JP7082798B2 - Expansion valve - Google Patents

Description

The present invention relates to an expansion valve.

Conventionally, in the refrigeration cycle used for an air conditioner mounted on an automobile, a temperature-sensitive expansion valve that adjusts the amount of refrigerant passing through according to the temperature has been used in order to omit installation space and piping.

By the way, it was confirmed that noise is generated in such an expansion valve. The factors that generate noise will be explained in detail. In one type of expansion valve, the refrigerant passes through the valve chamber from the inlet port and through the valve consisting of the valve seat and valve body as it travels toward the outlet port. Here, in order to secure the opening / closing function of the valve, a coil spring for urging the valve body toward the valve seat is provided in the valve chamber. However, when the refrigerant flowing in from the inlet port passes between the narrow windings of the coil spring, the flow is turbulent, which becomes a vibrating force and vibrates the coil spring, which causes noise.

On the other hand, in Patent Document 1, a columnar hanging body extending along the inside of the coil spring is provided in the spring receiver connecting the valve body and the coil spring, whereby the space between the windings of the coil spring is provided. An expansion valve capable of suppressing the passage of a refrigerant and reducing noise is disclosed.

Japanese Patent No. 6182363

According to the expansion valve described in Patent Document 1, a large noise suppression effect can be expected, but depending on the specifications of the expansion valve, it may be desired to prioritize and suppress the cost while reducing the noise.

Therefore, an object of the present invention is to provide an improved expansion valve that can realize low cost and low noise.

In order to achieve the above object, the expansion valve according to the present invention is
A valve body provided in a valve chamber provided between a supply-side flow path and a discharge-side flow path, and having an annular valve seat through which a fluid flowing from the supply-side flow path to the discharge-side flow path passes. ,
A valve body that blocks the passage of the fluid by sitting on the valve seat and allows the fluid to pass by separating from the valve seat.
A coil spring arranged in the valve chamber with the side surface facing the flow of the fluid flowing from the supply side flow path and urging the valve body toward the valve seat.
It has an actuating member that presses the valve body in a direction away from the valve seat against the urging force of the coil spring.
When the central axis of the inlet of the valve chamber into which the fluid flows from the supply side flow path does not intersect the central axis of the coil spring and is viewed in a direction orthogonal to the central axis of the coil spring. In addition, the angle between the central axis of the inlet and the central axis of the coil spring is 90 degrees.
The inlet is arranged on both sides of the central axis of the coil spring .

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an improved expansion valve that can realize low cost and low noise.

It is schematic cross-sectional view which shows typically the example which applied the expansion valve 1 in this embodiment to a refrigerant circulation system. It is a side view which looked at the expansion valve 1 of FIG. 1 from the side which has a supply side flow path. It is sectional drawing which shows the vicinity of the urging device 4 enlarged. It is a cross-sectional view similar to FIG. 3 which shows the structure which concerns on a comparative example. It is the same side view as FIG. 2 which shows the structure which concerns on the comparative example. It is a side view which shows the periphery of the 1st flow path 21 which concerns on the modification of this embodiment. It is a side view which shows the periphery of the 1st flow path 21 which concerns on another modification of this embodiment.

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

(Definition of direction)
In the present specification, the direction from the valve body 3 toward the actuating rod 5 is defined as "upward", and the direction from the actuating rod 5 toward the valve body 3 is defined as "downward". Therefore, in the present specification, the direction from the valve body 3 toward the operating rod 5 is referred to as "upward" regardless of the posture of the expansion valve 1.
The "center of the entrance" means the center of symmetry when the cross-sectional shape of the entrance is point-symmetrical, and the center of gravity of the cross-sectional shape when the cross-sectional shape of the entrance is non-point-symmetrical. .. Further, the "flow direction" is a direction from the first flow path 21 to the valve chamber VS through the connection path 21a, as shown by an arrow F in FIG. 3, and refers to the axial direction of the connection path 21a. do.

(Overview of expansion valve)
The outline of the expansion valve 1 in this embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 in the present embodiment is applied to the refrigerant circulation system 100. FIG. 2 is a side view of the expansion valve 1 of FIG. 1 as viewed from the side where the supply side flow path is located. In FIG. 1, the portion corresponding to the power element 8 is shown in a side view, and the other portion is shown in a cross-sectional view. In this embodiment, the expansion valve 1 is fluidly connected to the compressor 101, the condenser 102, and the evaporator 104.

In FIG. 1, the expansion valve 1 includes a valve body 2 provided with a valve chamber VS, a valve body 3, an urging device 4, an actuating rod (actuating member) 5, and a ring spring 6.

The valve body 2 includes a first flow path 21 and a second flow path 22 in addition to the valve chamber VS. The first flow path 21 is a supply-side flow path, and a refrigerant (also referred to as a 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, and the fluid in the valve chamber VS is discharged to the outside of the expansion valve through the operating rod insertion hole 27 and the discharge side flow path. The first flow path 21 and the valve chamber VS communicate with each other by a connecting path 21a having a smaller diameter than the first flow path 21.

In the present embodiment, a pair of connecting paths 21a having a circular cross-sectional shape, as shown in FIG. 2, are centered on the coil spring 41 (described later) on the partition wall 21b that separates the first flow path 21 and the valve chamber VS. They are arranged on both sides of the axis X. The connecting path 21a serves as an inlet for the valve chamber VS into which the fluid flows from the second flow path 22. Here, the central axis O of each connection path 21a (extending in the left-right direction in FIG. 1 and extending in the vertical direction of the paper surface in FIG. 2) is aligned with the central axis X of the coil spring 41 (extending in the vertical direction in FIG. 2). On the other hand, it does not intersect. Further, when the connecting path 21a is projected in the flow direction F (the direction perpendicular to the paper surface in FIG. 2), the projected connecting path 21a does not overlap with the central axis X of the coil spring 41.

In FIG. 1, the valve body 3 is arranged in the valve chamber VS. When the valve body 3 is seated on the annular valve seat 20 of the valve body 2, the first flow path 21 and the second flow path 22 are in a non-communication state. On the other hand, when the valve body 3 is separated from the valve seat 20, the first flow path 21 and the second flow path 22 are in a communicating state. FIG. 1 shows a state in which the valve body 3 is separated from the valve seat 20.

The lower end of the actuating rod 5 inserted through the actuating rod insertion hole 27 with a gap is in contact with the upper surface of the valve body 3. Further, the actuating rod 5 can press the valve body 3 in the valve opening direction against the urging force of the urging 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 ring spring 6 is a vibration-proof member that suppresses the vibration of the operating rod 5. The ring spring 6 is arranged in the annular portion 26 of the valve body 2 and is adapted to apply a predetermined elastic force to the outer peripheral surface of the operating rod 5 by the claw portion protruding toward the inner peripheral side.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of the urging device 4. The urging device 4 has a coil spring 41 in which a wire having a circular cross section is spirally wound, a valve body support 42, and a spring receiving member 43. The central axis O of the connecting path 21a extends in the left-right direction as shown by the alternate long and short dash line.

The valve body support 42 made of SUS is integrally formed of a flange-shaped holding portion 42a and a cylindrical inner cylinder 42b extending downward from the center of the lower end of the holding portion 42a. The outer diameter of the inner cylinder 42b is substantially equal to the inner diameter of the coil spring 41. A spherical valve body 3 is welded to the upper surface of the holding portion 42a, and both are integrated.

The resin-made spring receiving member 43 has a bottom portion 43a and an outer tubular portion 43b extending upward from the upper surface of the bottom portion 43a. On the outer circumference of the annular bottom 43a, a male screw 43c screwed into the female screw 2b formed near the opening end of the mounting hole 2a communicating with the valve chamber VS of the valve body 2 is formed, and on the lower surface of the annular bottom 43a. Is formed with an engaging recess 43d for rotating the spring receiving member 43 by engaging a tool or the like (not shown). The inner diameter of the outer tubular portion 43b is substantially equal to the outer diameter of the coil spring 41.

A step portion 43e is formed on the outer periphery of the outer tubular portion 43b, and a step portion 2c is formed at the intersection of the mounting hole 2a and the valve chamber VS so as to face the step portion 43e. The O-ring 44 is arranged in the annular space between the 2c and the ring 44. The O-ring 44 seals between the mounting hole 2a and the spring receiving member 43.

In FIG. 3, at the time of assembly, the inner cylinder 42b of the valve body support 42 to which the valve body 3 is welded is inserted into the inside from the upper end of the coil spring 41, and the upper end of the coil spring 41 is placed on the lower surface of the holding portion 42a. Make a contact. Further, the lower end of the coil spring 41 is inserted inside the outer tubular portion 43b of the spring receiving member 43 and brought into contact with the upper surface of the bottom portion 43a. At this time, the O-ring 44 is attached to the step portion 43e.

While maintaining this state, the assembly including the valve body support 42, the coil spring 41, and the spring receiving member 43 is made to enter the valve chamber VS from the mounting hole 2a, and the male screw 43c is screwed into the female screw 2b. Use a tool (not shown) to drive it into place. At this time, the side surface of the coil spring 41 faces the partition wall 21b.

An operation example of the expansion valve 1 will be described with reference to FIG. The 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 sent out to the evaporator 104, and the evaporator 104 exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator 104 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return flow path 23).

A high-pressure refrigerant is supplied 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 first flow path 21.

When the valve body 3 is seated on the valve seat 20 (in other words, when the expansion valve 1 is in the closed state), the first flow path 21 on the upstream side of the valve chamber VS and the downstream side of the valve chamber VS. The second flow path 22 is in a non-communication state. On the other hand, when the valve body 3 is separated from the valve seat 20 (in other words, when the expansion valve 1 is in the open state), the refrigerant supplied to the valve chamber VS is the working rod insertion hole 27 and the first. It is sent out to the evaporator 104 through the two flow paths 22. 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.

In the examples of FIGS. 1 and 2, the power element 8 is arranged at the upper end portion of the expansion valve 1. Although not shown, the inside of the power element 8 is provided with a first space and a second space partitioned by a diaphragm, and the first space is filled with a working gas.

The lower surface of the diaphragm is connected to the actuating rod 5 via the diaphragm support member. Therefore, when the working gas in the first space is liquefied, the working rod 5 moves upward, and when the liquefied working gas is vaporized, the working rod 5 moves downward. In this way, switching between the open state and the closed state of the expansion valve 1 is performed.

The second space of the power element 8 communicates with the return flow path 23. Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the first space changes according to the temperature and pressure of the refrigerant flowing through the return flow path 23, and the working rod 5 is driven. In other words, in the expansion valve 1 shown in FIGS. 1 and 2, the amount of the refrigerant supplied from the expansion valve 1 to 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. Is adjusted.

Next, the effect of this embodiment will be described with reference to a comparative example. FIG. 4 is a cross-sectional view similar to FIG. 3 showing the configuration according to the comparative example. FIG. 5 is a side view similar to FIG. 2 showing a configuration according to a comparative example. In the comparative example, as shown in FIG. 5, a single connecting path 21a'is formed in the center of the first flow path 21. That is, the central axis O of the connecting path 21a'(extending in the left-right direction in FIG. 4 and in the vertical direction of the paper surface in FIG. 5) intersects the central axis X of the coil spring 41. Other than that, the configuration is the same as that of the above-described embodiment.

In the case of the comparative example, when the valve body 3 is separated from the valve seat 20, the refrigerant flowing into the valve chamber VS from the first flow path 21 and the connection path 21a'is the coil spring 41 as shown by an arrow B in FIG. It enters the coil spring 41 from the gap δ between the windings, passes through the center, and exits from the opposite side. At this time, the refrigerant vibrates the coil spring 41, which causes noise.

On the other hand, according to the present embodiment, as shown in FIG. 2, a pair of connecting paths 21a are arranged on both sides of the central axis X of the coil spring 41, and the central axis of each connecting path 21a is the coil spring 41. When the connection path 21a is projected in the flow direction (vertical to the paper surface in FIG. 2), the projected connection path 21a is the center axis X of the coil spring 41. It is in a position deviated from. In other words, when the coil spring 41 is viewed from the connecting path 21a, the central axis X of the coil spring 41 is hidden behind the partition wall 21b that separates the valve chamber VS and the first flow path 21 and cannot be seen. That is, the partition wall 21b between the connection paths 21a serves as a shield that restricts the refrigerant from passing through the center of the coil spring 41.

Therefore, since the refrigerant flowing into the valve chamber VS from the connection path 21a passes away from the center of the coil spring 41, the force for vibrating the coil spring 41 is weakened, and the generation of noise can be suppressed. Since the noise can be suppressed only by changing the position of the connection path 21a in this way, the increase in cost can be minimized.

It is sufficient that the central axis O of the connection path 21a deviates from the central axis X of the coil spring 41, and the connection path 21a does not have to be a pair, and may be single or three or more. Further, the cross-sectional shape of the connecting path 21a is not limited to a circular shape, but may be a rectangular shape or another shape.

FIG. 6 is a side view showing the periphery of the first flow path 21 according to the modified example of the present embodiment. The central axis O of the connecting path 21c extends in the direction perpendicular to the paper surface and does not intersect the central axis X of the coil spring 41. In this modification, since the pair of connecting paths 21c have a vertically elongated substantially crescent-shaped cross section, the flow rate of the refrigerant passing through the connecting path 21c is increased as compared with the connecting path 21a having a circular cross section. Can be done. Further, a connecting path 21c is provided around the partition wall 21b, and the coil spring 41 is completely hidden by the partition wall 21b when viewed in the direction of the drawing. In other words, the connection path 21c projected along the flow direction of the refrigerant (the direction perpendicular to the paper surface in FIG. 6) does not overlap with the coil spring 41. As a result, the refrigerant flowing into the valve chamber from the connection path 21c flows away from the coil spring 41, so that the force for vibrating the coil spring 41 is further weakened, and the generation of noise can be suppressed.

FIG. 7 is a side view showing the periphery of the first flow path 21 according to another modification of the present embodiment. The central axis O of the connecting path 21d extends in the direction perpendicular to the paper surface and does not intersect the central axis X of the coil spring 41. Also in this modification, the pair of connecting paths 21d have a substantially crescent-shaped cross section, but the cross-sectional area is large, and a part of the coil spring 41 is visible through the connecting path 21d. However, when the connecting path 21d is projected in the flow direction of the refrigerant (the direction perpendicular to the paper surface in FIG. 7), the projected connecting path 21d does not overlap with the central axis X of the coil spring 41.

This modification is an example in which the cross-sectional area of the connecting path is further increased with respect to the modification of FIG. As a result, it is possible to reduce noise while increasing the inflow amount of the refrigerant.

In addition to the above embodiments, by inserting a member that restricts the flow of the refrigerant inside or outside the coil spring 41, noise can be further reduced by the synergistic effect.

The present invention is not limited to the above-described embodiment. Within the scope of the present invention, any component of the above-described embodiment can be modified. Further, in the above-described embodiment, any component can be added or omitted.

1: Expansion valve 2: Valve body 3: Valve body 4: Energizer 5: Actuating rod 6: Ring spring 8: Power element 20: Valve seat 21: First flow path 22: Second flow path 23: Return flow path 26: Circular portion 27: Operating rod insertion hole 41: Coil spring 42: Valve body support 43: Spring receiving member 100: Refrigerant circulation system 101: Compressor 102: Condenser 104: Evaporator VS: Valve chamber

Claims (4)

A valve body provided in a valve chamber provided between a supply-side flow path and a discharge-side flow path, and having an annular valve seat through which a fluid flowing from the supply-side flow path to the discharge-side flow path passes. ,
A valve body that blocks the passage of the fluid by sitting on the valve seat and allows the fluid to pass by separating from the valve seat.
A coil spring arranged in the valve chamber with the side surface facing the flow of the fluid flowing from the supply side flow path and urging the valve body toward the valve seat.
It has an actuating member that presses the valve body in a direction away from the valve seat against the urging force of the coil spring.
When the central axis of the inlet of the valve chamber into which the fluid flows from the supply side flow path does not intersect the central axis of the coil spring and is viewed in a direction orthogonal to the central axis of the coil spring. In addition, the angle between the central axis of the inlet and the central axis of the coil spring is 90 degrees.
The inlets are arranged on both sides of the central axis of the coil spring.
An expansion valve characterized by that. When the inlet of the valve chamber is projected from the supply side flow path toward the side surface of the coil spring, the projected inlet does not overlap the central axis of the coil spring.
The expansion valve according to claim 1. The projected inlet does not overlap the coil spring,
The expansion valve according to claim 1 or 2. The cross section of the entrance has a substantially circular or substantially crescent shape.
The expansion valve according to any one of claims 1 to 3 , wherein the expansion valve is characterized in that.

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