A bolt tightening test loading device

Abstract

The present invention discloses a bolt tightening test loading device, including a motor, a planetary reducer to be tested, a first coupling, a torque sensor, a second coupling and a simulated tightening loading end. The input end of the planetary reducer to be tested is connected to the output end of the motor; the output end of the planetary reducer to be tested is connected to one end of the first coupling; the other end of the first coupling is connected to the input end of the torque sensor; the output end of the torque sensor is connected to one end of the second coupling; the simulated tightening loading end includes a housing and a rotation and translation conversion mechanism and a nonlinear spring arranged inside the housing, the rotating part is rotationally connected to the housing, the other end of the second coupling is connected to one end of the rotating part, and the nonlinear spring is arranged between the translation part and the housing. Compared with the prior art, the present invention can solve the problem that repeated loading and repeated testing are required in experiments such as torque performance, fatigue, and reliability of bolt tightening devices, and the torque changes nonlinearly.

Description

Technical Field

[0001] The invention relates to the technical field of bolt tightening device load testing, in particular to a bolt tightening test loading device. Background Art

[0002] Bolt tightening device refers to electric, pneumatic and other auxiliary bolt tightening devices used to tighten bolts in mechanical equipment assembly. Commonly used ones include motor-reducer-torque sensor, etc., which are called tightening shafts. The load test of bolt tightening device is an experiment to simulate the load realization process during bolt tightening, which is used to test the performance of bolt tightening device.

[0003] During the process of bolt tightening, the load rises rapidly from zero to a rated value, showing a high degree of nonlinearity. In the current load test of bolt tightening devices, the loading device at the load end uses actual load torque such as magnetic powder brakes or servo motors. This device is a set of "tightening machines" composed of motors, planetary reducers, torque sensors, etc. During the performance test, the load end, that is, the output end, is loaded back-to-back by magnetic powder brakes or another device under test. When the load is applied, due to the characteristics of the magnetic powder brake and the working performance curve of the motor, the torque change law does not match the actual situation, there is a large error, and it is impossible to simulate the nonlinear load characteristics during the bolt tightening process, and to simulate the nonlinear change from torque 0 to stall torque (the bolt no longer rotates after tightening) during the bolt tightening process.

[0004] Therefore, how to provide a bolt tightening experimental loading device that can simulate the nonlinear change law of load during the bolt tightening process is a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a bolt tightening test loading device to solve the problem that repeated loading and repeated testing are required and the torque changes nonlinearly in experiments such as torque performance, fatigue and reliability of the bolt tightening device.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The invention discloses a bolt tightening test loading device, comprising:

[0008] Electric motor;

[0009] A planetary reducer to be tested, wherein the input end of the planetary reducer to be tested is connected to the output end of the motor;

[0010] A first coupling, wherein the output end of the planetary reducer to be tested is connected to one end of the first coupling;

[0011] A torque sensor, wherein the other end of the first coupling is connected to an input end of the torque sensor;

[0012] A second coupling, wherein the output end of the torque sensor is connected to one end of the second coupling;

[0013] The simulated tightening loading end includes a shell and a rotation and translation conversion mechanism and a nonlinear spring arranged inside the shell. The conversion mechanism has a rotating part and a translation part. The rotating part is rotatably connected to the shell, and the other end of the second coupling is connected to one end of the rotating part. The nonlinear spring is arranged between the translation part and the shell, and the nonlinear spring is squeezed when the translation part moves.

[0014] Preferably, it also includes a base, a guide rail, a slide and a fixed bracket, the simulated tightening loading end and the fixed bracket are fixed on the base, a plurality of guide rails are fixed on the fixed bracket in parallel with each other, the slide is slidably set on the guide rail, and the motor, the planetary reducer and the torque sensor are each slidably set on the guide rail through at least one slide.

[0015] Preferably, a spring tube, a ball retainer, a ball and a rubber spring are further provided inside the simulated tightening loading end, there are two spring tubes with openings facing each other, one spring tube is fixed to the top of the inner side of the shell, and the other spring tube is fixed to the bottom of the inner side of the shell, a rubber spring is fixed to the bottom of each spring tube, the nonlinear spring is arranged outside the rubber spring, the natural length of the nonlinear spring is greater than that of the rubber spring, the two ball retainers are respectively fixed to the upper and lower ends of the translation part, the ball is arranged on the ball retainer, and the upper and lower ball retainers are respectively slidably arranged in the upper and lower spring tubes.

[0016] Preferably, the rotating part includes a center shaft and a gear, the center shaft is rotatably connected to the housing, the center shaft is connected to the other end of the second coupling, the gear is key-connected to the center shaft, the translational part is a rack, and the gear is meshed with the rack.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] 1. It can simulate the process of bolt tightening and dynamically detect the torque-time curve from the beginning to the end of the work;

[0019] 2. The principle is simple, the layout is reasonable and the safety is high, which can meet the use requirements;

[0020] 3. The motor provides power, and the planetary reducer under test amplifies the torque of the motor and reduces the speed. The gears and racks realize the conversion from rotation to linear motion, and push the nonlinear spring to compress to achieve the final required 300Nm bolt tightening loading torque;

[0021] 4. A sliding structure is formed by fixing the bracket, guide rail and slide, which facilitates the replacement of the planetary reducer under test. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the structure of the bolt tightening experiment loading device of this embodiment;

[0024] Figure 2 It is the nonlinear spring torque variation curve;

[0025] Figure 3 It is a schematic diagram of the connection relationship between the gear and the rack;

[0026] Figure 4 Schematic diagram of the internal structure of the loading end for simulating tightening;

[0027] Explanation of reference numerals: 1. electric motor; 2. planetary reducer under test; 3. first coupling; 4. torque sensor; 5. second coupling; 6. simulated tightening loading end; 7. base; 8. guide rail; 9. slide; 10. fixed bracket; 11. center shaft; 12. gear; 13. spring cylinder; 14. nonlinear spring; 15. ball cage; 16. rack; 17. ball; 18. rubber spring. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide a bolt tightening test loading device to solve the problem that repeated loading and repeated testing are required and the torque changes nonlinearly in experiments such as torque performance, fatigue and reliability of the bolt tightening device.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1-4 As shown, this embodiment provides a bolt tightening test loading device, including a motor 1, a planetary reducer 2 to be tested, a first coupling 3, a torque sensor 4, a second coupling 5 and a simulated tightening loading end 6.

[0032] Among them, the input end of the planetary reducer 2 under test is connected to the output end of the motor 1, and the output end of the planetary reducer 2 under test is connected to one end of the first coupling 3. Torque sensor 4, the other end of the first coupling 3 is connected to the input end of the torque sensor 4. Second coupling 5, the output end of the torque sensor 4 is connected to one end of the second coupling 5. Simulated tightening loading end 6, the simulated tightening loading end 6 includes a shell and a rotation and translation conversion mechanism and a nonlinear spring 14 (steel) arranged inside the shell. The conversion mechanism has a rotating part and a translation part, and the rotating part is rotatably connected to the shell. The other end of the second coupling 5 is connected to one end of the rotating part, and the nonlinear spring 14 is arranged between the translation part and the shell, and the nonlinear spring 14 is squeezed when the translation part moves.

[0033] When the bolt tightening test loading device of this embodiment is in use, it is powered by the motor 1, and the planetary reducer 2 to be tested matched therewith amplifies the torque of the motor 1 and reduces the speed to achieve the final required loading torque of 300Nm. The planetary reducer 2 to be tested transmits the amplified torque to the torque sensor 4 to be tested through the first coupling 3, and then transmits it to the simulated tightening loading end 6 through the second coupling 5, and feeds back to the control circuit according to the measured value of the planetary reducer 2 to achieve the necessary load unloading, and finally obtains the torque curve according to the analysis. Since the simulated tightening loading end 6 converts the rotation of the rotating part into the translation of the translation part through the rotation and translation conversion mechanism, and then applies nonlinear resistance when the translation part moves through the nonlinear spring 14, the nonlinear change law of the load during the bolt tightening process is simulated.

[0034] In the test bench, when a prototype of the planetary reducer 2 under test has undergone a certain number of cyclic loading tests (such as 10,000 times), it needs to be disassembled and replaced with a new prototype. In order to facilitate replacement, this embodiment also includes a base 7, a guide rail 8, a slide 9 and a fixed bracket 10. The simulated tightening loading end 6 and the fixed bracket 10 are fixed on the base 7, a plurality of guide rails 8 are fixed on the fixed bracket 10 in parallel with each other, the slide 9 is slidably arranged on the guide rail 8, and the motor 1, the planetary reducer and the torque sensor 4 are each slidably arranged on the guide rail 8 through at least one slide 9.

[0035] When replacing the planetary reducer 2 under test, after loosening the first coupling 3, push the slide 9 to separate the motor, the planetary reducer 2 under test and the first coupling 3. After replacing the planetary reducer 2 under test, slide each slide 9 to the appropriate position again, reconnect the motor, the planetary reducer 2 under test and the first coupling 3 in sequence, and start a new prototype experiment.

[0036] Specifically, in this embodiment, the interior of the simulated tightening loading end 6 is also provided with a spring barrel 13, a ball retainer 15, a ball 17 and a rubber spring 18. There are two spring barrels 13 and the openings are arranged opposite each other, one spring barrel 13 is fixed to the top of the inner side of the shell, and the other spring barrel 13 is fixed to the bottom of the inner side of the shell. A rubber spring 18 is fixed to the bottom of each spring barrel 13, and a nonlinear spring 14 is arranged outside the rubber spring 18, and the natural length of the nonlinear spring 14 is greater than the rubber spring 18. The two ball retainers 15 are respectively fixed to the upper and lower ends of the translation part, and the ball 17 is arranged on the ball retainer 15. The upper and lower ball retainers 15 are respectively slidably arranged in the upper and lower spring barrels 13.

[0037] When the ball retainer 15 moves in the spring tube 13, the ball 17 rolls in contact with the inner wall of the spring tube 13, thereby guiding the up and down movement of the translation part. When the nonlinear spring 14 is compressed to a certain extent, the rubber spring 18 limits the translation part, thereby protecting the nonlinear spring 14.

[0038] In mechanical structures, there are many conversion mechanisms between rotation and translation, such as cam mechanisms, etc. In this embodiment, the rotating part includes a central shaft 11 and a gear 12, the central shaft 11 is rotatably connected to the housing, the central shaft 11 is connected to the other end of the second coupling 5, the gear 12 is key-connected to the central shaft 11, and the translation part is a rack 16, the gear 12 is meshed with the rack 16. This structure has low cost and high reliability, and those skilled in the art can also choose other forms of structure according to needs.

[0039] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A bolt tightening test loading device, characterized in that: include: Electric motor; A planetary reducer to be tested, wherein the input end of the planetary reducer to be tested is connected to the output end of the motor; A first coupling, wherein the output end of the planetary reducer to be tested is connected to one end of the first coupling; A torque sensor, wherein the other end of the first coupling is connected to an input end of the torque sensor; A second coupling, wherein the output end of the torque sensor is connected to one end of the second coupling; A simulated tightening loading end, the simulated tightening loading end comprises a housing, a rotation and translation conversion mechanism and a nonlinear spring arranged inside the housing, the conversion mechanism comprises a rotating part and a translation part, the rotating part is rotationally connected to the housing, the other end of the second coupling is connected to one end of the rotating part, the nonlinear spring is arranged between the translation part and the housing, and the translation part compresses the nonlinear spring when moving; A spring cylinder, a ball retainer, a ball and a rubber spring are also provided inside the simulated tightening loading end. There are two spring cylinders with openings facing each other. One spring cylinder is fixed to the top of the inner side of the shell, and the other spring cylinder is fixed to the bottom of the inner side of the shell. A rubber spring is fixed to the bottom of each spring cylinder. The nonlinear spring is provided outside the rubber spring. The natural length of the nonlinear spring is greater than that of the rubber spring. The two ball retainers are respectively fixed to the upper and lower ends of the translation part. The ball is provided on the ball retainer. The upper and lower ball retainers are respectively slidably provided in the upper and lower spring cylinders. The rotating part includes a central shaft and a gear, the central shaft is rotatably connected to the housing, the central shaft is connected to the other end of the second coupling, the gear is key-connected to the central shaft, and the translation part is a rack, the gear is meshed with the rack; The bolt tightening experiment loading device also includes a base, a guide rail, a slide and a fixed bracket. The simulated tightening loading end and the fixed bracket are fixed on the base. A plurality of guide rails are fixed on the fixed bracket in parallel with each other. The slide is slidably arranged on the guide rail. The motor, the planetary reducer and the torque sensor are each slidably arranged on the guide rail through at least one slide.

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