A test fixture for measuring the torsional strength of a rivet

Abstract

This application relates to the field of rivet testing fixture technology, specifically disclosing a testing fixture for measuring the torsional strength of rivets, including a nut clamp and a flat clamp. The nut clamp has a hexagonal hole that mates with a drive nut. The center of the nut clamp is hollowed out to observe the riveting process during the test. The hollowed-out part of the nut clamp is a through rectangular hole, the length of which is greater than the length of the threaded pull rivet sleeve. The hexagonal hole has a clearance fit with the drive nut. The flat clamp has a groove that mates with the flat end of the threaded pull rivet core. The groove is set along the diameter of the flat clamp and extends through both sides. The groove has a clearance fit with the flat end on the threaded pull rivet core. The nut clamp and the flat clamp are cylindrical in shape. The changes of the threaded pull rivet can be observed during the test, and the test results are reliable and intuitive. This testing fixture has a simple structure, low manufacturing cost, and simple operation.

Description

Technical Field

[0001] This utility model relates to the field of rivet testing fixtures, specifically a testing fixture for measuring the torsional strength of rivets. Background Technology

[0002] In the manufacturing and application of threaded blind rivets, it is necessary to determine the torsional strength of the rivets. This measures the rivet material's ability to resist plastic deformation or fracture under torque, ensuring that the rivets will not fail due to torque and guaranteeing the safety and stability of the rivet installation structure. Besides determining whether the manufactured rivets meet quality requirements, measuring torsional strength is also significant for design optimization during manufacturing. Currently, the commonly used equipment for measuring the torsional strength of rivets is a torque testing machine, also known as a torque tester. The testing process is as follows: A rivet sample is randomly selected, fixed in the fixture of the torque testing machine, the torsion test mode is selected, the torque range and rotation speed are set, the sensor is activated to record the torque value, rotation angle, and deformation data, and the torque is applied until the rivet breaks. The maximum torque value is recorded as the torsional strength. The failure mode is observed, and the fracture location and deformation are recorded.

[0003] like Figure 1 As shown, a threaded blind rivet includes a core rod 1, a sleeve 2, and a drive nut 3. The core rod 1 passes through the sleeve 2, and the drive nut 3 is sleeved on the core rod 1 and abuts against the end face of the sleeve 2. In use, the sleeve 2 is placed into the hole of the part to be fastened, and the drive nut 3 is rotated to move the core rod 1. The relative displacement between the core rod 1 and the sleeve 2 causes the sleeve 2 to expand, generating a clamping force for fastening. The end of the core rod 1 away from the sleeve 2 is provided with a flat end 101. In the prior art, there is no test fixture for measuring the torsional strength of this type of threaded blind rivet. Utility Model Content

[0004] To address the shortcomings of existing technologies, the present invention provides a test fixture for measuring the torsional strength of rivets, thus solving the problem that there is no existing test fixture for measuring the torsional strength of threaded core-pulling rivets with flat openings on the core rod.

[0005] To solve the above problems, the technical solution adopted by this utility model is: a test fixture for measuring the torsional strength of rivets, including a nut clamp and a flat clamp, wherein the nut clamp is provided with a hexagonal hole that mates with a drive nut, the center of the nut clamp is hollowed out, and the flat clamp is provided with a groove that mates with the flat end of the threaded core rivet rod.

[0006] Furthermore, the nut clamp and the flat clamp are cylindrical in shape.

[0007] Furthermore, the groove is provided along the diameter of the flat clamp and extends through both sides.

[0008] Furthermore, the cutout of the nut clamp is a through rectangular hole, the length of which is greater than the length of the threaded pull rivet sleeve.

[0009] Furthermore, the hexagonal hole is clearance-fitted with the drive nut.

[0010] Furthermore, the groove is clearance-fitted with the flat end on the core of the threaded pull rivet.

[0011] The beneficial effects of this solution are as follows: Compared with the prior art, the test fixture for measuring the torsional strength of rivets of this utility model can realize the installation of threaded mandrels and the application of torque by setting a hexagonal hole on the nut clamp to cooperate with the drive nut of the threaded mandrel, and setting a groove on the flat clamp to cooperate with the mandrel. The nut clamp is hollow in the middle, and the changes of the threaded mandrel can be observed during the test. The test results are reliable and intuitive. The test fixture has a simple structure, low manufacturing cost, and simple test operation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a threaded blind rivet structure.

[0013] Figure 2 This is a schematic diagram of the structure of this utility model;

[0014] Figure 3 This is a schematic diagram of the nut clamp of this utility model;

[0015] Figure 4 This is a schematic diagram of the flat clamp of this utility model;

[0016] In the diagram: 1-core rod, 2-nail sleeve, 3-drive nut, 101-flat mouth, 4-nut clamp, 5-flat clamp, 6-interlayer gasket, 7-clamping device, 401-hexagonal hole, 501-groove. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Implementation, for example, attached Figures 2 to 4As shown: A test fixture for measuring the torsional strength of rivets includes a nut clamp 4 and a flat clamp 5. The nut clamp 4 has a hexagonal hole 401 that mates with a drive nut 3. The nut clamp 4 has a hollow center for observing the riveting process during the test. The hollow center of the nut clamp 4 is a through rectangular hole, the length of which is greater than the length of the threaded mandrel rivet sleeve 2. This design is simple to manufacture and facilitates observation of the changes in the threaded mandrel rivet during the test. The hexagonal hole 401 has a clearance fit with the drive nut 3. The flat clamp 5 has a groove 501 that mates with the flat end 101 of the threaded mandrel rivet core 1. The groove 501 is set along the diameter of the flat clamp 5 and extends through both sides, facilitating the insertion of the core rivet 1 into the groove 501. The groove 501 has a clearance fit with the flat end 101 on the core rivet 1, allowing for the application of torque while facilitating the installation of the threaded mandrel rivet. The nut clamp 4 and the flat clamp 5 are cylindrical in shape, making them easy to clamp and install on the test equipment.

[0019] The specific implementation process is as follows:

[0020] The test equipment used is a torque wrench. A sandwich shim 6 is prepared. The nut clamp 4 is installed in the clamping device 7 on the fixed side of the torque wrench, so that the rectangular hole at the cutout is facing the operator for easy observation. The flat clamp 5 is installed in the clamping device 7 on the rotating side of the torque wrench. The clamping device 7 can use a three-jaw chuck. The threaded blind rivet is placed in the fixture, so that the drive nut 3 of the threaded blind rivet is located in the hexagonal hole 401 of the nut clamp 4, the flat end of the core rod 1 is located in the groove 501 on the flat clamp 5, and the rivet sleeve 2 is located at the rectangular hole at the cutout of the nut clamp 4. The sandwich shim 6 is placed on the outside of the rivet sleeve 2 to simulate the riveting situation. The torque wrench works and drives one side of the flat clamp 5 to rotate, applying torque to the threaded blind rivet. During the test, the torque wrench records data such as torsional force and torsional angle. Based on the recorded data and the changes in the threaded blind rivet during the test, the riveting performance of the threaded blind rivet can be intuitively demonstrated, which is beneficial for optimizing the structure of the threaded blind rivet.

[0021] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A testing fixture for measuring the torsional strength of rivets, characterized in that: It includes a nut clamp and a flat clamp. The nut clamp has a hexagonal hole that mates with the drive nut. The center of the nut clamp is hollowed out. The flat clamp has a groove that mates with the flat end of the threaded pull rivet rod.

2. The test fixture for measuring the torsional strength of rivets according to claim 1, characterized in that: The nut clamp and the flat clamp are cylindrical in shape.

3. The testing fixture for measuring the torsional strength of rivets according to claim 1, characterized in that: The groove is set along the diameter of the flat clamp and extends through both sides.

4. The test fixture for measuring the torsional strength of rivets according to claim 1, characterized in that: The nut clamp has a through rectangular hole, the length of which is greater than the length of the threaded pull rivet sleeve.

5. The testing fixture for measuring the torsional strength of rivets according to claim 1, characterized in that: The hexagonal hole is clearance-fitted with the drive nut.

6. The test fixture for measuring the torsional strength of rivets according to claim 1, characterized in that: The groove is clearance-fitted with the flat end on the core of the threaded pull rivet.

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