摘要:
The present invention is directed to an ultrasonic flow rate measuring device capable of improving the measurement accuracy. Such an ultrasonic flow rate measuring device comprises first to third ultrasonic flow rate sensors in the measurement passage which are equipped with first ultrasonic wave transmitter-receivers and second ultrasonic wave transmitter-receivers. First to third ultrasonic wave propagation paths connecting the first ultrasonic wave transmitter-receiver and the second ultrasonic wave transmitter-receivers, respectively, intersect at different angles with the flow direction of fluid flowing through the measurement passages. The ultrasonic flow rate measuring device of the present invention obtains a flow rate measurement selectively from one of the first to third ultrasonic flow rate sensors in response to a flow rate Q.
摘要:
A difference in the thermal expansion coefficient between a casing and a piezoelectric body is adapted to be reduced by making an adhesive expand and contract, and this can prevent the separation of connection between the casing and the piezoelectric body and the damage of the piezoelectric body. As a result, the ultrasonic vibrator can be used over an extended period of time in an outdoor use environment.
摘要:
An ultrasonic flowmeter includes a flow passage and an ultrasonic transducer for measuring the flow rate in the flow passage wherein the ultrasonic transducer is equipped with a piezoelectric material having electrodes on the opposed surfaces thereof, one of which is used as an ultrasonic wave transmitting/receiving surface and faces the flow passage. The lengths of the sides of the transmitting/receiving surface is so determined that the vibration in the electrode direction is the main mode, preferably that the ratio of the lengths of the sides of the transmission/reception surface to the thickness is not greater than 0.8. Consequently, because the flow meter uses the thickness longitudinal vibration of the piezoelectric material as the main mode, the ultrasonic transducer has a high sensitivity, a high speed response and a small size and the ultrasonic flow meter has a high accuracy and is compact.
摘要:
An ultrasonic probe to be used for an ultrasonic diagnostic apparatus for obtaining an ultrasonic image. The ultrasonic probe comprises a catheter having a hollow tubing structure, a joint having a tubing structure and arranged to be at its one end portion connected to a tip portion of said catheter, a bearing connected to the other end portion of the joint, a rotating shaft inserted into the bearing to be rotatable and arranged so that a portion of the rotating shaft contacts with one end portion of the bearing, and a rotator connected to the rotating shaft and arranged so that one end portion of the rotator contacts with the other end portion of the bearing so that the bearing is interposed and supported between the portion of the rotating shaft and the rotator. An ultrasonic transducer is inserted into the rotator for transmitting and receiving an ultrasonic wave, a torque transmission shaft having a hollow structure is at its one end portion connected to the rotating shaft, and a guide wire is inserted into the hollow of the torque transmission shaft. A rotating force generated by a drive section is applied through the torque transmission shaft to the ultrasonic transducer whereby the ultrasonic transducer rotationally driven to perform a radial scanning operation. This arrangement allows a free movement of the guidewire within the catheter so that the catheter can easily be lead along the guidewire up to a target portion within a blood vessel.
摘要:
A cleaning effect is improved by cleaning a component that has a recess structure by using a cleaning medium of a liquefied gas or a supercritical fluid. By the cleaning method of removing adhering substances adhering to at least the surface of the recess structure of the component that has the recess structure, cleaning is carried out by using the supercritical gas or the liquefied gas so that the cleaning medium spreads over the surface of the recess structure.
摘要:
A catheter type laser illuminating apparatus for thermally removing an atheroma generated in a blood vessel. The illuminating apparatus comprises a catheter arranged to be inserted into a blood vessel, the catheter being equipped with an ultrasonic transducer for transmitting and receiving an ultrasonic wave to generate an electric signal corresponding to the reception ultrasonic wave. The catheter is further equipped with a laser transmission fiber for emitting the laser light. Also included in the illumination apparatus is a M-mode image producing section for producing an image representative of the dimension of the atheroma on the basis of the electric signal from the ultrasonic transducer. The image is displayed on a CRT in a corresponding relation to an illumination condition of the laser light to the atheroma which is at least one of an illumination time and an illumination power.
摘要:
A shutoff valve according to the present invention includes: a motor configured to cause a rotating shaft to rotate; a lead screw formed on the rotating shaft; a lead nut into which the lead screw is screwed; and a valve element configured to block a passage, the valve element being configured to move in an axial direction in accordance with rotation of the rotating shaft. A dry lubricating coating is formed on a contact surface where the lead screw and the lead nut come into contact with each other. A thread pitch of the lead screw is set such that a current applied to the motor, the current being in relation to an inductance of the motor, is in a range that does not cause explosion of the fuel gas and that allows thrust force necessary for moving the valve element to be obtained.
摘要:
A shutoff valve according to the present invention includes: a motor configured to cause a rotating shaft to rotate; a lead screw formed on the rotating shaft; a lead nut into which the lead screw is screwed; and a valve element configured to block a passage, the valve element being configured to move in an axial direction in accordance with rotation of the rotating shaft. A dry lubricating coating is formed on a contact surface where the lead screw and the lead nut come into contact with each other. A thread pitch of the lead screw is set such that a current applied to the motor, the current being in relation to an inductance of the motor, is in a range that does not cause explosion of the fuel gas and that allows thrust force necessary for moving the valve element to be obtained.
摘要:
An ultrasonic flowmeter includes a transmission/reception means provided in a flow path for performing transmission/reception using a state change of fluid; repetition means for repeating the transmission/reception; time measurement means for measuring a time of propagation repeated by the repetition means; flow rate detection means for detecting a flow rate based on a value of the time measurement means; and number-of-times change means for changing to a predetermined number of repetition times. With such a structure, an influence caused by a variation of a flow can be suppressed by changing the number of repetition times so as to be suitable for a variation. As a result, reliable flow rate measurement with a high accuracy can be achieved.
摘要:
For the purpose of solving the above problems, the present invention includes: transmission/reception means provided in a flow path for performing transmission/reception using a state change of fluid; repetition means for repeating the transmission/reception; time measurement means for measuring a time of propagation repeated by the repetition means; flow rate detection means for detecting a flow rate based on a value of the time measurement means; and number-of-times change means for changing to a predetermined number of repetition times. With such a structure, an influence caused by a variation of a flow can be suppressed by changing the number of repetition times so as to be suitable for a variation. As a result, reliable flow rate measurement with a high accuracy can be achieved.