Turned parts are widely used in various fields, and the processing requirements of thin-walled parts are very strong. This article takes CNC machine tool turning of thin-walled parts as the object, analyzes and elaborate on product analysis, process development, machining process, product testing, etc., solves the problems that occur in the processing, completes the processing of the product, and achieves good results Economic benefits.
Keyword: Turning parts processing CNC lathe processing technology
Thin-walled parts have the advantages of light structure, compact structure, and material saving. They are widely used in the industrial field. However, there are many difficulties in processing thin-walled parts, which are prone to vibration. In order to prevent machining deformation, etc., the machining accuracy is ensured. This article is based on actual production examples, making full use of the knowledge of machining workpieces and tool clamping, tool-related parameter development, program establishment, workpiece detection, etc., and making full use of knowledge of tools, cutting forces, clamping and positioning. Researched new technological methods and successfully overcome this problem.
1. Product appearance and material analysis
Parts have thin hole walls, large diameters, and high machining accuracy, which is somewhat difficult in actual production. For example, the shape of a product consists of an outer circle with a diameter of 98mm, a length of 13mm and an outer circle with a diameter of 93mm and a length of 7mm. The inner contour contains two inner holes with a diameter of 95mm and a length of 12mm and a diameter of 89mm and a length 8mm inner hole. After analysis, the material of this part is AL6082-T6. This material strengthens aluminum alloy by heat treatment, has good formability, weldability, machinability and medium strength. Mainly used in mechanical structure, including bars, plates, pipes and profiles. Tensile strength b (MPa): 245, conditional yield strength 0.2 (MPa): 8805; 140 is a metal material that is easy to process. The wall thickness of the parts is 1.5mm and 2mm respectively. In order to overcome this problem, morphological deformation is easy to occur during processing. Corresponding processing technology has been developed. Processing is divided into roughing, aging, finishing and semi-finishing to achieve our production goals.
2. the development of product processing technology
1Specify the processing path
The left outer circle of the part has higher coaxial requirements on the right end of the part. In order to ensure the same axial degree, all the processing is completed with a jig when completed. The specific processing route is arranged in the following way:
Rough turning profile Dimensional accuracy requirements. The roughing product drawing should go from the rough outline of the car to the finishing.
The total length of cut guarantee is 20.1.
Aging treatment to eliminate internal stress.
Re-clamping, semi-precision turning, precision turning profile size requirements.
Semi-precision cars, dimensional accuracy requirements of the outer contour of precision cars.
Parts are cut.
Manually scrape chamfers with an acute angle of 0.5*45 degrees.
Delivery with full size inspection.
2 Select the blank
In order to save the material of the workpiece according to the process layout, choose the customized tube material (3 semi-finished products at one turning).
(1) Select the tool
To ensure the accuracy of the workpiece, the corresponding tool must be selected.
3.Product processing technology
How to ensure the concentricity of parts in the reference a? The method of requiring a one-time fixture to complete the full surface processing of the part and reducing the influence of the fixture on the deformation of the workpiece has become a problem of the finishing part. After many experiments, a bold idea was put forward. Make a special fixture, and then use 502 adhesive to fix the part on the fixture, thereby reducing any extra external force applied to the workpiece during clamping. Add the position of the clip used to fix the glue to the rough machining contour of the part.
2 Roughing and finishing of internal and external contours
For roughing, use the G71 command for machining. After the machining is completed, the finishing allowance of 0.5 is maintained. When the finishing allowance of the internal hole is maintained, u is a negative value. In order to ensure that the entire workpiece is processed at one time during finishing, the diameter of the adhesive is applied during clamping, and the force cannot be too large during processing, so the cutting amount used for finishing is 0.2 mm and the feed amount is 0.1 mm/min. From the left to right of the shape finishing, use the left sharp knife of this size to directly machine. The internal hole machining is directly executed as a conventional “internal hole machining” turning tool, and the radius of the tip arc of both tools is selected to be 0.4mm. Final processing until qualified size.
3 cut off
During the cutting process, the parts are easy to deform, and the method of reducing the deformation of the workpiece during the cutting process is mainly from the tool. Reduce the width of the cutting head while maintaining the rigidity of the tool to reduce the contact area between the tool and the part, and directly reduce the radial cutting force during the cutting process. Therefore, the cutting blade width is 1 mm. When cutting, directly guarantee the length tolerance of thin-walled parts, and establish a 0.5*45 degree chamfer.
4, product quality inspection
Improved process products processed can already guarantee the accuracy requirements of drawings. But the actual inspection shows that there is still some jitter in product quality. Through multiple inspections and analyses, the main fluctuation is caused by the radial force when measuring the size of the workpiece using an inner diameter micrometer or cursor caliper. So we have also improved the measurement process.
1 By detecting the outer diameter, turning a correction rod. Measure the exact size of the calibration rod, then place it on a flat plate, calibrate with a dial indicator, and adjust the corresponding reading to zero. Measuring the workpiece with this method can reduce the deformation of the radial force and confirm the dimensional accuracy and roundness of the workpiece.
2 Inner hole inspection uses pass-and-stop gauge detection to make suitable pass-stop rods to prevent radial pressure during the measurement of the inner diameter dial indicator or inner diameter dial indicator and deform the product.
Turned parts processing, through this process to improve, through test methods to improve, not only to ensure the swiss machining quality requirements of products, but also to complete production tasks on time, and obtain good economic benefits. Attaching 502 glue to the production fixture effectively solves the problem of installation and deformation of thin-walled workpieces during semi-finishing and finishing, and adds a variety of methods and methods for processing thin-walled parts. In the future production practice, I will continue my own thinking, continue to pioneer and innovate, and strive to achieve greater development in CNC lathe machining, and contribute to CNC machining.