JP3046667B2 - Expansion valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the temperature of a refrigerant sent from an evaporator in a refrigeration cycle to a compressor.
The invention relates to an expansion valve for automatically controlling the amount of refrigerant entering an evaporator.

[0002]

2. Description of the Related Art An expansion valve of this type is arranged such that a temperature-sensitive chamber filled with a saturated vapor gas which is the same as or similar to the refrigerant flowing through a refrigeration cycle is arranged in an outlet side passage of an evaporator, and has one wall surface of the temperature-sensitive chamber. The flow rate of the refrigerant sent to the evaporator is controlled by a valve mechanism driven by the displacement of the diaphragm forming the diaphragm.

[0003]

Generally, the above-described expansion valve is disposed in an atmosphere at a temperature higher than that of the flowing refrigerant. Condenses on the inner surface of the diaphragm and liquefies.

Therefore, there is no problem if the diaphragm is arranged so as to form the lower surface of the temperature sensing chamber. In other cases, for example, if the diaphragm is arranged so as to form the upper surface of the temperature sensing chamber, The droplets of the saturated vapor gas condensed on the diaphragm surface fall on the other high-temperature wall surface and evaporate again there, causing the pressure inside the temperature-sensitive chamber to rise rapidly. However, since the saturated vapor pressure due to the temperature of the diaphragm surface is lower than the pressure, condensation starts again on the inner surface of the diaphragm.

[0005] As a result, the pressure in the temperature sensing chamber fluctuates periodically, and the valve mechanism operates, whereby the amount of refrigerant flowing through the refrigeration cycle fluctuates continuously, and the refrigeration cycle becomes unstable. turn into. For this reason, in this type of conventional expansion valve, the diaphragm in the temperature sensing chamber can only be arranged so as to always be at the lower surface of the temperature sensing chamber, and the mounting position of the expansion valve is limited, which may be inconvenient. Was.

[0006] The valve opening characteristics of the expansion valve are determined by the characteristics of the gas charged into the temperature-sensitive chamber. However, even when the fluctuation of the refrigerant flow rate is reduced to stabilize the refrigeration cycle, if the gas to be charged into the temperature sensing chamber is the same or similar to the refrigerant as the saturated vapor gas, the valve opening characteristics of the expansion valve are desired. In some cases, it is difficult to set the ideal characteristics.

Accordingly, an object of the present invention is to provide an expansion valve which does not fluctuate the flow of the refrigerant regardless of the mounting posture and can provide a stable refrigeration cycle. It is an object of the present invention to provide an expansion valve that can freely set a valve opening characteristic for sending a refrigerant to a desired and most desirable characteristic.

[0008]

In order to achieve the above-mentioned object, an expansion valve according to the present invention is arranged so as to sense the temperature of a refrigerant flowing out of an evaporator and has a saturated steam gas sealed therein. A diaphragm made of a flexible thin plate arranged to form one wall surface of the temperature sensing chamber, and a valve mechanism driven by displacement of the diaphragm to change a flow rate of refrigerant entering the evaporator. The expansion valve, characterized in that an adsorbing means for adsorbing a liquid portion of the condensed and liquefied saturated vapor gas is added to the surface of the diaphragm on the temperature sensing chamber side, and further mixed with the saturated vapor gas, An inert gas may be sealed in the temperature-sensitive room.

[0009]

The condensation of the saturated vapor gas in the temperature-sensitive chamber occurs on the inner surface of the diaphragm. Then, the liquid portion of the condensed and liquefied saturated vapor gas is adsorbed by the adsorption means and held on the inner surface of the diaphragm regardless of the direction of the diaphragm surface.

If an inert gas is mixed with the saturated vapor gas and sealed in the temperature-sensitive chamber, the temperature-pressure characteristic of the expansion valve is determined by the pressure obtained by adding the partial pressure of the inert gas to the saturated vapor pressure of the gas. Translate by a minute.

Therefore, the slope of the valve opening characteristic (temperature-pressure characteristic) of the expansion valve remains the same as the characteristic of the saturated steam gas sealed in the temperature-sensitive chamber, and the pressure level in the operating temperature range becomes inactive. To the desired pressure level depending on the gas,
Overall enhanced.

When the inclination of the characteristic does not conform to the desired inclination, a desired inclination characteristic can be obtained by using a plurality of types of saturated steam gases having different inclination characteristics. Can be translated to the desired pressure level.

[0013]

An embodiment will be described with reference to the drawings. FIG. 1 shows a refrigeration cycle, and 1 is an evaporator. 2 is a compressor. 3
Is a condenser. Reference numeral 4 denotes a receiver connected to the outlet side of the condenser 3 and containing a high-pressure liquid refrigerant. 10 is an expansion valve.

The block 11 of the expansion valve 10 is formed with a low-pressure passage 12 for passing a low-temperature and low-pressure refrigerant and a passage 13 for adiabatically expanding a high-temperature and high-pressure refrigerant. The low-pressure passage 12 has one end (inlet side) 12 a connected to the outlet of the evaporator 1, and the other end (outlet side) 12 b connected to the inlet of the compressor 2. One end (inlet side) 13 a of the passage 13 for adiabatically expanding the high-pressure side refrigerant is connected to the outlet of the liquid receiver 4, and the other end (outlet side) 13 b is connected to the inlet of the evaporator 1.

The low-pressure passage 12 and the passage 13 for adiabatic expansion are formed in parallel to each other, and a through hole 14 perpendicular to the passage extends through the two passages 12 and 13. Outside the low-pressure passage 12 (upper side in the figure), a large hole 14a that penetrates outward is formed, and a temperature sensing chamber 30 is attached to the opening.

A valve mechanism 20 is provided from the through hole 14 to the passage 13 for adiabatic expansion. On the other hand, a valve seat 23 is formed at the center of the passage 13 for adiabatic expansion, and when a ball valve 25 urged toward the valve seat 23 from below by a coil spring 24 closes the valve seat 23, The passage 13 for adiabatic expansion is closed.

Reference numeral 26 denotes a ball valve receiver for supporting the ball valve 25. 27 is an adjusting nut which is screwed with the block 11 to adjust the urging force of the coil spring 24. 21 and 22 are O-rings for sealing.

A rod 28 inserted into the through hole 14 is provided so as to be slidable in the axial direction.
0, and the lower end is in contact with the upper end of the ball valve 25.
Therefore, when the ball valve 25 is pushed downward by the rod 28 against the urging force of the coil spring 24 and moved downward, the passage 13 for adiabatic expansion is opened, and the rod 28 is opened.
The passage area of the passage 13 changes in accordance with the amount of movement of the refrigerant, and the amount of refrigerant supplied to the evaporator 1 changes.

The temperature sensing chamber 30 is hermetically surrounded by a housing 31 made of a thick metal plate and a diaphragm 32 made of a flexible thin metal plate (eg, a stainless steel plate having a thickness of 0.1 mm). The passages 12 and 13 are located in the temperature sensing chamber 30.
A gas in a saturated vapor state having the same or similar properties as the refrigerant flowing therein is filled therein, and a gas filling injection hole is closed by a blind plug 34.

Reference numeral 33 denotes a temperature-sensitive chamber mounting seat for mounting the temperature-sensitive chamber 30 to the block 11, and its outer peripheral portion is hermetically welded to the housing 31 and the diaphragm 32 over the entire circumference to form an inner cylindrical portion. Screw part 3
3a is screwed into the block 11. 36 is an O-ring for sealing.

On the surface of the diaphragm 32 on the temperature-sensitive room side,
An adsorbing means 35 for adsorbing the liquid portion when the saturated vapor gas inside condenses and liquefies is added. As the adsorption means 35, for example, a hydrophilic porous synthetic resin may be applied to the inner surface of the diaphragm 32, or water glass may be applied to the inner surface of the diaphragm 32 and fired, such as felt or various fibers. May be adhered to the inner surface of the diaphragm 32. The suction means 35 may be provided on the entire inner surface of the diaphragm 32 or may be provided partially.

A top portion 28a of a rod 28 having a large area is in contact with the center of the lower surface of the diaphragm 32. Therefore, the temperature of the refrigerant flowing in the low-pressure passage 12 is transmitted to the diaphragm 32 via the rod 28 and the temperature-sensitive chamber mounting seat 33.

Therefore, when the temperature of the refrigerant flowing through the low-pressure passage 12 decreases, the temperature of the diaphragm 32 decreases,
Saturated steam gas in the temperature sensing chamber 30 condenses on the inner surface of the diaphragm 32. Then, since the pressure in the temperature sensing chamber 30 is reduced, the rod 28 is pushed and moved by the coil spring 24, and as a result, the ball valve 25 approaches the valve seat 23 and the flow path area of the refrigerant is reduced. The flow rate of the refrigerant flowing into the tank decreases.

At this time, the diaphragm 3 in the temperature sensing chamber 30
The liquid portion of the saturated vapor gas that has condensed on the inner surface of 2 is adsorbed by the adsorption means 35. Therefore, regardless of the orientation of the expansion valve, the condensed liquid portion is retained by the suction means, that is, the inner surface portion of the diaphragm 32, and does not touch the inner surface of the housing 31.

When the temperature of the refrigerant flowing in the low-pressure passage 12 rises, the temperature of the diaphragm 32 rises, so that the liquid portion of the saturated vapor gas adsorbed by the adsorbing means 35 evaporates again, and the pressure in the temperature-sensitive chamber 30 becomes Rise. Then, the rod 28 is pushed in a direction of separating the ball valve 25 from the valve seat 23, and the flow rate of the refrigerant flowing into the evaporator 1 increases.

In this embodiment, R
-12 and R-114 are mixed and sealed at a ratio of, for example, 2 to 3, and an inert gas such as nitrogen gas is mixed with the saturated steam gas to form a temperature-sensitive chamber. 30.

Then, as saturated steam gas, R-12 and R-12 are used.
By mixing -114 with 2 to 3, the slope of the temperature-pressure characteristic becomes a desired and most desirable slope as shown by -1 in FIG. 2, and by mixing nitrogen gas which is an inert gas, Translate to higher pressure levels, such as -2. The valve opening characteristic of the expansion valve to which the urging force of the coil spring 24 is applied is -2 as shown in -3.
This translates into a slightly lower pressure level from the above characteristics to become the desired most desirable characteristics.

Therefore, the slope of this characteristic can be arbitrarily set by selecting the mixture ratio of a plurality of saturated steam gases, and the pressure level in the operating temperature range can be set by selecting the mixture ratio of the inert gas. It can be set freely, and the most ideal valve opening characteristics can be set.

FIG. 3 shows the saturated vapor diagram when the mixing ratio of R-12 and R-114 is 4: 1, 3: 2, 2: 3 and 1: 4. A saturated vapor diagram of RC-318 which can be used as a saturated vapor gas is shown in FIG.

The slopes of the characteristics of RC-318 are R-12 and R-12.
Since the slope is in the middle of −114, if the slope is suitable for the use condition, only the pressure vapor needs to be corrected by using only RC 318 as the saturated vapor gas and mixing it with the inert gas.

[0031]

According to the present invention, since the liquid portion of the saturated vapor gas condensed in the temperature sensing chamber is always held on the surface of the diaphragm by the adsorption means, the expansion valve is mounted in any position. Therefore, the refrigeration cycle can be stably obtained without touching other portions of the temperature-sensitive chamber, and therefore, there is no unnecessary opening / closing operation of the valve mechanism, and there is no fluctuation in the flow of the refrigerant.

Further, if an inert gas is filled in the temperature-sensitive chamber, the opening characteristics (temperature-pressure characteristics) of the expansion valve can be freely set to the most desirable state for the refrigeration cycle, and the refrigerant is sent to the evaporator. The state can be controlled ideally.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an expansion valve according to an embodiment of the present invention.

FIG. 2 is a diagram showing temperature-pressure characteristics of gas.

FIG. 3 is a saturated vapor diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Evaporator 20 Valve mechanism 30 Temperature sensing room 32 Diaphragm

Claims (2)

(57) [Claims] A temperature sensing chamber arranged to sense a temperature of a refrigerant flowing out of an evaporator and filled with a saturated vapor gas condensed and liquefied therein; and one wall of the temperature sensing chamber. A diaphragm formed of a flexible thin plate disposed therein, and an expansion valve having a valve mechanism driven by the displacement of the diaphragm to change the flow rate of the refrigerant entering the evaporator. The gas portion of the saturated vapor gas condensed and liquefied does not adsorb ,
An expansion valve characterized by adding an adsorption means for adsorbing only air. 2. The expansion valve according to claim 1, wherein an inert gas mixed with the saturated steam gas is sealed in the temperature-sensitive chamber.