JP4831808B2 - Expansion valve and air conditioner - Google Patents

Description

  The present invention relates to an expansion valve and an air conditioner, and more particularly to an expansion valve that can reduce noise generated in a throttle passage and an air conditioner having such an expansion valve.

In the expansion valve, when a large amount of refrigerant passes through the throttle passage at the time of operation, there is a problem that high-frequency noise (flute sound) is generated. This is thought to be caused by the generation of vortices in the refrigerant that has passed through the throttle passage and the growth of the vortices, which causes the valve body to vibrate and generate noise.
In this problem, a technique described in Patent Document 1 is known for a conventional expansion valve. A conventional expansion valve has a valve body that is displaced so as to adjust an opening area of a throttle passage hole that decompresses and expands a high-pressure side liquid refrigerant, and a low-pressure side that sends low-pressure side two-phase refrigerant that has passed through the throttle passage hole to an evaporator. In the expansion valve including the two-layer refrigerant passage, the low-pressure side two-phase refrigerant passage is located on the first passage located on the throttle passage hole side and on the downstream side of the refrigerant flow in the first passage, and is disconnected from the first passage. A second passage having a large area, and the first passage includes a projecting member projecting toward the second passage.

JP 2001-263864 A

  However, the one shown in Patent Document 1 attenuates pressure fluctuations in the first passage and the second passage after passing through the throttle passage formed by the valve body, and no consideration is given to noise in the throttle passage. There was no problem.

  An object of this invention is to provide the expansion valve which can reduce the noise which generate | occur | produces in a throttle passage, and the air conditioner which has this expansion valve in view of the said problem.

  In order to achieve the above object, an expansion valve according to the present invention includes an expansion valve main body and a valve body, and a throttle portion for fluid is formed by a seat surface of the expansion valve main body and a side surface of a distal end portion of the valve body. And an expansion valve in which the opening degree of the valve is controlled by the displacement of the valve body, and the axial chamfer dimension a and the radial chamfer dimension b of the seat surface in the axial sectional view of the valve body. Is 0.1 mm or less, and the ratio a / b between the axial chamfer dimension a and the radial chamfer dimension b of the sheet surface is a / b <1.

  In this expansion valve, since the chamfer dimensions a and b of the seat surface are optimized, the fluid vortex generated in the flow direction when passing through the throttle portion is reduced, and the vortex of the fluid on the downstream side of the throttle portion is reduced. Amplification is reduced. Furthermore, since the length of the seat surface in the fluid flow direction is small and flat, it is less likely that the vortex generated in the throttle portion diffuses quickly and strikes the valve body. Thereby, there exists an advantage by which the noise which generate | occur | produces in an aperture part is reduced effectively.

  Further, the expansion valve according to the present invention has an axial cross section of the valve body in a configuration in which the seat surface and the shoulder surface of the valve body come into contact with each other and the throttle portion of the fluid is sealed when the valve is fully closed. When viewed, the inclination angle φ of the shoulder surface with respect to the axial direction is configured to be substantially equal to the inclination angle θ of the seat surface.

  In this expansion valve, since the inclination angle φ of the shoulder surface of the valve body with respect to the axial direction is configured to be substantially equal to the inclination angle θ of the seat surface, the shape and dimensions of the seat surface are optimized as described above. When this is done, the diffusion direction of the fluid vortex on the downstream side of the throttle portion is more suitable. Thereby, there exists an advantage by which the noise which generate | occur | produces in the aperture | diaphragm | squeeze part R3 is reduced effectively.

  In the expansion valve according to the present invention, the valve passage chamber through which the valve body is inserted is formed in the expansion valve body, and the fluid that has passed through the throttle portion expands in the valve passage chamber. The ratio S1 / S2 between the radial sectional area S1 of the valve body and the radial sectional area S2 of the valve passage chamber is S1 / S2 ≧ 0.40.

  In this expansion valve, since the ratio S1 / S2 between the radial cross-sectional area S1 of the valve body and the radial cross-sectional area S2 of the valve passage chamber is optimized, the growth of fluid vortices in the valve passage chamber is suppressed, There is an advantage that noise generated in the throttle portion is more effectively reduced.

  In the expansion valve according to the present invention, the valve passage chamber through which the valve body is inserted is formed in the expansion valve body, and the fluid that has passed through the throttle portion expands in the valve passage chamber. The bending eigenvalue of the valve body is above the audible frequency range.

  In this expansion valve, since the bending eigenvalue of the valve body is higher than the audible frequency, even when the valve body vibrates due to the vortex of the fluid in the valve passage chamber, the noise becomes higher than the audible frequency, which is effective as a noise countermeasure.

  Further, the expansion valve according to the present invention is characterized in that a groove is provided on the side surface of the distal end portion of the valve body so as to intersect the axial direction.

  In this expansion valve, in addition to the above-described invention, since the groove is provided on the side surface of the distal end portion of the valve body so as to intersect the axial direction, the fluid is decomposed by the groove, and the size of the generated vortex can be reduced. . Thereby, since the magnitude | size of the vortex | eddy which flows into a throttle part can be made small, there exists an advantage by which the noise which generate | occur | produces in a throttle part is reduced more effectively.

Further , the expansion valve according to the present invention includes a main body side surface of the valve body, a front end facing surface facing the front end portion of the valve body of the expansion valve body, and a main body facing the main body side surface of the valve body of the expansion valve main body. A groove is provided on at least one of the opposing surfaces so as to intersect the axial direction of the valve body.

  The expansion valve according to the present invention is provided on at least one of the main body side surface of the valve body, the front end facing surface facing the front end portion of the valve body of the expansion valve body, and the main body facing surface facing the main body side surface of the valve body of the expansion valve main body. Since the groove is provided so as to intersect the axial direction of the valve body, the size of the generated vortex can be further reduced, or the vortex having passed through the throttle portion can be quickly reduced. For example, if a groove is provided in the main body side surface of the valve body and / or the main body facing surface that opposes the main body side surface of the expansion valve main body, the vortex that has passed through the throttle portion is decomposed and forcibly reduced. Further, if a groove is provided on the tip-facing surface facing the tip of the valve body of the expansion valve body, the vortex generated by decomposing the fluid passing through the throttle is reduced. Thereby, there exists an advantage by which the noise which generate | occur | produces in an aperture part is reduced more effectively.

  The air conditioner according to the present invention is characterized in that the expansion mechanism of the working refrigerant is constituted by the expansion valve.

  An expansion valve according to the present invention is an expansion valve having a passage communicating with the valve passage chamber via a throttle portion, and a valve body for adjusting the communication state between the passage and the valve passage chamber with the throttle portion. The inclined surface of the chamfered portion of the seat portion formed in the throttle portion that contacts the valve body is formed so as to be substantially parallel to the opposing surface of the valve body that contacts the inclined surface. And

  In the expansion valve according to the present invention, since the chamfer dimensions a and b of the seat surface are optimized, the fluid vortex generated in the flow direction when passing through the throttle portion is reduced, and the fluid on the downstream side of the throttle portion is reduced. Vortex amplification is reduced. Thereby, there exists an advantage by which the noise which generate | occur | produces in an aperture part is reduced effectively.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same. Further, a plurality of modifications described in this embodiment can be arbitrarily combined within the scope obvious to those skilled in the art.

[First embodiment]
1st Embodiment of this invention is described using FIGS.
FIG. 1 is a cross-sectional view showing an expansion valve according to this embodiment. 2-4 is the elements on larger scale which show the throttle part of the expansion valve described in FIG. FIG. 5 is a system configuration diagram showing an application example of the expansion valve described in FIG. 1.

  The expansion valve 1 is, for example, an electronic expansion valve, and includes an expansion valve body 2 and a valve body 3 (see FIG. 1). A passage R1, a passage R2, a throttle portion R3, and a valve passage chamber R4 are formed in the expansion valve main body 2. The passage R1 is a passage serving as a fluid inlet, and the passage R2 is a passage serving as a fluid inlet. These passages R1 and R2 communicate with the valve passage chamber R4 in the expansion valve body 2. The expansion valve 1 is connected to an external element (see FIG. 5) through these passages R1 and R2.

The restricting portion R3 is a passage that restricts the fluid flow path, and is formed on the way from the passage R1 to the valve passage chamber R4. The valve body 3 includes a valve body portion (valve body main body) 33, a distal end portion (a distal end portion of the valve body) 34, and a shoulder portion 35 that connects the valve body portion 33 and the distal end portion 34. The valve body portion 33 has a cylindrical shape, and the shoulder portion 35 and the distal end portion 34 have a truncated conical shape formed in a tapered manner. The length of the tip portion 34 is, for example, approximately 3 mm.
The valve body portion 33 is slidably inserted into the expansion valve main body 2 from the outside, and is disposed so as to penetrate the valve passage chamber R4 and the distal end portion 34 is inserted into the throttle portion R3.
The valve body 3 can be displaced in the axial direction by being driven by, for example, a stepping motor (not shown).

The valve passage chamber R4 of the expansion valve body 2 is provided with a seat portion 22 that is substantially orthogonal to the axial direction of the valve body 3 and a body facing surface 23 that faces the valve body portion 33. The sheet portion 22 is provided with a through hole 24 that communicates with the passage R1 and through which the distal end portion 34 is inserted. A seat surface 21 facing the shoulder portion is formed on the inner portion of the seat portion 22.
The inner peripheral surface of the through hole 24 constitutes a tip facing surface 25 that faces the tip portion 34.
The diameter of the through hole 24 is referred to as the diameter of the expansion valve 1. Here, the aperture is, for example, 1.8 mm. Note that the diameter is not limited to this, and there are various sizes such as 2.4 mm and 3.0 mm.

  Here, the expansion valve 1 can adjust the flow rate and pressure state of the fluid that has entered from either the passage R1 side or the passage R2 side depending on the flow path configuration used. For example, when used in a refrigerant circuit constituting a refrigeration cycle, which will be described later, in the expansion valve 1 during heating, the refrigerant that has flowed into the expansion valve body 2 from the passage R1 has a flow path at the throttle portion R3. By being throttled, it is decompressed and expanded in the valve passage R4 and flows out from the passage R2. On the other hand, during cooling, the refrigerant flow direction is reversed by a four-way valve or the like, so that the refrigerant flowing from the passage R2 side is decompressed by the throttle portion R3 and then flows out to the passage R1 side.

  Further, by changing the axial displacement by the drive control of the valve body 3 when the fluid flows, the flow passage cross-sectional area of the fluid at the throttle portion R3 can be adjusted, and the valve opening degree can be controlled. By controlling the opening degree, the pressure of the fluid flowing into the expansion valve 1 can be adjusted to a required pressure such as an intermediate pressure or a low pressure and can be discharged.

[Sheet face of throttle passage]
In the expansion valve 1, the narrowest portion (the portion where the flow path cross-sectional area is the narrowest) of the throttle portion R <b> 3 is the seat surface 21 of the expansion valve body 2, the tapered surface (side surface) 31 of the distal end portion 34 of the valve body 3, and the shoulder portion. It is comprised by the shoulder surface 32 which is the surrounding surface of 35 (refer FIG. 2). When the valve body 3 is displaced in the axial direction, the clearance between the seat surface 21 and the tapered surface 31 and between the seat surface 21 and the shoulder surface 32 is changed to adjust the fluid flow path cross-sectional area.

  The seat portion 22 of the expansion valve main body 2 is configured to have a substantially right-angle shape (pin angle shape) in the axial cross-sectional view of the valve body 3 (see FIG. 3). Specifically, the chamfer dimensions a and b (the axial chamfer dimension a and the radial chamfer dimension b) of the sheet surface 21 are 0.1 [mm] or less, preferably 0.05 mm or less. The Even with such a configuration, the opening / closing durability performance of the expansion valve 1 is maintained.

  In such a configuration, the vortex becomes smaller corresponding to the fluid scale (in the case of the present embodiment, the chamfer dimension), so that the fluid vortex generated in the flow direction when passing through the throttle portion R3 is reduced. More specifically, in the present embodiment, a configuration is adopted in which the area where the flowing fluid is compressed between the tapered surface 31 and the tapered surface 31 is reduced by reducing the area of the seat surface 21. Thereby, there exists an advantage by which the noise which generate | occur | produces in the aperture | diaphragm | squeeze part R3 is reduced effectively.

The seat surface 21 of the expansion valve main body 2 has a ratio a / b between the chamfer dimension a in the axial direction and the chamfer dimension b in the radial direction as a / b <1 in the axial sectional view of the valve body 3. (See FIG. 3). That is, the inclination angle of the seat surface 21 relative to the axial direction θ (tanθ = b / a) is configured to be 4 5 degrees or more. In addition, although mentioned later for details, it is more preferable that (theta) set to 60 degree | times in this embodiment is more than 60 degree | times.

  In such a configuration, the vortex of the fluid generated in the throttle portion R3 diffuses in the valve passage chamber R4 in the radial direction along the inclination direction of the seat surface 21. At this time, the passage R1 side end portion of the seat surface 21 is closest to the tapered surface 31, but by increasing the inclination angle, the fluid vortex amplification on the downstream side of the throttle portion R3 is reduced. Excitation of the structure (valve element 3 etc.) due to vortex energy is suppressed. Thereby, there exists an advantage by which the noise which generate | occur | produces in the aperture | diaphragm | squeeze part R3 is reduced effectively.

[Relationship between seat surface and tapered surface of valve body]
As shown in FIG. 4B, when the expansion valve 1 is fully closed, the seat surface 21 and the shoulder surface 32 of the valve body 3 come into contact with each other to seal the throttle portion R3. For this reason, it is preferable that the shoulder surface 32 is configured such that the inclination angle φ with respect to the axial direction is substantially equal to the inclination angle θ of the seat surface 21 in a sectional view of the valve body 3 in the axial direction.

  That is, as described above, in the present embodiment, a configuration having the seat surface 21 that is the inclined surface of the chamfered portion of the seat portion 22 formed in the throttle portion R3 that contacts the valve body 3 is employed. It is preferable to form the seat surface 21 so that the seat surface 21 is substantially parallel to the shoulder surface 32, which is the opposing surface of the valve body that is in contact with the seat surface 21, in the axial sectional view of the valve body 3 (FIG. 4A). )reference).

  In such a configuration, when the expansion valve 1 is open, the fluid flowing in from the passage R1 side is guided by the shoulder surface 32 as the throttle portion R3 flows, so that the fluid on the downstream side of the throttle portion R3. The flow path direction is along the inclination direction of the sheet surface 21 (direction of the inclination angle θ). Therefore, if the shape and dimensions of the seat surface 21 and the shoulder surface 32 are optimized to 45 degrees or more, preferably 60 degrees or more as described above, the vortex generated when the fluid flows through the throttle portion R3. Can be suppressed by changing the direction of the flow at the shoulder surface 32, so that the diffusion of the vortex of the fluid on the downstream side of the throttle portion R3 can be promoted. Thereby, there exists an advantage by which the noise which generate | occur | produces in the aperture | diaphragm | squeeze part R3 is reduced effectively.

  Further, in such a configuration, the shoulder surface 32 and the seat surface 21 are in surface contact when the valve is fully closed, so that the sealing performance of the throttle portion R3 when fully closed is compared with the conventional expansion valve in which these are in line contact. Has the advantage of improving.

[Additional items]
In the expansion valve 1, the radial cross-sectional area S1 (= πd ^2/4) in the radial direction of the Bendori chamber R4 sectional area S2 (= πD ^2/4) ratio of S1 / S2 of the valve element 3 is S1 It is preferable that /S2≧0.40. Thereby, since the growth of the vortex of the fluid in the valve passage chamber R4 is suppressed, there is an advantage that the noise generated in the throttle portion R3 is more effectively reduced.

  Moreover, in this expansion valve 1, it is preferable that the expansion valve main body 2 (especially the formation part of the seat surface 21) is stainless steel. In such a configuration, the durability of the seat surface 21 against erosion (erosion) is improved as compared with the case of brass, so that the shape and dimensions of the seat surface 21 optimized as described above are preferably maintained. There are advantages.

  Moreover, in this expansion valve 1, it is preferable that the bending eigenvalue of the valve body 3 is more than an audible frequency. As a result, even when the valve body vibrates due to the vortex of the fluid in the valve passage chamber, the noise becomes higher than the audible frequency, which is effective as a noise countermeasure.

[Air conditioner]
Said expansion valve 1 (1A, 1B) is used as a throttle mechanism of the refrigerant | coolant (fluid) in the air conditioner 10, for example (refer FIG. 5 ).

  The air conditioner 10 includes an outdoor unit 12 disposed outside, an indoor unit 13 disposed indoors, and a control unit 14. The outdoor unit 12 and the indoor unit 13 have heat exchangers 121 and 131, respectively, and these heat exchangers 121 and 131 are connected to each other by a pipe 15. The air conditioner 10 can perform indoor air conditioning, heating, or air conditioning by circulating a refrigerant (fluid) between the heat exchangers 121 and 131 and exchanging heat indoors and outdoors.

  The outdoor unit 12 includes an outdoor heat exchanger 121, an outdoor expansion valve 1A, a compressor 123, an accumulator 124, and a four-way switching valve 125, which are connected by a pipe 15. The outdoor heat exchanger 121 is a device that performs heat exchange of refrigerant with the outside air, and functions as an evaporator during heating operation and as a condenser during cooling operation. The outdoor expansion valve 1A is a valve that restricts the refrigerant flow path, and is mainly used during heating operation. Further, the outdoor expansion valve 1A can adjust the flow rate of the refrigerant in the pipe 15 by adjusting the opening thereof. The compressor 123 has a function of sucking and compressing the refrigerant and increasing the pressure of the refrigerant. The accumulator 124 has a function of temporarily storing excess refrigerant and adjusting the flow rate of the refrigerant. The four-way switching valve 125 has a function of switching between a piping configuration for heating operation and a piping configuration for cooling by switching the connection of the piping 15 in the outdoor unit 12.

  The indoor unit 13 includes an indoor heat exchanger 131 and an indoor expansion valve 1B, which are connected by a pipe 15. The indoor heat exchanger 131 is a device that performs heat exchange of refrigerant with room air, and functions as a condenser during heating operation and as an evaporator during cooling operation. The indoor expansion valve 1B is a valve that throttles the refrigerant flow path, and is mainly used during cooling operation. The indoor expansion valve 1B can adjust the flow rate of the refrigerant in the pipe 15 by adjusting the opening degree. In this air conditioner 10, a plurality of indoor units 13, 13 are installed, and these indoor units 13, 13 can operate independently of each other. Therefore, by installing each indoor unit 13 in a different room, the air in each room is harmonized individually.

  The control unit 14 includes a control unit 141 and various sensors (not shown). The control unit 141 controls each component of the outdoor unit 12 and the indoor unit 13, and in particular, controls the opening degree of the outdoor expansion valve 1A and the indoor expansion valve 1B. The various sensors are installed at the main components of the outdoor unit 12 and the indoor unit 13 and the piping 15 to detect necessary information.

  In this air conditioner 10, the expansion valve 1A of the outdoor unit 12 functions as a refrigerant throttling mechanism during heating operation. On the other hand, the expansion valve 1B of the indoor unit 13 functions as a refrigerant throttling mechanism during the cooling operation.

  Here, as an example, the operation of the air conditioner 10 during heating operation will be described (see FIG. 5). In this air conditioner 10, the heating operation and the cooling operation are switched (not shown) by driving the four-way switching valve 125 and switching the piping configuration in the outdoor unit 12.

  During the heating operation, first, the refrigerant pressurized by the compressor 123 is supplied to the indoor units 13 and 13 in a high-temperature and high-pressure gas state. The refrigerant condenses and liquefies in the indoor heat exchanger 131 to release heat. Thereby, heat exchange is performed and indoor air is warmed. Next, the heat-exchanged refrigerant is returned to the outdoor unit 12 side, and the refrigerant flow path is throttled by the outdoor expansion valve 1A. Then, the refrigerant adiabatically expands in the outdoor heat exchanger 121, evaporates and absorbs heat. Then, the refrigerant returns to the compressor 123 through the four-way switching valve 125 and the accumulator 124. Thereby, a refrigerant | coolant circulates between the outdoor unit 12 and each indoor unit 13 and 13, and indoor heating is performed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The expansion valve 1 according to the present embodiment is different from that of the first embodiment described above in the configuration of the distal end portion 34 of the valve body 3, and is otherwise the same as that of the first embodiment described above. The different tip portion 34 will be described, and the redundant description of the other portions will be omitted.
In addition, the same code | symbol is attached | subjected to the member same as 1st embodiment mentioned above.
The expansion valves (1A, 1B) are used, for example, as a refrigerant (fluid) throttling mechanism in the air conditioner 10 shown in the first embodiment (see FIG. 5 ).
FIG. 6 is a cross-sectional view showing the expansion valve 1 according to this embodiment. FIG. 7 is a partially enlarged view showing the distal end portion 34 of the valve body 3 of the expansion valve shown in FIG.

The tapered surface 31 of the distal end portion 34 is provided with a groove 4 having a triangular cross-sectional shape. The groove 4 is formed in a spiral shape and is provided over substantially the entire area of the tapered surface 31.
The pitch P of the grooves 4 is set to be smaller than at least the radial gap at the time of maximum lift. Here, it is approximately 0.5 mm. Note that the smaller the pitch P, the better.
Further, the depth of the groove 4 is approximately the same as the pitch P.
The inclination angle θ of the spiral in the groove 4 is set so as to deviate by a pitch P by one turn. Note that the inclination angle θ is not limited to this and may be set as appropriate.

In the distal end portion 34 of the valve body 33, a plurality of concave portions and convex portions extending in a direction crossing the axial direction of the valve body 33 are alternately formed.
Therefore, the fluid flowing from the passage R1 into the throttle portion R3 is alternately acted on the convex portions and the concave portions and flows into the throttle portion R3.

In such a configuration, for example, the fluid flowing from the passage R1 into the throttle portion R3 is decomposed by the grooves, and the scale of the fluid is reduced. For this reason, since the magnitude | size of the produced | generated vortex becomes small corresponding to the scale of the fluid, the magnitude | size of the produced | generated vortex can be made small. Since the size of the vortex corresponds to the size of the pitch P, the smaller the pitch P, the better.
Thereby, since the magnitude | size of the vortex | eddy which flows into throttle part R3 can be made small, there exists an advantage by which the noise which generate | occur | produces in throttle part R3 is reduced effectively.
Thus, since the magnitude | size is made small in the generation | occurrence | production stage of a vortex, there exists an advantage by which the noise generate | occur | produced in the aperture | diaphragm | squeeze part R3 is reduced more effectively by the synergistic effect with above-mentioned 1st embodiment. .

In the present embodiment, the groove 4 has a triangular cross section and a spiral shape in terms of workability, but is not limited to this.
For example, as shown in FIG. 8, a plurality of grooves 4 that extend in a direction intersecting the axial direction and surround the tapered surface 31 are provided so as to be substantially parallel to each other, instead of being spiral. Also good.
As for the cross-sectional shape, an appropriate shape such as a semicircle shown in FIG. 9 or a quadrangle shown in FIG. 10 can be used.
Furthermore, as shown in FIG. 11, the distal end portion 34, a plurality of cylindrical bodies stacked state diameter increases toward the tip end is reduced, i.e., it may be stepped.

In the present embodiment, the groove 4 is provided only on the tapered surface 31, but in addition to this, the groove 4 may be provided at a place as follows.
That is, the groove 4 extending in the direction intersecting with the axial direction of the valve body 3 is provided on substantially the entire surface (tip A shown in FIG. 6) of the tip facing surface 25.
With this configuration, the fluid flowing into the throttle portion R3 is further finely decomposed, so that the size of the generated vortex can be further reduced. For this reason, there exists an advantage by which the noise which generate | occur | produces in an aperture part is reduced more effectively.

Further, the axial direction of the valve body 3 is formed on a portion of the main body facing surface 23 on the throttle portion R3 side (location B shown in the figure) and / or on a side surface on the shoulder portion 35 side of the valve body portion 33 (location C shown in FIG. A groove 4 extending in a direction intersecting with is provided.
With this configuration, the vortex that has passed through the throttle portion can be decomposed and forcibly reduced, so that there is an advantage that noise generated in the throttle portion can be more effectively reduced.

It is sectional drawing which shows the expansion valve concerning 1st embodiment of this invention. It is the elements on larger scale which show the throttle part of the expansion valve described in FIG. It is the elements on larger scale which show the throttle part of the expansion valve described in FIG. It is the elements on larger scale which show the throttle part of the expansion valve described in FIG. It is a system block diagram which shows the application example of the expansion valve described in FIG. It is sectional drawing which shows the expansion valve concerning 2nd embodiment of this invention. It is the elements on larger scale which show the front-end | tip part of the valve body of the expansion valve described in FIG. It is sectional drawing which shows another embodiment of the front-end | tip part of the expansion valve concerning 2nd embodiment of this invention. It is sectional drawing which shows another embodiment of the front-end | tip part of the expansion valve concerning 2nd embodiment of this invention. It is sectional drawing which shows another embodiment of the front-end | tip part of the expansion valve concerning 2nd embodiment of this invention. It is a front view which shows another embodiment of the front-end | tip part of the expansion valve concerning 2nd embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Expansion valve 2 Expansion valve main body 21 Seat surface 23 Main body opposing surface 25 Tip part opposing surface 3 Valve body 31 Tapered surface 32 Shoulder surface 34 Tip part 4 Groove 10 Air conditioner R1 High pressure side passage R2 Low pressure side passage R3 Restriction part R4 Valve Passing through

Claims (7)

The expansion valve body includes a valve body, and a fluid throttle is formed by the seat surface of the expansion valve body and the side surface of the tip of the valve body, and the opening degree of the valve is controlled by the displacement of the valve body. Expansion valve,
The axial chamfer dimension a and the radial chamfer dimension b of the seat surface are 0.1 mm or less and the axial chamfer dimension a and the diameter of the seat surface in the axial cross-sectional view of the valve body. An expansion valve characterized in that the ratio a / b to the chamfer dimension b in the direction is a / b <1. In the configuration where the seat surface and the shoulder surface of the valve body are in contact with each other when the valve is fully closed, and the fluid throttle is sealed,
2. The expansion valve according to claim 1 , wherein an inclination angle φ of the shoulder surface with respect to the axial direction is substantially equal to an inclination angle θ of the seat surface in an axial sectional view of the valve body. In the configuration in which the valve passage chamber through which the valve body is inserted is formed in the expansion valve body, and the fluid that has passed through the throttle portion expands in the valve passage chamber.
The expansion valve according to claim 1 or 2 , wherein a ratio S1 / S2 between a radial cross-sectional area S1 of the valve body and a radial cross-sectional area S2 of the valve passage chamber is S1 / S2≥0.40. In the configuration in which the valve passage chamber through which the valve body is inserted is formed in the expansion valve body, and the fluid that has passed through the throttle portion expands in the valve passage chamber.
The expansion valve according to any one of claims 1 to 3 , wherein a bending eigenvalue of the valve body is not less than an audible frequency region. The expansion valve according to any one of claims 1 to 4 , wherein a groove is provided on a side surface of a tip portion of the valve body so as to intersect in an axial direction. The valve on at least one of the main body side surface of the valve body, the front surface facing the front end portion of the valve body of the expansion valve main body, and the main body facing surface of the expansion valve main body facing the main body side surface of the valve body. The expansion valve according to claim 5 , wherein a groove is provided so as to intersect the axial direction of the body. An air conditioner, wherein the expansion valve according to any one of claims 1 to 6 constitutes a throttle mechanism for the working refrigerant.

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