JP2021127845A - Expansion valve and refrigeration cycle device - Google Patents

Abstract

To provide an expansion valve capable of suppressing or reducing vibration of a valve element itself as a vibration generation source to suppress valve vibration.SOLUTION: An expansion valve comprises: a valve body having a valve chamber 13 that communicates with an inflow path 21 for introducing a refrigerant and communicates with an outflow path 22 for discharging the refrigerant through a throat part 20; a valve element 15 that is arranged in the valve chamber, and changes a refrigerant flow rate by advancing and retreating with respect to a valve seat 14 between a valve closing state of being seated on the valve seat and a valve opening state of being separated from the valve seat; a valve element support part 16 that supports the valve element; an energization member 17 that energizes the valve element toward the valve seat through the valve element support part; an actuation rod 19 that is in contact with the valve element, and moves the valve element in a valve opening direction against the energization force of the energization member; and a drive part that drives the actuation rod. A tip part 19a of the actuation rod forms a narrowed part 31 that narrows a refrigerant flow path at the downstream end part of the throat part, in an expansion valve that is in contact with the valve element through the throat part.SELECTED DRAWING: Figure 2

Description

The present invention relates to an expansion valve and a refrigeration cycle device, and particularly relates to a technique for suppressing valve vibration of an expansion valve provided in a refrigeration cycle such as an air conditioner to prevent generation of abnormal noise.

Refrigeration cycle devices such as car air conditioners are equipped with expansion valves to maximize the capacity of the evaporator. This expansion valve throttles the flow of the refrigerant supplied to the evaporator in response to the temperature of the refrigerant in the outlet side piping of the evaporator, and controls the flow rate to the optimum flow rate.

On the other hand, in such an expansion valve, valve vibration occurs when the opening degree of the valve is small, and this vibration may generate an abnormal noise from the expansion valve. Therefore, a proposal for suppressing valve vibration as in Patent Document 1 below has been conventionally made.

Japanese Unexamined Patent Publication No. 2019-11885

By the way, in the invention described in Patent Document 1, the vibration damping spring enables effective vibration damping by restraining the vibration of the valve support portion and the operating rod, while the additional component that damps the vibration by mechanical damping. It is necessary to newly provide an anti-vibration spring.

Therefore, an object of the present invention is to provide an expansion valve capable of suppressing or reducing the vibration of the valve body itself as a vibration source to suppress the valve vibration.

In order to solve the above problems and achieve the object, the expansion valve according to the present invention has a valve body having a valve chamber that communicates with an inflow path for introducing a refrigerant and also communicates with an outflow path for discharging the refrigerant through a throat portion. And a valve body that is arranged inside the valve chamber and changes the flow rate of the refrigerant by advancing and retreating with respect to the valve seat between the valve closed state seated on the valve seat and the valve open state separated from the valve seat. , The valve body support part that supports the valve body, the urging member that urges the valve body toward the valve seat via the valve body support part, and the urging member that comes into contact with the valve body and resists the urging force by the urging member. An expansion valve that includes an operating rod that moves the valve body in the valve opening direction and a driving unit that drives the operating rod, and the tip of the operating rod is in contact with the valve body through the throat. A narrowed portion for narrowing the flow path of the refrigerant was formed at the downstream end of the portion.

According to the present invention, the inertial force of the refrigerant flowing from the throat to the outflow path causes a delay in the actual flow rate change of the throat with respect to the valve opening / closing operation, and this delay causes or increases the self-excited vibration of the valve. This is done by paying attention to the fact that the valve vibration is suppressed by reducing the inertial force of the refrigerant near the outlet of the throat portion to suppress the vibration generated by the valve body itself. Specifically, it is as follows.

FIG. 7 shows a conventional expansion valve. As shown in this figure, the throat portion 20 connecting the valve chamber 13 and the outflow passage 22 has a straight circular tubular shape having a constant inner diameter. The tip portion 19a of the operating rod 19 penetrates the throat portion 20 and is in contact with the valve body 15. The tip 19a of the operating rod 19 has a cylindrical shape having a constant outer diameter, and a flow path for the refrigerant is between the tip 19a of the operating rod 19 and the inner wall surface of the throat 20. That is, when the valve body 15 is pushed by the operating rod 19 and separated from the valve seat 14, the refrigerant in the valve chamber 13 penetrates into the throat portion 20 from the valve chamber 13 and is between the operating rod 19 and the inner wall of the throat portion 20. It flows out from the throat outlet 20a to the outflow path 22 through the throat.

On the other hand, when the valve body 15 advances toward the valve seat 14 from this valve open state and the valve is gradually closed, the opening area (flow path cross-sectional area) of the valve at the inlet (valve seat portion) of the throat portion 20 is reached. ) Will decrease and the flow rate will decrease. However, since the refrigerant flowing in the valve has an inertial force, the outlet side 20a of the throat portion 20 cannot immediately follow the decrease in the flow rate due to the decrease in the opening area of the throat portion inlet. Therefore, the amount of refrigerant flowing out from the throat outlet 20a is relatively large compared to the amount of refrigerant flowing in from the throat inlet squeezed by the valve body 15, and the pressure in the throat 20 is temporarily lowered. As a result, the pressure difference from the inside of the valve chamber 13 temporarily increases, and a force is applied to the valve body 15 in the valve closing direction. Then, when the force due to this pressure difference is applied at the timing of causing the vibration of the valve body 15, self-excited vibration is generated. Moreover, in the situation where the vibration has already occurred, the vibration will be increased.

On the contrary, when the valve is further opened from the state where the valve is slightly opened, the flow rate at the inlet of the throat portion 20 tends to increase due to the increase in the opening area of the valve. However, on the outlet side 20a of the throat portion 20, it is not possible to immediately follow the increase in the flow rate due to the increase in the opening area of the throat portion entrance. Therefore, the amount of refrigerant outflow from the throat outlet 20a is relatively small compared to the amount of refrigerant inflow from the throat inlet, the pressure in the throat 20 is temporarily increased, and the pressure difference from the valve chamber 13 is increased. Temporarily becomes smaller and a force is applied to the valve body 15 in the valve opening direction. Then, when this force is applied at the timing of causing the vibration or the timing of promoting the vibration, self-excited vibration is generated and the vibration is increased as in the case of the operation in the valve closing direction.

Therefore, in the present invention, a narrowed portion narrowed so as to reduce the cross-sectional area of the flow path of the refrigerant is provided at the downstream end portion (outlet portion of the throat portion) of the throat portion. By forming the narrowed portion, the inertial force of the refrigerant near the outlet of the throat portion can be reduced and its influence can be suppressed, and the temporary fluctuation of the pressure difference between the throat portion and the valve chamber can be reduced. This makes it possible to suppress the generation of self-excited vibration and the increase in vibration as compared with the conventional case. Further, in the present invention, it is not necessary to newly provide a separate member (vibration-proof spring) as in the invention described in Patent Document 1, but it is also possible to use a vibration-proof spring in combination in order to further enhance the vibration-proof effect. ..

As a specific embodiment of the narrowed portion, for example, an enlarged diameter portion whose outer diameter increases toward the downstream side may be provided at the tip end portion of the operating rod. Further, the throat portion may be provided with a reduced diameter portion whose inner diameter decreases toward the downstream side.

Further, the refrigeration cycle apparatus according to the present invention includes a compressor that compresses the refrigerant, a condenser that cools and liquefies the refrigerant compressed by the compressor, and an expansion valve that depressurizes and expands the refrigerant liquefied by the condenser. , A refrigeration cycle device including an evaporator that evaporates and vaporizes the refrigerant expanded under reduced pressure by the expansion valve, and the expansion valve according to the present invention described above is used as the expansion valve.

Although the present invention can be preferably applied to car air conditioners, its use and application are not limited to car air conditioners, and it can be applied to various other refrigeration cycle devices such as room air conditioners and refrigerators.

According to the present invention, since the vibration generated by the valve body itself can be prevented or suppressed, the valve vibration can be suppressed without relying on the anti-vibration spring as an additional component.

Other objects, features and advantages of the present invention will be clarified by the following description of embodiments of the present invention described with reference to the drawings. In each figure, the same reference numerals indicate the same or corresponding parts. Further, the present invention is not limited to these embodiments, and it is clear to those skilled in the art that various modifications can be made within the scope of the claims.

FIG. 1 is a vertical cross-sectional view showing an expansion valve according to a first embodiment of the present invention. FIG. 2 is an enlarged vertical cross-sectional view showing a throat portion (reference numeral A portion in FIG. 1) of the expansion valve (valve closed state) according to the first embodiment. FIG. 3 is a vertical cross-sectional view showing the throat portion of the expansion valve (valve closed state) according to the second embodiment of the present invention in the same manner as in FIG. FIG. 4 is a vertical cross-sectional view showing the throat portion of the expansion valve (valve closed state) according to the third embodiment of the present invention in the same manner as in FIG. FIG. 5 is a vertical cross-sectional view showing the throat portion of the expansion valve (valve closed state) according to the fourth embodiment of the present invention in the same manner as in FIG. FIG. 6 is a conceptual diagram showing a refrigeration cycle device according to a fifth embodiment of the present invention. FIG. 7 is a vertical cross-sectional view showing the throat portion of the conventional expansion valve (valve closed state) in the same manner as in FIG.

[First Embodiment]
The first embodiment of the present invention will be described with reference to FIGS. 1 to 2. Although FIG. 1 shows two-dimensional Cartesian coordinates representing each of the up, down, left, and right directions, the description will be given below based on these directions.

As shown in FIGS. 1 to 2, the expansion valve 11 according to the first embodiment of the present invention includes a valve body 12 having a valve chamber 13 inside, a valve seat 14 formed in the upper part of the valve chamber, and a valve seat 14. A valve body 15 that faces the valve seat 14 and is installed so as to be able to move forward and backward (up and down) with respect to the valve seat 14, a valve body support portion 16 that supports the valve body 15 from below, and a lower surface portion of the valve body 12. A spring receiving member 18 that seals the valve chamber 13 by being mounted on the valve chamber 13 and a valve body 15 that is arranged between the spring receiving member 18 and the valve body supporting portion 16 and the valve body 15 is connected to the valve seat 14 via the valve body supporting portion 16. A coil spring (urging member) 17 that urges upward toward the valve, an operating rod 19 that retracts (moves downward) the valve body 15 from the valve seat 14 against the urging force of the coil spring 17, and a valve body. It has a diaphragm device (driving unit) 24 provided on the upper surface portion of the 12 to move the operating rod 19 up and down. The operating rod 19 extends in the vertical direction inside the valve body 12, the upper end thereof is connected to the diaphragm device 24, and the lower end thereof is in contact with the valve body 15.

Further, the valve body 12 has an inflow path 21 for introducing the refrigerant into the valve chamber 13, an outflow path 22 for discharging the refrigerant from the valve chamber 13 to the outside of the valve 11, and a refrigerant so as to penetrate the upper part of the valve body 12 to the left and right. It is further provided with a return flow path 23 for circulating the water. The details of the return flow path 23 and the diaphragm device 24 will be described in the fifth embodiment described later in which the expansion valve 11 of the present embodiment is used.

Further, the valve body 12 has a throat portion 20 that connects the valve chamber 13 (valve seat 14) and the outflow passage 22. In the present embodiment, the throat portion 20 is formed in a circular tubular shape having a circular horizontal cross section and a constant inner diameter. Further, the tip portion 19a of the operating rod 19 is inserted through the throat portion 20.

The inflow passage 21 and the outflow passage 22 communicate with each other via the valve chamber 13 and the throat portion 20, but the valve body 15 is in contact with the valve seat 14 due to the upward urging force of the coil spring 17, and is seated in a closed state. In (the state shown in FIGS. 1 and 2), the inflow path 21 and the outflow path 22 do not communicate with each other and are cut off. On the other hand, when the valve body 15 moves downward due to the downward pressing force of the operating rod 19 and separates from the valve seat 14, the inflow path 21 and the outflow path 22 communicate with each other. As a result, the refrigerant that has flowed into the valve chamber 13 through the inflow path 21 passes between the valve seat 14 and the valve body 15 and enters the throat portion 20, passes through the throat portion 20, and then exits from the throat portion. It flows into the outflow passage 22 from 20a, is discharged to the outside of the expansion valve 11 through the outflow passage 22, and is introduced into the evaporator 64 (see FIG. 6 described later). Then, the flow rate of the refrigerant is adjusted by changing the distance between the valve body 15 and the valve seat 14.

Further, a narrowed portion 31 for narrowing the flow path of the refrigerant is formed at the upper end portion of the operating rod tip portion 13a. In the present embodiment, the narrowed portion 31 has a round bar shape in which the tip portion 13a of the operating rod arranged in the throat portion 20 has a constant outer diameter smaller than that of the operating rod main body portion 19b (upper portion of the operating rod 19). It is formed by a cylindrical portion 190 and an inverted conical trapezoidal tapered portion 191 having a tapered outer peripheral surface whose outer diameter gradually increases from the upper end of the cylindrical portion 190, and the tapered portion 191 is on the downstream side of the throat portion 20. It is arranged so that it is located at the end (upper end) of the.

With this configuration, according to the present embodiment, the flow path of the refrigerant formed between the operating rod 19 and the inner wall surface of the throat portion 20 is tapered at the upper end portion of the throat portion 20 (in other words, it is tapered. The cross-sectional area of the flow path of the refrigerant can be reduced at the upper end of the throat portion), and the inertial force of the refrigerant near the outlet 20a of the throat portion can be reduced. Therefore, it is possible to reduce the temporary fluctuation of the pressure difference between the throat portion 20 and the inside of the valve chamber 13 as described above, and it is possible to suppress the generation of self-excited vibration and the increase of vibration as compared with the anti-vibration spring or the conventional one. It will be possible. Further, according to the present embodiment, it is only necessary to change the shape of the operating rod tip portion 13a, and it is not necessary to newly provide a separate member such as an anti-vibration spring, which causes an increase in the number of parts and the number of manufacturing processes. Nor. However, it does not prevent the combined use of anti-vibration springs in accordance with the desire to effectively prevent the occurrence of valve vibration even under peculiar conditions.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same components as those in the first embodiment are designated by the same reference numerals, duplicated explanations are omitted, and the differences will be mainly described (the same applies to the subsequent embodiments).

The expansion valve according to the second embodiment of the present invention has a narrowed portion formed by forming the tip portion 19a of the operating rod 19 into a unique shape as in the first embodiment, but is different from the first embodiment. The entire tip 19a of the operating rod was formed into an inverted truncated cone shape to form the narrowed portion 31.

That is, as in the first embodiment, the operating rod tip portion 19a penetrating the circular tubular throat portion 20 having a constant inner diameter is provided with a tapered outer peripheral surface 192 whose outer diameter increases toward the downstream (upward) direction. I made it. As a result, the cross-sectional area of the refrigerant flow path in the throat portion 20 can be reduced toward the outlet 20a of the throat portion 20, and the narrowed portion 31 can be formed at the throat portion outlet 20a.

[Third Embodiment]
Explaining the third embodiment of the present invention with reference to FIG. 4, the narrowed portion 31 is formed by providing the operating rod 19 with a shape peculiar to the first and second embodiments. In such an expansion valve, the narrowed portion 31 is formed by forming the throat portion side into a shape different from the conventional one.

Specifically, as shown in FIG. 4, a tapered surface 200 whose inner diameter decreases toward the downstream (upward) direction, that is, toward the throat outlet 20a, and a tapered surface 200 extending vertically upward from the upper edge of the tapered surface 200. A ring-shaped small-diameter inner wall surface 201 having a constant inner diameter and an inner diameter smaller than the inner diameter of the lower portion of the throat portion 20 constitutes an upper end portion of the throat portion 20. The operating rod tip 19a inserted through the throat 20 has a columnar shape having a constant outer diameter.

With such a narrowed portion 31, the refrigerant flow path in the vicinity of the throat outlet 20a can be narrowed as in the first and second embodiments, and the inertial force of the refrigerant in the portion can be reduced.

[Fourth Embodiment]
Explaining the fourth embodiment of the present invention with reference to FIG. 5, the expansion valve according to the present embodiment has a constricted portion 31 by making the throat portion side different from the conventional shape as in the third embodiment. Is formed.

Specifically, as shown in FIG. 5, the entire inner wall surface of the throat portion 20 is formed into a tapered surface 202 that is narrowed so as to taper toward the throat portion outlet 20a, thereby forming the narrowed portion 31. The operating rod tip 19a inserted into the throat 20 has a columnar shape having a constant outer diameter as in the third embodiment.

[Fifth Embodiment]
As a fifth embodiment of the present invention, a refrigeration cycle device using the expansion valve 11 of the first embodiment will be described.

As shown in FIG. 6, the refrigeration cycle device 41 is liquefied by a compressor (compressor) 42 that compresses the refrigerant, a condenser (condenser) 43 that cools and liquefies the refrigerant compressed by the compressor 42, and a condenser 43. An expansion valve 11 that decompresses and expands the generated refrigerant and an evaporator (evaporator) 44 that evaporates and vaporizes the refrigerant that has been decompressed and expanded by the expansion valve 11 are provided, and the expansion valve 11 according to the first embodiment is used as the expansion valve. do.

In such a refrigeration cycle device 41, the refrigerant pressurized by the compressor 42 is liquefied by the condenser 43 and sent to the expansion valve 11. Further, the refrigerant adiabatically expanded by the expansion valve 11 is sent to the evaporator 44, and the evaporator 44 exchanges heat with the air flowing around the evaporator 44. The refrigerant returning from the evaporator 44 is returned to the compressor 42 through the return flow path 23 of the expansion valve 11.

A high-pressure refrigerant is supplied to the expansion valve 11 from the condenser 43. More specifically, the high-pressure refrigerant sent from the condenser 43 flows into the valve chamber 13 through the inflow path 21. If the valve body 15 is pressed against the valve seat 14 by the coil spring 17 and is seated in the valve closed state, the valve chamber 13 and the outflow passage 22 do not communicate with each other, so that the refrigerant in the valve chamber 13 comes from the expansion valve 11. Not discharged.

On the other hand, when the operating rod 19 moves downward against the urging force of the coil spring 17 and the valve body 15 is retracted from the valve seat 14, the valve chamber 13 and the outflow path 22 are in a communicating state (valve open state). , The refrigerant in the valve chamber 13 is discharged from the outflow passage 22 and sent out to the evaporator 44. The operation of the operating rod 19 is performed by the diaphragm device 24 provided on the upper surface of the valve body 12.

The diaphragm device 24 includes an upper lid member 25, a receiving member 26 having an opening at the center, and a diaphragm (not shown) arranged between the upper lid member 25 and the receiving member 26. The first space surrounded by the upper lid member 25 and the diaphragm is filled with working gas. Further, the upper end of the working rod 19 is connected to the diaphragm, and when the working gas in the first space is liquefied, the working rod 19 is pulled upward by the diaphragm and the liquefied working gas is vaporized. , The actuating rod 19 is pushed down by the diaphragm. In this way, the expansion valve 11 is switched between the valve open state and the valve closed state.

Further, the second space between the diaphragm and the receiving member 26 communicates with the return flow path 23 through the opening in the center of the receiving member. Therefore, the phase (gas phase or liquid phase) of the working gas in the first space changes according to the temperature and pressure of the refrigerant flowing through the return flow path 23, and the working rod 19 is driven according to this change. NS. In this way, the expansion valve 11 automatically adjusts the amount of the refrigerant supplied from the expansion valve 11 toward the evaporator 44 according to the temperature and pressure of the refrigerant returning from the evaporator 44 to the expansion valve 11.

Further, since the refrigerating cycle device 41 of the present embodiment uses the expansion valve 11 of the first embodiment, it is possible to suppress the generation of self-excited vibration and the increase of vibration and prevent the generation of abnormal noise.

In the refrigeration cycle apparatus according to the present embodiment, the expansion valve 11 of the first embodiment is used, but other than the expansion valve 11, the expansion valve according to another embodiment or other components that can be configured based on the present invention. It is also possible to use the expansion valve of.

11 Expansion valve 12 Valve body 13 Valve chamber 14 Valve seat 15 Valve body 16 Valve body support 17 Coil spring (urging member)
18 Spring receiving member 19 Operating rod 19a Tip of operating rod 19b Main body of operating rod 20 Throat 20a Throat outlet 21 Inflow path 22 Outflow path 23 Return flow path 24 Diaphragm device 25 Top lid member 26 Receiving member 31 Narrowing part 41 Refrigeration Cycle device 42 Compressor
43 Capacitor (condenser)
44 Evaporator (evaporator)
190 Cylindrical part 191 Tapered part 192 Tapered outer peripheral surface 200, 202 Tapered surface 201 Small diameter inner wall surface

Claims (4)

A valve body having a valve chamber that communicates with the inflow path for introducing the refrigerant and also communicates with the outflow path for discharging the refrigerant through the throat.
A valve that is arranged inside the valve chamber and changes the flow rate of the refrigerant by advancing and retreating with respect to the valve seat between a valve closed state seated on the valve seat and a valve opened state separated from the valve seat. With the body
A valve body support portion that supports the valve body and
An urging member that urges the valve body toward the valve seat via the valve body support portion, and
An actuating rod that comes into contact with the valve body and moves the valve body in the valve opening direction against the urging force of the urging member.
A drive unit for driving the operating rod is provided.
An expansion valve in which the tip end portion of the operating rod is in contact with the valve body through the throat portion.
An expansion valve characterized in that a constricted portion that narrows the flow path of the refrigerant is formed at the downstream end of the throat portion. The expansion valve according to claim 1, wherein the constricted portion is formed by providing the tip end portion of the operating rod with an enlarged diameter portion whose outer diameter increases toward the downstream side. The expansion valve according to claim 1 or 2, wherein the narrowed portion is formed by providing the throat portion with a reduced diameter portion whose inner diameter decreases toward the downstream side. A compressor that compresses the refrigerant and
A condenser that cools and liquefies the refrigerant compressed by the compressor, and
An expansion valve that decompresses and expands the refrigerant liquefied by the condenser,
A refrigeration cycle apparatus including an evaporator that evaporates and vaporizes the refrigerant that has been decompressed and expanded by the expansion valve.
A refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the expansion valve is the expansion valve according to any one of claims 1 to 3.

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