In order to solve the complicated problem of precision adjustment of vertical column assembly in horizontal machining center, the base structure is designed to make the adjustment of vertical column assembly precision more convenient, significantly improve the working efficiency and ensure the accuracy of machine tool.
With the progress of science and technology, the machine tool as the industrial basic equipment develops towards the direction of high speed and high precision. The main factors that affect the precision of machine tools are machining precision, assembly precision, ambient temperature and humidity, etc. In this paper, a new type of column and base structure is designed to improve the assembly precision, simplify the production process and improve the work efficiency.
In this paper, a base assembled with the column is designed, which is not only convenient for the installation of guide rail slider, but also convenient for the accuracy adjustment of the column. Taking the HP200/D horizontal machining center of our factory as an example, this paper expounds the structure of vertical column and base, and analyzes the advantages of the structure over the traditional vertical column structure.
1. Column and base structure
The lower surface of the column is at the center of the left, right and rear sides, respectively with 100mm*170mm*30mm keyway. The two sides of the groove are finishing surfaces.
The upper surface of the base corresponds to the position of the column keyway, and the keyway A1, A2 and a3 with 100mm*170mm*30mm are also opened. The two sides of the groove are the finishing surfaces. On the upper surface of the base, 100mm*140mm*30mm grooves B1, B2, B3 and B4 are cut on the left and right side, and 8 filling areas are processed around the screw holes that are fastened with the upright column
2. Assembly and adjustment accuracy
(1) assembly of column and base. After the accuracy of the bed is adjusted, the base and the guide rail slider on the bed body are connected with screws, and the perpendicularity and parallelism of the base and the base rail of the bed are adjusted according to the process requirements.
The wedge block K3 for adjusting the column torsion (B axis direction) is loaded into A1, A2 and A3 slots, and the base is firmly fastened with screws. Then load the wedge blocks T1 and T2 of the tilting adjusting column into the slots of B1, B2, B3 and B4, as shown in FIG. 2. After that, put the sealing strip into the groove on the outside of 8 filling areas.
The bottom surface of the column will be coated with the release agent, to release the agent naturally dry, the surface without bare metal point, the column will be lifted to the bottom of the seat. After the initial alignment between the column and the base, screw on the mounting screw and tighten it, as shown in FIG. 4. Then put three groups of wedge blocks K1 and K2 into both sides of wedge block K3.
(2) adjust the accuracy. In order to ensure that the center line of the machine tool spindle is parallel to the z-axis reference side, the column torsion must be adjusted. At this time, wedge blocks K1 and K2 installed in A1, A2 and A3 slots can be inserted into the depth of the slot to adjust the column torsion.
When the wedge K2 in the three slots A1, A2 and A3 moves to the center of the column, and the wedge K1 moves away from the center, the column rotates along the positive direction of axis B. On the contrary, the vertical column rotates to the negative direction of axis B to achieve the purpose of adjusting the vertical column torsion and making the Central Line of the main axis parallel to the reference side of the Z axis. When adjusting the perpendicularity of Y-axis guide plane and z-axis guide plane of machine tool, it is necessary to adjust wedge block T1.
Wedge T1, T2 joint surface is 1∶100 slope, when the screw screw into the wedge T2 internal thread, the screw compression washer so that the washer and wedge T1 at the same time to the center of the column, and by the slope of the upward movement. In this way, the wedge blocks in the slots of B1, B2, B3 and B4 will lift the column up to a certain displacement on the left front, left back, right front and right back four points. In this way, the perpendicularity of Y-axis guide plane and z-axis guide plane can be adjusted by adjusting the tilt of the column.
3. Glue
After the main functional parts of the headstock, worktable and other machine tools are installed, the precision of the X, Y and Z axes of the machine tools is adjusted to meet the acceptance standards of the machine tools, and the machine tools are accepted by the customer. The use of common epoxy resin as the main component of the liquid packing adhesive, its advantages are high strength, high temperature resistance and good chemical stability.
When pouring glue, the worker screws the perfusion tool into the threaded hole on the side of the base and pours glue into the hole. The glue will flow upward along the injection hole to expel the air from the filling area. When glue appears in the outlet hole on the side of the column, the glue fills the filling area, as shown in FIG. 5, and the filling stops.
Finish the operation of 8 gluing areas in turn and wait for the glue to solidify according to the time specified in the gluing instruction. The solidified glue and mounting screws together tighten the column and base, so that the column not only maintains the accuracy of the Y-axis, but also bears the cutting force and overturning moment, ensuring the machine tool to carry out rough machining and finishing machining.
4. Advantages of the structure design
The bottom surface of traditional column is scraped to adjust the precision after assembly. In this process, a crane is needed to lift and unload the vertical column and flip it to a position convenient for scraping and grinding, so that the workers can scrape and grinding. When the precision does not reach a reasonable range, but also repeated scraping and grinding, but also with color agent, the research, the process is complex, the amount of work, the production efficiency is very low. Some machine tool manufacturing enterprises will improve the above method for the column and guide rail slider between the gasket method.
When adjusting the accuracy of the upright column, it is still necessary to use a crane to lift and unload the upright column, mark the spacers on the slide block of the guide rail respectively, and scrape and grind according to the thickness that needs to be adjusted respectively. Because the gasket in machining often choose the grinding method, so the gasket surface is very smooth, the surface has the effect of machining hardening, to the workers of scraping and grinding bring great difficulty. In addition, the gasket sequence a but chaos, early measurement, adjustment of the work lost.
When adjusting the precision of the traditional design structure, it needs to be disassembled by crane for many times, which wastes production resources, and has a large scraping and grinding intensity, which costs manpower and time. The design of the column base in this paper solves the problem of repeatedly disassembling the column in the process of adjusting the accuracy, and eliminates the time-consuming step of scraping and grinding. The method of screw fastening and cementing ensures the rigidity and precision of the machine tool.
This design only increases the cost of base wood mold, mold release agent and epoxy resin gum, but after the mass production of general machine tools, the enterprise benefit brought by the great improvement of production efficiency is far greater than the above increased cost. This scheme has been verified in the large horizontal machining center of our factory.
5. Conclusion
This design not only simplified the column assembly, improved the production efficiency, but also with a simple pouring method, greatly maintain the precision of the machine. In view of the significant advantages of the design, I plant production of CNC gantry machine tools, floor boring and milling machine and other products have been used in this design, has achieved good economic and social benefits.
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