Control valve for variable displacement compressor
First Claim
1. A control valve for a variable displacement compressor, which is mounted on the variable displacement compressor to control pressure within a gastightly-formed crankcase thereof to thereby change discharging capacity of refrigerant, comprising:
- a body having a refrigerant passage formed therethrough;
a valve section including a valve element moving to and away from a valve seat formed in the body so as to adjust a flow rate of refrigerant when part of refrigerant discharged from the variable displacement compressor is caused to flow into the crankcase, and a shaft configured to be axially slidably supported by the body and support the valve element such that the valve element can be caused to operate in unison therewith; and
a solenoid including a core fixed within the body, a plunger for moving the valve element forward and backward within the body via the shaft so as to cause the valve element to open and close, and a solenoid coil for generating a magnetic circuit including the plunger and the core by electric current supplied from outside, wherein the plunger is formed by arranging a first plunger opposed to the core, and a second plunger to which an end of the shaft, opposite to the valve element, is connected, in series in an axial direction, the plunger being formed by arranging a pressure-sensing member for sensing suction pressure from a suction chamber, and a hollow cylindrical magnetic member for fixing the pressure-sensing member to the solenoid, between the first and second plungers, wherein the first plunger is configured to be urged in a direction away from the core, and support the second plunger in an axial direction when the solenoid is energized, and wherein the second plunger includes a small-diameter portion inserted into the magnetic member such that a predetermined space is formed therebetween, and a large-diameter portion radially outwardly extending from the small-diameter portion and having an opposed surface formed thereon which is axially opposed to an opposed surface of the magnetic member, the second plunger being urged in a direction away from the first plunger, while the magnetic circuit being formed via the opposed surfaces during energization of the solenoid.
1 Assignment
0 Petitions
Accused Products
Abstract
To provide a control valve for a variable displacement compressor, including a plunger divided into separate members, which is improved in the attractive force characteristic and reduced in manufacturing costs. In a control valve for a variable displacement compressor, a predetermined space is formed between a holder and a small-diameter portion of a second plunger inserted into the holder, so that it is possible to reduce an attractive force acting in the radial direction of the second plunger during energization of a solenoid. On the other hand, opposed surfaces and 41a axially opposed to each other are formed on a large-diameter portion of the second plunger and the holder, respectively, and when the solenoid is energized, a magnetic circuit is formed via the opposed surfaces. This arrangement makes it possible to increase an attractive force in the operating direction of the second plunger. As a result, when the solenoid is energized, it is possible to relatively increase an attractive force in the valve-closing direction of a valve element connected to the second plunger to thereby enhance the attractive force characteristic of the whole control valve for a variable displacement compressor.
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Citations
4 Claims
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1. A control valve for a variable displacement compressor, which is mounted on the variable displacement compressor to control pressure within a gastightly-formed crankcase thereof to thereby change discharging capacity of refrigerant, comprising:
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a body having a refrigerant passage formed therethrough;
a valve section including a valve element moving to and away from a valve seat formed in the body so as to adjust a flow rate of refrigerant when part of refrigerant discharged from the variable displacement compressor is caused to flow into the crankcase, and a shaft configured to be axially slidably supported by the body and support the valve element such that the valve element can be caused to operate in unison therewith; and
a solenoid including a core fixed within the body, a plunger for moving the valve element forward and backward within the body via the shaft so as to cause the valve element to open and close, and a solenoid coil for generating a magnetic circuit including the plunger and the core by electric current supplied from outside, wherein the plunger is formed by arranging a first plunger opposed to the core, and a second plunger to which an end of the shaft, opposite to the valve element, is connected, in series in an axial direction, the plunger being formed by arranging a pressure-sensing member for sensing suction pressure from a suction chamber, and a hollow cylindrical magnetic member for fixing the pressure-sensing member to the solenoid, between the first and second plungers, wherein the first plunger is configured to be urged in a direction away from the core, and support the second plunger in an axial direction when the solenoid is energized, and wherein the second plunger includes a small-diameter portion inserted into the magnetic member such that a predetermined space is formed therebetween, and a large-diameter portion radially outwardly extending from the small-diameter portion and having an opposed surface formed thereon which is axially opposed to an opposed surface of the magnetic member, the second plunger being urged in a direction away from the first plunger, while the magnetic circuit being formed via the opposed surfaces during energization of the solenoid. - View Dependent Claims (2, 3, 4)
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Specification