Ultrasonic transmitting unit and manufacturing method of ultrasonic transmitting unit

摘要

A distal side transmitting member of an ultrasonic transmitting unit includes a projecting portion protruding from a distal side abutment portion toward a proximal direction, and a proximal side transmitting member includes a depressed portion depressed from a proximal side abutment portion toward the proximal direction. A cavity portion having a space is formed between a protruding end of the projecting portion and a bottom portion of the depressed portion inside the proximal side transmitting member when the depressed portion is engaged with the projecting portion, and one of antinode positions of an ultrasonic vibration is located within a range from the protruding end to the bottom portion.

主权项

1. An ultrasonic transmitting unit which extends along a longitudinal axis and which is configured to transmit an ultrasonic vibration from a proximal direction toward a distal direction and thereby configured to vibrate at a predetermined resonance frequency, the ultrasonic transmitting unit comprising:
a vibration generating portion which is configured to generate the ultrasonic vibration; a proximal side transmitting member to which the vibration generating portion is attached and to which the ultrasonic vibration is configured to be transmitted from the vibration generating portion, the proximal side transmitting member including a proximal side abutment portion which forms a distal end of the proximal side transmitting member; a distal side transmitting member connected to the proximal side transmitting member to which the ultrasonic vibration is transmitted from the vibration generating portion, the distal side transmitting member including a distal side abutment portion on which the proximal side abutment portion of the proximal side transmitting member abuts when the distal side transmitting member is connected to the proximal side transmitting member; a projecting portion protruding from the distal side abutment portion toward the proximal direction in the distal side transmitting member, the projecting portion including a protruding end located a predetermined protruding dimension apart from the distal side abutment portion; and a depressed portion which is depressed from the proximal side abutment portion toward the proximal direction and which includes a bottom portion spaced a depression dimension equal to or more than the predetermined protruding dimension apart from the proximal side transmitting member, the depressed dimension being set in accordance with a Young's modulus of the proximal side transmitting member based on a relation between the Young's modulus of the proximal side transmitting member and the depression dimension so that the proximal side transmitting member and the distal side transmitting member vibrates at the predetermined resonance frequency where an antinode position of the ultrasonic vibration is located within a range in which a cavity portion formed between the protruding end of the projecting portion and the bottom portion of the depressed portion in a situation in which the ultrasonic transmitting unit transmits the ultrasonic vibration.