Valve gear, equipment piping connection structure, and freezing cycle system

Abstract

To provide a valve gear that can braze stainless steel refrigerant piping to equipment body, other piping and so on with a suppressed workload, an equipment piping connection structure, and a freezing cycle system.SOLUTION: A valve gear as refrigerant equipment 10a constituting a freezing cycle for circulating a refrigerant comprises an equipment body 15, and a stainless steel refrigerant piping 16 joined to the equipment body 15. The equipment body 15 and one end part 161 of the refrigerant piping 16 are brazed by a brazing filler metal 17, a plated layer 18 is provided on the outer peripheral surface 163a in a prescribed range 163 including the other end part 162 of the refrigerant piping 16, and the melting point of the brazing filler metal 17 is lower than the melting point of the plated layer 18. The equipment body 15 comprises a valve body in which a valve chamber is formed and to which the refrigerant piping 16 is joined, and the valve body is made of stainless steel.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a valve device, an equipment piping connection structure, and a refrigeration cycle system that constitute a refrigeration cycle system of an air conditioner or the like. [Background technology]

[0002] Conventionally, refrigerant equipment in which coupling members (refrigerant piping) are joined to the equipment body as refrigerant discharge and suction pipes have been known as equipment constituting air conditioners (refrigeration cycle systems, refrigeration devices) and the like (see, for example, Patent Document 1). In many cases, in such refrigerant equipment, one end of the refrigerant piping is joined to the equipment body by brazing. When the refrigerant equipment is installed in a refrigerant circuit as a valve device, the other end of the refrigerant piping is joined to other piping constituting the refrigerant circuit by brazing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-125238 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, due to the rising cost of materials, copper pipes have been replaced with stainless steel pipes. When such stainless steel pipes are used as refrigerant pipes, for example, when brazing the refrigerant pipes to the main body of the equipment or other pipes during part replacement, it is necessary to remove the oxide film, and the brazing work is often complicated and burdensome for the worker.

[0005] An object of the present invention is to provide a valve device, an equipment piping connection structure, and a refrigeration cycle system that enable stainless steel refrigerant piping to be brazed to an equipment body, other piping, etc. with reduced workload. [Means for solving the problem]

[0006] The valve device of the present invention is a valve device as a refrigerant equipment that constitutes a refrigeration cycle through which a refrigerant circulates, and comprises an equipment main body and a stainless steel refrigerant piping joined to the equipment main body, the equipment main body and one end of the refrigerant piping are brazed together with a brazing material, a plating layer is provided on at least one of the inner and outer circumferential surfaces in a predetermined range including the other end of the refrigerant piping, the melting point of the brazing material is lower than the melting point of the plating layer, the equipment main body comprises a valve body having a valve chamber formed therein and to which the refrigerant piping is joined, and the valve body is made of stainless steel.

[0007] According to this valve device, the material of the plating layer provided in a predetermined area including the other end of the stainless steel refrigerant pipe can be appropriately selected according to the material of the other pipe, etc., so that the other end of the refrigerant pipe can be brazed to the other pipe, etc. with reduced workload. In this case, according to the above valve device, the melting point of the brazing material used to braze one end of the refrigerant pipe to the device body is lower than the melting point of the plating layer. Therefore, the plating layer on the other end side is prevented from melting or changing in quality due to the heat when brazing the one end of the refrigerant pipe to the device body. Therefore, when brazing the one end of the refrigerant pipe to the device body, there is almost no concern about the influence on the plating layer, and a method such as furnace brazing, which has a low workload, can be adopted to airtightly join the device body to the stainless steel refrigerant pipe. Furnace brazing is a method of brazing in which the entire refrigerant pipe and the device body to be brazed are placed in a furnace filled with a high-temperature atmosphere (e.g., a hydrogen atmosphere) that can remove an oxide film. Such furnace brazing requires less work than burner (torch) brazing, which involves applying flux and removing an oxide film while brazing manually. Thus, with the valve device described above, the stainless steel refrigerant pipes can be brazed to the device body, other pipes, etc. with less work required.

[0008] Here, it is preferable that the brazing filler metal is a metallic material containing two or more metals and is an alloy material having, as its melting point, two types of temperatures, a solidus temperature and a liquidus temperature higher than the solidus temperature, or an alloy material having, as its melting point, a eutectic point temperature at which the solidus temperature and the liquidus temperature are the same, and that the plating layer is formed by plating a single metal having a single melting point, and that the solidus temperature or the eutectic point temperature of the brazing filler metal is lower than the melting point of the plating layer.

[0009] According to this configuration, the use of an alloy material as the brazing material can expand the range of brazing material options, and by setting the solidus or eutectic temperature of the brazing material lower than the melting point of the plating layer, melting or deterioration of the plating layer at one end of the refrigerant pipe can be effectively suppressed when brazing the other end of the refrigerant pipe to the device body.

[0010] It is further preferable that the brazing filler metal is an alloy material having two melting points, a solidus temperature and a liquidus temperature higher than the solidus temperature, and that the liquidus temperature of the brazing filler metal is lower than the melting point of the plating layer.

[0011] For example, in general, when brazing is performed using an alloy material having the above-mentioned two melting points as a brazing filler metal, it may be desirable to perform brazing at a temperature higher than the liquidus temperature of the brazing filler metal from the viewpoint of the solderability of the molten brazing filler metal. According to the above configuration, even when brazing is performed at such a temperature, the liquidus temperature of the brazing filler metal is lower than the melting point of the plating layer, so that melting and deterioration of the plating layer can be effectively suppressed.

[0012] It is also preferable that the plating layer is formed by plating containing copper as a main component, and the brazing material contains copper as a main component or copper and silver as main components.

[0013] This configuration allows for good brazing and joining to copper piping or copper-plated piping, which is often assumed as the other end of the refrigerant piping, and effectively prevents melting or deterioration of the plating layer at the other end when brazing one end of the refrigerant piping to the device body.

[0014] Furthermore, the equipment piping connection structure of the present invention is characterized in that it comprises the above-mentioned valve device as refrigerant equipment, the refrigerant piping is a first refrigerant piping, an end of a second refrigerant piping is inserted or inserted into the other end of the first refrigerant piping and joined, and an opposing surface of the second refrigerant piping that faces an inner or outer circumferential surface of the first refrigerant piping is formed from a metal of the same material or a similar material as the plating layer.

[0015] According to this equipment piping connection structure, the opposing surface of the second refrigerant piping to which the other end of the first refrigerant piping is joined is formed from a metal of the same material or a similar material as the plating layer, so that brazing of this other end to the joint can be performed with even less labor.

[0016] It is also preferable that the second refrigerant pipe is made of the same material as the plating layer or a metal of the same type.

[0017] According to this configuration, the plating layer of the first refrigerant pipe and the opposing surface of the second refrigerant pipe can be effectively made of the same material or similar materials.

[0018] It is also preferable that the plating layer is a first plating layer, and at least the opposing surface of the second refrigerant pipe is provided with a second plating layer formed by plating the same material as or a similar material to the first plating layer.

[0019] This configuration also effectively allows the plating layer of the first refrigerant pipe and the opposing surface of the second refrigerant pipe to be made of the same material or similar materials, and also increases the freedom of selection of the material for the second refrigerant pipe.

[0020] In the above-mentioned configuration in which the second plating layer is provided, it is more preferable that the second refrigerant pipe is made of stainless steel.

[0021] According to this configuration, the plating layer of the first refrigerant pipe and the opposing surface of the second refrigerant pipe are made of the same material or similar materials, while inexpensive stainless steel piping is used as the second refrigerant pipe, thereby reducing costs.

[0022] It is also preferable that the brazing material used to braze the one end of the first refrigerant piping to the equipment body is a first brazing material, the second refrigerant piping is brazed to the other end of the first refrigerant piping with a second brazing material, and the melting point of the second brazing material is lower than the melting point of the first brazing material.

[0023] With this configuration, melting or alteration of the first brazing material at the joint between one end of the first refrigerant piping and the equipment body due to heat generated when brazing the other end of the first refrigerant piping to the second refrigerant piping can be effectively suppressed.

[0024] Furthermore, both of the first brazing filler metal and the second brazing filler metal are metal materials containing two or more metals, and are alloy materials having two melting points, a solidus temperature and a liquidus temperature higher than the solidus temperature, or alloy materials having a melting point at a eutectic point temperature at which the solidus temperature and the liquidus temperature are the same, and it is preferable that the solidus temperature or eutectic point temperature of the second brazing filler metal is lower than the solidus temperature or eutectic point temperature of the first brazing filler metal.

[0025] According to this configuration, by using alloy materials as the first brazing filler metal and the second brazing filler metal, the range of choices for these brazing filler metals can be expanded. In addition, by setting the solidus temperature or eutectic temperature of the second brazing filler metal lower than the solidus temperature or eutectic temperature of the first brazing filler metal, melting or deterioration of the first brazing filler metal at the joint between the first refrigerant pipe and the device body can be effectively suppressed when brazing the first refrigerant pipe and the second refrigerant pipe.

[0026] It is further preferable that the second brazing filler metal is an alloy material having two melting points, a solidus temperature and a liquidus temperature higher than the solidus temperature, and that the liquidus temperature of the second brazing filler metal is lower than the solidus temperature or eutectic temperature of the first brazing filler metal.

[0027] According to this configuration, even if brazing is performed at a temperature higher than the liquidus temperature of the second brazing material from the standpoint of brazing properties, the liquidus temperature of the second brazing material is lower than the solidus temperature or eutectic point temperature of the first brazing material, so that melting or deterioration of the first brazing material can be effectively suppressed.

[0028] In the above configuration in which the melting point of the second brazing filler metal is lower than the melting point of the first brazing filler metal, it is preferable that the second brazing filler metal contains copper and at least one of silver and phosphorus.

[0029] According to this configuration, the melting point of the second brazing filler metal can be effectively set lower than the melting point of the first brazing filler metal.

[0030] It is also preferable that the plating layer at the other end of the first refrigerant pipe is provided so as to extend toward the one end beyond an insertion length by which the second refrigerant pipe is inserted or inserted.

[0031] According to this configuration, when the first refrigerant pipe and the second refrigerant pipe are brazed together, a fillet can be reliably formed at the brazed portion without forming a gap where no brazing material exists between the inserted pipes. This prevents the occurrence of crevice corrosion after brazing, and allows the joining of refrigerant pipes with excellent corrosion resistance.

[0032] As described above, the valve device of the present invention is a valve device as the above-mentioned refrigerant equipment, wherein the equipment main body includes a valve body having a valve chamber formed therein and to which the refrigerant piping is joined, and the valve body is made of stainless steel.

[0033] According to this valve device, the above-mentioned refrigerant equipment is utilized as the valve device, so that the stainless steel refrigerant piping can be brazed to the equipment body, other piping, etc. with reduced workload.

[0034] The refrigeration cycle system of the present invention is characterized by including the valve device as the refrigerant equipment described above, or the equipment piping connection structure described above.

[0035] According to this refrigeration cycle system, since it is equipped with the valve device as the above-mentioned refrigerant equipment or the above-mentioned equipment piping connection structure, the stainless steel refrigerant piping can be brazed to the equipment body, other piping, etc. with reduced workload. Effect of the Invention

[0036] According to the valve device, equipment piping connection structure, and refrigeration cycle system of the present invention, stainless steel refrigerant piping can be brazed to the equipment body, other piping, etc. with reduced workload. [Brief description of the drawings]

[0037] [Figure 1] 1 is a partial cross-sectional view showing a motor-operated valve which is a first embodiment of a refrigerant device and a valve device. [Diagram 2] FIG. 2 is a schematic diagram showing a refrigeration cycle system including the motor-operated valve shown in FIG. [Diagram 3] 2 is a schematic diagram showing a state in which a side refrigerant pipe is joined to the valve body shown in FIG. 1. FIG. [Figure 4] FIG. 4 is a schematic diagram equivalent to FIG. 3 showing a refrigerant device according to a second embodiment. [Diagram 5] FIG. 4 is a schematic diagram equivalent to FIG. 3 showing a refrigerant device according to a third embodiment. [Figure 6] FIG. 11 is a schematic diagram equivalent to FIG. 5 showing a refrigerant device according to a fourth embodiment. [Figure 7] FIG. 11 is a schematic diagram equivalent to FIG. 3 showing a refrigerant device according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Hereinafter, a first embodiment of a refrigerant device, a device piping connection structure, a valve device, and a refrigeration cycle system will be described with reference to Figs. 1 to 3.

[0039] FIG. 1 is a partial cross-sectional view showing a motor-operated valve which is a first embodiment of a refrigerant device and a valve device, and FIG. 2 is a schematic diagram showing a refrigeration cycle system including the motor-operated valve shown in FIG.

[0040] The motor-operated valve 10 of this embodiment is used as an expansion valve 100 described below in the refrigeration cycle system 1 shown in Fig. 2. This motor-operated valve 10 comprises an equipment body 11, a bottom refrigerant pipe 12, and a side refrigerant pipe 13. The motor-operated valve 10 is a valve device that adjusts the flow rate of refrigerant flowing between the bottom refrigerant pipe 12 and the side refrigerant pipe 13 via the valve chamber 11a by moving the valve element 11b in the valve chamber 11a back and forth relative to the valve seat member 11c by being driven by a motor. The equipment body 11 comprises a valve body 111-1 having a valve chamber 11a formed therein, and a valve seat member 11c. The valve body 111-1 is welded to the case 111-2 to form the housing 111 of the device body 11 having a cylindrical shape with both ends closed. The bottom refrigerant pipe 12 is a cylindrical pipe joined by brazing to the bottom wall portion 111a of the valve chamber 11a in the valve body 111-1 of the device body 11 at one end so as to extend along the axis X. The side refrigerant pipe 13 is a cylindrical pipe joined by brazing to the peripheral wall portion 111b of the valve chamber 11a in the valve body 111-1 at one end so as to extend perpendicular to the axis X. In this embodiment, the valve body 111-1 to which the bottom refrigerant pipe 12 and the side refrigerant pipe 13 are joined in the device body 11 is a stainless steel part. The bottom refrigerant pipe 12 and the side refrigerant pipe 13 are also stainless steel pipes.

[0041] As shown in FIG. 1, a bottom wall through hole 111c communicating with the bottom refrigerant pipe 12 is formed in the bottom wall portion 111a of the valve chamber 11a in the valve body 111-1. A pipe receiving tube 111d for receiving one end of the bottom refrigerant pipe 12 protrudes from the outer periphery of the bottom wall through hole 111c toward the outside of the valve chamber 11a. A valve seat member 11c of the motor-operated valve 10 is inserted into the bottom wall through hole 111c and fixed by brazing or the like. One end of the bottom refrigerant pipe 12 is inserted into the pipe receiving tube 111d and brazed and fixed in a state in which it can communicate with the valve chamber 11a via the valve seat member 11c in the bottom wall through hole 111c. In addition, a peripheral wall through hole 111g through which an end of the side refrigerant pipe 13 passes is formed in the peripheral wall portion 111b of the valve chamber 11a. One end of the side refrigerant pipe 13 is inserted into this peripheral wall through hole 111g and fixed thereto by brazing.

[0042] Next, a refrigeration cycle system 1 that includes the motor-operated valve 10 as an expansion valve 100 and circulates a refrigerant will be outlined with reference to Fig. 2. The refrigeration cycle system 1 of this embodiment includes the expansion valve 100, an outdoor heat exchanger 200, an indoor heat exchanger 300, a flow path switching valve 400, and a compressor 500, which are connected by conduits as shown in the figure to form a heat pump type refrigeration cycle. Note that an accumulator, a pressure sensor, a temperature sensor, etc. are not shown in the figure.

[0043] The flow path of the refrigeration cycle is switched between two flow paths, one for cooling operation and the other for heating operation, by the flow path switching valve 400. During cooling operation, as shown by the solid arrow in Fig. 2, the refrigerant compressed by the compressor 500 flows from the flow path switching valve 400 into the outdoor heat exchanger 200. This outdoor heat exchanger 200 functions as a condenser, and the liquid refrigerant flowing out of the outdoor heat exchanger 200 flows into the indoor heat exchanger 300 via the expansion valve 100, and this indoor heat exchanger 300 functions as an evaporator.

[0044] 2, the refrigerant compressed by the compressor 500 is circulated in the following order: from the flow path switching valve 400, through the indoor heat exchanger 300, the expansion valve 100, the outdoor heat exchanger 200, the flow path switching valve 400, and finally the compressor 500. The indoor heat exchanger 300 functions as a condenser, and the outdoor heat exchanger 200 functions as an evaporator. The expansion valve 100 reduces the pressure and expands the liquid refrigerant flowing in from the outdoor heat exchanger 200 during cooling operation, or the liquid refrigerant flowing in from the indoor heat exchanger 300 during heating operation, and further controls the flow rate of the refrigerant. 2, the expansion valve 100 is provided so that liquid refrigerant from the outdoor heat exchanger 200 flows into the second joint pipe 102 (side refrigerant piping 13) during cooling operation, and liquid refrigerant from the indoor heat exchanger 300 flows into the first joint pipe 101 (bottom refrigerant piping 12) during heating operation. However, this is not limiting, and the expansion valve 100 may be provided so that liquid refrigerant from the outdoor heat exchanger 200 flows into the first joint pipe 101 during cooling operation, and liquid refrigerant from the indoor heat exchanger 300 flows into the second joint pipe 102 during heating operation.

[0045] Next, the bottom refrigerant piping 12 and the side refrigerant piping 13 that are joined to the stainless steel valve body 111-1 of the device body 11 in the motor-operated valve 10 shown in Figure 1 will be explained, using the side refrigerant piping 13 as a representative example.

[0046] FIG. 3 is a schematic diagram showing a state in which a side refrigerant pipe is joined to the valve body shown in FIG. 1. In FIG. 3, only the member corresponding to the valve body 111-1 in FIG. 1 and the member corresponding to the side refrigerant pipe 13 are shown, but in the following, the configuration including these two members will be referred to as the refrigerant equipment 10a and will be described. In FIG. 3, the member corresponding to the valve body 111-1 in FIG. 1 is shown in a cross-sectional view of only the pipe joint portion, and the other parts are simplified, but in the following, this member will be referred to as the equipment body 15. In addition, the member corresponding to the side refrigerant pipe 13 will be simply referred to as the refrigerant pipe 16. In addition, the structure related to the refrigerant pipe 16 described below can be similarly applied to the bottom refrigerant pipe 12 shown in FIG. 1, so the illustration in FIG. 3 and the overlapping description will be omitted.

[0047] In the refrigerant equipment 10a shown in Fig. 3, both the equipment body 15 and the refrigerant piping 16 are made of stainless steel, and the equipment body 15 and one end 161 of the refrigerant piping 16 are brazed together with a brazing material 17. In addition, a plating layer 18 is provided on an outer circumferential surface 163a in a predetermined range 163 including the other end 162 of the refrigerant piping 16. The predetermined range 163 on which this plating layer 18 is formed is a portion to which other refrigerant piping, etc., will be joined by brazing.

[0048] In this embodiment, the melting point of the brazing material 17 is lower than the melting point of the plating layer 18. In this case, the plating layer 18 is formed of a plating of a single metal having a single melting point, specifically, a plating mainly composed of copper. The plating layer 18 mainly composed of copper is intended for use as a joint by brazing, for example, a copper pipe or a pipe with a copper-plated joint, and has a melting point of 1085°C. The plating of a single metal (plating layer 18 mainly composed of copper) may contain not only the main metal element forming the plating layer, but also other elements resulting from the plating bath.

[0049] On the other hand, the brazing material 17 is a metal material containing two or more metals, and is an alloy material having two melting points: a solidus temperature and a liquidus temperature higher than the solidus temperature. The brazing material 17 of this alloy material may be phosphorus bronze brazing material, silver brazing material, or Ni brazing material. The solidus temperatures and liquidus temperatures of these brazing materials are shown in Table 1 below.

[0050] [Table 1]

[0051] In addition to phosphorus bronze brazing filler metal, silver brazing filler metal, and Ni brazing filler metal, the solidus and liquidus temperatures of phosphorus copper brazing filler metal, which is relatively inexpensive compared to other brazing filler metals, are shown in Table 1. Although not exemplified in Table 1, brazing filler metals having a eutectic point temperature where the solidus and liquidus temperatures are the same depending on the amount of main components and the amount of elements added to the main components, can also be used.

[0052] Phosphorus copper brazing filler metal is a brazing material whose main component is copper with phosphorus or silver and phosphorus added, and physical properties such as solidus temperature and liquidus temperature change depending on the amount of silver and phosphorus added. Table 1 shows the solidus temperature and liquidus temperature for the first to fifth phosphorus copper brazing filler metals, which have different amounts of silver and phosphorus added.

[0053] Phosphorus bronze brazing filler metal is a brazing filler metal whose main component is copper with the addition of phosphorus and tin, and its physical properties such as solidus temperature, liquidus temperature, etc. change depending on the amount of phosphorus and tin added. Table 1 shows the solidus and liquidus temperatures of the first and second phosphorus bronze brazing filler metals, which have different amounts of phosphorus and tin added.

[0054] Silver brazing filler metal is a brazing material whose main components are copper and silver, and its physical properties such as solidus temperature, liquidus temperature, etc. vary depending on the copper content. Table 1 shows the solidus temperature and liquidus temperature for silver brazing filler metals No. 1 to No. 7, which have different copper contents.

[0055] Ni brazing filler metal is a brazing filler metal that contains Ni as the main component and Cr, and its physical properties such as solidus temperature, liquidus temperature, etc. change depending on the difference in other additives. Table 1 shows the solidus temperature and liquidus temperature of the first to third Ni brazing filler metals, which have different additives.

[0056] Here, the brazing material 17 used has a solidus temperature lower than the melting point (1085°C) of the plating layer 18 containing copper as a main component. More strictly, the brazing material 17 used has a liquidus temperature lower than the melting point of the plating layer. Among the brazing materials shown in Table 1, all brazing materials except for the third Ni brazing material have a liquidus temperature as well as a solidus temperature lower than the melting point of the plating layer, and can be used as the brazing material 17 as the above-mentioned more preferable material. With such a brazing material 17, melting and alteration of the plating layer 18 can be effectively suppressed even if brazing is performed at a brazing temperature exceeding the liquidus temperature of the brazing material 17 from the viewpoint of the brazing property of the molten brazing material 17.

[0057] On the other hand, the third Ni brazing filler metal has a solidus temperature (1080°C) lower than the melting point of the plated layer 18, and strict control of the brazing temperature can prevent melting and alteration of the plated layer 18. However, since the difference between the solidus temperature of the third Ni brazing filler metal and the melting point of the plated layer 18 is only 5°C, it is necessary to strictly control the temperature of the brazing atmosphere. In addition, since the liquidus temperature (1135°C) of the third Ni brazing filler metal is higher than the melting point of the plated layer 18, brazing at high temperatures must be avoided from the viewpoint of the brazing properties described above.

[0058] Furnace brazing is possible when phosphorus bronze brazing is used as the brazing material 17. Furnace brazing is a method of brazing in which the refrigerant pipe 16 and the device body 15 to be brazed are entirely placed in a furnace filled with a high-temperature atmosphere (e.g., a hydrogen atmosphere) capable of removing the oxide film on the stainless steel surface.

[0059] Next, two examples, a second embodiment and a third embodiment, will be described as modifications of the first embodiment described with reference to Figs. 1 to 3. In both of these two embodiments, the position at which the plating layer is formed on the refrigerant pipe is different from that of the first embodiment. Below, the two embodiments will be described, focusing on the differences from the first embodiment. On the other hand, a description of the motor-operated valve and the refrigeration cycle system as refrigerant devices equivalent to those of the first embodiment will be omitted.

[0060] Fig. 4 is a schematic diagram of the refrigerant equipment of the second embodiment, similar to Fig. 3. In Fig. 4, components equivalent to those shown in Fig. 3 are given the same reference numerals as in Fig. 3, and hereinafter, redundant explanations of those equivalent components will be omitted.

[0061] 4, in a refrigerant pipe 16 having one end 161 brazed to an equipment body 15 with a brazing material 17, a plating layer 28 on the other end 162 side is provided on an inner circumferential surface 263a in a predetermined range 163 including the other end 162. Except for the fact that the plating layer 28 is provided on the inner circumferential surface 263a, the difference in melting point between the plating layer 28 and the brazing material 17, the material of the plating that forms the plating layer 28, and the like are the same as those in the first embodiment.

[0062] Fig. 5 is a schematic diagram of the refrigerant equipment of the third embodiment, similar to Fig. 3. In Fig. 5, the same components as those shown in Fig. 3 are denoted by the same reference numerals, and the following description of the same components will be omitted.

[0063] In the refrigerant equipment 30a shown in FIG. 5, in the refrigerant pipe 16 having one end 161 brazed to the equipment body 15 by the brazing material 17, the plating layer 38 on the other end 162 side is provided at the following position in a predetermined range 163 including the other end 162. That is, the plating layer 38 is provided over the inner circumferential surface 363a, the opening edge 363b, and the outer circumferential surface 363c in the above-mentioned predetermined range 163. The difference in melting point between the plating layer 38 and the brazing material 17 and the plating material forming the plating layer 38 are the same as those in the first embodiment, except that the plating layer 38 is provided over the inner circumferential surface 363a to the outer circumferential surface 363c. Since the plating layer 38 is formed on both the inner circumferential surface 363a and the outer circumferential surface 363c, another refrigerant pipe made of copper or plated with copper can be attached and brazed to the other end 162 of the refrigerant pipe 16 in either an internal or external manner. Furthermore, since the plating layer 38 is also formed on the opening edge 363b, a good fillet is formed during brazing on both the opening edge side of the other refrigerant pipe attached to the other end 162 and the opening edge 363b side of this refrigerant pipe 16. That is, the opening edge 363b of the refrigerant pipe 16 is also copper due to the plating layer 38, and has the same surface system as the other refrigerant pipe made of copper or plated with copper, so a good fillet can be formed.

[0064] The refrigerant equipment 10a, 20a, 30a, motor-operated valve 10, and refrigeration cycle system 1 of the first to third embodiments described above can achieve the following effects. That is, according to the first to third embodiments, the material of the plating layer 18, 28, 38 on the other end 162 side of the stainless steel refrigerant pipe 16 can be appropriately selected according to the material of other pipes, etc., so that the work load can be reduced and the refrigerant pipe 16 can be brazed to other pipes, etc. According to the first to third embodiments, the melting point of the brazing material 17 used to braze the one end 161 of the refrigerant pipe 16 to the device body 15 is lower than the melting point of the plating layers 18, 28, 38. Therefore, the plating layers 18, 28, 38 on the other end 162 side are prevented from melting or changing in quality due to the heat generated when the one end 161 of the refrigerant pipe 16 is brazed to the device body 15. Therefore, there is almost no concern about the influence of the plating layers 18, 28, 38 on the brazing of the one end 161 of the refrigerant pipe 16 to the device body 15. According to the first to third embodiments, in anticipation of this, a method such as furnace brazing, which requires less work, can be adopted to airtightly join the device body 15 and the stainless steel refrigerant pipe 16. Furnace brazing requires less work than a method such as burner (torch) brazing, in which brazing is performed manually while applying flux and removing an oxide film. In this way, according to the first to third embodiments, the stainless steel refrigerant pipe 16 can be brazed to the device body 15 or other pipes with reduced work load.

[0065] Here, in the first to third embodiments, the brazing material 17 is an alloy material having two melting points, a solidus temperature and a liquidus temperature, and the plating layer 18 is formed by plating a single metal having a single melting point. The brazing material 17 has a solidus temperature lower than the melting point of the plating layer 18. First, by adopting an alloy material as the brazing material 17, the range of choices for the brazing material 17 can be expanded. Furthermore, according to the above configuration, by making the solidus temperature of the brazing material 17 lower than the melting point of the plating layer 18, melting or alteration of the plating layer 18 at the other end 163 can be effectively suppressed when the one end 161 of the refrigerant pipe 16 is brazed to the other end 163 of the device body 15.

[0066] In the first to third embodiments, the brazing material 17 has a liquidus temperature lower than the melting point of the plating layer 18. With this configuration, even when brazing is performed at a high temperature from the viewpoint of the above-mentioned brazing property, the liquidus temperature of the brazing material 17 is lower than the melting point of the plating layer 18. Since the temperature is lower than the melting point, melting or deterioration of the plating layer 18 can be effectively prevented.

[0067] In the first to third embodiments, the plating layers 18, 28, 38 are formed by plating mainly containing copper. This configuration allows good brazing and joining to a copper pipe or a copper-plated pipe, which is often assumed to be joined to the other end 162 of the refrigerant pipe 16. On the other hand, the brazing material 17 may be phosphor bronze brazing material mainly containing copper, or may be silver brazing material mainly containing copper and silver, or may be Ni brazing material. This configuration allows the melting point of the brazing material 17 to be effectively set lower than the melting point of the plating layers 18, 28, 38. Therefore, when the one end 161 of the refrigerant pipe 16 is brazed to the device body 15, melting and deterioration of the plating layers 18, 28, 38 at the other end 62 can be effectively avoided.

[0068] The first to third embodiments have been described above, and the fourth and fifth embodiments will now be described. Both the fourth and fifth embodiments are embodiments relating to the equipment piping connection structure using the third embodiment described above, and one end of a stainless steel refrigerant piping is brazed to the equipment body, and another piping is brazed to the other end side of the stainless steel refrigerant piping. Below, the fourth and fifth embodiments will be described, focusing on the differences from the third embodiment. On the other hand, the motor-operated valve and the refrigeration cycle system as refrigerant equipment equivalent to the third embodiment (i.e., equivalent to the first embodiment) will not be described. In addition, hereinafter, the refrigerant piping on the equipment body side will be referred to as the first refrigerant piping, and the other piping brazed to the first refrigerant piping will be referred to as the second refrigerant piping. In addition, the brazing material used for brazing the equipment body and the first refrigerant piping will be referred to as the first brazing material, and the brazing material used for brazing the first refrigerant piping and the second refrigerant piping will be referred to as the second brazing material.

[0069] Fig. 6 is a schematic diagram of an equipment piping connection structure according to a fourth embodiment, similar to Fig. 5. In Fig. 6, components equivalent to those shown in Fig. 5 are given the same reference numerals as in Fig. 5, and redundant explanations of those equivalent components will be omitted below.

[0070] In the equipment piping connection structure 40a shown in Fig. 6, one end 161 of a first refrigerant pipe 46-1 is brazed to an equipment body 15 of a refrigerant equipment 40b with a first brazing material 47-1. In a predetermined range 163 including the other end 162 of the first refrigerant pipe 46-1, a plating layer 38 is formed over an inner circumferential surface 363a, an opening edge 363b, and an outer circumferential surface 363c. An end of a second refrigerant pipe 46-2 is fitted onto the other end 162 of the first refrigerant pipe 46-1 and brazed to the other end 162 with a second brazing material 47-2. An opposing surface 464 of the second refrigerant pipe 46-2 opposing the outer circumferential surface of the first refrigerant pipe 46-1 is formed of a metal of the same material as the plating layer 38 or a similar material. Specifically, the plating layer 38 is formed of plating containing copper as a main component, and the second refrigerant pipe 46-2 itself including the opposing surface 464 is a copper pipe formed of a metal containing copper as a main component.

[0071] Here, in this embodiment, the length of the first refrigerant pipe 46-1 is longer than the outer diameter of the first refrigerant pipe 46-1. It is preferable that the length of the first refrigerant pipe 46-1 from the position of the end face of the plating layer 38 on the device body 15 side to the position of the outer circumferential surface of the device body 15 is longer than the outer diameter of the first refrigerant pipe 46-1. By making the first refrigerant pipe 46-1 have such a length, the influence of the heat during brazing of the second refrigerant pipe 46-2 on the brazed portion of the first refrigerant pipe 46-1 can be further reduced. This effect can be more reliably obtained when the length from the position of the end face of the plating layer 38 on the device body 15 side to the position of the outer circumferential surface of the device body 15 is more than twice the length of the plating layer 38.

[0072] In addition, in this embodiment, the first refrigerant pipe 46-1 and the second refrigerant pipe 46-2 are illustrated as straight pipes, but these pipes may be bent. The bending process may be appropriately performed according to the layout.

[0073] In this embodiment, both the first brazing filler metal 47-1 and the second brazing filler metal 47-2 are the above-mentioned alloy materials. Then, each brazing filler metal is selected from the brazing filler metals shown in Table 1 above so that the melting point of the second brazing filler metal 47-2 is lower than the melting point of the first brazing filler metal 47-1, specifically, the solidus temperature of the second brazing filler metal 47-2 is lower than the solidus temperature of the first brazing filler metal 47-1. More strictly, the selection is performed so that the liquidus temperature of the second brazing filler metal 47-2 is lower than the solidus temperature of the first brazing filler metal.

[0074] Either the first or second phosphorus bronze brazing filler metal is used as the first brazing filler metal 47-1. These phosphorus bronze brazing filler metals are less expensive than Ni brazing filler metals, and have relatively high melting points (solidus and liquidus temperatures), so they are less susceptible to the effects of heating during brazing with the second brazing filler metal 47-2.

[0075] As the second brazing filler metal 47-2, any one of the first to fifth phosphorus copper brazing filler metals is adopted. These phosphorus copper brazing filler metals are mainly composed of inexpensive copper, and have relatively low solidus and liquidus temperatures. Depending on the combination of the first and second phosphorus bronze brazing filler metals 47-1 as the first brazing filler metal 47-1 and the first to fifth phosphorus copper brazing filler metals 47-2 as the second brazing filler metal 47-2, the solidus temperature of the first brazing filler metal 47-1 can be set to be nearly 100°C higher than the liquidus temperature of the second brazing filler metal 47-2. As a result, even if the second brazing filler metal 47-2 is locally overheated during brazing, if the first brazing filler metal 47-1 is phosphorus bronze brazing filler metal, the influence of overheating can be minimized.

[0076] In this embodiment, the plating layer 38 at the other end 162 of the first refrigerant pipe 46-1 is provided extending toward the one end 161 side beyond the insertion length L41 by which the second refrigerant pipe 46-2 is extrapolated.

[0077] Fig. 7 is a schematic diagram of an equipment piping connection structure according to a fifth embodiment, similar to Fig. 3. In Fig. 7, components equivalent to those shown in Fig. 3 are given the same reference numerals as in Fig. 3, and redundant explanations of those equivalent components will be omitted below.

[0078] In the equipment piping connection structure 50a shown in FIG. 7, a first plating layer 58-1 equivalent to the plating layer 38 of the third embodiment is formed on the other end 162 side of the first refrigerant piping 46-1, one end 161 of which is brazed to the equipment body 15 of the refrigerant equipment 50b by the first brazing material 47-1. Here, in this embodiment, the second refrigerant piping 56-2 that is sheathed on the other end 162 side of the first refrigerant piping 46-1 is a stainless steel piping. Then, a second plating layer 58-2 formed by plating of the same material or a similar material as the first plating layer 58-1 is provided on the inner peripheral surface of the second refrigerant piping 56-2, including the surface 564 facing the outer peripheral surface of the first refrigerant piping 46-1. That is, in this embodiment, the second plating layer 58-2 is formed on the stainless steel second refrigerant piping 56-2 by plating of the same material or a similar material as the first plating layer 58-1, mainly composed of copper. In this embodiment, the second brazing filler metal 57-2 is the same as that in the above-described fourth embodiment, and its melting point is lower than the melting point of the first brazing filler metal 47-1.

[0079] Needless to say, the equipment piping connection structures 40a, 50a, the motor-operated valve 10, and the refrigeration cycle system 1 of the fourth and fifth embodiments described above also provide the same effects as those of the first to third embodiments. That is, the fourth and fifth embodiments also enable the stainless steel refrigerant piping 16 to be brazed to the equipment body 15, other piping, etc., with reduced workload.

[0080] In the fourth and fifth embodiments, the first refrigerant pipe 46-1 is connected to the second refrigerant pipes 46-2 and 46-5. 6-2 is extrapolated and joined. In addition, surfaces 464, 564 of the second refrigerant pipes 46-2, 56-2 facing the first refrigerant pipe 46-1 are formed of a metal of the same material or a similar material as the plating layer 38 or the first plating layer 58-1 of the first refrigerant pipe 46-1. With this configuration, the first refrigerant pipe 46-1 and the second refrigerant pipes 46-2, 56-2 can be brazed by facing each other with metals of the same material or a similar material, so that the brazing work for both can be further reduced.

[0081] In the fourth embodiment, the second refrigerant pipe 46-2 is formed from a metal of the same material or a similar material as the plating layer 38 of the first refrigerant pipe 46-1. With this configuration, the plating layer 38 of the first refrigerant pipe 46-1 and the opposing surface 464 of the second refrigerant pipe 46-2 can be effectively made of the same material or a similar material.

[0082] In the fourth embodiment, the plating layer 38 of the first refrigerant pipe 46-1 is provided so as to extend beyond the insertion length L41 of the second refrigerant pipe 46-2. With this configuration, when the first refrigerant pipe 46-1 and the second refrigerant pipe 46-2 are brazed to each other, a fillet can be reliably formed at the brazed portion without forming a gap where no brazing material exists between the inserted pipes. As a result, no crevice corrosion or the like occurs after brazing, and the refrigerant pipes can be joined with excellent corrosion resistance.

[0083] In the fifth embodiment, a second plating layer 58-2 formed by plating of the same material or a similar material as the first plating layer 58-1 is provided in an area including the opposing surface 564 of the second refrigerant pipe 56-2 facing the first refrigerant pipe 46-1. This configuration also makes it possible to effectively make the first plating layer 58-1 of the first refrigerant pipe 46-1 and the opposing surface 564 of the second refrigerant pipe 56-2 of the same material or a similar material. This configuration also increases the freedom of selecting the material of the second refrigerant pipe 56-2.

[0084] In the fifth embodiment, in response to the increased freedom in selecting the material of the second refrigerant pipe 56-2, a stainless steel pipe is adopted as the second refrigerant pipe 56-2. With this configuration, the first plating layer 58-1 and the opposing surface 564 of the second refrigerant pipe 56-2 are made of the same material or a similar material, and inexpensive stainless steel pipe is adopted as the second refrigerant pipe 56-2, thereby reducing costs.

[0085] In the fourth and fifth embodiments, the melting point of the second brazing material 47-2, 57-2 used to braze the first refrigerant pipe 46-1 and the second refrigerant pipes 46-2, 56-2 is lower than the melting point of the first brazing material 47-1 used to braze the first refrigerant pipe 46-1 and the device body 15. With this configuration, it is possible to effectively suppress melting and deterioration of the first brazing material 47-1 at the joint between the first refrigerant pipe 46-1 and the device body 15 due to heat generated when brazing the first refrigerant pipe 46-1 and the second refrigerant pipes 46-2, 56-2.

[0086] In the fourth and fifth embodiments, both the first brazing filler metal 47-1 and the second brazing filler metal 47-2 are alloy materials, and the solidus temperature of the second brazing filler metal 47-2 is lower than the solidus temperature of the first brazing filler metal 47-1. According to this configuration, first, by adopting alloy materials as the first brazing filler metal 47-1 and the second brazing filler metal 47-2, the selection range of these brazing filler metals can be expanded. In addition, due to the above-mentioned relationship in magnitude of the solidus temperature, melting and deterioration of the first brazing filler metal 47-1 at the joint between the first refrigerant pipe 46-1 and the device main body 15 can be effectively suppressed when brazing the first refrigerant pipe 46-1 and the second refrigerant pipe 46-2.

[0087] In the fourth and fifth embodiments, the liquidus temperature of the second brazing filler metal 47-2 is lower than the solidus temperature of the first brazing filler metal 47-1. With this configuration, even if brazing is performed at a temperature higher than the liquidus temperature of the second brazing filler metal 47-2 from the viewpoint of brazing performance, the liquidus temperature and the solidus temperature are close to each other. Due to the above-mentioned magnitude relationship, melting and deterioration of the first brazing filler metal 47-1 can be effectively suppressed.

[0088] In the fourth and fifth embodiments, the second brazing filler metal 47-2, 57-2 contains copper and at least one of silver and phosphorus. This configuration allows the melting points of the second brazing filler metal 47-2, 57-2 to be effectively set lower than the melting point of the first brazing filler metal 47-1.

[0089] The first to fifth embodiments described above merely show typical forms of the present invention, and the present invention is not limited to these. In other words, the present invention can be embodied in various modifications without departing from the gist of the present invention. As long as the refrigerant equipment, equipment piping connection structure, valve device, and refrigeration cycle system of the present invention are still provided, such modifications are of course included in the scope of the present invention.

[0090] For example, in the above-mentioned first to fifth embodiments, the motor-operated valve 10 used as the expansion valve 100 in the refrigeration cycle system 1 is illustrated as an example of the refrigerant equipment and the valve device. However, the refrigerant equipment and the valve device are not limited to this. The valve device is not limited to a motor-operated valve as an expansion valve, and may be various valve devices other than the motor-operated valve, such as a solenoid valve or a manual valve, or various valve devices other than the expansion valve, such as a flow path switching valve, a check valve, a closing valve, etc. Furthermore, the refrigerant equipment is not limited to a valve device, and may be various devices such as an accumulator, an oil separator, a compressor, etc.

[0091] In the above-mentioned first to fifth embodiments, the motor-operated valve 10 is exemplified as an example of the refrigerant equipment and valve device, which includes two joint pipes, namely, a bottom refrigerant pipe 12 and a side refrigerant pipe 13, and the structure related to the side refrigerant pipe 13 is also applied to the bottom refrigerant pipe 12. However, the refrigerant equipment and valve device are not limited to this. The number of refrigerant pipes such as joint pipes can be set to any number, and the structure related to the brazing or plating layer of the refrigerant pipes described above may be applied to only some of the refrigerant pipes.

[0092] In the above-mentioned first to fifth embodiments, the refrigerant equipment 10, 10a, 20a, 30a, 40b, 50b in which the brazing material 17 and the first brazing material 47-1 are alloy materials having two melting points, the solidus temperature and the liquidus temperature, are exemplified as an example of the refrigerant equipment. However, the refrigerant equipment and the equipment piping connection structure are not limited to these, and the brazing material and the first brazing material on the equipment main body side may be alloy materials having a melting point of a eutectic temperature at which the solidus temperature and the liquidus temperature are the same. In the above-mentioned fourth and fifth embodiments, the equipment piping connection structure 40a, 50a in which the first brazing material 47-1 and the second brazing material 47-2, 57-2 are alloy materials having two melting points, the solidus temperature and the liquidus temperature, are exemplified as an example of the equipment piping connection structure. However, the equipment piping connection structure is not limited to these, and an alloy material having a melting point equal to the eutectic temperature may be used as at least one of the first brazing filler metal and the second brazing filler metal.

[0093] In the above-mentioned first to fifth embodiments, the refrigerant equipment 10, 10a, 20a, 30a, 40b, 50b is exemplified as an example of the refrigerant equipment, in which the brazing material 17 and the first brazing material 47-1 are alloy materials, and the plating layers 18, 28, 38 and the first plating layer 58-1 are formed by plating of a single metal. In this example, the solidus temperature of the brazing material 17 and the first brazing material 47-1 is lower than the melting points of the plating layers 18, 28, 38 and the first plating layer 58-1. However, the refrigerant equipment is not limited to these, and the specific types of the brazing material and the plating layer can be appropriately set, and the specific type of melting point such as the solidus temperature does not matter as long as the melting point of the brazing material is lower than the melting point of the plating layer. However, as described above, by making the brazing material 17 and the first brazing material 47-1 into an alloy material, the selection range of the brazing material can be expanded. As described above, by lowering the solidus temperatures of the brazing filler metal 17 and the first brazing filler metal 47-1 and the melting points of the plating layers 18, 28, 38 and the first plating layer 58-1, melting and deterioration of the plating layers during brazing of the device body side can be effectively suppressed. Note that, although an alloy material having the above-mentioned eutectic point temperature as its melting point may be used as the brazing filler metal and the first brazing filler metal, in this case, it is more preferable that the eutectic point temperature is lower than the melting points of the plating layer and the first plating layer.

[0094] In the above-mentioned first to fifth embodiments, the refrigerant equipment 10, 10a, ..., 50a in which the liquidus temperature of the brazing material 17 and the first brazing material 47-1 is lower than the melting point of the plating layer 18, 28, 38 and the first plating layer 58-1 is exemplified as an example of the refrigerant equipment. However, the refrigerant equipment is not limited to these, and the specific type of the melting point of the brazing material is not important as long as it is lower than the melting point of the plating layer. However, as described above, by making the liquidus temperature of the brazing material 17 and the first brazing material 47-1 lower than the melting point of the plating layer 18, 28, 38 and the first plating layer 58-1, melting and deterioration of the plating layer during brazing of the equipment main body side can be effectively suppressed.

[0095] In the above-mentioned first to fifth embodiments, the plating layers 18, 28, 38 and the first plating layer 58-1 formed by plating mainly made of copper are shown as an example of the plating layer formed on the refrigerant pipe on the device body side. However, the plating layer formed on the refrigerant pipe on the device body side is not limited to this, and can be selected arbitrarily according to the material of the expected joint destination. However, as described above, the plating layers 18, 28, 38 and the first plating layer 58-1 formed by plating mainly made of copper can be satisfactorily brazed to copper pipes or copper-plated pipes, which are often expected to be joint destinations.

[0096] In the above-described fourth and fifth embodiments, the equipment piping connection structures 40a and 50a are exemplified as an example of the equipment piping connection structure in which the end of the second refrigerant piping 46-2, 56-2 is inserted and joined to the other end 162 of the first refrigerant piping 46-1. However, the equipment piping connection structure is not limited thereto, and may be one in which the end of the second refrigerant piping is inserted into the other end of the first refrigerant piping.

[0097] In the above-mentioned fourth and fifth embodiments, as an example of the equipment piping connection structure, the equipment piping connection structures 40a, 50a in which the facing surfaces 464, 564 of the second refrigerant piping 46-2, 56-2 to the first refrigerant piping 46-1 are formed as follows. That is, in these equipment piping connection structures 40a, 50a, the facing surfaces 464, 564 of the second refrigerant piping 46-2, 56-2 are formed of a metal of the same material or a similar material as the plating layer 38 or the first plating layer 58-1 of the first refrigerant piping 46-1. However, the refrigerant equipment is not limited to this, and the facing surface of the second refrigerant piping may be formed of a metal of a different material or a different material type from the plating layer of the first refrigerant piping. However, as described above, by using the same material or a similar material for both, the brazing of the first refrigerant piping 46-1 and the second refrigerant piping 46-2, 56-2 can be performed with further reduced work load.

[0098] In the fourth and fifth embodiments described above, the following second refrigerant pipes 46-2 and 56-2 are illustrated as an example of the second refrigerant pipe having an opposing surface formed of a metal of the same material or a similar material as the plating layer of the first refrigerant pipe. That is, the second refrigerant pipe 46-2 of the fourth embodiment is formed of a metal of the same material or a similar material as the plating layer 38 of the first refrigerant pipe 46-1. In addition, the second refrigerant pipe 56-2 of the fifth embodiment is provided with a second plating layer 58-2 formed of plating of the same material or a similar material as the first plating layer 58-1 at least on the opposing surface 564 with the first refrigerant pipe 46-1. Furthermore, the second refrigerant pipe 56-2 of the fifth embodiment is a pipe made of stainless steel. However, the second refrigerant pipe is not limited to these, and the pipe material, the plating layer material, and the like can be set appropriately. However, according to the second refrigerant pipes 46-2 and 56-2 described above, the plating layer 38 and the second plating layer 58-1 are not formed of the metal of the same material or a similar material as the first plating layer 58-1. As described above, the first plating layer 58-1 and the opposing surfaces 464, 564 of the second refrigerant pipes 46-2, 56-2 can be effectively made of the same material or a similar material. In addition, as described above, by providing the second plating layer 58-2 and making the second refrigerant pipe 56-2 out of stainless steel, costs can be reduced.

[0099] In the fourth and fifth embodiments described above, the second brazing filler metal 47-2, 57-2 having a lower melting point than the first brazing filler metal 47-1 used to braze the first refrigerant pipe 46-1 to the device body 15 is exemplified as an example of the second brazing filler metal used to braze the second refrigerant pipe to the first refrigerant pipe. However, the second brazing filler metal is not limited to this, and its melting point, etc. can be set arbitrarily. However, as described above, the second brazing filler metal 47-2, 57-2 having a lower melting point than the first brazing filler metal 47-1 can effectively suppress melting and deterioration of the first brazing filler metal caused by heat when brazing the two refrigerant pipes.

[0100] In the fourth and fifth embodiments described above, the first brazing filler metal 47-1 and the second brazing filler metal 47-2, 57-2 are exemplified as examples of the first brazing filler metal and the second brazing filler metal, both of which are alloy materials and the solidus temperature of the latter is lower than the solidus temperature of the former. However, the first brazing filler metal and the second brazing filler metal are not limited to this, and may be a single metal and the single melting point of the second brazing filler metal is lower than the single melting point of the first brazing filler metal, etc. However, as described above, by using an alloy material, the range of brazing filler metals can be expanded, and by lowering the solidus temperature of the second brazing filler metal to be lower than the solidus temperature of the first brazing filler metal, melting or alteration of the first brazing filler metal during brazing with the second brazing filler metal can be effectively suppressed. Note that an alloy material having the above-mentioned eutectic temperature as a melting point may be used as at least one of the first brazing filler metal and the second brazing filler metal. When an alloy material having a eutectic temperature is used as the first brazing material and an alloy material having a solidus temperature and a liquidus temperature is used as the second brazing material, it is preferable to set the solidus temperature of the second brazing material lower than the eutectic temperature of the first brazing material. Conversely, when an alloy material having a solidus temperature and a liquidus temperature is used as the first brazing material and an alloy material having a eutectic temperature is used as the second brazing material, it is preferable to set the eutectic temperature of the second brazing material lower than the solidus temperature of the first brazing material. When alloy materials having a eutectic temperature are used for both the first brazing material and the second brazing material, it is preferable to set the eutectic temperature of the second brazing material lower than the eutectic temperature of the first brazing material.

[0101] In the fourth and fifth embodiments described above, the first brazing filler metal 47-1 and the second brazing filler metal 47-2, 57-2 are exemplified as an example of the first brazing filler metal and the second brazing filler metal, the latter of which has a lower liquidus temperature than the former solidus temperature. However, the first brazing filler metal and the second brazing filler metal are not limited to this, and as long as the melting point of the second brazing filler metal is lower than the melting point of the first brazing filler metal, the specific type of the melting point of each brazing filler metal is not important. However, as described above, by making the liquidus temperature of the second brazing filler metal 47-2, 57-2 lower than the solidus temperature of the first brazing filler metal 47-1, melting and deterioration of the first brazing filler metal 47-1 can be effectively suppressed during brazing with the second brazing filler metal 47-2, 57-2. Furthermore, when an alloy material having a eutectic point temperature is used as the first brazing material and an alloy material having a solidus temperature and a liquidus temperature is used as the second brazing material, it is preferable to set the liquidus temperature of the second brazing material lower than the eutectic point temperature of the first brazing material.

[0102] In the fourth and fifth embodiments, the plating layer 18 mainly made of copper, the first brazing material 47-1 using phosphorus bronze brazing material, and the second brazing material 47-2, 57-2 using phosphorus copper brazing material are exemplified as examples of the plating layer, the first brazing material, and the second brazing material. However, the plating layer, the first brazing material, and the second brazing material are not limited to these, and can be appropriately selected depending on the materials of the device body and the first and second refrigerant pipes, the brazing conditions, etc. However, as described above, the combination of the above materials is preferable in terms of the material cost of the brazing material and in terms of suppressing the influence of overheating during brazing.

[0103] In the fourth and fifth embodiments described above, the second brazing filler metal has a melting point lower than that of the first brazing filler metal. As an example, the second brazing filler metal 47-2, 57-2 is shown, which is mainly composed of copper and contains at least one of silver and phosphorus. However, the second brazing filler metal is not limited to this, and the material and the like can be set arbitrarily. However, as described above, the melting point of the second brazing filler metal 47-2, 57-2 of the above material can be effectively set lower than the melting point of the first brazing filler metal 47-1.

[0104] In the fourth and fifth embodiments described above, the plating layer 38 and the first plating layer 58-1 extending toward the device body 15 beyond the insertion length L41 of the second refrigerant pipes 46-2, 56-2 are exemplified as an example of the plating layer at the other end of the first refrigerant pipe. However, the plating layer at the other end of the first refrigerant pipe is not limited to this, and the plating range can be set to any range. However, as described above, the plating layer 38 and the first plating layer 58-1 extending beyond the insertion length L41 of the second refrigerant pipes 46-2, 56-2 enable the joining of refrigerant pipes with excellent corrosion resistance. [Explanation of symbols]

[0105] 1 Refrigeration cycle system 10 Motor-operated valve 10a,20a,30a,40b,50b Refrigerant equipment 11 Device body 11a Valve chamber 11b Valve body 11c Valve seat material 12 First refrigerant piping 13 Second refrigerant piping 15 Device body 16 Refrigerant piping 17 Brazing material 18, 28, 38 plating layer 40a, 50a Equipment piping connection structure 46-1 First refrigerant piping 46-2,56-2 Second refrigerant piping 47-1 First brazing material 47-2,57-2 Second brazing material 58-1 First plating layer 58-2 Second plating layer 100 Expansion valve 101 First joint pipe 102 Second joint pipe 111 Housing 111-1 Valve body 111-2 Case 111a Bottom wall part 111b Peripheral wall part 111c Bottom wall through-hole 111d Pipe receiving cylinder 111g Peripheral wall through-hole 161 One end 162 The other end 163 Specified range 163a, 363c Outer peripheral surface 200 Outdoor heat exchanger 263a, 363a Inner peripheral surface 300 Indoor heat exchanger 363b Opening edge 400 Flow path switching valve 464 Opposing surface 500 Compressor L41 Insertion length X-axis

Claims

1. A valve device as a refrigerant device constituting a refrigeration cycle through which a refrigerant flows, The device body, A stainless steel refrigerant pipe joined to the device body, The device body and one end of the refrigerant pipe are brazed together with a brazing material, a plating layer is provided on at least one of an inner circumferential surface and an outer circumferential surface in a predetermined range including the other end of the refrigerant pipe; the melting point of the brazing material is lower than the melting point of the plating layer; The valve device is characterized in that the equipment body includes a valve body having a valve chamber formed therein and to which the refrigerant piping is joined, the valve body being made of stainless steel.

2. The brazing material is a metal material containing two or more metals, and is an alloy material having, as a melting point, two types of temperatures, namely, a solidus temperature and a liquidus temperature higher than the solidus temperature, or an alloy material having, as a melting point, a eutectic point temperature at which the solidus temperature and the liquidus temperature are the same; the plating layer is formed by plating a single metal having a single melting point; 2. The valve device according to claim 1, wherein the solidus temperature or the eutectic temperature of the brazing material is lower than the melting point of the plating layer.

3. The brazing material is an alloy material having two melting points, a solidus temperature and a liquidus temperature higher than the solidus temperature, 3. The valve device according to claim 2, wherein the liquidus temperature of the brazing material is lower than the melting point of the plating layer.

4. A refrigerant device comprising the valve device according to claim 1, The refrigerant pipe is a first refrigerant pipe, and an end of a second refrigerant pipe is inserted or inserted into the other end of the first refrigerant pipe and joined thereto, An equipment piping connection structure, characterized in that the opposing surface of the second refrigerant piping that faces the inner or outer surface of the first refrigerant piping is formed from a metal of the same material or a similar material as the plating layer.

5. 5. The equipment piping connection structure according to claim 4, wherein the second refrigerant piping is formed from a metal of the same material or a similar material to the plating layer.

6. The equipment piping connection structure described in claim 4, characterized in that the plating layer is a first plating layer, and a second plating layer formed of the same material or a similar material as the first plating layer is provided on at least the opposing surface of the second refrigerant piping.

7. 7. The equipment piping connection structure according to claim 6, wherein the second refrigerant piping is made of stainless steel.

8. a brazing material that brazes and joins the one end of the first refrigerant pipe and the equipment body is a first brazing material, The equipment piping connection structure according to claim 4, characterized in that the second refrigerant piping is brazed to the other end of the first refrigerant piping using a second brazing material, and the melting point of the second brazing material is lower than the melting point of the first brazing material.

9. Both the first brazing material and the second brazing material are metal materials containing two or more metals. an alloy material having, as a melting point, two kinds of temperatures, i.e., a solidus temperature and a liquidus temperature higher than the solidus temperature, or an alloy material having, as a melting point, a eutectic point temperature at which the solidus temperature and the liquidus temperature are the same; 9. The equipment piping connection structure according to claim 8, wherein the solidus temperature or the eutectic temperature of the second brazing filler metal is lower than the solidus temperature or the eutectic temperature of the first brazing filler metal.

10. The second brazing filler metal is an alloy material having two melting points, a solidus temperature and a liquidus temperature higher than the solidus temperature, 10. The equipment piping connection structure according to claim 9, wherein the liquidus temperature of the second brazing filler metal is lower than the solidus temperature or the eutectic temperature of the first brazing filler metal.

11. The equipment piping connection structure according to claim 8, wherein the second brazing material contains copper and at least one of silver and phosphorus.

12. The equipment piping connection structure according to claim 4, characterized in that the plating layer at the other end of the first refrigerant piping extends toward the one end side beyond an insertion length into which the second refrigerant piping is inserted or inserted.

13. A refrigeration cycle system comprising: a valve device as a refrigerant device according to any one of claims 1 to 3; or an equipment piping connection structure according to any one of claims 4 to 12.

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