The highly accurate "gears" processing method used in industrial machinery include gears -cured methods that use the gear creation method for efficiently processing the entire gear, the gear molding method that processes each tooth, and the machining center. The most commonly used is gear creation using an NC hob. "Hob" refers to a dedicated tool used when processing gear teeth. This article explains the tasks generated by gear processing by hob and the points you want to keep for efficient crisp.
In gear processing, tasks such as reduced surface roughness, defective shape, and unpleasant sound during operation. I will explain each issue.
By reducing the surface roughness of the gears, the wear of parts that contacts the gears is faster than expected, causing deterioration of performance and failure, which hinders the operation of the machine. In addition, when surface treatment is applied to the gear, the low surface of the gear may not be intended to have the wetness and thickness of the paint as intended.
It is assumed that the "hob" used at the time of processing is caused by the "hob" used during processing. Bad shape of the gears may lead to broken gears and abnormal wear. It is important to note that if the gears with poor shapes are leaked into the market, it will lead to the incorporated machine failure or accident.
If the processing of the gear deteriorates due to poor processing, a strange noise will be generated during operation. The noise of the gear has a complicated factor, and it is difficult to find out the cause. However, leaving unpleasant sounds may lead to failures and accidents, so it is necessary to identify and eliminate the cause. The factors of the noise of the gear include dents, scratches, surface roughness, meshing rate, and rigidity of gear cases.
We will explain measures for issues to be noted in gear processing by assignment.
In order to prevent the surface roughness of the gears, the material and coating of the tools are reviewed, the supply of cutting oil is improved, and the tools are replaced at the right time.
If the sharpness of the hob is reduced, the surface roughness will worsen. Therefore, by reviewing the material and coating of the hob and suppressing the decrease in sharpness, the surface roughness can be prevented. It is necessary to select a coating according to the characteristics of the gear material, such as the hardness of the gear material.
Factors that lead to a reduction in the sharpness of hobs include the temperature rise in the processing surface and the scratches due to the cut powder. Appropriate supply of cutting oil promotes the discharge of the cut powder, and by suppressing the temperature rise due to the cooling effect, it can prevent hobs from decreasing.
Even if the tool material is changed and the supply of cutting oil is improved, the wear of the hob will progress as the processing progresses. Therefore, it is important to understand the status of wear and exchange tools at the right time.
In order to prevent shape defective, it is effective to adjust the cutting speed, adoption of coating with high wear resistance, and apply a climb cut.
Adjusting the cutting speed is effective in suppressing hob wear and chipping that leads to poor gears. Adjusting the cutting speed will reduce the load and the temperature rise during cutting, reducing the wear and less tipping.
In order to suppress hob wear and chipping, it is effective to adopt a coating with high wear resistance. Even if the work efficiency and quality balance must be processed under severe conditions, applying high wear -resistant coatings will make hobs less likely to wear, which will prevent shape defective.
The adoption of a climb cut is also effective to suppress the shape of the gear. The climb is a processing method that combines the rotation direction of the tool and the transfer direction of the material. Climbuts are the benefits of reducing the wear of hobs and the fact that the cutting resistance is small, and is a processing method that can prevent shape defective.
In order to prevent the unpleasant sound of the gear working, the adjustment of the teeth with "crowning" and "relief room" is effective. Crowning is a processing method that gives the center of the gear a roundness, and the relief is a processing method that escapes both ends of the teeth. By making these adjustments, you can prevent bad teeth that lead to abnormal noise.
When ordering a hob used for gear processing, it is important to prepare the necessary information in advance. If the size and shape of the dento do not match completely, the hob cannot be processed. The following factors that should be confirmed when selecting a hob is the following: Module size Pressure angle Gear tooth shape Confirm coefficient Tip and valley diameter Twist angle Required gear accuracy Used tool diameter range (minimum -maximum) Coupling type and size Check the drawings and others firmly and select Bob that satisfies each element.
In this article, we explained the issues generated by gear processing by hobs and proposals to eliminate issues. Gears are important parts that handle the power transmission of various machines. It is necessary to pay close attention to reduced surface roughness and defective shape so that it does not lead to the incorporated machine.
