JPH0141189Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a rolling roll heating machine that has an improved mechanism for making the temperature distribution uniform in the lengthwise direction of the roll body during quenching of the rolling roll.

[Technical background of the invention and its problems]

In general, rolling rolls are hardened by hardening the surface of the roll to improve wear resistance against the material to be rolled, and the inside of the roll body and shaft are made tougher to ensure bending stress applied during operation. It is necessary to improve the strength against.

When performing surface hardening treatment on this rolling roll,
A high-frequency induction heating rolling roll heating machine with solenoid-shaped heating coils arranged vertically is used, and the roll surface is induction heated while the rolling roll is inserted vertically into the heating coil and rotated. ing.

However, when the roll surface is heated by high frequency induction, if the heating temperature is below the Curie point,
Because the magnetic permeability is 1 or more, the temperature rises slower at both ends than at the center of the roll body length.Also, once the Curie point is exceeded, the magnetic permeability becomes 1, so magnetic flux concentrates at both ends. On the other hand, there is a problem in that the temperature rise at both ends of the roll body is higher than at the center of the roll body length, resulting in uneven baking due to non-uniform temperature distribution.

For this reason, in conventional rolling roll heating machines, multiple taps are attached to the heating coil, and the taps are switched while checking the heating state distribution, and the coil feeding length is adjusted to achieve uniform heating in the lengthwise direction of the roll body. was going there.

However, in conventional temperature control by switching taps, the structure is complicated because multiple taps are attached to the heating coil and a mechanism for switching the taps is required, and the power must be shut off each time the taps are switched. In addition, it is difficult to uniformly control the temperature even if the temperature changes each time.

[Purpose of invention]

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a rolling roll heating machine which uniformly heats the surface of the roll body length with an extremely simple structure and prevents the occurrence of uneven heating.

[Summary of the idea]

The present invention provides a rolling roll heating machine in which a rolling roll is vertically inserted inside a heating roll and the roll body is heated by induction while the rolling roll is rotated. Another feature is that a block-shaped magnetic concentrator is attached so as to be movable up and down, so that the flow of magnetic flux in the roll body is uniform, so that uniform heating is achieved in the lengthwise direction of the roll body.

[Example of idea]

An embodiment of the present invention will be described in detail below with reference to FIG.

In the figure, reference numeral 1 denotes a heating coil formed by winding a water cooling coil into a solenoid shape, which is erected vertically and connected to a high frequency power source 2. A plurality of thermometers 3 are installed between the coils at intervals along the axial direction of the heating coil 1, and these thermometers 3 are further connected to a control device 4.

Reference numeral 5 denotes a rolling roll, which is inserted vertically inside the heating coil 1, and whose lower end shaft portion 5c is supported by a rotating frame 6.

Reference numeral 7 denotes a magnetic concentrator in the shape of a half ring, which is connected to the tip of the cylinder 8, and is arranged in a ring shape, two each near the upper and lower ends of the rolling roll 5.
It is supported so that it can move up and down.

Note that the magnetic focusing body 7 is made of, for example, silicon steel,
It is made of ferromagnetic material such as carbon steel, ferrite, or diverter.

Further, the cylinders 8 are each connected to a control device 4, and the expansion and contraction operations thereof are controlled by changes in the temperature state of the roll body 5a along the lengthwise direction of the body.

Next, the operation of the above-mentioned rolling roll heating machine will be explained.

First, a rolling roll 5 serving as a material to be heated is suspended by a crane or the like, inserted into the inside of the heating coil 1, and the shaft portion 5c at the lower end is supported by the rotating frame 6.

Next, when the rotating frame 6 is driven and the heating coil 1 is energized from the high frequency power source 2 while rotating the rolling roll 5, the roll body 5 is heated by induction heating.
The surface of a is heated.

At this time, the temperature distribution along the length direction (vertical direction) of the roll body 5a is measured by the thermometer 3..., and when the temperature distribution becomes uneven beyond a specified value, a drive signal is sent from the control device 4. is released and cylinder 8...
expands and contracts, and the distance between the upper and lower magnetic concentrators 7, 7 combined in a ring shape and both ends of the roll body 5a is adjusted.

For example, at a heating temperature below the Curie point, magnetic flux concentrates at the center of the roll body 5a, but by bringing the magnetic flux body 7 close to the roll body 5a, the magnetic flux is attracted as shown in FIG. 2A. I was told,
The length of the heated material is expanded as a whole. Therefore, by having both ends where the temperature increase is low be supported by the magnetic concentrating body 7, the surface temperature of the magnetic concentrating body 7 becomes as shown by the broken line B, and the surface temperature distribution in the roll body 5a becomes as shown by the solid line A. As shown, the temperature is almost uniform, and the temperature of the shaft portions 5b and 5c can be kept low.

Also, when the heating temperature exceeds the Curie point,
Although heating is faster at both ends of the roll body 5a than at the center, by moving the magnetic flux body 7 away, the magnetic flux is no longer concentrated at the end of the roll and is concentrated on the magnetic flux body 7. As a result, as shown in FIG. 2B, the part with a high temperature rise is received by the magnetic concentrator 7, and the roll body 5a is uniformly heated.
It is possible to prevent uneven baking.

In the above embodiment, the half-ring-shaped magnetic concentrators 7, 7 are combined in a ring shape, but since the rolling roll 5 is heated by induction while rotating, it is possible to use a block-shaped magnetic concentrator. Also good.

In addition, by combining this with tap switching, it is possible to even out the roll surface temperature with even greater precision.

[Effect of idea]

As explained above, according to the present invention, the magnetic fluxing body is provided with an extremely simple structure that is movable up and down, and by adjusting the distance between both ends of the roll body and the magnetic fluxing body, the surface of the roll body is It is possible to obtain a rolling roll heating machine that uniformly heats the rolls and prevents uneven heating.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a rolling roll heating machine according to an embodiment of the present invention, and FIGS. 2A and 2B are explanatory diagrams showing the temperature distribution on the surface of the rolling roll. 1... Heating coil, 2... High frequency power supply, 3...
Temperature meter, 4...control device, 5...rolling roll, 5
a...Body part, 5b, 5c...Shaft part, 6...Rotating stand, 7...Magnetic concentrator, 8...Cylinder.

Claims (1)

[Scope of utility model registration request] In a rolling roll heating machine that inserts a rolling roll in the vertical direction inside a heating coil and induction heats the roll body while rotating the rolling roll, a ring-shaped or block-shaped A rolling roll heating machine characterized by having a magnetic focusing body attached so as to be able to move up and down.