Polycrystalline diamond reamer used for machining holes with discontinuous hole walls

Abstract

The invention discloses a reamer used for machining discontinuous holes. The discontinuous holes comprise hole central axes and hole walls provided with hole wall discontinuous parts and solid parts, the hole wall discontinuous parts define central angles of the hole wall discontinuous parts with respect to the hole central axes, the reamer comprises a rigid reamer body which defines the central axis of the reamer, at least three tooth-shaped bases which are formed by extending the reamer body and parallelly arranged at intervals, and polycrystalline diamond blades which are respectively fixed on each tooth-shaped base in a corresponding mode. Each polycrystalline diamond blade comprises a cutting edge located at axial remote end and a sleeking edge connected with the cutting edge, blade central included angles which are the same with the blades in number are respectively defined between the sleeking edges of adjacent blades with respect to the central axis of the reamer, the blade central included angles are not equant, and the difference between the largest central included angle and the smallest central included angle is greater than to equal to the central angles of the hole wall discontinuous parts.

Description

technical field [0001] The invention relates to a reamer for machining holes, in particular to a polycrystalline diamond reamer for machining holes with discontinuous walls. Background technique [0002] The reamer is a finishing tool used for the final process on the surface of a metal hole to ensure the dimensional accuracy, shape accuracy and surface roughness of the hole. Commonly used reamers in production include solid carbide reamers and high-speed steel reamers; at present, polycrystalline diamond (PCD) reamers, polycrystalline diamond reamers and solid carbide reamers are being widely used in the hole processing of non-ferrous metals. Compared with high-speed steel reamers, reamers can achieve smaller surface roughness values ​​and stable dimensional accuracy [0003] At present, the length of the axial working part of the commonly used cemented carbide reamer is generally 0.8-3 times the diameter of the reamer, and the length of the calibration part is generally 0...

AI Technical Summary

Problems solved by technology

[0003] At present, the length of the axial working part of the commonly used cemented carbide reamer is generally 0.8-3 times the diameter of the reamer, and the length of the calibration part is generally 0.8-1.5 times the diameter of the reamer. The length is only less than 7mm, and the actual axial working length (wiper edge) is less than or equal to 5mm; Continuous, when a tooth enters the discontinuous part (gap part, no metal to be processed), the cutting force of this tooth will suddenly drop to zero, and the reamer may lose balance and vibrate; and the vibration is on the hole wall It is difficult to eliminate the impact

In addition, due to the influence of uneven allowance after the previous process (drilling and expansion) (for non-continuous workpieces with hole walls, it is very easy to have uneven allowance), the existing reamer is usually designed so that the angle between the teeth is equally divided In the form of arrangement, when a cutter tooth enters the discontinuous part, the vibration that may occur during the reaming work will cause the rest of the cutter teeth to affect the accuracy of the processed hole wall, resulting in hole inclination and hole ellipse

However, due to the short axial length of the teeth of the existing polycrystalline diamond reamer, it is easier to cause the phenomenon of hole inclination and hole ellipse due to the above reasons, which will damage the tool more seriously.

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