Clamping device for tension test

Abstract

The invention relates to the technical field of material mechanics testing, and particularly provides a clamping device for tension testing, which comprises a clamp bottom plate, an upper end clamping plate, a locking structure and an auxiliary tensioning structure. According to the invention, the upper end clamping plate is hinged to the clamp bottom plate, the gradual change of the clamping force is set, the to-be-clamped sections of the tested piece are all stressed, and a segmented clamping mode is matched, so that the contact between the tested piece and the device is better, and the clamping force is more uniform; meanwhile, through cooperation of the locking structure and the auxiliary tensioning structure, in the process of clamping the tested piece, the tested piece is firstly tensioned in an auxiliary mode and then clamped in a segmented mode, the auxiliary tensioning structure can stretch wrinkles of the tested piece in the clamping process, the accuracy and reliability of the tension test are improved, and after the test is completed, the tested piece is clamped in a segmented mode. The auxiliary tensioning structure can be used for collecting the broken and torn tested piece, so that the use is convenient.

Description

Technical Field

[0001] The invention relates to the technical field of material mechanics testing, and in particular to a clamping device for tensile testing. Background Art

[0002] In the field of material mechanics testing, tensile testing is one of the important means of evaluating material strength and durability. For tensile testing of strip-shaped items (such as cloth, fiber, plastic belt, etc.), a clamping device is usually installed on the testing machine to clamp the test piece, and then the testing machine applies tension to the test piece for testing.

[0003] In actual applications, when testing strip-shaped items, the clamping device for tensile testing in the prior art is prone to stress concentration at the first clamping position where the tested piece contacts the clamp, causing excessive stress in this area. This uneven stress distribution may cause the tested piece to break prematurely at this point during the test, failing to truly reflect its actual strength and affecting the accuracy of the test structure. At the same time, during the clamping process, due to unreasonable clamp design or improper clamping force control, the tested piece is prone to local wrinkles or excessive pulling force. Local wrinkles not only affect the accuracy of the test, but may also change the mechanical properties of the tested piece. Excessive pulling force may directly cause the tested piece to break, making the test impossible. In addition, the clamping device in the related art needs to manually clean the broken tested piece after the test, further increasing the processing cost of the operation. Summary of the invention

[0004] Based on this, it is necessary to provide a tension test clamping device that can evenly apply clamping force to the test piece, reduce local stress concentration and wrinkling, and facilitate the handling of the test piece after testing in order to address the problems existing in the current tension test clamping device.

[0005] The above object is achieved by the following technical solution: A clamping device for tensile testing comprises: Fixture base plate; An upper clamping plate, which is located above the clamp bottom plate and one end of which is hingedly connected to the corresponding end of the clamp bottom plate, and the upper clamping plate is connected to a driving device to rotate under the drive of the driving device; A locking structure, which is arranged on the bottom plate of the fixture and corresponds to the hinged position of the upper clamping plate, and the locking structure is configured to at least fix the end of the clamping section of the tested piece to the bottom plate of the fixture; Among them, the upper surface of the clamp base plate is provided with a lower clamping corrugation, and the lower surface of the upper clamping plate is provided with an upper clamping corrugation. The lower clamping corrugation and the upper clamping corrugation are arranged correspondingly, so that the upper clamping plate and the clamp base plate can fit together, and the clamping force of the lower clamping corrugation and the upper clamping corrugation gradually increases from the hinged end away from the upper clamping plate to the hinged end close to the upper clamping plate.

[0006] Optionally, the locking structure includes a pressing plate, a first elastic member, a second elastic member, a locking block and an article clamping plate; A placement groove is provided at the position of the hinged end of the clamping plate at the upper end inside the clamp base plate, and at least part of the placement groove passes through both sides of the clamp base plate in the width direction; the pressing plate is movably arranged in the placement groove along the up and down directions and at least one end extends out of the clamp base plate; there are multiple first elastic members, and the multiple first elastic members are arranged at intervals between the bottom of the pressing plate and the bottom of the placement groove; there are multiple second elastic members, and the multiple second elastic members are arranged at intervals on the upper surface of the pressing plate, and the locking blocks correspond to the second elastic members one by one and are fixedly connected to the upper ends of the corresponding second elastic members; the article clamping plate is located at the upper notch of the placement groove, the article clamping plate is a double-layer plate, and the lower layer of the article clamping plate is provided with multiple through holes corresponding to the locking blocks one by one.

[0007] Optionally, the clamping device for tensile testing also includes an auxiliary tensioning structure, which includes a hinge block and a swing rod; two movable grooves are provided at one end of the upper clamping plate away from its hinged end, and two hinge blocks and swing rods are correspondingly provided; the hinge block is movably connected to the upper clamping plate at the movable groove, and the swing rod is hingedly connected to the hinge block; the swing rod can synchronously expand forward and outward obliquely when the upper clamping plate is rotated and tightened, and reset when the upper clamping plate is reset.

[0008] Optionally, the auxiliary tensioning structure further includes a third elastic member and a fourth elastic member; a matching hole is provided on one side of the hinge block close to the bottom of the movable groove, a power hinge column is provided in the movable groove, the power hinge column is connected to the matching hole for rotation around the vertical axis, and the third elastic member is used to reset the rotation of the hinge block; A matching shaft is arranged in the hinge block, the matching shaft is located at the opposite side of the matching hole, the swing rod is hinged to the matching shaft, and the fourth elastic member is used for resetting the rotation of the swing rod.

[0009] Optionally, the first elastic member, the second elastic member, and the third elastic member are all springs, and the fourth elastic member is a torsion spring.

[0010] Optionally, the power hinge column and the matching hole are matched in an electromagnetic swing manner.

[0011] Optionally, the width of the swing rod when it is swung and unfolded is adapted to the width of the object to be tested.

[0012] Optionally, the upper plate body of the article clamping plate is provided with through holes, the through holes of the upper plate body and the through holes of the lower plate body correspond one to one, and a sensing device is provided on the locking block and / or at the through holes.

[0013] Optionally, the driving device is a motor.

[0014] Optionally, a plurality of locking holes are provided on the clamp bottom plate.

[0015] The beneficial effects of the present invention are as follows: the upper clamping plate and the fixture bottom plate are hingedly connected in the present invention, and the clamping force of the upper corrugated structure on the upper clamping plate and the lower corrugated structure on the fixture bottom plate gradually increases from the hinged end far from the upper clamping plate to the hinged end close to the upper clamping plate, so that the clamping force of the upper clamping plate gradually changes when the clamping device clamps the workpiece to be tested, thereby making the contact between the workpiece to be tested and the clamping device actually participating in the action greater when clamping the workpiece to be tested, and the entire clamped part of the workpiece to be tested can participate in the bearing Under tension, the workpiece under test is not easy to break at the clamping position, avoiding fracture caused by local action; during the clamping process, the upper clamping plate rotates close to the bottom plate of the fixture, and the clamping section of the workpiece under test is gradually compressed from the hinged end close to the upper clamping plate to the hinged end away from the upper clamping plate, thereby realizing segmented compression. Compared with the overall downward pressing method, the segmented compression method can make the contact between the workpiece under test and the clamping device better, prevent tearing of the workpiece under test, make the clamping force more uniform, and make the test results more accurate.

[0016] Furthermore, through the setting of the auxiliary tensioning structure, in the process of the upper clamping plate rotating to press the workpiece under test, the auxiliary tensioning structure first pre-tightens the workpiece under test and then gradually contacts and presses it through the clamping device. The clamping device and the workpiece under test are in better contact, preventing local uneven clamping force from causing looseness due to insufficient clamping force. At the same time, the auxiliary tensioning structure can swing and unfold to both sides to stretch the transverse and longitudinal wrinkles of the workpiece under test, so that the workpiece under test can be in better contact with the upper clamping plate and the bottom plate of the fixture. In addition, the auxiliary tensioning structure can limit the workpiece under test from being dispersed randomly after it breaks during the tensile test, and gather the broken and damaged workpiece under test to the middle after the tension is over, making it easier to clean.

[0017] Furthermore, the expansion range of the auxiliary tensioning structure of the auxiliary tensioning mechanism matches the width of the piece under test, further ensuring that during the clamping process, the piece under test can be effectively pulled and the wrinkles of the piece under test can be stretched. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of a clamping device for tensile testing according to an embodiment of the present invention; Figure 2 A front view of a clamping device for tensile testing according to an embodiment of the present invention; Figure 3 for Figure 2 Middle AA section view; Figure 4 A top view of a clamping device for tensile testing according to an embodiment of the present invention; Figure 5 for Figure 4 Middle BB section view; Figure 6 Schematic diagram of an exploded view of a clamping device for tensile testing according to an embodiment of the present invention.

[0019] in: 100, fixture bottom plate; 101, rotating support block; 102, driving device; 103, lower clamping corrugation; 104, locking hole; 105, placement slot; 110, locking structure; 111, first elastic member; 112, second elastic member; 113, locking block; 114, article clamping plate; 115, pressing plate; 120, upper clamping plate; 121, hinge shaft; 122, power hinge column; 123, movable groove; 124, mounting groove; 125, upper clamping corrugation; 130. Auxiliary tensioning structure; 131. Articulated block; 1311. Matching hole; 1312. Matching shaft; 1313. Fourth elastic member; 132. Swing rod; 133. Third elastic member. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0022] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0023] Refer to the following Figures 1 to 6A clamping device for tensile testing according to some embodiments of the present invention is described.

[0024] like Figures 1 to 6 As shown, a clamping device for tensile testing of the present invention (hereinafter referred to as the clamping device) can clamp the ends of strip-shaped articles (such as cloth, strip-shaped plastic belt, glass fiber, etc.) to assist in tensile testing and evaluate their physical properties. When in use, the present invention is installed on a tensile testing machine and used in pairs. Two of the present inventions clamp the two ends of the cloth respectively. The action of the tensile testing machine drives the two present inventions to move away from each other. The cloth or other test piece clamped between the two present inventions is stretched to a preset degree (damaged or broken), and the physical properties of the test piece are judged according to the tensile value.

[0025] The clamping device for tensile testing includes a clamp base plate 100, an upper clamping plate 120 and a locking structure 110; like Figure 1 , Figure 2 , Figure 5 , Figure 6 As shown, the fixture base plate 100 is a square plate structure with a plurality of locking holes 104 provided thereon. The fixture base plate 100 can be installed on the tensile testing machine through the locking holes 104 using fasteners such as bolts and nuts to ensure that during the test, the entire tensile test clamping device will not move, thereby ensuring the reliability of the test.

[0026] The upper clamping plate 120 is the main component that cooperates with the clamp base plate 100 for clamping. The upper clamping plate 120 is located above the clamp base plate 100 and one end of the upper clamping plate 120 is hingedly connected to the corresponding end of the clamp base plate 100. In order to facilitate the connection between the upper clamping plate 120 and the clamp base plate 100, the structure of the clamp base plate 100 is further optimized. Specifically, a step protrusion is provided at one end of the clamp base plate 100. Two rotating support blocks 101 are provided on the clamp base plate 100 near the step protrusion. The two rotating support blocks 101 are provided at the top of the clamp base plate 100 and are arranged on both sides of the width direction of the clamp base plate 100; hinge shafts 12 are provided on both sides of one end of the upper clamping plate 120. 1. The upper clamping plate 120 is hingedly connected to the rotating support block 101 through the hinge shaft 121, realizing the rotation connection between the upper clamping plate 120 and the fixture base plate 100. The upper clamping plate 120 can be rotated to completely fit with the fixture base plate 100 to clamp and fix the tested object, and the step-shaped protrusion structure provided on the fixture base plate 100 can effectively limit the rotation angle of the upper clamping plate 120 to ensure the convenience of use of the upper clamping plate 120. A driving device 102 is also provided on the rotating support block 101 on one side. The driving device 102 is used to provide a power source for the upper clamping plate 120 to control the rotation of the upper clamping plate 120. The selected driving device 102 is specifically a motor, the output shaft of which is connected to the hinge shaft 121. Through an externally connected power supply, it can effectively provide driving force for the clamping device for tensile testing.

[0027] The locking structure 110 is used as a structure for pre-fixing the workpiece under test. The locking structure 110 is arranged on the fixture base plate 100 and corresponds to the hinge position of the upper clamping plate 120. The locking structure 110 is configured to at least fix the end of the clamping section of the workpiece under test on the fixture base plate 100, so as to facilitate the clamping of the workpiece under test by the upper clamping plate 120 and the fixture base plate 100.

[0028] In order to ensure that the upper clamping plate 120 better cooperates with the fixture base plate 100 during the clamping process, clamps the test piece, and improves the clamping stability, the upper surface of the fixture base plate 100 (the surface close to the upper clamping plate 120) is provided with a lower clamping corrugation 103, and the lower surface of the upper clamping plate 120 (the surface close to the fixture base plate 100) is provided with an upper clamping corrugation 125. The lower clamping corrugation 103 and the upper clamping corrugation 125 are arranged correspondingly, so that the upper clamping plate 120 and the fixture base plate 100 can fit together. Specifically, in the present embodiment, the lower clamping corrugation 103 and the upper clamping corrugation 125 are wavy structures that can cooperate with each other, and the protrusion of the lower clamping corrugation 103 corresponds to the groove of the upper clamping corrugation 125, or the groove of the lower clamping corrugation 103 corresponds to the protrusion of the upper clamping corrugation 125. In other embodiments, other corresponding matching structures can be selected, such as a fold line structure or a tooth structure. When using a fold line structure or a tooth structure, the corners where stress is concentrated can be rounded to avoid damage to the measured piece during the clamping process.

[0029] The clamping force of the lower clamping corrugation 103 and the upper clamping corrugation 125 gradually increases from the hinged end far away from the upper clamping plate 120 to the hinged end close to the upper clamping plate 120, so that the clamping force of the upper clamping plate of the clamping device changes gradually when the tested object is clamped, thereby making the area of ​​the tested object and the clamping device actually participating in the force when the tested object is clamped larger, avoiding local action and causing fracture. It can be understood that if the clamping force of the clamping device is consistent over the clamping length, then after the clamping is completed, the stress is usually concentrated on the first clamping position where the tested object contacts the clamping device (that is, the first position far away from the hinged end of the upper clamping plate 120), then when the tensile testing machine applies tension to pull the tested object, the tested object is very likely to break at the first clamping position, affecting the accuracy of the test, while the gradual clamping force of the present invention enables the entire clamped part of the tested object to participate in bearing the tension, the tested object is not easy to break at the clamping position, and the test result is more accurate. At the same time, one end of the upper clamping plate 120 is hingedly connected to one end of the fixture base plate 100. When clamping, the workpiece to be tested is placed between the upper clamping plate 120 and the fixture base plate 100, and the end of the clamping section of the workpiece to be tested is pre-fixed on the fixture base plate 100 through the locking structure 110. The workpiece to be tested is appropriately tightened, and the upper clamping plate 120 is rotated toward the fixture base plate 100. The clamping section of the workpiece to be tested is gradually compressed from the hinged end close to the upper clamping plate 120 to the hinged end away from the upper clamping plate 120, thereby realizing segmented compression. Compared with the overall downward pressing method, the segmented compression method can make the contact between the workpiece to be tested and the clamping device better, thereby preventing the workpiece to be tested from being torn, thereby causing uneven local clamping force. In this embodiment, the preferred method given by the present invention is that the friction force between the protrusion and the groove of the lower clamping corrugation 103 and the upper clamping corrugation 125 gradually increases from the hinged end away from the upper clamping plate 120 to the hinged end close to the upper clamping plate 120, so that the clamping force gradually increases.

[0030] In this embodiment, the locking structure 110 includes a pressing plate 115, a first elastic member 111, a second elastic member 112, a locking block 113 and an article clamping plate 114; Reference Figure 2 , Figure 3 and Figure 5 , it can be clearly seen from the cross-sectional view that a placement groove 105 is provided inside the fixture bottom plate 100 at a position corresponding to the rotation support block 101 (that is, the position of the hinged end of the upper clamping plate 120), and at least part of the placement groove 105 passes through both sides of the fixture bottom plate 100 in the width direction; Figure 3 , Figure 5As shown, the pressing plate 115 is movably arranged in the placement groove 105 along the up and down directions. The main body of the pressing plate 115 is a long rectangular plate, and is arranged transversely to the clamp bottom plate 100 and at least one end extends out of the clamp bottom plate 100; there are multiple first elastic members 111, and the multiple first elastic members 111 are arranged at intervals between the bottom of the pressing plate 115 and the bottom of the placement groove 105, so as to support the pressing plate 115; there are multiple second elastic members 112, and the multiple second elastic members 112 are arranged at intervals on the upper surface of the pressing plate 115, and the locking block 113 corresponds to the second elastic member 112 one by one, and is fixedly connected to the upper end of the corresponding second elastic member 112, and the second elastic member 112 plays a supporting elastic role for the locking block 113; the article clamping plate 114 seals the upper notch of the placement groove 105, and the article clamping plate 114 is a double-layer plate, and the lower layer of the article clamping plate 114 is provided with multiple through holes corresponding to the locking blocks 113 one by one. When the locking structure 110 is used to pre-fix the workpiece to be tested, the pressing plate 115 is pressed down, the locking block 113 is moved down and withdrawn from the through hole, and the end of the workpiece to be tested is placed between the upper plate and the lower plate of the object clamping plate 114. The pressing plate 115 is released, and the pressing plate 115, under the action of the first elastic member 111, drives the locking block 113 to pass through the through hole on the lower plate of the object clamping plate 114 to press the end of the workpiece to be tested.

[0031] In a further embodiment, the clamping device of the present invention further includes an auxiliary tensioning structure 130, which is configured to pre-tighten the test piece when the upper clamping plate 120 rotates, and to stretch the transverse and longitudinal wrinkles of the test piece.

[0032] The auxiliary tensioning structure 130 includes a hinge block 131 and a swing rod 132; Figure 1 , Figure 4 , Figure 6 As shown, the upper clamping plate 120 is provided with two movable grooves 123 at one end away from its hinged end, and two hinge blocks 131 and swing rods 132 are provided accordingly; the hinge block 131 is movably connected to the upper clamping plate 120 at the movable groove 123, and the swing rod 132 is hingedly connected to the hinge block 131; the swing rod 132 can be synchronously expanded forward and outward obliquely when the upper clamping plate 120 is rotated and pressed, providing continuous tensioning force to the test piece, and is reset when the upper clamping plate 120 is reset.

[0033] When the upper clamping plate 120 is rotated and pressed against the fixture bottom plate 100, the swing rod 132 is expanded forward and outward, and can pre-tighten the tested piece and stretch the longitudinal wrinkles of the tested piece when moving forward, and can stretch the transverse wrinkles of the tested piece when expanding outward. It can be seen that compared with the related art that simply sets the corresponding clamping plate to clamp the tested piece, thereby causing stress concentration and wrinkles, the present invention, in this embodiment of the present invention, sets the locking structure 110 and the auxiliary tensioning structure 130, so that the clamping device for tension testing can use the locking structure 110 to pre-fix the tested piece, use the auxiliary tensioning structure 130 to tighten the tested piece during the clamping process, and stretch the transverse and longitudinal wrinkles of the tested piece, thereby improving the authenticity of the test data, and more accurately performing tension tests on the tested piece, and at the same time, no manual assistance is required to tighten the tested piece, thereby ensuring the test effect and efficiency. After the test is finished, the swing rod 132 returns to its original position, and the broken test pieces are gathered together, thus solving the technical problem that the test pieces are scattered and difficult to clean up.

[0034] Preferably, the auxiliary tensioning structure 130 in this embodiment is further defined, and the auxiliary tensioning structure 130 further includes a third elastic member 133 and a fourth elastic member 1313; Figure 5 and Figure 6 As shown, in this embodiment, a matching hole 1311 is provided on one side of the hinge block 131 close to the bottom of the movable groove 123, and a power hinge column 122 matching with the matching hole 1311 is provided in the movable groove 123. The rotation of the hinge block 131 around the vertical axis is realized through the cooperation between the power hinge column 122 and the matching hole 1311; the third elastic member 133 is used to reset the rotation of the hinge block 131.

[0035] A mating shaft 1312 is provided in the hinge block 131, and the mating shaft 1312 is located on the opposite side of the mating hole 1311. The swing rod 132 is hinged to the mating shaft 1312. Through the mating of the mating shaft 1312 and the swing rod 132, the swing rod 132 can be rotated around the horizontal axis. The fourth elastic member 1313 is used to reset the rotation of the swing rod.

[0036] It can be understood that, through such a structural design, the auxiliary tensioning structure 130 can achieve that when the upper clamping plate 120 is rotated and tightened, the hinge block 131 and the swing rod 132 in the auxiliary tensioning structure 130 can follow the change of the clamping angle, and maintain contact with the test piece during the clamping process.

[0037] Furthermore, the auxiliary tensioning structure 130 in this embodiment is further defined, the movable groove 123 is correspondingly provided with a mounting groove 124, one end of the third elastic member 133 is fixedly connected to the side of the hinge block 131, and the other end is fixedly connected to the mounting groove 124; the lower end of the movable groove 123 is expanded outward to facilitate the rotation of the hinge block 131. The fourth elastic member 1313 is provided between the swing rod 132 and the matching shaft 1312.

[0038] Specifically, in the present embodiment, the first elastic member 111, the second elastic member 112, and the third elastic member 133 are all springs, and the fourth elastic member 1313 is a torsion spring. In other embodiments, other selections may be made according to actual use requirements.

[0039] Preferably, the auxiliary tensioning structure 130 in this embodiment is further limited, and the matching mode between the power hinge column 122 and the matching hole 1311 is specifically electromagnetic swing matching, and the rotation amplitude of the hinge block 131 is controlled by the electromagnetic swing matching.

[0040] In a further embodiment, the swing width of the swing arm 132 is adapted to the width of the workpiece to be tested, so that the movement of the swing arm 132 is synchronously adapted to the clamping movement of the upper clamping plate 120. In the process of the upper clamping plate 120 clamping the workpiece to be tested, the swing arm 132 is always in contact with the side piece. After the clamping of the upper clamping plate 120 is completed, the swing arm 132 is swung to the outside of the workpiece to be tested, which will not affect the tensile test and can gather and collect the broken workpiece to be tested when resetting after the test is completed.

[0041] In this embodiment, a through hole is provided on the upper plate body of the article clamping plate 114, and the through holes of the upper plate body and the lower plate body correspond to each other one by one. A sensing device is provided on the locking block 113 and / or at the through hole to sense the movement state of the locking block 113, and then the width of the measured object is obtained. The power hinge column 122 controls the rotation angle and speed of the hinge block 131 according to the width of the measured object. After the upper clamping plate 120 is clamped in place, the power hinge column 122 and the hinge block 131 are disengaged from the electromagnetic connection, and the hinge block 131 is reset under the action of the third elastic member 133.

[0042] After the workpiece passes through the upper and lower plates of the article clamping plate 114, the pressure plate 115 is released to allow the locking block 113 to move upward. The locking block 113 corresponding to the workpiece is blocked by the workpiece to clamp the workpiece. After the remaining locking blocks 113 pass through the through holes on the lower plate of the article clamping plate 114, they can simultaneously pass through the through holes on the upper plate due to internal obstructions. After the width signal of the workpiece is obtained, it is transmitted to the auxiliary tensioning structure 130, and the swing rod 132 maintains synchronous oblique expansion during the clamping process. Through such a coordinated action relationship, it is ensured that the width can be measured during the pre-clamping process of the workpiece, and data support is provided for the synchronous oblique expansion of the auxiliary tensioning structure 130 during the subsequent clamping process of the upper clamping plate 120, so as to ensure the abutment and compression of the workpiece as much as possible to avoid stress concentration and wrinkles.

[0043] Next, the specific use process of the clamping device for tensile testing provided by the present invention is described as follows: First, the workpiece to be tested is passed between the fixture bottom plate 100 and the upper clamping plate 120, and then the pressure plate 115 of the locking structure 110 is pressed down, at which time the locking block 113 moves downward to expose the through hole of the article clamping plate 114, and then the workpiece to be tested is placed in the middle of the article clamping plate 114, and then the pressure plate 115 is released; some locking blocks 113 are blocked and limited by the workpiece to be tested, clamping the workpiece to be tested, while the locking blocks 113 that are not blocked by the workpiece to be tested pass through the article clamping plate 114, and at this time the width of the workpiece to be tested is obtained; after the width of the workpiece to be tested is obtained, the power hinge column 122 obtains the corresponding signal.

[0044] After that, the motor driving device 102 is started, and the two swinging rods 132 are gradually pressed on the workpiece to be tested. The power hinge column 122 controls the hinge block 131 to start rotating, and the swinging rod 132 is spread out obliquely forward and to both sides to tighten the workpiece to be tested and flatten the wrinkles. After the workpiece to be tested is tensioned, the rotation energy of the upper clamping plate 120 can gradually press the workpiece to be tested linearly to prevent the workpiece to be tested from being pulled and damaged by being pressed at the same time, thereby ensuring that the workpiece to be tested and the clamping device are in better contact when the clamping device is clamped; after the upper clamping corrugation 125 of the upper clamping plate 120 and the lower clamping corrugation 103 of the fixture bottom plate 100 are pressed together, the opening degree of the swinging rod 132 is just greater than the width of the workpiece to be tested, thereby ensuring that there is continuous tension on the workpiece to be tested when it is not clamped; and the obliquely opened swinging rod 132 can not only pull open the horizontal wrinkles of the workpiece to be tested, but also pull open the vertical wrinkles, thereby ensuring that the workpiece to be tested and the fixture are in better contact when the fixture is clamped.

[0045] After both ends of the tested piece are clamped by the clamping device of the present invention, the tensile force is detected. The tensile testing machine applies tensile force to the tested piece for tensile detection. Generally, the tested piece is broken. When the tested piece is broken, the driving device 102 opens the upper clamping plate 120. At this time, the electromagnetic effect is cancelled. Under the action of the third spring member and the fourth elastic member 1313, the swing rod 132 and the hinge block 131 will return to their original positions, and the broken tested pieces will be gathered together to prevent the tested pieces from being scattered and difficult to clean.

[0046] Finally, the pressing plate 115 of the locking structure 110 is pressed down, and the tested object is pulled out, thereby ending the tensile test of the tested object.

[0047] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A clamping device for tensile testing, characterized in that: include: Fixture base plate; An upper clamping plate, which is located above the clamp bottom plate and one end of which is hingedly connected to the corresponding end of the clamp bottom plate, and the upper clamping plate is connected to a driving device to rotate under the drive of the driving device; A locking structure, which is arranged on the bottom plate of the fixture and corresponds to the hinged position of the upper clamping plate, and the locking structure is configured to at least fix the end of the clamping section of the tested piece to the bottom plate of the fixture; Among them, the upper surface of the clamp base plate is provided with a lower clamping corrugation, and the lower surface of the upper clamping plate is provided with an upper clamping corrugation. The lower clamping corrugation and the upper clamping corrugation are arranged correspondingly, so that the upper clamping plate and the clamp base plate can fit together, and the clamping force of the lower clamping corrugation and the upper clamping corrugation gradually increases from the hinged end away from the upper clamping plate to the hinged end close to the upper clamping plate.

2. The clamping device for tensile testing according to claim 1, characterized in that: The locking structure includes a pressing plate, a first elastic member, a second elastic member, a locking block and an article clamping plate; A placement groove is provided at the position of the hinged end of the clamping plate at the upper end inside the clamp base plate, and at least part of the placement groove passes through both sides of the clamp base plate in the width direction; the pressing plate is movably arranged in the placement groove along the up and down directions and at least one end extends out of the clamp base plate; there are multiple first elastic members, and the multiple first elastic members are arranged at intervals between the bottom of the pressing plate and the bottom of the placement groove; there are multiple second elastic members, and the multiple second elastic members are arranged at intervals on the upper surface of the pressing plate, and the locking blocks correspond to the second elastic members one by one and are fixedly connected to the upper ends of the corresponding second elastic members; the article clamping plate is located at the upper notch of the placement groove, the article clamping plate is a double-layer plate, and the lower layer of the article clamping plate is provided with multiple through holes corresponding to the locking blocks one by one.

3. The clamping device for tensile testing according to claim 2, characterized in that: The clamping device for tensile testing also includes an auxiliary tensioning structure, which includes a hinge block and a swing rod; two movable grooves are provided at one end of the upper clamping plate away from its hinged end, and two hinge blocks and swing rods are correspondingly provided; the hinge block is movably connected to the upper clamping plate at the movable groove, and the swing rod is hingedly connected to the hinge block; the swing rod can be synchronously expanded forward and obliquely outward when the upper clamping plate is rotated and pressed, and can be reset when the upper clamping plate is reset.

4. The clamping device for tensile testing according to claim 3, characterized in that: The auxiliary tensioning structure also includes a third elastic member and a fourth elastic member; a matching hole is provided on one side of the hinge block close to the bottom of the movable groove, a power hinge column is provided in the movable groove, the power hinge column is connected to the matching hole for rotation around the vertical axis, and the third elastic member is used to reset the rotation of the hinge block; A matching shaft is arranged in the hinge block, the matching shaft is located at the opposite side of the matching hole, the swing rod is hinged to the matching shaft, and the fourth elastic member is used for resetting the rotation of the swing rod.

5. The clamping device for tensile testing according to claim 4, characterized in that: The first elastic member, the second elastic member and the third elastic member are all springs, and the fourth elastic member is a torsion spring.

6. The clamping device for tensile testing according to claim 4, characterized in that: The power hinge column and the matching hole are matched in an electromagnetic swing manner.

7. The clamping device for tensile testing according to claim 6, characterized in that: The width of the swing rod when it swings out is matched with the width of the object to be tested.

8. The clamping device for tensile testing according to claim 7, characterized in that: The upper plate body of the article clamping plate is provided with through holes, the through holes of the upper plate body and the lower plate body correspond to each other, and a sensing device is provided on the locking block and / or at the through holes.

9. The clamping device for tensile testing according to claim 1, characterized in that: The driving device is a motor.

10. The clamping device for tensile testing according to claim 1, characterized in that: The clamp bottom plate is provided with a plurality of locking holes.

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