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Predication method of stress relaxation life of torsion spring

A torsion spring and stress relaxation technology, applied in the field of predicting the life of torsion springs, can solve problems such as torsion springs that have not yet been found, and achieve the effects of reducing test costs and cycles, good reliability, and high prediction accuracy.

Inactive Publication Date: 2016-08-31
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] After searching, it is found that there are only reports on the predicted life of coil spring stress relaxation, and it has not been found that the relationship between the torque-time, torsion angle-time, and torque-torsion angle of the torsion spring is measured, and the stress relaxation curve of the torsion spring is used to predict the life of the torsion spring. papers or patents

Method used

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  • Predication method of stress relaxation life of torsion spring
  • Predication method of stress relaxation life of torsion spring
  • Predication method of stress relaxation life of torsion spring

Examples

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Embodiment 1

[0052] This embodiment adopts the torsion spring that adopts normalizing state beryllium bronze QBe2 to test, and the basic parameter of spring is: d 簧丝 =0.55mm, n=19, D 内径 = (2.4±0.25)mm. Before starting the test, first preheat the instrument for 1 h to eliminate the influence of the thermal expansion of the fixture on the test results. Four temperature points of 140°C, 160°C, 180°C and 200°C were selected as the test temperature. Because the spring wire is very thin, preheat the torsion spring for 5 minutes before loading. Then twist the spring at a torsion speed of 0.5° / s until the torsion angle is 65° and remains unchanged. The test duration is 24h. During the test, the computer automatically records the torque data every 1s.

[0053] At four temperature points of 140°C, 160°C, 180°C and 200°C, about 86,400 points were collected at each temperature point from the beginning of torsion to the end of the test, and representative points were selected at intervals of 7200 ...

Embodiment 2

[0059] Present embodiment adopts the torsion spring that adopts quenched state beryllium bronze QBe2 to test, and the basic parameter of spring is: d 簧丝 =0.55mm, n=19, D 内径 = (2.4±0.25)mm. Before starting the test, first preheat the instrument for 1 h to eliminate the influence of the thermal expansion of the fixture on the test results. Four temperature points of 140°C, 160°C, 180°C and 200°C were selected as the test temperature. Because the spring wire is very thin, preheat the torsion spring for 5 minutes before loading. Then twist the spring at a torsion speed of 0.5° / s until the torsion angle is 65° and remains unchanged. The test duration is 24h. During the test, the computer automatically records the torque data every 1s.

[0060] At four temperature points of 140°C, 160°C, 180°C and 200°C, about 86,400 points were collected at each temperature point from the beginning of torsion to the end of the test, and representative points were selected at intervals of 7200 ...

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Abstract

The invention discloses a predication method of the stress relaxation life of a torsion spring, and belongs to a torsion spring life prediction technology. The method comprises the following steps: drawing the torque-time curve of the torsion spring at different temperatures; drawing the internal stress-time curve of the torsion spring at different temperatures; reckoning the semi-logarithmic relationship between the relax rate and time; calculating a relaxation factor A room temperature and a relaxation factor B room temperature; and calculating the stress relaxation life of the torsion spring. The method is characterized in that the torque-time curve, the internal stress-time curve and the relaxation rate-time logarithm curve at a test temperature are obtained in a different temperature accelerated torsion spring mode, and a stress relaxation equation at a practical use temperature of the torque spring is derived to predicate the stress relaxation life of the torsion spring. The method has the advantages of high predication accuracy, effective reduction of the test cost and the cycle, and efficiency increase.

Description

technical field [0001] The invention relates to a method for predicting the stress relaxation life of a torsion spring, which belongs to the technology of predicting the life of a torsion spring. Background technique [0002] The essence of stress relaxation is that the material produces microplastic deformation under the action of stress, and gradually accumulates it. Under the premise of keeping the strain or displacement constant, it is a phenomenon that the stress decreases with time. Stress relaxation is a fairly common phenomenon. It exists not only in elastic elements or components made of metal materials, but also in components made of non-metallic materials. It is a variety of mechanical springs (such as valve springs and buffer springs, etc.) One of the main failure modes of elastic components in basic parts such as bolts, precision instruments and meters. These phenomena are not uncommon in daily life, and serious cases will cause huge economic losses. [0003] ...

Claims

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Application Information

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IPC IPC(8): G01N3/00G01M13/00
CPCG01N3/00G01M13/00G01N2203/0021G01N2203/0222
Inventor 师春生刘斌赵乃勤何春年刘恩佐李家俊
Owner TIANJIN UNIV
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