JPH03294429A - Heating furnace extractor for bar wire multiple strand mill - Google Patents

Abstract

PURPOSE:To improve and stabilize the quality of a product by arranging a conveyor table provided with a holding furnace having a roller to be independently driven in each line between a heating furnace and a bar wire rolling mill to prevent the temp. deviation in the longitudinal direction of a material. CONSTITUTION:The material baked up in a walking beam type or walking hearth type heating furnace 1 is discharged outside the furnace. The material is passed through a hot straightener 5 and conducted to a bar wire rolling mill 10 by the conveyor table 7 provided with a holding furnace. The roller 7B of the table 7 is independently driven in each line, and the speed is controlled in accordance with the material conveying state in each line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an extraction device for a rod mill heating furnace.

[Prior Art] The heating furnaces used in conventional rod and wire mills are either the Butscher type or the Okinck Hearth type as disclosed in Japanese Patent Application Laid-open No. 48-213. The layout has a layout in which the material is distributed one by one into a predetermined row and guided directly from the heating furnace to the rolling mill using an extractor installed at the extraction end of the furnace and rollers in the extraction furnace, which is installed just before the bar rolling mill. was.

[Invention or problem to be solved U] The material used in bar wire mills (small cross-section long fillets) is usually about 18 to 20 meters long, and the rolling time of one piece is about 200 meters.
It takes about 3 minutes.

Therefore, if there is a rolling mill immediately after the heating furnace, the time from when the tip of the material gets caught in the rolling mill to when the tail end comes out, the time in the furnace on the tail end side will be longer, and the temperature deviation in the longitudinal direction of the material will increase. As a result, the quality of products such as dimensional accuracy and mechanical properties was adversely affected.

Furthermore, this tendency becomes more noticeable in walking hearth type and walking beam type heating furnaces, which require a higher set furnace temperature than pusher type heating furnaces. As a countermeasure for this, it is possible to perform inclined heating in the longitudinal direction of the material with a temperature deviation in the width direction of the heating furnace in advance, but this is sufficient to prevent variations in continuous material length and fluctuations in rolling T/H. It could not be a solution.

[Means for Solving the Problems] The present invention is a heating furnace extraction device for improving the temperature deviation in the longitudinal direction of the material described above, and includes: 1. A walking beam type or walking hearth type heating furnace and a bar and wire rolling mill. A heating furnace extraction device for a multi-strand rod mill, characterized in that a transfer table with a heat retention furnace is arranged between the heating furnace and the transfer table with a heat retention furnace; 2. A hot straightening device is arranged between the heating furnace and the transfer table with a heat retention furnace. 3. The heating furnace extraction device according to item 1 above, characterized in that: 3. The rollers of the conveyance table with a heat retention furnace are driven independently in each row, and the speed is controlled according to the material conveyance state of each row. The gist of the present invention is to provide a heating furnace extraction device according to item 1 or 2 above, which is characterized by:

The contents will be explained below based on the drawings. FIG. 1 is a plan view illustrating the present invention. In the present invention, as shown in FIG. 1, a conveyance table 7 with a heat retention furnace 7A corresponding to the length of the material is arranged between the heating furnace 1 and the rolling mill 10. In the figure, 7B is a table roller for conveyance.

This conveying table roller 7B is an independent cantering type roller table for each row corresponding to the number of rolling strands, and rotates at high speed until the tip of the material extracted from the heating furnace 1 is bitten by the rolling mill 10. After that, the rotation speed is controlled to be synchronized with the speed of the rolling mill.

Further, the heat retention furnace 7A has a fireproof material structure that covers the entire transporting table roller 'tB, and a combustion burner is disposed therein. The capacity and number of combustion burners are determined by the dimensions of the material and
The relationship between the shape and rolling speed should be such that it can cover the temperature drop on the tail end side, and the combustion amount can be adjusted to accommodate fluctuations in rolling speed and number of rolling rows that change due to changes in rolling size, etc. It is now possible to do it.

Furthermore, a hot straightening device 5 is arranged between the heating furnace 1 and the conveying table 7 with a heat holding furnace, which straightens bends in the longitudinal direction of the material that occur due to temperature deviations in the cross section in the heating furnace, and at the same time straightens the material at high speed. A center link is performed to each strand position on the conveyance table 6.

[Function] By rotating at high speed, the conveying table 7 with a heat retention furnace extracts the material baked to a predetermined temperature in the heating furnace 1 out of the furnace in a short time, and after it is caught in the rolling mill 10, it is conveyed. In order to prevent the occurrence of scratches on the material due to slipping with the rolling table roller 7B, the rolling speed is synchronized with the rolling speed. This table roller 7B is compatible with a multi-strand mill as shown in FIG. 3, and has an independent roller structure for every 1 to 4 rows of each strand, and for each row,
The speed is controlled according to the stock status of materials. The cover and combustion burner of the heat retention furnace 7A are installed to prevent a temperature drop on the tail end side of the rolling mill.

In addition, the hot straightening device 5 ensures the inductivity of the conveying table 7 with a heat retention furnace, and in particular, in walking beam type heating, in order to perform rapid heating in the shortest time, it is necessary to It is easy to reach high temperatures, and bends occur due to temperature deviations within the cross section, so straightening the bends on the extraction side of the walking hearth heating furnace is an important technique.

[Example] As shown in Fig. 1, a transfer table 7 with a heat retention furnace and a hot straightening device 5 are arranged to prevent temperature deviation in the longitudinal direction of the material, and the extraction efficiency (rolling T/H) is maximized. In order to ensure this, a high-speed conveyance table 6 was placed between the hot straightening device and the heat retention furnace.

The materials baked to a predetermined temperature in the heating furnace 1 are transferred one by one to an in-furnace roller table 2 by an extractor 3, passed through a hot straightening device 5, and transferred to a high-speed conveyance table 6.
Then, it is guided to the rolling mill 10 by a transfer table 7 with a heat retention furnace.

The hot straightening device 5 has a vertical multistage roll structure and is controlled to shift to the extraction row. The high-speed conveyance table 6 has a distance longer than the length of the material, and non-contact type material sensors 11 and 12 are installed at two locations along the way.

Moreover, a non-contact type material sensor 13 corresponding to the number of strands is installed between the heat retention furnace and the rolling mill.

As shown in FIG. 2, the high-speed conveying table 6 is an all-row type roller table, and the conveying speed is set so that the extraction material always passes through one tree at a time.

In the figure, 6A to 6D indicate rollers.

Since the material extracted from the heating furnace 1 expands in length due to hot conditions, the material sensor 11 measures the time t when the tip passes and the time t2 when the tail passes, and the required time tJf (
t2 tl) is calculated. Further, the material sensor 12 measures the tip passage time t3, and calculates the required time tv (t3-t,) from the previous tl. Here, since the distance 1llIL between the material sensors 11 and 12 is constant, t,
÷! ■ Material conveyance speed on the high-speed conveyance table. is required. Therefore, the length of the hot material extracted by t and 1xvo can be obtained with good results.

Furthermore, the tip passing time t4 is measured by the material sensor 13, and from the relationship between the rolling speed 1 and the hot material length, 1
．． 1+1. The expected tail end passing time t5 at the position of the material sensor 13 can be determined by the formula ÷v1.

On the other hand, since the time T1 required for transportation from the heating furnace extraction end position to the material sensor 13 is approximately a constant value depending on the equipment capacity, if the time interval between the tail end of the front matter and the leading edge of the next material in the same row is T2, Timing of extraction of material is t5+T2
−T, is obtained. Material 1
By automatically processing each book and each row by the control device 14 and automatically controlling the timing of extraction from the heating furnace,
By adjusting the time interval T2 between the tail end of the front attachment and the tip of the next material to the minimum necessary time, extraction with high T/H is possible.

In addition, the hot straightening device moves and stops in accordance with the command from the control device to the next material extraction line determined by the above-mentioned extraction timing calculation and the availability status signal of the rolling line, and the transfer table with a heating furnace is 11 or 1 material sensor for each row
The rotation speed is switched to high speed by the tip passage number 18 of No. 2, and the rotation speed is switched to a rotation speed synchronized with the rolling speed by the tip passage signal from the material sensor 13.

[Effect of the invention] The following effects can be expected from the present invention.

(1) Improving and stabilizing product quality by preventing temperature deviation in the longitudinal direction of the material (2) Achieving high efficiency (high T/H) (3) Product quality by applying a walking beam heating furnace to a multi-rod strand mill (reduction of surface scratches,
decarburization reduction)

[Brief explanation of the drawing]

FIG. 1 is a plan view illustrating the present invention, FIG. 2 is a plan view of a high-speed conveyance table, and FIG. 3 is a plan view showing the roller structure of a conveyance table with a heat retention furnace.

Claims (1)

[Claims] 1. A heating furnace extraction for a multi-strand rod mill, characterized in that a conveyance table with a heat retention furnace is arranged between a walking beam type or walking hearth type heating furnace and a rod rolling mill. Device. 2. The heating furnace extraction device according to claim 1, further comprising a hot straightening device disposed between the heating furnace and the transfer table with a heat retention furnace. 3. The heating furnace extractor according to claim 1 or 2, wherein the rollers of the conveyance table with a heat retention furnace are driven independently in each row, and the speed is controlled according to the material conveyance state of each row. Device.