JPS586442A - Pipe expanding tester for steel pipe ring - Google Patents

Abstract

PURPOSE:To ensure a highly efficient test for a sample piece ring of a steel pipe, by holding said piece ring at a certain position on the contrary to a conentional tester and pushing a spindle into the piece ring to expand and break the steel pipe. CONSTITUTION:A rod 6 is pressed into a sample piece ring 2 put on a pawl 10 by a descent of a press device. In this case, the downward conical circumference of the rod 6 abuts on the pawl 10 at an opening part, and the two sides forming an acute angle at the tip of each pawl slides mutually to press and open the pawl 10 outward. At the same time, the rod 6 turns with the ring 2 and in the same direction of the ring 2 via a thrust ball bearing provided to a long bearing at the basement of the rod 6 and synchronously with the rotary shift of the ring 2 which is caused by the expansion of the pawl 10. The ring 2 is held until it is expanded and broken. In such way, the rings 2 are consecutively supplied to a supporting part to perform a highly efficient test for expansion of a steel pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel pipe ring expansion test device for small diameter steel pipes.

It is compulsory to conduct all expansion tests on steel pipes using specimen rings taken from both ends of the pipe. This is cut into lengths of 75 to 10 mm from both ends of the steel pipe using a high-speed cutting machine.
The tube is cut into rings with a dimension of 0 mm, and then a small ring-shaped specimen with a length of 15 to 20 mm is cut out from the sliced tube, and after the pars on the inner and outer surfaces are completely removed, a tube expansion test is performed. There was no special purpose testing machine for seeds, and tube expansion tests were usually performed by pressing from above using a device like the one shown in Figure 1. This tube expansion test complies with German standard D I
It is based on N50137 and has the provisions shown in Table 1.

FIG. 1 shows a conventional device that satisfies this regulation, in which reference numeral 1 is a conical spindle 1 fixed on a workbench. The operation is to insert the entire specimen ring 2 into the spindle 1, place several specimen rings 2 on top of it, and press them together with a press machine through all the fitting tools 3, and from the lower specimen ring to the upper specimen ring 2. The work of expanding and breaking the tube is carried out sequentially on the specimen.

In this way, the entire surface of the fractured specimen is investigated for defects, but this device has the following drawbacks.

In other words, when pressing several specimen rings 2' together, if the upper specimen breaks off before the lower specimen gets caught in the spindle 1 and cannot be removed, the spindle is removed and the specimen is pressed separately. This was extremely inefficient since it required the entire operation of removing the dirt specimen, and also caused a long work interruption such as replacing the spindle with another spindle 1 and reassembling the specimen ring 2. Moreover, the exam dates are irregular and a large number of exams are concentrated in a short period of time, so it must be done manually? The main conventional equipment was not able to keep up with the demand and caused many problems in terms of production and delivery of the steel pipes. As described above, the object of the present invention is to provide a specimen ring expansion device for steel pipes that satisfies all DIN standards and is highly efficient by making various improvements on the device in order to eliminate the drawbacks of the conventional device. .

Next, the entire process leading up to the present invention will be explained.

The basic problem in this test work is that the outer diameter of the specimen ring is 38.1 to 114.31111. Thickness (1
) ≧ 2, and the required number of tests is 4,800 pieces/day for a 38III tube and 2,000 pieces/day for a 14 mm tube. In order to process multiple specimens, is it necessary to fix the spindle like in conventional equipment? The method of interpolating and placing them one by one is inefficient.

Therefore, the present inventors devised a method in which, contrary to the conventional apparatus, the specimen ring is held in a fixed position, and the specimen ring is pushed into the spindle twice to expand and break.

However, the problem in this case is how to hold the specimen ring in place until the specimen ring is completely broken. Since there are different sizes up to The axial center of the entire press (the center of the specimen ring) is provided at 8 equal parts in 8 places, and the holding part 22 is set at 8 equal parts, and the holding part 22 is held by the link mechanism 5, and the press of the spindle 1 is We made a prototype of a device that opens outward due to force, fully expands the specimen ring 2, and breaks it. However, the results of fully expanding the specimen ring 2 using this prototype device are shown in Figure 3. That is, (1) Only the ring holding part is stretched, causing a concave deformation a, and a break occurs in the center of the holding part.

(2) Expansion rate (original diameter (il-10
The ratio of the expanded pipe diameter to the original diameter (when it is set to 0) decreases from 150 to 180% in the past to about 140 cm.

(3) When the specimen rings are stacked in two stages, even the upper specimen ring is deformed.

(4) When the specimen rings are stacked in five stages, the specimen rings in the upper stage undergo buckling deformation.

(5) The deformation caused by the breakage of the intermediate specimen ring spreads to the adjacent upper and lower normal specimen rings, which are pressed.

Problems such as these occurred.

Based on these results, the main points for improvement were the specimen ring holding structure and the lubrication method for the holding part. First, we investigated the effects of the type of lubricant applied to the specimen ring holding part. In this regard, some kind of lubricant (1.0~
2. Q mm concave deformation is 0.3 to 0.6 m
Although it was improved to tx, it was still not a drastic improvement.

Is the present invention part of these processes? Based on this, is there any major innovation in the holding structure of the specimen/g? In addition, we have developed a highly efficient steel pipe ring expansion device that satisfies predetermined standards using inexpensive conventional oil without using any special lubricating oil. In other words, the support member that holds the entire specimen ring cut from the steel pipe consists of a large number of claws arranged radially from the periphery of the support part toward the central opening, and is fixed to the entire base cover plate of the winter melon. A frame (two downward conical rods placed in the center of the opening part) is provided rotatably between the pin and the claw (with two elastic bodies suspended between them), and is connected to the press device above. , when the rod descends and the lower circumferential surface of the rod comes into contact with the pawl and is pushed outward, the rod This apparatus is characterized in that a rotating thrust bearing is provided on the long bearing part of all the rods so as to hold the specimen ring on a claw.

The apparatus of the present invention will be explained in detail below with reference to the drawings.

FIG. 4 is a diagram showing an embodiment of the present invention, in which the right half of the drawing shows a large diameter version (diameter 114.311), and the left half shows a small diameter version (diameter 38.1 ++n). It is.

6 is a press device (
Long bearing portion 21 fixed to the pedestal 7 connected to (not shown)
It is rotatable via a thrust ball bearing 8 installed in the

9 is a support that stands on the work floor, and 4 is placed in the center of the
It is installed in the corner, and is arranged so that seven pedestals can be raised and lowered by sliding along with two presses.

Reference numeral 19 denotes a fixing base that supports the support portion 4 that holds the entire sample ring 2, and a plate 17° 13 whose lower surface is mounted on the base 19
The upper cover plate 12 and the upper cover plate 12 are respectively hollowed out in a circular shape in the center, and in particular, the outer periphery of the hollowed out hole in the lower cup plate 17°13 is sufficiently large to withstand the load applied by the claws 1.0 and i1 until the specimen ring 2 breaks. (It is placed close to the outer peripheral surface of the specimen ring so that it can be supported by two, and is fastened to the four corners of the fixing base 19 with bolts 18.

FIG. 5 is a view taken along arrow A-A in FIG. 12.13.17 (two fixed vias 14)
, 16, and the tip of the winter melon is formed at an acute angle.
They are arranged radially from the base of the pawl 10 toward the opening device of the support part 4 so that the sides slide against each other.

10 is an elastic body, which in this example is a ring-shaped spring;
A 24-metal spring receiving pin protruding from the front part of the winter melon is interposed between each claw (two tensions are installed), and the rod 6 is lowered and the rod 6
When the downward conical circumferential surface of the lower part comes into contact with the claws 10 of the opening device and is pushed outward, it expands, and as the rod 6 rises and the pressure decreases, it contracts and returns the claws 10 to their original position. The claws are arranged so that they can be rotated so that they can be returned to their original positions.

The right side view of Fig. 4 (=The pin 14 shown is used when the diameter of the specimen S/g is 114.3s+i, but it is 38.111
As shown in the left side view of Fig. 4, for the small diameter specimen ring, use the pin 16 located near the two central openings, and replace the lower cover plate 17. 6 and 7 are cross-sectional views showing the details of the attachment parts of the large-diameter specimen ring and the small-diameter specimen ring, respectively.
The diameter □ of the pin 14 of the plate 13 is made large, and the bearing part is equipped with a metal bearing and 15 thrust ball bearings. The pin 16 may be approximately 172 mm larger than the large-diameter pin 14, and there is no problem in practical use if the thrust ball bearing is not used and only the bearing metal is added.

Next, the operation of the device of the present invention will be explained. As shown in the explanatory diagram of tube expansion of the apparatus of the present invention in FIG. The downward conical circumferential surface of the lower part of the rod 6 comes into contact with the claw 10 of the opening device, and due to the pushing force, the two sides forming an acute angle at the tip of each claw slide toward the outside of the claw. At the same time as the claws are expanded, the specimen ring 2 is rotated in synchronization with the rotational movement of the specimen ring 2, and the four are moved in the same direction together with the specimen ring through the thrust ball bearing 8 provided in the long bearing 21 of the base of the Rondoro 0. The specimen ring is held completely until the specimen ring expands and breaks by continuing to press.

Several specimen rings may be stacked and tested. However, it is more reliable to continuously process the sample rings one by one, and the amount of processing is almost the same as when they are stacked. In this way, the specimen rings can be successively supplied to the support section, allowing a highly efficient tube expansion test to be performed.

Example (1) In the case of a tube expansion test for small diameter pipes a g, I Iim A tube expansion test was conducted using the testing apparatus of the present invention with the bottom cover plate 17 and pin 16 shown in FIG. 7, and the results shown in Table 2 were obtained. Obtained.

Table 2 (2) In case of tube expansion test for large diameter pipe 114°3 Dragon All tube expansion tests were conducted using the lower cover plate 13 in Figure 6 and 14 bottles installed in the test equipment of the present invention, and the results shown in Table 3 were obtained. I got it.

Table 3 As shown in Tables 2 and 3, the spindle jamming, concave deformation, and deformation defects that were observed in conventional equipment and prototype equipment have disappeared, and the tube expansion rate has become highly stable, resulting in an improvement in processing capacity. . In the prototype device (2), there was a difference depending on the lubricant applied to the holding surface, but in the present invention, there was no difference, and the result was that there was no problem even if inexpensive ordinary oil was used.

As described above, the device of the present invention has the following advantages: firstly, it has become possible to sufficiently and efficiently test steel pipe specimen rings that are produced irregularly and in large quantities over a short period of time, and secondly, the steel pipe rings can be supported uniformly over the entire surface. Because this process is carried out, there is no unnecessary deformation during pipe expansion and there is no failure, and thirdly, there is no need for special lubricating oil, resulting in lower costs.

[Brief explanation of the drawing]

Figure 1 is a complete explanatory diagram of the conventional method, Figures 2 (a) and (b) are a plan view and front view of a test machine in the middle of development leading up to the device of the present invention, and Figure 3 is a tube expansion test using a prototype machine. Later state diagram,
Fig. 4 is a front view of the device implementing the present invention, and Fig. 5 is A of Fig. 4.
-A arrow view; FIG. 6 is an installation sectional view of the bottle 14 in FIG. 4;
FIG. 7 is a sectional view of the attachment of the pin 16 shown in FIG. 4, and FIG. 8 is an explanatory diagram showing the entire situation during pipe expansion of the apparatus of the present invention. 1... Spindle, 2... Specimen ring, 3
...resting tool, 4...supporting part, 5...link mechanism, 6...rod, 7...frame, 8.15...
・Thrust ball bearing, 9... Support, 10... Claw, 11
...-spring, 12...top cover play), 13.
17...Bottom cover plate, 14.16...Bin, 18...Bolt, 19...Fixing base, processing...Bearing metal, 21...Long bearing part, 22...Holding part ,
n...opening, 24...splash is pin. Patent applicant representative patent attorney Tomoyuki Yabuki (and 1 other person) @231 (a) Figure 3 Figure 5 Figure 6 @'7 Sen

Claims (1)

[Scope of Claims] 1. A tapered iron is provided that can be moved vertically around the axis of the tube to completely expand the ring by pushing it into the specimen ring. A ring support member is installed which supports the ring and has an opening through which the tapered iron is inserted, and which consists of a number of claws that are arranged radially around the opening and touch each other without a gap at the tip side. A pipe expansion testing device for steel pipe rings, characterized in that each of the above-mentioned molds is provided with all 5 double rail rotation centers in order to freely expand and contract by vertical movement of a tapered rod.2. 2. The tube expansion test device according to claim 1, wherein a plurality of pin attachment holes are formed in the winter melon to change and adjust the center of rotation.