JP6955760B2 - Expansion valve - Google Patents

Description

The present invention relates to an expansion valve, and more particularly to a technique for suppressing a temperature change of a power element due to an increase in environmental temperature.

When the expansion valve is installed in the engine room of the vehicle, the atmosphere in the engine room becomes high temperature, which may affect the refrigerant flow rate control characteristics of the expansion valve. Therefore, a method of insulating the power element for driving the valve body of the expansion valve from the environment is known.
For example, in the expansion valve described in Patent Document 1, the power element is covered with a heat-resistant cap so that the power element is not easily affected by the temperature of the atmosphere and the temperature characteristics of the expansion valve are improved (Patent). See FIG. 1, reference numeral 26 in Document 1).

Japanese Patent No. 3899055

In the expansion valve described in Patent Document 1, a heat-resistant cap, that is, a cap formed of a material having a low thermal conductivity (a material having a low thermal conductivity) is put on the power element to suppress the transfer of ambient heat to the power element. It is said. However, even if a heat-resistant cap having such a low thermal conductivity is used, it may not be sufficient as a measure against the environmental temperature around the expansion valve.

Therefore, an object of the present invention is to provide an expansion valve capable of reducing the influence of the environmental temperature around the expansion valve.

In order to achieve the above object, the expansion valve according to the present invention is expanded by an inlet port for introducing a high-pressure refrigerant condensed by a condenser, a valve chamber communicating with the inlet port, an orifice provided in the valve chamber, and the orifice. A valve body having an outlet port for leading out the refrigerant to the outside and a return passage through which the refrigerant returning from the evaporator to the compressor passes, a valve body arranged inside the valve chamber, and a valve body arranged inside the valve chamber. It includes an urging member that urges the valve body toward the valve seat, and a power element that drives the valve body against the urging force of the urging member and controls the opening degree of the orifice. The further example Bei a heat transfer member for transferring heat to the ambient temperature of the power element to the valve body, the heat transfer member is a flexible film made of a metal, the surface contact with the power element It is characterized by having one part.

In the expansion valve, the heat transfer member may include a first portion arranged in the vicinity of the exposed portion of the power element and a second portion connected to the valve body.

In the expansion valve, it may be a cover member that covers at least a part of the power element.

In the expansion valve, the heat transfer member may have flexibility.

In the expansion valve, the second portion of the heat transfer member may be connected in the vicinity of the return passage of the valve body.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an expansion valve capable of reducing the influence of the environmental temperature around the expansion valve.

FIG. 1 is a vertical cross-sectional view of the expansion valve according to the first embodiment. FIG. 2 is a perspective view showing an expansion valve before attaching the heat transfer member. FIG. 3 is a perspective view of the expansion valve according to the first embodiment. FIG. 4 is a perspective view showing the front side of the heat transfer member. FIG. 5 is a perspective view showing the back side of the heat transfer member. FIG. 6 is a perspective view showing the bottom surface side of the heat transfer member. FIG. 7 is a front view showing the expansion valve in the second embodiment. FIG. 8 is a side view showing the expansion valve in the second embodiment. FIG. 9 is a diagram schematically showing an example in which the expansion valve in the embodiment is applied to the refrigeration cycle.

Hereinafter, the expansion valve according to the embodiment will be described with reference to the drawings.

(Definition of direction)
In the present specification, the direction from the valve body 3 to the operating rod 5 along the direction of the paper surface described in each drawing is defined as "upward", and the direction from the operating rod 5 to the valve body 3 is "downward". Is defined as.

(First Embodiment)
The expansion valve 1 in the first embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is a cross-sectional view showing the overall structure of the expansion valve 1 according to the first embodiment. FIG. 2 is a perspective view showing the expansion valve 1 before the heat transfer member 7 is attached. FIG. 3 is a perspective view showing the expansion valve 1 after the heat transfer member 7 is attached. FIG. 4 is a perspective view showing the front side of the heat transfer member 7. FIG. 5 is a schematic perspective view showing the back side of the heat transfer member 7. FIG. 6 is a perspective view showing the bottom surface side of the heat transfer member 7.

As shown in each figure, the expansion valve 1 in the first embodiment has a valve body 2, and a high-pressure refrigerant supplied from a compressor (not shown) is introduced into the valve body 2. A flow path (inlet port) 21 is provided, and the first flow path 21 communicates with the valve chamber VS via the small diameter portion 21a.
An orifice 20a and a valve seat 20 opened and closed by the valve body 3 are formed in the valve chamber VS, and the flow rate of the fluid (refrigerant) passing through the orifice 20a is controlled by the valve body 3, and this is the second flow including the small diameter port 22a. It is sent to an evaporator (not shown) through a road (exit port) 22.
The refrigerant returning from the evaporator to the compressor (not shown) passes through the third flow path (return passage) 23 provided in the valve body 2. A part of the refrigerant passing through the third flow path 23 is introduced to the power element 6 side (inside the second space SP2) through the opening 23a, and the heat (cold heat) of the refrigerant is transferred to the power element 6. NS.
A power element 6 is screwed onto the upper surface of the valve body 2 via a sealing material 62b. The power element 6 includes an upper lid member 61 and a receiving member 62, and a diaphragm 63 sandwiched between them, and the outer peripheral portions thereof are fixed by welding. The space defined by the upper lid member 61 and the diaphragm 63 is filled with a working fluid (refrigerant), and then sealed by a plug 61b to form a first space (working pressure chamber) SP1. The fluctuation of the internal pressure of the first space SP1 is converted into the displacement of the diaphragm 63 and transmitted to the operating rod 5 via the diaphragm support member 64 arranged between the diaphragm 63 and the receiving member 62.
The operating rod 5 controls the valve opening degree by pressing the spherical valve body 3. The valve body 3 is supported by a valve body support member (spring receiver) 32. Further, the spring receiver 32 is supported by an urging spring 80 provided between the spring receiver 32 and the plug 24 that seals the valve chamber VS. The plug 24 is a screw-shaped member having a hexagon nut-shaped recess 24a at the top, and the urging force of the valve body 3 in the valve closing direction can be adjusted by adjusting the screwing amount thereof. This plug is screwed onto the bottom surface of the valve body 2 via an O-ring 24b. Further, reference numeral 5a is a vibration-proof spring that suppresses vibration of the operating rod 5.
In this embodiment, a heat transfer member 7 (a cover member 70a in the first embodiment) is further provided around the power element 6.

The heat transfer member 7 (cover member 70a) is a member that suppresses the temperature rise of the power element 6 by releasing the heat around the power element 6 to the valve body 2, and is made of a material having high thermal conductivity. .. The heat transfer member 7 comes into contact with the valve body 2 with the first portion 7a arranged in the vicinity of the exposed portion 6a of the power element 6, that is, at least around a part of the exposed portion 6a of the power element 6 in this embodiment. A second portion 7b connected to the valve body 2 is provided. Therefore, the ambient temperature of the heat transfer member 7 is transmitted to the valve body 2 after being transmitted to the heat transfer member 7, but the valve body 2 becomes a low temperature when functioning as an expansion valve, so that the heat transfer member The heat transferred to 7 is positively and effectively released to the valve body 2.

In this way, since the first portion 7a of the heat transfer member 7 is arranged around the exposed portion 6a of the power element 6, the temperature of the exposed portion 6a of the power element 6 and the space in the vicinity thereof escapes to the valve body 2. The temperature is maintained at a temperature close to the temperature of the heat transfer member 7. Further, since the second portion 7b of the heat transfer member 7 is in contact with and connected to the valve body 2, the temperature of the heat transfer member 7 is close to the temperature of the valve body 2. Further, since a fluid (for example, a refrigerant) flows through the valve body 2 through the third flow path 23 or the like, the valve body 2 itself is cooled by the fluid and becomes a temperature close to the temperature of the fluid. ..

As described above, in the embodiment, the temperature of the valve body 2 is close to the temperature of the fluid flowing through the valve body 2, the temperature of the heat transfer member 7 is close to the temperature of the valve body 2, and the exposed portion 6a of the power element 6 The temperature is close to the temperature of the heat transfer member 7. Further, the unexposed portion of the power element 6 (that is, the portion in contact with the valve body 2) is also close to the temperature of the fluid. Therefore, in the embodiment, the automatic adjustment of the valve opening degree by the power element 6 according to the temperature of the fluid is performed more accurately.

When the power element 6 is covered with a heat insulating member as shown in Patent Document 1, the temperature of the heat insulating member approaches the external environmental temperature over time. On the other hand, in the embodiment, the heat transfer member 7 is placed around the exposed portion 6a of the power element 6 by using the idea opposite to the heat insulation (that is, the idea of releasing heat to the cooled valve body 2). It is arranged. As a result, the heat around the exposed portion 6a of the power element 6 is continuously released to the valve body 2 side via the heat transfer member 7. That is, in the embodiment, the heat transfer member 7 is connected to the valve body 2, and the valve body 2 is used as a heat sink for absorbing the heat around the exposed portion 6a of the power element 6. Therefore, the temperature of the exposed portion 6a of the power element 6 is unlikely to deviate from the temperature of the valve body 2.

In the present specification, the "non-exposed portion of the power element" refers to a portion of the outer surface of the power element 6 that is not exposed to the external environment, that is, a portion of the outer surface of the power element 6 that comes into direct contact with the valve body 2. It means the part that is doing. On the other hand, in the present specification, the "exposed portion of the power element" means a portion other than the non-exposed portion. The exposed portion 6a is typically the upper surface of the power element 6 (more specifically, the upper surface 61a of the upper lid member 61), but the exposed portion 6a is not limited to the upper surface of the power element 6. For example, the lower surface 62a of the outer edge portion of the receiving member 62 is also included in the exposed portion 6a.

Next, the configuration of the cover member 70a will be described in detail. The cover member 70a includes a top plate 71, a side wall 72 (for example, an annular wall) extending downward from the top plate, a bottom surface 73, and a mounting portion 75. Then, the top plate 71 and the side wall 72 function as the first portion 7a arranged around the exposed portion 6a of the power element 6, and the bottom surface 73 functions as the second portion 7b connected to the valve body 2.

The top plate 71 covers the upper surface of the power element 6, and the side wall 72 covers the side surface of the power element 6. In the example shown in FIG. 4, the top plate 71 has a flat plate shape, and the side wall 72 has a ring shape. However, the shapes of the top plate 71 and the side wall 72 are not limited to the example shown in FIG. The top plate 71 and the side wall 72 may have a dome shape as a whole, for example.

The bottom surface 73 comes into contact with the main body upper surface 2a of the valve body 2 and functions as a second portion 7b connected to the valve body 2. In the example shown in FIG. 6, the shaded area contacts the upper surface 2a of the main body of the valve main body 2. In the example described in FIG. 6, the second portion 7b connected to the valve body 2 is an annular surface surrounding the power element 6. Therefore, the heat around the power element 6 is effectively transferred to the valve body 2.

The mounting portion 75 is a portion to be mounted on the valve body 2. In the example described in FIG. 6, the mounting portion 75 includes a surface contact portion that makes surface contact with the main body upper surface 2a of the valve main body 2. More specifically, the mounting portion 75 includes a plate-shaped portion protruding from the side wall 72 and extending in a direction along the main body upper surface 2a of the valve main body 2. Therefore, a sufficient contact area between the mounting portion 75 and the valve body 2 is secured, and the heat transfer characteristic from the cover member 70a to the valve body 2 is improved.

In the example described in FIG. 3, the mounting portion 75 extends outward from the side wall 72. Therefore, it is easy to perform the work of attaching the attachment portion 75 to the valve body 2. In the example shown in FIGS. 3 and 6, the mounting portion 75 includes a through hole 76a for receiving a fastening member 76b such as a bolt. The attachment portion 75 is attached to the valve body 2 by inserting the fastening member 76b into the hole portion 28 (see FIG. 2) of the valve body 2 via the through hole 76a.

In the example shown in FIG. 3, the mounting portion 75 is mounted on the upper surface 2a of the main body of the valve main body 2. Then, the cover member 70a and the upper surface 2a of the main body are in surface contact with each other. Alternatively or additionally, the mounting portion 75 may be mounted on the main body side surface 2b of the valve main body 2. Further, the cover member 70a and the side surface 2b of the main body may be in surface contact with each other.

The cover member 70a is made of a material having a high thermal conductivity (high thermal conductivity material). Further, the thermal conductivity of the cover member 70a is preferably higher than the thermal conductivity of air. Therefore, the heat around the power element 6 is endothermic to the valve body 2 via the cover member 70a.
The material of the cover member 70a is preferably a metal, for example, aluminum (in the present specification, "aluminum" includes an aluminum alloy containing aluminum as a main material). The thermal conductivity of the material constituting the cover member 70a is, for example, 10 W / m · K or more, more preferably 50 W / m · K or more, and even more preferably 100 W / m · K or more at room temperature.

The cover member 70a and the upper surface 61a of the upper lid member 61 may be in contact with each other or may be separated from each other. Similarly, the cover member 70a and the side surface of the power element 6 may be in contact with each other or may be separated from each other.

(Second Embodiment)
Next, the expansion valve 1B in the second embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 is a front view showing the expansion valve 1B in the second embodiment. FIG. 8 is a side view showing the expansion valve 1B in the second embodiment. In FIGS. 7 and 8, the same reference numerals as those in FIGS. 1 to 6 indicate the same or equivalent portions, and thus the description thereof will be omitted.

The expansion valve 1B in the second embodiment is different from the expansion valve 1 in the first embodiment in that the heat transfer member 7 is a flexible film. In other respects, the expansion valve 1B in the second embodiment is similar to the expansion valve 1 in the first embodiment.

In this second embodiment, the heat transfer member 7 is a flexible film 70b. The first region AR1 located in the center of the flexible film 70b comes into contact with the exposed portion 6a of the power element 6 (for example, the upper surface 61a of the upper lid member 61), and the second region located at both ends of the flexible film 70b. The AR2 is in contact with the valve body 2 (surface contact) and is fixed by using an adhesive or an appropriate fixing means. In other words, the first region AR1 functions as the first portion 7a arranged around at least a part of the exposed portion 6a of the power element 6, and the second region AR2 is connected to the valve body 2. Functions as part 7b.

Since the heat transfer member 7 is a flexible film 70b, the shape of the heat transfer member 7 can be deformed according to the shape of the exposed portion 6a of the power element 6. In this way, a sufficient contact area between the exposed portion 6a of the power element 6 and the heat transfer member 7 is secured, and the heat transfer efficiency from the exposed portion 6a to the heat transfer member 7 is improved. In the examples shown in FIGS. 7 and 8, the exposed portion 6a of the power element 6 and the heat transfer member 7 (flexible film 70b) are in surface contact with each other. Further, the valve body 2 and the heat transfer member 7 (flexible film 70b) are in surface contact with each other.

The flexible film 70b may include a surface adhesive layer 700. When the flexible film 70b includes the surface adhesive layer 700, the flexible film 70b is passed through the surface adhesive layer 700 to the exposed portion 6a of the power element 6 and / or the valve body 2 (the upper part of the valve body 2). It can be adhered to the side surface, that is, in the vicinity of the return flow path (third flow path) from the evaporator to the compressor. In this case, the connection mechanism between the flexible film 70b and the exposed portion 6a of the power element 6 is simplified.

In the examples shown in FIGS. 7 and 8, the portion of the exposed portion 6a of the power element 6 that contacts the flexible film 70b is the upper surface 61a of the upper lid member 61, but this contacting portion is the upper lid. It may be a portion other than the upper surface 61a of the member 61.

Further, in the examples shown in FIGS. 7 and 8, the portion of the valve body 2 that comes into contact with the flexible film 70b is the side surface 2b of the main body of the valve body 2, but the flexible film 70b of the valve body 2 The portion in contact with the valve body 2 may be the upper surface 2a of the main body of the valve body 2.

Further, in the examples shown in FIGS. 7 and 8, the first end portion 701 of the flexible film 70b is in surface contact with the valve body 2 (more specifically, the first side surface 2b-1 of the valve body 2). , The second end portion 702 of the flexible film 70b is in surface contact with the valve body 2 (more specifically, the second side surface 2b-2 of the valve body 2), and the central portion 703 of the flexible film 70b is It is in surface contact with the exposed portion 6a of the power element 6 (more specifically, the upper surface 61a of the upper lid member 61). Alternatively, the first end portion 701 of the flexible film 70b is in surface contact with the valve body 2, and the second end portion 702 of the flexible film 70b is in surface contact with the exposed portion 6a of the power element 6. May be good.

The flexible film 70b is made of a highly heat conductive material. Further, the thermal conductivity of the flexible film 70b is preferably higher than the thermal conductivity of air.
The material of the flexible film 70b is preferably a thin metal, for example, an aluminum foil (in the present specification, "aluminum" includes an aluminum alloy containing aluminum as a main material). The thermal conductivity of the material constituting the flexible film 70b is, for example, 10 W / m · K or more, more preferably 50 W / m · K or more, and even more preferably 100 W / m · K or more at room temperature. be.

The thickness of the flexible film 70b is not particularly limited, but it is better to be as thick as possible in order to enhance the endothermic action of the film 70b, and conversely, in order to bring it into close contact with the exposed portion formed by the curved surface of the power element 6. Should be thin. Therefore, the thickness of the film 70b can be determined in consideration of both the heat transfer / endothermic action of the film 70b itself and the adhesion of the power element 6 to the exposed curved surface.
In addition, in this specification, the term film is not only in the form of a thin film or a thin-skinned flexible material, but also has a thickness such that it can be adhered to at least a part of a curved surface exposed portion of a power element. Also includes those made of flexible materials.
The size of the flexible film 70b is not particularly limited, but from the viewpoint of suppressing the influence of the atmospheric temperature on the power element 6, the flexible film 70b is the power element 6 in a plan view (top view). It is preferable to cover as wide a range as possible, for example, 50% or more.

Further, the width of the flexible film 70b is not particularly limited. The flexible film 70b may be a wide film or a narrow film, that is, a flexible tape. Furthermore, the flexible film 70b may be one sheet or a plurality of sheets.

(Application example of expansion valve 1)
An application example of the expansion valve 1 will be described with reference to FIG. FIG. 9 is a diagram schematically showing an example in which the expansion valves 1 and 1B in each embodiment are applied to the refrigeration cycle 100. In FIG. 9, the same reference numerals as those in FIGS. 1 to 8 are the same or equivalent parts, and thus the description thereof will be omitted.

In FIG. 9, the first flow path 21 of the expansion valve 1 is connected to the discharge port side of the compressor 101, and the second flow path 22 is connected to the refrigerant introduction side of the evaporator 104. Further, one of the third flow paths 23 is connected to the refrigerant discharge side of the evaporator 104, and the other side is connected to the suction port side of the compressor 101.

In the refrigeration cycle, the refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valves 1 and 1B. The opening area of the orifice 20a is controlled by the power element 6, whereby the adiabatic expanded refrigerant is sent to the evaporator 104, and the evaporator 104 exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator 104 is returned to the compressor 101 side through the third flow path 23.

Next, the operations of the expansion valves 1 and 1B will be described in detail.
When the valve body 3 is seated on the valve seat 20 (in other words, when the expansion valves 1 and 1B are closed), the first flow path 21 on the upstream side of the valve chamber VS and the valve chamber VS The second flow path 22 on the downstream side is in a non-communication state. On the other hand, when the valve body 3 is separated from the valve seat 20 (in other words, when the expansion valves 1 and 1B are in the open state), the refrigerant supplied to the valve chamber VS is the second flow path 22. It is sent out to the evaporator 104 through. The valve body 3 is driven by the operating rod 5 connected to the power element 6.

In the example described in FIG. 9, the second space SP2 between the diaphragm 63 and the receiving member 62 communicates with the third flow path 23. Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the first space SP1 changes according to the temperature and pressure of the refrigerant flowing through the third flow path 23, and the working rod 5 is driven. In other words, in the expansion valve 1 shown in FIG. 9, the amount of the refrigerant supplied from the expansion valve 1 toward the evaporator 104 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1. It will be adjusted.

By the way, in the above description, it is assumed that the heat transfer member 7 is made of a metal such as aluminum, but the present invention is not limited to this, and any material having a high thermal conductivity can be made of resin. It may be made of any material such as ceramic.
Further, a clay-like material having high thermal conductivity may be used to cover at least a part of the power element so as to connect the valve body, and then the clay-like material may be solidified.
As described above, the present invention is not limited to the above-described configuration. Within the scope of the present invention, any combination of the above-described embodiments is possible, and any component of each embodiment can be modified. In addition, any component can be added or omitted in each embodiment.

1, 1B: Expansion valve 2: Valve body 2a: Body top surface 2b: Body side surface 2b-1: First side surface 2b-2: Second side surface 3: Valve body 5: Actuating rod 6: Power element 6a: Exposed part 7: Heat transfer member 7a: 1st part 7b: 2nd part 20: Valve seat 21: 1st flow path (inlet port)
22: Second flow path (exit port)
23: Third flow path (return passage)
24: Biasing member receiving member 28: Hole 32: Valve body supporting member 61: Upper lid member 61a: Upper surface 62: Receiving member 62a: Lower surface 63: Diaphragm 64: Diaphragm support member 70a: Cover member 70b: Flexible film 71 : Top plate 72: Side wall 73: Bottom surface 75: Mounting portion 76a: Through hole 76b: Fastening member 80: Biasing spring 100: Refrigeration cycle 101: Compressor 102: Capacitor 104: Evaporator 700: Surface adhesive layer 701: First end 702: Second end 703: Central part AR1: First area AR2: Second area SP1: First space SP2: Second space VS: Valve chamber

Claims (3)

An inlet port for introducing high-pressure refrigerant condensed by a condenser, a valve chamber communicating with the inlet port, an orifice provided in the valve chamber, an outlet port for leading out the refrigerant expanded by the orifice, and a compressor from an evaporator. A valve body with a return passage through which the refrigerant passes back to
With the valve body arranged inside the valve chamber,
An urging member arranged in the valve chamber and urging the valve body toward the valve seat,
An expansion valve including a power element that drives the valve body against the urging force of the urging member and controls the opening degree of the orifice.
Further example Bei a heat transfer member for transferring heat to ambient temperature of the power element to the valve body,
The heat transfer member is a flexible metal film, and has a first portion that comes into surface contact with the power element . The expansion valve according to claim 1 , wherein the heat transfer member has a second portion that comes into surface contact with the side surface of the main body of the valve body. The expansion valve according to claim 2, wherein the second portion of the heat transfer member is connected in the vicinity of the return passage of the valve body.

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