JPH10337609A - Method and apparatus for remotely operating internal bead cutting of steel pipe - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an optimum pressing force required for cutting an inner bead of a welded steel pipe to a cutting bite by remote control easily, to greatly increase the applicable range of the inner diameter of a welded steel pipe, and to provide a lower roller. To improve the transmission efficiency of the motion by the cylinder thrust to the inner surface and to make the cutting pressure of the inner bead uniform. SOLUTION: Cutting bit 11, guide roll 13A,
A cylinder 15 is disposed so as to be slidable in the axial direction within a hydraulic cylinder chamber 14 inside a steel pipe inner surface bead cutting device R provided with 13B, and 16 is an elastic body that can be extended and contracted so as to always urge it to return in a retreating direction. And a lower roller holder 19 having a lower roller 18 so as to be swingable around a fulcrum C via a link mechanism 17 connected to the cylinder 15. The lower roller 18 is rotated by introducing hydraulic pressure from an air-hydro booster type or equivalent hydraulic source into the hydraulic cylinder chamber 14 and pressing and sliding the cylinder 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to cutting an inner bead of a welded steel pipe such as an electric resistance welded pipe generated at an abutting welded portion when both side edges of a strip-shaped plate are heated and welded into a pipe shape by a work coil or the like. The present invention relates to a method and an apparatus for remotely operating an internal bead cutting of a steel pipe to perform the method.

[0002]

2. Description of the Related Art Conventionally, as a method for cutting an inner bead of a steel pipe of this kind, as disclosed in Japanese Patent Application Laid-Open No. 50-7192, a lower roll is fixed to one end of a cutting device body by using a laminated leaf spring. There is provided a technique in which a cutting tool is provided so as to be pressed against an inner surface of a pipe by an elastic force, and a necessary cutting force is applied to a cutting bit attached to a tip of a cutting device main body by a reaction force. Further, as disclosed in Japanese Patent Application Laid-Open No. 54-24390, a mandrel header is provided with a cantilever that is rotatable by expansion and contraction of a cylinder around a lever mounting pin, and is provided at the tip of the cantilever. There is provided a technique in which a lower roller is provided so as to be at the same position in the vertical direction as a cutting tool.

[0003] Further, as disclosed in Japanese Utility Model Publication No. 6-44569, a heart-shaped oscillating cam in which a projection of an oscillating body having a lower roller pivotally attached thereto comes into sliding contact with a tip end surface of a cylindrical sliding body. The lower roller is brought into sliding contact with the lower part of its inner surface corresponding to the diameter of the welded steel pipe via a sliding body and a swing cam by the spring force of a spring member, and the upper and lower upper and lower rollers are brought into pressure contact with each other. There is provided a technique of cutting a bite by cutting a bite into an inner bead by force.

[0004]

However, in the prior art, for example, in the case of the leaf spring system disclosed in Japanese Patent Application Laid-Open No. 50-7192, a pressure change occurs in accordance with the amount of deflection, and the motion is transmitted. There is a problem that the application range of the inner diameter of the welded steel pipe is extremely small because the efficiency is deteriorated.

Further, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 54-24390, it is very difficult to uniformly adjust the lower roller by a cylinder, and it is difficult to maintain an optimum pressing force on a cutting tool.

Further, the swing cam type disclosed in Japanese Utility Model Publication No. 6-44569 has a problem that a loss due to sliding friction and a jamming obstacle due to a foreign matter such as a scale are caused. Manufacturing of the mechanism itself was also difficult.

The conventional hydraulic cylinder type cutting device generally uses an electric pump type hydraulic pressure source, and as shown in FIG. 8, a stepwise change based on the hysteresis of the detector with respect to the elapsed time. A pressure difference occurs near the set pressure, and the pressure drops each time a leak occurs.Therefore, pressure cannot be adjusted steplessly at high pressure, making it impossible to ensure uniform cylinder thrust for the lower roller. As a result, there was a problem that a necessary optimum pressing force for the cutting tool could not be obtained.

In view of the above, the present invention has been made in view of the above-mentioned problems, and an optimum pressing force required for cutting an inner bead of a welded steel pipe against a cutting tool can be easily obtained by remote control. In addition, the remote control type internal bead cutting of the steel pipe which greatly increases the applicable range of the inner diameter of the welded steel pipe, improves the transmission efficiency of the motion by the thrust of the hydraulic cylinder to the lower roller, and makes the cutting pressure of the internal bead uniform. It is intended to provide a method and an apparatus therefor.

[0009]

In order to achieve the above-mentioned object, according to the present invention, one end of a mandrel rod 6 is fixed via a mandrel support bracket 7, and a cutting tool is attached to the other end of the mandrel rod 6. The internal bead cutting device body R of the steel pipe provided with 11 and two or more guide rolls 13A, 13B at the front and rear upper portions is disposed inside the welded steel pipe 1 to cut the inner bead of the welded steel pipe 1 by the cutting tool 11. In the remote operation type internal bead cutting method for steel pipes, the lower roller 18 is pressed and rotated by hydraulic pressure of an air-hydro booster type or an equivalent hydraulic source to press the inside of the welded steel pipe 1, and the reaction force of the lower roller 18 is applied to the cutting tool 11. On the other hand, the above-described problem was solved by applying an averaged cutting force.

At this time, a cylinder 15 is disposed so as to be slidable in the axial direction within a hydraulic cylinder chamber 14 provided inside the inner surface bead cutting device main body R, and a lower roller is connected via a link mechanism 17 connected to the cylinder 15. A lower roller holder having a pivot 18 is provided so as to be able to swing around a fulcrum C other than the linking part by the link mechanism 17,
The lower roller 18 is turned by pressing and sliding the cylinder 15 by introducing hydraulic pressure from an air-hydro booster type or an equivalent hydraulic source into the hydraulic cylinder chamber 14 and pressed against the inner surface of the welded steel pipe 1. The above-mentioned problem has also been solved by using a remotely operated inner bead cutting method for a steel pipe in which an averaged cutting force is applied to the cutting tool 11 by a reaction force.

Further, one end of the mandrel rod 6 is fixed via a mandrel support bracket 7, a cutting bit 11 for cutting the inner surface beat of the welded steel pipe 1 is provided on the other end of the mandrel rod 6, and two or more cutting tools are provided at the front and rear upper parts. In a remote operation type internal bead cutting device for steel pipes provided with guide rolls 13A and 13B, a cylinder 15 slidably disposed in an axial center direction in a hydraulic cylinder chamber 14 provided inside the inner bead cutting device main body R, A lower roller holder 19 having a lower roller 18 provided so as to be able to swing around a fulcrum C other than a connection part by the link mechanism 17 via a link mechanism 17 connected to the cylinder 15.
The hydraulic pressure is introduced into the hydraulic cylinder chamber 14 by an air-hydro booster type or equivalent hydraulic pressure source, and the cylinder 15 is pressed and slid to rotate the lower roller 18 to rotate the inner surface of the welded steel pipe 1. The above-mentioned problem was also solved by applying an averaged cutting force to the cutting tool 11 by the reaction force.

At this time, one of the upper guide rolls 13A (13B) is connected to the hydraulic cylinder chamber 1.
4. The lower roller 18 based on hydraulic pressure from an air-hydro booster type or equivalent hydraulic pressure source introduced into
In conjunction with the pressing operation on the inner surface of the welded steel pipe 1 due to the downward or upward rotation, the guide roll 13A (13
B) is rotated downward or upward, and is positioned at the upper or lower position of the cutting tool 11 while being pressed against the inner surface of the welded steel pipe 1 by the uniform pressing force. Also, the above-mentioned problem has been solved.

In the method and apparatus for remotely controlling the inside bead of a steel pipe according to the present invention, the hydraulic pressure of an air-hydro booster type or equivalent hydraulic source capable of fine pressure adjustment and capable of maintaining a constant pressure is shown in FIG. As shown in (1), the lower roller 18 is pressed and rotated to press against the inner surface of the welded steel pipe 1 while maintaining a constant pressure, and an averaged cutting force is applied to the cutting tool 11 by the reaction force. At this time, the optimum pressing force required for cutting the inner bead of the welded steel pipe 1 is remotely controlled with respect to the cutting tool.

As shown in FIG. 6, the link mechanism 17 connected to the cylinder 15 reduces the component of the cylinder thrust exerted on the point of application of the lower roller 18 via the fulcrum C on the forward stroke side of the cylinder 15. On the reverse stroke side, by increasing the component force of the cylinder thrust exerted on the point of application of the lower roller 18 via the fulcrum C, the total cylinder thrust is averaged, and the bias of the maximum and minimum pressing forces is prevented. .

At this time, one of the upper guide rolls 13A (13B) is connected to the hydraulic cylinder chamber 1.
When the hydraulic pressure of the air-hydro booster type or the equivalent hydraulic pressure source introduced into the inside 4 is increased, the lower roller 18 is pivotally protruded downward, and in conjunction with this pressing operation, the lower roller 18A is driven. Is rotated and retracted downward to position the cutting tool 11 closer to the upper side. On the other hand, if the oil pressure decreases, the lower roller 1
The guide roll 13A is pivotally retracted upward, and in conjunction with this pressing operation, the guide roll 13A is pivotally protruded upward to position the cutting tool 11 downward.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a welded steel pipe such as an electric resistance welded pipe is used for forming a strip-shaped iron plate P derived from an uncoiler (not shown) from a state of an open pipe through a forming process 2 for induction heating. The squeeze roll 4 is passed through the coil 3 while being heated and welded on both side edges in the longitudinal direction.
It is formed in the shape of a pipe by being passed between and being edge-welded on both side edges. Then, an outer bead generated in a protruding manner on the outer surface of the welded steel pipe 1 in the longitudinal direction at the time of the abutting welding is shaved off by the OD cutter 5.

An inner bead which is formed in a projecting manner on the inner surface in the longitudinal direction of the welded steel pipe 1 at the time of the above-mentioned joint welding is a mandrel which is introduced along the longitudinal direction of the welded steel pipe 1 at the time of the above-mentioned joint welding. It is cut off by a hydraulic inner bead cutting device R provided at the tip of the rod 6. In other words, one end of the mandrel rod 6 is fixed via the mandrel support bracket 7, and the other end of the mandrel rod 6 is provided with an impeder core (ferrite) 9 for induction heating inside via the connecting piece 8. A case 10 is provided so as to face the work coil 3,
An inner bead cutting device R is mounted at the tip of the impeder case 10.

A cutting tool 11 for cutting the inner beat of the welded steel pipe 1 is attached to the tip of the inner bead cutting device R via a holder 12, and two guides are provided at the front and rear upper portions of the inner bead cutting device R. Rolls 13A and 13B are rotatably pivoted.

As shown in FIGS. 3, 4 and 5, a hydraulic cylinder chamber 14 is bored inside the inner bead cutting device R so that it can slide in the axial direction inside. The cylinder 15 is disposed so as to be as shown in FIG. Also,
An elastic body 16 is stretchably wound around the cylinder 15 so as to always urge the cylinder 15 in the retreating direction, and a link mechanism 17 is connected to the tip of the cylinder 15 by a pin fulcrum method. A lower roller holder 19 holding a lower roller 18 is provided so as to be able to swing around a fulcrum C other than the linking part by the link mechanism 17 via the link mechanism 17.

As shown in FIG. 2, the hydraulic pressure of an air-hydraulic booster type equipped with a hydraulic gauge 20 or a hydraulic source equivalent thereto is supplied to the hydraulic cylinder chamber 14, for example, by a safety valve 21 and a hydraulic hose 22. The lower roller 18 is rotated downward by welding the cylinder 15 by hydraulic pressure against the return biasing force of the elastic body 16 and welding by welding. The cutting tool 11 is pressed against the inner surface of the steel pipe 1, and an average cutting force is applied to the cutting tool 11 by the reaction force.

At this time, as shown in FIGS. 3 and 4, the upper front guide roll 13A can be rotated through the holder 23 in the forward and reverse directions by the inner bead cutting device R.
The upper cylinder 2 is pivotally mounted on the upper portion, and a tapered portion 24 is provided at the rear end of the holder 23, and the upper cylinder 2 is inserted into an upper hydraulic cylinder chamber 25 communicating with the hydraulic cylinder chamber 14.
6 so that the upper cylinder 26 is slidably inserted and the upper cylinder 26 is always urged to return in the retreating direction.
A flexible elastic body 27 pre-pressed to an average pressure required for cutting is wound around 6, and a tapered portion 28 A of a slider 28 provided at the tip of the upper cylinder 26 is brought into contact with a tapered portion 24 at the rear end of the holder 23. The inner surface of the welded steel pipe 1 due to the downward rotation of the lower roller 18 based on the hydraulic pressure of an air-hydro booster type or an equivalent hydraulic source introduced into the hydraulic cylinder chamber 14 The guide roll 13A is pivotally urged downward in conjunction with the pressing operation to the lower side, so that the pressing force made uniform by the lower roller 18 above and below the inside of the welded steel pipe 1 and the upper front guide roll 13A. This presses the inner surface of the welded steel pipe 1.

Therefore, when the hydraulic pressure of the air-hydro booster type hydraulic source introduced into the hydraulic cylinder chamber 14 increases, the lower roller 18 pivotally projects downward. And at the same time, the guide roll 1
3A is pivoted and retracted downward to position the cutting bite 11 upward, while if the hydraulic pressure decreases, the lower roller 18 is pivotally retracted upward and this pressing is performed. In conjunction with the operation, the guide roll 13A is pivotally protruded upward, and the cutting tool 11A is rotated.
Is positioned downward. Here, it goes without saying that the upper rear guide roll 13B side may be made rotatable forward and backward via the holder 23.

As shown in FIG. 5, the holder 23 of the two guide rolls 13A is fixed, and the lower roller 18 and the upper front guide in the upper and lower portions of the inside of the welded steel pipe 1 are provided only by the link mechanism 17. Roll 13
It is possible to press the inner surface portion of the welded steel pipe 1 by the pressing force uniformed with A.

Next, an example of the use of the present invention will be described.
For example, as shown in FIG. 1, a strip-shaped iron plate P derived from an uncoiler (not shown) is passed through a forming step 2 from an open pipe state to a work coil 3 for induction heating, and both side edges in the longitudinal direction thereof Is passed between the squeeze rolls 4 while being heated and welded, and the both side edges are butted and welded to form the welded steel pipe 1 in a pipe shape.

An outer bead generated in a projecting manner on the outer surface of the welded steel pipe 1 in the longitudinal direction at the time of the above-mentioned joint welding is shaved off by the OD cutter 5. In addition, the inner bead generated in a protruding manner on the inner surface of the welded steel pipe 1 in the longitudinal direction at the time of the abutment welding is used for the mandrel rod 6 introduced along the longitudinal direction of the welded steel pipe 1 at the time of the abutment welding. It is cut off by a hydraulic inner bead cutting device R provided at the tip.

At this time, the link mechanism 17 connected to the cylinder 15 causes the lower roller 1 via the fulcrum C on the forward stroke side of the cylinder 15 as shown in FIG.
8 lowers the force of the cylinder thrust exerted on the point of action, and the lower roller 1 via the fulcrum C on the reverse stroke side.
By increasing the component force of the cylinder thrust exerted on the eight action points, all cylinder thrusts are averaged, and deviation of the maximum and minimum pressing forces is prevented. Thus, if the oil pressure is constant, the cutting pressure of the inner bead is always made uniform.

The upper front guide roll 13A
If the hydraulic pressure of an air-hydro booster type or an equivalent hydraulic source introduced into the hydraulic cylinder chamber 14 increases, the lower roller 18 is pivotally protruded downward, and this pressing operation is In conjunction with this, the guide roll 13A is rotated and retracted downward, and positions the cutting tool 11 upward. On the other hand, when the hydraulic pressure decreases, the lower roller 18 is pivoted and retracted upward, and in conjunction with this pressing operation, the guide roll 13A is pivotally projected upward and the cutting tool 1A is rotated.
1 will be positioned downward.

[0028]

The present invention is configured as described above.
In particular, the lower roller 18 is pressed and rotated by hydraulic pressure from an air-hydro booster type or equivalent hydraulic source to press against the inner surface of the welded steel pipe 1, and the cutting tool 1
Since an average cutting force is applied to the welding steel pipe 1, an optimum pressing force required for cutting the inner bead of the welding steel pipe 1 can be easily obtained by remote control on the cutting tool 11. Can be significantly increased from the thin-walled tube to the thick-walled tube.

Further, in each case, an operation such as oxygen blowing is not required, and the productivity can be greatly improved. Especially,
With the addition of a cutting tool vertical positioning function, the cutting depth of the inner bead can be set remotely, which is extremely effective in reducing setup time and improving material yield. Furthermore, even if a slight leak occurs in the hydraulic circuit, the constant pressure can be maintained at all times, and there is an advantage that quality is improved.

In addition, the cylinder 15 is provided slidably in the axial direction within a hydraulic cylinder chamber 14 provided inside the inner surface bead cutting device main body R, and the link is provided via a link mechanism 17 connected to the cylinder 15. Lower roller holder 1 having lower roller 18 provided so as to be able to swing around fulcrum C other than the link by mechanism 17
9 by introducing hydraulic pressure from an air-hydro booster type or an equivalent hydraulic source into the hydraulic cylinder chamber 14 and pressing and sliding the cylinder 15 against the return biasing force of the elastic body 16. By rotating the lower roller 18 and pressing it against the inner surface of the welded steel pipe 1,
An average cutting force is applied to the cutting tool 11 by the reaction force, so that the transmission efficiency of the motion by the thrust of the cylinder 15 to the lower roller 18 is improved and the cutting pressure of the inner bead 18 is made uniform. No loss due to sliding friction as seen in the conventional cam type, eliminates obstacles for foreign matter such as scale to be caught,
The manufacturing process of the cutting device itself can be simplified.

At this time, one of the upper guide rolls 13A (13B) is connected to the hydraulic cylinder chamber 1
4. The lower roller 18 based on hydraulic pressure from an air-hydro booster type or equivalent hydraulic pressure source introduced into
In conjunction with the pressing operation on the inner surface of the welded steel pipe 1 due to the downward or upward rotation, the guide roll 13A (13
B) is rotated downward or upward, and the cutting tool 11 is positioned at the upper position or the lower position while being pressed against the inner surface of the welded steel pipe 1 by a uniform pressing force. The stroke range for positioning the cutting tool 11 up and down can be greatly expanded, and the applicable range of the inner diameter of the welded steel pipe 1 can be made much larger from the thin-walled pipe to the hardened pipe.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a cross-sectional view of an inner bead cutting device having a cutting tool vertical positioning function.

FIG. 4 is an enlarged sectional view of an inner bead cutting device having a cutting bit up / down positioning function.

FIG. 5 is a cross-sectional view of an internal bead cutting device showing another embodiment of the present invention.

FIG. 6 is a conceptual diagram illustrating the operation principle of the link mechanism of the present invention.

FIG. 7 is a graph showing a pressure-time relationship of the air-hydro booster type hydraulic cylinder mechanism of the present invention.

FIG. 8 is a graph showing a pressure-time relationship of a conventional electric pump type hydraulic cylinder mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Welded steel pipe 2 ... Forming process 3 ... Work coil 4 ... Squeeze roll 5 ... OD cutter 6 ... Mandrel rod 7 ... Mandrel support bracket 8 ... Connection piece 9 ... Impeder core 10 ... Impeder case 11 ... Cutting tool 12 ... Holder 13A, 13B ... guide roll 14 ... hydraulic cylinder chamber 15 ... cylinder 16 ... elastic body 17 ... link mechanism 18 ... lower roller 19 ... lower roller holder 20 ... hydraulic gauge 21 ... safety valve 22 ... hydraulic hose 23 ... holder 24, 28A ...
Tapered part 25 ... Upper hydraulic cylinder chamber 26 ... Upper cylinder 27 ... Elastic body 28 ... Slider R ... Inner surface bead cutting device P ... Strip iron plate

Claims (4)

[Claims] At least one end of a mandrel rod is fixed via a mandrel support bracket, and an inner bead cutting device body of a steel pipe having a cutting bite at the other end of the mandrel rod and two or more guide rolls at front and rear upper parts is welded. In a remote-controlled inner bead cutting method of a steel pipe in which an inner bead of a welded steel pipe is cut by the cutting tool by arranging the inner roller inside the steel pipe, the lower roller is pressed and rotated by hydraulic pressure of an air-hydro booster type or an equivalent hydraulic source. And pressing the inner surface of the welded steel pipe against the inner surface of the welded steel pipe, and applying an averaged cutting force to the cutting tool by the reaction force. 2. A lower roller holder having a lower roller through a link mechanism connected to the cylinder, wherein the cylinder is slidably disposed in an axial direction within a hydraulic cylinder chamber provided inside the inner bead cutting device main body. By being provided so as to be able to swing around a fulcrum other than the linking part by the link mechanism, by introducing hydraulic pressure from an air-hydro booster type or equivalent hydraulic source into the hydraulic cylinder chamber, and pressing and sliding the cylinder 2. The remote-operated internal bead cutting of a steel pipe according to claim 1, wherein the lower roller is rotated and pressed against the inner surface of the welded steel pipe, and the reaction force exerts an averaged cutting force on the cutting tool. Method. 3. One end of a mandrel rod is fixed via a mandrel support bracket, a cutting bit for cutting an inner surface beat of a welded steel pipe is provided at the other end of the mandrel rod, and two or more guide rolls are provided at upper front and rear ends. In a remote operation type internal bead cutting device for a steel pipe, a cylinder slidably disposed in an axial direction in a hydraulic cylinder chamber provided inside the inner bead cutting device main body, and a link mechanism connected to the cylinder via a link mechanism connected to the cylinder. A lower roller holder having a lower roller provided so as to be capable of swinging around a fulcrum other than a connecting portion by a mechanism, and introducing hydraulic pressure by an air-hydro booster type or an equivalent hydraulic source into the hydraulic cylinder chamber. And press and slide the cylinder to rotate the lower roller to weld the steel. A remote-operated internal bead cutting apparatus for steel pipes, wherein the apparatus is pressed against the inner surface of a pipe, and imparts an averaged cutting force to the cutting tool by the reaction force. 4. The one of the upper guide rolls is adapted to turn the lower roller downward or upward based on hydraulic pressure from an air-hydro booster type or equivalent hydraulic source introduced into the hydraulic cylinder chamber. In conjunction with the pressing operation on the inner surface of the welded steel pipe by the movement, the guide roll is rotated downward or upward, and pressed against the inner surface of the welded steel pipe by the uniform pressing force, while the upper position of the cutting tool or 4. A method and an apparatus for remotely operating an internal bead cutting of a steel pipe according to claim 1, wherein the method is adapted to perform positioning to a lower position.