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What methods are used to remove burrs in machining equipment?

Release date:

2021-11-17

Author:

Zhongshan Zhisai Automation Equipment Co., Ltd.

Nowadays, as industries place increasing emphasis on deburring, even a small burr can significantly impact product quality in CNC precision machining. Consequently, a wide variety of deburring methods have emerged. Electrolytic deburring is particularly well suited for removing burrs from concealed areas, intersecting holes, or complex‑shaped components, offering high production efficiency with typical processing times ranging from a few seconds to several tens of seconds.

Nowadays, as industries place increasing emphasis on deburring, even a small burr can significantly impact product quality in CNC precision machining. Consequently, a wide array of deburring methods has emerged. Electrolytic deburring is particularly well suited for removing burrs from concealed areas, intersecting holes, or complex‑shaped components, offering high production efficiency with typical processing times ranging from a few seconds to several tens of seconds. This technique is commonly employed for deburring gears, splines, connecting rods, valve bodies, and oil‑passage ports in crankshafts, as well as for rounding sharp edges. However, a notable drawback is that the electrolytic process also affects the material adjacent to the burr, potentially diminishing surface luster and, in some cases, compromising dimensional accuracy.

Currently, the most commonly used edge‑finishing and deburring methods are as follows:

1. Traditionally, deburring was performed using steel files, sandpaper, and grinding heads; however, edge‑trimming knives have gradually replaced these conventional methods. They are easy and convenient to use, require no specialized skills, reduce costs, and are environmentally friendly.

2. Chemical deburring. Based on the principles of electrochemical reactions, this process automatically and selectively removes burrs from metal parts. It is widely applicable to deburring operations on pump bodies, valve bodies, connecting rods, plunger‑needle valve assemblies, and other components made of various metallic materials in industries such as pneumatics, hydraulics, construction machinery, fuel injectors and oil pumps, automotive, and engine manufacturing. It is particularly suitable for removing difficult-to‑eliminate internal burrs, as well as for parts that have undergone heat treatment or precision finishing.

3. Electrolytic Deburring: An electrochemical machining process that removes burrs from metal parts by means of electrolysis, abbreviated as ECD in English. The tool cathode—typically made of brass—is securely positioned near the burr‑bearing area of the workpiece, with a small gap (generally 0.3 to 1 mm) maintained between them. The conductive portion of the tool cathode is aligned with the burr’s sharp edge, while the remaining surfaces are insulated to confine the electrolytic action to the burr region. During operation, the tool cathode is connected to the negative terminal of a DC power supply, and the workpiece to the positive terminal. A low‑pressure electrolyte—usually an aqueous solution of sodium nitrate or sodium chlorate—at a pressure of 0.1 to 0.3 MPa flows between the workpiece and the cathode. Upon applying the DC voltage, the burr undergoes anodic dissolution and is removed, with the dissolved material carried away by the electrolyte. Since the electrolyte is mildly corrosive, the deburred workpiece should be thoroughly cleaned and subjected to a rust‑preventive treatment.