JPH11173453A - Multi-stage flow rate control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure fixed valve closing operation irrespective of changes of viscosity of refrigerant by supporting two solenoid valves arranged in parallel for a flow of a fluid by one valve support block and providing orifices in parallel for a flow of a fluid of two solenoid valves on this support block. SOLUTION: When valve elements 30A, 30B of each solenoid valve 10A, 10B are closed, refrigerant flows only through an orifice 26, and its flow rate becomes the minimum. Next, when the valve element 30A only is opened, refrigerant flows through a first valve hole 27 and the orifice 26, and its flow rate becomes the middle extent. When the valve elements 30B is also opened, refrigerant flows through the first valve hole 27, a second valve hole 28, and the orifice 26, and its flow rate becomes the maximum extent. When each valve element 30A, 30B is closed and the refrigerant having high viscosity is used, the valve elements 30A, 30B receive its back pressure, but valve closing operation can be smoothly done by letting the back pressure escape to an inlet passage 23 side inside a conduit 23A through a plurality of longitudinal slits and horizontal slits formed in each valve element 30A, 30B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage flow control valve, and more particularly to a multi-stage flow control valve suitable for controlling the flow rate of a highly viscous refrigerant.

[0002]

2. Description of the Related Art Conventionally, it has been important to stably control condensing pressure (temperature) in a refrigeration circulation system in terms of securing an optimum refrigerant flow rate to an expansion valve and preventing overload on a compressor. As a control valve for adjusting the flow rate of the refrigerant, there are a control valve that adjusts in a stepless manner and a control valve that adjusts in a multistep manner. FIG. 5 is a diagram schematically showing a control valve for adjusting the refrigerant flow rate in multiple stages. A first control valve 1 and a second control valve 2 are provided between the condenser and the evaporator. And the orifice 3 are provided, and the flow rate of the refrigerant guided to the evaporator side is determined by the valve opening operation of the first control valve 1, the second control valve 2, and the orifice 3. ing.

That is, when the first control valve 1 and the second control valve 2 are closed, the refrigerant flows only through the orifice 3, so that the flow rate of the refrigerant is minimized. When the first control valve 1 is opened, the refrigerant flows through the first control valve 1 and the orifice 3, so that the flow rate is medium. When the second control valve 2 is also opened, the refrigerant flows. First
Since the refrigerant flows through the control valve 1, the second control valve 2, and the orifice 3, three-stage control is performed such that the flow rate is maximized.

[0004]

By the way, in the above-mentioned conventional multi-stage refrigerant flow adjustment, the first control valve 1, the second control valve 2, and the orifice 3 needs to be provided separately, so that the number of parts is increased, the configuration becomes complicated, and there is a problem that cost reduction is hindered.

In addition, the conventional first and second control valves 1 and 2 have a valve body having a function of simply opening and closing a valve hole. When a refrigerant having such a high viscosity is used, the valve body has a slow valve closing operation due to the influence of the back pressure of the refrigerant, and not only does the appropriate valve closing operation not be performed, but also the viscosity of the refrigerant increases. However, there is also a problem that the valve closing operation cannot be kept constant even if the pressure changes. The present invention has been made in view of such a problem, and an object of the present invention is to reduce cost with a simple configuration and to keep the valve closing operation constant even when the viscosity of the refrigerant changes. To provide a multi-stage flow control valve.

[0006]

In order to achieve the above object,
The multi-stage flow control valve according to the present invention has two solenoid valves disposed in parallel to the flow of fluid, and one valve that constitutes a valve body of the two solenoid valves and supports the two solenoid valves. It is characterized by comprising a valve support block and an orifice provided in the valve support block in parallel with the fluid flow of the two solenoid valves. In the multi-stage flow control valve according to the present invention configured as described above, the flow rate of the refrigerant is minimized only through the orifice, and the total amount of the orifice at the time of opening one of the solenoid valves is a medium level. When the two solenoid valves are opened, the total amount of the two solenoid valves and the orifice is controlled to a maximum of three stages. Further, since the two solenoid valves and the orifice are incorporated into one valve support block, the number of parts is greatly reduced.

Further, since a valve element is attached to the end of each plunger of each of the two solenoid valves, it is possible to easily select a valve element according to the shape of the valve hole and the type of refrigerant. . Furthermore, by providing the orifice and the valve holes of the respective valve chambers of the two solenoid valves between the inlet passage and the external passage provided in the valve support block, the valve chamber can be made smaller. . Further, by forming a passage for releasing the back pressure due to the fluid in the valve body, even when using a refrigerant having a high viscosity, the influence of the back pressure due to the refrigerant when the valve is closed is reduced. Therefore, the valve closing operation is performed smoothly.

Further, by providing a passage for releasing the back pressure due to the fluid so as to communicate the valve chamber and the inlet passage, the internal pressure in the valve chamber due to the back pressure due to the refrigerant received when the valve is closed. Since the rise is suppressed, not only the valve closing operation is performed smoothly, but also the valve closing operation is performed irrespective of the difference in viscosity. Furthermore, by forming the passage provided in the valve body as a slit, the valve body and the slit can be integrally molded, which is advantageous in terms of workability.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a multi-stage flow control valve (hereinafter, simply referred to as a control valve) according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view illustrating a main part of the control valve in FIG. 3 is a plan view showing the control valve of FIG. 1, and FIG. 4 is a perspective view showing a valve element of the multi-stage flow control valve of FIG.

The illustrated control valve 10 is used by being incorporated in a refrigeration circulation system.
0A and 10B, and a rectangular valve support block 20 constituting a valve body of the solenoid valves 10A and 10B. The two solenoid valves 10A and 10B are arranged on opposing surfaces 20A and 20B of the valve support block 20, respectively.

The two solenoid valves 10A and 10B are provided with a housing 11, a coil 12, a suction element 14 attached and fixed by a set screw 13, a guide sleeve 15, and the like. The guide sleeve 1
A plunger 18 urged in the valve closing direction by a coil spring 17 is slidably fitted into the inside of the housing 5, and a fitting hole 19 provided at a tip end portion of the plunger 18 is made of, for example, rubber. Are caulked.

Here, for example, as shown in FIGS. 4 (a) and 4 (b), the rubber valve bodies 30A and 30B have the same construction as those shown in FIGS. 4 (a) and 4 (b). ), Four longitudinal slits 31 formed on the peripheral surface along the axial direction.
Is provided. A lateral slit 34 is provided on a surface 33 of the valve bodies 30A and 30B opposite to the valve hole closing surface 32.

Further, steps 35 and 36 are provided on the valve hole closing surface 32 and the opposite surface 33 side, and four vertical slits 31 are provided through these step portions 35 and 36, respectively.
Are communicated, and the four vertical slits 31 and the horizontal slits 34 are also communicated with each other. Thereby, even when a high-viscosity refrigerant such as lithium bromide is used, the influence of the valve closing operation due to the back pressure of the refrigerant is reduced. I do.

1 and 2, a flange 15a is provided at an end of the guide sleeve 15, and an end of the guide sleeve 15 is provided with a nut 21.
The screw is screwed and fixed to the valve support block 20 side. Furthermore, the flange 15 at the end of the guide sleeve 15
An O-ring 22 is interposed between the joint a and the valve support block 20 so that the O-ring 22 maintains the hermetically sealed state inside the valve support block 20.

Further, an inlet passage 2 communicating with a refrigerant condenser (not shown) is provided at a central portion of the valve support block 20.
3 is connected to a conduit 24A having an outlet passage 24 communicating with an evaporator (not shown), and a strainer 25 is provided on the inlet passage 23 side. Impurities of the refrigerant sent from the refrigerant condenser (not shown) are removed.

An orifice 26, a first valve hole 27 and a second valve hole 28 are provided in the valve chambers 20a and 20b between the inlet passage 23 and the outlet passage 24. The valve opening of the valve hole 27 and the second valve hole 28 and the orifice 26
Thus, the capacity of the refrigerant flow rate can be varied in three stages.

Next, the operation of the control valve 10 configured as described above will be described. First, each of the two solenoid valves 10
When an exciting current is applied to the solenoids 16 of the A and 10B and the plunger 18 is drawn toward the suction element 14 against the urging force of the coil spring 17, the rubber valve bodies 30A and 30B of the plunger 18 are moved to the first position. The first valve hole 27 and the second valve hole 28 are opened away from the first valve hole 27 and the second valve hole 28. As a result, the refrigerant flowing into the valve support block 20 through the inlet passage 23 of the conduit 23A connected to the refrigerant condenser flows from the valve chambers 20a and 20b inside the valve support block 20 to the first refrigerant. Through the valve hole 27 and the second valve hole 28 to the outlet passage 24 side inside the conduit 24A, and further guided to the evaporator side. At this time, the refrigerant flows out to the outlet passage 24 side inside the conduit 24A via the orifice 26 provided inside the valve chambers 20a and 20b.

Here, the rubber valve bodies 30A, 30B
The flow rate of the refrigerant flowing from the first valve hole 27 and the second valve hole 28 to the outlet passage 24 inside the conduit 24 </ b> A when the valve is opened is defined as (α), and the refrigerant flows through the orifice 26. Assuming that the flow rate of the refrigerant flowing out to the outlet passage 24 side inside the conduit 24A is (β), the flow rate of the refrigerant controlled by the control valve 10 is multi-step by opening and closing the two solenoid valves 10A and 10B. Is controlled.

That is, when the valve body 30A of the solenoid valve 10A and the valve body 30B of the solenoid valve 10B are closed, the refrigerant flows only through the orifice 26, and the flow rate becomes the minimum (β). When only the valve body 30A on the solenoid valve 10A side is opened, the refrigerant flows through the first valve hole 27 on the solenoid valve 10A side and the orifice 3, so that the flow rate is moderate (α + β ), And when the valve element 30B of the solenoid valve 10B is also opened, the first and second valve holes 2
Since the refrigerant flows through 7, 28 and the orifice 3,
Three-stage control is performed such that the flow rate becomes the maximum (2α + β).

On the other hand, when the valves 30A, 30B of the solenoid valves 10A, 10B close the first and second valve holes 27, 28 when the valves are closed, for example, as described above, lithium bromide is used. When a refrigerant having a high viscosity is used, the valve bodies 30A and 30B inside the valve chambers 20a and 20b receive the back pressure of the high viscosity refrigerant. Is reduced for the following reasons.

That is, as described with reference to FIGS. 4 (a) and 4 (b), the valve bodies 30A and 30B have four longitudinal slits 31 formed along the axial direction on the peripheral surface thereof and the valve A lateral slit 34 formed in a surface 33 opposite to the hole closing surface 32
Are provided, and the four vertical slits 31 communicate with each other through the step portions 35 and 36 by the step portions 35 and 36 provided on the valve hole closing surface 32 and the opposite surface 33 side. The four vertical slits 31 and the horizontal slits 34 are also connected to each other. Therefore, the back pressure from the high-viscosity refrigerant when the valve is closed can be released to the inlet passage 23 side inside the conduit 23A through the four vertical slits 31 and the horizontal slits 34, The internal pressure rise due to the back pressure inside the valve chambers 20a and 20b is suppressed, and the valve closing operation is performed smoothly.

As described above, in the present embodiment, the flow rate of the refrigerant is set to a minimum value via only the orifice 26 and a medium flow rate which is the total amount of the orifice 26 when one of the solenoid valves 10A or 10B is opened. And the two solenoid valves 10
The function of performing the maximum three-stage control, which is the total amount with the orifice 26 when the valves A and 10B are opened, is incorporated in one valve support block 20, so that the number of parts is greatly reduced. .

Further, since the valve bodies 30A, 30B are attached to the ends of the plungers 18 of the two solenoid valves 10A, 10B, the shape and the shape of the first and second valve holes 27, 28 are determined. The valve 30 according to the type of the refrigerant
A and 30B can be easily selected. Furthermore, between the inlet passage 23 provided in the valve support block 20 and the external passage 24, the orifice 26 and the first and second valve chambers 20a and 20b of the two solenoid valves 10A and 10B are provided. By providing the valve holes 27 and 28, the valve chambers 20a and 20b can be reduced. Also,
Since the passage provided in the valve bodies 30A and 30B for releasing the back pressure due to the fluid is communicated between the valve chambers 20a and 20b and the inlet passage 23, the back pressure due to the refrigerant received when the valves are closed. As a result, the internal pressure rise inside the valve chambers 20a and 20b is suppressed, so that not only the valve closing operation is performed smoothly, but also the valve closing operation is performed irrespective of the difference in viscosity.

Further, the passages provided in the valve bodies 30A, 30B are formed by the vertical slits 31 and the horizontal slits 34, so that the valve bodies 30A, 30B and the vertical slits 31 and the horizontal slits 34 can be integrally formed. This is possible, which is advantageous in terms of workability. In the present embodiment, the valve 30
A case has been described in which four longitudinal slits 31 are formed along the axial direction on the peripheral surfaces of A and 30B. However, the present invention is not limited to this example, and the number of the longitudinal slits 31 may be three or less or five or more. Of course. Further, the valve hole closing surface 3
Although the case where one horizontal slit 34 is formed on the surface 33 on the side opposite to 2 has been described, the present invention is not limited to this example, and the number of the horizontal slits 34 may be two or more. May be made to cross each other. Furthermore, the case where the vertical slits 31 of the valve bodies 30A and 30B are formed along the axial direction of the peripheral surface has been described. However, the present invention is not limited to this example, and the vertical slits 31 may be formed in a spiral shape.

[0025]

As will be understood from the above description, according to the multistage flow control valve according to the present invention, the parts are realized by incorporating the two solenoid valves and the orifice into one valve support block. The number of points was greatly reduced, and a passage was formed in the valve body to release the back pressure due to the fluid, so that the cost could be reduced with a simple configuration and the valve closed even if the viscosity of the refrigerant changed. The operation can be constant.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a multi-stage flow control valve according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the control valve of FIG. 1;

FIG. 3 is a plan view showing the control valve of FIG. 1;

FIG. 4 is a perspective view showing a valve body of the multi-stage flow control valve of FIG. 1;

FIG. 5 is a schematic diagram showing a conventional mode of adjusting the flow rate of refrigerant in multiple stages.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Control valve 10A, 10B Solenoid valve 11 Housing 12 Coil 13 Set screw 14 Attractor 15 Guide sleeve 16 Solenoid 17 Coil spring 18 Plunger 20 Valve support block 20a, 20b Valve room 23A, 24A Duct 23 Inlet passage 24 Outlet passage 25 Strainer 26 Orifice 27 first valve hole 28 second valve hole 30A, 30B valve element 31 vertical slit 34 horizontal slit 35, 36 stepped portion

Claims (6)

[Claims] 1. Two solenoid valves arranged in parallel with a flow of fluid, one valve support block constituting a valve body of the two solenoid valves and supporting the two solenoid valves, An orifice provided in the valve support block in parallel with the fluid flow of the two solenoid valves. 2. Each of the two solenoid valves is provided with a plunger which is movable back and forth with respect to the valve chamber, and a valve body is attached to an end of the plunger facing the valve chamber. The multi-stage flow control valve according to claim 1, wherein: 3. The valve support block is provided with an inlet passage and an outer passage communicating with the outside, and a valve between the orifice and the two solenoid valves is provided between the inlet passage and the outer passage. The multi-stage flow control valve according to claim 1, wherein a valve hole of the chamber is provided. 4. The multi-stage flow control valve according to claim 2, wherein a passage for releasing a back pressure caused by the fluid is formed in the valve body. 5. The multi-stage flow control valve according to claim 4, wherein a passage for releasing the back pressure by the fluid is provided so as to communicate the valve chamber and the inlet passage. 6. The multi-stage flow control valve according to claim 4, wherein the passage for releasing the back pressure caused by the fluid is a slit.