JP2011002140A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise when a liquid refrigerant with which air bubbles are mixed is introduced.SOLUTION: Since a refrigerant flow hole 17 is provided on an inlet side of a valve chamber 18 so as to be shifted from the center of a high pressure inlet port 13 to the gravity direction, the liquid refrigerant made to flow on the lower side of the high pressure inlet port 13 is made to pass and air bubbles made to flow on the upper side are blocked by a wall 37. A valve support 22 is arranged to block a flow of the refrigerant within the valve chamber 18, and a notch part or opening part having a small flow passage cross section is provided in the valve support 22, so as to atomize the air bubbles entering to the valve chamber 18. A corner inner wall 32 leading to an orifice 19 is formed to have a round shape, so as to make the atomized air bubbles flow smoothly and suppress generation of new air bubbles.

Description

  The present invention relates to an expansion valve, and is used in particular in a refrigeration cycle of an air conditioner for automobiles, and decompresses and expands a normal temperature / high pressure liquid refrigerant to form a low temperature / low pressure mist-like refrigerant, and the refrigerant at the evaporator outlet. The present invention relates to an expansion valve having a function of adjusting a flow rate of a refrigerant supplied to an evaporator so that an evaporation state has an appropriate degree of superheat.

  Automobile air conditioners use a refrigeration cycle that uses thermal energy when the refrigerant is confined in a sealed pipe and the refrigerant is continuously subjected to a phase change from gas to liquid and a phase change from liquid to gas. ing. In this refrigeration cycle, an expansion valve is a squeezed and expanded liquid refrigerant at room temperature and high pressure to form a liquid refrigerant at low temperature and low pressure.

FIG. 17 is a central longitudinal sectional view showing a configuration example of a conventional expansion valve.
The expansion valve 100 constitutes a refrigeration cycle by piping the compressor 101, the condenser 102, the receiver / dryer 103, and the evaporator 104 so that the refrigerant circulates. The refrigerant is compressed by the compressor 101 to become a high-temperature / high-pressure gas refrigerant, is condensed by releasing heat from the condenser 102, becomes a room-temperature / high-pressure liquid refrigerant, and is accumulated in the receiver / dryer 103. The liquid refrigerant separated into gas and liquid by the receiver / dryer 103 is subjected to throttle expansion and flow control by the expansion valve 100 to become a low-temperature / low-pressure vapor refrigerant. The vaporized refrigerant is evaporated by absorbing heat from the air in the passenger compartment in the evaporator 104, becomes a normal temperature / low pressure gas refrigerant, and is returned to the compressor 101.

  The expansion valve 100 has a high-pressure inlet port 111 that receives liquid refrigerant from the receiver / dryer 103, and the high-pressure inlet port 111 is connected to the valve chamber 113 via a refrigerant flow hole 112 having a smaller passage cross-sectional area than this. Has been. The valve chamber 113 communicates with the low pressure outlet port 115 via the orifice 114. A ball-shaped valve body 116 that opens and closes the orifice 114 is disposed in the valve chamber 113. The valve body 116 is supported by a valve support 117 and is urged by a compression coil spring 118 in a direction to close the orifice 114. ing.

  The expansion valve 100 also has a low-pressure inlet port 119 connected to the outlet of the evaporator 104 and a low-pressure outlet port 120 connected to the inlet of the compressor 101. The low-pressure inlet port 119 and the low-pressure outlet port 120 are refrigerants. The return passage 121 communicates.

  A power element 122 is provided at the upper end of the expansion valve 100. The power element 122 includes a diaphragm 123 that senses the temperature and pressure of the refrigerant flowing through the refrigerant return passage 121 and whose center portion is displaced in the axial direction in accordance with the temperature and pressure. The displacement of the diaphragm 123 is transmitted to the valve body 116 through the shaft 124.

  According to the expansion valve 100 having the above configuration, the liquid refrigerant introduced into the high-pressure inlet port 111 enters the valve chamber 113 through the refrigerant flow hole 112, and the clearance between the valve body 116 and its valve seat and the orifice 114 are set. To the low pressure outlet port 115. When the refrigerant passes through the gap between the valve body 116 and the valve seat and the narrow orifice 114 and exits to the wide low-pressure outlet port 115, the refrigerant is expanded into a low-temperature / low-pressure vapor refrigerant, and the low-pressure outlet port 115. To the evaporator 104. The gas refrigerant evaporated by the evaporator 104 is returned to the compressor 101 through the refrigerant return passage 121 of the expansion valve 100. When the gas refrigerant passes through the refrigerant return passage 121, its temperature and pressure are detected by the power element 122, and the diaphragm 123 is displaced accordingly. The displacement is transmitted to the valve body 116 via the shaft 124, and the valve The flow rate of the refrigerant supplied to the evaporator 104 is controlled by adjusting the gap between the body 116 and its valve seat. As a result, the refrigerant supplied to the evaporator 104 is controlled to a flow rate at which the degree of superheat of the refrigerant at the outlet of the evaporator 104 maintains a predetermined value.

  By the way, when the refrigerant that has exited the condenser 102 is not sufficiently subcooled, such as immediately after the start of the automobile air conditioner, or when the refrigerant that has exited the condenser 102 without heat exchange is present, such as immediately after the operation is stopped. When the refrigerant flows toward the expansion valve 100 in order to equalize the pressure in the refrigeration cycle, the refrigerant introduced into the high-pressure inlet port 111 may be in a gas-liquid mixed state in which bubbles are mixed. In the case of a liquid refrigerant in which bubbles are mixed, it is known that the bubbles burst in the expansion valve and generate noise. On the other hand, it has been proposed that a throttle portion is provided in front of the valve chamber as in the refrigerant circulation hole 112 to prevent bubbles that are the cause of noise from entering the valve chamber (for example, Patent Documents). 1). Still, for the air bubbles that have entered the valve chamber, the refrigerant introduced into the valve chamber is passed through the gaps between the lines of the compression coil springs to make the air bubbles finer, thereby reducing the noise caused by the collapse of the air bubbles. It is also proposed to plan (see, for example, Patent Document 2). Furthermore, it is also known that noise is reduced by using a taper wall as a refrigerant passage from the valve chamber to the valve portion to mitigate the impact of bubbles and prevent the foam from collapsing (see, for example, Patent Document 3).

JP-A-8-159616 JP 2008-180475 A JP-A-8-145506

  However, in the configuration in which the bubbles that have entered the valve chamber together with the liquid refrigerant are refined using the existing compression coil spring, the pitch between the lines of the compression coil spring is constantly changing according to the valve opening, There is a problem that it is difficult to produce a certain effect. In addition, since the compression coil spring is not arranged so as to allow all the refrigerant introduced into the valve chamber to pass therethrough, for the bubbles that flow through the gap between the inner wall of the valve chamber and the compression coil spring, It is not miniaturized and noise is not reduced.

  This invention is made | formed in view of such a point, and it aims at providing the expansion valve which reduced the noise when the liquid refrigerant mixed with the bubble was introduced.

  In order to solve the above-described problems, the present invention introduces an expansion valve that includes a valve section that squeezes and expands the refrigerant and a power element that controls the opening degree of the valve section in accordance with the pressure and temperature of the refrigerant. An expansion valve is provided with a bubble inflow suppressing means that is disposed at a position where the entire amount of the refrigerant passes toward the valve portion and suppresses bubbles mixed in the refrigerant from flowing into the valve portion. Provided.

  According to such an expansion valve, since the bubble inflow suppression means suppresses the inflow of bubbles to the valve portion with respect to all the refrigerant flowing into the valve portion, there is no large bubble in the refrigerant sent to the valve portion. Therefore, no loud popping sound is generated. Moreover, even if air bubbles are mixed in the refrigerant sent to the valve portion, it is a small air bubble, so even if it bursts in the middle, the noise caused by it is extremely small. For this reason, this expansion valve can greatly reduce noise due to bursting of bubbles even when liquid refrigerant mixed with bubbles is introduced.

  The expansion valve having the above configuration is provided with the bubble inflow suppressing means at a position where the entire amount of the introduced refrigerant passes, so that a large bubble with a loud sound when bursting into the refrigerant sent to the valve portion is not mixed. Even if it is mixed, the noise when bursting is a small bubble that is extremely small, so that the noise during mixing of the bubble can be greatly reduced.

  In expansion valves that have bubble fragmentation means as bubble inflow suppression means, even if large bubbles enter the valve chamber, they are subdivided by the bubble fragmentation means, greatly reducing the passage sound of refrigerant passing through the valve section. There is an advantage that you can.

  Further, in the expansion valve having the bubble blocking means as the bubble inflow suppressing means, the bubble blocking means sends the liquid refrigerant into the valve chamber while blocking large bubbles mixed in the liquid refrigerant introduced into the high pressure inlet port. Therefore, there is no advantage that large bubbles do not enter the valve chamber, so that the passage sound of the refrigerant passing through the valve portion can be greatly reduced.

  Furthermore, since the inner wall leading to the orifice of the valve chamber has an R shape, the refrigerant can smoothly flow into the orifice, so that the flow of the refrigerant is not greatly disturbed, so that bubbles are not easily generated. Yes. For this reason, even if a refrigerant in which small bubbles are mixed is introduced into the valve chamber, the bubbles do not grow and pass through the valve portion as they are, and the passage noise of the refrigerant in the valve portion can be reduced. .

It is a center longitudinal cross-sectional view which shows the structural example of the expansion valve which concerns on 1st Embodiment. It is a figure which shows a valve support, Comprising: (A) is a top view of a valve support, (B) is aa arrow sectional drawing of the valve support in (A). It is a figure which shows the modification of a valve support, Comprising: (A) is a top view of a valve support, (B) is bb arrow sectional drawing of the valve support in (A). It is a center longitudinal cross-sectional view which shows the structural example of the expansion valve which concerns on 2nd Embodiment. It is a figure which shows the principal part of the expansion valve which concerns on 2nd Embodiment, (A) is a front view of a bubble subdivision part, (B) is a center longitudinal cross-sectional view of a bubble subdivision part, (C) is It is cc arrow sectional drawing of FIG. It is a center longitudinal cross-sectional view which shows the structural example of the expansion valve which concerns on 3rd Embodiment. It is dd arrow sectional drawing of FIG. It is a center longitudinal cross-sectional view which shows the structural example of the expansion valve which concerns on 4th Embodiment. It is a figure which shows the example of a toothed ring, Comprising: (A) is a top view of a toothed ring, (B) is ee arrow sectional drawing of (A). It is the side view which looked at the expansion valve which concerns on 1st Embodiment from the side with a high pressure inlet port. It is the side view which looked at the expansion valve which concerns on 5th Embodiment from the side with a high pressure inlet port. It is a center longitudinal cross-sectional view which shows the expansion valve which concerns on 6th Embodiment. It is the figure which looked at the expansion valve which concerns on 6th Embodiment from the side with a high pressure inlet port. It is a center longitudinal cross-sectional view which shows the expansion valve which concerns on 7th Embodiment. It is the figure which looked at the expansion valve which concerns on 7th Embodiment from the side with a high pressure inlet port. It is a center longitudinal cross-sectional view which shows the expansion valve which concerns on 8th Embodiment. It is a center longitudinal cross-sectional view which shows the structural example of the conventional expansion valve.

  Hereinafter, an embodiment of the present invention is used in a refrigeration cycle of an air conditioner for an automobile, and a liquid refrigerant at normal temperature and high pressure is decompressed and expanded to form a low-temperature and low-pressure mist-like refrigerant, and at the evaporator outlet. A case where the present invention is applied to a temperature-type expansion valve having a function of adjusting the flow rate of the refrigerant supplied to the evaporator so that the evaporation state has an appropriate degree of superheat will be described in detail with reference to the drawings.

FIG. 1 is a central longitudinal sectional view showing a configuration example of an expansion valve according to the first embodiment.
The expansion valve 10 is a temperature type expansion valve provided with a main body 11 that accommodates the valve portion and a power element 12 that controls the valve portion in response to the temperature and pressure of the refrigerant. The main body 11 includes a high-pressure inlet port 13 that receives high-pressure refrigerant, a low-pressure outlet port 14 that leads out low-pressure refrigerant, a low-pressure inlet port 15 that receives refrigerant that has exited the evaporator, and a low-pressure outlet port 16 that returns the refrigerant to the compressor. And are provided.

  The high-pressure inlet port 13 is connected to a cylindrical valve chamber 18 via a refrigerant flow hole 17 having a smaller passage cross-sectional area. The valve chamber 18 is communicated with the low pressure outlet port 14 via the orifice 19. The end of the orifice 19 on the valve chamber 18 side is a valve seat 20, and a ball-shaped valve body 21 is disposed in the valve chamber 18 so as to be seated on the valve seat 20. The valve body 21 and the orifice 19 constitute a valve portion of the expansion valve 10.

  The valve body 21 is supported by a valve support 22, and the valve support 22 is urged by a compression coil spring 23 that is an elastic body in a direction in which the valve body 21 is seated on the valve seat 20. The compression coil spring 23 is received by an adjustment screw (biasing force adjusting member) 24 that is screwed into the main body 11 on the side opposite to the valve support 22, and adjusts the screwing amount of the adjustment screw 24. Thus, the spring load for biasing the valve support 22 in the direction of closing the orifice 19 is adjusted. As a result, the set value of the expansion valve 10 is adjusted, and the superheat degree of the refrigerant at the outlet of the evaporator to be controlled by the expansion valve 10 is set.

  The main body 11 of the expansion valve 10 also has a refrigerant return passage 25 that communicates between the low-pressure inlet port 15 and the low-pressure outlet port 16, and the refrigerant flowing through the refrigerant return passage 25 is disposed at the upper end of the figure. A power element 12 for sensing temperature and pressure is provided. The power element 12 is partitioned by a diaphragm 26 and has a temperature sensing chamber 27 in which a predetermined gas is sealed. A disk 28 is disposed on the lower surface of the diaphragm 26 in the figure. A shaft 29 that transmits the displacement of the diaphragm 26 to the valve body 21 is disposed below the disk 28. The upper portion of the shaft 29 is held by a holding member 30 disposed across the refrigerant return passage 25. The lower chamber of the power element 12 partitioned by the diaphragm 26 communicates with the refrigerant return passage 25 through a gap in the head of the holding member 30 so that the refrigerant flowing through the refrigerant return passage 25 is introduced. ing. In addition, a spring 31 that applies a lateral load to the shaft 29 is provided at the head of the holding member 30 to prevent the valve body 21 from vibrating in the opening and closing direction due to fluctuations in the high-pressure refrigerant.

  According to the expansion valve 10 having the above configuration, the liquid refrigerant introduced into the high-pressure inlet port 13 enters the valve chamber 18 through the refrigerant flow hole 17, and the clearance between the valve seat 20 and the valve body 21 and the orifice 19 to the low pressure outlet port 14. At this time, the refrigerant is squeezed and expanded to become a low-temperature / low-pressure vapor refrigerant, and is supplied from the low-pressure outlet port 14 to the evaporator. The gas refrigerant evaporated by heat exchange with the passenger compartment air in the evaporator enters the low-pressure inlet port 15, passes through the refrigerant return passage 25, and returns to the compressor from the low-pressure outlet port 16. When the gas refrigerant passes through the refrigerant return passage 25, its temperature and pressure are detected by the power element 12, and the diaphragm 26 is displaced accordingly. The displacement of the diaphragm 26 is transmitted to the valve body 21 through the disk 28 and the shaft 29, and the valve lift from the valve seat 20 of the valve body 21 is adjusted to control the flow rate of the refrigerant supplied to the evaporator. In this way, the expansion valve 10 controls the flow rate so that the degree of superheat of the refrigerant at the outlet of the evaporator maintains a predetermined value, and supplies it to the evaporator.

  Here, the components around the valve chamber 18 into which the high-pressure refrigerant is introduced will be described in detail. First, the valve support 22 arranged in the valve chamber 18 and supporting the valve body 21 will be described.

2A and 2B are views showing the valve support, in which FIG. 2A is a plan view of the valve support, and FIG. 2B is a cross-sectional view of the valve support in FIG.
The valve support 22 has a cylindrical portion 22a for supporting the valve body 21 on the upper end of the center, and an annular spring receiving portion 22b extending radially outward from the upper end of the cylindrical portion 22a. Yes. The spring receiving portion 22b is formed like a gear with a plurality of cutout portions 22c arranged uniformly in the circumferential direction on the outer periphery thereof. The outer diameter of the spring receiving portion 22b is smaller than the inner diameter of the valve chamber 18 so that the valve support 22 supported by the compression coil spring 23 does not hit the inner wall of the valve chamber 18 even if the valve support 22 is displaced in the opening / closing direction of the valve portion. Is formed. In order to increase the efficiency of the assembly operation of the expansion valve 10, the valve support 22 and the valve body 21 are preferably fixed to each other by welding.

  When the valve support 22 is disposed in the valve chamber 18, the notch 22 c functions as a bubble inflow suppressing unit, and more specifically, functions as a bubble subdividing unit. That is, when a refrigerant mixed with large bubbles flows into the valve chamber 18, the liquid refrigerant passes through the notch 22c of the valve support 22 as it is, and the large bubbles are subdivided into the size of the notch 22c. Will be passed. If the bubbles are subdivided, even if they burst and collapse, the resulting noise is greatly reduced.

  3A and 3B are diagrams showing a modification of the valve support, in which FIG. 3A is a plan view of the valve support, and FIG. 3B is a cross-sectional view of the valve support in FIG. In FIG. 3, the same components as those shown in FIG. 2 are denoted by the same reference numerals.

  According to the valve support 22 of this modification, a plurality of openings 22d are equally drilled in the circumferential direction in the vicinity of the outer periphery of the spring receiving portion 22b. The opening 22d functions as bubble fragmentation means in the valve support 22. That is, large bubbles are subdivided into the size of the opening 22d when passing through the opening 22d.

  Further, referring back to FIG. 1, the valve chamber 18 has an R-shaped corner inner wall 32 having no flat surface from the position where the valve support 22 is installed to the valve seat 20. The R-shaped corner inner wall 32 can be processed by a ball end mill.

  By making the corner inner wall 32 of the valve chamber 18 on the side where the orifice 19 and the valve seat 20 are formed into an R shape, the refrigerant that has passed through the notch 22c or the opening 22d of the valve support 22 is not disturbed and is smooth. Will flow into the orifice 19. Thus, the refrigerant flow is not disturbed before flowing into the orifice 19 and the refrigerant does not peel off from the corner inner wall 32, so that no bubbles are generated. The refrigerant is less disturbed and the flow noise of the refrigerant can be reduced.

  FIG. 4 is a central longitudinal sectional view showing a configuration example of an expansion valve according to the second embodiment, FIG. 5 is a view showing a main part of the expansion valve according to the second embodiment, and FIG. The front view of a bubble subdivision part, (B) is the center longitudinal cross-sectional view of a bubble subdivision part, (C) is cc arrow sectional drawing of FIG. In FIG. 4, the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve 10a according to this embodiment, the cylindrical bubble subdividing member 33 is fitted into the valve chamber 18 into which the refrigerant is introduced so as to block the flow of the refrigerant. The tubular bubble subdividing member 33 is formed in such a size that end portions 33 a and 33 b at both ends in the axial direction are fitted to the inner wall of the valve chamber 18. As shown in (A), (B), and (C) of FIG. 5, the axial intermediate portion 33 c of the cylindrical bubble subdividing member 33 is recessed in a circumferential groove shape, and A plurality of slits 33d elongated in the axial direction are evenly arranged in the circumferential direction. Since this cylindrical bubble subdividing member 33 has a recessed intermediate portion 33c, when fitted into the valve chamber 18, an annular passage is formed with the inner wall of the valve chamber 18, and this annular passage is formed in the annular passage. The refrigerant circulation hole 17 is connected.

  The entire amount of the refrigerant introduced into the high-pressure inlet port 13 is introduced into the annular passage through the refrigerant circulation hole 17, and is introduced from the entire circumference of the annular passage into the space where the valve element 21 is disposed through the slit 33d. . Therefore, even if large bubbles are mixed in the refrigerant introduced into the high-pressure inlet port 13, such bubbles are first suppressed from flowing into the annular passage from the refrigerant circulation hole 17, and further to the annular passage. Even if there are inflowing bubbles, the bubbles are subdivided when passing through the slit 33d.

  FIG. 6 is a central longitudinal sectional view showing a configuration example of an expansion valve according to the third embodiment, and FIG. 7 is a sectional view taken along the line dd in FIG. 6 and 7, the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve 10b according to this embodiment, the bubble fragmentation means as the bubble inflow suppression means forms the inner wall of the valve chamber 18 in a shape like an internal gear. That is, the plurality of ribs 34 extending in the axial direction are equally arranged on the inner wall of the valve chamber 18 in the circumferential direction. Thus, as shown in FIG. 6, in the valve chamber 18, a passage having a small passage cross-sectional area is formed by the outer peripheral surface of the valve support 22 and the valley between the adjacent ribs 34, and this is the bubble fragmentation means. Function as.

  When the refrigerant introduced into the valve chamber 18 from the high-pressure inlet port 13 through the refrigerant circulation hole 17 passes between the inner wall surface of the valve chamber 18 and the valve support 22, passage of large bubbles is suppressed. It will be subdivided into small bubbles.

  FIG. 8 is a central longitudinal sectional view showing a configuration example of an expansion valve according to the fourth embodiment, FIG. 9 is a view showing an example of a toothed ring, (A) is a plan view of the toothed ring, B) is a sectional view taken along the line ee of FIG. In FIG. 8, the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve 10c according to this embodiment, the bubble fragmentation means is configured by adding one separate part. That is, a toothed ring 35 is disposed between a valve support 22 that supports the valve body 21 so as to open and close the orifice 19 and a compression coil spring 23 that urges the valve support 22 in the valve closing direction. ing. As shown in FIGS. 9A and 9B, the toothed ring 35 includes a ring portion 35a and a plurality of protrusions 35b arranged on the outer periphery thereof. In this embodiment, the protrusion 35b of the toothed ring 35 is bent at the tip, but may have a straight shape.

  When the refrigerant introduced into the valve chamber 18 from the high-pressure inlet port 13 through the refrigerant flow hole 17 passes between the inner wall surface of the valve chamber 18 and the toothed ring 35, the passage of large bubbles is suppressed. Is done. At the same time, the passage formed by the inner wall of the valve chamber 18 and the valley between the protrusions 35b functions as the bubble subdividing means, and allows large bubbles to be subdivided and passed. Since this expansion valve 10c has a configuration in which only one toothed ring 35, which is a separate component, is added, it can be easily applied to an existing expansion valve.

Next, a bubble damming means which is another example of the bubble inflow suppressing means will be described.
FIG. 10 is a side view of the expansion valve according to the first embodiment as viewed from the side having the high-pressure inlet port.

  This expansion valve 10 is particularly in the case where the mounting posture in which the power element 12 is mounted on the vehicle with the power element 12 up is vertical, and the boundary between the high pressure inlet port 13 of the expansion valve 10 and the valve chamber 18 The center of the refrigerant circulation hole 17 is located at a position shifted in the gravity direction 36 from the center of the high-pressure inlet port 13. That is, when the expansion valve 10 is attached to the vehicle in a vertical posture, the refrigerant circulation hole 17 is arranged so as to move in the gravity direction 36 from the center of the high-pressure inlet port 13. The upper side of the refrigerant circulation hole 17 is a wall 37, and is configured to dam the bubbles floating on the upper surface of the liquid refrigerant in the high-pressure inlet port 13.

  The expansion valve 10 is configured such that when a refrigerant mixed with bubbles is introduced into the high-pressure inlet port 13, the liquid refrigerant flows below the high-pressure inlet port 13, and the bubbles float above the liquid refrigerant. We are using. Therefore, by installing the refrigerant circulation hole 17 on the lower side with respect to the mounting posture of the expansion valve 10, the refrigerant circulation hole 17 allows the liquid refrigerant flowing under the high-pressure inlet port 13 to pass therethrough, and the wall 37 , Will block the passage of bubbles. Thereby, since the approach of the bubble to the valve chamber 18 is significantly reduced, the noise due to the burst of the bubble can be greatly reduced.

  FIG. 11 is a side view of the expansion valve according to the fifth embodiment as viewed from the side having the high-pressure inlet port. In FIG. 11, the same or equivalent components as those shown in FIG. 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  This expansion valve 10d is in particular when the power element 12 is attached to the vehicle in a state where the power element 12 is on the left side, and the expansion valve 10d is in a horizontal orientation. The refrigerant circulation hole 17 at the boundary is installed at a position where the center thereof moves in the direction of gravity 36 from the center of the high-pressure inlet port 13.

  Also in this case, the refrigerant circulation hole 17 allows only the liquid refrigerant flowing under the high-pressure inlet port 13 to pass therethrough, and the wall 37 blocks the bubbles floating above the liquid refrigerant and prevents passage of the refrigerant circulation hole 17. It will be. As a result, the intrusion of bubbles into the valve chamber 18 is greatly reduced, and the burst sound of bubbles in the valve chamber 18 is greatly reduced.

  FIG. 12 is a central longitudinal sectional view showing an expansion valve according to the sixth embodiment, and FIG. 13 is a view of the expansion valve according to the sixth embodiment as viewed from the side having the high-pressure inlet port. 12 and 13, the same or equivalent components as those shown in FIGS. 1 and 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve 10 e, the refrigerant flow hole 17 is formed by processing the adjustment member accommodation chamber 38 that accommodates the high-pressure inlet port 13 and the adjustment screw 24. That is, the high-pressure inlet port 13 is formed by drilling a hole in the side surface of the main body 11, and the adjusting member accommodating chamber 38 is formed by drilling a hole having a larger diameter than the valve chamber 18 and coaxially with the valve chamber 18. When the tip of the hole of the adjustment member housing chamber 38 is crossed with the tip of the high pressure inlet port 13, the semicircular refrigerant circulation hole 17 is formed at the lower back of the high pressure inlet port 13 as shown in FIG. It is formed.

  Here, when a refrigerant mixed with bubbles is introduced into the high-pressure inlet port 13, only the liquid refrigerant flowing on the lower side flows through the refrigerant circulation hole 17 to the valve chamber 18, and the large bubbles floating in the liquid refrigerant are The wall 37 prevents passage to the valve chamber 18.

  FIG. 14 is a central longitudinal sectional view showing an expansion valve according to the seventh embodiment, and FIG. 15 is a view of the expansion valve according to the seventh embodiment as viewed from the side having the high-pressure inlet port. 14 and 15, the same or equivalent components as those shown in FIGS. 12 and 13 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve 10 f, the refrigerant flow hole 17 is formed by processing the high-pressure inlet port 13 and the valve chamber 18. That is, the high-pressure inlet port 13 is formed by drilling a hole in the side surface of the main body 11, and the valve chamber 18 is formed by drilling a hole coaxially with the adjusting member accommodating chamber 38. As shown in FIG. 15, the lower end of the high-pressure inlet port 13 is made by crossing the tip of the hole in the valve chamber 18 with the tip of the high-pressure inlet port 13 by shifting the hole toward the power element 12 side. A semicircular refrigerant circulation hole 17 is formed in the back.

  Here, when a refrigerant mixed with bubbles is introduced into the high-pressure inlet port 13, only the liquid refrigerant flowing on the lower side flows through the refrigerant circulation hole 17 to the valve chamber 18, and the large bubbles floating in the liquid refrigerant are The wall 37 prevents passage to the valve chamber 18.

  FIG. 16 is a central longitudinal sectional view showing an expansion valve according to the eighth embodiment. In FIG. 16, the same or equivalent components as those shown in FIG. 12 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The expansion valve 10g has a refrigerant circulation hole 17 drilled obliquely downward from the lower back of the high-pressure inlet port 13. Thereby, when the refrigerant in which bubbles are mixed is introduced into the high-pressure inlet port 13, only the liquid refrigerant flowing on the lower side flows through the refrigerant circulation hole 17 to the valve chamber 18, and the large bubbles floating in the liquid refrigerant are 37 prevents passage to the valve chamber 18.

  In the first embodiment, the bubble subdividing means and the bubble damming means are provided as the bubble inflow suppressing means so as to prevent the bubble 19 from entering as large as possible, and further to the orifice 19 of the valve chamber 18. It is formed in an R shape so that no flat surface remains on the corner inner wall 32, thereby smoothing the flow of the refrigerant and suppressing the generation of bubbles. However, in the expansion valves 10a, 10b, and 10c according to the second, third, and fourth embodiments that do not have the R shape of the corner inner wall 32 in the valve chamber 18 and the bubble damming means, the bubble damming means or R A shaped corner inner wall 32 can be added and both a bubble damming means and an R shaped corner inner wall 32 can be provided. Similarly, the bubble subdividing means, the R-shaped corner inner wall 32 or the bubbles are added to the expansion valves 10e, 10f, 10g according to the sixth to eighth embodiments which do not have the bubble subdividing means and the R-shaped corner inner wall 32. Subdividing means and R-shaped corner inner walls 32 can be provided.

10, 10a, 10b, 10c, 10d, 10e, 10f, 10g Expansion valve 11 Main body 12 Power element 13 High pressure inlet port 14 Low pressure outlet port 15 Low pressure inlet port 16 Low pressure outlet port 17 Refrigerant flow hole 18 Valve chamber 19 Orifice 20 Valve seat DESCRIPTION OF SYMBOLS 21 Valve body 22 Valve support 22a Cylindrical part 22b Spring receiving part 22c Notch part 22d Opening part 23 Compression coil spring 24 Adjustment screw 25 Refrigerant return passage 26 Diaphragm 27 Sensitivity chamber 28 Disc 29 Shaft 30 Holding member 31 Spring 32 Corner inner wall 33 Cylindrical bubble subdividing member 33a, 33b End portion 33c Intermediate portion 33d Slit 34 Rib 35 Toothed ring 35a Ring portion 35b Projection portion 36 Gravitational direction 37 Wall 38 Adjustment member accommodating chamber

Claims (14)

In an expansion valve comprising a valve portion for constricting and expanding the refrigerant, and a power element for controlling the opening degree of the valve portion according to the pressure and temperature of the refrigerant,
The expansion is provided with a bubble inflow suppressing means which is disposed at a position where the entire amount of the introduced refrigerant passes toward the valve portion and suppresses the bubbles mixed in the refrigerant from flowing into the valve portion. valve.   The bubble inflow suppression means is a bubble fragmentation means that is arranged so as to block the flow of the refrigerant in a valve chamber into which the refrigerant is introduced, and has a plurality of passages having a small passage cross-sectional area. The expansion valve described.   The bubble subdividing means is formed on a valve support that supports the valve body so as to be openable and closable with respect to an orifice communicating with the valve chamber, and is disposed on the outer periphery of an annular spring receiving portion on which the valve body is mounted. The expansion valve according to claim 2, wherein the expansion valve is a plurality of notches constituting the passage.   The bubble subdividing means is formed in a valve support that supports the valve body so as to be openable and closable with respect to an orifice communicating with the valve chamber, and is circular in the vicinity of an outer periphery of an annular spring receiving portion on which the valve body is mounted. The expansion valve according to claim 2, wherein the expansion valve is a plurality of openings that are arranged in the circumferential direction and constitute the passage.   The bubble fragmentation means is configured so that both axial ends are fitted to the inner wall of the valve chamber, and the axial intermediate portion guides the entire amount of refrigerant introduced between the outer peripheral surface of the valve chamber and the inner wall of the valve chamber. It is a cylindrical cell subdividing member that is recessed so as to form an annular passage and that has a plurality of slits that are arranged in the circumferential direction and are elongated in the axial direction constituting the passage. Item 3. The expansion valve according to Item 2.   The bubble fragmentation means includes a plurality of circumferentially extending ribs extending in the axial direction on the inner wall of the valve chamber, and an outer peripheral surface of a valve support that supports the valve body so as to be openable and closable with respect to an orifice communicating with the valve chamber. The expansion valve according to claim 2, wherein the passage is constituted by a trough between the adjacent ribs.   The bubble subdividing means is disposed between a valve support that supports the valve body so as to be openable and closable with respect to the orifice communicating with the valve chamber, and an elastic body that urges the valve support in a direction to close the orifice. The expansion valve according to claim 2, wherein the expansion valve is a toothed ring having a plurality of protrusions on the outer periphery and constituting the passage by a valley between the inner wall of the valve chamber and the adjacent protrusions. .   The bubble inflow suppression means is disposed between a high pressure inlet port into which liquid refrigerant is introduced and a valve chamber, and the liquid refrigerant is damped while damaging bubbles mixed in the liquid refrigerant introduced into the high pressure inlet port. 2. The expansion valve according to claim 1, wherein the expansion valve is a bubble damming means for feeding into the valve chamber.   The bubble damming means has a refrigerant flow hole communicating from the high-pressure inlet port to the valve chamber, which is installed below the center of the high-pressure inlet port with respect to the mounting posture of the expansion valve. The expansion valve according to claim 8, wherein:   The refrigerant flow hole is provided with a biasing force adjusting member for an elastic body that biases a valve support that supports the valve body so as to be openable and closable with respect to the orifice communicating with the valve chamber in a direction in which the orifice is closed. The expansion valve according to claim 9, wherein the expansion member is formed in a half-moon shape by crossing an adjustment member housing chamber having a larger diameter than the valve chamber and the high-pressure inlet port.   The expansion valve according to claim 9, wherein the refrigerant circulation hole is formed in a half moon shape by crossing the valve chamber and the high pressure inlet port.   The expansion valve according to claim 9, wherein the refrigerant circulation hole is formed obliquely downward from a lower position in the gravity direction of the high-pressure inlet port.   The bubble inflow suppression means is arranged so as to block the flow of the refrigerant in the valve chamber into which the refrigerant is introduced, and the bubble fragmentation means having a plurality of passages having a small passage cross-sectional area, and the high-pressure inlet into which the liquid refrigerant is introduced A bubble blocking means that is disposed between the port and the valve chamber and feeds the liquid refrigerant into the valve chamber while blocking bubbles mixed in the liquid refrigerant introduced into the high-pressure inlet port; The expansion valve according to claim 1.   The valve chamber into which the refrigerant is introduced has a smooth, flat inner wall at the corner from the vicinity of the position where the valve support for supporting the valve body to open and close to the orifice communicating with the valve chamber is provided to the orifice. The expansion valve according to claim 1, wherein the expansion valve is formed in a shape.

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