JPS6018932B2 - Steel pipe impact test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refitting method for automatically testing the roughness of a steel pipe in a direction perpendicular to the rolling direction (circumferential direction).

Generally, the toughness of steel pipes is evaluated by comparing the arm fracture transition temperatures (vT) obtained by impact testing JIS No. 4 impact test pieces at various temperatures using a Charpy tester.

However, for small, light, and thin-walled steel pipes, it is often impossible to collect test pieces for graininess in the direction perpendicular to rolling, with the longitudinal direction of the test piece being in the circumferential direction of the steel pipe. Because there is an escape space for the hammer of the enemy, it is not possible to test the toughness of steel pipes with an outer diameter of 4 mm or less in the direction perpendicular to rolling.

Therefore, the inventors filed an application for an impact test method for steel pipes suitable for evaluating the toughness in the direction perpendicular to rolling of 4-diameter thin-walled pipes.

In this application, a steel pipe to be tested is sliced into two lengthwise, an impact test piece with a set size and shape with a vertical notch in the center is placed on Albir, and a weight of a set weight is applied from a set height. The method is characterized in that each test piece is dropped and maintained at a set temperature, and then broken, and the fracture surface transition temperature is determined from the longitudinal fracture surface ratio.
This invention provides a safe, accurate and accurate method for impact testing of steel pipes.
The purpose is to present a device that can be implemented quickly, and its structure will be explained with reference to FIG.

1 is the base of the test equipment, 2 is a column raised on the base, 3 is an anvil installed on the base on the side of the column, and above the column is a pulley for suspending a dowel 4 via a lifting magnet 5. 6 is installed.

Between the pulley 6 and the anvil 3, a cylindrical guide 7 whose axis is the vertical line of the weight suspended from the pulley is slidably held by support rings 8, 8 fixed to the column. , mounted on the column by a fluid-operated cylinder 9 fixed to the column so that it can travel approximately 15 degrees in the axial direction.

As shown in FIG. 2, the lower end of this cylindrical guide 7 is formed with a convex step part 1 whose diameter is smaller than that of the cylindrical internal guide 2.

The dowel 4 falling inside this guide has a smaller diameter than the inner seal 2 of the guide, and has an inner diameter d. It consists of an upper columnar shape with a larger diameter, an inner wall d of the entrance part, and a lower columnar shape with a smaller diameter and higher than the height of the convex step part 10. Therefore, this dowel is
As the guide rises, the heavy twill is also lifted up by being stopped by the convex step portion without deviating from the lower end of the guide. The lifting magnet 5 has a permanent magnet provided with an electromagnetic coil that excites the magnet in a reverse polarity, and normally attracts the upper surface of the weight 4 to the lower surface, and demagnetizes the permanent magnet by energizing the excitation coil and lifts the tortoise weight. Release it from suction and let it fall.

To explain the lifting magnet hoisting machine 12,
A wire 13 with one end tied to the upper end of the column goes down the column, passes through a pulley 15 at the upper end of the rod of a fluid cylinder 14 attached to the column, ascends the column, passes through pulleys 6' and 6, and is tied to the lifting magnet 5. There is.

Further, the excitation current cord 16 of the lifting magnet is also connected to an external DC power source via a cord winder 17 at the upper end of the column. (not shown) Therefore, by actuating the cylinder 14 and moving its rod up and down, the wire 13 is pulled through the pulley 15 to raise or lower the lifting magnet 5. 18 and 18' are limit switches for upper and lower limits of lifting magnet winding, 19 is a limit switch for upper limit of guide rise, and 2
0 illustrates the operation panel of this device.

To explain the operating procedure and order of operation of the impact tester with the above structure, the operation power switch SI on the operation panel 20, the fluid pump start switch S2, and the excitation power switch S3
After closing the device to make it ready for operation, turn on the guide raising switch S4.

As a result, the lower end of the guide 7 rises from the surface of the anvil 3 with the weight lifted by the operation of the cylinder 9, and is stopped by the operation of the limit switch 19. Next, when the lifting magnet lowering switch S5 is turned on, the cylinder 14 is operated and the pulley 15 is raised via the rod.
is loosened, the lifting magnet 5 suspended from the pulley 18 is lowered, and the excitation cord 16 is simultaneously lowered. After the lifting magnet contacts the weight and confirms the attraction (lamp) signal, turning on the lifting magnet raise switch S6 activates the cylinder 14 and pulls the wire 13 downward, so that it is attracted to it together with the lifting magnet. Lift up the weight and ascend. When the set height is reached from the anvil, the limit switch 18
It will stop at that position when activated. Next, a test piece 21 having a predetermined shape that has been sufficiently maintained in a preset temperature bath is placed on the anvil 3 at the lower end of the guide using tweezers or the like, and then the guide lowering switch S7 is turned on. Then, after confirming the signal that the guide is lowered by the operation of the cylinder 9 and the lower end has contacted the anvil, the lifting magnet excitation nail S8 is pushed to reverse excite and demagnetize the lifting permanent magnet, and the dowel is released to guide the guide. The test piece 21 on the anvil is broken by letting it fall naturally inside the inner cylinder. The falling height of the flea weight and the rising height of the guide for placing the test piece on the anvil are adjusted by the height of limit switches 18 and 19. This procedure is repeated as many times as the number of test pieces, and the arm fracture transition temperature of the steel pipe is determined from the arm fracture ratio of the test piece. The above operating procedures and operating order of the equipment have been explained in the manual case, but the operation panel 20' is equipped with a sequence control device (not shown) that automatically controls the order of these manual operations.
is incorporated.

S-9 is an automatic/manual changeover switch, and S-10 is a foot switch for instructing the start of the sequence circuit. In other words, if you change the S-9 switch from manual to automatic and turn on the S-10 switch, (S-7) ON guide descent → (S
-8) ON car weight falls → (S-5) ON lifting magnet lowers → (S-4) ON guide rises → Doll weight glue lifting magnet adsorbs → (S-6) lifting magnet rises. Return to the origin of automatic operation.

This kind of sequence control can not only be easily incorporated using commonly used methods and equipment, but can also be automated, making dangerous work involving falling dowels safer, and removing test specimens from overflowing tanks. Since the time required to complete the test can be shortened, there is an advantage that the temperature change during the test can be minimized and the test accuracy can be improved.

[Brief explanation of the drawing]

Figure 1 is a front view of the steel pipe impact testing apparatus of the present invention, Figure 2
The figure is a cutaway front view of the test piece mounting portion. In the diagram, 1...Foundation, 2...Column, 3
... Anvil, 4... Weight, 6...
・Lifting magnet, 7...Guide, 1
0...Dan section, 12...Rolled up iso foundation, 13
...Wire, 9, 14 ... Cylinder, 16 ... Cord, 17 ... Cord winder, 18, 18', 19 ... Limit switch , 20
......Operation panel, 21...Test piece, d,...
・・・Open □ inner diameter, flat.・・・・・・Inner diameter of cylindrical part, sn
······switch. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a testing device that breaks steel pipe test specimens by letting a weight fall naturally, there is a space between the albil for placing the test specimen on the base of an upright column and the lifting magnet winding pulley installed above the column. A cylindrical guide with a small-diameter step formed at the lower end opening is attached to the column by a cylinder so that it can move up and down, and the upper part is such that a weight falling inside the guide is stopped by the step at the lower end of the guide. The weight has a cylindrical shape with a large diameter and a small diameter at the bottom, and a lifting magnet that can be attracted to and released from the upper surface of the weight, and a lifting magnet winding mechanism that lifts the lifting magnet above the guide are provided. A steel pipe impact testing device is also incorporated with a sequence circuit that sequentially controls the operations of lowering the guide, dropping the weight, lowering the lifting magnet, raising the guide, and raising the lifting magnet.