US 11,833,631 B2
Main spindle device for machine tool
Seiji Kamiura, Aikawa-machi (JP); and Motoki Murase, Aikawa-machi (JP)
Assigned to MAKINO J CO., LTD., Aikawamachi (JP)
Appl. No. 16/772,833
Filed by MAKINO J CO., LTD., Aikawa-machi (JP)
PCT Filed Dec. 15, 2017, PCT No. PCT/JP2017/045203
§ 371(c)(1), (2) Date Jul. 21, 2020,
PCT Pub. No. WO2019/116573, PCT Pub. Date Jun. 20, 2019.
Prior Publication US 2020/0353580 A1, Nov. 12, 2020
Int. Cl. B23Q 1/70 (2006.01); B23Q 17/00 (2006.01); B23Q 17/22 (2006.01)
CPC B23Q 1/70 (2013.01) [B23Q 17/005 (2013.01); B23Q 17/22 (2013.01); B23Q 2220/006 (2013.01); Y10T 409/309352 (2015.01)] 6 Claims
OG exemplary drawing
 
1. A main spindle device of a machine tool using compressed air to confirm seating of a tool holder, the main spindle device comprising:
a main spindle having a distal end face which a flange end face of the tool holder closely contacts;
an annular recess formed at the distal end face of the main spindle so as to be covered by the flange end face of the tool holder;
an air supply flow channel connecting with the annular recess and supplying the annular recess with compressed air;
a compressed air source supplying air to the air supply flow channel; and
a pressure detector detecting pressure of the compressed air inside the air supply flow channel,
wherein the annular recess has a first section and a second section, wherein the first section has a first bottom surface spaced from the distal end face of the main spindle, and the second section has a second bottom surface spaced from the distal end face of the main spindle,
wherein a distance between the second bottom surface and the distal end face of the main spindle is greater than a distance between the first bottom surface and the distal end face of the main spindle, the air supply flow channel opening at the second section.