JP2020143690A - Valve device - Google Patents

Abstract

To provide an improved valve device superior in durability at low costs.SOLUTION: An expansion valve 10 has a valve element 19, an operation rod 18 moving with the valve element 19, a case 122 including a small-diameter cylindrical portion 122c, and a coil spring 13 energizing the valve element 19 toward a lower end 122f of the small-diameter cylindrical portion 122c. The operation rod 18 has an outer peripheral face slidable to an inner peripheral cylindrical face 122h of the small-diameter cylindrical portion 122c, and a groove 181 forming a clearance to the outer peripheral face. A refrigerant passes between the valve element 19 and a lower end 122f of the small-diameter cylindrical portion 122c, and flows in the clearance between the inner peripheral cylindrical face 122h of the small-diameter cylindrical portion 122c and the groove 181, when the valve element 19 is separated from the lower end 122f of the small-diameter cylindrical portion 122c.SELECTED DRAWING: Figure 2

Description

The present invention relates to a valve device.

Mechanical constant pressure valves, expansion valves, differential pressure valves, and the like are known as valve devices that control the flow rate of refrigerant in air conditioners. In such a valve device, durability that can withstand long-term operation is required.

Patent Document 1 discloses a temperature-type expansion valve in which the housing of the temperature-sensitive portion and the body of the valve portion are formed of a pressed product.

Japanese Unexamined Patent Publication No. 2003-75025

By the way, in the expansion valve shown in FIG. 1 of Patent Document 1, a packing is provided to support the shaft so as to be able to advance and retreat in the axial direction and to seal between the high pressure chamber and the greenhouse. However, in general, when a material having good sealing property is used for the packing, the durability against sliding is lowered. For this reason, the material of the packing that can be used is limited, which leads to an increase in the cost of parts.

Further, in the expansion valve of Patent Document 1, when the packing material is relatively soft, there is a problem that the vibration suppressing effect cannot be expected so much when the valve body vibration occurs when the refrigerant passes through.

Therefore, an object of the present invention is to provide an improved valve device at low cost and excellent in durability.

In order to achieve the above object, the valve device according to the present invention
With the valve body
An actuating rod that moves with the valve body and
A valve body with a tubular orifice and a valve seat,
It has an urging member that urges the valve body toward the valve seat.
The operating rod has a sliding contact portion slidable with respect to the orifice portion and a flow path portion having a gap with respect to the orifice portion.
When the valve body is separated from the valve seat, the refrigerant passes between the valve body and the valve seat and flows through the gap between the orifice portion and the flow path portion.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an improved valve device at low cost and excellent in durability.

FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve in the present embodiment is applied to a refrigerant circulation system. FIG. 2 is a cross-sectional view of the expansion valve. FIG. 3A is a bottom view of the cross section of the operating rod according to the present embodiment in line AA of FIG. 2, and FIG. 3B is a similar sectional view of the operating rod according to the modified example. Is. FIG. 4 is a cross-sectional view similar to FIG. 2 showing an expansion valve according to the second modification. FIG. 5 is a side view showing the expansion valve according to the third modification. FIG. 6 is a cross-sectional view of the expansion valve according to the third modification. FIG. 7 is a cross-sectional view similar to FIG. 2 showing a constant pressure valve as a valve device according to the second embodiment. FIG. 8 is a schematic cross-sectional view schematically showing an example in which the expansion valve according to the third embodiment is applied to a refrigerant circulation system. FIG. 9 is an enlarged cross-sectional view showing the vicinity of the valve body in the expansion valve of FIG. FIG. 10 is a perspective view showing the ring spring 206. FIG. 11 is a cross-sectional view showing a state in which the differential pressure valve according to the fourth embodiment is assembled to the pipe. FIG. 12 is a perspective view of the operating rod of the present embodiment.

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

(Definition of direction)
In the present specification, in the embodiment having a diaphragm, 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 "lower".

(First Embodiment)
The outline of the expansion valve 10 which is the valve device in the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 10 in the present embodiment is applied to the refrigerant circulation system CS1.

In the present embodiment, the passage housing 20 accommodating the expansion valve 10 is fluidly connected to the compressor CP, the condenser CD, and the evaporator EV. First, the passage housing 20 will be described.

The metal passage housing 20 includes a first flow path 20a formed on the right side surface in FIG. 1, an intermediate chamber 20b formed in the center, and a second flow path 20c formed on the left side surface in FIG. It has a return flow path 20d penetrating from the left side surface to the right side surface. The first flow path 20a and the intermediate chamber 20b are communicated with each other by the first communication passage 20e, and the intermediate chamber 20b and the second flow path 20c are communicated with each other by the second communication passage 20f. A female screw 20 g is formed on the inner circumference of the cylindrical first passage 20e.

The first flow path 20a is a supply-side flow path, and a refrigerant (also referred to as a fluid) is supplied from the condenser CD to the intermediate chamber 20b via the supply-side flow path and the first communication passage 20e. The second flow path 20c is a discharge side flow path, and the fluid in the intermediate chamber 20b is discharged to the evaporator EV outside the expansion valve via the second continuous passage 20f and the discharge side flow path.

The passage housing 20 is formed at the intersection of the large-diameter hole 20h facing the return flow path 20d, the small-diameter hole 20i formed on the back side of the large-diameter hole 20h, and the large-diameter hole 20h and the small-diameter hole 20i. It has an annular recess 20j. The large diameter hole 20h communicates with the return flow path 20d. The inside of the small diameter hole 20i serves as an intermediate chamber 20b for accommodating the expansion valve 10. A rubber or resin sealing seal OR is arranged in the annular recess 20j.

The through hole 20k formed on the wall surface of the return flow path 20d facing the large diameter hole 20h of the intermediate chamber 20b is provided to allow the expansion valve 10 to pass through during assembly, and the expansion valve 10 is provided. After attachment, it is sealed and closed by the lid 21.

FIG. 2 is a cross-sectional view of the expansion valve 10. The expansion valve 10 includes a case 12, a coil spring 13 constituting an urging member, a stopper member 16, a diaphragm 17, an operating rod 18, and a valve body 19. Let L be the axis of the expansion valve 10.

The case 12 has a substantially disk-shaped upper lid member 121 having an upper opening 121a in the center, and a receiving member 122 facing the upper lid member 121 with the diaphragm 17 interposed therebetween. The upper lid member 121 and the receiving member 122 are each formed by pressing a single metal plate material. In this embodiment, the receiving member 122 constitutes the valve body.

The center of the upper lid member 121 is raised in a dome shape, the circumference of the upper opening 121a is thin, and the recessed portion 121b is circularly depressed toward the inside. The stopper 123 seals the upper opening 121a so as to be joined to the recessed portion 121b.

The receiving member 122 is provided coaxially with an annular flange portion 122a having an outer diameter substantially equal to that of the upper lid member 121, a large-diameter cylindrical portion 122b having an upper end connected to the inner circumference of the flange portion 122a, and a large-diameter cylindrical portion 122b. It has a small-diameter cylindrical portion 122c and an intermediate portion 122d in which a large-diameter cylindrical portion 122b and a small-diameter cylindrical portion are connected in series. A plurality of communication holes 122g are formed on the outer circumference of the large-diameter cylindrical portion 122b.

A male screw 122e is formed on the outer circumference of a small-diameter cylindrical portion (circular tube portion) 122c that is circularly tubular. The inner peripheral cylindrical surface 122h of the small-diameter cylindrical portion 122c constitutes the orifice portion, and the lower end 122f constitutes the valve seat.

The diaphragm 17 is made of a thin flexible plate material in which a plurality of concentric uneven shapes are formed, and has an outer diameter substantially the same as the outer diameter of the flange portion 122a.
The space surrounded by the upper lid member 121 and the diaphragm 17 forms the pressure operating chamber PO, and the space surrounded by the diaphragm 17 and the receiving member 122 becomes the pressure detecting chamber PD.

A stopper member 16 is arranged below the diaphragm 17. The stopper member 16 that can be formed by press working has an upper disk 161 facing the diaphragm 17 and a lower disk 162 that is shifted downward with respect to the upper disk 161 and has an opening in the center of the lower disk 162. 163 is formed.

The upper end of the operating rod 18 is joined to the opening 163 by welding. The lower end of the operating rod 18, which is a cylindrical member, penetrates the small-diameter cylindrical portion 122c of the receiving member 122, and is welded to the spherical valve body 19 below the small-diameter cylindrical portion 122c. There is a slight gap between the outer peripheral surface of the operating rod 18 and the inner peripheral cylindrical surface 122h, and both can slide relative to each other.

FIG. 3A shows a bottom view of the cross section taken along the line AA of FIG. The operating rod 18 is cylindrical as a whole, but has a pair of grooves 181 open to the lower end facing each other. As shown in FIG. 2, each groove 181 is terminated at a position above the small-diameter cylindrical portion 122c of the receiving member 122, and the terminal portion 182 is gradually shallowed upward. The groove 181 has an arcuate cross section, but may have a rectangular cross section, and can be formed by plastic working as well as machining. Similar to the embodiments and modifications described later, the groove 181 of the operating rod 18 constitutes the flow path portion, and the outer peripheral surface 183 of the operating rod 18 other than the groove 181 constitutes the sliding contact portion.

(First modification)
FIG. 3B is a cross-sectional view similar to FIG. 3A showing a modified example of the operating rod. The operating rod 18A forms three grooves 181A. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted by adding the same reference numerals.

In FIG. 2, the coil spring 13 is arranged between the lower disk 162 of the stopper member 16 and the intermediate portion 122d of the receiving member 122. As a result, the two are urged in a direction to be separated from each other, and the stopper member 16 is raised together with the valve body 19 by the urging force, so that the valve body 19 comes into contact with the lower end 122f of the small diameter cylindrical portion 122c (valve closed state). .. However, even when the valve body 19 comes into contact with the lower end 122f of the small-diameter cylindrical portion 122c, a limited amount of refrigerant may flow.

When the diaphragm 17 is displaced downward from such a state, the outer circumference of the operating rod 18 slides with respect to the inner peripheral cylindrical surface 122h of the small-diameter cylindrical portion 122c and moves downward, and the valve body 19 is separated from the lower end 122f (open). (Valve state) allows the refrigerant to pass through the orifice.

(Expansion valve assembly process)
The assembly process of the expansion valve 10 will be described. First, the metal plate material is plastically deformed into the shape shown in FIG. 1 by press working to obtain the upper lid member 121 and the receiving member 122. Next, the upper opening 121a is formed in the upper lid member 121 by press punching or the like, and the communication hole 122g and the male screw 122e are formed in the receiving member 122 by machining or the like. Cost reduction can be achieved by forming the case 12 using the pressed product.

Next, in the embodiment shown in FIG. 2, the coil spring 13 and the operating rod 18 having the stopper member 16 joined to the upper end are inserted into the receiving member 122 from above, and the lower end of the operating rod 18 is compressed while compressing the coil spring 13. Is exposed from the lower end 122f of the small-diameter cylindrical portion 122c. While maintaining this state, the operating rod 18 and the valve body 19 are welded.

After that, in a state where the outer peripheral portions (contact portions) of the upper lid member 121, the diaphragm 17, and the flange portion 122a of the receiving member 122 are overlapped with each other, the outer peripheral portion is rotated by, for example, TIG welding, laser welding, plasma welding, or the like. Welded and integrated to form the welded portion W1. The case 12 is formed by the upper lid member 121 and the receiving member 122 joined in this way.

Subsequently, from the upper opening 121a formed in the upper lid member 121, a working gas such as an inert gas is sealed in the space (pressure working chamber PO) surrounded by the upper lid member 121 and the diaphragm 17, and then the upper opening 121a Is sealed with a stopper 123, and the stopper 123 is fixed to the upper lid member 121 by projection welding or the like.
At this time, since the circumference of the depressed portion 121b is thin, appropriate welding can be performed. Further, since the recessed portion 121b is formed in a predetermined conical shape corresponding to the outer peripheral shape of the stopper 123, it is possible to prevent spatter and the like generated by welding from falling onto the diaphragm 17. With the above, the expansion valve 10 is completed.

Next, assembling the expansion valve 10 to the passage housing 20 will be described. In FIG. 1, the expansion valve 10 is inserted into the passage housing 20 through the through hole 20k, and the male screw 122e of the small-diameter cylindrical portion 122c is screwed into the female screw 20g of the first continuous passage 20e. As a result, the entire expansion valve 20 descends while being screwed with respect to the passage housing 20.

When the expansion valve 10 is lowered, the flange portion 122a of the receiving member 122 presses the sealing seal OR in the annular recess 20j to seal the sealing, and separates the intermediate chamber 20b from the return flow path 20d. As a result, it is possible to prevent a shortcut of the refrigerant from the intermediate chamber 20b to the return flow path 20d. Further, since the upper lid member 121 is exposed in the return flow path 20d, the pressure operating chamber PO is affected by the refrigerant temperature of the return flow path 20d.

(Operation of expansion valve)
An operation example of the expansion valve 10 will be described with reference to FIGS. 1 and 2. The refrigerant (fluid) pressurized by the compressor CP is liquefied by the condenser CD and sent to the first flow path 20a of the passage housing 20.

When the expansion valve 10 is opened, the refrigerant in the first flow path 20a passes through the gap between the valve body 19 and the lower end 122f of the small-diameter cylindrical portion 122c, and further between the operating rod 18 and the inner peripheral cylindrical surface 122h. To the inside of the large-diameter cylindrical portion 122b of the receiving member 122. At this time, since the groove 181 is formed on the outer periphery of the operating rod 18, a controlled amount of refrigerant can be passed through.

If a groove is not formed in the operating rod 18, the refrigerant will flow through the gap between the inner peripheral cylindrical surface 122h of the small-diameter cylindrical portion 122c and the outer circumference of the operating rod 18, but the cross-sectional area of the gap is constant. Nevertheless, the flow rate of the flowing refrigerant changes depending on the degree of eccentricity of the operating rod 18 with respect to the inner peripheral cylindrical surface 122h. On the other hand, by forming the groove 181 in the operating rod 18, the flow rate of the refrigerant passing through the orifice portion can be made less affected by the degree of eccentricity of the operating rod 18.

Further, the refrigerant escapes to the outside of the large-diameter cylindrical portion 122b through the communication hole 122g, passes through the second communication passage 20f and the second flow path 20c, is sent to the evaporator EV, and flows around the evaporator EV. It exchanges heat with air. Further, the refrigerant that has passed through the evaporator EV is returned to the compressor CP side via the return flow path 20d of the passage housing 20. In this way, the refrigerant circulates in the refrigerant circulation system CS1.

In the present embodiment, the pressure operating chamber PO is affected by the temperature of the refrigerant in the return flow path 20d, and the pressure detecting chamber PD communicates with the refrigerant inlet of the evaporator EV. Therefore, the volume of the working gas in the pressure working chamber PO separated by the diaphragm 17 changes according to the temperature of the refrigerant in the return flow path 20d and the pressure of the refrigerant in the intermediate chamber 20b. When the working gas in the pressure working chamber PO is liquefied, the internal pressure decreases, the working rod 18 is displaced upward together with the diaphragm 17 without being able to withstand the urging force of the coil spring 13, and the valve body 19 has a small diameter cylindrical portion 122c. Sit at the lower end 122f of.

On the other hand, when the working gas in the pressure working chamber PO is vaporized, the internal pressure increases, the working rod 18 is displaced downward together with the diaphragm 17 against the urging force of the coil spring 13, and the valve body 19 is a small-diameter cylindrical portion. It is separated from the lower end 122f of 122c. When the upper disk 161 of the stopper member 16 comes into contact with the upper surface of the flange portion 122a of the receiving member 122, the operating rod 18 does not descend any further, whereby the deformation of the diaphragm 17 is suppressed. ..

In this way, the expansion valve 10 is switched between the valve open state and the valve closed state. If the valve opening pressure is to be changed, the lid 21 may be removed, the expansion valve 10 may be pulled out from the passage housing 20, and the expansion valve 10 may be replaced with another expansion valve 10 in which the elastic force of the coil spring 13 is adjusted.

In the expansion valve 10 of the present embodiment, since the operating rod 18 is slid with respect to the inner peripheral cylindrical surface 122h as the orifice portion, it is not necessary to provide a sliding member as a separate part, and the cost can be reduced. Can be planned. In addition, since the sliding between the operating rod 18 and the inner peripheral cylindrical surface 122h of the small-diameter cylindrical portion 122c is contact between metals, it can withstand long-time sliding and is excellent in durability. Further, since the operating rod 18 is slid with respect to the inner peripheral cylindrical surface 122h of the small-diameter cylindrical portion 122c, when the refrigerant flows around the valve body 19 at the time of valve opening, the valve body vibration caused by the refrigerant is suppressed. It also has the effect of

(Second modification)
FIG. 4 is a cross-sectional view similar to FIG. 2 showing a second modification of the present embodiment. In the expansion valve 10B of this modification, the shape of the operating rod 18B is different from that of the above-described embodiment. More specifically, in the cylindrical operating rod 18B, the groove 181B extends from the upper end to the vicinity of the lower end, and the end portion 182B of the groove 181B gradually becomes shallower downward. In this modified example, the spherical valve body is not provided. The shaft end 183B of the operating rod 18B is cylindrical with no groove formed on the outer periphery thereof. The shaft end 183B constitutes the valve body.

In this modification, the operating rod 18B rises when the valve is closed, so that the end portion 182B of the groove 181B is located inside the small diameter cylindrical portion 122c in the radial direction, and a part of the outer circumference of the shaft end 183B of the operating rod 18B is formed. , In contact with the inner peripheral edge of the lower end 122f of the small diameter cylindrical portion 122c (valve closed state). At this time, since there is only a slight gap between the outer peripheral surface of the shaft end 183B and the inner peripheral edge of the lower end 122f, the amount of refrigerant flowing through this gap is limited.

On the other hand, when the valve is opened, the operating rod 18B is lowered, so that the shaft end 183B of the operating rod 18B is shifted downward from the inner peripheral edge of the lower end 122f of the small diameter cylindrical portion 122c, and the end portion 182B of the groove 181B has a small diameter. It is exposed to the outside from the lower end 122f of the cylindrical portion 122c (valve open state). As a result, the increased refrigerant flows through the groove 181B through the orifice portion. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted by adding the same reference numerals.

(Third modification example)
FIG. 5 is a side view showing an expansion valve according to a third modification of the present embodiment. FIG. 6 is a cross-sectional view similar to FIG. 2 showing a third modification of the present embodiment. In the above-described embodiment and modification, the urging force of the coil spring is fixed. On the other hand, in this modification, the urging force of the coil spring can be made variable.

The expansion valve 10C of the present embodiment forms a pair of notches 122Ch near the lower end of the large-diameter cylindrical portion 122Cb of the receiving member 122C in the case 12C. Further, on the outer peripheral surface of the large-diameter cylindrical portion 122Cb, a female screw 122Ci is formed from the lower end thereof to the notch 122Ch, and a nut 124 is screwed into the female screw 122Ci.

The operating rod 18 is fitted in the fitting hole 125a formed in the center of the plate 125. Both ends of the plate 125 project outward from the notch 122Ch, and the lower surface thereof is supported by nuts 124. A coil spring 13 is arranged between the plate 125 and the stopper member 16. The nut 124 and the plate 125 form an adjusting member. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted by adding the same reference numerals.

According to this modification, by tightening the nut 124 with respect to the receiving member 122C, the plate 125 is raised, so that the distance between the plate 125 and the stopper member 16 is reduced and the urging force of the coil spring 13 is increased. be able to. As a result, the valve opening pressure increases.

On the other hand, by loosening the nut 124 with respect to the receiving member 122C, the plate 125 is lowered, so that the distance between the plate 125 and the stopper member 16 is increased, and the urging force of the coil spring 13 can be reduced. As a result, the valve opening pressure is reduced. The expansion valve 10C adjusted in this way can be assembled to the passage housing 20 in the same manner as in the above-described embodiment.

(Second Embodiment)
FIG. 7 is a cross-sectional view similar to FIG. 2 showing a constant pressure valve as a valve device according to the second embodiment. Here, a valve having substantially the same configuration as the expansion valve shown in FIG. 2 is used as the constant pressure valve 10D. However, in the constant pressure valve 10D, no male screw is formed on the outer circumference of the small diameter cylindrical portion 122Dc of the receiving member 122D in the case 12D, and only one communication hole 122Dg is formed in the large diameter cylindrical portion 122Db of the receiving member 122D. Has been done.

Further, the inner circumference of the upper end of the inflow pipe IT connected to the outlet of the evaporator (not shown) is inserted into the outer circumference of the small-diameter cylindrical portion 122Dc of the receiving member 122D, and both are joined by brazing. Further, the outer circumference of one end of the outflow pipe OT connected to the inlet of the compressor (not shown) is inserted into the communication hole 122Dg of the large-diameter cylindrical portion 122Db of the receiving member 122D, and both are joined by brazing. Let L be the axis of the constant pressure valve 10D and O be the axis of the outflow pipe OT. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted by adding the same reference numerals.

An operation example of the constant pressure valve 10D will be described. The refrigerant pressurized by the compressor is liquefied by the condenser and sent to the constant pressure valve 10D via the inflow pipe IT. The refrigerant discharged from the constant pressure valve 10D is sent from the outflow pipe OT to the evaporator, and the evaporator exchanges heat with the air flowing around the evaporator. Further, the refrigerant that has passed through the evaporator is returned to the compressor side. In this way, the refrigerant circulates in the refrigerant circulation system.

A high-pressure refrigerant is supplied to the constant pressure valve 10D from a capacitor. More specifically, the high-pressure refrigerant from the condenser enters the inflow pipe IT and reaches the periphery of the valve body 19.

In the present embodiment, the pressure detection chamber PD communicates with the refrigerant inlet of the evaporator via the outflow pipe OT. Therefore, the volume of the working gas in the pressure working chamber PO separated by the diaphragm 17 changes according to the pressure of the refrigerant flowing into the outflow pipe OT. When the refrigerant pressure in the outflow pipe OT rises and the volume in the pressure working chamber PO decreases, the working rod 18 is displaced upward together with the diaphragm 17 without being able to withstand the urging force of the coil spring 13, and the valve body 19 has a small diameter. It sits on the lower end 122f of the cylindrical portion 122Dc.

On the other hand, when the refrigerant pressure in the outflow pipe OT decreases and the volume of the operating gas in the pressure operating chamber PO increases, the operating rod 18 is pushed down together with the diaphragm 17 against the urging force of the coil spring 13. , The small-diameter cylindrical portion 122Dc slides with respect to the inner peripheral surface and is displaced downward, so that the valve body 19 is separated from the lower end 122f of the small-diameter cylindrical portion 122Dc. In this way, the constant pressure valve 10D is switched between the valve open state and the valve closed state.

When the constant pressure valve 10D is in the valve open state, the refrigerant that has passed between the valve body 19 and the lower end 122f
It passes between the groove 181 of the operating rod 18 and the inner peripheral surface of the small diameter cylindrical portion 122Dc, enters the large diameter cylindrical portion 122Db, and is further sent from the large diameter cylindrical portion 122Db to the evaporator via the outflow pipe OT. .. In this way, in the constant pressure valve 10D, the amount of the refrigerant supplied from the constant pressure valve 10D toward the evaporator is automatically adjusted according to the pressure of the refrigerant returning to the evaporator.

(Third Embodiment)
Next, with reference to FIG. 8, an outline of the expansion valve 10E, which is a valve device according to the third embodiment, will be described. FIG. 8 is a schematic cross-sectional view schematically showing an example in which the expansion valve 10E in the present embodiment is applied to the refrigerant circulation system CS2. In this embodiment, the expansion valve 10E is fluidly connected to the compressor CP, the condenser CD, and the evaporator EV.

The expansion valve 10E includes a valve body 202 having a valve chamber VS, a valve body 203, an urging device 204, an operating rod 205, a ring spring 206, and a power element 208. Let L be the axis of the expansion valve 10E.

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 a refrigerant (also referred to as a fluid) is supplied to the valve chamber VS from the capacitor CD 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 via the orifice portion 227 and the discharge side flow path, and reaches the evaporator EV. The first flow path 221 and the valve chamber VS are communicated with each other by a connecting path 221a having a diameter smaller than that of the first flow path 221. The orifice portion 227 whose inner circumference is a cylindrical surface intersects with a connecting path 228 communicating with the second flow path 222. Following the lower edge of the orifice portion 227, a valve seat 220 whose diameter is gradually increased in a tapered shape is provided.

A spherical valve body 203 is in contact with the lower end of the operating rod 205. The valve body 203 is arranged in the valve chamber VS. When the valve body 203 is in contact with the valve seat 220 of the valve body 202, the first flow path 221 and the second flow path 222 are in a non-communication state. On the other hand, when the valve body 203 is separated from the valve seat 220, the first flow path 221 and the second flow path 222 are in a communicating state.

FIG. 9 is an enlarged cross-sectional view showing the vicinity of the valve body in the expansion valve of FIG. The operating rod 205 is cylindrical as a whole, but is formed with a pair of grooves 205a open to the lower end facing each other (see FIG. 3). Each groove 205a terminates in the connecting path 228, and the termination thereof gradually becomes shallower upward.

The operating rod 205, which is a cylindrical member, is inserted into the orifice portion 227 with a small gap, and can press the valve body 203 in the valve opening direction against the urging force of the urging device 204. When the operating rod 205 moves downward, it slides with respect to the orifice portion 227, the valve body 203 is separated from the valve seat 220, and the expansion valve 10E is opened.

Next, the power element 208 for driving the operating rod 205 will be described. In FIG. 8, the power element 208 is attached to a recess 202a provided at the top of the valve body 202. The recess 202a communicates with the return passage 223 in the valve body 202 through which the refrigerant from the evaporator EV passes through the communication passage 202b. The operating rod 205 passes through the communication passage 202b. A female screw is formed on the inner circumference of the recess 202a.

The power element 208 has a stopper 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 periphery. An opening 282c is formed at the top of the conical portion 282a and can be sealed by a plug 281.

The diaphragm 283 is made of a thin plate material in which a plurality of concentric uneven shapes are formed, and has an outer diameter substantially the same as 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 an outer diameter substantially the same as the outer diameter of 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 screw is formed on the outer circumference of the hollow cylindrical portion 286d.

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

Further, in a state where 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 with each other, the outer peripheral portion is peripherally welded by, for example, TIG welding, laser welding, plasma welding, or the like. And integrate. The upper lid member 282 and the receiving member 286 form a case.

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

At this time, since the diaphragm 283 receives pressure in a form of projecting toward the receiving member 286 due to the working gas sealed in the pressure operating chamber PO, the space (pressure detection chamber PD) surrounded by the diaphragm 283 and the receiving member 286 is filled. It is supported in contact with the upper surface of the arranged stopper member 284.

When assembling the power element 208, the valve body communicates the male screw of the hollow cylindrical portion 286d of the receiving member 286 with the return flow path 223 while the upper end of the operating rod 205 is fitted into the fitting hole 284a of the stopper member 284. The power element 208 is fixed to the valve body 202 by being screwed into the female screw of the recess 202a of 202.
At this time, a packing PK is interposed between the power element 208 and the valve body 202 to prevent the refrigerant from leaking from the recess 202a when the power element 208 is attached to the valve body 202. In this state, the pressure detection chamber PD of the power element 208 communicates with the return flow path 223.

Next, the ring spring 206 will be described. The ring spring 206 is installed in the concavely recessed annular portion 226 of the valve body 202 in FIG. FIG. 10 is a perspective view showing the ring spring 206.

The ring spring 206 is formed by bending a plate-shaped member into a cylindrical shape as shown in FIG. 10 and bending the first elastic piece 261 and the second elastic piece 262 and the third elastic piece 263 inward. Will be done.

The first elastic piece 261 and the second elastic piece 262 and the third elastic piece 263 are bent so as to be cut up inward, and the first convex contact portion 261a and the first convex contact portion 261a provided near the tip ends, respectively. The convex contact portion 262a of No. 2 and the third convex contact portion 263a are designed to be positioned so that the circumference is divided into three equal parts. Then, in the plane orthogonal to the axis L (FIG. 8), the inscribed circle connecting the tops of the first convex contact portion 261a, the second convex contact portion 262a, and the third convex contact portion 263a. The diameter dimension of the circle is formed to be smaller than the outer diameter of the working 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. It becomes.

Next, the urging device 204 will be described. In FIG. 8, the urging device 204 includes a coil spring (biasing member) 241 in which a circular wire rod is spirally wound, a valve body support 242 attached to the upper end of the coil spring 241 to support the valve body 203, and a valve body support 242. It has a spring receiving member (adjusting member) 243 attached to the valve body 202 while supporting the lower end of the coil spring 241. The spring receiving member 243 has a function of sealing the valve chamber VS of the valve body 202 and supporting the end portion of the coil spring 241 that urges the valve body 203 toward the valve seat 220.

The valve body support 242 has a support support portion 242a forming an upper portion, a support cylindrical portion 242b forming a lower portion, and a support flange portion 242c extending radially from the central outer circumference. The support support portion 242a includes a conical recess that supports the valve body 203. The support cylindrical portion 242b and the support flange portion 242c are fitted and contacted with the upper end of the coil spring 241 arranged in the valve chamber VS to support the support cylindrical portion 242b and the support flange portion 242c.

(Operation of expansion valve)
An operation example of the expansion valve 10E will be described with reference to FIG. The refrigerant pressurized by the compressor CP is liquefied by the condenser CD and sent to the expansion valve 10E. Further, the refrigerant adiabatically expanded by the expansion valve 10E is sent to the evaporator EV, and the evaporator EV exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator EV is returned to the compressor CP side through the expansion valve 10E (more specifically, the return flow path 223).

A high-pressure refrigerant is supplied to the expansion valve 10E from the condenser CD. More specifically, the high-pressure refrigerant from the condenser CD is supplied to the valve chamber VS via the first flow path 221.

When the valve body 203 is in contact with the valve seat 220 (in other words, when the expansion valve 10E is in the closed state), the first flow path 221 on the upstream side of the valve chamber VS and the downstream of the valve chamber VS. The second flow path 222 on the side is in a non-communication state. On the other hand, when the valve body 203 is separated from the valve seat 220 (in other words, when the expansion valve 10E is in the valve open state), the refrigerant supplied to the valve chamber VS is the orifice portion 227 and the groove 205a. It is sent out to the evaporator EV through the gap between the two and the second flow path 222. The expansion valve 10E is switched between the closed state and the opened state by the operating rod 205 connected to the power element 208.

In FIG. 8, a pressure operating chamber PO and a pressure detecting chamber PD partitioned by a diaphragm 283 are provided inside the power element 208. 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. In this way, the expansion valve 10E is switched between the valve open state and the valve closed state.

Further, the pressure detection chamber PD of the power element 208 communicates with the return flow path 223. Therefore, the pressure of the refrigerant flowing through the return flow path 223 is transmitted to the working gas in the pressure working chamber PO via the stopper member 284 and the diaphragm 283. As a result, the volume of the working gas in the pressure working chamber PO changes, and the working rod 205 is driven. In other words, in the expansion valve 10E shown in FIG. 6, the amount of the refrigerant supplied from the expansion valve 10E toward the evaporator EV is automatically adjusted according to the pressure of the refrigerant returning from the evaporator EV to the expansion valve 10E. To.

(Fourth Embodiment)
Next, the differential pressure valve 10F, which is a valve device according to the fourth embodiment, will be described with reference to FIG. FIG. 11 is a cross-sectional view showing a state in which the differential pressure valve 10F is assembled to the pipe TB. Let L be the axis of the differential pressure valve 10F. FIG. 12 is a perspective view of the operating rod of the present embodiment.

The differential pressure valve 10F includes an operating rod 301 provided with a valve body, a valve body 302 into which the operating rod 301 is inserted, a coil spring 303 which is an urging member, and an adjusting member 304 that adjusts the urging force of the coil spring 303. Has.

In FIG. 12, the operating rod 301 is integrally formed by, for example, forging, and a cylindrical upstream shaft portion 301a, a conical portion 301b, and a cylindrical downstream shaft portion 301c are continuously provided. It becomes.

The cylindrical upstream shaft portion 301a is generally cylindrical, but is formed with a pair of grooves 301d open to one end facing each other (see FIG. 3). Each groove 301d is terminated at a position intersecting the conical portion 301b, and the terminal portion 301e becomes a part of the outer surface of the conical portion 301b, and the groove depth gradually becomes shallower toward the downstream side. A narrow groove 301f is formed from the terminal portion 301e to the outer surface of the conical portion 301b. The narrow groove 301f does not necessarily have to be provided. The conical portion 301b constitutes the valve body.

In FIG. 11, the valve body 302 is formed by coaxially connecting a thick circular tube portion 302a and a thin circular tube portion 302b. The thick-walled circular tube portion 302a and the thin-walled circular tube portion 302b may be formed separately and then integrated by welding or brazing. The inner circumference of the thick circular pipe portion 302a is an orifice portion 302c, and a peripheral groove 302d is formed on the central outer circumference of the thick circular pipe portion 302a. The inner diameter of the orifice portion 302c is slightly larger than the outer diameter of the upstream shaft portion 301a. The inner peripheral edge of the end of the orifice portion 302c constitutes the valve seat 302g.

The thin-walled circular tube portion 302b has a communication hole 302e that communicates inside and outside in the radial direction, and a female screw 302f formed on the inner circumference of the end portion away from the thick-walled circular tube portion 302a. The outer diameter of the thin-walled circular tube portion 302b is smaller than the outer diameter of the thick-walled circular tube portion 302a.

The bottomed cylindrical adjusting member 304 has a through hole 304a formed in the center and a male screw 304b formed on the outer periphery. The inner circumference of the adjusting member 304 is preferably non-circular (for example, hexagonal) so that a tool (not shown) can be fitted and rotated.

When assembling the differential pressure valve 10F, the operating rod 301 is inserted from the thin-walled circular pipe portion 302b side of the valve body 302, and the upstream shaft portion 301a is inserted into the orifice portion 302c. Further, the coil spring 303 is inserted into the thin-walled circular tube portion 302b, one end thereof is engaged with the downstream shaft portion 301c of the operating rod 301, and the coil spring 303 is abutted against the back surface of the conical portion 301b.

After that, while pushing the other end of the coil spring 303 with the end surface of the adjusting member 304, the male screw 304b of the adjusting member 304 is screwed into the female screw 302f of the thin circular tube portion 302b. The valve opening pressure can be adjusted by adjusting the amount of screwing between the male screw 304b and the female screw 302f.

The adjusted differential pressure valve 10F is inserted into the pipe TB in the fluid communication system including the refrigerant circulation system. The protrusion PJ protrudes from the inner circumference by caulking a part of the outer circumference of the pipe TB from the outside with respect to the differential pressure valve 10F arranged at a predetermined position. The differential pressure valve 10F can be fixed to the pipe TB by fitting the protrusion PJ into the peripheral groove 302d of the valve body 302.

(Operation of differential pressure valve)
In FIG. 11, the upper side is the upstream side and the lower side is the downstream side across the differential pressure valve 10F. Here, when the fluid pressure on the upstream side is equal to or less than the threshold value with respect to the fluid pressure on the downstream side, the pressure in the orifice portion 302c is lower than the urging force of the coil spring 303 and the fluid pressure on the downstream side. The state in which the conical portion 301b of the above is in contact with the valve seat 302g of the valve body 302 is maintained (valve closed state).

If the narrow groove 301f is formed at this time, the fluid having a limited flow rate passes through the valve body 302 and flows to the downstream side through the gap between the narrow groove 301f and the valve seat 302g. It becomes.

On the other hand, when the fluid pressure on the upstream side exceeds the threshold value with respect to the fluid pressure on the downstream side, the pressure in the orifice portion 302c exceeds the urging force of the coil spring 303 and the fluid pressure on the downstream side. The upstream shaft portion 301a slides, and the conical portion 301b of the operating rod 301 is separated from the valve seat 302g of the valve body 302 (valve closed state).

As a result, the fluid flows out to the inside of the thin-walled circular tube portion 302b through the gap between the orifice portion 302c and the groove 301d of the operating rod 301. Further, the fluid passes through the communication hole 302e, passes between the outer circumference of the thin-walled circular pipe portion 302b and the pipe TB, and reaches the downstream side of the pipe TB.

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

10, 10B, 10C, 10E: Expansion valve 10D: Constant pressure valve 10F: Differential pressure valve 12, 12C, 12D: Case 13, 241, 303: Coil spring 16, 284: Stopper member 17, 283: Diaphragm 18, 18A, 205, 301: Acting rods 181, 181A, 205a, 301d: Groove 19, 203: Valve body 20: Passage housing CS1, CS2: Refrigerant circulation system CP: Compressor CD: Condenser EV: Evaporator

Claims (11)

With the valve body
An actuating rod that moves with the valve body and
A valve body with a tubular orifice and a valve seat,
It has an urging member that urges the valve body toward the valve seat.
The operating rod has a sliding contact portion slidable with respect to the orifice portion and a flow path portion having a gap with respect to the orifice portion.
When the valve body is separated from the valve seat, the refrigerant passes between the valve body and the valve seat and flows through the gap between the orifice portion and the flow path portion.
A valve device characterized by that. A case equipped with a pressure detection chamber through which the refrigerant passes and a pressure operating chamber filled with gas.
In the case, it has a flexible diaphragm that separates the pressure detecting chamber and the pressure operating chamber.
The orifice portion has a cylindrical surface and has a cylindrical surface.
The actuating rod is a cylindrical member having a groove formed on the outer circumference, the flow path portion is the groove, and the sliding contact portion is an outer peripheral surface of the operating rod other than the groove.
The valve device according to claim 1. A circular tube portion is formed in a part of the valve body, the inner circumference of the circular tube portion is the orifice portion, and a male screw is formed on the outer periphery of the circular tube portion.
The valve device according to claim 2. By screwing the male screw into the female screw of the passage housing, it can be attached to the passage housing.
The valve device according to claim 3. The valve body is formed at one end of the operating rod, and the groove is terminated near the one end.
The valve device according to any one of claims 2 to 4. The other end of the operating rod is connected to a stopper member that abuts on the diaphragm.
An adjusting member is attached to the case so that the position can be adjusted.
The urging member is arranged between the stopper member and the adjusting member.
The valve device according to any one of claims 2 to 5, wherein the valve device. The case is connected to a pipe through which the refrigerant flows and a pipe through which the refrigerant flows out.
The valve device according to claim 2. The other end of the operating rod is connected to a stopper member that abuts on the diaphragm.
An adjusting member is attached to the valve body so that the position can be adjusted.
The urging member is arranged between the valve body and the adjusting member.
The valve device according to claim 2. The valve body is spherical and is in contact with one end of the operating rod.
The valve device according to claim 8. The valve body is formed integrally with the operating rod, the operating rod is inserted into the valve body, and the valve body is inserted into a pipe through which the refrigerant passes.
The valve device according to claim 1. An adjusting member is attached to the valve body so that the position can be adjusted.
The urging member is arranged between the operating rod and the adjusting member.
The valve device according to claim 10.

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