Method for applying tension to a held object, biaxial tensile test method, and holding device

Abstract

An object of the present disclosure is to provide a method for applying tension to a held object that can easily apply tension in two axial directions to a relatively small held object. [Solution] A tensioning method according to one embodiment of the present disclosure is a method for applying tension to a held object (1) made of a metallic material in a first direction (X) and a second direction (Y) perpendicular to the first direction (X), and includes the steps of: attaching a holding jig (20) having holders for holding the held object (1) to a device (10) that applies tension in the first direction (X) and the second direction (Y); connecting actuators (11a, 11b, 12a, 12b) of the tensioning device (10) to the holders; and operating the actuators (11a, 11b, 12a, 12b) to apply tension to the held object (1).

Description

[Technical Field]

[0001] The present disclosure relates to a method for applying tension to a held object, a biaxial tensile test method, and a holding tool. [Background technology]

[0002] Biaxial tensile testing machines for measuring deformation behavior are known. A jig for use in such testing machines to measure strain in a test piece has been proposed (Japanese Patent Application Laid-Open No. 2019-219235). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-219235 Summary of the Invention [Problem to be solved by the invention]

[0004] The testing machine of Patent Document 1 includes a central mold that clamps a test piece with a strain gauge attached from both sides, and the central mold has a soft member with a predetermined Young's modulus on the surface that clamps the test piece. The test piece clamped by the central mold has its ends clamped between a pair of first side molds and a pair of second side molds, and a compressive load or a tensile load is applied in two axial directions. Patent Document 1 claims that clamping the test piece between the central mold via the soft member can prevent damage to the strain gauge and enable highly accurate strain measurement.

[0005] In Patent Document 1, a test piece having a length of 320 mm is used as an example. When the set of first side molds and the set of second side molds move toward each other, their tips come into contact with each other. Therefore, if a relatively small test piece is used, there is a risk that the test piece cannot be clamped between the set of first side molds and the set of second side molds. There is a demand for the ability to perform tests on small test pieces (held objects).

[0006] In view of these circumstances, the present disclosure aims to provide a method for applying tension to a held object that can hold a relatively small held object and easily apply tension in two axial directions. [Means for solving the problem]

[0007] A method of applying tension to a held object according to one aspect of the present disclosure, which has been made to solve the above-mentioned problems, is a method of applying tension to a held object formed of a metal-based material in a first direction and in a second direction perpendicular to the first direction, and includes the steps of attaching a holding jig having a holder for holding the held object to a device that applies tension in the first direction and the second direction, connecting an actuator of the device that applies tension to the holder, and operating the actuator to apply tension to the held object. [Effects of the Invention]

[0008] A method for applying tension to a held object according to one aspect of the present disclosure can easily apply tension in two axial directions to a relatively small held object. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic plan view showing an object to be held that is used in a tension applying method according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic plan view showing a tension applying device used in the tension applying method. [Figure 3] FIG. 3 is a schematic plan view showing a state in which a holding jig is attached to the tension applying device of FIG. [Figure 4] FIG. 4 is a schematic enlarged plan view showing the holding jig of FIG. [Figure 5] FIG. 5 is a schematic plan view showing the base of the holding jig of FIG. [Figure 6] FIG. 6 is a schematic side view showing a holder disposed in the holding jig of FIG. [Figure 7] FIG. 7 is a schematic side view showing a first member of the holder of FIG. [Figure 8] FIG. 8 is a schematic plan view showing the first member of FIG. [Figure 9] FIG. 9 is a schematic front view showing the first member of FIG. [Figure 10] FIG. 10 is a schematic rear view showing the first member of FIG. [Figure 11] FIG. 11 is a schematic side view showing a second member of the holder of FIG. [Figure 12] FIG. 12 is a schematic bottom view showing the second member of FIG. [Figure 13] FIG. 13 is a schematic front view showing the second member of FIG. [Figure 14] FIG. 14 is a schematic plan view showing a clamping member of the holder of FIG. [Figure 15] FIG. 15 is a schematic side view showing the clamping member of FIG. [Figure 16] FIG. 16 is a schematic front view showing a connecting member that can be attached to the holder of FIG. [Figure 17] FIG. 17 is a schematic plan view showing the connecting member of FIG. [Figure 18] 18 is a schematic perspective view showing a state in which the connecting member of FIG. 16 is attached to the holder of FIG. [Figure 19] 19 is a schematic perspective view showing a connecting portion that connects the actuator and the holder of the tension applying device in FIG. [Figure 20] FIG. 20 is a schematic side view showing the connecting portion of FIG. [Figure 21] FIG. 21 is an end view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0011] (1) A method of applying tension to a held object according to one aspect of the present disclosure is a method of applying tension to a held object in a first direction and in a second direction perpendicular to the first direction, and includes the steps of: attaching a holding jig having a holder for holding the held object to a device that applies tension in the first direction and the second direction; connecting an actuator of the device that applies tension to the holder; and operating the actuator to apply tension to the held object.

[0012] The tensioning method for a held object (hereinafter simply referred to as the tensioning method) involves attaching a holding jig having a holder for holding the held object to a device that applies tension in the first direction and the second direction (biaxial directions), and connecting the holding jig to an actuator of the tensioning device to apply tension to the held object. That is, the tensioning device applies tension to the held object in the biaxial directions via the holding jig. Therefore, the chuck portion of the actuator can hold and apply tension to a held object that is closer (shorter) than the distance at which adjacent chuck portions come into contact in the biaxial directions.

[0013] (2) In the above (1), the method may further include a step of holding the object to be held by the holder, and the length of the object to be held in at least one of the first direction and the second direction may be less than 130 mm. In other words, the tensioning method is suitable for applying tension to an object to be held that has a length of less than 130 mm.

[0014] (3) A biaxial tensile testing method according to one aspect of the present disclosure includes the steps of: attaching a holding jig having a holder for holding a held object to a biaxial tensile testing machine; connecting an actuator of the biaxial tensile testing machine to the holder; and operating the actuator to perform a biaxial tensile test on the held object.

[0015] In the biaxial tensile testing method, a holding jig having a holder for holding an object to be held is attached to the biaxial tensile testing machine, and the holding jig is connected to an actuator of the biaxial tensile testing machine to perform a biaxial tensile test on the object to be held. That is, the biaxial tensile testing machine applies tension to the object to be held in biaxial directions via the holding jig. Therefore, a biaxial tensile test can be performed by holding the object to be held at a distance smaller than the contact distance between adjacent chuck portions in the biaxial directions.

[0016] (4) A holder according to one aspect of the present disclosure is a holder that holds an end of an object to be held that is applied with tension in one direction, and includes a first member having a support surface that supports the end of the object to be held from one side, a second member having a pressing surface facing the support surface and positioned on the first member so that the object to be held is sandwiched between the first member and the support surface using this pressing surface, and a fixing member that fixes the positioned second member to the first member, wherein the first member and the second member have a pair of abutting surfaces that abut against each other, and the pair of abutting surfaces are formed so that the pressing surface is inclined backward in a direction away from the support surface, and the fixing member includes a first fixing member that is inserted from the first member and engages with the second member via the pair of abutting surfaces, and a second fixing member that is inserted from the second member and engages with the first member.

[0017] The holder comprises a first member having a support surface that supports the object to be held from one side, and a second member having a pressing surface facing the support surface, and the object to be held is sandwiched and held between the support surface of the first member and the pressing surface of the second member. The first member and the second member have a pair of abutment surfaces formed so that the pressing surface is inclined backward in a direction away from the support surface, and are fixed to each other via the pair of abutment surfaces by a first fixing member that engages with the second member, and a second fixing member that is inserted from the second member and engages with the first member. Therefore, it is easy to position the second member relative to the first member so as to sandwich the object to be held, and it is possible to apply a high pressing force to the object to be held.

[0018] (5) In (4) above, the first fixing member and the second fixing member may be orthogonal to fix the first member and the second member. By fixing the first member and the second member by being orthogonal to the first fixing member, the reliability of holding the object to be held can be improved.

[0019] (6) In the above (4) or (5), the holder may further include a connecting member that has a fixing portion fixed to the second member and a leg portion extending from the fixing portion so as to be attached to a side surface of the first member, and that connects the first member and the second member. By further including a connecting member that connects the first member and the second member, the reliability of holding the object to be held can be further improved.

[0020] [Details of the Mode for Carrying Out the Invention] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0021] <Tensioning method> The tension applying method applies tension to a held object in a first direction and a second direction perpendicular to the first direction, and includes the steps of: attaching a holding jig having a holder for holding the held object to a device that applies tension in the first direction and the second direction; connecting an actuator included in the device that applies tension to the holder; and operating the actuator to apply tension to the held object.

[0022] The tension applying device may be a biaxial tensile testing machine. That is, the tension applying method may be a biaxial tensile testing method including the steps of: attaching a holding jig having a holder for holding a held object to the biaxial tensile testing machine; connecting an actuator of the biaxial tensile testing machine to the holder; and operating the actuator to perform a biaxial tensile test on the held object.

[0023] <Object to be held> The object to be held is not particularly limited, and may be formed from a plate-like material, a round bar material, a square bar material, or the like. The object to be held may be formed in a generally cross shape as shown in FIG. 1. Specifically, the object to be held 1 may be formed to have a central portion 1a and extension portions 1b extending in all directions from this central portion 1a. By forming the object to be held 1 in a generally cross shape, the ease of holding by the holder is improved, and generally uniform tension can be applied in the two axial directions to the center point (central portion 1a) of the object to be held 1. In this embodiment, the object to be held 1 will be described as being plate-shaped.

[0024] The size (external dimensions) of the held object is not particularly limited, but is preferably relatively small from the perspective of obtaining the held object easily and at low cost. Specifically, the external dimensions of the held object in a plan view (the maximum external dimension W of the held object 1 shown in FIG. 1) should be less than 130 mm. That is, the held object should be less than 130 mm square. The upper limit of the external dimensions may be 115 mm or 100 mm. The lower limit of the external dimensions is not particularly limited and may be 25 mm, 30 mm, or 40 mm. The thickness (or diameter) of the held object is not particularly limited. For example, if the held object 1 is plate-shaped, the upper limit of the thickness may be 10 mm, 5 mm, or 2 mm. The lower limit of the thickness may be 0.1 mm, 0.2 mm, or 0.5 mm. If the held object is a round bar or square bar, the upper limit of the thickness may be 20 mm, 15 mm, or 10 mm. The lower limit of the thickness may be 0.5 mm, 1.0 mm, or 1.5 mm.

[0025] The material forming the object to be held used in this tensioning method is not particularly limited, and may be a metal-based material, a resin-based material, or a material containing metal or resin (composite material). The metal-based material is not particularly limited as long as it is a metal or alloy, and examples thereof include iron, aluminum, and stainless steel. The resin-based material is not particularly limited, and examples thereof include polypropylene. The resin-based material may be a resin reinforced with glass fibers, such as glass fiber polypropylen (GFPP).

[0026] <Tensioning device> The device for applying tension in the biaxial direction to the held object 1 is not particularly limited, and an example thereof is a known biaxial tensile testing machine 10 as shown in Fig. 2. In other words, this tension application method is suitable for biaxial tensile testing.

[0027] The biaxial tensile testing machine 10 includes a pair of first actuators 11a, 11b that move away from each other in one direction (X-axis direction) and a pair of second actuators 12a, 12b that move away from each other in a direction perpendicular to the one direction (Y-axis direction). The first actuators 11a, 11b have a pair of first chucks 13a, 13b arranged opposite each other to hold the object 1 at their tips, and the second actuators 12a, 12b similarly have a pair of second chucks 14a, 14b. The biaxial tensile testing machine 10 also includes a temporary stage 15 for adjusting the position, height (position in Z-axis direction), and inclination of the object 1 when holding it between the chucks 13a, 13b, 14a, 14b. The biaxial tensile testing machine 10 is a device that holds and applies tension to a sample (object) measuring, for example, 250 mm or larger in plan view.

[0028] <Holding jig> 3 and 4, the holding jig 20 attached to the biaxial tensile testing machine 10 has a base 21 that is detachable from the biaxial tensile testing machine 10, holders 101, 102, 103, and 104 that are placed on the base 21 and hold the object 1 to be held, and connecting portions 201, 202, 203, and 204 that connect the holders 101, 102, 103, and 104 to the actuators 11a, 11b, 12a, and 12b of the biaxial tensile testing machine 10. The base 21 is placed on a temporary stand 15 of the biaxial tensile testing machine 10.

[0029] Specifically, the holding jig 20 has a pair of first holders 101, 102 arranged opposite each other in the X-axis direction to hold the object to be held 1, a pair of second holders 103, 104 arranged opposite each other in the Y-axis direction, first connecting portions 201, 202 that connect the pair of first holders 101, 102 to first actuators 11a, 11b, respectively, and second connecting portions 203, 204 that connect the pair of second holders 103, 104 to second actuators 12a, 12b, respectively.

[0030] The four holders 101, 102, 103, and 104 are arranged so as to be freely movable on rails 22 provided on base 21 in the direction in which actuators 11a, 11b, 12a, and 12b, to which they are respectively connected, move. Specifically, holders 101, 102, 103, and 104 are attached to sliders (not shown) that can move back and forth on rails 22. One end (tip) of connecting portions 201, 202, 203, and 204 is fixed to the backs of holders 101, 102, 103, and 104 (the part opposite the side that holds object 1).

[0031] <Holder> Holders 101, 102, 103, and 104 (hereinafter referred to as holder 101) hold the end of the object to be held 1 to which tension is applied in one direction. Hereinafter, the direction of tension applied to the object to be held 1 in the one direction will also be referred to as the rear, and the opposite direction will also be referred to as the front.

[0032] 6, the holder 101 includes a first member 110 having a support surface 111 that supports an end of the object to be held 1 from one side, a second member 150 having a pressing surface 151 facing the support surface 111 and positioned on the first member 110 so that the object to be held 1 is sandwiched between the first member 110 and the support surface 111 by the pressing surface 151, and a fixing member that fixes the positioned second member 150 to the first member 110. The first member 110 and the second member 150 have a pair of abutting surfaces that abut against each other, and the pair of abutting surfaces are formed so that the pressing surface 151 is inclined backward in a direction away from the support surface 111. The fixing member includes a first fixing member T1 that is inserted from the first member 110 and engages with the second member 150 via the pair of abutting surfaces, and a second fixing member T2 that is inserted from the second member 150 and engages with the first member 110.

[0033] The first fixing member T1 and the second fixing member T2 may be orthogonal to fix the first member 110 and the second member 150. Fixing the first member 110 and the second member 150 by orthogonalizing the first fixing member T1 and the second fixing member T2 can improve the reliability of holding the object to be held 1. The fixing members T1 and T2 are not particularly limited and may be, for example, known bolts. The pair of abutting surfaces includes a first abutting surface 112 of the first member 110 and a second abutting surface 152 of the second member 150.

[0034] The holder 101 preferably includes a pair of clamping members 180 that clamp the object 1, and the pair of clamping members 180 preferably constitute the support surface 111 and the pressing surface 151. That is, the first member 110 and the second member 150 preferably hold the object 1 via the pair of clamping members 180 that constitute the support surface 111 and the pressing surface 151. The pair of clamping members 180 that clamp the object 1 are arranged in the holder 101 so that when the object 1 is pulled and moves in the above-mentioned one direction (forward), the distance between them (the distance between the support surface 111 and the pressing surface 151) gradually decreases. This improves the reliability of holding the extension portion 1b, which stretches and becomes thinner when tension is applied. The surfaces (support surface 111 and pressing surface 151) that the clamping members 180 use to clamp the object 1 are preferably rough-grained. That is, it is preferable that a plurality of minute irregularities are formed on the support surface 111 and the pressing surface 151. By forming the support surface 111 and the pressing surface 151 by roughening, the object 1 to be held can be held more reliably.

[0035] As shown in Figures 7 to 10, the first member 110 has a first bottom surface 113 parallel to the support surface 111, a first top surface 114 facing the first bottom surface 113 and connected to the rear end of the first abutment surface 112, a first back surface 115 connecting the rear ends of the first bottom surface 113 and the first top surface 114, a first front surface 116 facing the first back surface 115 and connected to the front end of the first bottom surface 113, a first intermediate surface 117 connected to the front end of the first abutment surface 112 and extending forward, a first through hole 118 that penetrates the first back surface 115 and the first abutment surface 112 and into which the first fixing member T1 is inserted, and a first engagement hole 119 formed from the first intermediate surface 117 toward the first bottom surface 113 and into which the second fixing member T2 engages. The first through-hole 118 is formed as an elongated hole having a major axis in the vertical direction (Z-axis direction).

[0036] The first member 110 has a first connecting surface 120 connecting the front end of the first abutment surface 112 and the rear end of the first intermediate surface 117, a first vertical surface 121 that is parallel to the first front surface 116 and connects to the front end of the first intermediate surface 117, and a first inclined surface 122 that connects the first front surface 116 and the first vertical surface 121 and is inclined downward toward the first bottom surface 113. The first vertical surface 121 and the first inclined surface 122 are preferably connected by an inverted round chamfered portion 123. The inverted round chamfered portion 123 is preferably provided so that at least a portion of the circumferential surface is formed rearward (toward the first rear surface 115) and downward (toward the first bottom surface 113) from an imaginary line where the first vertical surface 121 and the first inclined surface 122 intersect.

[0037] The pair of first side surfaces 124 and the first front surface 116 of the first member 110 may be connected by first chamfered portions 125. The first member 110 has the first chamfered portions 125, which can prevent the pair of first holders 101, 102 and the pair of second holders 103, 104 from coming into contact with each other when they are close to each other on the base 21. The pair of first side surfaces 124 may also have engagement holes 126 in locations close to the first front surface 116 and the first bottom surface 113.

[0038] The first rear surface 115 has an insertion hole 127 into which a portion of the connection portion 201 is inserted, and a coupling portion female screw hole 128 formed in the insertion hole 127 for threading in a fastening member such as a known bolt for fastening the portion of the connection portion 201. The first bottom surface 113 may be formed in any shape (configuration) that can be suitably engaged with the slider.

[0039] 11 to 13, the second member 150 has a second top surface 153 facing the pressing surface 151 and connected to the rear end of the second abutment surface 152, a second front surface 154 connected to the front end of the second top surface 153 and extending toward the pressing surface 151, a second intermediate surface 155 connected to the front end of the second abutment surface 152, extending forward and facing the second top surface 153, a second through hole 156 penetrating the second top surface 153 and the second intermediate surface 155 and into which the second fixing member T2 is inserted, and a second engagement hole 157 formed from the second abutment surface 152 toward the second front surface 154 and into which the first fixing member T1 is engaged. The second through hole 156 is formed as an elongated hole having a major axis in the front-rear direction (X-axis direction). The second member 150 of this embodiment has two second through holes 156.

[0040] The second member 150 has a second inclined surface 158 that slopes upward from the lower end of the second front surface 154 toward the second top surface 153, and a second vertical surface 159 that connects the front end of the second intermediate surface 155 and the rear end of the second inclined surface 158. The pair of second side surfaces 160 of the second member 151 and the second front surface 154 are preferably connected by a second chamfered portion 161. The second front surface 154 is preferably provided with a protrusion 163 that protrudes forward at approximately the center. Increasing the distance of the second front surface 154 from the second abutting surface 152 (increasing the length of the second member 150 in the front-to-rear direction) increases the length of the second inclined surface 158 in the front-to-rear direction, thereby improving the effect of preventing the clamping member 180 that constitutes the pressing surface 151 from being pulled out of the second member 150 by the held object 1 to which tension is applied. On the other hand, by increasing the length of second member 150 in the front-to-rear direction, the pair of first holders 101, 102 and the pair of second holders 103, 104 are more likely to come into contact with each other when they approach each other on base 21. By providing protrusion 163 on second front surface 154, the effect of preventing clamping member 180 from being removed from second member 150 can be improved while preventing the above-mentioned contact with each other.

[0041] It is preferable that a gap is formed between the second intermediate surface 155 and the first member 110. In other words, it is preferable that the first intermediate surface 117 and the second intermediate surface 155 do not abut on each other. By forming a gap between the first intermediate surface 117 and the second intermediate surface 155, the reliability with which the holder 101 holds the object 1 to be held can be improved.

[0042] A clamping member 180 is disposed on the first inclined surface 122 of the first member 110 and the second inclined surface 158 of the second member 150. As shown in FIGS. 14 and 15 , the clamping member 180 is formed in a generally rectangular shape in a plan view and includes a clamping surface 181 that constitutes the support surface 111 or the pressing surface 151 and clamps the object to be held 1, an abutting surface 182 that is inclined with respect to the clamping surface 181 and abuts against the first inclined surface 122 or the second inclined surface 158, and a pair of side surfaces 183, a front surface 184, and a back surface 185 that connect the clamping surface 181 and the abutting surface 182. The pair of side surfaces 183 and the front surface 184 are preferably connected by a chamfered portion 186. The abutting surfaces 182 are formed at an angle such that the clamping surfaces 181 are generally parallel to each other when the pair of clamping members 180 are disposed on the first member 110 and the second member 150.

[0043] 16 to 18, the holder 101 may further include a connecting member 190. The connecting member 190 has a fixing portion 191 fixed to the second member 150 and a leg portion 192 extending from the fixing portion 191 so as to be attached to the side surface (first side surface 124) of the first member 110, and connects the first member 110 and the second member 150 together.

[0044] The fixing portion 191 has one or more female screw holes 193 (two in this embodiment) that screw into a third fixing member T3 such as a known bolt. The fixing portion 191 is indirectly fixed to the second member by the third fixing member T3. The legs 192 extend from the fixing portion 191 so as to sandwich the pair of second side surfaces 160 of the second member 150 and the pair of first side surfaces 124 of the first member 110. Each of the pair of legs 192 has a through hole 194 that penetrates in the left-right direction (Y-axis direction) and is formed to correspond to the engagement hole 126 of the first member 110. The side surface 195 and the front surface 196 of the connecting member 190 may be connected by a third chamfered portion 197.

[0045] <Connection section> The connecting part 201 that connects the holder 101 and the actuator 11a of the biaxial tensile testing machine 10 is not particularly limited, and may be, for example, a shaft whose one end is fixed to the insertion hole 127 of the holder 101 and whose other end is chucked by the chuck part 13a. However, by using the connecting part 201 as shown in Figures 19 to 21, the tension of the actuator 11a can be efficiently transmitted to the holder 101, and the holder 101 and the actuator 11a can be easily connected.

[0046] The connecting portion 201 has, in order from the holder 101 side, an insertion portion 211 fixed to the insertion hole 127, a shaft portion 212, a first joint portion 213, and a second joint portion 214. The second joint portion 214 includes a shaft portion 214a, and this shaft portion 214a is chucked by the chuck portion 13a. As shown in FIG. 21 , the connecting portion 201 may further have a block body 215 connected to the shaft portion 214a of the second joint portion 214 and disposed in the space R within the chuck portion 13a.

[0047] The fitting portion 211 that is fitted into the fitting hole 127 of the first member 110 has a through hole 211a formed therein through which a fixing member such as a known bolt that engages with the connecting portion female screw hole 128 is inserted. The fitting portion 211 is fixed to the first member 110 by the fixing member.

[0048] The shaft portion 212 has a tip (end portion on the first member 110 side) joined to the back surface (chuck portion 13a side) of the fitting portion 211, and a rear end joined to the first joint portion 213. The first joint portion 213 has a first flange portion 213a and a boss portion 213b protruding forward from the first flange portion 213a. A through hole 213c is formed in the first flange portion 213a, through which a fixing member such as a known bolt is inserted. The through hole 213c is preferably formed as an elongated hole having a major axis in the circumferential direction.

[0049] The joining of the fitting portion 211 and the first joint portion to the shaft portion 212 is not particularly limited, and for example, the front and rear ends of the shaft portion 212 may be male screw portions 212a, 212b, and female screw holes (not shown) may be formed in the fitting portion 211 and the boss portion 213b, and these may be joined by screwing them together.

[0050] The second joint portion 214 has a second flange portion 214b and a shaft portion 214a extending rearward from the second flange portion 214b. The shaft portion 214a includes a male thread portion 214c at its rear end. The second flange portion 214b has a female thread hole (not shown) formed therein into which the fixing member inserted through the through hole 213c of the first flange portion 213a is screwed. The fitting portion 211, the shaft portion 212, the first joint portion 213, and the second joint portion 214 are joined so that their respective axes are aligned.

[0051] The block body 215 is formed in a substantially cubic shape and is joined to the second joint portion 214. The block body 215 has a female screw hole (not shown) into which the male screw portion 214c of the second joint portion 214 screws. The block body 215 is arranged so that its front surface abuts against the back surface of the claw of the chuck portion 13a. By having the chuck portion 13a chuck the shaft portion 214a while abutting the back surface of the claw against the block body 215, it is possible to improve the reliability of applying tension.

[0052] The tension application method will be described below.

[0053] [Attaching process] The mounting step includes a step of mounting a holding jig 20 having holders 101, 102, 103, and 104 for holding an object 1 to a device (biaxial tensile tester 10) that applies tension in the first direction and the second direction.

[0054] Specifically, the base 21 is placed on the temporary table 15. The base 21 on which the holders 101, 102, 103, and 104 are arranged may be placed on the temporary table 15, or the holders 101, 102, 103, and 104 may be arranged on the base 21 placed on the temporary table 15.

[0055] [Connecting step] In the connecting step, the actuators 11a, 11b, 12a, and 12b of the tension applying device (biaxial tensile tester 10) are connected to the holders 101, 102, 103, and 104. Specifically, one end of each of connecting portions 201, 202, 203, and 204 is fixed to the back of each of the holders 101, 102, 103, and 104, and the other end of each of connecting portions 201, 202, 203, and 204 is chucked by chuck portions 13a, 13b, 14a, and 14b, thereby connecting the holders 101, 102, 103, and 104 to the actuators 11a, 11b, 12a, and 12b.

[0056] The connecting portion 201 may be connected to the holder 101 and the actuator 11a (chuck portion 13a) after the fitting portion 211, the shaft portion 212, the first joint portion 213, the second joint portion 214, and the block body 215 are connected and integrated together, or the fitting portion 211 may be fixed to the fitting hole 127, and then the shaft portion 212, the first joint portion 213, the second joint portion 214, and the block body 215 are connected and integrated in order, or the fitting portion 211, the shaft portion 212, and the first joint portion 213 may be integrated and connected to the holder 101, the second joint portion 214 and the block body 215 may be integrated and connected to the chuck portion 13a, and then the first joint portion 213 and the second joint portion 214 may be connected.

[0057] [Retention step] The tension applying method includes a step of holding the object 1 to be held by the holders 101, 102, 103, and 104. The holding step may be performed before the attaching step, after the attaching step and before the connecting step, or after the connecting step.

[0058] The holder 101 includes the first member 110 and the second member 150 having the pair of contact surfaces 112, 152, so that the second member 150 can be easily positioned relative to the first member 110, and the object to be held 1 can be easily held. Furthermore, by fastening the first member 110 and the second member 150 orthogonally between the first fixing member T1 and the second fixing member T2, the object to be held 1 can be held with sufficient pressing force. Specifically, the fastening point of the first fixing member T1 acts as a fulcrum, the fastening point of the second fixing member T2 acts as a force point, and the points that hold the object to be held 1 (the support surface 111 and the pressing surface 151) act as points of application, so that a high pressing force can be applied to the object to be held 1 by the principle of leverage. The pressing force that the holder 101 can apply to the object to be held 1 is 15 kN or more. The lower limit of the pressing force may be 18 kN, 20 kN, 22 kN, or 25 kN. The upper limit of the pressing force is not particularly limited and may be, for example, 50 kN.

[0059] The holder 101 forms a gap between the second intermediate surface 155 of the second member 150 and the first intermediate surface 117 of the first member 110, thereby suitably alleviating the stress acting on the point of application and improving the reliability of holding the object to be held 1. The stress relaxation can be controlled by adjusting the size (inner dimension) of the gap. Furthermore, it is preferable that the first intermediate surface 117 and first connecting surface 120 of the first member 110 are connected to the second intermediate surface 155 and second vertical surface 159 of the second member 150 by a reverse round chamfer. The stress relaxation can also be controlled by adjusting the size (diameter) of this reverse round chamfer.

[0060] The first member 110 of the holder 101 can preferably withstand the high pressing force by having the inverted round chamfered portion 123. The withstand load of the pressing force can be controlled by adjusting the size (diameter) of the inverted round chamfered portion 123.

[0061] In the holding step, the holders 101, 102, 103, and 104 hold the object to be held 1, and the connecting member 190 is attached to the holders 101, 102, 103, and 104. The connecting member 190 temporarily fastens the third fixing member T3 to the female screw hole 193, aligns the through hole 194 of the leg portion 192 with the engagement hole 126 of the first member 110, and inserts an engagement pin (not shown) into these to attach the leg portion 192 to the first member 110. Subsequently, by further tightening the third fixing member T3, the second member 150 is pressed against the first member 110, and a high pressing force can be applied by the held object to be held 1.

[0062] [Step of applying tension] In the tension applying step, actuators 11a, 11b, 12a, and 12b are operated to apply tension to held object 1. That is, tension is applied to held object 1 via holders 101, 102, 103, and 104 connected to actuators 11a, 11b, 12a, and 12b. The tension applying device (biaxial tensile testing machine 10) has holding jig 20, so it can apply tension to a relatively small held object 1, and because holding jigs 101, 102, 103, and 104 of holding jig 20 hold held object 1 with a high load, the tension applying device can apply a relatively large tension to held object 1.

[0063] [Other embodiments] The above-described embodiments do not limit the configuration of the present invention. Therefore, the above-described embodiments may include omissions, substitutions, or additions of components based on the description in this specification and common general technical knowledge, and all of these should be construed as belonging to the scope of the present invention.

[0064] The holder placed on the holding jig is not limited to the holder 101 described above, as long as it can be placed on a base and can be connected to the actuator of the tension applying device by a connecting portion.

[0065] The holding jig arranged in the tension applying device is not limited to the above-described holding jig 20, as long as it has a holding jig that can be connected to the actuator by a connecting portion.

[0066] The holder or holding jig may be used to apply unidirectional (uniaxial) tension to the object to be held.

[0067] In the tension application method or the biaxial tensile test, tension may be applied continuously or intermittently. Intermittent tension application means that tension is repeatedly applied and stopped. [Industrial Applicability]

[0068] The tension application method of the present disclosure can easily apply tension in two axial directions to a relatively small object to be held, and is therefore suitable for use in biaxial tensile tests, etc. [Explanation of symbols]

[0069] 1 Object to be held 1a central part 1b Extension part 10. Biaxial tensile testing machine 11a, 11b First actuator 12a, 12b Second actuator 13a, 13b First chuck part 14a, 14b Second chuck part 15 Temporary stand 20 Holding jig 21 Foundation 21a Mating hole 22 Rail 101,102 1st holder 103,104 Second holder 110 First member 111 Support surface 112 1st contact surface 113 1st bottom 114 First Top 115 1st back 116 1st front 117 First Intermediate Surface 118 First Through Hole 119 First engagement hole 120 First connection surface 121 1st vertical plane 122 1st slope 123 Reverse rounded chamfer 124 First aspect 125 First chamfer 126 Engagement hole 127 Inset hole 128 Female screw hole for connecting part 150 Second member 151 Pressing surface 152 Second contact surface 153 Second Top 154 2nd front 155 Second Intermediate Plane 156 Second Through Hole 157 Second engagement hole 158 Second slope 159 Second vertical plane 160 Second aspect 161 Second chamfer 163 Protrusion 180 Clamping member 181 Clamping surface 182 Contact surface 183 Side 184 Front 185 Back 186 Chamfered part 190 Connecting member 191 Fixed part 192 Legs 193 Female screw hole 194 Through Hole 195 Side 196 Front 197 Third chamfer 201,202 1st connection part 203,204 2nd connection part 211 Inset part 211a Through hole 212 Shaft section 212a, 212b Male screw part 213 1st joint 213a First flange portion 213b boss part 213c through hole 214 Second joint 214a Shaft part 214b Second flange portion 214c Male screw part 215 Block Letters R space (inside the chuck) T1 First fixing member T2 Second fixing member T3 Third fixing member W External dimensions

Claims

1. A method for applying tension to a held object in a first direction and a second direction perpendicular to the first direction, a step of attaching a holding jig having a holder for holding the object to a device that applies tension in the first direction and the second direction; a step of connecting an actuator of the tension applying device to the holder; a step of applying tension to the object to be held by operating the actuator; A method for applying tension to a held object, comprising:

2. The step of holding the object to be held by the holder is further included, The method for applying tension to a held object according to claim 1, wherein the length of the held object in at least one of the first direction and the second direction is less than 130 mm.

3. A step of attaching a holding jig having a holder for holding an object to a biaxial tensile testing machine; connecting an actuator of the biaxial tensile testing machine to the holder; a step of operating the actuator to perform a biaxial tensile test on the held object; A biaxial tensile test method comprising:

4. A holder that holds an end of an object to which tension is applied in one direction, A first member having a support surface that supports an end of the object to be held from one side; a second member having a pressing surface facing the support surface and positioned on the first member so that the object to be held is sandwiched between the pressing surface and the support surface; a fixing member for fixing the positioned second member to the first member; Equipped with the first member and the second member have a pair of contact surfaces that contact each other, the pair of contact surfaces are formed so as to be inclined rearward in a direction in which the pressing surface is separated from the support surface, The fixing member is a first fixing member inserted from the first member and engaging with the second member via the pair of abutment surfaces; a second fixing member inserted from the second member and engaged with the first member; A holder including:

5. 5. The holder according to claim 4, wherein the first fixing member and the second fixing member are orthogonal to each other to fix the first member and the second member.

6. a fixing portion fixed to the second member; a leg extending from the fixed portion so as to be attached to a side surface of the first member; and The holder according to claim 4 or 5, further comprising a connecting member that connects the first member and the second member.

Images