Tension detection device for high-strength bolt

Abstract

The tension detection device comprises a detection barrel and a hydraulic cylinder installed at one end of the detection barrel, a tension block is movably arranged in the detection barrel and is provided with a containing cavity, and the two ends of a rod penetrating hole are communicated with the containing cavity and the end face, penetrating through the tension block and deviating from the hydraulic cylinder, of the rod penetrating hole respectively; the end plate is fixed to the end, away from the hydraulic cylinder, of the detection cylinder and provided with a limiting hole, an inlet-outlet is formed in the detection cylinder, and the containing cavity and the rod penetrating hole are each provided with an opening facing the inlet-outlet. The drum rotatably sleeves the outer peripheral surface of the detection cylinder and is provided with a notch, and the inlet / outlet can be closed or opened by rotating the drum; a piston rod of the hydraulic cylinder is fixed on the tension block; and a hydraulic valve and a pressure gauge are mounted on a hydraulic pipe of the hydraulic cylinder. The rotary drum and the remote control piston cylinder are utilized, so that the damage of fragments generated after the to-be-tested bolt is broken is avoided; the tension borne by the bolt is obtained through the pressure gauge on the hydraulic pipe, and data errors caused by eccentricity of a dynamometer and a traction screw in the prior art are avoided.

Description

Technical Field

[0001] This utility model relates to a tensile testing device for high-strength bolts. Background Technology

[0002] High-strength bolts for steel structures are widely used in steel structures for the construction of industrial and civil facilities such as railways, highway bridges, industrial plants, civil buildings, and machinery. The mechanical properties and quality of high-strength bolts have a significant impact on the safety of steel structures. Therefore, it is necessary to test various performance parameters of high-strength bolts to ensure product quality and safety.

[0003] like Figure 5 As shown, the existing bolt tensile strength testing equipment includes a mounting box 81 with an open top and roughly rectangular shape. A positioning block 85 is slidably disposed in the inner cavity of the mounting box 81 and can move along the length of the mounting box. A traction screw 86 extends along the length of the mounting box, with one end of the traction screw 86 extending into the inner cavity of the mounting box and fixed to the positioning block 85. The other end of the traction screw 86 extends outward from the mounting box and is screwed with a positioning cylinder 83. A force gauge 82 is sleeved on the traction screw between the positioning cylinder 83 and the mounting box. A tension cavity 84 and a screw groove 87 connecting the inside and outside of the tension cavity are provided in the positioning block. The screw groove passes through the side wall of the tension cavity away from the force gauge. A guide groove 88 is provided on the end plate of the mounting box away from the force gauge. The tension cavity 84, screw groove 87 and guide groove 88 all have upward openings. The bolt head A92 of the bolt A90 to be tested is accommodated in the tension cavity. The screw A91 of the bolt A90 to be tested passes through the screw groove and the guide groove and is screwed with a traction nut 93. The traction nut presses against the outer wall of the mounting box 81 away from the force gauge 82. Rotating the traction nut can stretch the bolt A90 to be tested. The tension force on the bolt A90 to be tested can be obtained according to the force gauge, and thus the strength of the bolt A90 to be tested can be obtained.

[0004] When using the above equipment to test the strength of bolts, the tester needs to tighten the traction nut 93. When the bolt A90 to be tested breaks, metal fragments may sometimes fly out, which can easily cause injury to the tester. In addition, during the test, the force gauge is prone to being eccentric with the traction screw, resulting in unstable test data. Utility Model Content

[0005] To address the problems in existing technologies, such as the potential for injury to testing personnel due to flying metal fragments when the bolt breaks, and the instability of test data caused by the force gauge easily becoming misaligned with the traction screw, this application proposes a tensile testing device for high-strength bolts. The device includes a testing cylinder and a hydraulic cylinder. The central axis of the testing cylinder extends along a first axis direction. The cylinder barrel is detachably mounted on one end of the testing cylinder along the first axis direction. A tension block is movably disposed inside the testing cylinder, and the tension block has a receiving cavity. One end of the rod hole communicates with the receiving cavity. The other end of the rod hole passes through the end face of the tension block away from the hydraulic cylinder; an end plate is fixed at the end of the detection cylinder away from the hydraulic cylinder, and a limiting hole extending along the first axis is provided on the end plate. An inlet and outlet are provided on the side wall of the detection cylinder, and both the receiving cavity and the rod hole have openings facing the inlet and outlet; a rotating cylinder is rotatably fitted on the outer circumferential surface of the detection cylinder, and a notch is provided on the rotating cylinder. Rotating the rotating cylinder can make the notch connect the inlet and outlet, and the bolt to be tested can enter the detection cylinder through the notch and the inlet and outlet. Rotating the rotating cylinder again can make the rotating cylinder cover the inlet and outlet.

[0006] After the piston rod of the hydraulic cylinder extends freely into the detection cylinder, it is fixed on the tension block. Driven by the piston rod, the tension block can reciprocate along the first axis inside the detection cylinder. A hydraulic valve and a pressure gauge are installed on the hydraulic pipe of the hydraulic cylinder.

[0007] When using this method, firstly, rotate the drum to connect the notch of the drum to the inlet / outlet. Then, start the hydraulic cylinder and adjust the position of the piston rod so that the bolt to be tested can enter the testing cylinder. Pause the operation of the hydraulic cylinder and feed the bolt to be tested sequentially through the notch and the inlet / outlet into the inner cavity of the testing cylinder, ensuring that the bolt head enters the receiving cavity. Insert the bolt shank into the through-hole, and after the bolt passes through the limiting hole along the first axis, tighten the positioning nut. Then, rotate the drum again to cover the inlet / outlet. Then, start the hydraulic cylinder again to retract the piston rod, stretching the bolt to be tested and measuring its tensile strength. Use a hydraulic gauge to obtain the tensile force on the bolt.

[0008] During the testing process, after installing the bolt to be tested, the operator can move away from the testing cylinder and remotely control the movement of the piston rod using the hydraulic valve on the hydraulic pipe connected to the hydraulic cylinder. Even if the bolt breaks and produces fragments, the fragments are retained inside the testing cylinder due to the obstruction of the rotating cylinder, preventing injury to the operator. Because the tension on the bolt is obtained through a pressure gauge on the hydraulic pipe during testing, the data error caused by the eccentricity between the force gauge and the traction screw, as in existing technologies, is avoided.

[0009] Specifically, to prevent the bolt from twisting during the tensioning process and affecting the test data, the receiving cavity, the through hole, and the limiting hole are coaxially arranged.

[0010] Specifically, for ease of disassembly, an end cap is detachably installed at one end of the testing cylinder near the hydraulic cylinder, and the cylinder barrel of the hydraulic cylinder is fixed on the end cap.

[0011] Furthermore, to facilitate the stabilization of the rotating drum, a flange is provided at one end of the testing drum near the hydraulic cylinder, and an end cover is detachably installed on the flange. Annular grooves are provided on both the flange and the end plate, and the two ends of the rotating drum are respectively inserted into an annular groove.

[0012] Specifically, for ease of disassembly, the piston rod of the hydraulic cylinder is screwed onto the tension block using a threaded method.

[0013] Specifically, the tension block includes a body, a tension cylinder, and a support plate. The tension cylinder is fixed to the side of the body away from the hydraulic cylinder, and its inner cavity forms a receiving cavity with an opening that radially penetrates the cylinder. The support plate is fixed to the end of the tension cylinder away from the body, and a rod-through hole is provided on the support plate with an opening that radially penetrates the outer circumferential surface of the support plate. This design allows the bolts to be tested to be installed in place individually.

[0014] Specifically, to facilitate the installation of the bolt to be tested, the openings of the receiving cavity and the through hole face the same direction.

[0015] Furthermore, to reduce the amount of processing required for the equipment, the main body, tension cylinder, and support plate are integrated into a single structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of this application.

[0017] Figure 2 yes Figure 1 A view from the center AA direction.

[0018] Figure 3 This is a schematic diagram of the tension block.

[0019] Figure 4 yes Figure 3 A view from the center (BB direction).

[0020] Figure 5 This is a simplified diagram of existing bolt tensile strength testing equipment. Detailed Implementation

[0021] See Figures 1-4In the accompanying drawings, the arrow X points to the direction of the first axis. The tensile testing device for high-strength bolts in this application is described below. It includes a testing cylinder 10 and a hydraulic cylinder 20. The testing cylinder is a steel structure. The central axis of the testing cylinder 10 extends along the first axis. The testing cylinder 10 includes a cylinder body 11 extending along the first axis, an end plate 13 welded to one end of the cylinder body, and a flange 12 welded to the other end of the cylinder body. The end cover 14 is fixed to the flange with bolts, so that the end cover can be detachably installed on the testing cylinder. The cylinder barrel 21 of the hydraulic cylinder 20 is fixed to the end cover with bolts.

[0022] A tension block 30 is movably disposed inside the detection cylinder. The tension block includes a body 31, a tension cylinder 32, and a support plate 34. The body, tension cylinder, and support plate are an integral structure. The tension cylinder is fixed to the side of the body away from the hydraulic cylinder. The inner cavity of the tension cylinder 32 is formed as a receiving cavity 33, and the first opening of the receiving cavity radially penetrates the tension cylinder. The support plate is fixed to the end of the tension cylinder away from the body. A rod-through hole 35 is provided on the support plate, and the second opening 351 of the rod-through hole radially penetrates the outer peripheral surface of the support plate. In this embodiment, the first opening of the receiving cavity and the second opening of the rod-through hole face the same direction.

[0023] The through hole is a through hole extending along the first axis. One end of the through hole is connected to the receiving cavity. The end face of the support plate away from the main body is the end face of the tension block away from the hydraulic cylinder. That is, the other end of the through hole passes through the end face of the tension block away from the hydraulic cylinder.

[0024] A limiting hole 131 extending along the first axis is provided on the end plate 13, and the receiving cavity, the through hole and the limiting hole are coaxially arranged.

[0025] An internal threaded hole 36 is provided on the main body. The piston rod 22 of the hydraulic cylinder 20 extends into the detection cylinder 10 and is screwed into the internal threaded hole 36, thereby detachably connecting the tension block to the piston rod of the hydraulic cylinder. Driven by the piston rod, the tension block can reciprocate within the detection cylinder along the first axis.

[0026] An inlet / outlet 111 is provided on the side wall of the cylinder. A rotating cylinder 15 is rotatably fitted on the outer circumference of the cylinder. The rotating cylinder has a notch 151. Rotating the rotating cylinder allows the notch to connect with the inlet / outlet, allowing the bolt 50 to be tested to enter the testing cylinder through the notch and the inlet / outlet. Rotating the rotating cylinder again allows it to cover the inlet / outlet.

[0027] A first annular groove 121 is provided on the side of the flange facing the end plate, and a second annular groove 132 is provided on the side of the end plate facing the flange. The two ends of the rotating cylinder are respectively inserted into the first annular groove 121 and the second annular groove 132.

[0028] In this embodiment, the hydraulic cylinder is a single-rod hydraulic cylinder. A piston inside the cylinder divides the cylinder's inner cavity into a rod-side chamber and a rodless chamber. A first connecting port 23 communicating with the rod-side chamber and a second connecting port 24 communicating with the rodless chamber are provided on the cylinder. The first connecting port 23 and the second connecting port 24 are respectively connected to a hydraulic valve 41 via a first hydraulic pipe 43 and a second hydraulic pipe 45. This hydraulic valve is connected to a hydraulic station 42. A first pressure gauge 44 is installed on the first hydraulic pipe 43, and a second pressure gauge 46 is installed on the second hydraulic pipe 45.

[0029] In this embodiment, the rotating drum is first rotated to connect the inlet and outlet. Then, the hydraulic cylinder is activated, and the position of the piston rod is adjusted so that the bolt 50 to be tested can enter the testing cylinder. The operation of the hydraulic cylinder is paused, and the bolt 50 to be tested is sequentially fed into the inner cavity of the testing cylinder through the inlet and outlet. The bolt head 52 of the bolt to be tested enters the receiving cavity through the first opening, and the screw 51 of the bolt to be tested is inserted into the through hole through the second opening 351. The screw 51 passes through the limiting hole 131 along the first axis and is screwed with a positioning nut 53. A washer 54 is placed between the positioning nut 53 and the end plate 13. The rotating drum 15 is rotated to cover the inlet and outlet. Then, the hydraulic cylinder is activated again to retract the piston rod and stretch the bolt to be tested to detect its tensile strength. During the stretching process, the bolt head is supported on the support plate 34, and the tensile force on the bolt to be tested is obtained using the first hydraulic gauge.

[0030] During the testing process, after installing the bolt to be tested, the operator can move away from the testing cylinder and use hydraulic valve 41 to control the movement of the piston rod. Even if the bolt breaks and produces fragments, the fragments are retained inside the testing cylinder due to the obstruction of the rotating cylinder, preventing injury to the operator. Because the tension on the bolt is obtained through a pressure gauge on the hydraulic pipe during testing, the data error caused by the eccentricity between the force gauge and the traction screw in existing technologies is avoided.

Claims

1. A tensile force testing device for high-strength bolts, characterized in that, The device includes a detection cylinder and a hydraulic cylinder. The central axis of the detection cylinder extends along a first axis. The cylinder barrel of the hydraulic cylinder is detachably mounted on one end of the detection cylinder along the first axis. A tension block is movably disposed inside the detection cylinder and has a receiving cavity. One end of a rod-through hole connects to the receiving cavity, and the other end of the rod-through hole passes through the end face of the tension block away from the hydraulic cylinder. An end plate is fixed at the end of the detection cylinder away from the hydraulic cylinder. A limiting hole extending along the first axis is provided on the end plate. An inlet and outlet are provided on the side wall of the detection cylinder. Both the receiving cavity and the rod-through hole have openings facing the inlet and outlet. A rotating cylinder is rotatably fitted on the outer circumference of the detection cylinder. The rotating cylinder has a notch. Rotating the rotating cylinder allows the notch to connect to the inlet and outlet, allowing the bolt to be tested to enter the detection cylinder through the notch and the inlet and outlet. Rotating the rotating cylinder again allows the rotating cylinder to cover the inlet and outlet. After the piston rod of the hydraulic cylinder extends freely into the detection cylinder, it is fixed on the tension block. Driven by the piston rod, the tension block can reciprocate along the first axis direction inside the detection cylinder. A hydraulic valve and a pressure gauge are installed on the hydraulic pipe of the hydraulic cylinder.

2. The tensile force testing device according to claim 1, characterized in that, The receiving cavity, the rod-through hole, and the limiting hole are arranged coaxially.

3. The tensile force testing device according to claim 1, characterized in that, An end cap is detachably installed at one end of the test cylinder near the hydraulic cylinder, and the cylinder barrel of the hydraulic cylinder is fixed on the end cap.

4. The tensile force testing device according to claim 3, characterized in that, A flange is provided at one end of the detection cylinder near the hydraulic cylinder, and an end cover is detachably installed on the flange. Annular grooves are provided on both the flange and the end plate, and the two ends of the rotating cylinder are respectively inserted into an annular groove.

5. The tensile force testing device according to claim 1, characterized in that, The piston rod of the hydraulic cylinder is screwed onto the tension block using a threaded method.

6. The tensile force testing device according to claim 1, characterized in that, The tension block includes a body, a tension cylinder, and a support plate. The tension cylinder is fixed on the side of the body away from the hydraulic cylinder. The inner cavity of the tension cylinder is formed as a receiving cavity, and the opening of the receiving cavity extends radially through the tension cylinder. The support plate is fixed to the end of the tension cylinder away from the main body, and the rod hole is set on the support plate. The opening of the rod hole penetrates the outer circumference of the support plate radially.

7. The tensile force testing device according to claim 6, characterized in that, The openings of the receiving cavity and the through hole face the same direction.

8. The tensile force testing device according to claim 6, characterized in that, The main body, tension cylinder, and support plate are integrated into one structure.

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