SPINDLE DEVICE OF MACHINE TOOL
First Claim
1. A spindle device of machine tool comprising:
- a spindle rotatably supported by a housing;
a rod movably supported along an axial direction in the spindle;
a collet that clamps and unclamps a tool by movement of the rod;
a biasing unit that biases the rod in a tool clamping direction by the collet;
a drive that presses the rod against a biasing force of the biasing unit to move the tool in an unclamping direction;
a rod-pressing-force detecting unit that detects a pressing force to the rod by the drive;
a rod-displacement detecting unit that detects displacement of the rod;
a tool-clamping-force detecting unit that detects a tool clamping force by the collet based on the pressing force to the rod detected by the rod-pressing-force detecting unit and the displacement of the rod detected by the rod-displacement detecting unit; and
a replacement-timing determining unit that determines a replacement timing of the biasing unit based on the tool clamping force detected by the tool-clamping-force detecting unit and a preset biasing force characteristic value of the biasing unit.
1 Assignment
0 Petitions
Accused Products
Abstract
A spindle device of machine tool includes a pressure sensor (31) that detects a pressing force to a rod (18) by a drive (25), a displacement sensor (32) that detects displacement of the rod (18), a tool clamping-force detector (33) that detects a clamping force to a tool (19) by a collet (20) based on the pressing force to the rod (18) and the displacement of the rod (18), and a spring-replacement-timing determining unit (36) that determines a replacement timing of disc springs (24) based on the tool clamping force and a preset biasing force characteristic value of the disc springs (24), thereby allowing highly accurate determination of a replacement timing of a biasing unit by appropriately detecting a tool clamping force.
-
Citations
8 Claims
-
1. A spindle device of machine tool comprising:
-
a spindle rotatably supported by a housing; a rod movably supported along an axial direction in the spindle; a collet that clamps and unclamps a tool by movement of the rod; a biasing unit that biases the rod in a tool clamping direction by the collet; a drive that presses the rod against a biasing force of the biasing unit to move the tool in an unclamping direction; a rod-pressing-force detecting unit that detects a pressing force to the rod by the drive; a rod-displacement detecting unit that detects displacement of the rod; a tool-clamping-force detecting unit that detects a tool clamping force by the collet based on the pressing force to the rod detected by the rod-pressing-force detecting unit and the displacement of the rod detected by the rod-displacement detecting unit; and a replacement-timing determining unit that determines a replacement timing of the biasing unit based on the tool clamping force detected by the tool-clamping-force detecting unit and a preset biasing force characteristic value of the biasing unit. - View Dependent Claims (2, 3, 7, 8)
-
-
4. A spindle device of machine tool comprising;
-
a spindle rotatably supported by a housing; a rod movably supported along an axial direction in the spindle; a collet that clamps and unclamps a tool by movement of the rod; a biasing unit that biases the rod in a tool clamping direction by the collet; a drive that presses the rod against a biasing force of the biasing unit to move the tool in an unclamping direction; a rod-pressing-force detecting unit that detects a pressing force to the rod by the drive; a rod-displacement detecting unit that detects displacement of the rod; a tool-clamping-force detecting unit that detects a tool clamping force by the collet based on the pressing force to the rod detected by the rod-pressing-force detecting unit and the displacement of the rod detected by the rod-displacement detecting unit; and a replacement-timing determining unit that determines a replacement timing of the biasing unit based on a change in the tool clamping force with time detected by the tool-clamping-force detecting unit. - View Dependent Claims (5, 6)
-
Specification