JP4897428B2 - Differential pressure control valve and air conditioner - Google Patents

Description

  The present invention relates to a differential pressure control valve suitable for a throttle device that restricts the flow rate of refrigerant between an outdoor heat exchanger and an indoor heat exchanger in a refrigeration cycle of an air conditioner, and an air conditioner using the differential pressure control valve.

  Conventionally, a system using a capillary as a throttling device is widely known in a refrigeration cycle of an air conditioner, but this capillary is a fixed type, and when the rotation speed of the compressor is varied, an appropriate expansion capacity is obtained. There is a problem of poor efficiency. On the other hand, if an electric expansion valve is used instead of the capillary, it can be adjusted to an appropriate expansion capacity, but a configuration such as driving a movable valve with, for example, a motor or solenoid is required, and the drive system is also It becomes necessary and becomes economically expensive.

Therefore, as an apparatus that can control the opening degree of the valve using the differential pressure of the refrigerant, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 4-227444 (Patent Document 1). In this apparatus, a piston 76 is disposed in a cylindrical main body 42, and a rod-like and tapered bearing 72 provided in the center of the main body 42 is inserted into a port 78 in the center of the piston 76, and the piston 76 is spring-loaded. 102 is configured to be biased to one side. The piston 76 is moved against the urging force of the spring 102 due to the pressure difference between the two sides of the piston 76, and the gap between the bearing 72 and the port 78 is made variable to control the flow rate of the refrigerant. .
JP-A-4-227444

  According to the conventional expansion device of Patent Document 1, when the refrigerant pressure becomes extremely high, there is a possibility that the port of the piston may be fitted and fixed to the bearing. It has become. In the example of Patent Document 1, it is described as operating in the cooling mode. However, because of its structure, the heating mode is a fixed orifice, and the control of the cross-sectional area of the refrigerant passage is only one point. Can not. In addition, since the bearing 72 (rod) has a cantilevered structure, there is a problem that variations in accuracy are likely to occur. Further, an O-ring is provided between the piston and the inner peripheral surface of the main body, and the friction between the piston and the main body is large, so that it is difficult to obtain a fine accuracy.

  The present invention provides a differential pressure control valve and an air conditioner that can control the refrigerant flow rate in both directions of the cooling mode and the heating mode, can easily set the valve opening degree, and become fail-safe even at abnormally high pressures. Let it be an issue.

The differential pressure control valve according to claim 1 is formed with a cylindrical main body pipe through which a fluid passes, and a valve seat opening which is disposed in the main body pipe and divides the main body pipe into two spaces and conducts the two spaces. A valve seat and a valve body that adjusts the flow rate of fluid flowing through the valve seat opening of the valve seat according to the differential pressure between the fluid pressures of the two spaces in the main body pipe, and by increasing the differential pressure In addition to having a flow rate characteristic that increases the flow rate, the shape of the outer peripheral surface of the valve body independently sets the flow rate characteristic for the flow from one side of the two spaces to the other and the flow rate characteristic for the flow flowing from the other side to the other. It is possible to do it.

The differential pressure type regulating valve according to claim 2 is formed with a cylindrical main body pipe through which a fluid passes, and a valve seat opening which is disposed in the main body pipe and divides the main body pipe into two spaces and conducts both the spaces. A valve seat, a rod-shaped valve body, the shaft of which is disposed in the main body pipe in parallel with the axis of the main body pipe and penetrates the valve seat opening of the valve seat section; Urging means for urging the valve body in the direction of the valve seat from both the space sides, and the outer peripheral surface of the valve body at the valve seat opening of the valve seat in the neutral position by the urging means An inclined surface whose diameter decreases from the corresponding portion toward both ends, and the valve body can be moved in the axial direction by the differential pressure of the fluid in both spaces, and the valve seat of the inclined surface and the valve seat portion The clearance between the opening and the valve seat opening is adjusted, and the fluid flow through the main body pipe is determined by the clearance between the inclined surface and the valve seat opening. As squeeze, the shape of the outer peripheral surface of said valve body, said the flow characteristic for flow from one to the other of the two spaces, that it has to the flow characteristics can be independently set to flow through the one from the other Features.

The differential pressure regulating valve according to claim 3 is the differential pressure regulating valve according to claim 1 or 2 , wherein the valve seat portion is fixed in the main body tube by caulking the entire circumference of the main body tube. The diameter of the valve seat opening of the valve seat portion is finely adjusted.

The air conditioner according to claim 4 is provided with the differential pressure regulating valve according to any one of claims 1 to 3 as a throttle device at a refrigerant connecting portion between the indoor heat exchanger and the outdoor heat exchanger of the refrigeration cycle. The characteristics of the cooling mode and the heating mode are made variable by the flow rate characteristics of the differential pressure type regulating valve in both directions.

According to the differential pressure type regulating valve of claim 1, the flow rate characteristic is such that the flow rate is increased by increasing the differential pressure between the two spaces in the main body pipe, and the flow rate characteristic with respect to the flow from one side of the two spaces to the other side, Since the flow rate characteristics for the flow of air can be set independently, fail-safe operation is realized by acting in a direction in which a large amount of refrigerant flows even at abnormally high pressures. Further, in the refrigeration cycle, the refrigerant is throttled between the cooling mode and the heating mode. Capability can be switched and controlled. In addition, the flow characteristics for the flow from one side of the two spaces to the other and the flow characteristics for the flow from one side to the other can be set independently depending on the shape of the outer peripheral surface of the valve body. it can.

According to the differential pressure type adjusting valve of the second aspect, the simple structure of the main body pipe, the valve seat portion, the rod-shaped valve body and the urging means is provided. Further, since the outer peripheral surface of the valve body is an inclined surface whose diameter decreases from the portion corresponding to the valve seat opening of the valve seat portion toward the both ends in the neutral position by the urging means, the differential pressure increases. Along with this, the opening of the gap increases, and even when the pressure is abnormally high, it acts in the direction in which a large amount of refrigerant flows to achieve fail-safe. In addition, the flow characteristics for the flow from one side of the two spaces to the other and the flow characteristics for the flow from one side to the other can be set independently depending on the shape of the outer peripheral surface of the valve body. it can.

According to the differential pressure type regulating valve of claim 3 , in addition to the effect of claim 1 or 2 , the valve seat portion is fixed in the main body pipe by caulking the entire circumference of the main body pipe. Since the diameter of the seat opening is finely adjusted, it is possible to reduce variations in flow characteristics due to dimensional variations.

According to the air conditioner of the fourth aspect , in addition to the effect of any one of the first to third aspects, the operation capacity of the cooling mode and the heating mode can be set according to the application.

  Next, an embodiment of a differential pressure control valve and an air conditioner of the present invention will be described with reference to the drawings. FIG. 4 is a view showing a main part of the air conditioner according to the embodiment. In FIG. 20 is an outdoor heat exchanger mounted on the outdoor unit, 30 is an indoor heat exchanger mounted on the indoor unit, 40 is, for example, a rotary flow path switching valve constituting a four-way valve, and 50 is a compressor. The differential pressure control valve 10, the outdoor heat exchanger 20, the indoor heat exchanger 30, the flow path switching valve 40, and the compressor 50 are each connected by a conduit as shown in the figure to form a heat pump refrigeration cycle. . The accumulator, pressure sensor, temperature sensor, etc. are not shown.

  The flow path of the refrigeration cycle is switched to two flow paths of “cooling mode” and “heating mode” by the flow path switching valve 40. In the cooling mode, as indicated by solid arrows in FIG. 4, the refrigerant compressed by the compressor 50 flows into the outdoor heat exchanger 20 from the flow path switching valve 40, and exchanges indoor heat via the differential pressure control valve 10. The refrigerant that has flowed into the compressor 30 flows into the compressor 50 via the flow path switching valve 40. And the outdoor heat exchanger 20 functions as a condenser, the indoor heat exchanger 30 functions as an evaporator, and indoor cooling is made | formed. On the other hand, in the heating mode, as indicated by broken arrows in FIG. 4, the refrigerant compressed by the compressor 50 flows into the indoor heat exchanger 30 from the flow path switching valve 40, and the differential pressure control valve 10 and the outdoor heat exchange. The unit 20, the flow path switching valve 40, and the compressor 50 are circulated in this order. And the indoor heat exchanger 30 functions as a condenser, and the outdoor heat exchanger 20 functions as an evaporator, and indoor heating is made.

  FIG. 1 is a cross-sectional view (FIG. 1 (A)) and a partially enlarged view (FIG. 1 (B)) of a differential pressure regulating valve 10 of the embodiment. In the drawing, the hatched lines indicating the cross section are appropriately omitted for easy understanding of details. This differential pressure regulating valve 10 includes a cylindrical main body pipe 1, a valve seat portion 2, a rod valve 3 as a valve body, bearings 4 and 4, and biasing springs 5 and 5 as biasing means. The main body pipe 1 is formed of a copper pipe, one end of which is connected to the outdoor heat exchanger 20 side, and the other end is connected to the indoor heat exchanger 30. Each of the valve seat portion 2 and the bearings 4 and 4 has a substantially disc shape, and the outer diameter thereof is formed to match the inner periphery of the main body tube 1. And the valve seat part 2 is arrange | positioned in the center of the main body pipe | tube 1, and the bearings 4 and 4 are each arrange | positioned in the position spaced apart from the valve seat part 2. As shown in FIG.

  The valve seat part 2 is fixed in the main body pipe 1 by caulking a part of the entire circumference of the main body pipe 1 and recessing a part of the main body pipe 1 in a groove 2 a on the outer periphery of the valve seat part 2. . The positions of the bearings 4 and 4 also serve to adjust the biasing force applied to the rod valve 3 by the biasing springs 5 and 5 and to adjust the position of the rod valve 3 with respect to the valve seat portion 2. It is adjusted by adjusting the press-fitting into the main body pipe 1. The caulking portion of the main body pipe 1 prevents the back leakage of the refrigerant between the main body pipe 1 and the valve seat portion 2 as well as fixing the valve seat portion 2, and further finely adjusts the diameter of the valve seat portion 2. Doubles as

  A valve seat opening 21 is formed at the center of the valve seat portion 2, and shaft holes 4 b and 4 b are formed at the centers of the bearings 4 and 4, respectively. The rod valve 3 is disposed so as to penetrate the valve seat opening 21 and the shaft holes 4b and 4b. The urging springs 5, 5 are disposed between the bearings 4, 4 and the spring receivers 6, 6 fitted to the rod valve 3 on both sides of the rod valve 3. The spring receivers 6 and 6 are in contact with the protrusions 3 a and 3 a formed in the circumferential direction of the rod valve 3 and are fixed to the rod valve 3 by the urging force of the urging springs 5 and 5. Thereby, the rod valve 3 is urged | biased toward the center from the bearings 4 and 4 side of both sides. The bearings 4 and 4 are formed with through holes 4c and 4c.

  As described above, in the differential pressure regulating valve 10, the inside of the main body pipe 1 through which the refrigerant as the fluid flows is partitioned by the valve seat portion 2, and the space A sandwiched between the valve seat portion 2 and one bearing 4, the valve A space B sandwiched between the seat portion 2 and the other bearing 4 is formed. Further, the valve seat portion 2 is formed with a valve seat opening 21 for conducting both spaces A and B. Further, the rod valve 3 as a valve body is disposed in the main body pipe 1 with its axis L1 parallel to the axis L2 of the main body pipe 1 (in this example, coaxial), and the valve seat opening 21 of the valve seat portion 2. It penetrates. Furthermore, urging springs 5 and 5 as urging means urge the rod valve 3 from both the spaces A and B toward the valve seat portion 2 (center side).

  As shown in FIG. 1B, the periphery of the valve seat opening 21 of the valve seat portion 2 is formed in a tapered shape, the space A side is a cooling direction valve seat 2A, and the space B side is a heating direction valve seat 2B. Yes. The outer peripheral surface of the rod valve 3 is inclined surfaces 31 and 32 so that the diameter gradually decreases from the central ridge line 3b toward both sides. The inclined surface 32 on the space B side has a larger inclination angle than the inclined surface 31 on the space A side, and the angle of the inclined surface 31 on the space A side is slight. 1 (A) and 1 (B) illustrate a state in which the differential pressure between the space A and the space B is 0. In this state, the rod valve 3 has a central ridgeline 3b at the valve seat opening of the valve seat portion 2. The position is set to 21.

  That is, the diameter of the outer peripheral surface of the rod valve 3 decreases from the portion corresponding to the valve seat opening 21 (the central ridge line 3b) of the valve seat portion 2 toward the both ends in the neutral position by the biasing springs 5 and 5. The inclined surfaces 31 and 32 are provided. Then, the rod valve 3 can be moved in the direction of the axis L1 by the differential pressure of the refrigerant in both spaces A and B, the gap between the inclined surface 31 or 32 and the valve seat opening 21 of the valve seat portion 2 is adjusted, and the gap Thus, the flow rate of the refrigerant passing through the main body tube 1 is reduced.

  When there is a differential pressure between the refrigerant pressure in the space A and the refrigerant pressure in the space B, this differential pressure acts to urge the rod valve 3 from the high pressure side to the low pressure side. That is, as shown in FIG. 2A, in the cooling mode, the refrigerant pressure in the space A becomes higher than the refrigerant pressure in the space B, the rod valve 3 moves closer to the space B, and the refrigerant moves from the space A to the valve seat portion. 2 flows through the gap D between the rod valve 3 and the space B. Further, as shown in FIG. 2 (B), in the heating mode, the pressure of the refrigerant in the space B becomes higher than the refrigerant pressure in the space A, and the refrigerant passes through the gap D between the valve seat portion 2 and the rod valve 3 from the space B. It flows to the space A side. At this time, the gap D between the valve seat portion 2 and the rod valve 3 becomes a throttle portion (orifice) that restricts the flow of the refrigerant between the space A and the space B.

If the biasing force due to the differential pressure is F, the differential pressure is Δp, and the cross-sectional area of the rod valve 3 in the plane including the valve seat opening 21 is S (x), F = Δp · S (x). . Further, when the biasing force of the biasing spring 5 is f and the displacement of the central ridge 3b from the valve seat opening 21 is x, f = k · x (Hooke's law). Further, the area of the valve seat opening 21 is S0, the cross-sectional area of the central ridge 3b of the rod valve 3 is S ₀ , the area of the gap D is SD, and the reduction rate of the axial cross-sectional area of the rod valve 3 is a (a > 0), S (x) = (S ₀ −a · x), SD = S 0 −S (x), and the biasing force F due to the differential pressure and the biasing force f of the biasing spring 5 are In a balanced state, x = S ₀ / (k / Δp + a), and the displacement x increases as the differential pressure Δp increases. Therefore, as the differential pressure increases, the gap D of the throttle portion becomes wider, and the flow rate of the refrigerant passing through the gap D increases.

  FIG. 3 is a diagram illustrating a flow rate characteristic of the differential pressure regulating valve 10 in the embodiment. Both the flow rate of refrigerant flowing from space A to space B in the cooling mode (cooling direction) and the flow rate of refrigerant flowing from space B to space A in the heating mode (heating direction) both increase as the differential pressure increases. However, since the inclined surface 32 on the space B side has a larger inclination angle than the inclined surface 31 on the space A side, the amount of change of the refrigerant flow rate with respect to the differential pressure is larger in the heating direction. In the embodiment, the amount of change is larger in heating, but not limited to this, it goes without saying that the flow rate characteristic can be freely set between cooling and heating.

  As described above, the flow rate of the refrigerant in either the cooling mode or the heating mode can be controlled by the single differential pressure control valve 10. In addition, since the opening of the throttle portion (gap D) becomes wider as the differential pressure of the refrigerant increases, fail safe is realized by acting in a direction in which a large amount of refrigerant flows even at an abnormally high pressure.

  In the embodiment, the inclined surfaces 31 and 32 of the rod valve 3 are conical surfaces (parts thereof). In other words, the shape is such that the generatrix is a straight line, but it may be a curved surface that is slightly curved along the axial direction. Further, it may be a multi-stage inclined surface with a plurality of angles. These shapes determine the flow characteristics, but can be easily set by simple processing of the rod valve 3.

  In the embodiment, two urging springs 5 for urging the rod valve 3 are provided. However, such an urging spring is 1 if the mounting relationship between the rod valve 3 and the bearing 4 is considered. One may be sufficient. Such an urging means may use other elastic members or the like as long as it has a simple structure.

It is sectional drawing and the partially expanded view of the differential pressure type | formula adjustment valve of embodiment of this invention. It is a figure which shows the state of the air_conditioning | cooling mode and heating mode of the differential pressure type adjustment valve. It is a figure which shows the flow volume characteristic of the differential pressure type adjustment valve. It is a figure which shows the principal part of the air conditioning apparatus of embodiment of this invention.

Explanation of symbols

1 Body Pipe 2 Valve Seat 21 Valve Seat Opening 3 Rod Valve (Valve)
31, 32 Inclined surface 4 Bearing 4b Shaft hole 5 Biasing spring (Biasing means)
A, B Space D Gap 10 Differential pressure regulating valve 20 Outdoor heat exchanger 30 Indoor heat exchanger 40 Flow path switching valve 50 Compressor

Claims (4)

A cylindrical main body tube that allows fluid to pass through;
A valve seat portion disposed in the main body pipe and partitioning the main body pipe into two spaces and formed with a valve seat opening that conducts both the spaces;
A valve body that adjusts the flow rate of the fluid flowing through the valve seat opening of the valve seat portion in accordance with the differential pressure of the fluid pressure between the two spaces in the main body pipe;
With
The flow rate is increased by the differential pressure, and the flow rate characteristic for the flow from one side of the two spaces to the other and the flow rate for the flow from one side to the other by the shape of the outer peripheral surface of the valve body. A differential pressure control valve characterized in that the characteristics can be set independently. A cylindrical main body tube that allows fluid to pass through;
A valve seat portion disposed in the main body pipe and partitioning the main body pipe into two spaces and formed with a valve seat opening that conducts both the spaces;
A rod-shaped valve body, the valve body being disposed in the main body pipe in parallel with the axis of the main body pipe and penetrating the valve seat opening of the valve seat portion;
Urging means for urging the valve body from the both space sides toward the valve seat portion;
With
The outer peripheral surface of the valve body is inclined so that the diameter decreases from the portion corresponding to the valve seat opening of the valve seat portion toward both ends in the neutral position by the biasing means, and the fluid in both the spaces is The valve body can be moved in the axial direction by the differential pressure, the gap between the inclined surface and the valve seat opening of the valve seat portion is adjusted, and the fluid passing through the main body pipe by the gap between the inclined surface and the valve seat opening The flow rate characteristic for the flow from one side of the two spaces to the other and the flow rate characteristic for the flow from one side to the other can be set independently by the shape of the outer peripheral surface of the valve body. A differential pressure regulating valve characterized by that. 3. The diameter of the valve seat opening of the valve seat portion is finely adjusted by caulking the entire circumference of the main body tube and fixing the valve seat portion in the main body tube. The differential pressure regulating valve described in 1. The differential pressure type adjusting valve according to any one of claims 1 to 3 is provided as a throttle device at a refrigerant connecting portion between the indoor heat exchanger and the outdoor heat exchanger of the refrigeration cycle,
An air conditioner characterized in that the characteristics of the cooling mode and the heating mode are made variable by the flow characteristics of the differential pressure type regulating valve in both directions.

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