JPH11142026A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold the body of an expansion valve with a synthetic resin while improving the fastening rigidity of a power element. SOLUTION: The body 301 of a resin-made valve of an expansion valve 101 is provided with a metal member 322 which includes a valve chamber 35, a first path 32, a second path 34 and an orifice 32a and is formed by an insert molding, a valve body 32b, a thermosensitive bar 36f, an working bar 37f and a compression coil spring 32d composing a valve body drive bar and a power element part 36. The power element part 36 has a diaphragm 36a, an upper cover 36d, a lower cover 36h and a steel ball 36k. The power element part 36 is fixed in a hole 362 formed at the upper end of the valve body 301 through a packing 303. A metal fastening member 50 such as aluminum or stainless steel formed in the valve body 301 by the insert molding is screwed down on the lower cover 36h composing the power element part 36 and the power element part 36 is fixed firmly in the hole 362.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve used for controlling a flow rate of a refrigerant supplied to an evaporator in a refrigerating cycle of an air conditioner, a refrigerating device, or the like.

[0002]

2. Description of the Related Art An expansion valve of this type is used in a refrigeration cycle of an air conditioner of an automobile or the like.
FIG. 5 is a longitudinal sectional view of an expansion valve which has been widely used in the past, together with an outline of a refrigeration cycle. FIG. 5 is a perspective view of the expansion valve and FIG. 6 is a front view from the direction A in FIG.
In the prismatic aluminum valve body 30, a liquid-phase refrigerant interposed in a portion of the refrigerant line 11 of the refrigeration cycle from the refrigerant outlet of the condenser 5 to the refrigerant inlet of the evaporator 8 via the receiver 6 is provided. The first passage 32 passing therethrough and the second passage 34 passing the gaseous refrigerant interposed in the refrigerant pipe 11 at a portion from the refrigerant outlet of the evaporator 8 to the refrigerant inlet of the compressor 4 are vertically separated from each other. It is formed. 5 and FIG.
Is a bolt insertion hole.

The first passage 32 has an orifice 32a for adiabatically expanding the liquid refrigerant supplied from the refrigerant outlet of the receiver 6. A valve seat is formed on the inlet side of the orifice 32a, that is, on the upstream side of the first passage, and a spherical valve body 32b supported by a valve member 32c from the upstream side is disposed on the valve seat. Valve member 32
c is fixed by welding. The valve member 32c is fixed to the valve body by welding and is disposed between the valve body 32b and a biasing means 32d such as a compression coil spring, and transmits the biasing force of the biasing means 32d to the valve body 32b. It is biased in the approaching direction. The first passage 32 into which the liquid refrigerant from the receiver 6 is introduced is a passage for the liquid refrigerant, and has an inlet port 321 and a valve chamber 35 connected to the inlet port 321. The valve chamber 35 is a bottomed chamber formed coaxially with the orifice 32a, and is closed by a plug 39. The plug 39 is provided with an O-ring 39a.

Further, in order to apply a driving force to the valve body 32b in accordance with the outlet temperature of the evaporator 8 to open and close the orifice 32a, the valve body 30 has a small diameter hole 37 and a diameter larger than the hole 37. A hole 38 having a diameter penetrates through the second passage 34 and is formed coaxially with the orifice 32a. At the upper end of the valve body 30, a screw hole 361 to which the power element portion 36 serving as a heat sensitive portion is fixed is formed.

The power element portion 36 is provided with a stainless steel diaphragm 36a, which is provided in close contact with each other with the diaphragm 36a interposed therebetween by welding, and an upper pressure operating chamber 36b and two lower pressure operating chambers which form two airtight chambers above and below the diaphragm 36a. An upper cover 36d and a lower cover 36h which form the respective chambers 36c, and a sealing pipe 36i for sealing a predetermined refrigerant serving as a diaphragm driving fluid in the upper pressure working chamber 36b.
The lower cover 36h is screwed into the screw hole 361 via the packing 40. The lower pressure working chamber 36c communicates with the second passage 34 via a pressure equalizing hole 36e formed concentrically with the center line of the orifice 32a. Refrigerant vapor from the evaporator 8 flows through the second passage 34, and the passage 34 serves as a passage for a gas-phase refrigerant, and the pressure of the refrigerant vapor is applied to the lower pressure working chamber 36c via the equalizing hole 36e. .

Further, the evaporator 8 abuts on the diaphragm 36a in the lower pressure working chamber 36c and is slidably disposed in the large-diameter hole 38 through the second passage 34.
Is transmitted to the lower pressure working chamber 36c, and the large diameter 3 according to the displacement of the diaphragm 36a due to the pressure difference between the upper pressure working chamber 36b and the lower pressure working chamber 36c.
Aluminum temperature sensing rod 36f which gives a driving force by sliding in the inside 8
The temperature sensing rod 36 is slidably disposed in the small diameter hole 37.
and a stainless steel operating rod 37f having a diameter smaller than that of the temperature sensing rod 36f which presses the valve body 32b against the elastic force of the urging means 32d in accordance with the displacement of the pressure sensing element f. A sealing member for ensuring airtightness between the second passage 32 and the second passage 34, for example, an O-ring 36g is provided. The upper end of the temperature sensing rod 36f contacts the lower surface of the diaphragm 36a as a receiving portion of the diaphragm 36a, the lower end of the temperature sensing rod 36f contacts the upper end of the operation rod 37f, and the lower end of the operation rod 37f contacts the valve body 32b. And the temperature sensing rod 36f and the operating rod 37
and f constitute a valve body drive rod. Accordingly, the valve drive rod extending from the lower surface of the diaphragm 36a to the orifice 32a of the first passage 32 is concentrically arranged in the pressure equalizing hole 36e. The operating rod 37f
The portion 37e is formed thinner than the inner diameter of the orifice 32a, passes through the orifice 32a, and the refrigerant passes through the orifice 32a.

A known diaphragm driving fluid is filled in the pressure operating chamber 36b above the pressure operating housing 36d, and the diaphragm driving fluid is uniformly communicated with the second passage 34 and the second passage 34. The heat of the refrigerant vapor from the refrigerant outlet of the evaporator 8 flowing through the second passage 34 is transmitted through the valve body drive rod exposed to the pressure hole 36e and the diaphragm 36a.

[0008] The diaphragm driving fluid in the upper pressure working chamber 36b is gasified in response to the transferred heat and applies pressure to the upper surface of the diaphragm 36a. Diaphragm 3
6a is displaced up and down due to the difference between the pressure of the diaphragm driving gas applied to the upper surface and the pressure applied to the lower surface of the diaphragm 36a. The displacement of the center of the diaphragm 36a in the vertical direction is transmitted to the valve body 32b via the valve body drive rod, and moves the valve body 32b toward or away from the valve seat of the orifice 32a. As a result, the flow rate of the refrigerant is controlled.

That is, since the temperature of the low-pressure gas-phase refrigerant sent from the outlet side of the evaporator 8, that is, from the evaporator, is transmitted to the upper pressure working chamber 36b, the pressure of the upper pressure working chamber 36b changes according to the temperature. Evaporator 8
Outlet temperature rises. That is, when the heat load of the evaporator increases, the pressure of the upper pressure working chamber 36b increases,
Accordingly, the temperature sensing rod 36f, that is, the valve body drive rod is driven downward to lower the valve body 32b, so that the opening degree of the orifice 32a increases. Thus, the supply amount of the refrigerant to the evaporator 8 increases, and the temperature of the evaporator 8 decreases. Conversely, the temperature of the refrigerant sent from the evaporator 8 decreases. That is, when the heat load of the evaporator decreases, the valve element 32b is driven in the opposite direction to the above, the opening degree of the orifice 32a decreases, the supply amount of the refrigerant to the evaporator decreases, and the temperature of the evaporator 8 increases. .

In order to reduce the influence of the ambient temperature on the conventional expansion valve, the operation of the expansion valve shown in FIG. 4 is the same as that of the refrigerant flow control. An expansion valve formed by insert molding of a metal member is proposed in Japanese Patent Application Laid-Open No. 9-89154. That is, FIG. 7 shows a vertical cross-sectional view thereof (illustrated with a refrigeration cycle omitted), FIG. 8 shows a front view from the direction A in FIG. 7, and the same reference numerals as those in FIG. Description is omitted. In FIG. 7, the expansion valve 10 '
The valve body 301 made of resin has a first passage 32 through which a liquid-phase refrigerant flows from the outlet of the condenser to the refrigerant inlet of the evaporator via the receiver, and the gas flowing from the refrigerant outlet of the evaporator to the refrigerant inlet of the compressor. The second passage 34 through which the phase refrigerant passes is formed vertically separated from each other. The first passage 32 is provided with an orifice 32 a for insulating the liquid refrigerant supplied from the receiver by a metal member 322. The metal member 322 is, for example, aluminum and is fixed to the valve body 301 by insert molding. A valve seat is formed on the inlet side of the orifice 32a, that is, on the upstream side of the first passage, and a spherical valve body 32b supported by a valve member 32c from the upstream side is disposed on the valve seat. The valve member 32c is fixed by welding. The valve member 32c is
The urging force of the urging means 32d is disposed between the valve body 32b and the urging means 32d such as a compression coil spring.
2b is biased in a direction to approach the valve seat.

The first passage 32 into which the liquid refrigerant is introduced from the receiver serves as a passage for the liquid refrigerant.
There is a valve chamber 35 connected to the inlet port 321. The valve chamber 35 is a bottomed chamber formed coaxially with the orifice 32a, and is closed by a plug 39. In addition,
The plug 39 is provided with an O-ring 39a. Further, a metal collar 41 is attached to the pipe part attachment hole 40 of the valve body 301.

Further, in order to open and close the orifice 32a by applying a driving force to the valve body 32b in accordance with the outlet temperature of the evaporator, the valve body 301 has a small hole 37 and a larger diameter than the hole 37. A hole 38 is formed coaxially with the orifice 32a through the second passage 34, and a hole 362 is formed at the upper end of the valve body 30 to which the power element portion 36 serving as a heat sensitive portion is fixed.

The power element section 36 is provided with a stainless steel diaphragm 36a, which is provided in close contact with each other with the diaphragm 36a interposed therebetween by welding, and an upper pressure operating chamber 36b and two lower pressure operating chambers which form two airtight chambers above and below the diaphragm 36a. It has an upper cover 36d and a lower cover 36h which respectively define the chamber 36c, and these covers fix the diaphragm 36a by welding at the outer peripheral portion thereof. A rigid ball 36k is fixed by welding to a hole 36j for enclosing a predetermined refrigerant serving as a diaphragm driving fluid in the upper pressure working chamber 36b, thereby maintaining airtightness. The lower pressure working chamber 36c communicates with the second passage 34 via a pressure equalizing hole 36e formed concentrically with the center line of the orifice 32a. Second
The refrigerant vapor from the evaporator flows through the passage 34,
The passage 34 serves as a passage for the gas-phase refrigerant, and the pressure of the refrigerant vapor is applied to the lower pressure working chamber 36c via the equalizing hole 36e.

In order to fix the power element 36 in the hole 362 of the valve body 301, a flange 302 is formed on the outer periphery of the upper end of the valve body 301, and a lower cover 36h is provided with a packing 303 above the flange 302. Placed via The power element section 36 includes a valve body 301.
It is fixed to the valve body 301 by caulking the upper and lower parts of a cylindrical caulking member 304 that covers the outer peripheral part of the power element part 36 together with the flange 302 of the power element part 36. Note that, for example, aluminum is used as the caulking member.

Further, a diaphragm 36a is abutted against the diaphragm 36a in the lower pressure working chamber 36c, and is slidably disposed in the large-diameter hole 38 through the second passage 34 so that the refrigerant outlet temperature of the evaporator can be lowered. In addition to transmitting to the working chamber 36c, the large diameter 3 according to the displacement of the diaphragm 36a due to the pressure difference between the upper and lower pressure working chambers 36b and 36c.
Aluminum temperature sensing rod 36f which gives a driving force by sliding in the inside 8
The temperature sensing rod 36 is slidably disposed in the small diameter hole 37.
and a stainless steel operating rod 37f having a diameter smaller than that of the temperature sensing rod 36f which presses the valve body 32b against the elastic force of the urging means 32d in accordance with the displacement of the pressure sensing element f. A sealing member for ensuring airtightness between the second passage 32 and the second passage 34, for example, an O-ring 36g is provided. The upper end of the temperature sensing rod 36f forms a large-diameter portion 36f ', and abuts against the lower surface of the diaphragm 36a as a receiving portion of the diaphragm 36a. The lower end of the temperature sensing rod 36f contacts the upper end of the operating rod 37f. The lower end is in contact with the valve body 32b,
The valve element driving rod is constituted by the temperature sensing rod 36f and the operating rod 37f. Accordingly, the valve drive rod extending from the lower surface of the diaphragm 36a to the orifice 32a of the first passage 32 is concentrically arranged in the pressure equalizing hole 36e. The portion 37e of the operating rod 37f is connected to the orifice 3
The coolant is formed smaller than the inner diameter of the orifice 2a, passes through the orifice 32a, and the refrigerant passes through the orifice 32a.

The pressure operation chamber 36b above the pressure operation housing 36d is filled with a known diaphragm driving fluid, and the diaphragm driving fluid is uniformly communicated with the second passage 34 and the second passage 34. The heat of the refrigerant vapor from the refrigerant outlet of the evaporator 8 flowing through the second passage 34 is transmitted through the valve body drive rod exposed to the pressure hole 36e and the diaphragm 36a.

The diaphragm driving fluid in the upper pressure working chamber 36b gasifies in response to the transferred heat and applies a pressure to the upper surface of the diaphragm 36a. Diaphragm 3
6a is displaced up and down due to the difference between the pressure of the diaphragm driving gas applied to the upper surface and the pressure applied to the lower surface of the diaphragm 36a. The displacement of the center of the diaphragm 36a in the vertical direction is transmitted to the valve body 32b via the valve body drive rod, and moves the valve body 32b toward or away from the valve seat of the orifice 32a. As a result, the flow rate of the refrigerant is controlled.

[0018]

In the conventional expansion valve 10 'shown in FIG. 7, the power element portion 36 is fixed by caulking with a caulking member 304 to form a resin valve body 30.
1, the power element portion 36 is fixed to the valve body by screwing the power element portion 36 to the metal valve body as in the conventional expansion valve shown in FIG. , The entire power element portion 36 is lifted up, the upper cover 36d is elastically deformed, the caulking portion of the caulking member 304 used for caulking is loosened during the operation of the expansion valve, and strength may be insufficient. When the strength is insufficient, the power element is separated from the valve main body, which may cause a problem that the operation function of the expansion valve is impaired, and furthermore, there is a possibility that moisture may enter from the swaged portion. Therefore, if the operation of the expansion valve fails, accurate flow control becomes impossible, and if moisture invades, problems such as breakage due to icing or crevice corrosion may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to enable a power element portion to be firmly fixed to a valve body even when the valve body is molded from resin, and to provide an accurate flow rate. An object of the present invention is to provide an expansion valve capable of realizing a stable controllable operation.

[0020]

In order to achieve the above object,
An expansion valve according to the present invention is a resin valve body having a first passage through which a liquid refrigerant passes and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor, and an orifice provided in the first passage. And a valve element for adjusting the amount of refrigerant passing through the orifice, a power element part provided on the valve body and operating in accordance with the temperature of the gas-phase refrigerant, and a power element part provided between the power element part and the valve element. A valve element driving rod, wherein the valve element driving rod transmits the temperature of the vapor-phase refrigerant to the power element portion, and is driven by the power element portion to cause the valve element to move toward and away from the orifice. The power element is fixed to the valve body by a fixing member formed by insert molding on the valve body.

The expansion valve according to the present invention comprises a resin valve body having a first passage through which a liquid refrigerant passes and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor; An orifice, a valve element for adjusting the amount of refrigerant passing through the orifice, a power element section having a diaphragm provided on the valve body and operated by a pressure difference between the upper and lower sides, and the valve element is displaced by the displacement of the diaphragm. One end of the drive is in contact with the diaphragm, and the other end is a valve drive rod that drives the valve. The valve drive transmits the temperature of the refrigerant sent from the evaporator to the power element. In the expansion valve that drives the valve element to move the valve element toward and away from the orifice, the power element section includes:
It is characterized by being fixed to the valve body by a fixing member formed by insert molding and fixed to the valve body.

In a preferred embodiment of the expansion valve according to the present invention, the fixing member is formed by insert molding a ring-shaped metal member. Further, in a preferred form of the expansion valve according to the present invention, the power element portion is formed by sandwiching and welding the diaphragm between outer peripheral edges of an upper cover and a lower cover, and a part of the lower cover. Are screwed to the valve body by the fixing means, the power element portion is fixed to the valve body, and the upper cover and the diaphragm and the lower cover and the diaphragm form an upper pressure working chamber and a lower pressure working chamber, respectively. The diaphragm is displaced by a pressure difference formed by these working chambers.

Another embodiment of the expansion valve according to the present invention is a resin valve body having a first passage through which a liquid refrigerant passes and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor. An orifice provided in the first passage, a valve body for adjusting an amount of refrigerant passing through the orifice, a power element provided on the valve body, and operating in accordance with the temperature of the gaseous phase refrigerant; A valve element driving rod provided between the element part and the valve element. The valve element driving rod transmits the temperature of the gas-phase refrigerant to the power element part and is driven by the power element part to form a valve element. In the expansion valve that comes into contact with and separates from the orifice, the valve body has a flange formed at the upper end thereof, and the power element is disposed on the flange, The power element portion is fixed to the valve body by a tubular connecting member connecting the power element portion and the flange portion being fixed to a fixing member formed by insert molding in the flange portion. It is characterized by having.

In a preferred embodiment of the expansion valve according to the present invention, the fixing member is formed by insert-molding an annular metal member. In the above expansion valve, the metal member is screwed to the cylindrical connecting member.

Still another embodiment of the expansion valve according to the present invention is a resin valve body having a first passage through which a liquid refrigerant passes and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor. An orifice provided in the first passage, a valve body for adjusting an amount of refrigerant passing through the orifice, a power element provided on the valve body, and operating in accordance with a temperature of the gaseous phase refrigerant; A valve element driving rod provided between the power element part and the valve element. The valve element driving rod transmits the temperature of the gas-phase refrigerant to the power element part and is driven by the power element part to form a valve. In an expansion valve for moving a body toward or away from an orifice, the valve body has a flange formed at an upper end thereof, and the power element is disposed on the flange. , The power element portion,
The ring-shaped disk-shaped member placed on the outer peripheral edge is fixed to the valve body by being fixed to a fixing member formed by insert molding in the flange portion.

In the present invention, the fixing member is formed by insert molding of a metal member. Further, a preferred embodiment of the expansion valve according to the present invention is characterized in that the metal member is screwed to the ring-shaped disk-shaped member.

The expansion valve of the present invention thus configured has
Since the power element portion is fixed to the valve body by a fixing member formed by insert molding on the resin valve body, even if the valve body is made of resin, the power element portion is firmly fixed to the valve body. That is, there is no lack of strength. Therefore, the power element portion does not separate from the valve body, and accurate flow rate control is possible. Furthermore, there is no risk of water entering from the swaged portion, and no inconvenience due to freezing occurs.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an expansion valve according to the present invention will be described below with reference to the drawings. In describing the above-described embodiment, the same reference numerals as those in the above-described conventional example indicate the same or equivalent parts, and have the same functions.

FIG. 1 is a longitudinal sectional view of an expansion valve 101 showing an embodiment of an expansion valve according to the present invention.
1 includes a valve chamber 35, a first passage 32, and a second passage 34.
A metal member 322 having an orifice 32a formed by insert molding; a valve element 32b; a temperature sensing rod 36f and an operating rod 37f constituting a valve element driving rod;
A compression coil spring 32d for urging the valve 2b toward the valve seat of the orifice 32a;
And the power element section 36 has a diaphragm 36a, an upper cover 36d, a lower cover 36h, and a hard sphere 36k.

In this embodiment, the state of fixing the power element portion 36 to the valve body 301 is different from that of the conventional expansion valve of FIG. 7, and the other configuration and operation are the same. However, the flange 302 is not formed on the valve body 301. The power element portion 36 is fixed to a hole 362 formed at the upper end of the valve main body 301 via a packing 303. At this time, for example, a metal ring made of metal such as aluminum or stainless steel formed in the valve main body 301 by insert molding. The fixing member 50 is screwed to the lower cover 36h constituting the power element portion 36, and the power element portion 36 is firmly fixed to the hole 362. That is, a part of the lower cover 36h existing inside the hole 362 and the surface 362a of the hole 362 are fixed to the fixing member 50 via the packing 303 provided at the upper end of the valve body 301.
End surface 50 of the fixing member 50 so that it can be connected by a screw.
For example, a male screw is formed in the lower cover 36h.
Is formed with a female screw, for example, and is screwed to a male screw of the fixing member 50.

In the expansion valve configured as described above,
The power element 36 is fixed by being screwed to the upper end of the valve body 301 made of resin with a metal fixing member 50 formed by insert molding, so that a strong fixing can be realized. Moreover, since the power element portion is fixed to the fixing member formed by insert molding by screw connection, the power element portion can be easily fixed to the valve body. Therefore, in the expansion valve of the present embodiment, even if the valve body is formed of resin, the problem of insufficient strength of the power element portion does not occur, and there is no possibility that a malfunction occurs in the operation of the expansion valve. There is no danger that inconvenience will occur due to the intrusion of moisture caused by the insufficient strength.

FIG. 2 is a longitudinal sectional view of an expansion valve 101 'showing another embodiment of the expansion valve according to the present invention. A valve body 35, a first passage 32, A second passage 34, a metal member 322 formed by insert molding having an orifice 32a, a valve element 32b, a temperature sensing rod 36f and an operating rod 37f constituting a valve element driving rod,
A compression coil spring 32d for urging the valve body 32b in a direction approaching the valve seat of the orifice 32a, and a power element portion 36 are provided. The power element portion 36 includes a diaphragm 36a, an upper cover 36d, a lower cover 36h, It has a hard sphere 36k.

Thus, in the present embodiment, only the state of fixing the power element portion 36 to the valve body 301 is different from that of the conventional expansion valve of FIG. 7, and the other configuration and operation are the same. The power element 36 is fixed to a hole 362 formed at the upper end of the valve main body 301 via a packing 303. At this time, the power element 36 is connected to the valve main body 301 by a cylindrical metal connecting member 51. The connecting member 51 is integrally connected to the flange 302 of the valve body 301.
The power element portion 36 is firmly fixed to the hole 362 by being screwed to an annular fixing member 50 made of metal such as aluminum or stainless steel formed by insert molding.

The connecting member 51 is a cylindrical metal member having a hole 51c formed in the bottom. For example, aluminum or stainless steel is used, and the inner surface 51a of the bottom of the cylindrical connecting member 51 is The power element portion 36 is covered with the power element portion 36 so as to cover the cover 35d, and the power element portion 36 and the valve body 301 are connected to each other without being integrated.
1b is formed.

The fixing member 50 is formed by insert molding on the side surface of the flange 302 of the valve body 301, and the fixing member 50 has a female screw 51 of the connecting member 51.
A male screw 50a screw-coupled to b is formed. In the expansion valve configured as described above, the power element portion 36 is integrally connected to the valve body 301 by the cylindrical connecting member 51, and the connecting member 51 is fixed to the valve body 301 by the fixing member 50 formed by insert molding. Therefore, the power element portion 36 is firmly fixed to the valve body 301. Moreover, the power element section 36
Can be easily and firmly fixed to the valve body 301 by fixing the cylindrical connecting member 51 to the fixing member 50 formed by insert molding on the valve body 301 by screw connection. .

Therefore, in the expansion valve of the present embodiment, even if the valve body is formed of resin as in the above-described embodiment, the problem of insufficient strength of the power element portion does not occur. There is no danger of malfunction of the valve, and no danger of inconvenience due to intrusion of moisture caused by insufficient strength.

FIG. 3 is a longitudinal sectional view of an expansion valve 101 ″ showing still another embodiment of the expansion valve according to the present invention. A valve chamber 35 and a first passage are provided in a valve body 301 made of resin. 32, a second passage 34, a metal member 322 formed by insert molding having an orifice 32a, and a valve body 32b.
And a temperature sensing rod 36f and an operating rod 37 constituting a valve body drive rod.
f, a compression coil spring 32d for urging the valve body 32b in a direction in which the orifice 32a approaches, and a power element portion 36. The power element portion 36 includes a diaphragm 36a, an upper cover 36d, a lower cover 36h, It has a hard sphere 36k.

Thus, in this embodiment, the power element 36 is fixed to the valve body 301 only in a different state from the conventional expansion valve of FIG. 7, and the other configuration and operation are the same. The power element part 36 is provided with a packing 30 in a hole 362 formed in the flange 302 at the upper end of the valve body 301.
At this time, the power element portion 36 has, for example, a ring nut 52 mounted as a metal ring-shaped disc-shaped member on the outer edge portion of the upper cover 35d. For example, a male screw 52 a is formed at the outer end, and the flange 30 of the valve body 301 is formed.
2 has a metal annular fixing member 50 formed by insert molding. The fixing member 50 has, for example, a female screw 50b, and the male screw 5 of the ring nut 52.
It is screwed to 2a. That is, the power element portion 36 is attached to the fixing member 50 formed by insert molding on the flange portion 302 of the valve body 301.
Since the ring nut 52 is integrally screwed to the power element 1, the power element 36 and the valve body 301 are easily and firmly fixed.

In the present embodiment, for example, aluminum or stainless steel is appropriately used for the disc-shaped fixing member and the fixing member. In the expansion valve of the present embodiment as well, even if the valve body is formed of resin, as in the above-described embodiment, the problem of insufficient strength of the power element unit does not occur, and the operation of the expansion valve is not satisfactory. There is no danger of the occurrence of inconvenience due to the invasion of moisture caused by insufficient strength.

[0040]

As will be understood from the above description, the expansion valve of the present invention uses a metal fixing member formed by insert molding on the valve body to fix the power element portion to the resin valve body. Since it is used, it can be firmly fixed even if the valve body is made of resin. In addition, the power element can be easily fixed to the valve body by allowing the fixing member to be screw-coupled.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a conventional expansion valve and an explanatory diagram of a refrigeration cycle.

FIG. 5 is a perspective view of the expansion valve of FIG. 4;

FIG. 6 is a side view of the expansion valve of FIG. 4;

FIG. 7 is a cross-sectional view of a conventional expansion valve.

FIG. 8 is a side view of a conventional expansion valve.

[Explanation of symbols]

 32a orifice 32b valve element 36 power element 36a diaphragm 36d upper cover 36f operating rod 36h lower cover 50 fixing member 101 expansion valve 301 valve body 322 metal member

Claims (10)

[Claims] 1. A resin valve body having a first passage through which a liquid refrigerant passes, and a second passage through which a vapor-phase refrigerant passes from an evaporator to a compressor, an orifice provided in the first passage, and an orifice. A valve element that is provided in the valve body and operates according to the temperature of the gas-phase refrigerant; and a valve element that is provided between the power element and the valve element. A drive rod, wherein the valve body drive rod transmits the temperature of the gas-phase refrigerant to the power element portion, and is driven by the power element portion to move the valve body toward and away from the orifice. An expansion valve, wherein the element portion is fixed to the valve body by a fixing member formed by insert molding on the valve body. 2. A resin valve body having a first passage through which a liquid refrigerant passes and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor, an orifice provided in the first passage, and an orifice. A valve element for adjusting the amount of refrigerant passing through the diaphragm, a power element section provided on the valve body and having a diaphragm that operates according to a pressure difference between the upper and lower sides thereof, and the diaphragm at one end for driving the valve element by displacement of the diaphragm. And a valve element driving rod that drives the valve element at the other end, and the valve element driving rod transmits the temperature of the refrigerant sent from the evaporator to the power element section, thereby transmitting the valve element. When the expansion valve is driven to move the valve body toward and away from the orifice, the power element is formed by insert molding in the valve body. An expansion valve fixed to the valve body by being fixed by a fixed fixing member. 3. The expansion valve according to claim 1, wherein said fixing means is formed by insert molding of a metal member. 4. The power element portion is formed by clamping and welding the diaphragm between outer peripheral edges of an upper cover and a lower cover, and a part of the lower cover is attached to the valve body by the fixing member. And the power element portion is fixed to the valve body, and the upper cover and the diaphragm and the lower cover and the diaphragm constitute an upper pressure working chamber and a lower pressure working chamber, respectively.
3. The expansion valve according to claim 2, wherein the diaphragm is displaced by a pressure difference formed by the working chambers. 5. A resin valve body having a first passage through which a liquid refrigerant passes, and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor, an orifice provided in the first passage, and an orifice. A valve element that is provided in the valve body and operates according to the temperature of the gas-phase refrigerant; and a valve element that is provided between the power element and the valve element. A drive rod, wherein the valve element drive rod transmits the temperature of the gas-phase refrigerant to the power element section, and is driven by the power element section to move the valve body to or away from the orifice. The main body has a flange formed at an upper end thereof, and the power element is disposed on the flange, and the power element is provided with the power element. A tubular connecting member connecting the flange portion and the flange portion is fixed to a fixing member formed by insert molding in the flange portion, so that the expansion portion is fixed to the valve body. valve. 6. The expansion valve according to claim 5, wherein the fixing member is formed by insert molding of a metal member. 7. The expansion valve according to claim 6, wherein the metal member is screwed to the connection member. 8. A resin valve body having a first passage through which a liquid refrigerant passes, and a second passage through which a gas-phase refrigerant passes from an evaporator to a compressor, an orifice provided in the first passage, and an orifice. A valve element that is provided in the valve body and operates according to the temperature of the gas-phase refrigerant; and a valve element that is provided between the power element and the valve element. A drive rod, wherein the valve element drive rod transmits the temperature of the gas-phase refrigerant to the power element section, and is driven by the power element section to move the valve body to or away from the orifice. The main body has a flange formed at an upper end thereof, and the power element is disposed on the flange, and the power element is mounted on an outer peripheral edge thereof. An expansion valve, wherein the ring-shaped disc-shaped member is fixed to the valve body by being fixed to a fixing member formed by insert molding in the flange portion. 9. The expansion valve according to claim 8, wherein the fixing member is formed by insert molding of a metal member. 10. The expansion valve according to claim 9, wherein the metal member is screwed to the ring-shaped disk-shaped member.