JPH08197146A - Position controller for high-frequency heating coil - Google Patents

Abstract

PURPOSE: To constantly control a clearance between a tube and a heating coil in a position controller for a high-frequency heating coil for bending of a tube. CONSTITUTION: A tube 10 is put through with a heating coil 11, heated by a high-frequency current and bent. The coil 11 is attached to a transformer moving table 12 through a frame 3 and a supporting arm 8; and the moving table 12 is loaded on a supporting base 13 and moved up and down/left and right on the base 13 by means of a driving device 7 attached to the base 13 for up and down/left and right adjustment so that the coil is movably adjusted. The frame 3 is provided with a pair of noncontact clearance sensors 1, which detect the displacement of a clearance against the tube 10, inputting the detection in a personal computer 6 through a converter 5. The personal computer 6 controls the driving device 7 for up and down/left and right adjustment, controlling the clearance constantly between the coil 11 and the tube 10. As a result, a uniform heating is made possible on the tube, improving precision of the bending shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating coil position control device for bending a pipe.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view of a heating coil portion of a conventional high-frequency bender (bending machine) for bending a pipe.
Is a BB arrow view. In both figures, 10 is a tube for bending, 11 is a heating coil for passing a high frequency current, 1
Reference numeral 2 is a transformer moving base, 13 is a supporting base on which the transformer moving base 12 is mounted, and 14 is a pair of transport racks that mesh with pinion gears attached to the supporting base 13 (not shown) to move the supporting base 13 in the front-back direction. It is a thing. A support arm 15 has one end fixed to the transformer moving base 12 and the other end fixed and supporting the heating coil 11. Also, the support base 1
An up / down / left / right adjustment drive device 7 is incorporated in the device 3, and the transformer moving table 12 mounted thereon is vertically and horizontally driven and adjusted by operating the operation box 16. Reference numeral 17 is a cable connecting the operation box 16 to the vertical and horizontal adjustment drive device 7 and a pinion gear drive device (not shown).

In such a high frequency bender, the tube 1
When the bending process of 0 is performed, a high frequency current is passed through the heating coil 11 to perform high frequency induction heating on the tube 10 with a constant narrow width (about twice the wall thickness in the case of a thin tube). In this case, as the wall thickness of the tube is smaller, wrinkles 18 as shown in FIG. 5 are more likely to occur inside the tube 10 unless the heating area 19 of the tube is uniformly heated in the circumferential direction of the tube. As shown in FIG. 4, the gap t between the tube 10 and the heating coil 11 greatly affects the uniform heating of the tube 10.

Therefore, conventionally, during bending of the pipe 10, a gap t
Is constantly monitored in the circumferential direction, the operator constantly monitors the operation box 16 and operates the operation box 16 to visually drive the transformer moving base 12 to drive the vertical / horizontal / horizontal adjusting driving device 7, thereby to I was moving and adjusting.

[0005]

In the conventional position control method for the heating coil 11 shown in FIG. 3, it is necessary for the operator to constantly monitor the heating condition during bending of the pipe 10, and the gap t cannot be confirmed. However, since it depends on the operator's visual inspection, the circumferential clearance t of the tube 10 becomes non-uniform, and there is a disadvantage that uniform circumferential heating cannot be obtained.

In order to solve such a problem, the present invention accurately and automatically performs position control in high-frequency heating during bending of a pipe without visually observing heating conditions. It is an object of the present invention to provide a position control device for a high-frequency heating coil capable of performing the above.

[0007]

Therefore, according to the present invention, a heating coil for heating a pipe, a supporting device for the heating coil, a moving device of the supporting device, a pair of non-contact gap sensors, and a pipe based on a detection signal of the sensor are used. A control means for controlling the moving means for adjusting the circumferential gap of the heating coil is provided.

That is, according to the present invention, a heating coil for inserting the tube and heating the same with a high-frequency current, a supporting device for the heating coil, and the supporting device are attached, and the supporting device is vertically moved. Moving means that can move to the left and right, a pair of non-contact gap sensors that are attached to the support device and that are arranged around the tube that passes through the heating coil, and detection signals from the same pair of non-contact gap sensors. A non-contact gap sensor of the same pair, and a control unit for calculating the gap between the pipe and the pipe to have a predetermined value, and controlling the vertical and horizontal movement amount of the moving unit. A position control device for a high-frequency heating coil, wherein a gap between the heating coil and the periphery of the tube can be adjusted.

[0009]

According to the present invention, it is necessary to set a heating coil in the tube by such means and to maintain a uniform gap in the circumferential direction between the tube and the heating coil when heating and bending by applying a high frequency current. However, when this gap is displaced, a pair of non-contact gap sensors detect it and input the displacement signal to the control means. The control means compares the signals of the pair of non-contact gap sensors, and if there is a difference, outputs a signal that makes them uniform to the moving means. As the moving means, for example, an up / down / left / right adjustment drive device is provided on the support base, and the support device is moved and adjusted on the support base in response to a signal of the amount of vertical or horizontal movement from the control means. Since the support device supports the heating coil, the heating coil moves up and down, left and right, and moves so as to make the circumferential gap between the coil and the tube uniform according to the displacement signal detected by the non-contact gap sensor. To do.

As described above, according to the present invention, since the circumferential gap between the heating coil and the pipe is uniformly maintained during the heating, the operator does not need to monitor the gap as in the conventional case, and the pipe can be removed. Unmanned heating and bending can be achieved, and the accuracy of the shape of the bent pipe can be improved.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall perspective view of a high-frequency heating coil position control device according to an embodiment of the present invention, and FIG.
FIG. In both figures, 1 is a non-contact gap sensor, and 2 is a thermocouple, which are connected to a personal computer 6 via converters 5, respectively. 3 is a pair of non-contact gap sensors 1
Is a frame to be mounted so that the mounting interval can be changed when the pipe is set in the pipe 10. 4 is attached to the frame 3, and is a protective cylinder for the magnetic shield of the non-contact gap sensor 1,
Reference numeral 7 denotes the vertical / horizontal / horizontal adjustment drive device described in the conventional example.
3 is attached to 3, and 8 is a supporting arm, one end of which is fixed to the transformer moving base 12, the other end holds the frame 3, and the frame 3 supports the heating coil 11.

A transformer moving table 12 is mounted on the supporting table 13 and can be moved vertically and horizontally on the supporting table 13 by the vertical / horizontal adjusting driving device 7. Further, the support base 13 can move in the front-rear direction by driving a pinion gear (not shown) on the upper rack 14 for transportation. Reference numeral 5 is the above-mentioned converter, which converts the signals of the non-contact gap sensor 1 and the thermocouple 2 and inputs them to the personal computer 6, which converts the control signal from the personal computer 6, the vertical and horizontal adjustment drive device 7 and a pinion gear (not shown). The drive signal is output to the drive unit.

When the pipe 10 is bent in the apparatus having such a configuration, first, the gap between the heating coil and the pipe 10 and the pair of the non-contact gap sensor 1 and the pipe 10 are formed at the bending position of the pipe 10. Adjust so that the gaps are almost equal,
Attach to frame 3. The position in the front-rear direction is adjusted by operating the personal computer 6 and driving the pinion gear to move the support base 13 on the transport rack 14. After that, a high-frequency current is passed from the transformer moving table 12 to the heating coil 11, and the tube 1
Heat 0. During heating of the pipe 10 and during bending, the signal detected by the non-contact gap sensor 1 is converted into a digital value by the converter 5 and is taken into the personal computer 6, and the displacement from the pair of sensors 1 is compared in the personal computer 6, The drive signals of the horizontal and vertical movement amounts and the vertical movement amount are converted into drive signals via the converter 5 and output to the vertical and horizontal adjustment drive device 7 so that the left and right gaps become equal.

The vertical / horizontal adjustment drive device 7 receives these signals, moves the transformer moving base 12 left / right and up / down on the support base 13, moves the frame 3 supported by the support arm 8, and is held thereby. Further, the heating coil 11 is moved up and down, and left and right to hold the gap t so as to be uniform in the circumferential direction. The non-contact gap sensor 1 is an eddy current type sensor, the measurement accuracy is ± 0.5 mm or less, and the measurement range is 1
5 mm or less is possible, and it is possible to cope with small radius bending with large gap displacement.

Further, while the tube 10 is being heated by the heating coil 11, thermocouples 2 are attached to the attachment members of the non-contact gap sensors 1 on both sides of the frame 3 in order to maintain the heating temperature at an appropriate value. The detected value is input to the converter 5, converted into a digital value, and then input to the personal computer 6, and heating by a high frequency current is controlled so that the temperature becomes a predetermined temperature.

According to such an embodiment, the gap displacement amount from the non-contact gap sensor 1 is taken into the personal computer 6 in real time during heating of the pipe 10, and the movement amount of the gap t is constantly uniformed. A signal is output to the up / down / left / right adjustment drive device 7, and the device 7 moves the transformer moving table 12 up / down, left / right, and moves the support arm 8 and the frame 3 held by the transformer moving table 12 to be fixed to the frame 3. Since the heating coil 11 is adjusted to control the gap t to be uniform, the bending of the tube 10 is automated, and the accuracy of the bent tube shape is improved by heating at a stable position.

[0017]

As described above in detail, in the present invention, the heating coil for heating the tube, the heating coil support device, the support device moving means, the pair of non-contact gap sensors, and the same sensor. The control means for controlling the moving means for adjusting the circumferential gap between the pipe and the heating coil by the detection signal of the above is provided. No need for monitoring,
Since automation and unmanned operation can be achieved, and stable heating is performed, the shape of the bent tube is smooth without wrinkles and the like, and the quality is improved.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a high-frequency heating coil position control device according to an embodiment of the present invention.

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is a perspective view showing a heating control state of a conventional high-frequency bending machine.

FIG. 4 is a view taken along the line BB of FIG.

FIG. 5 is a perspective view of a conventional tube after bending.

[Explanation of symbols]

 1 Non-contact gap sensor 3 Frame 5 Converter 6 Personal computer 7 Vertical / horizontal adjustment drive device 8 Support arm 10 Tube 11 Heating coil 12 Transformer moving stand 13 Support stand 14 Transport rack

Claims (1)

[Claims] 1. A heating coil for heating the same with a high-frequency current through a tube, a support device for the heating coil, and a support device attached to the support device, and the support device can be moved vertically and horizontally. Moving means and a pair of non-contact gap sensors arranged around the tube which is attached to the supporting device and which inserts the heating coil, and detection signals from the same pair of non-contact gap sensors, The heating coil includes a pair of non-contact gap sensors and a control unit that calculates the gap between the pipe and the pipe to a predetermined value and controls the amount of vertical and horizontal movement of the moving unit. A position control device for a high-frequency heating coil, wherein a gap between the pipe and the periphery thereof can be adjusted.