Tension test fixture

Abstract

The utility model provides a tension test fixture. The tension test fixture comprises a shell, a plurality of connecting pieces and a plurality of elastic components, the shell is provided with a through hole, and the fixing piece is arranged in the through hole in a penetrating mode. The connecting pieces are distributed on the shell at intervals in the circumferential direction of the shell, one end of each connecting piece is connected with the shell, and the other end is used for being connected with a testing instrument. The multiple elastic assemblies are distributed at intervals in the circumferential direction of the through hole and fixed in the shell. The multiple elastic assemblies can elastically stretch out and draw back, so that the end of each elastic assembly can stretch into the corresponding through hole, the ends of the multiple elastic assemblies can be fixedly connected with the fixing piece, the ends of the multiple elastic assemblies can define a penetrating hole with the adjustable caliber, or the end of each elastic assembly can retreat from the corresponding through hole. According to the tension test fixture, the through hole is formed in the fixing part, so that the fixing part is connected and fixed in the through hole, the tension test fixture can adapt to and fix the fixing parts with different diameters, tension tests of connecting holes with various diameters are realized, and the universality and compatibility of the tension test fixture are improved.

Description

Technical Field

[0001] This utility model relates to the field of testing tooling technology, and in particular to a tensile testing fixture. Background Technology

[0002] In industrial manufacturing and mechanical engineering, the ultimate tensile strength test of hole structures is a core step in evaluating the safety of components. For any workpiece specimen that requires hole structures as connection points, the ultimate tensile force that the hole structures can withstand directly determines the reliability of the overall structure.

[0003] Currently, tensile testing instruments and fixtures are generally used to perform ultimate tensile tests on hole structures. Specifically, during the test, a bolt with a diameter matching the hole is fixed inside the hole structure, and the bolt is clamped and fixed using a fixture. The tensile testing instrument applies different tensile forces to the fixture to perform ultimate tensile tests on the hole structure.

[0004] However, traditional clamps mainly adapt to the aperture of the hole structure by changing the jaws or adding bushings. This requires frequent changes of jaws or bushings of the appropriate size for samples with multiple apertures, resulting in cumbersome operation. Furthermore, the aforementioned replacement and disassembly processes are prone to errors, and tensile testing instruments are susceptible to varying degrees of impact and vibration during loading, which can reduce system stiffness and cause deviations in measurement data. Utility Model Content

[0005] The purpose of this utility model is to provide a tensile testing fixture with high versatility and compatibility, which can realize tensile testing of connecting holes with different diameters on the workpiece to be tested.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] According to one aspect of this application, a tensile testing fixture is provided for use in conjunction with a testing instrument to perform tensile testing on a connecting hole in a workpiece to be tested. A fixing member is provided within the connecting hole, and the workpiece to be tested is connected and fixed to the testing instrument. The tensile testing fixture includes:

[0008] The outer casing has a through hole, and the end of the fastener passes through the through hole;

[0009] Multiple connectors are distributed circumferentially on the housing. One end of each connector is connected to the housing, and the other end is used to connect to the testing instrument. The testing instrument is used to pull the connector upward to apply an upward pulling force to the fixing member.

[0010] Multiple elastic components are distributed circumferentially along the through hole. Each elastic component is fixed inside the housing. All elastic components are elastically expandable and contractible, allowing the end of each elastic component to extend into the through hole so that the ends of the multiple elastic components can be connected and fixed to the fixing member. The ends of the multiple elastic components can surround and form an adjustable-diameter perforation, or allow the end of each elastic component to exit the through hole so that the fixing member is connected and fixed in the through hole.

[0011] In some embodiments, each of the elastic components includes an elastic element and a fixing claw, one end of the elastic element is fixedly connected to the fixing claw, and the other end of the elastic element is located inside the housing and fixedly connected to the inner wall of the housing;

[0012] The elastic element can elastically extend and retract, allowing the fixing claw to retract from the through hole so that the fixing element can be connected and fixed within the through hole, or allowing the fixing claw to enter the through hole so that the fixing element can be connected and fixed.

[0013] In some embodiments, the housing is provided with a plurality of receiving grooves spaced circumferentially along the through hole inside, each receiving groove contains an elastic member, and the outer periphery of each elastic member abuts against the corresponding receiving groove; each receiving groove opens to the side facing the through hole, and the opening of the receiving groove is used for the elastic member to extend out.

[0014] The elastic element is capable of elastic expansion and contraction along the radial direction of the through hole.

[0015] In some embodiments, the surface of each fixing claw that faces away from the elastic element is an arc surface;

[0016] Each of the aforementioned fixing claws includes a fixing part and a connecting part. The fixing part is fixedly connected to the elastic member, and the connecting part is fixed to the end of the fixing part away from the elastic member. The connecting part is used to connect and fix with the fixing member.

[0017] The outer periphery of the fixing member is provided with an external thread; the connecting part is a threaded structure that matches the external thread, and the connecting parts of the plurality of fixing claws are used to engage with the external thread to realize the connection and fixation of the plurality of fixing claws with the fixing member.

[0018] In some embodiments, the through hole is located at the center of gravity of the housing, and the center of the through hole coincides with the center of gravity of the housing.

[0019] In some embodiments, the connector is used to hook onto the hook of the testing instrument;

[0020] All of the connectors are of equal length;

[0021] When each of the connecting parts is hooked to the hook and is in a taut state, the center of gravity of the hook and the outer shell are located on the same vertical line.

[0022] In some embodiments, the tensile testing fixture further includes a plurality of pins, which are circumferentially spaced on the housing and are detachably connected to the housing; each connector is correspondingly sleeved on one of the pins.

[0023] In some embodiments, the housing is provided with a plurality of mounting slots spaced circumferentially, each mounting slot opening on one side of the housing along the axial direction of the through hole; each pin engages with one of the mounting slots.

[0024] In some embodiments, each of the pins is provided with a slot for engaging with the connector.

[0025] In some embodiments, the outer shell is a regular polygonal structure;

[0026] A connector is provided at the midpoint of each side of the outer shell;

[0027] Each side of the outer shell is fixed with one of the elastic components, and each elastic component is arranged along the center line of one side of the outer shell.

[0028] As can be seen from the above technical solution, this utility model has at least the following advantages and positive effects:

[0029] In this application, since multiple elastic components are fixedly fixed at circumferential intervals along the through hole inside the housing, and each of the multiple elastic components can elastically expand and contract, the ends of each elastic component can extend into the through hole, so that the ends of the multiple elastic components can be connected and fixed to the fixing member, thereby realizing the connection and fixation between the fixing member and the tensile test fixture; or, the ends of each elastic component can be withdrawn from the through hole, so that each elastic component is completely housed inside the housing, so that the fixing member is connected and fixed in the through hole, thereby realizing the connection and fixation between the fixing member and the tensile test fixture.

[0030] In other words, the tensile testing fixture of this application utilizes the elastic expansion and contraction properties of elastic components, allowing the ends of multiple elastic components facing the through hole to collectively enclose and form a through hole with an adjustable diameter. This enables the through hole and the through hole to automatically adapt to fasteners with different diameters, without the need for frequent replacement of jaws of different sizes or the addition of bushings. This allows for the connection and fixation between the tensile testing fixture and fasteners of different diameters, thereby enabling tensile testing of connection holes with multiple diameters. This improves the versatility and compatibility of the tensile testing fixture and simplifies operation.

[0031] When the ends of multiple elastic components extend into the through hole and are connected to the fixing member, based on the elastic expansion and contraction performance of the elastic components, the cooperation of multiple elastic components can realize the automatic reset of the fixing member during the dynamic process of subsequent tensile testing, so that the fixing member can maintain the initial fixed position. This makes it easier to make the force applied by the fixing member to the workpiece coincide with the axis of the connecting hole, so as to eliminate the angular deviation between the axis of the connecting hole and the direction of the tensile force, thereby eliminating the purpose of eliminating the additional bending moment. This ensures that the tensile test data does not contain nonlinear errors and improves the accuracy of the tensile test of the connecting hole of the workpiece.

[0032] Furthermore, when multiple elastic components extend and contract to allow the ends of each elastic component to exit the through hole, while the fastener is fixed inside the through hole, based on the elastic extension and contraction properties of the elastic components, the ends of each elastic component will abut against the outer periphery of the fastener located inside the through hole. That is, the ends of each elastic component are flush with the inner peripheral wall of the through hole. This allows the ends of multiple elastic components to cooperate with the inner peripheral wall of the through hole to connect and fix with the fastener, thereby improving the connection strength of the fastener and enhancing its stability.

[0033] After the test is completed, the fastener is removed from the tensile test fixture, and the elastic component can automatically reset using its elastic stretching properties, which facilitates the next test operation. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the tensile testing fixture in this embodiment.

[0035] Figure 2 yes Figure 1 Enlarged structural diagram at point A in the middle.

[0036] Figure 3 This is a schematic diagram of the structure of the fixing claw in this embodiment.

[0037] The annotations in the attached figures are explained as follows:

[0038] 1. Outer shell; 11. Through hole; 12. Mounting slot; 2. Connector; 3. Elastic component; 31. Elastic component; 32. Fixing claw; 321. Fixing part; 322. Connecting part; 4. Pin; 41. Slot. Detailed Implementation

[0039] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the descriptions and illustrations therein are for illustrative purposes only and not intended to limit this utility model.

[0040] In the description of this application, it should be understood that, in the embodiments shown in the accompanying drawings, the indications of direction or positional relationships (such as up, down, left, right, front, and back) are merely for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the accompanying drawings. If the description of the positions of these elements changes, these directional indications also change accordingly.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] This application provides a tensile testing fixture for use with a testing instrument to perform tensile testing on connecting holes in a workpiece.

[0043] It should be noted that this application does not improve the structure of the testing instrument. For information on the structure of the testing instrument, please refer to existing instruments such as universal testing machines used for tensile testing.

[0044] The testing instrument includes a frame and a hook. For example, a support platform is formed on the frame to support the workpiece to be tested. The hook is vertically mounted on the frame and is located directly above the support platform.

[0045] In practical applications, the workpiece to be tested is connected and fixed to the testing instrument, the tensile testing fixture is connected to the hook, the tensile testing fixture is connected and fixed to the workpiece to be tested, and the tensile testing fixture is located above the workpiece to be tested.

[0046] Specifically, the workpiece to be tested is placed on the support platform with the axis of its connecting hole extending vertically, and the workpiece to be tested is fixedly connected to the support platform.

[0047] A fixing member is provided inside the connecting hole. Exemplarily, the fixing member is threadedly connected to the inner circumferential wall of the connecting hole, and the fixing member protrudes upward from the workpiece to be tested for connection and fixation with a tensile testing fixture, such that the tensile testing fixture is positioned above the workpiece to be tested. The axis of the fixing member is collinear with the axis of the connecting hole.

[0048] In practical applications, by moving the hook upward relative to the frame, a vertically upward tensile force is applied to the tensile testing fixture. The vertically upward tensile force applied by the hook can be transmitted to the fixing component through the tensile testing fixture, and then applied by the fixing component to the connection hole of the workpiece to be tested, which is fixed on the bearing platform located below the hook. When the upward tensile force applied by the hook causes the workpiece to be tested to break at its connection hole, the instantaneous value of the upward tensile force applied by the hook is the ultimate tensile force of the connection hole.

[0049] This embodiment uses a circular connecting hole as an example for explanation. The shape of the fastener matches the shape of the connecting hole; that is, the fastener is cylindrical.

[0050] The following detailed description, in conjunction with the accompanying drawings, describes specific embodiments of the tensile testing fixture of this application.

[0051] Figure 1 This is a schematic diagram of the tensile testing fixture in this embodiment.

[0052] refer to Figure 1 The tensile testing fixture includes a housing 1, multiple connectors 2, and multiple elastic components 3. The housing 1 has a through hole 11, and the end of a fixing component passes through the through hole 11. Multiple connectors 2 are spaced apart circumferentially on the housing 1. One end of each connector 2 is connected to the housing 1, and the other end is used to connect to a testing instrument. The testing instrument is used to pull the connector 2 upwards to apply an upward tensile force to the fixing component. Multiple elastic components 3 are spaced apart circumferentially along the through hole 11, and each elastic component 3 is fixed inside the housing 1. All elastic components 3 are elastically expandable and contractible, allowing the end of each elastic component 3 to extend into the through hole 11, so that the ends of the multiple elastic components 3 can connect and fix the fixing component. Alternatively, the ends of the multiple elastic components 3 can enclose to form an adjustable-diameter perforation, or allow the end of each elastic component 3 to exit the through hole 11, so that the fixing component is connected and fixed within the through hole 11.

[0053] In this application, the tensile testing fixture utilizes the elastic expansion and contraction properties of the elastic component 3, enabling the ends of multiple elastic components 3 facing the through hole 11 to collectively enclose and form a through hole with an adjustable diameter. This allows the through hole and the through hole 11 to automatically adapt to fasteners with different diameters, eliminating the need for frequent replacement of jaws of different sizes or the addition of bushings. This enables the connection and fixation between the tensile testing fixture and fasteners of different diameters, thereby achieving tensile testing of connection holes with multiple diameters, improving the versatility and compatibility of the tensile testing fixture, and simplifying operation.

[0054] When the ends of multiple elastic components 3 extend into the through hole 11 and are connected to the fixing member, based on the elastic expansion and contraction performance of the elastic components 3, the multiple elastic components 3 cooperate to realize the automatic reset of the fixing member during the dynamic process of subsequent tensile testing, so that the fixing member can maintain the initial fixed position, that is, so that the axis of the fixing member can coincide with the axis of the connecting hole. This makes it easier to realize that the force applied by the fixing member to the workpiece under test coincides with the axis of the connecting hole, so as to eliminate the angular deviation between the axis of the connecting hole and the tensile force direction, thereby eliminating the purpose of eliminating additional bending moment, so that the tensile test data does not contain nonlinear error, and improving the accuracy of the tensile test of the connecting hole of the workpiece under test.

[0055] Furthermore, when the ends of each elastic component 3 are dislodged from the through hole 11 by the elastic expansion and contraction of the multiple elastic components 3, and the fastener is fixed inside the through hole 11, based on the elastic expansion and contraction performance of the elastic components 3, the ends of each elastic component 3 will abut against the outer periphery of the fastener located inside the through hole 11. That is, the ends of each elastic component 3 are flush with the inner peripheral wall of the through hole 11. This allows the ends of the multiple elastic components 3 to cooperate with the inner peripheral wall of the through hole 11 to connect and fix with the fastener, thereby improving the connection strength of the fastener and improving the stability of the fastener.

[0056] After the test is completed, the fastener is removed from the tensile test fixture, and the elastic component 3 can automatically reset by utilizing its own elastic stretching properties, which facilitates the next test operation.

[0057] In this embodiment, the interior of the outer shell 1 is hollow, and a through hole 11 is provided on the outer shell 1 for the fastener to pass through. In actual application, the lower end of the fastener passes through the connecting hole and is connected and fixed to the connecting hole, while the upper end of the fastener passes through the through hole 11.

[0058] Specifically, the through hole 11 is located at the center of gravity of the outer shell 1, and the center of the through hole 11 coincides with the center of gravity of the outer shell 1.

[0059] In this embodiment, the outer shell 1 has a regular polygonal structure, which facilitates the determination of the center of gravity of the outer shell 1. At this time, the center of the outer shell 1 is the center of gravity, and the center line of each side of the outer shell 1 is the center of gravity line.

[0060] Multiple connectors 2 are distributed circumferentially on the housing 1. One end of each connector 2 is connected to the housing 1, and the other end is used to connect to the test instrument.

[0061] Specifically, a connector 2 is provided at the midpoint of each side of the outer shell 1. Because the outer shell 1 adopts a regular polygonal structure, the connecting piece 2, which is connected to the midpoint of each side of the outer shell 1, ensures that the forces on each side of the outer shell 1 are uniform after being connected to the testing instrument. This balances the forces on the outer shell 1 in the circumferential direction and forms a surrounding constraint on the outer shell 1. This facilitates the automatic vertical calibration and leveling of the outer shell 1 using symmetrical geometric relationships. Furthermore, during the subsequent upward pulling of the tensile testing fixture by the testing instrument, it effectively suppresses lateral swaying of the outer shell 1. This ensures that when the testing instrument applies a vertically upward pulling force to the connecting piece 2, the outer shell 1 remains horizontal and has a tendency to move vertically upward, only experiencing vertical force. After transmitting the received vertical force to the fixing piece, the fixing piece can apply a vertically upward pulling force to the workpiece fixed on the bearing platform. This ensures that the pulling force on the workpiece coincides with the axis of the connecting hole, eliminating any angular deviation between the axis of the connecting hole and the direction of the pulling force. This eliminates the additional bending moment and ensures that the tensile test data does not contain nonlinear errors, thus improving the accuracy of the tensile test of the connecting hole of the workpiece.

[0062] In this embodiment, the two opposite ends of each connector 2 are a first end and a second end, respectively. The first end of each connector 2 is fixedly connected to the outer casing 1, and the second end of each connector 2 is connected to the testing instrument. Specifically, the second end of the connector 2 is hooked to the hook of the testing instrument.

[0063] The tensile testing fixture also includes multiple pins 4, which are spaced circumferentially on the outer shell 1. Each connector 2 is fitted onto a corresponding pin 4 to connect the first end of the connector 2 to the outer shell 1.

[0064] Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle.

[0065] refer to Figure 1 and Figure 2 Each pin 4 is detachably connected to the outer casing 1, which facilitates quick assembly and disassembly of the pin 4 and the outer casing 1 for operations such as replacing the pin 4. At the same time, this design also enables quick assembly and disassembly of the connector 2 and the outer casing 1 for operations such as replacing the connector 2.

[0066] For example, the outer casing 1 is provided with a plurality of mounting slots 12 spaced apart along the circumference, and each mounting slot 12 is open on one side of the outer casing 1 along the axial direction of the through hole 11. Each pin 4 engages with a mounting slot 12 to realize the connection between the connector 2 and the outer casing 1.

[0067] Specifically, a mounting groove 12 is provided at the center of each side of the outer casing 1. Multiple mounting grooves 12 are arranged symmetrically about the center of the outer casing 1. This design ensures that the relative positions of the corresponding mounting grooves 12 and the sides of the outer casing 1 remain consistent.

[0068] Each mounting slot 12 includes a slot body and blind holes arranged on opposite sides thereof. The slot body opens on one side of the housing 1 along the axial direction of the through hole 11, and each blind hole opens on the side close to the slot body, so that each blind hole communicates with the slot body. The axes of the two blind holes are on the same straight line, and the straight line containing the axes of the two blind holes coincides with the centroid line of the housing 1.

[0069] For example, in practical applications, the first end of the connector 2 can be first fitted onto the pin 4, and then the pin 4 can be inserted into the mounting groove 12 through the opening of the groove body. This facilitates the one-to-one insertion of the opposite ends of the pin 4 into the two blind holes, thereby achieving a snap-fit ​​engagement between the pin 4 and the mounting groove 12, and thus connecting the connector 2 to the housing 1. At this time, the second end of the connector 2 can protrude from the housing 1 through the opening of the mounting groove 12, so as to facilitate subsequent connection with testing instruments. Alternatively, the above design also facilitates the removal of the pin 4 from the housing 1 through the opening of the groove body.

[0070] During the installation of the aforementioned pin 4, since the straight line containing the axes of the two blind holes coincides with the center line of the outer shell 1, the axis of the pin 4 after being engaged with the mounting groove 12 can also coincide with the center line of the outer shell 1, and the connector 2 sleeved on the pin 4 can be located at the midpoint of the edge of the outer shell 1, which facilitates the positioning of the connector 2.

[0071] In this embodiment, each pin 4 is provided with a slot 41, which is used to engage with the connector 2. This design can limit the position of the connector 2 and prevent measurement errors caused by the axial movement of the connector 2 along the pin 4 during subsequent testing, thereby improving measurement accuracy.

[0072] For example, the pin 4 is recessed inward at the midpoint along the axial direction to form an outward-facing groove 41, that is, the groove 41 extends circumferentially along the pin 4. Since the multiple mounting slots 12 are arranged symmetrically about the center of the housing 1, the multiple pins 4 that are engaged with the multiple mounting slots 12 can be arranged symmetrically about the center of the housing 1. This ensures that the relative position between the first end of each connector 2 engaged with each pin 4 and the corresponding edge of the housing 1 remains consistent. This allows the connector 2 connected at the midpoint of each side of the housing 1 to further improve the uniformity of force on each side of the housing 1 after being connected to the testing instrument, balance the force on the housing 1 in the circumferential direction, and help improve the accuracy of automatically calibrating and leveling the housing 1.

[0073] In other embodiments, the correspondingly arranged pins 4 and the edges of the housing 1 can also be parallel. In this case, the slot 41 can also extend along the axial direction of the pin 4.

[0074] In this embodiment, the diameter of the pin 4 can be set according to the different maximum tensile forces that need to be measured. This design makes it easy for the pin 4 to break reliably when the tensile force exceeds the threshold, so that the outer shell 1 is disconnected from the connector 2, that is, the force on the outer shell 1 in the vertical direction is interrupted, so as to realize automatic overload protection and prevent damage to the outer shell 1 and other structures.

[0075] In this embodiment, all connectors 2 are of equal length. When each connector 2 is hooked to the hook and in a taut state, the center of gravity of the hook and the outer casing 1 are located on the same vertical line. Since the outer shell 1 in this embodiment adopts a regular polygonal structure, the multiple connectors 2 arranged in the above manner, after being hooked to the hook, together with the outer shell 1 and the hook, form a regular pyramidal structure. This allows the vertical upward tension applied by the hook to be evenly distributed across the multiple connectors 2 and evenly transmitted to the outer shell 1 through the multiple connectors 2. This ensures that the forces on each side of the outer shell 1 are uniform, so that the forces on the outer shell 1 in the circumferential direction can be balanced. This helps to automatically achieve vertical calibration and leveling of the outer shell 1 using symmetrical geometric relationships, effectively suppressing lateral swaying of the tensile testing fixture. This ensures that the outer shell 1 is only subjected to vertical force. During the force transmission process, the fixing component can apply a vertical upward tension to the workpiece to be tested fixed on the bearing platform. This allows the tension on the workpiece to be tested to coincide with the axis of the connecting hole, ensuring that there is no angular deviation between the axis of the connecting hole and the direction of the tension, thereby eliminating the purpose of additional bending moment. This ensures that the tensile test data does not contain nonlinear errors and improves the accuracy of the tensile test of the connecting hole of the workpiece to be tested.

[0076] In this embodiment, the connector 2 is ring-shaped. This design facilitates direct connection of the connector 2 to the pin 4 and direct hooking of the connector 2 to the hook, making operation convenient and simple.

[0077] Connector 2 is made of steel wire rope, which gives it high strength and makes it easy to meet the requirements of tensile testing.

[0078] refer to Figure 1Multiple elastic components 3 are distributed circumferentially along the through hole 11, and each elastic component 31 is fixed inside the outer shell 1. Specifically, an elastic component 3 is fixed to each side of the outer shell 1, and each elastic component 3 is arranged along the centroid line of one side of the outer shell 1. Furthermore, among the elastic components 3 and connectors 2 provided on the same side of the outer shell 1, the elastic component 3 is located inside the connection point between the connector 2 and the outer shell 1. The multiple elastic components 3 are arranged symmetrically about the center of the outer shell 1. Since the outer shell 1 is a regular polygonal structure, the through hole 11 is located at the centroid of the outer shell 1, and the center of the through hole 11 coincides with the centroid of the outer shell 1. According to the symmetrical geometric relationship, the above design will make the multiple elastic components 3 evenly and spaced along the circumference of the through hole 11, and make the elastic components 3 arranged along the centroid line of the outer shell 1 extend radially along the through hole 11.

[0079] Multiple elastic components 3 can elastically extend and retract, so that the end of each elastic component 3 can extend into the through hole 11, so that the ends of multiple elastic components 3 can be connected and fixed to the fastener. The ends of multiple elastic components 3 can surround and form a through hole with an adjustable diameter, or, so that the end of each elastic component 3 can exit the through hole 11, so that the fastener is connected and fixed in the through hole 11.

[0080] In other words, the tensile testing fixture of this embodiment utilizes the elastic expansion and contraction of the elastic component 3, allowing the ends of multiple elastic components 3 facing the through hole 11 to collectively form a through hole with an adjustable diameter. This allows it to mate with the through hole 11 on the housing 1, facilitating automatic adaptation to fasteners of different diameters without the need for frequent replacement of jaws of different sizes or the addition of bushings. This enables the connection and fixation between the tensile testing fixture and fasteners of different diameters, thereby achieving tensile testing of connection holes of various diameters, improving the versatility and compatibility of the tensile testing fixture, and simplifying operation. Furthermore, after the test is completed and the fastener is removed from the tensile testing fixture, the elastic component 3 can automatically reset using its own elastic expansion and contraction properties, facilitating the next testing operation.

[0081] When the ends of multiple elastic components 3 extend into the through hole 11 and are connected to the fixing member, based on the elastic expansion and contraction performance of the elastic components 3, the multiple elastic components 3 cooperate to realize the automatic reset of the fixing member during the dynamic process of subsequent tensile testing, so that the fixing member can maintain the initial fixed position, that is, so that the axis of the fixing member can coincide with the axis of the connecting hole. This makes it easier to realize that the force applied by the fixing member to the workpiece under test coincides with the axis of the connecting hole, so as to eliminate the angular deviation between the axis of the connecting hole and the tensile force direction, thereby eliminating the purpose of eliminating additional bending moment, so that the tensile test data does not contain nonlinear error, and improving the accuracy of the tensile test of the connecting hole of the workpiece under test.

[0082] Furthermore, when the ends of each elastic component 3 are dislodged from the through hole 11 by the elastic expansion and contraction of the multiple elastic components 3, and the fastener is fixed inside the through hole 11, based on the elastic expansion and contraction performance of the elastic components 3, the ends of each elastic component 3 will abut against the outer periphery of the fastener located inside the through hole 11. That is, the ends of each elastic component 3 are flush with the inner peripheral wall of the through hole 11. This allows the ends of the multiple elastic components 3 to cooperate with the inner peripheral wall of the through hole 11 to connect and fix with the fastener, thereby improving the connection strength of the fastener and improving the stability of the fastener.

[0083] refer to Figure 1 and Figure 2 Each elastic component 3 includes an elastic element 31 and a fixing claw 32. One end of the elastic element 31 is fixedly connected to the fixing claw 32, and the other end of the elastic element 31 is located inside the outer casing 1 and fixedly connected to the inner peripheral wall of the outer casing 1. The elastic element 31 can elastically extend and retract, allowing the fixing claw 32 to exit the through hole 11 so that the fixing component is connected and fixed within the through hole 11, or allowing the fixing claw 32 to enter the through hole 11 so that the ends of all the fixing claws 32 facing away from the elastic element 31 form an adjustable-diameter perforation, through which the fixing component is accommodated and connected and fixed via the fixing claw 32.

[0084] Specifically, when the elastic element 31 is in a naturally extended / retracted state, the fixing claws 32 are at least partially located within the through hole 11. At this time, the diameter of the perforation formed by the multiple fixing claws 32 is at its minimum. This minimum diameter is the minimum diameter of the fixing element that the perforation can accommodate, which is also the minimum diameter of the connecting hole. When the elastic element 31 is compressed to the point that the fixing claws 32 are completely housed within the outer casing 1, they are fitted and connected to the fixing element through the inner peripheral wall of the through hole 11. At this time, the diameter of the through hole 11 is the maximum diameter of the fixing element that can be accommodated, which is also the maximum diameter of the connecting hole. Furthermore, even when the elastic member 31 is compressed to the point that the fixing claw 32 is completely contained within the outer casing 1, under the action of the elastic member 31, the end of the fixing claw 32 facing away from the elastic member 31 will abut against the outer periphery of the fixing member located in the through hole 11. That is, the end of the fixing claw 32 facing away from the elastic member 31 can be flush with the inner peripheral wall of the through hole 11. This allows the fixing claw 32 and the inner peripheral wall of the through hole 11 to cooperate and connect and fix with the fixing member, thereby improving the connection strength of the fixing member and improving the stability of the fixing member.

[0085] In this embodiment, the elastic element 31 can elastically expand and contract along the radial direction of the through hole 11. This design allows the elastic element 31 to maintain its radial extension along the through hole 11 (i.e., the direction of the center line of the outer shell 1) during the elastic expansion and contraction process. Since the outer shell 1 is a regular polygonal structure, each side of the outer shell 1 is perpendicular to its center line. That is, the elastic element 31 extending along the radial direction of the through hole 11 (i.e., the direction of the center line of the outer shell 1) will also perpendicularly abut against the fixing claw 32. This allows each fixing claw 32 to abut against the supporting fixing member along the radial direction of the through hole 11 when multiple fixing claws 32 are used to connect and fix the fixing member. As a result, the lines connecting the interaction points between the outer shell 1 and the elastic elements 31 of each elastic component 3, the interaction points between the elastic elements 31 of each elastic component 3 and the fixing claws 32, and the interaction points between the fixing claws 32 of each elastic component 3 and the fixing member extend along the radial direction of the through hole 11 (i.e., the direction of the center line of the outer shell 1). This can improve the connection stability and support stability between the elastic component 3 and the fixing member.

[0086] The outer casing 1 has multiple accommodating grooves spaced circumferentially along the through hole 11 inside. Each accommodating groove contains an elastic member 31, and the outer periphery of each elastic member 31 abuts against the corresponding accommodating groove. Each accommodating groove is open on the side facing the through hole 11, and the opening of the accommodating groove is used for the elastic member 31 to extend out. That is, the accommodating groove can circumferentially limit the elastic member 31 so as to realize the elastic extension and contraction of the elastic member 31 in its axial direction.

[0087] Figure 3 This is a schematic diagram of the structure of the fixing claw 32 in this embodiment.

[0088] refer to Figure 2 and Figure 3 Exemplarily, each fixing claw 32 includes a fixing portion 321 and a connecting portion 322. The fixing portion 321 is fixedly connected to the elastic member 31. The connecting portion 322 is fixed to the end of the fixing portion 321 facing away from the elastic member 31, and is used to connect and fix with the fixing member. Specifically, the outer periphery of the fixing member is provided with external threads. The connecting portion 322 is a threaded structure that matches the external threads. The connecting portions 322 of the multiple fixing claws 32 are used to engage with the external threads to achieve connection and fixation between the multiple fixing claws 32 and the fixing member. This design facilitates quick connection and fixation between the fixing member and the multiple fixing claws 32, and also facilitates quick disassembly between the fixing member and the multiple fixing claws 32.

[0089] refer to Figure 1 and Figure 2 In this embodiment, each fixing claw 32 protrudes outward from the elastic member 31 in the circumferential direction, which can increase the contact area between the fixing claw 32 and the fixing member, thereby improving the connection strength between the fixing claw 32 and the fixing member.

[0090] In this embodiment, the surface of each fixing claw 32 facing away from the elastic member 31 is an arc surface. This design facilitates the matching of the arc surface of the fixing claw 32 with the outer periphery of the columnar fixing member, so that the end of the fixing claw 32 facing away from the elastic member 31 can fully contact the outer periphery of the fixing member, thereby increasing the contact area between the fixing claw 32 and the fixing member and improving the connection strength between the fixing claw 32 and the fixing member.

[0091] Because the surfaces of each fixing claw 32 facing away from the elastic element 31 are curved, the perforation formed by the ends of all the fixing claws 32 facing away from the elastic element 31 is a circular hole. The axis of the perforation coincides with the axis of the through hole 11. That is, the axis of the perforation and the center of the through hole 11 are on the same straight line, thus making the axis of the perforation and the center of gravity of the outer shell 1 on the same straight line. This design ensures that when the fixing claws 32 are used to connect and fix the fixing component, the axis of the fixing component coincides with the axis of the perforation, thereby achieving collinearity between the axis of the fixing component and the center of gravity of the outer shell 1. This ensures that when the hook applies a vertically upward force to the outer shell 1, the force transmitted from the outer shell 1 to the fixing component also remains vertically upward. Consequently, the tensile force on the workpiece under test coincides with the axis of the connecting hole, eliminating any angular deviation between the axis of the connecting hole and the direction of the tensile force, thus eliminating additional bending moment and ensuring that the tensile test data does not contain nonlinear errors, improving the accuracy of the tensile test of the connecting hole of the workpiece under test.

[0092] Furthermore, within the diameter range of the aforementioned adaptable fasteners, under the action of the elastic element 31, the elastic component 3 can automatically adapt to the elastic support and connection fixation of different fixing claws 32 on the fasteners, and the cooperation of multiple elastic elements 31 can automatically achieve the alignment of the axis of the perforation formed by the multiple fixing claws 32 with the center of the through hole 11, that is, to keep the axis of the fastener located in the perforation collinear with the axis of the perforation, both passing through the center of gravity of the outer shell 1.

[0093] As can be seen from the above technical solution, this utility model has at least the following advantages and positive effects:

[0094] First, the tensile testing fixture of this application utilizes the elastic expansion and contraction of the elastic component 3, allowing the ends of multiple elastic components 3 facing the through hole 11 to collectively form a through hole with an adjustable diameter. The through hole and the through hole 11 mate easily and automatically adapt to fasteners of different diameters, eliminating the need for frequent replacement of jaws of different sizes or the addition of bushings. This enables the connection and fixation between the tensile testing fixture and fasteners of different diameters, thereby achieving tensile testing of connection holes of various diameters, improving the versatility and compatibility of the tensile testing fixture, and simplifying operation. Furthermore, after the test is completed and the fastener is removed from the tensile testing fixture, the elastic component 3 can automatically reset using its own elastic expansion and contraction properties, facilitating the next testing operation.

[0095] Secondly, the tensile testing fixture adopts a geometrically symmetrical design. During the measurement of the tensile force of the connecting hole of the workpiece under test, after the workpiece under test and the tensile testing fixture are connected by the fixing component, the axis of the connecting hole, the center of gravity of the outer shell 1, and the hook of the measuring instrument are always kept collinear in the vertical direction. This ensures that the tensile force applied by the hook to the outer shell 1, the force transmitted by the outer shell 1 to the fixing component, and the force transmitted by the fixing component to the workpiece under test are all vertical forces. As a result, the tensile force on the workpiece under test can coincide with the axis of the connecting hole, so that there is no angular deviation between the axis of the connecting hole and the direction of the tensile force, thereby eliminating the additional bending moment and ensuring that the tensile test data does not contain nonlinear errors, thus improving the accuracy of the tensile force test of the connecting hole of the workpiece under test.

[0096] Furthermore, the connector 2 is mounted on the housing 1 via a pin 4. Since the pin 4 is detachably connected to the housing 1, it facilitates quick assembly and disassembly of the pin 4, making it easy to replace the pin 4 or the connector 2. The diameter of the pin 4 can be set according to the different maximum tensile forces to be measured. This design ensures that the pin 4 will reliably break when the tensile force exceeds the threshold, thus disconnecting the housing 1 from the connector 2, interrupting the force on the housing 1 in the vertical direction, thereby achieving automatic overload protection and preventing damage to the housing 1, elastic component 3, and other structures.

[0097] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A tensile test fixture for use in cooperation with a testing instrument to perform a tensile test on a connection hole in a workpiece under test, the connection hole having a fixture disposed therein, the workpiece under test being connected and secured to the testing instrument; characterized by, The tensile testing fixture includes: The outer casing has a through hole, and the end of the fastener passes through the through hole; Multiple connectors are distributed circumferentially on the housing. One end of each connector is connected to the housing, and the other end is used to connect to the testing instrument. The testing instrument is used to pull the connector upward to apply an upward pulling force to the fixing member. Multiple elastic components are distributed circumferentially along the through hole. Each elastic component is fixed inside the housing. All elastic components are elastically expandable and contractible, allowing the end of each elastic component to extend into the through hole so that the ends of the multiple elastic components can be connected and fixed to the fixing member. The ends of the multiple elastic components can surround and form an adjustable-diameter perforation, or allow the end of each elastic component to exit the through hole so that the fixing member is connected and fixed in the through hole.

2. The pull test fixture of claim 1, wherein, Each of the elastic components includes an elastic element and a fixing claw. One end of the elastic element is fixedly connected to the fixing claw, and the other end of the elastic element is located inside the housing and fixedly connected to the inner wall of the housing. The elastic element can elastically extend and retract, allowing the fixing claw to retract from the through hole so that the fixing element can be connected and fixed within the through hole, or allowing the fixing claw to enter the through hole so that the fixing element can be connected and fixed.

3. The pull test fixture of claim 2, wherein, The housing has a plurality of receiving grooves spaced circumferentially along the through hole inside. Each receiving groove contains an elastic member, and the outer periphery of each elastic member abuts against the corresponding receiving groove. Each receiving groove opens to the side facing the through hole, and the opening of the receiving groove is used for the elastic member to extend out. The elastic element is capable of elastic expansion and contraction along the radial direction of the through hole.

4. The pull test fixture of claim 2, wherein, The surface of each of the fixing claws that faces away from the elastic element is an arc surface; Each of the aforementioned fixing claws includes a fixing part and a connecting part. The fixing part is fixedly connected to the elastic member, and the connecting part is fixed to the end of the fixing part away from the elastic member. The connecting part is used to connect and fix with the fixing member. The outer periphery of the fixing member is provided with an external thread; the connecting part is a threaded structure that matches the external thread, and the connecting parts of the plurality of fixing claws are used to engage with the external thread to realize the connection and fixation of the plurality of fixing claws with the fixing member.

5. The pull test fixture of claim 1, wherein, The through hole is located at the center of gravity of the outer shell, and the center of the through hole coincides with the center of gravity of the outer shell.

6. The pull test fixture of claim 1, wherein, The connector is used to hook onto the hook of the testing instrument; All of the connectors are of equal length; When each of the connecting parts is hooked to the hook and is in a taut state, the center of gravity of the hook and the outer shell are located on the same vertical line.

7. The pull test fixture of claim 6, wherein, The tensile testing fixture also includes a plurality of pins, which are spaced circumferentially on the housing and are detachably connected to the housing; each connector is correspondingly sleeved on one of the pins.

8. The pull test fixture of claim 7, wherein, The outer casing is provided with a plurality of mounting slots spaced circumferentially, and each mounting slot opens on one side of the outer casing along the axial direction of the through hole; each pin engages with one of the mounting slots.

9. The tensile testing fixture according to claim 7, characterized in that, Each of the latches is provided with a clamping groove for clamping cooperation with the connecting piece.

10. The pull test fixture of claim 1, wherein, The shell is a regular polygon structure. Each of the connecting pieces is arranged at the midpoint of each side of the shell. Each of the elastic assemblies is arranged along the gravity center line of each side of the shell.

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