JP2019163887A - Expansion valve - Google Patents

Abstract

To provide an improved expansion valve which can achieve low costs and low noise.SOLUTION: An expansion valve includes: a valve body 2 including an annular valve seat 20; a valve element 3 which is seated on the valve seat 20 to block passage of a fluid and separates from the valve seat 20 to allow passage of the fluid; a coil spring 41 which is disposed in a valve chamber VS with its side surface facing flow of the fluid flowing from a supply side passage 21 and biases the valve element 3 toward the valve seat 20; and an operation rod 5 which presses the valve element 3 in a direction away from the valve seat 20 against biasing force generated by the coil spring 41. The coil spring 41 has a first coil area A1 facing the flow of the fluid flowing from the supply side passage 21 and a second coil area A2 different from the first coil area A1. A coil gap P1 in the first coil area A1 is smaller than a coil gap P2 in the second coil area A2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an expansion valve.

  Conventionally, for a refrigeration cycle used in an air conditioner or the like mounted on an automobile, a temperature-sensitive expansion valve that adjusts the passage of refrigerant according to temperature is 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 cause of noise will be specifically described. In one type of expansion valve, the refrigerant passes through a valve consisting of a valve seat and a valve body as it passes from the inlet port through the valve chamber and toward the outlet port. Here, in order to ensure 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, a turbulence of the flow is generated, and this acts as an oscillating force to vibrate the coil spring, thereby causing noise.

  On the other hand, in Patent Document 1, a columnar hanging body extending along the inner side of the coil spring is provided on a spring receiver that connects the valve body and the coil spring, and thereby, between the windings of the coil spring. An expansion valve capable of suppressing the passage of 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. However, depending on the specifications of the expansion valve, there is a case where it is desired to suppress the cost with priority while reducing the noise.

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

In order to achieve the above object, an expansion valve according to the present invention comprises:
A valve body including an annular valve seat that is disposed in a valve chamber provided between the supply-side flow path and the discharge-side flow path, and through which a fluid from the supply-side flow path toward the discharge-side flow path passes; ,
A valve body that prevents passage of the fluid by sitting on the valve seat, and allows passage of the fluid by separating from the valve seat;
A coil spring that is disposed in the valve chamber with a side faced with respect to the flow of fluid flowing in from the supply-side flow path, and biases the valve body toward the valve seat;
An actuating member that presses the valve body in a direction away from the valve seat against an urging force of the coil spring;
A valve body support disposed between the valve body and one end of the coil spring;
A spring receiving member attached to the valve body and holding the other end of the coil spring;
The coil spring includes a first winding region facing a flow of fluid flowing in from the supply-side flow path, and a second winding region different from the first winding region. The inter-winding gap in one winding area is smaller than the inter-winding gap in the second winding area.

  According to the present invention, it is possible to provide an improved expansion valve that can be realized at low cost and low noise.

It is a schematic sectional drawing which shows typically the example which applied the expansion valve 1 in this embodiment to the refrigerant | coolant circulation system. It is sectional drawing which expands and shows the vicinity of the urging | biasing apparatus 4. FIG. 3 is an enlarged cross-sectional view showing the periphery of a coil spring 41. FIG. It is sectional drawing similar to FIG. 2 which shows the structure concerning a comparative example.

  Embodiments according to the present invention will be described below with reference to the drawings.

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

(Outline of expansion valve)
With reference to FIG. 1, the outline | summary of the expansion valve 1 in this embodiment is demonstrated. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 according to this embodiment is applied to a refrigerant circulation system 100. In FIG. 1, the part corresponding to the power element 8 is shown in a side view, and the other part is shown in a sectional view. In this embodiment, the expansion valve 1 is fluidly connected to the compressor 101, the capacitor 102, and the evaporator 104.

  The expansion valve 1 includes a valve body 2 including a valve chamber VS, a valve body 3, an urging device 4, an operating rod (operating 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 through 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 out of the expansion valve via 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 through a connection path 21a having a smaller diameter than the first flow path 21.

  The valve body 3 is disposed 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 communication state. FIG. 1 shows a state in which the valve body 3 is separated from the valve seat 20.

  The lower end of the operating rod 5 inserted through the operating rod insertion hole 27 with a gap is in contact with the upper surface of the valve element 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 isolating member that suppresses vibration of the operating rod 5. The ring spring 6 is disposed in the annular portion 26 of the valve body 2 and applies a predetermined elastic force to the outer peripheral surface of the operating rod 5 by a claw portion protruding toward the inner peripheral side.

  FIG. 2 is an enlarged sectional view showing the vicinity of the urging device 4. The urging device 4 includes 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 SUS valve body support 42 is integrally formed from a flange-shaped holding portion 42a and a cylindrical inner cylindrical body 42b extending downward from the lower end center of the holding portion 42a. The outer diameter of the inner cylinder 42 b is substantially equal to the inner diameter of the coil spring 41. The spherical valve body 3 is welded to the upper surface of the holding part 42a, and both are integrated.

  In FIG. 2, the spring receiving member 43 made of resin 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 periphery of the annular bottom portion 43a, a male screw 43c is formed which is screwed into a female screw 2b formed in the vicinity of the opening end of the mounting hole 2a communicating with the valve chamber VS of the valve body 2, and on the lower surface of the annular bottom portion 43a. Is formed with an engaging recess 43d for engaging a tool (not shown) or the like to rotate the spring receiving member 43. The inner diameter of the outer tubular portion 43 b 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. An O-ring 44 is arranged in the annular space between 2c. The O-ring 44 seals between the attachment hole 2 a and the spring receiving member 43.

  FIG. 3 is an enlarged sectional view showing the periphery of the coil spring 41. As shown in FIG. 3, the coil spring 41 has windings of unequal pitch. Specifically, the coil spring 41 is divided into two regions in the axial direction, such as a first winding region A1 in the upper part and a second winding region A2 in the lower part.

  The first winding region A1 has a side surface facing the connection path 21a and a winding pitch P1. On the other hand, the side surface of the second winding region A2 does not face the connection path 21a, has a winding pitch P2, and P2> P1. The winding pitches P1 and P2 do not need to be equal to each other in each winding region. In this case, the winding pitches P1 and P2 are average values in the respective winding regions.

  In the present embodiment, the winding pitch P1 is substantially equal to the winding diameter d (so-called tight winding) in a state in which the valve body 3 is seated on the valve seat 20, so that the side faces the connection path 21a. In the first winding region A1, the gap between the windings is substantially zero. However, the winding pitch P1 does not necessarily have to be equal to the winding diameter d, and a gap that is narrow enough to limit the passage of the refrigerant is sufficient. In this embodiment, the elastic force which urges | biases the valve body 3 is exhibited by 2nd coil | winding area | region A2 which is the predetermined amount where the clearance gap between windings exceeded zero. The elastic force that urges the valve body 3 may be the sum of the initial tension of the winding region A1 and the elastic force of the winding region A2.

  In FIG. 2, at the time of assembly, the inner cylindrical body 42b of the valve body support 42 to which the valve body 3 is welded is inserted from the upper end of the coil spring 41 to the inside, and the upper end of the coil spring 41 is placed on the lower surface of the holding portion 42a. Make 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 stepped 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 caused to enter the valve chamber VS from the mounting hole 2a, and the male screw 43c is screwed into the female screw 2b. Drive to a predetermined position using a tool (not shown). At this time, the connection path 21a faces the side surface of the first winding region A1 of the coil spring 41, but does not face the side surface of the second winding region A2. The spring receiving member 43 functions as a plug that seals the valve chamber VS by being attached to the valve body 2.

  In the present embodiment, the first winding region A1 of the coil spring 41 is connected to the connection path 21a when viewed in the flow direction (here, the left-right direction) of the refrigerant flowing into the valve chamber VS from the connection path 21a. It extends below the lower end. However, it is sufficient that the first winding region A1 overlaps at least a part of the connection path 21a.

  An example of the operation 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. In addition, the refrigerant adiabatically expanded by the expansion valve 1 is sent out to the evaporator 104, and heat is exchanged with the air flowing around the evaporator in the evaporator 104. 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).

  The expansion valve 1 is supplied with a high-pressure refrigerant from a capacitor 102. More specifically, the high-pressure refrigerant from the capacitor 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 closed), 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 passes through the operating rod insertion hole 27 and the first It is sent out to the evaporator 104 through the two flow paths 22. Note that 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 example of FIG. 1, the power element 8 is disposed at the upper end portion of the expansion valve 1. Although not shown, 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 operating rod 5 through a diaphragm support member. For this reason, 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. Thus, 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 working gas phase (gas phase, liquid phase, etc.) 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 FIG. 1, the amount of refrigerant supplied from the expansion valve 1 toward the evaporator 104 is automatically set in accordance with the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1. 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. 2 showing a configuration according to a comparative example. In FIG. 4, the coil spring 41 ′ of the comparative example has windings of equal pitch, so that the gap δ between the windings of the coil spring 41 ′ is equal. Other configurations are the same as those 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 21 a is transferred to the coil spring 41 ′ as indicated by an arrow B in FIG. The coil enters the coil spring 41 ′ from the gap δ between the windings and exits from the opposite side. At this time, the refrigerant vibrates the coil spring 41 ′, thereby generating noise.

  On the other hand, according to the present embodiment, since the first winding region A1 (FIG. 3) of the coil spring 41 faces the connection path 21a, the first flow path 21 and the connection are connected as shown in FIG. The refrigerant flowing into the valve chamber VS from the passage 21a is bounced to the outer periphery of the coil spring 41 as shown by an arrow A and is prevented from entering the inside, and does not pass through the gap between the windings. Will not vibrate. Thereby, noise can be effectively suppressed.

  In addition, this invention is not limited to the above-mentioned embodiment. Within the scope of the present invention, any of the components of the above-described embodiments can be modified. In addition, arbitrary components can be added or omitted in the above-described embodiment.

1: Expansion valve 2: Valve body 3: Valve body 4: Energizing device 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: Annular portion 27: Actuating 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 (3)

A valve body including an annular valve seat that is disposed in a valve chamber provided between the supply-side flow path and the discharge-side flow path, and through which a fluid from the supply-side flow path toward the discharge-side flow path passes; ,
A valve body that prevents passage of the fluid by sitting on the valve seat, and allows passage of the fluid by separating from the valve seat;
A coil spring that is disposed in the valve chamber with a side faced with respect to the flow of fluid flowing in from the supply-side flow path, and biases the valve body toward the valve seat;
An actuating member that presses the valve body in a direction away from the valve seat against an urging force of the coil spring;
The coil spring includes a first winding region facing a flow of fluid flowing in from the supply-side flow path, and a second winding region different from the first winding region. The inter-winding gap in one winding area is smaller than the inter-winding gap in the second winding area,
An expansion valve characterized by that. In a state where at least the valve body is seated on the valve seat, the first winding region of the coil spring has zero inter-winding gap,
The expansion valve according to claim 1. The coil spring has windings of unequal pitch,
The expansion valve according to claim 1 or 2, wherein

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