초록 ▼

Method and apparatus are provided for sealing interfaces within an injection mold having a first surface and a second surface includes an active material actuator configured to be disposed in a manner suitable for generating a force between the first surface and the second surface. The active materi

Method and apparatus are provided for sealing interfaces within an injection mold having a first surface and a second surface includes an active material actuator configured to be disposed in a manner suitable for generating a force between the first surface and the second surface. The active material actuator is configured to generate a force in response to sense signals from a transmission structure. Methods and apparatus are also provided for centering a nozzle tip within a gate opening, and adjusting tip height of a nozzle tip with respect to a gate opening, also using active material inserts.

대표청구항 ▼

What is claimed is: 1. Apparatus for sealing a first surface comprising an injection molding nozzle head and a second surface comprising a hot runner manifold in an injection mold, comprising: an active material actuator disposed to move the first surface toward the second surface; and transmission

What is claimed is: 1. Apparatus for sealing a first surface comprising an injection molding nozzle head and a second surface comprising a hot runner manifold in an injection mold, comprising: an active material actuator disposed to move the first surface toward the second surface; and transmission structure configured to transmit electricity, in use, to said active material actuator, to cause said active material actuator to seal the injection molding nozzle head to the hot runner manifold. 2. Apparatus according to claim 1, wherein said active material actuator comprises a tubular piezo-electric actuator. 3. Apparatus according to claim 1, further comprising an active material sensor configured to detect pressure between the first surface and the second surface and provide a sense signal corresponding thereto, and further comprising control structure configured to receive the sense signal and provide a corresponding actuation signal to said active material actuator. 4. Apparatus according to claim 1, further comprising an insulator disposed between the first surface and the second surface, and wherein said active material actuator is disposed between the insulator and the first surface. 5. Apparatus according to claim 1, wherein said active material actuator comprises a tubular piezo-electric material configured to expand axially upon the application of an electrical voltage. 6. Apparatus for moving the nozzle tip of an injection mold hot runner nozzle with respect to a mold gate, comprising: an active material actuator configured to move the nozzle tip with respect to the mold gate; and transmission structure configured to supply an actuation signal, in use, to said active material actuator to cause said active material actuator to change at least one dimension to effect relative movement between the nozzle tip and the mold gate. 7. Apparatus according to claim 6, further comprising biasing structure configured to bias the nozzle toward the mold gate, and wherein said active material actuator is configured to move the nozzle against the biasing structure. 8. Apparatus according to claim 6, further comprising: a sensor for detecting at least one of (i) a distance between the nozzle and the mold gate, and (ii) a pressure between the nozzle and the mold gate, and output a sense signal corresponding thereto; and control structure coupled, in use, to said transmission structure and to said sensor, and configured to cause said active material actuator to adaptively adjust the distance between the nozzle and the mold gate in accordance with the sense signal. 9. Apparatus according to claim 8, wherein said sensor and said actuator each comprises piezoceramic element. 10. Apparatus according to claim 6, wherein the nozzle has a nozzle head disposed adjacent a hot runner manifold, and further comprising a second active material actuator configured to change at least one dimension upon receipt of an electrical voltage and effect a seal between the nozzle head and the hot runner manifold. 11. Sealing apparatus for an injection mold having a manifold plate and a nozzle, comprising: a piezo-electric sensor configured to be disposed adjacent at least one of the nozzle and the manifold plate, and configured to sense a compressive force applied between the nozzle and the manifold plate, and to generate a corresponding sense signal; a piezo-electric actuator configured to be disposed between the nozzle and the manifold plate, and configured to change dimension upon application of an actuation signal to change a sealing force between the nozzle and the manifold plate; and transmission structure coupled, in use, to said piezo-electric sensor and to said piezo-electric actuator, and configured to carry the sense signal and the actuation signal. 12. Apparatus according to claim 11, wherein said piezo-electric sensor is configured to be disposed in an annular groove in at least one of the nozzle and the manifold plate. 13. Apparatus according to claim 11, further comprising a plurality of piezo-electric sensors configured to be disposed at different locations between the nozzle and the manifold plate. 14. Apparatus according to claim 11, further comprising a processor configured to receive the sense signal from said piezo-electric sensor and to generate one or more of corresponding (i) a clamping force signal, (ii) an injection pressure signal, and (iii) an injection rate signal. 15. Apparatus according to claim 11, further comprising a second piezo-electric actuator configured to be disposed between a manifold and the manifold plate, and configured to apply a sealing force between the manifold and the manifold plate. 16. Apparatus according to claim 11, wherein said piezo-electric actuator is disposed adjacent said piezo-electric sensor, and wherein said piezo-electric sensor is configured to sense a change in dimension of said piezo-electric actuator corresponding to a change in distance between the nozzle and the manifold plate. 17. Apparatus according to claim 11, further comprising a plurality of piezo-electric actuators configured to be disposed at different locations between the nozzle and the manifold plate. 18. Apparatus according to claim 17, wherein said plurality of piezo-electric actuators are configured to control a deflection of the manifold plate. 19. Apparatus according to claim 11, further comprising a plurality of piezo-electric sensors configured to be disposed at different locations between the nozzle and the manifold plate, and wherein the injection molding machine includes a plurality of nozzles, and wherein at least one piezo-electric sensor and at least one piezo-electric actuator is configured to be disposed adjacent each nozzle. 20. Apparatus according to claim 19, further comprising control structure configured to (i) receive sense signals from said plurality of piezo-electric sensors, and (ii) transmit actuator signals to said plurality of piezo-electric actuators to control a deflection of the manifold plate. 21. An apparatus for sealing a nozzle head against an injection mold manifold, comprising: a nozzle body provided with a nozzle tip insert; a nozzle insulator provided around said nozzle body; a tip insulator provided around said nozzle tip; a manifold; a manifold plate; a mold cavity insert; and, a piezoelectric actuator positioned "within said apparatus" between at least two of: said nozzle body, said nozzle tip insert, said nozzle insulator, said tip insulator, said manifold, and said manifold plate, to provide an expansive force to provide a sealing force between the nozzle head and the injection mold manifold. 22. The apparatus of claim 21, further comprising: a piezoelectric sensor positioned within said apparatus to transmit signals based on pressure applied to said sensor; and a controller for providing closed loop control over the expansive force provided by said piezoelectric actuator, in accordance with transmitted signals from said piezoelectric sensor. 23. The apparatus of claim 21, wherein said piezoelectric actuator is provided between said nozzle insulator and a manifold plate. 24. The apparatus of claim 21, wherein said piezoelectric actuator is provided between said nozzle insulator and a head end of said nozzle body. 25. The apparatus of claim 21, wherein said piezoelectric actuator is provided between said nozzle tip and a mold cavity insert. 26. A system for sealing a hot runner assembly, comprising: a sprue bushing; a manifold; and a nozzle body comprising a nozzle housing and a nozzle tip, wherein interfaces between the sprue bushing and the manifold and between the manifold and the nozzle are sealed by changes of dimensions of active material elements. 27. The system of claim 26, further including at least one active material element centering said nozzle tip with respect to a gate of a mold cavity insert. 28. The system of claim 26, wherein the interface between the sprue bushing and the manifold is sealed using an active material element positioned between the manifold and a manifold plate. 29. The system of claim 26, wherein the interface between the nozzle housing and the manifold is sealed using an active material element positioned between the manifold and a manifold backing plate. 30. Apparatus for controlling the position of a melt channel plug with respect to the melt channel in a molding machine, comprising: the melt channel plug, which is disposed adjacent the melt channel; a set screw disposed adjacent the melt plug; and an active material element positioned between the melt channel plug and the set screw, and configured to control the position of the melt channel plug with respect to the melt channel. 31. An apparatus for regulating the height of a hot runner nozzle tip, comprising: a hot runner nozzle including a nozzle body and a nozzle tip; a manifold plate having said hot runner nozzle disposed therein; a mold cavity insert having a gate provided therein; and a piezoceramic actuation means provided within said cavity insert for positioning the nozzle tip with respect to the gate in said cavity insert. 32. The apparatus of claim 31, said apparatus further comprising: piezoceramic sensor means; and processor means, wherein a combination of said piezoceramic actuation means and said sensor means communicate with said processor means in real time, providing closed loop feedback control of the height of the hot runner nozzle tip. 33. An injection mold, comprising: a mold cavity; a nozzle configured to provide a molding material to said cavity; a plate configured to provide the molding material to said nozzle; an active material actuator configured, in use, to receive an actuation signal, and in response thereto to change a dimension to adjust a sealing force between said nozzle and said plate; and control structure configured to provide the actuation signal to said active material actuator. 34. An injection mold hot runner system, comprising: a hot runner manifold configured to carry molten material to a nozzle; the nozzle configured to carry the molten material from said manifold to a mold cavity; a manifold plate configured to house at least a portion of said nozzle; an active material actuator disposed between said manifold plate and said nozzle, and configured to change dimension upon receipt of an electrical signal and cause a change in a sealing force between said nozzle and said hot runner manifold; and electric transmission structure configured to carry the electrical signal to said active material actuator.