Tensile testing apparatus and tensile testing apparatus set

Abstract

To provide a tensile testing device with a simple structure that allows for continuous observation of a predetermined position on a test specimen. [Solution] A mechanical moving link mechanism 7 is provided to move the support base 3 and the observation base 4 linearly relative to each other such that the first movement L1, which is the linear movement amount of the support base 3 relative to the one-end support 1, is a predetermined multiple of the second movement L2, which is the linear movement amount of the observation base 4 relative to the one-end support 1. The ratio of the first movement amount L1 to the second movement amount L2 is N, and the initial length of the test piece T before the tensile test is L T The length from one end of the test piece T, which is the initial length, to the observation position is defined as L. K When this is the case, the equation is: N = L T / L K The moving link mechanism 7 is configured to satisfy the following conditions.

Description

[Technical Field]

[0001] The present invention relates to a tensile testing apparatus and a tensile testing apparatus set equipped therewith. [Background technology]

[0002] Conventionally, tensile testing devices have been known that are used to obtain the tensile properties of, for example, resin films and sheets (see, for example, Patent Document 1). In a tensile test using this type of device, one end of the test piece is attached to a load measuring device and the other end is held in a holding device, and the other end of the test piece is pulled relative to the other end, and the load applied to the test piece is measured at that time. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2005-148057 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Currently, in the tensile tests described above, there is a desire to observe, for example, the state of the specimen before and after the longitudinal center reaches the yield point, or the change in the state of the delamination position in T-shaped delamination. However, when the specimen deforms (stretches) during a tensile test, the longitudinal center of the specimen and the delamination position in T-shaped delamination also move from their initial positions, making it difficult to continuously observe the target position.

[0005] Therefore, the present invention provides a tensile testing apparatus and a tensile testing apparatus set that have a simple structure and can continuously observe a predetermined position on a test specimen. [Means for solving the problem]

[0006] A tensile testing apparatus according to one aspect of the present invention is a tensile testing apparatus for performing a tensile test in which a test piece extending in a film-like manner is pulled so that one end of the test piece is separated from the other end of the test piece, comprising: a one-end holder for holding the one end of the test piece; a other-end holder for holding the other end of the test piece; a holder support base that supports the other-end holder and is linearly movable toward the side away from the one-end holder (hereinafter referred to as the separation side); an observation base that is linearly movable toward the separation side relative to the one-end holder and is relatively movable relative to the holder support base; and provided on the observation base, The system comprises an imaging unit capable of observing a predetermined position in the longitudinal direction of the test specimen (hereinafter referred to as the observation position), a mechanical moving link mechanism that linearly moves the support base and the observation base relative to each other such that the amount of linear movement of the support base toward the separation side relative to the one-end holder (hereinafter referred to as the first movement) is a predetermined multiple of the amount of linear movement of the observation base toward the separation side relative to the one-end holder (hereinafter referred to as the second movement), and a load measuring device for measuring the load applied to the test specimen in the tensile test, wherein the ratio of the first movement to the second movement is N, and the initial length of the test specimen before the tensile test is L. T The initial length is defined as the length from one end of the test piece to the observation position, L. K In this case, the moving link mechanism is configured to satisfy the following equation (1). N=L T / L K ...(1)

[0007] In the tensile testing apparatus described above, the imaging unit is positioned to observe the central part of the longitudinal direction of the test piece as the observation position, and the ratio N of the first movement to the second movement may be N=2.

[0008] The tensile testing apparatus described above further comprises a main drive unit that linearly moves the observation base toward the separation side relative to the one-end holder, and the moving link mechanism may include a first rotating body, which is a gear or pulley that rotates in conjunction with the linear movement of the observation base toward the separation side, and a second rotating body, which is a gear or pulley that is rotated by the rotational force of the first rotating body and transmits its own rotational force as the linear movement force of the holder support base.

[0009] The tensile testing apparatus described above further comprises a main drive unit that linearly moves the base for moving the holder toward the separation side relative to the one-end holder, and the moving link mechanism may include a first rotating body which is a gear or pulley that rotates in conjunction with the linear movement of the base for supporting the holder toward the separation side, and a second rotating body which is a gear or pulley that is rotated by the rotational force of the first rotating body and transmits its own rotational force as the linear movement force of the observation base.

[0010] A tensile testing apparatus set according to one aspect of the present invention comprises the above-described tensile testing apparatus, a test specimen used for tensile testing by the tensile testing apparatus, and a test specimen holder which is frame-shaped and holds both ends of the test specimen in the longitudinal direction, and whose ends in the frame length direction, which coincides with the longitudinal direction of the test specimen, are held by the tensile testing apparatus. [Effects of the Invention]

[0011] The tensile testing apparatus and tensile testing apparatus set described above allow for continuous observation of a predetermined position on the test specimen with a simple structure. [Brief explanation of the drawing]

[0012] [Figure 1] This is an overall plan view of a tensile testing apparatus according to an embodiment of the present invention, where (a) shows the state before the start of the test, and (b) shows the state after the start of the test when the test piece has been stretched. [Figure 2] This figure shows how the test specimen stretches when a tensile test is performed using the tensile testing apparatus described above. [Figure 3] It is a front view showing the state where a test piece set is installed in the above tensile test apparatus. [Figure 4] It is a graph showing the relationship between the test time and the tensile speed when performing a tensile test in the above tensile test apparatus. [Figure 5] It is a view showing the above test piece set, where (a) is a front view and (b) is a cross-sectional view taken along line IV-IV of (a). [Figure 6] It is a view showing a test piece forming jig for forming the above test piece set, where (a) is a plan view and (b) is a front view as viewed from arrow VI of (a). [Figure 7] It is a view showing the procedure for forming the above test piece set in chronological order as (a), (b), and (c). [Figure 8] It is a view showing the test preparation when performing a tensile test using the above test piece set, where (a) shows the state immediately after attaching the test piece set to the tensile test apparatus, and (b) shows the state where the test piece is bent. [Figure 9] It is a view showing a modified example of the test piece forming jig for forming the above test piece set. [Figure 10] It is an overall plan view when the above tensile test apparatus is used for a T-peel test.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (Overall Configuration) As shown in FIGS. 1(a) and (b), the tensile test apparatus 100 is an apparatus that performs a tensile test for pulling a test piece T in a film shape (film-like, sheet-like) such that the other end Tb of the test piece T moves away from one end of the test piece T. The test piece T is formed of, for example, a resin or the like, and has a shape with a longer dimension in the film length direction than in the film width direction.

[0014] Specifically, the tensile testing apparatus 100 comprises a plate-shaped main base 10, a one-end holder 1, a other-end holder 2, a holder support base 3, an observation base 4, a main drive unit 5, an imaging unit 6, a moving link mechanism 7, and a load measuring device 8, all of which are mounted on the main base 10.

[0015] The main base 10 is, for example, a plate-shaped member installed on a horizontal surface. The main base 10 is equipped with a control unit 9 that controls the operation of the main drive unit 5, which will be described in detail later. The control unit 9 is composed of a computer including a processor.

[0016] The one-end holder 1 holds one end Ta of the test specimen T in the longitudinal direction. The one-end holder 1 is, for example, a chuck that clamps the test specimen T from the thickness direction (hereinafter referred to as the film thickness direction) of the test specimen, and is connected to a load measuring device 8, which will be described in detail later.

[0017] The other end holder 2 is positioned at a distance from the one end holder 1 in the longitudinal direction of the test piece T and holds the other end Tb of the test piece T. The other end holder 2 is a chuck that, like the one end holder 1, clamps the test piece T from, for example, the thickness direction of the test piece (hereinafter referred to as the film thickness direction).

[0018] The support base 3 for the holder supports the other end holder 2 from below and is able to move linearly in the device length direction, which coincides with the longitudinal direction of the test piece T, in the horizontal direction relative to the main base 10, together with the other end holder 2. The support base 3 for the holder is able to reciprocate in the device length direction so as to bring the one end holder 1 and the other end holder 2 closer together and further apart.

[0019] The observation base 4 is provided between the main base 10 and the holder support base 3, and is capable of reciprocating linearly in the device length direction relative to the main base 10 on the main base 10, and is also capable of reciprocating linearly in the device length direction relative to the holder support base 3. Specifically, for example, a slide rail 40 is provided between the observation base 4 and the holder support base 3, and the observation base 4 moves linearly while being guided in the device length direction by this slide rail 40, but the guide structure of the observation base 4 is not particularly limited.

[0020] The main drive unit 5 moves the observation base 4 back and forth linearly in the direction of the device length relative to the one-end holder 1 on the main base 10. The main drive unit 5, although not shown in detail in the illustration, includes, for example, a stepping motor and a ball screw driven by the stepping motor. The main drive unit 5 is driven and controlled by a control unit 150 provided on the main base 10, making it possible to move the observation base 4 at any speed and stop it at any position. The configuration of the main drive unit 5 is not particularly limited and may be configured by other known methods, such as a linear motor.

[0021] The imaging unit 6 is fixedly mounted on the observation base 4 and consists of a camera or the like capable of observing the observation position, which is a predetermined position in the longitudinal direction of the test piece T. In this embodiment, this observation position is the central part Tc in the longitudinal direction of the test piece T.

[0022] The moving link mechanism 7 is a mechanical mechanism that moves the observation base 4 relative to the holder support base 3 when the observation base 4 is moved by the main drive unit 5. The moving link mechanism 7 is configured such that the first movement amount (which may be a speed of movement) L1, which is the linear movement amount (distance) of the holder support base 3 toward the away side (the side toward the away side of the holder support base 3 relative to the one-end holder 1), is a predetermined multiple of the second movement amount (which may be a speed of movement) L2, which is the linear movement amount (distance) of the observation base 4 toward the away side (the distance) relative to the one-end holder 1. Specifically, let N be the ratio of the first movement amount L1 to the second movement amount L2, and let L be the initial length of the test piece T before the tensile test. T Let L be the length from one end Ta of the test specimen T, which is the initial length, to the position to be observed. K When this is the case (see Figure 2), the moving link mechanism 7 is configured to satisfy the following equation (1).

[0023] N=L T / L K ...(1) In this embodiment, equation (1) above is N=2. That is, the first movement L1, which is the movement of the support base 3 for the holder, is twice the second movement L2, which is the movement of the observation base 4.

[0024] The configuration of the moving link mechanism 7 is not particularly limited, but as an example, it includes a first rack 70 provided on the support base 3 for the holder, a first rotating body 71 which is a gear, a second rack 72, and a second rotating body 73 which is a gear, provided on the observation base 4, and a belt 74 which serves as a power transmission part interposed between the first rotating body 71 and the second rotating body 73.

[0025] The first rotating body 71 is engaged with the first rack 70 and is rotated as the observation base 4 moves linearly toward the separation side.

[0026] The rotational force of the first rotating body is transmitted to the second rotating body 73 by the belt 74, and the second rotating body 73 is rotated by the rotational force of the first rotating body 71. The second rotating body 73 is engaged with the second rack 72 and transmits its own rotational force as linear movement force to the support base 3 for the holder through the second rack 72.

[0027] The gear ratios of the first rack 70, the first rotating body 71, the second rack 72, and the second rotating body 73 are set to such a value that the first movement L1 of the support base 3 is twice the second movement L2 of the observation base 4, as described above. Note that the first rotating body 71 and the second rotating body 73 may be replaced with pulleys instead of gears.

[0028] The load measuring device 8 measures the load (tensile force) applied to the test specimen T when it is pulled during a tensile test, and in this embodiment, it is composed of a load cell. The load measuring device 8 is supported by a frame 11 on the main base 10 and is fixed to the main base 10. The load measuring device 8 is also electrically connected to the control unit 9, and its output is transmitted to the control unit 9. The method of detecting the load in the load measuring device 8 is not particularly limited and may be any of the following: strain gauge type, piezoelectric type, capacitive type, electromagnetic type, or tuning fork type.

[0029] (Effects and Benefits) When a tensile test of a test specimen T is performed using the tensile testing apparatus 100 of this embodiment described above, the test specimen T elongates as shown in Figure 2, and the elongation amount ΔLb at the other end Tb becomes twice the elongation amount ΔLc at the central part Tc. In this embodiment, the movement link mechanism 7 is configured such that the first movement amount L1, which is the linear movement amount of the support base 3 that holds the other end Tb of the test specimen T, is twice the second movement amount L2, which is the linear movement amount of the observation base 4 on which the imaging unit 6 is provided. Therefore, the imaging unit 6 can move in conjunction with the movement of the central part Tc accompanying the elongation of the test specimen T, and can continuously observe the central part Tc, which is at a predetermined position on the test specimen T.

[0030] And with such a simple structure, using a mechanical moving link mechanism 7, it becomes possible to continuously observe the position to be observed, which is a predetermined position on the test specimen T.

[0031] Furthermore, the main drive unit 5 operates only the observation base 4, while the mechanical moving link mechanism 7 moves the support base 3 for the holder. Compared to the case where the support base 3 for the holder and the observation base 4 are moved by separate drive units, this allows for a more reliable maintenance of a constant relative movement between the support base 3 for the holder and the observation base 4.

[0032] (Other examples of test specimens) Incidentally, the tensile testing apparatus 100 described above may use a set of test specimens Ts as shown in Figure 3 instead of the test specimen T described above. Specifically, the set of test specimens Ts comprises the test specimen T which extends in a film-like manner, and a frame-shaped test specimen holder H made of thin plates which holds both ends of the test specimen T in the longitudinal direction.

[0033] The specimen holder H is provided so as to surround the specimen T from the outer circumference, and both ends of the specimen T in the frame length direction, which coincides with the longitudinal direction of the specimen T, are held by the one-end holder 1 and the other-end holder 2 of the tensile testing apparatus 100, respectively. The material of the specimen holder H is not particularly limited, but it is preferable that it be made of thick paper, which has greater strength in the frame length direction than the strength of the specimen T in the longitudinal direction.

[0034] Furthermore, the specimen holder H has an inner space S formed therein, which is a through-hole that penetrates the specimen holder H in the thickness direction (frame thickness direction) and where the specimen T is placed. The specimen T is positioned so as to occupy a portion of the inner space S, and a portion of the specimen T in the longitudinal direction is exposed to the inner space S. In addition, the specimen holder H has a slit Ha formed on one side in the frame width direction, which coincides with the film width direction of the specimen T, connecting this inner space S to the outside of the specimen holder H. In other words, the specimen holder H is separated into one region in the frame length direction and the other region only on one side in the frame width direction, and when viewed from the frame thickness direction, the specimen holder H has a roughly C shape.

[0035] Here, the width dimension in the frame length direction of the slit Ha, that is, the slit width dimension W, is larger than the time integral value of the tensile speed from zero to the constant speed u when a constant speed tensile test is performed as a tensile test. That is, the slit width dimension W is larger than the area of the triangular region (acceleration region) R shown by the slanted lines in the graph of the function showing the relationship between the test time t and the tensile speed u shown in FIG. 4. c Furthermore, as shown in FIGS. 5(a) and 5(b), the test piece holder H has a first side region Hx and a second side region Hy that overlap in the frame thickness direction. These first side region Hx and second side region Hy are connected to each other across the broken line PL on one side in the frame width direction (or it may be on one side in the frame length direction) of the test piece holder H. Also, in the test piece holder H, the first side inner surface Hxa that is the inner surface of the first side region Hx and the second side inner surface Hya that is the inner surface of the second side region Hy are in a facing state, and an adhesive P is interposed between these first side inner surface Hxa and second side inner surface Hya, and the first side region Hx and the second side region Hy are adhered to each other. Also, both ends of the test piece T are sandwiched between the first side inner surface Hxa and the second side inner surface Hya, respectively, whereby the test piece T and the test piece holder H are integrated.

[0036]

[0037] Next, a test piece forming jig 200 for forming a test piece set Ts and a method for forming (manufacturing) the test piece set Ts using the test piece forming jig 200 will be described. As shown in FIGS. 6(a) and 6(b), the test piece forming jig 200 has a plate-like jig body 210 provided with a reference line LX indicating the position where the test piece T is to be arranged on the upper surface 210a, and a convex portion 220 provided so as to project from the upper surface 210a of the jig body 210. The upper surface 210a is provided with, for example, a fluororesin coating or the like.

[0038] Two reference lines LX of the jig body 210 are provided in parallel, and the region A between these two reference lines has a shape substantially matching the test piece T.

[0039] The protrusion 220 forms a positioning surface 220a for aligning the position of the specimen holder H when the first inner surface Hxa of the first side region Hx of the specimen holder H is positioned opposite the upper surface 210a. In this embodiment, when the first side region Hx of the specimen holder H is positioned opposite the upper surface 210a, the edge of the positioning surface 220a is L-shaped when viewed from above in the thickness direction of the specimen forming jig 200, so that the specimen holder H faces the positioning surface 220a from one side in the frame width direction and one side in the frame length direction of the first side region Hx.

[0040] In the test preparation method when preparing for a tensile test using the test specimen set Ts, the test specimen set Ts is first formed. That is, as shown in Figure 7(a), the test specimen T is placed along the reference line LX provided on the upper surface 210a of the test specimen forming jig 200. Then, as shown in Figure 7(b), the first inner surface Hxa of the first side region Hx of the test specimen holder H, to which adhesive P has been applied, is positioned opposite the upper surface 210a. This adheres both sides of the longitudinal direction of the test specimen T to the first inner surface Hxa. At this time, on the other side in the frame width direction of the test specimen holder H, which is the side without the positioning surface 220a, the second side region Hy of the test specimen holder H is positioned to protrude to the outside of the test specimen forming jig 200.

[0041] Then, with the specimen T attached, the first side region Hx of the specimen holder H is removed from the upper surface 210a, and as shown in Figure 7(c), the second side region Hy of the specimen holder H is folded back along the broken line LP and attached so that the first side inner surface Hxa of the first side region Hx and the second side inner surface Hya of the second side region Hy overlap. This completes the specimen set Ts in which the specimen T is sandwiched between the first side region Hx and the second side region Hy of the specimen holder H (see Figures 5(a) and 5(b)).

[0042] Next, in the above test preparation method, the test specimen set Ts is attached to the tensile testing apparatus. That is, one side of the test specimen holder H in the frame length direction is clamped by the one-end holder 1 of the tensile testing apparatus 100, and the other side of the test specimen holder H in the frame length direction is clamped by the other-end holder 2. Then, as shown in Figure 8(a), on the other side in the frame width direction where the slit Ha is not formed on the test specimen T, the test specimen holder H is cut along the direction in which the slit Ha extends, i.e., along the frame width direction, at a position between the one-end holder 1 and the other-end holder 2, dividing it into two parts in the frame length direction. When cutting the test specimen holder H, it is preferable to cut the test specimen holder H at two virtual cutting lines VL that are spaced approximately the same distance as the slit width dimension W in the frame length direction. After that, as shown in Figure 8(b), the one-end holder 1 and the other-end holder 2 of the tensile testing apparatus 100 are brought closer together (so-called "setback"), thereby bending the test specimen T in the longitudinal direction. The tensile test is started from this state, and the tensile speed is gradually increased as the train approaches, reaching the predetermined speed u mentioned above. c Constant-speed tensioning is initiated after reaching a certain point (see Figure 4). The tensioning speed u increases from zero to a predetermined speed u c In this case, it would be ideal if the test piece T is neither bent nor stretched, but at its natural length.

[0043] By using the specimen set Ts described above, the risk of the specimen T being attached to the tensile testing apparatus 100 in a deformed state can be reduced compared to when the specimen T is attached to the apparatus 100 individually. Therefore, the accuracy of the tensile test can be improved.

[0044] As shown in Figure 9, in the specimen forming jig 200 described above, it is also possible to form a set of specimens Ts in which multiple specimens T are arranged in the film width direction by providing three or more reference lines LX at intervals, that is, by arranging multiple regions A between a pair of reference lines LX at intervals in the film width direction of the specimen T.

[0045] Here, it is not necessary to form a slit Ha in the specimen set Ts. If there is no slit Ha, the specimen holder H can be cut on both sides in the frame width direction relative to the specimen T, and the test can be started.

[0046] (T-shaped peel test) Furthermore, as shown in Figure 10, the tensile testing apparatus 100 may also be used for a T-type peel test. In this case, the peel position PP of the test piece T can be observed at a fixed point by the imaging unit 6.

[0047] Herein, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the above case, the observation base 4 was moved linearly by the main drive unit 5, but the support base 3 for the holder body may be moved linearly by the main drive unit 5, and the observation base 4 may be moved relative to the support base 3 by the movement link mechanism 7.

[0048] Furthermore, the position of the test specimen T observed by the imaging unit 6 does not necessarily have to be the central part Tc of the test specimen T, but may be any other position in the longitudinal direction of the test specimen T. [Industrial applicability]

[0049] According to the tensile testing apparatus of the present invention, a predetermined position on a test specimen can be continuously observed with a simple structure. [Explanation of Symbols]

[0050] 1...One end holding body 2...Other end side holding body 3...Base for supporting the holder 4… Observation base 5…Main drive unit 6… Imaging Department 7…Moving link mechanism 8…Load measuring device 9... Control Unit 70...First rack 71…First rotating body 72... Second rack 73…Second Rotating Body 100...Tensile testing device 200... Test specimen forming jig 210... Jig body 210a…Top surface 220a... Positioning surface H... Test specimen holder Ha... Slit Hx…first side area Hxa...first side inner surface Hy…Second side area Hya... Second inner side LX...Reference line S…Inner space T... Test piece Ta…One end Tb...other end Tc…Central part Ts... Test piece set L1…First movement amount L2…Second movement amount W...Slit width dimension

Claims

1. A tensile testing apparatus for performing a tensile test in which one end of a test piece extending in a film-like manner is pulled so that the other end of the test piece separates from the other end, A one-end holder that holds one end of the test piece, The other end holder holds the other end of the test piece, A base for supporting the holder that supports the other end holder and is linearly movable toward the side away from the one end holder (hereinafter referred to as the separation side), An observation base which is linearly movable toward the separation side with respect to the one-end holder and is relatively movable with respect to the holder support base, An imaging unit is provided on the observation base and is capable of observing a predetermined position in the longitudinal direction of the test piece (hereinafter referred to as the observation position), A mechanical moving link mechanism that moves the support base for the support body and the observation base linearly relative to each other such that the amount of linear movement of the support base for the support body relative to the one-end support body toward the separation side (hereinafter, the first amount of movement) is a predetermined multiple of the amount of linear movement of the observation base relative to the one-end support body toward the separation side (hereinafter, the second amount of movement), A load measuring device for measuring the load applied to the test specimen in the tensile test, Equipped with, Let N be the ratio of the first displacement to the second displacement, and let L be the initial length of the test specimen before the tensile test. Ｔ The initial length of the test piece is defined as the length from one end to the observation position, L. Ｋ A tensile testing apparatus in which the moving link mechanism is configured to satisfy the following equation (1). =L Ｔ / L Ｋ ・・・(1)

2. The imaging unit is provided so as to be able to observe the central part of the longitudinal direction of the test piece as the observation position. The tensile testing apparatus according to claim 1, wherein the ratio N of the first displacement to the second displacement is N = 2.

3. The observation base is further provided with a main drive unit that linearly moves it toward the separation side relative to the one-end holder, The aforementioned movable link mechanism is A first rotating body, which is a gear or pulley, rotates in conjunction with the linear movement of the observation base toward the separation side, A second rotating body, which is rotated by the rotational force of the first rotating body and acts as a gear or pulley that transmits its own rotational force as the linear movement force of the support base for the holder, A tensile testing apparatus according to claim 1, having the following features.

4. The base for moving the holder is further provided with a main drive unit that linearly moves the holder at one end toward the separation side, The aforementioned movable link mechanism is A first rotating body, which is a gear or pulley, rotates in conjunction with the linear movement of the support base for the holder toward the separation side, A second rotating body, which is rotated by the rotational force of the first rotating body and acts as a gear or pulley that transmits its own rotational force as the linear movement force of the observation base, A tensile testing apparatus according to claim 1, having the following features.

5. A tensile testing apparatus according to any one of claims 1 to 4, The test specimen used for tensile testing by the tensile testing apparatus, A specimen holder is provided, which is frame-shaped and holds both ends of the specimen in the longitudinal direction, and whose ends in the frame length direction, which coincides with the longitudinal direction of the specimen, are held by the tensile testing device. A tensile testing apparatus set having [specific features / features].

Images