JP2008139259A - Metal fatigue testing machine and method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal fatigue testing machine capable of performing metal fatigue test at low speed and improving control responsiveness and provide a metal fatigue testing method using the same. <P>SOLUTION: A stepping motor 4 is fastened to a first coupling 2B for gripping one end of a test piece 1 for metal fatigue test. The first coupling 2B is mounted to a rotary shaft 4a, which is provided for the stepping motor, in such a way that the axis of the first coupling 2B may be matched with the axis S-S of the rotary shaft 4a. A second coupling 2A for gripping the other end of the test piece 1 for metal fatigue test is mounted in such a way that its axis may be matched with the axis S-S of the rotary shaft 4a provided for the stepping motor 4 in the metal fatigue testing machine and the metal fatigue testing method using the metal fatigue testing machine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metal fatigue tester and a metal fatigue test method using the metal fatigue tester, and relates to, for example, a metal fatigue test of a material.

  Solder is generally recognized as a conductive adhesive material having plasticity (or thermoplasticity). In recent years, various alloy components have been studied as lead-free solder materials. For example, lead-free solder materials having excellent tensile strength and creep characteristics have been developed.

  The strength required for lead-free solder materials in actual use is the relationship between the strain range (ie, amplitude) generated during use of the lead-free solder material and the number of strain repetitions (ie, fatigue life) until crack initiation. It is represented by

  The above-mentioned definition concerning the relationship between the distortion range and the distortion repetition number does not exist in the JIS (Japan Industrial Standard) standard. Therefore, the material manufacturer does not collect data regarding the relationship between the strain range and the number of strain repetitions, and the user needs to measure the data.

  Also, on the user side, commercially available metal fatigue testing machines (for example, electric bending / torsion fatigue testing machines, electrically controlled hydraulic tension / compression fatigue testing machines) can be applied for metal fatigue testing of lead-free solder materials. Conceivable.

  However, these commercially available metal fatigue testing machines are targeted at metal materials (mainly structural metal materials), so metal fatigue tests on low-strength alloys such as solder materials (for example, at low speed) It is not suitable for metal fatigue tests). Therefore, the user has performed a metal fatigue test using a modified metal fatigue tester for a metal fatigue test related to a solder material.

In addition, the metal fatigue testing machine provided with the stepping motor is also employ | adopted as the metal fatigue testing machine used for the said metal fatigue test (for example, refer patent document 1).
JP-A 2004-17093 (paragraphs [0024] to [0026] etc.).

  The metal fatigue testing machine as described above is designed on the premise of testing steel materials. The steel material has a feature that it is hardly affected by the test speed in a test performed at room temperature. Based on its characteristics, the above-described metal fatigue testing machine is designed to be able to test at high speed in order to shorten the test time.

  However, since the metal fatigue testing machine related to the solder material needs to perform the metal fatigue test at a low speed (for example, a speed corresponding to 1 cycle to 1 day), in the design of the above-mentioned metal fatigue testing machine, Not suitable for metal fatigue tests on solder materials.

  Moreover, the accuracy of the load detector provided in the above-described metal fatigue testing machine is designed with accuracy according to the strength of the steel material. Therefore, the test cannot be performed with accuracy according to the strength of the solder material (for example, a strength that is about one digit weaker than the steel material). That is, the metal fatigue test on the solder material requires a metal fatigue tester with improved load detection accuracy and control response.

  The present invention has been made on the basis of the above problems, and provides a metal fatigue tester that performs a metal fatigue test at a low speed and has improved control response, and a metal fatigue test method using the metal fatigue tester. It is to provide.

  In order to solve the above problems, the present invention provides a metal fatigue testing machine for testing metal fatigue of a test piece, wherein a stepping motor is fixed, and one end of the test piece is fixed. A first coupling to be gripped is installed on the rotating shaft so that its axis coincides with the axis of the rotating shaft provided in the stepping motor, and a second coupling for gripping the other end of the test piece has its axis Is installed so as to coincide with the axis of the rotary shaft provided in the stepping motor.

  The invention according to claim 2 is a metal fatigue test method, wherein the first coupling of the metal fatigue tester according to claim 1 is made to grip one end of the test piece, and the second cup of the metal fatigue tester is further provided. The other end of the test piece is gripped by a ring, a step signal corresponding to a sine wave simulating a torsion angle is given to the stepping motor of the metal fatigue testing machine, and the rotation of the rotating shaft of the stepping motor according to the step signal Torsional deformation is applied to the test piece, and the torsional torque between the test piece and the metal fatigue testing machine is detected.

  According to the first aspect of the present invention, the metal fatigue test can be performed with the stepping motor. The torsion from the stepping motor can be directly transmitted to the coupling.

  According to the second aspect of the invention, torsional deformation corresponding to an arbitrary torsion angle can be applied to the test piece.

  As described above, according to the first aspect of the present invention, the result of the metal fatigue test can be obtained. Moreover, the control responsiveness concerning a metal fatigue test can be improved.

  According to invention of Claim 2, the torsion torque concerning a test piece is detectable.

  These can contribute to the field of metal fatigue testing technology.

  Hereinafter, a metal fatigue tester and a metal fatigue test method according to embodiments of the present invention will be described in detail with reference to the drawings.

  In the present embodiment, the stepping motor is fixed, and the first coupling that grips one end of the metal fatigue test specimen has its axis aligned with the axis of the rotation axis provided in the stepping motor. A metal fatigue testing machine, wherein a second coupling that grips the other end of the test piece for metal fatigue testing is installed such that its axis coincides with the axis of the rotary shaft provided in the stepping motor, and This is a metal fatigue test method using a metal fatigue tester.

  The shape of a metal fatigue test specimen (hereinafter referred to as a test specimen) in the present embodiment will be described below with reference to FIG. FIG. 2A is a front view of the test piece. FIG. 2B is a side view of the test piece. 2A and 2B, the horizontal line passing through the center of gravity of the test piece is the HH line.

  The general shape of the test piece is a cylindrical shape. For example, like the test piece 1 in FIG. 2, a cylindrical shape (that is, a middle shape) is formed so that the body is gradually narrowed from the end surface toward the center of gravity. Thin cylindrical shape). A body of the test piece 1 (for example, a portion where the CC line in FIG. 2A intersects the test piece 1) is a target portion (that is, a test portion) 1c of the metal fatigue test.

  Chuck portions 1 a and 1 b are formed at both ends of the test piece 1 in order to hold the test piece 1. Further, an anti-slip groove 1d is formed in the chuck portions 1a and 1b so that the chuck portions 1a and 1b can be gripped more reliably.

  In addition, the said test piece 1 shall be comprised with the material (for example, solder material) which has plasticity.

  A configuration of a metal fatigue tester that performs a metal fatigue test using the test piece 1 will be described below with reference to FIG. FIG. 1 is a sectional view in the axial direction of the metal fatigue testing machine (axial sectional view with the SS line as the axis). Also, the description of the same reference numerals in FIG. 1 as those in FIG. 2 is omitted.

  In the metal fatigue testing machine 100 in FIG. 1, a stepping motor 4 for loading metal fatigue related to the test piece 1 is fixed to a main body (for example, a housing or a frame) of the metal fatigue testing machine 100.

  In addition, the said stepping motor 4 shall be equipped with the reduction gear (for example, built-in). The speed reducer has the following characteristics.

  The speed reducer can set the angle per step to 1/1000 ° or less. That is, arbitrary torsional deformation can be applied to the test piece 1.

  Since the reduction gear has a very small backlash, the torsion angle does not become smaller than the set value of the torsion angle due to the rigidity of the test piece. That is, highly accurate distortion control can be performed.

  In the metal fatigue testing machine 100, the couplings 2A and 2B for holding the test piece 1 are arranged so that their axes are aligned with the axis SS of the rotating shaft 4a of the stepping motor 4. . That is, in this arrangement, the test piece 1 is gripped by the couplings 2A and 2B, thereby forming a direct drive structure.

  In addition, the rotating shaft 4a and the coupling 2B in FIG. 1 are directly connected by the fixing screw 5C. Further, the coupling 2A in FIG. 1 is fixed to a part of the main body of the metal fatigue testing machine 100 (for example, the fixing portion 3 in FIG. 1).

  More specifically, the test piece 1 is gripped as follows.

  The chuck portion 1a formed at one end of the test piece 1 is inserted into the attachment hole 2Ba of the coupling 2B directly connected to the rotating shaft 4a provided in the stepping motor 4.

  Furthermore, by screwing the fixing screw 5B into the anti-slip groove (the portion indicated by reference numeral 1d in FIG. 2) of the coupling 2B and tightening the test piece 1, one end of the test piece 1 is gripped. It will be. In FIG. 1, the anti-slip groove portion is not shown.

  Further, the chuck portion 1 b formed at the other end of the test piece 1 is inserted into the mounting hole 2 Aa of the coupling 2 A fixed to the fixing portion 3.

  Furthermore, the other end of the test piece 1 is gripped by screwing the fixing screw 5A into the anti-slip groove portion of the coupling 2A and tightening the test piece 1.

  The couplings 2A and 2B may be exchangeable couplings that can be exchanged according to the shape of both ends of the test piece, for example. For example, the fixing screw 5C in FIG. 1 is loosened, the coupling 2B is removed from the rotating shaft 4a, the rotating shaft 4b is inserted into the mounting hole of another coupling, the fixing screw 5c is tightened, and the other coupling is rotated. This is a system directly connected to the shaft 4a.

  The metal fatigue test method in the present embodiment will be described below. In the following description, detailed description of what is indicated by the reference numerals in FIG. 1 is omitted.

  First, the test piece 1 is gripped by the couplings 2A and 2B of the metal fatigue testing machine 100 in FIG.

  Next, a step signal corresponding to a sine wave simulating a torsion angle is given to the stepping motor 4 of the metal fatigue testing machine 100, and torsional deformation is performed by rotation of the rotating shaft 4a of the stepping motor 4 according to the step signal. Is loaded on the test piece 1.

  That is, by selecting an arbitrary sine wave, an arbitrary torsional deformation can be applied to the test piece 1 regardless of time.

  In order to detect the torsion torque, between the metal fatigue testing machine 100 and the test piece 1 in FIG. 1 (for example, between the stepping motor 4 and the test piece 1 or between the fixing part 3 and the test piece 1). The torsional deformation of the coupling is measured with a strain gauge for torque measurement.

  For example, when measuring the torsional deformation of the coupling between the stepping motor 4 and the test piece 1 in FIG. 1, a torque measuring gauge 6 is installed on the rotating shaft 4a as shown in FIG. Measure.

  As described above, according to the present embodiment, it is possible to perform a metal fatigue test at an extremely low speed (for example, a speed at which one cycle of strain is repeated in one hour to one day) with an arbitrary sine waveform. .

  Further, the torsional deformation amount of the test piece can be measured with extremely high accuracy.

  Furthermore, since the apparatus (for example, a stepping motor and a reduction gear) which comprises the said metal fatigue testing machine is a common apparatus, this metal fatigue testing machine can be manufactured at low cost.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

  For example, as a modification in the present embodiment, a coupling and a rotating shaft are integrally formed to provide a rotating shaft with a coupling, or a coupling and a fixing portion of a metal fatigue testing machine are integrally formed to have a coupling. It may be a metal fatigue testing machine provided with a fixed part. That is, when performing a metal fatigue test on test pieces having chuck portions having different diameters, the metal fatigue test can be performed by exchanging the rotating shaft with coupling or the fixed portion with coupling.

Configuration diagram of metal fatigue testing machine in the present embodiment Schematic diagram of metal fatigue test specimen

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Metal fatigue test specimen 1a, 1b ... Chuck part 1c ... Test part 1d ... Anti-slip groove part 2A, 2B ... Coupling 2Aa, 2Ba ... Mounting hole 3 ... Fixed part 4 ... Stepping motor 4a ... Rotating shaft 5A , 5B, 5C ... Fixing screw 6 ... Gauge for torque measurement 100 ... Metal fatigue testing machine

Claims (2)

A metal fatigue testing machine for testing metal fatigue of a test piece,
Stepping motor is fixed,
A first coupling for gripping one end of the test piece is installed on the rotating shaft such that its axis coincides with the axis of the rotating shaft provided in the stepping motor;
A second coupling for gripping the other end of the test piece was installed with its axis aligned with the axis of the rotating shaft provided in the stepping motor;
A metal fatigue testing machine characterized by that. The first coupling of the metal fatigue testing machine according to claim 1 is made to grip one end of the test piece, and the second coupling of the metal fatigue testing machine is made to hold the other end of the test piece,
A step signal corresponding to a sine wave simulating a torsion angle is applied to the stepping motor of the metal fatigue testing machine, and torsional deformation is applied to the test piece by rotation of the rotation shaft of the stepping motor according to the step signal. And
Detecting torsion torque between the specimen and the metal fatigue testing machine;
Metal fatigue test method characterized by the above.

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