JP2002210503A - Rolling method with ring rolling mill and controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rolling method with a ring rolling mill and a controller for obtain a good ring of a product with the ring rolling mill. SOLUTION: This method is a rolling method with the ring rolling mill provided with a main roll and a mandrel for performing thickness reduction in the radial direction of a ring-like material to be rolled and a pair of upper and lower edger rolls for performing height reduction in the axial direction of the ring-like material to be rolled. On the way of a rolling stage from the initial stage of rolling to the end stage of rolling, the rolling method has a steady-state stage condition of one or more times for stopping the movement of the mandrel and the edger in the rolling direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling method and a control apparatus for a ring-shaped rolling mill using a ring rolling mill.

[0002]

2. Description of the Related Art In the rolling of a ring-shaped material to be rolled, the thickness of an annular wasteland, which is a rolling material, is rolled by a large-diameter main roll and a bar-shaped mandrel, and the height is rolled by a conical edger roll. In this way, a product having a target radial dimension and height dimension is finished.

[0003] As a method for rolling such a ring-shaped material to be rolled, there is a method based on constant pressure control in which rolling is performed with a constant rolling force from the start to the end of rolling, and an outer diameter for controlling the growth rate of the outer diameter of the ring to be constant. There is a method of controlling the growth rate, a method of final constant pressure control in which rolling is performed with a constant rolling force and rolling is performed at a slightly lower constant pressure in the final stage of rolling.

In any of the above methods, in the main rolling process from the initial rolling to the final rolling, the mandrel always moves in the direction approaching the main roll, and the edger roll always moves downward, thereby reducing the thickness and height. Is continuously reduced.

[0005]

As described above, in the main rolling process from the initial rolling stage to the final rolling stage, the mandrel and the edger roll are continuously rolled while constantly moving, so that the rolling control is not appropriate and the ring is not properly controlled. When the cross-sectional shape of the material to be rolled collapses from a rectangular shape, the collapse is amplified as rolling is repeated. Finally, the upper and lower surfaces of the ring-shaped material to be rolled 1 as shown in FIG. 4 (indentation in the height direction) 1a and 1b and the indentations on both side surfaces (indentation in the thickness direction).
1c and 1d will occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a rolling method and a control device by a ring rolling mill for obtaining a good product ring by the ring rolling mill.

[0007]

SUMMARY OF THE INVENTION A rolling method using a ring rolling mill according to the present invention comprises: a main roll and a mandrel for reducing a thickness of a ring-shaped material to be rolled in a radial direction; A rolling method using a ring rolling mill having a pair of upper and lower edger rolls for performing height reduction in an axial direction, wherein movement of a mandrel and an edger in a rolling direction is performed during a rolling process from an initial rolling to a final rolling. It has one or more steady state steps to stop.

The control apparatus for a ring rolling mill according to the present invention includes a main roll and a mandrel for reducing the thickness of a ring-shaped material to be rolled in a radial direction, and a height reduction of an axial direction of the ring-shaped material to be rolled. A control device for a ring rolling mill including a pair of upper and lower edger rolls for performing a rolling progress pattern is stored,
A control unit that performs position control of the mandrel and the edger roll based on the rolling progress pattern, wherein the rolling progress pattern moves the mandrel and the edger in the rolling direction during the rolling process from the initial rolling to the final rolling. A control device for a ring rolling mill, comprising one or more steady state steps of stopping.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view for explaining the concept of the rolling method of the present invention. FIG. 1 (a) shows a time-varying state of a wall thickness by a mandrel, and FIG. 1 (b) shows an edger. It shows a state of a height change over time due to a roll. As shown in FIG. 1, the present embodiment has a steady state process in which the thickness and height of the ring-shaped material to be rolled do not change during the rolling from the start to the final stage of rolling.

That is, when a predetermined time has elapsed from the start of the reduction (or when the outer diameter of the ring has reached a certain size), the movement of the mandrel and the edger roll in the rolling direction is stopped and the same position is reached. So that rolling is performed. By performing rolling in this steady state process, the ring-shaped material to be rolled has the same rectangular cross section over the entire cross section.

When the steady state process is completed, rolling is performed under the same control as before the steady state process is started. Immediately before the final stage, the rolling reduction is reduced, and in the final stage, the final shape is adjusted in the same state as the above-mentioned steady state, and the rolling is completed.

Although the length of time in which the above-mentioned steady state is carried out depends on the outer diameter of the ring-shaped material to be rolled, it is preferable that the ring makes four or five rounds. However,
If the time of this steady state is too long, the temperature of the ring-shaped material to be rolled may be lowered during this time, making it difficult to perform rolling. Therefore, it is not sufficient that the steady state is long.

FIGS. 2A and 2B schematically show the configuration of the ring rolling mill according to the present embodiment. FIG. 2A is a side view including a partial sectional view, and FIG. 2B is a plan view. In the figure,
1 is a ring-shaped material to be rolled, 2 is a main roll, 3 is a mandrel, 4 is an edger roll, and 5 is a tracer roll.

The main roll 2 is fixed and has a function of rotating the rolled material 1 at a constant peripheral speed while rotating at a constant speed. The mandrel 3 is driven and disposed on the inner diameter side of the ring-shaped material to be rolled 1, sandwiches the ring-shaped material to be rolled 1 together with the main roll 2, moves in the direction of the main roll, and performs reduction in the thickness direction. Has become.

The edger rolls 4 and 4 are generally arranged at positions symmetrical about the center of the main roll 2 and the ring-shaped material to be rolled 1 and have conical rolls vertically above and below the ring-shaped material 1 to be rolled. ing. Then, one or both rolls are driven, and the upper roll usually moves downward to reduce the height of the ring-shaped material 1 to be rolled. The reason why the edger rolls 4 and 4 have a conical shape is that the peripheral speed of the ring-shaped material to be rolled 1 to be rolled is different between the inner peripheral side and the outer peripheral side (inner peripheral side <outer peripheral side). This is because it is necessary to absorb the difference. Therefore, the edger rolls 4 and 4 are arranged so that the tip of the conical roll coincides with the center of the ring-shaped material 1 to be rolled, and as the diameter of the ring-shaped material 1 grows, the ring-shaped material on the roll peripheral surface is rolled. The rolling position with respect to the rolled material 1 moves in the horizontal direction (diameter increasing side).

The tracer roll 5 is brought into rolling contact with the outer peripheral surface of the ring-shaped material to be rolled 1 at a position symmetrical about the center of the main roll 2 and the ring-shaped material to be rolled 1, and the outer diameter of the ring-shaped material to be rolled 1 is advanced by reciprocation. The dimension is to be regarded as the dimension between the rolling contact surfaces of the tracer roll 5 and the main roll 2 with respect to the material to be rolled.

In the ring rolling mill configured as described above, while detecting the diameter of the ring-shaped material to be rolled 1 by the tracer roll 5, the ring-shaped material to be rolled 1 is radially moved by the main roll 2 and the mandrel 3. And height rolling in the axial direction is performed by upper and lower edger rolls 4 and 4.

Next, a control device in the ring rolling mill configured as described above will be described. FIG.
FIG. 4 is an explanatory view of the configuration of the control device. The mandrel position detecting means 7 for detecting the position of the mandrel 3, the edger roll position detecting means 8 for detecting the height position of the edger roll 4, and the position of the tracer roll 5 are detected. And a tracer roll position detecting means 9 for detecting the position. Also, signals from these mandrel position detecting means 7, edger roll position detecting means 8, and tracer roll position detecting means 9 are input, and control signals are sent to the mandrel position control section 11 and the position control section 12 of the edger roll. Output control unit 13
It has.

The control unit 13 stores a preset rolling progress pattern, and the control unit 13 sends control signals to the mandrel position control unit 11 and the edger roll position control unit 12 based on the rolling progress pattern. Output. As the rolling progress pattern, for example, the basic control is to make the outer diameter growth rate constant in the process from the initial stage to the final stage of the rolling, and during the rolling from the initial stage to the final stage of the rolling, When the outer diameter reaches a predetermined constant value, a steady state process for 10 seconds is performed on both the mandrel and the edger, and then the same rolling control as before the steady state process is performed. Control is performed so that the constant value becomes slower than before.

Also, signals from the mandrel position detecting means 7, the edger roll position detecting means 8, and the tracer roll position detecting means 9 are inputted, and the actual shape of the material to be rolled is calculated from these signals. And the desired shape of the material to be rolled by the preset rolling progress pattern,
If there is a difference between the two, a control signal is output to the mandrel position control unit 11 and the position control unit 12 of the edger roll so as to correct the difference.

Next, the operation of the control device configured as described above when rolling the ring-shaped material to be rolled will be described. First, a rough material to be rolled is selected, and the rough material is set in a ring rolling mill shown in FIG. 2. The mandrel position control unit 11 is controlled by the control unit 13 so that the rolling progress pattern is set in advance. And a control signal to the edger roll height control unit 12 is output. After the start of rolling, the control unit 13 inputs signals from the mandrel position detecting means 7, the edger roll position detecting means 8, and the tracer roll position detecting means 9, and from these signals, the actual rolling material The mandrel position control unit 11 and the edge are calculated by calculating the shape, comparing the shape with the desired shape of the material to be rolled according to the preset rolling progress pattern, and correcting any difference between the two. A control signal is output to the jar roll position controller 12. The mandrel position control unit 11 and the position control unit 12 of the edger roll receive a signal from the control unit 13 and perform position control of the mandrel 3 and the edger roll 4 based on the signal.

The rolling by the feedback control based on the rolling progress pattern as described above is continued. Then, when the tracer roll 5 detects a preset outer diameter, the control unit 13 outputs a signal to the mandrel position control unit 11 and the position control unit 12 of the edger roll to stop the movement. The mandrel position control unit 11 and the position control unit 12 of the edger roll input a signal from the control unit 13 and control to stop the movement of the mandrel 3 and the edger roll 4 for a preset time. Thus, the ring-shaped material to be rolled is rolled in a steady state in which the mandrel 3 and the edger roll 4 do not move, and the cross-sectional shape is shaped into a rectangular shape. After the preset time has elapsed, the control is returned to the control before the steady state is entered, and the rolling is performed.

When the initial and middle main rolling steps are completed and the shape approaches the final shape, the finishing process is switched to a control such that the outer diameter growth rate is constant, and the shape is changed to a product shape. Perform rolling to prepare. Thereafter, based on the information from the tracer roll position detecting means, when it is confirmed that the outer diameter of the ring-shaped material to be rolled has reached the target value, the rolling is completed.

The inventor compared the results of the method according to the present embodiment with the results of other methods in order to verify the effects of the above-described embodiment. The specifications, the method of the present embodiment, and the comparative example are as follows.

1. Specifications Steel type: S48C Material shape: (i) outer diameter 480.11mm, (ii) inner diameter 140mm, (iii) height 110mm, (iv) wall thickness 170.06mm Product shape: (i) outer diameter 1500mm, (ii) inner diameter 1400mm, (iii)
1. height 80mm, (iv) wall thickness 50mm The method of the present embodiment is based on the outer diameter growth rate control Outer diameter of 480.11 mm to the initial molding from 1480 mm, in the middle period, the outer diameter growth rate is controlled to be 6 mm / sec, the outer diameter of the middle 1000 mm, A steady state process for 10 seconds at 85 mm height was performed on both the mandrel and the edger. Outer diameter is 1480mm
In the final period from to 1500 mm, the outer diameter growth rate was controlled to be 2 mm / sec. 3. Comparative Example (1) Constant Pressure Control From the beginning to the end of molding, the pressure was controlled to be constant at 55 kg / cm ² , and the process was terminated when the outer diameter of the tracer detection reached 1500 mm. (2) Outer diameter growth rate control In the initial and middle stages of molding from an outer diameter of 480.11 mm to 1480 mm, the outer diameter growth rate is controlled to be 6 mm / sec, and the outer diameter is 1 mm.
The outer diameter growth rate is 2mm / sec at the end of 480mm to 1500mm
So that the change in the height of the ring-shaped rolled material is proportional to the change in the outer diameter, that is, the outer diameter 480.11 mm
The height was controlled so as to change linearly with respect to the outer diameter from the initial height of 110 mm at the time to the height of 80 mm at the outer diameter of 1500 mm. (3) Final constant pressure control In the initial and middle stages of molding from an outer diameter of 480.11 mm to 1480 mm, the pressure is controlled to be constant at 55 kg / cm ² and the outer diameter is 14
The pressure was controlled to be constant at 30 kg / cm ² from 80 mm to 1500 mm, and the process was terminated when the outer diameter of the tracer detection reached 1500 mm.

Table 1 which shows the amount of dents, dimensional accuracy, and judgment of the experimental results under the above rolling conditions is shown.

[0027]

[Table 1]

As shown in Table 1, according to the present embodiment, the dimensional accuracy of the final molded product is good, the dent of the surface is small, and it can be seen that it is superior to the prior art as a comparative example.

As described above, in the present embodiment,
Since the steady state process is inserted during the rolling, the shape of the ring-shaped material to be rolled is adjusted in the steady state process. Therefore, even if the shape collapses during rolling, the shape collapse is temporarily eliminated in the steady state process, so that irreparable dents and the like can be prevented as much as possible.

In the above-described embodiment, an example in which the outer diameter growth rate control is used as the basic control has been described. However, the present invention is not limited to this.
The present invention can also be applied to a case where the final constant pressure control is a basic control. Further, in the above-described embodiment, an example is described in which the steady state step is performed once, but the present invention is not limited to this, and may be performed a plurality of times. Furthermore, in the above-described embodiment, the tracer roll that comes into contact with the ring-shaped material to be rolled is described as an example of the tracer that detects the outer diameter of the ring-shaped material to be rolled. May be a non-contact type.

[0031]

As described above, in the present invention, the steady state process is inserted during the rolling, so that the shape of the ring-shaped material to be rolled is adjusted in the steady state process, and Even if there is a collapse, the collapse of the shape is temporarily eliminated in the steady state process, so that occurrence of irreparable dents and the like can be prevented as much as possible.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram showing a ring rolling mill according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a control device according to an embodiment of the present invention.

FIG. 4 is an explanatory view of a problem of ring rolling molding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ring-shaped rolling material 2 Main roll 3 Mandrel 4 Edger roll 5 Tracer roll 7 Mandrel position detecting means 8 Edger roll position detecting means 9 Tracer roll position detecting means 11 Mandrel position control unit 12 Edger roll position control unit 13 Control Department

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sadaka Masuda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (72) Inventor Takeshi Yamada 4-6 Kojimacho, Kawasaki-ku, Kawasaki-shi, Kawasaki, Kanagawa Prefecture Inside NUK Metalworking Co., Ltd. (72) Inventor Shoichi Ando 4-6 Kojimacho, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture

Claims (2)

[Claims] 1. A ring comprising: a main roll and a mandrel for reducing a thickness of a ring-shaped material to be rolled in a radial direction; and a pair of upper and lower edger rolls for reducing an axial height of the ring-shaped material to be rolled. A rolling method using a rolling rolling mill, comprising at least one steady state step of stopping movement of a mandrel and an edger in a rolling direction during a rolling step from an initial rolling stage to a rolling end stage. By rolling method. 2. A ring comprising: a main roll and a mandrel for reducing a thickness of a ring-shaped material to be rolled in a radial direction; and a pair of upper and lower edger rolls for reducing an axial height of the ring-shaped material to be rolled. A control device for a rolling mill, wherein the control device stores a rolling progress pattern, and includes a control unit that performs position control of the mandrel and the edger roll based on the rolling progress pattern, wherein the rolling progress pattern is A control device for a ring rolling mill, comprising one or more steady-state steps of stopping movement of a mandrel and an edger in a rolling direction during a rolling process from an initial rolling stage to a final rolling stage.