摘要:
A controller for an electromagnetic actuator comprises a pair of springs acting on opposite directions, and an armature connected to the springs. The armature is held in a neutral position given by the springs when the armature is not activated. The actuator also comprises a pair of electromagnets for driving the armature between two end positions. In response to a release of the armature held in one of the end positions, the controller applies brake to the armature according to a load condition of the armature. In high-load conditions, the valve can surely be opened without additional electric power. In low-load conditions, the armature is prevented from colliding with a yoke of the electromagnet. The application of brake includes over-excitation operation, flywheel operation and suspension of power supply. In the over-excitation operation, voltage is applied to the electromagnet corresponding to one of the end positions from which the armature is released for a first period. The first period may be determined according to a load condition of the armature. After the first period elapses, flywheel current is supplied to the electromagnet for a second period. After the second period elapses, power supply to the electromagnet is suspended. Appropriate combination of over-excitation operation, flywheel operation and suspension of power supply allows the braking force to be adjusted according to a load condition of the armature.
摘要:
A controller for an electromagnetic actuator comprises a pair of spring acting in opposite directions, and an armature coupled to a mechanical element. The armature is connected to the springs and held in a neutral position given by the springs when the actuator is not activated. The actuator includes a pair of electromagnets for driving the armature between two end positions. The controller includes voltage application means for applying voltage to an electromagnet providing one end position for a first predetermined period so as to attract the armature to the end position. The controller also includes a peak current detector for detecting the peak of current flowing through the electromagnet in the first predetermined period. In accordance with the peak value, a decision means decides the application period of voltage that is to be applied to the electromagnet after the first application period has elapsed. Thus, the armature can make a stable seating at a controlled speed without generating substantial noise.
摘要:
A controller for an electromagnetic actuator is provided that enables detection of a minute movement of the armature leaving the seating position and carries out pullback operation responsive to such detection. The electromagnetic actuator has a pair of springs acting on opposite directions, and an armature coupled to a mechanical element such as a exhaust/intake valve of an automobile engine. The armature is held in a neutral position given by the springs when the actuator is not activated. The actuator includes a pair of electromagnets for driving the armature between two end positions. The controller having current supplying means for supplying holding current to the electromagnet corresponding to one of the end positions when holding the armature in said one of the end positions. The controller includes determining that the armature is leaving (falling or lifting) the seated position when the holding current increases more than a predetermined value while the holding current is supplied to the electromagnet corresponding to said end position. Leaving armature is detected based on the variation of the holding current, which allows earlier detection of the leaving armature.
摘要:
Displacement of a mechanical element is accurately detected by a simple and inexpensive structure. To provide displacement detecting device including: a mechanical element capable of being displaced; a magnet connected to the mechanical element and magnetized in displacement direction of the mechanical element; and a magnetic sensor for detecting a magnetic flux generated by the magnet and outputting a sensor output corresponding to a detected magnetic-flux value, so as to detect displacement of the mechanical element in accordance with the sensor output. In one embodiment, a Hall element is used as the magnetic sensor and the magnet longer than distance of movement of the mechanical element is used. Thus, an output having a linear relation with displacement of the mechanical element is obtained, and detection of the displacement is easily implemented. The displacement detecting device can be applied to an actuator of intake/exhaust valves of an engine. In another embodiment, a magnetic material provided between the Hall element and a spring to reduce the disturbance caused by the spring. Moreover, a transfer shaft connected to the intake/exhaust valve is made of a non-magnetic material or a material having characteristics close to the non-magnetic material to reduce the effect of leakage flux.
摘要:
A valve timing control system for an internal combustion engine is provided which is capable of ensuring reliable holding of a valve by an actuator, and attaining energy saving by efficient operation of the actuator. The valve timing control system controls valve-closing timing of a valve opened by a cam provided on a camshaft, by temporarily holding the valve. A response delay of the actuator is predicted as a response delay prediction value. Output timing is set in which a drive signal for driving the actuator is output, according to the predicted response delay prediction value. Holding timing is controlled in which the valve is held by the actuator, by outputting the drive signal to the actuator, based on the set output timing.
摘要:
In an alternate energization process for alternately energizing a valve closing electromagnet and a valve opening electromagnet periodically, one of the valve opening electromagnet and the valve closing electromagnet is de-energized and thereafter the other electromagnet is de-energized at a time delayed by a predetermined time Toff. The alternate energization process is finished when the displaced position of a valve head which is detected by a displacement sensor has reached a predetermined position Vinit while the valve opening electromagnet is being energized. Thereafter, the valve opening electromagnet is continuously energized to seat the valve head in a closed position (initial position) from the time when the displaced position of the valve head has reached a predetermined position Vstart.
摘要:
A main journal 25a of a crank-shaped swinging shaft 25 which swings in a range of a predetermined angle is supported by bearing metals 51 and 52 each divided into two pieces. In supplying a lubrication oil through an oil bore 51b in the bearing metal 51 to a sliding surface of the main journal 25a and to inlet openings of lubrication oil passages P1 and P2 of the swinging shaft 25 open to the sliding surface, the inlet openings of the lubrication oil passages P1 and P2 of the swinging shaft 25 are designed so that they do not move past division portions 55 of the bearing metals 51 and 52 upon swing of the swinging shaft 25 in the range of the predetermined angle. Therefore, it is possible to prevent the lubrication oil to be supplied to the lubrication oil passages P1 and P2 from leaking from the division portions 55 of the bearing metals 51 and 52, thereby reliably lubricating a pin journal 25b of the swinging shaft 25 by the lubrication oil supplied from the lubrication oil passages P1 and P2.
摘要:
A plurality of hard particles 102 is arranged in a mold 302 which suppresses movement of the hard particles 102 so as to be close to each other, and the hard particles 102 arranged in the mold 302 are fixed with resin 103, thereby forming a friction surface 101. Therefore, a pad 100a in which the plurality of hard particles 102 is arranged on the friction surface 101 can be more easily manufactured.
摘要:
A recognition result extraction unit and an agreement determination unit are provided. The recognition result extraction unit extracts, from a recognition result storage unit, N best solutions A and B obtained by an utterance B. The utterance B follows an utterance A corresponding to the N best solutions A and made by a speaker b who is different from a speaker of the utterance A. In a case where a repeat utterance determination unit determines that the N best solutions B are N best solutions obtained by a repeat utterance B according to the utterance A corresponding to the N best solutions A, when the best solution A and B are different each other, the agreement determination unit determines that some or all of the N best solutions A can be replaced with some or all of the N best solutions B.
摘要:
There is provided a braking device including a pad having a friction surface, and a disc having a friction surface sliding on the friction surface. The pad includes, in the friction surface, a plurality of hard particles tilted in the opposite direction to a direction in which the friction surface slides on the friction surface, and the disc includes, in the friction surface, a plurality of hard particles tilted in the direction in which the friction surface slides on the friction surface. Thereby, mutually pressing forces between the hard particles are increased. Additionally, the mutually pressing forces between the hard particles are increased, and consequently the distance between the friction surfaces is shortened. Therefore, a higher frictional force can be obtained.