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RU-2861702-C1 - MANDREL WITH REPLACEABLE END MILL, END MILL AND MANDREL FOR INSTALLING MILL

RU2861702C1RU 2861702 C1RU2861702 C1RU 2861702C1RU-2861702-C1

Abstract

FIELD: metal processing. SUBSTANCE: group of inventions is used for milling various surfaces. A mandrel with a replaceable end mill are detachably connected to each other by means of a three-start cylindrical thread with conical helical surfaces. An external thread is made in the mandrel, and an internal thread in the mill. The mandrel has a base cone at the base of the thread for interaction with the base cone of the mill in its shank part. One of the base cones has a height of not more than 1/4 of the smaller diameter of this cone. EFFECT: increasing the centering accuracy of the mill body on the mandrel, enabling the use of additive technologies for manufacturing the mandrel with a removable end mill. 6 cl, 3 dwg

Inventors

  • Pizhenkov Evgenii Nikolaevich
  • Kostousova Daria Mikhailovna

Dates

Publication Date
20260507
Application Date
20250514

Claims (6)

  1. 1. An end mill comprising a cutter body having an internal three-start cylindrical thread with conical helical surfaces for interaction with the corresponding thread of the mandrel, wherein in the tail part of the cutter body there is a base cone with a height of no more than 1/4 of the smaller diameter of the cone for interaction with the base cone of the mandrel, or the base cone for interaction with the base cone of the mandrel has a height of no more than 1/4 of the smaller diameter of this cone of the mandrel.
  2. 2. A milling cutter according to claim 1, characterized in that the angle between the generatrix of the lower conical helical surface of the milling cutter thread and the axis of the milling cutter and the mandrel is from 20 to 45°.
  3. 3. A mandrel for mounting an end mill, characterized in that for securing the milling cutter on it, it has an external three-start cylindrical thread with conical screw surfaces for interaction with the corresponding thread of the milling cutter, and below the thread, the mandrel has a base cone with a height of no more than 1/4 of the smaller diameter of this cone for interaction with the base cone of the milling cutter, or the base cone for interaction with the base cone of the milling cutter has a height of no more than 1/4 of the smaller diameter of this cone of the milling cutter.
  4. 4. The mandrel according to item 3, characterized in that the angle between the generatrix of the lower conical helical surface of the mandrel thread and the axis of the cutter and mandrel is from 20 to 45°.
  5. 5. A mandrel with a replaceable end mill, comprising a cutter body configured to be detachably connected to the mandrel, wherein the cutter body has an internal three-start cylindrical thread with conical helical surfaces, and the mandrel has a corresponding external three-start cylindrical thread with conical helical surfaces, wherein the mandrel has a base cone below the thread for interaction with the base cone of the cutter in its tail section, and the height of the base cone of the cutter or the base cone of the mandrel does not exceed 1/4 of the smaller diameter of this cone.
  6. 6. A mandrel with a replaceable end mill according to paragraph 5, characterized in that the angle between the generatrix of the lower conical helical surface of the thread of the milling cutter and the mandrel and between the axis of the milling cutter and the mandrel is from 20 to 45°.

Description

The group of inventions relates to the field of metalworking, specifically to milling with end mills, in particular prefabricated ones, and can be used for processing (milling) surfaces of various types, including planes, grooves, ledges, pockets, etc. One of the most important problems in fixing axial rotating tools, including milling cutters, is their precise centering, that is, the coincidence of the axes of the tool (milling cutter), the mandrel, and then the spindle. Similar end mills are known from the prior art, for example, milling cutters with a helical shank: the ZA FUGA series (Source: Catalog. Milling tool: electronic//KZTS: [site]. - URL: http://www.kzts.ru/core/user_files/3_Frezerovanie.pdf, pp. 208, 306 (date accessed: 11/12/2024)). In similar milling cutters, centering occurs via a short cylindrical surface 06 (see Fig. 1 for an image of the similar solution), located between the end 05 of the cutter body 01 and the threaded portion 07 of the cutter. There is a gap (play) between the cylindrical surface 06 of the body 01 and the arbor 02, which allows for misalignment and, consequently, tool alignment errors. This leads to axial and radial runout, which in turn results in uneven loading of the cutting edges of the tool, and, consequently, uneven wear and vibration. The thread in this case serves only as a fastening element and does not participate in locating the cutter body on the arbor. More precise centering can also be achieved using devices that use tapered threads as a centering and fastening element. However, the use of such devices is often impractical due to the extremely high precision requirements and, consequently, the labor-intensive nature of producing tapered threads on both the milling cutter and the mandrel. Thus, the technical problem solved by creating the present group of inventions is the insufficient accuracy of centering the cutter body on the mandrel when using a smooth cylindrical surface and using a cylindrical thread as a fastening element, as well as the need for additional processing of the device surfaces during their manufacture using additive technologies. The technical result achieved by implementing the claimed solutions is more precise centering of the cutter body on the arbor than with similar milling cutters, meaning the cutter axis aligns with the arbor axis. This reduces uneven loads on the tool's cutting edges, resulting in reduced tool wear and vibration. Another technical result achieved through the implementation of the stated solutions is the ability to obtain base surfaces—the base cone and the conical helical surface of the thread inside the cutter body—using additive technology without subsequent additional processing, which increases the manufacturability of the product and reduces labor costs for its manufacture. The group of inventions includes technical solutions for a mandrel and an end mill attached to it, characterizing their interaction with each other. The claimed devices are technically interconnected, manifested in the presence of specific technical features that distinguish the claimed solutions from those known in the prior art. The claimed end mill comprises a cutter body with an internal three-start cylindrical thread with tapered helical surfaces for engagement with a corresponding external three-start cylindrical thread of a mandrel with tapered helical surfaces. Moreover, to ensure centering without limiting the cutter's movement, a base cone is formed in the tail of the cutter body for engagement with the base cone of the mandrel. The height of this cutter cone does not exceed 1/4 of the smaller diameter of this cone. Alternatively, a base cone is formed in the tail of the cutter body, designed to engage the base cone of the mandrel, having a height no greater than 1/4 of the smaller diameter of this mandrel cone. The claimed end mill arbor, designed for mounting an end mill, is characterized by having an external three-start cylindrical thread with tapered helical surfaces for securing the milling cutter. This thread engages a corresponding internal three-start cylindrical thread with tapered helical surfaces on the milling cutter. Moreover, to ensure centering without restricting the milling cutter's movement, a base cone no more than 1/4 the smaller diameter of this cone is formed below the arbor thread for engagement with the base cone of the milling cutter. Alternatively, a base cone is formed below the arbor thread for engagement with the base cone of the milling cutter, which has a height no more than 1/4 the smaller diameter of this cone. The proposed arbor with a replaceable end mill comprises a cutter body that can be detachably attached to the arbor. For this purpose, the cutter body has an internal three-start cylindrical thread with tapered helical surfaces, while the arbor has a corresponding external three-start cylindrical thread with tapered helical surfaces. To ensure centering without restricting the cutter'