JP2004330199A - Method and apparatus for selecting and rejecting defective steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for selecting and rejecting a defective steel pipe by which the erroneous detection of the defective steel pipe in a steel pipe producing line can be reduced and the running cost can be reduced without causing contamination and flaw in the pipe. <P>SOLUTION: The method for selecting and rejecting the defective steel pipe comprises: a process of attaching a hitting mark with a mechanical marking device 1 to a designated portion with tracking of the steel pipe during carrying after pipe-making; a process of detecting the hitting mark 5 by detecting the flaw on the plurality of pipes 12 composed of the steel pipes through the process with a flaw detecting instrument 2; and a process of rejecting the pipe 13 having the hitting mark selected with the detection from a product carrying system 4 with a rejection device 3. The mechanical marking device is provided with: a head part 40 dropped down and collided against part; a fluid-cylinder 41 for holding the head part, a buffering part 42 for reducing the dropping speed of the head part; and a pipe hold-down part 43 for holding down the pipe at the colliding time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for selecting and rejecting defective steel pipes, which are suitable for selecting and rejecting defective quality products in a production line for steel pipes such as welded pipes, seamless pipes, and forged pipes.
[0002]
[Prior art]
The steel pipe production line is divided into two processes, a pipe production line and a refinement line. The pipe making line consists of lines for forming, welding, cutting, etc., if the pipe to be welded is a welded pipe, the line for heating, forming, cutting, etc., if it is a forged pipe, and the heating, if it is a seamless pipe. And lines for drawing and rolling.
[0003]
Regarding poor quality parts on the production line, for example, if it is a forged pipe, poor quality during welding (cold welding: low welding temperature, excessive melting: high welding temperature, end face scale biting, etc.) or flaws during transportation etc. However, the former can be prevented to a considerable extent by controlling the welding temperature, or it can be detected online by installing flaw detection equipment immediately after forming and welding (outside of the squeeze device). Is possible (for example, Patent Document 1).
[0004]
In terms of quality control, it is generally known to reject defective quality parts detected online online, or to reject them on the production line after marking them online, and then reject them based on the results of the marching in the refining line. ing. However, the former method is disadvantageous in that the processing speed of the pipe-making line is generally higher than that of the refinement line, and the reject device becomes large-scale. There are many. As for the latter method, a method of performing marking with a paint has been conventionally implemented. For example, in the pipe forming line of a normal ERW pipe manufacturing plant, a defective joining portion is detected using an online ultrasonic flaw detector on the exit side of the squeezing device, and based on the result, the welding temperature is controlled, and the welding temperature is controlled. The position of the defective joint of the pipe (steel pipe to be processed in the line) is tracked, the paint is marked on the defective joint by the paint marking device installed on the hot saw entry side, and the marked paint is applied to the refinement line. In the inspection zone, an operator visually detects the pipe, and pulls out the pipe with the detected paint marking (rejects it as a downgraded product). In addition, it is difficult to use the tracking information in the pipe making line in the refining line in which the transport mode is different. In the transportation and processing in the refining line, the passing process is complicated (for example, the horizontal holding process, the removal of the inspection pipe may be performed in the middle), and therefore, a large-scale process is required to complete the tracking. Investment is required.
[0005]
[Patent Document 1]
JP-A-9-141331
[Problems to be solved by the invention]
However, the defective product selection / rejection method of performing on-line paint marking in a pipe production line and visually detecting the marking portion in a refining line in a later process has the following problems.
1) When an operator visually detects the marked paint in the inspection zone of the refinement line, if a plurality of pipes are lined up in the inspection zone, it is difficult to find the paint on the underside of the pipe, and a detection error occurs.
[0007]
2) If the marked paint is removed by rubbing with a roll or the like when passing the pipe through a straightening machine arranged at the entrance of the adjustment line, it is difficult to find it in the inspection zone of the adjustment line, and a detection error occurs. .
3) When marking with paint on the pipe making line or cooling bed, the scattered paint adheres and accumulates on transport devices such as rollers, troughs, and screw conveyors. Problems may occur.
[0008]
4) There is also a cost problem that the paint cost is considerably large as the running cost. Incidentally, paints for hot materials are generally expensive. For example, in the above-mentioned ERW pipe manufacturing plant, the cost of paints has sometimes been about 1000 yen per ton of product pipe.
The present invention solves the above-mentioned problems of the prior art, and can reduce detection errors of poor quality pipes in a steel pipe production line, do not cause dirt and scratches on the pipes, and reduce the running cost. And to provide facilities.
[0009]
[Means for Solving the Problems]
The present invention that has achieved the above object is the following method of the present invention and equipment of the present invention.
The method of the present invention comprises the steps of: making a dent at a designated site by tracking the steel pipe during transportation after pipe making; detecting the dent by flaw-detecting a plurality of pipes made of the steel pipe after the step; And removing the pipe with dents from the product conveying system.
[0010]
The equipment of the present invention is a mechanical marking device that makes a dent at a designated site by tracking the steel pipe during transportation after pipe making, and detects the dent by flawing a plurality of pipes made of the steel pipe that has exited the mechanical marking device. A rejection device for selecting and rejecting defective steel pipes, comprising: a flaw detection device for detecting; and a reject device for rejecting a pipe having a dent due to the detection from a product transport system.
[0011]
In the equipment of the present invention, the mechanical marking device is configured such that a head unit that falls and collides with a pipe, a fluid cylinder that holds the head unit, a buffer unit that reduces the falling speed of the head unit, And a pipe holding part for holding the pipe.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The method of the present invention has the following first to third steps. The equipment of the present invention is suitable equipment for use in carrying out the method of the present invention. For example, as shown in the plan view of FIG. 1, the mechanical marking device 1 used in the first step and the mechanical marking apparatus 1 used in the second step And a reject device 3 used in the third step.
[0013]
The first step is a step of using the mechanical marking device 1 to make a dent on a designated portion by tracking of the steel pipe 10 being conveyed in the direction 11 of the passing material after pipe making. Here, the designated part by the tracking is a part in the longitudinal direction of the steel pipe where it has been confirmed that a defect has occurred upstream, and the part is marked by the tracking from the time of the confirmation and the denting execution point (mechanical marking device) (1 disposition point) is measured, and at this timing, the execution of a dent on the downstream side is designated. The means for performing the tracking may be constituted by a general technique for tracking a specific position of the continuous conveyed material. The mechanical marking device 1 is arranged on the pipe forming line 30 and, if it can make a dent on the steel pipe 10 in response to the designated site notification signal 20 by tracking sent from the upstream, its configuration Is not particularly limited, but a drop weight type device is preferable in that the device configuration can be simplified. This will be described later.
[0014]
In the prior art, the paint was applied to the designated portion, which caused the problems 2) to 4). On the other hand, in the present invention, the dents were formed instead of the paint, and the problems 2) to 4) occurred. Absent.
The second step is a step in which the plurality of steel pipes 12 having undergone the first step are inspected using the flaw detector 2 to detect the dents. Thus, even if the position of the dent is below the pipe, the presence of the dent can be detected, so that the problem 1) does not occur. The configuration of the flaw detector 2 is not particularly limited, and for example, any of a magnetic saturation type eddy current flaw detector manufactured by Hara Denshi Sokki and an ultrasonic flaw detector manufactured by Mitsubishi Electric Corporation can be preferably used.
[0015]
Between the first step (or the mechanical marking device 1) and the second step (or the flaw detection device 2), a step not included in the constituent requirements of the present invention (as long as the dent is not eliminated) ( Other steps) or an apparatus (other apparatus) may or may not be interposed as necessary. Such other steps (or other devices) include, for example, a cutting step (or a cutting machine) for cutting the steel pipe 10 to a predetermined length, a straightening step (or a straightening machine) for correcting the bending of the steel pipe 10, and the like.
[0016]
In the third step, the pipe (the punctured pipe 13) determined to have the dent 5 by the detection using the flaw detector 2 in the second step is converted into, for example, a dent detection signal 21 from the flaw detector 2. Accordingly, this is a step of using the reject device 3 to remove the product from the product transport system 4 in, for example, the reject direction 15. Needless to say, the pipe determined to have no dent (the dentless pipe 14) is stored in the product transport system 4. As a result, the dented pipe 13, that is, the pipe having the poor quality portion, is reliably rejected, so that the rate of oversight of the defective pipe can be significantly reduced. The configuration of the reject device 3 is not particularly limited, and for example, a long product kicking device widely used in a cooling bed or the like can be preferably used.
[0017]
Between the second step (or the flaw detection device 2) and the third step (or the reject device 3), the other step (or the other apparatus) may or may not be interposed as necessary, either. However, in the case of intervening, the other intervening step must not disturb the sign relationship between the discrimination signal 15 and the actual pipe discriminated by the signal to make it unclear. In order to eliminate the concern that the sign relationship becomes unclear, the third step (or the reject device 3) is arranged immediately after the second step (or the flaw detection device 2) as shown in FIG. Is preferred.
[0018]
Next, the device of the falling weight type will be described. FIGS. 2A and 2B are front views (a) and (b) and a partial side view (c) showing an example of a falling weight type mechanical marking device which can be preferably used in the facility of the present invention. FIG. 2A shows a state during standby, and FIG. 2B shows a state during drop. As shown in FIG. 2, the mechanical marking device 1 includes a head unit 40 that falls and collides with the pipe 10, a fluid cylinder 41 that holds the head unit 40, and a buffer unit that reduces the falling speed of the head unit 40. 42, and a pipe holding portion 43 for holding the pipe 10 at the time of the collision.
[0019]
The head section 40 is provided with a metal tip 40a for hitting the pipe 10 to make a dent at the tip of a rod-shaped head rod 40M, and the rear end of the head rod 40M is, for example, a cylinder rod 41a of a fluid cylinder 41 composed of an air cylinder. The head rod 40M is vertically slidably attached to the support frame 44 by a head sliding support guide 45 formed of, for example, a bush. The head rod 40M is equipped with a counterweight 40b above a sliding portion with the head sliding support guide 45. When the head part 40 falls, the counter weight 40b presses the buffer part 42 made of, for example, a spring provided at the upper end of the support frame 44 and receives a reaction force from the buffer part 40, thereby reducing the falling speed of the head part 40. Slow down. The weight of the counterweight 40b is changed variously in advance, the head is dropped onto the dummy pipe, the falling speed is measured by a falling speed measuring device (not shown), and the dents attached to the dummy pipe are measured by the eddy current flaw detector. Detected and based on those results, the weight was set to give a drop speed that would provide the most detectable dent depth in a range that would not obstruct the tubing.
[0020]
Further, the head rod 40M is provided with a pipe pressing portion 43 at a position below a sliding portion with the head sliding support guide 45 and on both sides of the tip hardware 40a. At the same time that the tip hardware 40a hits the pipe 10, the pipe pressing portion 43 presses the pipe 10 to prevent the pipe 10 from jumping up.
In addition, the mechanical marking device 1 has an optical sensor 46 for detecting that the pipe 10 is present at a position immediately below the tip metal fitting 40a in order to prevent a blank hit. The fluid cylinder 41 pushes out the cylinder rod 41a and drops the head unit 40 only when the designated part notification signal 20 by tracking (see FIG. 1) and the pipe 10 presence detection signal from the optical sensor 46 are simultaneously received. After the metal fitting 40a hits the pipe 10, the fluid cylinder 41 immediately retracts the cylinder rod 41a to return the head unit 40 to the standby position.
[0021]
【Example】
The present invention was implemented in the electric resistance welded pipe production line. Heretofore, in this production line, defective parts have been sorted out and rejected by visually detecting the specified portion marked with paint in the pipe making line on the cooling bed of the refining line. The applicable objects are SGP, STKM, and steel pipes for automobiles with an outer diameter of 21.7 to 114.3 mmφ and a wall thickness of 1.8 to 7.5 mm. The steel type used is C: 0.6 to 4.5 mass%. It contains. In the embodiment of the present invention, the mechanical marking device shown in FIG. 2 is disposed on the upstream side of the existing cutting machine near the end of the pipe-making line, and the mechanical marking device shown in FIG. After making a mark, the pipe sent to the refining line after cutting is passed through the eddy current flaw detector installed on the cooling bed entry side to determine whether or not there is a dent. The deployed kicking device kicks out of the product transport system to make scraps, and only the non-dented pipes are stored in the product transport system. In the mechanical marking device, the metal tip was made of hot tool steel (JIS SKD61 class), the air cylinder was used for the fluid cylinder, and the buffer was made of a spring.
[0022]
As a result, the defect occurrence rate in the ultrasonic flaw detection of the strictly used leading pipe performed in the subsequent process is significantly reduced from 1.2% in the past to 0.2%, and it is possible to effectively prevent defective product detection errors. confirmed. In addition, by eliminating the visual detection of the marking, labor saving of 2 persons / direct was achieved. In addition, since paint is not used for marking, the problem of stains and flaws on pipes due to peeling of paint has been solved, and the running cost of paint has been eliminated.
[0023]
【The invention's effect】
According to the present invention, a method of detecting dent markings by eddy current flaw detection instead of the conventional method of visually detecting paint markings in the selection and rejection of defective products in a steel pipe production line is employed. An excellent effect is obtained that it is possible to reduce detection errors of defective tubes at low cost without causing flaws.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of an embodiment of the present invention.
FIG. 2 is a front view (a), (b) and a partial side view (c) showing an example of a falling weight mechanical marking device that can be preferably used in the facility of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mechanical marking device 2 Flaw detection device 3 Reject device 4 Product transfer system 5 Dent 10 Steel pipe (pipe)
DESCRIPTION OF SYMBOLS 11 Direction of passing material 12 Pipe 13 Marked pipe 14 Non-marked pipe 15 Reject direction 20 Notification signal of designated part by tracking 21 Signal of discrimination of presence or absence of dent 30 Pipe forming line 31 Refinement line 40 Head part 40a Tip hardware 40b Counter Weight 40M Head rod 41 Fluid cylinder (Example: Air cylinder)
41a Cylinder rod 42 Buffer part (example: spring)
43 Pipe holder 44 Support frame 45 Head sliding support guide (Example: bush)
46 Optical Sensor

Claims (3)

A step of making a dent at a designated site by tracking of the steel pipe during the transportation after pipe making, a step of detecting the dent by flaw-detecting a plurality of pipes made of the steel pipe having passed through the step, and having a dent by the detection. Removing the used pipe from the product conveying system. A mechanical marking device that makes a dent at a designated site by tracking of a steel pipe during pipe making and transport, and a flaw detection device that detects the dent by flaw-detecting a plurality of pipes made of a steel pipe that has exited the mechanical marking device. And a rejecting device for rejecting a pipe with a dent due to the detection from a product conveying system. A head section, wherein the mechanical marking device falls and collides with the pipe, a fluid cylinder holding the head section, a buffer section for reducing the falling speed of the head section, and a pipe holding section for holding the pipe at the time of the collision 3. The equipment for selecting and rejecting defective steel pipes according to claim 2, comprising:

Images