CNC Machining Case for Plastic Parts: Efficient Production of the Dust Suction Port Filter Cover for Robot Vacuum Cleaners
1. Project Background
A well – known home appliance manufacturing enterprise planned to launch a new – model robot vacuum cleaner. The filter cover of the dust suction port, as a key component, needed to have precise structural dimensions and good filtering performance to ensure the dust suction effect and smooth air circulation of the robot vacuum cleaner. Due to the high requirements of the product design for the hole layout, edge precision, etc. of the filter cover, after a comprehensive evaluation, it was decided to use CNC machining to produce the filter cover of the dust suction port made of plastic.
2. Requirement Analysis
(1) Material Requirement
Polycarbonate (PC) plastic was selected as the part material. PC plastic has good transparency, strength, and toughness, which can meet the mechanical performance requirements of the filter cover during use. At the same time, it also has a certain degree of chemical corrosion resistance and can adapt to the use of the robot vacuum cleaner in different cleaning environments.
(2) Precision Requirement
The diameter tolerance of the small holes on the filter cover needed to be controlled within ±0.1mm to ensure the consistency of the filtering effect; the overall dimension error of the filter cover was controlled within ±0.2mm to ensure the precise assembly with the dust suction port of the robot vacuum cleaner and avoid gaps that would reduce the dust suction efficiency.
(3) Appearance Requirement
The surface of the part needed to be smooth and flat, without obvious tool marks, burrs, and other defects. The edges needed to be chamfered to prevent scratching users. At the same time, the yellow appearance color should be uniform, meeting the aesthetic design requirements of the product as a whole.
3. Production Process
(1) Pre – production Preparation
- Design and Modeling: The product design team used CAD software to carry out 3D modeling of the filter cover, accurately planning the hole layout and overall dimensions, so as to provide accurate model data for subsequent CNC programming.
- Material Preparation: Procured polycarbonate plastic sheets that met the requirements, and cut and blanked them according to the size specifications of the filter cover to ensure that the thickness and size of the sheets met the processing requirements.
(2) CNC Machining
- Programming: The programming engineer generated the CNC machining program using CAM software according to the 3D model of the filter cover. For the small holes on the filter cover, the drilling cycle command was adopted, and the appropriate drill bit diameter and feed rate were set; for the overall contour machining, the contour milling command was used, and the tool path was optimized to reduce the machining time and tool wear.
- Clamping and Positioning: Fixed the cut plastic sheet on the worktable of the CNC machining center through a special fixture, and used a right – angle edge of the sheet as the positioning reference. A dial indicator was used for precise alignment to ensure that the sheet would not shift during the machining process.
- Machining Process: First, the drilling process was carried out. A high – speed steel drill bit with an appropriate diameter was selected, and the drilling operation was carried out at a spindle speed of 1200r/min and a feed rate of 0.1mm/r, so as to quickly and accurately machine the small holes on the filter cover. After the drilling was completed, the end mill was replaced for the overall contour milling. The spindle speed was adjusted to 1500r/min, and the feed rate was set to 100mm/min. The overall contour of the filter cover was machined step by step through the layered milling method, and the edges were chamfered. The CNC machining time for a single filter cover was about 5 minutes.
(3) Post – processing
- Deburring: Put the machined filter cover into a vibratory deburring machine, add an appropriate amount of abrasive and polishing liquid, and make the filter cover fully contact with the abrasive through vibration to remove the burrs on the part surface and hole edges, making the part surface smoother.
- Cleaning: Use an ultrasonic cleaning machine to clean the filter cover to remove the residual abrasive, polishing liquid, and machining debris on the surface, ensuring that the part is clean.
- Inspection: Use a 2D optical measuring instrument to accurately measure the dimensions of the filter cover, and check whether the diameter of the small holes, overall dimensions, etc. meet the design requirements; at the same time, visually inspect the appearance quality of the filter cover to ensure that there are no obvious defects.
4. Project Achievements
(1) Quality Compliance
Through strict machining processes and quality inspection, both the dimensional precision and appearance quality of the filter cover met the design requirements. The diameter tolerance of the small holes was controlled within ±0.08mm, and the overall dimension error was within ±0.15mm. The surface was smooth and flat, without obvious tool marks and burrs. The edge chamfers were uniform, and the yellow appearance color was consistent.
(2) Improved Production Efficiency
Compared with the traditional method of secondary processing after injection molding, CNC machining directly processes the plastic sheet into the filter cover, reducing the time and cost of mold making, and the production cycle is shortened by about 30%. At the same time, the flexibility of CNC machining enables a quick response to product design changes without remaking the mold, greatly improving the R & D and production efficiency of the product.
(3) Good Application Effect
After the batch of plastic filter covers produced by CNC machining were assembled on the robot vacuum cleaner, the dust suction effect was stable, the air circulation was smooth, effectively filtering dust and debris, and improving the cleaning performance of the robot vacuum cleaner. It has been widely recognized by the market, laying a solid foundation for the successful launch of the enterprise’s new – model robot vacuum cleaner.
