JPH07108415B2 - High frequency heating bending machine for metal tubes - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing machine for bending metal pipes used for power generation, chemical plant piping, shipbuilding piping systems, etc. while heating them by a high frequency heating system.

[0002]

2. Description of the Related Art In a high-frequency heating bending machine, the surface temperature of a metal tube to be bent should be empirically determined by visual observation, or one or two optical thermometers should be used to measure the surface temperature from outside.
The heating part of the metal tube below the heating coil is measured from 0 mm to 2000 mm). For example, real fairness 4-405
Japanese Patent No. 78 discloses an example in which thermometers 18 and 18 'are attached at positions apart from the heating coil 4.

[0003]

However, during bending, since cooling water is discharged from the heating coil to the heating portion of the metal tube during the bending process, water vapor is generated and interferes. It was difficult to accurately measure the heating temperature of the side metal tube. Also, as shown in FIG.
Since the clamp portion 5 for clamping the tube 1 is close to the heating coil 6 on the rotary table 4, the arrows a, b
As shown in Fig. 4, it is impossible to make measurements using an optical thermometer from the front and the outside because of the mechanical structure.
Even if the thermometers 18 and 18 'are attached as described in Japanese Patent No. 0578, it is impossible to measure the temperature accurately because it is measured from the outside of the heating coil 4. Further, when the thermometer is arranged near the heating coil 4 in this way, the thermometer 1
8 and 18 'are heated and the durability deteriorates. Reference numeral 2 in the drawing is a guide roller.

An object of the present invention is to make it possible to accurately measure the surface temperature of a metal pipe from the beginning of bending to the end of bending in a high-frequency heating and bending machine for metal pipes, which has been a drawback of the prior art. That is.

[0005]

The structure of a high-frequency bending machine for metal pipes according to the present invention is as follows.

A metal tube is heated locally by a high frequency induction heating coil to a temperature capable of plastic deformation, and a bending moment is applied to the heating section while moving the heating section relatively in the longitudinal direction of the tube. Immediately after that, a cooling water channel is formed in the annular high-frequency induction heating coil in a bending machine for metal pipes that continuously plastically deforms the heating region in the heating region. Insert a protective tube through the cooling water channel inside, insert the light condensing part of the fiber type radiation thermometer into the protective tube and face the heating part, radiate temperature on the operation panel or other easy-to-see place. A high-frequency heating and bending machine for metal tubes, characterized by being equipped with a meter display or recorder.

[0007]

When the metal pipe to be processed is set in the bending machine and the power is turned on, a current flows through the high frequency induction heating coil, and the metal pipe to be processed is locally heated to a high temperature. The heating temperature is measured by a radiation thermometer, and the measured temperature is, for example, digitally displayed or recorded on a display. By performing the work while monitoring the temperature display, the operator can sufficiently control the heating temperature especially at the start of the work and can manufacture a high-quality bent pipe. The condensing part of the fiber type radiation thermometer is cooled by the cooling water in the coil.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an overall view of a bending machine according to the present invention. In this figure, 1 is a metal pipe to be processed (hereinafter referred to as "metal pipe"), and this metal pipe 1 is a guide roller 2
The tip is fixed to the clamp portion 5 on the rotary table 4 via.

Reference numeral 3 denotes an annular shape, which is a high-frequency heating device which locally heats the metal tube 1 from its outer periphery to a narrow width and incorporates a water cooling device. The heating device 3 is a high-frequency induction device as shown in FIG. A cooling water passage 7 is formed in the heating coil 6, a cooling water jet nozzle 8 is formed, and further, the cooling water passage 7 in the heating coil 6 is penetrated to insert a protective pipe 10.
The temperature condensing part 11 of the heating temperature detecting tube 9 is provided in the protective tube 10.
Is inserted.

Reference numeral 12 is a converter for converting a signal inputted from the light condensing unit 11 through the cable 13 into a digital signal, and 14
Is a display for digitally displaying the temperature signal converted by the converter 12 via a signal line 15. The display 14 is attached to the operation panel 16 in the case of the embodiment.

In the above embodiment, when the high frequency induction heating coil 6 is supplied with electric power, the metal tube 1 is locally heated to a high temperature by the action of the high frequency heating coil 6, and the heating temperature is the temperature of the detection tube 9. The light is collected by the light collector 11 and displayed on the display 14. The operator heats the metal tube 1 at an appropriate temperature while monitoring the temperature displayed on the display unit 14,
The metal tube 1 is propelled in the direction of the arrow in FIG. 1 by an appropriate means to rotate the turntable 4 for bending, and cooling water is jetted from the cooling water jet nozzle 8 to the front of the heating portion a in FIG. The cooling water b is jetted to cool the heated portion a with water.
Further, the temperature condensing unit 11 is cooled by the cooling water via the protection tube 10 inserted in the cooling water passage 7.

[0012]

As described above, according to the present invention, in the high-frequency heating and bending machine, the thermometer condensing part is directly attached to the high-frequency induction heating device, and the temperature of the heating part is directly detected and displayed on the display. Since it is configured as described above, the following effects are produced.

A. Since the temperature of the heating portion can be accurately measured at the center of the heating coil, temperature control can be accurately performed. As a result, since the temperature control can be sufficiently performed especially at the start of bending, the temperature control is insufficient as in the conventional case, so that a structural problem remains in the metal pipe or wrinkles occur. Disappears.

B. Since the temperature during the bending process can be constantly monitored, it is possible to efficiently manufacture a bent pipe of stable quality under the best heating conditions by adjusting the feed speed of the metal pipe.

C. Since the temperature condensing portion is cooled by the cooling water, the durability does not deteriorate due to overheating.

[Brief description of drawings]

FIG. 1 is a plan view of a bending machine according to the present invention.

FIG. 2 is an explanatory diagram of a heating device and a temperature indicator.

FIG. 3 is an explanatory diagram of a conventional heating temperature monitoring method.

[Explanation of symbols]

 1 Metal Tube 2 Guide Roller 3 Heating Device 4 Rotating Table 5 Clamping Section 6 High Frequency Induction Heating Coil 7 Cooling Water Channel 8 Cooling Water Jet Nozzle 9 Heating Temperature Detection Tube 10 Protective Tube 11 Temperature Condensing Section 12 Converter 13 Cable 14 Temperature Indicator 15 signal line 16 operation panel

Claims (1)

[Claims] 1. A metal tube is heated locally to a plastically deformable temperature by a high-frequency induction heating coil, and a bending moment is applied to the heating section while moving the heating section relatively in the longitudinal direction of the tube. , Immediately after that, perform the cooling operation,
In a bending machine for metal pipes that continuously plastically deforms the pipe in its heating region, a cooling water channel is formed in the annular high frequency induction heating coil, and the cooling water channel in the heating coil is penetrated. Inserting a protective tube, inserting the condensing part of the fiber type radiation thermometer into the protective tube and facing the heating part, and installing the indicator or recorder of the radiation thermometer on the operation panel or other easy-to-see place. A high-frequency heating and bending machine for metal tubes, characterized by being installed.