JPS5940088Y2 - Variable crown roll - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a variable crown roll (hereinafter referred to as VC roll) whose roll crown blades are adjustable.

For example, the VC roll has an annular gap 3 between the arm μ1 and the sleeve 2 as shown in FIG. This is designed to adjust the deflection of the sleeve 2 in the direction of expansion to obtain a predetermined amount of crown, and is conventionally used for light rolling load mills such as temper rolling mills for hot rolled steel sheets. It is not used for mills where abnormal loads such as drawing are likely to occur, such as cold rolling tandem mills.

Therefore, when VC rolls are used for the mill, there is a risk of rolling troubles caused by abnormal loads such as narrowing of the coil, which did not occur during light load rolling. During assembly), the sleeve 2 was not small enough to bend in the concave direction and contact the arm μ1 when an abnormal load was applied.
The generated stress σ increases approximately in proportion to the load P, and when the load exceeds a certain value, the sleeve 2 does not hit μ1 and is freely bent in the concave direction, exceeding the yield point and tensile strength of the sleeve material and causing the sleeve to bend. There is a risk that there will be a loss.

Therefore, in the conventional VC roll, abnormal loads are likely to occur.7 For example, when used in a tandem mill, there may be restrictions in terms of sleeve strength.

The present invention was devised to solve the above-mentioned problems of the conventional technology. We provide a variable crown roll in which the sleeve is supported in contact with ARμ, so that the abnormal load is supported by the sleeve and ARμ, and the stress generated in the sleeve is greatly alleviated, so that it can be used for mills where abnormal loads are likely to occur. The purpose is to

Hereinafter, the present invention will be explained with reference to an illustrated embodiment. 1 is an arm μ, 2 is a sleeve, and 3 is a gap. A high-pressure medium 4 is supplied into the gap through a rotary joint 5 so that the sleeve 2 expands in the direction of expansion. The VC roll is assembled so that a predetermined amount of crown can be obtained by adjusting the deflection of the VC roll.

In the assembled state of this roll, in addition to the case where the opposing surfaces of the sleeve 2 and the arm μ1 that form the gap 3 at the bottom of the tank are parallel as shown in the figure, the opposing surface of the sleeve 2 is inclined toward the center of the sleeve so that the gap amount gradually increases. Therefore, when considering the gap at the center of the sleeve as a standard, the initial gap at the time of roll assembly is smaller than the amount of deflection when the sleeve 2 is freely deflected in the concave direction under normal load. The gap 3 is determined so that the amount is small.

In consideration of the responsiveness of the medium 4, it is practically preferable to set the gap 3 to 0 to 20%.

At the tank bottom described above, the stress σ generated by the load P on the sleeve 2 increases approximately in proportion to the load P until the sleeve 2 contacts the arm μ1, but when the load becomes abnormally high, the sleeve 2 contacts the arm μ1. However, the abnormal load is supported by the sleeve 2 and the arm μ1, and the stress σ generated in the sleeve 2 is greatly alleviated at the time of the abnormal load compared to the conventional case where it is supported only by the sleeve 2.

Figure 2 shows the roll assembly state when the medium pressure is O1 and the load is 0.
The two-dot chain line in the figure shows the state immediately after the sleeve 2 contacts the arm μ1 under an abnormal load.

Further, FIG. 3 shows the deformed state of the sleeve and roll body after the sleeve 2 has come into contact with the arm μ1.

In Figures 2 and 3, I, n, III, iv are attached to the surface of the center of the roll body in each state.
1 shows the change in the surface of the center part of the roll body length according to the load based on the state indicated by the dashed-dotted line (2).

Fig. 4 shows the relationship between the maximum sleeve stress σ and the load P in comparison with the conventional case shown by the two-dot chain line. The correspondence with the diagram is clarified.

That is, the sleeve 2 is in the normal rolling range from ■ to ■ and is deflected in the direction of expansion, and in the range of ■ to ■, it is within the range of A μ and the initial gap σ between the sleeves and is freely deflected in the direction of concavity.
Furthermore, the free deflection of the sleeve 2 is restricted in contact with the arc μ1 in ■～, and the maximum generated stress σ of the sleeve 2, which is conventionally shown as ■', is greatly reduced to the one shown as ■ in ■～. This can be clearly seen from Figure 4.

As described above, the present invention has a simple tank bottom in which the initial gap between the arm and the sleeve is smaller than the amount of free deflection of the sleeve in the concave direction when an abnormal load is applied. When abnormal loads occur during rolling troubles, the sleeve is supported in contact with the arm and the load is transferred between the sleeve and the arm.
Since the stress generated in the sleeve supported by the roll can be greatly reduced, the VC roll can be used even in mills where abnormal loads are likely to occur, and its advantages can be utilized to the fullest.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the structure of the variable crown roll, Figure 2 is a schematic diagram showing the structure of the variable crown roll.
The figure is an enlarged sectional view of a main part showing an embodiment of the present invention, FIG. 3 is a sectional view for explaining the operation, and FIG. 4 is a diagram showing the relationship between the maximum stress generated in the sleeve and the load. 1...Arμ, 2...Sleeve, 3.
...Gap, 4...Medium, 5...
Rotary joint, σ... Initial gap amount.

Claims (1)

[Scope of utility model registration request] In the variable crown roll, an annular gap is provided between the arm and the sleeve, and a high pressure medium is supplied from the outside into the gap to adjust the deflection of the sleeve to obtain a predetermined crown amount. A variable crown roll characterized in that the initial gap between μ and the sleeve is smaller than the amount of free deflection of the sleeve in the concave direction when an abnormal load is applied.