A tool for detecting the holding force of an aluminum alloy blind rivet

Abstract

This application relates to the field of fastener testing technology, specifically disclosing a tooling for testing the holding force of aluminum alloy blind rivets. The tooling includes a lower top cylinder, an upper top cylinder, and a mounting plate. The blind rivet to be tested is mounted on the mounting plate. The upper top cylinder has a mounting groove with a discharge hole in the center. A push rod auxiliary sleeve is mounted in the mounting groove, positioned above the mounting plate. The push rod auxiliary sleeve has an auxiliary hole in its center, coaxial with the mounting hole. A push rod is inserted into the auxiliary hole. The bottom end of the push rod auxiliary sleeve has an annular rib that can be inserted into the mounting plate, located on the outer periphery of the mounting hole. The annular rib generates a pressing force on the outer periphery of the mounting hole, preventing deformation of the mounting plate around the mounting hole. This ensures that the pressure acting on the rivet from top to bottom remains vertically downward, guaranteeing the accuracy of the final measured holding force.

Description

Technical Field

[0001] This utility model relates to the field of fastener testing technology, specifically to a tooling for testing the holding force of aluminum alloy blind rivets. Background Technology

[0002] Blind rivets, also known as pop rivets or blind rivets, are a common type of fastener used to join two or more materials. They are particularly suitable for single-sided operations, meaning installation can only be performed from one side of the workpiece. A blind rivet consists of two parts: a hollow rivet body (usually made of metal) and a mandrel (also called a shank) that passes through the center of the rivet body. During installation, a special rivet gun is used to pull the mandrel, causing the rivet body to expand and securely fasten to the materials being joined, while the mandrel breaks off, leaving a smooth rivet head.

[0003] To verify the quality of blind rivets, it is generally necessary to measure their mandrel holding force. This is to assess the locking performance of the locking ring in securing the rivet sleeve and mandrel together. The test requires applying a certain thrust to the end face of the mandrel, pushing it out axially. When the force reaches a certain limit, exceeding the maximum deformation resistance of the locking ring in the wedge-shaped space, the mandrel will loosen, indicating product failure. The pressure that pushes the mandrel out is the holding force of the blind rivet. To avoid the push rod tilting during testing, Chinese invention patent CN114414118B discloses a tooling for measuring the holding force of blind rivets, including a push rod, a guide sleeve, and a mounting plate. The mounting plate has mounting holes for installing the blind rivet to be tested. The bottom of the guide sleeve has a through groove corresponding to the width of the mounting plate. The guide sleeve is assembled to the upper end face of the mounting plate through this groove. The upper end face of the guide sleeve has a through guide hole, which is coaxial with the mounting hole, and its diameter corresponds to the diameter of the push rod. The blind rivet is installed in the mounting hole of the mounting plate. A push rod is aligned perfectly with the cross-section of the rivet's mandrel. Pressure is applied to the push rod, and this pressure pushes the mandrel out of the plate. Because the blind rivet is mounted on the mounting plate, the plate deforms under pressure as it is applied to the mandrel from top to bottom. This causes the pressure to expand downwards, meaning the pressure is not always perpendicular to the mandrel. To push the mandrel out, greater pressure is required, resulting in an inaccurate measured holding force. Utility Model Content

[0004] The purpose of this invention is to provide a tooling for detecting the holding force of aluminum alloy blind rivets, so as to solve the problem that existing tooling easily causes the pressure acting on the mandrel to expand in the direction, resulting in inaccurate measurement of the holding force.

[0005] To address the above issues, the following technical solution is provided:

[0006] A fixture for testing the holding force of aluminum alloy blind rivets includes a lower top cylinder, an upper top cylinder, and a mounting plate. The mounting plate has mounting holes for mounting the blind rivet to be tested. The upper top cylinder has a mounting groove corresponding to the length and width of the mounting plate, and a discharge hole penetrating the bottom of the upper top cylinder is opened in the center of the mounting groove. A push rod auxiliary sleeve is installed in the mounting groove, which is above the mounting plate. The push rod auxiliary sleeve has an auxiliary hole in the center, which is coaxial with the mounting hole. A push rod is inserted into the auxiliary hole. The bottom end of the push rod auxiliary sleeve has an annular rib that can be inserted into the mounting plate. The annular rib is located on the outer periphery of the mounting hole. The upper top cylinder has a threaded hole on the outer periphery of the mounting groove. A bolt is fitted in the threaded hole. The bolt nut is pressed onto the push rod auxiliary sleeve, and the height of the bolt nut is always lower than the height of the push rod.

[0007] The basic principle of the above technical solution is as follows: the rivet to be tested is installed in the mounting plate through the mounting hole, the mounting plate is inserted into the upper top cylinder through the mounting groove, the push rod is inserted into the push rod auxiliary sleeve through the auxiliary hole, the push rod auxiliary sleeve is inserted into the upper top cylinder through the mounting groove and is simultaneously inserted into the mounting plate. At this time, the cross-section of the push rod and the core rod of the rivet to be tested can be completely aligned. The annular rib at the bottom of the push rod auxiliary sleeve is inserted into the mounting plate. The annular rib is located on the outer periphery of the mounting hole. The bolt is assembled into the threaded hole so that the bolt nut is pressed on the push rod auxiliary sleeve. Finally, the upper top cylinder is placed on the lower top cylinder, and pressure is applied to the push rod until the core rod is ejected, and the holding force of the rivet is measured.

[0008] The beneficial effect of the above technical solution is that, compared with the existing method where the pressure direction applied to the core rod from top to bottom expands, making it impossible for the pressure direction to always act perpendicularly to the core rod, resulting in inaccurate final measured holding force, this technical solution has an annular rib at the bottom end of the top rod auxiliary sleeve that can be inserted into the mounting plate. When the top rod applies pressure to the core rod of the mandrel in the mounting hole, the annular rib, located on the outer periphery of the mounting hole, generates a pressing force, preventing deformation of the mounting plate around the mounting hole. This ensures that the pressure direction applied to the core rod from top to bottom remains unchanged, always acting vertically downwards on the core rod, thus guaranteeing the accuracy of the final measured holding force.

[0009] Furthermore, the lower top cylinder is positioned below the upper top cylinder. The lower top cylinder has a discharge trough corresponding to the mounting groove. A bottom hole, penetrating the top of the lower top cylinder, is located in the center of the discharge trough. The bottom hole has the same diameter as the discharge hole and is connected to it. The pressed-out core rod flows sequentially through the discharge hole and the bottom hole into the discharge trough.

[0010] Furthermore, the top rod includes rod one and rod two. The diameter of rod one corresponds to the diameter of the auxiliary hole, and the diameter of rod two is smaller than the diameter of the core rod of the mandrel to be tested.

[0011] Furthermore, rod one and rod two are connected by a tapered connecting block, and rod one, rod two, and the tapered connecting block are integrally connected and formed.

[0012] Furthermore, the upper top cylinder has a positioning pin at its bottom end and a positioning hole at its top end. The upper top cylinder is placed on the lower top cylinder so that the positioning pin is inserted into the positioning hole. The positioning pin and the positioning hole work together to accurately position the upper top cylinder on the lower top cylinder.

[0013] Furthermore, the mounting plate has notches at its corners, and the bottom corner of the push rod auxiliary sleeve also has notches. These notches facilitate the quick and easy placement of the mounting plate and push rod auxiliary sleeve into the mounting groove. Attached Figure Description

[0014] Figure 1 This is a cross-sectional structural diagram of the holding force measuring fixture of this utility model;

[0015] Figure 2 This is a cross-sectional disassembly diagram of the holding force measuring fixture of this utility model;

[0016] The reference numerals in the accompanying drawings include: lower top cylinder 1, upper top cylinder 2, mounting plate 3, pop rivet 4, mounting hole 5, mounting groove 6, discharge hole 7, top rod auxiliary sleeve 8, auxiliary hole 9, top rod 10, annular rib 11, threaded hole 12, bolt 13, positioning pin 14, positioning hole 15, discharge groove 16, and bottom hole 17. Detailed Implementation

[0017] The following detailed description illustrates the specific implementation method:

[0018] The basic implementation examples are as follows: Figure 1-2 As shown:

[0019] A fixture for testing the holding force of an aluminum alloy blind rivet 4 includes a lower ejector cylinder 1, an upper ejector cylinder 2, and a mounting plate 3. The mounting plate 3 has mounting holes 5 for mounting the blind rivet 4 to be tested, and notches are provided at the corners of the mounting plate 3. The upper ejector cylinder 2 has a mounting groove 6 corresponding to the length and width of the mounting plate 3, and a discharge hole 7 penetrating the bottom end of the upper ejector cylinder 2 is provided in the center of the mounting groove 6. A push rod auxiliary sleeve 8 is installed in the mounting groove 6 above the mounting plate 3. The bottom corners of the push rod auxiliary sleeve 8 are provided with notches, and a discharge hole 7 is provided in the center of the push rod auxiliary sleeve 8. An auxiliary hole 9 is provided, which is coaxial with the mounting hole 5. A push rod 10 is tightly inserted into the auxiliary hole 9. The bottom end of the push rod auxiliary sleeve 8 is provided with an annular rib 11 that can be inserted into the mounting plate 3. The cross-section of the annular rib 11 is an inverted triangle. The annular rib 11 is located on the outer periphery of the mounting hole 5. A threaded hole 12 is opened in the upper push cylinder 2, which is located on the outer periphery of the mounting groove 6. A bolt 13 is installed in the threaded hole 12. The nut of the bolt 13 is pressed onto the push rod auxiliary sleeve 8. The height of the nut of the bolt 13 is always lower than the height of the push rod 6. A positioning pin 14 is provided at the bottom end of the upper push cylinder 2. A positioning hole 15 is opened at the top end of the lower push cylinder 1. The upper push cylinder 2 is placed on the lower push cylinder 1 so that the positioning pin 14 is inserted into the positioning hole 15. A discharge groove 16 corresponding to the mounting groove 6 is provided in the lower push cylinder 16. A bottom hole 17 penetrating the top end of the lower push cylinder 1 is provided in the center of the discharge groove 16. The bottom hole 17 has the same diameter as the discharge hole 7 and is connected to the discharge hole 7. The top rod 10 includes rod one and rod two. The diameter of rod one corresponds to the diameter of the auxiliary hole 9. The diameter of rod two is smaller than the diameter of the core rod of the core-pulling rivet 4 to be tested. Rod one and rod two are connected by a tapered connecting block. Rod one, rod two and tapered connecting block are integrally connected and formed.

[0020] The specific implementation process is as follows:

[0021] The rivet 4 to be tested is installed in the mounting plate 3 through the mounting hole 5. The mounting plate 3 is inserted into the upper top cylinder 2 through the mounting groove 6. The push rod 10 is inserted into the push rod auxiliary sleeve 8 through the auxiliary hole 9. The push rod auxiliary sleeve 8 is inserted into the upper top cylinder 2 through the mounting groove 6 and is also inserted into the mounting plate 3. At this time, the cross-section of the push rod 10 and the core rod of the rivet 4 to be tested can be completely aligned. The annular rib 11 at the bottom of the push rod auxiliary sleeve 8 is inserted into the mounting plate 3. The annular rib 11 is located on the outer periphery of the mounting hole 5. The bolt 13 is assembled into the threaded hole 12 so that the bolt 13... The nut is pressed onto the push rod auxiliary sleeve 8, and finally the upper push cylinder 2 is placed on the lower push cylinder 1. The entire fixture is placed on the mechanical performance testing machine. The pressure head of the mechanical performance testing machine applies pressure to the push rod 10. The annular rib 11 is located on the outer periphery of the mounting hole 5 and generates a pressing force, so that the mounting plate 3 around the mounting hole 5 will not deform. Thus, the direction of the pressure acting on the core rod from top to bottom will not change, and it will always act vertically downward on the core rod until the core rod is pushed out. The holding force of the pull rivet 4 is measured to ensure the accuracy of the final measured holding force.

[0022] 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 tool for testing the holding force of an aluminum alloy blind rivet comprising a lower punch, an upper punch, and a mounting plate, characterized in that: The mounting plate is provided with mounting holes for installing the core-pulling rivets to be tested; the upper top cylinder is provided with a mounting groove corresponding to the length and width of the mounting plate, and a discharge hole penetrating the bottom end of the upper top cylinder is provided in the center of the mounting groove; a push rod auxiliary sleeve is installed in the mounting groove above the mounting plate, and an auxiliary hole is provided in the center of the push rod auxiliary sleeve. The auxiliary hole is coaxial with the mounting hole, and a push rod is inserted in the auxiliary hole. The bottom end of the push rod auxiliary sleeve is provided with an annular rib that can be inserted into the mounting plate. The annular rib is located on the outer periphery of the mounting hole. The upper top cylinder is provided with a threaded hole on the outer periphery of the mounting groove. A bolt is installed in the threaded hole. The nut of the bolt is pressed on the push rod auxiliary sleeve, and the height of the bolt nut is always lower than the height of the push rod.

2. The tool for testing the holding force of a blind rivet of an aluminum alloy according to claim 1, characterized in that: The lower top cylinder is positioned below the upper top cylinder. The lower top cylinder has a discharge groove corresponding to the mounting groove. The discharge groove has a bottom hole in the center that penetrates the top of the lower top cylinder. The bottom hole has the same diameter as the discharge hole and the bottom hole is connected to the discharge hole.

3. The tool for testing the holding force of a blind rivet of an aluminum alloy according to claim 2, characterized in that: The top rod includes rod one and rod two. The diameter of rod one corresponds to the diameter of the auxiliary hole, and the diameter of rod two is smaller than the diameter of the core rod of the core-pulling rivet to be tested.

4. The tool for testing the holding force of a blind rivet of an aluminum alloy according to claim 3, characterized in that: Rod 1 and Rod 2 are connected by a tapered connecting block, and Rod 1, Rod 2, and the tapered connecting block are integrally formed.

5. The tooling for detecting the holding force of aluminum alloy blind rivets according to claim 4, characterized in that: The upper top cylinder is provided with a positioning pin at its bottom end, and the lower top cylinder is provided with a positioning hole at its top end. The upper top cylinder is placed on the lower top cylinder so that the positioning pin is inserted into the positioning hole.

6. The tooling for detecting the holding force of aluminum alloy blind rivets according to claim 5, characterized in that: The mounting plate has notches at its corners, and the bottom corner of the top rod auxiliary sleeve also has notches.

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