JPS58221147A - Tester for yield strength of chain - Google Patents

Abstract

PURPOSE:To prevent the generation of bending stress in a linked ring and to obtain the stable result of a test having reproducibility by supporting the horizontal linked ring of a chain in such a way that the axial center of the chain is on the line connecting the chucks on both sides. CONSTITUTION:Both end parts of a sample chain 6 apart from each other at a prescribed spacing are gripped by means of a chuck, 3a and a chuck 4a, and the perpendicular linked ring 7a of a chain link 7 is chorded and fitted in the groove 5a of a grooved stand 5 and the bottom surface of a horizontal linked ring 7b is placed on the top surface 5b of the stand 5. When a tension F is loaded on the chain 6, the play between the rings 7a and 7b is eliminated and the prescribed tension is applied on the ring 7 thereafter. The axial center of the chain 6 in this stage coincides with the direction of the force F from the beginning. The stable result of the test having reproducibility is thus obtained without generating bending stress.

Description

[Detailed description of the invention] Regarding equipment.

After the anchor chain is manufactured, it undergoes a strength test in accordance with the standards of Nippon Kaiji Kyokai and other organizations. In this test, a series of chains with a standard length of 27.5 m was subjected to a strength test load specified by the standard, and was tested for low-strength cutting,
Fissures are used to check for scratches and other abnormalities.

As shown in FIG. 1, the conventional chain strength testing device grips both ends of a chain 040 at a predetermined distance in a test chain using a chuck 02a of a fixed block 02 and a chuck 03a of a movable block 03 provided on a base 01. , the movable block 03 is moved horizontally to apply a tensile load to the chain, and as a result of measuring the stress in the link ring 05 of the chain configuration during the test, the following problems were found.

When the chain 04 held by the chucks 02a and 03a is attached to the chucks, the center portion becomes slack due to its own weight and becomes suspended. Even after the load is applied, this state remains as friction at the contact portion between the vertical link ring 05a and the horizontal link ring 05I), and the axis of the chain 04 is not completely horizontal, causing bending stress in the link ring. . Horizontal link ring 05b is easily affected by this, causing a large difference in stress between the top and bottom surfaces of the link ring, with the stress generated on the top surface being more than three times as high as the stress occurring on the bottom surface. does not reach the predetermined stress.

(stomach). The stress on the upper and lower surfaces of the link ring varies widely and is not reproducible, making it impossible to obtain stable test results.

The present invention has been made in order to eliminate the drawbacks of the above-mentioned conventional products.The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional products. To provide a chain strength testing device including a supporting means configured to support a horizontal link ring of a chain and allow displacement in the chain axis direction.

Hereinafter, the present invention will be explained based on an embodiment shown in the drawings.

In the chain strength testing device 1 shown in Fig. 2, 2 is a base;
3 is a fixed block erected on a base, ) 3a is a chuck, 4 is a movable block that can be moved left and right on the base by a hydraulic mechanism (not shown), etc., 4a is a The chuck is mounted at the same height as the chuck 3a, and 5 is a grooved mount that serves as a chain support means and is attached to the base 2. In the figure, reference numeral 6 denotes a test chain, in which both ends of the chain at a predetermined interval are held by chucks 3a and 4a, and as shown in detail in FIG. The vertical link ring 7a is the grooved frame 5
The lower surface of the horizontal link ring 7b is placed on the upper surface 51) of the grooved frame 5. Moreover, the arrow symbol in FIG. 2 indicates the tensile force F applied to the chain 6 by the rightward movement of the moving block 4, and the
The height of the chain 6 is set to match the direction of the axial core force 1 and the tension F of the chain 6 placed thereon. The chain support means is not limited to the grooved frame 5 of this embodiment, and other types may be used as long as they have the same function.

When tensile force F is applied to the test chain 6 in the above configuration, the play between the vertical link ring 7a and the horizontal link ring 7b is first removed, and then a predetermined tension is applied to the link ring 7. Since the axis is aligned with the direction of the tensile force F from the beginning, there is no friction between the two links i7a, 7b due to displacement as in the case of the conventional one, and therefore no bending stress is generated, so the link ring There is almost no difference in the stress between the top and bottom surfaces of the test tube, and stable test results with reproducibility can be obtained.

Comparing the test results of the present device for the same type of chain (Fig. 4) with the test results of the conventional chain (Fig. 5), it can be seen at a glance that the present device is superior. The strains ε0, ε8, and ε were measured using strain gauges G, G[, and GM installed at the center of the upper surface, lower surface, and side surface of the horizontal link ring 7b shown in FIG.

[Brief explanation of drawings]

Fig. 1 is a side view of the conventional device, Fig. 2 is a side view showing an embodiment of the present invention, Fig. 3 is a sectional view taken along the line T in Fig. 2, and Fig. 4 is a side view of the device according to the present invention. Load versus strain test results chart,
FIG. 5 is a conventional load vs. strain test result diagram, and FIG. 6 is a side view of the link ring showing strain measurement positions in FIGS. 4 and 5. j: Strength test device 5: Grooved frame (chain support means) 6: Chain 7: Link ring 7b: Horizontal link ring F: Tensile load 1 ■ Multi 3 Leap

Claims (1)

[Claims] In a mechanism that applies a tensile load in the horizontal direction between predetermined intervals on a test chain formed by connecting link rings, the chain is adjusted such that the axis of the chain coincides with the above load line and the chain is allowed to displace in the horizontal direction. A chain strength testing device characterized by comprising chain support means that supports only the horizontal link ring.