CN110542522A - A Dynamic Test Method for Stress Relaxation of Torsion Spring - Google Patents

A Dynamic Test Method for Stress Relaxation of Torsion Spring Download PDF

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CN110542522A
CN110542522A CN201810533327.3A CN201810533327A CN110542522A CN 110542522 A CN110542522 A CN 110542522A CN 201810533327 A CN201810533327 A CN 201810533327A CN 110542522 A CN110542522 A CN 110542522A
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torsion spring
torsion
angle
torque value
stress relaxation
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CN110542522B (en
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张慧博
李志鹏
金伟
任德春
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Institute of Metal Research of CAS
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01MTESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M5/00Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
    • G01M5/0041Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/32Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces

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Abstract

本发明涉及扭簧应力测试领域,尤其涉及一种扭簧应力松弛的动态测试方法。采用计算机程序控制扭转试验机循环载荷加载方式,模拟扭簧的实际使用工况,每周次循环中包含若干个微动循环;根据使用工况,在上下限扭转角度包括上下限的范围内、在加载和/或卸载过程中的任何角度,加载所需次数和振幅的微动循环,扭簧经多周次的全循环后测定扭矩值,并与试验前的初始扭矩值进行对比,确定其应力松弛行为。本发明的测试方法能够准确反映扭簧实际使用时的应力松弛情况,准确预测扭簧使用寿命,具有实际意义。The invention relates to the field of stress testing of torsion springs, in particular to a dynamic testing method for stress relaxation of torsion springs. The computer program is used to control the cyclic load loading mode of the torsion testing machine to simulate the actual working conditions of the torsion spring. Each cycle contains several fretting cycles; according to the working conditions, within the range of the upper and lower torsion angles including the upper and lower limits, At any angle during the loading and/or unloading process, load the required number and amplitude of micro-motion cycles, measure the torque value of the torsion spring after multiple full cycles, and compare it with the initial torque value before the test to determine its stress relaxation behavior. The test method of the invention can accurately reflect the stress relaxation situation of the torsion spring in actual use, accurately predict the service life of the torsion spring, and has practical significance.

Description

一种扭簧应力松弛的动态测试方法A Dynamic Test Method for Stress Relaxation of Torsion Spring

技术领域technical field

本发明涉及扭簧应力测试领域,尤其涉及一种扭簧应力松弛的动态测试方法。The invention relates to the field of stress testing of torsion springs, in particular to a dynamic testing method for stress relaxation of torsion springs.

背景技术Background technique

对弹簧或其它弹性元件而言,在承受静态载荷或动态交变载荷时都会发生承载能力随承载时间的延长而下降的现象,被称为应力松弛或弹性衰退,这是弹簧及弹性元件在服役过程中常见的失效形式。因此,测试并预测弹簧的应力松弛行为是研究弹簧使用寿命的重要手段。虽然,早在1868年J.c.Maxwell对应力松弛规律及其影响因素进行相关研究,然而迄今人们对应力松弛机制、发生条件等尚未建立起统一的理论,且无通用的应力松弛测试方法。我国在1988年颁发《金属应力松弛试验方法》(GB10120-88),但也只是对于结构件用棒材等金属材料等作标准规定,并没有针对弹簧产品的使用标准。For springs or other elastic elements, when they are subjected to static loads or dynamic alternating loads, the phenomenon that the bearing capacity decreases with the extension of the load time will occur, which is called stress relaxation or elastic decline. This is the spring and elastic elements in service. Common failure modes in the process. Therefore, testing and predicting the stress relaxation behavior of the spring is an important means to study the service life of the spring. Although, as early as 1868, J.c. Maxwell conducted relevant research on the law of stress relaxation and its influencing factors, but so far people have not established a unified theory on the mechanism and conditions of stress relaxation, and there is no general stress relaxation test method. my country issued the "Metal Stress Relaxation Test Method" (GB10120-88) in 1988, but it is only a standard for metal materials such as bars for structural parts, and there is no standard for the use of spring products.

对于弹簧产品来说,应力松弛试验方法可分为静态测试和动态测试两类,前者由于装置简单应用较多,但对于在复杂应力状态下工作的各种弹性元件或构件的应力松弛的评定仍不通用,不能够反应弹簧产品的实际使用情况。而动态测试方法是一种更加贴合实际的测试方法,因要求在循环载荷(即在弹簧最大载荷和最小载荷的范围内作往复运动)下实验,实验装置复杂、费时费事,很少被人采用。For spring products, stress relaxation test methods can be divided into two categories: static test and dynamic test. The former is widely used due to the simplicity of the device, but it is still difficult to evaluate the stress relaxation of various elastic elements or components working under complex stress states. It is not universal and cannot reflect the actual use of spring products. The dynamic test method is a more practical test method, because the test is required to be performed under cyclic load (that is, reciprocating motion within the range of the maximum load and the minimum load of the spring), the experimental device is complicated, time-consuming and troublesome, and is rarely used. use.

发明内容Contents of the invention

本发明的目的是提供一种扭簧应力松弛的动态测试方法,采用循环载荷加载方式,模拟扭簧的实际使用工况且包含若干个微动循环,解决目前扭簧应力测试方法偏差较大的问题。The purpose of the present invention is to provide a dynamic testing method for stress relaxation of torsion springs, which adopts a cyclic load loading method, simulates the actual working conditions of torsion springs and includes several fretting cycles, and solves the problem of large deviations in current torsion spring stress testing methods .

为了解决现有技术中存在的不足之处,本发明的技术方案是:In order to solve the deficiencies in the prior art, the technical solution of the present invention is:

一种扭簧应力松弛的动态测试方法,采用计算机程序控制扭转试验机循环载荷加载方式,模拟扭簧的实际使用工况,一个周次的循环中包含模拟实际工况的微动循环;根据使用工况,在上下限扭转角度包括上下限的范围内、在加载和/或卸载过程中的任何角度,加载所需次数和振幅的微动循环,并与试验前的初始扭矩值进行对比,确定其应力松弛行为。A dynamic test method for stress relaxation of torsion springs, using computer programs to control the cyclic load loading mode of torsion testing machines, simulating the actual working conditions of torsion springs, and including fretting cycles simulating actual working conditions in one cycle cycle; according to the use Working conditions, within the range of the upper and lower torsion angles including the upper and lower limits, at any angle during the loading and/or unloading process, the number of fretting cycles required for loading and the amplitude are compared with the initial torque value before the test to determine its stress relaxation behavior.

所述的扭簧应力松弛的动态测试方法,扭簧每个工作循环后都由计算机程序控制测定其扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低扭矩值最低容限值x%以上,试验结束;如果扭矩值降低小于扭矩值最低容限值x%,继续试验,直至达到指定工作循环后,试验结束。In the dynamic test method for the stress relaxation of the torsion spring, the torsion spring is controlled by a computer program to measure its torque value after each working cycle, and compared with the initial torque value before the test, if the torque value is lower than the minimum tolerance value of the torque value If the torque value is lower than x% of the minimum tolerance value of the torque value, continue the test until the specified working cycle is reached, and the test ends.

所述的扭簧应力松弛的动态测试方法,具体步骤如下:The dynamic testing method of described torsion spring stress relaxation, concrete steps are as follows:

(1)制备扭簧样品,将扭簧安装于夹具;(1) Prepare the torsion spring sample, and install the torsion spring on the fixture;

(2)根据实际使用工况,确定总循环周次N,加载角的最小扭转角α、最大扭转角β,微动角θ以及振幅△θ和振动次数n,扭矩值最低容限值x%;(2) According to the actual working conditions, determine the total cycle number N, the minimum torsion angle α, the maximum torsion angle β of the loading angle, the fretting angle θ, the amplitude △θ and the number of vibrations n, and the minimum tolerance value of the torque value x% ;

(3)根据实际使用工况,将扭簧扭转到最小扭转角;(3) According to the actual working conditions, twist the torsion spring to the minimum torsion angle;

(4)根据实际使用工况,将扭簧扭转到微动角;(4) According to the actual working conditions, twist the torsion spring to the inching angle;

(5)根据实际使用工况,在微动角附近做n次振幅为△θ的微动循环;(5) According to the actual working conditions, do n times of fretting cycles with an amplitude of △θ near the fretting angle;

(6)根据实际使用工况,如果存在两个以上的微动循环,则重复上述步骤4~5;(6) According to the actual working conditions, if there are more than two fretting cycles, repeat the above steps 4-5;

(7)根据实际使用工况,将扭簧加载到最大扭转角,测定扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低扭矩值最低容限值x%以上,试验结束;如果扭矩值降低小于扭矩值最低容限值x%,继续试验;(7) According to the actual working conditions, load the torsion spring to the maximum torsion angle, measure the torque value, and compare it with the initial torque value before the test. If the torque value decreases by more than x% of the minimum tolerance value of the torque value, the test ends; If the torque value decreases by less than x% of the minimum tolerance value of the torque value, continue the test;

(8)重复上述步骤3~7,直至循环次数达到总循环周次N后,试验结束。(8) Repeat steps 3 to 7 above until the number of cycles reaches the total number of cycles N, and the test ends.

所述的扭簧应力松弛的动态测试方法,夹具的组成和结构如下:The dynamic testing method of described torsion spring stress relaxation, the composition and structure of fixture are as follows:

夹具由夹头A、夹头B、芯杆三个部分组成,夹头A的外侧端与扭转试验机从动夹头端连接,夹头A外侧端的尺寸与形状由扭转试验机从动夹头端的尺寸和形状确定;夹头A的内侧端与扭簧端部连接,夹头A内侧端的尺寸与形状由扭簧端部的尺寸和形状确定;夹头B的外侧端与扭转试验机主动夹头端连接,夹头B外侧端的尺寸与形状由扭转试验机主动夹头端确定;夹头B的内侧端与扭簧端部连接,夹头B内侧端的尺寸与形状由扭簧端部的尺寸和形状确定;芯杆两端分别与夹头A和夹头B连接,扭簧套在芯杆上分别与夹头A和夹头B的内侧连接。The fixture consists of three parts: collet A, collet B and core rod. The outer end of collet A is connected to the driven collet end of the torsion testing machine. The size and shape of the outer end of collet A are determined by the driven collet of the torsion testing machine The size and shape of the end are determined; the inner end of the chuck A is connected to the end of the torsion spring, and the size and shape of the inner end of the chuck A are determined by the size and shape of the end of the torsion spring; the outer end of the chuck B is connected to the active clamp of the torsion testing machine The head end is connected, and the size and shape of the outer end of chuck B are determined by the active chuck end of the torsion testing machine; the inner end of chuck B is connected with the end of the torsion spring, and the size and shape of the inner end of chuck B are determined by the size of the end of the torsion spring and the shape is determined; the two ends of the core rod are respectively connected with the collet A and the collet B, and the torsion spring is sleeved on the core rod and connected with the inner sides of the collet A and the collet B respectively.

所述的扭簧应力松弛的动态测试方法,总循环周次N为≥10,加载角的最小扭转角α为1°~36000°,加载角的最大扭转角β为1°~36000°,微动角θ为α≤θ≤β,振幅△θ为≤0.4(β-α),振动次数n为≥2,扭矩值最低容限值x%为≤50%。In the dynamic test method for stress relaxation of torsion springs, the total number of cycles N is ≥ 10, the minimum torsion angle α of the loading angle is 1° to 36000°, and the maximum torsion angle β of the loading angle is 1° to 36000°. The dynamic angle θ is α≤θ≤β, the amplitude Δθ is ≤0.4(β-α), the number of vibrations n is ≥2, and the minimum tolerance value x% of the torque value is ≤50%.

所述的扭簧应力松弛的动态测试方法,扭簧材料和形状不受限制。In the dynamic test method for the stress relaxation of the torsion spring, the material and shape of the torsion spring are not limited.

所述的扭簧应力松弛的动态测试方法,扭簧样品尺寸与夹具尺寸根据需要进行调整,互不受限。In the dynamic test method for the stress relaxation of the torsion spring, the size of the torsion spring sample and the size of the fixture are adjusted according to needs, and are not limited by each other.

所述的扭簧应力松弛的动态测试方法,能够实时测量和记录扭转角对应的扭矩值,能够实时反映扭簧使用时的应力松弛情况。The dynamic test method for the stress relaxation of the torsion spring can measure and record the torque value corresponding to the torsion angle in real time, and can reflect the stress relaxation situation of the torsion spring in real time when it is used.

本发明的设计思想是:Design idea of the present invention is:

扭转弹簧(扭簧)用于各种机构中承受扭转力矩的场合,是常用的弹簧类型之一。它的用途十分广泛,大到飞机军舰,小到手机相机等各种产品均用到扭簧。在实际使用中,扭簧的使用工况是在最小扭转角和最大扭转角之间做往返运动,在一个周期的往返运动中,常常包含有在加载和(或)卸载过程中的、在最小扭转角和最大扭转角之间的某些或某个特定扭转角处的微小振动。因此,为了测试扭簧实际使用情况下的应力松弛行为,准确预测扭簧的使用寿命,本发明提出一种扭簧的应力松弛动态测试方法,能够模拟扭簧的实际使用工况。在测试过程中,扭簧不仅在最小扭转角和最大扭转角之间做周期性的往返转动,还包含在加载和(或)卸载过程中的、在某些或某个特定扭转角处的微小振动行为。Torsion springs (torsion springs) are used in various mechanisms to withstand torsional moments, and are one of the commonly used spring types. It has a wide range of uses, ranging from aircraft and warships to mobile phones and cameras and other products that use torsion springs. In actual use, the working condition of the torsion spring is to make a reciprocating motion between the minimum torsion angle and the maximum torsion angle. In a cycle of reciprocating motion, it often includes in the process of loading and (or) unloading, in the minimum Small vibrations at some or a specific twist angle between the twist angle and the maximum twist angle. Therefore, in order to test the stress relaxation behavior of the torsion spring under actual use conditions and accurately predict the service life of the torsion spring, the present invention proposes a dynamic test method for stress relaxation of the torsion spring, which can simulate the actual use conditions of the torsion spring. During the test, the torsion spring not only makes periodic reciprocating rotations between the minimum torsion angle and the maximum torsion angle, but also includes a small torsion at some or a specific torsion angle during the loading and (or) unloading process. vibration behavior.

扭簧通过专用安装夹具安装在扭转试验机上,专用安装夹具依据扭簧端部的形状和尺寸进行匹配设计和制造,该测试方法可以模拟任意尺寸和形状的扭簧实际使用工况下的应力松弛行为。测试过程采用计算机程序控制扭转试验机进行循环载荷加载的方式,根据扭簧的实际使用工况来确定试验参数,包括全循环载荷的加载周次、最小扭转角、最大扭转角、微动角及其振幅和振动次数、以及扭簧扭矩值的最低容限值等。The torsion spring is installed on the torsion testing machine through a special installation fixture. The special installation fixture is designed and manufactured according to the shape and size of the end of the torsion spring. This test method can simulate the stress relaxation of a torsion spring of any size and shape under actual working conditions. Behavior. The test process adopts the computer program to control the torsion testing machine for cyclic load loading. The test parameters are determined according to the actual use conditions of the torsion spring, including the loading cycle of the full cyclic load, the minimum torsion angle, the maximum torsion angle, the fretting angle and Its amplitude and frequency of vibration, as well as the minimum tolerance value of torsion spring torque value, etc.

本发明的优点及有益效果是:Advantage of the present invention and beneficial effect are:

1、本发明循环载荷加载中包含若干个微动循环,其作用和效果是:模拟扭簧实际使用工况,在最小扭转角和最大扭转角之间做周期性的往返转动,还包含在加载和(或)卸载过程中的、在某些或某个特定扭转角处的多次小角度的振动行为。1. The cyclic load loading of the present invention includes several fretting cycles, and its function and effect are: to simulate the actual working conditions of the torsion spring, to perform periodic reciprocating rotation between the minimum torsion angle and the maximum torsion angle, and also included in the loading And (or) multiple small-angle vibration behaviors at some or a specific torsion angle during the unloading process.

2、本发明能够准确实时测量和记录扭转角对应的扭矩值。2. The present invention can accurately measure and record the torque value corresponding to the torsion angle in real time.

3、本发明的测试方法能够准确反映任意尺寸和形状的扭簧实际使用时的应力松弛情况,准确预测扭簧的使用寿命。3. The test method of the present invention can accurately reflect the stress relaxation situation of the torsion spring with any size and shape during actual use, and accurately predict the service life of the torsion spring.

附图说明Description of drawings

图1为每次循环的工作循环曲线。图中,横坐标N代表循环周次(Cycle),纵坐标Torsion angle代表扭转角(°)。Figure 1 is the working cycle curve of each cycle. In the figure, the abscissa N represents the cycle number (Cycle), and the ordinate Torsion angle represents the torsion angle (°).

图2为第1~20000次循环的188°扭矩值曲线。图中,横坐标N代表循环周次(Cycle),纵坐标Torque代表扭簧扭矩(Nm)。Figure 2 is the 188° torque value curve of the 1st to 20000th cycle. In the figure, the abscissa N represents the number of cycles (Cycle), and the ordinate Torque represents the torsion spring torque (Nm).

图3为每次循环的工作循环曲线。Figure 3 is the working cycle curve of each cycle.

图4为第1~15000次循环的142°扭矩值曲线。Figure 4 is the 142° torque value curve of the 1st to 15,000 cycles.

图5为扭簧夹具结构示意图。图中,1.夹头A,2.夹头B,3.芯杆。Figure 5 is a schematic diagram of the structure of the torsion spring clamp. In the figure, 1. Chuck A, 2. Chuck B, 3. Core rod.

具体实施方式Detailed ways

在具体实施过程中,本发明扭簧应力松弛的动态测试方法,采用计算机程序控制扭转试验机循环载荷加载方式,模拟扭簧的实际使用工况。一个周次的循环中包含模拟实际工况的若干个微动循环,具体步骤如下:In the specific implementation process, the dynamic testing method for the stress relaxation of the torsion spring of the present invention uses a computer program to control the cyclic load loading mode of the torsion testing machine to simulate the actual working conditions of the torsion spring. A cycle cycle includes several fretting cycles simulating actual working conditions, the specific steps are as follows:

1、制备扭簧样品、专用安装夹具见图5,夹具的组成和结构如下:1. Prepare the torsion spring sample and the special installation fixture as shown in Figure 5. The composition and structure of the fixture are as follows:

夹具由夹头A1、夹头B2、芯杆3三个部分组成,夹头A1的外侧端与扭转试验机从动夹头端连接,夹头A1外侧端的尺寸与形状由扭转试验机从动夹头端的尺寸和形状确定。夹头A1的内侧端与扭簧端部连接,夹头A1内侧端的尺寸与形状由扭簧端部的尺寸和形状确定。夹头B2的外侧端与扭转试验机主动夹头端连接,夹头B2外侧端的尺寸与形状由扭转试验机主动夹头端确定。夹头B2的内侧端与扭簧端部连接,夹头B2内侧端的尺寸与形状由扭簧端部的尺寸和形状确定。芯杆3两端分别与夹头A1和夹头B2连接,扭簧套在芯杆3上分别与夹头A1和夹头B2的内侧连接,芯杆3的高度由扭簧工作高度确定。The fixture is composed of chuck A1, chuck B2, and core rod 3. The outer end of chuck A1 is connected to the driven chuck end of the torsion testing machine. The size and shape of the outer end of chuck A1 are determined by the driven chuck of the torsion testing machine. The size and shape of the head end is determined. The inner end of the chuck A1 is connected to the end of the torsion spring, and the size and shape of the inner end of the chuck A1 are determined by the size and shape of the end of the torsion spring. The outer end of the chuck B2 is connected to the active chuck end of the torsion testing machine, and the size and shape of the outer end of the chuck B2 are determined by the active chuck end of the torsion testing machine. The inner end of the chuck B2 is connected to the end of the torsion spring, and the size and shape of the inner end of the chuck B2 are determined by the size and shape of the end of the torsion spring. The two ends of the core rod 3 are respectively connected with the collet A1 and the collet B2, and the torsion spring is sleeved on the core rod 3 and respectively connected with the inner sides of the collet A1 and the collet B2, and the height of the core rod 3 is determined by the working height of the torsion spring.

本发明专用安装夹具所起的作用和达到的效果如下:The effect that special-purpose mounting fixture of the present invention plays and the effect that reaches are as follows:

夹头A1的内侧端与扭簧端部连接,将扭簧端部固定在夹头A1的内部,消除装配间隙后,可以实现扭簧端部与夹头A1的同步转动。夹头A1的外侧端与扭转试验机从动夹头端连接,将夹头A1的外侧端固定在扭转试验机从动夹头端内部,消除装配间隙后,可以实现夹头A1与扭转试验机从动夹头的同步转动,即实现扭簧端部与扭转试验机从动夹头的同步转动。夹头B2的内侧端与扭簧端部连接,将扭簧端部固定在夹头B2的内部,消除装配间隙后,可以实现扭簧端部与夹头B2的同步转动。夹头B2的外侧端与扭转试验机主动夹头端连接,将夹头B2的外侧端固定在扭转试验机主动夹头端内部,消除装配间隙后,可以实现夹头B2与扭转试验机主动夹头的同步转动,即实现扭簧端部与扭转试验机主动夹头的同步转动。将扭簧套在芯杆3上,同时安装在夹头A1和夹头B2的内侧端,实现扭簧的安装高度即为扭簧的工作高度。芯杆3两端分别与夹头A1和夹头B2连接,以保证夹头A1和夹头B2的同轴度。专用安装夹具可以实现扭簧与扭转试验机同步转动,且保证扭簧与扭转试验机的同轴度。The inner end of the collet A1 is connected with the end of the torsion spring, and the end of the torsion spring is fixed inside the collet A1. After eliminating the assembly gap, the synchronous rotation of the end of the torsion spring and the collet A1 can be realized. The outer end of the chuck A1 is connected with the driven chuck end of the torsion testing machine, and the outer end of the chuck A1 is fixed inside the driven chuck end of the torsion testing machine. After eliminating the assembly gap, the connection between the chuck A1 and the torsion testing machine can be realized. The synchronous rotation of the driven chuck is to realize the synchronous rotation of the end of the torsion spring and the driven chuck of the torsion testing machine. The inner end of the collet B2 is connected with the end of the torsion spring, and the end of the torsion spring is fixed inside the collet B2. After eliminating the assembly gap, the synchronous rotation of the end of the torsion spring and the collet B2 can be realized. The outer end of the chuck B2 is connected with the active chuck end of the torsion testing machine, and the outer end of the chuck B2 is fixed inside the active chuck end of the torsion testing machine. After eliminating the assembly gap, the chuck B2 and the active chuck of the torsion testing machine can be realized. The synchronous rotation of the head, that is, the synchronous rotation of the end of the torsion spring and the active chuck of the torsion testing machine. Put the torsion spring on the core rod 3, and install it on the inner side of the chuck A1 and the chuck B2 at the same time, so that the installation height of the torsion spring is the working height of the torsion spring. The two ends of the core rod 3 are respectively connected with the collet A1 and the collet B2 to ensure the coaxiality of the collet A1 and the collet B2. The special installation fixture can realize the synchronous rotation of the torsion spring and the torsion testing machine, and ensure the coaxiality of the torsion spring and the torsion testing machine.

2、根据实际使用工况,确定总循环周次N,加载角的最小扭转角α、最大扭转角β,微动角θ以及振幅△θ和振动次数n,扭矩值最低容限值x%;其中,总循环周次N为≥10,加载角的最小扭转角α为1°~36000°,加载角的最大扭转角β为1°~36000°,微动角θ为α≤θ≤β,振幅△θ为≤0.4(β-α),振动次数n为≥2,扭矩值最低容限值x%为≤50%;2. According to the actual working conditions, determine the total cycle times N, the minimum torsion angle α, the maximum torsion angle β of the loading angle, the fretting angle θ, the amplitude △θ and the number of vibrations n, and the minimum tolerance value of the torque value x%; Among them, the total number of cycles N is ≥ 10, the minimum torsion angle α of the loading angle is 1° to 36000°, the maximum torsion angle β of the loading angle is 1° to 36000°, and the fretting angle θ is α≤θ≤β, The amplitude △θ is ≤0.4(β-α), the number of vibrations n is ≥2, and the minimum tolerance value x% of the torque value is ≤50%;

3、根据实际使用工况,将扭簧扭转到最小扭转角;3. According to the actual working conditions, twist the torsion spring to the minimum torsion angle;

4、根据实际使用工况,将扭簧扭转到微动角;4. According to the actual working conditions, twist the torsion spring to the inching angle;

5、根据实际使用工况,在微动角附近做n次振幅为△θ的微动循环,微动循环的具体含义是:模拟扭簧实际使用工况中在某个/某些特定角度θ附近做n次△θ角度的振动行为;5. According to the actual working conditions, do n times of fretting cycles with an amplitude of △θ near the fretting angle. Do n times of vibration behavior at △θ angle nearby;

6、根据实际使用工况,如果存在多个微动循环,则重复上述步骤4~5;6. According to the actual working conditions, if there are multiple fretting cycles, repeat the above steps 4-5;

7、根据实际使用工况,将扭簧加载到最大扭转角,测定扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低x%以上,试验结束;如果扭矩值降低小于x%,继续试验;7. According to the actual working conditions, load the torsion spring to the maximum torsion angle, measure the torque value, and compare it with the initial torque value before the test. If the torque value decreases by more than x%, the test ends; if the torque value decreases by less than x% , to continue the test;

8、重复上述步骤3~7,直至循环次数达到总循环周次N后,试验结束。8. Repeat steps 3 to 7 above until the number of cycles reaches the total number of cycles N, and the test ends.

以下结合具体实施例对上述方案作进一步的说明。应该声明的是,这些实施例仅用于说明本发明而不限于本发明的范围。凡是基于本发明进行的研究方案(做同等变化和改进的行为),均应属于本发明保护范围。The above scheme will be further described below in conjunction with specific examples. It should be noted that these examples are only for illustrating the present invention and do not limit the scope of the present invention. All research schemes carried out based on the present invention (behaviors of making equivalent changes and improvements) should belong to the protection scope of the present invention.

实施例1:Example 1:

本实施例中,扭簧实际使用工况参数见下表1,扭簧共完成20000次工作循环应力松弛试验,每次循环的工作循环曲线见图1,由表1和图1可以看出,该扭簧的实际使用工况是:首先将扭簧加载至最小扭转角97°→在(97°±15°)附近振动7次,最终停止在97°→扭簧继续加载到143°,并有(143±10)°的振动5次,最终停止在微动角143°→继续加载至最大扭转角188°→卸载到最小扭转角97°。扭簧每个工作循环后,测定其最大扭转角188°的扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低5%以上,试验结束;如果扭矩值降低小于5%,继续试验直至完成20000个工作循环后,试验结束。In this embodiment, the actual working condition parameters of the torsion spring are shown in Table 1 below. The torsion spring has completed 20,000 working cycle stress relaxation tests in total, and the working cycle curve of each cycle is shown in Figure 1. As can be seen from Table 1 and Figure 1, The actual working condition of the torsion spring is: first load the torsion spring to the minimum torsion angle of 97° → vibrate 7 times near (97°±15°), and finally stop at 97° → continue to load the torsion spring to 143°, and There are (143±10)°vibrations for 5 times, and finally stop at the fretting angle of 143°→continue to load to the maximum torsion angle of 188°→unload to the minimum torsion angle of 97°. After each working cycle of the torsion spring, measure the torque value of its maximum torsion angle of 188°, and compare it with the initial torque value before the test. If the torque value decreases by more than 5%, the test ends; if the torque value decreases by less than 5%, continue The test ends after 20,000 working cycles are completed.

表1扭簧实际使用工况参数Table 1 Actual working condition parameters of torsion spring

1~20000次工作循环,每次循环中188°的扭矩值曲线见图2,扭簧应力松弛试验前后扭矩的检验结果见表2,由图2和表2可以看出,该扭簧经过20000周次工作循环后扭矩值变化+0.1%,说明该扭簧经20000周次全循环试验后未发生应力松弛,满足扭矩值最低容限<5%的要求,扭簧未失效。1 to 20,000 working cycles, the torque value curve of 188° in each cycle is shown in Figure 2, and the torque test results before and after the stress relaxation test of the torsion spring are shown in Table 2. It can be seen from Figure 2 and Table 2 that the torsion spring has passed through 20,000 The torque value changes +0.1% after one cycle of working cycle, indicating that the torsion spring has no stress relaxation after 20,000 cycles of full cycle test, meets the requirement of the minimum tolerance of torque value <5%, and the torsion spring has not failed.

表2扭簧应力松弛试验前后扭矩的检验结果Table 2 Test results of torque before and after torsion spring stress relaxation test

实施例2:Example 2:

本实施例中,扭簧实际使用工况参数见下表3,扭簧共完成15000次工作循环应力松弛试验,每次循环的工作循环曲线见图3,由表3和图3可以看出,该扭簧的实际使用工况是:首先将扭簧加载至最小扭转角82°→继续加载至微动角107°→在(107°±10°)附近振动14次,最终停止在微动角107°→继续加载至最大扭转角142°→卸载到最小扭转角82°。扭簧每个工作循环后,测定其最大扭转角142°的扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低10%以上,试验结束;如果扭矩值降低小于10%,继续试验直至完成15000个工作循环后,试验结束。In this embodiment, the parameters of the actual operating conditions of the torsion spring are shown in Table 3 below. The torsion spring has completed 15,000 working cycle stress relaxation tests in total. The working cycle curve of each cycle is shown in Figure 3. As can be seen from Table 3 and Figure 3, The actual working condition of the torsion spring is: first load the torsion spring to the minimum torsion angle of 82°→continue to load to the micro-motion angle of 107°→vibrate 14 times around (107°±10°), and finally stop at the micro-motion angle 107°→continue to load to the maximum torsion angle of 142°→unload to the minimum torsion angle of 82°. After each working cycle of the torsion spring, measure the torque value of its maximum torsion angle of 142°, and compare it with the initial torque value before the test. If the torque value decreases by more than 10%, the test ends; if the torque value decreases by less than 10%, continue The test ends after 15,000 working cycles are completed.

表3扭簧实际使用工况参数Table 3 Actual working condition parameters of torsion spring

1~15000次每次循环中142°的扭矩值曲线见图4,扭簧应力松弛试验前后扭矩的检验结果见表4,由图4和表4可以看出,该扭簧经过15000周次工作循环后扭矩值变化+0.4%,说明该扭簧经15000周次全循环试验后未发生应力松弛,满足扭矩值最低容限<10%的要求,扭簧未失效。The torque value curve of 142° in each cycle from 1 to 15,000 times is shown in Figure 4, and the test results of the torque before and after the torsion spring stress relaxation test are shown in Table 4. It can be seen from Figure 4 and Table 4 that the torsion spring has worked 15,000 times After the cycle, the torque value changes by +0.4%, indicating that the torsion spring has no stress relaxation after 15,000 cycles of the full cycle test, and the torsion spring has not failed.

表4扭簧应力松弛试验前后扭矩的检验结果Table 4 Torque inspection results before and after torsion spring stress relaxation test

实施例结果表明,本发明采用计算机程序控制扭转试验机循环载荷加载方式,模拟扭簧的实际使用工况,每周次循环中包含若干个微动循环,扭簧经多周次的全循环后测定扭矩值,并与试验前的初始扭矩值进行对比,确定其应力松弛行为。本发明的测试方法能够准确反映扭簧实际使用时的应力松弛情况,准确预测扭簧使用寿命,具有实际意义。The result of the embodiment shows that the present invention adopts the computer program to control the cyclic load loading mode of the torsion testing machine to simulate the actual working conditions of the torsion spring. Each cycle includes several micro-movement cycles, and the torsion spring passes through multiple rounds of full cycles. Measure the torque value and compare it with the initial torque value before the test to determine its stress relaxation behavior. The test method of the invention can accurately reflect the stress relaxation situation of the torsion spring in actual use, accurately predict the service life of the torsion spring, and has practical significance.

Claims (8)

1.一种扭簧应力松弛的动态测试方法,其特征在于,采用计算机程序控制扭转试验机循环载荷加载方式,模拟扭簧的实际使用工况,一个周次的循环中包含模拟实际工况的微动循环;根据使用工况,在上下限扭转角度包括上下限的范围内、在加载和/或卸载过程中的任何角度,加载所需次数和振幅的微动循环,并与试验前的初始扭矩值进行对比,确定其应力松弛行为。1. a dynamic testing method of torsion spring stress relaxation, it is characterized in that, adopt computer program control torsion testing machine cyclic load loading mode, simulate the actual working condition of torsion spring, comprise the simulation of actual working condition in the cycle of a cycle Micro-movement cycle; according to the working conditions, within the range of the upper and lower limit torsion angles including the upper and lower limits, at any angle during the loading and/or unloading process, load the required number of times and amplitude of the fretting cycle, and compare with the initial test before the test Torque values were compared to determine its stress relaxation behavior. 2.根据权利要求1所述的扭簧应力松弛的动态测试方法,其特征在于,扭簧每个工作循环后都由计算机程序控制测定其扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低扭矩值最低容限值x%以上,试验结束;如果扭矩值降低小于扭矩值最低容限值x%,继续试验,直至达到指定工作循环后,试验结束。2. the dynamic testing method of torsion spring stress relaxation according to claim 1, is characterized in that, after torsion spring every working cycle, all is measured its torque value by computer program control, and compares with the initial torque value before test, If the torque value decreases by more than x% of the minimum tolerance value of the torque value, the test ends; if the torque value decreases by less than x% of the minimum tolerance value of the torque value, the test continues until the specified working cycle is reached, and the test ends. 3.根据权利要求1所述的扭簧应力松弛的动态测试方法,其特征在于,具体步骤如下:3. the dynamic testing method of torsion spring stress relaxation according to claim 1, is characterized in that, concrete steps are as follows: (1)制备扭簧样品,将扭簧安装于夹具;(1) Prepare the torsion spring sample, and install the torsion spring on the fixture; (2)根据实际使用工况,确定总循环周次N,加载角的最小扭转角α、最大扭转角β,微动角θ以及振幅△θ和振动次数n,扭矩值最低容限值x%;(2) According to the actual working conditions, determine the total cycle number N, the minimum torsion angle α, the maximum torsion angle β of the loading angle, the fretting angle θ, the amplitude △θ and the number of vibrations n, and the minimum tolerance value of the torque value x% ; (3)根据实际使用工况,将扭簧扭转到最小扭转角;(3) According to the actual working conditions, twist the torsion spring to the minimum torsion angle; (4)根据实际使用工况,将扭簧扭转到微动角;(4) According to the actual working conditions, twist the torsion spring to the inching angle; (5)根据实际使用工况,在微动角附近做n次振幅为△θ的微动循环;(5) According to the actual working conditions, do n times of fretting cycles with an amplitude of △θ near the fretting angle; (6)根据实际使用工况,如果存在两个以上的微动循环,则重复上述步骤4~5;(6) According to the actual working conditions, if there are more than two fretting cycles, repeat the above steps 4-5; (7)根据实际使用工况,将扭簧加载到最大扭转角,测定扭矩值,并与试验前的初始扭矩值进行对比,如果扭矩值降低扭矩值最低容限值x%以上,试验结束;如果扭矩值降低小于扭矩值最低容限值x%,继续试验;(7) According to the actual working conditions, load the torsion spring to the maximum torsion angle, measure the torque value, and compare it with the initial torque value before the test. If the torque value decreases by more than x% of the minimum tolerance value of the torque value, the test ends; If the torque value decreases by less than x% of the minimum tolerance value of the torque value, continue the test; (8)重复上述步骤3~7,直至循环次数达到总循环周次N后,试验结束。(8) Repeat steps 3 to 7 above until the number of cycles reaches the total number of cycles N, and the test ends. 4.根据权利要求3所述的扭簧应力松弛的动态测试方法,其特征在于,夹具的组成和结构如下:4. the dynamic testing method of torsion spring stress relaxation according to claim 3, is characterized in that, the composition and structure of fixture are as follows: 夹具由夹头A、夹头B、芯杆三个部分组成,夹头A的外侧端与扭转试验机从动夹头端连接,夹头A外侧端的尺寸与形状由扭转试验机从动夹头端的尺寸和形状确定;夹头A的内侧端与扭簧端部连接,夹头A内侧端的尺寸与形状由扭簧端部的尺寸和形状确定;夹头B的外侧端与扭转试验机主动夹头端连接,夹头B外侧端的尺寸与形状由扭转试验机主动夹头端确定;夹头B的内侧端与扭簧端部连接,夹头B内侧端的尺寸与形状由扭簧端部的尺寸和形状确定;芯杆两端分别与夹头A和夹头B连接,扭簧套在芯杆上分别与夹头A和夹头B的内侧连接。The fixture consists of three parts: collet A, collet B and core rod. The outer end of collet A is connected to the driven collet end of the torsion testing machine. The size and shape of the outer end of collet A are determined by the driven collet of the torsion testing machine The size and shape of the end are determined; the inner end of the chuck A is connected to the end of the torsion spring, and the size and shape of the inner end of the chuck A are determined by the size and shape of the end of the torsion spring; the outer end of the chuck B is connected to the active clamp of the torsion testing machine The head end is connected, and the size and shape of the outer end of chuck B are determined by the active chuck end of the torsion testing machine; the inner end of chuck B is connected with the end of the torsion spring, and the size and shape of the inner end of chuck B are determined by the size of the end of the torsion spring and the shape is determined; the two ends of the core rod are respectively connected with the collet A and the collet B, and the torsion spring is sleeved on the core rod and connected with the inner sides of the collet A and the collet B respectively. 5.根据权利要求3所述的扭簧应力松弛的动态测试方法,其特征在于,总循环周次N为≥10,加载角的最小扭转角α为1°~36000°,加载角的最大扭转角β为1°~36000°,微动角θ为α≤θ≤β,振幅△θ为≤0.4(β-α),振动次数n为≥2,扭矩值最低容限值x%为≤50%。5. The dynamic testing method of torsion spring stress relaxation according to claim 3, characterized in that the total cycle times N is ≥ 10, the minimum torsion angle α of the loading angle is 1°~36000°, and the maximum torsion angle of the loading angle is 1°~36000°. The angle β is 1°~36000°, the fretting angle θ is α≤θ≤β, the amplitude △θ is ≤0.4(β-α), the number of vibrations n is ≥2, and the minimum tolerance value x% of the torque value is ≤50 %. 6.根据权利要求1至5之一所述的扭簧应力松弛的动态测试方法,其特征在于,扭簧材料和形状不受限制。6. The dynamic testing method for stress relaxation of a torsion spring according to any one of claims 1 to 5, wherein the material and shape of the torsion spring are not limited. 7.根据权利要求1至5之一所述的扭簧应力松弛的动态测试方法,其特征在于,扭簧样品尺寸与夹具尺寸根据需要进行调整,互不受限。7. The dynamic test method for stress relaxation of torsion spring according to any one of claims 1 to 5, characterized in that the size of the torsion spring sample and the size of the fixture are adjusted as required and are not limited to each other. 8.根据权利要求1至5之一所述的扭簧应力松弛的动态测试方法,其特征在于,能够实时测量和记录扭转角对应的扭矩值,能够实时反映扭簧使用时的应力松弛情况。8. The dynamic testing method for stress relaxation of a torsion spring according to any one of claims 1 to 5, characterized in that the torque value corresponding to the torsion angle can be measured and recorded in real time, and the stress relaxation situation when the torsion spring is used can be reflected in real time.
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