An umbrella-shaped plastic corrugated pipe drawing force test clamping device

Abstract

The present invention relates to a clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe, which includes a testing machine, a first plastic corrugated pipe joint clamping device and a second plastic corrugated pipe joint clamping device. A plastic corrugated pipe joint assembly is placed between the first plastic corrugated pipe joint clamping device and the second plastic corrugated pipe joint clamping device. Both the first plastic corrugated pipe joint clamping device and the second plastic corrugated pipe joint clamping device include a central main pulling screw rod, a clamping range adjusting structure and a clamping structure. The top end of the central main pulling screw rod is connected to the testing machine and is non-rotatable itself. A sleeve is sleeved on the outer periphery of the central main pulling screw rod. The sleeve is connected with a top rod through the clamping range adjusting structure, and the top of the top rod is hinged with an arc-shaped inner lining strip. The present invention transmits the force to the inner wall of the plastic corrugated pipe through the top rods around the central main pulling screw rod of the clamping device, and adjusts the clamping range through a structure similar to an umbrella shape to meet the need of clamping plastic corrugated pipes with different pipe diameters.

Description

Technical Field

[0001] The present invention relates to the technical field of test equipment, and particularly to a clamping device for the drawing force test of umbrella-shaped plastic corrugated pipes. Background Art

[0002] A general corrugated pipe tensile test fixture is disclosed in Chinese Patent (Application No.: 201510618935.0), which includes a pull rod, a shaft, a support base, a support arm and a fixed clamp. A pull ring is provided at the top end of the pull rod. The pull rod is connected to the shaft, and the shaft is connected to the support base. The support arm is hinged to the support base by bolts, and the fixed clamp is hinged to the support arm. An activity plate and a fixed plate are provided at the bottom end of the fixed clamp. The activity plate is slidably connected to the fixed plate and fixed by bolts.

[0003] A prestressed corrugated pipe tensile property test fixture is disclosed in Chinese Patent (Application No.: 201920840296.6), which includes a tapered column, a tapered sleeve, a connecting rod and a stop block. The tapered sleeve is circumferentially divided into multiple structures and is movably sleeved on the tapered surface of the tapered column. The connecting rod is a stepped shaft structure with a large outer end and a small inner end. After passing through the tapered column, the inner end is spirally connected to the stop block. The stop block abuts against the inner end of the tapered sleeve. After the stop block rotates through the connecting rod, the tapered sleeve can be opened to lock the corrugated pipe. A plug hole for installing a tensile meter tester is provided at the large end of the connecting rod.

[0004] A fixture for the corrugated pipe tensile test is disclosed in Chinese Patent (Application No.: 201721327728.0), which includes: an outer tightening ring provided on the outer surfaces at both ends of the corrugated pipe, and it includes at least three arc-shaped members surrounding the corrugated pipe; a ring buckle steel belt which surrounds the outer surface of the outer tightening ring and is fastened by bolts; an inner support ring whose outer diameter has an interference fit with the inner diameter of the corrugated pipe and is inserted into both ends of the corrugated pipe. The inner support ring and the outer tightening ring cooperate to clamp the corrugated pipe; the inner diameter of the inner support ring continuously decreases from the inside towards the port direction of the corrugated pipe; a pull rod which includes a conical frustum that matches the internal shape of the inner support ring and has an interference fit and a section connecting the test machine rod, and the conical frustum and the rod are integrally formed.

[0005] The defects of the above three solutions are as follows: The first treatment method: The biggest difficulty lies in the reliability of the connection between the activity plate and the corrugated pipe. How to ensure its firm clamping, because when the plastic corrugated pipe is stressed, it is very likely that the clamping will become loose due to the deformation of the clamping part of the corrugated pipe. The patent solution does not elaborate on this key point. The second treatment method: The opening range of the tapered sleeve is limited. For the drawing force tests of plastic corrugated pipes of different specifications, corresponding matching outer tightening rings and inner support rings need to be equipped. The matching requirements are high and it is not economical. When installing the corrugated pipe on the outer tightening ring, the ring buckle steel belt needs to be disassembled and installed every time, which affects the test work efficiency. Summary of the Invention

[0006] The object of the present invention is to provide a clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe, so as to solve the problems put forward in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe includes a testing machine, a first plastic corrugated pipe joint clamping device, and a second plastic corrugated pipe joint clamping device. A plastic corrugated pipe joint assembly is placed between the first plastic corrugated pipe joint clamping device and the second plastic corrugated pipe joint clamping device. Both the first plastic corrugated pipe joint clamping device and the second plastic corrugated pipe joint clamping device include a central main pulling screw rod, a clamping range adjusting structure, and a clamping structure. The top end of the central main pulling screw rod is connected to the testing machine and is not rotatable by itself. A sleeve is sleeved on the outer periphery of the central main pulling screw rod. The sleeve is connected to a top rod through the clamping range adjusting structure. The top of the top rod is hinged with an arc-shaped inner lining strip.

[0009] As a further scheme of the present invention: The clamping range adjusting structure includes a sleeve ear plate, a pull rod, and a pull rod lower bolt. The sleeve ear plate is fixed on the sleeve. The pull rod is rotatably connected to the sleeve ear plate. One end of the pull rod away from the sleeve ear plate is rotatably connected to the pull rod lower bolt. A central main pulling screw rod ear plate is provided at the lower end of the central main pulling screw rod. The pull rod lower bolt is rotatably connected to the central main pulling screw rod ear plate. A top rod lower bolt is connected between the top rod and the central main pulling screw rod ear plate.

[0010] As a further scheme of the present invention: A top rod upper bolt is connected between the arc-shaped inner lining strip and the top rod.

[0011] As a further scheme of the present invention: A screw rod nut is provided at the upper end of the sleeve. The screw rod nut is sleeved on the outer periphery of the central main pulling screw rod. A handle is fixed on the outer periphery of the screw rod nut.

[0012] As a further scheme of the present invention: A limit movable table is provided at one end of the sleeve close to the screw rod nut. A limit movable groove for the limit movable table to move is provided on one side of the screw rod nut close to the sleeve.

[0013] As a further scheme of the present invention: The thickness of the limit movable table is m, and 2 cm ≤ m ≤ 5 cm.

[0014] As a further scheme of the present invention: The included angle between the top rod and the horizontal direction is α, and 30° ≤ α ≤ 70°.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: It ensures that the plastic corrugated pipe can be effectively clamped during the drawing force test of the plastic corrugated pipe. When the plastic corrugated pipe is clamped and stretched, even if the plastic corrugated pipe is deformed, it can still ensure that the sample pipe section is uniformly and effectively stressed, and stress concentration will not occur, resulting in the damage of the plastic corrugated pipe or the loosening of the clamping area, which affects the test results. The device of the present invention can quickly adjust the clamping range of the clamping device for plastic corrugated pipes of different specifications, and only need to install a matching clamping device according to the pipe diameter range of the corrugated pipe. When the device of the present invention is used for the drawing force test of the plastic corrugated pipe, it is convenient to install and disassemble the sample, and no additional auxiliary fixture needs to be installed, with high working efficiency. In summary, the device of the present invention can effectively complete the test with high working efficiency, economy and reliability, and can make up for the deficiencies of the existing solutions. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the clamping device for the drawing force test of the umbrella-shaped plastic corrugated pipe described in the present invention;

[0017] Figure 2 It is a schematic diagram of the connection mode between the screw nut and the sleeve in the clamping device for the drawing force test of the umbrella-shaped plastic corrugated pipe described in the present invention;

[0018] Figure 3 It is a schematic diagram when the clamping device for the drawing force test of the umbrella-shaped plastic corrugated pipe described in the present invention adjusts the corrugated pipe;

[0019] Figure 4 It is a schematic diagram of the overall structure of the clamping device for the drawing force test of the umbrella-shaped plastic corrugated pipe described in the present invention.

[0020] In the figure: 1, central main pulling screw rod; 2, screw nut; 3, handle; 4, sleeve; 5, sleeve ear plate; 6, circular arc-shaped inner lining strip; 7, ejector rod; 8, central main pulling screw rod ear plate; 9, lower bolt of ejector rod; 10, lower bolt of pull rod; 11, upper bolt of ejector rod; 12, pull rod; 13, upper bolt of pull rod; 14, first plastic corrugated pipe section clamping device; 15, plastic corrugated pipe section assembly; 16, second plastic corrugated pipe section clamping device; 17, testing machine; 18, limit moving groove; 19, limit moving table. Detailed Embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0022] Please refer to Figures 1 to 4, in the embodiments of the present invention, a clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe includes a testing machine 17, a first plastic corrugated pipe joint clamping device 14 and a second plastic corrugated pipe joint clamping device 16. A plastic corrugated pipe joint assembly 15 is placed between the first plastic corrugated pipe joint clamping device 14 and the second plastic corrugated pipe joint clamping device 16. The first plastic corrugated pipe joint clamping device 14 and the second plastic corrugated pipe joint clamping device 16 both include a central main pulling screw rod 1, a clamping range adjusting structure and a clamping structure. The top end of the central main pulling screw rod 1 is connected to the testing machine 17 and is non-rotatable itself. A sleeve 4 is sleeved on the outer periphery of the central main pulling screw rod 1. The sleeve 4 is connected to a top rod 7 through the clamping range adjusting structure. The top of the top rod 7 is hinged to an arc-shaped inner lining strip 6. The clamping range adjusting structure includes a sleeve 4 ear plate, a pull rod 12 and a pull rod 12 lower bolt 10. The sleeve 4 ear plate is fixed on the sleeve 4. The pull rod 12 is rotatably connected to the sleeve 4 ear plate. One end of the pull rod 12 away from the sleeve 4 ear plate is rotatably connected to the pull rod 12 lower bolt 10. The lower end of the central main pulling screw rod 1 is provided with a central main pulling screw rod 1 ear plate. The pull rod 12 lower bolt 10 is rotatably connected to the central main pulling screw rod 1 ear plate. A top rod 7 lower bolt is connected between the top rod 7 and the central main pulling screw rod 1 ear plate. A top rod 7 upper bolt is connected between the arc-shaped inner lining strip 6 and the top rod 7. The upper end of the sleeve 4 is provided with a screw rod nut 2. The screw rod nut 2 is sleeved on the outer periphery of the central main pulling screw rod 1. A handle 3 is fixed on the outer periphery of the screw rod nut 2. The sleeve 4 is provided with a limit movable table 19 near the screw rod nut 2. The screw rod nut 2 is provided with a limit movable groove 18 for the limit movable table 19 to move on one side close to the sleeve 4.

[0023] During use, when conducting a drawing force test on a plastic corrugated pipe on a testing machine, the following steps are carried out: (1) Sampling of the plastic corrugated pipe. If the test object is an assembled part, it needs to be assembled by pipe fittings and pipes, and the length of each pipe section is at least 300 mm; (2) Install this clamping device on the testing machine and adjust the distance between the clamping devices, slightly longer than the length of the plastic corrugated pipe assembly; (3) First, put the corrugated pipe into the lower clamping device, rotate the screw rod nut through the hand rod, open the top rods around the central main pulling screw rod, adjust the clamping device to a suitable range, so that the four hinged arc-shaped inner lining strips of the clamping device just fit the annular thread recessed in the inner wall of the corrugated pipe; (4) Use the testing machine to adjust the distance between the upper and lower clamping devices, and install the upper clamping device according to step (3); (5) Start the test program; (6) After the test is completed, rotate the screw rod nut in the reverse direction with the hand rod to retract the top rods around the central main pulling screw rod; (7) Take out the damaged specimen.

[0024] This device ensures that the plastic corrugated pipe can be effectively clamped during the drawing force test. When the plastic corrugated pipe is clamped and stretched, even if the plastic corrugated pipe deforms, it can still ensure that the sample pipe section is uniformly and effectively stressed, and stress concentration will not occur, resulting in the damage of the plastic corrugated pipe or the loosening of the clamping area, which will affect the test results. This device can quickly adjust the clamping range of the clamping device for plastic corrugated pipes of different specifications. It only needs to install a matching clamping device according to the pipe diameter range of the corrugated pipe. When this device is used in the drawing force test of the plastic corrugated pipe, it is convenient to install and disassemble the sample, and there is no need to install additional auxiliary fixtures, so the working efficiency is high.

[0025] In this embodiment, the thickness of the limit movable table 19 is m, and 2 cm ≤ m ≤ 5 cm. Specifically, in this embodiment, m is 3.5 cm, so as to ensure the stability of the limit movable table 19 during movement. It can be understood that m can also be 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm, etc.

[0026] In this embodiment, the included angle between the ejector rod 7 and the horizontal direction is α, and 30° ≤ α ≤ 70°. Specifically, in this embodiment, α is 50°. With such a setting, a larger adjustable range of the ejector rod 7 during support can be ensured. It can be understood that α can also be 30°, 35°, 40°, 45°, 55°, 60°, 65°, 70°, etc.

[0027] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0028] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An umbrella-shaped plastic corrugated pipe drawing force test clamping device, characterized in that, It includes a testing machine, a first clamping device for plastic corrugated pipe joints and a second clamping device for plastic corrugated pipe joints. A plastic corrugated pipe joint assembly is placed between the first clamping device for plastic corrugated pipe joints and the second clamping device for plastic corrugated pipe joints. Both the first clamping device for plastic corrugated pipe joints and the second clamping device for plastic corrugated pipe joints include a central main pulling screw rod, a clamping range adjusting structure and a clamping structure. The top end of the central main pulling screw rod is connected to the testing machine and is non-rotatable itself. A sleeve is sleeved on the outer periphery of the central main pulling screw rod. The sleeve is connected to a push rod through the clamping range adjusting structure. The top of the push rod is hinged with an arc-shaped inner lining strip. The clamping range adjusting structure includes a sleeve ear plate, a pull rod and a lower pull rod bolt. The sleeve ear plate is fixed on the sleeve. The pull rod is rotatably connected to the sleeve ear plate. One end of the pull rod away from the sleeve ear plate is rotatably connected to the lower pull rod bolt. A central main pull screw rod ear plate is provided at the lower end of the central main pull screw rod. A lower push rod bolt is connected between the push rod and the central main pull screw rod ear plate. The lower push rod bolt is rotatably connected to the central main pull screw rod ear plate. The number of the pull rods, push rods and arc-shaped lining strips is 4 each. An upper push rod bolt is connected between the arc-shaped inner lining strip and the push rod.

2. The clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe according to claim 1, wherein A screw rod nut is provided at the upper end of the sleeve. The screw rod nut is sleeved on the outer periphery of the central main pull screw rod. A handle is fixed on the outer periphery of the screw rod nut.

3. The clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe according to claim 1, wherein, A limit movable table is provided at one end of the sleeve close to the screw rod nut. A limit movable groove for the limit movable table to move is provided on one side of the screw rod nut close to the sleeve.

4. The clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe according to claim 3, characterized in that, The thickness of the limit movable table is m, and 2 cm ≤ m ≤ 5 cm.

5. The clamping device for the drawing force test of an umbrella-shaped plastic corrugated pipe according to claim 1, characterized in that, The included angle between the push rod and the horizontal direction is α, and 30° ≤ α ≤ 70°.

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