JP2017172702A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion valve in which occurrence of noise caused by refrigerant passing through a return passage is restricted.SOLUTION: This invention relates to an expansion valve having a feature comprising a power element; a valve main body including an inlet port, a valve chamber communicated with the inlet port, a valve hole communicated with the valve chamber, an outlet port communicated with the valve hole, a valve seat formed at an opening part of the valve hole facing the valve chamber side, a return passage where the refrigerant discharged out of the outlet port passes, and a power element fixing part; a valve member for controlling an opening area of the valve hole; and a displacement transmitting member for transmitting a displacement of a diaphragm to the valve member. The displacement transmitting member is configured by a first rod-like member positioned at the power element side; a second rod-like member positioned at the valve member; and a ring member having a cylinder part held between the first rod-like member and the second rod-like member. The ring member is arranged in the return passage in such a way that a direction of the center axis line of the cylindrical part may be coincided with a flowing direction of the refrigerant.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a temperature sensing mechanism built-in type expansion valve used in a refrigeration cycle, and more particularly to an expansion valve having a power element attached to a valve body.

  Conventionally, for refrigeration cycles used in air conditioners installed in automobiles, a temperature expansion valve with a built-in temperature sensing mechanism that adjusts the refrigerant flow rate according to the temperature is used to save installation space and piping work. Has been. The valve body of such an expansion valve has an inlet port into which high-pressure refrigerant is introduced and a valve chamber communicating with the inlet port, and a valve member drive mechanism called a power element is provided on the top of the valve body. Is done.

  The spherical valve member disposed in the valve chamber is driven by a valve rod (displacement transmission member) that transmits the displacement of the diaphragm provided inside the power element, facing the valve seat of the valve hole that opens in the valve chamber. Thus, the opening degree of the throttle passage between the valve seat and the opening area of the valve hole is controlled. Moreover, the refrigerant | coolant which passed the valve hole is sent to an evaporator side from an exit port. The refrigerant returning from the evaporator to the compressor side passes through a return passage provided in the valve body. In the return passage, the valve stem is exposed, and the refrigerant passes while hitting the valve stem (for example, Patent Document 1).

  FIG. 14 is a partial cross-sectional view showing the vicinity of a return passage in an example of a conventional expansion valve. In the expansion valve 10, a power element 70 is fixed to the power element mounting portion 12 at the top of the valve body 11. The power element 70 includes an upper lid member 71 and a receiving member 72, a diaphragm 73 sandwiched between the upper lid member 71 and the receiving member 72, and a stopper member 90 disposed between the diaphragm 73 and the receiving member 72. Has been. On the other hand, the upper end of the valve rod 60 abuts against the stopper member 90, passes through the central portion of the return passage 30 in the vertical direction, and is arranged so that the lower end contacts the valve member (not shown). The displacement of the diaphragm 73 is transmitted to a valve member (not shown) via the stopper member 90 and the valve rod 60.

  The refrigerant returning from the evaporator to the compressor passes through the return passage 30 in FIG. At that time, the refrigerant flow A passes through the return passage 30 while hitting the cylindrical valve rod 60.

JP-A-11-173705

  However, in a conventional expansion valve, a Karman vortex may be generated when the refrigerant flows around the valve rod due to the valve rod exposed in the return passage (low-pressure refrigerant flow path). This Karman vortex is a phenomenon in which when a flowing fluid hits an object in a flow path, vortices are alternately generated on the left and right sides of the object. Then, when the generated Karman vortex disappears in the wake, abnormal noise (Karman vortex sound) is generated, which may be a factor that impedes the quietness of the passenger compartment as refrigerant passing sound.

  Therefore, an object of the present invention is to provide an expansion valve that suppresses the generation of abnormal noise due to the refrigerant passing through the return passage.

  To achieve the above object, one of the representative expansion valves according to the present invention includes an upper lid member, a receiving member, a power element including a diaphragm sandwiched between the upper lid member and the receiving member, an inlet port, A valve chamber communicating with the inlet port, a valve hole communicating with the valve chamber, an outlet port communicating with the valve hole, a valve seat formed at an opening of the valve hole on the valve chamber side, and exiting from the outlet port A valve body including a return passage through which the refrigerant passes and a power element mounting portion, a valve member for controlling the opening area of the valve hole, and displacement of the diaphragm are transmitted to the valve member to drive the valve member A displacement transmitting member, wherein the displacement transmitting member is a first rod-shaped member located on the power element side, a second rod-shaped member located on the valve member side, the first rod-shaped member, and the second rod-shaped member. Part A ring member having a cylindrical part sandwiched between the ring part, and the ring member is disposed in the return passage so that a direction of a central axis of the cylindrical part coincides with a refrigerant flow direction. It is characterized by being.

  In an embodiment of the expansion valve according to the present invention, the ring member may have a streamline shape in a cross section cut by a plane having the central axis.

  The valve main body may include a guide portion that protrudes toward the center of the return passage on the upstream side of the ring member in the return passage. Furthermore, the first rod-shaped member may be integrally formed with a stopper member that contacts the diaphragm. Furthermore, the displacement transmission member may be formed integrally with all or part of the first rod-shaped member, the ring member, and the second rod-shaped member.

  Since the expansion valve according to the present invention is configured as described above, it is possible to reduce or suppress the generation of abnormal noise due to the refrigerant passing through the return passage.

It is a longitudinal cross-sectional view which shows 1st Example of the expansion valve by this invention. It is a partial expanded sectional view of the ring member 105 vicinity of FIG. It is a partially broken perspective view which shows the return channel | path vicinity of 1st Example. In the expansion valve of the first embodiment, it is a longitudinal sectional view when a joint (a tip portion of a refrigerant passage pipe not shown) is attached to the return passage 30. It is a partial expanded sectional view of the ring member 105 vicinity of FIG. It is a disassembled perspective view for demonstrating the assembly example of the expansion valve of 1st Example. It is a disassembled perspective view which shows the modification of the expansion valve of 1st Example, and its assembly example. It is an expansion longitudinal cross-sectional view of the ring member in 2nd Example of the expansion valve by this invention. It is an expanded longitudinal cross-sectional view of the ring member in 3rd Example of the expansion valve by this invention. It is a longitudinal cross-sectional view which shows 4th Example of the expansion valve by this invention. It is a fragmentary sectional view which shows the dimensional relationship of the ring part vicinity of FIG. It is a longitudinal cross-sectional view which shows 5th Example of the expansion valve by this invention. It is a fragmentary sectional view which shows the dimensional relationship of the ring part vicinity of FIG. It is a fragmentary sectional view showing the neighborhood of the return passage in an example of the conventional expansion valve.

  Hereinafter, examples will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a longitudinal sectional view showing a first embodiment of an expansion valve according to the present invention. FIG. 2 is a partially enlarged sectional view of the vicinity of the ring member 105 of FIG. FIG. 3 is a partially broken perspective view showing the vicinity of the return passage of the first embodiment.

  As shown in FIG. 1, the expansion valve 10 includes a power element 70, a valve body 11, a valve member 40, a displacement transmission member 100 corresponding to a conventional valve rod, a support member 42, a coil spring 44, a plug 50, and the like. Yes.

  The power element 70 includes an upper lid member 71 formed of, for example, stainless steel, a receiving member 72 having a through-hole in the center, a diaphragm 73 sandwiched between the upper lid member 71 and the receiving member 72, and the diaphragm 73. And a stopper member 90 disposed between the receiving member 72 and the like. And the end part which piled up the upper cover member 71, the diaphragm 73, and the receiving member 72 is circumferential-welded, and these are integrated. A pressure working chamber 75 is formed between the upper lid member 71 and the diaphragm 73. After the working gas is sealed in the pressure working chamber 75, the pressure working chamber 75 is sealed with a sealing plug 65. The lower part of the receiving member 72 is cylindrical, and a male screw 72a is formed around it, and is screwed with a female screw of the power element mounting portion 12 (female screw formed on the upper surface of the valve body 11).

  The power element 70 is attached to the valve body 11 via the packing 35.

  The valve body 11 is made of, for example, an aluminum alloy, and can be obtained, for example, by extruding an aluminum alloy or the like with the X direction in FIG. The valve body 11 includes a power element mounting portion 12 that is a female screw that is screwed into and fixed to a male screw formed in a lower portion of the power element 70, an inlet port 20 into which a high-pressure refrigerant is introduced, and an inlet port 20 The refrigerant outlet port 28 from which the refrigerant that has flowed in further flows out, the return path 30 of the refrigerant, the female screw hole 11a formed in the bottom surface of the valve main body 11, and the valve main body 11 to an evaporator or other parts not shown in the figure. And mounting holes (or mounting female screws) 80 for mounting.

  The power element mounting portion 12 is formed at the upper end of the valve body 11 and is formed as a bottomed cylindrical hole having a circular opening on the upper surface of the valve body 11 and having an internal thread on its inner wall surface. Is formed with a pressure equalizing hole 32 that leads (communicates) with the return passage 30. Here, the direction of the central axis of the power element mounting portion 12 is the direction (Y direction) of the valve body 11 processed by extrusion molding, that is, the direction (Y) substantially orthogonal to the passing direction of the refrigerant passing through the return passage 30. Direction).

  The female screw hole 11a is formed to open on the lower surface of the valve main body 11, and the valve chamber 24 is formed inside the valve main body 11 by sealing the opening of the female screw hole 11a with a plug 50.

  The inlet port 20 is formed in communication with the valve chamber 24 from the side of the valve chamber 24 through the small diameter hole 20a. The outlet port 28 is formed above the valve chamber 24. The outlet port 28 communicates with the upper end portion of the valve chamber 24 through the valve hole 26. A valve seat 25 is formed on the valve chamber 24 side of the valve hole 26. A through hole 29 is formed in the valve body 11 in the vertical direction (Y direction in FIG. 1). The valve hole 26, the through hole 29, the pressure equalizing hole 32, and the valve chamber 24 are arranged so that their central axes are on the same straight line.

  The return passage 30 is formed further above the outlet port 28 in the valve body 11, and is formed so as to penetrate the valve body 11 in the lateral direction (X direction in FIG. 1).

  The valve member 40 is a spherical member disposed so as to face the valve seat 25, and is provided in the valve chamber 24. The support member 42 is a member that supports the valve member 40 in the direction of the valve seat 25. The support member 42 includes an upper surface 42a having a conical recess for supporting the valve member 40, and is integrated with the valve member 40 by welding. Further, the support member 42 includes a flange portion 42 b that protrudes on the side surface (to the outer peripheral side), and the lower surface of the flange portion 42 b is configured to receive one end of the coil spring 44.

  The coil spring 44 is elastically accommodated between the lower surface of the flange portion 42 b provided in the support member 42 and the recess 52 formed in the plug 50, whereby the valve member 40 causes the support member 42 to move. It is urged | biased toward the valve seat 25 via.

  The plug 50 is attached in such a manner that it is screwed into a female screw hole 11a opened on the lower surface of the valve body 11, and a tool (not shown) is inserted into the hexagonal hole 53 formed on the surface facing the recess 52 and rotated. The screwing amount can be adjusted. By adjusting the screwing amount of the plug 50, the spring force of the coil spring 44 that supports the valve member 40 can be adjusted. Further, a seal member 54 such as an O-ring is provided on the outer peripheral portion of the plug 50, thereby sealing the valve chamber 24 against the atmosphere outside the expansion valve 10.

  In this embodiment, the displacement transmission member 100 that transmits the displacement of the diaphragm 73 to the valve member 40 is in contact with the diaphragm 73 and is provided at the lower portion of the stopper member 90 that senses the displacement of the diaphragm 73. And a ring member 105 disposed below the first rod member 101 and a second rod member 102 disposed below the ring member 105 and in contact with the upper surface of the valve member 40.

  The first rod-shaped member 101 is a rod-shaped member such as a cylinder, and in this example, the upper end thereof is integrally formed with the lower portion of the stopper member 90 of the power element 70. It is good also as a separate structure which an upper end is attached to the stopper member 90, or contact | abuts. The first rod-shaped member 101 passes through the pressure equalizing hole 32, and the lower end thereof is connected to or abuts on the ring member 105.

  As shown in FIG. 2, the ring member 105 has a cylindrical shape having a predetermined thickness B and a predetermined width C except for grooves and recesses 105a and 105b for connecting to the first and second rod-shaped members 101 and 102. Both ends (front end edge 105f and rear end edge 105g in FIG. 2) of the member (cylindrical part) have a semicircular cross section, and the overall cross section has an oval (race track) shape. ing. The outer diameter 105 d of the ring member 105 is set to be smaller than the inner diameter 30 a of the return passage 30. The ring member 105 is disposed in the return passage 30 so that the central axis of the cylindrical portion thereof is coincident with or parallel to the central axis of the return passage 30, and is connected to the lower end of the first rod-shaped member 101 at the outer peripheral upper portion 105a. The lower part 105b is connected to the second rod-like member 102. In this example, the outer peripheral upper portion 105a and the outer peripheral lower portion 105b are provided with grooves and dents so that they can be easily connected to the first rod-shaped member 101 and the second rod-shaped member 102, and the first and second rod-shaped members are provided on this. Although the end portions of the members 101 and 102 are engaged or fixed, these connection modes are not particularly limited to this configuration.

  The thickness B and the width C of the ring member 105 are determined so as to maintain a strength suitable for transmitting the displacement of the diaphragm 73 to the valve member 40 between the first rod-shaped member 101 and the second rod-shaped member 102. Composed of width. In the first embodiment, the width C of the ring member 105 is set larger than the thickness B.

  The second rod-like member 102 is a rod-like member such as a cylinder, and the upper end thereof is connected to the ring member 105, and the lower end thereof is disposed so as to penetrate the through hole 29 and contact the valve member 40.

  Next, the operation will be described. In the expansion valve 10 of the first embodiment of the present invention, the refrigerant flows in from the inlet port 20, expands through the valve chamber 24 and the valve hole 26, and is sent out from the outlet port 28 to the evaporator (not shown). It is. Further, the refrigerant sent out from the evaporator passes from the left inlet of the return passage 30 so as to escape to the right outlet, and returns to the compressor (not shown).

  As shown in FIG. 3, when the refrigerant flow A passing through the return passage 30 reaches the displacement transmission member 100, the refrigerant near the center of the high flow velocity passes through the inside of the ring member 105 and exits from the return passage 30. And sent to a compressor (not shown). A part of the refrigerant passing through the return passage 30 flows into the lower portion of the power element 70 from the pressure equalizing hole 32. The movement of the displacement transmitting member 100 is controlled by changing the pressure of the working gas in the pressure working chamber 75 in accordance with the temperature change of the refrigerant flowing into the lower part of the power element 70.

  Specifically, the stopper member 90 moves up and down in response to the movement of the diaphragm 73 deformed in accordance with the fluctuation of the internal pressure in the pressure working chamber 75 of the power element 70. Then, the displacement of the stopper member 90 is transmitted to the valve member 40 via the displacement transmission member 100. Thereby, it can serve as an expansion valve. At this time, the ring member 105 of the displacement transmitting member 100 moves up and down in the return passage 30.

Thus, the displacement transmission member 100 is configured to have the ring member 105 in the return passage 30, so that the refrigerant in the vicinity of the center of the return passage 30 having a high flow velocity passes through the inside of the ring member 105 where no obstacle exists. First, there is no Karman vortex generation in this region.
Further, the refrigerant that collides with the front end edge 105f of the ring member 105 passes through the inner peripheral wall and the outer peripheral wall of the ring member 105 because the front end edge 105f and the rear end edge 105g have a smooth semicircular shape. Also when moving backward from the rear edge 105g, the generation of Karman vortices is suppressed.
Thus, the refrigerant passing through the return passage 30 does not hit an obstacle (the valve rod in the conventional expansion valve) in the central portion in the return passage 30 where the refrigerant speed is high unlike the conventional expansion valve, and thus the displacement The generation of Karman vortices in the wake of the transmission member 100 is extremely less than that of the conventional expansion valve, so that it is possible to prevent or effectively reduce abnormal noise (refrigerant passing sound) due to the generation and disappearance of vortices.

  Further, in this example, the ring member 105 has a width C larger than the diameter of the first rod-like member 101, so that the passage of the refrigerant flowing into the power element 70 from the pressure equalizing hole 32 is narrowed. Specifically, the minimum gap D through which the refrigerant passes when the ring member 105 has a certain width C with respect to the minimum gap D through which the refrigerant passes when the ring member 105 is not provided in FIG. It becomes. At this time, the gap E is narrower than the gap D. For this reason, it becomes difficult for a refrigerant | coolant to flow into the lower part of the power element 70, the reaction speed of the power element 70 is made slow, and the hunting which the valve member 40 repeats opening and closing periodically can be prevented.

  FIG. 4 is a longitudinal sectional view of the expansion valve according to the first embodiment when a joint (a tip portion of a refrigerant passage pipe not shown) is attached to the return passage 30. FIG. 5 is a partially enlarged sectional view of the vicinity of the ring member 105 in FIG.

  In FIG. 4, joints 130 are inserted into the return passage 30 of the expansion valve 10 from both sides of the valve body 11. The joint 130 has, for example, a shape having an insertion portion 131 at one end of a main body portion 135 of a refrigerant passage pipe (not shown). The outer diameter of the insertion portion 131 is smaller than the outer diameter of the main body portion 135. As a result, a step portion 134 is formed between the main body portion 135 and the insertion portion 131. The outer diameter of the insertion portion 131 is an outer diameter that can be fitted to the inner wall surface of the return passage 30. The outer diameter of the main body 135 is larger than the inner diameter 30 a of the inner wall surface of the return passage 30. And the insertion part 131 of the joint 130 is inserted until the step part 134 contacts the side surface of the valve body 11, and the joint 130 and the valve body 11 are connected.

  In the connected state of the joint 130, the distal end portion 132 of the joint 130 is disposed in the vicinity of the ring member 105. Further, a groove portion 133 is formed on the outer diameter side of the insertion portion 131 of the joint 130, and a seal member 140 such as an O-ring is disposed in the groove portion 133.

  As shown in FIG. 5, the inner diameter 136 of the joint 130 is formed to be at least smaller than the outer diameter 105 d of the ring member 105. Further, the inner diameter 136 of the joint 130 may be formed smaller than the inner diameter 105 c of the ring member 105.

  Further, if the gap F between the distal end portion 132 of the joint 130 and the ring member 105 is narrowed, it becomes difficult for the refrigerant to flow to the lower portion of the power element 70, the reaction speed of the power element 70 is slowed, and hunting can be prevented. . The gap F can be narrowed by increasing the width C of the ring member 105 or lengthening the insertion portion 131 of the joint 130. By adjusting the relationship including the relationship between the ring member 105 and the gap E between the pressure equalizing holes 32, an appropriate time constant for the reaction speed of the power element 70 can be controlled.

  Further, the inner diameter 136 of the joint 130 is made at least smaller than the outer diameter 105d of the ring member 105, and the gap F between the tip 132 of the joint 130 and the ring member 105 is set to a predetermined value or less. Even when receiving a force in the direction of rotation around the valve shaft from the refrigerant passing through the passage 30, the ring member 105 can be prevented from rotating by contacting the tip 132 of the joint 130. It is possible to prevent adverse effects on the passage of the refrigerant.

  If the inner diameter 136 of the joint 130 is smaller than the inner diameter 105 c of the ring member 105, most of the refrigerant passes through the inner diameter 105 c of the ring member 105 when reaching the ring member 105. For this reason, the ring member 105 itself hardly affects the passage of the refrigerant.

  FIG. 6 is an exploded perspective view for explaining an assembly example of the expansion valve of the first embodiment.

  First, the valve member 40, the support member 42, the coil spring 44, the seal member 54, and the plug 50 are inserted from the female screw hole 11a on the lower side of the valve body 11. Then, the plug 50 is screwed into the female screw hole 11a of the valve body 11 and attached. Thereby, as shown in FIG. 1, the valve member 40, the support member 42, the coil spring 44, and the plug 50 are arranged in the valve chamber 24.

  Subsequently, the second rod-like member 102 is inserted from the pressure equalizing hole 32 at the upper part of the valve body 11, and passes through the return passage 30 to the through hole 29. At this time, the lower part of the second rod-shaped member 102 contacts the valve member 40. Next, the ring member 105 is inserted from the opening of the return passage 30 to the vicinity of the center, and the upper end of the second rod-shaped member 102 and the lower outer peripheral portion 105 b of the ring member 105 are connected.

  Subsequently, a first rod-like member 101 (not shown in FIG. 6) provided at the lower portion of the stopper member 90 is inserted from the pressure equalizing hole 32, and the lower end of the first rod-like member 101 is connected to the outer peripheral upper portion 105 a of the ring member 105. Connect to. At the same time, the power element 70 is attached by screwing the male screw 72 a to the power element attaching portion 12 via the packing 35. Thereby, the expansion valve 10 is assembled. When the first rod-shaped member 101 is separate from the stopper member 90, the first rod-shaped member 101 is inserted from the pressure equalizing hole 32, and the lower end portion of the ring member 105 is inserted from the return passage 30. Attach to 105a. Then, the power element 70 may be attached to the power element attachment portion 12 with the upper end of the first rod-like member 101 attached to or in contact with the stopper member 90.

  By such an assembling method, the ring member 105 can be disposed in the valve main body 11 without changing the shape of the valve main body 11 conventionally used.

  FIG. 7 is an exploded perspective view showing a modified example and an assembled example of the expansion valve of the first embodiment, and is the same view as FIG. In FIG. 7, the same reference numerals as those in the above-mentioned drawings indicate the same or equivalent parts. In the modification shown in FIG. 7, an assembly hole 33 is formed in the valve body 11 for assembly.

  The assembly hole 33 is formed in a rectangular shape in the upper part of the valve body 11 so as to be concentric with the pressure equalizing hole 32 and to pass through the ring member 105 in a direction perpendicular to the central axis. In this example, the orientation of the rectangular contour of the assembly hole 33 is set so that the ring member 105 is set in a predetermined direction in the valve body 11 just by inserting the ring member 105.

  Next, the assembly method will be described. First, the valve member 40, the support member 42, the coil spring 44, the seal member 54, and the plug 50 are inserted from the female screw hole 11a on the lower side of the valve body 11. Then, the plug 50 is screwed into the female screw hole 11a of the valve body 11 and attached. Thereby, as shown in FIG. 1, the valve member 40, the support member 42, the coil spring 44, and the plug 50 are arranged in the valve chamber 24.

  Subsequently, the second rod-shaped member 102, the ring member 105, and the first rod-shaped member 101 (not shown in the view angle in FIG. 7) are inserted into the valve body 11 through the assembly hole 33. And the upper end of the 1st rod-shaped member 101 is attached to the stopper member 90 of the power element 70, and the power element 70 is screwed and attached to the power element attachment part 12 via the packing 35 after that. Thereby, the expansion valve 10 is assembled.

  The second rod-shaped member 102, the ring member 105, and the first rod-shaped member 101 are all configured in advance or a part thereof, and are inserted into the valve body 11 in advance. Also good.

  Thus, by providing the assembly hole 33, the displacement transmitting member 100 can be mounted in the valve body 11 by inserting components only from the same direction (vertical direction, that is, the arrow Y direction in FIG. 1) with respect to the valve body 11. Therefore, the assembly can be performed efficiently.

<Second embodiment>
FIG. 8 is an enlarged longitudinal sectional view of a ring member in the second embodiment of the expansion valve according to the present invention. The second embodiment has a configuration in which the displacement transmission member 100 of the first embodiment is replaced with a displacement transmission member 200, and the other portions are the same as those shown in the first embodiment (FIGS. 1 to 7). The description of common parts is omitted.

  The displacement transmitting member 200 is sandwiched between the first rod-shaped member 101 located on the power element 70 side, the second rod-shaped member 102 located on the valve member 40 side, and the first rod-shaped member 101 and the second rod-shaped member 102. The ring member 205 is constituted. The first rod-like member 101 and the second rod-like member 102 are the same as those in the first embodiment. In short, only the ring member 205 is different from the first embodiment.

  The ring member 205 has an elliptical cross section on a plane passing through the central axis thereof. Here, the outermost outer diameter 205 d of the ring member 205 is smaller than the inner diameter 30 a of the return passage 30. Further, it is desirable that the innermost inner diameter 205c of the ring member 205 is set to a size that allows the refrigerant to pass through so as not to cause pressure loss. The ring member 205 is connected to the first rod-shaped member 101 at the outer peripheral upper portion 205a, and is connected to the second rod-shaped member 102 at the outer peripheral lower portion 205b. Further, a groove or a recess may be provided in the outer peripheral upper portion 205 a and the outer peripheral lower portion 205 b of the ring member 205 so that the ring member 205 can be easily connected to the first rod-shaped member 101 and the second rod-shaped member 102.

  The cross-sectional shape of the ring member 205 is an ellipse whose major axis direction is the central axis direction of the return passage 30 and whose minor axis direction is a direction orthogonal to the direction of the return passage 30. Not only the ellipse but also the major axis and the minor axis can be the same length to form a circular cross section.

  Then, the refrigerant passing through the return passage 30 has an elliptical cross-sectional shape of the ring member 205, so that when the refrigerant passes through the ring member 205, as in the case of a cylindrical shape having an end face on the upstream side or the downstream side. Separation of the fluid is less likely to occur, and as a result, the resistance to the ring member 205 is reduced and the refrigerant passing sound around the ring member 205 is quiet.

<Third embodiment>
FIG. 9 is an enlarged longitudinal sectional view of the ring member in the third embodiment of the expansion valve according to the present invention, and is the same view as FIG. The third embodiment has a configuration in which the displacement transmission member 100 of the first embodiment is replaced with a displacement transmission member 300, and the rest are the same as those shown in the first embodiment (FIGS. 1 to 7). Therefore, the description of the common parts is omitted.

  In the third embodiment, instead of the ring member 105 described in the first embodiment, the ring member 305 has a teardrop-shaped cross-section in a plane passing through the central axis thereof.

  The displacement transmission member 300 is sandwiched between the first rod-shaped member 101 located on the power element 70 side, the second rod-shaped member 102 located on the valve member 40 side, and the first rod-shaped member 101 and the second rod-shaped member 102. The ring member 305 is configured. The first rod-like member 101 and the second rod-like member 102 are the same as in the first embodiment.

  The ring member 305 has a teardrop shape in cross-section on a plane passing through the central axis. The ring member 305 is disposed in the return passage 30 so that the direction of the central axis thereof coincides with or parallel to the direction of the central axis of the return passage 30, and is connected to the first rod-like member 101 at the outer peripheral upper portion 305a. The second rod-shaped member 102 is connected at 305b. Here, the outermost outer diameter 305 d of the ring is smaller than the inner diameter 30 a of the return passage 30. Further, it is desirable that the innermost inner diameter 305c of the ring is set to a size that allows the refrigerant to pass without causing pressure loss. Further, in the ring member 305, a groove or a recess may be provided in the outer peripheral upper part 305 a and the outer peripheral lower part 305 b so as to be easily connected to the first rod-shaped member 101 and the second rod-shaped member 102.

  Here, in the teardrop shape, the upstream end portion 306 through which the refrigerant flows is a round shape with a semicircular or semi-elliptical shape on the front end side, and a streamline portion 307 on the downstream side. The streamline part 307 is smoothly connected to the tip part 306, and has a curved shape in which the thickness decreases toward the wake side. The shape of the ring member 305 is symmetrical on the inner peripheral side and the outer peripheral side, and the rear end 308 is sharp or formed with a smaller curvature than the front end 306. The length of the streamline portion 307 in the return passage 30 direction is set to be at least longer than the length of the distal end portion 306 in the return passage 30 direction.

  For the refrigerant that hits the ring member 305, by making the cross-sectional shape of the ring member 305 a teardrop-shaped, the downstream of the refrigerant when passing through the ring member 305 rather than when the cross-sectional shape is rectangular or elliptical As a result, the resistance to the ring member 305 is reduced, and the sound of the refrigerant flowing around the ring member 305 becomes quieter.

<Fourth embodiment>
FIG. 10 is a longitudinal sectional view showing a fourth embodiment of the expansion valve according to the present invention. FIG. 11 is a partial cross-sectional view showing a dimensional relationship near the ring portion in FIG. 10 and is equivalent to FIG. In the fourth embodiment, among the configurations of the expansion valve 10, those having the same functions and arrangement as those shown in the first embodiment (FIGS. 1 to 7) are denoted by the same reference numerals. Further, re-explanation will be omitted for parts other than the main part of the invention.

  In the fourth embodiment, a guide part 110 is provided on the refrigerant passage upstream side of the displacement transmission member 100 (ring member 105) in the return passage 30 of the valve body 11. The guide portion 110 is provided integrally with the valve main body 11 so as to protrude toward the central axis side (inside) in the return passage 30. Further, the inner diameter 111 of the guide portion 110 is formed to be at least smaller than the outer diameter 105 d of the ring member 105. In this example, the inner diameter 111 of the guide part 110 is made smaller than the inner diameter 105 c of the ring member 105.

  By setting the inner diameter 111 of the guide portion 110 to be at least smaller than the outer diameter 105d of the ring member 105 and setting the gap K between the guide portion 110 and the ring member 105 to be narrow, for example, the ring member 105 can return to the return path. Even when a force in the direction of rotation around the valve shaft is received from the refrigerant passing through 30, the ring member 105 can be prevented from rotating by the ring member 105 coming into contact with the guide portion 110, and the refrigerant can pass therethrough. Can be prevented from being adversely affected.

  Further, by narrowing the gap K between the guide part 110 and the ring member 105, it becomes difficult for the refrigerant to flow under the power element 70, the reaction speed of the power element 70 is slowed, and hunting can be prevented. This gap K is determined by the width C of the ring member 105 and the formation position of the guide portion 110 in the direction of the return passage 30.

  Furthermore, the guide part 110 is installed on the upstream side of the passage of the refrigerant from the ring member 105, so that the refrigerant that directly hits the ring member 105 can be reduced. Thereby, refrigerant passage noise can be reduced. In particular, by forming the inner diameter 111 of the guide portion 110 to be smaller than the inner diameter 105c of the ring member 105, most of the refrigerant that has passed through the guide portion 110 passes within the range of the inner diameter 105c of the ring member 105. . As a result, the refrigerant passing sound can be further reduced.

  When assembling the displacement transmission member 100 including the ring member 105 according to the fourth embodiment, in the assembly example shown in FIG. 6, the ring member 105 may be inserted into the return passage 30 from the side where the guide portion 110 is not formed. .

<Fifth embodiment>
FIG. 12 is a longitudinal sectional view showing a fifth embodiment of the expansion valve according to the present invention. 13 is a partial cross-sectional view showing a dimensional relationship near the ring portion in FIG. 12, and is equivalent to FIG. 2 and FIG. In the fifth embodiment, among the configurations of the expansion valve 10, the functions, the arrangement, and the like that are the same as those shown in the first embodiment (FIGS. 1 to 7) are denoted by the same reference numerals. Further, re-explanation will be omitted for parts other than the main part of the invention.

  In the fifth embodiment, the guide portion 110 shown in FIGS. 10 and 11 is separated from the valve body 11 (guide member 120). In the fifth embodiment, a guide member 120 is attached to the upstream side of the displacement transmission member 100 in the return passage 30 of the valve body 11. The guide member 120 has a step portion 122 c in the outer diameter portion 122, and the step portion 122 c is engaged with and attached to a step portion 31 formed on the inner surface of the return passage 30. The step portion 31 is formed in a shape that decreases in the vicinity of the displacement transmitting member 100 so that the inner diameter 30b is smaller than the inner diameter 30a of the portion that is not reduced.

  The guide member 120 has a hole in the center, and the inner diameter 121 of the hole is formed at least smaller than the outer diameter 105 d of the ring member 105. Further, the outer diameter portion 122 of the guide member 120 is formed with a first outer diameter portion 122a, a second outer diameter portion 122b, and a stepped portion 122c therebetween.

  The guide member 120 is attached from the upstream side in which the refrigerant flows in the return passage 30. The step 122c of the outer diameter portion 122 of the guide member 120 and the step 31 of the return passage 30 can be fitted and attached.

  The refrigerant passing through the return passage 30 from the evaporator first passes within the range of the inner diameter 121 of the guide member 120 (inside the guide member 120), and then passes through the ring member 105 and exits the return passage 30. Go.

  By making the inner diameter 121 of the guide member 120 at least smaller than the outer diameter 105d of the ring member 105 and forming the gap L between the guide member 120 and the ring member 105 narrow, for example, the refrigerant through which the ring member 105 passes through the return passage 30 Even when receiving a force in the direction of rotation about the valve shaft from the ring, the ring member 105 can be prevented from rotating by contacting the guide member 120, and the passage of the refrigerant is not adversely affected. Can be.

  Further, by narrowing the gap L between the guide member 120 and the ring member 105, it becomes difficult for the refrigerant to flow under the power element 70, the reaction speed of the power element 70 can be reduced, and hunting can be prevented. The gap L is determined by the width C of the ring member 105 and the installation position of the guide member 120 in the direction of the return path 30 and the thickness of the guide member 120.

  Further, since the guide member 120 is installed on the upstream side of the passage of the refrigerant from the ring member 105, the refrigerant that directly hits the ring member 105 can be reduced. Thereby, the resistance to the ring member 105 and the refrigerant passing sound due to the flowing refrigerant can be reduced.

  Further, by forming the inner diameter 121 of the guide member 120 to be smaller than the inner diameter 105 c of the ring member 105, most of the refrigerant that has passed through the guide member 120 passes through the inner diameter 105 c of the ring member 105. As a result, it is possible to further reduce resistance to the ring member 105 and refrigerant passing sound due to the flowing refrigerant.

  Thus, by making the guide member 120 a separate component from the valve body 11, the guide member 120 can be attached to the conventional expansion valve without changing the valve body 11.

  As described above, the first to fifth examples of the embodiment of the present invention have been shown. However, the present invention is not limited to the above-described examples, and includes various modifications. For example, the invention is not limited to the one having all the configurations (structures) provided in the above-described embodiments. It is also possible to delete a part of the configuration of a certain embodiment, replace it with the configuration of another embodiment, or add the configuration of another embodiment to the configuration of a certain embodiment.

For example, the power element 70 shown in the above embodiment shows the attachment by screws, but in addition to this, a cylindrical portion formed on the upper part of the valve body is provided, and the power element 70 is inserted inside the cylindrical portion. The power element 70 may be attached by caulking the cylindrical portion.
In addition, the cross-sectional shape of the ring member (cross-sectional shape cut along a plane including the central axis of the cylindrical portion of the ring-shaped member) is an ellipse, an ellipse, and a teardrop shape. Any streamline shape including an airfoil, a rhombus, and the like may be used as long as Karman vortices hardly occur on the rear end side.

DESCRIPTION OF SYMBOLS 10 Expansion valve 11 Valve main body 20 Inlet port 24 Valve chamber 25 Valve seat 26 Valve hole 28 Outlet port 29 Through hole 30 Return passage 32 Pressure equalizing hole 40 Valve member 42 Support member 44 Coil spring 50 Plug 60 Valve rod 70 Power element 71 Top cover Member 72 Receiving member 73 Diaphragm 90 Stopper member 100, 200, 300 Displacement transmission member 101 First rod member 102 Second rod member 105, 205, 305 Ring member 110 Guide portion 120 Guide member 130 Joint

Claims (5)

A power element including an upper lid member, a receiving member, and a diaphragm sandwiched between the upper lid member and the receiving member;
An inlet port, a valve chamber communicating with the inlet port, a valve hole communicating with the valve chamber, an outlet port communicating with the valve hole, a valve seat formed at an opening of the valve hole on the valve chamber side, and the outlet A return passage through which the refrigerant exiting the port passes, and a valve body including a power element mounting portion;
A valve member for controlling an opening area of the valve hole;
A displacement transmitting member that transmits the displacement of the diaphragm to the valve member and drives the valve member;
With
The displacement transmitting member includes a first rod-shaped member positioned on the power element side, a second rod-shaped member positioned on the valve member side, and a cylinder sandwiched between the first rod-shaped member and the second rod-shaped member. A ring member having a shape part,
The expansion valve according to claim 1, wherein the ring member is disposed in the return passage so that a direction of a central axis of the cylindrical portion coincides with a flow direction of the refrigerant. The ring member has a streamline shape in a cross section cut by a plane having the central axis.
The expansion valve according to claim 1. The valve body includes a guide portion that protrudes toward the center of the return passage on the upstream side of the ring member in the return passage.
The expansion valve according to claim 1 or 2.   The expansion valve according to any one of claims 1 to 3, wherein the first rod-shaped member is integrally formed with a stopper member that contacts the diaphragm.   5. The displacement transmitting member according to claim 1, wherein all or a part of the first rod-shaped member, the ring member, and the second rod-shaped member are integrally formed. The expansion valve described in 1.

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