JPS6358055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a three-axis drive rolling mill that is advantageously adapted for plate rolling, particularly plate rolling.

A typical thick plate rolling mill is a quadruple reversing type rolling mill shown in FIG. As shown in the figure, this rolling mill is designed so that the upper and lower work rolls are each driven from one side.

Here, the rolling situation in thick plate rolling will be explained by taking as an example the case where this quadruple reversing type rolling mill is used.

Generally, the relationship between rolling load and rolling torque for each rolling pass is as shown in FIG. 2. That is, in the first half pass, the rolling load is not increased to the maximum allowable rolling load of the mill housing.
This is because in the first half pass, a large rolling torque is required to increase the reduction rate to the allowable rolling load limit of the mill housing, but the rolling torque also has an allowable limit and is subject to restrictions. Therefore, in controlled rolling, etc., it is not possible to obtain a sufficient rolling reduction rate, which may restrict the material quality, and the number of rolling passes increases, causing problems in terms of productivity.

As a means of solving this problem, a method can be considered in which both the upper and lower work rolls are driven by a total of four drive shafts from both sides, as shown in FIG.
In this method, since the rolling torque can be doubled, the rolling reduction ratio can also be increased to almost double.

However, in this method, two roll shaft drive devices are installed on each side of the rolling mill, which has the disadvantage of significantly impairing work efficiency such as safety of the work yard and speed of changing rolls. Also, if the rolling reduction ratio is doubled, the rolling load will be approximately √
As can be seen from FIG. 2, the rolling reduction rate is doubled and sometimes exceeds the allowable rolling load limit of the mill housing, making it impossible to make full use of the doubled rolling reduction effectively and economically.

This invention advantageously solves the above-mentioned problems, and not only maintains good workability and economy, but also eliminates the need for special improvements such as increasing the strength of the mill housing or increasing the roll diameter. This paper proposes a three-axis drive rolling mill that increases the permissible torque of the rolling mill and enables rolling at a high reduction rate.

Now, in order to double the rolling torque, it is convenient to drive the work rolls from both sides, so-called two-axis drive, but as mentioned above, it is not convenient to use two-axis drive for both the upper and lower rolls. There is a problem with this.

Therefore, in this invention, in consideration of workability and suitability, one of the upper and lower work rolls, more preferably the upper work roll, remains uniaxially driven as before, and only the other is made biaxially driven. Moreover, by applying different speed rolling in which the upper and lower work rolls rotate at different circumferential speeds, the uniaxially driven roll is able to apply the conventional torque even if the reduction rate increases, and the uniaxially driven roll is applied to the biaxially driven roll. It is trying to apply twice the torque. By doing this, it is possible to obtain an allowable rolling torque that is 1.5 times that of a normal rolling mill.

In other words, the allowable rolling torque of a rolling mill is expressed as the sum of the allowable rolling torques for the reforming rolls, but in a normal rolling mill, both the upper and lower work rolls are each uniaxially driven, so one If the allowable rolling torque for the roll is T, then the allowable rolling torque of this rolling mill is 2T.
In contrast, in this invention, one of the upper and lower work rolls is uniaxially driven, so the allowable rolling torque for that roll is T, but the other roll is biaxially driven. The allowable rolling torque for this roll is 2T, so
The permissible rolling torque of the rolling mill is 3T, which means that the permissible rolling torque of a normal rolling mill is 3T/2T=1.5 times.

Next, this invention was applied to a quadruple reversing rolling mill as shown in Fig. 4, and the upper and lower work rolls were set at different circumferential speeds, and the upper work roll was driven uniaxially to achieve the same torque value as before. FIG. 5 shows the relationship between rolling torque and rolling load when the lower work roll is a biaxially driven roll with a torque value approximately twice that of the previous roll. At this time, the permissible limit of rolling load remains unchanged, but the permissible limit of rolling torque is increased by 1.5 times.

As shown in Fig. 5, the rolling mill according to the present invention is capable of strong rolling with a torque 1.5 times that of a conventional rolling mill, and therefore, even during the first half pass of thick plate rolling, the mill housing can be kept within its permissible rolling range. You can fully utilize the load to its fullest limit. Therefore, the number of rolling passes can be advantageously reduced, which is extremely advantageous in improving production efficiency. It is also highly effective in improving material quality during controlled rolling.

As described above, according to the present invention, the strength of the mill housing can be fully utilized over all passes of thick plate rolling, and rolling efficiency can be significantly improved without impairing workability or economic efficiency.

[Brief explanation of the drawing]

Figure 1 is a front view of a quadruple reversing rolling mill, Figure 2 is a graph showing the relationship between rolling load and rolling torque for each rolling pass in conventional plate rolling, and Figure 3 is for both upper and lower operations. A front view of a quadruple reversing rolling mill in which both rolls are driven by two shafts, FIG. 4 is a front view of a three-shaft drive rolling mill according to the present invention, and FIG. 5 is a thick plate using a three-shaft drive rolling mill according to the present invention. It is a graph showing the relationship between rolling load and rolling torque for each rolling pass in rolling.

Claims (1)

[Claims] 1 Equipped with a pair of upper and lower work rolls that rotate at different peripheral speeds or the same peripheral speed, one work roll has a drive shaft connected to one end, and the other work roll has a drive shaft connected to both ends. This is a three-axis drive rolling mill.