Design and research of the hottest 3D precision mo

2022-08-18
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Research on the design of three-dimensional precision mobile workbench

in the field of modern industrial applications, different requirements are put forward for precision mobile workbench. Most of the precision mobile worktables in the field of optical fiber communication are required to be assembled, which are assembled into two-dimensional precision mobile worktables by precision mobile mechanisms in the X and Y directions, and three-dimensional precision mobile worktables by precision mobile mechanisms in the X, y and Z directions. Because the accuracy and stiffness of the contact surface of the assembly and the relative movement of the moving parts will affect the accuracy of the workbench, the accuracy of the existing three-dimensional precision mobile workbench can not meet the use requirements. In order to meet the application requirements in the field of optical fiber communication, a three-dimensional precision mobile workbench with a fine adjustment stroke of 15 ~ 20mm in three directions and an accuracy of 0.003mm must be designed

1 overall design

according to the use requirements, the designed three-dimensional precision mobile workbench should meet the specified travel range. The justice and Development Party under his leadership has experienced three parliamentary elections, and the requirements of accuracy and sensitivity: at the same time, the working performance should be stable and reliable, eliminate the air return, and reduce the error. In the design, the assembly type is adopted, and its three directions are perpendicular to each other, so the motion directions of the driving part and the driven part in the three directions from bottom to top can be set as the X, y, z axes in the Cartesian coordinate system. Since the fitting surfaces and assembly relations in X, y and Z directions directly affect the accuracy of the overall operation, it is required to maintain the corresponding accuracy of each assembly surface and the contact surface of the operating parts

structural design

the three-dimensional precision mobile workbench is mainly composed of a support device, a micro displacement driving reading device, a load-bearing and micro displacement mechanism, and a connecting device. The selection and design of micro displacement driving reading device, load-bearing and micro displacement mechanism play an important role in the design of the whole product. It is mainly driven by the screw with the help of the whole process cooperation mode, the micro rotation device, the reading device of the dividing cylinder, and the rolling friction guide rail. That is to say, the whole three-dimensional precision mobile workbench is composed of support device - base, base plate, micro displacement driving reading device, load-bearing and micro displacement mechanism - sliding plate and guide rail in the three-dimensional direction, and connecting device - right angle fixed block, etc

design principles and design principles

on the basis of long-term practice in the design of geometric measurement instruments, some design principles and design principles with universality or universality on certain occasions have been formed. These design principles and principles, according to the specific situation of different instrument designs, as technical measures in instrument design, have brought good results in ensuring and improving instrument accuracy, improving instrument performance, and reducing instrument cost. Therefore, how to follow or properly apply these principles and principles in the overall scheme of the instrument is a prominent consideration in the overall design stage of the instrument. In this design, in order to reduce the influence of Abbe error, try to ensure the linear relationship between the motion of the driving part and the driven part in the design of the base, and try to ensure that the guide rail has good motion linearity in the structural design and technology of the guide rail. The spiral micro displacement driving reading device is adopted, and the principle of the shortest measurement chain is followed to minimize the measurement links as far as possible, so as to reduce errors and improve the accuracy of the overall mechanism

the principle of spiral micrometer refers to the principle that the linear displacement of spiral motion is proportional to the angular displacement. The sleeve is engraved with upper and lower rows of scribed lines, the spacing of the scale lines in the same row is 1mm, and the upper and lower rows of scribed lines are staggered by 0.5mm, which is equal to the pitch of the micrometer screw. The differential cylinder is engraved with 50 bisection lines. When it rotates for one cycle, the lead screw displacement is 0.5mm: rotate one grid, and the lead screw moves 0.01mm. Therefore, the division value of the screw micrometer is 0.01mm and the sensitivity is 0.001mm

Figure 1 Schematic diagram of length calculation of moving parts

2 design of key components

the key parts of the three-dimensional precision mobile workbench are mainly rolling friction guide rail, micro displacement drive reading device and spring tension device. The Pearl Spring is the most critical part to make the operation more stable. It can be seen from Figure 1 that

the above formula shows that when the stroke is Smax, the shortest length of the moving part can be calculated by formula (5). When the stroke takes the maximum displacement of 30mm, l is the center distance between the two balls. In order to ensure the bearing capacity, four steel balls are selected on each side of the three-dimensional precision mobile workbench, and l can take the distance between the two middle or two steel balls on both sides. E is the insurance amount, which is isolated and fixed with reeds, so the e of two balls on both sides can be 5mm

3 accuracy analysis

accuracy is an important technical index of the instrument. The accuracy analysis of the instrument is an important part of the instrument design, and it is usually a major problem that should always be considered in the design process. The accuracy analysis here not only refers to the synthesis of the errors of various parts and components of the instrument, but also refers to the allocation of tolerances and the determination of main technical conditions in the instrument design, and even includes considering the technical measures that need to be taken to further reduce the instrument error if the assumption is true: such as the error adjustment method, the design of compensation parts, etc

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