Method for producing a holding frame or a transmission frame for a stacked piezoactuator and electrostrictive drive with a frame of said type

Abstract

The invention relates to a method for producing a holding or transmission frame ( 12, 20 ) for an electrostrictive actuator, in particular, a stacked piezoactuator ( 5 ). Said method consists of the following steps: a) a winding spindle ( 52 ), corresponding to the shape of the inner periphery of the frame ( 12, 20 ), is wound with several layers of a unidirectional prepreg for forming a laminate body; b) said laminate body is hardened; c) the hardened laminate body in the frame is cut by sections parallel to the direction of winding. An electrostrictive drive ( 100 ) comprises an electrostrictive actuator ( 5 ) in which the length varies during actuation, and a transmission frame ( 12 ) that surrounds the actuator, is connected to said actuator for initiating the variation in length of the actuator and for amplifying said actuator, the transmission frame ( 12 ) being made of a prepreg that is wound in the laminate body and hardened.

1 . Process for producing a holding or traversing frame ( 12 ;  20 ) for an electrostrictive actuator, especially a stacked piezoactuator ( 5 ), containing the steps:
 (a) winding a winding mandrel ( 52 ) that corresponds to the shape of the inner periphery of the frame ( 12 ;  20 ) with several layers of a unidirectional prepreg for forming a laminate body;   (b) curing the laminate body; and   (c) cutting the cured laminate body in the frame by cuts parallel to the winding direction.   
   
   
       2 . Process according to  claim 1 , characterized in that several individual cut pieces of the prepreg are wound around the winding mandrel ( 52 ), junctions between the cut pieces being offset between the layers in the peripheral direction. 
   
   
       3 . Process according to  claim 1 , wherein cut pieces of the prepreg and cut pieces of a separating film are located in the peripheral direction along the laminate body in alternation in defined layers of the laminate body so that along the laminate body in the peripheral direction, zones with separating film ( 13 ;  23 ) and zones without separating film ( 14 ;  24 ) are formed. 
   
   
       4 . Process according to  claim 3 , wherein the zones with separating film ( 13 ;  23 ) and the zones without separating film ( 14 ;  24 ) of various layers of the laminate body lie on top of one another in the direction of the layer. 
   
   
       5 . Process according to  claim 3 , wherein prepreg and separating film are placed in alternation in the zones with separating film ( 13 ;  23 ) in the direction of the layer. 
   
   
       6 . Process according to  claim 3 , wherein the film is a Tedlar film. 
   
   
       7 . Process according to  claim 2 , wherein the cut pieces of prepreg and/or film are positioned by means of positioning stops ( 56 ) on the winding mandrel ( 52 ) during winding. 
   
   
       8 . Process according to  claim 1 , wherein the prepreg is a CFK prepreg, especially a prepreg with an M40J carbon fiber. 
   
   
       9 . Electrostrictive drive ( 100 ) with an electrostrictive actuator ( 5 ) that changes length upon activation, and a traversing frame ( 12 ) that surrounds the actuator, which is connected to it for applying the change of length of the actuator and that amplifies the change in length of the actuator, the traversing frame ( 12 ) being formed from a laminate body composed of wound and cured prepreg. 
   
   
       10 . Electrostrictive drive ( 100 ) according to  claim 9 , wherein surrounding the traversing frame ( 12 ) is a holding frame ( 20 ). 
   
   
       11 . Electrostrictive drive ( 100 ) according to  claim 10 , wherein the holding frame ( 20 ) is formed from a laminate body of wound and cured prepreg. 
   
   
       12 . Electrostrictive drive ( 100 ) according to  claim 10 , wherein the holding frame ( 20 ) is cemented to the traversing frame ( 12 ) along regions ( 16 ) of their peripheries. 
   
   
       13 . Electrostrictive drive ( 100 ) according to  claim 9 , wherein the laminate body of the traversing frame ( 12 ) and/or of the holding frame ( 20 ) is formed from several individual cut pieces of the prepreg that are wound around a winding mandrel ( 52 ), junctions between the cut pieces being offset between the layers in the peripheral direction of the laminate body. 
   
   
       14 . Electrostrictive drive ( 100 ) according to  claim 13 , wherein in the peripheral direction along the traversing frame ( 12 ) and/or the holding frame ( 20 ), there are zones with separating film ( 13 ;  23 ) and zones without separating film ( 14 ;  24 ) that are formed by alternating arrangement of cut pieces of the prepreg and cut pieces of a separating film along the peripheral direction of the laminate body in defined layers. 
   
   
       15 . Electrostrictive drive ( 100 ) according to  claim 14 , wherein in zones with separating film ( 13 ;  23 ), a layer of prepreg and a layer of separating film are provided in alternation in the direction of the layer. 
   
   
       16 . Electrostrictive drive ( 100 ) according to  claim 14 , wherein the film is a Tedlar film. 
   
   
       17 . Electrostrictive drive ( 100 ) according to  claim 9 , wherein the traversing frame ( 12 ) and/or the holding frame ( 20 ) is formed from a CFK prepreg, especially a prepreg with a carbon fiber M40J. 
   
   
       18 . Electrostrictive drive ( 100 ) according to  claim 9 , wherein the electrostrictive actuator is a stacked piezoactuator ( 5 ). 
   
   
       19 . Electrostrictive drive ( 100 ) according to  claim 9 , wherein in the traversing frame ( 12 ), metallic force application elements ( 8 ) are attached to which the electrostrictive actuator ( 5 ) is connected and on which it acts. 
   
   
       20 . Electrostrictive drive ( 100 ) according to  claim 19 , wherein the metallic force application elements ( 8 ) in positions opposite one another are cemented into the traversing frame ( 12 ), preferably along the stacking direction on the two end sides of a stacked piezoactuator ( 5 ).