JPS6024546B2 - Electric heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical heating device capable of uniformly heating the entirety of not only a single-shaped steel pipe but also an irregularly shaped steel pipe such as a flanged steel pipe.

Conventionally, electrical heating has been used to line steel pipes and the like with resin, but the conventional general electrical heating method has many drawbacks.

In other words, in conventional electrical heating of steel pipes, a fixed steel pipe is gripped with clamps that also serve as electrodes at both ends, and electricity is applied and heated in that state. When heating with this method, it takes time to attach and detach the clamp that also serves as an electrode, which reduces the efficiency of heating work, or the clamp that also serves as an electrode has a fixed gripping position with respect to the steel pipe, or conduction Because heat is radiated, there are drawbacks such as the tendency for temperature unevenness to occur. In view of this, a device has been proposed in which the electrode is made of a wax-like material and the steel pipe can be electrically heated while rotating and moving. In addition to not being able to heat objects with different diameters such as flanged steel pipes, even steel pipes with a single shape that have seams such as welding are difficult to heat when they come into contact with rollers that serve as electrodes during movement. There are disadvantages in that sparks are generated, making it difficult to achieve uniform heating, and the sparks may lead to melting and damage of the steel pipes and electrodes.

In view of the above-mentioned drawbacks of conventional electrical heating, the present invention is capable of heating objects of a single shape even if they have different diameters and lengths. The purpose of this device is to provide an electrical heating device that can heat objects with different outer diameters without causing temperature unevenness. At least one set of rotating members is movable in the axial direction of the material to be heated. two sets are provided, and supported in the same direction as the rotating member at a portion facing the rotating member of each set with the heated material in between,
In addition, two sets of rotating members such as conductive rollers, at least one set of which is movable in the direction of the material to be heated, are provided, and each of the rotating members is connected to a single-phase or three-phase power source. It is characterized by this. Next, an embodiment of the heating device of the present invention will be described with reference to the drawings.

In Figure 1, 1 is a steel pipe with a single outer diameter, which is the material to be heated to a predetermined temperature, and 2, 2', 3, and 3' are made of a material with good conductivity, such as true anchor. These rollers are rollers that are rotating members, each consisting of two rollers 2, 2' and 3, 3', arranged on the lower side of the steel pipe 1 in all radial directions near the pipe shape, and approximately aligned with the axis of the steel pipe 1. They are supported on parallel axes and spaced apart as appropriate.

4 and 5 are roller supports that rotatably support the respective rollers in an electrically insulated state; 6 and 7 are electric motors that transmit rotation to the respective rollers 2 and 3; and 8 is a motor that transmits rotation to each of the rollers. A single-phase power supply device 9, which is electrically connected to each of the rollers 2, 2', 3, and 3' and provides each roller with a function as an electrode, is equipped with the roller support 5 and the electric motor 7. A moving mechanism formed by mounting wheels 9a on a frame (not shown) on rails 9b laid along the axis of the steel pipe 1 moves the loaves 2, 2' and , 3' can be adjusted in advance.

The steel pipe 1 also includes rollers 2, 2', 3, which are rotation imparting members,
3' and when energized while being rotated, the rotation of the steel pipe 1 is ensured and each roller 2, 2 of the steel pipe 1 is
The rollers 2, 2', 3, and 3' are placed in close contact with the rollers 2, 2', 3, and 3' in order to prevent the generation of sparks and to ensure that the current from each loaf is conducted. a presser loaf 10 that presses down the steel pipe 1 from above;
10', 11, 11' are supported by air cylinders 12, 13, etc. In addition, this presser roller 1,
1', like the rollers 3 and 3', has, for example, a wheel 91a of an attached frame (not shown) supported on a rail 91b so that it can move in the vertical direction in accordance with the length of the steel pipe 1. . On the other hand, in the case of heating an object to be heated that does not have a single shape, such as a steel pipe with a flange, the presser rollers 10, 10
', 11, 11' can be connected to a power supply device 8 other than the above-mentioned power supply device 8 to function as a heating electrode separate from the above example. For example, when lining the flanged steel pipe 1' shown in Figure 2, including the flange part, the flanges la, la' and the steel pipe part must be heated uniformly, but the flange parts la, la' The rollers 2, 2', 3, which were mentioned earlier have a wall thickness greater than that of the steel pipe section.
In the case of electrical heating using only 3', the flange parts la, la'
It is almost impossible to uniformly raise the temperature of the roller 10 as shown in FIG.
, 10', 11, 11' are formed as electrodes, and the current flowing through the flange parts la, la' can be appropriately selected and set according to the size of the flange, the pressure resistance of the flange, etc., so that the flange part and the steel pipe can be connected. Uniform heating of parts can be achieved. That is, the device shown in the second figure has presser rollers 10, 10.
11, 11' are used as electrodes for heating the flange portions la, la' with electricity, but the structure is similar to that of the device shown in FIG. In each of the above heating devices, each roller 2, 2', 3, 3' and 10, 10', 11, 11
' may be provided with a cooling function that allows water to flow through the center of their shafts through a sieve joint or the like in order to cool them during electrical heating.

Next, an example of energization heating using the apparatus shown in FIG. 1 will be described. First, rollers 2, 2', 10, 10' of each paper
, 3', 11, 11' to match the length of the steel pipe 1 which is the material to be heated.
11' as appropriate, presser loaf 10, 10', 11
, 11' are released upward, and the steel pipe 1 is placed between the rollers 2 and 2.
After remounting on the pipes 1 and 3, 3', the presser rollers 0, 10', 11, 11' are returned to their original positions, and the steel pipe 1 is pressed down to complete the setting work.

Next, when the electric motors 6 and 7 are started to rotate the rollers 2 and 3 and the power is turned on to start energizing, the steel pipe 1
While rotating on the spot, it is heated by electricity. Actually, in the heating device of the present invention shown in FIG.
．． When a 5M steel pipe was heated by passing electricity through it, the temperature was 350
The time required to obtain a heating temperature of 0.00 was 5 minutes, and in the case of 28 x 5.5M steel pipes under the same conditions, it took 2 minutes. Almost no temperature unevenness occurred.

The apparatus of the present invention is provided with four sets of rotating members that sandwich the heated material at both ends of the heated material and are supported by shafts parallel to the axis of the heated material. They face each other with the material to be heated in between.

Two sets of rotating members can be moved in the direction of the heated material, while when the heated material has a single shape such as a straight pipe, two sets of rotating members face each other in the longitudinal direction of the heated material. is used as a current-carrying electrode connected to a single-phase power source, and if the material to be heated is a steel pipe with a flange, the rotating member is applied to the flange portion, and each rotating member is connected to a three-phase power source. Since the current-carrying electrode is used, it is possible to rotate and heat a single-shaped material to be heated without moving it, and uniform heating can be achieved without generating sparks due to movement. Even if the diameter of the flange and main body are different, such as a flanged steel pipe, the flange and main body can be used without generating sparks, etc., as in the case of a steel pipe with a single shape. This provides the unique effect of being able to heat the part and the main body substantially uniformly.

In addition, even if the length of the heated material with a single shape or a flange is different, the device of the present invention moves the movable rotary member in all directions of its axis, and the length of the heated material is different. Since it is possible to support the materials correspondingly, these materials to be heated can be heated with the above-mentioned effect.

Furthermore, since the material to be heated is heated while being rotatably supported without being moved, the lining device can be directly attached to the heating device of the embodiment, for example, in a continuous manner. All of the above-mentioned effects are unique to the device of the present invention, which cannot be obtained with conventionally known or recently proposed electrical heating devices. Therefore, the heating device of the present invention is suitable for lining processing of steel pipes, etc. It is extremely useful when employed in the heating step during heat treatment.

[Brief explanation of the drawing]

The drawings show an embodiment of the heating device of the present invention; FIG. 1 is a perspective view showing the basic structure of one example, and FIG. 2 is a perspective view of another example. 1... Steel pipe, 2, 2', 3, 3'... Loaf, 4, 5.
...Roller support, 6,7...Electric motor,
8...Power supply device, 9...Movement mechanism, 10,10
', 11, 11'...Press roller, 12, 13...Air cylinder, 1'...Flanged steel pipe, la, la'
...Flange part. Figure 1 Figure 2

Claims (1)

[Claims] 1 At least one set of rotating members such as conductive rollers supported by shafts parallel to the shafts of the material to be heated, such as steel pipes, and rotated by the driving force of a motor, etc. Two sets of members are provided so as to be movable in the axial direction of the heated material, and the members are supported in the same direction as the rotating members at a portion facing each set of rotating members with the heated material sandwiched therebetween, and at least One set includes two sets of rotating members such as conductive rollers that are movable in the axial direction of the material to be heated, and each of the rotating members is connected to a single-phase or three-phase power source. Electrical heating device.