BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ultrasonic transducer including a piezoelectric element which is configured to generate ultrasonic vibration by an electric energy being supplied, and a method of manufacturing the ultrasonic transducer.

2. Description of the Related Art

U.S. Patent Application Publication No. 2009/275864 A1 discloses an ultrasonic treatment instrument that treats a treatment target using ultrasonic vibration. This ultrasonic treatment instrument is provided with an ultrasonic transducer including a piezoelectric element which is configured to generate ultrasonic vibration by an electric energy being supplied. In this ultrasonic transducer, a distal portion of a bolt is connected to a distal side block so that the bolt anti the distal side block are integrally formed. A driving unit including a piezoelectric element is attached to an outer periphery of the bolt. A proximal portion of the bolt is connected to a proximal side block so that the proximal side block is fastened to the outer periphery of the bolt. The driving unit is sandwiched between the distal side block and the proximal side block, and a pressing force toward the distal side acts on the driving unit from the proximal side block.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the invention, an ultrasonic transducer including: a bolt which includes a proximal end and a distal end, and which is extended along a longitudinal axis from the proximal end to the distal end; a distal side block to which a distal portion of the bolt is connected; a proximal side block to which a proximal portion of the bolt is connected; and a driving source which includes a piezoelectric element, and which is attached to an outer periphery of the bolt in a state in which the driving source is sandwiched between the distal side block and the proximal side block in a direction along the longitudinal axis, the piezoelectric element being configured to generate ultrasonic vibration by an electric energy being supplied, by transmission of the ultrasonic vibration generated in the piezoelectric element, and the driving source being configured to vibrate together with the bolt, the distal side block, and the proximal side block in a state in which a first vibration node that is generated in the driving source and a second vibration node that is generated in the bolt are prevented from being displaced with respect to each other in the direction along the longitudinal axis.

According to one another aspect of the invention, a manufacturing method of an ultrasonic transducer, the method including: attaching a driving source which includes a piezoelectric element, to an outer periphery of a bolt which is extended along a longitudinal axis from a proximal end to a distal end; sandwiching the driving source between a distal side block, to which a distal portion of the bolt is connected, and a proximal side block, to which a proximal portion of the bolt is connected, in a direction along the longitudinal axis; generating ultrasonic vibration by an electric energy being supplied to the piezoelectric element, and vibrating the driving source together with the bolt, the distal side block, and the proximal side block by the generated ultrasonic vibration; in a state in which the bolt, the distal side block, the proximal side block, and the driving unit vibrate together, detecting a relative position in the direction along the longitudinal axis between a first vibration node that is generated in the driving unit and a second vibration node that is generated in the bolt; and on a basis of a detection result of the relative position between the first vibration node and the second vibration node, adjusting a vibration state in an outer vibration system that generates the first vibration node and a vibration state in an inner vibration system that generates the second vibration node in a manner such that the first vibration node and the second vibration node are prevented from being displaced with respect to each other in the direction along the longitudinal axis.

Advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and obtained means of the instrumentalities and combinations particularly pointed out hereinafter.

