JPS5835373Y2 - Monitoring device for cutting tool for inner bead of welded pipe - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for monitoring the cutting status of a cutting tool for cutting and removing the inner bead of a welded pipe such as an electric resistance welded pipe or a submerged arc welded pipe.

The bead formed at the welded joint of the welded pipe is removed by cutting off both the inner and outer surfaces in order to smooth the inner and outer surfaces of the welded pipe and make the wall thickness constant.

This bead cutting and removal is done using a cutting tool.

Cutting defects may occur due to wear or breakage of the cutting tool.

It is easy to visually observe the bead cutting condition on the outer surface of the welded pipe immediately after cutting with the cutting tool, so when a cutting defect occurs, measures such as replacing the tool can be taken quickly. Bead cutting defects cannot be visually observed online, so the cutting status can be monitored off-line by visually inspecting the inner surface after cutting to a predetermined length after forming the pipe, or by palpating it with your fingers. The reality is that there are cases where prompt responses cannot be taken and a large number of defective products are produced.

Therefore, early detection of cutting defects on the inner bead has been a major issue from the standpoint of process control and improving yield.

By the way, as a device that can monitor the cutting status of the inner bead online, there is a device that uses ultrasonic waves.
72 are known.

This involves immersing the test tube in water, injecting ultrasonic waves from the outside of the test tube toward the bead cutting area, and detecting surface echoes from the outside and reflected echoes from the inside, which remain uncut. This method attempts to measure the thickness of the remaining bead, but the equipment costs are high (and installing such a costly device on a pipe production line causes too many layout problems and is impractical).

There are also devices that use ultrasonic waves to detect during cold working, which is done to correct the outer diameter of the pipe or adjust the roundness after pipe making, but these devices also detect problems such as internal bead cutting defects, material defects, welding defects, etc. It is not easy to distinguish between the two, making it impossible to respond quickly.

The present invention was developed in view of the above circumstances, and focuses on the fact that the cause of internal bead cutting defects is a broken cutting tool, and indirectly detects the occurrence of internal bead cutting defects from the detection of broken cutting tools. An object of the present invention is to provide a monitoring device for cutting a bead on the inner surface of a welded pipe.

The present invention will be described in detail below with reference to drawings showing embodiments thereof.

FIG. 1 is a suggested vertical cross-sectional view of a monitoring device for a cutting tool for cutting an inner bead of a welded pipe according to the present invention (hereinafter referred to as the device of the present invention), shown above with an electric resistance welded pipe P that is welded and moved in the direction of the white arrow; FIG. 2 is an enlarged sectional view taken along the line ■-■ in FIG. 1.

The electric resistance welded pipe P is an open pipe made by bending a metal strip from a U-shape into a substantially cylindrical shape, and the opposing edges are welded together by selectively heating the opposing edges and applying lateral pressure, By this welding, beads (only the inner bead B is shown) are formed on the inner and outer surfaces of the tube.

In this electric resistance welded pipe P, there is a part where the welding is performed (
A mandrel M is inserted using the gap between opposing edges of the open pipe upstream of the welding point, and the mandrel M is inserted so that its axial direction is the same as the axial direction of the ERW pipe. It is supported at the base end on the open pipe side.

At a position near the tip of the mandrel M located downstream of the welding point, a cutting tool 1 for cutting and removing the inner bead B is removably attached to a tool holder 2 fixed to the mandrel M, and the tip of the tooth is It is supported horizontally so that it can swing slightly up and down.

Incidentally, outside the electric resistance welded pipe P (not shown), a cutting tool for cutting the external bead is provided at a suitable location before and after the cutting tool 1.

A bracket 11 for attaching a support roll 12 is provided closer to the tip of the mandrel M than the attachment position of the cutting tool 1.

The length of the support roll 12 is determined so as to contact the inner bottom surface of the ERW pipe P at a position closer to the proximal end of the mandrel M than the bracket 11, and the arm 13 passes through a hole formed on the lower surface of the mandrel M. The base end of the arm 130 is pivotally connected to the distal end of the arm 13. The support roll 120 is supported by the bracket 11 so as to be able to swing back and forth.

An air cylinder 10 with its piston rod 10a connected to the middle of the arm 13 is disposed directly below the position of the mandrel M where the tool holder 2 is disposed. is pressed against the inner bottom surface of the electric resistance welded tube P to support the cutting load of the arm 13 by the cutting tool 1.

No. 9 1, the main parts of the present device are arranged closer to the tip of the mandrel M than the bracket 11, that is, on the downstream side in the direction of movement of the electric resistance welding tube P.

That is, near the tip of the mandrel M, an appropriate length notch is cut out in the upper part of the mandrel M in both the circumferential and axial directions, and the channel-shaped receiving box 6 is fitted into this notch.

At least the top surface of this receiving box 6 is open, and a channel-shaped roll holder 4 whose external dimension is smaller than the internal dimension of the receiving box 6 is inserted from above the receiving box 6. An appropriate number of springs 8 are interposed between the outer bottom surface of the receiving box 6 and the inner bottom surface of the receiving box 6 to provide a floating elastic support for urging the roll holder 4 upward.

The side wall 6a of the receiver box 6 has a guide groove 6b facing the fir tree on the inner surface of the 6a.

6b are formed, and the side wall 4a of the roll holder 4,
4a guide pieces 4b of appropriate length protruding from the outer surface side, 4b
are slidably engaged in the guide grooves 6b, 6b, so that the roll holder 4 can only be moved up and down with respect to the receiving box 6 in a circular manner.

And between the side walls 4a and the upper part of 4a of the roll holder 4,
The barrel-shaped touch roll 3 is arranged so that the center of its circular surface in the axial direction faces the welded part 20 of the electric resistance welded pipe P, that is, faces the passage area of the bead part cut by the cutting tool 1.
It is supported horizontally so that it can rotate freely.

The dimensional specifications of the receiver box 6, roll holder 4, and touch roll 3, as well as the elastic dimensions of the spring 8, etc., are based on the touch roll 30 when the tip of the mandrel M is supported from below by the operation of the air cylinder 10. is in contact with the inner circumferential surface of the electric resistance welded tube P with no remaining inner bead B under an appropriate pressure, and is configured so that it can roll as the electric resistance welded tube P moves.

Flanges 5a, 5a are formed on the upper ends of the side walls 4a, 4a of the roll holder 4, and flanges 5a, 5a protrude outward. 3 are in rolling contact, an appropriate gap is provided between the lower surfaces of the D flanges 5a, 5a and the upper end surfaces of the side walls 6a, 6a of the receiving box 6.

Flange 5a. A vertical hole is formed at an appropriate position where 5a faces the upper end surface of side wall 6a y6a, and insulating sleeves γlb and γ1b are fitted into these holes, and furthermore, a rivet-shaped electrode 71a is inserted into this insulating sleeve. .

71a is fitted, and a lead wire 71 is attached to the upper end surface of the lead wire 71a.
c and 71c are welded, and the lead wires are drawn out of the electric resistance welded tube P through the mandrel M.

Electrodes γla are provided on the side walls 6a, 6a of the receiving box 6.

71a and rivet-shaped electrodes γ2ay7 facing each other.
2a is inserted so that it can move up and down, and its upper end is connected to the side wall 6a.
It is exposed from the upper end surface.

Electrode 72a. A set screw 72b is inserted from the outside of the hole into which the hole 72a is inserted.

72b are screwed together, and the inner end of the side wall and the electrode 72a,
The vertical positions of the electrodes 72a, 72a are fixed by contact with the electrodes 72a, and the lead wires γ2c2γ2c are connected to the outer ends of the side walls, and the lead wires 72c, 72c are also electrically connected through the mandrel M in the same manner as the lead wires 71c, 71c. It is a drawer to the outside of the sewing tube P.

When the cutting tool 1 breaks, the inner bead B reaches the area where the touch roll 3 is installed without being cut, so the touch roll 3
is pushed down together with the roll holder 4 against the elasticity of the spring 80, and due to the downward movement of the roll holder 4 at this time, the electrode 71a.

The electrode 72a is adjusted according to the generated height of the inner bead B so that the electrode 71a and the electrodes 72a, 72a are in contact with each other.

The amount of protrusion of 72a from the upper end surface of side walls 6a, 6a is limited.

This is due to the loose tightening of the setscrews 72b and 72b.
, 72a by adjusting and fixing the vertical positions.

The electrodes 71a, 71a and 72 facing each other in this way
a and 72a function as a sensor that detects downward movement of the touch roll 3 by more than a certain amount, but this sensor does not rely on such a counter electrode, but can be made by arbitrarily selecting a photocoupler, a limit switch, etc. Bye.

The lead wires 71c, 71c and 72c.

The electric circuit connected to 72c is constructed as shown in FIG.

A parallel circuit of a sensor S1 constituted by opposing electrodes 71c and 72c on one side and a sensor S2 constituted by opposing electrodes γ1c and 72c on the other side is connected to a warning light 30, a switch 31. It is connected in series with the series circuit of battery 32.

Note that the electrodes 72a, 72a are not particularly insulated from the receiving box 6 and therefore from the mandrel M, so the lead wire 72c is used.

The electrodes 72a, 72a and the cathode of the battery 32 may be connected using the receiving box 6 and the mandrel M without using the electrode 72c.

Further, the switch 31 is a switch that is closed in conjunction with the air cylinder 10 when it is operated.

Now, the proposed device uses the electrodes according to the height of the inner bead B. The vertical positions of 2a and 72a are adjusted and fixed in advance before use.

Then, when the air cylinder 10 is activated to start cutting the inner bead B with the cutting tool 1, the touch roll 3 will roll onto the surface to be cut as long as the cutting tool 1 is cutting the inner bead B normally without breaking. Therefore, the roll holder 4 is in contact with the electrode r1a, 71a and the electrode 72a.

72a are separated by an appropriate length, the warning light 30 is not energized even though the switch 31 is closed in conjunction with the operation of the air cylinder 10.

However, when the cutting tool 1 breaks and the inner bead B is not cut and reaches the touch roll 3 placement position, and the touch roll 3 and therefore the old roll holder 4 are pushed down, the electrode 71
a, 71a and electrode 72a.

72a, the warning light 30 lights up, and the observer can immediately detect the breakage of the cutting tool 1.

Therefore, by promptly taking measures such as replacing the cutting tool 1, it is possible to prevent the occurrence of defective products due to internal bead cutting in the future.

In this manner, the device of the present invention can immediately detect a broken cutting tool, so it can indirectly but reliably detect a bead cutting defect.

By appropriately determining the upper and lower positions of the electrodes 72a, 72a, it is possible to detect whether the cutting tool 1 has not broken or if the cutting ability has deteriorated due to wear caused by striking. be.

The device for reporting the contact between the button electrodes 71 a, 71 a and the electrodes γ2 ay γ2 a or the detection of the downward movement of the touch roll 30 by other sensors is not limited to a warning light, but may be any suitable device such as a buzzer or a recorder. Of course.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a suggested vertical sectional view of the proposed device, Fig. 2 is an enlarged sectional view taken along the line ■-■ of Fig. 1, and Fig. 3 is an illustration of the alarm device. 1 is a circuit diagram conceptually showing an electric circuit. 1...Bite, 3...Touch roll, 71a, 72
a...electrode, 10...air cylinder, 30...warning light, P...- insulator tube, M...mandrel.

Claims (1)

[Scope of utility model registration request] It is located downstream in the direction of movement of the welded pipe from the cutting tool that cuts the inner bead of the welded pipe that is moved in the axial direction, faces the passage area of the part to be cut of the welded pipe by the cutting tool, and is in rolling contact with the part to be cut. The present invention is characterized by comprising: a touch roll that is pivotally supported; a sensor that performs a detection operation when the touch roll moves by a predetermined amount or more in a direction away from the inner surface of the welded pipe; and a device that notifies the detection operation of the sensor. A monitoring device for cutting tools for cutting the inner bead of welded pipes.