Abstract: A butterfly valve includes a valve element that turns with a shaft to control open/closed states of a passage or adjust an opening degree of the passage. The valve element includes a plate and an elastic member provided along an outer circumference of the plate. The elastic member has seal parts that touch and leave an inner surface of the passage to close and open the passage. The plate has specific shapes on both sides with respect to an axis of the shaft, the specific shapes narrowing gaps between the plate and the inner surface on lower-pressure sides of seal centers of the seal parts in a valve closed state.

Abstract: An electromagnetic valve according to one embodiment includes a body having a lead-in port through which a refrigerant is led in, a lead-out port through which the refrigerant is led out, and a valve hole formed in a passage joining the lead-in port to the lead-out port, a main valve element that opens and closes a valve section by moving toward and away from the valve hole, and a solenoid that supplies a drive force in a direction of axis line to the valve element, the solenoid being mounted on the body. The main valve element has a pilot passage that is open to the valve hole and an orifice that throttles and expands the refrigerant led in from the lead-in port so as to be led out to the pilot passage, the orifice being so formed as to communicate between the lead-in port and the pilot passage.

Abstract: A butterfly valve includes a valve element that turns with a shaft to control open/closed states of a passage or adjust an opening degree of the passage. The valve element includes a plate and an elastic member provided along an outer circumference of the plate. The elastic member has seal parts that touch and leave an inner surface of the passage to close and open the passage. The plate has specific shapes on both sides with respect to an axis of the shaft, the specific shapes narrowing gaps between the plate and the inner surface on lower-pressure sides of seal centers of the seal parts in a valve closed state.

Abstract: A valve element has a packing material, whose one side surface touches and leaves a valve seat as a sealing surface, and a support member, which is driven in opening and closing directions of a valve section by actuating an actuator. The support member includes a supporting surface, which is in contact with a side surface of the packing material opposite to the sealing surface of the packing material, and an engagement part, which supports a peripheral edge part of the packing material in a manner such that the engagement part is engaged with the peripheral edge part. A ring-shaped fluid flow passage is formed between the supporting surface of the support member and the packing material, and this fluid flow passage communicates with an upstream passage.

Abstract: A piston is configured by a piston body and a support such that the piston is divided, along a direction of axis line, into the piston body, which is formed integrally with a valve element, and the support, which is provided separately from the valve element. A piston ring, which slides along a body, is held between the piston body and the support. The piston body is constantly in contact with one side face of the piston ring, and the support is constantly in contact with the other side face of the piston ring.

Abstract: A pilot valve element includes a metallic pilot valve body formed integrally with a plunger, a flexible sealing member, fitted on a tip of the pilot valve body, which touches and leaves a pilot valve seat, and a stopper for restricting the displacement of the pilot valve element relative to a driven member in a manner such that the sealing member is stopped in a direction of axis line after the sealing member has seated on a pilot valve seat. The stopper is configured such that the pressure-receiving diameter of the sealing member, which receives a pressure difference between an upstream side and a downstream side of the pilot valve, remains unchanged from when the sealing member comes in contact with the pilot valve seat until when the sealing member is stopped by the stopper with the result that the sealing member has completely seated on the pilot valve seat.

Abstract: An electromagnetic valve according to one embodiment includes a body having a lead-in port through which a refrigerant is led in, a lead-out port through which the refrigerant is led out, and a valve hole formed in a passage joining the lead-in port to the lead-out port, a main valve element that opens and closes a valve section by moving toward and away from the valve hole, and a solenoid that supplies a drive force in a direction of axis line to the valve element, the solenoid being mounted on the body. The main valve element has a pilot passage that is open to the valve hole and an orifice that throttles and expands the refrigerant led in from the lead-in port so as to be led out to the pilot passage, the orifice being so formed as to communicate between the lead-in port and the pilot passage.

Abstract: An electromagnetic valve according to one embodiment includes a driven member configured such that a piston and a valve element are vertically coupled with each other and configured such that a pilot passage runs through the driven member. Here, the piston separates a high-pressure chamber from a back pressure chamber. The valve element opens and closes a main valve by moving toward and away from a valve hole. The pilot passage communicates between a low-pressure chamber and the back pressure chamber. A communicating path, through which the high-pressure chamber and the back pressure chamber communicate with each other, is formed in the piston. The communicating path is formed such that an orifice, which is open to the back pressure chamber, and a communication hole, having a larger cross section than that of the orifice, are vertically connected with each other. The orifice is located above the communication hole.

Abstract: A pilot valve element includes a metallic pilot valve body formed integrally with a plunger, a flexible sealing member, fitted on a tip of the pilot valve body, which touches and leaves a pilot valve seat, and a stopper for restricting the displacement of the pilot valve element relative to a driven member in a manner such that the sealing member is stopped in a direction of axis line after the sealing member has seated on a pilot valve seat. The stopper is configured such that the pressure-receiving diameter of the sealing member, which receives a pressure difference between an upstream side and a downstream side of the pilot valve, remains unchanged from when the sealing member comes in contact with the pilot valve seat until when the sealing member is stopped by the stopper with the result that the sealing member has completely seated on the pilot valve seat.

Abstract: A valve element has a packing material, whose one side surface touches and leaves a valve seat as a sealing surface, and a support member, which is driven in opening and closing directions of a valve section by actuating an actuator. The support member includes a supporting surface, which is in contact with a side surface of the packing material opposite to the sealing surface of the packing material, and an engagement part, which supports a peripheral edge part of the packing material in a manner such that the engagement part is engaged with the peripheral edge part. A ring-shaped fluid flow passage is formed between the supporting surface of the support member and the packing material, and this fluid flow passage communicates with an upstream passage.

Abstract: A piston is configured by a piston body and a support such that the piston is divided, along a direction of axis line, into the piston body, which is formed integrally with a valve element, and the support, which is provided separately from the valve element. A piston ring, which slides along a body, is held between the piston body and the support. The piston body is constantly in contact with one side face of the piston ring, and the support is constantly in contact with the other side face of the piston ring.

Abstract: A device for use in a tape driving apparatus for detecting the tape end made of transparent material, comprising means for generating signals consisting of a first output and a second output having a delay time behind the first output, a device for emitting light upon the existence of the second output, a sensor for receiving the light emitting from the light emitting device through the tape end of transparent material, and a discriminating means for controlling, by means of the first output, the output supplied from the sensor during the existence of the second output, whereby the tape end is correctly detected without causing trouble in connection with extraneous light to be introduced from the outside.