KR20090059830A - Apparatus for fixing specimen having a curved surface - Google Patents

Abstract

An apparatus for fixing a specimen having a curved surface is provided to obtain accurate test data and evaluate the mechanical property a specimen exactly. An apparatus for fixing a specimen having a curved surface comprises a grip part(20) connected to a tester, and a test piece clamping part(40) connected to the grip part via a connector(30). The grip part is moved by the power source of the tester to extend or compress the specimen. The grip part is composed of a fixing unit(21) fixed to the tester and a moving unit(22) which is movably connected to the tester.

Description

Apparatus for fixing specimen having a curved surface}

The present invention relates to a specimen holding device having a curved surface, and more particularly, it is possible to firmly clamp the specimen having a curved surface so as not to slip during a tension or compression test, thereby easily and accurately performing a tensile or compression test of the curved specimen. It relates to a specimen holding device having a curved surface.

In general, the representative test method used for the evaluation of the mechanical properties of metal materials is the tensile test method, through which data such as yield strength, tensile strength, work hardening index, stress coefficient and uniform elongation can be obtained.

This tensile test method contributes to the application of a metallic material to the appropriate field to match the mechanical properties by applying the tensile force to the test specimen to calculate the above-described mechanical properties.

Recently, due to the development of the automobile industry, much attention has been paid to reducing the weight of automobiles for the purpose of improving fuel efficiency of automobiles.

Representative lightweight methods include a hydroforming process. In the hydroforming process, a product is molded and manufactured by pressing a pipe material at a high pressure using a liquid.

Products produced by the hydroforming process as described above is subjected to a tensile test as described above for the evaluation of mechanical properties.

To this end, a part of the product is cut for a tensile test to produce a test piece (2).

The test piece 2 is clamped at both ends of the upper and lower ends by a jaw 130 provided in the tester 1, as shown in FIG. 1, and the jaw 130 clamping the test piece 2 is connected to the tester 1. After being bitten by the provided upper grip 110 and the lower grip 120, the upper grip 110 is moved upward to perform a tensile test of the test piece 2.

The test piece 2 produced from a curved product such as a pipe produced by a hydroforming process has a curved surface as shown in FIG.

When the test piece 2 having the curved surface is clamped by the jaw 130 and subjected to the tensile test as described above, the jaw 130 does not clamp the test piece 2 closely by the curved surface of the test piece 2. I can't.

Therefore, there may be a case in which the test piece 2 slips off the jaw 130 during the tensile test, and thus there is a problem that the tensile test itself cannot be made impossible or easy.

In addition, even if the test piece 2 was clamped by the jaw 130 to enable the tensile test, there was a problem that the test data was not accurate because the test piece 2 could slide in the jaw 130 during the tensile test. .

Accordingly, there was also a problem that the mechanical property evaluation of the test piece 2 having a curved surface was not made properly.

The present invention has been made to solve the above problems, an object of the present invention can be firmly clamped so as not to slip the test piece having a curved surface in the tension or compression test of the test piece having a curved surface, the tension or compression of the test piece having a curved surface To provide a specimen holding device having a curved surface to facilitate and accurately test.

The present invention to achieve the above object

A grip portion coupled to the tester to be moved by a drive source of the tester to tension or compress a test piece having a curved surface; And

A test piece clamping part connected to the grip part by a connecting means and provided to clamp the test piece having a curved surface;

It provides a specimen holding device having a curved surface configured to include.

More preferably, the grip portion is fixed to the tester; And a movable table movably connected to the tester while facing the fixing table. It includes.

More preferably, the connecting means comprises: a first rotating shaft rotatably connected to a fixture, one side of which is included in the grip portion; One side is movable to the first rotational shaft and is connected to rotate together, the other side is a second rotational shaft rotatably connected to the moving table included in the grip portion; A first moving rotary shaft whose one side is rotatably connected to the first movable groove formed on the fixing base; And a second moving rotary shaft connected to the first movable rotary shaft and rotatably coupled to the first movable rotary shaft, and the other side rotatably connected to the second movable groove formed on the movable table. It includes.

More preferably, the first rotating shaft and the second rotating shaft or the first moving rotating shaft and the second moving rotating shaft are separated from each other.

More preferably, the test piece clamping portion has an outer circumferential surface consisting of at least one convex surface and a convex jaw provided on the first moving shaft and the second moving rotating shaft or the first rotating shaft and the second rotating shaft included in the connecting means; And an outer circumferential surface of at least one concave surface to closely clamp a test piece having a curved surface together with the convex surface of the convex jaw, wherein the first rotating shaft and the second rotating shaft or the first moving rotating shaft and the second moving rotating shaft Concave jaw; It includes.

More preferably, the stator or the movable table is provided with a motor connected to the first rotary shaft or the second rotary shaft to rotate it, and a moving cylinder connected to the first movable rotary shaft or the second movable rotary shaft to move it. do.

More preferably, when the first rotary shaft or the second rotary shaft is rotated so that the first movable rotary shaft or the second movable rotary shaft rotates, the first rotary shaft and the first movable rotary shaft or the second rotary shaft and the second rotary shaft The moving axis of rotation is connected by a rotary connector.

More preferably, at least one spring is installed in the first moving groove or the second moving groove so that the position of the first moving shaft or the second moving shaft is stabilized by a spring force.

According to the present invention described above, there is an effect that the curved specimen can be firmly clamped without slipping during the tension or compression test of the curved specimen.

Therefore, it is easy to tension or compress the test piece having a curved surface by using a tester, and there is an effect that the test data value obtained by the tension or compression test of the test piece having a curved surface is accurate.

Since the test data values are accurate, the mechanical properties of curved specimens can be evaluated properly.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a view showing an embodiment of a test piece holding device having a curved surface according to the present invention, Figure 3 is a perspective view showing a convex jaw and concave jaw of an embodiment of the test piece holding device having a curved surface according to the present invention, 4 is a view showing the use of one embodiment of a test piece holding device having a curved surface according to the present invention to fix the test specimen having a curved surface and to perform a tensile test.

As shown in FIG. 2, the test piece holding device having the curved surface according to the present invention includes a grip part 20 connected to the tester so as to be moved by a driving source of the tester so as to tension or compress the test piece 2 having the curved surface. 20) and a test piece clamping portion 40 which is connected by means of connecting means 30 and provided to clamp the test piece 2 having a curved surface during a tensile or compression test.

The grip part 20 includes a fixed base 21 fixed to the tester and a movable base 22 movably connected to the tester while facing the fixed base 21.

Therefore, as shown in FIG. 2 and FIG. 4, the test piece 2 having a curved surface is clamped by the test piece clamping part 40 connected to the fixing table 21 and the moving table 22 by the connecting means 30. In the above, the movable table 22 is moved up and down in the tester by a drive source (not shown) such as a motor provided in the tester and a gear connected thereto, so that a tensile or compression test can be performed on the test piece 2 having a curved surface. do.

In the present embodiment, the grip part 20 is composed of a fixed base 21 and a movable base 22 to be fixed, but if the test piece 2 is made to be capable of tensile or compression test any configuration such as moving both members It is also possible.

In addition, in this embodiment, the movable table 22 is moved up and down to perform a tension or compression test on the test piece 2, but the movable table 22 is moved left and right to tension the test piece 2. However, it may be configured to perform a compression test.

As shown in FIG. 2, the connecting means 30 connecting the test piece clamping part 40 to the grip part 20 formed of the fixing table 21 and the moving table 22 has a bearing (shown on one side thereof). The first rotary shaft 31 is rotatably connected to the first rotary shaft 31 and one side is rotatably connected to the first rotary shaft 31 and the other side is connected to the movable table 22 by a bearing (not shown). A second rotatable shaft 32 rotatably connected, a first rotatable shaft 33 rotatably connected by a bearing (not shown) while being movable on a first movable groove 23 formed at one side of the fixing base 21; The second moving rotary shaft 34 is rotatably connected to the second movable groove 24 formed on the movable table 22, and one side is connected to the first movable rotating shaft 33 and is rotatable together. It includes.

As shown in FIG. 2, a part of the first rotation shaft 31 is in the shape of a gear, and the shape of the gear of the first rotation shaft 31 is inserted into the second rotation shaft 32 so that the gear groove ( (Not shown), the first rotating shaft 31 and the second rotating shaft 32 are rotated together, and the second rotating shaft 32 is movable from the first rotating shaft 31.

Like the first rotating shaft 31 and the second rotating shaft 32, the first moving rotating shaft 33 and the second moving rotating shaft 34 also have a part of the first moving rotating shaft 33 in the shape of a gear and the second moving. A gear groove (not shown) is formed in the rotary shaft 34 so that the shape of the gear of the first movable rotary shaft 33 can be engaged with each other, such that the first movable rotary shaft 33 and the second movable rotary shaft 34 are formed. This can rotate together, and the 2nd movement rotating shaft 34 is movable from the 1st movement rotating shaft 33. As shown in FIG.

However, this is only a preferred embodiment, and the first rotary shaft 31 and the second rotary shaft 32 or the first movable rotary shaft 33 and the second movable rotary shaft 34 are rotated together, from the first rotary shaft 31. As long as the second rotating shaft 32 is movable and the second moving rotating shaft 34 is movable from the first moving rotating shaft 33, any one can be used.

As shown in FIG. 2, the movable table 22 may rotate the first rotary shaft 31 connected to the second rotary shaft 32 so that the first rotary shaft 31 is rotated together with the second rotary shaft 32. 25 is provided.

In addition, the first movable rotation shaft 33 connected to the second movable rotation shaft 34 may move in the first movable groove 23 so that the second movable rotation shaft 34 is movable in the second movable groove 24. The moving cylinder 26 is connected to the second moving rotary shaft 34 so as to be provided.

The moving cylinder 26 and the second moving rotary shaft 34 are connected by a bearing (not shown), that is, a bearing is provided at the rod end of the moving cylinder 26 and the bearing of the second moving rotary shaft 34 is provided. One end is connected in a way that is connected, the second moving rotary shaft 34 is movable by the moving cylinder 26 is connected to the second movable groove 24 so as to be rotatable.

This is only a preferred embodiment, as long as the second movable rotation shaft 34 is movable in the second movable groove 24 and is also rotatably connected.

As shown in FIG. 2, the second rotary shaft 32 and the second movable rotary shaft 34 are connected by a rotary connector 28 such as a belt or a chain. Therefore, when the second rotary shaft 32 is rotated by the motor 25, the second movable rotary shaft 34 connected to rotate by the rotary connector 28 also rotates.

As shown in FIG. 2, the first moving grooves 23 are provided with springs 27 at both ends of one end of the first moving shaft 33 inserted therein.

In addition, as shown in the second moving groove 24, a spring 27 is installed on one side of one end of the second moving rotary shaft 34 inserted therein.

As shown, when one or two springs 27 are installed in the first moving groove 23 and the second moving groove 24, one end portion of the first moving groove 23 or the second moving groove 24 is provided. The position of the first moving rotary shaft 33 or the second moving rotary shaft 34 into which the is inserted is stable is preferable.

The number of springs 27 and springs 27 installed in the first moving groove 23 or the second moving groove 24 used in the present embodiment is only a preferred embodiment, and the first moving groove 23 or As long as the first moving rotary shaft 33 or the second moving rotary shaft 34 can be stably positioned in the second moving groove 24, any one can be used.

In this embodiment, only the movable table 22 is provided with a rotary driving means or a moving means such as the motor 25 and the moving cylinder 26 and is connected to the second rotating shaft 32 or the second moving rotating shaft 34. In addition, the stator 21 may also be provided with a motor 25 or a moving cylinder 26 to be connected to the first rotary shaft 31 or the first movable rotary shaft 33.

In addition, in the present embodiment, only the second rotary shaft 32 and the second movable rotary shaft 34 are connected by the rotary connector 28, but the first rotary shaft 31 and the first movable rotary shaft 33 are also rotationally connected. It is also possible to be connected by the sieve 28.

In this embodiment, the first rotary shaft 31 and the second rotary shaft 32 or the first movable rotary shaft 33 and the second movable rotary shaft 34 are connected to be movable while rotating together, but the first rotary shaft ( 31 and the second rotary shaft 32 or the first movable rotary shaft 33 and the second movable rotary shaft 34 may be separated from each other.

However, at this time, as described above, the motor 25 and the moving cylinder 26 are provided not only on the moving table 22 but also on the fixing table 21, and are connected to the first rotating shaft 31 and the first moving rotating shaft 33. The first rotary shaft 31 and the first movable rotary shaft 33 should also be connected by the rotary connector 28, but the test piece clamping part connected to the grip part 20 by the connecting means 30 will be described later. By 40, it becomes possible to clamp the test piece 2 having a curved surface.

As illustrated in FIGS. 2 to 4, the test piece clamping part 40 includes four convex surfaces 43 having an outer circumferential surface thereof, and a convex jaw 41 provided on the first moving shaft 33 and the second moving shaft 34. ) And the outer circumferential surface is composed of four concave surfaces 44 so as to tightly clamp the test piece 2 having a curved surface together with the convex jaw 41, and the first and second rotation shafts 31 and 32. It includes a recessed groove (42) provided.

As shown, the four convex surfaces 43 constituting the outer circumferential surface of the convex jaw 41 have different sizes, and the four concave surfaces 44 constituting the outer circumferential surface of the concave jaw 42 also have different sizes.

In addition, each convex surface 43 and the concave surface 44 correspond to each other. That is, the convex surface 43 and the concave surface 44 having the same size and corresponding to each other are present in the convex jaw 41 and the concave jaw 42, respectively, thereby clamping the test piece 2 having various curved surfaces. You can do it.

Accordingly, as shown in FIGS. 3 and 4, the curved surface, such as a pipe, is formed between the convex surface 43 of the convex jaw 41 and the concave surface 44 of the concave jaw 42 having the same size and corresponding to each other. Test piece 2 can be positioned and clamped.

As described above, the portion for clamping the test piece 2 having the curved surface, that is, the convex surface 43 of the convex jaw 41 and the concave surface 44 of the concave jaw 42 are also curved surfaces of the test piece 2 having the curved surface. Since the same size and curved surfaces correspond to each other, even when the curved specimens 2 are clamped and stretched or compressed for tension or compression testing of the curved specimens 2, the curved specimens 2 ) Can be clamped without slipping.

Therefore, in the case of tension or compression test of the curved specimen (2), accurate test data values can be obtained.

As shown, irregularities are formed in the convex surface 43 of the convex jaw 41 and the concave surface 44 of the concave jaw 42 which clamp the test piece 2 having the curved surface.

Therefore, the test piece 2 having a curved surface between the convex surface 43 of the convex jaw 41 and the concave surface 44 of the concave jaw 42 can be clamped more easily and firmly when it is clamped, which is preferable.

In the present embodiment, the convex surface 43 formed on the outer circumferential surface of the convex jaw 41 and the concave surface 44 formed on the outer circumferential surface of the concave jaw 42 are each four, but this is only a preferred embodiment and has a curved surface. Any number may be used as long as the specimen (2) can be clamped without slipping during tension or compression testing.

In addition, in the present embodiment, the convex jaw 41 is installed on the first moving shaft 33 and the second moving rotating shaft 34, and the concave jaw 42 is the first rotating shaft 31 and the second rotating shaft 32. Although it is installed in the convex jaw (41) is installed on the first rotary shaft 31 and the second rotary shaft 32, the concave jaw (42) to the first movable rotary shaft (33) and the second movable rotary shaft (34) It is also possible to provide the clamp because the convex jaw 41 and the concave jaw 42 have no problem in clamping the test piece 2 having a curved surface.

Figure 4 is a view showing the clamping and tensile test of the test piece having a curved surface using an embodiment of the test piece holding device having a curved surface according to the present invention. Figure 4 (a) shows the clamping of the test piece having a curved surface before the tensile test, Figure 4 (b) shows after the tensile test of the test piece having a curved surface.

As shown in (a) of FIG. 4, a test piece 2 having a curved surface such as a pipe or the like is positioned between the convex jaw 41 and the concave jaw 42, which are each paired up and down.

In this state, the convex surface 43 of the convex jaw 41 equal to and corresponding to the size of the curved surface of the test piece 2 having the curved surface and the concave surface 44 of the concave jaw 42 having the same size and corresponding thereto. The second rotating shaft 32 connected to the motor 25 is rotated by driving the motor 25 provided in the movable table 22 so that the test piece 2 having the curved surface is located between the

When the second rotary shaft 32 is rotated as described above, the first rotary shaft 31 connected to be rotated with the rotary shaft 32 also rotates, such that the concave jaw 42 positioned up and down is rotated together.

Since the second rotary shaft 32 is also connected to the second movable rotary shaft 34 by the rotary connector 28, when the second rotary shaft 32 is rotated, the second movable rotary shaft 34 also rotates.

In addition, the first moving rotary shaft 33 is also rotated together with the second moving rotary shaft 34 to rotate.

Therefore, the convex jaw 41 and the concave jaw 42 are formed on the first moving axis of rotation so that the convex surface 43 of the convex jaw 41 and the concave surface 44 of the concave jaw 42 correspond to each other. When installed on the 33 and the second moving rotary shaft 34 and the first rotary shaft 31 and the second rotary shaft 32, the convex jaw 41 having the same size and corresponding to each other due to the driving of the motor 25 The convex surface 43 and the concave surface 44 of the concave jaw 42 can be positioned to correspond to the curved surface of the test piece 2 having a curved surface.

In the above state, when the second moving rotary shaft 34 is moved toward the second rotating shaft 32 in the second moving groove 24 by using the moving cylinder 26 provided on the moving table 22, The first moving rotary shaft 33 connected to the moving rotary shaft 34 is also moved toward the first rotating shaft 31 in the first moving groove 23.

When the second moving rotary shaft 34 and the first moving rotary shaft 33 are moved using the moving cylinder 26, the test piece 2 having a curved surface is formed with the convex surface 43 and the concave jaw (of the convex jaw 41). It is to be clamped in close contact with the concave surface 44 of the 42.

As described above, the second rotary shaft 32 is movable on the first rotary shaft 31, and the second movable rotary shaft 34 is movable on the first movable rotary shaft 33.

Therefore, as shown in (b) of FIG. 4, a driving source including a motor, a gear, etc., provided with the moving table 22 in the tester 1 in a state in which the test piece 2 having a curved surface is clamped as described above. When the tension or compression test is performed by moving up and down, the curved test piece 2 can be clamped without slipping, so that the accurate test of the tension or compression test of the curved test piece 2 can be performed. Test data can be obtained.

As described above, two springs 27 are provided at both ends of one end of the first moving rotation shaft 33 in the first moving groove 23, and one spring 27 in the second moving groove 24. ) Is provided on one side of one end of the second moving rotary shaft 34, one end of the second moving rotary shaft 34 and one end of the first moving rotary shaft 33 are respectively the second moving groove (24). And it can be moved stably in the first moving groove (23).

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and the technical concept of the present invention will be described by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

1 is a view showing a tensile test of a test piece having a curved surface using a conventional tester and the same.

Figure 2 is a view showing an embodiment of a test piece holding device having a curved surface according to the present invention.

Figure 3 is a perspective view showing a convex jaw and concave jaw of one embodiment of a test piece holding device having a curved surface according to the present invention.

4 is a view showing the fixing of the test piece having a curved surface and the tensile test using an embodiment of the test piece holding device having a curved surface according to the present invention.

           Explanation of symbols on the main parts of the drawings

1: tester 2: test piece

10: test piece fixing device 20: grip part

21: fixed base 22: moving table

23: the first moving groove 24: the second moving groove

25: motor 26: moving cylinder

27: spring 28: rotary connection

30: connecting means 31: first rotating shaft

32: second rotating shaft 33: the first moving rotary shaft

34: second moving rotary shaft 40: test piece clamping part

41: convex jaw 42: concave jaw

43: convex surface 44: concave surface

110: upper grip 120: lower grip

130: jaw

Claims (8)

A grip portion 20 connected to the tester 1 to be moved by a drive source of the tester 1 to tension or compress the test piece 2 having a curved surface; And A test piece clamping part 40 connected to the grip part 20 by a connecting means 30 and provided to clamp the test piece 2 having a curved surface; Test piece holding device having a curved surface configured to include. The method of claim 1, wherein the grip portion 20 Fixture (21) fixed to the tester (1); And A movable table 22 movably connected to the tester 1 while facing the fixing table 21; Test piece holding device having a curved surface characterized in that it comprises a. The method of claim 1, wherein the connecting means 30 A first rotating shaft 31 of which one side is rotatably connected to the fixing base 21 included in the grip part 20; One side is movable to the first rotation shaft 31 and connected to rotate together, the other side is a second rotation shaft (32) rotatably connected to the movable table (22) included in the grip portion (20); A first movement rotating shaft 33, the one side of which is rotatably connected to the first movement groove 23 formed in the holder 21; And One side is rotatably coupled to the first movable rotary shaft 33, the other side is rotatable and rotatably connected to the second movable groove 24 formed on the movable table 22 34); Test piece holding device having a curved surface characterized in that it comprises a. The curved surface of claim 3, wherein the first rotary shaft 31 and the second rotary shaft 32 or the first movable rotary shaft 33 and the second movable rotary shaft 34 are separated from each other. Specimen fixture. The method of claim 1, wherein the test piece clamping portion 40 The outer circumferential surface is composed of one or more convex surfaces 43 and the first moving rotary shaft 33 and the second moving rotary shaft 34 or the first rotating shaft 31 and the second rotating shaft 32 included in the connecting means 30. A convex jaw 41 installed in the groove; And The outer circumferential surface is formed of at least one concave surface 44 to clamp the test piece 2 having a curved surface together with the convex surface 43 of the convex jaw 41, and the first rotating shaft 31 and the A concave jaw (42) provided on a second rotating shaft (32) or on the first moving rotating shaft (33) and on the second moving rotating shaft (34); Test piece holding device having a curved surface characterized in that it comprises a. The method of claim 2, wherein the fixing table 21 or the movable table 22 A motor 25 connected to the first rotary shaft 31 or the second rotary shaft 32 to rotate the motor 25; Test piece holding device having a curved surface, characterized in that provided with a moving cylinder (26) connected to the first moving rotary shaft (33) or the second moving rotary shaft (34) to move it. The method of claim 3, wherein when the first rotary shaft 31 or the second rotary shaft 32 is rotated, the first rotary shaft (34) or the second rotary shaft (34) is rotated, the first rotary shaft ( 31) and the test piece fixing device having a curved surface, characterized in that the first movable rotary shaft (33) or the second rotary shaft (32) and the second movable rotary shaft (34) are connected by a rotary connector (28). The method of claim 3, wherein the position of the first moving shaft 33 or the second moving shaft 34 is stabilized by the spring force in the first moving groove 23 or the second moving groove 24. Test piece holding device having a curved surface characterized in that at least one spring (27) is installed.

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