Slide-type switching valve and refrigeration cycle system

Abstract

To provide a slide type switch valve and a refrigeration cycle system eliminating the need of difficult machining such as burring, and capable of reducing product costs.SOLUTION: A pilot valve 2 is equipped with a valve housing 20 made of stainless steel, a valve body 40 that can slide in the valve housing 20, and a D-capillary 11d through which a refrigerator passes. The D-capillary 11d is equipped with a tube expanding portion 11d1 that is provided on one end side in an axial direction L2, a tube contracting portion 11d2 that is provided closer to one end side than the tube expanding portion 11d1 and has diametrical dimensions smaller than the tube expanding portion 11d1, and a locking portion 11d3 that couples the tube expanding portion 11d1 and the tube contracting portion 11d2. The tube expanding portion 11d1 stores a strainer 11d4. The tube contracting portion 11d2 is inserted in a connection hole h5 of the valve housing 20, and while the locking portion 11d3 abuts on a peripheral edge h51 of the connection hole h5, the D-capillary 11d1 is connected to the valve housing 20.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a slide-type switching valve and a refrigeration cycle system.

Background Art

[0002] Conventionally, as a switching valve that communicates at least one pair of joint pipes among a plurality of joint pipes and enables switching of the joint pipes to be communicated, a slide-type switching valve such as a four-way switching valve is known (see, for example, Patent Document 1). In a conventional slide-type switching valve, a plurality of joint pipes are connected to the peripheral wall of a cylindrical main valve housing, and a slide valve body installed inside is slid in the axial direction to enable communication between the joint pipes in a switchable manner. The slide movement of the slide valve body is performed by circulating a driving fluid from a pilot valve to a pair of spaces that axially sandwich the slide valve body inside the main valve housing. The slide-type switching valve and the pilot valve are connected by a plurality of copper-made thin pipes for circulating the driving fluid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the main valve housing of a conventional slide-type switching valve and the solenoid tube which is the housing of the pilot valve are generally cutting or pressing products using a copper alloy. However, when the material is switched from a copper alloy to stainless steel and made into a pressing product, burring or the like for fixing pipes such as joints becomes necessary, resulting in high processing difficulty and difficulty in suppressing processing costs.

[0005] The objective of the present invention is to provide a slide-type switching valve and refrigeration cycle system that eliminates the need for highly difficult processing such as burring, thereby reducing product costs. [Means for solving the problem]

[0006] To solve the aforementioned problems and achieve the objective, the present invention provides a sliding type switching valve comprising a stainless steel valve housing, a valve body that can slide within the valve housing, and a piping for passing fluid, wherein the piping comprises an expanded section provided at one axial end, a retracted section provided at the axial end further toward the expanded section and having a smaller radial dimension than the expanded section, and a locking section connecting the expanded section and the retracted section, wherein a strainer is housed in the expanded section, the retracted section is inserted into a connection hole in the valve housing, and the piping is connected to the valve housing with the locking section in contact with the periphery of the connection hole, the periphery of the connection hole is provided on the outer circumferential surface of the valve housing, and the locking section is in contact with the periphery provided on the outer circumferential surface of the valve housing.

[0007] According to this invention, the retracted portion of the piping can be inserted into the connection hole of the valve housing, and the piping can be connected to the valve housing with the locking portion in contact with the periphery of the connection hole. In other words, for processing to connect the piping, it is only necessary to form a connection hole in the stainless steel valve housing, and there is no need to perform processing that is difficult to process and difficult to reduce processing costs, such as burring. Therefore, it is possible to provide a slide-type switching valve that does not require difficult processing such as burring and can reduce product costs. In addition, since the piping can be positioned in the valve housing by the contact between the periphery of the connection hole and the locking portion, if brazing is to be performed in this state, for example, the brazing process can be easily carried out.

[0008] In this case, the valve housing is preferably cylindrical. With this configuration, the piping can be connected to the valve housing while the locking portion of the piping abuts against the peripheral edge of the connection hole on the outer surface side of the valve housing. Therefore, compared to configurations that require a mechanism to fix the piping inside the valve housing, the connection of the piping can be made simpler.

[0009] Furthermore, it is preferable that the connection hole has a guide surface formed along the wall thickness of the valve housing, and that the retracted portion is provided passing through the connection hole along the guide surface. With such a configuration, the retracted portion of the piping can be passed through the connection hole along the guide surface, so that the piping can be connected to the valve housing more smoothly compared to a configuration in which no guide surface is formed.

[0010] Furthermore, it is preferable that the piping is made of stainless steel. With such a configuration, since the piping is made of stainless steel, which is the same material as the valve housing, if, for example, the piping connected to the valve housing is to be fixed to the valve housing by welding or the like, the piping can be fixed to the valve housing more easily compared to a configuration in which a different material from the valve housing is used for the piping.

[0011] Furthermore, it is preferable that at least one weld is formed across the piping and the valve housing, and that the piping and the valve housing are joined by brazing that covers the weld and extends around the entire circumference of the piping. With this configuration, since at least one weld is formed across the piping and the valve housing, the piping can be joined to the valve housing by brazing around the entire circumference of the piping while the piping is temporarily fixed to the valve housing. Therefore, positioning is not required when brazing the piping, and the brazing work time can be reduced.

[0012] Alternatively, a ring protruding from one end in the axial direction may be inserted into the inner diameter of the expanded section, with the protruding portion of this ring forming the constricted section, and the end face of the expanded section on one end in the axial direction forming the locking portion. With such a configuration, the constricted section can be formed by inserting a ring into the inner diameter of the expanded section, and the end face of one end of the expanded section can be used as a locking portion. This eliminates the need to form a constricted section at the axial end of the pipe by, for example, drawing, and reduces the man-hours required to form the pipe.

[0013] Furthermore, a frame-shaped retaining member may be inserted inside the strainer, and the strainer may be fixed to the expanded section by being sandwiched between the retaining member and the inner circumferential wall of the expanded section. With this configuration, even if the strainer deforms, the retaining member acts as a retainer, preventing the strainer from passing through the constricted section and falling out. When forming the constricted section by narrowing the expanded section, it is desirable to adjust the amount of narrowing to the extent that the strainer does not fall out of the expanded section, and that the contact area between the locking part and the periphery of the connection hole is secured. However, when using a retaining member as in this configuration, the locking part does not necessarily need to have the function of preventing the strainer from falling out, thus making the narrowing process easier.

[0014] The refrigeration cycle system according to the present invention is characterized by comprising a slide-type switching valve as described above. With such a configuration, the slide-type switching valve described above can be applied to the refrigeration cycle system, eliminating the need for difficult processing such as burring when connecting piping, and thus providing a refrigeration cycle system that can reduce product costs. Furthermore, the present invention relates to a connection structure for connecting a joint pipe connected to a sliding type switching valve for switching the flow path of a fluid, and a thin tube communicating with the joint pipe, wherein the thin tube comprises an expanded section provided at one end in the axial direction, a constricted section provided at the axial end further toward the expanded section and having a smaller radial dimension than the expanded section, and a locking section connecting the expanded section and the constricted section, wherein a strainer is housed in the expanded section, the constricted section is inserted into the connection hole of the joint pipe, and the thin tube is in contact with the periphery of the connection hole when the locking section is in contact with the periphery of the connection hole. The fitting is connected to a joint pipe, and the connecting hole is provided with a guide surface, the guide surface is a flat surface that extends along the wall thickness of the joint pipe so as to be perpendicular to the front and back surfaces of the joint pipe, and the length of the fitting pipe in the direction perpendicular to the front and back surfaces is equal to the length of the wall thickness of the joint pipe, and when the retracted portion is inserted into the connecting hole, the guide surface abuts against the outer circumferential surface of the retracted portion to guide the retracted portion in the insertion direction, and the periphery of the connecting hole is provided on the outer circumferential surface of the joint pipe, and the locking portion abuts against the periphery. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a slide-type switching valve and refrigeration cycle system that eliminates the need for difficult processing such as burring, thereby reducing product costs. [Brief explanation of the drawing]

[0016] [Figure 1] A schematic diagram of a refrigeration cycle system according to one embodiment of the present invention. [Figure 2] A cross-sectional view of the pilot valve that constitutes the aforementioned refrigeration cycle system. [Figure 3] A partially enlarged cross-sectional view of the aforementioned pilot valve. [Figure 4] An exploded cross-sectional view of the section where the piping is connected to the aforementioned pilot valve. [Figure 5] A partially enlarged cross-sectional view of the portion where the piping is connected to the aforementioned pilot valve. [Figure 6] (A) and (B) are diagrams showing modified examples of the end of a pipe, respectively.

Best Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 5. FIG. 1 shows a refrigeration cycle system 100 according to an embodiment of the present invention. The refrigeration cycle system 100 includes a four-way valve 1, a pilot valve 2, an indoor heat exchanger 3, a throttling device 4, an outdoor heat exchanger 5, and a compressor 6.

[0018] The four-way valve 1 is a valve device that switches the refrigerant flow path by switching the communication state of four pipes, and together with the pilot valve 2, constitutes a slide-type switching valve in the present invention. This four-way valve 1 has a structure including a slide valve body 16 (valve body) that can slide within a valve housing 10. The valve housing 10 is a tubular member with both ends closed, and includes a cylindrical valve body 10A and cover members 10B that close the openings at both ends of the valve body 10A, respectively. The valve body 10A and the cover members 10B are formed by pressing a metal plate made of stainless steel or the like, and each cover member 10B is fixed to the valve body 10A by welding. In this embodiment, the central axis of the valve body 10A is the axis L of the valve housing 10.

[0019] On the peripheral wall of the valve body 10A, that is, the peripheral wall of the valve housing 10, there are connection holes h1, h2, h3, h4 for connecting four pipes, namely, a D joint pipe 11 (pipe), an E joint pipe 12 (pipe), an S joint pipe 13 (pipe), and a C joint pipe 14 (pipe), which are formed of stainless steel or the like, and penetrate through so as to communicate between the inside and outside of the valve housing 10. On the intermediate portion in the axial direction L of the inner peripheral surface of the valve body 10A, a valve seat portion 15 with which the slide valve body 16 makes sliding contact is provided and extends in the axial direction L. The connection holes h2, h3, h4 corresponding to the above-mentioned E joint pipe 12, S joint pipe 13, and C joint pipe 14 are respectively formed in a straight line in the axial direction L so as to penetrate through this valve seat portion 15. The connection hole h1 corresponding to the above-mentioned D joint pipe 11 is formed at a position facing the valve seat portion 15. And an E joint pipe 12 as a conduit is connected to the connection hole h2. A C joint pipe 14 as a conduit is connected to h4. An S joint pipe 13 as a low-pressure pipe is connected to the connection hole h3. A D joint pipe 11 as a high-pressure pipe is connected to the connection hole h1 facing the valve seat portion 15.

[0020] The slide valve body 16 is provided inside the valve body 10A so as to be slidable in the axial direction L, and is a member for switching the communication state of the above four pipes 11, 12, 13, 14. This slide valve body 16 includes a valve body 16A, a pair of pistons 16B, a connecting plate 16C, and a stopper plate 16D. The valve body 16A has a bowl-shaped recess 16A1 that opens toward the valve seat portion 15, and the opening edge of the bowl-shaped recess 16A1 is formed so as to make sliding contact with the valve seat portion 15. In the left end position shown in FIG. 1, the valve body 16A communicates the E joint pipe 12 and the S joint pipe 13, and also communicates the D joint pipe 11 and the C joint pipe 14. And when it moves from this state to the right side in FIG. 1 and moves to a right end position not shown, it communicates the C joint pipe 14 and the S joint pipe 13, and also communicates the D joint pipe 11 and the E joint pipe 12.

[0021] A pair of pistons 16B are arranged so as to sandwich the valve body 16A in the direction of the axis L. Due to this arrangement of pistons 16B, the inside of the valve housing 10 is divided into a high-pressure chamber s1 sandwiched between the pistons, a first working chamber s2 adjacent to the left side of the high-pressure chamber s1 in Figure 1, and a second working chamber s3 adjacent to the right side of the high-pressure chamber s1 in Figure 1. Driving fluid (fluid) flows from the pilot valve 2 shown in Figure 2 to the first working chamber s2 and the second working chamber s3, and the pistons 16B receive driving force through this driving fluid, causing them to reciprocate in the direction of the axis L while pressing the packing 16B1 against the inner circumferential surface of the valve body 10A. The connecting plate 16C is made of metal and is placed between the pistons 16B to connect them, and is positioned on the axis L. The connecting plate 16C holds the valve body 16A in its center. Furthermore, the connecting plate 16C has through-holes 16C1 through which the high-pressure refrigerant in the high-pressure chamber s1 can pass. The stopper plate 16D is a plate member installed on the side of each piston 16B facing the cover member 10B, and is provided to restrict the movement of the piston 16B in the axial direction L by contacting the cover member 10B.

[0022] In the refrigeration cycle system 100 shown in Figure 1, the D-joint pipe 11 is connected to the discharge port of the compressor 6, and the S-joint pipe 13 is connected to the suction port of the compressor 6. In addition, the C-joint pipe 14 is a conduit connected to the outdoor heat exchanger 5, and the E-joint pipe 12 is a conduit connected to the indoor heat exchanger 3. The outdoor heat exchanger 5 and the indoor heat exchanger 3 are connected via a throttling device 4. Thus, the refrigeration cycle system 100 is composed of a path consisting of the C-joint pipe 14, the outdoor heat exchanger 5, the throttling device 4, the indoor heat exchanger 3, and the E-joint pipe 12, and a path consisting of the S-joint pipe 13 to the compressor 6 and the D-joint pipe 11.

[0023] The pilot valve 2 shown in Figure 2, together with the four-way valve 1, constitutes the slide-type switching valve of the present invention. This pilot valve 2 is a direct-acting electromagnetic slide valve that circulates a driving fluid for moving the slide valve body 16 between itself and the four-way valve 1. This pilot valve 2 comprises a valve housing 20 formed by press-forming a metal plate made of stainless steel or the like, an electromagnetic drive unit 30, and a valve body 40 that slides within the valve housing 2 on the valve seat portion 20B1 of the valve seat member 20B described later by the electromagnetic drive unit 30.

[0024] The valve housing 20 comprises a valve body 20A formed in the shape of a bottomed cylindrical valve, and a valve seat member 20B that fits into the valve body 20A via a mounting hole 21, which will be described later. Inside the valve body 20A, a partition plate 22 is installed with a through hole 22A that penetrates in the axial direction L in the center. This partition plate 22 divides the inside of the valve body 20A into a plunger arrangement chamber 20A1 on the electromagnetic drive unit 30 side and a valve chamber 20A2 on the opposite side of the electromagnetic drive unit 30. The peripheral wall of the valve body 20A has a connection hole h5 that communicates with the valve chamber 20A2 and a mounting hole 21 opposite the connection hole h5.

[0025] The connection hole h5 is a hole through which the D-tube 11d (pipe), which serves as high-pressure piping, is connected, and as shown in Figure 4, it comprises a guide surface h50 and a peripheral edge h51. The guide surface h50 is a flat surface that extends along the wall thickness of the valve body 20A so as to be perpendicular to the front and back surfaces of the valve body 20A (valve housing 20). Since this guide surface h50 extends along the insertion direction of the D-tube 11d (in this embodiment, the radial direction of the valve body 20A), its entire surface is in contact with the outer circumferential surface of the retracted portion 11d2 of the D-tube 11d, which will be described later. The peripheral edge h51 is provided on the outer circumferential surface of the valve body 20A (valve housing 20) and is the portion that comes into contact with the locking portion 11d3 of the D-tube 11d, which will be described later. When inserting the D tube 11d into the connection hole h5, the guide surface h50 contacts the outer surface of the D tube 11d to guide the D tube 11d in the insertion direction, and the peripheral edge h51 contacts the locking portion 11d3, thereby positioning the D tube 11d on the valve body 20A. Therefore, there is no need to perform burring or other processing to fix the piping to the valve body 20A.

[0026] The D-tube 11d is a pipe through which the drive fluid passes, and is made of stainless steel or the like, and is in communication with the D-joint pipe 11 described above. A valve seat member 20B is fitted into the mounting hole 21. The valve seat member 20B is formed in a cylindrical shape, and a valve seat portion 20B1 is formed on the inside of the valve chamber 20A2. The valve seat portion 20B1 has recesses E recess 12e1, S recess 13s1, and C recess 14c1 which open into the valve chamber 20A2 in a direction perpendicular to the axis L direction.

[0027] The E recess 12e1, the S recess 13s1, and the C recess 14c1 are formed on the same plane and aligned in a straight line along the axis L in the cross-sectional view shown in Figure 2. A connecting hole h6 is formed in the E recess 12e1 so as to communicate with it. A connecting hole (not shown) is formed in the S recess 13s1 so as to communicate with it. This connecting hole is the same as the connecting hole h6. A connecting hole h7 is formed in the C recess 14c1 so as to communicate with it. Each of these connecting holes h6, h7, and the connecting hole (not shown) opens to the outside of the valve chamber 20A2.

[0028] The connection holes h6, h7, and the unshown connection hole in the valve seat member 20B are formed in a straight line along the axis L in the cross-sectional view shown in Figure 2. In the cross-sectional view shown in Figure 2, the leftmost connection hole h6 and the rightmost connection hole h7 are aligned on the same plane, while the middle connection hole (unshown) is located towards the back in Figure 2, resulting in a so-called staggered arrangement. The first working tube 12e2, which communicates with the first working chamber s2 described above, is connected to the leftmost connection hole h6 in Figure 2. The S-tube 13s2, which communicates with the S-joint pipe 13 described above, is connected to the middle connection hole. The second working tube 14c2, which communicates with the second working chamber s3 described above, is connected to the rightmost connection hole h7.

[0029] The electromagnetic drive unit 30 includes a plunger 31 positioned in the plunger arrangement chamber 20A1, a connecting shaft 32 provided at the center of the plunger 31 and extending into the valve chamber 20A2 through the aforementioned through hole 22A, an suction element 33 positioned opposite the plunger 31 and the connecting shaft 32, and a plunger spring 34 positioned between the plunger 31 and the suction element 33. It also includes an electromagnetic coil 36 with a winding wound around a bobbin 35 positioned on the outer circumference of the valve body 20A, and a case 37 enclosing the bobbin 35 and the electromagnetic coil 36.

[0030] With this configuration, when the electromagnetic drive unit 30 is not energized, the force of the plunger spring 34 biases the plunger 31 and the connecting shaft 32 to the left in Figure 2, causing the valve body 40, which will be described later, to move to the leftmost position in Figure 2. On the other hand, when energized, the magnetizer 33 is energized, generating an attractive force between the plunger 31 and the magnetizer 33, causing the plunger 31, the connecting shaft 32, and the valve body 40 to move to the right.

[0031] The valve body 40 is connected to the left end of the connecting shaft 32 in Figure 2, and has a bowl-shaped recess 40A that opens toward the valve seat member 20B1, with its opening edge sliding against the valve seat member 20B1. At the left end position shown in Figure 2, this bowl-shaped recess 40A connects the first working tube 12e2 and the S tube 13s2, and also connects the D tube 11d and the second working tube 14c2. In this state, high-pressure refrigerant that flows into the valve chamber 20A1 through the D tube 11d flows into the second working chamber s3 through the second working tube 14c2. On the other hand, low-pressure refrigerant that flows into the bowl-shaped recess 40A through the S tube 13s2 flows into the first working chamber s2 through the first working tube 12e2. This creates a pressure difference between the first working chamber s2 and the second working chamber s3, causing the slide valve body 16 of the four-way valve 1 to move to the leftmost position shown in Figure 1.

[0032] Then, from this state, when the valve body 40 moves to the rightmost position (not shown) in Figure 2, the valve body 40 connects the second working tube 14c2 with the S tube 13s2, and also connects the D tube 11d with the first working tube 12e2. In this state, the high-pressure refrigerant that has flowed into the valve chamber 20A1 through the D tube 11d flows into the first working chamber s2 through the first working tube 12e2. On the other hand, the low-pressure refrigerant that has flowed into the bowl-shaped recess 40A through the S tube 13s2 flows into the second working chamber s3 through the second working tube 14c2. As a result, a pressure difference is generated between the first working chamber s2 and the second working chamber s3, and the slide valve body 16 of the four-way valve 1 moves to the rightmost position (not shown).

[0033] With the above configuration, the high-pressure refrigerant compressed by the compressor 6 flows into the high-pressure chamber s1 from the D joint pipe 11. In cooling operation (cooling mode), the high-pressure refrigerant flows into the outdoor heat exchanger 5 from the C joint pipe 14. In heating operation (heating mode) when the position of the slide valve body 16 is switched, the high-pressure refrigerant flows into the indoor heat exchanger 3 from the E joint pipe 12. In other words, during cooling operation, the refrigerant discharged from the compressor 6 circulates through the C joint pipe 14 → outdoor heat exchanger 5 → throttling device 4 → indoor heat exchanger 3 → E joint pipe 12, with the outdoor heat exchanger 5 functioning as a condenser and the indoor heat exchanger 3 as an evaporator, thus providing cooling. The throttling device 4 expands and reduces the pressure of the refrigerant between the outdoor heat exchanger 5 and the indoor heat exchanger 3. Furthermore, during heating operation, the refrigerant is circulated in reverse, with the indoor heat exchanger 3 functioning as a condenser and the outdoor heat exchanger 5 as an evaporator, thus providing heating.

[0034] Next, the detailed structure of the piping according to the present invention will be explained using the D-tube 11d shown in Figure 3 as an example. Note that the D-tube 11d is merely an example, and this piping structure can be applied to any or all of the above-mentioned D-joint pipes 11, E-joint pipes 12, S-joint pipes 13, and C-joint pipes 14, which are piping connected to the four-way valve 1 and through which refrigerant (fluid) passes. As shown in Figure 3, the D-tube 11d comprises an expanded section 11d1 provided at the tip side (one end side) in the axial direction L2, a contracted section 11d2 provided further to the tip than the expanded section 11d1 and having a smaller radial dimension than the expanded section 11d1, a locking section 11d3 connecting the expanded section 11d1 and the contracted section 11d2, and a strainer 11d4 housed within the expanded section 11d1.

[0035] The expanded section 11d1 is the part that houses the strainer 11d4, and is formed by deforming the tip of the D tube 11d so that its radial dimension is larger than the radial dimension of the other part of the D tube 11d. In this embodiment, the contracted section 11d2 is formed by narrowing or other processes on the tip of the expanded section 11d1 so that its radial dimension is smaller than the radial dimension of the expanded section 11d1. The outer circumferential surface of the contracted section 11d2 is capable of contacting the guide surface h50 of the connection hole h5, and when connecting the D tube 11d to the valve housing 20, the outer circumferential surface contacts the guide surface h50 so that the D tube 11d is guided in the insertion direction.

[0036] The locking portion 11d3 is formed by a stepped portion between the expanded portion 11d1 and the retracted portion 11d2. This locking portion 11d3 functions as a stopper to prevent the strainer 11d4 from coming off, and also functions as a stopper to define the insertion amount of the D tube 11d into the valve housing 20. Furthermore, the locking portion 11d3 is configured to contact the periphery h51 of the aforementioned connection hole h5 when fixing the D tube 11d to the valve housing 20, facilitating positioning during brazing, which will be described later. When forming the retracted portion 11d2, it is preferable to adjust the amount of restriction so that the strainer 11d4 does not fall out of the expanded portion 11d1, and so that contact between the locking portion 11d3 and the periphery h51 is secured, so that the function of the locking portion 11d3 can be effectively performed.

[0037] When connecting the D tube 11d to the valve housing 20, as shown in Figures 3 and 4, the retracted portion 11d2 is first inserted into the connection hole h5, and the locking portion 11d3 is brought into contact with the periphery h51 of the connection hole h5 to position the D tube 11d. In this state, the retracted portion 11d2 is provided passing through the connection hole h5 along the guide surface h50. Then, in this state, as shown in Figure 5, at least one welding point is made between the D tube 11d and the valve body 20A (valve housing 20) to form a welded joint w. This step is a so-called temporary fixing step. Next, the D tube 11d and the valve housing 20 are joined by brazing, which covers this welded joint w and extends around the entire circumference of the D tube 11d. In the figure, the symbol b indicates the brazing material that has been solidified by brazing. As a result, the D tube 11d is connected to the valve housing 20. In this manner, the retracted tube portion 11d2 is inserted into the connection hole h5 of the valve housing 20, and the locking portion 11d3 is in contact with the periphery h51 of the connection hole h5, so that the D-tube 11d is connected to the valve housing 20.

[0038] As described above, according to this embodiment, the D-tube 11d can be connected to the valve housing 20 by inserting the retracted portion 11d2 of the D-tube 11d (piping) into the connection hole h5 of the valve housing 20 and bringing the locking portion 11d3 into contact with the periphery h51 of the connection hole h5. In other words, for processing to connect the piping, it is only necessary to form the connection hole h5 in the stainless steel valve housing 20, and there is no need to perform processing that is difficult to process and difficult to reduce processing costs, such as burring. Therefore, it is possible to provide a four-way valve 1 and pilot valve 2 (slide-type switching valve) that do not require difficult processing such as burring and can reduce product costs. In addition, since the D-tube 11d can be positioned in the valve housing 20 by bringing the periphery h51 of the connection hole h5 into contact with the locking portion 11d3, the brazing process can be easily performed.

[0039] Furthermore, since the D-tube 11d can be connected to the valve housing 20 while the locking portion 11d3 of the D-tube 11d is in contact with the peripheral edge h51 on the outer surface side of the connection hole h5 of the valve housing 20, the connection of the piping can be simplified compared to a configuration that requires a mechanism to fix the piping inside the valve housing 20.

[0040] Furthermore, since the retracted portion 11d2 of the D-tube 11d can be passed through the connection hole h5 along the guide surface h50, the piping can be connected to the valve housing 20 more smoothly compared to a configuration in which the guide surface h50 is not formed.

[0041] Furthermore, since the D-tube 11d is made of stainless steel, the same material as the valve housing 20, if, for example, the D-tube 11d connected to the valve housing 20 is to be fixed to the valve housing 20 by welding or the like, it can be fixed to the D-tube 11d more easily compared to a configuration in which a different material from the valve housing 20 is used for the D-tube 11d.

[0042] Furthermore, since at least one welded joint w is formed across the D tube 11d and the valve housing 20, the D tube 11d can be joined to the valve housing 20 by brazing along its entire circumference while the D tube 11d is temporarily fixed to the valve housing 20. In this way, positioning is not required when brazing the piping, thus reducing the brazing work time.

[0043] Furthermore, as described above, since the refrigeration cycle system 100 is equipped with the four-way valve 1 and pilot valve 2 according to the present invention, difficult processing such as burring is not required when connecting the piping, and a refrigeration cycle system that can reduce product costs can be provided.

[0044] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and any design changes, etc., that do not depart from the gist of the present invention are also included. Figures 6(A) and 6(B) show modified examples of the tip of the D tube 11d, respectively. The D tube 11d shown in Figure 6(A) differs from this embodiment in that a washer, i.e., a ring-shaped member R1 (retaining member), is installed inside the strainer 11d4 within the expanded tube section 11d1. By doing so, the strainer 11d4 is sandwiched between the ring-shaped member R1 and the inner circumferential wall of the expanded tube section 11d1 and fixed to the expanded tube section 11d1. Therefore, even if the strainer 11d4 deforms, the ring-shaped member R1 acts as a retainer, preventing the strainer 11d4 from passing through the retracted tube section 11d2 and falling out. Furthermore, when the expanded portion 11d1 is narrowed to form the constricted portion 11d2, it is not necessary to provide the function of preventing the strainer 11d4 from coming off as described above. Therefore, it is sufficient to narrow the portion only by the amount necessary for the locking portion 11d3 to function as a stopper as described above, thereby simplifying the narrowing process. In this modified example, the ring-shaped member R1 is formed in an annular shape, but the shape of the ring-shaped member R1 is not limited to this. For example, if the expanded portion 11d1 is formed in a rectangular tube shape, the ring-shaped member R1 may be formed in a rectangular tube shape to conform to its inner circumference. In other words, the ring-shaped member R1 only needs to function as a preventative for the strainer 11d4 and be formed in a frame shape so as not to block the inside of the expanded portion 11d1.

[0045] The D-tube 11d shown in Figure 6(B) differs from this embodiment in that a ring R2, which abuts against the inner circumferential surface of the expanded section 11d1, is inserted into the inner diameter of the expanded section 11d1. This ring R2 is fixed to the expanded section 11d1 by press-fitting or spot welding. The tip of the ring R2 protrudes axially L2 from the tip of the expanded section 11d1, and this protruding portion constitutes the retracted section 11d2. The end face on the tip side of the expanded section 11d1 constitutes the locking portion 11d3. With this configuration, the retracted section 11d2 can be formed by inserting the ring R2 into the inner diameter of the expanded section 11d1, and the end face on the tip side of the expanded section 11d1 can be used as the locking portion 11d3. Therefore, it is not necessary to form the retracted section 11d2 by drawing or the like, and the man-hours required to form the piping can be reduced. In this modified example, ring R2 is formed in an annular shape, but the shape of ring R2 is not limited to this. For example, if the expanded tube portion 11d1 is formed in a rectangular tube shape, ring R2 may be formed in a rectangular tube shape to conform to its inner circumference.

[0046] In this embodiment and its modifications, as examples of a slide-type switching valve, a four-way valve 1 that switches the communication state of four pipes, and a pilot valve 2 that circulates the drive fluid for moving the slide valve body 16 of the four-way valve 1 between the four-way valve 1 and the four-way valve 1 are given as examples, and the details of the D-tube 11d, which is the piping for the pilot valve 2, have been mainly described. However, as stated above, the D-tube 11d is merely an example, and as stated above, this piping structure can be applied to any or all of the D-joint pipe 11, E-joint pipe 12, S-joint pipe 13, and C-joint pipe 14, so it is of course possible to apply the piping structure of the present invention to the four-way valve 1 described above. Furthermore, the slide-type switching valve is not limited to these four-way valve 1 and pilot valve 2. The slide-type switching valve may be any three-way valve that switches the pipe to be communicated when communicating a pair of pipes out of three pipes, for example, using a slide valve body, as long as at least one pair of pipes is connected to the valve housing. Alternatively, it may be a two-way valve that opens and closes the connection between two pipes using a slide valve body. Alternatively, the number of pipes to be connected can be further increased to create a multi-way valve. In this way, the number of pipes in a slide-type diverter valve, the method of switching the connected state, etc., may be changed according to the application of the slide-type diverter valve, etc.

[0047] Furthermore, although this embodiment has described in particular the connection between the valve body 20A (valve housing 20) and the D tube 11d, for example, the expansion portion 11d1, contraction portion 11d2, locking portion 11d3, and connection hole h5, guide surface h50, and peripheral edge h51 of this embodiment may be provided at the connection portion between the D tube 11d and the D joint pipe 11. In other words, the present invention can also be applied to the connection of pipes to pipes. [Explanation of Symbols]

[0048] h5 connection hole h51 Periphery L2 axial direction 1. Four-way valve (slide-type switching valve) 2. Pilot valve (slide-type switching valve) 20 valve housing 11d D-tube (piping) 11d1 Expansion section 11d2 Constriction section 11d3 Locking part 11d4 Strainer

Claims

1. A sliding type switching valve comprising a stainless steel valve housing, a valve body that can slide within the valve housing, and piping for passing fluid, The piping comprises an expanded section provided at one axial end, a contracted section provided at the axial end further axially than the expanded section and having a smaller radial dimension than the expanded section, and a locking section connecting the expanded section and the contracted section, wherein a strainer is housed in the expanded section. The piping is connected to the valve housing with the retracted portion inserted into the connection hole of the valve housing and the locking portion in contact with the periphery of the connection hole. A sliding type switching valve characterized in that the periphery of the connection hole is provided on the outer circumferential surface of the valve housing, and the locking portion abuts against the periphery provided on the outer circumferential surface of the valve housing.

2. The slide-type switching valve according to claim 1, characterized in that the valve housing is cylindrical.

3. The sliding switching valve according to claim 1 or 2, characterized in that the connection hole has a guide surface formed along the wall thickness of the valve housing, and the retracted pipe portion is provided passing through the connection hole along the guide surface.

4. The sliding type switching valve according to any one of claims 1 to 3, characterized in that the aforementioned piping is made of stainless steel.

5. A sliding type switching valve according to any one of claims 1 to 4, characterized in that at least one weld is formed between the piping and the valve housing, and the piping and the valve housing are joined by brazing that covers the weld and extends around the entire circumference of the piping.

6. A sliding switching valve according to any one of claims 1 to 5, characterized in that a ring protruding from one end in the axial direction is inserted into the inner diameter of the expanded pipe portion, the protruding portion of the ring constitutes the retracted pipe portion, and the end face of the expanded pipe portion on the one end in the axial direction constitutes the locking portion.

7. A frame-shaped retaining member is inserted inside the strainer. The slide-type switching valve according to any one of claims 1 to 6, characterized in that the strainer is fixed to the expanded pipe portion by being sandwiched between the retaining member and the inner circumferential wall of the expanded pipe portion.

8. A refrigeration cycle system characterized by comprising a slide-type switching valve as described in any one of claims 1 to 7.

9. A connecting structure for connecting a joint pipe connected to a sliding type switching valve for switching the flow path of a fluid, and a thin tube communicating with the joint pipe, The aforementioned narrow tube comprises an expanded section provided at one axial end, a retracted section provided at the axial end further toward the expanded section and having a smaller radial dimension than the expanded section, and a locking section connecting the expanded section and the retracted section, wherein a strainer is housed in the expanded section. The tube is connected to the joint pipe with the retracted portion inserted into the connection hole of the joint pipe and the locking portion in contact with the periphery of the connection hole. The aforementioned connection hole is equipped with a guide surface, The guide surface is a flat surface that extends along the wall thickness of the joint pipe so as to be perpendicular to the front and back surfaces of the joint pipe, and the length of the joint pipe in the direction perpendicular to the front and back surfaces is equal to the length of the wall thickness of the joint pipe. When inserting the retractable portion into the connection hole, the guide surface contacts the outer circumferential surface of the retractable portion to guide it in the insertion direction. The connection structure is characterized in that the periphery of the connection hole is provided on the outer surface of the joint pipe, and the locking portion abuts against the periphery.

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