JPH0338013B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method and apparatus for monitoring a steel pipe upsetter.

[Background technology] In order to ensure joint strength at the pipe joint part of oil country tubular goods, that is, the threaded part of the pipe end, the upsetter is used to
A thickened section, that is, an upset section, is formed on the inner and outer surfaces of the tube end using an upset punch and a die. Figure 2 shows the temperature of the pipe end of steel pipe 1 at 1250°C.
FIG. 3 is a cross-sectional view showing an example in which an outer surface upset portion 2A, an inner surface upset portion 2B, and an inner and outer surface upset portion 2C are formed on the tube end after heating to a certain degree.

Conventionally, in the operation of the above-mentioned upset machine, after the shapes of the upset punch and die are determined based on the thickening schedule of the steel pipe, continuous operation similar to that of a press mechanism is carried out. In other words, in the conventional operation of a riser, for example, as described in Kobe Steel Technical Report Vol. 31, No. 1, the mechanical operation of the riser is set to the optimum condition, and then the operation is continued on the assumption that the condition is maintained. It is merely carrying out operations.

[Object of the Invention] An object of the present invention is to measure the load value applied to the setup punch and the amount of displacement of the setup punch during setup, and to monitor whether the setup is carried out normally.

[Structure of the Invention] The first aspect of the present invention is a method for monitoring a steel pipe upset that forms an upset portion by heating the end of a steel pipe, in which an upset load value applied to an upset punch and an amount of displacement of the upset punch are measured. Then, each of the above measured values is displayed as an actual load pattern and an actual displacement pattern, and the actual load pattern and actual displacement pattern are compared with a load reference pattern and a displacement reference pattern that are predetermined for an appropriate setup, and the quality of the setup is evaluated. It is designed to be judged.

A second aspect of the present invention is a monitoring device for a steel pipe upset that heats the tube end of a steel pipe to form an upset section, which is attached to the upset load acting surface of a punch holder equipped with an upset punch, and which is attached to the upset load application surface of a punch holder equipped with an upset punch. A load cell for measuring the setup load value, a carrier capable of interlocking with a punch holder equipped with an setup punch, and a linear scale for measuring the displacement of the setup punch, in which a carrier capable of interlocking with a punch holder equipped with an setup punch is coupled so as to be movable relative to the scale body; It has a storage device that stores the load measurement value and the displacement measurement value of the linear scale, and an XY plotter that displays the load measurement value and displacement measurement value stored in the storage device as an actual load pattern and an actual displacement pattern, respectively. This is how it works.

[Specific Description of the Invention] FIG. 1 shows an amplifier 10 to which the present invention is applied.
FIG. 2 is a perspective view schematically showing the whole. The upsetter 10 includes a crankshaft 11, a flywheel 12 that is integrated with the main shaft of the crankshaft 11 and connected to a motor (not shown), a connecting rod 13 that has one end connected to a crank pin of the crankshaft 11, and a connecting rod. a punch holder 15 connected to the other end of the punch holder 13 via a hydraulic cushion device 14; an upset punch 16 equipped on the punch holder 15;
It is comprised of a clamp jaw 17 that grips and holds the body portion 1A of the steel pipe 1, a die 18, a hydraulic cushion device 19 that supports the clamp jaw 17 and the die 18, and the like.

That is, the steel pipe 1 with the pipe end 1B heated to about 1250°C is fed horizontally to the upsetter 10, the pipe end 1B is stopped at a predetermined position relative to the clamp jaw 17 and the die 18, and the heated pipe end 1B of the steel pipe 1 is heated. When the body part 1A, which is a non-heated part, is inserted into the die 18 and firmly gripped by the clamp jaw 17, a motor (not shown) and a flywheel 1
A clutch interposed between 2 and 2 is connected,
The flywheel 12 starts rotating. The rotational torque of the flywheel 12 is transmitted to the punch holder 15 via the crankshaft 11, the connecting rod 13, and the hydraulic cushion device 14, and the punch holder 15 performs one cycle of reciprocating motion in about 6 seconds. The steel pipe 1 is set up near the top dead center of the reciprocating movement of the punch holder 15, and the set-up punch 16
The process is completed within 0.6 seconds after contacting the pipe end 1B of the steel pipe 1. Upset punch 16 is die 18
Although it enters into the pipe end 1B of the steel pipe 1 inserted into the pipe, it does not reach into the body part 1A which is gripped by the clamp jaw 17. The steel pipe 1 that has been upset by the upper die 18 of the upsetter 10 may be upset completely in one shot, or may be upset a second time by the lower die 18. The former is called [1 heat, 1 shot], and the latter is called [1 heat, 2 shots]. However, if extremely thick processing is required, where the upsetting cannot be completed even with 1 heat and 2 shots, [2 heat, 3 shots] is used. As it is called,
It is necessary to reheat the steel pipe 1 and perform a third upset.

Here, the upsetter 10 includes a punch holder 15, an upset punch 16,
The shock acting on the clamp jaw 17 and die 18 can be absorbed by hydraulic cushion devices 14 and 19. The hydraulic cushion devices 14 of the punch holder 15 and the upset punch 16 play a particularly important role in the operation of the upset. That is, due to variations in the wall thickness and uneven thickness of the steel pipe 1, and errors in setting tools such as the upset punch 16 and the die 18, when the steel pipe 1 is set up, the die 18
In some cases, the die 18 may be underfilled, and in other cases, the die 18 may be overfilled, causing burrs to come out from the die 18. In extreme cases, the upsetter 10 may be damaged. Therefore, the hydraulic cushion device 1
When the oil pressure of the pump 4 reaches a certain pressure value, the relief valve 20 is opened to relieve the hydraulic fluid of the hydraulic cushion device 14, thereby making it possible to suppress further advancement of the upset punch 16.

FIG. 3 shows the deformation process of the steel pipe 1 by the upsetter 10. The steel pipe 1 receives a compressive force from the upset punch 16 and initially buckles, bringing the outer surface of the steel pipe 1 into contact with the inner wall surface of the die 18.
Thereafter, the steel pipe 1 undergoes thickening deformation while being restrained between the upset punch 16 and the die 18, and the contact length between the upset punch 16 and the die 18 increases. At this stage, if the metal flow in the thickness direction of the material of the steel pipe 1 is large, wrinkles will not be formed on the inner and outer surfaces of the upset part 2, but if the buckling deformation progresses significantly, As shown in FIG. 2, wrinkles remain on the inner and outer surfaces of the upset portion 2.

Therefore, the inventor of the present invention detected the process of deformation of the steel pipe 1 as described above by the upsetter 10 based on the load value applied to the upset punch 16 and the amount of deformation of the upset punch 16, and patterned the deformation process of the steel pipe 1 as described above. This makes it possible to judge whether the upset is good or bad.

FIG. 5 is a perspective view showing a load measuring means for measuring the load value applied to the upset punch 16. Reference numeral 21 denotes a load cell as a load measuring means that can directly measure the load value applied to the upset punch 16. The load cell 21 is attached to the back surface of the punch holder 15, that is, the surface on which the upset load is applied, and measures the load value applied to the upset punch 16 during upset while being interposed between the punch holder 15 and the hydraulic cushion device 14. possible. The load cells 21 are of a desk type, with a mechanical strength of 400 TON, and because the offset punch 16 has an unbalanced load, there is one each behind the axis of the upper and lower punches 16, so there are two in total. It is assumed that the number of units is used. The punch holder 15 moves back and forth about 700 mm during upsetting, and is located in a bad environment due to splashing of cooling water and hot lubricant due to hot working, and the signal output cable 2 of the load cell 21
Although it is difficult to secure wiring space for 2, the selection of signal output cable 22, connection method,
By strengthening the seal and providing a groove for taking out the cable on the side of the hydraulic cushion device 14, it becomes possible to attach the load cell 21 to the punch holder 15 without impairing maintenance and inspection performance.

It is also possible to consider using a load measuring means that makes it possible to indirectly measure the load value applied to the upset punch 16 by measuring the back pressure of the hydraulic cushion device 14 with a strain gauge type high-speed response pressure gauge. However, in this case, since the back pressure of the hydraulic cushion device 14 passes through the cushion cylinder and the hydraulic piping, the steel pipe 1
It is not possible to observe subtle changes in load, such as buckling, and it is not possible to observe the back pressure of the hydraulic cushion device 14 after the relief valve 20 is activated. Therefore, the inventor has developed a hydraulic cushion device 1.
A load cell 21 is attached to a punch holder 15 located closer to the upset punch 16 than the load cell 21.
was used as a load measuring means as described above.

FIG. 6 shows a linear scale 23 as a displacement measuring means for measuring the amount of displacement of the upset punch 16.
FIG. In other words, non-contact measurement is preferable as a means of measuring displacement, but considering that the wiring space is narrow and the device is installed in an atmosphere containing water droplets and oil smoke due to hot working, the measurement accuracy must be ± A 0.1 mm magnetic linear scale 23 was selected. 24 is a scale body, 25 is a magnetic tape, 26 is a carrier, 27 is a carrier head, 2
8 is a signal extraction cable. In addition, 29 is a connecting arm fixed to the hydraulic cushion device 14, 30 is a pin fixed to the carrier 26, and the engagement of the connecting arm 29 and the pin 30,
The displacement of the setup punch 16 can be transmitted to the carrier 26.

That is, in the case of the linear scale 23, the carrier 26, which can be interlocked with the punch holder 15 provided with the setup punch 16, is attached to the scale body 2.
4 so as to be movable relative to each other.

Figure 7 shows the load cell 21 and linear scale 2.
FIG. 3 is a control circuit diagram of a monitoring device using No. 3.

After the measured values of the two load cells 21 are added together, they are amplified in an amplifier 31, passed through a high-speed A/D converter 32, and transmitted to a digital storage 33 using a large-capacity IC memory, where they are read. Furthermore, the measured values of the linear scale 23 are also stored in the digital storage 33 and read therein.

The sample values read into the digital storage 33 are transmitted to the microcomputer 34,
It can be displayed as an actual load pattern and an actual displacement pattern. Reference numeral 35 denotes a setting device, in which a load reference pattern and a displacement reference pattern for an appropriate upset are predetermined. The microcomputer 34 compares the actual load pattern with the load reference pattern of the setter 35 and also compares the actual displacement pattern with the displacement reference pattern of the setter 35 to determine whether the upset is good or not, and displays the determination result display 36. It can be displayed on

The reason why the digital storage 33 and microcomputer 34 are used instead of a high-speed computer in the above monitoring device is as follows.
That is, the upsetting is completed within one second at most after the upsetting punch 16 comes into contact with the end of the steel pipe 1 as described above. It is necessary to use a high-speed computer to collect and store phenomena that occur in an extremely short period of time in real time, and to determine patterns of their measured values. However, in actual operation, it is not necessary to complete the determination of the measured value pattern within one second when the upset is performed. Therefore, in the above monitoring device, the load cell 21 and the linear scale 2 are used in the digital storage 33 using a large capacity IC memory.
By reading each measurement value of 3 and then determining the measurement pattern using the microcomputer 34, it is possible to make the device smaller and more economical. Further, according to the monitoring device, the measured values once stored in the digital storage device 33 can be stored as needed.
It can be outputted as a visible measurement pattern to the XY plotter 38 via the D/A converter 37.

FIGS. 8, 9, and 10 are diagrams showing monitoring results by the monitoring device.

FIG. 8 shows an example in which the upset has been successfully completed. In this case, the setup specifications are as follows:
APIJ-55, outer diameter 2.7/8 inch (73.0 mm), wall thickness
5.51 mm, the heating temperature is 1260°C, the relief pressure of the hydraulic cushion device is 1.3 Kg/cm ² , and the grip pressure of the clamp jaw is 162 Kg/cm ² . In this setup, it is recognized that the cushion amount of the setup change is 30 mm, the load pattern is bell-shaped, and the peak load value is 100 TON. At this time, the upset steel pipe is naturally normal.

FIG. 9 is an example in which the relief pressure of the hydraulic cushion device is low. The setup specifications in this case are that the steel pipe is APIN-80, outer diameter 2.3/8 inches (60.3 mm), wall thickness 4.83 mm, and heating temperature 1250°C.
The relief pressure of the hydraulic cushion device is 0.6Kg/cm ² ,
The grip pressure of the clamp jaw is 160Kg/ ^cm2 . In this upset, the relief pressure of the hydraulic cushioning device is abnormally low, and the peak load value of the upset is about 30 TON lower, and the upset steel pipe does not fill the die with metal, and there are no holes on the inner and outer surfaces of the upset. It is observed that wrinkles are formed as shown in Figure 4.

FIGS. 10A and 10B show an example in which the gripping action of the clamp jaw was not proper and the steel pipe slipped against the clamp jaw during setup. In this case, the setup specifications are that the steel pipe is APIJ-55,
The outer diameter is 2.7/8 inches (73.0 mm), the wall thickness is 5.51 mm, and the relief pressure of the hydraulic cushion device is 1.3
Kg/cm ² , grip pressure of clamp jaw is 162
Kg/cm ² , the steel pipe heating temperature in Figure 10A is 1230℃, and the steel pipe heating temperature in Figure 10B is
The temperature is 1260℃. In each of the upsets shown in FIGS. 10A and 10B, the operation of the clamp jaw is abnormal, with a slippage of 10 mm occurring in FIG. 10A and a slippage of 30 mm occurring in FIG. 10B. In this case, the pattern of the displacement amount and load value of the upset changes depending on the amount of slippage of the steel pipe, and it becomes extremely easy to determine that the upset is abnormal.

In addition, in implementing the above monitoring device, the setting device 3
The load reference pattern and displacement reference pattern set in 5 are determined by the increase rate of the pipe end wall thickness (thickness after assembling/wall thickness of the original pipe), regardless of the steel type, external shape, and wall thickness of the steel pipe. It has been recognized that it is sufficient to set these standard patterns for each 10% increase in thickness. Here, since the thickness increase rate in actual operation is about 250% at most, it is sufficient to set 10 to 15 of the above-mentioned reference patterns.

[Effects of the Invention] As described above, according to the method and device for monitoring a steel pipe upset according to the present invention, the load value applied to the upset punch and the displacement amount of the upset punch are measured during upsetting, and the upsetting is performed normally. It becomes possible to monitor whether or not the

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing the entire upsetter to which the present invention is applied, FIG. 2 is a cross-sectional view showing the shape of the upset part, and FIG. 3 is a state diagram showing the process of deformation of a steel pipe by upsetting. Fourth
The figure is a photograph showing the shape of fibers in the cross section of an upset steel pipe, Figure 5 is a perspective view showing an example of a load measuring means, Figure 6 is a perspective view showing an example of a displacement measuring means, and Figure 7 is a monitoring device. A control circuit diagram showing an example; FIG. 8 is a line diagram showing the load pattern and displacement pattern in a normal upset; FIG. 9 is a line diagram showing the load pattern and displacement pattern in an upset where the relief pressure of the hydraulic cushion device is low; FIGS. 10A and 10B are diagrams showing load patterns and displacement patterns in an setup where the gripping action of the clamp jaw is not proper. 1... Steel pipe, 2... Upset section, 10...
Upset punch, 16... Upset punch, 1
8...Dice, 21...Load cell, 23...Linear scale, 33...Digital storage device, 34...
... Microcomputer, 35 ... Setting device, 36
...Judgment result display.

Claims (1)

[Scope of Claims] 1. In a method for monitoring a steel pipe upsetter that forms an upset part by heating the end of a steel pipe, the upset load value applied to the upset punch and the amount of displacement of the upset punch are measured, and each of the above measurements is performed. The values are displayed as an actual load pattern and an actual displacement pattern, and the actual load pattern and actual displacement pattern are compared with a load reference pattern and a displacement reference pattern that are predetermined for an appropriate upset to determine whether the upset is good or bad. Characteristic method for monitoring steel pipe upsets. 2. A monitoring device for a steel pipe upset that heats the tube end of a steel pipe to form an upset section, includes a load cell that is attached to the upset load acting surface of a punch holder equipped with an upset punch, and that measures the value of the upset load applied to the upset punch. , a linear scale that connects a carrier capable of interlocking with a punch holder equipped with an upset punch so as to be movable relative to the scale body, and measures the amount of displacement of the upset punch; and a load measurement value of the load cell and the linear scale. and an XY plotter that displays the load measurement value and displacement measurement value stored in the storage device as an actual load pattern and an actual displacement pattern, respectively. Upsetta monitoring device.