摘要:
PROBLEM TO BE SOLVED: To solve the problems wherein, in an electromagnetic actuator provided with an excitation coil instead of an electromagnet, a large power consumption is required in an excitation part regardless of the intensity of a required test force, and when malfunction in which a heavy current flows in a movable coil occurs, an excessive test force is suddenly generated, to thereby generate a dangerous state. SOLUTION: A magnetic flux density generated by the excitation coil included in the electromagnetic actuator 12 is switched according to an operation mode, namely, the state of a material test. In a mounting stage of a test piece TP, a thrust enough to grip the test piece TP by grippers 38, 40 by moving vertically a piston rod 13A is generated from the electromagnetic actuator 12. In a test execution stage, the magnetic flux density is set so that a rated test force is acquired. After the material test is finished, the magnetic flux density is set so that a magnetic flux density equivalent to that in a preparation stage of the material test is acquired. COPYRIGHT: (C)2010,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide an elastic constant measuring instrument and method for measuring an elastic constant of a sample, based on a variation in a resonance frequency of an oscillator caused by contact of the oscillator with the sample. SOLUTION: This elastic constant measuring instrument 10 is provided with the oscillator 12 constituted of a piezoelectric substance vibrated by piezoelectric and reverse effects in an oscillation electric field, an electric field inducing means for inducing a vibrational electric field, and a reception means for receiving the vibration of the oscillator by the piezoelectric effect. The measuring instrument is provided also with a holding means for holding the oscillator dynamically in a position of a node of the vibration of the oscillator when the oscillator is oscillated, and the oscillator contacts with the sample in an antinode position of the vibration, and is not in contact with other elements except the sample and the holding means when oscillated. COPYRIGHT: (C)2005,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a preventive conservation method and device that has a simple configuration, and reduces tensile residual stress and sensitization by utilizing thermal shock strain. SOLUTION: For the surface region of a welding part in a tensile stress state, the surface region being heated-up by a high-frequency heating coil 1 is quickly cooled by jetting a coolant from a nozzle 11, thus generating transitional temperature difference between the surface region and a part directly under a surface layer, applying tensile thermal shock stress to the surface layer for generating tensile strain, and at the same time for partially allowing the surface layer to yield. Then, cooling is stopped for heat-up for allowing the thermal shock stress to disappear. The surface of the welding part is improved to a state where deformation is elastically returned for relieving tensile stress or a compression residual stress state from a partial yield state. Heating and cooling speed is adjusted, thus reducing the sensitization of welding thermal influence part.
摘要:
PROBLEM TO BE SOLVED: To drive an actuator more accurately by improving a control resolution of the electrokinetic actuator and making it possible to detect an accurate operating speed signal of the actuator. SOLUTION: The ring shaped magnet 40A and 40B, and yoke 32A and 32B are set on the upside and underside of a flange 30Af of a core 30A, and two independent magnetic circuits S1 and S2 are formed. A coil 10A is wound on a cylinder section 24a of a bobbin 24 and a coil 109B and a sensor coil 50A are wound on a cylinder 24b. The bobbin 24 is able to reciprocate in a direction of an arrow F and a given thrust is generated by supplying an electrical voltage to the coil 10A and 10B. Supplying only AC component of the driving current to the coil 10A and only DC current component to the coil 10B makes it possible to narrower a dynamic range of the output of a DC chiven circuit 66 and an AC driven circuit 64. As the only DC current is supplied to the coil 10B adjacent to the sensor coil 50A, there is no unfavorable effect on the sensor coil 50A caused by a mutual inductive operation.