JPS6111131B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to hot strip conveying equipment for producing hot strips with high efficiency. In order to improve productivity when manufacturing hot strips, it is necessary to reduce dead time between preceding and succeeding strips. In general, in hot strip rolling, semi-finished steel sheets are rolled between a rough rolling mill and a finishing mill, so that the rolling speed of the semi-finished steel sheets rolled by the rough rolling mill (hereinafter referred to as "rough rolled steel sheets") is lower than the rolling speed of the semi-finished steel sheets that are being finished rolled. Since the rolling speed is higher than that of the rolling section (hereinafter referred to as the "finish rolling steel plate"), while the finishing rolling steel plate is running on the day table between the rough rolling mill and the finishing rolling mill, the following steel plate is roughly rolled. If this is done, there is a risk that the rough rolled steel plate may bump against the tail end of the preceding steel plate during finish rolling, and the subsequent steel plate cannot be rough rolled until the finish rolling of the preceding steel plate is completed. For this reason, conventionally, the rough rolling of the succeeding steel plate was started at the same time as the finish rolling of the preceding steel plate was completed, and the time it took to complete the rough rolling of the succeeding steel plate was unnecessarily long due to idle time of the finishing mill. This is a cause of reduced rolling efficiency. An object of the present invention is to provide hot strip conveying equipment capable of shortening the conventional hot strip rolling dead time based on the difference in rolling speed between a rough rolling mill and a finishing rolling mill, and improving hot strip rolling efficiency. In the present invention, two upper and lower conveyor tables are provided between a rough rolling mill and a finishing rolling mill, a subsequent rough rolled steel plate is placed on the upper table, and after finishing rolling of the preceding steel plate is completed, the subsequent steel plate on the upper table is placed. The unfinished rolled portion of the steel plate is held in a finishing mill, and then finish rolling is carried out, while the unfinished rolled portion of the steel plate is held on an upper conveying table by an elevating device that can be raised and lowered.The upper table is opened, for example, at the center portion, and the steel plate is raised and lowered. After the equipment is lowered and placed on the lower table, the upper table is closed and the subsequent rough rolled steel plate is received.
The steel plate is finish rolled while being placed on the lower table. As a result, there is no risk that the subsequent rough-rolled steel plate will bump into the preceding steel plate during finish rolling, and the subsequent rough-rolling of the subsequent steel plate can be performed concurrently with the finishing rolling of the preceding steel plate. By keeping it on standby on the table, it is possible to shorten the wasted time from the completion of finish rolling of the preceding steel plate to the start of finish rolling of the succeeding steel plate. The installation length L of the lower table in the table between the rough rolling mill and the finishing rolling mill is determined by the rolling speed of the rough rolling mill and the finishing rolling mill and the distance between the two rolling mills, as shown in the formula (1) below.
It is determined by Lo and margin time Tb. L=V _F (Ta+Lo/V _R +Tb) (1) (L: Lower table length, V _F : Finishing mill rolling speed, V _R : Roughing mill rolling speed, Ta: Lowering the steel plate from the upper table to the lower table. (Time required for lowering) The present invention will be explained in more detail with reference to the figures below. In FIGS. 1 and 2, the upper table 3 has a pair of transport rollers 31 that are rotatable around a fulcrum 34.
a lower table 4 consisting of a group of rollers 41 and a cylinder 33 fixed to the lower part of the roller 31 and rotating the roller 31 in the horizontal and downward directions;
, and an elevating device having a support roller 51 that can be moved up and down by a cylinder 53 between each group of rollers 31 and 41 is provided. First, the first steel plate is rolled by rough rolling mill A, and the rough rolled steel plate 1 is rolled by rough rolling mill A and finish rolling mill B.
The rolling mill progresses over the upper table 3, and once the rough rolling is completed, it is temporarily stopped at the entry side of the finishing rolling mill B. Thereafter, the rough rolled steel sheet 1 moves on the upper table 3 again, and is bitten by the finishing mill B, where finishing rolling is started. While this finish rolling is continuing and before the rough rolling of the subsequent steel plate is started, the rear end side of the rough rolled steel plate 1 is held by the lifting device 5, and the upper table 3 is moved by the cylinder 33 rotates downward about the fulcrum 34 to the open state, and the rough rolled steel plate 1 is lowered to the lower table 4 by the operation of the cylinder 53 while being supported by the support rollers 51 of the lifting device 5, and the lower table 4 is lowered by the operation of the cylinder 53. 4. During this time, finish rolling continues. As can be seen from Table 1 below, the finishing mill speed V _F is considerably lower than the roughing mill speed V _R . Therefore, the support roller 51 is also lowered relatively slowly in accordance with the speed _VF . In this way, the progress of the rough rolled steel sheet 1 is not affected in any way. Thereafter, the upper table 3 rotates the roller 31 upward about the fulcrum 34 by the operation of the cylinder 33 and returns to the closed state. Next, the second rough rolling is started, and the rough rolled steel plate 1 after the completion of the rough rolling is temporarily stopped at the entry side of the finishing rolling mill B, as in the previous time, and
Waiting for completion of finish rolling of the preceding rough rolled steel plate 1. After the finish rolling of the preceding rough rolled steel sheet 1 is completed, the same operations as described above are repeated again. Near the junction of the upper and lower tables, the rollers 31 of the upper table 3 simply open and close to allow the preceding steel plate 1 to pass downward. Since the preceding steel plate 1 has already been bitten into the finishing rolling mill B, no special guidance is required. Moreover, since the roller 31 closes to its original state after the preceding steel plate 1 is lowered, it does not interfere with the passage of the succeeding steel plate 1. In the device of the present invention, the lower table roller 31
The reason why the group is made into a center-divided roller group that can be opened and closed on the left and right is to reduce the distance between the upper table 3 and the lower table 4, and the upper roller 31 is made into a single roller structure so that it can be opened and closed on either the left or right side. It is also possible to do so. Additionally, each cylinder 33, 53 for opening and closing the upper table 3 and raising and lowering the lifting device 5 may be hydraulically operated, since it is inexpensive in terms of equipment. A rotary method is preferred. Various dimensions used in the above equation (1) are shown in FIG. 1, and specific examples are shown in Table 1.

【table】

[Table] In addition, the rolling pitch was 40 sec/piece in the conventional equipment, but it was reduced to 37 sec/piece in the equipment of the present invention, achieving an efficiency improvement of about 5%. As explained in detail above, with the device of the present invention,
It is possible to completely prevent collision accidents between rough rolled steel sheets and finish rolled steel sheets, and also to reduce wasted time in hot strip rolling as much as possible, thereby greatly improving productivity.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram showing an example of the equipment of the present invention, Fig. 2 is a front view of the equipment of the invention and a sectional view taken along the Z-Z line in Fig. 1, and Fig. 3 is a schematic diagram illustrating the movement of a steel plate by the equipment of the invention. It is. 1... Rough rolled steel plate, 2... Finish rolled steel plate, 3
...Top table, 4...Bottom table, 5...
Lifting device, 31, 41, 51...Roller, 32,
42, 52... bearing, 33, 53... cylinder, A... rough rolling mill, B... finishing rolling mill.

Claims (1)

[Claims] 1 In hot strip rolling equipment, between a rough rolling mill and a finish rolling mill, there is an upper table that can be opened and closed to transport and hold the rough rolled steel plate before finish rolling, and a table that is installed in parallel below the upper table to convey and hold the rough rolled steel plate before finish rolling. a lower table for transporting and holding the rolled portion; and a lifting device for lowering the rear unrolled portion of the rough rolled steel plate from the upper table to the lower table after the tip of the rough rolled steel plate is bitten by a finishing rolling mill. Hot strip conveyance equipment characterized by being equipped with.