GB2177953A - Machine tools - Google Patents

Machine tools Download PDF

Info

Publication number
GB2177953A
GB2177953A GB08617834A GB8617834A GB2177953A GB 2177953 A GB2177953 A GB 2177953A GB 08617834 A GB08617834 A GB 08617834A GB 8617834 A GB8617834 A GB 8617834A GB 2177953 A GB2177953 A GB 2177953A
Authority
GB
United Kingdom
Prior art keywords
holder
tool
actuator
workpiece
machine
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
GB08617834A
Other versions
GB2177953B (en
GB8617834D0 (en
Inventor
Nigel Henry New
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.)
AE PLC
Original Assignee
AE PLC
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 AE PLC filed Critical AE PLC
Publication of GB8617834D0 publication Critical patent/GB8617834D0/en
Publication of GB2177953A publication Critical patent/GB2177953A/en
Application granted granted Critical
Publication of GB2177953B publication Critical patent/GB2177953B/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
    • B23Q1/25—Movable or adjustable work or tool supports
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/182—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control
    • G05B19/184—Generation of cam-like surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
    • B23Q1/25—Movable or adjustable work or tool supports
    • B23Q1/26—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members
    • B23Q1/34—Relative movement obtained by use of deformable elements, e.g. piezoelectric, magnetostrictive, elastic or thermally-dilatable elements
    • B23Q1/36—Springs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q11/00—Accessories fitted to machine tools for keeping tools or parts of the machine in good working condition or for cooling work; Safety devices specially combined with or arranged in, or specially adapted for use in connection with, machine tools
    • B23Q11/14—Methods or arrangements for maintaining a constant temperature in parts of machine tools
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/19—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
    • G05B19/39—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path using a combination of the means covered by at least two of the preceding sub-groups G05B19/21, G05B19/27, and G05B19/33
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
    • G05B2219/30—Nc systems
    • G05B2219/42—Servomotor, servo controller kind till VSS
    • G05B2219/42089—Quick but coarse loop and slow but fine loop, dexterity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T82/00—Turning
    • Y10T82/13—Pattern section
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T82/00—Turning
    • Y10T82/25—Lathe
    • Y10T82/2585—Tool rest

Description

1 GB 2 177 953 A 1
SPECIFICATION
Machinetools v The invention relates to machine tools and in particu- lar to the tool holders of such machine tools and their actuation.
In conventional machine tools, even machine tools of the numerical controlled (NC) and computer numerical controlled (MC) type, thetool is mounted on a carnagewhich is moved by a motor driving the carriage through a lead screw. Tool control signals are supplied to the motor by a control system to cause thetool to machine a rotating workpieceto a required profile.
It is a disadvantage of such machine tools thatthe inertia of the tool carriage and the backlash in the lead screw limitsthe rate atwhich the tool can be moved.
Thus such machine tools cannot rapidly machine workpiecesto complex surface profiles.
According to a first aspect of the invention, there is provided a machine tool comprising a workpiece hol derfor holding and rotating a workpieceto be machined, an elongate tool holder having two ends and being mounted, intermediate said ends, for pivotal movement, a tool carried towards one end of the elongate tool holderfor machining the workpiece, an electric actuator having an actuator coil and a movable output member connected to the other end of the elongate tool holder, and a control system for supplying to the actuator coil, signals corresponding to a required workpiece profile, operation of the actuator moving the movable output memberto pivot the tool holderto cause the tool to machinethe workpiece to said profile.
According to a second aspect of the invention, there is provided a machine tool comprising a work piece holderfor holding and rotating a workpiece to be machined, an elongate tool holder having two ends and mounted intermediate said ends for pivotal movement about an axis normal to the length of said holder, said mounting including two spring strips which are connected between the tool holder and a mounting, which diverge towards the tool holder and which lie in respective planes intersecting atsaid pivotaxis, a tool atone end of saidtool holderfor machining theworkpiece and an actuatoratthe other end of thetool holderfor pivoting thetool holder about said axis in accordance with control signals supplied thereto, to causethetool to machinethe workpiece to a required profile.
Thefollowing is a more detailed description of one embodimentof the invention, byway of example, reference being madetothe accompanying drawings inwhich:
Figure 1 is a schematicviewof a machinetool incorporating an elongatetool holderpivotable about an axis bythe actuator, and including a positiontrans ducer, and Figure2 is a view, to a largerscalethan Figure 1, of 125 thetool holder actuator and position transducerof Figure 1, the actuator and the position transducer being shown in section.
Referring firstto Figure 1, the machinetool corn prises a workpiece holder 10 for holding and rotating 130 a workpiece 11. This workpiece 11 maybe, for example, a piston or a bearing whose surface is to have a complex profile, such as the profiles disclosed in our U.K.Patent Specification No.2104188.
A carriage 12 is mounted for movement in a direction parallel to the axis of rotation of the workpiece 11 by a motor 13 acting through a lead screw 14. The carriage 12 carries a tool holder 15 connected to a mounting 16 and movable by an actuator 17. One end of the tool holder 15 carries a tool 18 and the other end of the tool holder is connected to a linearvariable displacement position transducer 19.
These latter parts will now be described in more details with reference to Figure 2.
The tool holder 15 is of low interia and is formed by a straight bar of generally rectangular cross-section which may be of titanium or an aluminium alloy. The tool holder 15 is carried on the mounting 16 for pivotal movement about an axis normal to the length of the tool holder 15. This mounting is effected by two flat spring strips 20 which are connected between the tool holder 15 and the mounting 16, which diverge towards the tool holder 15 and which lie in respective planes intersecting said pivot axis. The spring strips 20 are received in respective slots 21 provided in the tool holder 15 and the mounting 16.
In the embodiment shown, these spring strips 20 are approximately one third the way along the tool holderfrom the tool 18. This provides a lever arm effect, which can be varied as required by altering the position of the spring strips along the tool holder 15.
The end of the tool holder 15 opposite the tool 18 carries a rod 22 which extends in a direction normal to the pivot axis of the tool holder 15 and normal to the length of the tool holder 15. The rod 22 is conneted to, and forms a movable output member of,a movable coil 23 of the actuator 17 operating between the pole pieces 25,26 of a magnetic core of the actuator 17.
Asecond rod 29 extendsfromthetool holder 15ina direction which is the same as the direction of the rod 22. However, the second rod 29 is on the opposite side of the tool holder 15 to the rod 22. This second rod 29 carries a core 30 which is arranged within a coil 31 to from the position transducer 19.
With reference to Figure 1, the coil 23 of the actuator 17 is connected to an amplifier 35 which receives a feedbacksignal from the position transducer 19. A control system 36 supplies control signals in digital form to a digital-to-analogue converter37 whose analogue output is provided as a second input to the amplifier 35. The control system also supplies positioning signals to the motor 13 and is connected to the drive of the workpiece holder 10.
The control system 37 may be of any convenient kind which produces as an output a succession of signals defining required tool positions to machine a predetermined profile on the workpiece 11. For exampie, the control system could be the control system described in ourco-pending U.K.Patent Application No.85.18609 filed 23rd July 1985. Inthis system,the workpiece holder 10 includes a stepping motorwhich receives a predetermined number of steps perrevolution.Before machining,a computer within the control system works outthe required tool positionsto machine a workpiece profile, the computer storing a 2 GB 2 177 953 A 2 required tool position for each step of the workpiece stepping motor, starting from a datum. When machining commences, the workpiece motor is stepped, and after it passes the datum, the computer outputs a succession of workpiece motor stepping signals and a corresponding succession of tool position signals which are fed to the digital-to-analogue converter and the carriage motor 13 to effect required tool movement.
Thewaythe signals are applied to the digital-toanalogue converter37 are dealtwith, asfollows.
In the digital-to-analogue converter37, each digital position signal is converted into an analogue signal.
This is applied as one input of the amplifier35 togetherwith a feedback signal from the position transducer 19. The corrected tool position signal so derived isfed tothe actuator 17to energisethe coil 23. The magneticfield so induced in the coil 23 movesthe rod 22 and causesthetool holderto pivot on the spring strips 20 about its pivotal axis. Thus,thetool 18 is movedto position to machine the workpiece to the required profile.
Thespring strips 20 provide a restoring forcewhich tendsto return theworkpiece holder 15to a datum position. This obviatesthe needforany restoring spring means in the actuator 17.
The movement of the too[ holder 15 moves the core 30 of the position transducer 19, so providing the feedback signal to the amplifier 35.
It will be appreciated that actuators otherthan that shown in the drawings may be used. For example, a linear motor may be used, in which the core is moved relative to a stationary coil.
Although the spring strips 20 represent a particular- ly beneficial way of mounting thetool holder 15, because they are substantially free from frictional losses and back-lash, itwill be appreciated thatthe too[ holder may be mounted for pivotal movement in otherwaysthan by spring strips 20.
The machine tool described above with reference to the drawings is a tool holderwhich is of lowweight and inertia. The actuator and tool holder can respond quicklyto positioning signals and this meansthatthe too[ can machine on the workpiece complex profiles at high speed; certainly at much higher speeds than conventional carriage and lead screw arrangements. The tool holder, its mounting and the actuator are of simple and comparatively inexpensive construction but are robust and reliable in operation.

Claims (12)

1. A machine tool comprising a workpiece holder for holding and rotating a workpieceto be machined, an elongatetool holder having two ends and being mounted, intermediate said ends, for pivotal movement, a tool carriedtowards one end of the elongate tool holderfor machining the workpiece, an electrifc actuator having an actuator coil and a movable out- put member connected to the other end of the elongatetool holder, and a control system for supplying to the actuatorcofl, signals corresponding to a required workpiece profile, operation of the actuator moving the movable output memberto pivotthetool holder to cuase the tool to machine the workpiece to said profile.
2. A machine tool according to claim 1, wherein means are provided which apply to the tool holder a restoring force urging the tool holder towards a datum position.
3. A machine tool according to claim 2, wherein the restoring means comprise two spring strips which extend between a mounting and the tool holder and which lie in respective planes intersecting at the pivot axis of the tool holder and diverging therefrom.
4. A machine tool according to anyone of claims 1 to 3, wherein the movable output member comprises a rod fixed atone end to the elongate too] holder and at an opposite end to the electric actuator.
5. A machine tool according to claim 4, wherein the rod is connected to the actuator coil, which is movable with the rod.
6. A machine tool according to claim 4, wherein the coil and a core of the actuator are fixed, with the rod connected to a diaphragm of the actuatorspaced from a pole of the coil, the diaphragm being moved in accordance with the signals from the control system.
7. A machine tool according to anyone of claims 1 to 6, wherein the control system produces signals in digital form, a dig ital-to-analogue converter being provided for converting said digital signals to analogue signals, which are fed to the actuator.
8. A machine too[ according to anyone of claims 1 to 7, wherein an amplifier is provided for amplifying the control system signals before said signals are applied to the actuator.
9. A machine tool according to claim 8, wherein a position transducer is provided forfeeding positional feedback signals to the amplifier.
10. A machine tool according to claim 9, wherein the position transducer comprises a linearvariable displacement transducer having a core which extends from the tool holder in a direction which is the same as the direction of movement of the output member of the actuator but which core is on the opposite side of the tool holder.
11. A machine tool comprising a workpiece holderfor holding an rotating a workpieceto be machined, an elongatetool holder having two ends and mounted intermediate said endsfor pivotal movement aboutan axis normal tothe length of said holder, said mounting including two spring strips which are connected between thetool holder and a mounting, which diverge towards the tool holder and which lie in respective planes intersecting at said pivot axis, a tool at one end of said tool holderfor machining the workpiece and an actuator atthe other end of thetool holderfor pivoting the tool holder about said axis in accordance with control signals supplied thereto, to cause the tool to machine the workpiece to a required profile.
12. A machine too[ substantially as hereinbefore described with reference to the accompanying draw- ings.
Printed for Her Majesty's Stationery Office by Croydon Printing Company (11 K) Ltd, 12186, D8817356. Published by The Patent Office, 25 Southampton Buildings, London WC2A l AY, from which copies maybe obtained.
GB8617834A 1985-07-23 1986-07-22 A machine tool with tool holder operated by electric actuator Expired GB2177953B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB858518610A GB8518610D0 (en) 1985-07-23 1985-07-23 Machine tools

Publications (3)

Publication Number Publication Date
GB8617834D0 GB8617834D0 (en) 1986-08-28
GB2177953A true GB2177953A (en) 1987-02-04
GB2177953B GB2177953B (en) 1989-05-10

Family

ID=10582737

Family Applications (2)

Application Number Title Priority Date Filing Date
GB858518610A Pending GB8518610D0 (en) 1985-07-23 1985-07-23 Machine tools
GB8617834A Expired GB2177953B (en) 1985-07-23 1986-07-22 A machine tool with tool holder operated by electric actuator

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB858518610A Pending GB8518610D0 (en) 1985-07-23 1985-07-23 Machine tools

Country Status (7)

Country Link
US (1) US4936173A (en)
EP (1) EP0231245B1 (en)
JP (1) JPS63500362A (en)
KR (1) KR870700446A (en)
DE (1) DE3666371D1 (en)
GB (2) GB8518610D0 (en)
WO (1) WO1987000473A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE8504754D0 (en) * 1985-10-14 1985-10-14 Kurz Fredrik W A PROCEDURE FOR MANUFACTURING BUILDING MATERIAL
US5082501A (en) * 1985-10-14 1992-01-21 Kurz Fredrik W A Method of preparing building materials
FR2612434A1 (en) * 1987-03-17 1988-09-23 Sonim Numerically controlled lathe for machining a complex shape
DE3828854A1 (en) * 1988-08-25 1990-03-08 Mahle Gmbh FINE DRILLING MACHINE FOR PRODUCING HOLES WITH ANY POLAR AND / OR AXIAL ANY MANTELINE DEVELOPMENT
WO1993009911A1 (en) * 1991-11-15 1993-05-27 Yotaro Hatamura Feed screw device and precisely positioning micromotion feed system
JPH05138484A (en) * 1991-11-18 1993-06-01 Yotaro Hatamura Precision positioning fine moving feed device and system
US5442565A (en) * 1992-05-01 1995-08-15 Seamx Autonomous selective cutting method and apparatus
US6120364A (en) * 1998-07-06 2000-09-19 Laflamme; Robert Grinding fixture and assembly

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3361018A (en) * 1965-10-08 1968-01-02 Elihu I. Druckman Spring mounted tool holder
GB2046160A (en) * 1979-03-03 1980-11-12 Goetze Ag Apparatus for machining non-circular workpieces
EP0044200A1 (en) * 1980-07-12 1982-01-20 Ae Plc Machine tools
GB2149144A (en) * 1983-09-21 1985-06-05 Ae Plc Machine tools

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1759196A (en) * 1928-12-13 1930-05-20 Thaddeus A Jackson Drill grinder
US2525216A (en) * 1945-08-24 1950-10-10 Cone Automatic Mach Co Inc Toolholder
DE2724808C3 (en) * 1977-06-02 1980-01-17 Purolator Filter Gmbh, 7110 Oehringen Drive device for the cross-feed movement of the tool on devices for material-removing machining of turned parts
GB8316428D0 (en) * 1983-06-16 1983-07-20 Ae Plc Machine tools
US4509002A (en) * 1983-12-20 1985-04-02 International Business Machines Corporation Precision X-Y positioner

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3361018A (en) * 1965-10-08 1968-01-02 Elihu I. Druckman Spring mounted tool holder
GB2046160A (en) * 1979-03-03 1980-11-12 Goetze Ag Apparatus for machining non-circular workpieces
EP0044200A1 (en) * 1980-07-12 1982-01-20 Ae Plc Machine tools
GB2149144A (en) * 1983-09-21 1985-06-05 Ae Plc Machine tools

Also Published As

Publication number Publication date
EP0231245A1 (en) 1987-08-12
GB8518610D0 (en) 1985-08-29
GB2177953B (en) 1989-05-10
GB8617834D0 (en) 1986-08-28
WO1987000473A1 (en) 1987-01-29
KR870700446A (en) 1987-12-29
DE3666371D1 (en) 1989-11-23
EP0231245B1 (en) 1989-10-18
US4936173A (en) 1990-06-26
JPS63500362A (en) 1988-02-12

Similar Documents

Publication Publication Date Title
KR860008835A (en) CNC turning machine
FR2375647A1 (en) THREADING MACHINE-TOOL, DIGITAL CONTROL BY COMPUTER
CA2180787A1 (en) Numerical control apparatus
EP0374259A4 (en) Two opposed main shaft type cnc lathe
GB2177953A (en) Machine tools
GB1583741A (en) Apparatus for the peripheral machining of non-circular workpieces in particular piston rings
US4343206A (en) Slide system for machine tools
JP2635332B2 (en) Synchronous control method of spindle motor and feed servo motor in machining
GB2157988A (en) Positioning system
WO1999044108A1 (en) Synchronization controller
KR870001900A (en) Tool changer of machining center
EP0038158A3 (en) Machine tool including a tool transfer mechanism
CN2094415U (en) Knurling apparatus
KR920006064A (en) NC compound automatic lathe
JP2611037B2 (en) Milling head for a machining robot and method for performing machining with a robot using the milling head
JPS624568A (en) Feed device
JPH049139Y2 (en)
JPS6186104A (en) Automatic lathe
GB2231290A (en) Milling cutter grinding machine
CN213998215U (en) Long workpiece carving positioning device for laser carving machine
WO2006068083A1 (en) Working device
JPH10286737A (en) Hybrid feed drive system in machine tool
JP2737235B2 (en) Facing unit
JP2796624B2 (en) Gear processing machine
JPH08141866A (en) Slide driving device

Legal Events

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

Effective date: 19990722