Machining apparatus

Abstract

A machining apparatus for conducting at least one of a cutting process and a grinding process, comprises a stationary base; and a working device mounted on the stationary base and having a degree of freedom of more than two axes to conduct at least one of a cutting process and a grinding process, the working device comprising a first working bench which is formed of a ceramic material and is movable linearly with a degree of freedom of not less than one axes or more while holding a work piece or a tool.

1 . A machining apparatus for conducting at least one of a cutting process and a grinding process, comprising: 
 a stationary base; and    a working device mounted on the stationary base and having a degree of freedom of more than two axes to conduct at least one of a cutting process and a grinding process, the working device comprising a first working bench which is formed of a ceramic material and is movable linearly with a degree of freedom of not less than one axes or more while holding a work piece or a tool.    
   
   
       2 . The machining apparatus of  claim 1 , wherein the ceramic material has a coefficient of linear expansion of not more than 5×10 −6  K −1 .  
   
   
       3 . The machining apparatus of  claim 1 , wherein the ceramic material contains silicon nitride of not less than 50% by weight as converted into Si 3 N 4  and has a specific weight of not more than 4 g/cm 3 .  
   
   
       4 . The machining apparatus of  claim 1 , wherein the ceramic material has a Young's modulus of not less than 200 GPa.  
   
   
       5 . The machining apparatus of  claim 1 , wherein the first working bench is driven along a static-pressure guide by an axis driving device with a frequency of not less than 50 Hz with a servo gain of −3 dB.  
   
   
       6 . The machining apparatus of  claim 5 , wherein the axis driving device is a linear motor.  
   
   
       7 . The machining apparatus of  claim 1 , wherein the working device further comprises a measurement device having a resolution of not more than 10 nm for measuring the position of the first working bench.  
   
   
       8 . The machining apparatus of  claim 1 , wherein a machining speed for a work piece or a tool held by the first working bench is not less than 600 mm/min.  
   
   
       9 . The machining apparatus of  claim 8 , wherein the first working bench is driven at the highest speed in the machining apparatus.  
   
   
       10 . A machining apparatus for conducting at least one of a cutting process and a grinding process, comprising: 
 a stationary base; and    a working device mounted on the stationary base and having a degree of freedom of more than two axes to conduct at least one of a cutting process and a grinding process, the working device comprising a second working bench which is formed of a ceramic material and is rotatable with a degree of freedom of not less than one axes while holding a work piece or a tool.    
   
   
       11 . The machining apparatus of  claim 10 , wherein the ceramic material has a coefficient of linear expansion of not more than 5×10 −6  K −1 .  
   
   
       12 . The machining apparatus of  claim 10 , wherein the ceramic material contains silicon nitride of not less than 50% by weight as converted into Si 3 N 4  and has a specific weight of not more than 4 g/cm 3 .  
   
   
       13 . The machining apparatus of  claim 10 , wherein the ceramic material has a Young's modulus of not less than 200 GPa.  
   
   
       14 . The machining apparatus of  claim 10 , wherein the second working bench is driven along a static-pressure guide by an axis driving device with a frequency of not less than 50 Hz with a servo gain of −3 dB.  
   
   
       15 . The machining apparatus of  claim 14 , wherein the axis driving device is an AC servomotor.  
   
   
       16 . The machining apparatus of  claim 10 , wherein the working device further comprises a measuring device having a resolution of not more than a 1 angular second for measuring the angle of the second working bench.  
   
   
       17 . The machining apparatus of  claim 10 , wherein a rotational machining speed for a work piece or a tool held by the second working bench is not less than 1°/sec.  
   
   
       18 . The machining apparatus of  claim 17 , wherein the second working bench is driven at the highest speed in the machining apparatus.  
   
   
       19 . The machining apparatus of  claim 10 , wherein the working device further comprises a support table for supporting the second working bench and the support table is formed of at least one of a ceramic material satisfying at least one of conditions of having a coefficient of linear expansion of not more than 5×10 −6  K −1 , containing silicon nitride of not less than 50% by weight as converted into Si 3 N 4  and having a specific weight of not more than 4 g/cm 3 , and having a Young's modulus of not less than 200 GPa, and an alloy containing nickel from 10% by weight to 50% by weight.  
   
   
       20 . The machining apparatus of  claim 5 , wherein at least one of the static-pressure guide and a base for fixing it is formed of a ceramic material satisfying at least one of the conditions of having a coefficient of linear expansion of not more than 5×10 −6  K −1 , containing silicon nitride of not less than 50% by weight as converted into Si 3 N 4  and having a specific weight of not more than 4 g/cm 3 , and having a Young's modulus of not less than 200 GPa.  
   
   
       21 . The machining apparatus of  claim 14 , wherein at least one of the static-pressure guide and a base for fixing it is formed of a ceramic material satisfying at least one of the conditions of having a coefficient of linear expansion of not more than 5×10 −6  K −1 , containing silicon nitride of not less than 50% by weight as converted into Si 3 N 4  and having a specific weight of not more than 4 g/cm 3 , and having a Young's modulus of not less than 200 GPa.  
   
   
       22 . The machining apparatus of  claim 5 , wherein a pressure transmission medium of the static-pressure guide is a liquid having a viscosity of not more than 10 pois.  
   
   
       23 . The machining apparatus of  claim 14 , wherein a pressure transmission medium of the static-pressure guide is a liquid having a viscosity of not more than 10 pois.  
   
   
       24 . The machining apparatus of  claim 1 , wherein the working device further comprises an active control device for suppressing the transmission of a vibration from the floor on which the machining apparatus is installed to the machining apparatus.  
   
   
       25 . The machining apparatus of  claim 10 , wherein the working device further comprises an active control device for suppressing the transmission of a vibration from a floor on which the machining apparatus is installed to the machining apparatus.  
   
   
       26 . A machining apparatus for conducting at least one of a cutting process and a grinding process, comprising: 
 a stationary base; and    a working device mounted on the stationary base and having a degree of freedom of more than two axes to conduct at least one of a cutting process and a grinding process, the working device comprising a first working bench which is made of a material having a specific weight of not more than 4 g/cm 3  and is moved along a first static-pressure guide by a driving device with a frequency of not less than 50 Hz with a servo-gain of −3 dB and a measuring device with a resolution of not more than 10 nm for measuring the position of the first working bench.    
   
   
       27 . The machining apparatus of  claim 26 , wherein the working device further comprises a second working bench made of a material having a specific weight of not more than 4 g/cm 3  swiveling along a second static-pressure guide and a measuring device having a resolution of not more than 1 angular second for measuring the angle of the second working bench.  
   
   
       28 . The machining apparatus of  claim 26 , wherein a machining speed is not less than 600 mm/min.  
   
   
       29 . The machining apparatus of  claim 27 , wherein at least one of the first working bench, the second working bench, the first static-pressure guide, the second static-pressure guide, and a base for fixing them is formed of a material having a coefficient of linear expansion of not more than 5×10 −6  K −1 .  
   
   
       30 . The machining apparatus of  claim 27 , wherein at least one of the first working bench, the second working bench, the first static-pressure guide, the second static-pressure guide, and a base for fixing them is formed of a material having a Young's modulus of not less than 200 Gpa.  
   
   
       31 . The machining apparatus of  claim 26 , wherein a pressure transmission medium of the first static-pressure guide is a liquid having a viscosity of not more than 10 pois.  
   
   
       32 . The machining apparatus of  claim 26 , the working device further comprises an active suppressing device for vibration from a floor on which the machining apparatus is installed to the machining apparatus.  
   
   
       33 . The machining apparatus of  claim 27 , wherein at least one of the first working bench, the second working bench, the first static-pressure guide, the second static-pressure guide and a base for fixing them is formed of a material containing a silicon nitride component of not less than 50% by weight as converted into Si 3 N 4 .