JPH11281545A - Material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material testing machine of a simple constitution which can highly accurately detect a displacement applied to a specimen without being influenced by a displacement at a load detector. SOLUTION: A displacement gage 43 is set between a pair of chucks 21 arranged to face each other for use in holding a specimen. A displacement of the specimen is directly detected as a change of a distance between the opposing chucks 21. That is, the displacement between the pair of chucks 21 is directly detected in place of a movement amount of a moving body applying a load to the specimen, whereby a displacement at a loaddetecting meter is eliminated and highly accurate measurement is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material testing machine for testing the material properties of a test specimen from the relationship between the load and the displacement of the test specimen to which a load is applied. The present invention relates to a material testing machine capable of detecting displacements such as displacements with high accuracy.

[0002]

[Related Background Art] A material testing machine for testing the material properties of a specimen such as a material specimen is a means for applying a load such as a compressive load or a tensile load to the specimen, and a means for applying a load to the specimen by the load. Load detecting means such as a load cell for detecting the applied load, and displacement detecting means such as a position detector for detecting displacement such as elongation, contraction, or bending generated in the specimen by the load. You. Material properties such as strength and proof stress of the specimen are determined from the relationship between the detected load and displacement.

[0003] Specifically, the material testing machine has a pair of chucks on which a specimen is mounted, attached to a fixed body (first unit) and a movable body (second unit), the distance between which is variable. It is configured to apply a load to the specimen mounted between the chucks by moving and driving the movable body. And the chuck and the fixed body (first unit)
While the load applied to the specimen is detected by a load cell interposed between the movable body (the second unit) and the load cell, the displacement is applied to the specimen using a displacement meter that measures the amount of movement of the movable body (second unit). It is configured to detect the displacement.

[0004]

However, the load cell in the material testing machine constructed as described above detects the load by utilizing the elastic deformation caused by the load. For this reason, it cannot be denied that the fixed position of the specimen defined by the chuck supported by the fixed body (first unit) via the load cell is strictly displaced. Therefore, when the displacement of the specimen is obtained from the movement amount of the moving body (second unit) as described above, the displacement includes the displacement of the load cell as a detection error.

In particular, when the amount of elastic deformation of the load cell with respect to the load is increased in order to increase the load detection accuracy of the load cell, the displacement cannot be ignored and the measurement accuracy of the displacement meter deteriorates. Specifically, for example, when evaluating the strength and mechanical properties of a specimen having a dissimilar material micro-joined structure, such as a part used in an electronic device or an electronic device, a microscopic structure is applied while applying a relatively light load. Since such a test is performed by detecting a large load or displacement, the above-mentioned error cannot be ignored.

The present invention has been made in view of such circumstances, and has as its object to apply a load to a specimen without being affected by displacement of a load detector for detecting a load applied to the specimen. Another object of the present invention is to provide a material testing machine having a simple configuration capable of detecting a displacement applied to a specimen with high accuracy. That is, an object of the present invention is to provide a material testing machine capable of directly and highly accurately detecting a displacement generated in a specimen to which a load is applied.

[0007]

In order to achieve the above-mentioned object, a material testing machine according to the present invention uses a material of the specimen based on a relationship between a load and a displacement in the specimen when a load is applied to the specimen. A pair of chucks, which are to be tested for characteristics and are arranged to face each other and are provided for holding the specimen, respectively support these chucks, and at least one of them is in a load direction in which the chucks face each other. First and second units provided so as to be able to move forward and backward, and load means for moving one of the first and second units to apply a load to the specimen held between the chucks;
In particular, a displacement meter for interposing a load detector for detecting a load applied to the specimen between one of the chucks and a unit supporting the chuck, and detecting a displacement applied to the specimen. Is provided between the pair of chucks, and a change in an opposing distance between the chucks is detected.

That is, the material testing machine according to the present invention supports one of a pair of chucks for holding a specimen and moves the chuck, thereby moving a unit (moving body) for applying a load to the specimen. Instead of detecting the amount as the displacement applied to the specimen, directly detecting the displacement between the pair of chucks that are relatively displaced, regardless of the displacement in the load detector caused by the load, The present invention is characterized in that the displacement applied to the specimen is directly and accurately detected.

According to a preferred aspect of the present invention, as described in claim 2, the displacement detector is mounted on the unit in accordance with an opposing distance between the pair of chucks which is initially set according to a length of a specimen or the like. And a detector body that is mounted on one of the chucks with its position adjusted in the moving direction of the chuck, and is implemented as a sensing body that forms a position detection surface of the detector body and is mounted on the other side of the chuck. In particular, the invention is characterized in that the detector main body or the sensing body is provided so as to be finely adjustable in a moving direction of the unit via a micrometer head.

According to a preferred aspect of the present invention, the displacement detector is provided in a position laterally eccentric from an axis formed between the pair of chucks and parallel to the axis. The present invention is characterized in that the mounting of the test piece between the chucks is not hindered.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a small-sized material testing machine according to an embodiment of the present invention will be described with reference to the drawings. The material testing machine according to this embodiment is suitable for use in evaluating the strength and mechanical properties of a specimen having a micro-joined structure of a dissimilar material such as a component used in an electronic device or an electronic device. , And is realized as a desktop type device that operates using electricity as a power source.

FIG. 1 is a perspective view showing a schematic structure of a material testing machine main body, and 1 is a base made of a surface plate or the like having a vibration-proof structure. On this base 1, a first unit 10 and a second unit 2 for applying a load consisting of a load or displacement such as compression, tension or bending to a specimen S to be tested.
0 are mounted separately from each other in the direction in which the load is applied (X-axis direction).

Incidentally, the first unit 10 has two axes (Y-axis) provided perpendicular to the load direction (X-axis direction).
An axis and a Z-axis) table is mainly used, and for example, a chuck 11 for holding one end of the specimen S is attached to the biaxial table. And with a two-axis table,
The chuck 11 is provided such that its position can be adjusted in the depth direction (Y-axis direction) and the vertical direction (Z-axis direction) of the base 1. Also, the second unit 20
Is mainly composed of a moving table provided so as to be movable in the load direction (X-axis direction). The moving table is provided with a chuck 21 paired with the chuck 11 attached to the moving table. The chuck 21 serves, for example, to hold the other end of the specimen S and apply a load to the specimen S as the movable table moves in the X-axis direction.

In this case, both ends of the specimen S are held by a pair of chucks 11 and 21 and the position of the chuck 21 in the X-axis direction is displaced by driving a moving table (second unit). Although a description will be given assuming that a load consisting of a compressive load or a tensile load is applied to the specimen S, it is of course possible to apply a compressive displacement or a tensile displacement as a load. The specimen S is mounted on one of the chucks 11 and 21 in a direction (YZ plane) perpendicular to the X axis, and a jig for bending the specimen S is mounted on the other side of the chucks 11 and 21. Thus, it is also possible to apply a bending load or bending displacement to the specimen S from a direction perpendicular to the specimen S by driving the moving table.

The first unit 10 includes the base 1
An X table 12 mounted thereon so as to be adjustable in the X-axis direction and serving as a base of the above-described two-axis table, and a screen-shaped Y table 13 mounted on the X table 12 so as to be adjustable in the Y-axis direction. , And this Y table 13
A Z table 14 which is mounted on the vertical wall surface of the Z
And an axis table. And the chuck 11
Is fixedly supported on the Z table 14 via a rod-shaped load cell 15 and a rod-shaped holding member 16 for holding the load cell 15 as described later.

Incidentally, the X table 12 is mounted on the base 1 (position in the X-axis direction) in accordance with the length of the specimen S mounted between the chucks 11 and 21.
Is adjusted, it is firmly fixed to the base 1 by bolting. Further, the Y table 13 constituting the biaxial table is provided so that its position can be adjusted in the Y axis direction while its base is guided by a rail provided on the upper surface of the X table 12. Then, as shown in FIG. 2, the Y table 13 is adjusted in position with high precision by a pair of left and right feed screw mechanisms 13a provided on both ends of the X table 12, and then bolted to the X table 12. Is firmly fixed. Further, the Z table 14 is provided with a guide 13 b provided on an upright surface (front surface) of the Y table 13.
And is provided so as to be position-adjustable in the Z-axis direction. Then, after the position is adjusted with high precision by a pair of upper and lower feed screw mechanisms 14a, 14a provided at the upper and lower ends of the guide body 13b, it is firmly fixed to the Y table 13 by bolting.

Such adjustment of the positions of the Y table 13 and the Z table 14 is performed in order to position the axis between the pair of chucks 11 and 12 with high accuracy. The feed screw mechanisms 13a, 13a, 14a, and 14a advance and retreat their shafts by rotation of a thimble (micrometer head) having a built-in ratchet stop mechanism as seen in a micrometer, and the shafts move the respective shafts. Table 1
It is configured such that the position is adjusted by pressing the side surfaces of 3,14.

On the other hand, the chuck 1 is mounted on the front surface of the Z table 14 via the load cell 15 and the holding member 16.
1 is mounted as follows. For example, the rod-shaped load cell 15 is provided perpendicular to the load direction (X-axis direction). The load cell 15 physically constitutes a parallel link that receives a load at one end thereof and displaces the two ends in parallel. According to the deflection of the main body caused by the displacement, the load applied to the one end is reduced. It is configured to detect electrically. In particular, the load is detected with high resolution and high accuracy by increasing the length of the load cell 15 in the Y-axis direction. It is needless to say that a conventional general magnetostrictive type can be used instead of the rod-shaped load cell 15.

The holding member 16 fixedly holds the other end (fixed end) of the load cell 15 at a position distant from the axis of the load cell 15.
The one end side (displacement end) to which the load is applied is made to coincide with the axis of the Z table 14, and is a rod-shaped body arranged substantially parallel to the load cell 15. The load cell 15 is supported by using such a holding member 16,
By attaching the chuck 11 to the displacement end of the load cell 15, the chuck 11 is arranged on the axis of the Z table 14, and the load applied to the chuck 11 is surely applied by the Z table 14 (the first unit 10). It can be received.

The second knit 20 is configured as follows with respect to the first unit 10 configured as described above. That is, as described above, the second unit 20 mainly includes a movable table provided on the base 1 so as to be movable in the load direction (X-axis direction), and the chuck 21 is attached to the movable table. Is done. This moving table is fixed on the base 1 as shown in FIG. 3, and has legs 23, 23 between both ends in the X-axis direction of a pedestal 22 forming a storage space for a linear motor mechanism to be described later. The movable table 25 is provided so as to be able to move forward and backward in the load direction (X-axis direction). The chuck 21 is fixed to the vertical surface at the front end of the movable table 25 via a substantially triangular block (reaction table) 26 on the moving table 25 and is disposed to face the chuck 11 of the first unit 10. . Then, the chuck 21 is moved by the displacement of the moving table 25 in the load direction (X-axis direction) so that a predetermined load is applied to the specimen S mounted between the chucks 11 and 21. It has become.

As shown in FIG. 4, the moving table 25 has an upper structure 25a surrounding the shaft 24 and a pair of side structures 25b, 25.
b, and the lower structure 25c, and the bearing portion thereof
An air bearing is configured to introduce compressed air between the shaft body 24 via the air introduction passage 27 and to support the shaft body 24 in a non-contact manner. In particular, this air bearing efficiently supports the moving table 25 by introducing compressed air also between the lower surface of the lower structure 25c and the upper surface of the pedestal 22. As a result, the moving table 25 is supported by the shaft body 24 and can move smoothly without being affected by frictional resistance.

On the other hand, a linear motor mechanism 30 is used as a drive source of the moving table 25 here.
The linear motor mechanism 30 includes, for example, a first magnetic mechanism including a plurality of rod-shaped permanent magnets 31 arranged on the pedestal 22 along the shaft body 24 and the moving mechanism incorporated in a coil holding member 33. A second magnetic mechanism including an electromagnetic coil 32 attached to both sides of the table 25 and opposed to the permanent magnet 31. Incidentally, the permanent magnets 31 are arranged at regular intervals at a predetermined pitch while alternately changing their polarities, and both poles are positioned at both ends of the pedestal 22 in the width direction (Y-axis direction). The electromagnetic coil 32
The magnetic poles (not shown) are opposed to both ends (poles) of each of the permanent magnets 31 with a minute gap therebetween, and are selectively magnetically coupled.

The linear motor mechanism 3 configured as described above
0 controls the driving phase of the electromagnetic coil 32 to generate an attractive / repulsive force between the N pole and the S pole of the permanent magnet 31 fixedly disposed as described above. A moving thrust is generated in the direction in which the permanent magnets 31 are arranged, whereby the permanent magnets 31 move sequentially between the permanent magnets 31. With such a linear motor mechanism 30, the movement of the moving table 25 in the X-axis direction along the shaft 24 is controlled, and the thrust of the linear motor mechanism 30 is applied as the load described above.

The moving table 25 driven by the linear motor mechanism 30 incorporates, for example, an optical position sensor (not shown) for detecting a moving displacement position with respect to the shaft 24. The linear motor mechanism 30 is servo-controlled in accordance with position information (displacement information) detected by such a position sensor, and its moving position is controlled with high precision. Incidentally, in the moving table according to this embodiment, the moving stroke L of the moving table 25 is set to a maximum of 100 mm,
Further, the moving table 25 is configured to be capable of controlling the position with high precision at a resolution of 0.1 μm.

Further, as shown in FIG.
At the front and rear ends in the movement direction of No. 5, detection pieces 35 for limiting the movement range are provided. When the moving table 25 reaches the limit of its moving range, the detecting piece 35 enters the optical path of the photocouplers 36, 36 attached to the legs 23, 23 and blocks the optical path. The movement limit position (stop position) of the movement table 25 is detected.

The chuck 21 attached via the block 26 to the moving table 25 of the second unit 20 constructed as described above is a chuck attached to the first unit 10 as shown in FIG. 11 are arranged. And these chucks 11,2
The test piece S is mounted between the test pieces and subjected to a material test. At this time, the relative position between the chucks 11 and 21 is adjusted by the position adjustment in the Y-axis direction and the Z-axis direction by the two-axis table in the first unit 10 as described above,
The specimen S can be chucked without the axial displacement.
It is designed to be mounted in between. In this state, when the linear motor mechanism 30 of the second unit 20 is driven, the moving table, and eventually the chuck 21 advances and retreats in the X-axis direction, and a load is applied to the specimen S. Then, the load applied to the specimen S by this load is detected by the load cell 15 described above.

Next, a description will be given of a mounting structure of a displacement detector which is a characteristic configuration of the material testing machine according to the present invention. This displacement detector is provided with a displacement between the pair of chucks 11 and 21 as shown in FIG. Is directly detected. That is, to the bases of the chucks 11, 21, arm bodies 41, 42 extending laterally from the axes thereof are attached, respectively. And one arm body 4
1 is provided with a displacement meter 43 made of a magnet scale having a slide shaft that moves forward and backward in the X-axis direction, and the other arm 42 is provided with a jig 44 serving as a reference surface for detecting displacement of the displacement meter 43. Have been. This jig 44
Functions as a sensing body that contacts the tip of the slide shaft of the displacement meter 43 to move the slide shaft forward and backward. In particular, the displacement meter 43 is provided on the arm body 41 via a holding member 45 for holding the same so as to be capable of adjusting the position in the X-axis direction. The jig 44 is connected to the arm body via a feed screw mechanism 46. The body 42 is provided so as to be adjustable in position. The feed screw mechanism 46 is composed of, for example, a micrometer head that adjusts the position of the jig 44 with respect to the slide axis of the displacement meter 43 by finely adjusting the amount of movement (advance / retreat).

The holding member 45 is roughly adjusted in the X-axis direction with respect to the arm 41 in accordance with the distance between the chucks 11 and 21 which is adjusted according to the length of the specimen S. It is firmly screwed to the arm body 41. On the other hand, the feed screw mechanism 46 moves the jig when the specimen S is in a no-load state with respect to the displacement meter 43 which is positioned by roughly adjusting the mounting position of the holding member 45 as described above. 44 for fine adjustment of the position of the displacement meter 4.
It plays the role of zero-adjusting the slide shaft 3.

The displacement meter 43 attached between the chucks 11 and 21 as described above measures the compression and elongation of the specimen S when a load is applied to the specimen S mounted between the chucks 11 and 21. Is directly measured as a change in the distance L2 between the chucks 11 and 21. That is, the linear motor mechanism 30 driven by servo control as described above is used.
The displacement (moving position) of the chuck 21 moved by
The displacement amount of the moving table 25 can be detected by the position sensor described above. However, this displacement indicates the displacement of the absolute position of the chuck 21 with respect to the base 1, and furthermore, the displacement of the distance L1 between the first unit 10 and the second unit 20 (moving table) as shown in FIG. Therefore, it cannot be denied that the above-mentioned displacement includes the above-mentioned displacement Δ caused by the deflection of the load cell 15 due to the load applied to the specimen S by the movement of the second unit 20.

In this regard, as described above, the pair of chucks 1
According to the displacement meter 43 provided between the chucks 11 and 21 so as to detect a change in the distance L2 between the load cells 15 and 21, even if the load cell 15 is bent by the load, the load cell 15 is bent. Since the displacement itself is detected as a change in the distance between the chucks 11 and 21, the displacement is directly
In addition, detection can be performed with high accuracy. In particular, even when the displacement (bending) with respect to the load of the load cell 15 is increased in order to detect the load applied to the specimen S by the load with high sensitivity and high precision, the specimen S is not affected by the displacement. The amount of displacement due to the load can be directly and accurately detected as the displacement between the chucks 11 and 21.

The tester main body including the first unit 10 and the second unit 20 configured as described above is controlled by a control unit 51 mainly including a microprocessor as shown in FIG. 6, for example. Driven under Specifically, the air pump 52 is operated to make the air bearing function, and in this state, the linear motor driving unit 53 is operated to drive the linear motor mechanism 30. The linear motor driving section 53 forms a servo control circuit, and detects the load from the control section 51 while detecting the position of the moving table 25 (the position of the chuck 21) with respect to the shaft body 24 using the position sensor described above. The linear motor mechanism 30 is driven in accordance with the displacement command. By the operation of the linear motor mechanism 30 driven in this manner, a load consisting of a load or a displacement is applied to the specimen S held between the chucks 11 and 21.

The load and the displacement of the specimen S loaded as described above are determined by the load cell 1
5 and the output of the displacement meter (magnet scale) 43 are detected by the load detecting unit 54 and the displacement detecting unit 55, respectively, and are taken in the measuring unit 56 of the control unit 51 as digital data sampled at a predetermined cycle, for example. Then, in the measuring section 56, for example, a predetermined measurement calculation process is performed to evaluate the material characteristics and the mechanical strength characteristics of the specimen S.

Thus, according to the material testing machine configured as described above, when the second unit 20 is driven to apply a load to the specimen S held between the pair of chucks 11 and 21, the specimen is removed. The load applied to S and its displacement can be detected with high accuracy. In particular, since the displacement of the specimen S is directly detected as a change in the distance L2 between the pair of chucks 11, 21, the displacement of the specimen S is not affected by the amount of deformation of the load cell (load meter) 15 due to the load. Can be detected with high accuracy. Therefore, the specimen S
Even if the load applied to the specimen itself is small and the load applied to the specimen S and its displacement are small, this can be detected with high sensitivity, and the measurement accuracy can be greatly improved. Thus, a great effect can be obtained in practical use.

Further, as described above, a pair of chucks 11,
The chuck 1 is attached to the base of the chuck 21 via the arm bodies 41 and 42.
Since the displacement gauge 43 is mounted parallel to and displaced from the axes of the chucks 11 and 21, the displacement gauge 43 does not hinder the mountability of the specimen S on the chucks 11 and 21. Further, the mounting position itself of the displacement meter 43 is provided so as to be roughly adjustable in the X-axis direction via the holding member 45, and the position of the jig 44 forming the measurement reference plane of the displacement meter 43 is adjusted by the feed screw mechanism 46 in the X-axis direction. Therefore, the displacement of the distance L2 can be measured with high accuracy regardless of the distance L2 between the chucks 11 and 21 which is adjusted according to the length of the specimen S or the like. Therefore, also in this respect, the accuracy of the displacement measurement can be improved.

The present invention is not limited to the above embodiment. For example, in the embodiment, a case where a compressive load is applied to the specimen S has been described as an example, but a case where a tensile load is applied can also be measured. However, in this case, the jig 44 may be realized as a structure in which the slide shaft of the displacement meter 43 is pulled. It is also possible to set the position as a zero point with the displacement axis of the magnet scale pushed in, and measure the amount of pulling from the amount of protrusion from this zero point position. Further, as the displacement meter 43, a device such as a laser length measuring device can be used instead of a device such as a magnet scale having a slide shaft described above. In this case, the jig 44 may be realized as a laser light reflector.

Further, as a drive mechanism of the second unit 20, not only the linear motor mechanism 30 described above, but also a conventional general feed screw mechanism may be used, and a hydraulic cylinder mechanism may of course be used. is there. Needless to say, the present invention is applicable not only to the small-sized material testing machine described in the embodiment but also to a large-sized material testing machine. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0037]

As described above, according to the present invention, the displacement generated in the specimen held between the chucks is directly detected by the displacement detector provided between the pair of chucks holding the specimen. Therefore, the displacement applied to the specimen can be detected with high accuracy regardless of the elastic deformation of the load detector caused by the load. In other words, the displacement between the chucks is directly detected instead of the displacement of the moving body that applies a load to the specimen, so that the measurement error caused by the amount of deformation in the load cell (load cell) can be effectively determined from the measured value. Can be excluded. Therefore, even when the load and displacement of the loaded test specimen are small, it can be detected with high sensitivity and high accuracy, and the measurement accuracy can be sufficiently improved with a simple structure. Can produce a great effect in practical use.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a material testing machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a two-axis table in a first unit of the material testing machine according to the embodiment.

FIG. 3 is a diagram showing a configuration of a moving table in a second unit of the material testing machine according to the embodiment.

FIG. 4 is a sectional view showing a configuration of an air bearing between a shaft body and a moving table and an arrangement relationship of a linear motor mechanism.

FIG. 5 is a view showing a mounting structure of a displacement detector, which is a characteristic structure in the material testing machine according to the present invention.

FIG. 6 is a block diagram showing an overall control system of the material testing machine.

[Explanation of symbols]

 Reference Signs List 1 base 10 first unit 11 chuck 15 load cell 16 holding member 20 second unit 21 chuck 22 pedestal 25 moving table 26 block 30 linear motor mechanism 41, 42 arm 43 displacement sensor (displacement detector) 44 jig (sensing) Body) 45 Holding member 46 Feed screw mechanism

Continued on the front page. (72) Inventor Yu Qiang 87 Suncoat Garden A202, 87 Higashikawashima-cho, Hodogaya-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Hiroshi Okumoto 2-20-46 Horifune Kita-ku, Tokyo Japan Tobacco Machinery Co., Ltd. Within the business division (72) Inventor Yuzo Ishii 202 Kitajima, Kitajima-cho, Toyohashi-shi, Aichi Prefecture JT Toshi Corporation

Claims (4)

[Claims] 1. A material testing machine for testing material properties of a test piece from a relationship between a load and a displacement of the test piece when a load is applied to the test piece. A pair of chucks provided for holding a sample, first and second units each supporting the chuck, at least one of which is provided so as to be able to advance and retreat in a load direction opposed to the chuck; Loading means for moving one of the first and second units provided to apply a load to the specimen held between the chucks; and between one of the chucks and a unit supporting the chuck. A load detector that detects a load applied to the specimen by being interposed therebetween; and a displacement detector that is provided between the chucks and that detects a change in a facing distance between the chucks. Material testing machine according to claim. 2. A detector main body which is adjusted in a moving direction of the unit according to an initially set opposing distance between the chucks and is attached to one of the chucks, wherein the displacement detector is attached to one of the chucks. 2. A material testing machine according to claim 1, wherein said material testing machine comprises a sensing body which forms a position detection surface by means of a chuck and which is attached to the other of said chucks. 3. The material testing machine according to claim 2, wherein the detector main body or the sensing body is provided so as to be finely adjustable in a moving direction of the unit via a micrometer head. 4. The material testing machine according to claim 1, wherein the displacement detector is provided at a position laterally eccentric from an axis formed between the pair of chucks and parallel to the axis. .