Design method of fan-shaped metal conductor tensile test chuck and chuck

Abstract

A design method of a fan-shaped metal conductor tensile test clamp head, comprising the steps of: S1 decomposing the problem: the joint characteristics of the fan-shaped cross-section conductor require the design of the clamp head; the clamping action requires the design of the clamp head; S2 analyzing the difficulty and primary and secondary of the problem, determining the solution sequence and direction; S3 designing the clamp block to solve the main problem; S4 designing the clamping degree adjusting mechanism to solve the secondary problem. A fan-shaped metal conductor tensile test clamp head, comprising a conductor clamping mechanism and a clamping degree adjusting mechanism; the conductor clamping mechanism comprises: a pair of first and second clamp block units; the clamping degree adjusting mechanism is connected to the two clamp block units respectively; the front surface of the two clamp block units is the clamping surface, and the clamping surfaces are opposite and the spacing is adjustable with the clamping degree adjusting mechanism. The clamp head designed by the method can effectively prevent the conductor from sliding during the tensile test and the sample from breaking in the clamp.

Description

Technical Field

[0001] This technical solution relates to the technical field of testing devices, specifically a design method and clamp for a sector-shaped metal conductor tensile test. Background Technology

[0002] Solid sector-shaped aluminum conductors are extruded at high temperatures using specialized aluminum extrusion equipment, which solves the problems that often occur when installing aluminum conductors with conventional stranded and compressed structures, such as poor end contact, high contact resistance, and easy wire breakage at the joint.

[0003] The grips on commonly used tensile testing machines are manually clamped, which is laborious and provides low clamping force. The commonly used clamping blocks are two flat plates, which are only suitable for tensile testing of round or sheet-shaped materials. If the commonly used tensile grips are used to perform tensile tests on sector-shaped metal conductors, the sector-shaped conductors will either slip or easily break at the jaws during the test, making the test impossible. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by proposing a sector-shaped metal conductor tensile test clamp and its processing method. This method effectively strengthens the clamping force of the clamp and ensures continued clamping even after the metal has deformed. By employing an asymmetrical V-shaped clamp that matches the sector shape, it ensures that the final conductor breakage occurs outside the clamp. The specific details are as follows.

[0005] A design method for a sector-shaped metal conductor tensile test clamp, comprising the following steps:

[0006] S1. Decomposition problem:

[0007] Question 1: A sector-shaped conductor has three clamping surfaces: two planes and one curved surface; therefore, a clamping block that conforms to the three clamping surfaces needs to be designed.

[0008] Question 2: The clamping action of the chuck block on the sector-shaped conductor comes from the radial force. Therefore, the clamping action can be completed by using a radial force application mechanism on the chuck block.

[0009] S2. Difficulty in solving Problem 1 and Problem 2:

[0010] The radial force application mechanism used for clamping in the existing tensile testing machine is an alternative method to solve problem two.

[0011] The solution to problem one is that a corresponding mechanism cannot be found on the existing tensile testing machine, and a completely new design is required;

[0012] Problem 1 is more difficult to solve than Problem 2, so let's solve Problem 1 first.

[0013] S3. Designing a chuck block to solve problem one:

[0014] To solve problem one, increase the contact area between the clamping surface of the chuck and the conductor, as well as the friction between them.

[0015] 1) Increase contact area: If the two straight sides of the conductor's sector-shaped cross-section are approximated to the two legs of an isosceles triangle, then the two sides of the conductor are supported by the same V-groove. The two sides of the V-groove are in contact with the two sides of the conductor, thus maximizing the contact area.

[0016] If the arc-shaped side of the conductor's sector-shaped cross-section is approximately an obtuse isosceles triangle with a large angle, then it is determined that the arc surface of the conductor is supported by another V-shaped groove. This V-shaped groove supports the arc surface of the conductor at two points, namely the tangent points. After compression, the arc-shaped side only undergoes slight deformation, and the deformation at the two points forms a large contact surface.

[0017] 2) Design anti-slip teeth for the clamping blocks:

[0018] The V-groove has reverse anti-slip teeth engraved on its side. After the conductor is compressed, the metal surface of the conductor is compressed and deformed by the anti-slip teeth, forming tooth marks that mesh with the anti-slip teeth.

[0019] Next, let's address the second most important issue.

[0020] S4. Design a clamping adjustment mechanism to solve problem two:

[0021] When the clamping block holds the conductor, the conductor's axis must remain unchanged; therefore, the two V-grooves clamp radially synchronously.

[0022] Due to the small overall structure of the chuck and the limited space required for its application, a radial synchronous linkage mechanism is not suitable. Therefore, the design utilizes the V-groove as a synchronous radial clamping mechanism, transforming a single axial linear motion into two synchronous, opposing radial linear motions.

[0023] 1) Axial linear motion mechanism: hydraulic cylinder, pneumatic cylinder or electric push rod;

[0024] The electric actuator has a fixed stroke, which can easily apply strong force to the conductor and damage it.

[0025] The medium in hydraulic and pneumatic cylinders is liquid or gas. A conductor can apply force to resist it, and the energy is absorbed by the compression of the pressure medium.

[0026] Compared to pneumatic systems, hydraulic systems have a faster response time because hydraulic oil is in a closed circulation channel and has a higher density, while pneumatic systems do not.

[0027] 2) Vertical linear motion mechanism: It uses sliding between inclined planes to change the direction of the force;

[0028] The limit block and clamping block are designed to slide on an inclined plane. The limit block is fixed, and an axial force is applied to the clamping block. The limit block restricts the axial movement tendency of the clamping block, and the axial force is converted into radial movement and movement along the inclined plane.

[0029] The two sets of limit blocks and clamping blocks are at the same angle, which achieves synchronous relative radial linear motion.

[0030] In the design of the anti-slip teeth of the clamping block: the anti-slip teeth are distributed at an angle of 10 to 20 degrees with the horizontal direction. Compared with the horizontally distributed anti-slip gears, the anti-slip teeth have a larger contact area after biting the conductor, and the anti-slip effect is better. The single tooth height is 1 to 2 mm and the single tooth angle is 45 degrees.

[0031] The chuck designed using the above design method is as follows:

[0032] A fan-shaped metal conductor tensile test clamp includes a conductor clamping mechanism and a clamping degree adjustment mechanism. The conductor clamping mechanism includes: a pair of first and second clamping block units; the clamping degree adjustment mechanism is connected to the two clamping block units respectively; the front of the two clamping block units is the clamping surface, the clamping surfaces face each other and the spacing between them is adjustable according to the clamping degree adjustment mechanism;

[0033] The clamping surfaces of both chuck block units are provided with grooves; the radial cross-section of the groove is "V" shaped, and the length and width of the two sides of the groove are the same;

[0034] The bottom angles of the grooves on the two clamping surfaces (i.e., the included angles formed by the two sides of the grooves) are α and β, respectively; the angle of α is smaller than the angle of β.

[0035] Anti-slip teeth are engraved on both sides of the groove;

[0036] The clamping surfaces of the two clamping block units are close to each other, and the grooves on the two clamping surfaces enclose the space where the fan-shaped metal conductor is located. The length direction of the groove is in the same direction as the axis of the fan-shaped metal conductor.

[0037] Further optimization: There are multiple anti-slip teeth on the same side of the groove. They are parallel helical teeth that form a helical rack shape. The helix angles of the helical teeth on the two sides of the same groove are opposite, and the angle formed by the corresponding helical teeth on the two sides points towards the insertion end of the sector-shaped metal conductor. The tooth tip of each anti-slip tooth faces the opposite direction to the insertion end of the sector-shaped metal conductor.

[0038] Specifically:

[0039] The clamping adjustment mechanism includes a clamp block unit limiting mechanism and a hydraulic or pneumatic cylinder.

[0040] The piston rod of the cylinder is connected to the piston, and the piston rod extends out of / retracts from the head of the cylinder along with the piston.

[0041] The clamp block unit limiting mechanism includes a pair of first and second limiting blocks, both of which are connected to the head of the cylinder; the front faces of the first and second limiting blocks face each other and they are mirror-symmetrical about plane a; and the position between them is where the first and second clamp block units are located;

[0042] The back sides of the first and second chuck block units are slidably connected to the front sides of the first and second limiting blocks, respectively; and the axial direction of the sector-shaped metal conductor is in the same direction as the axial direction of the cylinder body; the first and second chuck block units are slidably connected to the end of the piston rod, and the sliding direction is perpendicular to plane a.

[0043] The connection structure between the back of the first clamping block unit and the front of the first limiting block is as follows: the upper part of the back of the first clamping block unit is an inclined plane, and the angle between the inclined plane and plane a is γ; the upper part of the front of the first limiting block is an inclined plane, and the angle between the inclined plane and plane a is γ.

[0044] The connection structure between the back of the second clamping block unit and the front of the second positioning block is as follows: the upper part of the back of the second clamping block unit is an inclined plane, and the angle between the inclined plane and plane a is 180°-γ; the upper part of the front of the second positioning block is an inclined plane, and the angle between the inclined plane and plane a is 180°-γ.

[0045] The space enclosed by the front of the first and second limiting blocks is a space that is larger at the bottom and smaller at the top, with the smaller end of the space away from the cylinder body. The fan-shaped metal conductor is inserted from one side of the smaller end of the space.

[0046] Further optimization: The first and second chuck block units respectively include a first and a second chuck block and a first and a second chuck seat; the first chuck block is detachably connected to the first chuck seat; the second chuck block is detachably connected to the second chuck seat;

[0047] The clamping surfaces are located on the front sides of the first and second clamping blocks, respectively.

[0048] The back sides of the first and second clamp block units are on the back sides of the first and second clamp seats;

[0049] The bottoms of the first and second chucks are connected to the ends of the piston rod via a sliding connection structure. For example, the end face of the piston rod is connected to a slide rail, and the bottoms of the first and second chucks each have a corresponding slide groove connected to the slide rail.

[0050] Specifically: the back of the first chuck block has a protrusion, and the front of the first chuck seat has a corresponding concave shape; the protrusion is embedded in the concave shape.

[0051] During implementation, the first and second limiting blocks are integral with the cylinder body, with the first and second limiting blocks located at the head of the cylinder body.

[0052] The principle of this chuck is that the piston inside the (hydraulic or pneumatic) cylinder extends forward, causing two test clamping blocks to extend forward as well. These blocks then move in opposite directions via an inclined plane, generating a clamping force to hold the conductor. The piston then retracts, causing the two clamping blocks to move backward and release the clamping force.

[0053] During testing: Each tensile testing machine is equipped with two test chucks, and each chuck is equipped with two clamping blocks. The clamping blocks are installed on the clamping block seat and can be replaced according to different specifications. The two clamping blocks in the set have different inner surface inclination angles. The inner surface inclination angle of one clamping block is the same as the included angle between the two sides of the sector-shaped metal conductor, and the inner surface of the other clamping block is tangent to the outer circle of the sector-shaped metal conductor. The inner surface of the clamping blocks is machined with anti-slip teeth with inclination angles. The (hydraulic) cylinder drives the clamping and releasing action of the pressure blocks by extension and retraction.

[0054] This test clamp effectively prevents conductor slippage and specimen breakage within the clamp during tensile testing. The clamp can be adapted to accommodate tensile requirements of specimens with different shapes by replacing the clamp blocks. Attached Figure Description

[0055] Figure 1a This is a schematic diagram of the axial cross-section of the conductor tension clamp in this embodiment;

[0056] Figure 1b yes Figure 1a A top-down view diagram;

[0057] Figure 2a This is a schematic diagram of the first or second chuck block;

[0058] Figure 2b yes Figure 2a The right view;

[0059] Figure 3 This is a schematic diagram of the first and second clamps;

[0060] Figure 4 It is an assembly drawing (exploded view) of the first or second chuck block;

[0061] Figure 5a This is a side view of the first chuck block;

[0062] Figure 5b yes Figure 5a The right and left views;

[0063] Figure 6a This is a front view of the second chuck block;

[0064] Figure 6b yes Figure 6a The right view;

[0065] Figure 7 This is a top view of the V-shaped clamp holding the sector-shaped metal conductor.

[0066] Figure 8 It is the cross-section of the V-shaped clamping block anti-slip teeth;

[0067] Figure 9 This is a flowchart illustrating the design method of the clamp for the tensile test of a sector-shaped metal conductor;

[0068] In the diagram: 1. Sealing flange; 2. First screw; 3. Piston; 4. Cylinder body; 5. Second screw; 6. Baffle; 7. Cylinder head; 8. Chuck seat; 9. Chuck block; 10. Lower cavity connector through hole; 11. Upper cavity connector through hole; 12. Sealing ring; 13. Positioning pin; 14. First clamping block; 15. First V-shaped surface (groove); 16. Weld; 17. Second clamping block; 18. Second V-shaped surface (groove); 19. Positioning pin; 20. First included angle of inclined surface; 21. Second included angle of inclined surface; 22. Sector-shaped metal conductor; 23. Anti-slip teeth; 24. Slide rail; 25. Protrusion; 26. Concave surface. Detailed Implementation

[0069] This section will describe in detail the specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention. However, they should not be construed as limiting the scope of protection of the present invention.

[0070] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limiting this invention.

[0071] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0072] In the description of this invention, unless otherwise explicitly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0073] The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0074] refer to Figure 9 A design method for a sector-shaped metal conductor tensile test clamp, comprising the following steps:

[0075] S1. Decomposition problem:

[0076] Question 1: A sector-shaped conductor has three clamping surfaces: two planes and one curved surface; therefore, a clamping block that conforms to the three clamping surfaces needs to be designed.

[0077] Question 2: The clamping action of the chuck block on the sector-shaped conductor comes from the radial force. Therefore, the clamping action can be completed by using a radial force application mechanism on the chuck block.

[0078] S2. Difficulty in solving Problem 1 and Problem 2:

[0079] The radial force application mechanism used for clamping in the existing tensile testing machine is an alternative method to solve problem two.

[0080] The solution to problem one is that a corresponding mechanism cannot be found on the existing tensile testing machine, and a completely new design is required;

[0081] Problem 1 is more difficult to solve than Problem 2, so let's solve Problem 1 first.

[0082] S3. Designing a chuck block to solve problem one:

[0083] To solve problem one, increase the contact area between the clamping surface of the chuck and the conductor, as well as the friction between them.

[0084] 1) Increase contact area: If the two straight sides of the conductor's sector-shaped cross-section are approximated to the two legs of an isosceles triangle, then the two sides of the conductor are supported by the same V-groove. The two sides of the V-groove are in contact with the two sides of the conductor, thus maximizing the contact area.

[0085] If the arc-shaped side of the conductor's sector-shaped cross-section is approximately an obtuse isosceles triangle with a large angle, then it is determined that the arc surface of the conductor is supported by another V-shaped groove. This V-shaped groove supports the arc surface of the conductor at two points, namely the tangent points. After compression, the arc-shaped side only undergoes slight deformation, and the deformation at the two points forms a large contact surface.

[0086] 2) Design anti-slip teeth for the clamping blocks:

[0087] The V-groove has reverse anti-slip teeth engraved on its side. After the conductor is compressed, the metal surface of the conductor is compressed and deformed by the anti-slip teeth, forming tooth marks that mesh with the anti-slip teeth.

[0088] It also includes the following steps:

[0089] S4. Design a clamping adjustment mechanism to solve problem two:

[0090] When the clamping block holds the conductor, the conductor's axis must remain unchanged; therefore, the two V-grooves clamp radially synchronously.

[0091] Due to the small overall structure of the chuck and the limited space required for its application, a radial synchronous linkage mechanism is not suitable. Therefore, the design utilizes the V-groove as a synchronous radial clamping mechanism, transforming a single axial linear motion into two synchronous, opposing radial linear motions.

[0092] 1) Axial linear motion mechanism: hydraulic cylinder, pneumatic cylinder or electric push rod;

[0093] The electric actuator has a fixed stroke, which can easily apply strong force to the conductor and damage it.

[0094] The medium in hydraulic and pneumatic cylinders is liquid or gas, which can be resisted by a conductor applying force, and this energy is absorbed by the compression of the pressure medium.

[0095] Compared to pneumatic pressure, hydraulic oil is superior because it circulates in a closed system and has a higher density, resulting in a more timely response.

[0096] 2) Vertical linear motion mechanism: It uses sliding between inclined planes to change the direction of the force;

[0097] The limit block and clamping block are designed to slide on an inclined plane. The limit block is fixed, and an axial force is applied to the clamping block. The limit block restricts the axial movement tendency of the clamping block, and the axial force is converted into radial movement and movement along the inclined plane.

[0098] The two sets of limit blocks and clamping blocks are at the same angle, which achieves synchronous relative radial linear motion.

[0099] In the design of the anti-slip teeth of the clamping block: the anti-slip teeth are distributed at an angle of 10 to 20 degrees with the horizontal direction. Compared with the horizontally distributed anti-slip gears, the anti-slip teeth have a larger contact area after biting the conductor, and the anti-slip effect is better. The single tooth height is 1 to 2 mm and the single tooth angle is 45 degrees.

[0100] refer to Figures 1a to 8 A fan-shaped metal conductor tensile test clamp includes a conductor clamping mechanism and a clamping degree adjustment mechanism.

[0101] The conductor clamping mechanism includes: a pair of first and second clamping block units; a clamping degree adjustment mechanism is connected to the two clamping block units respectively; the front of the two clamping block units is the clamping surface, the clamping surfaces face each other and the spacing is adjustable according to the clamping degree adjustment mechanism;

[0102] The clamping surfaces of both chuck block units are provided with grooves (as indicated by the first V-shaped surface 15 and the second V-shaped surface 18 in the attached figure); the radial cross-section of the groove is "V" shaped, and the length and width of the two sides of the groove are the same;

[0103] The bottom angles of the grooves on the two clamping surfaces (i.e., the included angles formed by the two sides of the grooves) are α (the first included angle 20 of the inclined plane as shown in the attached figure) and β (the second included angle 21 of the inclined plane as shown in the attached figure); the angle of α is smaller than the angle of β.

[0104] Anti-slip teeth 23 are engraved on both sides of the groove;

[0105] The clamping surfaces of the two clamping block units are close to each other, and the grooves on the two clamping surfaces enclose the space where the fan-shaped metal conductor 22 is located. The length direction of the groove is in the same direction as the axis of the fan-shaped metal conductor.

[0106] refer to Figure 2a , Figure 2b and Figure 8 There are multiple anti-slip teeth 23 on the same side of the groove. They are parallel helical teeth that form a helical rack shape. The helix angles of the helical teeth on the two sides of the same groove are opposite, and the angle formed by the corresponding helical teeth on the two sides points towards the insertion end of the sector-shaped metal conductor. The tooth tip of each anti-slip tooth faces the opposite direction to the insertion end of the sector-shaped metal conductor.

[0107] See again Figure 1a , Figure 1b The clamping adjustment mechanism includes a chuck block unit limiting mechanism and a hydraulic or pneumatic cylinder 4;

[0108] The piston rod of the cylinder is connected to the piston 3. The piston rod extends out of / retracts from the head of the cylinder along with the piston.

[0109] The clamping block unit limiting mechanism includes a pair of first and second limiting blocks (i.e., the position of cylinder head 7 marked in the attached figure), both limiting blocks are connected to the head of the cylinder; the front faces of the first and second limiting blocks face each other, and they are mirror symmetrical about plane a; and the position between them is where the first and second clamping block units are located;

[0110] exist Figure 1a , Figure 1b In the middle, the first and second chuck block units are composed of chuck seat 8 and chuck block 9.

[0111] The back sides of the first and second chuck block units are slidably connected to the front sides of the first and second limiting blocks, respectively; and the axial direction of the sector-shaped metal conductor is in the same direction as the axial direction of the cylinder body; the first and second chuck block units are slidably connected to the end of the piston rod, and the sliding direction is perpendicular to plane a.

[0112] The connection structure between the back of the first clamping block unit and the front of the first limiting block is as follows: the upper part of the back of the first clamping block unit is an inclined plane, and the angle between the inclined plane and plane a is γ; the upper part of the front of the first limiting block is an inclined plane, and the angle between the inclined plane and plane a is γ.

[0113] The connection structure between the back of the second clamping block unit and the front of the second positioning block is as follows: the upper part of the back of the second clamping block unit is an inclined plane, and the angle between the inclined plane and plane a is 180°-γ; the upper part of the front of the second positioning block is an inclined plane, and the angle between the inclined plane and plane a is 180°-γ.

[0114] The space enclosed by the front of the first and second limiting blocks is a space that is larger at the bottom and smaller at the top, with the smaller end of the space away from the cylinder body. The fan-shaped metal conductor is inserted from one side of the smaller end of the space.

[0115] Further reference Figures 2a to 6b The first and second chuck block units respectively include first and second chuck blocks (i.e., chuck block 9 in the attached drawing) and first and second chuck seats (i.e., chuck seat 8 in the attached drawing); the first chuck block is detachably connected to the first chuck seat; the second chuck block is detachably connected to the second chuck seat;

[0116] The clamping surfaces are located on the front sides of the first and second clamping blocks, respectively.

[0117] The back sides of the first and second clamp block units are on the back sides of the first and second clamp seats;

[0118] Further reference Figure 2a and Figure 2b The bottoms of the first and second chucks are connected to the end of the piston rod on top of the piston 3 via a sliding connection structure. The end face of the piston rod is connected to a slide rail 24, and the bottoms of the first and second chucks are respectively provided with slide grooves that correspond to the slide rails.

[0119] The back of the first chuck block has a protrusion of 25, for further reference. Figure 3 The front of the first chuck has a recess 26 corresponding to the protrusion; the protrusion is embedded in the recess.

[0120] In this example, the first and second limiting blocks are integral with the cylinder body, and the first and second limiting blocks are located at the head of the cylinder body.

[0121] The engineering implementation method of this clamp is as follows:

[0122] 1) Referring to Figure 1, the selected hydraulic telescopic structure consists of cylinder 4, piston 5, and sealing flange 1:

[0123] The piston is assembled in the cylinder body. The piston has a sealing ring 12 and divides the cylinder body into an upper chamber and a lower chamber. There are two holes on the cylinder body (lower chamber connector through hole 10 and upper chamber connector through hole 11) corresponding to the upper chamber and the lower chamber, and they are connected to the oil circuit through the oil pipe connector.

[0124] The upper chamber is formed by the piston and cylinder, and the lower chamber is formed by the piston, cylinder, and sealing flange.

[0125] 2) Referring to Figure 1, the piston moves axially in the cylinder. There is a boss on the top surface of the sealing flange 1. The piston's downward position is limited by the boss on the sealing flange. In addition, there is an inner circular step in the cylinder 4. The piston's upward position is limited by the inner step in the cylinder, thus determining the piston stroke.

[0126] 3) Referring to Figure 1, the hydraulic cylinder head 7 (i.e. the first and second limit blocks) is provided with an inclined surface, and one side of the chuck seat (the first and second chuck seats) is also in the form of an inclined surface. When the piston pushes the chuck seat axially, the two chucks clamp in the horizontal direction.

[0127] Refer to the machining of a T-shaped platform on the piston 2, and a T-shaped groove on the bottom of the chuck seat. The dimensions of the T-shaped platform and the T-shaped groove are matched, and the two chuck seats can slide in the axial direction of the T-shaped platform. The angle of the inclined surface inside the opening of the hydraulic cylinder is the same as that of the inclined surface of the chuck seat.

[0128] 4) Design the angle of the V-shaped surface (groove) of the clamping block:

[0129] Design principle: Maximize the contact area between the inner inclined surface of the V-shaped clamp and the fan-shaped sample;

[0130] refer to Figure 7 Asymmetrical V-shaped chucks matching the fan-shaped pattern are machined. The first included angle 20 of the inclined surface of the first V-shaped surface (groove) 15 is the same as the angle of the fan-shaped sample, and the two sides of the second V-shaped surface (groove) 18 are tangent to the arc of the fan.

[0131] 5) Design of anti-slip teeth 23 on the clamping block:

[0132] Design principle: To prevent slippage of the sample during tensile testing, anti-slip teeth should be designed on the inclined surface of the clamping block;

[0133] refer to Figures 5a-6b as well as Figure 8 The anti-slip teeth are distributed at an angle of 10 to 20 degrees to the horizontal direction, with a single tooth height of 1 to 2 mm and a single tooth angle of 45 degrees.

[0134] refer to Figures 5a-6b Figure 6 shows a protrusion 25 on the back of the chuck block that can be inserted into the recess 26 of the chuck block seat.

[0135] refer to Figure 4 During the machining of the chuck block, the chuck block body and the V-shaped surface can be machined separately. The connecting support part of the chuck block is machined using a conventional planer or milling machine, and the V-shaped surface is machined using a conventional planer or milling machine, followed by wire EDM machining of the anti-slip teeth. The connecting support part and the V-shaped surface are assembled using a boss and recess, and finally, holes are drilled and locating pins are used for insertion.

[0136] The clamping device of this method can be adapted to the tensile requirements of specimens of different shapes by changing the clamping blocks.

[0137] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A design method for a sector-shaped metal conductor tensile test clamp, characterized in that: Including the following steps: S1. Decomposition problem: Question 1: A sector-shaped conductor has three clamping surfaces: two planes and one curved surface; therefore, a clamping block that conforms to the three clamping surfaces needs to be designed. Question 2: The clamping action of the chuck block on the sector-shaped conductor comes from the radial force. Therefore, the clamping action can be completed by using a radial force application mechanism on the chuck block. S2. Difficulty in solving Problem 1 and Problem 2: The radial force application mechanism used for clamping in the existing tensile testing machine is an alternative method to solve problem two. The solution to problem one is that a corresponding mechanism cannot be found on the existing tensile testing machine, and a completely new design is required; Problem 1 is more difficult to solve than Problem 2, so let's solve Problem 1 first. S3. Designing a chuck block to solve problem one: To solve problem one, increase the contact area between the clamping surface of the chuck and the conductor, as well as the friction between them. 1) Increase contact area: If the two straight sides of the conductor's sector-shaped cross-section are approximated to the two legs of an isosceles triangle, then the two sides of the conductor are supported by the same V-groove. The two sides of the V-groove are in contact with the two sides of the conductor, thus maximizing the contact area. If the arc-shaped side of the conductor's sector-shaped cross-section is approximately an obtuse isosceles triangle with a large angle, then it is determined that the arc surface of the conductor is supported by another V-shaped groove. This V-shaped groove supports the arc surface of the conductor at two points, namely the tangent points. After compression, the arc-shaped side only undergoes slight deformation, and the deformation at the two points forms a large contact surface. 2) Design anti-slip teeth for the clamping blocks: The V-groove has reverse anti-slip teeth engraved on its side. After the conductor is compressed, the metal surface of the conductor is compressed and deformed by the anti-slip teeth, forming tooth marks that mesh with the anti-slip teeth. S4. Design a clamping adjustment mechanism to solve problem two: When the clamping block holds the conductor, the conductor's axis must remain unchanged; therefore, the two V-grooves clamp radially synchronously. Due to the small overall structure of the chuck and the limited space required for its application, a radial synchronous linkage mechanism is not suitable. Therefore, the design utilizes the V-groove as a synchronous radial clamping mechanism, transforming a single axial linear motion into two synchronous, opposing radial linear motions. 1) Axial linear motion mechanism: hydraulic cylinder, pneumatic cylinder or electric push rod; The electric actuator has a fixed stroke, which can easily apply strong force to the conductor and damage it. The medium in hydraulic and pneumatic cylinders is liquid or gas. A conductor applies force to it to resist the force, and the energy is absorbed by the compression of the pressure medium. Compared to pneumatic pressure, hydraulic oil is superior because it circulates in a closed system and has a higher density, resulting in a more timely response. 2) Vertical linear motion mechanism: It uses sliding between inclined planes to change the direction of the force; The limit block and clamping block are designed to slide on an inclined plane. The limit block is fixed, and an axial force is applied to the clamping block. The limit block restricts the axial movement tendency of the clamping block, and the axial force is converted into radial movement and movement along the inclined plane. The two sets of limit blocks and clamping blocks are at the same angle, which achieves synchronous relative radial linear motion.

2. The design method of the sector-shaped metal conductor tensile test clamp according to claim 1, characterized in that: The engineering implementation method for designing the chuck using the aforementioned design method is as follows: 1) The selected hydraulic telescopic structure consists of a cylinder (4), a piston (5), and a sealing flange (1): The piston is assembled in the cylinder body. The piston has a sealing ring (12). The piston divides the cylinder body into an upper chamber and a lower chamber. There are two holes in the cylinder body, namely the lower chamber connector through hole (10) corresponding to the lower chamber and the upper chamber connector through hole (11) corresponding to the upper chamber. The two holes are connected to the oil circuit through the oil pipe connector. The upper chamber is formed by the piston and cylinder, and the lower chamber is composed of the piston, cylinder, and sealing flange; 2) The piston moves axially in the cylinder. There is a boss on the top surface of the sealing flange (1). The piston moves down and is limited by the boss on the sealing flange. There is an inner circular step in the cylinder (4). The piston moves up and is limited by the step in the cylinder. Thus, the piston stroke is determined. 3) The hydraulic cylinder head (7) is provided with inclined surfaces, namely the first and second limit blocks, and one side of the first and second chuck seats is also in the form of an inclined surface. When the piston pushes the chuck seats axially, the two chucks clamp in the horizontal direction. A T-shaped platform is machined on the piston, and a T-shaped groove is machined on the bottom of the chuck seat. The dimensions of the T-shaped platform and the T-shaped groove are matched, and the two chuck seats slide in the axial direction of the T-shaped platform. The angle between the inner inclined surface of the hydraulic cylinder opening and the inclined surface of the chuck seat is the same. 4) Design the V-shaped surface of the clamping block, i.e., the angle of the groove: The contact area between the inner inclined surface of the V-shaped clamp and the fan-shaped sample should be maximized; Asymmetrical V-shaped chucks matching the fan-shaped shape are processed, wherein the first included angle (20) of the inclined surface of the first V-shaped surface (15) is the same as the angle of the fan-shaped sample, and the two sides of the second V-shaped surface (18) are tangent to the arc of the fan-shaped sample; 5) Design anti-slip teeth for the clamping blocks (23): To prevent slippage of the sample during tensile testing, anti-slip teeth should be designed on the inclined surface of the clamping block. The anti-slip teeth are distributed at an angle of 10 to 20 degrees to the horizontal direction, with a single tooth height of 1 to 2 mm and a single tooth angle of 45 degrees. The back of the chuck block has a protrusion (25) to insert into the recess (26) of the chuck block seat; During the machining of the chuck block, the chuck block body and the V-shaped surface are machined separately. The connecting support part of the chuck block is machined with a conventional planer or milling machine, and the V-shaped surface is machined with a conventional planer or milling machine and then anti-slip teeth are machined with wire EDM. The connecting support part and the V-shaped surface are assembled with a boss and concave platform and finally drilled and inlaid with locating pins. The clamping device can be adapted to the tensile requirements of specimens of different shapes by changing the clamping blocks.

3. A sector-shaped metal conductor tensile test clamp, comprising a conductor clamping mechanism and a clamping degree adjustment mechanism, characterized in that... The conductor clamping mechanism includes: a pair of first and second clamping block units; a clamping degree adjustment mechanism is connected to the two clamping block units respectively; the front of the two clamping block units is the clamping surface, the clamping surfaces face each other and the spacing is adjustable according to the clamping degree adjustment mechanism; The clamping surfaces of both chuck block units are provided with grooves; the radial cross-section of the groove is V-shaped, and the length and width of the two sides of the groove are the same; The bottom angles of the grooves on the two clamping surfaces are α and β, respectively; the angle of α is smaller than the angle of β. Anti-slip teeth are engraved on both sides of the groove; the anti-slip teeth are distributed at an angle of 10 to 20 degrees with the horizontal direction; The clamping surfaces of the two clamping block units are close to each other, and the grooves on the two clamping surfaces enclose the space where the fan-shaped metal conductor is located. The length direction of the groove is in the same direction as the axis of the fan-shaped metal conductor. The clamping adjustment mechanism includes a clamp block unit limiting mechanism and a hydraulic or pneumatic cylinder. The piston rod of the cylinder is connected to the piston, and the piston rod extends out of or retracts from the head of the cylinder along with the piston. The clamp block unit limiting mechanism includes a pair of first and second limiting blocks, both of which are connected to the head of the cylinder; the front faces of the first and second limiting blocks face each other and they are mirror-symmetrical about plane a; and the position between them is where the first and second clamp block units are located; The back sides of the first and second chuck block units are slidably connected to the front sides of the first and second limiting blocks, respectively; and the axial direction of the sector-shaped metal conductor is in the same direction as the axial direction of the cylinder body; the first and second chuck block units are slidably connected to the end of the piston rod, and the sliding direction is perpendicular to plane a. The connection structure between the back of the first clamping block unit and the front of the first limiting block is as follows: the upper part of the back of the first clamping block unit is an inclined plane, and the angle between the inclined plane and plane a is γ; the upper part of the front of the first limiting block is an inclined plane, and the angle between the inclined plane and plane a is γ. The connection structure between the back of the second clamping block unit and the front of the second positioning block is as follows: the upper part of the back of the second clamping block unit is an inclined plane, and the angle between the inclined plane and plane a is 180°-γ; the upper part of the front of the second positioning block is an inclined plane, and the angle between the inclined plane and plane a is 180°-γ. The space enclosed by the front of the first and second limiting blocks is a space that is larger at the bottom and smaller at the top, with the smaller end of the space away from the cylinder body. The fan-shaped metal conductor is inserted from one side of the smaller end of the space.

4. The sector-shaped metal conductor tensile test clamp according to claim 3, characterized in that: There are multiple anti-slip teeth on the same side of the groove. They are parallel helical teeth that form a helical rack shape. The helix angles of the helical teeth on the two sides of the same groove are opposite, and the corresponding helical teeth on the two sides form an angle pointing towards the insertion end of the fan-shaped metal conductor.

5. The sector-shaped metal conductor tensile test clamp according to claim 3, characterized in that: The tip of each anti-slip tooth faces the opposite direction to the insertion end of the sector-shaped metal conductor.

6. The sector-shaped metal conductor tensile test clamp according to claim 3, characterized in that: The first and second chuck block units each include a first and a second chuck block and a first and a second chuck seat; the first chuck block is detachably connected to the first chuck seat; the second chuck block is detachably connected to the second chuck seat. The clamping surfaces are located on the front sides of the first and second clamping blocks, respectively. The back sides of the first and second clamp block units are on the back sides of the first and second clamp seats; The bottom of the first and second chuck seats is connected to the end of the piston rod via a sliding connection structure.

7. The sector-shaped metal conductor tensile test clamp according to claim 6, characterized in that: The back of the first chuck block has a protrusion, and the front of the first chuck seat has a corresponding concave shape, with the protrusion embedded in the concave shape.

8. The sector-shaped metal conductor tensile test clamp according to claim 3, characterized in that: The first and second limiting blocks are integral with the cylinder body, and the first and second limiting blocks are located at the head of the cylinder body.

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