A clamping device for tensile testing

Abstract

The present invention relates to the technical field of material mechanics testing, and specifically provides a clamping device for tensile testing, which includes a clamp base plate, an upper clamping plate, a locking structure, and an auxiliary tensioning structure. The present invention hinges the upper clamping plate and the clamp base plate, and simultaneously sets a gradual change in clamping force. All sections of the tested piece to be clamped participate in the force, and the segmented clamping method is combined to achieve better contact between the tested piece and the device, and more uniform clamping force. At the same time, through the cooperation of the locking structure and the auxiliary tensioning structure, in the process of clamping the tested piece, the tested piece is first auxiliary tightened and then clamped in segments. During the clamping process, the auxiliary tensioning structure can stretch the wrinkles of the tested piece, thereby improving the accuracy and reliability of the tensile test. After the test is completed, the auxiliary tensioning structure can collect the broken and torn tested pieces, which is convenient to use.

Description

Technical Field

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

[0002] In the field of material mechanics testing, tensile testing is a key method for assessing material strength and durability. Tensile testing of strips of material (such as fabric, fiber, and plastic straps) typically involves installing a clamping device on a testing machine to hold the object under test. The machine then applies a tensile force to the object.

[0003] In actual applications, when testing strip-shaped items, conventional clamping devices for tensile testing are prone to stress concentration at the first clamping point where the test piece contacts the fixture, causing excessive stress in that area. This uneven stress distribution can cause the test piece to break prematurely at this point during testing, failing to truly reflect its actual strength and affecting the accuracy of the test structure. Furthermore, during the clamping process, due to improper fixture design or improper clamping force control, the test piece is prone to local wrinkling or excessive pulling force. Local wrinkling not only affects test accuracy but may also alter the mechanical properties of the test piece. Excessive pulling force can directly cause the test piece to break, making the test impossible. Furthermore, the clamping devices of related technologies require manual cleaning of broken test pieces after the test, further increasing the handling cost of the operation. Summary of the Invention

[0004] Based on this, it is necessary to address the problems existing in the current tensile test clamping device and provide a tensile 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.

[0005] The above object is achieved by the following technical solution: A clamping device for tensile testing comprises:

[0006] fixture base plate;

[0007] an upper clamping plate, which is located above the clamp base plate and has one end hingedly connected to the corresponding end of the clamp base plate, and the upper clamping plate is connected to a driving device to rotate under the drive of the driving device;

[0008] A locking structure, which is provided on the fixture base plate and corresponds to the hinged position of the upper clamping plate, and is configured to fix at least the end of the clamping section of the workpiece to the fixture base plate;

[0009] 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 be adapted and 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.

[0010] Optionally, the locking structure includes a pressing plate, a first elastic member, a second elastic member, a locking block and an article clamping plate;

[0011] A placement slot is provided at the hinged end of the clamping plate at the upper end of the inside of the clamp base plate, and at least part of the placement slot passes through both sides of the clamp base plate in the width direction; the pressing plate is movably arranged in the placement slot 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 spaced between the bottom of the pressing plate and the bottom of the placement slot; there are multiple second elastic members, and the multiple second elastic members are spaced on the upper surface of the pressing plate, and the locking blocks correspond one-to-one to the second elastic members 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 slot, and 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 one-to-one to the locking blocks.

[0012] Optionally, the clamping device for tensile testing also includes an auxiliary tightening 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 provided accordingly; 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 outward obliquely when the upper clamping plate is rotated and tightened, and reset when the upper clamping plate is reset.

[0013] 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;

[0014] A matching shaft is provided in the hinge block, the matching shaft is located on the opposite side of the matching hole, the swing arm is hinged to the matching shaft, and the fourth elastic member is used to reset the rotation of the swing arm.

[0015] 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.

[0016] Optionally, the power hinge column and the matching hole are matched in an electromagnetic swing manner.

[0017] Optionally, the width of the swing rod when it swings out is adapted to the width of the workpiece under test.

[0018] Optionally, the upper plate of the article clamping plate is provided with through holes, the through holes of the upper plate correspond to the through holes of the lower plate, and a sensing device is provided on the locking block and / or at the through holes.

[0019] Optionally, the driving device is a motor.

[0020] Optionally, a plurality of locking holes are provided on the clamp bottom plate.

[0021] 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 away 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 actual contact between the workpiece to be tested and the clamping device greater when clamping the workpiece to be tested, and the entire clamped part of the workpiece to be tested can participate in the support 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 closer 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, realizing segmented compression. Compared with the overall downward pressure method, the segmented compression method can make the contact between the workpiece under test and the clamping device better, prevent the workpiece from being torn, and the clamping force is more uniform, and the test results are more accurate.

[0022] 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 has better contact with the workpiece under test, preventing local uneven clamping force, which causes insufficient clamping force and loosening. At the same time, the auxiliary tensioning structure can swing and expand to both sides to stretch the transverse and longitudinal wrinkles of the workpiece under test, so that the workpiece under test can have better contact with the upper clamping plate and the fixture bottom plate. In addition, the auxiliary tensioning structure can limit the workpiece under test from being scattered randomly after it breaks during the tensile test, and will gather the broken and damaged workpiece under test to the middle after the tension is over, making it easier to clean.

[0023] Furthermore, the expansion range of the auxiliary tensioning structure of the auxiliary tensioning mechanism matches the width of the test piece, further ensuring that the test piece can be effectively pulled and the wrinkles of the test piece can be stretched during the clamping process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of a clamping device for tensile testing according to an embodiment of the present invention;

[0025] Figure 2 A front view of a clamping device for tensile testing according to an embodiment of the present invention;

[0026] Figure 3 for Figure 2 Middle AA section view;

[0027] Figure 4 A top view of a clamping device for tensile testing according to an embodiment of the present invention;

[0028] Figure 5 for Figure 4 Middle BB cross-section;

[0029] Figure 6 Schematic diagram of an exploded view of a clamping device for tensile testing according to an embodiment of the present invention.

[0030] in:

[0031] 100, fixture base; 101, rotating support block; 102, driving device; 103, lower clamping corrugation; 104, locking hole; 105, placement slot;

[0032] 110. Locking structure; 111. First elastic member; 112. Second elastic member; 113. Locking block; 114. Article clamping plate; 115. Pressing plate;

[0033] 120, upper clamping plate; 121, hinge shaft; 122, power hinge column; 123, movable groove; 124, mounting groove; 125, upper clamping corrugation;

[0034] 130. Auxiliary tensioning structure; 131. Articulated block; 1311. Matching hole; 1312. Matching shaft; 1313. Fourth elastic member; 132. Swinging rod; 133. Third elastic member. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be 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 intended to limit the present invention.

[0036] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings). In the description of the present invention, it should be understood that terms such as "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the device or component being referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0037] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0038] Refer to the following Figures 1 to 6 The following describes a clamping device for tensile testing according to some embodiments of the present invention.

[0039] like Figures 1 to 6 As shown, the present invention discloses a clamping device for tensile testing (hereinafter referred to as the clamping device) capable of clamping the ends of strips of material (such as fabric, plastic strips, fiberglass, etc.) to assist in tensile testing and assessing their physical properties. The clamping device is mounted on a tensile testing machine and used in pairs, with two clamps respectively clamping the ends of the fabric. The operation of the tensile testing machine moves the two clamps away from each other, stretching the fabric or other test object held between the two clamps to a predetermined degree (breaking or rupturing). The physical properties of the test object are then determined based on the tensile force.

[0040] The clamping device for tensile testing includes a clamp base plate 100, an upper clamping plate 120 and a locking structure 110;

[0041] 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 the entire tensile test clamping device will not move during the test, thereby ensuring the reliability of the test.

[0042] 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 via a hinge shaft 121, achieving a rotational connection between the upper clamping plate 120 and the fixture base plate 100. The upper clamping plate 120 can be rotated until it is completely in contact with the fixture base plate 100 to clamp and fix the workpiece. The stepped protrusion structure provided on the fixture base plate 100 can effectively limit the rotation angle of the upper clamping plate 120 to ensure that the upper clamping plate 120 is easy to use. 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 the motor is connected to the hinge shaft 121. Through an external power supply, it can effectively provide driving force for the clamping device for tensile testing.

[0043] The locking structure 110 is a structure for pre-fixing the workpiece to be tested. 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 to be tested on the fixture base plate 100, so as to facilitate the clamping of the workpiece to be tested by the upper clamping plate 120 and the fixture base plate 100.

[0044] 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 adapt and fit together. Specifically, in this 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 broken line structure or a tooth-shaped structure. When using a broken line structure or a tooth-shaped structure, the corners where stress is concentrated can be rounded to avoid damage to the measured piece during the clamping process.

[0045] The clamping force 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 near the upper clamping plate 120, so that the clamping force of the upper clamping plate gradually changes when the clamping device clamps the test piece. This further increases the area of the test piece and the clamping device that actually participates in the force when clamping the test piece, thereby avoiding fracture caused by localized effects. It is understandable that if the clamping force of the clamping device is consistent along the clamping length, then after clamping is completed, stress is usually concentrated at the first clamping position where the test piece contacts the clamping device (that is, the first position away from the hinged end of the upper clamping plate 120). Then, when the tensile testing machine applies tension to pull the test piece, the test piece is very likely to fracture at the first clamping position, affecting the accuracy of the test. However, the gradual clamping force of the present invention allows the entire clamped portion of the test piece to participate in the tensile force, making the test piece less likely to fracture at the clamping position, and providing more accurate test results. 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, realizing segmented compression. Compared with the overall downward pressing method, the segmented compression method can make the workpiece to be tested better in contact with the clamping device, prevent the workpiece to be tested from being torn, and thus cause uneven local clamping force. In this embodiment, the preferred method given by the present invention is that the friction force between the protrusion and 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.

[0046] 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 ;

[0047] 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 base 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 a portion of the placement groove 105 passes through both sides of the fixture base 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 base plate 100 and at least one end extends out of the clamp base plate 100; there are multiple first elastic members 111, and multiple first elastic members 111 are spaced apart between the bottom of the pressing plate 115 and the bottom of the placement groove 105, which support the pressing plate 115; there are multiple second elastic members 112, and multiple second elastic members 112 are spaced apart 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 supports the locking block 113 elastically; 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 one by one to the locking blocks 113. 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 moves down and withdraws 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 article 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 article clamping plate 114 to press the end of the workpiece to be tested.

[0048] 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 simultaneously to stretch the transverse and longitudinal wrinkles of the test piece.

[0049] 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 tightened, providing continuous tension to the test piece, and is reset when the upper clamping plate 120 is reset.

[0050] When the upper clamping plate 120 rotates and presses against the fixture base plate 100, the swing rod 132 expands forward and outwards. When moving forward, it can pre-tighten the test piece and stretch the longitudinal wrinkles of the test piece. When expanding outwards, it can stretch the transverse wrinkles of the test piece. It can be seen that compared with the related art that simply sets corresponding clamps to clamp the test piece, thereby causing stress concentration and wrinkles, the embodiment of the present invention sets a locking structure 110 and an auxiliary tensioning structure 130, so that the clamping device for tension testing can use the locking structure 110 to pre-fix the test piece, and use the auxiliary tensioning structure 130 to tighten the test piece during the clamping process and stretch the transverse and longitudinal wrinkles of the test piece, thereby improving the authenticity of the test data, performing tension tests on the test piece more accurately, and at the same time, no manual assistance is required to tighten the test piece, thereby ensuring the test effect and efficiency. After the test is completed, the swing rod 132 returns to its original position, gathering the broken test pieces together, thereby solving the technical problem that the test pieces are scattered and difficult to clean up.

[0051] As a preference, 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 mating 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 that cooperates with the mating 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 mating hole 1311; the third elastic member 133 is used to reset the rotation of the hinge block 131.

[0052] 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 arm 132 is hinged to the mating shaft 1312. Through the mating of the mating shaft 1312 and the swing arm 132, the swing arm 132 is rotated around the horizontal axis; the fourth elastic member 1313 is used to reset the rotation of the swing arm.

[0053] It can be understood that through such a structural design, the auxiliary tensioning structure 130 can realize 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.

[0054] Furthermore, the auxiliary tensioning structure 130 of this embodiment is further defined. A mounting slot 124 is correspondingly provided within the movable slot 123. One end of a 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 slot 124. The lower end of the movable slot 123 is flared outward to facilitate the rotation of the hinge block 131. A fourth elastic member 1313 is provided between the swing lever 132 and the mating shaft 1312.

[0055] Specifically, in this 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 can be made according to actual usage requirements.

[0056] Preferably, the auxiliary tensioning structure 130 in this embodiment is further defined, 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.

[0057] 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 action 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 workpiece. After the upper clamping plate 120 completes the clamping, the swing arm 132 is swung to the outside of the workpiece to be tested, which will not affect the tensile test and can collect the broken workpieces to be tested when resetting after the test is completed.

[0058] 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 one to 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 obtain the width of the measured object. 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.

[0059] 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 and clamps 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 obtaining the width signal of the workpiece, 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 cooperative relationship, it is ensured that the width can be measured during the pre-clamping process of the workpiece to be measured, 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 to be measured as much as possible to avoid stress concentration and wrinkles.

[0060] The following is a description of the specific use of the clamping device for tensile testing provided by the present invention:

[0061] 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 this time, the locking block 113 moves down to expose the through hole of the article clamping plate 114, and then the workpiece to be tested is placed in the middle position 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 the width of the workpiece to be tested is obtained at this time; after the width of the workpiece to be tested is obtained, the power hinge column 122 obtains the corresponding signal.

[0062] After that, the motor drive device 102 is started, and the two swing arms 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 swing arm 132 is extended 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 of the upper clamping plate 120 can linearly and gradually press the workpiece to be tested, preventing the workpiece to be tested from being pulled and damaged by being pressed at the same time, 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 cooperate to press, the opening degree of the swing arm 132 is just greater than the width of the workpiece to be tested, ensuring that there is continuous tension on the workpiece to be tested when it is not clamped; and the obliquely extended swing arm 132 can not only pull open the horizontal wrinkles of the workpiece to be tested, but also pull open the vertical wrinkles, ensuring that the workpiece to be tested and the clamp are in better contact when the clamp is clamped.

[0063] After both ends of the test 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 test piece to perform tensile testing. Generally, the test piece is broken. When the test 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 arm 132 and the hinge block 131 will return to their original position, gathering the broken test pieces to prevent the test pieces from being scattered and difficult to clean.

[0064] 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.

[0065] The technical features of the above embodiments can 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.

[0066] The above-described embodiments merely illustrate several embodiments of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended 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 base plate and has one end hingedly connected to the corresponding end of the clamp base 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 provided on the fixture base plate and corresponds to the hinged position of the upper clamping plate, and is configured to fix at least the end of the clamping section of the workpiece to the fixture base plate; Among them, the upper surface of the clamp base 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 can fit together. The clamping force of the lower clamping corrugation and the upper clamping corrugation gradually increases from the hinge end away from the upper clamping plate to the hinge end close to the upper clamping plate. The clamping device for tensile testing further includes an auxiliary tensioning structure, which includes a hinge block and a swing rod; the upper clamping plate is provided with two movable grooves at one end away from its hinged end, and the hinge block and the swing rod are correspondingly provided with two; 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 extended forward and outward in an oblique direction when the upper clamping plate is rotated and pressed, and is reset when the upper clamping plate is reset; 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 near the bottom of the movable groove, a power hinge column is provided in the movable groove, and the power hinge column is connected to the matching hole for rotation around the vertical axis. The third elastic member is used to reset the rotation of the hinge block; A matching shaft is provided in the hinge block, which is located on the opposite side of the matching hole. The swing arm is hinged to the matching shaft, and the fourth elastic member is used to reset the rotation of the swing arm. The matching method between the power hinge column and the matching hole is electromagnetic swing matching.

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 a position corresponding to the hinged end of the upper clamping plate 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 spaced 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 spaced on the upper surface of the pressing plate, and the locking blocks correspond one-to-one to the second elastic members 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 one-to-one to the locking blocks.

3. The clamping device for tensile testing according to claim 2, 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.

4. The clamping device for tensile testing according to claim 2, characterized in that: The width of the swing rod when it swings is adapted to the width of the workpiece being tested.

5. The clamping device for tensile testing according to claim 4, characterized in that: The upper plate of the article clamping plate is provided with through holes, the through holes of the upper plate correspond to the through holes of the lower plate, and a sensing device is provided on the locking block and / or at the through holes.

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

7. 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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