Expansion valve

Information

  • Patent Grant
  • 6293472
  • Patent Number
    6,293,472
  • Date Filed
    Wednesday, October 28, 1998
    26 years ago
  • Date Issued
    Tuesday, September 25, 2001
    23 years ago
Abstract
A power element portion 36′ mounted on the upper portion of an expansion valve body comprises an upper cover 36d and a lower cover 36h, and is divided into an upper pressure chamber 36b and a lower pressure chamber 36c by a diaphragm 36a. A heat sensing drive shaft 101 is formed of a large radius portion 105 and a heat conducting shaft 103 integrally formed thereto. The stopper portion 104 contacting the lower surface of the diaphragm 36a is a member which is formed separately from the heat sensing drive shaft 101, and supported within the lower cover 36h. When the expansion valve is taken apart, the heat sensing drive shaft 101 is pulled out from the inside of the mounting seat 362 of the power element portion 36′, and the refrigerant remaining inside the upper pressure chamber 36b is taken out and collected from the side of the diaphragm.
Description




BACKGROUND OF THE INVENTION




The present invention relates to an expansion valve for controlling the flow rate of a refrigerant supplied to an evaporator in a refrigeration cycle of an air conditioning device, a refrigerating device and the like.




This type of expansion valve is used in a refrigeration cycle of an air conditioning device of a vehicle and the like, wherein

FIG. 15

is a vertical cross-sectional view of one example of an expansion valve widely used conventionally shown together with an outline of the refrigeration cycle, and

FIG. 16

shows the main portion thereof. The expansion valve


10


includes a roughly prismatic-shaped aluminum valve body


30


comprising a first passage


32


mounted in a refrigerant duct


11


of the refrigeration cycle from a refrigerant exit of a condenser


5


through a receiver


6


to a refrigerant entrance of an evaporator


8


through which a liquid-phase refrigerant travels, and a second passage


34


mounted in the refrigerant duct


11


from a refrigerant exit of the evaporator


8


to a refrigerant entrance of a compressor


4


through which a gas-phase refrigerant travels, said first passage


32


and said second passage


34


positioned above or below one another and separated by a separation wall


38




f.






On the first passage


32


is formed an orifice


32




a


for performing an adiabatic expansion of the liquid refrigerant being supplied from the refrigerant exit of the receiver


6


. A valve seat is formed on the entrance side of the orifice


32




a


or upper stream side of the first passage, and a valve


32




b


having a spherical shape supported by a valve member


32




c


from the upper stream side is positioned on said valve seat, wherein the valve


32




b


and the valve member


32




c


are fixed together by welding. The valve member


32




c


is positioned between the valve and a biasing means


32




d


of a compression spring and the like mounted on the lower portion of the valve body, and transmits the biasing force of the biasing means


32




d


to the valve


32




b


. The valve


32




b


is biased in the direction approaching the valve seat.




The first passage


32


to which the liquid refrigerant from the receiver


6


is introduced works as a passage for the liquid refrigerant, which comprises an entrance port


321


and a valve chamber


35


connected to the entrance port


321


. The valve chamber


35


is a chamber with a bottom formed coaxial to the orifice


32




a


, which is sealed by a plug


39


. The valve chamber


35


is communicated to the exit port


322


through the orifice


32




a


, and the exit port


322


is connected to the refrigerant entrance of the evaporator


8


.




Further, the valve body


30


includes a small radius hole


37


and a large radius hole


38


having a larger radius than the hole


37


formed coaxial to the orifice


32




a


and penetrating the second passage


34


, so as to provide a driving force to the valve


32




b


and to open or close the orifice


32




a


in correspondence to the exit temperature of the evaporator


8


. On the upper end of the valve body


30


is formed a screw hole


361


where a power element portion


36


working as a heat sensing portion is fixed.




The power element portion


36


is a member driven in correspondence to pressure, comprising a diaphragm


36




a


which is a metallic thin plate made of stainless steel with flexibility, an upper cover


36




d


and a lower cover


36




h


made of stainless steel mounted so as to contact each other with the diaphragm


36




a


positioned therebetween and working as sealing walls each defining a pressure chamber, an upper pressure chamber


36




d


and a lower pressure chamber


36




c


, having said diaphragm as one wall surface and divided into the upper and lower chambers by the diaphragm, and a blind plug


36




i


made of stainless steel for filling a predetermined refrigerant for sensing temperature and working as a diaphragm driving medium into said upper pressure chamber


36




b


, wherein said lower pressure chamber


36




c


is communicated to the second passage


34


through a pressure equalization hole


36




e


formed concentric to the center line of the orifice


32




a


. A refrigerant steam from the evaporator


8


flows through the second passage


34


, and the passage


34


works as a passage for the gas-phase refrigerant, the pressure of said gas-phase refrigerant being loaded to the lower pressure chamber


36




c


through the pressure equalization hole


36




e


. Further, a pipe-like mounting seat


362


is formed on the lower cover


36




h


, the mounting seat


362


being screwed onto the screw hole


361


, thereby being fixed to the valve body


30


.




The present body further includes a heat sensing shaft


36




f


made of aluminum, which contacts the diaphragm


36




a


inside the lower pressure chamber


36




c


and positioned so as to penetrate the second passage


34


and mounted slidably inside the large radius hole


38


in the separation hole


38




f


, thereby communicating the refrigerant exit temperature of the evaporator


8


to the lower pressure chamber


36




c


, and at the same time, provides drive force by being slided inside the large radius hole in correspondence to the displacement of the diaphragm


36




a


accompanied by the pressure difference between the upper pressure chamber


36




b


and the lower pressure chamber


36




c


. The body further includes an operation shaft


37




f


made of stainless steel positioned slidably inside the small radius hole


37


and having a smaller radius than the heat sensing shaft


36




f


for pressing the valve


32




b


against the bias force of the biasing means


32




d


in correspondence to the displacement of the heat sensing shaft


36




f


. The heat sensing shaft


36




f


is equipped with a sealing member for securing the sealing ability between the first passage


32


and the second passage


34


, such as an o-ring


36




g


. An upper end portion


36




k


of the heat sensing shaft


36




f


contacts the lower surface of the diaphragm


36




a


as a receiving portion, and comprises a stopper portion


36


L enlarged to the radial direction so as to gain a large contact area with the diaphragm. The displacement of the diaphragm


36




a


is transmitted to the valve


32




b


through the heat sensing shaft


36




f


, and the stopper portion


36


L is supported by the lower cover


36




h


so that the upper end portion


36




k


of the heat sensing shaft


36




f


may be slid inside the lower pressure chamber


36




c.






Moreover, the lower end of the heat sensing shaft


36




f


contacts the upper end of the operation shaft


37




f


at the bottom portion of the large radius hole


38


and the lower end of the operation shaft contacts the valve


32




b


. The heat sensing shaft


36




f


together with the operation shaft


37




f


form a heat sensing drive shaft, and this heat sensing drive shaft acts as a valve drive shaft for transmitting the displacement of the diaphragm


36




a


to the valve


32




b


, which comprises of an upper end portion and a heat conducting portion.




In the structure of the power element portion


36


, the heat sensing shaft


36




f


and the operation shaft


37




f


, when the operation shaft


37




f


is inserted to the small radius hole


37


and the heat sensing shaft


36




f


is inserted to the large radius hole


38


, the mounting seat


362


on the lower cover


36




h


is fixed by being connected to a screw hole


361


, the seal between the lower cover


36




h


and the valve body


30


being secured by the o-ring


36




m


. The screw hole


361


together with the lower cover


36




h


and the diaphragm


36




a


form the lower pressure chamber


36




c.






Accordingly, on the pressure equalization hole


36




e


, a valve drive shaft extended from the lower surface of the diaphragm


36




a


to the orifice


32




a


of the first passage


32


is concentrically positioned. Further, the portion


37




e


of the operation shaft


37




f


is formed smaller (narrower) than the inner radius of the orifice


32




a


so as to be inserted through the orifice


32




a


, and thereby, the refrigerant may pass through the orifice


32




a.






FIG.


16


(A) is a schematic view showing the structure of the power element portion


36


and the heat sensing shaft


36




f


in the expansion valve


10


explained above, and FIG.


16


(B) is a view taken from the direction of the arrow of FIG.


16


(A), showing the state where the lower cover


36




h


is rotated and removed from the screw hole


361


, so that the power element portion


36


and the heat sensing shaft are separated. FIG.


16


(C) is a vertical cross-sectional view showing the structure of the power element portion


36


and the heat sensing shaft


36




f


. In the above structure, a predetermined refrigerant for sensing temperature is filled inside the upper pressure chamber


36




b


of the pressure housing


36




d


as a diaphragm drive medium (for example, the same gas as the refrigerant gas used in the refrigeration cycle), and the temperature of the refrigerant coming out from the refrigerant exit of the evaporator


8


and flowing through the second passage


34


is transmitted to the diaphragm drive medium through the diaphragm


36




a


and the heat sensing shaft


36




f


exposed to the second passage


34


or the pressure equalization hole


36




e


communicated to the second passage


34


.




The diaphragm drive medium inside the upper pressure chamber


36




b


changes into gas in correspondence to the temperature being transmitted thereto, thereby changing the pressure inside said chamber which is loaded to the upper surface of the diaphragm


36




a


. The diaphragm


36




a


is vertically displaced by the difference between the pressure of the diaphragm drive gas loaded to the upper surface thereof and the pressure loaded to the lower surface thereof.




The displacement of the center area of the diaphragm


36




a


in the vertical direction is transmitted to the valve


32




b


through the heat sensing drive shaft, and moves the valve


32




b


close to or away from the valve seat of the orifice


32




a


. As a result, the flow path area of the orifice


32




a


is changed, and the flow rate of the refrigerant is controlled.




In other words, the heat sensing shaft


36




f


positioned inside the second passage


34


connected to the exit side of the evaporator


8


transmits the temperature of the low-pressure gas-phase refrigerant sent out from the evaporator to the upper pressure chamber


36




b


, and corresponding to the temperature, the pressure inside the upper pressure chamber


36




b


is changed. When the exit temperature of the evaporator


8


is high or heat load of the evaporator is increased, the pressure inside the upper pressure chamber


36




b


is raised, and in response, the heat sensing shaft


36




f


or heat sensing drive shaft is driven to the lower direction so as to lower the valve


32




b


, thereby increasing the opening of the orifice


32




a


. Accordingly, the quantity of the refrigerant supplied to the evaporator


8


will be increased, thereby lowering the temperature of the evaporator


8


. In contrast, if the temperature of the refrigerant sent out from the evaporator


8


is decreased or heat load of the evaporator is decreased, the valve


32




b


is driven to the opposite direction, and the opening of the orifice


32




a


is decreased. Accordingly, the quantity of the refrigerant supplied to the evaporator


8


will be decreased, thereby increasing the temperature of the evaporator


8


.




Similar to the expansion valve of the prior art shown in

FIG. 15

,

FIG. 17

shows an expansion valve according to the prior art comprising a valve positioned to oppose to an orifice formed in the middle of a high-pressure refrigerant passage through which a high-pressure refrigerant sent into the evaporator travels, wherein the valve is driven to open or close in correspondence to the temperature of the low-pressure refrigerant sent out from the evaporator.





FIG. 17

is a vertical cross-sectional view showing the prior art expansion valve, and

FIG. 18

is a drawing showing the main portion of FIG.


17


. In

FIG. 17

, the same reference numbers as the prior art expansion valve of

FIG. 15

show either the same or similar portions, but the structure of the heat sensing drive shaft differs from that shown in FIG.


15


. In the expansion valve


101


shown in

FIG. 17

, the valve body


30


comprises a similar valve body as in the example shown in

FIG. 15

, and basically comprises an orifice


32




a


formed in a high-pressure refrigerant passage


32


through which a high-pressure refrigerant to be sent into the evaporator


8


travels, a spherical valve


32




b


positioned so as to oppose to said orifice


32




a


from the upper stream side of said refrigerant, a biasing means


32




d


for biasing said valve toward said orifice from the upper stream side, a valve member


32




c


positioned between said biasing means and said valve so as to transmit the biasing force of said biasing means to said valve


32




b


, a power element portion


36


driven in correspondence to the temperature of the low-pressure refrigerant sent out from said evaporator, and a heat sensing drive shaft or rod portion inserted through said orifice comprising a heat sensing shaft and an operation shaft formed integrally and positioned between said power element portion


36


and said valve


32




b


, wherein said valve could be driven close to or away from said orifice by said rod portion according to the movement of said power element portion, so that the flow rate of the refrigerant passing through the orifice may be controlled.




The heat sensing drive shaft


318


comprises a separately formed upper end portion


36




k


and an integrally formed heat sensing shaft and operation shaft as, for example, a stainless steel rod portion


316


having a small radius. The upper end portion


36




k


acts as a receiving portion contacted to the lower surface of the diaphragm


36




a


, comprising a stopper portion


312


enlarged to the radial direction and a large radius portion


314


whose other end portion forms a protrusion


315


on the center thereof and inserted slidably to the lower pressure chamber


36




c


. Further, the upper end of the rod portion


316


is connected to the interior of the protrusion


315


on the large radius portion


314


, and the lower end thereof contacts the valve


32




b.






The rod portion


316


forming the heat sensingshaft is driven vertically traversing the passage


34


in correspondence to the displacement of the diaphragm


36




a


in the power element portion


36


, so a clearance communicating the passage


322


and the passage


34


may be formed along the rod portion


316


. In order to prevent such communication, an o-ring


40


contacted to the outer peripheral of the rod portion


316


is positioned inside the large radius hole


38


, so that the o-ring exists between the two passages. Moreover, as a detent for preventing the o-ring


40


from moving by the force operating in the longitudinal direction (the direction of the power element portion


36


) by the refrigerant pressure of the passage


321


and the coil spring


32




d


, a washer or snap ring with teeth


41


is positioned inside the large radius hole


38


contacting the o-ring


40


so as to fix the o-ring. The rod portion


316


is formed for example by stainless steel, having a diameter of approximately 2.4 mm, and the portion where the orifice


32




a


of the rod portion


316


is inserted is formed to have a diameter of approximately 1.6 mm.




In the prior art example shown in

FIG. 16

, the stopper portion


312


and the large radius portion


314


may be formed of brass, and the rod portion


316


may be formed of aluminum. Further, the stopper portion, the large radius portion and the rod portion may all be formed of stainless steel. In the prior art expansion valve shown in

FIG. 18

, the displacement of the diaphragm


36




a


is transmitted by the rod portion


316


to the spherical valve


32




b


, which moves the valve


32




b


close to or away from the orifice


32




a


so as to control the flow rate of the refrigerant, which is similar to the example shown in FIG.


15


.




Further, similar to the expansion valve of

FIG. 15

, the valve shown in

FIG. 17

is also filled with a predetermined refrigerant by use of a plug body


36




i


. The plug body


36




i


made for example of stainless steel is inserted so as to cover the hole


36




j


formed on the stainless steel upper cover


36




d


and fixed thereto by welding.




FIG.


18


(A) shows a schematic view of the structure of the power element portion


36


of the expansion valve


101


explained above, and FIG.


18


(B) is a view taken from the direction of the arrow of FIG.


18


(A), wherein the lower cover


36




h


is rotated and removed from the screw hole


361


, separating the power element portion


36


. FIG.


18


(C) is a cross-sectional view showing the structure of the power element portion


36


.




SUMMARY OF THE INVENTION




In the prior art expansion valve, a material such as aluminum, stainless steel or brass and the like are used as the metal material. In the recent years, the recycling of materials are strongly requested from the point of saving resources. In the prior art expansion valve, it was easy to recycle metal material when the expansion valve was formed by the same kind of metal. However, when various metal materials were used in the expansion valve, for example, stainless steel material for the diaphragm and aluminum material for the heat sensing drive shaft, it was difficult to recycle each metal material unless these various materials were segregated. Especially, in the prior art expansion valve, there was a problem that no consideration was made on recycling each metal material.




Moreover, there is a strong request from the point of view of the protection of earth environment that the refrigerant used in the refrigeration cycle should be collected without being discharged into the atmosphere. The prior art expansion valve had such refrigerant filled inside the pressure chamber of the power element portion as the diaphragm drive medium for displacing the diaphragm according to the change of pressure.




However, in the expansion valve of the prior art, there was a problem that no consideration was made on the collection of such refrigerant therefrom.




Therefore, the object of the present invention is to provide an expansion valve solving the problems of the prior art expansion valve by enabling recycling without having to change the structure drastically.




Moreover, the present invention aims at providing an expansion valve whose refrigerant could also be collected accompanying said recycling.




In order to solve the problem, the expansion valve according to the present invention has a diaphragm forming one portion of a sealing wall in a power element portion filled with a heat sensing refrigerant, and a valve driven in correspondence to the displacement of said diaphragm by a heat sensing drive shaft for changing the flow path area of an orifice through which a high-pressure refrigerant to be sent to an evaporator travels:




wherein said heat sensing drive shaft includes a stopper portion contacted to said diaphragm, said shaft being formed so as to be separated from said power element portion by leaving said stopper portion inside said power element portion.




Further, the expansion valve according to the present invention comprises a valve body having a first passage through which a high-pressure refrigerant travels and a second passage through which a low-pressure refrigerant travels, a valve positioned inside said valve body for controlling the flow of the refrigerant traveling through said first passage, a power element portion mounted to the upper end portion of said valve body, a biasing means positioned in the lower portion of said valve body for biasing said valve, and a heat sensing drive shaft mounted between said power element portion and said valve, wherein said power element portion comprises an upper pressure chamber and a lower pressure chamber divided by a diaphragm mounted in the interior thereof; said drive shaft comprises a stopper portion formed on the upper end portion thereof for contacting to said diaphragm; and said drive shaft is formed to separate by leaving said stopper portion inside said lower pressure chamber.




Moreover, the expansion valve according to the present invention has a diaphragm forming one portion of a sealing wall in a power element portion filled with a heat sensing refrigerant, and a valve driven in correspondence to the displacement of said diaphragm by a heat sensing drive shaft for changing the flow path area of an orifice through which a high-pressure refrigerant to be sent to an evaporator travels, wherein said heat sensing drive shaft comprises an upper end portion and a heat conducting shaft, said upper end portion comprising a stopper portion and a large radius portion, one surface of each said portion being formed so as to contact one surface of the other said portion, and the other surface of said stopper portion being contacted to the lower surface of said diaphragm and the other surface of said large radius portion being equipped with said heat conducting shaft; and said large radius portion is formed to be separated from said power element.




Said expansion valve is characterized in that said stopper portion is equipped with a refrigerant collecting means.




Said expansion valve is characterized in that said collecting means is a penetrating hole which penetrates said stopper portion.




Further, the present invention characterizes in an expansion valve comprising a power element portion filled with a predetermined refrigerant, a diaphragm constituting one wall surface of said power element portion which is displaced in correspondence to the change in pressure of said power element portion, a heat sensing drive shaft for transmitting the temperature of said refrigerant flowing out from an evaporator to said diaphragm, and a valve to which said displacement of the diaphragm is transmitted by said heat sensing drive shaft for controlling the flow rate of said refrigerant flowing into said evaporator, wherein the upper end portion of said heat sensing drive shaft comprises a stopper portion for contacting to said diaphragm, said upper end portion being formed so as to separate from said power element portion by leaving said stopper portion inside said power element portion.




Moreover, the present invention characterizes in an expansion valve comprising a power element portion filled with a predetermined refrigerant, a diaphragm constituting one wall surface of said power element portion which is displaced in correspondence to the change in pressure of said power element portion, a heat sensing drive shaft for transmitting the temperature of said refrigerant flowing out from an evaporator to said diaphragm, and a valve to which said displacement of the diaphragm is transmitted by said heat sensing drive shaft for controlling the flow rate of said refrigerant flowing into said evaporator, wherein the upper end portion of said heat sensing drive shaft includes a separating means for separation from said diaphragm, and said heat sensing drive shaft is positioned so that said separating means contacts said diaphragm.




Further, the center area of said separating means is positioned so as to contact said diaphragm, and the end portion thereof is made of a metal member and being held by said lower pressure chamber.




Said metal member comprises a portion formed by expanding the center area of a metal plate, said portion being positioned so as to contact said upper end portion, and the rim portion of said metal plate further comprises a bent portion so that said rim may be held by said lower pressure chamber.




Said metal member is characterized in that the center area of said metal member is staked and fixed to a convex portion formed on the center area of the upper end portion of said drive shaft, and the rim portion thereof being held by said lower pressure chamber.




Said separating means is equipped with a retrieving means for retrieving the predetermined refrigerant inside said power element portion.




Said metal member is equipped with a retrieving means for retrieving the predetermined refrigerant inside said power element portion.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is vertical cross-sectional view showing the main portion of the expansion valve according to one embodiment of the present invention;





FIG. 2

is a vertical cross-sectional view and a schematic view showing the state where the power element of

FIG. 1

is separated;





FIG. 3

is a vertical cross-sectional view equipped with the refrigerant collecting means on the main portion of the expansion valve according to the present invention;





FIG. 4

is a vertical cross-sectional view explaining the way to collect refrigerant according to the refrigerant collecting means of

FIG. 3

;





FIG. 5

is an explanatory view showing the method to collect the refrigerant from the refrigerant collecting means shown in

FIG. 4

by use of a jig;





FIG. 6

is a vertical cross-sectional view showing the structure of the main portion of the expansion valve according to another embodiment of the present invention;





FIG.7

is a cross-sectional view of the large radius portion of

FIG. 6

;





FIG. 8

is a vertical cross-sectional view showing the structure of the main portion of the expansion valve according to yet another embodiment of the present invention;





FIG. 9

is a vertical cross-sectional view and a schematic view showing the state where the power element portion of

FIG. 8

is separated;





FIG. 10

is a vertical cross-sectional view explaining the way to collect the refrigerant by the refrigerant collecting means;





FIG. 11

is an explanatory view showing the method to collect refrigerant from the refrigerant collecting means shown in

FIG. 10

by use of a jig;





FIG. 12

is a vertical cross-sectional view showing the main structure of the expansion valve according to yet another embodiment of the present invention;





FIG. 13

is a vertical cross-sectional view and a schematic view showing the state where the power element portion is separated in

FIG. 12

;





FIG. 14

is a vertical cross-sectional view explaining other shapes of the metal members shown in

FIG. 8

or

FIG. 12

;





FIG. 15

is a vertical cross-sectional view showing the structure of the prior art expansion valve;





FIG. 16

is a schematic view and a vertical cross-sectional view showing the state where the power element portion of

FIG. 15

is separated;





FIG. 17

is a cross-sectional view showing the structure of another prior art expansion valve; and





FIG. 18

is a schematic view and a vertical cross-sectional view showing the state where the power element portion of

FIG. 17

is separated.











PREFERRED EMBODIMENT OF THE INVENTION




The embodiment according to the present invention will now be explained with reference to the drawings.





FIG. 1

is a vertical cross-sectional view showing the structure of the power element portion of the main portion of the expansion valve according to one embodiment of the present invention, and corresponds to the power element portion of the prior art expansion valve shown in FIG.


16


(C).




The expansion valve of the present invention shown in FIG.


1


and that of the prior art shown in FIG.


15


and FIG.


16


(C) have the same structure except for the heat sensing drive shaft of the power element portion. Therefore, in the present embodiment, the power element portion will only be shown while the other structures will be omitted. Similarly, in the other embodiments of the expansion valve according to the present invention disclosed hereinafter, only the structure of the power element portion will be shown in a vertical cross-sectional view, with other structures omitted.




In

FIG. 1

, a power element portion


36


′ comprises a heat sensing drive portion


101


which differs from the heat sensing drive shaft


36




f


in the prior art, but the other structures are the same as the power element portion


36


of the prior art shown in

FIG. 15

, the explanation of which are omitted by providing the same reference numbers. That is, the heat sensing drive shaft


101


comprises an upper end portion


102


and a heat conducting shaft


103


, wherein the upper end portion


102


includes a stopper portion


104


and a large radius portion


105


, each having one surface contacted to one surface of the other. The other surface of the stopper portion


104


being enlarged to the radial direction contacts the lower surface of a diaphragm


36




a


, and the other surface of the large radius portion


105


is equipped with the heat conducting shaft


103


being integrally formed to the large radius portion


105


.




According to such structure, even if the power element portion


36


′ is composed of various metals, that is, if the blind plug


36




i


, the upper cover


36




d


, the lower cover


36




h


and the diaphragm


36




a


are formed of a stainless steel material and the large radius portion


105


and the heat conducting shaft


103


are formed of an aluminum metal, by utilizing a stainless steel material as the stopper portion


104


, the various metals could be separated. That is, since the stopper portion


104


is enlarged to the radial direction and stopped by the lower cover


36




h


, the large radius portion


105


may be separated from the stopper portion


104


, and the large radius portion


105


together with the heat conducting shaft


103


could be removed from the lower pressure chamber


36




c


of the power element portion


36


′ along the mounting seat


362


.




Therefore, according to the present embodiment, the metal portion made of stainless steel shown in FIG.


2


(A) and the metal portion made of aluminum shown in FIG.


2


(B) may be separated. Accordingly, these materials may be separated and recycled.




Moreover, according to the present invention, by mounting a collecting means in advance for collecting the refrigerant to the metal portion made of stainless steel shown in FIG.


2


(A) which is enabled to be recycled as explained above, the refrigerant could easily be collected.




That is, in the state where the metal portion is separated as shown in FIG.


2


(A), the predetermined refrigerant being filled inside the upper pressure chamber


36




b


may be collected. By providing a penetrating hole


36




n


with a diameter of approximately 3 mm as the collecting means to the center portion and the like of the stopper portion


104


as shown in

FIG. 3

, the refrigerant could be collected in the separated state as shown in FIG.


4


.




Moreover, even if the penetrating hole


36




n


is formed on the stopper portion


104


, the expansion valve may perform the same movement since the penetrating hole


36




n


contacts the lower surface of the diaphragm


36




a


and will be covered by the diaphragm


36




a.






In the structure shown in

FIG. 4

, a jig or the like shown in

FIG. 5

is used to collect the predetermined gas.




In

FIG. 5

, the metallic jig


50


is formed to have a cylindrical shape, comprising a disk-shaped bottom


51


, an outer wall


52


formed on said bottom in the circumference area, an interior space


53


surrounded by the outer wall


52


, and a convex portion


54


mounted inside the interior space


53


with a needle portion


55


mounted on the tip end thereof. On the outer wall


52


is formed a side hole


56


communicated to the interior space


53


. On the upper end of the outer wall


52


of the jig


50


is formed a step portion


57


, and the lower cover


36




h


shown in

FIG. 4

is mounted on the upper end of the surrounding outer wall


52


through an o-ring


58


placed inside said step portion


57


as sealing means.




At this time, the needle portion


55


on the convex portion


54


is mounted inside the interior space


53


corresponding to the position of the penetrating hole


36




n


formed on the stopper


104


. By pressing the power element


36


, the needle portion


55


advances inside the penetrating hole


36




n


, breaking the diaphragm


36




a


formed of a metallic thin-film having flexibility (for example, a stainless steel plate having a plate thickness of approximately 0.1 mm) by the needle


55


. As a result, the interior space


53


of the jig


50


and the upper pressure chamber


36




b


will be communicated through the penetrating hole


36




n


, and the refrigerant inside the upper pressure chamber


36




b


becomes confined inside the interior space


53


of the jig


50


. This refrigerant will be sucked into a refrigerant collecting device not shown through the side hole


56


communicated to the interior space, and thereby, the refrigerant could be collected.




Further, either manual or automatic means may be used to press the power element


36




h


mounted to the jig


50


.





FIG. 6

is a vertical cross-sectional view of a power element portion


106


showing the main portion of the expansion valve according to another embodiment of the present invention, and corresponds to the power element portion


36


of the prior art expansion valve


10


shown in FIG.


16


. Only the upper end portion


107


of the present expansion valve shown in

FIG. 6

differs from the upper end portion


36




k


of the prior art expansion valve


100


, so the explanation of the other members having the same reference numbers as that of the prior art expansion valve


100


are omitted.




In

FIG. 6

, the upper end portion


107


comprises a stopper portion


108


and a large radius portion


109


each having one surface contacting one surface of the other member, and the other surface of the stopper portion


108


being enlarged to the radial direction contacts the lower surface of the diaphragm


36




a


, and the other surface of the large radius portion


109


is equipped with a protrusion


110


which is integrally formed to the large radius portion


109


, the interior of which is contacted to the upper end of the rod portion


316


.




According to such structure, even if the power element portion


106


is formed of various metal materials, that is, if the blind plug


36




i


, the upper cover


36




d


, the lower cover


36




h


and the diaphragm


36




a


are formed of a stainless steel, and the large radius portion


109


is made of aluminum metal, the different metal materials could be separated by utilizing a stainless steel material as the stopper portion


108


.




That is, since the stopper portion


106


is enlarged to the radial direction and held by the lower cover


36




h


, only the large radius portion


109


could be separated from the stopper portion


108


and removed from the lower pressure chamber


36




c


along the mounting seat


362


. Therefore, according to the present embodiment, the large radius portion


109


made of aluminum may be separated as shown in FIG.


7


. Accordingly, the different metal materials could each be separated and recycled.




Moreover, in the embodiment shown in

FIG. 6

, in order to collect the refrigerant being filled inside the upper pressure chamber


36




b


, a penetrating hole similar to that of the penetrating hole


36




n


shown in

FIG. 3

may be formed to the stopper portion


108


of the embodiment shown in

FIG. 6

, and the refrigerant could be collected by utilizing the jig shown in FIG.


5


.




The above explanation referred to the structure for separating the stopper portion and the large radius portion in the embodiment of the expansion valve according to the present invention. However, the present invention is not limited to such structure, but could utilize a separating means for separating the upper end portion of the heat sensing drive shaft from the diaphragm.





FIG. 8

is a vertical cross-sectional view of a power element portion


200


showing the main portion of yet another embodiment of the expansion valve according to the present invention, showing the example of utilizing a plate-like disk-shaped member made of metal material as said separating means. In the embodiment shown in

FIG. 8

, the structure except for the heat sensing drive shaft is the same as the power element portion


36


of the prior art expansion valve shown in FIG.


16


(C).




That is, a heat sensing drive shaft


201


comprises an upper end portion


202


and a heat conducting shaft


203


, wherein the upper end portion


202


comprises a plate-like member


204


and a large radius portion


205


each having one surface contacting one surface of the other member. The center portion on the other surface of the plate-like member


204


contacts the center portion of the lower surface of the diaphragm


36




a


, and the end portion of the plate-like member


204


is bent so as to be held by the lower pressure chamber


36




c


and positioned so as to contact the lower cover


36




h.






In other words, the plate-like member


204


is positioned between the lower surface of the diaphragm


36




a


and the large radius portion


205


, so as to contact the diaphragm


36




a


and the large radius portion


205


. On the other surface of the large radius portion


205


is integrally equipped a heat conducting shaft


203


.




According to such structure, even when the blind plug


36




i


, the upper cover


36




d


, the lower cover


36




h


and the diaphragm


36




a


are formed of a stainless steel material, and the large radius portion


205


is made of aluminum metal, the different metal materials could be separated by utilizing a stainless steel with a plate thickness of few millimeters, for example 2 mm, as the plate-like member


204


.




That is, since the plate-like member


204


is held by the lower cover


36




h


, only the large radius portion


205


could be separated from the plate-like member


204


, so the large radius portion


205


and the heat conducting shaft


203


may both be removed from the lower pressure chamber


36




c


of the power element


200


along the mounting seat


362


.




As explained, according to the present embodiment, the metal member made of stainless steel shown in FIG.


9


(A) and the metal member made of aluminum shown in FIG.


9


(B) could be separated. Therefore, these metals could each be segregated and recycled.




Moreover, according to the present invention, the refrigerant filled inside the upper pressure chamber


36




b


may also be collected in the separated state shown in FIG.


9


(A).




That is, in the center portion of the plate-like member


204


shown in the embodiment of

FIG. 8

, a penetrating hole having a diameter of approximately 3 mm or the like is formed in advance. When in the state where the members are separated as shown in

FIG. 10

, a penetrating hole


206


exists on the plate-like member


204


.




Accordingly, the refrigerant inside the chamber


36




b


may be collected by the same method as the collecting method shown in FIG.


5


and utilizing a jig


50


′ as shown in FIG.


11


. Further, even when the penetrating hole


206


is formed on the plate-like member


204


, the plate-like member


204


contacts the lower surface of the diaphragm


36




a


, so the penetrating hole


206


is covered by the diaphragm


36




a


and covered therewith. Therefore, the expansion valve could be operated just like the prior art expansion valve. The jig


50


′ of

FIG. 11

is the same as the jig


50


shown in

FIG. 5

, so the same members are shown by the same reference numbers, and the explanations thereof are omitted.





FIG. 12

is a vertical cross-sectional view of a power element portion


207


showing the main portion of the expansion valve according to yet another embodiment of the present invention, wherein the structure of the power element portion


207


only differs in the structure of an upper end portion


210


from the power element portion


36


of the prior art expansion valve shown as the main portion in FIG.


17


(C), and the other structures are the same. Accordingly, the same members are provided with the same reference numbers as the prior art structure, and the explanations thereof are omitted.




In

FIG. 12

, the upper end portion


210


comprises a plate-like member


208


and a large radius portion


209


similar to the embodiment shown in

FIG. 8

, and the plate-like member


208


and the large radius portion


209


each have one surface contacting one surface of the other member, and the center portion of another surface of the plate-like member


208


contacts the center portion on the lower surface of the diaphragm


36




a


, and the rim portion of the plate-like, member


208


is bent so as to be held by the lower pressure chamber


36




c


and positioned so as to contact the lower cover


36




h


. The other surface of the large radius portion


209


is equipped with an integrally formed protrusion


211


.




The plate-like member


208


has one surface contacting the large radius portion


209


and the other surface contacting the lower surface of the diaphragm


36




a


, so accordingly, the plate-like member


208


is positioned between the diaphragm


36




a


and the large radius portion


209


. According to such structure, even when the blind plug


36




i


, the upper cover


36




d


, the lower cover


36




h


and the diaphragm


36




a


are formed of a stainless steel material, and the large radius portion


209


is made of an aluminum or brass metal, the different metal materials could be separated by utilizing a stainless steel with a plate thickness of few millimeters, for example 2 mm, as the plate-like member


208


.




Therefore, the plate-like member


208


is held at its end portion by the lower cover


36




h


, so only the large radius portion


205


may be separated from the plate-like member


208


and the large radius portion


209


may be removed from the lower pressure chamber


36




c


of the power element portion


207


along the mounting seat


362


.




According to the present embodiment, the power element portion


207


could be separated into a metal portion made of stainless steel as shown in FIG.


13


(A) and a metal portion made of aluminum or brass as shown in FIG.


13


(B). Therefore, these materials could each be segregated and recycled.




Moreover, according to the embodiment shown in

FIG. 12

,


213


shows a penetrating hole formed on the plate-like member


213


, and the penetrating hole


213


is formed to have a diameter of approximately 3 mm, which may be used for collecting the refrigerant filled inside the upper pressure chamber


36




b


of the power element portion


207


. The collection of this refrigerant utilizes a jig as explained in

FIG. 11

, and is performed by the same method.




FIGS.


14


(A),


14


(B),


14


(C) and


14


(D) show the structure of the power element portion which is the main member of the expansion valves according to yet other embodiments of the present invention. The embodiment shown in FIG.


14


(A) and FIG.


14


(B) only differ from that of

FIG. 8

in the structure of the plate-like member and the large radius member, and the other structures are the same. The same members are shown by the same reference numbers, and the explanations thereof are omitted. Further, in the embodiment shown in FIG.


14


(C) and FIG.


14


(D), only the plate-like member and the large radius member differs from the embodiment shown in

FIG. 12

, and the other structures are the same. The same members are shown by the same reference numbers, and the explanations thereof are omitted.




In the embodiments shown in FIG.


14


(A) and FIG.


14


(C), a concave portion


214


or


215


is formed on the center of the large radius portion


205


′ or


209


′ on the surface contacting the plate-like member


204


′ or


208


′. On the center of the plate-like member


204


′ or


208


′ is formed a convex-shaped portion


216


or


217


which extends in the direction to contact the concave portion


214


or


215


.




According to such embodiments, there is an advantage in that the plate-like member


204


′ and


208


′ may be contacted to the large radius portion


205


′ or


209


′ by adjusting the center to the convex-shaped portion.




Moreover, the peak portion of the convex-shaped portion


216


or


217


of the plate-like member


204


′ or


208


′ is formed a penetrating hole


218


or


219


similar to the penetrating holes mentioned before for collecting refrigerant. In the embodiments shown in FIG.


14


(B) and FIG.


14


(D), a convex portion


220


or


221


is formed on the large radius portion


205


″ or


209


″ on the surface contacting the plate-like member


204


″ or


208


″, and on the center area of the concave portion


220


or


221


is formed a convex portion


222


or


223


. A disk-shaped small hole


224


or


225


formed on the center area of the plate-like member


204


″ or


208


″ is fit to the convex portion


222


or


223


, and the plate-like member


204


″ or


208


″ is fixed thereto by staking.




According to such structure, there is an advantage in that the plate-like member


204


″ or


208


″ may strongly contact the large radius portion


205


″ or


209


″. According further to the embodiments shown in FIG.


14


(B) and FIG.


14


(D), the small hole


224


or


225


formed on the plate-like member


204


″ or


208


″ could be utilized as the penetrating hole for collecting refrigerant through which the needle portion


55


on the jig


50


′ shown in

FIG. 5

penetrates, so there is an advantage in that there is no need to further mount a penetrating hole.




According to the embodiments shown in FIGS.


13


(A) through


13


(D), the members formed of different metals may be separated from each other in the same method as the other embodiments mentioned before by use of the plate-like member


204


′,


204


″,


208


′ or


208


″.




As explained, the expansion valve according to the present invention is formed so that the different kinds of metal material could be separated easily, so the metal materials could be segregated and recycled.




Moreover, the expansion valve according to the present invention may realize such recycle by separating the large radius portion and the stopper portion contacting the diaphragm, so there is no need to change the structure of the prior art expansion valve greatly.




Moreover, by utilizing a separating means for separating the upper endportion of the heat sensing drive shaft contacting the diaphragm from the diaphragm, and by applying a metal corresponding to the various metals to be recycled as the separating means, the power element portion and the heat sensing drive shaft which are the main portions of the expansion valve may be formed by combining appropriate kinds of metal materials.




Even further, according to the expansion valve of the present invention, the recycle of the metal materials may also enable a simple collection of the refrigerant, so not only the saving of resources but also the collection of regulated refrigerant may be promoted.



Claims
  • 1. An expansion valve comprising:a valve body, a power element seated at the top of the valve body having, a body for housing a diaphragm, the diaphragm made of stainless steel located in the interior of the power element forming a sealing wall separating an upper pressure chamber and a lower pressure chamber, said power element forming a head of the valve and filled with a heat sensing refrigerant, a heat sensing drive shaft made of aluminum extending from the diaphragm through a lower end of the body of the power element into the valve body, a valve, at the end of the heat sensing drive shaft opposite the diaphragm, driven in correspondence to the displacement of said diaphragm by the heat sensing drive shaft for changing a flow path area of an orifice through which a refrigerant to be sent to an evaporator travels, said heat sensing drive shaft further includes, a stainless steel stopper portion contacted to said diaphragm on an upper end and connected, so as to be removable therefrom, to the heat sensing drive shaft on a lower end.
  • 2. An expansion valve comprising:a valve body having, a first passage through which a high-pressure refrigerant travels, and a second passage through which a low-pressure refrigerant travels, a valve positioned inside said valve body for controlling the flow of the refrigerant traveling through said first passage, a power element mounted to the upper end of said valve body, a biasing means positioned in the lower portion of said valve body for biasing said valve, and an aluminum heat sensing drive shaft mounted between said power element and said valve, power element comprises, an upper pressure chamber, a lower pressure chamber, and a stainless steel diaphragm mounted in the interior of the power element dividing the upper pressure chamber and the lower pressure chamber; the drive shaft comprises, a stainless steel stopper portion formed on the upper end thereof for contacting to said diaphragm; and a heat sensing shaft connected to a lower end of the stopper and removable therefrom.
  • 3. An expansion valve comprising:a valve body, a power element seated at the top of the valve body having, a body for housing a diaphragm, the diaphragm made of stainless steel located in the interior of the power element forming a sealing wall separating an upper pressure chamber and a lower pressure chamber, said power element forming a head of the valve and filled with a heat sensing refrigerant, an aluminum heat sensing drive shaft extending from the diaphragm through a lower end of the body of the power element into the valve body, a valve, at the end of the heat sensing drive shaft opposite the diaphragm, driven in correspondence to the displacement of said diaphragm by the heat sensing drive shaft for changing a flow path area of an orifice through which a refrigerant to be sent to an evaporator travels, the heat sensing drive shaft comprises: an upper end portion, and a heat conducting shaft, said upper end portion comprising a stainless steel stopper portion and an aluminum large radius portion integrally formed on the top of the heat conducting shaft, one surface of each said portion being formed so as to contact one surface of the other said portion, and the other surface of said stopper portion being connected to a lower surface of said diaphragm and the other surface of said large radius portion being integrally formed on said heat conducting shaft; and said large radius portion is formed to be removable from said power element.
  • 4. An expansion valve according to claim 1, claim 2 or claim 3, wherein said stopper portion is equipped with a refrigerant collecting means.
  • 5. An expansion valve according to claim 1, claim 2 or claim 3, wherein said stopper portion is equipped with a refrigerant collecting means being a penetrating hole which penetrates said stopper portion.
  • 6. An expansion valve comprising a power element portion filled with a predetermined refrigerant, a diaphragm constituting one wall surface of said power element portion which is displaced in correspondence to the change in pressure of said power element portion, a heat sensing drive shaft for transmitting the temperature of said refrigerant flowing out from an evaporator to said diaphragm, and a valve to which said displacement of the diaphragm is transmitted by said heat sensing drive shaft for controlling the flow rate of said refrigerant flowing into said evaporator:wherein the upper end portion of said heat sensing drive shaft comprises a stopper portion for contacting to said diaphragm, said upper end portion being formed so as to separate from said power element portion by leaving said stopper portion inside said power element portion.
Priority Claims (1)
Number Date Country Kind
10-028039 Feb 1998 JP
US Referenced Citations (7)
Number Name Date Kind
3450345 Orth et al. Jun 1969
3640311 Gotzenberger Feb 1972
5026022 Bastle Jun 1991
5257737 Vestergaard Nov 1993
5303864 Hirota Apr 1994
5957376 Rujimoto et al. Sep 1999
5961038 Okada Oct 1999
Foreign Referenced Citations (9)
Number Date Country
91 10 384 U Jan 1992 DE
0 306 113 A Mar 1990 EP
0 664 425 A Jul 1995 EP
0 691 517 A Jan 1996 EP
0 836 061 A1 Apr 1998 EP
0 864 826 A2 Sep 1998 EP
0 871 000 A1 Oct 1998 EP
02 154955 Jun 1990 JP
09 089154 Mar 1997 JP