JP2022163447A - expansion valve - Google Patents

Abstract

To provide an expansion valve capable of connecting double piping and suppressing vibration of a valve body unit.SOLUTION: An expansion valve can be connected with double piping in which a low-pressure refrigerant passes the inside of inner piping and a high-pressure refrigerant passes an intermediate flow path as a space between the inner piping and outer piping disposed around the inner piping. The expansion valve includes: a valve body including a valve chamber having a valve seat and a high-pressure flow path in which a high-pressure refrigerant flows while being connected from the intermediate flow path to the valve chamber; and a valve body unit including a valve body that can be seated in the valve seat. The high-pressure flow path is formed while being tilted relative to an axis of the valve body unit such that a high-pressure refrigerant flowing through the high-pressure flow path from the intermediate flow path to the valve chamber hits against the valve body unit.SELECTED DRAWING: Figure 2

Description

The present invention relates to expansion valves.

2. Description of the Related Art Conventionally, in a refrigerating cycle used in an air conditioner or the like mounted on an automobile, a temperature-sensitive expansion valve that adjusts the amount of refrigerant that passes through according to the temperature is used.

A general expansion valve is separately connected to a high-pressure pipe through which refrigerant is delivered from a condenser of a refrigeration cycle and a low-pressure pipe through which refrigerant is delivered from an evaporator. On the other hand, in the expansion valve disclosed in Patent Document 1, a system is disclosed in which a double pipe with a low-pressure pipe on the inside and a high-pressure pipe on the outside is connected to the expansion valve. According to such a system, it is possible to simplify the routing of piping.

JP 2020-94793 A

By the way, the expansion valve is provided with a power element having a temperature sensing portion sealed with an inert gas or the like. The power element opens and closes the valve via an operating rod by utilizing the fact that the volume of gas changes due to the heat transferred between the inside and outside of the temperature sensing part. However, when the time constant of the temperature sensing part is small, there is a possibility that the valve element vibrates and causes a so-called hunting phenomenon in which the valve is repeatedly opened and closed. However, Patent Document 1 does not disclose a specific structure for suppressing the hunting phenomenon.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an expansion valve capable of connecting double pipes and suppressing vibration of a valve body unit.

In order to achieve the above object, the expansion valve according to the present invention
An expansion valve capable of connecting a double pipe in which a low-pressure refrigerant passes through an inner pipe, and a high-pressure refrigerant passes through an intermediate passage that is a space between an outer pipe arranged around the inner pipe and the inner pipe. and
a valve body including a valve chamber having a valve seat; and a high-pressure passage connected to the valve chamber from the intermediate passage through which a high-pressure refrigerant flows;
a valve body unit including a valve body that can be seated on the valve seat;
The high-pressure flow path is inclined with respect to the axis of the valve body unit so that the high-pressure refrigerant flowing through the high-pressure flow path from the intermediate flow path toward the valve chamber hits the valve body unit. characterized by

ADVANTAGE OF THE INVENTION By this invention, the expansion valve which can connect double piping and can suppress the vibration of a valve body unit can be provided.

FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve of this embodiment is applied to a refrigerant circulation system. FIG. 2 is a vertical cross-sectional view showing an enlarged periphery of the valve body of the present embodiment. FIG. 3 is a longitudinal sectional view similar to FIG. 2 showing a modification of this embodiment. FIG. 4 is a perspective view showing a cover member according to this modification. FIG. 5 is a longitudinal sectional view of an expansion valve according to a second embodiment;

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(definition of direction)
In this specification, the direction from the valve body 3 to the operating rod 5 is defined as "upward direction", and the direction from the operating rod 5 to the valve body 3 is defined as "downward direction". Therefore, in this specification, the direction from the valve body 3 toward the operating rod 5 is referred to as the "upward direction" regardless of the orientation of the expansion valve 1 .

(First embodiment)
An outline of an expansion valve 1 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 of this embodiment is applied to a refrigerant circulation system 100. As shown in FIG. FIG. 2 is a vertical cross-sectional view showing an enlarged periphery of the valve body of the present embodiment.

In this embodiment, expansion valve 1 is fluidly connected to compressor 101 , condenser 102 and evaporator 104 . Let L be the axis of the expansion valve 1 .

In FIG. 1, an expansion valve 1 includes a valve body 2 having a valve chamber VS, a valve body 3, an urging device 4, an operating rod 5, and a power element 8.

The valve body 2 includes, in addition to the valve chamber VS, a first channel (also referred to as a high-pressure channel) 21 , a second channel 22 , an intermediate chamber 221 and a return channel 23 . The first flow path 21 is a supply-side flow path, and refrigerant (also referred to as fluid) is supplied to the valve chamber VS via the supply-side flow path. The second flow path 22 is a discharge side flow path (also referred to as an outlet side flow path), and the fluid in the valve chamber VS is discharged out of the expansion valve through the valve communication hole 27, the intermediate chamber 221 and the discharge side flow path. be done. A pipe (not shown) connected to the inlet side of the evaporator 104 is connected to the second flow path 22 .

The return channel 23 extends perpendicularly to the axis L through the valve body 2 . Let O be the axis of the return channel 23 . The return channel 23 includes an inlet channel 23a to which a pipe (not shown) connected to the outlet side of the evaporator 104 is connected, an intermediate channel (also referred to as a low-pressure channel) 23b, and a first channel having a larger diameter than the intermediate channel 23b. An enlarged diameter hole 23c, a second enlarged diameter hole 23d larger in diameter than the first enlarged diameter hole 23c, and a third enlarged diameter hole 23e larger in diameter than the second enlarged diameter hole 23d are coaxially connected. . Although the details will be described later, the intermediate passage 23b communicates with the lower space LS of the power element 8 via the vertical hole 2a.

A double pipe 50 is connected to the return flow path 23 . The double pipe 50 has an inner pipe 51 whose end is fitted to the intermediate passage 23b, and an outer pipe 52 which encloses the inner pipe 51 and whose end is fitted to the second enlarged diameter hole 23d. The inner pipe 51 has a flange portion 51a near the end thereof, which is formed by expanding a portion of the pipe and crushing it in the axial direction. An O-ring OR1 held by the flange portion 51a is arranged between the end portion of the inner pipe 51 and the flange portion 51a, thereby sealing the space between the first enlarged diameter hole 23c and the outer circumference of the inner pipe 51. stop to prevent refrigerant leakage.

The outer pipe 52 also has a flange portion 52a in the vicinity of the end thereof, which is formed by expanding a part of the pipe and crushing it in the axial direction. The end of the outer pipe 52 does not touch the stepped portion of the second enlarged diameter hole 23 d , and the flange portion 52 a abuts the side surface of the valve body 2 . An O-ring OR2 held by the flange portion 52a is arranged between the end portion of the outer pipe 52 and the flange portion 52a, thereby sealing the space between the third enlarged diameter hole 23e and the outer circumference of the outer pipe 52. stop to prevent refrigerant leakage.

The inner pipe 51 is connected to the inlet of the compressor 101 , and the annular space (referred to as an intermediate flow path) between the outer pipe 52 and the inner pipe 51 is connected to the outlet of the condenser 102 .

The first flow path 21 has an axis (central axis) X1 (FIG. 2) in a plane containing the axis L and the axis O, and is inclined with respect to the axis L and the axis O. The inner circumference of the diameter hole 23d is open. On the other hand, the first flow path 21 is coaxially provided with a small path 21a having a diameter smaller than that of the first flow path 21 at its lower end. This small path 21a is connected to the inner circumference of the valve chamber VS below the valve seat 20. As shown in FIG. That is, the inside of the second enlarged diameter hole 23 d and the valve chamber VS communicate with each other via the first flow path 21 . Referring to FIG. 2, when the small path 21a is projected along the axis X1 of the first flow path 21 toward the valve chamber VS, the projection image overlaps the valve body 3 and the valve body support .

The valve chamber VS and the intermediate chamber 221 communicate with each other via the valve seat 20 and the valve communication hole 27 . The actuating rod insertion hole 28 formed above the intermediate chamber 221 has the function of guiding the actuating rod 5, and the annular recess 29 formed above the actuating rod insertion hole 28 has the function of accommodating the ring spring 6. have The ring spring 6 has a plurality of spring pieces contacting the outer circumference of the operating rod 5 to apply a predetermined biasing force.

The valve body 3 is arranged in the valve chamber VS. When the valve body 3 is seated on the valve seat 20 of the valve body 2, the refrigerant flow through the valve passage hole 27 is restricted. This state is called a non-communication state. However, even when the valve body 3 is seated on the valve seat 20, a limited amount of refrigerant may flow. On the other hand, when the valve body 3 is separated from the valve seat 20, the flow of refrigerant passing through the valve hole 27 increases. This state is called a communication state.

The operating rod 5 is inserted through the valve passage hole 27 with a predetermined gap. A lower end of the operating rod 5 is in contact with the upper surface of the valve body 3 . The upper end of the operating rod 5 is fitted into the fitting hole at the lower end of the stopper member 84 .

The operating rod 5 can press the valve body 3 along the axis L in the valve opening direction against the biasing force of the biasing device 4 . When the operating rod 5 moves downward, the valve body 3 is separated from the valve seat 20 and the expansion valve 1 is opened.

The urging device 4 has a coil spring 41 formed by spirally winding a wire having a circular cross section, a valve body support 42 , and a spring receiving member 43 .

The valve body support 42 is attached to the upper end of the coil spring 41, and the spherical valve body 3 is welded to the upper surface thereof, and both are integrated. The valve body 3 and the valve body support 42 constitute a valve body unit. However, the valve body unit may be composed of only the valve body 3 . In that case, when the small path 21a is projected onto the valve chamber VS side along the axis X1 of the first flow path 21, the projection image overlaps only the valve body 3. As shown in FIG. The axis of the valve body unit means a straight line including the trajectory along which the center of gravity of the valve body unit moves according to the valve opening operation, and coincides with the axis L of the expansion valve 1 here.

A spring receiving member 43 that supports the lower end of the coil spring 41 can be screwed into the valve body 2 and has a function of sealing the valve chamber VS and a function of adjusting the biasing force of the coil spring 41. .

The power element 8 has a plug 81 , an upper lid member 82 , a diaphragm 83 , a receiving member 86 and a stopper member 84 .

The top opening of the substantially conical upper lid member 82 can be sealed with a plug 81 .

The diaphragm 83 is made of a thin metal (for example, SUS) plate material having a plurality of concentric concave and convex shapes, and has an outer diameter substantially the same as the outer diameters of the upper cover member 82 and the receiving member 86 .

The receiving member 86 is formed by press-molding a metal plate, for example, and connects a flange portion and a hollow cylindrical portion.

The stopper member 84 is arranged between the upper lid member 82 and the receiving member 86 , and its upper surface is in contact with the center of the lower surface of the diaphragm 83 .

In the assembly of the power element 8, while the stopper member 84 is arranged between the diaphragm 83 and the receiving member 86, the outer peripheral portions of the upper lid member 82, the diaphragm 83, and the receiving member 86 are overlapped, and the outer peripheral portions are, for example, Circumferential welding is performed by TIG welding, laser welding, plasma welding, or the like.

Subsequently, after the working gas is sealed from the opening formed in the upper lid member 82 into the space (referred to as pressure actuation chamber PO) surrounded by the upper lid member 82 and the diaphragm 83, the opening is sealed with the plug 81, and further The plug 81 is fixed to the upper cover member 82 using projection welding or the like.

When the power element 8 assembled as described above is assembled to the valve main body 2, the external thread 86a on the outer periphery of the lower end of the hollow cylindrical portion of the receiving member 86 is inserted into the vertical hole 2a communicating with the return passage 23 of the valve main body 2. It is screwed into the internal thread 2b formed on the circumference. As the male screw 86a of the receiving member 86 is screwed with respect to the female screw 2b, the lower surface of the flange portion of the receiving member 86 comes into contact with the upper end surface of the valve body 2. As shown in FIG. Thereby, the power element 8 can be fixed to the valve body 2 .

At this time, a packing PK is interposed between the power element 8 and the valve body 2 to prevent refrigerant leakage when the power element 8 is attached to the valve body 2 . In this state, the lower space LS of the power element 8 communicates with the return channel 23 through the vertical hole 2a.

(Operation of expansion valve)
An operation example of the expansion valve 1 will be described with reference to FIG. A high-pressure refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1 . Further, the refrigerant adiabatically expanded by the expansion valve 1 is delivered to the evaporator 104, where it exchanges heat with the air flowing around the evaporator. Refrigerant returning from the evaporator 104 enters the return passage 23 of the expansion valve 1, passes through the inner pipe 51 of the double pipe 50, and is returned to the compressor 101 side. At this time, as the refrigerant passes through the evaporator 104 , the fluid pressure in the return channel 23 becomes lower than the fluid pressure in the second channel 22 . The refrigerant that has passed through the evaporator 104 is called low-pressure refrigerant.

A low-pressure refrigerant is sent from the expansion valve 1 to the compressor 101 and a high-pressure refrigerant is sent to the expansion valve 1 from the condenser 102 . More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the valve chamber VS via the intermediate flow passage between the outer pipe 52 and the inner pipe 51 of the double pipe 50 and the first flow passage 21. .

When the valve body 3 is seated on the valve seat 20 (in a non-communication state), the valve body 3 is delivered from the valve chamber VS to the evaporator 104 through the valve communication hole 27, the intermediate chamber 221 and the second flow path 22. Refrigerant flow is restricted. On the other hand, when the valve body 3 is separated from the valve seat 20 (when in a communicating state), the gas flows from the valve chamber VS to the evaporator 104 through the valve communication hole 27, the intermediate chamber 221 and the second flow path 22. The flow rate of the pumped refrigerant increases. The switching between the closed state and the open state of the expansion valve 1 is performed by the operating rod 5 connected to the power element 8 via the stopper member 84 .

In FIG. 1, inside the power element 8, a pressure actuation chamber PO and a lower space LS, which are partitioned by a diaphragm 83, are provided. Therefore, when the working gas in the pressure working chamber PO is liquefied, the diaphragm 83 and the stopper member 84 rise, so that the working rod 5 moves upward according to the biasing force of the coil spring 41 . On the other hand, when the liquefied working gas is vaporized, the diaphragm 83 and the stopper member 84 are pressed downward, so that the working rod 5 moves downward. Thus, the expansion valve 1 is switched between the open state and the closed state.

Further, the lower space LS of the power element 8 communicates with the return channel 23 through the vertical hole 2a. Therefore, the volume of the working gas in the pressure working chamber PO changes according to the temperature and pressure of the refrigerant flowing through the return passage 23, and the working rod 5 is driven. In other words, in the expansion valve 1 shown in FIG. 1, the amount of refrigerant supplied from the expansion valve 1 toward the evaporator 104 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1. adjusted.

By the way, if the time constant of the power element 8 is relatively small, a hunting phenomenon is likely to occur, which may cause the valve body 3 to vibrate. In contrast, according to the present embodiment, the axis X1 of the first flow path 21 is a straight line, and the valve body 3 or the valve body support 42 is arranged on an extension line of the axis X1, or the axis of the first flow path 21 When the small path 21a is projected along the line X1 toward the valve chamber VS, the projection image overlaps the valve body 3 or the valve body support . Therefore, when the valve is opened, the refrigerant flowing out from the small path 21a into the valve chamber VS is directed toward the valve body 3 or the valve body support 42 in an oblique direction (that is, in a direction inclined with respect to the axis L), as indicated by the arrow in FIG. Vibration can be suppressed by applying fluid resistance to the valve body 3 due to the loose contact. In particular, when the valve body 3 vibrates vertically, the refrigerant strikes the valve body 3 obliquely, so that resistance can be applied when the valve body 3 moves upward, and a high damping effect can be exhibited.

In addition, since the small path 21a having a diameter smaller than that of the first flow path 21 other than the small path 21a is arranged at the outlet of the first flow path 21, the outflow speed of the refrigerant is reduced by the throttling effect of the small path 21a. Vibration of the valve body 3 can be suppressed more effectively.

(Modification)
FIG. 3 is a longitudinal sectional view similar to FIG. 2 showing a modification of this embodiment. FIG. 4 is a perspective view showing a cover member 60 according to this modification. Since other configurations are the same as those of the above-described embodiment, the same reference numerals are given and redundant explanations are omitted.

In this modified example, a cover member 60 is arranged between the valve body support 42 and the coil spring 41 . As shown in FIG. 4, the cover member 60 has a topped cylindrical shape in which a peripheral wall 61 and a top wall 62 are connected, and a circular opening 63 is formed in the center of the top wall 62 . The cover member 60 can be formed by press-molding a metal plate.

The valve body support 42 has a cylindrical main body 42a and a flange portion 42b extending radially outward from the main body 42a. When the cover member 60 is installed to cover the upper portion of the coil spring 41 at the time of assembly, the lower surface of the top wall 62 abuts the upper end of the coil spring 41 , and the periphery of the upper portion of the coil spring 41 is surrounded by the peripheral wall 61 . Further, the valve body support 42 is approached from above the cover member 60, and the body 42a is fitted to the circular opening 63 and the inner circumference of the upper end of the coil spring 41, whereby assembly is performed. The top wall 62 of the cover member 60 is sandwiched and held between the upper end of the coil spring 41 and the flange portion 42b of the valve body support 42 .

According to this modification, as shown in FIG. 3, since the upper portion of the coil spring 41 is covered with the cover member 60, the refrigerant flowing from the small path 21a to the valve chamber VS flows along the smooth surface of the cover member 60. As a result, the generation of turbulent flow is suppressed, the vibration damping effect of the valve body 3 is enhanced, and the generation of abnormal noise can be suppressed.

(Second embodiment)
FIG. 3 is a longitudinal sectional view of an expansion valve 1A according to the second embodiment. This embodiment differs from the first embodiment only in the shape of the first flow path 21A of the valve body 2A. Since other configurations are the same as those of the above-described embodiment, the same reference numerals are given and redundant explanations are omitted. In addition, in this embodiment, 1st flow path 21A other than small path 21Aa comprises a 1st channel|path, and small path 21Aa comprises a 2nd channel|path.

In the first flow path 21A of the present embodiment, the axis X2 of the small path 21Aa intersects the axis X1 of the first flow path 21A other than the small path 21Aa. More specifically, the intersection angle θ2 between the axis X2 of the small path 21Aa and the axis L is smaller than the intersection angle θ1 between the axis X1 and the axis L of the first flow path 21A other than the small path 21Aa. According to the present embodiment, when the small path 21Aa is projected along the axis X2 toward the valve chamber VS, the projected image overlaps the valve body support 42 . Note that the intersection angle θ1 and the intersection angle θ2 can be arbitrarily changed according to the specifications of the expansion valve 1A. Therefore, the intersection angle θ1 may be smaller than the intersection angle θ2.

The axis X1 of the first flow path 21A other than the small path 21Aa does not intersect the inner periphery of the return flow path 23, and the axis X2 of the small path 21Aa does not intersect the inner periphery of the valve chamber VS. Therefore, by inserting a tool such as a drill into the return channel 23 from the outside of the third enlarged diameter hole 23e obliquely to the axis O, that is, along the axis X1, the first flow other than the small channel 21Aa is inserted. The path 21A can be machined. On the other hand, by inserting a tool such as a drill obliquely with respect to the axis L, that is, along the axis X2 from below the opening forming the valve chamber VS, the small path 21Aa is formed so as to be connected to the first flow path 21A. can be machined.

According to this embodiment, when the valve is opened, the refrigerant flowing out from the small path 21Aa into the valve chamber VS strikes the valve body support 42 from an oblique direction, thereby suppressing the vibration of the valve body 3 . When suppressing the vibration of the valve body 3, there are cases in which the damping effect is higher if the refrigerant is brought into contact with the valve body support 42 without contacting the valve body 3 with the refrigerant. Therefore, by arbitrarily angling the small path 21Aa of the first flow path 21A, it becomes possible to direct the coolant to the optimum position.

It should be noted that the present invention is not limited to the above-described embodiments. Variations of any of the components of the above-described embodiments are possible within the scope of the invention. Also, arbitrary components can be added or omitted in the above-described embodiments.

Reference Signs List 1, 1A: Expansion valves 2, 2A: Valve body 3: Valve body 4: Biasing device 5: Operating rod 6: Ring spring 8: Power element 20: Valve seats 21, 21A: First flow path 22: Second flow Path 23: Return flow path 27: Valve passage hole 41: Coil spring 42: Valve body support 43: Spring receiving member 50: Double pipe 60: Cover member 100: Refrigerant circulation system 101: Compressor 102: Condenser 104: Evaporator VS: valve chamber

Claims (7)

An expansion valve capable of connecting a double pipe in which a low-pressure refrigerant passes through an inner pipe, and a high-pressure refrigerant passes through an intermediate passage that is a space between an outer pipe arranged around the inner pipe and the inner pipe. and
a valve body including a valve chamber having a valve seat; and a high-pressure channel connected to the valve chamber from the intermediate channel and through which a high-pressure refrigerant flows;
a valve body unit including a valve body that can be seated on the valve seat;
The high-pressure flow path is inclined with respect to the axis of the valve body unit so that the high-pressure refrigerant flowing through the high-pressure flow path from the intermediate flow path toward the valve chamber hits the valve body unit.
An expansion valve characterized by: A central axis passing through the center of the high-pressure flow path becomes a straight line,
The valve body unit is arranged on an extension line of the central axis,
The expansion valve according to claim 1, characterized in that: The valve body unit has the valve body and a valve body support that supports the valve body,
The expansion valve according to claim 1 or 2, characterized in that: a coil spring that biases the valve body toward the valve seat via the valve body support;
4. The cover member according to claim 3, further comprising a top wall arranged between the valve body support and the coil spring, and a peripheral wall surrounding at least a part of the periphery of the coil spring. Expansion valve as described. The high-pressure flow path has a first passage on the side of the outer pipe and a second passage on the side of the valve chamber, and the inner diameter of the first passage is larger than the inner diameter of the second passage.
The expansion valve according to any one of claims 1 to 4, characterized in that: the axis of the first passage and the axis of the second passage intersect;
The expansion valve according to claim 5, characterized in that: When the high-pressure flow path is projected onto the valve chamber side along the axis of the high-pressure flow path, the projected image overlaps the valve body unit.
The expansion valve according to any one of claims 1 to 6, characterized in that:

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