A device for testing the rigidity and strength of irregular rods in a composite environment

Abstract

A device for testing the rigidity of an irregular rod under a composite environment comprises a fixed frame, an angle sensor, a coupling, a bearing, a hollow cylinder, a lever arm disc, a locking device, a steel wire rope, a force sensor, a servo actuator, an environmental chamber, a rod-shaped test piece, a fixed platform, and a data acquisition instrument. The bottom of the rod-shaped test piece is fixed to the test platform by a clamp, a lever arm disc is installed on the top of the rod-shaped test piece, a hollow cylinder is installed on the upper part of the lever arm disc, a connecting shaft at the top of the hollow cylinder is connected to a connecting shaft at the bottom of the angle sensor by a coupling, connecting devices are provided diagonally on both sides of the lever arm disc, a force sensor is installed between the connecting device and the servo actuator, and two force sensors and an angle sensor are respectively connected to the data acquisition instrument through cables. The invention has the advantages of simple structure, easy operation, small size, low energy consumption, strong versatility, and low cost, and can be used for measuring the torsional rigidity of various irregular rod structures under specific environments.

Description

Technical Field

[0001] The invention relates to a device for measuring the stiffness and testing the strength of a rod, and in particular to a device for testing the stiffness and strength of an irregular rod in a composite environment. Background Art

[0002] The so-called rod refers to a component whose longitudinal (length direction) dimension is much larger than the transverse (perpendicular to the length direction) dimension. The shape and size of the rod can be described by two main geometric elements: the cross section and the axis of the rod. The cross section refers to the section perpendicular to the length of the rod, and the axis is the line connecting the centers of each cross section. The cross section and the axis of the rod are perpendicular to each other. Rods with a straight axis and the same cross section are called straight rods with equal cross-sections. Structural mechanics and material mechanics mainly study straight rods with equal cross-sections. Rods whose cross-sections vary along the axis are called variable cross-section rods. Rods are increasingly used as transmission parts and supporting parts in today's society. However, due to various design needs, different processing techniques are often required on the rods, such as hollowing out and milling grooves. Different processing techniques cause changes in the stiffness and strength of the rods. In order to verify whether the stiffness and strength of irregular rods meet the requirements in the actual use environment and obtain torsion parameters, it is necessary to conduct tests on torsion testing machines.

[0003] Existing torsion testing machines are large, heavy, and energy-intensive. In addition, the torque range is difficult to adjust and is not very versatile. They are only suitable for measuring the torsional stiffness of regular rod structures in specific environments. They are not suitable for complex test requirements in laboratories, especially for testing the stiffness and strength of antenna rods. Summary of the invention

[0004] According to the above technical problems, the present invention provides a rigidity testing device for irregular rods in a composite environment, which is characterized by comprising a fixed frame, an angle sensor, a coupling, a bearing, a hollow cylinder, a lever arm disc, a locking device, a steel wire rope, a force sensor, a servo actuator, an environmental chamber, a rod-shaped test piece, a fixed platform, and a data acquisition instrument. The rod-shaped test piece is placed in the environmental chamber, the bottom of the rod-shaped test piece is fixed to the test platform by a clamp, the top of the rod-shaped test piece is installed with a lever arm disc, the lever arm disc is connected to the rod-shaped test piece by a thread, the lever arm disc is respectively installed with locking devices on the top and bottom, the upper part of the lever arm disc is installed with a hollow cylinder, the hollow cylinder is connected to the lever arm disc by a flange, and the top of the hollow cylinder A bearing is provided, and the upper part of the hollow cylinder passes through the bearing. The top of the hollow cylinder and the bottom of the angle sensor are respectively provided with connecting shafts, and the connecting shaft at the top of the hollow cylinder is connected to the connecting shaft at the bottom of the angle sensor through a coupling. The angle sensor and the bearing are both installed on the same fixed frame, and the fixed frame is installed on a fixed platform. The rod-shaped test piece is connected to the angle sensor through a force arm disk, a hollow cylinder, and a coupling. Two connecting devices are diagonally fixed on both sides of the force arm disk, and the other ends of the connecting devices are respectively fixed on two servo actuators of the same model. A force sensor is respectively installed between the connecting device and the servo actuator, and the two force sensors and the angle sensor are respectively connected to a data acquisition instrument through cables.

[0005] Furthermore, the locking device is a high-strength self-locking nut.

[0006] Furthermore, the locking device is a double nut.

[0007] Furthermore, the connecting device is a steel wire rope.

[0008] Furthermore, the steel wire rope is pre-wound on the lever arm disc, the number of turns is greater than one turn, and the two steel wire ropes extending out of the lever arm disc after winding are in an anti-parallel position relationship.

[0009] Furthermore, the servo actuator is hydraulically driven, and two servo actuators are simultaneously connected to one controller.

[0010] Furthermore, the coupling is a cross slider coupling.

[0011] Furthermore, the bearing and the hollow cylinder are clearance-fitted.

[0012] The beneficial effects of the present invention are as follows: the present invention is a device for testing the stiffness of irregular rods in a composite environment, which has a simple structure, is easy to operate, has a small volume, low energy consumption, strong versatility, and low cost. It can be used to measure the torsional stiffness of various irregular rod structures in a specific environment. The measurement results are accurate and the results of multiple measurements are consistent. It can meet the stiffness and strength measurements of most non-standard rods, specifically:

[0013] 1. It integrates a complete stiffness measurement system for antenna rods in a complex environment, which can effectively provide a stable temperature and humidity environment for rod-shaped test pieces, apply torsional loads, and measure angles;

[0014] 2. In this system, the use of couple loading not only avoids the generation of bending and shearing forces, but also makes the operation more convenient and the results more accurate;

[0015] 3. The use of disc force arm ensures that the loading force is always tangent to the disc, ensuring the accuracy and effectiveness of the measurement results;

[0016] 4. Using a cross slider coupling to indirectly connect the shaft of the angle sensor to the rod solves the problem of different axis centers and also makes the measurement error smaller;

[0017] 5. Use bearings to indirectly fix the loading device, which avoids the influence of shear force on the test results and ensures that the rod-shaped test piece will not be affected by resistance when rotating, while also protecting the angle sensor from damage by shear force. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the main structure diagram of the present invention;

[0019] Figure 2 This is a schematic diagram of the connection between the lever arm disc and the wire rope.

[0020] As shown in the figure, fixed frame-1, angle sensor-2, coupling-3, bearing-4, hollow cylinder-5, lever arm disc-6, self-locking nut-7, wire rope-8, force sensor-9, servo actuator-10, environmental chamber-11, rod-shaped test piece-12, fixed platform-13, data acquisition instrument-14. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings: The present invention is a device for testing the rigidity of an irregular rod in a composite environment, characterized in that it includes a fixed frame 1, an angle sensor 2, a coupling 3, a bearing 4, a hollow cylinder 5, a lever arm disc 6, a locking device 7, a wire rope 8, a force sensor 9, a servo actuator 10, an environmental chamber 11, a rod-shaped test piece 12, a fixed platform 13, and a data acquisition instrument 14. The rod-shaped test piece 12 is placed in the environmental chamber 11, and environmental stresses such as temperature and humidity are applied to the rod-shaped test piece 12 through the environmental chamber 11. The bottom of the rod-shaped test piece 12 is fixed to the test platform 13 by a clamp, and a force arm disc 6 is installed on the top of the rod-shaped test piece 12. The force arm disc 6 is connected to the rod-shaped test piece 12 by threads, and locking devices are installed on the upper and lower parts of the force arm disc 6. A hollow cylinder 5 is installed on the upper part of the force arm disc 6. The hollow cylinder 5 is connected to the force arm disc 6 by a flange. A bearing 4 is provided on the top of the hollow cylinder 5. The upper part of the hollow cylinder 5 passes through the bearing 4. The hollow cylinder 5 can only rotate in the axial direction and cannot move horizontally. The top of the hollow cylinder 5 is at an angle. The bottom of the sensor 2 is respectively provided with a connecting shaft, and the connecting shaft at the top of the hollow cylinder 5 is connected to the connecting shaft at the bottom of the angle sensor 2 through the coupling 3. The angle sensor 2 and the bearing 4 are installed on the same fixed frame 1, and the fixed frame 1 is installed on the fixed platform 13. The rod-shaped test piece 12 is connected to the angle sensor 2 through the force arm disc 6, the hollow cylinder 5, and the coupling 3. When the rod-shaped test piece 12 rotates, the rotation angle of the rod-shaped test piece 12 can be measured by the angle sensor 2. Two connecting devices are diagonally fixed on both sides of the force arm disc 6. The other end of the connecting device is respectively fixed on two servo actuators 10 of the same model. A force sensor 9 is installed between the connecting device and the servo actuator 10. By controlling the output load of the servo actuator 10, the power arm disk 6 can be pulled, thereby applying a force to the rod-shaped test piece 12. The two force sensors 9 and the angle sensor 2 are respectively connected to the data acquisition instrument 14 through cables. The controller is set to ensure that the pulling force is the same and the load is synchronized. The load value of the two servo actuators 10 and the measurement value of the angle sensor 2 are monitored simultaneously through the data acquisition instrument 14.

[0022] Furthermore, the locking device is a high-strength self-locking nut 7 or a double nut for providing torque reaction force.

[0023] Furthermore, the connecting device is a steel wire rope 8.

[0024] Furthermore, the steel wire rope 8 is pre-wound on the lever arm disc 6, the number of winding turns is greater than one turn, and the two steel wire ropes 8 extending out of the lever arm disc 6 after winding are in an anti-parallel position relationship, ensuring that when the rod-shaped test piece 12 rotates, the tension direction of the steel wire rope 8 is tangent to the outer diameter of the lever arm disc 6.

[0025] Furthermore, the servo actuator 10 is hydraulically driven, and two servo actuators 10 are simultaneously connected to one controller.

[0026] Furthermore, the coupling 3 is a cross-slider coupling.

[0027] Furthermore, the bearing 4 and the hollow cylinder 5 are clearance-fitted.

[0028] Working principle:

[0029] (1) First, fix the bottom of the rod-shaped test piece 12 to the test platform 13 by a clamp, then insert the rod-shaped test piece 12 into the environmental chamber 11, install the lever arm disc 6 on the top of the rod-shaped test piece 12, and connect the lever arm disc 6 to the rod-shaped test piece 12 by threads;

[0030] (2) A high-strength self-locking nut 7 is installed on the upper and lower parts of the lever arm disc 6, or a double nut can be used for locking. When the torque load is large, a spline structure is purchased to transmit the torque. A hollow cylinder 5 is installed on the upper part of the lever arm disc 6. The hollow cylinder 5 is connected to the lever arm disc 6 through a flange. A bearing 4 passes through the top of the hollow cylinder 5. The bearing 4 and the hollow cylinder 5 are clearance-matched. The role of the hollow cylinder 5 and the bearing 4 is to reduce the influence of the possible shear force on the test results;

[0031] (3) Considering that shear force should be avoided as much as possible when applying load, the test system applies torque in the form of a couple, that is, two forces of equal magnitude and opposite directions are simultaneously applied to the rod-shaped test piece 12;

[0032] (4) Considering that when the rod-shaped test piece 12 rotates, especially when the torsion angle is large, the direction of the force also changes with the angle, so that the torque is reduced, a lever arm disc 6 is used, and two steel wire ropes 8 are diagonally fixed on both sides of the lever arm disc 6, and the steel wire ropes 8 are pre-wound on the lever arm disc 6 to ensure that when the rod-shaped test piece 12 rotates, the pulling direction of the steel wire rope 8 is tangent to the outer diameter of the lever arm disc 6. The load force acts directly on the lever arm disc 6 and is indirectly transmitted to the rod-shaped test piece 12 through the lever arm disc 6. In this way, when the rod-shaped test piece 12 rotates, the lever arm disc 6 also rotates. However, no matter how the lever arm disc 6 rotates, the direction of the force is always tangent to the lever arm disc 6, which ensures the effectiveness of the force. In addition, the distance of the lever arm can be adjusted by changing the diameter of the lever arm disc 6, so that the magnitude of the force can be easily adjusted.

[0033] (5) The other ends of the two steel wires 8 are respectively fixed on two servo actuators 10 of the same model. A force sensor 9 is installed between the steel wires 8 and the servo actuator 10. By controlling the output load of the servo actuator 10, the power arm disc 6 can be pulled, thereby applying a force to the rod-shaped test piece 12. The two servo actuators 10 are hydraulically driven and connected to a controller at the same time. The setting of the controller ensures that the pulling force is the same and the load is synchronized;

[0034] (6) The rod-shaped test piece 12 is connected to the angle sensor 2 through the arm disc 6, the hollow cylinder 5, and the cross slider coupling 3. When the rod-shaped test piece 12 rotates, the rotation angle of the rod-shaped test piece 12 can be measured by the angle sensor 2. The advantage of this method is that the rotation angle in the stiffness measurement is generally small, and direct measurement is more accurate.

[0035] (7) applying environmental stress, such as temperature and humidity, to the rod-shaped test piece 12 through the environmental chamber 11, which can also be extended to other environmental conditions;

[0036] (8) The data acquisition device 14 simultaneously monitors the load values ​​of the two servo actuators 10 and the measured values ​​of the angle sensor 2. When the load F reaches the specified value, the monitored value θ of the angle sensor 2 is recorded. Given the diameter D of the lever arm disk 6, the torque M=D / 2*F can be calculated. The rotational stiffness of the rod-shaped test piece 12 can then be calculated using the rotational stiffness formula K=M / θ.

[0037] In summary, the device has a complete system configuration, full functions, accurate and reliable measurement, and the environmental stress and torque load meet the requirements. It can effectively complete the stiffness measurement test of irregular rods, especially antenna rods in complex environments.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the scope of protection of the present invention.

Claims

1. A device for testing the rigidity of irregular rods in a composite environment, characterized in that It includes a fixed frame, an angle sensor, a coupling, a bearing, a hollow cylinder, a force arm disc, a locking device, a wire rope, a force sensor, a servo actuator, an environmental chamber, a rod-shaped test piece, a fixed platform, and a data acquisition instrument. The rod-shaped test piece is placed in the environmental chamber, the bottom of the rod-shaped test piece is fixed to the test platform by a clamp, the top of the rod-shaped test piece is equipped with a force arm disc, the force arm disc is connected to the rod-shaped test piece by threads, the upper and lower parts of the force arm disc are respectively equipped with locking devices, the upper part of the force arm disc is equipped with a hollow cylinder, the hollow cylinder and the force arm disc are connected by a flange, the top of the hollow cylinder is provided with a bearing, the upper part of the hollow cylinder passes through the bearing, and the top of the hollow cylinder and the bottom of the angle sensor are respectively provided with connecting shafts , the connecting shaft at the top of the hollow cylinder is connected to the connecting shaft at the bottom of the angle sensor through a coupling, the angle sensor and the bearing are installed on the same fixed frame, the fixed frame is installed on a fixed platform, the rod-shaped test piece is connected to the angle sensor through a force arm disk, a hollow cylinder, and a coupling, two connecting devices are diagonally fixed on both sides of the force arm disk, and the other ends of the connecting devices are respectively fixed on two servo actuators of the same model, a force sensor is respectively installed between the connecting device and the servo actuator, and the two force sensors and the angle sensor are respectively connected to the data acquisition instrument through cables; the servo actuator is hydraulically driven, and the two servo actuators are simultaneously connected to a controller; the coupling is a cross slider coupling.

2. The device for testing the rigidity of an irregular rod under a composite environment according to claim 1, characterized in that The locking device is a high-strength self-locking nut.

3. The device for testing the rigidity of an irregular rod under a composite environment according to claim 1 is characterized in that The locking device is a double nut.

4. The device for testing the rigidity of an irregular rod under a composite environment according to claim 1, characterized in that The connecting device is a steel wire rope.

5. The device for testing the rigidity of an irregular rod under a composite environment according to claim 4, characterized in that The steel wire rope is pre-wound on the lever arm disc, the number of turns of the winding is greater than one turn, and after the winding, the two steel wire ropes extending out of the lever arm disc are in an anti-parallel position relationship.

6. The device for testing the rigidity of an irregular rod under a composite environment according to claim 1, characterized in that The bearing and the hollow cylinder are clearance-fitted.

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