Valve device, manufacturing method for valve device, and connection structure of refrigerant pipe in valve device

Abstract

To provide a valve device that can be easily connected by using brazing even if mutual materials are different, a manufacturing method for the valve device, and a connection structure of a refrigerant pipe in the valve device.SOLUTION: In a joint member 100 made of stainless steel, a coating 200 of copper or a copper alloy is formed by metallic bond on an inner peripheral surface 100a or an outer peripheral surface 100b in one end part in at least a longitudinal direction. Therefore, even if the joint member 100 itself is made of the stainless steel, it can be easily connected to a connection object via the end part in which the coating 200 of the copper or the copper alloy is formed, by using brazing.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a valve device, a method for manufacturing the valve device, and a connection structure of a refrigerant pipe in the valve device.

Background Art

[0002] Conventionally, in an air conditioner such as a room air conditioner, during cooling operation, refrigerant is circulated to the compressor via a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger connected via a refrigerant pipe, and during heating operation, the refrigerant is circulated to the compressor via the compressor, the indoor heat exchanger, the expansion valve, and the outdoor heat exchanger, so that the circulation direction of the refrigerant is reversed. Thus, as a flow path switching valve (so-called four-way switching valve), which is a valve device for reversing the refrigerant circulation path, a slide type switching valve having a valve body slidably provided inside a valve body is widely used (see, for example, Patent Document 1). And in such an air conditioner, a refrigerant pipe piped in the device and a joint member (refrigerant pipe) provided as a discharge pipe and a suction pipe of the slide type switching valve are connected by brazing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, such a valve device (slide type switching valve) generally has a brass body and parts such as other joint members made of copper. However, in recent years, due to the rapid increase in the price of copper, there has been a tendency to switch from copper, which has been conventionally used as the material for joint members in valve devices, to stainless steel. On the other hand, in air conditioning devices in which valve devices are installed, copper is still used as the material for refrigerant pipes as before due to the ease of processing and the stability of performance. Therefore, since the stainless steel joint members of the valve device and the copper refrigerant pipes of the air conditioning device are made of different materials, there has been a problem that it is difficult to simply connect them using brazing as in the past.

[0005] Moreover, in the brazing of the joint members of the valve device and the refrigerant pipes of the air conditioning device, when using a flux to ensure wettability, it takes time to remove the flux, so flux has not been used conventionally. That is, since the refrigerant pipes containing stainless steel in the material and the joint members containing copper in the material are made of different materials and no flux is used, brazing these has been an extremely difficult task.

[0006] Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a valve device, a method for manufacturing a valve device, and a connection structure for a refrigerant pipe in a valve device that can be easily connected using brazing even when the materials thereof are different from each other.

Means for Solving the Problems

[0007] The valve device of the present invention is a valve device including a valve body having a valve chamber inside and a joint member joined to the valve body, wherein the joint member is a refrigerant pipe made of stainless steel, and a film of copper or a copper alloy is formed on at least the inner peripheral surface or the outer peripheral surface at one end in the longitudinal direction by a metal bond, the film extends to the end surface at the one end, and the film is formed with a uniform thickness over the entire circumference of the end surface.

[0008] According to the present invention as described above, even when the refrigerant pipe itself is made of stainless steel, it can be easily connected to a connection target using brazing through an end portion where a coating of copper or a copper alloy is formed. Further, since the coating extends to the end face at the one end portion, not only the surface (inner peripheral surface or outer peripheral surface) that contacts the surface (outer peripheral surface or inner peripheral surface) of the connection target in the refrigerant pipe, but also the end face of the refrigerant pipe is extended and provided with a coating. When the material of the connection target is the same copper or copper alloy as the coating, a fillet is likely to be formed well. As a result, it can be joined without gaps, the airtightness of the brazed portion can be surely ensured, and the reliability of the connection can be further ensured.

[0009] At this time, in the valve device of the present invention, the coating member made of copper or a copper alloy forming the coating is preferably a sheet-like body and is arranged in a state of being rounded in a C shape. According to such a configuration, when the coating member is arranged on the inner peripheral surface at the end portion of the refrigerant pipe, the coating member is held on the inner peripheral surface of the refrigerant pipe by an elastic force for shape retention in the opening direction from the state of being rounded in a C shape. When the coating member is arranged on the outer peripheral surface at the end portion of the refrigerant pipe, the coating member is held on the outer peripheral surface of the refrigerant pipe by an elastic force for shape retention in the direction in which the coating member is rounded in a C shape. Therefore, the trouble of holding the coating member at the arrangement site by, for example, spot welding is saved, and it can be easily arranged. Further, since the joints between the opposing end portions of the coating member are arranged with a gap therebetween, at the portion where the gap is provided, the outer peripheral side and the inner peripheral side of the coating member are penetrated, so that gases and bubbles such as air existing between the coating member and the wall surface of the refrigerant pipe can be removed.

[0010] Furthermore, in the valve device of the present invention, the coating member made of copper or a copper alloy forming the coating is preferably an annular cylindrical body. According to such a configuration, by expanding the cylindrical coating member in the outer diameter direction or contracting it in the inner diameter direction according to the arrangement site, for example, the trouble of holding the coating member at the arrangement site by spot welding or the like is saved, and it can be easily arranged.

[0011] In addition, when the film member made of copper or a copper alloy forming the film is the sheet-like body or the cylindrical body, it is preferable that the film member is provided with a slit in the circumferential direction or the axial direction. According to such a configuration, at the slit portion, the outer peripheral side and the inner peripheral side of the film member are penetrated, so that gases and bubbles such as air existing between the film member and the wall surface of the refrigerant pipe can be removed from the slit. In addition, the slit can remove the distortion generated during heating when metal-bonding.

[0012] Furthermore, in the valve device of the present invention, the film member made of copper or a copper alloy forming the film is preferably a net-like body and is preferably arranged in a state of being rounded in a C shape or in an annular shape. According to such a configuration, when the film member is arranged in a state of being rounded in a C shape, it is held at the end of the refrigerant pipe by the elastic force of the film member, and when the film member is arranged in an annular shape, it is held by expanding in the outer diameter direction or contracting in the inner diameter direction according to the arrangement site. Therefore, the trouble of holding the film member at the arrangement site by, for example, spot welding is saved, and it can be easily arranged. In addition, since the film member has net-like holes penetrating the outer peripheral side and the inner peripheral side as a whole, gases and bubbles such as air existing between the film member and the wall surface of the refrigerant pipe can be removed. In addition, the net-like holes can remove the distortion generated during heating when metal-bonding.

[0013] Also, in the valve device of the present invention, the film member made of copper or a copper alloy forming the film is preferably a strip-shaped body having a circular or rectangular cross section and is preferably arranged in a spiral shape along the axial direction. According to such a configuration, since it is held at the end of the refrigerant pipe by the elastic force of the strip-shaped film member, the trouble of holding the film member at the arrangement site by, for example, spot welding is saved, and it can be easily arranged. In addition, minute gaps are formed in the film member so that the outer peripheral side and the inner peripheral side penetrate in a spiral shape, so that gases and bubbles such as air existing between the film member and the wall surface of the refrigerant pipe can be removed from the gaps. In addition, the minute gaps can remove the distortion generated during heating when metal-bonding.

[0014] Furthermore, in the valve device of the present invention, the coating member made of copper or a copper alloy that forms the coating is preferably a C-shaped or annular ring-shaped body, and a plurality of them are arranged adjacent to each other along the axial direction. According to such a configuration, when the ring-shaped coating member is arranged in a state of being rounded into a C shape, it is held at the end of the refrigerant pipe by the elastic force of the coating member. When the coating member is arranged in an annular shape, it is held by expanding in the outer diameter direction or contracting in the inner diameter direction according to the arrangement site. Therefore, the trouble of holding the coating member at the arrangement site by, for example, spot welding is saved, and it can be easily arranged. In addition, since a minute gap penetrating the outer peripheral side and the inner peripheral side is formed between the coating members adjacent in a multilayered manner, gases and bubbles such as air existing between the coating members adjacent in a multilayered manner and the wall surface of the refrigerant pipe can be removed from the gap. In addition, the minute multilayered gaps can remove the distortion generated during heating when metal bonding occurs.

[0015] Also, in the valve device of the present invention, the coating member made of copper or a copper alloy that forms the coating is preferably a wire-shaped body and is preferably arranged in a state of being rounded into a C shape or in an annular shape. According to such a configuration, when the wire-shaped coating member is arranged in a state of being rounded into a C shape, it is held at the end of the refrigerant pipe by the elastic force of the coating member. When the coating member is arranged in an annular shape, it is held by expanding in the outer diameter direction or contracting in the inner diameter direction according to the arrangement site. Therefore, the trouble of holding the coating member at the arrangement site by, for example, spot welding is saved, and it can be easily arranged.

[0016] Also, in the valve device of the present invention, it is preferable that the surface of the cross section orthogonal to the axial direction of the coating member made of copper or a copper alloy that forms the coating has an uneven shape along the circumferential direction.

[0017] The manufacturing method of the valve device of the present invention is a manufacturing method of a valve device including a valve body having a valve chamber inside and a joint member joined to the valve body, wherein the joint member is a refrigerant pipe made of stainless steel, and copper or a copper alloy is heated to a temperature between the solidus temperature and the liquidus temperature to form a semi-molten state on the inner peripheral surface or the outer peripheral surface at at least one end in the longitudinal direction of the refrigerant pipe in an environment where the oxide film can be removed, and a film of the copper or the copper alloy is formed. According to such the present invention, even when the refrigerant pipe itself is made of stainless steel, a film of copper or a copper alloy is formed on the inner peripheral surface or the outer peripheral surface of the connecting end, so that it can be easily connected using brazing.

[0018] At this time, in the manufacturing method of the valve device of the present invention, it is preferable that the environment where the oxide film can be removed is a hydrogen reduction furnace. According to such a method, since the hydrogen reduction furnace used for joining the refrigerant pipe can form a film of copper or a copper alloy while removing the oxide film, man-hours can be reduced.

[0019] Also, in the manufacturing method of the valve device of the present invention, it is preferable that the film of copper or a copper alloy is formed by laser irradiation. According to such a method, a film made of copper or a copper alloy can be directly formed while removing the oxide film by laser irradiation.

[0020] The connection structure of the refrigerant pipe in the valve device of the present invention is a connection structure of the refrigerant pipe in a valve device including a valve body having a valve chamber inside and a joint member joined to the valve body, and is a connection structure of the refrigerant pipe in which a first refrigerant pipe and a second refrigerant pipe are connected by brazing. The first refrigerant pipe is made of stainless steel, and a film of copper or copper alloy is formed on the inner peripheral surface or the outer peripheral surface of the end portion on the second refrigerant pipe side by metal bonding. The second refrigerant pipe is made of copper or copper alloy, or a film of copper or copper alloy is formed on the outer peripheral surface or the inner peripheral surface of the end portion on the first refrigerant pipe side by metal bonding. The film extends to the end face at the end portion on the second refrigerant pipe side of the first refrigerant pipe and is formed with a uniform thickness over the entire circumference of the end face at the end portion on the second refrigerant pipe side of the first refrigerant pipe. And when the second refrigerant pipe is not made of copper or copper alloy, it extends to the end face at the end portion on the first refrigerant pipe side of the second refrigerant pipe and is formed with a uniform thickness over the entire circumference of the end face at the end portion on the first refrigerant pipe side of the second refrigerant pipe. According to such a present invention, even when the first refrigerant pipe is made of stainless steel, since it has a film of copper or copper alloy formed by metal bonding on the inner peripheral surface or the outer peripheral surface of the end portion on the second refrigerant pipe side, it can be easily connected by brazing to the second refrigerant pipe which is the connection target and is made of copper or copper alloy or has a film of copper or copper alloy formed by metal bonding on the outer peripheral surface or the inner peripheral surface of the end portion on the first refrigerant pipe side.

[0021] Furthermore, since films are provided not only on the surfaces that come into contact with each other in both the first and second refrigerant pipes, that is, not only on the surfaces (outer peripheral surface or inner peripheral surface) of the end portions on the connection target side of both, but also extending to the end faces of the end portions on the connection target side of both, when the material of the second refrigerant pipe that is the connection target for the first refrigerant pipe or the film formed on the end portion on the first refrigerant pipe side is the same copper or copper alloy as the film of the first refrigerant pipe, it becomes easier to form a good fillet. As a result, it can be joined without gaps, the airtightness of the brazed portion can be surely ensured, and the reliability of the connection can be further ensured.

Advantages of the Invention

[0022] According to the valve device, the method for manufacturing the valve device, and the connection structure of the refrigerant pipe in the valve device of the present invention, even when the materials of each other are different, they can be easily connected using brazing.

Brief Description of the Drawings

[0023]

Figure 1

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Figure 17

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of a valve device, a method for manufacturing a valve device, and a connection structure of a refrigerant pipe in a valve device according to the present invention will be described in detail with reference to the drawings.

[0025] As shown in FIG. 1, the four-way switching valve (slide type switching valve) 10 of the present embodiment includes a pair of pistons 2L, 2R, a connecting plate 3, a valve seat 4, and a valve body 5 in a valve housing 1 as a “valve body”.

[0026] The valve housing 1 is composed of a cylindrical portion 11 made of metal such as stainless steel in a cylindrical shape and two cap portions 12L and 12R made of metal such as stainless steel. The cap portions 12L and 12R are attached to the cylindrical portion 11 so as to close the ends of the cylindrical portion 11 respectively. Also, the central axes of the cylindrical portion 11 and the cap portions 12L and 12R are the axis X of the valve housing 1. A pair of pistons 2L and 2R are arranged opposite to each other and are capable of reciprocating while pressing the packing 21 against the inner peripheral surface of the cylindrical portion 11. Thereby, the inside of the valve housing 1 is partitioned by the two pistons 2L and 2R into a high-pressure chamber 11A at the central portion and two first working chambers 12A and two second working chambers 12B on both sides of the high-pressure chamber 11A. The connecting plate 3 is made of a metal plate, and this connecting plate 3 is installed between the pistons 2L and 2R so as to be arranged on the axis X of the valve housing 1, and holds the valve body 5 at its center. Also, a through hole 3a is formed in the connecting plate 3. Then, when the pistons 2L and 2R move, the valve body 5 slides on the valve seat 4 in conjunction with the connecting plate 3 and stops at predetermined left and right positions.

[0027] The valve seat 4 is disposed at an intermediate portion within the cylindrical portion 11, and at a position facing the valve seat 4 at the intermediate portion of the cylindrical portion 11, a D joint pipe 13d as a joint member of the refrigerant pipe of the present embodiment that opens into the cylindrical portion 11 is attached. Also, to the valve seat 4, an E joint pipe 13e, an S joint pipe 13s, and a C joint pipe 13c as joint members of the refrigerant pipe of the present embodiment are attached in a straight line in the direction of the axis X of the valve housing 1. A bowl-shaped recess 5A is formed inside the valve body 5. Then, at the end position on the left side in FIG. 1, the valve body 5 conducts the S joint pipe 13s and the E joint pipe 13e through the bowl-shaped recess 5A. At this time, the C joint pipe 13c is mainly conducted to the D joint pipe 13d through the through hole 3a in the high-pressure chamber 11A. Also, at the end position on the right side in FIG. 1, the valve body 5 conducts the S joint pipe 13s and the C joint pipe 13c through the bowl-shaped recess 5A. At this time, the E joint pipe 13e is mainly conducted to the D joint pipe 13d through the through hole 3a in the high-pressure chamber 11A.

[0028] Here, the slide type switching valve 10 of the present embodiment is provided, for example, in a refrigeration cycle (not shown). Since a general refrigeration cycle can be widely applied as the refrigeration cycle, illustration thereof is omitted here for the sake of convenience.

[0029] In such a refrigeration cycle, the D joint pipe 13d is connected to the discharge port of the compressor, and the S joint pipe 13s is connected to the suction port of the compressor. The C joint pipe 13c is connected to the outdoor heat exchanger, and the E joint pipe 13e is connected to the indoor heat exchanger. The outdoor heat exchanger and the indoor heat exchanger are connected via a throttling device. A refrigeration cycle is constituted by a path including the outdoor heat exchanger, the throttling device, the indoor heat exchanger, and the E joint pipe 13e from the C joint pipe 13c, and a path including the compressor and the D joint pipe 13d from the S joint pipe 13s. Note that a small amount of refrigerant oil is contained in the refrigerant in the refrigeration cycle for protecting the compressor and other devices.

[0030] The pilot valve is connected to the slide type switching valve 10. The pilot valve has, for example, the same structure as the slide type switching valve 10, and moves a valve body by an electromagnetic actuator or the like to switch a flow path. Then, this pilot valve switches the connection destination of a conduit communicating with the S joint pipe 13s of the slide type switching valve 10 connected to the suction port of the compressor between a pressure introduction pipe 14L communicating with the first working chamber 12A on the left side of the slide type switching valve 10 and a pressure introduction pipe 14R communicating with the second working chamber 12B on the right side, and at the same time switches the connection destination of a conduit communicating with the D joint pipe 13d of the slide type switching valve 10 connected to the discharge port of the compressor between the pressure introduction pipe 14R and the pressure introduction pipe 14L. Thereby, due to the pressure difference between the pressure of the first working chamber 12A into which the suction pressure or the discharge pressure of the compressor is introduced and the pressure of the second working chamber 12B on the opposite side, the pistons 2L, 2R, the connecting plate 3, and the valve body 5 are moved along the axis X of the valve housing 1, and the position of this valve body 5 is switched to switch the flow path of the refrigeration cycle.

[0031] With the above configuration, the high-pressure refrigerant compressed by the compressor flows into the main valve chamber 11A from the D joint pipe 13d. In the state of the cooling operation, the high-pressure refrigerant flows into the outdoor unit from the C joint pipe 13c. Also, in the state of the heating operation where the valve body 5 is switched, the high-pressure refrigerant flows into the indoor unit from the E joint pipe 13e. That is, during the cooling operation, the refrigerant discharged from the compressor circulates as C joint pipe 13c → outdoor heat exchanger → throttling device → indoor heat exchanger → E joint pipe 13e, and the outdoor heat exchanger functions as a condenser, and the indoor heat exchanger functions as an evaporator, and cooling is performed. Also, during the heating operation, the refrigerant circulates in the reverse direction, the indoor heat exchanger functions as a condenser, and the outdoor heat exchanger functions as an evaporator, and heating is performed.

[0032] As shown in FIG. 1, each piston 2L, 2R of the slide type switching valve 10 has a mirror-symmetrical structure. The pistons 2L, 2R each include a packing 21, a fixed disk 22 fixed to the connecting plate 3, a leaf spring 23, and a disk-shaped stopper plate 24. These packing 21, fixed disk 22, leaf spring 23, and stopper plate 24 are coaxially arranged around the axis X and are integrally fixed by rivets, and the integral pistons 2L, 2R are fixed to the connecting plate 3 by bolts.

[0033] Hereinafter, the D joint pipe 13d, E joint pipe 13e, S joint pipe 13s, and C joint pipe 13c, which are the joint members of the refrigerant piping of the present embodiment attached to the slide type switching valve 10 having such a configuration, will be described. In the following, these D joint pipe 13d, E joint pipe 13e, S joint pipe 13s, and C joint pipe 13c are collectively referred to as joint member 100. In the following, for the joint member 100, the case where the coating 200 described later is formed on the inner peripheral surface and the case where it is formed on the outer peripheral surface will be described in order with reference to FIGS. 2 to 5 and FIGS. 6 to 8, respectively.

[0034] As shown in FIGS. 2 and 3, the joint member 100, which is a refrigerant pipe of the present embodiment, is made of stainless steel, and a sheet-like coating 200 made of copper or a copper alloy (here, phosphor bronze containing tin) is formed on the inner peripheral surface 100a at at least one end in the longitudinal direction by metal bonding. The coating 200 is formed over a range wider than the length into which the refrigerant pipe 60 is inserted into the joint member 100. More specifically, it is formed over a range sufficient to fully satisfy the brazing strength with the refrigerant pipe connected to the joint member 100. Specifically, it is formed over a range of at least the thickness of the joint member 100 or more from the end face of the joint member 100, preferably over a range of at least half the inner diameter of the joint member 100 or more, and more preferably over a range of the inner diameter of the joint member 100 or more. The coating 200 is composed of a coating member 200A of a sheet-like body described later, and the interface with the inner peripheral surface 100a of the joint member 100 is formed by metal bonding in which the temperature is heated to a temperature exceeding the solidus temperature of phosphor bronze. The heating temperature may be a semi-molten state by heating to the limit temperature at which phosphor bronze melts (near the liquidus temperature). When such a heating temperature is used, the adhesiveness of the coating member 200A to the joint member 100 can be enhanced, so that the coating 200 can be formed uniformly on the joint member 100. Further, by melting and fixing the coating member 200A to form the coating 200, peeling of the coating 200 from the joint member 100 due to thermal expansion and thermal contraction is less likely to occur compared to the case where a copper or copper alloy cylinder is fixed to the joint member 100 by brazing or the like. Note that FIG. 2 shows the state of the joint member 100 before heating with the coating member 200A arranged, and FIG. 3 shows the state of the joint member 100 after heating with the coating member 200A arranged, that is, the state in which the coating 200 is formed.

[0035] Here, as shown in FIG. 4, such a coating 200 is composed of a coating member 200A in the form of a sheet-like body in a strip state with a thickness of 0.04 mm to 0.2 mm. At the portion of the coating member 200A disposed at the opening-side end of the joint member 100, a plurality of adjacent cuts 200A1 are provided in the longitudinal direction. Thereby, when the coating member 200A is bent into a C shape, it is bent radially outward as a flange portion 200A2, so that when disposed at the opening end of the joint member 100, the coating member 200A can be easily positioned with respect to the opening end.

[0036] The coating member 200A having such a configuration is disposed in a C-shaped bent state on the inner peripheral surface 100a at one end in the longitudinal direction of the joint member 100, as shown in FIG. 2. At this time, the opposing end portions 200A3 and 200A4 of the coating member 200A may be disposed in contact with each other or may be disposed with a gap therebetween.

[0037] And the joint member 100 having the coating 200 is manufactured by the following procedure. That is, with the coating member 200A disposed at the end of the joint member 100 as described above, in an environment where the oxide film can be removed, for example, in a hydrogen reduction furnace, the coating member 200A is heated to near the melting point exceeding the solidus temperature to be in a semi-molten state. As a result, as shown in FIG. 3, although a portion slightly thinner than the thickness of the coating member 200A in the state before heating is generated with respect to the inner peripheral surface 100a of the joint member 100, the coating 200 of substantially the same thickness is formed with a thickness of 0.04 mm to 0.2 mm, preferably about 0.08 mm to 0.1 mm. In this way, the coating 200 is firmly fixed to the inner peripheral surface 100a of the end of the joint member 100 by metallic bonding. At this time, the respective end faces of the coating member 200A are rounded by the heat treatment to have a rounded R shape.

[0038] In the stainless steel joint member 100 having the phosphor bronze coating 200 formed in this manner, as shown in FIG. 5, even when the refrigerant pipe 60 in a refrigeration cycle (not shown) connected to the inner peripheral surface 100a side of the joint member 100 is made of copper or a copper alloy, it can be easily connected using brazing. At this time, not only the surface (in this case, the inner peripheral surface 100a) in contact with the outer peripheral surface 60a of the refrigerant pipe 60 of the joint member 100, but also the end surface 100c of the joint member 100 is extended and the phosphor bronze coating 200 is provided. Therefore, when the material of the refrigerant pipe 60 is the same copper or copper alloy as the coating 200, the fillet 70 is likely to be formed well. Thereby, it is joined without gaps, and the airtightness of the brazed portion can be surely ensured. Therefore, the reliability of the connection between the joint member 100 and the refrigerant pipe 60 can be further ensured. Also, similarly on the end surface 60c side of the refrigerant pipe 60, since the phosphor bronze coating 200 is provided on the inner peripheral surface 100a of the joint member 100 over a range wider than the length by which the refrigerant pipe 60 is inserted into the joint member 100, the coating 200 is also formed on the tip side of the end surface 60c of the refrigerant pipe 60. Thereby, when the material of the refrigerant pipe 60 is the same copper or copper alloy as the coating 200, a fillet is likely to be formed well between the end surface 60c and the inner peripheral surface 100a of the joint member 100. Thereby, it is joined without gaps, the airtightness of the brazed portion can be surely ensured, and the reliability of the connection between the joint member 100 and the refrigerant pipe 60 can be further improved.

[0039] So far, the case where the coating 200 is provided on the inner peripheral surface 100a of the joint member 100 has been described. However, as shown in FIGS. 6(a) and 6(b) with the same reference numerals as the corresponding parts in FIGS. 2(a) and 3(a), the coating 200 may be provided on the outer peripheral surface 100b of the joint member 100. In this case, the coating member 200A constituting the coating 200 is configured substantially in the same manner as shown in FIG. 7 with the same reference numerals as the corresponding parts in FIG. 4, except that the shape of the notch 200A1 is slightly different. Note that even when the coating 200 is provided on the outer peripheral surface 100b of the joint member 100, the coating 200 is formed over a range wider than the length at which the joint member 100 is inserted into the refrigerant pipe 60. More specifically, it is formed over a range sufficient to fully satisfy the brazing strength with the refrigerant pipe connected to the joint member 100. Specifically, it is formed over a range of at least the thickness of the joint member 100 from the end face of the joint member 100, preferably over a range of at least half the inner diameter of the joint member 100, and more preferably over a range of at least the inner diameter of the joint member 100. The shape of the notch 200A1 is formed such that the flange portions 200A2 do not overlap each other depending on whether the flange portion 200A2 is bent radially outward or radially inward when rounded into a C shape. And in the joint member 100 having the coating 200 formed by metal bonding as described above, as shown in FIG. 8 with the same reference numerals as the corresponding parts in FIG. 5, even when the refrigerant pipe 60 connected to the outer peripheral surface 100b side of the joint member 100 is made of copper or a copper alloy, it can be easily connected using brazing. At this time, not only the surface (in this case, the outer peripheral surface 100b) in contact with the inner peripheral surface 60b of the refrigerant pipe 60 of the joint member 100 but also the end face 100c of the joint member 100 is extended and the phosphor bronze coating 200 is provided. Therefore, when the material of the refrigerant pipe 60 is the same copper or copper alloy as the coating 200, a fillet 70 is likely to be formed well. Thereby, it can be joined without a gap, and the airtightness of the brazed portion can be surely ensured. Therefore, the reliability of the connection between the joint member 100 and the refrigerant pipe 60 can be further improved.Also, similarly on the end face 60c side of the refrigerant pipe 60, since the phosphor bronze coating 200 is provided on the outer peripheral surface 100b of the joint member 100 over a range wider than the length into which the joint member 100 is inserted into the refrigerant pipe 60, the coating 200 is also formed on the tip side of the end face 60c of the refrigerant pipe 60. As a result, when the material of the refrigerant pipe 60 is the same copper or copper alloy as the coating 200, a fillet is likely to be formed well between the end face 60c and the outer peripheral surface 100b of the joint member 100. Thereby, it can be joined without a gap, the airtightness of the brazed portion can be surely ensured, and the reliability of the connection between the joint member 100 and the refrigerant pipe 60 can be further improved.

[0040] In addition, in the present embodiment, the case of connecting the joint member 100, which is a refrigerant pipe, to the copper or copper alloy refrigerant pipe 60 of the refrigeration cycle has been described. However, the connection target of the joint member 100 is not limited to the copper or copper alloy refrigerant pipe, and for example, a metal joint member such as stainless steel or iron having a copper or copper alloy coating 200 on the inner peripheral surface or the outer peripheral surface of the connection side end portion may be used in the same manner as the joint member 100. The material of the refrigerant pipe having the coating 200 is preferably a metal having a melting point higher than that of copper or copper alloy.

[0041] According to the present embodiment as described above, there are the following effects. That is, even when the joint member 100 itself is made of a material containing stainless steel, since the copper or copper alloy coating 200 is formed on the inner peripheral surface 100a or the outer peripheral surface 100b of the connecting end portions by metallic bonding, they can be easily connected using brazing.

[0042] At this time, in the joint member 100, it is preferable that the film member made of copper or a copper alloy forming the film 200 is a sheet-like body and is arranged in a state of being rounded in a C shape. According to such a configuration, when the film member 200A is arranged on the inner peripheral surface at the end of the joint member 100, the film member 200A of the sheet-like body elastically deformed to an inner diameter smaller than the inner diameter of the joint member 100 is held on the inner peripheral surface of the refrigerant pipe by the elastic force for shape retention in the opening direction from the C-shaped rounded state. When the film member 200A is arranged on the outer peripheral surface at the end of the refrigerant pipe, the film member 200A plastically deformed to an inner diameter smaller than the outer diameter of the joint member 100 is held on the outer peripheral surface of the refrigerant pipe by the elastic force for shape retention in the direction of being rounded in a C shape. Therefore, the trouble of holding the film member 200A at the arrangement site by, for example, spot welding is saved, and it can be easily arranged. Further, since the joints of the opposing end portions 200A3 and 200A4 of the film member 200A are arranged with a gap, the outer peripheral side and the inner peripheral side of the film member 200A penetrate at the portion where the gap is provided. Thus, gases and bubbles such as air existing between the film member 200A and the wall surface (inner peripheral surface 100a or outer peripheral surface 100b) of the joint member 100 can be removed. When the film member 200A is arranged on the inner peripheral surface 100a of the joint member 100, the adhesion of the film member 200A to the inner peripheral surface 100a of the joint member 100 is further improved due to the thermal expansion generated during the heat treatment. This point is the same in the case of other modification examples described later.

[0043] Note that the present invention is not limited to the above-described embodiments, includes other configurations and the like that can achieve the object of the present invention, and modifications and the like as shown below are also included in the present invention.

[0044] For example, in the joint member 100 which is the refrigerant pipe of the present invention, as shown in FIG. 9, it is preferable that the film member 200A made of copper or a copper alloy forming the film 200 is an annular cylindrical body. According to such a configuration, by performing plastic working to expand the cylindrical film member 200A in the outer diameter direction or plastic working to contract it in the inner diameter direction according to the arrangement site, the trouble of holding it at the arrangement site by, for example, spot welding is saved, and it can be easily arranged.

[0045] In addition, as shown in FIG. 10 or FIG. 11, it is preferable that the coating member 200A of a sheet-like body or a cylindrical body made of copper or a copper alloy forming the coating 200 is provided with slits in the circumferential direction or the axial direction. According to such a configuration, at the slit portion, the outer peripheral side and the inner peripheral side of the coating member 200A are penetrated, so that gases and bubbles such as air existing between the coating member 200A and the wall surface (in this case, the inner peripheral surface 100a) of the joint member 100 can be removed from the slit. In addition, the slits can remove the distortion generated during heating when metal-bonding.

[0046] Furthermore, in the joint member 100 which is the refrigerant pipe of the present invention, as shown in FIG. 12, the coating member 200A made of copper or a copper alloy forming the coating 200 is a net-like body, and it is preferably formed in a C-shaped state or arranged annularly. According to such a configuration, when the coating member 200A is arranged in a C-shaped state, it is held at the end of the joint member 100 by the elastic force of the coating member 200A. When the coating member 200A is arranged annularly, it is held by the elastic force for shape retention in the direction of contracting in the inner diameter direction by elastic deformation that expands in the outer diameter direction according to the arrangement site of the coating member 200A, or the elastic force for shape retention in the direction of expanding in the outer diameter direction by elastic deformation that contracts in the inner diameter direction. Therefore, the trouble of holding the coating member 200A at the arrangement site by, for example, spot welding is saved, and it can be easily arranged. In addition, since the coating member 200A has net-like holes that penetrate the outer peripheral side and the inner peripheral side as a whole, gases and bubbles such as air existing between the coating member 200A and the wall surface (in this case, the inner peripheral surface 100a) of the joint member 100 can be removed. In addition, the net-like holes can remove the distortion generated during heating when metal-bonding.

[0047] Further, in the joint member 100 which is the refrigerant pipe of the present invention, as shown in FIG. 13, the coating member 200A made of copper or a copper alloy forming the coating 200 is preferably a strip-shaped body with a rectangular cross-section, or as shown in FIG. 14, a strip-shaped body with a circular cross-section, and is preferably arranged in a spiral shape along the axial direction. According to such a configuration, since it is held at the end of the joint member 100 by the elastic force of the strip-shaped coating member 200A, the labor of holding the coating member 200A at the arrangement site by, for example, spot welding can be saved, and it can be easily arranged. Further, since minute gaps are formed in the coating member 200A so as to penetrate the outer peripheral side and the inner peripheral side in a spiral shape, gases and bubbles such as air existing between the coating member 200A and the wall surface of the joint member 100 (in this case, the inner peripheral surface 100a) can be removed from the gaps. In addition, the minute gaps can remove the distortion generated during heating when metal bonding occurs.

[0048] Furthermore, in the joint member 100 which is the refrigerant pipe of the present invention, as shown in FIG. 15, the coating member 200A made of copper or a copper alloy forming the coating is preferably a C-shaped or annular ring-shaped body, and is preferably arranged with a plurality of adjacent ones along the axial direction. According to such a configuration, when the ring-shaped coating member 200A is arranged in a state of being bent into a C shape, it is held at the end of the joint member 100 by the elastic force of the coating member 200A. When the coating member 200A is arranged in an annular shape, it is held by performing plastic processing to expand it in the outer diameter direction or plastic processing to contract it in the inner diameter direction according to the arrangement site. Therefore, the labor of holding the coating member 200A at the arrangement site by, for example, spot welding can be saved, and it can be easily arranged. Further, since minute gaps penetrating the outer peripheral side and the inner peripheral side are formed between the adjacent ring-shaped coating members 200A in a multilayered manner, gases and bubbles such as air existing between the adjacent coating members 200A in a multilayered manner and the wall surface of the joint member 100 (in this case, the inner peripheral surface 100a) can be removed from the gaps. In addition, the multilayered minute gaps can remove the distortion generated during heating when metal bonding occurs.

[0049] In addition, in the joint member 100 which is the refrigerant pipe of the present invention, the coating member 200A made of copper or a copper alloy forming the coating is a wire-like body, and it is preferably in a state of being rounded in a C shape or arranged in a ring shape. Note that as a diagram of the wire-like coating member 200A, it is almost the same as FIG. 15 showing the ring-shaped coating member 200A, so here, for the sake of convenience, the illustration is omitted. According to such a configuration, when the wire-like coating member 200A is arranged in a state of being rounded in a C shape, it is held at the end of the refrigerant pipe by the elastic force of the coating member 200A. When the coating member 200A is arranged in a ring shape, it is held by performing plastic working to expand it in the outer diameter direction or plastic working to contract it in the inner diameter direction according to the arrangement site. Therefore, the trouble of holding the coating member 200A at the arrangement site by, for example, spot welding is saved, and it can be easily arranged.

[0050] In addition, in the joint member 100 which is the refrigerant pipe of the present invention, as shown in FIG. 16, the coating member 200A made of copper or a copper alloy forming the coating is formed in a ring shape, and it is preferable that the surface of the cross section orthogonal to the axial direction (that is, the inner peripheral surface and / or the outer peripheral surface) has an uneven shape along the circumferential direction. That is, the coating member 200A may be provided with uneven portions 90 on the inner peripheral surface and / or the outer peripheral surface. In this case, various shapes such as a semi-circular shape, a mountain shape, or a rectangular shape can be widely applied to the uneven portions. By using such a coating member 200A, it is held by an elastic force for shape retention in the direction of contracting in the inner diameter direction by elastic deformation that expands it in the outer diameter direction according to the arrangement site of the coating member 200A, or an elastic force for shape retention in the direction of expanding in the outer diameter direction by elastic deformation that contracts it in the inner diameter direction. Therefore, the trouble of holding the coating member 200A at the arrangement site by, for example, spot welding is saved, and it can be easily arranged.

[0051] Furthermore, the joint member 100, which is a refrigerant pipe of the present invention, is a refrigerant pipe made of stainless steel. As shown in FIGS. 17(a) and 17(b), a film 200 of copper or a copper alloy may be formed on the outer peripheral surface 100b (or the inner peripheral surface 100a) at at least one end in the longitudinal direction by laser irradiation using a laser 300. According to such a configuration, while removing the oxide film by laser irradiation, the film 200 can be directly formed by spraying the powder-like film member 200A made of copper or a copper alloy onto the outer peripheral surface 100b (or the inner peripheral surface 100a) of the joint member 100, so that the film 200 can be formed more easily.

[0052] The manufacturing method of the refrigerant pipe (joint member 100) described above is a manufacturing method of the joint member 100 made of stainless steel. With respect to the inner peripheral surface 100a or the outer peripheral surface 100b at at least one end in the longitudinal direction of the joint member 100, in an environment where the oxide film can be removed, copper or a copper alloy is heated to near the melting point to be in a semi-molten state, and a film of the copper or the copper alloy is formed. According to such a manufacturing method of the joint member 100, even when the joint member 100 itself is made of a material containing stainless steel, since a film of copper or a copper alloy is formed on the inner peripheral surface or the outer peripheral surface of the end portion to be connected, it can be easily connected using brazing.

[0053] The connection structure of the refrigerant pipe (joint member 100) described above is a connection structure of the joint member 100 in which the joint member 100 (the first refrigerant pipe) and the refrigerant pipe 60 (the second refrigerant pipe) are connected by brazing. The stainless steel joint member 100 has a copper or copper alloy film 200 formed on the inner peripheral surface 100a (or the outer peripheral surface 100b) of the end portion on the refrigerant pipe 60 side by metal bonding. The refrigerant pipe 60 is preferably made of copper or copper alloy (or a copper or copper alloy film 200 is formed on the outer peripheral surface 100b or the inner peripheral surface 100a of the end portion on the joint member 100 side by metal bonding). According to such a connection structure of the joint member 100, even when the joint member 100 (the first refrigerant pipe) is made of stainless steel, since it has a copper or copper alloy film 200 formed by metal bonding on the inner peripheral surface 100a or the outer peripheral surface 100b of the end portion on the refrigerant pipe 60 (the second refrigerant pipe) side, it can be easily connected to a second refrigerant pipe made of copper or copper alloy or having a copper or copper alloy film formed by metal bonding on the outer peripheral surface 60a or the inner peripheral surface 60b of the end portion on the first refrigerant pipe side, using brazing.

[0054] The slide type switching valve 10 as the valve device described above is a valve device in which a joint member 11 is connected to a valve housing 1 as a valve body, and it is preferable that any of the refrigerant pipes (joint member 100) described above is used as the joint member. According to such a slide type switching valve 10, similar to the joint member 100 described above, even when the joint member 100 is made of stainless steel, since a copper or copper alloy film 200 is formed by metal bonding on the inner peripheral surface 100a or the outer peripheral surface 100b of the connection side end portion of the joint member 100, it can be easily connected to the target refrigerant pipe using brazing. In addition, the same effects as those of each of the joint members 100 described above can be obtained.

[0055] In addition, the best configurations, methods, etc. for carrying out the present invention are disclosed in the above description, but the present invention is not limited thereto. That is, the present invention has been particularly illustrated and described mainly with respect to specific embodiments. However, without departing from the scope of the technical idea and purpose of the present invention, those skilled in the art can make various modifications to the above-described embodiments in terms of shape, material, quantity, and other detailed configurations. Therefore, the descriptions that limit the shape, material, etc. disclosed above are exemplary descriptions for facilitating the understanding of the present invention and do not limit the present invention. Thus, the descriptions using the names of members with some or all of the limitations on those shapes, materials, etc. removed are included in the present invention.

Explanation of Reference Numerals

[0056] 1 Valve housing (valve body) 11 Cylindrical portion 12 Cap portion 2 Piston 21 Packing 22 Fixed disk 23 Leaf spring 3 Connecting plate 4 Valve seat 5 Valve element 10 Slide type switching valve 100 Joint member (refrigerant pipe, first refrigerant pipe) 100a Inner peripheral surface 100b Outer peripheral surface 100c End face 200 Coating 200A Coating member 200A1 Notch 200A2 Flange portion 200A3 End portion 200A4 End portion 60 Refrigerant pipe (second refrigerant pipe) 60a Outer peripheral surface 60b Inner peripheral surface 60c End face 70 Fillet 80 Slit 81 Slit 90 Concavo-convex portion 300 Laser

Claims

1. A valve device comprising a valve body having a valve chamber therein and a coupling member joined to the valve body, The joint member is a refrigerant pipe made of stainless steel, A coating of copper or a copper alloy is formed by metal bonding on the inner or outer circumferential surface at least at one end in the longitudinal direction; The coating is formed to extend to an end surface at the one end, The valve device according to claim 1, wherein the coating is formed to a uniform thickness around the entire periphery of the end face.

2. 2. The valve device according to claim 1, wherein the coating member made of copper or a copper alloy that forms the coating is a sheet-like body that is arranged in a rolled C-shape.

3. 2. The valve device according to claim 1, wherein the coating member made of copper or a copper alloy that forms the coating is an annular tubular body.

4. 4. The valve device according to claim 2, wherein a coating member made of copper or a copper alloy that forms the coating is provided with slits in a circumferential direction or an axial direction.

5. 2. The valve device according to claim 1, wherein the coating member made of copper or a copper alloy forming the coating is a mesh-like body and is arranged in a C-shaped roll or in a ring shape.

6. 2. The valve device according to claim 1, wherein the coating member made of copper or a copper alloy that forms the coating is a strip having a circular or rectangular cross section and is arranged spirally along the axial direction.

7. 2. The valve device according to claim 1, wherein the coating member made of copper or a copper alloy that forms the coating is a C-shaped or annular ring-shaped body, and a plurality of coating members are arranged adjacent to each other along the axial direction.

8. 2. The valve device according to claim 1, wherein the coating member made of copper or a copper alloy that forms the coating is a wire-like body and is arranged in a C-shape or in a ring shape.

9. The valve device according to any one of claims 2 to 8, wherein a coating member made of copper or a copper alloy that forms the coating has a surface in a cross section perpendicular to the axial direction that has an uneven shape along a circumferential direction.

10. A method for manufacturing a valve device including a valve body having a valve chamber therein and a coupling member joined to the valve body, comprising the steps of: The joint member is a refrigerant pipe made of stainless steel, The inner circumferential surface or the outer circumferential surface at least at one end in the longitudinal direction of the refrigerant pipe is A method for manufacturing a valve device, comprising the steps of: heating copper or a copper alloy to a temperature between its solidus temperature and liquidus temperature in an environment in which an oxide film can be removed, to bring the copper or copper alloy into a semi-molten state, and forming a film of the copper or copper alloy.

11. The method for manufacturing a valve device according to claim 10, wherein the environment capable of removing the oxide film is a hydrogen reduction furnace.

12. The method for manufacturing a valve device according to claim 10, wherein the copper or copper alloy coating is formed by laser irradiation.

13. A connection structure for a refrigerant pipe in a valve device including a valve body having a valve chamber therein and a joint member joined to the valve body, A refrigerant pipe connection structure in which a first refrigerant pipe and a second refrigerant pipe are connected by brazing, the first refrigerant pipe is made of stainless steel, and a coating of copper or copper alloy is formed by metallic bonding on an inner circumferential surface or an outer circumferential surface of the end portion of the second refrigerant pipe; The second refrigerant pipe is made of copper or a copper alloy, or a coating of copper or a copper alloy is formed by metallic bonding on an outer circumferential surface or an inner circumferential surface of the end portion of the first refrigerant pipe, The coating is a connection structure for refrigerant piping in a valve device, characterized in that the connection structure for refrigerant piping is formed to extend to an end face of the first refrigerant piping side end of the first refrigerant piping, and is formed with a uniform thickness around an entire circumference of the end face of the first refrigerant piping side end of the first refrigerant piping, and if the second refrigerant piping is not made of copper or a copper alloy, the connection structure for refrigerant piping in a valve device, characterized in that the connection structure for refrigerant piping is formed to extend to an end face of the first refrigerant piping side end of the second refrigerant piping, and is formed with a uniform thickness around an entire circumference of the end face of the second refrigerant piping side end of the first refrigerant piping.

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