End mill machining apparatus, CAM apparatus, NC program, and machining method
AssigneeNational University Corporation Nagoya University
InventorsTakehiro Hayasaka, Shunsuke Fujimaki, Eiji Shamoto
Life of this patent
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Abstract
An end mill machining apparatus, a CAM apparatus, an NC program, and a machining method which suppress regenerative self-excited vibration and mode-coupling self-excited vibration. An end mill machining apparatus includes an end mill, and a control section for controlling the end mill. The ratio of the protrusion length of the end mill to the diameter of the end mill falls within a range of 5 to 50. The end mill is a variable pitch, uniform helix type or a variable helix type. The control section controls the end mill such that the contact angle between the end mill and a workpiece M1 during machining becomes equal to or smaller than a critical contact angle θlim.
Claims17
An end mill machining apparatus comprising:
- an end mill;
- and
- a control section for controlling the end mill,
- a ratio of a protrusion length of the end mill to a diameter of the end mill falls within a range of 5 to 50;
- the end mill is a variable pitch, uniform helix type or a variable helix type;
- and
- the control section controls a contact angle between the end mill and a workpiece during machining to a critical contact angle θlim or smaller,
- the critical contact angle θlim is the angle when a solution satisfying the following equation does not appear even when the axial depth of cut a is increased to infinity,
- det
-
- [
- [
- I
- ]
- -
- 1
- 2
-
- aK
- t
-
- [
- A
- 0
- ]
-
- [
- G
-
- (
- i
-
-
- ω
- c
- )
- ]
- ]
- =
- 0
- I:
- two-dimensional unit matrix
- a:
- axial depth of cut
- Kt:
- specific cutting force
- ωc:
- chatter frequency
- A0:
- DC component of a cutting force coefficient matrix
- G(iωc):
- transfer function at the chatter frequency.
A machining method for machining a workpiece by using an end mill, the machining method comprising:
- using, as the end mill, an end mill of a variable pitch, uniform helix type or a variable helix type which is configured such that a ratio of a protrusion length of the end mill to a diameter of the end mill falls within a range of 5 to 50;
- and
- machining the workpiece in a state in which a contact angle between the end mill and the workpiece during the machining is a critical contact angle θlim or smaller,
- the critical contact angle θlim is the angle when a solution satisfying the following equation does not appear even when the axial depth of cut a is increased to infinity,
- det
-
- [
- [
- I
- ]
- -
- 1
- 2
-
- aK
- t
-
- [
- A
- 0
- ]
-
- [
- G
-
- (
- i
-
-
- ω
- c
- )
- ]
- ]
- =
- 0
- I:
- two-dimensional unit matrix
- a:
- axial depth of cut
- Kt:
- specific cutting force
- ωc:
- chatter frequency
- A0:
- DC component of a cutting force coefficient matrix
- G(iωc):
- transfer function at the chatter frequency.
Dependencies are inferred from the claim text.