JP2020122623A - Constant-pressure valve - Google Patents

Abstract

To provide an improved constant-pressure valve capable of realizing low costs.SOLUTION: A constant-pressure valve 1 has a case 8 that is equipped with a pressure detection chamber PD communicated with an inflow pipe 105 and an outflow pipe 104, and a pressure actuation chamber PO sealing gas inside, a flexible diaphragm 7 that partitions the pressure detection chamber PD and the pressure actuation chamber PO in the case 8, a valve body 3 that moves according to the displacement of the diaphragm 7, an orifice portion 20e that restricts opening when the valve body 3 approaches, and a coil spring 41 that energizes the valve body 3 toward the orifice portion 20e. The case 8 is formed by using a single plate material plastically deformed over a connecting portion of the outflow pipe 104 from an abutting portion with at least the diaphragm 7. Against the energizing force of the coil spring 41, when the diaphragm 7 separates the valve body 3 from the orifice portion 20e, a refrigerant flowing in from the inflow pipe 105 flows toward the pressure detection chamber PD through a clearance between the valve body 3 and the orifice portion 20e.SELECTED DRAWING: Figure 1

Description

The present invention relates to a constant pressure valve.

In home-use cooling and heating air conditioners, electrically operated valves that can arbitrarily control the flow rate of the refrigerant are used, while in cooling-only air conditioners, a capillary tube is used with a focus on cost. However, from the viewpoint of energy saving and improvement of cooling efficiency, there is a demand for replacing the air conditioner only for cooling with a substitute that is superior in flow rate control to the capillary tube. In response to such a request, it is being investigated whether a relatively low cost mechanical constant pressure valve can be used.

When the cost is emphasized in the mechanical constant pressure valve, it is an idea to form the case by using a steel plate that is plastically processed by press working, for example. By plastically deforming the steel sheet, multiple parts can be unified, and the number of welding and brazing points can be reduced, which can reduce costs and also prevent refrigerant leakage from the joints of parts. it can. Patent Document 1 discloses a thermal expansion valve in which a housing of a temperature sensing portion and a body of a valve portion are formed by press work.

JP, 2003-75025, A

By the way, in the expansion valve shown in FIG. 1 of Patent Document 1, the inside of the expansion valve is located between the upper housing and the diaphragm of the temperature sensing part, between the diaphragm and the first plate, and between the first plate and the second plate. It is divided into four sections, such as between the plate and between the second plate and the load adjusting piece. This is a structure necessary for introducing the refrigerant discharged from the evaporator between the diaphragm and the first plate, and thus complicates the structure inside the housing. Therefore, in the expansion valve of Patent Document 1, even if the housing is formed from a press-worked product, an increase in cost due to the complicated structure is inevitable. Further, in Patent Document 1, it is not clarified how to manufacture the expansion valve, and its feasibility is uncertain.

Therefore, an object of the present invention is to provide an improved constant pressure valve that can be manufactured at low cost.

In order to achieve the above object, a constant pressure valve according to the present invention is a constant pressure valve for a refrigeration cycle arranged between an inflow pipe connected to a condenser and an outflow pipe connected to an evaporator,
A case having therein a pressure detection chamber communicating with the inflow pipe and the outflow pipe, and a pressure working chamber in which gas is sealed, and a partition between the pressure detection chamber and the pressure working chamber in the case. A flexible diaphragm, a valve body that moves according to the displacement of the diaphragm, an orifice portion that restricts the opening when the valve body approaches, and a biasing force of the valve body toward the orifice portion. And a biasing member,
The case is formed by using a single plate material that is plastically deformed at least from a contact portion with the diaphragm to a connection portion of the outflow pipe,
When the diaphragm separates the valve body from the orifice portion against the urging force of the urging member, the fluid flowing from the inflow pipe passes through the gap between the valve body and the orifice portion. It is characterized in that it goes to the pressure detection chamber.

The present invention can provide an improved constant pressure valve that can be manufactured at low cost.

FIG. 1 is a schematic cross-sectional view schematically showing an example in which the constant pressure valve according to the first embodiment is applied to a refrigerant circulation system. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-1. FIG. 3A is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-2, and FIG. 3B is a top view of the cross section taken along the line AA of FIG. 3A. Is. FIG. 4 is a schematic sectional view of a constant pressure valve according to the second embodiment. FIG. 5 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 2-1. FIG. 6A is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 2-2, and FIG. 6B is a top view of the cross section taken along the line BB of FIG. 6A. Is. FIG. 7 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 2-3. FIG. 8 is a schematic sectional view of a constant pressure valve according to the third embodiment. FIG. 9 is a schematic sectional view of a constant pressure valve in Modification 3-1. FIG. 10 is a schematic sectional view of the constant pressure valve according to the fourth embodiment. FIG. 11 is a schematic sectional view of a constant pressure valve in Modification 4-1. FIG. 12 is a schematic sectional view of a constant pressure valve according to the fifth embodiment. FIG. 13 is a bottom view of a cross section taken along line CC of FIG. 12. FIG. 14 is a cross-sectional view showing an intersection of a cylindrical portion of a constant pressure valve receiving member and an inflow pipe according to a reference example. FIG. 15 is a diagram showing a state where a side wall opening is formed in the cylindrical portion of the reference example by press punching. FIG. 16 is a diagram showing a state in which a side wall opening is formed by press punching in the rectangular tube portion of the fifth embodiment.

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

(Definition of direction)
In this specification, the side from the valve body toward the diaphragm is defined as "upper side", and the side from the diaphragm toward the valve body is defined as "lower side".

(First embodiment)
The configuration of the constant pressure valve 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the constant pressure valve 1 according to this embodiment is applied to a refrigerant circulation system 100. The constant pressure valve 1 is fluidly connected to the compressor 101, the condenser 102, and the evaporator 103, and constitutes a part of the refrigeration cycle.

The constant pressure valve 1 includes a valve body 2, a valve body 3, an urging device 4, an actuating rod 5, a stopper member 6, a diaphragm 7, and a case 8 including these. The operating rod 5 and the stopper member 6 constitute an operating member. The axis of the constant pressure valve 1 is L.

The case 8 has a substantially disk-shaped upper lid member 81 having an upper opening 81a in the center, and a receiving member 82 that faces the upper lid member 81 with the diaphragm 7 interposed therebetween. The upper lid member 81 and the receiving member 82 are each formed by pressing a single metal plate material.

The center of the upper lid member 81 is raised in a dome shape, the periphery of the upper opening 81a is thin, and is a recessed portion 81b that is recessed in a circular shape toward the inside. The plug 83 seals the upper opening 81a so as to be joined to the recess 81b.

The receiving member 82 has an annular flange portion 82a having an outer diameter substantially equal to that of the upper lid member 81, and a hollow bottomed cylindrical portion 82b having an upper end joined to the inner circumference of the flange portion 82a. A lower opening 82c is formed in the center of the bottom of the cylindrical portion 82b, and a side wall opening 82d is formed in the side wall of the cylindrical portion 82b. One end of the outflow pipe 104 is fixed to the side wall opening 82d, which is a connecting portion, by brazing. The other end of the outflow pipe 104 is connected to the evaporator 103. The axis of the outflow pipe 104 is O.

The diaphragm 7 is made of a thin flexible plate material having a plurality of concentric concavo-convex shapes, and has an outer diameter substantially the same as the outer diameter of the flange portion 82a.

The substantially cylindrical valve body 2 includes a large-diameter portion 21 that is positioned in contact with the inner circumference of the cylindrical portion 82b of the receiving member 82, a small-diameter portion 22 coaxially connected below the large-diameter portion 21, and a small-diameter portion. A circular pipe portion 23 coaxially connected to the lower portion of the portion 22 and fitted in the lower opening 82c is provided. Although not shown, the large-diameter portion 21 has a plurality of grooves that extend in the axial direction on the outer circumference thereof, so that the refrigerant (fluid) can pass from the lower surface side to the upper surface side of the large-diameter portion 21. Is in communication with.

The lower end of the circular pipe portion 23 extends so as to project downward from the lower opening 82c of the case 8. In the lower opening 82c, the upper end of the inflow pipe 105 is inserted into the lower end of the circular pipe portion 23 and abuts against the step portion. In this state, the circular pipe portion 23 and the inflow pipe 105 are brazed. It is fixed by. The lower end of the inflow pipe 105 is connected to the condenser 102. The axis of the inflow pipe 105 coincides with the axis L of the constant pressure valve 1.

The valve body 2 is formed with a communication hole 20c penetrating the small diameter portion 22 in a direction orthogonal to the axis L. The axis of the communication hole 20c preferably coincides with the axis O of the outflow pipe 104, but may be displaced.

Further, the valve body 2 has a cylindrical upper opening 20a, a cylindrical lower opening 20b, and a cylindrical orifice portion 20e formed coaxially from the upper side along the axis L from the upper side. The upper opening 20a opens on the upper surface of an annular portion 20f formed so as to project upward from the valve body 2. The lower opening 20b has a smaller diameter than the upper opening 20a, and connects the upper opening 20a and the communication hole 20c. The orifice portion 20e has a larger diameter than the lower opening 20b, communicates with the communication hole 20c, and opens inside the circular pipe portion 23 and at the lower end of the small diameter portion 22. That is, the upper opening 20a, the lower opening 20b, the communication hole 20c, and the orifice portion 20e form a cylindrical space that penetrates the valve body 2 along the axis L. The inner diameter of the orifice portion 20e needs to be accurately formed from the viewpoint of controlling the flow rate, but it is relatively easy to process because a short distance to the communication hole 20c is sufficient.

The space surrounded by the upper lid member 81 and the diaphragm 7 forms a pressure working chamber PO, and the space surrounded by the diaphragm 7 and the receiving member 82 forms a pressure detection chamber PD.

A stopper member 6 is arranged below the diaphragm 7. The stopper member 6 has a disc 61 facing the diaphragm 7 and a cylindrical shaft 62 planted in the center of the lower surface of the disc 61. The cylindrical shaft 62 has an axial length shorter than that of the upper opening 20a of the valve body 2 and is slidably fitted in the upper opening 20a.

On the other hand, the circular actuation rod 5 inserted through the lower opening 20b of the valve body 2 and the orifice portion 20e has its upper end abutted against the lower end of the cylindrical shaft 62. The lower end of the operating rod 5 is exposed downward from the lower opening 20b and is welded to the spherical valve element 3. Since the lower opening 20b serves as a guide hole for guiding the actuation rod 5, the gap between the two is small. On the other hand, the gap between the orifice portion 20e and the operating rod 5 is larger than the gap between the lower opening 20b and the operating rod 5 in order to allow the refrigerant to pass therethrough.

When the valve body 3 abuts (seats) on the edge of the orifice portion 20e, the opening is restricted and the inflow pipe 105 and the outflow pipe 104 are not in communication with each other. On the other hand, when the actuation rod 5 moves downward to separate the valve body 3 from the orifice portion 20e, the inflow pipe 105 and the outflow pipe 104 are in communication with each other. However, even when the valve body 3 contacts the orifice portion 20e, a limited amount of refrigerant may flow from the inflow pipe 105 to the outflow pipe 104.

Next, the biasing device 4 will be described. In FIG. 1, the urging device 4 includes a coil spring 41 formed by spirally winding a circular wire, a valve body support 42 attached to the upper end of the coil spring 41 to support the valve body 3, and a lower end of the coil spring 41. And a spring receiving member 43 attached to the valve body 2 while supporting the valve. The coil spring 41, which is a biasing member, biases the valve body 3 toward the orifice portion 20e.

The valve body support 42 has a conical recess 42a on the upper surface, a flange portion 42b that spreads in the radial direction, and a cylindrical portion 42c connected to the flange portion 42b. The recess 42a supports the valve body 3 at a fixed position. The flange portion 42b supports the upper end of the coil spring 41. The cylindrical portion 42c engages with the inner circumference of the coil spring 41 to suppress relative displacement of the valve body support 42 in a direction orthogonal to the axis L.

The spring receiving member 43 is fixed to the inflow pipe 105, supports the lower end of the coil spring 41, and has a function of not blocking the passage of the refrigerant. Therefore, the spring receiving member 43 has a short circular tube shape and has an outer diameter smaller than the inner diameter of the inflow pipe 105. A peripheral groove 43a is formed at the center of the outer periphery of the spring receiving member 43.

(Constant pressure valve assembly process)
The assembly process of the constant pressure valve 1 will be described. First, a metal plate material is pressed to plastically deform it into the shape shown in FIG. 1 to obtain an upper lid member 81 and a receiving member 82. Next, the upper opening 81a is formed in the upper lid member 81 by press punching, and the lower opening 82c and the side wall opening 82d are formed in the receiving member 82 by press punching. The cost can be reduced by forming the case 8 using a pressed product.

The valve body 2 and the valve body support 42 are formed by cutting or the like, but since they are relatively small, the amount of cutting is small and the cost can be suppressed. In addition, general-purpose products can be used as the other components, and the cost can be reduced.

Next, in the mode shown in FIG. 1, the valve body 2 is inserted into the receiving member 82 from above, the circular pipe portion 23 is exposed from the lower opening 82c, and between the circular pipe portion 23 and the bottom wall of the cylindrical portion 82b. Are circumferentially welded and integrated by, for example, TIG welding, laser welding, plasma welding, etc. to form a welded portion W2.

After that, the end portion of the outflow pipe 104 is inserted into the side wall opening 82d of the receiving member 82, and fixed by brazing between the outer periphery of the end portion of the outflow pipe 104 and the periphery of the side wall opening 82d. Further, the cylindrical shaft 62 of the stopper member 6 is inserted into the upper opening 20a of the valve body 2.

While maintaining this state, the outer peripheral portion (contact portion) of the upper lid member 81, the diaphragm 7, and the flange portion 82a of the receiving member 82 are overlapped with each other, and the outer peripheral portion is subjected to, for example, TIG welding or laser welding, The welded portion W1 is formed by circumferential welding by plasma welding or the like and integration. The case 8 is constituted by the upper lid member 81 and the receiving member 82 which are joined in this way.

Then, a space (pressure working chamber PO) surrounded by the upper lid member 81 and the diaphragm 7 is filled with a working gas such as an inert gas through the upper opening 81a formed in the upper lid member 81. After that, the upper opening 81a is sealed with the plug 83, and the plug 83 is fixed to the upper lid member 81 by using projection welding or the like to seal the working gas. At this time, since the circumference of the depressed portion 81b is thin, appropriate welding can be performed. Further, since the depressed portion 81b is formed in a predetermined conical shape corresponding to the outer peripheral shape of the plug 83, it is possible to prevent spatter or the like generated by welding from falling onto the diaphragm 7.

After that, the operating rod 5 having the valve body 3 welded to the lower end is inserted into the lower opening 20b of the valve body 2 from the upper end thereof and brought into contact with the lower end of the cylindrical shaft 62 of the stopper member 6. Further, the upper end of the inflow pipe 105 in which the biasing device 4 is incorporated in advance is fitted to the inner circumference of the circular pipe portion 23 of the valve body 2. While maintaining this state, the outer periphery of the inflow pipe 105 and the end of the circular pipe portion 23 are brazed to fix the two.

In FIG. 1, below the spring receiving member 43 of the urging device 4, the projection PJ protruding to the inner circumference of the inflow pipe 105 can be formed by hitting the outer circumference of the inflow pipe 105 with a punch or the like. The projection PJ has a function of preventing the separate pipe from entering too much when the separate pipe is inserted into the inflow pipe 105, and a function of locking the spring receiving member 43 so as not to accidentally drop from the inflow pipe 105. Have and.

(Adjustment of coil spring)
Whether or not the diaphragm 7 is displaced is determined by the balance between the differential pressure between the pressure working chamber PO and the pressure detection chamber PD and the elastic force of the coil spring 41. In order to displace the diaphragm 7 at a desired timing, it is necessary to set the elastic force of the coil spring 41 to a predetermined value.

Therefore, in the present embodiment, the coil spring 41 is compressed by pushing up the spring receiving member 43 by using a jig (not shown) inserted inside the inflow pipe 105, and a desired elastic force can be applied. it can. Whether or not the desired elastic force is achieved can be measured by a load meter or the like connected to a jig (not shown).

When the coil spring 41 comes to exert a desired elastic force, the outer circumference of the inflow pipe 105 is crimped on the radially outer side of the spring receiving member 43. As a result, the plastically deformed crimp portion CK is fitted into the circumferential groove 43a of the spring receiving member 43, so that the spring receiving member 43 is fixed to the inflow pipe 105. With the above, the constant pressure valve 1 is completed.

(Operation of constant pressure valve)
An operation example of the constant pressure valve 1 will be described with reference to FIG. The refrigerant (fluid) pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the constant pressure valve 1 via the inflow pipe 105. The refrigerant discharged from the constant pressure valve 1 is sent to the evaporator 103, and the evaporator 103 exchanges heat with the air flowing around the evaporator. Further, the refrigerant that has passed through the evaporator 103 is returned to the compressor 101 side. In this way, the refrigerant circulates in the refrigerant circulation system.

High-pressure refrigerant is supplied to the constant pressure valve 1 from the condenser 102. More specifically, the high-pressure refrigerant from the condenser 102 enters the inflow pipe 105, passes through the spring receiving member 43, and reaches the periphery of the valve body 3.

In this embodiment, the pressure detection chamber PD communicates with the refrigerant inlet of the evaporator 103 via the outflow pipe 104. Therefore, the volume of the working gas in the pressure working chamber PO separated by the diaphragm 7 changes in accordance with the pressure of the refrigerant flowing to the outflow pipe 104. When the working gas in the pressure working chamber PO is liquefied, the inner pressure is reduced, the working rod 5 is displaced upward together with the diaphragm 7 without being able to resist the biasing force of the coil spring 41, and the valve body 3 is moved to the lower opening 20b. Sit on the edge.

On the other hand, when the working gas in the pressure working chamber PO is vaporized, the inner pressure increases, the working rod 5 is displaced downward together with the diaphragm 7 against the biasing force of the coil spring 41, and the valve body 3 is opened at the lower opening 20b. Away from the edges. In this way, the constant pressure valve 1 is switched between the open state and the closed state.

When the constant pressure valve 1 is in the open state, the refrigerant passing between the valve body 3 and the lower opening 20b enters the communication hole 20c from the lower opening 20b, further passes through the pressure detection chamber PD, and then flows out of the outflow pipe 104. It is sent to the evaporator 103. As described above, in the constant pressure valve 1, the amount of the refrigerant supplied from the constant pressure valve 1 toward the evaporator 103 is automatically adjusted according to the pressure of the refrigerant returning to the evaporator 103.

Further, as shown in FIG. 1, a gap Δ is formed between the inner circumference of the cylindrical portion 82b and the outer circumference of the small diameter portion 22 of the valve body 2. Therefore, the flow rate of the refrigerant passing through the constant pressure valve 1 can be secured regardless of the mounting positional relationship between the communication hole 20c and the outflow pipe 104 (even if the directions thereof are not matched). As a result, it is not necessary to position the communication hole 20c and the outflow pipe 104, and the number of manufacturing steps can be reduced.

Further, as will be described later in detail, when the end portion of the outflow pipe 104 is inserted into the side wall opening 82d of the cylindrical portion 82b, the upper and lower end portions of the outflow pipe 104 are cylindrical according to the geometrical relationship generated when the cylinders intersect each other. It projects from the inner peripheral surface of the portion 82b. Further, if the outer diameter of the valve main body 2 and the inner diameter of the cylindrical portion 82b are substantially equal to each other, it is necessary to spend a lot of time to remove the protruding portion of the outflow pipe 104, or to make the cylindrical portion 82b have a large diameter. Need to do so. Increasing the diameter of the cylindrical portion 82b leads to increasing the size of the constant pressure valve 1.

On the other hand, according to this embodiment, since the gap Δ is formed between the outer circumference of the small diameter portion 22 of the valve body 2, the upper and lower ends of the outflow pipe 104 project from the inner peripheral surface of the cylindrical portion 82b. However, there is no interference, and both reduction of man-hours for manufacturing the constant pressure valve 1 and downsizing can be achieved.

Further, according to the present embodiment, since the case is formed by the pressed product obtained by plastically deforming the plate material and the respective parts are joined by welding or brazing, there is less risk of refrigerant leakage at the joint between the parts. Further, for example, in a constant pressure valve in which the case and the valve body are screw-connected, a special seal may be necessary to prevent refrigerant leakage, but such a seal is not necessary in the present embodiment. Further, the pressure resistance of welding and brazing is higher than that of screw connection, and the reliability of the constant pressure valve 1 is improved because it is less affected by the refrigerant temperature and the environmental temperature.

(Modification 1-1 of the first embodiment)
Next, a modified example 1-1 of the first embodiment will be described with reference to FIG. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-1. In this modification 1-1, the operating rod, the valve body, and the valve body support are integrated, and this is referred to as the valve rod 3B. The valve rod 3B includes a large shaft portion 362a fitted and guided in the lower opening 20b of the valve body 2 along the axis L, a small shaft portion 362b inserted in the orifice portion 20e with a gap, and a cone. The valve body portion 303b and the valve body support portion 342 are coaxially connected to each other.

The valve rod 3B can be formed by cutting using a lathe. The valve body support portion 342 has a flange portion 42b that supports the coil spring 41, and a cylindrical portion 42c that is connected to the flange portion 42b and is inserted into the coil spring 41. The other configurations are similar to those of the first embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

In the present embodiment, by integrating the actuating rod, the valve body, and the valve body support with the valve rod 3B, it is possible to reduce the number of parts and further reduce the cost.

(Modification 1-2 of the first embodiment)
Next, a modified example 1-2 of the first embodiment will be described with reference to FIG. FIG. 3A is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-2, and FIG. 3B is a top view of the cross section taken along the line AA of FIG. 3A. Is. In the modified example 1-2, the shape of the valve rod 3C is different. Specifically, the valve rod 3C does not have a small shaft portion, and the large shaft portion 362a is connected to the hexagonal valve body portion 303c.

Depending on the specifications of the refrigeration cycle, there is a demand to pass a limited amount of refrigerant from the inflow pipe to the outflow pipe even when the valve is closed. In such a specification, for example, a bypass hole is formed in the valve body 2 to secure the flow of the refrigerant when the valve is closed, but the cost is required to form the bypass hole.

Therefore, in the present modification 1-2, as shown in FIG. 3B, the valve body portion 303c of the valve rod 3C has a hexagonal pyramid shape. Since the orifice portion 20e of the valve body 2 has a circular shape as shown by the dotted line in FIG. 3(b), even if the valve body portion 303c is seated, there is a gap between the two, so that the opening portion is also restricted. A certain amount of refrigerant can be passed through the orifice portion 20e. The valve body portion 303c is not limited to the hexagonal pyramid shape, and any polygonal pyramid shape can be adopted. The other configurations are similar to those of the modified example 1-1 of the first embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

(Second embodiment)
Next, a constant pressure valve 1D according to the second embodiment will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view of the constant pressure valve 1D according to this embodiment. In FIG. 4, the compressor, the condenser, and the evaporator are not shown, and the constant pressure valve 1D is also not shown with the welded portion.

The present embodiment differs from the first embodiment in that a coil spring 41D as a biasing member is provided in the case 8 instead of providing the biasing device in the inflow pipe 105. More specifically, the valve body 2D does not have a large diameter portion and a lower opening, but has a lower flange portion 24 that radially extends from the outer circumference of the joint between the small diameter portion 22 and the circular pipe portion 23. The lower surface of the lower flange portion 24 is in contact with the bottom surface of the case 8.

The stopper member 6D has a disc 61 and a cylindrical shaft 62D planted in the center of the lower surface of the disc 61. The cylindrical shaft 62D also serves as an operating rod, that is, the stopper member 6D constitutes an operating member. To do. The cylindrical shaft 62D has a large shaft portion 62a which is fitted and guided in the upper opening 20a of the valve body 2D, and a small shaft portion 62b which is inserted into the orifice portion 20e with a gap. The spherical valve element 3 is welded to the tip of the small shaft portion 62b.

A coil spring 41D is arranged between the disc 61 of the stopper member 6D and the lower flange portion 24 of the valve body 2D, and urges the coil spring 41D in a direction in which they are separated from each other. Since the valve body 3 is raised together with the valve body 3, the valve body 3 contacts the edge of the orifice portion 20e. When the diaphragm 7 is displaced downward from such a state, the valve body 3 is separated from the edge of the orifice portion 20e, whereby the refrigerant flows from the inflow pipe 105 into the pressure detection chamber PD through the orifice portion 20e. .. The other configurations are similar to those of the first embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

In the present embodiment, the valve body support and the spring receiving member can be omitted, and the cost can be further reduced.

(Modification 2-1 of the second embodiment)
Next, a modification 2-1 of the second embodiment will be described with reference to FIG. FIG. 5 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 2-1. In the present modification 2-1, the stopper member 6E is composed only of a disc 61a having a locking opening 61c in the center. The lower portion of the inner circumference of the locking opening 61c is reduced in diameter, whereby a step portion 61d is formed in the locking opening 61c.

Furthermore, in this modification 2-1, the operating rod and the valve body are integrated, and this is referred to as the valve rod 3E. More specifically, the valve rod 3E formed separately from the stopper member 6E includes a thin cylindrical portion 362c protruding from the upper opening 20a of the valve body 2D along the axis L and an upper opening of the valve body 2D. The large shaft portion 362a fitted and guided to the 20a, the small shaft portion 362b inserted in the orifice portion 20e with a gap, and the conical valve body portion 303e are connected to each other.

The valve rod 3E can be formed by cutting using a lathe or the like. At the time of assembly, the valve rod 3E is inserted from the side of the orifice portion 20e of the valve body 2D on which the stopper member 6E is mounted, the thin-walled cylindrical portion 362c is projected from the upper surface of the valve body 2D, and further inserted into the locking opening 61c. .. In this state, when the thin-walled cylindrical portion 362c is plastically deformed so as to be spread by using a tool (not shown), the thin-walled cylindrical portion 362c becomes a conical shape as shown in FIG. 5, and its outer peripheral surface contacts the step 61d. By contacting, the stopper member 6E and the valve rod 3E are fixed. That is, the thin-walled cylindrical portion 362c after processing is a plastically deformed portion. The other configurations are the same as those in the second embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

According to the present embodiment, not only the cost is reduced by reducing the number of welding points, but also the valve body portion 303e is formed in a conical shape, so that it is possible to suppress abnormal noise and cavitation generated when the refrigerant flows when the valve is opened. By adjusting the caulking amount of the thin-walled cylindrical portion 362c, the protruding amount of the valve rod 3E is changed, so that the seating timing of the valve body portion 303e with respect to the orifice portion 20e can be adjusted.

(Modification 2-2 of the second embodiment)
Next, a modified example 2-2 of the second embodiment will be described with reference to FIG. FIG. 6A is an enlarged cross-sectional view showing the vicinity of the valve body of Modification Example 2-2, and FIG. 6B is a top view of the cross section taken along the line BB of FIG. 6A. It is a figure.

In Modified Example 2-2, as shown in FIG. 6B, the valve body portion 303f of the valve rod 3F has a hexagonal pyramid shape. Since the orifice portion 20e of the valve body 2D has a circular shape as shown by the dotted line in FIG. 6(b), even if the valve body portion 303f is seated, there is a gap between the two, so that the opening is limited. A certain amount of refrigerant can be passed through the orifice portion 20e. The valve body portion 303f is not limited to the hexagonal pyramid shape, and any polygonal pyramid shape can be adopted. The other configurations are similar to those of the modification 2-1 of the second embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

(Modification 2-3 of the second embodiment)
Next, a modified example 2-3 of the second embodiment will be described with reference to FIG. 7. FIG. 7 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 2-3. In this modified example 2-3, the stopper member, the operating rod, the valve body, and the valve body support are integrated, and this is referred to as a valve rod 3G. The valve rod 3G has a disc 361g that is in contact with the diaphragm 7 along the axis L, a large shaft portion 302g that is fitted and guided in the upper opening 20a of the valve body 2D, and an orifice portion 20e. The inserted small shaft portion 362g, the conical valve body portion 303g, and the lower end cylindrical portion 313g having a diameter slightly smaller than the orifice portion 20e are connected to each other. As a result, the number of parts can be reduced.

Since the valve rod 3G can be formed by cutting using a lathe or the like, the distance from the disc 361g to the valve body portion 303g can be accurately formed. Further, since the lower end cylindrical portion 313g has a smaller diameter than the orifice portion 20e, the valve rod 3G can be inserted from the upper opening 20a side of the valve body 2D during assembly. The other configurations are similar to those of the modified example 2-2 of the second embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

In the modified example 2-3, since the lower end cylindrical part 313g has a smaller diameter than the orifice part 20e, the constant pressure valve of the modified example 2-3 also causes the refrigerant to flow through the orifice part 20e at the time of restricting the opening, similarly to the modified example described above. Can be passed through.

(Third Embodiment)
Next, a constant pressure valve 1H according to the third embodiment will be described with reference to FIG. FIG. 8 is a schematic cross-sectional view of the constant pressure valve 1H in this embodiment. 8 and 9 to be described later, the compressor, the condenser, and the evaporator are not shown, and the welding portion of the constant pressure valve is not shown.

In this embodiment, the shape of the case is different from that of the first embodiment, the valve body is omitted, and the stopper member and the operating rod are integrated. More specifically, the receiving member 82H of the case 8H is formed of a pressed plate material, and has a conical portion 82f that extends upward from the lower opening 82c of the bottom portion 82e. The central opening of the conically shaped conical portion 82f forms the orifice portion 82g.

The stopper member 6H has a main body portion 601, a stopper cylindrical portion 602, and a rod body 603. The main body 601 has an inverted conical shape whose upper surface abuts on the diaphragm 7. The stopper cylindrical portion 602 extends in the axial direction from the outer circumference of the main body portion 601, and is guided by the inner circumference of the cylindrical portion 82b of the receiving member 82H. The rod body 603 extends from the lower end of the main body portion 601, and the lower end thereof is joined to the valve body 3. Such a stopper member 6H can be formed by cutting using a lathe or the like. The other configurations are similar to those of the first embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

(Constant pressure valve assembly process)
The assembly process of the constant pressure valve 1H will be described. Similar to the above-described embodiment, a metal plate material is pressed to be plastically deformed into the shape shown in FIG. 1 to obtain the upper lid member 81 and the receiving member 82H. At this time, the shape of the conical portion 82f is also formed by pressing. The upper opening 81a of the upper lid member 81 is formed by pressing, and the lower opening 82c and the side wall opening 82d of the receiving member 82H are also formed by pressing. However, these may be formed by cutting or the like. ..

Next, in the mode shown in FIG. 1, the stopper member 6H is inserted into the receiving member 82H, the lower end of the rod body 603 is projected downward from the orifice portion 82g, and the lower end of the rod body 603 is maintained while maintaining this state. The valve body 3 is welded to.

After that, the end portion of the outflow pipe 104 is inserted into the side wall opening 82d of the receiving member 82H, and fixed by brazing between the outer periphery of the end portion of the outflow pipe 104 and the periphery of the side wall opening 82d.

Furthermore, the upper lid member 81, the diaphragm 7, and the flange portion 82a of the receiving member 82H are circumferentially welded and integrated with each other in a state where the outer peripheral portions thereof are overlapped. The upper lid member 81 and the receiving member 82H joined in this way form a case 8H.

Subsequently, a space (pressure working chamber PO) surrounded by the upper lid member 81 and the diaphragm 7 is filled with a working gas such as an inert gas through the upper opening 81a formed in the upper lid member 81, and then the upper opening 81a is formed. Is sealed with a plug 83, and the working gas is sealed by fixing the plug 83 to the upper lid member 81 using projection welding or the like.

After that, the upper end of the inflow pipe 105 in which the urging device 4 is incorporated in advance is fitted to the inner circumference of the lower opening 82c of the receiving member 82H. While maintaining this state, the outer periphery of the inflow pipe 105 and the end of the circular pipe portion 23 are brazed to fix the two.

Further, the spring receiving member 43 is pushed up by using a jig (not shown) inserted inside the inflow pipe 105 to compress the coil spring 41 and apply a desired elastic force. When the coil spring 41 comes to exert a desired elastic force, the outer circumference of the inflow pipe 105 is crimped on the radially outer side of the spring receiving member 43. As a result, the plastically deformed crimp portion CK is fitted into the circumferential groove 43a of the spring receiving member 43, so that the spring receiving member 43 is fixed to the inflow pipe 105. With the above, the constant pressure valve 1H is completed.

According to the present embodiment, since the stopper member 6H is provided instead of omitting the valve body, the number of parts and the number of processing steps can be reduced.

(Modification 3-1 of Third Embodiment)
Next, a modified example 3-1 of the third embodiment will be described with reference to FIG. FIG. 9 is a schematic cross-sectional view of the constant pressure valve in Modification 3-1. In the constant pressure valve 1I of the present modification example 3-1, the shape of the receiving member 82I of the case 8I is different from that of the third embodiment.

More specifically, the receiving circular pipe portion 82h is formed so as to surround the lower opening 82c of the bottom portion 82e of the receiving member 82I, and the flat top portion 82i is formed so as to close the upper end of the receiving circular pipe portion 82h. ing. The opening formed in the center of the flat top portion 82i forms the orifice portion 82g. The receiving member 82I can be formed by pressing from a single plate material. The stopper member 6I can be shared with the stopper member 6H in FIG. The other configurations are similar to those of the third embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

When the shape of the conical portion 82f shown in FIG. 8 is formed by press working, considering the spring back after the press working and the like, in order to accurately form the taper angle of the conical portion 82f that affects the flow rate of the refrigerant, It requires relatively advanced technology. On the other hand, according to the modification example 3-1, the orifice portion 82g can be accurately formed at the center of the plane top portion 82i that is orthogonal to the axis L with high precision. The orifice portion 82g may be formed by cutting as well as pressing.

(Fourth Embodiment)
Next, a constant pressure valve 1J according to the fourth embodiment will be described with reference to FIG. FIG. 10 is a schematic cross-sectional view of the constant pressure valve 1J according to this embodiment. 10 and 11 to be described later, the compressor, the condenser, and the evaporator are not shown, and the constant pressure valve is not shown with the welded portion.

In this embodiment, the shape of the case is different from that of the second embodiment, the valve body is omitted, and the stopper member and the operating rod are integrated. More specifically, the receiving member 82J of the case 8J is formed of a pressed plate material, and forms a conical portion 82f that extends upward from the lower opening 82c of the bottom portion 82e. The central opening formed in the conical portion 82f forms the orifice portion 82g. The case 8J can be shared with the case 8H in FIG.

The stopper member 6J, which is an operating member, extends in the axial direction from the outer periphery of the main body portion 601 and an inverted conical body portion 601 whose upper surface abuts the diaphragm 7, and is guided by the inner periphery of the cylindrical portion 82b of the receiving member 82J. Has a stopper cylindrical portion 602 and a rod body 603 extending from the lower end of the main body portion 601 and having the lower end joined to the valve body 3. The stopper member 6J can be shared with the stopper member 6H in FIG.

The upper end of the coil spring 41J, which is an urging device, is stably arranged at the intersection of the main body 601 of the stopper member 6J and the stopper cylindrical portion 602, and the lower end of the coil spring 41J is the bottom 82e of the receiving member 82J. It is stably arranged at the intersection of the conical portions 82f. The other configurations are the same as those in the second embodiment, and therefore, the same reference numerals are given and redundant description will be omitted.

The assembly is the same as that of the third embodiment except that the coil spring 41J is attached to the receiving member 82J before the stopper member 6J is assembled to the receiving member 82J, and the biasing device 4 is not inserted into the inflow pipe 105. Is. According to this embodiment, the number of parts can be further reduced.

(Modification 4-1 of the fourth embodiment)
Next, a modified example 4-1 of the fourth embodiment will be described with reference to FIG. FIG. 11 is a schematic cross-sectional view of the constant pressure valve in the present modification 4-1. In the constant pressure valve 1K of the present modification example 4-1, the shape of the receiving member 82K of the case 8K is different from that of the fourth embodiment. The case 8K can be shared with the case 8I of FIG. 9, and the stopper member 6K can be shared with the stopper member 6J of FIG.

More specifically, the receiving circular pipe portion 82h is formed so as to surround the lower opening 82c of the bottom portion 82e of the receiving member 82K, and the flat top portion 82i is formed so as to close the upper end of the receiving circular pipe portion 82h. ing. The opening formed in the center of the flat top portion 82i forms the orifice portion 82g. The receiving member 82K can be formed by pressing from one plate material. The other configurations are similar to those of the modified example 3-1, and therefore, the same reference numerals are given and duplicate description is omitted.

According to this modification 4-1, the orifice portion 82g can be accurately formed in the center of the plane top portion 82i that is orthogonal to the axis L with high precision. The orifice portion 82g may be formed by cutting as well as pressing.

(Fifth Embodiment)
Next, a constant pressure valve 1L according to the fifth embodiment will be described with reference to FIG. FIG. 12 is a schematic cross-sectional view of the constant pressure valve 1L according to this embodiment. Also in FIG. 12, the compressor, the condenser, and the evaporator are not shown, and the constant pressure valve is not shown. FIG. 13 is a bottom view of a cross section taken along line CC of FIG. 12.

In the present embodiment, the shape of the receiving member of the case and the shape of the valve body are different from the modification 2-1 of FIG. More specifically, the receiving member 82L of the case 8L includes an annular flange portion 82a having an outer diameter substantially equal to that of the upper lid member 81, and a hollow bottomed rectangular tubular portion 82m having an upper end joined to the inner circumference of the flange portion 82a. Have. A lower opening 82c is formed in the center of the rectangular bottom portion of the square tube portion 82m, and a side wall opening 82d is formed in the side wall of the square tube portion 82m.

The receiving member 82L can also be formed by pressing one plate material. Therefore, as shown in FIG. 13, the side wall of the rectangular tube portion 82m is substantially flat on both the inner peripheral surface 82j and the outer peripheral surface 82k around the side wall opening 82d.

The valve body 2L differs from the modification 2-1 in FIG. 5 only in that the lower portion of the orifice portion 20e of the small diameter portion 22 is tapered. The other configurations are the same as those of the modified example 2-1, and therefore, the same reference numerals are given and redundant description is omitted.

The effect of this embodiment will be described with reference to a reference example. FIG. 14 is a cross-sectional view showing an intersecting portion of the cylindrical portion 82 b ′ of the receiving member of the constant pressure valve according to the reference example and the outflow pipe 104. In the reference example of FIG. 14, the cylindrical portion 82b' has a hollow cylindrical shape. In other words, the inner peripheral surface 82j' of the cylindrical portion 82b' is a cylindrical surface.

Here, the outflow pipe 104, which is a circular pipe, is inserted into the side wall opening 82d of the cylindrical portion 82b', and the first horizontal point E1 and the second horizontal point E2 of the outflow pipe 104 in FIG. Even if they coincide with each other, the center of the end portion of the outflow pipe 104 will project inward from the circumferential surface 82j′ at a relatively large distance D. Therefore, when a valve body or the like is provided inside the receiving member 82', in order to avoid interference with the valve body or the like, it is necessary to spend man-hours to remove the protruding portion of the outflow pipe 104 or to make the cylindrical portion 82b' large in diameter. This is not preferable from the viewpoint of cost reduction.

On the other hand, according to the present embodiment, referring to FIG. 13, since the inner peripheral surface 82j around the side wall opening 82d in the side wall of the rectangular tube portion 82m is a flat surface, the end portion of the outflow pipe 104 is located in the side wall opening 82d. It is possible to suppress the amount of protrusion from the inner peripheral surface 82j when the is inserted. Further, without increasing the size of the square tube portion 82m, interference with the valve body inside thereof can be avoided. Further, by making the outer peripheral surface 82k around the side wall opening 82d in the side wall of the square tube portion 82m a flat surface, the brazing work becomes easy.

In addition, this embodiment has an advantage also in press working. FIG. 15 is a view showing a state in which the side wall opening 82d is formed by press punching on the cylindrical portion 82b' of the reference example. In the reference example shown in FIG. 15, a die DS' having a recess CV is arranged inside the cylindrical portion 82b', and a cylindrical punch PC' is arranged from the outside of the cylindrical portion 82b'. As a result, by pressing the blade edge of the punch PC' toward the recess CV with a strong press pressure, the plate material can be punched into a circular shape to form the side wall opening 82d.

Here, if the inner peripheral surface 82j' of the cylindrical portion 82b' is a cylindrical surface, in order to completely punch the plate material, the blade tip of the punch PC' must be a cylindrical surface as shown in FIG. For this reason, the blade tip first horizontal end F1 and the blade tip second horizontal end F2 of the punch PC' form an acute angle in plan view, and tool wear easily occurs at an early stage.

Also, in the recess CV of the die DS′, the receiving portions G1 and G2 for performing shearing are not formed at the positions facing the blade tip first horizontal end F1 and the blade tip second horizontal end F2 of the punch PC′, respectively. must not. Therefore, when the inner peripheral surface 82j' of the cylindrical portion 82b' is a cylindrical surface, the receiving portions G1 and G2 also have an acute angle in plan view, and tool wear is likely to occur early.

FIG. 16 is a view showing a state in which the side wall opening 82d is formed by press punching on the rectangular tube portion 82m of the present embodiment. According to the present embodiment, referring to FIG. 16, since the inner peripheral surface 82j around the side wall opening 82d in the side wall of the rectangular tube portion 82m is a flat surface, the end portion of the punch PC can be a flat surface. Thereby, tool wear can be suppressed. Similarly, since the inner peripheral surface 82j of the side wall of the square tube portion 82m is a flat surface, the receiving portions G1 and G2 of the die DS are closer to an obtuse angle in plan view, and tool wear can be suppressed.

In the above embodiments, the receiving member is provided with the square tubular portion. However, even if a part of the outer periphery of the cylindrical portion is pressed into a flat surface and then the side wall opening is formed by press punching this portion. Good.

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

1, 1D, 1H, 1I, 1J, 1K, 1L: constant pressure valve 2, 2D, 2L: valve body 3: valve body 3B, 3C, 3E, 3F, 3G: valve rod 4: biasing device 5: operating rod 6 , 6D, 6E, 6H, 6I, 6J: Stopper member 7: Diaphragm 8, 8H, 8I, 8J, 8K, 8L: Cases 20e, 82g: Orifice parts 41, 41D, 41J: Coil spring 42: Valve body support 43: Spring receiving member 81: Upper lid member 82, 82H, 82I, 82J, 82K, 82L: Receiving member 100: Refrigerant circulation system 101: Compressor 102: Condenser 103: Evaporator

Claims (12)

A constant pressure valve for a refrigeration cycle arranged between an inflow pipe connected to a condenser and an outflow pipe connected to an evaporator,
A case in which a pressure detection chamber communicating with the inflow pipe and the outflow pipe and a pressure working chamber in which gas is sealed are provided;
In the case, a flexible diaphragm that partitions the pressure detection chamber and the pressure working chamber,
A valve body that moves according to the displacement of the diaphragm,
An orifice portion whose opening is restricted by the valve body approaching,
A biasing member that biases the valve element toward the orifice portion,
The case is formed by using a single plate material that is plastically deformed at least from a contact portion with the diaphragm to a connection portion of the outflow pipe,
When the diaphragm separates the valve body from the orifice portion against the urging force of the urging member, the fluid flowing from the inflow pipe passes through the gap between the valve body and the orifice portion. Heading into the pressure detection chamber,
A constant pressure valve characterized in that. The single plate member has openings for inserting the ends of the outflow pipe and the inflow pipe, respectively.
The constant pressure valve according to claim 1, wherein: An operating member that connects the diaphragm and the valve body,
A valve body that includes a guide hole that guides the operating member, the orifice portion, and a communication hole that communicates the orifice portion with the outflow pipe.
The constant pressure valve according to claim 1 or 2, characterized in that. The biasing member is arranged in the inflow pipe,
The constant pressure valve according to claim 3, wherein The valve body is integral with the actuating member,
The constant pressure valve according to claim 3 or 4, characterized in that. The valve body is a separate body from the actuating member, and is connected to each other via a plastically deformed portion,
The constant pressure valve according to claim 3 or 4, characterized in that. The orifice portion has a circular opening, and the valve body has a spherical shape, a conical shape, or a polygonal pyramid shape,
The constant pressure valve according to any one of claims 3 to 6, characterized in that. The orifice portion is a part of the single plate material that is plastically deformed,
The constant pressure valve according to claim 1 or 2, characterized in that. A connecting member between the diaphragm and the valve body, having an actuating member guided to the inner peripheral surface of the case;
The constant pressure valve according to claim 8, wherein The biasing member is arranged in the inflow pipe,
The constant pressure valve according to claim 8 or 9, characterized in that. The biasing member is arranged between the case and the actuating member,
The constant pressure valve according to claim 9, wherein In the case, the inner peripheral surface around the connection portion of the outflow pipe is a substantially flat surface,
The constant pressure valve according to any one of claims 1 to 11, characterized in that.

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