material 18 by each polishing / cleaning material projecting device 12 is set to be large so that the polishing / cleaning material 18 is not projected onto a portion other than the strip plate 11.

It should be noted that the structure of the abrasive cleaning material projection device may be other than that of this embodiment without any problem, and in short, it is sufficient that the projection direction of the abrasive cleaning material can be changed.

<Effects of the Invention> According to the present invention, the projection direction of the abrasive cleaning material is changed by the plurality of abrasive cleaning material projecting devices according to the size of the work, so that the abrasive cleaning can be performed without wasting the abrasive material. The efficiency can be kept high, and the possibility of carrying out blasting of incidental equipment is reduced, and the reliability of the equipment is improved. Further, since the present invention can be realized by a mechanism that only changes the projection direction of the abrasive cleaning material by the abrasive cleaning material projection device, the structure of the device situation does not become so complicated and it is possible to minimize the increase in equipment costs. Is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an example of a polishing / cleaning material projecting device capable of realizing the method of the present invention, and FIGS. 2 and 3 are conceptual views showing the working state thereof, FIGS. 4 and 5 respectively. [Fig. 3] is a working principle diagram showing a conventional example. In the figure, reference numeral 11 is a strip plate, 12 is an abrasive cleaning material projection device,
Reference numeral 18 is a polishing agent.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Yoshio Egawa 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (72) Inventor Takashi Yamane 4-chome, Kannon Shinmachi, Nishi-ku, Hiroshima Prefecture 6-22 No. 22 Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Tadanori Miyamoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Shipyard (72) Inventor Hiroyasu Yuasa Mizushima, Kurashiki City, Okayama Prefecture Kawasaki-dori 1-chome (No house number) (72) Inventor Susanuma Nanao San-shima, Kurashiki-shi, Okayama Prefecture Kawashima-dori 1-chome house (No house) (72) Inventor Koji Tamada 3-1, Honohara, Toyokawa-shi, Aichi Shintoko Toyokawa Mfg. Co., Ltd. (72) Inventor, Kunrou Ota 3-1-1 Honohara, Toyokawa City, Aichi Shinto Kogyo Co., Ltd. (72) ) Inventor Rokutanda et al. 3-1, Honohara, Toyokawa City, Aichi Prefecture, Toyokawa Works, Shinto Industry Co., Ltd. (56) Reference JP-A-53-13284 (JP, A)

Claims (1)

[Claims] 1. A plurality of polishing / cleaning material projection devices for projecting the polishing / cleaning material with a constant spread are combined, and the projection direction of the polishing / cleaning material by the polishing / cleaning material projection device is changed according to the size of the work. A method for controlling a projection area of abrasive cleaning material, characterized in that.