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US 5,095,725 AGranted
Press and actuator using piezoelectric element
AssigneeFuji Electric Co., Ltd.
InventorsTatuya Wada, Hiroshi Hikita, Nobutaka Machida, Mituharu Nonami, Yukinori Kawamura, Norikatu Matumoto, Yoshiyuki Ohmura, Tetuo Nomoto
Life of this patent
Estimating the term…
Abstract
A press is described using piezoelectric actuators to achieve both the hold down of the work piece during the processing operation as well as powering the die used in deforming the work piece. The sub-assembly containing the piezoelectric element is structured to allow convenient removal from the main body of the press thereby facilitating repair operations, as well as coarse and fine adjusting facilities for the position of the piezoelectric element within the actuator assembly.
Claims16
A self-contained piezoelectric actuator unit comprising:
- a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion, said resilient means being a coil spring coupled in parallel with said piezoelectric element so as to extend around said piezoelectric element over a portion of its length, so that the overall axial dimension of the actuator unit is not increased by the presence of said coil spring;
- support means for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means;
- and
- attachment means for enabling attachment of said support means in a fixed operating position on a frame;
- whereby said self-contained piezoelectric actuator unit may be removably attached in an operating position so that displacement of said work piece means may be transmitted externally to said actuator unit under control of said applied electric voltage.
4 more elements
A self-contained piezoelectric actuator unit comprising:
- a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion;
- support means for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means;
- attachment means for enabling attachment of said support means in a fixed operating position on a frame;
- a member connected to said work piece means and extending laterally through said support means;
- and
- displacement measuring means fixed to said support means and arranged for measuring displacement of said member;
- whereby displacement of said work piece means during axial expansion of said piezoelectric element may be accurately measured.
6 more elements
A self-contained piezoelectric actuator unit comprising a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion;
- support means for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship and having a restraining end member so that expansion of said piezoelectric element displaces said work piece means;
- attachment means for enabling attachment of said support means in a fixed operating position on a frame;
- and additionally comprising an axial fine position adjusting mechanism located between the restraining end member and the piezoelectric element comprising:
- a first tapered wedge laterally contained within said support means,
- a second tapered wedge, complementing said first wedge, extending laterally through said support means, having a lateral position adjusting and locking means with respect to said first wedge,
- whereby the lateral position of said second wedge can be adjusted externally to said support means so that the total axial thickness of the first and second wedge combined can be changed in small increments to accurately adjust said predetermined position of said work piece.
5 more elements
A piezoelectric actuator as described in claim 6 additionally comprising a coarse axial position adjusting mechanism comprising an adjusting screw and lock nut combination threaded through the center of said restraining end member to axially adjust the spacing between said restraining end member and said first wedge, to permit a wider range of adjustment in cooperating with said fine position adjusting mechanism.
A self-contained piezoelectric actuator unit comprising:
- a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion;
- support means, for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means, made of a combination of a first material having a higher thermal expansion coefficient than the piezoelectric element and a second material having lower thermal expansion that said piezoelectric element, said expansion characteristics and axial dimensions of first and second materials being chosen so that the overall thermal expansion characteristics match those of said piezoelectric element;
- and
- attachment means for enabling attachment of said support means in a fixed operating position on a frame;
- whereby said self-contained piezoelectric actuator unit may be removably attached in an operating position so that displacement of said work piece means may be transmitted externally to said actuator unit under control of said applied electric voltage.
4 more elements
A self-contained piezoelectric actuator unit comprising:
- a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion;
- support means, for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means, made of a ceramic material having stiffer longitudinal elasticity than a ferrous material;
- and
- attachment means for enabling attachment of said support means in a fixed operating position on a frame;
- whereby said self-contained piezoelectric actuator unit may be removably attached in an operating position so that displacement of said work piece means may be transmitted external to said actuator unit under control of said applied electric voltage.
4 more elements
A self-contained piezoelectric actuator unit comprising:
- a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- enclosure means having a resilient sidewall structure coextensive with a portion of the axial dimension of said piezoelectric element for holding said piezoelectric element, and work piece means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means;
- and attachment means for enabling attachment of said support means in fixed operating position on a frame;
- whereby said resilient sidewall structure maintains said cooperative working relationship independently of any additional spring device and said self contained piezoelectric actuator unit may be removably positioned in an operating position so that displacement of said work piece means may be transmitted externally to said actuator unit under control of said applied electric voltage.
2 more elements
A self-contained piezoelectric actuator unit comprising:
- a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means, coupled to said element for transmitting a displacement for external application in response to said physical expansion, made of a material having a stiffer longitudinal elasticity than a ferrous material so that the displacement of said piezoelectric element is transmitted to the work being processed;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion;
- support means for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means;
- and
- attachment means for enabling attachment of said support means in a fixed operating position on a frame;
- whereby said self-contained piezoelectric actuator unit may be removably attached in an operating position so that displacement of said work piece means may be transmitted externally to said actuator unit under control of said applied electric voltage.
4 more elements
A press die system, including at least one self-contained piezoelectric unit comprising a piezoelectric element for providing physical expansion in response to an applied electric voltage;
- work piece means coupled to said element for transmitting a displacement for external application in response to said physical expansion;
- resilient means for returning said work piece means to a predetermined position in the absence of such physical expansion;
- support means for holding said piezoelectric element, work piece means and resilient means in cooperative working relationship so that expansion of said piezoelectric element displaces said work piece means;
- attachment means for enabling attachment of said support means in a fixed operating position on a frame, comprising:
- a support frame;
- a first die member, including resilient means, supported by said support frame;
- a first punch member supported by said die member and held in a retracted positioned by said resilient means;
- and
- a first said piezoelectric actuator unit removably attached to said support frame so that its work piece means is positioned to transmit a displacement to said first punch member;
- whereby said first punch member is activated in response to said applied electric voltage.
7 more elements
Dependencies are inferred from the claim text.