JPS5912334A - Device for detecting fatigue of member - Google Patents

Abstract

PURPOSE:To acknowledge the fact that the fatigue of a member has reached the limit readily and accurately, by providing notched parts at the intermediate part of a detecting piece, whose both ends are connected to a connecting member to which repeating loads are applied. CONSTITUTION:A detecting piece 2, which has notched parts 1 at the intermediate part thereof, is provided at the intermediate part of a connecting member 4, which has connecting parts 3 at both ends. Both ends parts of the piece 2 are fixed to the both sides of the member 4. A pair of electrodes 6 and 7 of an electric measuring and alarm generating device 5 are connected to both sides, forming the minimum cross sectional part by the parts 1. When the repeating loads, whose frequency is close to the limit of fatigue, are applied, cracks are yielded from the bottom part of the part 1. The cracks rapidly grow with the increase in the repeating frequency of the applied loads. Then the piece 2 is broken. The rapid increase in electric resistance due the break of the piece 2 is detected by the device 5. Then, the alarm is automatically generated, or a power source for a motor can be cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting fatigue in a part 2 of a hook, chain, etc. in a transportation device such as a crane or chain rope, or in a part side of a bridge, building, or other structure. be.

When a cyclic load is applied to a member, if N is the actual number of cyclic loads applied to Xundong and NL is the number of cyclic loads corresponding to the fatigue limit (at the time of fatigue failure), the fatigue life of the product S1 is S +
”” N/N1. , and the remaining fatigue life rate S2 is 52-(NL N )/N, (,), and the value of NL is approximately 106 to io7.

Conventionally, methods for determining the fatigue level of members include (1)
Hardness of member ′f: Method of measuring and determining fatigue level, (
2) A method of measuring the condition and depth of a crack that has occurred in a crack, and (3) a method of using X-ray photography are known.

However, in the case of methods (1) to (3) above, after the period of use of the part has increased to a certain extent, measurement or photography must be performed from time to time, which is complicated, and it is difficult to accurately determine fatigue. The problem is that it cannot be done.

An object of the present invention is to provide a member fatigue detection device that advantageously solves the above-mentioned problems.

Next, the invention will be explained in detail using fully illustrated examples.

1 to 6 show an embodiment of the present invention, in which a detection piece 2 made of a steel bar is provided with V-shaped notches 1 facing each other on both sides of the middle part, and a detection piece 2 is provided at both ends. The connecting part 6 is completely equipped with a through hole in the middle of the S steel frame-shaped connecting member 4) 4! K is arranged so as to extend in the longitudinal direction with a connecting part, and both ends of the detecting part 2 are connected to the connecting part 2 (]
4-1 welding or H? A pair of electric wires i1 < 6 + 7 of the electric 11111 stationary alarm generator 5, which is fixed by a bolt and which operates all the alarm devices etc. when the electric FB and resistance measurement value exceeds a certain level, are connected to the detection piece. 2 is connected to both side portions sandwiching the minimum cross section between the bottoms of the notch 1. Ma/ko, the above-mentioned air pressure measurement alarm generator ftt 5
is the electric resistance side 'jZ f! , F circuit and its measured electrical resistance value exceeds a certain level, turn on the control wholesale switch and set the ramp to 0. It is equipped with an alarm circuit for fully operating the buzzer-tongue flash flood device, and a power cutoff circuit for opening the electromagnetic switch of the power supply circuit of the winding 11 motive.

A wire rope 10 being fed out from an electric hoist 9 fixed to the F section of a traveling girder 8 in an overhead crane is wound around a hanging rope 12 equipped with a hook 11,
A mounting bracket 1 connected to the feeding end of the wire rope 1o is connected to one end of the connection part 4 by a bolt, and a support part fixed to the lower part of the running gear 8 is attached. The end of the connection layer 4 is connected to the 'a' i /I bracket by a +]5 bolt, and the electrical measurement alarm generating device 5 is fixed to the support member 14.

In the device having the member fatigue detection device shown in FIG. Then, as the number of repeated loads increases, the crank grows rapidly, and finally (the fourth
As shown in the figure, the detection piece 2 is divided by the crack 15.

When the detection piece 2 is separated between the bottom of the notch 1 by the crack 15, the electrical resistance between the electrodes 6 and 7 increases rapidly, so this is detected by the electrical resistance measuring circuit, and the detection signal triggers the alarm circuit. 9, the alarm buzzer will sound and the power to the electric motors for the first and second machines will be cut off, making hoisting and transportation impossible.

FIG. 51 shows another example of the use of the part-side fatigue detection device, in which a chain 1 in an electric chain block 18 suspended from a trolley 17 running along a rail 16 is shown.
One end Fm of the connecting member 4 is connected with a bolt to the hanging end of the connecting member 9, and the hook support fitting 20, which is attached to the hook 11 so as to be fully rotatable, is connected with a bolt to the connecting part of the connecting part 1 and the end of the pond of 1A4. The alarm generating device 5 is attached to the connection part shrine 4.

In the case of FIG. 2, the electrodes 6 and 7 are connected to the side surfaces of the groove of the notch 1, but as shown in FIG. May be connected.

Further, as shown in FIG. 7, in a state where the detection piece 2 having notches 1 on both sides of the intermediate part is arranged obliquely with respect to the direction in which the tension is applied in the connection portion 4, both ends of the detection piece 2 are All of the connecting members 4 may be welded or fixed by bolts or the like, and cracks may be generated in the minimum cross-sectional area of the detection piece 2 by forming a notch by the action of repeated shearing forces.

The cross-sectional shape of the detection piece 2 may be circular, square, rectangular, or any other shape, and the electrical measurement alarm generating device 5 is designed to prevent the detection piece 2 from being completely disconnected and causing a minimum disconnection of the detection piece due to the occurrence of cracks. It may have the function of activating an alarm device and cutting off the power supply circuit of the motor as necessary when the area becomes less than a certain level. Detection in which both ends are fixed to the moon 4. Since the notch 1 is provided in the middle of the protruding piece 2, when a repeated load close to the fatigue limit is applied, the notch 1 in the detection r12 A crack is generated from the bottom, and the crack rapidly grows due to the increase in the number of repetitions of the load, and the detection piece 2 is divided 1t, and the pair of electrodes 67 of the electrical measurement alarm generating device 5 are connected to the detection piece 2. Since the electrical measurement alarm generating device 5 detects a sudden increase in electrical resistance due to the separation of the detection piece 2, it automatically generates an alarm. Therefore, it is possible to easily and accurately confirm that the operating profit has reached near the fatigue limit.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention, in which FIG. 1 is a front view of a member fatigue detection device;
Fig. 5 is an enlarged front view showing a part of the outside, and Fig. 5 is a front view showing the use of the bottom layer fatigue detection device. Fig. 5 is a front view showing an example of the use of the song of the member fatigue production device. 1 is a front view showing another example of Katatori [moon-down state]. In the figure, 1 is a notch, 2 is a detection piece, 6 is a bow, a connecting part, 4 is a connecting part, and 5 is an electric measurement M report. - device, 6 and 7 are electrodes, 8 is a running girder, 9 is a rotating earth machine, 10
is wire row], 11 is hook, 15 is crack, 18
is a chain glock, and 19 is a chain. Agent Minoru Abe), ゛: 1. Niej Figure 1 Fallen Figure 2-4゜Figure 7

Claims (1)

[Claims] A detection piece 2 having an intermediate portion 1 and a cutout portion 1 is disposed at the intermediate portion of a connecting portion 4 having connecting portions 6 at both ends,
Both ends of the detection piece 2 are fixed to both sides of the connection member 4,
A member fatigue detection device characterized in that the pair of electrodes 6 and 7 of the electrical measurement alarm light generation device 615 are connected to both sides of the detection piece 2 across the minimum cross section formed by the notch.