Device and method for processing counterbore of circuit board

Abstract

The invention discloses a device and a method for processing a counterbore of a circuit board. The device comprises a bench-type drilling machine, a reaming knife, a working table and a depth control device fixed on the working table, wherein the reaming knife comprises more than two main / auxiliary cutting edges; the front angle of the reaming knife is between 13 and 17 degrees, the back angle isbetween 27 and 33 degrees, and the spiral angle is between 13 and 17 degrees; and the depth control device comprises a locking device, a positioning device, a positioning disc, a guide mechanism and a working table. When the device is in use, the relative positions of the depth control device and the bench-type drilling machine are adjusted to ensure that a positioning guide post in front of the reaming knife and the guide mechanism of the depth control device are positioned on the same axial line; and the feeding depth is set, the drilling machine is started, then a manual feed handle is rotated to drill the counterbore, and when the guide post contacts the positioning disc, a drilling bit is put up to finish the processing of the counter bore. The device and the method have the advantages of convenient use and adjustment, simple structure, easy maintenance, long service life, long processing cost and the like, and are suitable for wide popularization in the field of processing the counterbore.

Description

technical field [0001] The invention relates to a device and method for counterbore processing of circuit boards. Background technique [0002] Most of the holes on the printed circuit board for position fixing are countersunk holes. In traditional technology, these countersinks are processed on CNC drilling machines using conventional countersinks. CNC drilling machines use conventional countersinks when processing these countersinks. The tool breaks seriously. , the position accuracy and aperture accuracy cannot be effectively guaranteed, and normal production cannot be performed at all. The main manifestations and reasons are: [0003] 1. The diameter of the shank of the countersinking tool used in the CNC drilling machine is φ3.175mm, and the diameter of the counterbore is above φ4.0mm, even reaching φ12.0mm. The larger the tool diameter, the greater the torque on the tool shank during drilling The larger the torque is, when the torque reaches the maximum torque that th...

AI Technical Summary

Problems solved by technology

[0002] Most of the holes on the printed circuit board for position fixing are countersunk holes. In traditional technology, these countersinks are processed on CNC drilling machines using conventional countersinks. CNC drilling machines use conventional countersinks when processing these countersinks. The tool breaks seriously. , the position accuracy and aperture accuracy cannot be effectively guaranteed, and normal production cannot be performed at all. The main manifestations and reasons are:

[0003] 1. The diameter of the shank of the countersinking tool used in the CNC drilling machine is φ3.175mm, and the diameter of the counterbore is above φ4.0mm, even reaching φ12.0mm. The larger the tool diameter, the greater the torque on the tool shank during drilling The larger the torque is, when the torque reaches the maximum torque that the handle can bear, the breakage of the handle will occur; the breakage of the handle will cause the following hazards: first, the tool life is reduced (the average life is less than 200 holes), and the cost of the tool increases; The products produced will be discarded; the third is that the spindle is subjected to a large radial force at the moment of fracture, which affects the accuracy and life of the spindle; the fourth is that the processing efficiency is low, the time for loading and unloading the plate is long, and the processing time for the handle breaking is long

[0004] 2. Because the diameter of the drilled hole is larger than the diameter of the handle (the larger the diameter of the drilled hole, the greater the gap), the torque on the handle during the drilling process is very large. Large torsional force will also be unstable, and vibration will occur in the horizontal direction, which will affect the hole position accuracy and hole diameter of the drilled hole.

[0005] 3. As we all know, conventional countersinks have two cutting edges. The fewer cutting edges, the greater the cutting amount of each cutting edge per unit time, and the greater the force on the cutting edge, which will cause the tool to drill. Unstable in the middle, the result is to affect the aperture accuracy

[0006] 4. Utilize the design of the mutually restrictive relationship between the angle of the countersinking hole and the depth of the countersinking hole, and ensure the various technical indicators of the countersinking hole by controlling the degree of freedom of the Z-axis of the machine tool. However, it is difficult to ensure that the workpiece, tooling and cutting tools are The spatial position relationship among the three and the limited state of the degree of freedom cannot meet the depth requirements for controlling various counterbores

[0007] In this way, the method and existing problems of using conventional countersinks to process countersinking on CNC drilling machines cannot meet the quality, efficiency and cost requirements of countersunk drilling for printed circuit boards.

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