JPS5819154Y2 - Heat treatment equipment for metal straight pipes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for heat treating a straight metal pipe to prevent it from bending.

When applying heat treatments such as quenching and tempering to straight metal pipes, conventional methods involve heating the iron pipe through a ring-shaped heating device while propelling it straight ahead, and then cooling the heated portion from the outside using water or compressed air. However, in this method, the residual stress generated during the manufacturing of the metal straight pipe and the stress caused by uneven heating and cooling during heat treatment are released without restraint, causing bending and flattening. is extremely difficult to straighten after heat treatment.

However, if the metal straight pipe has the above-mentioned bends or flatness, there are many problems when using it.

For example, if the straight steel pipes used in pipelines, which are now often used to transport oil, chips, slurry, etc., have bends or flatness, it will not only be difficult to connect them when configuring the pipeline, but also make it difficult to transport the transported goods. The disadvantage is that the central convex portion is prone to wear due to friction.

In view of these difficulties, heat treatment apparatuses have been proposed that do not cause bending of objects to be treated, such as pipes, during heat treatment, but these apparatuses also have drawbacks.

That is, the above-mentioned conventionally proposed apparatus firmly grips both ends of the tube to be heat treated in the longitudinal direction with the axis centered at -, and
Since the gripping device is configured such that one gripping portion has a degree of freedom that allows it to move only in the axial direction of the tube, in order to align the axes of both gripping portions located at both ends of the tube, both gripping portions are moved. They must be installed on the same base, etc., and therefore the entire device is long (at least the length of the pipe to be processed), and since the pipe to be processed is grasped at both ends, it has to be bent before processing. The problem is that the tubes in which they are placed are difficult to grasp, or almost impossible to grasp.

The present invention was made with the aim of providing a device that can solve the above problems, and its structure is such that it is inserted into a straight metal pipe to be heat treated and the straight pipe is heated from the outside. An annular heating device that heats a fixed amount, and cooling that is installed inside or on both the outside and outside of the straight pipe at a position adjacent to the heating device and cools the heated portion of the straight pipe from its inner or outer surface. and a contact diameter corresponding to the outer diameter of the straight pipe that is fixedly disposed in close proximity to the front and rear of the heating device, and forcibly supports and guides the straight pipe while propelling the straight pipe in a straight line. The present invention is characterized by two sets of roll groups having variable rotation and a propulsion mechanism for the straight pipe by rotation of the roll groups in the same direction or by a feeding device provided separately from the roll groups.

Next, an embodiment of the present invention will be described with reference to the drawings.

1 is an electric motor 2. Pulley 3, 3 a, chain wheel 4, 4
a, a feeding device that presses and propels the metal straight pipe m to be heat-treated from the rear via a low chain 5, etc., and is equipped with four rollers 6 at the bottom so that it can run on the machine base 7; The roller chain 5 is tensioned by a tightening device 8 disposed on the machine base 7, and thus constitutes an example of a propulsion mechanism for linearly propelling the metal straight pipe m.

9 is a heating device using a high-frequency inductor that penetrates the metal straight pipe m propelled by the mechanism and heats it from the outside; 10
11 is a high frequency transformer, 11 is an external cooling device provided on the front circumferential side of the heating device 9, and 12 is a metal straight pipe m, which is placed on the inner side of the heating device 9 to inject water or compressed air. An internal cooling device, 13 is a pipe that supplies water or air to the cooling device 12, 14 is a support device for the iron pipe 13, 15 is a flexible tube that supplies water or air to the pipe 13, and 16 is a front side of the heating device 9. 17 is a roll stand placed in front of the heating device 9; 18 is a roll stand placed on the machine base 7;
is a roll disposed on the machine base 7 at the tip of the roll stand 17 to receive the metal straight pipe m passing through the stand 17.

19 is a jacket of the internal cooling device 12; 20 is a water or air injection hole provided in the jacket 19;
9 is connected to the pipe 13 via a flexible hose 21, and water or air supplied from the pipe 13 is injected from its injection hole 20 onto the inner surface of the metal having a diameter m.

Reference numeral 22 denotes a frame of a device that supports the jacket 19, on which rollers 23, 23 are mounted 90 degrees apart, and movable rollers 25, 25 are mounted symmetrically to the rollers 23, 23 via a pneumatic cylinder 24. Yes, jacket 1
A hydraulic cylinder 27 is attached to the mounting plate 26 fixed to the frame 22 and the jacket 1 is attached to the frame 22 by the operation of the cylinder.
The position within the metal straight pipe m of 9 can be adjusted.

Note that 13a is an attachment rod for fixing the frame 22 to the tip end side of the tube 13.

Further, 28 and 29 are two pillars each rotatably installed on the roll stand 16, 30, 30a, 31
, 31a are bearings attached to the supports 28 and 29, and the roll 3
2.33 is mounted on a shaft, and the worm gears 34 fixed to the upper ends of the pillars 28 and 29 are engaged with the worm 35 which is pivotally mounted on the stand 16, and by rotating the handle 36 attached to the worm shaft, the pillar 28 .29 rotates, bearing 30.
30a, 31, 31a move up and down and roll 32.32
The interval between 33 and 33 can be adjusted.

That is, the bearings are screwed onto the pillars, and the bearings 30, 3
1, 30a, and 31a are screwed together with screws in opposite directions, so that they move in opposite directions as the support column rotates.

37. 38 are two pillars each rotatably installed on the roll stand 17, 39, 39 a, 40, 40
a is a bearing screwed onto the support column 37.38, and the roll 41.4
2 is mounted on a shaft, and worm gears 43 fixed to the upper ends of the columns 37 and 38 are engaged with a worm 44 that is pivoted on the stand 17, and by rotating a handle 45 attached to the worm shaft, the columns 37 and 38 are rotated. Rotating, bearings 39, 39
a.

40.40 a moves up and down between O-ru 41, 41, 42
．． The spacing between the rollers 42 can be adjusted, and the structure is similar to that of the roll stand 16.

The roll stand 16, 17 uses rolls 32, 33, 41, 42 to move the metal straight pipe m heated by the heating device 9 in a straight line, with the heating device 9 in between. m is forcibly supported and guided.

The device configured as described above has the tip of the metal straight pipe m passed between the rolls 32, 32, 33, 33 and inserted into the heating device 9, and the rear end of the iron pipe passed between the rolls 41, 41, 42, 42. The metal pipe m is applied to the front surface of the feeding device 1, and the electric motor 2 is driven to propel the straight metal pipe m in a straight line, while the heating device 9 heats the iron pipe m from the outside.The heating device 11 then heats the heated portion of the metal pipe m. The heat treatment is carried out by cooling the iron pipe from the outside and jetting water or compressed air from the injection hole 20 of the jacket 19 of the cooling device 12 onto the heated part of the iron pipe m to cool the heated part from the inside. ,
During this heat treatment, even if the straight metal pipe m is likely to bend or flatten due to residual stress generated during pipe making or stress generated when the heating and cooling described above are performed unevenly, the metal straight pipe m will maintain a straight trajectory. a roll 32 arranged to form a
33, 41, 42, and heat treatment by heating and cooling is performed between the roll stands 16, 17 that constitute the roll group, and the heated part of the iron pipe m becomes soft. Therefore, the stress is absorbed by the heated portion, and therefore, the metal straight pipe m can be heat-treated without bending or flattening.

In addition, in the above, the roll group is placed on a roll stand 16.17.
However, the feeding device may be omitted by driving the rolls of the roll stand.
As shown in the figure, there are inclined rolls 46, 46.4 in the roll group.
7.47.48.48, 49.49 may be used, and the metal straight pipe m may be rotated and fed by rotating these rolls in the direction of the arrow.

In the case shown in FIG. 5, the straightness and roundness of the heat-treated metal straight pipe m are better than in the above-mentioned apparatus.

Further, in the above embodiment, the external cooling device 11 was provided on the front peripheral side of the heating device 9, but this external cooling device may not be provided in some cases.

The present invention is as described above, and two sets of rolls are placed close to each other before and after a fixed annular heating device that passes through a straight metal pipe to be heat treated and heats the straight pipe from the outside. By doing so, while forcibly supporting and guiding the straight pipe immediately before and after the heated portion of the straight pipe that has been locally heated by passing through the heating device, the rolls are used to remove any bends or flatness that may occur in the iron pipe after heat treatment. By forcibly absorbing stress in the heating zone located between the supporting parts of Since it is possible to change the contact diameter of the roll group with respect to the straight pipe, there is an advantage that metal straight pipes with different diameters can be processed with the apparatus described above.

Incidentally, straight pipes of different lengths can also be heat-treated using the equipment mentioned above in the same manner as described above.

On the other hand, since the cooling device is installed at least on the inner surface side of the pipe at a position adjacent to the heating device, it can contribute to making the device more compact, and the metal straight pipe heat-treated by the device of the present invention can No bends or flatness, and
At least the inner surface of the tube can be heat treated, and a straight steel tube with good inner wear resistance can be obtained.

Furthermore, the roller groups are arranged in a short span across the heating device, and the contact diameter of each roller group with respect to the straight metal pipe can be changed, so even if the raw pipe is slightly bent, the main The device of the present invention can be easily set in the device of the present invention for heat treatment, and therefore, the gapped raw tube can be straightened and heat treated by passing through the device of the present invention. This method is extremely useful because it allows the tube to be straightened and subsequently subjected to heat treatment without causing any bending.

In addition, using the apparatus described in Examples, 5TPG38 contains 0.25% carbon, 0.35% silicon, and 0.30 to 0.0% manganese.
90%, 0.04% phosphorus, 0.04% sulfur, outer diameter 1
50mm 1 wall thickness 5. Qmm, a length of 5500mm Nosunless steel pipe was quenched at a quenching temperature of 980 to 1000℃, a feed rate of 6mm/sec, and a cooling water pressure of 2kg/Cm2, and the hardness was 25 to 28°Hs as the original tube.
In addition, the bending of the tube after quenching was reduced to 1.5 to 3 mm, compared to 15 to 20 mm in the case of the conventional device.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, and FIG. 1 is a front view of an example, FIG. 2 is a plan view of the same, FIG. 3 is a front view of an example of an internal cooling device, and FIG. A vertical side view and FIG. 5 are front views showing a group of rolls of precedents. 1... Feeding device, 9... Heating device, 1
1.12... Cooling device, 16, 17...
・Roll stand, 46.47.48.49...
・Roll, m... Metal straight pipe.

Claims (1)

[Scope of utility model registration request] A stationary annular heating device that passes through a metal straight pipe to be heat treated and heats the straight pipe from the outside; a cooling device that cools the heated portion of the straight pipe from its inner or outer surface; and a cooling device that is fixedly disposed close to the front and back of the heating device, and that is forcibly disposed while propelling the straight pipe in a straight line. At least two sets of rolls that support and guide and have variable contact diameters depending on the outer diameter of the straight pipe to be supported and guided, and the straight pipe that rotates in the same direction of the rolls or uses a feeding device provided separately from the rolls. 1. A heat treatment device for metal straight pipes, comprising a pipe propulsion mechanism.