Machining method for removing burrs at four corners of rivet hole of solid separation type retainer
By using CNC programming to perform radius (R) treatment at the four corners of the bearing cage rivet holes, the problem of difficult removal of sharp-angle burrs is solved, improving machining accuracy and product quality. This method is suitable for high-precision parts in the aerospace field.
Patent Information
- Application Number
- CN202511833652.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-02-24
AI Technical Summary
Existing technologies are insufficient for efficiently and accurately removing sharp-angled burrs from the four corners of the bearing cage rivet holes, and traditional manual deburring methods can easily damage the surface of the parts, affecting processing quality and safety.
The CNC program controls the cutting tool to perform R-angle treatment at the four corners of the rivet hole. Through milling, the acute angle is transformed into a rounded transition surface of R0.3, avoiding burr formation and improving the accuracy and efficiency of deburring.
It has achieved a significant improvement in the surface quality of rivet holes, avoided secondary damage, improved processing consistency and product safety, and met the high precision requirements of the aerospace field.
Smart Images
Figure CN121552019A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aerospace, and specifically relates to a processing method for removing burrs from the four corners of the rivet holes of a solid separable cage. Background Technology
[0002] In the machinery manufacturing industry, the machining accuracy and surface quality of parts are core factors determining product performance, reliability, and service life. Burr formation, a common and unavoidable problem in machining, has long constrained the quality improvement of high-end machinery products. Whether it's cutting, grinding, stamping, or welding, burrs inevitably form on the surface, edges, and cavities of parts. These seemingly tiny metal protrusions can cause a series of negative chain reactions affecting subsequent assembly, performance, and overall quality. The presence of burrs directly compromises the dimensional accuracy and geometric tolerances of parts, leading to abnormal fit clearances and inaccurate positioning during assembly. This, in turn, increases friction and accelerates wear of moving parts, and in severe cases, can even cause parts to jam or fail, posing a significant threat to product safety. Furthermore, burrs also affect the cleanliness of the parts' appearance, reducing the product's market competitiveness.
[0003] To address the burr problem, deburring has become an indispensable and crucial step in the precision machining process of mechanical parts. However, implementing this process often requires a significant investment of manpower, resources, and time. Statistics show that in the precision machinery manufacturing sector, deburring accounts for 10%-30% of total machining time, significantly increasing production costs and potentially leading to decreased production efficiency due to its cumbersome nature. This has become a major bottleneck restricting cost reduction and efficiency improvement in the manufacturing industry. Therefore, developing efficient, precise, and low-cost deburring processes is of significant practical importance for improving the quality of mechanical products and optimizing production processes.
[0004] Currently, there are many deburring methods used in the market, among which manual deburring is a traditional and widely used method. This mainly involves operators manually removing burrs from the surface of parts using tools such as files, scrapers, and sandpaper. In some cases, impact and grinding methods are also used as supplementary techniques. However, this processing method has many insurmountable drawbacks: Firstly, manual operation is extremely inefficient. For parts with complex structures and hidden burrs, it often requires a lot of time to complete the deburring operation, making it difficult to meet the needs of large-scale production. Secondly, the quality of deburring heavily depends on the operator's skill level and sense of responsibility. Due to the subjectivity and uncertainty of human operation, problems such as incomplete burr removal, scratches on the part surface, and damage to dimensional accuracy are prone to occur, resulting in poor product quality stability. Furthermore, operational errors may leave potential quality hazards, affecting the subsequent use of the product.
[0005] In fields such as aerospace and high-end equipment manufacturing, where the precision requirements for parts are extremely high, the aforementioned problems are particularly prominent. Taking bearing cages in aerospace products as an example, as one of the core components of a bearing, their performance directly affects the bearing's rotational accuracy, load-bearing capacity, and service life, thus impacting the operational reliability of the entire aerospace equipment. The rivet holes of the bearing cage, as a critical assembly part, have extremely stringent processing quality requirements. However, during the processing of the rivet holes, due to the special structure and narrow space of the holes, sharp burrs easily form at the four corners. These burrs are not only small in size and have strong adhesion, but their distribution is also hidden, making it difficult to accurately reach and completely remove them using traditional manual deburring methods. More seriously, these sharp burrs are prone to breakage, detachment, and accumulation in the rivet holes during subsequent assembly and use. This not only affects the assembly accuracy and connection strength of the rivets but may also lead to increased friction between the rivets and the cage, causing abnormal wear, overheating, and other problems. In severe cases, it can even cause bearing jamming and failure, posing a significant risk to the flight safety of aerospace equipment.
[0006] Currently, there is no mature and efficient dedicated machining process for removing burrs at the four corners of bearing cage rivet cavities. Existing processes either fail to completely remove burrs or easily damage the surface quality and dimensional accuracy of the rivet cavities, failing to meet the high precision and high reliability requirements of the aerospace industry. Therefore, developing a solid separation deburring method that can accurately and efficiently remove sharp-angle burrs from the four sides of bearing cage rivet cavities without damaging the part itself and ensuring stable machining quality has become an urgent technical challenge. Summary of the Invention
[0007] The purpose of this invention is to solve the product quality problem caused by the accumulation of sharp burrs at the four corners of the rivet holes in existing bearing cages, and to provide a processing method for removing the four corner burrs from the rivet holes of a solid, separable cage.
[0008] The processing method for deburring the four corners of the rivet holes of a solid separable cage according to the present invention is carried out according to the following steps:
[0009] I. Initial machining: According to the design requirements, the following steps are performed in sequence: forming → fine turning of the cut surface and chamfering → rough grinding of the outer diameter → drilling of rivet holes → chamfering of rivet hole corners → pin insertion → marking → drilling and milling of holes → final grinding of the outer diameter → final turning of the inner diameter and chamfering;
[0010] II. Deburring and subsequent processes: Deburring → Pin removal → Milling → Rivet hole corner deburring → Finishing → Fluorescent penetrant testing → Final inspection → Pickling → Silver plating → Packaging.
[0011] Improved process features: Utilizing a CNC program, the machining center performs radius (R) treatment on the sharp corners of the rivet cavity, precisely controlling the R angle to R0.3. This treatment effectively removes sharp and difficult-to-machine burrs from the four corners of the rivet cavity, achieving a surface roughness of Ra1.25, significantly improving the surface quality of the rivet cavity and removing obstacles for subsequent processes.
[0012] The beneficial effects of this invention are:
[0013] This invention uses a CNC program to control the cutting tool to directly perform radius (R) treatment on the four acute corners while milling the rivet cavity. At the instant the material in the rivet cavity is removed by milling, the acute corners have not yet formed a stable burr structure. The cutting tool directly transforms the acute corners into a rounded transition surface with a radius of 0.3 using a preset R-angle trajectory. This effectively eliminates the basis for burr formation at its source, rather than peeling away existing burrs. This fundamentally improves the accuracy of deburring and avoids damage to the part body during secondary processing. This invention is more suitable for cavity milling, adding a sharp-angle removal function at the pointed corners of the cavity, ensuring processing quality and removing bottlenecks in subsequent processing steps. This design plays a decisive role in the entire cavity milling process for separable products, improving both product quality and consistency. Attached Figure Description
[0014] Figure 1 This is a tool path diagram of the machining process in Example 1;
[0015] Figure 2 This is a schematic diagram of the rivet cavity without the acute angle R in Example 1;
[0016] Figure 3 The image shows the finished product processed using Example 1.
[0017] Figure 4 This is a screenshot of the machine tool program segment used in Example 1. Detailed Implementation
[0018] Specific Implementation Method 1: This implementation method for deburring the four corners of the rivet holes of a solid separable cage is carried out according to the following steps:
[0019] I. Initial machining: According to the design requirements, the following steps are performed in sequence: forming → fine turning of the cut surface and chamfering → rough grinding of the outer diameter → drilling of rivet holes → chamfering of rivet hole corners → pin insertion → marking → drilling and milling of holes → final grinding of the outer diameter → final turning of the inner diameter and chamfering;
[0020] II. Deburring and subsequent processes: Deburring → Pin removal → Milling → Rivet hole corner deburring → Finishing → Fluorescent penetrant testing → Final inspection → Pickling → Silver plating → Packaging.
[0021] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: The dimensions of the cavity to be processed are drawn using AutoCAD drawing software. Then, chamfering is set according to a fixed radius (R) requirement, followed by offset setting. After all dimensions are drawn, the coordinate system to be processed is marked, and then CNC programming is performed according to the coordinate coefficient values. Other steps and parameters are the same as in Specific Implementation Method One.
[0022] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that an alloy end mill is selected based on the dimensional requirements of the processed product. All other steps and parameters are the same as in Specific Implementation Method One.
[0023] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the cutting tool used is a nano-coated alloy end mill. All other steps and parameters are the same as in Specific Implementation Method One.
[0024] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the rotational speed and feed rate are set according to the diameter of the selected milling cutter. Other steps and parameters are the same as in Specific Implementation Method One.
[0025] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that, when using a milling cutter with a diameter of φ4-φ5mm, the rotational speed S is 4500-4800 r / min, and the feed rate F is 150-180 mm / min. Other steps and parameters are the same as in Specific Implementation Method One.
[0026] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that: when using a milling cutter with a diameter less than φ4mm, the rotational speed is set to 5000-5500 r / min, and the feed rate F is 180-200 mm / min. Other steps and parameters are the same as in Specific Implementation Method One.
[0027] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that: after setting the basic parameters of the milling cutter, the program for the required chamfering of the cavity is compiled. Using the machine tool's own G-code, through human-computer interaction and in conjunction with the drawn coordinate system, a G02 sequence is executed at the location where the outer diameter chamfer needs to be machined on one side. Then, the normal milling cavity size is achieved using G03. Another G02 sequence is executed for the inner diameter chamfer. The other side is machined along the symmetrical axis, with the Y coordinate reversed to achieve integrated machining of the milled cavity and sharp angle removal by the CNC machining center. Other steps and parameters are the same as in Specific Implementation Method One.
[0028] The beneficial effects of the present invention are verified using the following embodiments:
[0029] Example 1: A method for deburring the four corners of the rivet holes of a solid separable cage is specifically carried out according to the following steps:
[0030] I. Initial machining: According to the design requirements, the 9 rivet holes are formed in sequence → fine turning of the cut surface and chamfering → rough grinding of the outer diameter → drilling of rivet holes → chamfering of rivet hole corners → inserting pins → marking → drilling and milling of holes → final grinding of the outer diameter → final turning of the inner diameter and chamfering;
[0031] II. Deburring and subsequent processes: Deburring → Pin removal → Milling → Rivet hole corner deburring → Finishing → Fluorescent penetrant testing → Final inspection → Pickling → Silver plating → Packaging.
[0032] In this embodiment, the CNC program controls the cutting tool to directly perform R-angle processing on the four acute corners while milling the shape. At the moment the material in the rivet cavity is removed by milling, the acute corners have not yet formed a stable burr structure. The cutting tool directly transforms the acute corners into a rounded transition surface of R0.3 through a preset R-angle trajectory. This is equivalent to eliminating the basis for burr generation from the root, rather than peeling off the burrs that have already formed. This fundamentally improves the accuracy of deburring and avoids damage to the part body from secondary processing.
Claims
1. A method for deburring the four corners of the rivet holes of a solid separable cage, characterized in that... The specific steps for deburring the four corners of the rivet holes in a solid, separable cage are as follows: I. Initial machining: According to the design requirements, the following steps are performed in sequence: forming → fine turning of the cut surface and chamfering → rough grinding of the outer diameter → drilling of rivet holes → chamfering of rivet hole corners → pin insertion → marking → drilling and milling of holes → final grinding of the outer diameter → final turning of the inner diameter and chamfering; II. Deburring and subsequent processes: Deburring → Pin removal → Milling → Rivet hole corner deburring → Finishing → Fluorescent penetrant testing → Final inspection → Pickling → Silver plating → Packaging.
2. The processing method for deburring the four corners of the rivet holes of a solid separable cage according to claim 1, characterized in that... Use AutoCAD drawing software to draw the dimensions of the cavity to be processed, then set the chamfer according to the fixed R requirement, and then set the offset. After all dimensions are drawn, mark the coordinate system to be processed, and then perform CNC programming according to the coordinate coefficient values.
3. The processing method for deburring the four corners of the rivet holes of a solid separable cage according to claim 1, characterized in that... Select the carbide end mill based on the size requirements of the product being processed.
4. The processing method for deburring the four corners of the rivet holes of a solid separable cage according to claim 3, characterized in that... The cutting tool is a nano-coated alloy end mill.
5. The processing method for deburring the four corners of the rivet holes of a solid separable cage according to claim 3, characterized in that... The spindle speed and feed rate are set according to the diameter of the selected milling cutter.
6. The processing method for deburring the four corners of the rivet holes of a solid separable cage according to claim 5, characterized in that... When using a milling cutter with a diameter of φ4-φ5mm, the rotational speed S is 4500-4800r / min, and the feed rate F is 150-180mm / min.
7. The processing method for deburring the four corners of the rivet holes of a solid separable cage according to claim 5, characterized in that... When using a milling cutter with a diameter less than φ4mm, the rotation speed is set to 5000-5500r / min, and the feed rate F is 180-200mm / min.
8. A method for deburring the four corners of the rivet holes of a solid separable cage according to claim 6 or 7, characterized in that... After setting the basic parameters of the milling cutter, start writing the program for the chamfering of the required cavity. Using the machine tool's own G-code, through human-computer interaction, and in conjunction with the drawn coordinate system, write a G02 at the part of the outer diameter chamfer that needs to be machined on one side, and then the normal milling cavity size is achieved according to G03. Then write another G02 for the inner diameter chamfer. Machining the other side along the symmetrical axis, with the Y coordinate being positive and negative in opposite directions, to achieve integrated machining of the milling cavity and the removal of the acute angle by the CNC machining center.