JPH01237036A - Ring rolling mill - Google Patents

Abstract

PURPOSE:To form the ring product having an excellent dimensional accuracy in labor saving with good efficiency by rolling a metal ring blank by a ring rolling mill, providing a heating equipment as well and heating or temp. reserving said blank under rolling. CONSTITUTION:A ring product is rolled by rolling a heated metal ring blank 30 by the ring rolling mill 10 consisting of a pair of the edge rolls 13 rolling from the upper and lower parts, the main roll 11 and middle roll 12 rolling from the inner and outer parts. In said ring rolling mill 10, a heating equipment is preferably arranged by adjoining to said edge roll 13 to heat or temp.- reserving said ring blank 30 under rolling. Said heating equipment is preferably made in the structure of feeding a high frequency current via a heating transformer 18 from a high frequency power source 16 to the heating electrode 15 surrounding the ring blank 30 movably. The temp. of the ring blank 30 can correctly be thus controlled and the rolling is enabled with high accuracy and good efficiency without the need for reheating by removing it on the way of rolling.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ring rolling mill, in particular a ring rolling mill equipped with induction heating equipment.

Conventionally, a ring rolling mill for forming a ring product by rolling a metal ring material from the inside and outside with a main roll and a middle roll and rolling the upper and lower end surfaces with an edge roll is known.

However, in the conventionally known ring rolling mills of this type, the main body is not equipped with heating equipment. For this reason, - When using a ring rolling mill like this for boat fishing to hot-form or warm-form a metal material, first heat the metal material in a separately installed heating furnace. After raising the temperature of this to the forming temperature, it is necessary to take it out of the heating furnace and finish forming with a ring rolling mill within the allowable rolling temperature range. Even if
If forming is not completed within this allowable rolling temperature range, when the temperature of the heated metal material falls below the rolling allowable temperature range during the forming process, forming will be temporarily interrupted and the material will be placed in the heating furnace. After heating it up to a temperature at which it could be molded again, it was necessary to continue forming and rolling it using a ring rolling mill. Also,
Depending on the size, dimensions, shape, material, etc. of the metal material, it may be necessary to repeat the reheating and reshaping rolling of the material two or three times or more.
Hot rolling of such metal materials requires a great deal of time and effort.

Also, depending on the diameter of the molded product when the molding process is interrupted, it may not be possible to accommodate it in the heating furnace.
Occasionally, this molded product had to be discarded. This occurs in the case of relatively large ring products that take a long time to roll and have a large temperature drop, or in the case of ring products that are made of a material that has a narrow rolling temperature range.

However, this not only wastes rolling time but also wastes valuable resources.

On the other hand, most ring products have very high dimensional accuracy. This dimensional accuracy is required in cold rolling, but since ring rolling is formed in a high temperature range, it is normal to form into a slightly larger diameter to allow for shrinkage during cold rolling. .

Therefore, the temperature difference between the completion of rolling and the cold state directly affects the dimensional accuracy of the diameter of the ring product during the cold state. For this reason, at what temperature and what diameter size to roll depends on the experience of the ring rolling mill operator and so-called cancer.

However, with this method, it is impossible to avoid dimensional variations in the final rolled product. It is designed to maintain the tolerance range of dimensional accuracy required for the ring product.

However, this makes the rolling operation very complicated.

Therefore, the present invention eliminates the need for reheating in a separate heating furnace in the middle of rolling to compensate for the temperature drop during rolling of a ring product from a metal material.
The aim is to obtain a new ring rolling mill.

The first invention with the title is this 52! ! In order to solve this problem, the ring rolling mill is equipped with a heating equipment capable of heating the rolled material as required, in particular, a ring rolling mill equipped with an induction heating device.

and-1-1 Hereinafter, the present invention will be explained in detail based on the accompanying drawings showing one embodiment thereof.

First, FIG. 1 schematically shows the arrangement of a ring rolling mill according to the present invention. As can be seen from the figure, this ring rolling mill 10 has a main roll 11, It is composed of a middle roll 12 and a pair of edge rolls 13, and by rolling the ring material 30 from the inside and outside by the rotating main roll 11 and the middle roll 12, the ring material 30 is rolled into a ring-shaped product. The upper and lower end surfaces of the ring material 30 are similarly rolled by a pair of rotating edge rolls 13, and in this way, the inner and outer diameters and thickness of the ring material 30 are gradually rolled into a rolled product having the required dimensions. However, in the present invention, a heating electrode having a hollow rectangular cross section, for example, is provided near the edge roll 13 of the ring rolling mill 10 having such a boat-like configuration. 15 is arranged so that the ring material 30 can pass through the hollow part thereof, and the heating electrode 15 is connected to a heating transformer 18 which is supplied with power from a high frequency power source 16 via a connecting cable 17, The ring material 30 passing through it is heated by induction. That is, as shown in FIG. 2, a high frequency current l is applied to the heating electrode 15.
When ^ flows, magnetic flux penetrates the inside of the link material 30, and an eddy current IH flows therein due to the alternating magnetic field, generating heat.

Further, although FIG. 3 shows an equivalent circuit of this arrangement, the figure shows that the high frequency power supply 16 has a 200 V
.

It is assumed that 60 Hz three-phase alternating current is supplied.

The present invention has the above-described configuration, and while the ring material 30 is being rolled by the ring rolling mill 10, it can be heated by the heating electrode 15, and in this case, the heating temperature is as follows. By controlling the heating transformer 18, it can be freely controlled, so that the ring material 30 is maintained at a predetermined temperature and can be rolled to a desired diameter at that temperature.

As described above, according to the present invention, it is possible to reduce the variation in the dimension of the link product due to the difference in the rolling temperature of the ring material 3o, and to improve the dimensional accuracy of the ring product during cold rolling.

11 Standing 11 Since the present invention has the above-described configuration and operation, while rolling the ring material with a ring rolling mill,
This can be heated or kept warm by a heating equipment, such as an induction heating device, so that the ring material is heated to a predetermined rolling temperature in a heating furnace during the rolling process, as in the conventional method. Interrupt this and try again.
Alternatively, there is no need to heat it with a painter's heating furnace,
Therefore, compared to conventional methods, it is possible to save energy and improve productivity.
Since the temperature of the ring material being rolled can be freely controlled, it is possible to roll it to a predetermined dimension at a predetermined temperature, thereby improving the dimensional accuracy of the ring product. In addition, unlike conventional ring rolling mills, there is no situation where it is impossible to reheat the ring material in the heating furnace due to the size of the ring material during the rolling process. This prevents the production of ring products that would otherwise have to be discarded, and can also contribute to saving materials.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall arrangement of the present invention, and FIG. 2 is a diagram showing the overall arrangement of the present invention.
FIG. 3, a schematic front view showing the heating electrode, is a diagram showing an equivalent circuit of the induction heating device according to the present invention. 1... Ring rolling mill, 11... Main roll,
12...Medium roll, 13...Edge roll, 15.
... Heating electrode, 16... High frequency power supply, 1 frame... Connection cable, 18... Heating transformer, 30... Ring material. Patent applicant Mitsubishi Nagasaki Kiko Co., Ltd. Figure 1 Figure 3 Procedural amendment April 13, 1988

Claims (1)

[Claims] 1. A main roll (11) for forming a ring product by rolling a heated metal ring material (30).
In a ring rolling mill (10) consisting of a middle roll (12) and an edge roll (13), a heating equipment is attached so as to heat or keep warm the ring material (30) during rolling. A ring rolling mill characterized by: 2. Ring rolling mill according to claim 1, wherein the heating equipment is arranged adjacent to the edge roll (13). 3. The heating equipment is composed of a heating electrode (17) which has a hollow cross section and is supplied with a high-frequency current, so that the ring material (30) moves through the hollow part, so that the ring material (30) is moved. Ring rolling mill according to claim 1 or 2, characterized in that the material (30) is heated by induction. 4. The ring rolling mill according to claim 3, wherein the heating electrode (17) is supplied with high frequency current from a high frequency power source (16) via a heating transformer (18).