The present application claims priority to Japanese Patent Application Number 2015-163015, filed Aug. 20,2015, the disclosure of which is hereby incorporated by reference herein in its entirety.
1. Field of the Invention
The present invention relates to a radiating structure for a main spindle in a machining apparatus.
2. Description of the Related Art
Since a bearing or the like in a machine tool generates heat due to rotation of a main spindle to bring about thermal displacement or a rise in the pressure on a bearing and affect machining accuracy, a main spindle in a machining apparatus has a cooling structure in order to curb a rise in the temperature of the main spindle.
As a prior art technique pertaining to a cooling structure for a main spindle in a machining apparatus, for example, Japanese Patent Application Laid-Open No. 2014-062620 discloses a structure for a main spindle adopting lubrication of a bearing with air oil, in which air cooling a shaft and the bearing of the main spindle and air oil for lubrication are not mixed together.
Japanese Patent Application Laid-Open No. 2014-117119 discloses a structure which is provided with a cooling air passage along an axial center of a main spindle and includes a blowing section that sucks in outside air from a proximal end of the cooling air passage along with rotation of the main spindle and pressure-feeds the air in an axial center direction of the main spindle.
In a machining apparatus which performs machining with a tool mounted at a distal end of a main spindle, the main spindle distal end includes a drive key for preventing a phase shift in rotation direction between the main spindle and the tool. In connection with this, Japanese Patent Application Laid-Open No. 10-337625 discloses a structure in which drive keys are attached to a distal end of a main spindle by fixing a ring plate that is a ring-like member provided with the drive keys to the distal end of the main spindle, and a distal end portion of the main spindle does not enlarge by a centrifugal force due to absence of a key groove at the main spindle distal end portion.
The aforementioned technique disclosed in Japanese Patent Application Laid-Open No. 2014-062620 implements cooling of the shaft and the bearing as cooling targets by supplying air for cooling but suffers from the problem of the need for a complicated mechanism or complicated equipment.
The technique disclosed in Japanese Patent Application Laid-Open No. 2014-117119 implements cooling of a shaft and a bearing as cooling targets by providing the cooling air passage at the axial center and sucking in outside air from the blowing section provided at the proximal end of the cooling air passage along with rotation of the main spindle. In a machining apparatus, a mechanism for grasping a tool at a main spindle distal end is generally provided at an axial center, and application of the technique to the machining apparatus is difficult.
An object of the present invention is to provide a radiating structure for a main spindle which does not need a complicated mechanism or complicated equipment and is applicable to a main spindle having a general structure that has a mechanism to grasp a tool in a machining apparatus.
The present invention solves the above-described problems by providing a radiator plate or a blade for heat radiation at a member including a drive key at a main spindle distal end.
In a radiating structure for a main spindle in a machining apparatus according to the present invention, a tapered bore is formed at a distal end of the main spindle, a tapered portion of a tool holder is detachably mounted into the tapered bore, a key fixing member provided with a drive key is fixed to the distal end of the main spindle, and the drive key is fit into a key groove formed in the tool holder. This configuration prevents a phase shift in rotation direction of the tool holder arising from rotation of the main spindle. A radiating member which exchanges heat with an ambient atmosphere is provided to the key fixing member provided with the drive key.
The radiating member may be shaped to extend from a base of the key fixing member in a radial direction. In this case, a groove for increasing an area of contact with the atmosphere and agitating the atmosphere may be formed in the radiating member.
The radiating member may include at least one blade-like member which extends from a base of the key fixing member in a radial direction.
The present invention does not need a complicated mechanism or complicated equipment and allows cooling of a shaft and a bearing in a main spindle having a general structure which has a mechanism to grasp a tool in a machining apparatus.
The above and other objects and features of the present invention will be apparent from the following description of embodiments with reference to the appended drawings, in which:
The structure of a main spindle having a radiating structure according to a first embodiment of the present invention will be described with reference to
As shown in
As in techniques described in Japanese Patent Application Laid-Open No. 10-337625 mentioned earlier and the like, the drive key 3a prevents a shift in rotation direction of a tool which fits in a key groove formed in a tool holder (not shown) from a main spindle. The radiating member 3b is shaped to extend from a base of the key fixing section 3 in a radial direction and increases heat capacity of the main spindle 1. When the main spindle 1 rotates, the key fixing section 3 fixed to the main spindle 1 rotates together to exchange heat with an ambient atmosphere. In this manner, a shaft 4 and a bearing 5 of the main spindle 1 are cooled.
The structure of a main spindle having a radiating structure according to a second embodiment of the present invention will be described with reference to
As shown in
The structure of a main spindle having a radiating structure according to a third embodiment of the present invention will be described with reference to
As shown in
In a main spindle 1, a key fixing section 3 is not designed with heat radiation in mind. The key fixing section 3 has low heat capacity and is not shaped to actively change heat with an ambient atmosphere.
In contrast, in the present invention, as described with reference to
Note that the shape of a radiating member is not limited by the above-described embodiments. To increase heat dissipation, a groove is formed in a radiating member or a radiating member itself is shaped like a fan to agitate an atmosphere in the embodiments. Besides these, it is possible to vary the thickness of a disk with a radial position in the disk-like radiating member shown in
As methods for fastening a key fixing section to a distal end of a main spindle, fastening with a bolt, bonding, shrinkage fitting, press fitting, and the like are generally conceivable. Any fastening method may be employed in the present invention.
Although a radiating member is made of metal in the above-described embodiments, a radiating member may be made using a resin with high thermal conductivity or the like instead of metal. A radiating member may be made of the same material as a key fixing section and be integral with the key fixing section or may be made of a different material. In the latter case, the radiating member and the key fixing section may be fixed through, for example, fastening with a bolt.
Number | Date | Country | Kind |
---|---|---|---|
2015-163015 | Aug 2015 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
1635769 | Royle | Jul 1927 | A |
5088362 | Schalles | Feb 1992 | A |
5150994 | Hsu | Sep 1992 | A |
5290130 | Beretta | Mar 1994 | A |
5593258 | Matsumoto | Jan 1997 | A |
5772367 | Daniel | Jun 1998 | A |
20030170087 | Sugata | Sep 2003 | A1 |
20090265783 | Huynh | Oct 2009 | A1 |
20100086373 | Kleiner | Apr 2010 | A1 |
20110001282 | Taniguchi | Jan 2011 | A1 |
20120121354 | Dickey | May 2012 | A1 |
20130327505 | Gonzalez | Dec 2013 | A1 |
20140020919 | Dvorak | Jan 2014 | A1 |
20150345510 | Beers | Dec 2015 | A1 |
20170341115 | Noll | Nov 2017 | A1 |
20180154507 | Roehm | Jun 2018 | A1 |
20180175703 | Zahradsky | Jun 2018 | A1 |
Number | Date | Country |
---|---|---|
1065028 | Jan 2001 | EP |
S52-132374 | Oct 1977 | JP |
61-1345 | Jan 1986 | JP |
S611345 | Jan 1986 | JP |
61025747 | Feb 1986 | JP |
62004550 | Jan 1987 | JP |
H0457650 | Feb 1992 | JP |
H10337625 | Dec 1998 | JP |
11090751 | Apr 1999 | JP |
H11-235608 | Aug 1999 | JP |
WO 2009107493 | Sep 2009 | JP |
2010149227 | Jul 2010 | JP |
2013-91134 | May 2013 | JP |
2013091134 | May 2013 | JP |
2013226616 | Nov 2013 | JP |
2014062620 | Apr 2014 | JP |
2014117119 | Jun 2014 | JP |
Entry |
---|
WO 2009107493 A1 Machine Translation English—Retrieved Jul. 2017. |
JP 11090751 A Machine Translation English—Retrieved Jul. 2017. |
JP61025747A Machine Translation English—Retrieved Jul. 2017. |
JPH1190751A Machine Translation English—Retrieved Jul. 2017. |
Thermal Conductivity of Engineering Materials—Blumm (Jan. 2013). |
JP2013226616A Machine Translation English—Retrieved Nov. 2017. |
JP S611345 U Machine Translation English—Retrieved May 2018. |
JP H10-337625 A Machine Translation English—Retrieved Jul. 2017. |
JP2013226616A Machine Translation English—Retrieved Jul. 2017. |
Ghoshdastidar, P.S.. (2012). Heat Transfer (2nd Edition). Oxford University Press. |
JP 2013091134 A Machine Translation English—Retrieved May 2018. |
JP2014117119A Machine Translation English—Retrieved May 2018. |
JPH0457650A Machine Translation English—Retrieved May 2018. |
Notice of Allowance in Japanese Application No. 2015-163015, dated Jun. 19, 2018, 6pp. |
Office Action in JP Application No. 2015-163015, dated Sep. 12, 2017, 7 pp. |
Number | Date | Country | |
---|---|---|---|
20170050283 A1 | Feb 2017 | US |