GB2137123A - Machine Tool Spindle with Coated Socket - Google Patents

Machine Tool Spindle with Coated Socket Download PDF

Info

Publication number
GB2137123A
GB2137123A GB08320501A GB8320501A GB2137123A GB 2137123 A GB2137123 A GB 2137123A GB 08320501 A GB08320501 A GB 08320501A GB 8320501 A GB8320501 A GB 8320501A GB 2137123 A GB2137123 A GB 2137123A
Authority
GB
United Kingdom
Prior art keywords
spindle
machine tool
tool
coating layer
main spindle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08320501A
Other versions
GB8320501D0 (en
GB2137123B (en
Inventor
Kiyokazu Kuwabara
Takahiro Chiyoda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Okuma Corp
Original Assignee
Okuma Tekkosho KK
Okuma Machinery Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Okuma Tekkosho KK, Okuma Machinery Works Ltd filed Critical Okuma Tekkosho KK
Publication of GB8320501D0 publication Critical patent/GB8320501D0/en
Publication of GB2137123A publication Critical patent/GB2137123A/en
Application granted granted Critical
Publication of GB2137123B publication Critical patent/GB2137123B/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
    • B23B31/006—Conical shanks of tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
    • B23B31/02—Chucks
    • B23B31/24—Chucks characterised by features relating primarily to remote control of the gripping means
    • B23B31/26—Chucks characterised by features relating primarily to remote control of the gripping means using mechanical transmission through the working-spindle
    • B23B31/261—Chucks characterised by features relating primarily to remote control of the gripping means using mechanical transmission through the working-spindle clamping the end of the toolholder shank
    • B23B31/265—Chucks characterised by features relating primarily to remote control of the gripping means using mechanical transmission through the working-spindle clamping the end of the toolholder shank by means of collets

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Gripping On Spindles (AREA)
  • Jigs For Machine Tools (AREA)

Abstract

In order to avoid abrasion called fretting corrosion on the contacting surfaces between the shank of a cutting tool 10 and the spindle 1, which abrasion leads first to oxidation of the surface and then fatigue rupture, the inner surface of the tapered hole of the spindle is provided with a coating 2, e.g. a soft plating of gold or hard coating of Ti-N or Ti-C. <IMAGE>

Description

SPECIFICATION Main Spindle for Machine Tool Background of the Invention The present invention relates to a main spindle of a machine tool for cutting workpieces by rotating the main spindle attached with a tool at its tip, and more particularly to the main spindle in which the inner surface of the hole for receiving the tool is provided with coating.
When workpieces are subjected to cutting by a machine tool, a machining center and so on, the cutting force acts on the tool itself and causes a minor relative sliding motion at surfaces where the tool and the main spindle are contacted.
When the cutting force is great, the relative sliding motion causes abrasion called fretting corrosion on the contacting surface between the tool and the spindle. The abrasion leads first to oxidation of the surface and then fatigue rupture.
Heretofore, various measures were taken to prevent the abrasion such as by selecting suitable material for the spindle or by improving the method for the heat treatment. The recent trend in machining requires greater cutting force and when an end-mill is attached to the spindle for operation, the table on which the workpiece is mounted may be raised as a counter-reaction to the pressing force on the tool. Under such conditions, conventional preventive measures become ineffective against fretting corrosion.
Summary of the Invention Accordingly, an object of this invention is to provide a main spindle for a machine tool which is resistant against the fretting corrosion by coating the inner surface of the tapered hole of the spindle.
Another object of this invention is to provide optimum coating materials for preventing the fretting corrosion.
Other aspects, objects and the several advantages of this invention will become apparent to one skilled in the art from a reading of the following disclosure and the appended claims.
Brief Description of the Drawings In the drawings: Fig. 1 is a sectional view of a spindle head which includes the tapered hole for receiving the cutting tool; and Fig. 2 is a sectional structural view of a spindle mounted with a cutting tool for ATC.
Detailed Description of the Invention As shown in Figs. 1 and 2, in this invention the main spindle 1 of a machine tool is attached with a tool 10 at its tip and rotated about a fixed member 5 through bearings 3 and 4 for cutting operation and so on with the tool 10. The tapered hole 6 of the spindle 1 for receiving a tool is provided with a coating layer 2 at its inner surface.
In other words, the spindle 1 has a structure as shown in Fig. 1, and the tapered hole 6 is provided at the center of the tip of the spindle 1 for receiving the tool at the working time. A key 7 is screwed at the end surface of the spindle 1 for securing the mounted tool and preventing the same from rotating. Uniform coating layer 2 of several microns (about 2 to 3 microns) in thickness is formed over the entire surface of the tapered hole 6. Fig. 2 shows the manner in which the tool 10 for automatic tool changer (ATC) is mounted in the tapered hole 6 of the spindle 1.
The tool 10 is tightly pressed against the inner surface of the tapered hole 6, or the coating layer 2, by pulling a mounting member 11 in the direction of arrow from the rear end thereof Further, the tool 10 is provided with a key groove 12 to be engaged with the key 7, whereby the tool 10 will not rotate in the tapered hole 6 of the spindle 1 during the machining work.
Soft plating of gold and hard plating of Ti-C or Ti-N are suggested as the coating material. Gold is excellent in ductility, malleability and resistance against oxidation, corrosion, and abrasion, and therefore has long been used in various fields such as coin, decoration and dental uses. Gold plating has been used mainly for decorative purposes and not so much as a material for preventing abrasion of a machine tool. In order to coat the tapered hole 6 of the spindle 1, the tapered hole 6 must be subjected first to conventional processes of cutting, heat treatment and grinding. The plating is then provided on the inner surface of the tapered hole 6 which has been finished with grinding. It is possible to obtain a uniform and smooth layer of plating several microns in thickness.Moreover, gold is more adaptable with iron: gold molecules diffuse and penetrate into iron molecules to prevent break away. Because of low coefficient of friction, the relative sliding movement between the inner surface of the tapered hole 6 of the spindle 1 and the tool 10 caused by strong cutting generates very small frictional force and this in turn causes little heat generation and thus no oxidation. There will therefore be no fretting corrosion. In case Ti-C coating is employed, the entire surface of the ground spindle is coated by chemical vapor deposition method to obtain a coating layer of about 10 to 15 microns in thickness. Ti-C coating has an extremely high hardness of 3800 HV with high corrosion and abrasion resistance. It is also highly resistant against flaking because the coating is chemically bonded with parent material. This helps prevent fretting corrosion.Ti N coating may be used in place of Ti-C coating.
Since Ti-N coating is treated at a temperature lower than that of Ti-C coating, deformation of the spindle as the parent material can be reduced.
As a soft coating, the tapered hole 6 can be treated with phosphate before dry-coated with molybdenum disulfide in dry state. Silver plating can also be employed in place of gold plating. The former has properties similar to those of solid lubricant and thus is highly resistant against abrasion and water. The latter is similar to gold plating in characteristics, but is slightly inferior because it gets rusted by water and air.
As a hard coating, VC (vanadium carbide), Nb-C (niobium carbide), Cr-C (chromium carbide), etc.
are suggested beside Ti-C and Ti-N. The former VC and Nb-C are higher in hardness and resistance against corrosion and exfoliation.
Moreover, they have a small coefficient of friction and are good in sliding. They also have good affinity with carbon steel. Cr-C is superior in corrosion resistance although it is slightly inferior in hardness.
As has been described in the foregoing, fretting corrosion which occurs due to relative sliding movement of the spindle with the tool can be prevented by coating the inner surface of the tapered hole.

Claims (8)

1. A main spindle for a machine tool for cutting workpieces by rotating the spindle attached with a tool at its tip, which is characterized in that the inner surface of the tapered hole for receiving the tool is formed with a coating layer.
2. The main spindle for a machine tool as claimed in Claim 1, wherein the coating layer is made of gold plating.
3. The main spindle for a machine tool as claimed in Claim 1, wherein the coating layer is made of Ti-C.
4. The main spindle for a machine tool as claimed in Claim 1 , wherein the coating layer is made of Ti-N.
5. The main spindle for a machine tool as claimed in Claim 1, wherein the coating layer is made of silver plating.
6. The main spindle for a machine tool as claimed in Claim 1, wherein the coating layer is made of dry-coated with molybdenum disulfide.
7. The main spindle for a machine tool as claimed in Claim 1, wherein the coating layer is made of VC.
8. The main spindle for a machine tool as claimed in Claim 1, wherein the coating layer is made of Cr-C.
GB08320501A 1982-12-29 1983-07-29 Machine tool spindle with coated socket Expired GB2137123B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19650882U JPS59105334U (en) 1982-12-29 1982-12-29 Machine tool spindle

Publications (3)

Publication Number Publication Date
GB8320501D0 GB8320501D0 (en) 1983-09-01
GB2137123A true GB2137123A (en) 1984-10-03
GB2137123B GB2137123B (en) 1986-06-18

Family

ID=16358916

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08320501A Expired GB2137123B (en) 1982-12-29 1983-07-29 Machine tool spindle with coated socket

Country Status (3)

Country Link
JP (1) JPS59105334U (en)
DE (1) DE3328224A1 (en)
GB (1) GB2137123B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4997324A (en) * 1988-04-21 1991-03-05 Toshiba Kikai Kabushiki Kaisha Spindle structure for machine tool
US5118231A (en) * 1991-05-03 1992-06-02 Daniels Edward J Tool holder
US6607850B2 (en) * 2000-06-29 2003-08-19 Borgwarner, Inc. Hard steel articles
EP1453629A1 (en) * 2001-07-23 2004-09-08 Korea Advanced Institute of Science and Technology High stiffness composition tool bar
US20170355024A1 (en) * 2016-06-14 2017-12-14 Roller Bearing Company Of America, Inc. Flexible coupling for attaching a collet to a draw bar

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS615502U (en) * 1984-06-19 1986-01-14 キタムラ機械株式会社 Machine Tools
JPS61136748A (en) * 1984-12-04 1986-06-24 Nippei Toyama Corp Cutting-tool holding apparatus
JPH0613770Y2 (en) * 1985-02-22 1994-04-13 京セラ株式会社 Machine tool rotary head
JP2559057B2 (en) * 1988-03-25 1996-11-27 キタムラ機械 株式会社 Machine tool spindle and tool holder
DE102009018813B4 (en) 2009-04-24 2023-02-16 Gühring KG tool system component
CN112247166A (en) * 2020-10-12 2021-01-22 吉林大学 Clamping device for machining electric spindle based on reliability and safety consideration

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB858153A (en) * 1959-03-16 1961-01-11 Humberg Willi Improvements in and relating to tool clamping devices
GB1135922A (en) * 1966-02-02 1968-12-11 Vsesoyuzny Ni Instr I Device for mounting tools and workpieces on metal-working machines
GB1518295A (en) * 1975-10-01 1978-07-19 Clay R Adaptor for rotary cutting tool holder

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5226217B2 (en) * 1972-11-16 1977-07-13
CH566183A5 (en) * 1973-06-26 1975-09-15 Mueller Sphinxwerke & Cie Ag Hard twist-drill for glass reinforced plastics, esp epoxy - has very thin titanium monoxide coating generating little heat
JPS5621706A (en) * 1979-07-27 1981-02-28 Toyoda Mach Works Ltd Cutting tool body holder
JPS56112462A (en) * 1980-02-08 1981-09-04 Hitachi Metals Ltd Surface-coated superhard alloy material and its manufacture

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB858153A (en) * 1959-03-16 1961-01-11 Humberg Willi Improvements in and relating to tool clamping devices
GB1135922A (en) * 1966-02-02 1968-12-11 Vsesoyuzny Ni Instr I Device for mounting tools and workpieces on metal-working machines
GB1518295A (en) * 1975-10-01 1978-07-19 Clay R Adaptor for rotary cutting tool holder

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4997324A (en) * 1988-04-21 1991-03-05 Toshiba Kikai Kabushiki Kaisha Spindle structure for machine tool
US5118231A (en) * 1991-05-03 1992-06-02 Daniels Edward J Tool holder
US6607850B2 (en) * 2000-06-29 2003-08-19 Borgwarner, Inc. Hard steel articles
EP1453629A1 (en) * 2001-07-23 2004-09-08 Korea Advanced Institute of Science and Technology High stiffness composition tool bar
EP1453629A4 (en) * 2001-07-23 2006-08-09 Korea Advanced Inst Sci & Tech High stiffness composition tool bar
US20170355024A1 (en) * 2016-06-14 2017-12-14 Roller Bearing Company Of America, Inc. Flexible coupling for attaching a collet to a draw bar
US10639726B2 (en) * 2016-06-14 2020-05-05 Schaublin Sa Flexible coupling for attaching a collet to a draw bar

Also Published As

Publication number Publication date
GB8320501D0 (en) 1983-09-01
GB2137123B (en) 1986-06-18
JPS59105334U (en) 1984-07-16
DE3328224A1 (en) 1984-07-05

Similar Documents

Publication Publication Date Title
Hintermann Adhesion, friction and wear of thin hard coatings
JP4874911B2 (en) Coating tool with long useful life
GB2137123A (en) Machine Tool Spindle with Coated Socket
US4621026A (en) Process for providing metallic articles and the like with wear-resistant coatings, and improved coated metallic articles and the like
US20070104953A1 (en) DLC coating, and DLC coating coated tool
Rathod et al. Evaluating the effectiveness of the novel surface textured tools in enhancing the machinability of titanium alloy (Ti6Al4V)
US5921727A (en) Reamer with friction resistant layer and method for forming same
Hintermann Thin solid films to combat friction, wear, and corrosion
JPS613888A (en) Material convertible to amorphous state from non-amorphous state under abrrasive load and manufacture
JP2004238736A (en) Hard film, and hard film-coated tool
US4484988A (en) Process for providing metallic articles and the like with wear-resistant coatings
Dingremont et al. Application of duplex coatings for metal injection moulding
EP1660694B1 (en) Coated bore cutting tools
KR920008127B1 (en) Tool holder for machine tool
US4997324A (en) Spindle structure for machine tool
JP2000233324A (en) Solid lubricating film for coating tool and manufacture thereof
JP4331807B2 (en) Hard film and hard film coated member with excellent wear resistance
Subramanian et al. Performance evaluation of TiN-coated twist drills using force measurement and microscopy
Bhushan Overview of Coating Materials, Surface Treatments, and Screening Techniques for Tribological Applications—Part 1: Coating Materials and Surface Treatments
Günther et al. Advanced coatings by vapour phase processes
JP2003112229A (en) Heading tool for stainless steel work
US6338879B1 (en) Solid lubricant film for coated cutting tool and method for manufacturing same
Lin et al. Analysis of the friction and wear mechanisms of structural ceramic coatings. Part 1: The effect of processing conditions
Wakabayashi et al. The action of gaseous lubricants in the orthogonal machining of an aluminium alloy by titanium nitride coated tools
Minevich et al. Case studies on tribological behavior of coated cutting tools

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee