JP2005257003A - Flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the structure and reduce the cost of a solenoid-driven flow control valve which can perform multistep operation. <P>SOLUTION: A movable portion of a solenoid comprises a first plunger 8 and a second plunger 13. At the time of non-energization, a spring 10 urges the first plunger 8 to close the valve. When a first current having a value smaller than the maximum supply current is supplied to the solenoid, the second plunger 13 is attracted to an end face 6a of a yoke 6. At this time, the first plunger 8 is forced up to the attraction position and a valve element 5 retained by the first plunger is lifted to thereby set the valve at a middle opening degree. Further, when a second current having a value the same as the maximum supply current value is supplied to the solenoid, the first plunger 8 is attracted to a core 9 so that the valve element 5 is further lifted to thereby set the valve on a maximum opening degree. By constituting a drive section with one solenoid, it is possible to reduce the cost. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flow control valve, and more particularly to a solenoid-driven flow control valve that can change the opening area of the valve stepwise and can be applied as an expansion device in a refrigeration cycle of an air conditioner.

  In the refrigeration cycle of the air conditioner, an expansion device is used. As this expansion device, there is one having a valve part and a motor or a solenoid capable of controlling the opening degree, and the opening degree is changed substantially in proportion to the rotational speed of the motor or the current supplied to the solenoid. Thus, the refrigerant flow rate is controlled linearly.

There is an expansion device that performs flow rate adjustment step by step with respect to such an expansion device capable of stepless flow rate adjustment (for example, see Patent Document 1). This expansion device has a configuration in which two on / off solenoid valves having different flow characteristics are arranged in parallel to the flow path, and opens one or the other or both of these solenoid valves. By operating it, it is possible to adjust the flow rate in four stages including the fully closed operation when both are closed.
JP-A-11-94121

  However, in the expansion device that performs multi-stage flow rate adjustment by combining the on / off operation of two solenoid valves, the multi-stage flow rate adjustment is realized by two solenoid valves. There was a problem that became high.

  The present invention has been made in view of these points, and an object of the present invention is to provide a flow control valve having a simple configuration and capable of multi-stage operation at a low cost.

  In the present invention, in order to solve the above problem, in the solenoid-driven flow rate control valve that changes the opening area of the valve stepwise, the valve element is adsorbed to the fully closed position where the valve element is seated on the valve seat and the core. A first plunger that holds the valve body in a valve opening or closing direction so that the body can move forward and backward in a fully open position away from the valve seat; and between the core and the first plunger. And a spring that biases the first plunger in the valve closing direction, and a yoke that is disposed on the outer peripheral side of the first plunger. And a second plunger that moves the first plunger in the valve opening direction.

  According to such a flow control valve, when the first current having a value smaller than the maximum supply current is supplied to the solenoid, the first plunger is opened when the second plunger is attracted to the end surface of the yoke. When the valve element held by the valve body is moved in the valve direction and lifted from the valve seat to set an intermediate opening area and the second current of the maximum value is supplied to the solenoid, the first plunger is The valve element was further lifted by adsorbing to the core, and the maximum opening area was set. As a result, the opening area can be changed stepwise according to the first and second currents having different current values.

  Since the flow control valve of the present invention is configured such that the opening area of the valve can be changed stepwise with a single solenoid valve, there is an advantage that the configuration becomes simple and the cost can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example a case where the present invention is applied to an expansion device.
FIG. 1 is a longitudinal sectional view showing a state when the flow control valve according to the first embodiment is not energized, and FIG. 2 is a state when the flow control valve according to the first embodiment is energized with a first current. FIG. 3 is a longitudinal sectional view showing a state when the flow rate control valve according to the first embodiment is energized with a second current.

  This flow control valve has a refrigerant introduction port 2 through which high-pressure refrigerant is introduced into the body 1 and a refrigerant outlet port 3 through which low-pressure refrigerant is led out, and communicates with an internal space formed in the body 1. ing. An open end of the refrigerant outlet port 3 that opens into the internal space constitutes a valve seat 4, and a ball-shaped valve body 5 that contacts and separates from the valve seat 4 is disposed in the internal space. The valve body 5 is held by a solenoid so as to advance and retreat in the axial direction.

  The solenoid has a cylindrical yoke 6 screwed to the body 1, and a sleeve 7 is coaxially arranged inside the yoke 6 and fixed by welding or press fitting. A first plunger 8 is disposed in the sleeve 7 so as to be slidable in the axial direction, and the valve body 5 is held at the tip thereof. The sleeve 7 is also tightly closed by press-fitting the core 9 from above in the figure or by welding after inserting the core 9. A spring 10 is disposed between the first plunger 8 and the core 9 and urges the valve body 5 fixed to the first plunger 8 in a direction to seat on the valve seat 4. The first plunger 8 is provided with a pressure equalizing hole 11 so that the space facing the core 9 communicates with the internal space of the body 1, and the high-pressure refrigerant introduced from the refrigerant introduction port 2 is the first plunger 8. The back pressure canceling structure is adopted so as not to generate a force to move the shaft in the axial direction.

  A second plunger 13 is disposed between the end surface 6a of the yoke 6 screwed to the body 1 and a step portion 12 formed in the body 1 so as to face the end surface 6a so as to be able to advance and retract in the axial direction of the solenoid. Has been. The second plunger 13 has a shape in which a cylindrical guide portion 13 a that slides in the body 1 and a locking portion 13 b that extends radially inward from the guide portion 13 a are integrally formed. And the valve body holding | maintenance part of the 1st plunger 8 is penetrated by the inner side opening part of the latching | locking part 13b. The locking portion 13 b of the second plunger 13 extends to a position that partially faces the end surface 8 a of the first plunger 8. As a result, when the second plunger 13 is attracted to the yoke 6 by the suction force generated between the end surface 6a of the yoke 6 and moves upward in the drawing, the second plunger 13 moves the first plunger 8 The hook acts to lift up until it is attracted to the yoke 6.

  When the first plunger 8 is in the state shown in FIG. 1 in which the valve body 5 is seated on the valve seat 4, the distance between the first plunger 8 and the core 9 is a, and the distance between the end face 8a and the end face 6a. Assuming that the distance in the axial direction is b, the relationship is a> b.

  Further, in the solenoid, a coil 14 is disposed between the yoke 6 and the sleeve 7, and a plate 15 is disposed in the upper opening of the yoke 6. The plate 15 is for forming a magnetic circuit between the yoke 6 and the core 9. And in order to seal the screwing part of the body 1 and the yoke 6, the O-ring 16 is arrange | positioned among them.

  In the flow control valve having the above configuration, when the solenoid is in a non-energized state, such as when the air conditioner is stopped, as shown in FIG. 1, the first force is applied by the biasing force of the spring 10 in the solenoid. One plunger 8 is pushed downward in the figure, whereby the valve body 5 fixed to the first plunger 8 is seated on the valve seat 4 and the flow control valve is in a fully closed state.

  Next, for example, when a first current having a value smaller than the maximum allowable supply current is supplied to the solenoid, the second plunger 13 is attracted by the yoke 6 and the first plunger 8 and moved upward in the figure. First, the second plunger 13 is attracted to the first plunger 8. Next, the second plunger 13 is sucked by the yoke 6, and the first plunger 8 and the second plunger 13 are united and moved upward in the figure, as shown in FIG. The plunger 13 is attracted to the yoke 6 and stops.

  At this time, since a suction force is also generated between the core 9 and the first plunger 8, the first plunger 8 is sucked by the core 9, but more than the suction force generated by the first current. The large spring force of the spring 10 is set, and the second plunger 13 attracted to the yoke 6 sucks the first plunger 8, and the first plunger 8 further moves toward the core 9. The first plunger 8 does not move any further upward in the drawing because it acts to brake the operation to be performed.

  As a result, the valve body 5 held by the first plunger 8 is lifted by an axial distance b between the end face 8a of the first plunger 8 and the end face 6a of the yoke 6, and the flow control valve is The opening area (opening) corresponding to the lift amount is set.

  Next, when the second current of the maximum supply current value is supplied to the solenoid, the attractive force generated between the core 9 and the first plunger 8 is the spring force of the spring 10 and the first plunger 8 and the second plunger 8. Therefore, the first plunger 8 is separated from the second plunger 13 and is adsorbed by the core 9 as shown in FIG.

  As a result, the valve body 5 held by the first plunger 8 is lifted by the distance a in the axial direction between the first plunger 8 and the core 9 which are separated when the solenoid is not energized. The control valve is set to a maximum opening area, that is, a fully opened state in which the refrigerant having the maximum flow rate flows.

  In this way, by changing the current value supplied to the solenoid, the distance by which the valve body 5 is lifted from the valve seat 4 can be changed stepwise, so that the flow rate of the refrigerant can be controlled stepwise. A control valve is configured.

  FIG. 4 is a longitudinal sectional view showing a state when the flow control valve according to the second embodiment is not energized, and FIG. 5 is a state when the flow control valve according to the second embodiment is energized with a first current. FIG. 6 is a longitudinal sectional view showing a state when the flow rate control valve according to the second embodiment is energized with a second current. 4 to 6, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this flow control valve, a second sleeve 17 is slidably disposed in the axial direction in a sleeve 7 fixed to the yoke 6, and the lower end portion of the second sleeve 17 in the figure is the second sleeve 17. It is fixed to the plunger 13 by welding or press fitting. A first plunger 8 holding the valve body 5 is slidably disposed through the second sleeve 17, and the first plunger 8 is more illustrated than the second sleeve 17. A step portion 18 is provided in a portion located above the second sleeve 17, and has a larger diameter than a portion in the second sleeve 17.

  In the flow control valve having such a configuration, when the solenoid is not energized, as shown in FIG. 4, the first plunger 8 is pushed downward by the urging force of the spring 10 in the solenoid. Thus, the valve body 5 fixed to the first plunger 8 is seated on the valve seat 4, and the flow control valve is in a fully closed state. At this time, the second sleeve 17 is also locked to the step portion 18 by the first plunger 8 and pushed downward in the figure.

  Next, for example, when a first current having a value smaller than the maximum supply current is supplied to the solenoid, the second plunger 13 is attracted by the yoke 6 and moves upward in the drawing, and is attracted to the end surface 6 a of the yoke 6. At this time, when the second sleeve 17 operating integrally with the second plunger 13 hooks the first plunger 8 on the stepped portion 18 and pushes it upward in the drawing, and the second plunger 13 is attracted to the yoke 6. Thus, the push-up of the first plunger 8 is stopped. After that, the first plunger 8 is attracted by the core 9 and tries to move further upward in the figure, but is pushed back by the spring force of the spring 10, and as shown in FIG. It stops in a state where it is in contact with the sleeve 17.

  As a result, the valve body 5 held by the first plunger 8 is lifted by the distance that the first plunger 8 is pushed up by the second plunger 13, and the flow control valve is opened corresponding to the lift amount. Will be set to degrees.

  Next, when the second current of the maximum supply current value is supplied to the solenoid, the attractive force generated between the core 9 and the first plunger 8 becomes larger than the spring force of the spring 10, and the first The plunger 8 is adsorbed by the core 9 as shown in FIG.

  As a result, the valve body 5 held by the first plunger 8 is lifted to a position farthest away from the valve seat 4, so that the flow control valve is set to the maximum opening through which the maximum flow rate of refrigerant flows. Is fully opened.

FIG. 7 is a diagram showing the characteristics of the flow control valve.
The characteristics shown in the figure are characteristics of the flow control valves according to the first and second embodiments. The horizontal axis indicates the current supplied to the solenoid, and the vertical axis indicates the opening area. According to this characteristic, when the flow control valve is in a non-energized state, its opening area is 0% and it is in a fully closed state. When the current supplied to the solenoid is changed stepwise, for example, to 0.5 amperes, the flow control valve has an opening area of, for example, 50% and, for example, when the maximum supply current value is changed to 1 ampere. The flow control valve has an opening area of 100% and is fully opened.

  In this way, the current supplied to the solenoid is changed stepwise to 0, the first current that is intermediate between 0 and the maximum supply current value, and the second current of the maximum supply current value. Accordingly, the opening area of the flow control valve can be changed in three stages.

FIG. 8 is a diagram illustrating a control example of the flow control valve.
By subjecting the current supplied to the solenoid to pulse modulation, the opening area of the flow control valve of the three-stage operation can be changed in more stages. That is, when the first current is pulse-modulated, the flow control valve opens and closes between 0% and 50%, so that the average opening area is 25% as shown by the broken line. When the second current is pulse-modulated, the flow control valve opens and closes between 0% and 100%, so that the average opening area can be 50%. When the second current is pulse-modulated with the peak value of the upper half, the flow control valve opens and closes between 50% and 100%, so the average opening area should be 75%. Can do.

  Therefore, by combining the flow control valve of the three-stage operation and the pulse modulation control of the current supplied thereto, the first stage when not energized, the second stage when the first current is pulse-modulated, The opening area can be changed between the third stage when the second current is pulse-modulated and the fourth stage when the second current is pulse-modulated with the upper half of the peak value. Further, in the case where the second current is not pulse-modulated, a fifth stage having an opening area of 100% can be added. The average opening area at each stage can also be adjusted by adjusting the duty ratio of the pulse.

It is a longitudinal cross-sectional view which shows the state at the time of the deenergization of the flow control valve which concerns on 1st Embodiment. It is a longitudinal section showing the state at the time of energization by the 1st current of the flow control valve concerning a 1st embodiment. It is a longitudinal cross-sectional view which shows the state at the time of the electricity supply by the 2nd electric current of the flow control valve which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the state at the time of the deenergization of the flow control valve which concerns on 2nd Embodiment. It is a longitudinal section showing the state at the time of energization by the 1st current of the flow control valve concerning a 2nd embodiment. It is a longitudinal cross-sectional view which shows the state at the time of the electricity supply by the 2nd electric current of the flow control valve which concerns on 2nd Embodiment. It is a figure which shows the characteristic of a flow control valve. It is a figure which shows the example of control of a flow control valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 2 Refrigerant introduction port 3 Refrigerant introduction port 4 Valve seat 5 Valve body 6 Yoke 6a End surface 7 Sleeve 8 First plunger 8a End surface 9 Core 10 Spring 11 Pressure equalizing hole 12 Step part 13 Second plunger 13a Guide part 13b Engagement Stop portion 14 Coil 15 Plate 16 O-ring 17 Second sleeve 18 Stepped portion

Claims (4)

In a solenoid-driven flow control valve that changes the valve opening area in stages,
By holding the valve element in the fully closed position where the valve element is seated on the valve seat and the core, the valve element is held in a fully open position away from the valve seat so that the valve element can be opened or closed in the valve closing direction A first plunger that
A spring disposed between the core and the first plunger and biasing the first plunger in a valve closing direction;
A second plunger which is disposed so as to be able to contact with and separate from an end surface of the yoke disposed on the outer peripheral side of the first plunger, and which moves the first plunger in a valve opening direction when attracted to the end surface of the yoke; ,
A flow control valve characterized by comprising:   By supplying a first current having a value smaller than the maximum supply current to the coil of the solenoid, the second plunger is attracted to the yoke while moving the first plunger and is set to an intermediate opening area. 2. The flow rate control valve according to claim 1, wherein the first plunger is attracted to the core and is set to a maximum opening area by supplying a second current having a maximum value to the coil.   The second plunger has a locking portion that extends to a position that partially faces the end surface of the first plunger on the side opposite to the core, and the engaging portion engages with the end surface of the yoke. 2. The flow rate control valve according to claim 1, wherein a stopper hooks the first plunger to move the first plunger to a suction position with the yoke. The second plunger is fixed to one end of a sleeve slidably disposed on the outer periphery of the first plunger so that the other end faces a step portion formed on the outer periphery of the first plunger. 2. The sleeve is brought into contact with the stepped portion of the first plunger at the time of suction to the end surface of the yoke, and the first plunger is moved to a suction position with the yoke. The flow control valve described.

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