JP7362558B2 - Check valves and refrigeration cycle systems - Google Patents

Description

The present invention relates to a check valve and a refrigeration cycle system.

Conventionally, a check valve includes an outer pipe that is continuous with a primary pipe (inlet) and a secondary pipe (outlet), a valve body provided inside the outer pipe, and a valve body provided inside the valve body. The valve body has a valve seat portion that constitutes a valve port, a cylindrical valve holder that movably accommodates a valve body, and has both ends of an outer tube that is a straight tube reduced in diameter. One in which a primary tube and a secondary tube are formed is known (for example, see Patent Document 1).

Patent No. 4842862

However, in the conventional check valve as described in Patent Document 1, high pressure acts on the outer pipe that covers the outside of the valve body, so especially when used with ultra-high pressure CO ₂ refrigerant, the pressure resistance performance may be affected. In order to increase the diameter, it is possible to increase the wall thickness of the outer tube, but it is difficult to reduce the diameter of a straight tube as in the past, and if the diameter is reduced or expanded, the wall thickness may be partially increased. Problems such as unevenness and reduced strength also occur.

An object of the present invention is to provide a check valve and a refrigeration cycle system that can secure a predetermined strength and improve pressure resistance without using complicated processing or parts.

The check valve of the present invention is provided on the primary side of a flow path and connected to the piping constituting the refrigeration cycle system, and the check valve is provided on the secondary side of the flow path and connected to the piping constituting the refrigeration cycle system. A secondary pipe to be connected , an outer pipe part connected between the primary pipe and the secondary pipe, a valve body built in the outer pipe part and having a valve seat part and a valve holder, and the valve holder. a valve body movably housed in a check valve, wherein the outer pipe part is formed separately from the primary pipe and the secondary pipe, and has a straight pipe shape extending in the axial direction. The secondary pipe side of the primary pipe is inserted and fixed into the valve seat portion .

According to the present invention, by using a straight pipe material for the outer tube part, strength is ensured by appropriately setting the wall thickness of the outer tube part, and there is no need for diameter reduction or diameter expansion. This makes it possible to suppress partial strength loss. In addition, it is preferable that the pipe material be manufactured by a relatively inexpensive pipe manufacturing method such as hot-seamless pipe making, which can reduce material costs compared to pipe materials manufactured by hollowing out by cutting. .

At this time, the secondary pipe is made of a pipe material having a smaller diameter than the outer pipe part, and the primary end of the secondary pipe has an outer diameter expanded to the same inner diameter as the outer pipe part. It is preferable that an insertion fixing part is formed to be inserted and fixed in the outer tube part. According to this configuration, by performing diameter expansion processing on the secondary tube, no connecting parts are required between the outer tube portion and the secondary tube, and costs can be kept low.

Furthermore, it is preferable that the inner circumferential surface of the primary end of the secondary pipe is provided with a tapered part that expands in the radial direction. According to this configuration, by providing the tapered portion on the inner circumferential surface of the secondary pipe, the flow of fluid can be made smooth and an appropriate flow rate can be ensured. Furthermore, compared to a secondary pipe not provided with a tapered part, the length of the outer pipe part can be shortened while maintaining the flow path, making it more compact and reducing costs.

Further, it is preferable that the valve seat portion and the valve holder are configured separately, and that the valve holder housing the valve body is welded and fixed to the valve seat portion. The valve seat portion and the valve holder may be integrally formed, and a retaining member for preventing the valve body from coming off may be attached to the valve holder on the opposite side of the valve seat portion.

Further, the valve seat portion is fixed to the outer peripheral surface of the end of the primary pipe, a male thread is formed on the outer peripheral surface of the valve seat, and a female thread is formed on the inner peripheral surface of the primary end of the outer pipe. It is preferable that the female threaded portion and the male threaded portion be screwed together, and that the outer tube portion and the valve seat portion be fixed by welding. According to such a configuration, the outer tube part and the valve seat part are fixed in a double manner by screwing and welding the threaded parts, thereby increasing the fixing strength. In addition, since strength can be ensured at the threaded portion, the welded portion only needs to maintain airtightness, so a high-output welding machine is not required, and equipment costs can be reduced.

The refrigeration cycle system of the present invention is characterized by comprising any one of the above check valves.

According to the check valve and refrigeration cycle system of the present invention, the outer pipe portion is constructed of straight pipe material, thereby ensuring a predetermined strength and pressure resistance without using complicated processing or parts. can be increased.

FIG. 1 is a sectional view showing a check valve according to a first embodiment of the present invention. It is a sectional view showing a check valve concerning a 2nd embodiment of the present invention. FIG. 1 is a diagram showing a refrigeration cycle system of the present invention. It is an enlarged sectional view showing a modification of the above-mentioned check valve. It is an enlarged sectional view showing a modification of the above-mentioned check valve.

A check valve according to a first embodiment of the present invention will be described based on FIG. 1. As shown in FIG. 1, the check valve 1 of this embodiment allows fluid flow (forward flow) from the primary side (left side in FIG. 1) to the secondary side (right side in FIG. 1), and This is a valve device that prohibits fluid flow from the primary side to the primary side (backflow). The check valve 1 includes a primary pipe 2 provided on the primary side of the flow path, a secondary pipe 3 provided on the secondary side of the flow path, and a cylindrical outer pipe portion 4 extending in the axial direction along the axis L. , a valve main body 5 built into the outer pipe portion 4, and a valve body 6 provided in the valve main body 5. The valve body 5 has a cylindrical valve holder 7 that supports the valve body 6 and a valve seat portion 8 on which the valve body 6 can be seated.

The primary tube 2 is a cylindrical joint member made of copper, and a primary joint portion is formed at the primary side (left side in FIG. 1) end (not shown). The secondary pipe 3 is a cylindrical joint member made of copper, and a secondary joint portion is formed at the secondary side (right side in FIG. 1) end (not shown). The primary pipe 2 and the secondary pipe 3 are made of pipe material with a smaller diameter than the outer pipe part, and the primary end of the secondary pipe 3 has an outer diameter expanded to the same inner diameter as the outer pipe part 4. An insertion and fixing part 11 that is inserted and fixed into the outer tube part 4 is formed. Further, a tapered portion 12 that expands in the radial direction is provided on the inner circumferential surface of the primary end of the secondary pipe 3. The secondary tube 3 and the outer tube section 4 are fixed by inserting the insertion fixing section 11 into the outer tube section 4 and brazing them.

The outer tube portion 4 is made of a straight SUS pipe extending in the axial direction. This pipe material is manufactured by a relatively inexpensive pipe manufacturing method such as hot-seamless pipe production. A female threaded portion 4A is formed on the inner circumferential surface of the primary end of the outer tube portion 4 and is threadedly engaged with the valve seat portion 8.

The valve body 5 includes a valve holder 7 and a valve seat portion 8 which are separate bodies and are welded and fixed to each other. The valve holder 7 is a cylindrical member made of SUS, and is provided with communication holes 21 at four locations passing through its circumferential surface in the radial direction. Further, the secondary end of the valve holder 7 is provided with a valve stopper portion 22 that is bent inward in the radial direction, and when the valve body 6 that has moved to the valve open position comes into contact with the valve stopper portion 22, the valve body Movement to the secondary side is restricted from the valve open position of No. 6. In other words, the valve open position is a position where the valve body 6 is away from the valve seat part 8, and the valve body 6 is in contact with the valve stopper part 22, so that the valve is located on the downstream side of the valve stopper part 22. This is the position where movement of the body 6 is restricted (maximum position in the downstream direction in the valve stroke).

The valve seat portion 8 is a stepped cylindrical member made of SUS, and is formed from the primary side to the secondary side, including a first cylindrical portion 31, a second cylindrical portion 32, and a third cylindrical portion 33. ing. In the valve seat portion 8, a valve seat 34 in the form of an annular projection is provided at the secondary end of the third cylinder portion 33, and the valve body 6 that has moved to the valve closed position is seated on the valve seat 34. . The first cylindrical portion 31 has an inner diameter equal to the outer diameter of the primary tube 2 and an outer diameter equal to the outer diameter of the outer tube portion 4 . The second cylindrical portion 32 has an inner diameter equal to the outer diameter of the primary tube 2, and has a male screw portion 35 formed on its outer peripheral surface to be screwed into the female screw portion 2A of the outer tube portion 4. The third cylindrical part 33 has an inner diameter equal to the inner diameter of the primary pipe 2 and an outer diameter equal to the outer diameter of the valve holder 7, and a valve port 36 is formed by the inner circumferential surface of the third cylindrical part 33. ing.

The valve body 6 has a cylindrical columnar member 41 made of brass, a valve seat 42 made of resin that can come into contact with the valve seat 34, and a locking ring 43 that locks the valve seat 42. The locking ring 43 and the valve seat 42 are fixed to the columnar member 41 by caulking the caulking piece 44 of the columnar member 41 . The outer diameter of the cylindrical member 41 is slightly smaller than the inner diameter of the valve holder 7, and the valve body 6 is provided so as to be movable in the axial direction along the inner peripheral surface of the valve holder 7.

In the valve closed position, the valve body 6 is seated with the valve seat 42 in contact with the valve seat 34 of the valve seat portion 6, thereby closing the valve port 36 and preventing backflow of fluid from the secondary side to the primary side. It is now possible to do so. On the other hand, in the valve open position shown in FIG. 1, the rear end surface of the valve body 6 comes into contact with the valve stopper part 22 to restrict its movement, so that part or all of the communication hole 21 of the valve holder 7 is opened. It has become. Therefore, in the valve open state in which the valve body 6 moves to the valve open position, the fluid that flows from the primary pipe 2 into the valve holder 7 through the valve port 36 flows out into the outer pipe portion 4 through the communication hole 21. Then, it flows into the secondary pipe 3.

The manufacturing procedure of the check valve 1 is as follows. First, the ends of the primary pipe 2 are inserted into the first cylindrical part 31 and the second cylindrical part 32 of the valve seat part 8, and these are brazed and fixed. Next, the insertion fixing part 11 of the secondary pipe 3 is inserted into the outer pipe part 4, and these are fixed by brazing. Next, after inserting the valve body 6 into the valve holder 7, the end portion of the valve holder 7 and the third cylindrical portion 33 of the valve seat portion 8 are welded and fixed by TIG welding or the like. Next, the female threaded part 4A of the outer tube part 4 and the male threaded part 35 of the valve seat part 8 are screwed together, and then the end of the outer tube part 4 and the first cylinder part 31 of the valve seat part 8 are TIG welded. Fix by welding etc. With the above steps, the assembly of the check valve 1 is completed.

According to the present embodiment described above, by using a straight pipe material for the outer tube part 4, strength is ensured by appropriately setting the wall thickness of the outer tube part 4, and the diameter reduction and diameter expansion can be performed. Since this can be made unnecessary, partial strength reduction can be suppressed. In addition, the pipe material of the outer tube portion 4 is preferably manufactured by a relatively inexpensive pipe manufacturing method such as a hot-seamless pipe, and the material cost is lower than that manufactured by hollowing out by cutting. Can be suppressed.

In addition, an insertion fixing part 11 with an enlarged diameter is formed at the end of the secondary pipe 3, and by performing diameter enlargement processing on the secondary pipe 3, a connecting part is formed between the outer pipe part 4 and the secondary pipe 3. It becomes unnecessary and costs can be kept low. Further, by providing the tapered portion 12 on the inner circumferential surface of the secondary pipe 3, the flow of fluid can be made smooth and an appropriate flow rate can be ensured. Moreover, with respect to the secondary pipe 3 in which the tapered part 12 is not provided, the length of the outer pipe part 4 can be shortened while securing the flow path, making it more compact and reducing costs.

Further, a male threaded portion 35 is formed on the outer circumferential surface of the valve seat portion 8, a female threaded portion 4A is formed on the inner circumferential surface of the outer tube portion, and the female threaded portion 4A and the male threaded portion 35 are screwed together. 4 and the valve seat part 8 are fixed by welding, and the outer tube part 4 and the valve seat part 8 are double fixed by screwing and welding, which increases the fixing strength and improves pressure resistance. can be improved. In addition, since strength can be ensured in the threaded part where the female threaded part 4A and the male threaded part 35 are screwed together, the welded part only needs to maintain airtight performance, so a high-output welding machine is not required, and equipment costs are reduced. can be suppressed and costs can be reduced.

Next, based on FIG. 2, a check valve 1A according to a second embodiment of the present invention will be described. The check valve 1A of this embodiment, like the check valve 1 of the first embodiment, includes a primary pipe 2, a secondary pipe 3, an outer pipe portion 4, a valve body 5, and a valve body 6. Configured with the necessary features. On the other hand, the check valve 1A is different from the check valve 1 in a partial configuration of the valve body 5. The differences will be explained in detail below.

The valve body 5A of the check valve 1A of this embodiment is a SUS member in which the valve holder 7 and the valve seat portion 8 are integrally formed. The valve holder 7 is provided with communication holes 21 at four locations, and a valve stopper 23 as a slip-off prevention member for preventing the valve body 6 from slipping out is attached to the inner circumferential surface of the end on the secondary side. The valve seat part 8 has a tapered valve seat surface 37 on the inner peripheral surface of the third cylinder part 33, and when the valve seat 42 of the valve body 6 that has moved to the valve closed position is seated on the valve seat surface 37, , the valve port 36 is closed.

According to the present embodiment described above, similarly to the first embodiment, by using a straight pipe material for the outer tube portion 4, strength is ensured by appropriately setting the wall thickness of the outer tube portion 4. , it is possible to eliminate the need for diameter reduction or diameter enlargement processing, thereby suppressing a partial decrease in strength.

Next, the refrigeration cycle system of the present invention will be explained based on FIG. 3. FIG. 3 is a diagram showing the refrigeration cycle system 50 of the embodiment. The refrigeration cycle system 50 is used, for example, in an air conditioner such as a commercial air conditioner. This refrigeration cycle system 50 includes an indoor heat exchanger 51, an outdoor heat exchanger 52, an expansion valve 53, a four-way valve 54, and three compressors 55 connected in parallel through piping. . The check valves 1 and 1A are provided between the discharge (high pressure output) side of each compressor 55 and the four-way valve 54 in order to prevent the backflow of refrigerant to each compressor 55. 54 as the secondary side.

During cooling operation, as shown by the solid arrow D51, the refrigerant that has absorbed heat in the indoor heat exchanger 51 flows to the compressor 55 via the four-way valve 54, and after being compressed by the compressor 55. , and reaches the outdoor heat exchanger 52 via the check valves 1 and 1A and the four-way valve 54. After the heat is released from the outdoor heat exchanger 52, it returns to the indoor heat exchanger 51 via the expansion valve 53. During heating operation, the refrigerant that has released heat in the indoor heat exchanger 51 reaches the outdoor heat exchanger 52 via the expansion valve 53, as indicated by the dotted arrow D52. After the heat is absorbed by the outdoor heat exchanger 52, it flows through the four-way valve 54 to the compressor 55, and after being compressed by the compressor 55, it passes through the check valves 1, 1A and the four-way valve 54. Returning to the indoor heat exchanger 51. The refrigeration cycle system 50 performs indoor cooling or heating by repeating these cycles.

Here, for example, under conditions where the cooling load is large, the three compressors 55 are operated simultaneously, so the three check valves 1 and 1A are fully open. Furthermore, under conditions where the cooling load is small, it is sufficient to operate only one compressor 55, so the other two compressors 55 are not operated. At this time, the pressure on the secondary side of the two check valves 1, 1A becomes higher than the pressure on the primary side, causing a backflow from the secondary side, and the two check valves 1, 1A become closed. .

Note that the embodiments and modifications described above merely show typical forms of the present invention, and the present invention is not limited thereto. That is, various modifications can be made without departing from the gist of the invention. Of course, such modifications fall within the scope of the present invention as long as they still have the structure of the check valve of the present invention.

For example, in the embodiments and modifications described above, the check valves 1 and 1A used in air conditioners such as commercial air conditioners are illustrated, but check valves can be used not only in commercial air conditioners but also in home air conditioners. It is also applicable not only to air conditioners but also to various types of refrigerators, refrigerators, etc. In addition, in the various refrigeration cycle systems described above, the installation is not limited to the discharge side of the compressor as in the installation example of the check valve of the refrigeration cycle in Figure 3, but can be installed at various locations in the refrigeration cycle. It can be applied to prevent backflow. In addition, there are a wide variety of refrigerants used in each refrigeration cycle system (for example, various fluorocarbon-based refrigerants, hydrocarbon-based refrigerants, and natural refrigerants such as _CO2 and ammonia), but which of these refrigerants is compatible? The check valve of the present invention can also be applied to a refrigeration cycle system.

Further, in the above embodiment, the outer tube part 4 is exemplified as having a female threaded part 4A formed on the inner circumferential surface of the primary side and not processed other than the female threaded part 4A, but as shown in FIG. Additionally, a stepped portion 4B having an enlarged diameter may be formed on the inner circumferential surface of the secondary side. This stepped portion 4B is formed by cutting to expand the inner diameter of the outer tube portion 4, and the inner diameter of the stepped portion 4B and the outer diameter of the insertion fixing portion 11 of the secondary tube 3 are equal. It has become. By forming a stepped portion 4B in the outer tube portion 4 and inserting the insertion fixing portion 11 of the secondary tube 3 into the stepped portion 4B, the position of the secondary tube 3 relative to the outer tube portion 4 can be fixed. This enables stable brazing. Furthermore, the difference in level between the inner circumferential surface of the outer tube section 4 and the end of the secondary tube 3 can be reduced, and the flow of fluid can be made smoother.

Further, in the above embodiment, the insertion fixing part 11 and the tapered part 12 are formed at the primary end of the secondary pipe 3, but as shown in FIG. An uneven portion 13 may be formed. The uneven portion 13 is, for example, fine unevenness formed by knurling or dimple processing. By forming such an uneven part 13, when the insertion fixing part 11 is press-fitted into the outer tube part 4 and then brazed, the brazing material can easily penetrate between the press-fit surfaces, and the brazing fixation can be performed easily. It is possible to ensure strength and improve pressure resistance.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the design may be changed without departing from the gist of the present invention. (For example, changes in the material and shape of each member) are included in the present invention.

1, 1A Check valve 2 Primary pipe 3 Secondary pipe 4 Outer pipe part 4A Female thread part 5,5A Valve body 6 Valve body 7 Valve holder 8 Valve seat part 11 Insertion fixing part 12 Tapered part 23 Valve stopper (retention member)
50 Refrigeration cycle system

Claims (7)

A primary pipe provided on the primary side of the flow path and connected to piping constituting the refrigeration cycle system; and a secondary pipe provided on the secondary side of the flow path and connected to the piping constituting the refrigeration cycle system ; an outer tube section connected between the primary tube and the secondary tube; a valve body built into the outer tube section and having a valve seat section and a valve holder; and a valve movably housed in the valve holder. A check valve comprising a body,
The outer pipe portion is formed separately from the primary pipe and the secondary pipe, and is composed of a straight pipe material extending in the axial direction ,
The check valve is characterized in that the secondary pipe side of the primary pipe is inserted into and fixed to the valve seat . The secondary pipe is made of a pipe material having a smaller diameter than the outer pipe part, and the outer pipe is expanded to have an outer diameter equal to the inner diameter of the outer pipe part at the primary end of the secondary pipe. 2. The check valve according to claim 1, further comprising an insertion and fixing part that is inserted into and fixed to the check valve. 3. The check valve according to claim 1, wherein the inner peripheral surface of the primary end of the secondary pipe is provided with a tapered part that expands in the radial direction. 4. The valve seat according to claim 1, wherein the valve seat portion and the valve holder are constructed as separate bodies, and the valve holder housing the valve body is welded and fixed to the valve seat portion. The check valve described in section. The valve seat portion and the valve holder are integrally formed, and a retaining member for preventing the valve body from slipping out is attached to the opposite side of the valve seat portion of the valve holder. The check valve according to any one of claims 1 to 3. The valve seat portion is fixed to the outer circumferential surface of the end of the primary pipe, and a male threaded portion is formed on the outer circumferential surface of the valve seat portion.
A female thread is formed on the inner circumferential surface of the primary end of the outer tube,
The reverse valve according to any one of claims 1 to 5, wherein the female threaded portion and the male threaded portion are screwed together, and the outer tube portion and the valve seat portion are fixed by welding. Stop valve. A refrigeration cycle system comprising the check valve according to any one of claims 1 to 6.

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