摘要:
A method for controlling welding forces of a weld tip to a work piece during a vibration-welding process includes positioning an Active Material (AM) element adjacently to a welding interface, and varying a property of the AM element to regulate the welding force. The AM element may be disposed between the weld tip and a weld face thereof, or between the work piece and an anvil. The property may be varied as a function of heat generated by the welding process. A property of each of a plurality of AM elements may be independently and selectively varied via an energy source, or passively. A vibration welding system includes a weld tip and an AM element connected adjacently to a welding interface. The system regulates a welding force applied by the weld tip to a work piece during the welding process by varying a property of the AM element.
摘要:
A method for controlling welding forces of a weld tip to a work piece during a vibration-welding process includes positioning an Active Material (AM) element adjacently to a welding interface, and varying a property of the AM element to regulate the welding force. The AM element may be disposed between the weld tip and a weld face thereof, or between the work piece and an anvil. The property may be varied as a function of heat generated by the welding process. A property of each of a plurality of AM elements may be independently and selectively varied via an energy source, or passively. A vibration welding system includes a weld tip and an AM element connected adjacently to a welding interface. The system regulates a welding force applied by the weld tip to a work piece during the welding process by varying a property of the AM element.
摘要:
A drain plug assembly that has particular application for sealing a drain hole in a high voltage battery compartment on a vehicle. The plug assembly includes a plug that inserted into the drain hole. The plug assembly further includes a return spring coupled to the plug and causing the plug to be biased into the drain hole. The plug assembly also includes at least one shape memory alloy device coupled to the plug and a support structure. The SMA device receives an electrical current that causes the device to contract and move the plug out of the drain hole against the bias of the return spring.
摘要:
A method of controlling and/or predicting the remaining useful life of an active material actuator, such as a shape memory alloy wire, includes obtaining historical actuation data of an inherent system variable, such as electrical resistance, over a secondary variable, such as time, determining a normal operating envelope having upper and lower bounds based on the data, determining a current profile for a given actuation cycle, and comparing the shape of the current profile to the envelope to determine an out-of-bounds event.
摘要:
A system for and method of providing overload protection for an active material actuator, includes a magnetically functioning mechanism comprising, for example, one or more permanent or electromagnets, and/or magnetorheological fluid, and configured to produce a holding force less than the capacity of the actuator, and more preferably, a modifiable holding force responsive to load influencing conditions.
摘要:
A device and method for controlling a phase transformation temperature of a shape memory alloy is provided. The device includes a primary wire composed of the shape memory alloy. The primary wire defines first and second ends, the first end being attached to a fixed structure and the second end being able to displace. An activation source is thermally coupled to the wire and is operable to selectively cause the primary wire to reversibly transform from a Martensitic phase to an Austenitic phase during a cycle. A loading element is operatively connected to the primary wire and configured to selectively increase a tensile load on the primary wire when an ambient temperature is at or above a threshold temperature, thereby increasing the phase transformation temperature of the primary wire.
摘要:
A method of starting a heat engine includes exposing an element of the heat engine to a source of thermal energy provided by a temperature difference between a heat source having a first temperature and a heat sink having a second temperature that is lower than the first temperature. The element is formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to the temperature difference between the heat source and the heat sink. The method further includes changing the crystallographic phase of the first shape memory alloy to thereby convert thermal energy to mechanical energy, and inducing initial movement of the element in a desired operational direction to thereby start the heat engine.
摘要:
Shape memory alloy (SMA) actuating elements are commonly simpler and of lower mass than alternative actuator designs and may find particular application in the transportation industry. Such SMA-powered devices are usually reliable and long-lived but the phase transformations which occur in the SMA alloy and are responsible for its utility are not totally reversible. This irreversibility, a consequence of irrecoverable strain, may progressively degrade the long-term actuator performance as the irrecoverable strain accumulates over many operating cycles. Methods and devices for compensating for these effects and extending the useful cycle life of SMA actuators are described.
摘要:
A baffle controller for moving a baffle disposed within an HVAC outlet housing between an open position and a closed position to control airflow through an HVAC outlet in a vehicle includes a Shape Memory Alloy (SMA) actuator that is controlled and actuated by an electrical signal. The SMA actuator rotates a main lever that rotates a valve plate. The valve plate is attached to the baffle such that the baffle rotates with the valve plate. The baffle controller may include a position biasing device that increases a position holding ability of the baffle controller, and a cut-off switch that interrupts the electrical signal to the SMA actuator to prevent over-rotating the baffle.
摘要:
A drain plug assembly that has particular application for sealing a drain hole in a high voltage battery compartment on a vehicle. The plug assembly includes a plug that inserted into the drain hole. The plug assembly further includes a return spring coupled to the plug and causing the plug to be biased into the drain hole. The plug assembly also includes at least one shape memory alloy device coupled to the plug and a support structure. The SMA device receives an electrical current that causes the device to contract and move the plug out of the drain hole against the bias of the return spring.