CN105716843B - One kind is bolted with reference to face Rigidity Experiment device - Google Patents

Abstract

An experimental device for the stiffness of a bolted joint surface is composed of a left beam, a right beam, a high-strength bolt, a washer, a nut, a pressure sensor, and a fulcrum cylinder. High-strength bolts pass through the holes of the left and right beams, washers and pressure sensors, and screw on the nuts to connect the lower parts of the left and right beams together. The upper parts of the left and right beams are processed with semi-cylindrical grooves, and the grooves are installed with The fulcrum cylinder is used as a fulcrum when the middle of the experimental device is subjected to a vertical downward force, so that the high-strength bolt connection below the experimental device is subjected to tension. Such experimental results are closer to the actual situation when the beam of the large machine tool is working, so the simulated results are closer to the actual situation and have more reference value.

Description

An experimental device for the stiffness of the joint surface of a bolted connection

technical field

The invention relates to an experimental device for researching the influence of the parameters of the crossbeam bolt connection joint part of a large machine tool on the rigidity of the crossbeam, and belongs to the technical field of large machine tool experiment application.

Background technique

Large-scale machine tools often use longer beams, which are generally manufactured in sections, and the bolted joints of the beams are generally connected by multiple high-strength bolts and pre-tightened. The lowermost connecting bolt at the crossbeam connection is subjected to the greatest tension, and the uppermost crossbeam connection joint surface is subjected to the greatest pressure. The upper joint surface can be increased by increasing the area of the joint surface and improving the hardness of the joint surface, which can reduce the deformation of the joint surface very well, but the lower part of the joint surface of the beam is connected by high-strength bolts, and the bolts are under tension. To increase the rigidity of this part Can rely on bolts, the lower bolt connection is the key to the rigidity of the beam connection and even the entire beam, that is, the stiffness of the lower bolt connection at the beam connection has a greater impact on the stiffness of the entire beam. There are many factors that affect the stiffness of the beam junction. At present, two circular steel plates are generally connected with high-strength bolts in the laboratory, and the pressure sensor is used to measure the real-time pressure. The strain gauge is used to measure the deformation of the bolts. By measuring different The contact area, the deformation of the bolts and the contact surface under the conditions of different surface roughness and different pressure, etc., are then simulated by computer software to simulate the deformation of the machine tool under different forces, in order to find ways to improve the stiffness of the beam. This measurement method has a large gap between the same force around the bolts and the actual situation. The experiment can only summarize the deformation of the joint surface under different preconditions, and the deformation of the beam needs to be simulated by computer, so that it can be simulated through virtual simulation The amount of deformation of the beam increases the workload and also brings a certain amount of error.

Contents of the invention

Aiming at the above-mentioned defects of the prior art, the present invention provides an experimental device for the stiffness of the joint surface of a bolt connection. The device uses bolts to connect a short beam structure to simulate a real longer beam structure. The beam structure consists of two sections, which are connected by a high-strength bolt. The bolt is connected to the lower end of the beam. There is a boss on the end surface of the two beams at the bolt connection. The size of the boss can be changed according to the experimental requirements. The end faces of the two beams at the upper end of the beam connection are processed with a semi-cylindrical notch, and a cylinder is placed in the notch. The radius of the cylinder is consistent with the radius of the semi-cylindrical notch. It is used as a lever fulcrum. When the bolt is subjected to pure tension. The pressure sensor on the bolt rod is used to measure the force on the bolt during the experiment. During the experiment, the pressure function of the tensile testing machine is used. The two ends of the connecting beam are placed horizontally with high-hardness pads, and the joint surface of the bolt is connected. A vertical downward pressure is applied directly above the beam, and the magnitude of the pressure and the deformation of the beam in the vertical direction are measured by the testing machine. The deformation of the crossbeam when different pressures are applied to the upper part of the joint surface of the bolted joint is measured through experiments under different areas and different roughnesses. Then through mathematical analysis, analyze the relationship between the stiffness of the beam and the area of the joint surface, the relationship between the stiffness of the beam and the surface roughness of the joint surface, and the relationship between the stiffness of the beam and the pressure exerted on the upper part of the joint surface. On this basis, through the analysis and summary, the law of the impact of the bolt joint surface roughness on the beam stiffness is provided to provide a basis for the design of the machine tool.

The technical solution adopted to solve its technical problems is:

An experimental device for the stiffness of a bolted joint surface is composed of a left beam, a right beam, a high-strength bolt, a washer, a nut, a pressure sensor, and a fulcrum cylinder. High-strength bolts pass through the holes of the left and right beams, washers and pressure sensors, and screw on the nuts to connect the lower parts of the left and right beams together. The upper parts of the left and right beams are processed with semi-cylindrical grooves, and the grooves are installed with The fulcrum cylinder is used as a fulcrum when the middle of the experimental device is subjected to a vertical downward force, so that the high-strength bolt connection below the experimental device is subjected to tension. Such experimental results are closer to the actual situation when the beam of the large machine tool is working, so the simulated results are closer to the actual situation and have more reference value.

Description of drawings

Fig. 1 is a main sectional view of the present invention;

Fig. 2 is the bottom view of Fig. 1;

Fig. 3 is the main sectional view of left and right beams (the structure of left and right beams is the same);

Fig. 4 is the left view of Fig. 3;

Fig. 5 is a right side view of Fig. 3 .

In the figure: 1, left beam, 2, fulcrum cylinder, 3, right beam, 4, high-strength bolt, 5, washer, 6, pressure sensor, 7, nut.

Detailed ways

As shown in Figures 1 to 5, an experimental device for the stiffness of a bolted joint surface is composed of a left beam 1, a right beam 3, a high-strength bolt 4, a washer 5, a nut 7, a pressure sensor 6, and a fulcrum cylinder 2; The crossbeam 1 and the right crossbeam 3 are symmetrically arranged, the bottoms of the left crossbeam 1 and the right crossbeam 3 are respectively provided with corresponding holes, and the high-strength bolts 4 pass through the corresponding holes of the left crossbeam 1 and the right crossbeam 2 to connect them. A washer 5 is provided at the joint between the end of the high-strength bolt 4 and the left crossbeam 1; the nut 7 matches the bottom thread of the high-strength bolt 4, and the pressure sensor 6 is arranged between the nut 7 and the right crossbeam 3; Gaskets 5 are also provided between the pressure sensors 6 .

The upper part of the left beam 1 and the right beam 3 is processed with a semi-cylindrical groove, and the fulcrum cylinder 2 is installed in the groove to serve as a fulcrum when the middle of the experimental device is subjected to a vertical downward force, so that the lower part of the experimental device is high-strength. The bolt 4 connection is under tension. Such experimental results are closer to the actual situation when the beam of a large machine tool works, so that the simulated results are closer to the actual situation.

Claims (1)

1. one kind is bolted with reference to face Rigidity Experiment device, it is characterised in that：The device by left crossbeam (1), right crossbeam (3), High-strength bolt (4), washer (5), nut (7), pressure sensor (6), fulcrum cylinder (2) composition；Left crossbeam (1), right crossbeam (3) symmetrical arrangement, left crossbeam (1), right crossbeam (3) bottom be respectively equipped with corresponding hole, high-strength bolt (4) is across a left side The two is connected behind crossbeam (1), right crossbeam (3) corresponding hole, the end of high-strength bolt (4) and the cooperation of left crossbeam (1) Place is equipped with washer (5)；It is matched at nut (7) and the bottom thread of high-strength bolt (4), pressure sensor (6) is arranged on spiral shell Between female (7) and right crossbeam (3)；Washer (5) also is provided between nut (7) and pressure sensor (6)；

The top of left crossbeam (1) and right crossbeam (3) is machined with semi-cylindrical groove, and fulcrum cylinder (2) is equipped in slot；

Fulcrum cylinder (2) is played when experimental provision middle is by power vertically downward, is used as fulcrum, is made experimental provision Lower section high-strength bolt (4) junction under tension；Such experimental result closer to heavy duty machine tools crossbeam work when reality Border situation, the result simulated in this way are more nearly with actual conditions.