JP2000213827A - Thermostatic refrigerant expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower a noise level generated due to the dissipation of bubbles by reducing the rapid pressure drop of a refrigerant when the refrigerant enters a second passage from an orifice and suppressing the generation of bubbles in the refrigerant. SOLUTION: A thermostatic refrigerant expansion valve comprises a valve main body 41 having a first passage 42, a second passage 43 and a third passage 44, a throttle mechanism 46 having a valve seat 47 provided with an orifice 47a and a valve disk 48 and a control mechanism 54 having a heat sensitive chamber 61 and a diaphragm 57 displaced in accordance with pressure in the heat sensitizing chamber 61. The control mechanism 54 includes a transfer member for transferring the temperature of a refrigerant flowing in the third passage 44 to gas in the heat sensitive chamber 61 and the displacement of the diaphragm 57 to the valve disk 48. In this case, the second passage side 43 of the orifice 47a is formed in an expanded wall surface whose area increases or a tapered wall surface 47c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature type expansion valve used for a refrigeration cycle of an air conditioner, and relates to a temperature type expansion valve which responds to the temperature of refrigerant sent from an evaporator of the refrigeration cycle toward a compressor. The present invention relates to a temperature type expansion valve for automatically controlling the amount of refrigerant to enter.

[0002]

2. Description of the Related Art FIG. 7 is a longitudinal sectional view showing a state in which a conventional temperature type expansion valve 4 is incorporated in a refrigeration cycle of an air conditioner for a vehicle. The apparatus includes a vessel 2, a receiver 3, an expansion valve 4, and an evaporator 5. The compressor 1 is driven by receiving the rotational force of an automobile engine via an electromagnetic clutch (not shown). The condenser 2 condenses the high-temperature and high-pressure gaseous refrigerant adiabatically compressed by the compressor 1 by exchanging heat with air outside the vehicle compartment to form a liquid refrigerant. The receiver 3 has a built-in dryer (not shown) for temporarily storing the liquid refrigerant cooled by the condenser 2 and removing moisture and dust in the refrigerant. The expansion valve 4 adiabatically expands the liquid refrigerant into a low-temperature and low-pressure mist refrigerant. The evaporator 5 vaporizes the mist refrigerant by heat exchange with air sent into the vehicle interior.

As shown in FIG. 7, a conventional expansion valve 4 has a first flow path 42 communicating with an outlet of a condenser 2 and a second flow path 42 communicating with an inlet of an evaporator in a resin valve body 41. A channel 43;
A third flow path 44 is provided for communicating the outlet of the evaporator 5 and the inlet of the compressor 1. The throttle mechanism 46 is disposed at the back of the first flow path 42, and includes an orifice 47 a and the valve body 4.
8 and a compression coil spring 49. The orifice 47a is formed in the valve main body 41 for communicating the first flow path and the second flow path, and has an inlet opening into the valve chamber 45, and a valve is provided around the inlet. A seat 50 is formed. The valve element 48 is urged toward a valve seat 50 by a compression coil spring 49. The valve element 48 abuts on the valve seat 50 to close the orifice 47 a, and separates from the valve seat 50. Orifice 47a
Is to be released.

The right side of the third flow path 44 is connected to the compressor 1, and the compressor 1 is connected to the first flow path 42 via the condenser 2 and the receiver 3. . The left side of the third flow path 44 is connected to the evaporator 5, and the evaporator 5 is connected to the second flow path 43.

On the other hand, a flange portion 41a at the top of the valve body 41
The upper lid 55, the lower lid 56, the upper lid 55 and the lower lid 56
And a diaphragm 57 made of a stainless steel thin plate sandwiched therebetween, and a control mechanism 54 is hermetically fixed by a stopper 60 through a packing 59.

A heat-sensitive chamber 61 formed by the upper lid 55 and the diaphragm 57 is filled with a saturated steam gas and sealed with a steel ball 62.

The temperature sensing rod 65 has a central portion that penetrates the third flow path 44 in a direction perpendicular to the third flow path 44, and controls the temperature of the refrigerant flowing through the third flow path 44 through the dish portion 67 through the diaphragm 57. In addition to transmitting the thermal expansion and thermal contraction of the saturated steam gas in the thermal chamber 61 to the valve body 48 via the diaphragm 57, the temperature sensing rod 65, and the operating rod 69, the thermal sensing chamber 61 is transmitted to the upper part. .

[0008]

However, in the conventional expansion valve configured as described above, the pressure is increased by passing through the throttle portion 47b from the first flow path 42 as shown in FIG. It descends, further passes through the orifice 47a, and expands in volume when flowing into the second flow path 43, so that the pressure drops rapidly. As a result, the differential pressure D is increased, and bubbles are generated. The bubbles disappear when the second flow path 43 collides with the surface on the opposite side of the orifice 47a because the direction of the second flow path 43 is changed at a right angle. There was a problem of generating noise.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an expansion valve having an orifice 47 at the outlet side, that is, a second flow path 43.
A temperature expansion valve which can reduce noise generated at the orifice 47a of the expansion valve by forming the shape of the side on a tapered wall surface or an expanded wall surface having an increased area.

That is, according to the present invention, the valve body 41 and the throttle mechanism 4 for adjusting the flow rate of the refrigerant sent to the evaporator 5 are provided.
6 and a control mechanism 54 for controlling the throttle mechanism 46 in accordance with the temperature of the refrigerant sent from the evaporator 5 toward the compressor 1
The valve body 41 includes a first flow path 42 for introducing the refrigerant, a second flow path 43 for sending out the introduced refrigerant to the evaporator, and the compressor 1 from the evaporator 5. Flow path 44 for passing the refrigerant discharged toward
The throttle mechanism 46 includes a valve seat 47 having an orifice 47a for communicating the first flow path 42 and the second flow path 43, and a valve body for adjusting the opening amount of the orifice 47a. The control mechanism 54 has a thermo-sensitive chamber 61 filled with a gas, and a diaphragm 57 that is displaced in accordance with the pressure in the thermo-sensitive chamber 61.
A temperature-type expansion valve having a transmission member for transmitting the temperature of the refrigerant flowing through the diaphragm 4 to the gas in the heat-sensitive chamber 61 and transmitting the displacement of the diaphragm 57 to the valve element 48.
The temperature type expansion valve is characterized in that the second flow path 43 side of 7a is formed on a tapered wall surface 47c or an expanded wall surface 47c 'having an increased area.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The same parts as those of the conventional expansion valve are not described in detail, and are denoted by the same reference numerals. FIG. 1 is a longitudinal sectional view showing a state in which the thermal expansion valve 4 of the present invention is incorporated in a refrigeration cycle of an automotive air conditioner. The temperature type expansion valve 4 of the present invention includes a valve body 41 made of resin, a throttle mechanism 46 and a control mechanism 54 integrally formed with the valve body 41.

A resin valve body 41 has a first flow passage 42 communicating with the outlet of the condenser 2 via the receiver 3 and a second flow passage 42 communicating with the outlet of the evaporator 5, similarly to the conventional product. A flow path 43 and a third flow path 44 that connects the outlet of the evaporator 5 and the inlet of the compressor 1 are formed, and a valve chamber is provided at the center of the valve body 41 at the back of the first flow path 42. 45 are formed.

The throttle mechanism 46 for adiabatically expanding the refrigerant is formed of exactly the same components as the conventional product. The throttle mechanism 46 includes a metal member 47 having an orifice 47a, a valve element 48, and a compression coil spring 49. . The metal member 47 is made of aluminum, and is fixed to the valve body 41 by insert molding so as to be located between the first channel 42 and the second channel 43. Further, a valve seat 50 is formed on the valve chamber 45 side of the orifice, and the tapered surface of the valve seat is used as a throttle portion 47b.

The difference between the present invention and the conventional product is that the shape of the orifice is different. In the conventional product, as shown in FIGS. 6 and 7, the orifice 47a is formed as a straight hole.
As shown in the figure, the shape on the outflow side of the orifice 47a, that is, the shape on the second flow path 43 side is formed on the tapered wall surface 47c whose area gradually increases. The tapered wall surface 47
The same effect can be obtained by setting c as an expanded wall surface 47c 'as shown in FIG. 4, that is, a stepped wall surface or a single tapered wall surface 47c''as shown in FIG.

Components such as the compression coil spring 49 via the adjusting screw 51 serving also as a cap, the compression coil spring 49, the spherical valve element 48, and the spring seat 52, and the arrangement thereof are exactly the same as those of the conventional product. Further, the spherical valve element 48 is configured to open and close the orifice 47a by separating from and coming into contact with the valve seat 50 on the lower surface of the orifice 47a. Is also the same as the conventional product.

A pressure equalizing chamber 58 formed at the center of the upper end of the valve body 41, a third flow path 44 formed under the pressure equalizing chamber 58, and an upper central part of the third flow path 44 A first sliding hole 63 formed in the up-down direction, and even when the shaft 66 of the temperature sensing rod 65 is inserted into the first sliding hole 63, as shown in FIG. The point that the groove 63a is formed so that the refrigerant is introduced into 58 is the same as the conventional product.

Further, a second sliding hole 64 formed at a lower central portion of the third flow passage 44, a lower end of the second sliding hole 64 and a deep portion of the second flow passage 43 are formed. The hole 68 for the operating rod 69 formed between them is the same as the conventional product.

A temperature sensing rod 65 comprising a shaft 66 and a dish 67 is vertically movably inserted into and supported by the first sliding hole 63 and the second sliding hole 64. The point that the portion 67 is disposed in the pressure equalizing chamber 58 and abuts on the lower surface of the diaphragm 57 is the same as the conventional product.

Further, the operating rod 69 is vertically movably connected to the hole 68 for the operating rod 69, the upper end of the operating rod 69 is brought into contact with the lower end surface of the temperature sensing rod 65, and the intermediate part is the first part. It is also the same as the conventional product in that it is inserted into the orifice 47a across the inner part of the second flow path 43 and the lower end thereof is brought into contact with the valve element 48.

The control mechanism 54 includes an upper cover 55 as a first cover, a lower cover 56 as a second cover,
And a diaphragm 57 made of a stainless steel plate sandwiched between the valve body 5 and the valve body 56.
It is the same as the conventional product in that it is airtightly fixed to the upper flange portion 41a by the cylindrical stopper 60 via the packing 59 via the packing 59.

[0021]

Next, the operation of this embodiment in the above configuration will be described with reference to FIG. The high-temperature, high-pressure gaseous refrigerant adiabatically compressed by the compressor 1 of the refrigeration cycle is condensed by the condenser 2 into a liquid refrigerant, and then flows through the first flow path 42 of the expansion valve 4 via the receiver 3. It is introduced into the valve chamber 45.
Further, the liquid refrigerant passes through the orifice 47a and is adiabatically expanded at this time to become a low-temperature mist-like refrigerant.
Will be introduced. Then, this refrigerant is introduced into the evaporator 5 through the second flow path 43 and is vaporized to become a gaseous refrigerant. Further, the gaseous refrigerant discharged from the evaporator 5 returns to the compressor 1 again through the third flow path 44.

Here, a description will be given based on explanatory diagrams showing the pressure values of the refrigerant liquid at the respective portions of the orifices of the product of the present invention (FIGS. 3, 4, and 5) and the conventional product (FIG. 6). In the product of the present invention, the refrigerant having passed through the orifice 47a is shown in FIGS.
As shown in FIG. 5, the tapered wall surface 47c and the expanded wall surface 47c '
When passing through the tapered wall surface 47c '', the pressure gradually decreases, and when flowing into the second flow path 43, the volume expands and the pressure further decreases, and at this time, bubbles are generated. However, the differential pressure C at the time of volume expansion is the differential pressure D in the conventional product shown in FIG.
Since it is smaller, the generation of bubbles is suppressed.

On the other hand, the temperature sensing rod 65 includes a compression coil spring 49.
Thus, it is constantly urged upward through the spring seat 52, the valve element 48, and the operating rod 69. Therefore, orifice 4
The position of the valve body 48 with respect to the valve seat 50 that determines the opening of the valve 7a is maintained at a position where the urging force of the compression coil spring 49, the refrigerant pressure in the pressure equalizing chamber 58, and the gas pressure in the heat sensitive chamber 61 are balanced. Dripping. The pressure of the refrigerant in the pressure equalizing chamber 58 is controlled by the evaporator 5.
Is the gas pressure evaporated.

The gaseous refrigerant passing through the third flow path 43 enters the pressure equalizing chamber 58 through the groove 63a of the first sliding hole 63, as shown in FIGS. Thus, the heat of the refrigerant is transferred from the shaft portion 66 of the temperature sensing rod 65 to the dish 6.
The heat is transmitted to the saturated steam gas in the heat-sensitive chamber 61 through the diaphragm 57. That is, the pressure in the heat-sensitive chamber 61 changes according to the refrigerant temperature on the outlet side of the evaporator 5. The vertical movement of the diaphragm 57 due to the pressure change in the heat-sensitive chamber 61 is transmitted to the valve element 48 via the temperature-sensitive rod 65 and the operating rod 69, and the valve element 48 is controlled to open and close, and the degree of superheat of the refrigerant at the outlet of the evaporator 5 is controlled. Is controlled to be constant. The superheat control system itself is exactly the same as a conventional product.

[0025]

In the expansion valve of the present invention constructed as described above, the second flow path side of the orifice is formed by an expanded wall surface or a tapered wall surface having an increased area so that the refrigerant flows through the second flow path. The rapid pressure drop of the refrigerant when flowing into the refrigerant can be reduced. Therefore, generation of bubbles in the refrigerant can be suppressed, and the noise level caused by disappearance of the bubbles can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a state in which an expansion valve of the present invention is incorporated in a refrigeration cycle of an automotive air conditioner.

FIG. 2 is an enlarged sectional view taken along line AA of FIG.

FIG. 3 is a schematic diagram illustrating a change in pressure of a refrigerant in an orifice portion of the present invention.

FIG. 4 is a schematic diagram illustrating a change in pressure of a refrigerant in an orifice portion according to another embodiment.

FIG. 5 is a schematic diagram illustrating a change in pressure of a refrigerant in an orifice portion according to another embodiment.

FIG. 6 is a schematic view illustrating a change in pressure of a refrigerant in a conventional orifice portion.

FIG. 7 is a longitudinal sectional side view showing a state where a conventional expansion valve is incorporated in a refrigeration cycle of an automotive air conditioner.

[Explanation of symbols]

1 compressor, 2 condenser, 3
Receiver, 4 expansion valve, 5 evaporator,
41 valve body, 41a flange,
42 first flow path, 43 second flow path, 44 third flow path, 45 valve chamber, 46 throttle mechanism, 47 metal member, 47a orifice,
47b throttle portion, 47c tapered wall surface, 47
c 'widening wall, 47c "single tapered wall, 48
Valve body, 49 compression coil spring, 50
Valve seat, 51 adjustment screw, 52 spring seat,
53 O-ring, 54 control mechanism, 55
Upper lid, 56 lower lid, 57 diaphragm,
58 pressure equalizing chamber, 59 packing, 60
Stopper, 61 Thermal chamber, 62 Steel ball, 63 First sliding hole, 63a groove,
64 second sliding hole, 65 temperature sensing rod, 66
Shaft, 67 dish, 68 holes,
69 operating rod,

Claims (1)

[Claims] A throttle mechanism for adjusting a flow rate of the refrigerant sent to the evaporator; and a throttle mechanism in accordance with the temperature of the refrigerant sent from the evaporator toward the compressor. The valve body 41 includes a first flow path 42 for introducing the refrigerant, and a second flow path 43 for sending out the introduced refrigerant to the evaporator.
And a third flow path 44 for allowing the refrigerant sent from the evaporator 5 toward the compressor 1 to pass therethrough. The throttle mechanism 46 includes a first flow path 42 and a second flow path 43. And a valve element 48 for adjusting the opening amount of the orifice 47a. The control mechanism 54 includes a heat-sensitive chamber 61 filled with gas.
And a diaphragm 57 that is displaced in accordance with the pressure in the heat-sensitive chamber 61, and transmits the temperature of the refrigerant flowing through the third flow path 44 to the gas in the heat-sensitive chamber 61 and changes the displacement of the diaphragm 57. A temperature type expansion valve having a transmission member for transmitting to a valve element 48, wherein the side of the second flow path 43 of the orifice 47a is formed as a tapered wall surface 47c or an expanded wall surface 47c 'having an increased area. Temperature expansion valve.