Method for Reducing the Regenerative Chatter of Chip-Removal Machines

• US 20180036851A1
• Filed: 02/23/2016
• Published: 02/08/2018
• Est. Priority Date: 02/27/2015
• Status: Active Grant

• Current Assignee: Rattunde & Co. GmbH
• Original Assignee: Rattunde & Co. GmbH
• Inventors: RATTUNDE, Ulrich
• Granted Patent: US 10,562,143 B2
• Time in Patent Office: Days
• CPC Class Codes: B23B 2215/72 Tubes, pipes
• CPC Class Codes: B23B 2250/16 Damping of vibrations
• CPC Class Codes: B23B 2270/30 Chip guiding or removal use of suction B23B2270/62, drilling tools with provision for suction B23B2251/68
• CPC Class Codes: B23B 27/002 with vibration damping means
• CPC Class Codes: B23B 5/167 Tools for chamfering the ends of bars or tubes
• CPC Class Codes: B23C 5/003 with vibration suppressing means
• CPC Class Codes: B23Q 11/0035 by adding or adjusting a mass, e.g. counterweights
• CPC Class Codes: B23Q 11/0039 by changing the natural frequency of the system or by continuously changing the frequency of the force which causes the vibration

Abstract

The invention relates to a method for reducing regenerative chatter in that a workpiece (1) rotates in relation to a tool head (2) having at least one chip-removal tool (3, 3a, 3b, 3c) arranged at one end of the tool head (2), the tool head (2) machines walls of the workpiece (1) by means of the at least one chip-removal tool (3, 3a, 3b, 3c), the tool head (2) is vibrationally excited during the machining, a loose additional mass (m_z) is moved by the vibration, which additional mass randomly touches the tool head (2) in first positions or randomly has no connection to the tool head (2) in second positions, and thus the total mass of the tool head (2) is randomly changed by the amount of the additional mass (m_z).

Claims

1. Method for reducing regenerative chatter in that a workpiece (1) rotates in relation to a tool head (2) having at least one chip-removal tool (3, 3a, 3b, 3c) arranged at one end of the tool head (2), the tool head (2) machines walls of the workpiece (1) by means of the at least one chip-removal tool (3, 3a, 3b, 3c), the tool head (2) is vibrationally excited during the machining, a loose additional mass (m_z) is moved by the vibration, which additional mass randomly touches the tool head (2) in first positions or randomly has no connection to the tool head (2) in second positions, and thus the total mass of the tool head (2) is randomly changed by the amount of the additional mass (m_z) and the vibrational behaviour of the tool head (2) is changed because of the mass change and thus counteracts regenerative chatter, and in that a receptacle (51), by means of which the tool head (2) can be exchangeably placed onto a spindle, is arranged at another end of the tool head (2) opposite the one end.

2. Method according to claim 1, characterised in that a wall is formed as an inner wall (53) with a radius (r1) and the corresponding wall is formed as a corresponding outer wall (57) with a corresponding radius (r2) which is smaller than the radius (r1).

3. Method according to claim 1, characterised in that the wall is formed as an outer wall (71) with a radius (r1) and the corresponding wall is formed as a corresponding inner wall (72) with the corresponding radius (r2) which is smaller than the radius (r1).

4. Chip-removal machine with a tool head (2) with at least one chip-removal tool (3, 3a, 3b, 3c) arranged on one end of the tool head for machining a wall of a workpiece (1), a loose additional mass (m_z) which can have randomly different positions relative to the tool head (2) and which touches the tool head (2) in first positions and which has no connection to the tool head (2) in second positions, wherein the tool head (2) has a first vibrational behaviour in the first positions and a second vibrational behaviour in the second positions and with a receptacle (51), by means of which the tool head (2) can be exchangeably placed onto a spindle, is arranged at another end of the tool head (2) opposite the one end.

5. Chip-removal machine according to claim 4, characterised in that the tool head (2) has a wall which, in operation, rotates about a longitudinal axis and the additional mass (m_z) has a rotating corresponding wall, which, along its entire extent, in the second positions is spaced apart from the rotating wall.

6. Chip-removal machine according to claim 4, characterised in that a wall (53, 71) is cylindrically shaped and a corresponding wall (57, 72) is likewise cylindrically shaped.

7. Chip-removal machine according to claim 4, characterised in that the wall is formed as an inner wall (53) with a radius (r1) and the corresponding wall is formed as a corresponding outer wall (57) with a corresponding radius (r2) which is smaller than the radius (r1).

8. Chip-removal machine according to claim 4, characterised in that the wall is formed as an outer wall (71) with the radius (r1) and the corresponding wall is formed as a corresponding inner wall (72) with the corresponding radius (r2) which is smaller than the radius.