JP4315060B2 - Expansion valve and refrigeration system - Google Patents

Description

  The present invention relates to an expansion valve and a refrigeration apparatus, and more particularly to a technique for reducing refrigerant passing sound of an expansion valve used in a refrigeration apparatus such as an air conditioner.

  FIG. 8 shows a basic refrigerant circuit of a separate type air conditioner as a basic refrigerant circuit of a conventional refrigeration apparatus. As shown in FIG. 8, the refrigerant circuit of the conventional cooling-only separate type air conditioner is formed in a circulation circuit in which a compressor 101, an outdoor coil 102, an expansion valve 103, and an indoor coil 104 are sequentially connected. The compressor 101 and the outdoor coil 102 are housed in the outdoor unit 105, and the expansion valve 103 and the indoor coil 104 are housed in the indoor unit 106. As the expansion valve 103, for example, an electric expansion valve as shown in FIG. 9 is used.

  This electric expansion valve has a refrigerant flow passage 112 formed in the valve body 111, and includes a partition wall 113 that partitions the refrigerant flow passage 112 in the flow direction. In addition, a valve body 114 is accommodated in the valve main body 111, and a valve hole 115 is formed in the partition wall 113. Then, the valve body 114 is driven by a pulse motor (not shown), and the tapered portion 116 formed at the tip of the valve body 114 is advanced and retracted with respect to the valve hole 115, whereby the valve body 111 is moved into the valve body 111. A throttle part 118 for adjusting the opening degree of the hole 115 is formed.

  Here, the cooling operation cycle in the cooling-only separate type air conditioner will be described with reference to FIG. In addition, the solid line arrow in this FIG. 8 shows the flow direction of the refrigerant | coolant at the time of a cooling operation cycle.

  The high-pressure gas refrigerant compressed by the compressor 101 is conveyed to the outdoor coil 102 and heat-exchanged with the outside air to be condensed and liquefied. The high-pressure liquid refrigerant is conveyed to the expansion valve 103 via the liquid pipe 107 and is sucked into the valve main body 111 from the inlet port 111 a of the expansion valve 103. The refrigerant sucked into the valve body 111 is depressurized by the throttle unit 118 and sent to the indoor coil 104 via the outlet port 111b. Then, the refrigerant sent to the indoor coil 104 evaporates by exchanging heat with the indoor air, and returns to the compressor 101 as a low-pressure gas refrigerant.

  In the cooling operation cycle of the separate type air conditioner for cooling that operates as described above, generally, bubbles are generated in the liquid pipe 107 from the outdoor coil 102 to the expansion valve 103 due to changes in installation conditions and operation conditions. May occur. Further, when the bubbles grow large, a slag flow or a plug flow in which large bubbles are intermittently present in the refrigerant flow. When such a slag flow or plug flow occurs, liquid refrigerant and gas refrigerant flow alternately when passing through the throttle, resulting in discontinuous pressure fluctuations, and as a result expressed as “churtul”. Discontinuous refrigerant flow noise was generated.

In order to solve such problems, a method of making the refrigerant flow continuous in the throttle section by providing a collection of narrow passages on the inlet side of the throttle section to subdivide the bubbles into a gas-liquid mixed state (hereinafter, conventional) A method) is known. As a specific example thereof, a porous body is provided on the inlet side of the throttle part as in the first embodiment of Patent Document 1, and a number of ultrathin tubes are provided on the inlet side of the throttle part as in the second example of Patent Document 1. As shown in Examples 5 to 7 of Patent Document 2, a honeycomb pipe in which a small diameter tube is bundled is provided on the inlet side of the throttle part, and on the throttle part inlet side as in Examples 8 to 10 of Patent Document 2. You can list things with molecular sieves. Also known is a method (hereinafter referred to as the conventional method B) in which the shape of the flow path on the inlet side is changed so as to smooth the refrigerant flow up to the constricted portion so that it does not receive a sudden pressure change at the constricted portion. It has been. As specific examples, the inlet side inner diameter of the orifice forming the valve hole is reduced stepwise or in a tapered manner as in the first to fifth embodiments of Patent Document 1 and Examples 1 to 10 of Patent Document 2. In addition, as in the fourth embodiment of Patent Document 1, the inlet side inner diameter of the orifice forming the valve hole can be reduced in a tapered shape, and a threaded groove can be provided. Further, there is known a method of dispersing refrigerant flow energy (hereinafter referred to as a conventional C method) by generating an intermediate pressure between two throttle portions with two throttle portions. As a specific example, Patent Document 3 can be listed. Further, there is known a method (hereinafter referred to as a conventional method D) which attempts to make the pulsation of the refrigerant continuous by providing a plurality of refrigerant passages in the throttle portion. As a specific example, Patent Document 4 can be listed.
JP-A-7-146032 Japanese Patent Laid-Open No. 11-325658 Japanese Patent Laid-Open No. 5-322851 Japanese Patent Laid-Open No. 5-288286

  However, the conventional method A is to subdivide the bubbles by passing a gas-liquid two-phase refrigerant flow containing large bubbles through a large number of thin passages, and impurities are likely to accumulate in the thin passages. Prone to clogging. In addition, porous bodies, honeycomb pipes, ultrathin tubes, and molecular sieves also have a problem that they are weak in mechanical strength and easily deformed. For this reason, it has been difficult for the conventional method A to maintain the reliability of the electric expansion valve.

  Further, in the conventional method B, it is not possible to subdivide bubbles contained in the refrigerant and mix them uniformly in the liquid refrigerant simply by changing the shape of the flow path on the inlet side of the throttle portion. It could not be reduced sufficiently.

  Further, in the conventional C method, since the pressure between the throttle portions formed in two stages is an intermediate pressure, the refrigerant flow resistance due to the upstream throttle portion must be set large, and in the case of plug flow or slag flow However, it was difficult to avoid the “church” noise although the pressure fluctuation in the upstream throttle portion could not be avoided and the noise was reduced. Further, in this conventional method C, it is difficult in terms of manufacturing technology to simultaneously make the two-stage throttle portions fully closed when fully closed, so that the intermediate pressure is maintained between the two throttle portions in the state near the fully closed state. It was difficult. Further, in the conventional method D, the total flow path area in the throttle portion becomes large, and the resolution in the refrigerant flow rate control becomes rough. In addition, if the flow path is made minute to avoid this, there is a problem that clogging or biting occurs.

  The present invention has been made paying attention to the problems existing in the above-described prior art, and without passing through the discontinuous refrigerant passage generated at the inlet side of the expansion valve when the gas-liquid two-phase refrigerant flows in without impairing the reliability. An object is to provide an expansion valve with reduced noise. It is another object of the present invention to provide a refrigeration apparatus that uses this expansion valve to reduce refrigerant passage noise on the inlet side of the expansion valve.

  The present inventor provides, as one means for solving the above-described problems of the prior art, by providing an auxiliary throttle that is not fully closed and has a small refrigerant flow resistance on the upstream side of the main throttle that can be fully closed. In addition to reducing the flow rate of refrigerant at the inlet, the auxiliary throttle part subdivides the bubbles before reaching the inlet of the main throttle part, reducing pressure fluctuations at the main throttle part, and reducing refrigerant passage noise at the inlet side of the expansion valve (See Japanese Patent Application No. 2003-203365). However, the present invention is intended to further improve the present invention and further reduce the refrigerant passing sound on the expansion valve inlet side.

The expansion valve of the present invention includes a valve main body, a refrigerant flow passage formed inside the valve main body, a valve body housed in the valve main body, a main throttle portion formed in the refrigerant flow passage, and a refrigerant flow passage. An auxiliary throttle portion formed on the upstream side of the main throttle portion, and the valve body includes a first partition wall that partitions the refrigerant flow in the refrigerant flow passage, and a refrigerant upstream of the first partition wall in the refrigerant flow passage And a second partition wall for partitioning the flow of the first throttle wall, the main partition valve hole is formed in the first partition wall, the auxiliary throttle valve hole is formed in the second partition wall, the valve body, It consists of a cylindrical part and a tapered part formed integrally with this cylindrical part, and the main throttle part moves the taper part of the valve element forward and backward with respect to the main throttle part valve hole. And a taper part that can be fully closed and has a variable opening, and the auxiliary throttle part is a valve hole for the auxiliary throttle part. With a substantially independent of the passage of a plurality of axially formed at equal intervals on the outer peripheral surface of the cylindrical portion of the peripheral surface or the valve body, so that the refrigerant flow resistance is reduced compared to the main throttle section a non fully closed The refrigerant flowing out from a plurality of substantially independent passages constituting the auxiliary throttle portion is mixed and flows into the main throttle portion .

  The plurality of substantially independent passages may be formed by providing a plurality of groove portions at substantially equal intervals on the inner peripheral surface of the valve hole for the auxiliary throttle portion or the outer peripheral surface of the columnar portion of the valve body. The plurality of substantially independent passages may be formed such that the overlapping length of the valve body and the groove changes as the valve body advances and retreats. The auxiliary throttle portion may be formed of a passage formed such that the refrigerant passage area changes as the valve body advances and retreats.

  Moreover, the refrigeration apparatus according to the present invention uses the above expansion valve.

According to the expansion valve of the present invention, when a slag flow or a plug flow occurs on the expansion valve inlet side, the bubbles are subdivided by passing through the auxiliary throttle portion, and the refrigerant flow to the main throttle portion is continuous. Is done. Moreover, by flowing of serially refrigerant to the main throttle portion from the auxiliary throttle section, so that with less kinetic energy of refrigerant passing through the main throttle section, the pressure variations in the main throttle section is reduced. As a result, the refrigerant passing sound generated on the expansion valve inlet side, that is, the so-called “church” sound is reduced. The refrigerant that has flowed into the expansion valve passes through a plurality of substantially independent passages in the axial direction that form the auxiliary throttle portions, so that the bubbles are subdivided and diverted, and the independent flow state in each independent passage. Is formed. The refrigerant flow in the independent fluid state flowing out of the independent passage is remixed and flows into the main throttle portion, so that the refrigerant flow in the main throttle portion can be made more continuous, and the refrigerant on the inlet side of the expansion valve The passing sound can be further reduced. Further, an auxiliary throttle section because the refrigerant flow resistance of its being smaller than the main throttle section while the total閉不ability, it is possible to reduce the influence of the refrigerant amount control width by the main throttle section. In addition, since the main throttle portion can be fully closed, a necessary throttle amount can be secured until the main throttle portion is fully closed. Further, the auxiliary throttle part is configured to include a plurality of substantially independent passages in the axial direction formed at equal intervals on the inner peripheral surface of the valve hole for the auxiliary throttle part or the outer peripheral surface of the cylindrical part of the valve body. Therefore, a small and simple configuration can be achieved without requiring separate parts.

Note that the problem of clogging does not occur because the speed of the refrigerant flow is not lowered on the upstream side of the main throttle portion and the flow is made to flow in a narrow passage unlike the conventional method A.
In addition, when the plurality of substantially independent passages are formed so that the overlap length between the valve body and the groove is variable by the advancement and retreat of the valve body, the refrigerant flow resistance of the main throttle part and the refrigerant flow resistance of the auxiliary throttle part Can be changed at the same time. Accordingly, the ratio of the refrigerant flow resistance between the main throttle part and the auxiliary throttle part can be maintained within an appropriate range in response to fluctuations in the load of the expansion valve, and the refrigerant on the expansion valve inlet side can be stably maintained over a wide operating range. Passing sound can be reduced.

  Further, when this substantially independent passage is formed by providing a plurality of groove portions at substantially equal intervals on the inner peripheral surface of the valve hole for the auxiliary throttle portion or the outer peripheral surface of the cylindrical portion of the valve body, a plurality of the substantially independent passages are formed. It is possible to easily produce a substantially independent passage.

  Further, the auxiliary throttle portion can be formed by a change passage with a refrigerant passage area by advancing and retracting the valve body. As a method of changing the refrigerant passage area, for example, a passage forming the auxiliary throttle portion is formed by a plurality of substantially independent passages, and a total passage sectional area of the plurality of substantially independent passages is changed, or By changing the cross-sectional area of each of the plurality of substantially independent passages, the refrigerant flow resistance of the auxiliary throttle portion can be set freely with respect to the change of the refrigerant flow resistance of the main throttle portion corresponding to the advancement and retreat of the valve body. can do.

  Further, when the expansion valve according to the above problem solving means is applied to a refrigeration apparatus, it is possible to provide a refrigeration apparatus in which the refrigerant passing sound on the outlet side is quiet with the expansion valve.

(Embodiment 1)
Hereinafter, an expansion valve according to Embodiment 1 embodying the present invention will be described with reference to FIGS. 1 and 2. 1 is a longitudinal sectional view of the expansion valve according to Embodiment 1, and FIG. 2 is a sectional view taken along the line AA in FIG. Moreover, in the following description, when referring to the vertical and horizontal directions, the vertical and horizontal directions in FIG. Moreover, in FIG. 1, the white arrow has shown the flow direction of the refrigerant | coolant.

The expansion valve according to Embodiment 1 is used, for example, in the refrigerant circuit as shown in FIG.
As shown in FIG. 1, the expansion valve includes a valve body 1, a refrigerant flow passage 2 formed in the valve body 1, and a valve body 3 housed in the valve body 1, and further includes a valve body. In order to form the main throttle portion 4 and the auxiliary throttle portion 5 inside the first partition wall 6 having a large wall height formed in the horizontal direction so as to partition the refrigerant flow at the intermediate portion of the refrigerant flow passage 2. And a second partition wall 7 having a small wall height formed in the horizontal direction so as to partition the refrigerant flow on the outlet side of the refrigerant flow passage 2. The first partition wall 6 is formed with a main throttle portion valve hole 8 having a large hole diameter, and the second partition wall 7 is formed with an auxiliary throttle portion valve hole 9 having a small hole diameter.

  The valve body 1 is formed in a substantially cylindrical shape having an axial center in the vertical direction, and a vertical refrigerant flow passage 2 is formed therein. Further, two ports, an inlet port 1a and an outlet port 1b, are provided as inlets and outlets connected to the valve body 1 and the refrigerant flow passage 2. The inlet port 1 a is provided in the lower part of the valve body 1, and the outlet port 1 b is provided in the side wall of the valve body 1. Therefore, the refrigerant is configured to flow from below to above in the valve body 1. A liquid pipe 10 that connects the outdoor coil and the expansion valve is connected to the inlet port 1a, and a pipe 11 that connects the expansion valve and the indoor coil is connected to the outlet port 1b.

  The valve body 3 is a substantially cylindrical body arranged concentrically with the refrigerant flow passage 2. More specifically, the valve body 3 has a large-diameter cylindrical portion 12 in the upper portion and a small-diameter cylindrical portion 13 in the lower portion, and the large-diameter cylindrical portion 12 and the small-diameter cylindrical portion 13 are connected by a tapered portion 14. ing. The valve body 3 is configured to be driven up and down using a pulse motor (not shown) as a drive source.

  The main restricting portion 4 moves the taper portion 14 of the valve body 3 in the vertical direction with respect to the main restricting portion valve hole 8 to move the surface of the tapered portion 14 and the valve seat (the upper end angle of the main restricting portion valve hole 8). A throttle passage that is variable in opening and can be fully closed.

  The auxiliary throttle portion 5 is formed with a throttle passage between the auxiliary throttle portion valve hole 9 and the surface of the small diameter cylindrical portion 13, and is formed on the upstream side of the main throttle portion 4. Further, the auxiliary throttle unit 5 has a refrigerant flow resistance smaller than that of the main throttle unit 4. As can be seen from FIG. 2, the auxiliary throttle valve hole 9 has a plurality of (in this case, four) independent grooves 15 formed at substantially equal intervals on the surface of the auxiliary throttle valve hole 9. ing. The groove 15 has a substantially triangular shape in cross section. As a result, a plurality of passages 16 (four in this case) are formed between the auxiliary restricting portion valve hole 9 and the small-diameter cylindrical portion 13. Moreover, the hole diameter of the valve hole 9 for auxiliary throttle parts is made into the grade which the small diameter cylindrical part 13 of the valve body 3 can slide. Thus, the passage forming the auxiliary throttle portion 5 is composed of a plurality of substantially independent passages 16 having a constant cross-sectional area. In this embodiment, since the tip of the small diameter cylindrical portion 13 always protrudes from the lower end of the auxiliary throttle portion valve hole 9, the refrigerant flow resistance characteristic of the auxiliary throttle portion 5 is kept constant. Is done.

  Since the expansion valve of the first embodiment is formed as described above, the liquid refrigerant flowing from the inlet port 1a is slightly decompressed by the auxiliary throttle unit 5 and greatly decompressed by the main throttle unit 4. The refrigerant decompressed by the main throttle 4 flows out from the outlet port 1b to the piping system.

  Further, when a slag flow or a plug flow flows in from the inlet port 1a, the bubbles are subdivided by passing through the auxiliary throttle portion 5, and the refrigerant flow to the main throttle portion 4 is made continuous. Further, since the refrigerant is circulated in series from the auxiliary throttle unit 5 to the main throttle unit 4, the throttle amount in the main throttle unit 4 is reduced, and the kinetic energy of the refrigerant passing through the main throttle unit 4 is reduced. The pressure fluctuation in the main throttle portion 4 is reduced. As a result, the refrigerant passing noise generated at the inlet of the expansion valve, that is, the so-called “church” noise is reduced. Further, since the passage forming the auxiliary throttle portion 5 is formed by a plurality of substantially independent passages 16 formed at substantially equal intervals, the gas-liquid two-phase refrigerant flow is divided. Moreover, the refrigerant | coolant flow state of each substantially independent channel | path 16 after being divided becomes different, respectively. Then, as a result of the refrigerant flowing out from the plurality of substantially independent passages being mixed and flowing into the main throttle portion 4, the refrigerant flow in the main throttle portion 4 is further continued, and the refrigerant passing sound on the expansion valve inlet side is further increased. Reduced. In addition, since the refrigerant flow resistance of the auxiliary throttle unit 5 is reduced, the influence of the main throttle unit 4 on the refrigerant amount control width can be reduced. Further, since the main throttle portion 4 can be fully closed, a necessary throttle amount can be secured until the main throttle portion 4 is fully closed.

Note that the problem of clogging does not occur because the speed of the refrigerant flow is not reduced on the upstream side of the main throttle portion 4 to flow through a narrow passage unlike the conventional method A.
Further, since the passage forming the auxiliary throttle portion 5 is formed by a plurality of substantially independent passages 16 formed at substantially equal intervals, the refrigerant flow from the auxiliary throttle portion 5 to the main throttle portion 4 is dispersed. . As a result, the kinetic energy of the refrigerant flow passing through the auxiliary throttle portion 5 is dispersed, and the refrigerant passing sound on the expansion valve outlet side can be further reduced.

  Further, since the plurality of substantially independent passages 16 have a structure in which the plurality of groove portions 15 are provided at substantially equal intervals on the inner peripheral surface of the auxiliary restricting portion valve hole 9, manufacturing is easy. For example, even if a plurality of protrusions are formed on the valve body 3 side, it is possible to form a substantially independent passage, but manufacture is easier than that.

(Embodiment 2)
Hereinafter, an expansion valve according to a second embodiment embodying the present invention will be described with reference to FIGS. 3 is a longitudinal sectional view of the expansion valve according to the second embodiment, and FIG. 4 is a sectional view taken along the line BB in FIG. Moreover, in the following description, when referring to the vertical and horizontal directions, the vertical and horizontal directions in FIG. Moreover, the arrow in FIG. 3 has shown the flow direction of the refrigerant | coolant.

  The expansion valve according to the second embodiment is used, for example, in the refrigerant circuit as shown in FIG. 8 described above, and unlike the first embodiment, the refrigerant flow resistance of the auxiliary throttle portion is set to the main throttle portion. The refrigerant flow resistance can be increased or decreased.

  As shown in FIG. 3, the expansion valve includes a valve main body 21, a refrigerant flow passage 22 formed in the vertical direction in the valve main body 21, and a valve body 23 accommodated in the valve main body 21. . Furthermore, in this expansion valve, in order to form the main throttle part 24 and the auxiliary throttle part 25 inside the valve body 21, it is formed in a horizontal direction so as to partition the refrigerant flow at the outlet side part of the refrigerant flow passage 22. A first partition wall 26 and a second partition wall 27 having a large wall height formed in the horizontal direction so as to partition the refrigerant flow at an intermediate portion of the refrigerant flow passage 2 are formed. The first partition wall 26 is formed with a main throttle valve hole 28, and the second partition wall 27 is formed with an auxiliary throttle valve hole 29.

  The valve body 21 is formed in a substantially cylindrical shape having an axial center in the vertical direction, and a vertical refrigerant flow passage 22 is formed therein. The valve body 21 includes two ports, an inlet port 21a and an outlet port 21b, as inlets / outlets connected to the refrigerant flow passage 22. The inlet port 21 a is provided at the side of the valve body, and the outlet port 21 b is provided at the lower part of the valve body 1. Therefore, unlike the case of the first embodiment, the refrigerant is configured to flow downward from the side in the valve main body 21. A liquid pipe 30 that connects the outdoor coil and the expansion valve is connected to the inlet port 21a, and a pipe 31 that connects the expansion valve and the indoor coil is connected to the outlet port 21b.

  The valve body 23 is a substantially cylindrical body arranged concentrically with the refrigerant flow passage 22. More specifically, the valve body 23 has a cylindrical portion 32, and a tapered portion 33 is integrally formed at a lower portion thereof. The valve body 23 is configured to be driven up and down using a pulse motor (not shown) as a drive source.

  The main throttle portion 24 moves the taper portion 33 of the valve body 23 in the vertical direction with respect to the main throttle portion valve hole 28 to move the surface of the taper portion 33 and the valve seat (the upper end angle of the main throttle portion valve hole 28). A throttle passage that is variable in opening and can be fully closed.

Further, the auxiliary throttle portion 25 is a passage formed between the auxiliary throttle portion valve hole 29 and the surface of the cylindrical portion 32 so that the refrigerant flow resistance is smaller than the refrigerant flow resistance in the main throttle portion 24. And is formed on the upstream side of the main throttle portion 24. Further, the auxiliary restricting portion 25 is formed so as to increase / decrease the refrigerant flow resistance simultaneously with the increase / decrease of the refrigerant flow resistance of the main restricting portion 24. As can be seen from FIG. 4 , the auxiliary throttle valve hole 29 has a plurality of (in this case, four) independent grooves 35 formed at substantially equal intervals on the surface of the auxiliary throttle valve hole 29. ing. The groove 35 has a constant width and a constant depth. Thereby, a plurality of (in this case, four) passages are formed between the auxiliary throttle valve hole 29 and the cylindrical portion 32. Further, the hole diameter of the auxiliary restrictor valve hole 29 is set such that the cylindrical portion 32 of the valve body 23 can slide. Thus, the passage forming the auxiliary throttle portion 25 is formed by a plurality of substantially independent passages 36 having a constant cross-sectional area. Further, in this embodiment, by controlling the movement of the valve body 23 in the axial direction, the overlapping length of the groove portion 35 and the cylindrical portion 32 (that is, the length of the passage 36) is the valve opening of the main throttle portion 24. The length of the groove 35 is set so as to change with the degree. Therefore, in this embodiment, the main throttle portion 24 and the auxiliary throttle portion 25 are each configured to be able to vary the refrigerant flow resistance so that the refrigerant flow resistance increases and decreases simultaneously.

  Since the expansion valve according to the second embodiment is formed as described above, the liquid refrigerant flowing in from the inlet port 21a is slightly decompressed by the auxiliary throttle unit 25 and greatly decompressed by the main throttle unit 24. The refrigerant depressurized by the main throttle 4 flows out from the outlet port 21b to the piping system.

  Further, when a slag flow or a plug flow flows in from the inlet port 21a, the bubbles are subdivided by passing through the auxiliary throttle portion 25, and the refrigerant flow to the main throttle portion 24 is made continuous. Moreover, the refrigerant pressure drop in the main throttle unit 24 is reduced by circulating the refrigerant in series from the auxiliary throttle unit 25 to the main throttle unit 24. For this reason, the kinetic energy of the refrigerant passing through the main throttle portion 24 is reduced, and the pressure fluctuation in the main throttle portion 24 is reduced. As a result, a refrigerant passing sound generated at the inlet of the expansion valve, that is, a so-called “church” sound is reduced. Further, since the passages forming the auxiliary throttle portion 25 are formed in a plurality of substantially independent passages 36 formed at substantially equal intervals, the refrigerant flow state differs between the substantially independent passages 16. As a result, the refrigerant flow in the main throttle portion 24 can be further continued, and the refrigerant passing sound on the inlet side of the expansion valve can be further reduced. In addition, since the refrigerant flow resistance of the auxiliary throttle unit 25 is reduced, the influence of the main throttle unit 24 on the refrigerant amount control width can be reduced. In addition, since the main throttle portion 24 can be fully closed, a necessary throttle amount can be ensured until the main throttle portion 24 is fully closed.

Note that the problem of clogging does not occur because the speed of the refrigerant flow is not reduced on the upstream side of the main throttle portion 24 as in the conventional method A so as to flow through a narrow passage.
Further, the refrigerant flow passage 22 in the valve body 21 is partitioned by the first and second partition walls 26 and 27, and the main throttle part valve hole 28 and the auxiliary throttle part provided in the first and second partition walls 26 and 27. One valve body 23 is driven with respect to the valve hole 29 to form a main throttle part 24 having a fully closed and variable opening between the main throttle part valve hole 28 and the taper part 33, and for the auxiliary throttle part. Since the auxiliary throttle portion 25 having a plurality of throttle passages is formed between the valve hole 29 and the valve body 23 cylindrical portion 32, an expansion valve having a two-stage throttle portion is formed with a simplified configuration. can do.

  Further, since the passage forming the auxiliary throttle portion 25 is formed as a plurality of substantially independent passages 36 formed at substantially equal intervals, the refrigerant flow from the auxiliary throttle portion 25 to the main throttle portion 24 is dispersed. . As a result, the kinetic energy of the refrigerant flow passing through the auxiliary throttle portion 25 is dispersed, and the refrigerant passing sound at the expansion valve inlet side can be further reduced.

In addition, since the plurality of substantially independent passages 36 have a structure in which the plurality of groove portions 35 are provided at substantially equal intervals on the inner peripheral surface of the auxiliary restricting portion valve hole 29, the manufacture is easy.
Further, since the plurality of substantially independent passages 36 are formed so that the length of overlap of the valve body 23 and the groove portion 35 is variable by the advancement and retraction of the valve body 23, the refrigerant flow resistance and the auxiliary of the main throttle portion 24 are changed. The refrigerant flow resistance of the throttle unit 25 can be changed simultaneously. Accordingly, the ratio of the refrigerant flow resistance between the main throttle portion 24 and the auxiliary throttle portion 25 can be kept substantially constant in response to fluctuations in the load of the expansion valve, and the expansion valve inlet side can be stably maintained over a wide operating range. The refrigerant passing noise can be reduced.

(Embodiment 3)
Next, Embodiment 3 will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view of an essential part of the expansion valve in the third embodiment, and FIG. 6 is a sectional view taken along the line CC in FIG. Since the present embodiment is a modification of the second embodiment, the same reference numerals are given to the same portions as those of the second embodiment in FIGS. 5 and 6 and the description thereof is omitted.

  In the third embodiment, a plurality of throttling passages 36 are provided in place of the configuration in which the plurality of throttling passages 36 are provided on the inner peripheral surface of the valve hole 29 in the auxiliary throttling portion 25 in the second embodiment. Are provided on the outer peripheral surface of the cylindrical portion 32 of the valve body 23.

  In the third embodiment, as shown in FIGS. 5 and 6, a plurality of throttle passages are not formed on the inner peripheral surface of the auxiliary throttle valve hole 29. Instead, the cylindrical portion 32 of the valve body 23 is provided with a groove portion 41 similar to the groove portion 35 described above. A plurality (four in this case) of groove portions 41 are provided at substantially equal intervals on the outer peripheral surface of the cylindrical portion 32. Moreover, the groove part 41 is formed over a fixed width, a fixed depth, and a predetermined length. As the cylindrical portion 32 of the valve body 23 enters the auxiliary throttle portion valve hole 29, the open portion of the groove portion 41 is covered with the inner peripheral surface of the auxiliary throttle portion valve hole 29. Thereby, a plurality of substantially independent passages 42 having a constant cross-sectional area are formed.

  As described above, as in the case of the second embodiment, the plurality of substantially independent passages 42 in the third embodiment change in length in accordance with the advancement and retreat of the valve body 23 so that the refrigerant flow resistance changes. Configured. Therefore, the expansion valve of the third embodiment can achieve the same effect as that of the second embodiment.

(Embodiment 4)
Next, the fourth embodiment will be described with reference to FIG. FIG. 7 is a longitudinal sectional view of an essential part of the expansion valve in the second embodiment. Since the present embodiment is a modification of the second embodiment, the same parts as those of the second embodiment are denoted by the same reference numerals in FIG.

  In the second embodiment, the plurality of substantially independent passages 36 are formed so as to have a constant cross-sectional area with respect to the advancement and retraction of the valve body 23. The substantially independent passage 52 is formed so as to change its cross-sectional area in accordance with the advancement and retreat of the valve body 23.

  In the fourth embodiment, the auxiliary throttle valve hole 29 is formed with a plurality of grooves 51. Unlike the second embodiment, the groove 51 has a constant groove width, but the bottom of the groove 51 is tapered so that the groove depth gradually decreases toward the outlet side (downward). Yes. Therefore, the passage 52 formed by covering the plurality of grooves 51 with the cylindrical portion 32 of the valve body 23 increases in length and decreases in cross-sectional area as the cylindrical portion 32 enters the valve hole 29. Formed to be.

  Since the plurality of throttle passages 52 in the fourth embodiment are configured as described above, the refrigerant passage area changes with the length corresponding to the advancement and retreat of the valve body 23, and the refrigerant flow resistance changes. Configured. More specifically, the cross-sectional area of the substantially independent passage 52 is reduced as the valve body 23 enters the valve hole 29. Therefore, the expansion valve of the third embodiment can achieve the same effect as that of the second embodiment. Further, the refrigerant flow resistance can be changed by a short movement amount of the valve body 23.

(Modification)
In addition, this invention can also be changed and embodied as follows.
(1) In each of the above-described embodiments, the example used in the refrigerant circuit using one indoor unit 106 for one outdoor unit 101 as shown in FIG. 8 has been described. Of course, it can be used for a so-called multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit. In the multi-type air conditioner, the operating condition on the inlet side of the expansion valve changes greatly, and the opportunity for large bubbles to enter increases. Therefore, when the expansion valve of the present invention is used in a multi-type air conditioner, the effect can be exhibited more remarkably.

  (2) In the first embodiment, the auxiliary throttle portion 5 may be configured to increase or decrease simultaneously with the increase or decrease of the refrigerant flow resistance of the main throttle portion 4. In this case, the height of the second partition wall 7 is increased so that the overlapping length of the groove 15 and the small diameter cylindrical portion 13 (that is, the length of the passage 16) together with the valve opening of the main throttle portion 4. What is necessary is just to set the length of the groove part 15 so that it may change.

  (3) In the second embodiment, the refrigerant flow resistance of the auxiliary throttle portion 25 may be fixed. In this case, as in the first embodiment, the wall height of the second partition wall 27 may be reduced so that the cylindrical portion 32 always penetrates.

  (4) The shapes of the groove portions 15 and 35 of the auxiliary throttle portions 5 and 25 in the first and second embodiments are formed in a substantially triangular shape as shown in FIGS. Alternatively, the cross-sectional shape may be an appropriate shape such as a circle, an oval, an ellipse, or a U-shape.

  (5) In the fourth embodiment, the refrigerant passage area of the passage forming the auxiliary throttle portion 25 is changed corresponding to the advancement and retreat of the valve body 23, and the valve body 23 is changed to the auxiliary throttle portion valve hole 29. Although an example in which the cross-sectional area of the plurality of substantially independent passages 52 is reduced as the vehicle enters is shown, conversely, the cross-sectional area of the plurality of substantially independent passages 52 can be increased. This can be realized, for example, by increasing the groove width toward the lower side of the groove 35 or increasing the groove depth in the second embodiment.

In the second embodiment, in order to change the cross-sectional area of each of the plurality of passages 36, the cross-sectional area can be changed stepwise by changing the cross-sectional area in a stepped manner.
Further, by changing the number of the groove portions 35 without changing the cross-sectional areas of the plurality of passages 36, the refrigerant passage area of the passage forming the auxiliary throttle portion 25 (that is, the plurality of independent passages in the auxiliary throttle portion 25). The overall cross sectional area of the passage 36 may be changed. For example, in the second embodiment, when the number of the passages 36 on the outlet side of the valve hole 29 for the auxiliary throttle portion is increased and the number of the passages 36 on the inlet side is decreased, the second auxiliary throttle against the advance / retreat of the valve body 23. The change in the refrigerant flow resistance in the portion 46 can be reduced.

  In this way, if the cross-sectional area of the passage of the throttle portion is changed by changing the cross-sectional area of the passage forming the auxiliary throttle portion, the change in the refrigerant flow resistance of the main throttle portion corresponding to the advancement and retreat of the valve body The refrigerant flow resistance of the auxiliary throttle portion can be set freely.

  Further, in order to change the refrigerant passage area of the passage forming the auxiliary throttle portion, a small taper may be provided on the cylindrical portion of the valve body entering the valve hole. For example, in the first embodiment, if the diameter of the small-diameter cylindrical portion is made slightly smaller as it goes to the tip, the refrigerant passage area of the passage forming the auxiliary throttle portion 5 moves the valve body 3 downward. Can be made smaller.

  The cross-sectional area of the passage that forms the auxiliary throttle portion in the first to fourth embodiments is not limited to the above example, and the refrigerant passage area can be changed according to the advancement and retreat of the valve body in various forms. it can.

It is a principal part longitudinal cross-sectional view of the expansion valve which concerns on Embodiment 1 of this invention. It is AA arrow sectional drawing in FIG. It is a principal part longitudinal cross-sectional view of the expansion valve which concerns on Embodiment 2 of this invention. It is a BB arrow sectional view in FIG. It is a principal part longitudinal cross-sectional view of the expansion valve which concerns on Embodiment 3 of this invention. It is CC sectional view taken on the line in FIG. It is a principal part longitudinal cross-sectional view of the expansion valve which concerns on Embodiment 4 of this invention. It is a basic refrigerant circuit diagram of the conventional freezing apparatus, Comprising: The basic refrigerant circuit of a separate type air conditioner is shown. It is a basic structure figure of the expansion valve used for the refrigerant circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 2 Refrigerant flow path 3 Valve body 4 Main throttle part 5 Auxiliary throttle part 6 1st partition wall 7 2nd partition wall 8 Valve hole for main throttle parts 9 Valve hole 12 for auxiliary throttle parts Large diameter cylindrical part 13 Small diameter cylinder Portion 14 taper portion 15 groove portion 16 passage 21 valve body 22 refrigerant flow passage 23 valve body 24 main throttle portion 25 auxiliary throttle portion 26 first partition wall 27 second partition wall 28 main throttle portion valve hole 29 auxiliary throttle portion valve hole 30 Liquid pipe 31 Pipe 32 Column 33 Tapered 35 Groove 36 Passage 41 Groove 42 Passage 51 Groove 52 Passage

Claims (4)

A valve body, a refrigerant flow passage formed inside the valve body, a valve body housed in the valve body, a main throttle portion formed in the refrigerant flow passage, and upstream of the main throttle portion in the refrigerant flow passage An auxiliary throttle portion formed,
The valve body includes a first partition wall that partitions the refrigerant flow in the refrigerant flow passage, and a second partition wall that partitions the refrigerant flow on the upstream side of the first partition wall of the refrigerant flow passage. Is formed with a valve hole for the main throttle part, a valve hole for the auxiliary throttle part is formed on the second partition wall,
The valve body is composed of a cylindrical portion and a tapered portion formed integrally with the cylindrical portion,
The main throttle part is formed by advancing and retreating the taper part of the valve body with respect to the main throttle part valve hole, so that the main throttle part is formed from a fully-closable and variable opening passage formed between the main throttle part valve hole and the taper part. Become
The auxiliary throttle part is composed of a plurality of substantially independent passages in the axial direction formed at equal intervals on the inner peripheral surface of the valve hole for the auxiliary throttle part or the outer peripheral surface of the cylindrical part of the valve body, and cannot be fully closed. It is formed so that the refrigerant flow resistance is smaller than the main throttle part,
An expansion valve characterized in that the refrigerant flowing out from a plurality of substantially independent passages constituting the auxiliary throttle part is mixed and flows into the main throttle part . 2. The expansion valve according to claim 1, wherein the plurality of substantially independent passages are formed such that an overlap length between the valve body and the groove portion is changed by the advancement and retreat of the valve body . The auxiliary throttle section, the expansion valve according to claim 1, characterized in that it is formed by the passage in which the refrigerant passage area is changed by advancing and retracting of the valve body.   A refrigeration apparatus using the expansion valve according to any one of claims 1 to 4.

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