KR20100002489A - Testing apparatus of load and testing method using the same - Google Patents

Abstract

PURPOSE: A micro load testing apparatus and a testing method thereof are provided to perform various tests on micro materials by calculating minute load through the driving force of a voice coil motor. CONSTITUTION: A voice coil motor(42) comprises a driver(421). According to supply of the power source, the driver straightly moves. An elastic member(44) is connected to the driver. A probe(43) is fixed to the driver or the elastic member. The probe is extended to a test piece. A sensor senses the displacement of the voice coil motor.

Description

Micro Load Tester and Test Method Using the Same {TESTING APPARATUS OF LOAD AND TESTING METHOD USING THE SAME}

The present invention relates to a load test apparatus for applying a load to a specimen to perform a tensile test, compression test, cyclic vibration test, thin film peeling test, and the like.

In general, micro load test apparatus for performing tensile test, compression test, cyclic vibration test, thin film peeling test, etc. for micro-unit materials is equipped with expensive transfer device such as piezoelectric actuator and displacement sensor for fine driving. In order to measure the micro load, an expensive load sensor such as a load cell is provided.

However, the conventional load test apparatus has a problem that the equipment is complicated, bulky, and expensive by providing an expensive transfer device and a displacement sensor and a load sensor for measuring the same.

The present invention is to solve the above problems, an object of the present invention to the displacement of the voice coil motor and the voice coil motor according to the amount of current applied while applying the load to the specimen using the driving force of the simple structure of the voice coil motor. By calculating the micro load from the correlation with the elastic modulus of the elastic member that provides the elastic restoring force, there is provided a micro load test apparatus that can perform the test on the material in micro units without using an expensive load sensor such as a load cell. It's there.

Micro load test apparatus according to the present invention for achieving the above object is a voice coil motor including a mover moving in a linear form according to the application of power, an elastic member connected to the mover, and fixed to the mover or elastic member And a probe extending toward the specimen, and a sensing sensor for detecting displacement of the voice coil motor.

Here, it is preferable for the elastic member to consist of a leaf spring attached to at least one side in the moving direction of the mover to simplify its structure.

The sensing sensor may include a light emitting unit for irradiating laser light and a light receiving unit for receiving laser light reflected from the specimen.

In addition, the test method using a micro load test apparatus according to the present invention for achieving the above object of the present invention, the voice coil motor including a mover moving in a linear form according to the application of a power source, and is connected to the mover In the load test apparatus including the elastic member, the first step of calculating data on the change in displacement amount (d) of the voice coil motor according to the change in the amount of applied current in the absence of the specimen, while applying a load to the specimen, The second step of measuring the current amount (i) applied to the voice coil motor and the displacement amount (d1) of the voice coil motor, the data calculated in the first step and the current amount (i) in the second step and the second step A third step of calculating the displacement amount d2 of the voice coil motor which cannot be displaced due to the presence of the specimen from the displacement amount d1 of the voice coil motor, the displacement amount d2 of the voice coil motor calculated in the third step, Devices coil using a modulus (Ks) of the motor constant (Ke) and the elastic member of the motor may be configured to include a fourth step of measuring the load applied to the specimen.

Micro load test apparatus according to the present invention is the elasticity of the elastic member for providing the elastic restoring force to the voice coil motor and the displacement amount of the voice coil motor according to the amount of current applied while applying the load to the specimen using the driving force of the simple voice coil motor By calculating the micro loads from the correlation with the coefficients, it is possible to perform tensile tests, compression tests, cyclic vibration tests, thin film peel tests, etc. on micro-materials without using expensive load sensors such as load cells.

Therefore, the micro load test apparatus according to the present invention can simplify the structure and reduce the size of the device, and can reduce the material cost of the device.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the load test apparatus according to the present invention.

As shown in Figure 1 and 2, the micro load test apparatus according to the present invention, the specimen table (2) on which the specimen (1) is seated, the table transfer device (3) for conveying the specimen table (2) and A measuring module 4 disposed on an opposite side of the specimen table 2 for applying and measuring an external load to the specimen 1, and positioned at one side of the specimen table 2, and having the measurement module 4 mounted thereon. It can be configured to include a measuring module mounting device (5).

The table transfer apparatus 3 may include an X-axis transfer unit 31, a Y-axis transfer unit 32, and a Z-axis transfer unit 33 so as to transfer the specimen table 2 in three axes. Accordingly, the specimen table 2 may be transferred to transfer the specimen 1 to the measurement position of the measurement module 4. However, the present invention is not limited thereto, and a configuration capable of transferring the measurement module 4 to at least one axis may be applied to the measurement module mounting apparatus 5. The table transfer device 3 may be applied automatically or manually.

The measurement module 4 includes a mover 421 disposed inside the housing 41 and a stator 422 disposed to be spaced apart from the mover 421 by a predetermined distance around the mover 421. The voice coil motor 42, the probe 43 fixed to the movable member 421 of the voice coil motor 42 and extending toward the specimen table 2 to pressurize the specimen 1, and the housing 41. Fixed to the elastic member 44 to impart an elastic restoring force to the voice coil motor 42, and is installed to be spaced apart from the voice coil motor 42 by a predetermined distance to detect the movement displacement of the voice coil motor 42 It is configured to include a sensor 45.

As shown in FIGS. 2 and 3, the mover 421 of the voice coil motor 42 extends from the main main body 423 and the main body 423 and is wound with a coil 425. It may be configured to include a carrier 424 disposed from the stator 422 with a predetermined gap. In addition, a yoke portion 426 extending from the stator 422 may be disposed between the main body 423 and the coil 425.

The mover 421 of the voice coil motor 42 may be formed in a cylindrical shape, but is not limited thereto, and may be formed in various shapes such as a quadrangular shape. The stator 422 may be made of a permanent magnet or an electromagnet.

When a current is applied to the coil 425 of the mover 421, the voice coil motor 42 may move the mover by the electromagnetic interaction (the Fleming's left hand law) between the mover 421 and the stator 422. 421 may move in a straight line.

Here, as shown in FIG. 4, as the amount of current i applied to the coil 425 of the mover 421 increases, the movement displacement d of the mover 421 increases, and the amount of current increases. The smaller the number (i), the smaller the displacement (d) d1 of the mover 421. Therefore, by measuring the amount of current i applied to the coil 425, it is possible to calculate the displacement amount d (d1) of the mover.

The probe 43 preferably extends coaxially with the central axis of the mover 421. The probe 43 serves to apply a direct load to the specimen 1 while being moved in the axial direction by the linear movement of the mover 421. In the embodiment of the present invention, a structure in which the probe 43 is connected to the mover 421 is provided, but the present invention is not limited thereto, and a structure in which the probe 43 is fixed to the elastic member 44 may be applied. .

The elastic member 44 is preferably made of a leaf spring connected to the circumference of the housing 41 and the main body 423 of the mover 421 to simplify the structure. In addition, it is preferable that the elastic member 44 is connected to one surface to which the probe 43 of the main body 423 is connected or one side to the opposite side thereof so that the elastic force can be properly applied to the mover 421. Such an elastic member 44 serves to act as an elastic restoring force inversely proportional to the displacement of the linear movement of the mover 421. In the embodiment of the present invention, a configuration in which the leaf spring is applied to the elastic member 44 is provided, but the present invention is not limited thereto, and a spring having various configurations, such as a coil spring, may be applied to the elastic member 44.

On the other hand, the elastic member 44 is connected to both the one surface on which the probe 43 of the movable member 421 is fixed and the opposite side thereof, that is, the front and rear sides of the movable member 421 in the linear movement direction (the movable member (42). 421 is preferable to prevent the tilting phenomenon which is eccentric at a predetermined angle from the central axis during the displacement.

The elastic modulus Ks of the elastic member 44 is preset through experiments or simulations, and the movable element 421 for the elastic modulus Ks value and the predetermined applied current value i of the elastic member 44 is preset. The load applied to the specimen 1 can be measured from the displacement amount d (d1).

The sensor 45 measures the displacement of the linear movement of the mover 421, and is spaced apart by a predetermined distance in the extending direction of the movement center axis of the mover 421, and moves the laser light to the mover 421. Alternatively, an optical sensor configured to include a light emitting unit for irradiating the elastic member 44 and a light receiving unit for receiving the laser light reflected from the movable member 421 or the elastic member 44 may be applied. However, the present invention is not limited to the application of the optical sensor as the sensor 45, a variety of sensors that can measure the micro displacement of the movable member 421 or the elastic member 44 may be applied.

5 to 7, the operation and test method of the load test apparatus according to the present invention configured as described above will be described.

First, prior to the load test on the specimen (1), the elastic modulus (Ks) of the elastic member 44 is measured by experiment or simulation.

Then, the assembly and the detection sensor 45, which combines the elastic member 44 within the optimum measurement range for the test of the test specimen 1 with the mover 421 of the voice coil motor 42, is equipped with a measurement module mounting apparatus ( 5) Mount on. Here, as shown in FIG. 5, the optimum range of the elastic member 44 measures the change in the movement of the elastic member 44 with respect to the change in the force applied to the elastic member 44, and from the measured data The section showing the slope can be obtained by selecting an optimal section.

Then, data about the change in the displacement amount d of the voice coil motor 42 according to the change in the applied current amount i in the case where there is no specimen 1 is calculated (S10). The displacement amount d of the voice coil motor 42 is measured by the sensor 45 irradiating the laser light to the mover 421 and receiving the laser light reflected from the mover 421. .

Here, when the specimen 1 is present, the displacement of the voice coil motor 42 is reduced by the repulsive force of the specimen 1. The displacement of the voice coil motor 42 with respect to the constant current amount i in the absence of the specimen 1 is referred to as d, and the displacement of the voice coil motor 42 with respect to the constant current amount i when the specimen 1 is present. When the displacement is called d1, and the displacement that the voice coil motor 42 cannot move due to the presence of the specimen (1) is called d2, these relations are as shown in Equation 1 below.

d = d1 + d2

When the measurement of the change in the displacement amount d of the voice coil motor 42 to the change in the applied current amount i in the absence of the elastic modulus Ks of the elastic member 44 and the test piece 1 is completed, the test piece After seating the specimen (1) on the table (2), the measuring module mounting device (5) or table feeder (3) is operated to transfer the measuring module (4) or specimen (1) to the optimum position for the load test. do.

Then, when power is applied to the mover 421 of the voice coil motor 42, the mover 421 is displaced in a straight line, whereby the probe 43 connected to the mover 421 is a specimen (1). It is moved toward) to apply a load to the specimen (1).

At the same time, the amount of current i applied to the coil 425 of the mover 421 is measured, and the displacement amount d1 of the voice coil motor 42 is measured using the detection sensor 45 (S20).

Then, when the loaded specimen 1 is deformed to a desired shape, for example, when the specimen 1 is destroyed in the case of the fracture test of the specimen 1, the current amount i and the voice at that instant By measuring the displacement amount d1 of the coil motor 42, the load applied to the specimen 1 is calculated and the load test is finished (S40).

As described above, the load applied to the specimen 1 from the amount of current i applied to the coil 425 of the mover 421 and the displacement d1 of the voice coil motor 42 sensed by the detection sensor 45. It can be measured, which will be described in detail as follows.

First, when the elastic modulus of the elastic member 44 is Fs, the elastic restoring force (Fs) with respect to the displacement amount (d) according to the applied current amount (i) of the voice coil motor (42) in the absence of the specimen is Can be obtained from Equation 2 below.

Fs = Ks × d

Further, when the motor constant is Ke and the current applied to the coil 425 is i, the driving force Fe of the voice coil motor 42 can be obtained from Equation 3 below.

Fe = Ke × i

On the other hand, when there is no specimen 1, when the power is applied to the coil 425 and the voice coil motor 42 is moved, the driving force (Fe) of the voice coil motor 42 and the restoring force of the elastic member 44 Since Fs is in equilibrium with each other (Fe = Fs), the relationship between the current i applied to the coil 425 and the transfer displacement d may be expressed by Equations 4 and 5 below. .

Fe = Fs = Ke × i = Ks × d = Ks × (d1 + d2)

i = (Ks / Ke) × d = (Ks / Ke) × (d1 + d2)

From this equation, the displacement amount d2 at which the voice coil motor 42 cannot move due to the repulsive force of the specimen 1 when a load is applied to the specimen 1 can be obtained from Equation 6 below.

d2 = i × (Ke / Ks)-d1

As a result, the load F acting on the specimen 1 from the relation between the elastic restoring force Fs and the elastic modulus Ks of the elastic member 42 can be obtained from Equation 7 below (S40).

F = Ks × d2

That is, when a load is applied to the specimen 1, the displacement amount d1 of the voice coil motor 42 according to the amount of current i applied to the coil 425 by the repulsive force acting on the specimen 1 is the amount of current. In (i), the displacement (d) of the voice coil motor 42 in the absence of the specimen (1) is reduced, and the force (F = Ks × d2) for the reduced displacement amount (d2) is thus reduced. It becomes the load applied to.

FIG. 6 is a diagram showing the relationship between the respective forces as described above, where Fe is a force due to a current applied to the coil 425, that is, a driving force of the voice coil motor 42, and Fs is a load on the specimen 1. Is the restoring force of the elastic member 44 with respect to the displacement d1 of the voice coil motor 42 when F is applied, F denotes the applied load acting on the specimen 1.

As described above, the current amount i applied to the voice coil motor 42, the displacement value d of the voice coil motor 42 when the specimen 1 is absent from the current amount i, and the current amount i Is applied to the specimen 1 from the displacement amount d1 of the voice coil motor 42 when the load is applied to the specimen 1, i.e., the probe 43 at the current amount i. The load test on the specimen (1) can be carried out by automatically calculating the load.

In the load test apparatus according to the present invention configured as described above, the micro load is applied to the specimen using the voice coil motor 42, and the amount of current i and the voice coil motor 42 applied to the voice coil motor 42 is applied. Since the load applied to the specimen () can be calculated from the displacement amount (d) (d1), there is an effect that the unit cost of the micro load test apparatus can be significantly reduced.

The micro load test apparatus according to the present invention is applicable to a test apparatus for applying displacement in micro units and millimeters.

Although the present invention has been described through the embodiments described in the drawings and the detailed description of the invention, this is merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art to which the present invention pertains. . Therefore, the technical protection scope of the present invention will be defined by the appended claims.

1 is a schematic view showing a load test apparatus according to the present invention.

2 is a cross-sectional view showing the voice coil motor of the load test apparatus of FIG.

3 is a perspective view illustrating the voice coil motor and the probe of the load test apparatus of FIG. 1.

4 is a graph showing a change in displacement amount of the voice coil motor with respect to a change in the amount of current applied to the voice coil motor of the load test apparatus of FIG. 1.

5 is a graph showing a change in displacement of an elastic member with respect to a change in force applied to the elastic member.

6 is an explanatory diagram for explaining the driving force of the voice coil motor, the elastic restoring force of the elastic member and the repulsive force of the specimen in the load test apparatus according to the present invention.

7 is a flowchart illustrating a method of measuring a load applied to a specimen using a load test apparatus according to the present invention.

*** Explanation of symbols for main parts of drawing ***

1: Psalm 2: Psalm Table

3: table feeder 4: measuring module

42: voice coil motor 43: probe

44: elastic member 45: detection sensor

421: mover 422: stator

Claims (4)

A voice coil motor including a mover moving in a straight line according to the application of power; An elastic member connected to the mover; A probe fixed to the movable member or the elastic member and extending toward the specimen; And Micro load test apparatus including a sensor for detecting the displacement of the voice coil motor. The method of claim 1, The elastic member is a micro load test apparatus, characterized in that consisting of a leaf spring attached to at least one side in the moving direction of the mover. The method of claim 1, The sensing sensor includes a light emitting unit for irradiating laser light, and a light receiving unit for receiving the laser light reflected from the specimen. In the load test apparatus comprising a voice coil motor including a mover moving in a linear form according to the application of power, and an elastic member connected to the mover, A first step of calculating data on a change in displacement amount d of the voice coil motor according to a change in the amount of applied current when there is no specimen; A second step of measuring a current amount (i) applied to the voice coil motor and a displacement amount d1 of the voice coil motor while applying a load to the specimen; From the data calculated in the first step, the current amount i in the second step, and the displacement amount d1 of the voice coil motor in the second step, the displacement amount d2 of the voice coil motor that cannot be displaced due to the presence of the specimen is determined. Calculating a third step; And A fourth step of measuring a load applied to the specimen using the displacement amount d2 of the voice coil motor, the motor constant Ke of the voice coil motor, and the elastic modulus Ks of the elastic member calculated in the third step; Load test method comprising.

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