JPS5953122B2 - Device for detecting tension or compression force acting on material during rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting tension or compression force (hereinafter referred to as external force) acting on a material being rolled in a rolling mill.

It is generally known from experience that during continuous rolling, when the external force acts on the material between the stands, various problems such as overload operation, misrolling, and poor product shape occur.

Various measures have been taken in the past to prevent this. For example, if the material is flexible, it can be used directly using a mechanical looper, or if it is not flexible, it can be used directly using the drive motor current, drive torque, or the ratio of rolling torque to rolling load (torque arm). This is a method of indirectly detecting the external force by using the fluctuation characteristics caused by the external force such as the above, and adjusting and controlling the roll rotation speed or roll opening degree accordingly. However, the former direct method can only be applied to materials with a small cross-sectional area, and has drawbacks such as the detection end coming into contact with the material. On the other hand, with the latter indirect method, if skid marks, thermal run-downs, or dimensional/shape changes occur in the material, these become disturbances that significantly impede accurate control, and since it is an indirect method, the detection accuracy is not very good. Moreover, although it is controlled when the leading edge of the material is bitten, it is difficult to control at any arbitrary position thereafter. Therefore, a pressure detector was installed between the roll chock and the housing post.
Methods and devices have been proposed for directly detecting the horizontal movement or rotational movement of a roll chock due to an external force, or the force with which the roll chock presses against a housing post. However, in all of these methods, it is impossible to detect front tension, front compression force, rear tension, and rear compression force with a single pressure detection device, and they necessarily require multiple pressure detection devices. . Therefore, it is clear that the device has a large economic burden, is structurally quite complex, and maintenance and inspection of the device is complicated, making it impractical. In view of the above, the present invention
The object of the present invention is to provide an economically advantageous tension/compression force detection device that uses a structure as simple as possible, has better measurement accuracy, stability, and reliability than conventional methods, and is economically advantageous.

The purpose of this is to make either the bottom surface of the roll chock or the top surface of the housing beam facing the bottom surface parallel to the roll axis and inclined with respect to the horizontal plane, and to interpose cylindrical rollers whose diameters change sequentially between both surfaces. Is it a roll check?
A part of the rolling load is supported by a housing post on one side, and the pressure applied to this housing post is measured by a pressure detector installed in the force transmission path from the roll chock to the housing post, and the pressure applied to the material being rolled is measured. This is accomplished by detecting the applied tension or compression force. EMBODIMENT OF THE INVENTION Hereinafter, the tension and compression force detection apparatus according to the present invention will be explained in detail based on the embodiment shown in the drawings. In the rolling mill shown in Fig. 1,
The housing post 1 and the lower housing beam 2 support upper and lower rolls 3 and 4 via roll jocks 5 and 6.

In a general rolling mill, a horizontal and symmetrical support jig is inserted between the lower roll chock 6 and the housing beam 2. However, in the rolling mill of the present invention, the support portion 7 of the roll chock has an asymmetrical inclined structure as shown in the figure so as to deviate the roll chock toward the entrance or exit side of the rolled material. With this structure, front tension and rear tension are detected as follows. Now, considering the state in which a rolled material is being rolled, rolling loads are naturally generated on the upper and lower rolls. This load generates a horizontal component force (side load) in the direction of inclination because the roll chock is supported on the inclined surface. The side load T is expressed as follows, where θ is the inclination angle and μ is the coefficient of friction between the roll chock and the housing beam.

This load T is detected by a pressure detector 8 installed between the side surface of the roll chock on the inclined side and the housing post.
detected by. Rolling load P. shows a fairly constant value over the entire length during rolling, so the side load T has a fairly constant value. Next, consider the case where an external force acts on one end of the rolled material.

Since the rolling load also changes with the action of external force, the side load under the action of external force is expressed as follows. σf:
Forward tension (signs are positive for tension and negative for compression) σb: Backward tension ('' K: Yield stress of material, A, b: constants When θ is a small angle, equation (2) becomes as follows. approximated.

Practically speaking, it is recommended that θ=1 to 10° and μ≦0.01.

Note that the variation in side load due to skid marks is caused by the first term in equation (3), but the variation due to external force is much larger in the second and third terms, so the influence of skid marks is relatively small. . FIG. 2 shows a specific structural example of the single-sided inclined support portion 7. As shown in FIG. Figure a shows the case where the inclined plate is fixed to the bottom of the lower roll chock. Multiple cylindrical rollers whose diameters change sequentially are inserted between the upper surface of the housing beam and the inclined plate in order to reduce the coefficient of friction μ, and the stepped structure of the inclined plate and beam prevents the rollers from escaping. has been done. Note that the rollers are held with a slight gap between them in order to reduce the rolling friction coefficient. The same effect can be obtained even if the structure of the support part 7 is inclined on the beam side as shown in b.
Next, the effectiveness of the present invention will be explained using an example using an experimental rolling mill.

Using a rolling mill equipped with oval hole type rolls having a diameter of 200 mm, the lower roll chock portion thereof was modified as shown in Fig. 1, and rolling from the corner of a lead square bar 9 to an oval was performed as a model at the center of the roll. FIG. 3 shows the output of the pressure detector 8 when tensionless rolling is performed from an idling state, then forward tension and rearward tension are applied, and tensionless rolling is performed again. The output of the detector, that is, the side load is the reference load T when there is no tension. , which decreases to T1 under forward tension and increases to T2 under backward tension. FIG. 4 shows the increase and decrease in side load when the magnitude of external force is changed, and the effectiveness of the present invention is clearly recognized. Although the above embodiment is for the lower roll chock, it can also be implemented for the upper roll chock by a similar method.
It may be performed on one or both of the drive sides.

It is also conceivable to use a device based on the same principle with both supporting surfaces being parallel inclined surfaces and cylindrical rollers of the same diameter being interposed, but the device of the present invention requires only one of the supporting surfaces to be an inclined surface. The benefit is that the above problems will be reduced. The device according to the present invention directly detects the magnitude and direction of external force with a pressure detector, so detection is reliable, and the number of installed pressure detectors can be reduced to half of the conventional one. It has the advantages of being economical because it requires only a light capacity, and that supporting parts are easy to form.It is not limited to tension-controlled rolling during continuous rolling, but is also suitable for constant tension rolling, including single rolling mills. It can also be used very effectively.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a rolling mill using the present invention, Fig. 2 is a side view showing two examples of its support portion, and Fig. 3 shows changes in side load in rolling experiments using the present invention. Figure 4 is a relationship diagram between side load and external force. 1...Housing post, 2...Housing lower beam, 5, 6...Roll choke,
7... Single side inclined support part, 8... Pressure detector.

Claims (1)

[Claims] 1 Either the bottom surface of the roll chock or the top surface of the housing beam facing the bottom surface is parallel to the roll axis and inclined with respect to a horizontal plane, and a plurality of cylindrical rollers with diameters sequentially changing are interposed between the two surfaces to form the roll chock. A part of the rolling load applied to the roll is supported by a housing post on one side, and the pressure applied to the housing post is measured by a pressure sensor installed in the force transmission path from the roll chock to the housing post. 1. A device for detecting tension or compression force acting on a material during rolling, characterized in that it detects tension or compression force acting on the material.