Abstract: A control valve of an embodiment includes a disc coaxially in contact with a diaphragm, and a shaft configured to transmit a drive force in an axial direction caused by displacement of the diaphragm to a valve element. The diaphragm has a corrugated portion between a flat portion and the outer peripheral portion, the flat portion having a contact surface with which the disc is in contact. The corrugated portion includes substantially N+0.5 corrugations (N being a natural number) each protruding relative to a reference surface, the corrugations being formed between the outer peripheral portion and the flat portion, the reference surface being one surface of the outer peripheral portion. A height of each of the N corrugations of the corrugated portion is smaller than a height of the flat portion, the heights each being a height relative to the reference surface in an unloaded condition.

Abstract: A downstream-side passage of an expansion valve includes a small-diameter part to which a valve hole and an insertion hole are open, and a large-diameter part to which a pipe leading to an evaporator is connected. A plate has a shield part partially covering a downstream end of the small-diameter part. The shield part has a height of 2 mm or larger in a radial direction of the small-diameter part from a projected position of an opening of the insertion hole at the downstream end of the small-diameter part, and a width equal to or larger than a radius of the shaft within a range of the height. The plate is provided so that the shield part does not cover at least a range of projection of an opening of the valve hole at the downstream end of the small-diameter part.

Abstract: A pipe mounting structure of an embodiment allows a pipe, which is connected to an outlet side of an evaporator, to be mounted on a second passage of an expansion valve in such a manner that the pipe is inserted into an inlet port, and allows a pipe, which is connected to an inlet side of a compressor, to be mounted on the second passage in such a manner that the pipe is inserted into an outlet port. These pipes are mounted so that the pipes face each other with a shaft therebetween. The pipe mounting structure includes a natural vibration suppressing structure configured to prevent or suppress natural vibration of a gas column having antinodes of a standing wave at an open end of one of the pipes and an open end of the other pipe.

Abstract: An expansion valve includes: a body having a second passage through which a refrigerant returning from an evaporator passes, and a mounting hole communicating with the second passage; a power element mounted on the body in such a manner as to close the mounting hole; a shaft that transmits a drive force from the power element to a valve element; and a plate that separates an open space from the second passage, has an insertion hole, through which the shaft extends, coaxially along a central axis of the plate, and limits a flow of the refrigerant from the second passage into the open space to a flow through a clearance between the shaft and the insertion hole. The insertion hole is formed such that an opening area of the clearance between the shaft and the insertion hole is 7.0 mm2 or smaller.

Abstract: An expansion valve includes a vibration-proof spring that develops the sliding resistance by biasing a shaft. The vibration-proof spring includes a base portion constituted by a circular plate having a hole, through which the actuating rod can be inserted, in the central region, a plurality of spring portions, which is installed upright on the base portion and which is so formed as to come in contact with the periphery of the actuating rod, and a plurality of supporting pieces, which extend outward from the base portion and which is formed so that the supporting pieces can be stopped by the body. The supporting piece is structured such that the supporting piece includes a low-rigidity portion whose rigidity is lower than that of the base portion.

Abstract: An expansion valve according to one embodiment includes a body having a valve hole, a valve element which opens and closes a valve section by moving toward and away from the valve hole, and a shaft one end side of which connects to a drive section and the other end side of which connects to the valve element through the valve hole, the shaft transmitting the drive force, generated by the drive section, to the valve element. Here, the shaft is so provided as to run through an insertion hole formed axially with the valve hole in the body. The insertion hole is formed in the body by a cutting work, and has a support that supports the shaft and a diameter-enlarged part that is open to a downstream side of the valve hole and whose diameter is larger than that of the support.

Abstract: An expansion valve includes: a body having an insertion hole in a partition separating a first passage from a second passage; a power element configured to generate a drive force for opening or closing a valve section; a shaft extending through the insertion hole and configured to transmit the drive force to a valve element; a vibration-proof spring coaxially supporting the shaft and biasing the shaft radially inward to apply a sliding resistance thereto; and a flexible O-ring supported by one of an inner surface of the support part defining the insertion hole and an outer surface of the shaft and being in close contact with the other thereof. The O-ring, sliding portions of the shaft and the support part, and the vibration-proof spring are arranged in this order from a first passage side toward a second passage side in an axial direction of the shaft.

Abstract: A vibration-proof spring, which coaxially inserts a shaft, is provided in a body of a control valve. The vibration-proof spring includes a cylindrical spring body, spring parts, which are integrally formed with a side wall of the spring body and are supported by the spring body in a cantilevered manner, and bulging portions, which are formed, on surfaces of the spring parts facing the shaft, in a protruding manner. The spring body is formed as a cylindrical body such that a plate-like body, which is obtained by punching a metallic plate through a press-forming process, is bent along a longitudinal direction of the plate-like body. Also, the spring body is formed in such a manner as to have edge parts that protrude radially outward from at least one of ends of the cylindrical body in the direction of axis line.

Abstract: An expansion valve includes a shaft for transmitting the drive force to a valve element and a vibration-proof spring, set between the body and the shaft, which generates the sliding friction by biasing the shaft. The vibration-proof spring includes a spring body of a hollow tube shape, a spring part, which is integrally formed with a side wall of the spring body, and a bulging portion formed on the spring part in a protruding manner such that the tip of the bulging portion is placed opposite to a part of the shaft. When the bulging portion abuts against the shaft inserted to the vibration-proof spring, the spring part is placed in a position along the spring body or is warped outwardly from the spring body, so that the elastically reactive force resulting from the warped spring part allows the shaft to slide in a stabilized manner.

Abstract: A downstream-side passage of an expansion valve includes a small-diameter part to which a valve hole and an insertion hole are open, and a large-diameter part to which a pipe leading to an evaporator is connected. A plate has a shield part partially covering a downstream end of the small-diameter part. The shield part has a height of 2 mm or larger in a radial direction of the small-diameter part from a projected position of an opening of the insertion hole at the downstream end of the small-diameter part, and a width equal to or larger than a radius of the shaft within a range of the height. The plate is provided so that the shield part does not cover at least a range of projection of an opening of the valve hole at the downstream end of the small-diameter part.

Abstract: A control valve of an embodiment includes a disc coaxially in contact with a diaphragm, and a shaft configured to transmit a drive force in an axial direction caused by displacement of the diaphragm to a valve element. The diaphragm has a corrugated portion between a flat portion and the outer peripheral portion, the flat portion having a contact surface with which the disc is in contact. The corrugated portion includes substantially N+0.5 corrugations (N being a natural number) each protruding relative to a reference surface, the corrugations being formed between the outer peripheral portion and the flat portion, the reference surface being one surface of the outer peripheral portion. A height of each of the N corrugations of the corrugated portion is smaller than a height of the flat portion, the heights each being a height relative to the reference surface in an unloaded condition.

Abstract: An expansion valve includes: a body having an insertion hole in a partition separating a first passage from a second passage; a power element configured to generate a drive force for opening or closing a valve section; a shaft extending through the insertion hole and configured to transmit the drive force to a valve element; a vibration-proof spring coaxially supporting the shaft and biasing the shaft radially inward to apply a sliding resistance thereto; and a flexible O-ring supported by one of an inner surface of the support part defining the insertion hole and an outer surface of the shaft and being in close contact with the other thereof. The O-ring, sliding portions of the shaft and the support part, and the vibration-proof spring are arranged in this order from a first passage side toward a second passage side in an axial direction of the shaft.

Abstract: A pipe mounting structure of an embodiment allows a pipe, which is connected to an outlet side of an evaporator, to be mounted on a second passage of an expansion valve in such a manner that the pipe is inserted into an inlet port, and allows a pipe, which is connected to an inlet side of a compressor, to be mounted on the second passage in such a manner that the pipe is inserted into an outlet port. These pipes are mounted so that the pipes face each other with a shaft therebetween. The pipe mounting structure includes a natural vibration suppressing structure configured to prevent or suppress natural vibration of a gas column having antinodes of a standing wave at an open end of one of the pipes and an open end of the other pipe.

Abstract: An expansion valve according to one embodiment includes a body having a valve hole, a valve element which opens and closes a valve section by moving toward and away from the valve hole, and a shaft one end side of which connects to a drive section and the other end side of which connects to the valve element through the valve hole, the shaft transmitting the drive force, generated by the drive section, to the valve element. Here, the shaft is so provided as to run through an insertion hole formed axially with the valve hole in the body. The insertion hole is formed in the body by a cutting work, and has a support that supports the shaft and a diameter-enlarged part that is open to a downstream side of the valve hole and whose diameter is larger than that of the support.

Abstract: A vibration-proof spring, which coaxially inserts a shaft, is provided in a body of a control valve. The vibration-proof spring includes a cylindrical spring body, spring parts, which are integrally formed with a side wall of the spring body and are supported by the spring body in a cantilevered manner, and bulging portions, which are formed, on surfaces of the spring parts facing the shaft, in a protruding manner. The spring body is formed as a cylindrical body such that a plate-like body, which is obtained by punching a metallic plate through a press-forming process, is bent along a longitudinal direction of the plate-like body. Also, the spring body is formed in such a manner as to have edge parts that protrude radially outward from at least one of ends of the cylindrical body in the direction of axis line.

Abstract: An expansion valve includes a vibration-proof spring that develops the sliding resistance by biasing a shaft. The vibration-proof spring includes a base portion constituted by a circular plate having a hole, through which the actuating rod can be inserted, in the central region, a plurality of spring portions, which is installed upright on the base portion and which is so formed as to come in contact with the periphery of the actuating rod, and a plurality of supporting pieces, which extend outward from the base portion and which is formed so that the supporting pieces can be stopped by the body. The supporting piece is structured such that the supporting piece includes a low-rigidity portion whose rigidity is lower than that of the base portion.