JP7190736B2 - valve device - Google Patents

Description

The present invention relates to valve devices.

Mechanical constant pressure valves and expansion valves are known as valve devices for controlling the flow rate of refrigerant in air conditioners. There is a demand for cost reduction in such valve devices.

One way to reduce the cost of the valve device is to reduce the number of parts by integrating the parts. Patent Literature 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-A-2003-75025 JP 2011-133157 A

By the way, in the expansion valve of Patent Document 1, the spherical valve element and the center disk that abuts on the diaphragm are connected by a rod-like member. are there. Moreover, although there is no specific disclosure in Patent Document 1, it is presumed that at least the valve body and the rod-shaped member are joined by welding or the like in order to improve handleability. However, such welding between members causes an increase in cost.

Patent document 2 discloses an expansion valve that opens by pushing down a spherical valve element with an operating rod. Here, if the operating rod and the valve body are connected to form an integrated product, the number of parts can be reduced. However, since such a one-piece product has an enlarged diameter only at one end, if it is attempted to form it by cutting, the amount of cutting will increase, the processing time will be increased, and the cutting tool will be significantly worn. is likely to increase.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved constant pressure valve that can be manufactured at low cost.

In order to achieve the above object, the valve device according to the present invention comprises:
a case internally provided with a pressure detection chamber through which a refrigerant passes and a pressure actuation chamber in which a gas is sealed;
a flexible diaphragm separating the pressure detection chamber and the pressure actuation chamber in the case;
a valve stem that includes a valve body and moves according to the displacement of the diaphragm;
a valve body having an orifice through which the refrigerant passes and joined to the case;
a biasing member that biases the valve body toward the orifice;
The opening of the orifice is restricted by the approach of the valve body to the orifice,
The valve stem is characterized by being inserted into the orifice portion and having a plastically deformed portion at one end.

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

FIG. 1 is a schematic cross-sectional view showing a constant pressure valve according to the first embodiment. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the lower portion of the valve body with the cylindrical shaft inserted through the upper opening. FIG. 3(a) is an enlarged cross-sectional view showing the vicinity of the lower portion of the valve body of Modification 1-1 during the manufacturing process, and FIG. 3(b) is Modification 1-1 after the manufacturing process. It is sectional drawing which expands and shows the valve body lower part vicinity. FIG. 4 is an enlarged sectional view showing the vicinity of the valve body in Modification 1-2 of the first embodiment. FIG. 5(a) is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-3, and FIG. 5(b) is a top view of the cross section taken along line AA of FIG. 5(a). It is a diagram. FIG. 6 is a schematic cross-sectional view schematically showing an example in which the expansion valve of the second embodiment is applied to a refrigerant circulation system. FIG. 7 is a perspective view showing a ring spring. FIG. 8 is a schematic cross-sectional view of an expansion valve in modification 2-1 applied to a refrigeration cycle.

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", and the side from the diaphragm toward the valve body is defined as "downward".

(First embodiment)
A configuration of a constant pressure valve 1 as a valve device in the first embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing a constant pressure valve 1 according to this embodiment.

A constant pressure valve 1 includes a valve body 2, a coil spring 3 forming an urging member, a stopper member 6 having a valve body and an operating rod, a diaphragm 7, and a case 8 enclosing them. Let L be the axis of the constant pressure valve 1 .

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 facing 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.

The center of the upper lid member 81 rises in a dome shape, and the periphery of the upper opening 81a is made thin to form a depressed portion 81b that is circularly depressed toward the inside. A plug 83 seals the upper opening 81a so as to be joined to the recessed portion 81b.

The receiving member 82 has an annular flange portion 82a whose outer diameter is substantially equal to that of the upper lid member 81, and a hollow bottomed cylindrical portion 82b whose upper end is 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 by brazing to the side wall opening 82d, which is the connecting portion. The other end of the outflow pipe 104 is connected to an evaporator (not shown). Let O be the axis of the outflow tube 104 .

The diaphragm 7 is made of a thin, flexible plate material with a plurality of concentric concave and convex shapes formed therein, 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 cylindrical body portion 22 separated from the cylindrical portion 82b, a circular tube portion 23 coaxially connected to the lower portion of the body portion 22 and fitted into the lower opening 82c, and the body portion 22. and a lower flange portion 24 extending radially outward from the connecting portion of the circular tube portion 23 . A cylindrical concave portion 25 is formed at the lower end of the body portion 22 .

A lower end of the circular tube portion 23 extends 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 is abutted against the stepped portion. is fixed by A lower end of the inflow pipe 105 is connected to a capacitor (not shown). The axis of the inflow pipe 105 coincides with the axis L of the constant pressure valve 1 .

A communication hole 20c is formed in the valve body 2 so as to pass through the body portion 22 in a direction perpendicular to the axis L. As shown in FIG. The axis of the communication hole 20c is preferably aligned with the axis O of the outflow pipe 104, but may be off.

In the valve body 2, a cylindrical upper opening 20a is formed along the axis L from the upper end to the communicating hole 20c, and a cylindrical orifice 20e is coaxially formed from the communicating hole 20c to the recess 25. ing. The orifice portion 20e has a smaller diameter than the upper opening 20a. The upper opening 20a and the orifice portion 20e form a cylindrical space passing through the valve body 2 along the axis L. As shown in FIG. The inner diameter of the orifice portion 20e needs to be formed with high accuracy from the viewpoint of flow rate control, but it is relatively easy to process because it is sufficient to process a short distance to the communicating hole 20c.

A space surrounded by the upper lid member 81 and the diaphragm 7 forms a pressure actuation chamber PO, and a 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 disk 61 facing the diaphragm 7 and a cylindrical shaft 62 implanted in the center of the lower surface of the disk 61 . The stopper member 6 can be formed by welding the upper end of the cylindrical shaft 62 to the center of the lower surface of the disk 61 . The cylindrical shaft 62 has a large diameter shaft 62a and a small diameter shaft 62b. The large-diameter shaft 62a has an axial length longer than that of the upper opening 20a of the valve body 2, extends into the communication hole 20c, and is slidably fitted in the upper opening 20a. The small-diameter shaft 62b is coaxially joined to the lower end of the large-diameter shaft 62a and is inserted through the orifice portion 20e with a gap therebetween. A conical valve body 62c is formed at the lower end of the small diameter shaft 62b as will be described later. A cylindrical shaft 62 constitutes a valve stem with a valve body.

A coil spring 3 is arranged between the disc 61 of the stopper member 6 and the lower flange portion 24 of the valve body 2 and urges them in the direction of separating them, thereby moving the stopper member 6 to the valve body 62c. Since the valve body 62c is raised together with the valve body 62c, the valve body 62c abuts against the edge of the orifice portion 20e. When the diaphragm 7 is displaced downward from this state, the valve body 62c is separated from the edge of the orifice portion 20e, whereby the refrigerant flows from the inflow pipe 105 through the orifice portion 20e into the pressure detection chamber PD. . However, even when the valve body 62 c contacts the orifice portion 20 e , a limited amount of refrigerant may flow from the inflow pipe 105 to the outflow pipe 104 .

(Constant pressure valve assembly process)
An assembling process of the constant pressure valve 1 will be described. First, a metal plate is pressed to be plastically deformed into the shape shown in FIG. Next, an upper opening 81a is formed in the upper lid member 81 by press punching or the like, and a lower opening 82c and a side wall opening 82d are formed in the receiving member 82 by press punching or the like. Cost reduction can be achieved by forming the case 8 using a pressed product.

Although the valve body 2 is formed by cutting or the like, since these are relatively small, the amount of cutting is small and the cost can be suppressed. In addition, general-purpose products can be used for other parts, and the cost can be reduced.

Next, in the manner 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 the space between the circular pipe portion 23 and the bottom wall of the cylindrical portion 82b is opened. are circumferentially welded together by, for example, TIG welding, laser welding, plasma welding, or the like to form a welded portion W2.

After that, the end of the outflow tube 104 is inserted into the side wall opening 82d of the receiving member 82, and the outer circumference of the end of the outflow tube 104 and the periphery of the side wall opening 82d are fixed by brazing.

The cylindrical shaft 62 of the stopper member 6 has a thin-walled cylindrical shape with a valve body 62c at the lower end parallel to the axis before being incorporated into the valve body 2, and has the same diameter as the small-diameter shaft 62b (dotted line in FIG. 2). reference). Therefore, with the coil spring 3 arranged around the valve body 2, the cylindrical shaft 62 of the stopper member 6 is inserted from the upper opening 20a of the valve body 2 to pass through the orifice portion 20e, and the valve body 62c is inserted into the recess 25. can be exposed inside.

FIG. 2 is an enlarged sectional view showing the vicinity of the lower portion of the valve body 2 with the cylindrical shaft 62 inserted through the upper opening 20a. The valve body 2 and the disk 61 of the stopper member 6 are fixed by a jig (not shown), and a caulking tool TL (indicated by the dotted line in FIG. 2) having a tapered tip is applied to the valve body 62c exposed in the recess 25 ) are coaxially approached and pressed with a large force, the valve body 62c is plastically deformed and expanded into a predetermined tapered shape (umbrella shape). The opening angle (taper angle) of the valve body 62c with respect to the axis L can be adjusted by adjusting the pressing force of the crimping tool TL and/or the taper shape of the tip. Since the maximum diameter of the tapered valve body 62c is larger than the diameter of the orifice portion 20e, the stopper member 6 can be separated from the valve body 2 even if it is biased by the coil spring 3 after it is removed from the jig. do not have.

Thereafter, in FIG. 1, the outer peripheral portions (contact portions) of the upper lid member 81, the diaphragm 7, and the flange portion 82a of the receiving member 82 are overlapped, and the outer peripheral portions are welded by, for example, TIG welding, laser welding, or plasma welding. They are circumferentially welded by welding or the like to be integrated to form a welded portion W1. The case 8 is composed of the upper lid member 81 and the receiving member 82 joined in this manner.

Subsequently, after filling a working gas such as an inert gas into the space (pressure working chamber PO) surrounded by the upper lid member 81 and the diaphragm 7 through the upper opening 81a formed in the upper lid member 81, the upper opening 81a is filled. is sealed with a plug 83, and the plug 83 is fixed to the upper cover member 81 using projection welding or the like. At this time, since the periphery of the depressed portion 81b is thin, appropriate welding can be performed. In addition, 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 and the like generated by welding from dropping onto the diaphragm . Thus, 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. A refrigerant (fluid) pressurized by a compressor (not shown) is liquefied by a condenser and sent to the constant pressure valve 1 through an inflow pipe 105 . The refrigerant discharged from the constant pressure valve 1 is sent to the evaporator, where it exchanges heat with air flowing around it. Furthermore, the refrigerant that has passed through the evaporator is returned to the compressor side. In this manner, the refrigerant circulates within the refrigerant circulation system.

The constant pressure valve 1 is supplied with high-pressure refrigerant from a condenser. More specifically, high pressure refrigerant from the condenser enters the inflow pipe 105 and reaches around the valve body 62c.

In this embodiment, the pressure detection chamber PD communicates with the refrigerant inlet of the evaporator via the outflow pipe 104 . Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the pressure-actuated chamber PO separated by the diaphragm 7 changes according to the temperature and pressure of the refrigerant flowing to the outflow pipe 104 . When the working gas in the pressure working chamber PO is liquefied, the internal pressure decreases, and the diaphragm 7 and the stopper member 6 are displaced upward together with the diaphragm 7, unable to resist the biasing force of the coil spring 3, and the valve body 62c moves toward the orifice portion 20e. take a seat.

On the other hand, when the working gas in the pressure working chamber PO is vaporized, the internal pressure increases, and the diaphragm 7 and the stopper member 6 are displaced downward against the biasing force of the coil spring 3, and the valve body 62c moves toward the orifice portion 20e. move away from Thus, switching between the open state and the closed state of the constant pressure valve 1 is performed.

When the constant pressure valve 1 is open, the refrigerant that has passed between the valve body 62c and the orifice portion 20e enters the communication hole 20c from the orifice portion 20e, passes through the pressure detection chamber PD, and exits the outflow pipe 104. sent to the evaporator. In this manner, the constant pressure valve 1 automatically adjusts the amount of refrigerant supplied from the constant pressure valve 1 to the evaporator in accordance with the temperature and pressure of the refrigerant returning to the evaporator.

According to this embodiment, since the valve body 62c is formed by plastically deforming one end of the cylindrical shaft 62, welding or the like is not required, and the manufacturing cost can be reduced.

Furthermore, according to the present embodiment, the case is formed of a press-processed product obtained by plastically deforming a plate material, and each part is joined by welding or brazing, so there is little risk of refrigerant leakage occurring at the joints between the parts. Further, for example, in a constant pressure valve in which a case and a valve body are screwed together, a special seal may be required to ensure refrigerant leakage, but such a seal is unnecessary in this embodiment. Furthermore, welding and brazing have higher pressure resistance than screw connection, and are less susceptible to refrigerant temperature and ambient temperature, so the reliability of the constant pressure valve 1 is also improved.

(Modification 1-1 of the first embodiment)
Next, modification 1-1 of the first embodiment will be described with reference to FIG. FIG. 3(a) is an enlarged cross-sectional view showing the vicinity of the lower portion of the valve body of Modification 1-1 during the manufacturing process, and FIG. 3(b) is Modification 1-1 after the manufacturing process. It is sectional drawing which expands and shows the valve body lower part vicinity.

In Modification 1-1, the configurations of the cylindrical shaft of the stopper member and the valve body are different. More specifically, as shown in FIG. 3A, the cylindrical shaft 62A has a crimped cylindrical portion 62d having a diameter smaller than that of the small diameter shaft 62b instead of forming a valve body at its lower end.

Further, in this modified example 1-1, the valve body 4 is provided separately from the stopper member. The valve body 4 is formed by pressing or machining a single metal plate and has a conical portion 41 and a top portion 42 connected to the upper end of the conical portion 41 . A circular opening 43 is formed in the center of the top portion 42 . A cylindrical shaft 62A to which the valve body 4 is attached constitutes a valve stem. Since other configurations are the same as those of the first embodiment, redundant description is omitted by attaching the same reference numerals.

At the time of assembly, as shown in FIG. 3A, the opening 43 is inserted into the caulked cylindrical portion 62d exposed in the recess 25 of the valve body 2, and the top portion 42 of the valve body 4 is attached to the lower end of the small diameter shaft 62b. When the tip of a crimping tool similar to that shown in FIG. 2 is brought coaxially close to the crimping cylindrical portion 62d protruding downward from the opening 43 and pressed with a large force, the crimping cylindrical portion 62d is plastically deformed to open. 43 is expanded in a tapered shape (umbrella shape) with a larger diameter. As a result, the valve body 4 is attached to the lower end of the small diameter shaft 62b.

According to this embodiment, by forming the valve body 4 having a precise shape separately from the stopper member, the gap between the valve body 4 and the orifice portion 20e can be maintained regardless of the degree of plastic deformation of the crimped cylindrical portion 62d. can be managed with high accuracy, and the flow rate of the refrigerant when the valve is opened can be controlled with high accuracy. Moreover, since the connection between the valve body 4 and the small-diameter shaft 62b is performed by plastic deformation without brazing or welding, the manufacturing cost can be reduced.

(Modification 1-2 of the first embodiment)
Next, modification 1-2 of the first embodiment will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-2. In Modified Example 1-2, the stopper member 6B is formed of a disk 61B having a locking opening 61c in the center and a cylindrical shaft 62B as a valve stem. The locking opening 61c is formed by reducing the diameter of the lower portion of the inner periphery, thereby forming a stepped portion 61d in the locking opening 61c.

Furthermore, in this modified example 1-2 as well, the cylindrical shaft and the valve body are integrated. More specifically, the cylindrical shaft 62B, which is formed separately from the disc 61B, includes a thin cylindrical portion 362c protruding from the upper opening 20a of the valve body 2 along the axis L, A large shaft portion 362a fitted and guided by the orifice portion 20a, a small shaft portion 362b inserted into the orifice portion 20e with a gap, and a conical valve body portion 303e are connected.

The cylindrical shaft 62B can be formed by cutting using a lathe. At the time of assembly, the cylindrical shaft 62B is inserted from the orifice portion 20e side of the valve body 2 on which the stopper member 6B is mounted, and the thin cylindrical portion 362c is protruded from the upper surface of the valve body 2 and further inserted into the locking opening 61c. . In this state, when a crimping tool (not shown) is used to plastically deform the thin cylindrical portion 362c so as to expand it, the thin cylindrical portion 362c becomes conical as shown in FIG. By abutting, the disk 61B and the cylindrical shaft 62B are fixed. Since other configurations are the same as those of the first embodiment, redundant description is omitted by attaching the same reference numerals.

According to this embodiment, in addition to cost reduction by reducing the number of welded portions, the amount of protrusion of the cylindrical shaft 62B is changed by adjusting the amount of crimping of the thin cylindrical portion 362c. The seating timing for 20e can be adjusted.

(Modification 1-3 of the first embodiment)
Next, modification 1-3 of the first embodiment will be described with reference to FIG. FIG. 5(a) is an enlarged cross-sectional view showing the vicinity of the valve body of Modification 1-3, and FIG. 5(b) is a top view of the cross section taken along line AA of FIG. 5(a). It is a diagram.

A stopper member 6C in Modification 1-3 is formed of a disc 61B similar to Modification 1-2 and a cylindrical shaft 62C as a valve stem. However, as shown in FIG. 5(b), the valve body portion 303f of the cylindrical shaft 62C has a hexagonal pyramid shape. Since the orifice portion 20e of the valve body 2 has a circular shape as indicated by the dotted line in FIG. 5(b), even if the valve body portion 303f is seated there is a gap between them, so that even when the opening is restricted, the opening is restricted. A quantity of refrigerant can be passed through the orifice portion 20e. Note that the valve body portion 303f is not limited to the hexagonal pyramidal shape, and any polygonal pyramidal shape can be adopted. Since other configurations are the same as those of the modified example 1-2 of the first embodiment, the same reference numerals are used to omit redundant description.

(Second embodiment)
Next, with reference to FIG. 6, an overview of the expansion valve 201, which is the valve device in the second embodiment, will be described. FIG. 6 is a schematic cross-sectional view schematically showing an example in which the expansion valve 201 of this embodiment is applied to the refrigerant circulation system 100. As shown in FIG. In this example, expansion valve 201 is fluidly connected to compressor 101 , condenser 102 and evaporator 103 .

The expansion valve 201 includes a valve body 202 having a valve chamber VS, a biasing device 204, an operating rod 205, a ring spring 206, and a power element 208. Let L be the axis of the expansion valve 201 . Actuating rod 205 constitutes a valve stem with a valve body.

The valve body 202 includes a first flow path 221 and a second flow path 222 in addition to the valve chamber VS. The first flow path 221 is a supply-side flow path, and refrigerant (also referred to as fluid) is supplied to the valve chamber VS via the supply-side flow path. The second flow path 222 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 227 and the discharge side flow path. The first flow path 221 and the valve chamber VS are communicated with each other by a connection path 221a having a diameter smaller than that of the first flow path 221 . The lower edge of the operating rod insertion hole 227 forms an orifice.

A valve body 203 is formed at the lower end of the operating rod 205 . The valve body 203 has a tapered shape by expanding a thin cylindrical portion formed at the lower end of the operating rod 205 with a caulking tool, as in the above embodiment.

The valve body 203 is arranged in the valve chamber VS. When the valve body 203 is in contact with the orifice portion of the valve body 202, the first flow path 221 and the second flow path 222 are out of communication. On the other hand, when the valve body 203 is separated from the orifice portion, the first flow path 221 and the second flow path 222 are in communication.

The operating rod 205 inserted through the operating rod insertion hole 227 with a gap can push the valve body 203 in the valve opening direction against the biasing force of the biasing device 204 . When the operating rod 205 moves downward, the valve body 203 is separated from the orifice portion and the expansion valve 201 is opened.

Next, the power element 208 will be explained. The power element 208 is attached to a recess 202 a provided on the top of the valve body 202 . The recess 202a communicates with a return passage 223 in the valve body 202 through which the refrigerant from the evaporator 103 passes through a communication passage 202b. An operating rod 205 passes through the communicating passage 202b. A female thread is formed on the inner periphery of the recess 202a.

The power element 208 has a plug 281 , an upper lid member 282 , a diaphragm 283 , a stopper member 284 and a receiving member 286 .

The upper lid member 282 has a central conical portion 282a and an annular flange portion 282b extending from the lower end of the conical portion 282a to the outer circumference. An opening 282c is formed at the top of the conical portion 282a and can be sealed with a plug 281. As shown in FIG.

The diaphragm 283 is made of a thin plate with a plurality of concentric concave and convex shapes, and has an outer diameter substantially equal to the outer diameter of the flange portion 282b.

The stopper member 284 has a fitting hole 284a at the center of the lower end.

The receiving member 286 includes a flange portion 286a having substantially the same outer diameter as the flange portion 282b of the upper lid member 282, a stepped portion 286c having an annular support surface 286b substantially orthogonal to the axis L, and a hollow cylindrical portion 286d. have. A male thread is formed on the outer circumference of the hollow cylindrical portion 286d.

A procedure for assembling the power element 208 will be described. An upper lid member 282, a diaphragm 283, a stopper member 284, and a receiving member 286 are arranged so as to have a positional relationship as shown in FIG.

Furthermore, in a state in which the outer peripheral portions of the flange portion 282b of the upper lid member 282, the diaphragm 283, and the flange portion 286a of the receiving member 286 are overlapped, the outer peripheral portions are circumferentially welded by TIG welding, laser welding, plasma welding, or the like. and unify. A case is composed of the upper cover member 282 and the receiving member 286 .

Subsequently, after the working gas is sealed from the opening 282c formed in the upper lid member 282 into the space (pressure actuation chamber PO) surrounded by the upper lid member 282 and the diaphragm 283, the opening 282c is sealed with the plug 281, Further, the plug 281 is fixed to the upper cover member 282 using projection welding or the like.

At this time, the working gas enclosed in the pressure actuation chamber PO causes the diaphragm 283 to receive pressure in a manner that the diaphragm 283 protrudes toward the receiving member 286, so that the space surrounded by the diaphragm 283 and the receiving member 286 (pressure detection chamber PD) It is supported in contact with the upper surface of the arranged stopper member 284 .

When assembling the power element 208, the male thread of the hollow cylindrical portion 286d of the receiving member 286 is engaged with the female thread of the recess 202a of the valve body 202 while the upper end of the operating rod 205 is fitted into the fitting hole 284a of the stopper member 284. A threaded engagement secures the power element 208 to the valve body 202 . In this state, the pressure detection chamber PD of the power element 208 communicates with the return channel 223, that is, has the same internal pressure.

Next, the ring spring 206 will be explained. The ring spring 206 is seated within a concavely recessed annulus 226 of the valve body 202 in FIG. FIG. 7 is a perspective view showing the ring spring 206. FIG.

The ring spring 206 is constructed by bending a plate-like member into a cylindrical shape as shown in FIG. be done.

The first elastic piece 261, the second elastic piece 262, and the third elastic piece 263 are cut and bent inward. The second convex contact portion 262a and the third convex contact portion 263a are designed to be positioned so as to divide the circumference into three equal parts. In a plane perpendicular to the axis L (FIG. 1), an inscribed contact connecting the tops of the first convex contact portion 261a, the second convex contact portion 262a, and the third convex contact portion 263a is provided. The diameter of the circle is smaller than the outer diameter of the operating rod 205 . As a result, a predetermined pressing force is applied to the outer circumference of the operating rod 205 from the first convex contact portion 261a, the second convex contact portion 262a, and the third convex contact portion 263a. becomes.

Next, the biasing device 204 will be described. 6, the biasing device 204 includes a coil spring (biasing member) 241 formed by spirally winding a circular wire, a valve body support 242 attached to the upper end of the coil spring 241 and supporting the valve body 203, and a spring receiving member 243 attached to the valve body 202 while supporting the lower end of the coil spring 241 . The spring receiving member 243 has the function of sealing the valve chamber VS of the valve body 202 and supporting the end of the coil spring 241 that biases the valve body 203 toward the orifice.

The valve body support 242 has a support conical portion 242a forming an upper portion, a support cylindrical portion 242b forming a lower portion, and a support flange portion 242c radially extending from the central outer periphery. The support conical portion 242a contacts the tapered lower surface of the valve body 203 formed at the lower end of the operating rod 205, and centers (positions) the operating rod 205 with respect to the axis L. As shown in FIG. The support cylindrical portion 242b and the support flange portion 242c are fitted into and abut against the upper end of the coil spring 241 arranged in the valve chamber VS to support it.

(Operation of expansion valve)
An operation example of the expansion valve 201 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 201 . Also, the refrigerant adiabatically expanded by the expansion valve 201 is delivered to the evaporator 103, where it exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator 103 is returned to the compressor 101 side through the expansion valve 201 (more specifically, the return flow path 223).

The expansion valve 201 is supplied with high-pressure refrigerant 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 221 .

When the valve body 203 is in contact with the orifice portion (in other words, when the expansion valve 201 is closed), the first flow path 221 on the upstream side of the valve chamber VS and the downstream side of the valve chamber VS are connected. The second channel 222 is in a non-communication state. On the other hand, when the valve element 203 is separated from the orifice (in other words, when the expansion valve 201 is open), the refrigerant supplied to the valve chamber VS flows through the operating rod insertion hole 227 and the second It is delivered to the evaporator 103 through the channel 222 . Switching between the closed state and the open state of the expansion valve 201 is performed by an operating rod 205 connected to a power element 208 .

In FIG. 6, inside the power element 208, a pressure actuation chamber PO and a pressure detection chamber PD separated by a diaphragm 283 are provided. Therefore, when the working gas in the pressure working chamber PO is liquefied, the working rod 205 moves upward, and when the liquefied working gas is vaporized, the working rod 205 moves downward. Thus, switching between the open state and the closed state of the expansion valve 201 is performed.

Furthermore, the pressure detection chamber PD of the power element 208 communicates with the return channel 223 . Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the pressure working chamber PO changes according to the temperature and pressure of the refrigerant flowing through the return passage 223, and the working rod 205 is driven. In other words, in the expansion valve 201 shown in FIG. 6, the amount of refrigerant supplied from the expansion valve 201 toward the evaporator 103 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 103 to the expansion valve 201. adjusted.

According to the prior art such as Patent Document 2, the spherical valve body is connected to the operating rod 205, resulting in an increase in the number of parts. In contrast, according to this embodiment, the valve body 203 is integrally formed by plastically deforming the lower end of the operating rod 205, thereby reducing the number of parts and cost.

(Modification 2-1 of Second Embodiment)
Next, with reference to FIG. 8, an expansion valve 201A, which is a valve device in Modification 2-1 of the second embodiment, will be described. FIG. 8 is a schematic cross-sectional view of an expansion valve 201A in Modification 2-1 applied to the refrigeration cycle 100A.

This modified example 2-1 is different from the second embodiment in that the shape of the stopper member is different and the urging device is omitted. More specifically, the stopper member 284A of the power element 208A is formed by pressing a single circular metal plate, and has an annular portion 284c with an opening 284b in the center and a contact portion 284d. . The annular portion 284 c swells around the opening 284 b and has a lower surface in contact with the diaphragm 283 . The contact portion 284 d is shifted downward around the annular portion 284 c and faces the support surface 286 b of the receiving member 286 . The upper end of the operating rod 205 is fitted into the opening 284b and joined to the stopper member 284A by brazing or the like.

Furthermore, in this modification, a coil spring 241A is arranged inside the receiving member 286 between the annular portion 284c of the stopper member 284A and the recess bottom wall 220c of the valve body 202A, and is attached in a direction separating them. I am gaining momentum.

As shown in FIG. 8, in this modified example, the first flow path 221A is extended, and the inside thereof is also used as the valve chamber VS. The valve body 203 at the lower end of the actuating rod 205 can be formed in the same manner as in the first embodiment after assembling the actuating rod 205 to the valve main body 202A. More specifically, the upper end of the operating rod 205 having a thin cylindrical portion formed at the lower end is joined to the stopper member 284A. The stopper member 284A is assembled into the power element 208A in the same manner as in the second embodiment, and the operating rod 205 is assembled into the valve main body 202A at the same time. At this time, the lower end of the operating rod 205 is inserted into the operating rod insertion hole 227 to project the thin cylindrical portion into the valve chamber VS. In this state, the tip of a crimping jig (not shown) inserted into the first flow path 221A is pressed against the thin cylindrical portion at the lower end of the operating rod 205 to plastically deform it, thereby forming the valve body 203. be able to. Since other configurations are the same as those of the second embodiment, redundant description is omitted by attaching the same reference numerals.

According to this modification, the annular portion 284c of the stopper member 284A and the bottom wall 220c of the valve body 202A are biased away from each other by the coil spring 241A. This urging force raises the stopper member 284A together with the operating rod 205 and the valve body 203, so that the valve body 203 comes into contact with the orifice. When the diaphragm 283 is displaced downward from such a state, the valve body 203 is separated from the orifice portion, whereby the refrigerant flows from the second flow path 222 into the operating rod insertion hole 227 via the orifice portion. The initial load of the coil spring 241A can be changed by adjusting the amount of screwing of the power element 208A into the valve body 202A.

In this modified example, the urging device can be omitted from the second embodiment, and further cost reduction can be achieved.

It should be noted that the present invention is not limited to the above-described embodiments. Variations of any components of the above-described embodiments are possible, and additions or omissions of any components of the above-described embodiments are possible within the scope of the invention.

Reference Signs List 1: Constant pressure valves 2, 202, 202A: Valve bodies 62c, 203: Valve bodies 62, 62A, 62B, 62C: Cylindrical shaft 204: Biasing device 205: Operating rods 6, 6B, 284, 284A: Stopper members 7, 283 : Diaphragm 8 : Case 20e : Orifice 3, 241, 241A : Coil spring 242 : Valve body support 243 : Spring receiving member 282 : Upper lid member 286 : Receiving member 100 : Refrigerant circulation system 101 : Compressor 102 : Condenser 103 : Evaporator

Claims (8)

a case internally provided with a pressure detection chamber through which a refrigerant passes and a pressure actuation chamber in which a gas is sealed;
a flexible diaphragm separating the pressure detection chamber and the pressure actuation chamber in the case;
a valve stem that includes a valve body and moves according to the displacement of the diaphragm;
a valve body having an orifice through which the refrigerant passes and joined to the case;
a biasing member that biases the valve body toward the orifice;
The opening of the orifice is restricted by the approach of the valve body to the orifice,
The valve stem is inserted through the orifice and has a plastically deformed portion at one end,
A valve device characterized by: The valve body is formed by plastically deforming one end of the valve stem into a predetermined shape.
2. The valve device according to claim 1, characterized in that: The valve body is formed separately from the valve stem, and is attached to the valve stem by plastically deforming one end of the valve stem.
2. The valve device according to claim 1, characterized in that: The valve stem is attached to a stopper member that contacts the diaphragm by plastically deforming one end of the valve stem.
2. The valve device according to claim 1, characterized in that: The valve body is formed at the other end of the valve stem,
5. The valve device according to claim 4, characterized in that: The orifice portion has a circular opening, and the valve body has a conical shape or a polygonal pyramid shape,
6. The valve device according to claim 5, characterized in that: The biasing member is arranged between the valve body and the case,
The valve device according to any one of claims 1 to 6, characterized in that: the biasing member is disposed within the valve body;
The valve device according to any one of claims 1 to 6, characterized in that:

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