JPS6137343A - Method and device for monitoring steel pipe upsetter - Google Patents

Abstract

PURPOSE:To monitor whether upsetting is normally executed or not by measuring the load value to be applied to an upsetting punch during upsetting and the displacement of said punch and processing the measured values. CONSTITUTION:A steel pipe 1 heated at end 1B is transversely fed to the upsetter shown in the figure and after the pipe end 1B stops in a prescribed end, said end is inserted into a die 18 and the pipe 1 is fixed. The upsetting punch 16 moves back and forth and the end 1B is upset. The load value of the punch 16 is measured by load cells 21, 21 and the displacement of the punch 16 is measured by a magnetic linear scale 23. The respective measured values are read into a digital storage device 33. The read sample values are transmitted to a microcomputer 34, by which the values are made displayable as an actual load-displacement pattern. Said pattern is compared with a standard load-displacement pattern with respect to the correct upsetting of a setter 35. The defectiveness and non-defectiveness of the upsetting are thus discriminated and the result thereof is made displayable on a display device 36 for the result of the discrimination.

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] Upsetting is a method of adding thickening to the inner and outer surfaces of the pipe end using an upset punch and a die, in order to ensure joint strength at the joint part of oil country tubular goods, that is, the threaded part of the pipe end. It forms an amplifier part. Figure 2 shows an example in which an outer surface upset portion 2A is formed on the tube end after the tube end of a steel pipe 1 is heated to about 1,250°C, an example in which an inner surface upset portion 2B is formed, and an example in which an inner surface upset portion is formed on the tube end. 2C
It is sectional drawing which shows each example which formed.

Conventionally, the above-mentioned upsetter is operated by determining the shapes of the upset punch and die based on the thickening schedule of the steel pipe, and then performing continuous operation similar to that of a press machine. In other words, conventional upsetter operation is based on the premise that after the mechanical operation of the upsetter is set to an optimal condition, that condition is maintained, as described in, for example, Kobe Steel Technical Report Vol. 31, No. 1. It is only a continuous operation.

[Object of the Invention] An object of the present invention is to measure the load value applied to five upset punches and the displacement amount of the upset punch during upset, and to monitor whether or not the upset has been executed normally. .

[Structure of the Invention] The first aspect of the present invention is a method for monitoring a steel pipe upsetter that forms an upset portion by heating the end of a steel pipe. The above measured 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 the load reference pattern and displacement reference pattern that are predetermined for proper upset. The system is designed to determine whether the upset is successful or not.

A second aspect of the present invention is a monitoring device for a steel pipe amplifier that forms an upset portion by heating the end of a steel pipe, and includes a load measuring means for measuring an upset load value applied to an upset punch; The apparatus includes a displacement measuring means for measuring the amount of displacement of the set punch, and a display means for displaying the measured values of each of the measuring means as an actual load pattern and an actual displacement pattern.

[Detailed Description of the Invention] FIG. 1 is a perspective view schematically showing the entire upsetter 10 to which the present invention is applied. 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 rod 13 via a hydraulic cushion device 14, an upset punch 16 equipped on the punch holder 15, and a steel 71.
It is comprised of a clamp jaw 17 that grips and holds the body portion IA, 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 l whose pipe end IB is heated to about 1.250°C
is transversely fed to the upsetter 10, the tube end IB is stopped at a predetermined position relative to the clamp jaw 17 and the die 18, and the heated tube end IB of the steel tube 1 is inserted into the die 18, and the body portion which is the non-heated portion IA is clamp jaw 17
When the flywheel 12 is firmly gripped, a clutch interposed between a motor (not shown) and the flywheel 12 is connected, and the flywheel 12 starts rotating. The rotational torque of the flywheel 12 is transmitted to the crankshaft 11.degree. punch holder 15, and the punch holder 15 performs one cycle of reciprocating motion in about 6 seconds. Upsetting of the steel pipe 1 is performed near the top dead center of the reciprocating movement of the punch holder 15, and is completed within 0.6 seconds after the upset punch 16 contacts the pipe end IB of the steel pipe 1. Although the upset punch 16 enters into the pipe end IB of the steel pipe 1 inserted into the die 18, it does not reach into the body portion IA which is gripped by the clamp jaws 17.

The steel pipe 1 that has been upset by the upper die 18 of the upsetter 10 may complete the upset in one shot, or may undergo a second upset by the lower die 18. The former is called [1 heat, 1 shot], and the latter is called [1 heat, 2 shots]. However, if an extremely thick whitening process that does not complete the upset even with 1 heat, 2 shots is required, [2 heat, 3 shots] It is necessary to reheat the steel pipe 1 and perform a third upset.

punch holder 15, punch 16,
The impact acting on the clamp jaw 17 and die 18 can be absorbed by hydraulic cushion devices 14 and 19. The hydraulic cushion device 14 of the punch holder 15 and upset punch 16 plays a particularly important role in the operation of the amplifier. In other words, there is a case where insufficient filling occurs in the die 18 when the steel pipe 1 is up-set due to variations in the wall thickness and uneven wall thickness of the steel pipe 1, and errors in the setting of the upset bonder 16, the die 18, etc., and vice versa. dice 1
The die 18 may become overfilled, causing burrs to come out of the die 18, and in extreme cases may cause damage to the apse center. Therefore, when the oil pressure in the hydraulic cushion device 14 reaches a certain pressure level 1, the relief valve 20 is opened to relieve the hydraulic fluid in the hydraulic cushion device 14, thereby allowing the upset punch 16 to advance further. It is possible to suppress this.

FIG. 3 shows the deformation process of the steel pipe 1 due to the upsetter 10. Steel pipe 1 is an amplifier set bonch 16
The steel pipe 1 is initially buckled by compressive force, and the outer surface of the steel pipe 1 contacts the inner wall surface of the die 18.

After this, the steel pipe 1 is inserted into the upset punch 16 and the die 1.
8, thickening deformation occurs in a state where it is restrained between 8 and 8, thereby increasing the contact length between the upset punch 16 and the die 18. 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 progress of buckling deformation is large,
As shown in the figure, wrinkles remain on the inner and outer surfaces of the upset portion 2.

Therefore, the inventor of the present invention detected the deformation process of the steel pipe l as described above by the upsetter 10 using the load value applied to the upset punch 16 and the amount of deformation of the upset punch 16, and created an upset by patterning them. It is possible to judge the quality of the product.

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 of the Nomanti holder 15,
The load value applied to the upset punch 16 during upset can be measured while being interposed between the punch holder 15 and the hydraulic cushion device 14. Load cell 2
1 is a desk type, and has a mechanical strength of 4007 ON, and since there is an uneven load on the upset punch 16, one each is used behind the axis of the upper and lower upset punches 16, so two in total are used. It is said that The punch holder 15 is approximately 7 when set up.
The load cell 21 is located in a bad environment due to the scattering of cooling water and hot lubricant due to hot working.
Although it is difficult to secure wiring space for the signal output cable 22, it is possible to
By improving the connection method, 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 add more load cells 21 to the punch holder 15 without impairing maintenance and inspection performance.

It is also conceivable to use a load measuring means that can 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. In this case, since the back pressure of the hydraulic cushion device 14 passes through the cushion cylinder and the hydraulic piping,
Subtle load changes such as buckling of the steel pipe 1 cannot be observed, and the back pressure of the hydraulic cushion device 14 cannot be observed after the relief valve 20 is activated. Therefore, the present inventor decided to use the load cell 21 attached to the punch holder 15 located closer to the upset punch 16 than the hydraulic cushion device 14 as the load measuring means as described above.

FIG. 6 is a perspective view showing a linear scale 23 as a displacement measuring means for measuring the amount of displacement of the upset punch 16. 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, and 28 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 3o causes the displacement of the upset punch 16 to be transferred to the carrier 26. It is possible to communicate.

The 70th is a control circuit diagram of a monitoring device using the load cell 21 and the linear scale 23.

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

The sample value read into the digital memory 33 is
It is transmitted to the microcomputer 34 and can be displayed as an actual load pattern and an actual displacement pattern. 35 is a setting device in which a load reference pattern and a displacement reference pattern for proper upset are determined in advance. The microcomputer 34 sets the actual load pattern to the setting device 3.
The actual displacement pattern is compared with the load reference pattern of No. 5, and the actual displacement pattern is compared with the displacement reference pattern of the setter 35 to determine whether the upset is good or not, and can be displayed on the determination result display 36.

The reason for using the digital storage device 33 and the microcomputer 34 instead of using a high-speed computer in the above-mentioned monitoring device is as follows.

That is, the upset is completed within one second at most after the upset punch 16 contacts 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 two measured value patterns within one second of the upset occurring. Therefore, in the above monitoring device,
The measurement values of the load cell 21 and the linear scale 23 are read in the digital storage 33 using a large-capacity IC memory, and the measurement pattern is then determined using the microcomputer 34, thereby making the device more compact and economical. made possible. Further, according to the above monitoring device, -
The measured values stored in the basic digital storage 33 can be outputted as a visible measurement pattern to the XY plotter 38 via the D/A converter 37, if necessary.

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 completed normally. In this case, the upset specifications are that the steel In is APIJ-55,
Outer diameter 2-7/8 inches (73,0mm), wall thickness 5.5
1 mm, the heating temperature is 1.260°C, the relief pressure of the hydraulic cushion device is 1.3 kg/crn', and the grip pressure of the clamp show is 162 kg/cm'.

In this upset, it is observed that the cushion amount of the upset change is 30 mm, the load pattern is bell-shaped, and the peak load value is 1007 ON. At this time,
Upseller) steel pipes are also normal.

FIG. 9 is an example where the relief pressure of the hydraulic cushion device is low. In this case, the upset specifications are that the steel pipe is APIN-80 and the outer diameter is 2.3/8 inches (80.3 mm).
), the wall thickness is 4.830m, the heating temperature is 1.250℃, and the relief pressure of the hydraulic cushion device is 0.8kg/
cm', grip pressure of clamp jaw is 160kg/
cnf. In this upset, the relief pressure of the hydraulic cushion device is abnormally low, and the peak load value of the upset is about 307 ON, and the upset part of the steel pipe is not filled with metal in the die. It is observed that wrinkles as shown in FIG. 4 are formed on the inner and outer surfaces.

FIGS. 10(A) and 10(B) are examples in which the gripping action of the clamp jaw was not proper and the steel pipe slipped against the clamp jaw during upset. In this case, the upset specifications are that the steel pipe is APIJ-55 and the outer diameter is 2-
7/8 inch (73,0mm), wall thickness 5.51mm, relief pressure of hydraulic cushion device is 1.3k
g/cm2, grip pressure of clamp jaw is 182
kg/cm', and the steel pipe heating temperature in Fig. 10 (A) is 1,230'O1 (the steel pipe heating temperature in Fig. 1 (B) is 1,280 °C.
, (B), the operation of the clamp jaw is abnormal, and in Fig. 10 (A), the operation of the clamp jaw is abnormal.
A slip of 0mm occurred, and in Figure 1O (B)
vaII+ slippage is occurring. In this case, the pattern of the upset displacement amount and load value changes depending on the amount of slippage of the steel pipe, and it can be determined very easily that the upset is abnormal.

In implementing the above monitoring device, the load reference pattern and displacement reference pattern set in the setting device 35 are independent of the steel type, external shape, and wall thickness of the steel pipe, and are based on the increase rate of the pipe end wall thickness (thickness after upsetting). Determined by thickness/wall thickness of original tube), thickness increase rate 1
It has been recognized that these reference patterns may be set for each '0%. Here, since the thickness increase rate in actual operation is about 250% at the maximum, it is sufficient to set the to-15 pattern as each of the above-mentioned reference patterns.

[Effect of the invention] As described below, according to the method and device for monitoring a steel pipe up center according to the present invention, the load value applied to the upset punch and the amount of displacement of the upset punch are measured during upsetting, and It becomes possible to monitor whether the set has been executed normally.

[Brief explanation of drawings]

Fig. 1 is a perspective view schematically showing the entire upcenter to which the present invention is applied, Fig. 2 is a cross-sectional view showing the shape of the upset part, and Fig. 3 shows the process of deformation of a steel pipe due to upsetting. 4 is a photograph showing a cross section of the steel pipe that has been upset. FIG. 5 is a perspective view showing an example of a load measuring means. FIG. 6 is a perspective view showing an example of a displacement measuring means. Figure 7 is a control circuit diagram showing an example of a monitoring device, Figure 8 is a diagram showing the load pattern and displacement pattern in a normal upset, and Figure 9 is a load pattern in an upset where the relief pressure of the hydraulic cushion device is low. Figure 1O (A) and (B) are diagrams showing the load pattern and displacement pattern in an upset where the gripping action of the clamp jaw is not appropriate.■...Steel pipe, 2. ... Upset part, 10... Upset center, 16... Upset punch, 18...
- Dice, 21... Load cell, 23... Linear scale, 33... Digital storage device, 34... Microcomputer, 35... Setting device, 36... Judgment result display device.

Claims (4)

[Claims] (1) In a method of monitoring a steel pipe upsetter that forms an upset portion by heating the end of a steel pipe, the value of the upset load applied to the upset punch and the amount of displacement of the upset punch are measured, and each of the above measured values is measured. 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 upset,
A method for monitoring a steel pipe upsetter, characterized by determining whether the upset is good or bad. (2) In a monitoring device for a steel pipe upsetter that forms an upset portion by heating the end of a steel pipe, there is a load measuring means that measures the upset load value applied to the upset punch and measures the amount of displacement of the upset punch. 1. A monitoring device for a steel pipe upsetter, comprising: displacement measuring means for measuring the displacement; and display means for displaying the measured values of the respective measuring means as an actual load pattern and an actual displacement pattern. (3) The steel pipe upsetter monitoring device according to claim 2, wherein the load measuring means is a load cell. (4) The steel pipe upsetter monitoring device according to claim 2, wherein the displacement measuring means is a linear scale.