JPS58109833A - Detector for mechanical fatigue of solid - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This development is based on deformation stress during periodic standard load cycles.
1 and relates to a device for detecting mechanical fatigue of a solid body.

Fertilizer fatigue of bodies subjected to mechanical stresses, such as elements of structures or machines, is caused by their repeated fatigue within a defined period of time constituting their operating cycle, especially in terms of tensile, compressive and torsional stresses. It is usually determined by calculating and evaluating based on the elucidation method. The calculated value reveals the degree of fatigue. This computational monitoring must be repeated periodically, and all past cycles must be included in the calculations during reexamination, so if the operation lasts for a long period of time, it is necessary to take a close look at the A large amount of calculation cost is required to obtain an accurate judgment about the fatigue state of the patient.

An object of the present invention is to provide an apparatus that can grasp the fatigue state mVc of 18 bodies in a more accurate and simpler manner than before without requiring lengthy calculations.

The object of this is that in a device of the abovementioned type, according to the invention, at least one senna is installed on the solid body, which detects its deformation, and the signal of this senna is detected during periodic standard duty cycles. This is achieved by K being ascertained and compared with reference values in an evaluation device.

The hysteresis is obtained by displaying a constant value corresponding to the mechanical stress and the resulting deformation, and by comparing its shape with the reference curve, it is possible to determine the degree of fatigue that has occurred up to the point of measurement and this solid body. The remaining technical safety can be clearly estimated.

Next, the present invention will be described in detail based on drawings showing embodiments of the present invention.

The figure shows a device for detecting mechanical fatigue of a shaft 1 of a power vehicle, one end of which is coupled to an electric motor 3 via a shaft coupling 2;
Further, the other end is connected to a pinion, which is not shown. In front of the inlet of the reduction gear, the shaft 1 is supported in bearings 4 and is provided with an accumulator wheel 6 for equalizing the pivot moments.

1 distributed on axis l to detect fatigue of axis 1
A detection unit 6 is used that transmits signals from one or more sensors 7 to the fixed portion without contact. For example, a resistance wire strain gauge or a piezoelectric element is placed as a sensor 7 at the point of the axis l where the stress is greatest, and it receives an AC voltage from an AC power source 8 through the stator 9m and rotor b of the rotary transformer without contact. is supplied. At this time, this secondary garden path (fl 11b) is connected to the rotor 101 of another rotary transformer via the sensor 7, so that the measurement signal that changes with the mechanical stress can be transferred to this secondary garden path without contact. Stator 1 of the rotating transformer of
0b Ic is given, evaluation device 1 via amplification l111
2. The amplified measurement signal is information about the torsional stress of the shaft 1. The signal curve is displayed in the evaluation device (evaluation device) and compared with a previously stored reference curve.

As an evaluation device, a pre-stored standard-Ml is used.

C and the hysteresis **b representing the course of the measured signal during operation of axis 1. It is better to use the dust markings f 4 The reference curve C represents the hysteresis immediately before fatigue failure. When the line aK approaches, it is estimated that fatigue failure is near. In this case, the electric motor 3 is automatically cut off via the switching element ls (for example, a breaker).

Also, an acoustic or optical alarm device 14 can be connected to the evaluation device 12 to perform danger awareness. In this case, the device is manually stopped by maintenance personnel.

It is also possible to use a Vc11 degree sensor instead of a resistance wire strain gauge or piezoelectric element. This is because heat is generated as the strain on the shaft 1 progresses. The temperature rise of shaft 1 is an indicator of whether mechanical fatigue has progressed.

[Brief explanation of drawings]

The figure is a layout diagram of a device showing a 111th embodiment of the present invention. In the figure, 1 is a solid body, 3 is a machine, and 7 is a sensor. 12 is an evaluation device, 13 is an opening/closing element, and 14 is an alarm device. Reference 1Eb is a hysteresis line representing the course of the measurement signal.

Claims (1)

[Claims] 1) ll during periodic standard duty cycles! In an apparatus for detecting mechanical fatigue of a solid based on deformation 1, at least one sensor for detecting the deformation process of the solid is provided.
Detection of mechanical fatigue in a solid body in which the sensor is installed and the sensor signal is captured during periodic load cycles and compared with the reference value in the evaluation device 3. Button L 2, Claim 11 [Apparatus according to K] In C. A solid body characterized in that a measured value proportional to the mechanical stress and the deformation caused by it K is ascertained, indicated in the coordinates Vcll) of the measuring device of the evaluation device, and compared with a reference hysteresis curve stored in advance. Mechanical fatigue detection device. 3) In the device according to claim 11. A device for detecting mechanical fatigue of a solid, characterized in that a resistance wire strain cage is used as the sensor. 4) A device for detecting mechanical fatigue of a body according to claim 1, wherein a piezoelectric element is used as the sensor. 5) A device for detecting mechanical fatigue of a solid body according to claim 1, wherein a temperature sensor is used as the sensor. 6) Scope of patent claims! In the device according to any one of paragraphs 1 to 5, the evaluation device includes an opening/closing element.
A device for detecting mechanical fatigue of a solid body, in which the opening/closing element is configured to cut off the machine acting on the solid body when fatigue failure of the solid body being monitored approaches. ? ) @Claims In the device according to any one of claims 1 to 6, a solid mechanical device characterized in that an acoustic or optical alarm device is connected to the advance warning device. Fatigue horizontal 1 device.