초록 ▼

Method and apparatus for controlling a vent gap in a mold for an injection molding machine are provided, and include an active material insert configured to be regulate the degree of opening of the vent gap. The active material insert is configured to be actuated in response to signals from a contro

Method and apparatus for controlling a vent gap in a mold for an injection molding machine are provided, and include an active material insert configured to be regulate the degree of opening of the vent gap. The active material insert is configured to be actuated in response to signals from a controller, so as to selectively block the opening of the vent gap during the molding process. Wiring structure is coupled to the active material insert, and is configured to carry the actuation signals. Melt flow sensors may also be provided to aid in regulating the vent gap, and may be connected to the controller in order to provide real-time closed loop control over the operation of the vent gap. Preferably, the methods and apparatus are used as part of a system for controlling the flow of melt within a mold cavity.

대표청구항 ▼

What is claimed is: 1. Apparatus for controlling an injection mold vent gap, comprising: an active material disposed adjacent the vent gap and configured to change dimension upon application of an electrical signal, in order to at least partially close the vent gap; wherein an active material is se

What is claimed is: 1. Apparatus for controlling an injection mold vent gap, comprising: an active material disposed adjacent the vent gap and configured to change dimension upon application of an electrical signal, in order to at least partially close the vent gap; wherein an active material is selected from the group consisting of piezoactuators, piezoceramics, electrostrictors, and magnetostrictors and Further a transmission structure configured to supply the electrical signal to said active material element, to cause said active material to change dimension to at least partially close the vent gap wherein said active material element disposed between a vent gap and a vent collector. 2. Apparatus according to claim 1, further comprising an active material sensor disposed to detect molding material approaching the vent gap, and to generate a sense signal corresponding thereto. 3. Apparatus according to claim 2, further comprising control structure configured, to (i) receive the sense signal, (ii) in response to the sense signal, generate the actuation signal, and (iii) transmit the actuation signal to said active material element. 4. Apparatus according to claim 3, further comprising a plurality of active material elements and a plurality of active material sensors, and wherein said control structure receives sense signals from said plurality of active material sensors, and transmits actuation signals to the plurality of active material elements. 5. Apparatus according to claim 4, wherein each of said active material elements and each of said active material sensors comprises a piezoceramic material. 6. An injection mold vent gap control device comprising: a piezo-electric actuator disposed to at least partially block a mold vent that is in communication with a mold cavity, said piezo-electric actuator, upon receiving an electical signal, changing dimension to at least partially close the mold vent gap. 7. The injection mold vent gap control device of claim 6, wherein in molds comprising multiple vents, at least one piezo-electric actuator is positioned in each vent. 8. The injection mold vent gap control device of claim 6, further comprising: a controller connected to said piezoelectric actuator by electrical wiring; and a sensor connected to said controller by electrical wiring, where the sensor sends data to the controller regarding the condition of the melt within the mold cavity. 9. The molding machine vent gap control device of claim 8, wherein said sensor comprises an active material element. 10. The molding machine vent gap control device of claim 8, wherein a combination of the actuator, the sensor, and the controller performs closed-loop control over the vent gap based on melt conditions. 11. An injection mold, comprising: a first mold half; a second mold half; a vent for venting gas from at least one of the first mold half and the second mold half; and a piezo-electric element configured to change dimension upon application and removal of an actuation signal thereto, said dimension change at least partially closing or opening said vent to control the venting of gas therethrough. 12. An injection mold hot half system, comprising; a heated mold half having at least one vent portion therein; and an active material element coupled to said heated mold half and configured to at least partially close the vent portion in response to a change in dimension caused by application or removal of an actuation signal wherein an active material is selected from the group consisting of piezoactuators, piezoceramics, electrostrictors, and magnetostrictors. 13. A vented injection mold, comprising: a mold cavity half; a mold core half; a vent in communication with a mold cavity formed between said cavity half and said core half; and a piezo-electric actuator positioned within said vent, said piezo-electric actuator, upon application or release of an electrical signal, changing dimension to at least partially block the vent. 14. The vented injection mold of claim 13, further comprising: a sensor in communication with said mold cavity, and control means in communication with each of said piezoelectric actuator and said sensor. 15. The vented injection mold of claim 14, wherein said control means, in response to a sense signal from said sensor, transmits an actuation signal to said piezo-electric actuator, to cause said actuator to change dimension to control a flow of injected material through said vent.