JPH03207514A - Spindle supporting device for rolling mill - Google Patents

Abstract

PURPOSE:To control the vibration of the spindle and to improve the productivity by providing the supporting device to suppress the movement near the central part of the spindle in the radius direction during its high speed rotation. CONSTITUTION:When the upper spindle 3-1 is moved upward, the piston of the upper cylinder 9 is pushed up, the liquid passes through the throttle valve 11, enters the lower cylinder 9', and always acts on the spindle supporting box 4-1. The force to suppress ascending of the spindle 3-1 can be adjusted with the throttle valve 11. If the spindle moving speed is late at the time of the roll changing, etc., the smooth moving can be executed without resistance. On the other hand, if the spindle moving speed is high at the time of high speed rotation of the spindle, etc., the resistance becomes larger, the movement (vibration) of the spindle can be suppressed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for suppressing radial vibration of a spindle for a rolling mill, and in particular, when the spindle is not rotating such as when changing rolls, it can move freely. The present invention also relates to a spindle support device for a rolling mill that eliminates radial movement of the shaft and suppresses vibration when the rotation speed is high.

[Conventional technology]

The structure of a conventional rolling mill spindle is shown in FIG. During rolling, the spindle 3 is supported by a work roll 1 at one end and a gear box 5 at the other end, and rotation is transmitted from the gear box 5 to the work roll 1. Generally, the two shafts at both ends of the double series do not support the work roll during rotation. When replacing the work roll, support the spindle coupling part on the work roll 1 side to prevent the spindle 3 from falling. Provide equipment.

When the work roll diameter is small, the spindle 3 needs to be made thinner accordingly. If the spindle 3 is thin, the bending rigidity will be reduced, and the deflection in the radial direction of the spindle shaft will increase during high-speed rotation, causing problems such as increased vibration.

Japanese Utility Model Publication No. 59-37293 proposes a method for supporting the center of the spindle. According to this, the spindle is prevented from deflecting due to its own weight, and vibration is reduced. However, this is not sufficient to prevent whirling vibrations caused by centrifugal force that occur when the spindle rotates at high speed. In particular, since no restraining force can be obtained against movement in the horizontal direction, there has been a problem that a sufficient vibration suppressing effect cannot be obtained.

[Problem to be solved by the invention]

In the conventional technology, when the rigidity of the spindle is low, the lateral vibration of the spindle becomes large during high speed rotation, which adversely affects the thickness of the product board. Therefore, the problem arises that rolling must be carried out at low speed, and that the production volume cannot be increased.

[Means for Solving the Problems] -3- The above problems are solved by providing a support device that suppresses radial movement in the vicinity of the center of the spindle during high-speed rotation. Note that since the axial center position when the spindle is rotating at high speed is different from the axial center position when the rolls are changed (spindle rotation is stopped), the spindle can move freely when the rolls are changed.

[Effect]

The present invention provides a spindle support box near the center of the spindle that allows rotation of the spindle and suppresses movement in the radial direction, and supports the spindle support box via a fluid cylinder.

The fluid cylinder shows almost no resistance to slow movements of the spindle shaft, such as when changing rolls, and no excessive force is applied to the fluid cylinder. However, in a fluid cylinder, when the spindle rotates at high speed and the shaft frequency is high, the fluid cylinder creates a large resistance and suppresses the spindle vibration.

〔Example〕

An embodiment of the invention is shown in FIG. The BB cross section is the second
As shown in the figure. The main components are the motor 6, gear box 5, -4, spindle 3, and work roll 1. The rotational force generated by the motor 6 is transmitted to the work roll 1 through the gear box 5 and the spindle 3, and rolls the material to be rolled. A spindle support box 4 is attached near the center of the spindle 3 to allow rotation of the spindle 3.
Horizontal movement is prevented by the spindle support frame l2, and vertical movement is suppressed by the cylinder 9. In this example, the cylinder 9 uses a liquid as the fluid, and the hydraulic pressure source 1
It is always supplied from 0.

Now, the effect of the cylinder 9 will be explained in detail using the upper spindle 3-1 as an example. When the upper spindle 3-1 tries to move upward, the piston of the upper cylinder 9 is pushed up and the fluid passes through the throttle valve 11 and enters the lower cylinder 9', always acting on the spindle support box 4-1. The force F that suppresses the rise of the spindle 4-1 can be adjusted by the throttle valve 11 and can be expressed by the following equation.

F=K-V" V: Spindle operating speed K: Constant water n: Constant (1 to 2) This means that when the spindle operating speed is slow, such as when changing rolls, it can move smoothly with almost no resistance. On the other hand, when the operating speed is high, such as when the spindle rotates at high speed, the resistance becomes large and the movement (vibration) of the spindle can be suppressed.

Other embodiments are shown in FIGS. 4 to 6.

FIG. 4 shows an example in which the fluid in the cylinder 9 is sealed, eliminating the need for a fluid supply source.

In FIG. 5, one cylinder 9 acts on each spindle, further providing a fluid seal and eliminating the need for a fluid source. Also, a fixed tightening 14 is installed inside the piston t3 as a throttle.
This is an example where . According to this, the structure is simple because there is no fluid piping.

FIG. 6 shows an example in which a cylinder 9 is also provided to suppress horizontal movement of the spindle. This has the advantage that no excessive force is applied even when the spindle moves slowly in the horizontal direction.

FIG. 7 shows the effect of this embodiment. This figure shows the vibration mode of the spindle shaft when the spin wheel rotates at high speed. The broken line represents conventional spindle vibration. The solid line represents the vibration of the present invention. It can be seen that the present invention has the effect of suppressing spindle vibration. The item to be noted here is that the natural frequency of the whirling vibration of spins 1 to 1 can be expressed by the following formula.

C N-- N: Natural frequency L2 L: Support interval C: Constant The explanation so far has been based on an example in which one support device is provided for each spin wheel, but it is also possible to provide multiple support devices. Good too.

〔Effect of the invention〕

The present invention shortens the support spacing of the above formula, but since the natural frequency increases with the square of the square, the drive system becomes extremely stable.

[Brief explanation of drawings]

Fig. 2 is a side view of one embodiment of the present invention, Fig. 7 is a system diagram, Fig. 3 is a side view of the prior art, and Figs. 4 to 6 are
The figure is a sectional view of another embodiment of the present invention, and FIG. 7 is an explanatory diagram showing the effects of the present invention. l...Work roll, 2...Chock, 3...Spindle, 4...Spindle support box, 5...Garbox, 6...Motor, 7...Workpiece to be rolled, 8 - Bearing , 9 cylinders, 10...hydraulic pressure source.

Claims (1)

[Claims] 1. In a spindle for rotating a roll for a rolling mill, an intermediate portion of the spindle allows rotation of the spindle;
A support box configured to restrain radial movement is provided, the support box being supported by one or more fluid cylinders, the other end of the fluid cylinder being fixed to the frame, and the fluid cylinder having a vibration damping structure. When the rotation speed of the spindle is low or when it is stopped, the suppressing force of the radial vibration of the spindle is small. The fluid circuit is characterized in that a damping mechanism is provided in the fluid circuit so that when the rotational speed of the spindle is high, a damping mechanism is provided in the fluid circuit so that the suppressing force of the radial vibration of the spindle becomes large. Spindle support device for rolling mills.