Sliding switching valve and refrigeration cycle system including the same

Abstract

To provide a slide type selector valve capable of suppressing valve leakage, and a refrigerating cycle system including the slide type selector valve.SOLUTION: In the valve-seat member 3, the recess 36 is formed on the connecting surface 33 connecting the valve-seat surface 31 and the joining curved surface 32 joined to the 21A of the inner peripheral surface of the main body 2, so that the brazing material can be accumulated in the recess 36. Since the joining surface 33 is separated from the 21A of the inner peripheral surface of the main body 2 over the boundary portion 35 with the joining curved surface 32 and the boundary portion 34 with the seat surface 31, the capillary phenomenon in which the brazing material passes through the gap between the seat member 3 and the main body 2 is suppressed on the side of the seat surface 31 with respect to the recess 36, and the brazing material is less likely to flow toward the seat surface 31. Therefore, the brazing material can be easily accumulated in the recessed portion 36 to prevent the brazing material from reaching the valve seat surface 31, and the brazing material is less likely to interfere with the slide valve 4 to prevent valve leakage.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a slide-type switching valve and a refrigeration cycle system equipped with the slide-type switching valve. [Background technology]

[0002] Generally, a slide-type switching valve is known in which a valve body that defines a valve chamber and a valve seat member that is housed in the valve chamber and has a valve seat surface are formed separately and joined by brazing. One such slide-type switching valve has been proposed in which gaps are formed between the valve body, the valve seat member, and the coupling member (see, for example, Patent Document 1). In the slide-type switching valve described in Patent Document 1, if molten brazing material overflows, it can flow into the gaps in each part. In particular, the portion of the valve seat member that faces the inner circumferential surface of the valve body is concave, allowing the brazing material to accumulate in this portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] China Utility Model Publication No. 219263258 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the slide-type switching valve described in Patent Document 1, depending on the brazing conditions, the brazing material may leak out toward the valve seat surface before it is completely accumulated in the recessed portion of the valve seat member. If the brazing material adheres to the valve seat surface and solidifies, it may interfere with the slide valve, making the valve more susceptible to leakage. Because the leakage of the brazing material toward the valve seat surface can occur regardless of the volume of the recessed portion, it was difficult to prevent the leakage by simply changing the dimensions of the recessed portion.

[0005] An object of the present invention is to provide a slide-type switching valve capable of suppressing valve leakage and a refrigeration cycle system equipped with the slide-type switching valve. [Means for solving the problem]

[0006] The slide-type switching valve of the present invention is a slide-type switching valve comprising: a cylindrical valve body forming a valve chamber; a valve seat member having a valve seat surface within the valve chamber; and a slide valve that slides on the valve seat surface, wherein the valve seat member has a joining curved surface that follows the inner circumferential surface of a cylindrical portion of the valve body and is joined to the inner circumferential surface, and a connecting surface between the valve seat surface and the joining curved surface, and is attached to the valve body so that the valve seat surface extends along the axial direction of the cylindrical portion, and the connecting surface is spaced from the inner circumferential surface across a boundary with the joining curved surface and a boundary with the valve seat surface, and has a portion that extends along a predetermined plane or curved surface that is continuous with the joining curved surface and faces the valve seat surface, and has a recess formed therein.

[0007] According to the present invention, a recess is formed on the connection surface of the valve seat member, allowing the brazing material to accumulate in the recess. In this case, the connection surface is spaced from the inner peripheral surface of the valve body across the boundary between the connection surface and the curved joining surface and the boundary between the connection surface and the valve seat surface. This suppresses capillary action, which would cause the brazing material to pass through the gap between the valve seat member and the valve body on the valve seat surface side of the recess, making it less likely for the brazing material to move toward the valve seat surface. In other words, in a configuration in which the valve seat member and the valve body are in contact with each other on the valve seat surface side of the recess, capillary action would easily cause the brazing material to pass through the gap and move toward the valve seat surface, but this phenomenon is less likely to occur in the present invention. Therefore, the brazing material is more likely to accumulate in the recess, preventing it from reaching the valve seat surface and less likely to interfere with the slide valve, thereby suppressing valve leakage.

[0008] In this case, in the slide-type switching valve of the present invention, it is preferable that the connection surface extends so as to move away from the inner circumferential surface from the boundary with the joining curved surface toward the boundary with the valve seat surface. With this configuration, it is easy to ensure a distance from the inner circumferential surface of the valve body at the boundary between the connection surface and the valve seat surface, and it is possible to make it difficult for the brazing material to reach the valve seat surface.

[0009] In the slide-type switching valve of the present invention, the recess preferably has a curved-surface-side inner surface extending from the curved-surface side toward the bottom, and the curved-surface-side inner surface extends away from the inner circumferential surface as it approaches the valve seat surface, or extends parallel to the valve seat surface. With this configuration, when brazing is performed such that the valve seat surface is aligned vertically and the axial direction of the tubular portion of the valve body is aligned horizontally, the curved-surface-side inner surface either extends upward as it approaches the valve seat surface or extends vertically. In this case, when the brazing filler metal that has flowed downward due to gravity from the curved-surface side toward the valve seat surface reaches the recess, the gravity acting on the brazing filler metal can be made relatively large relative to the surface tension that acts on the brazing filler metal toward the valve seat surface along the curved-surface-side inner surface, thereby preventing the brazing filler metal from passing through the recess and toward the valve seat surface.

[0010] In the slide-type switching valve of the present invention, it is preferable that the connecting surface has regions on both sides of the recess extending along a common plane or curved surface. With this configuration, the shape of the connecting surface can be simplified and workability can be improved.

[0011] Furthermore, in the slide-type switching valve of the present invention, the connection surface may extend along a plane perpendicular to the valve seat surface, or the connection surface may extend along a plane opposite to the side facing the inner circumferential surface and forming an acute angle with the valve seat surface on the side of the joining curved surface relative to the valve seat surface, or the connection surface may extend along a plane opposite to the side facing the inner circumferential surface and forming an obtuse angle with the valve seat surface on the side of the joining curved surface relative to the valve seat surface. These configurations make it easy to form recesses in the connection surfaces extending along each plane, and in particular, it is easy to form recesses that extend so that the inner surface on the joining curved surface side approaches the valve seat surface, as described above, or that extend parallel to the valve seat surface.

[0012] In the sliding selector valve of the present invention, the connecting surface may extend along a convex curved surface toward the inner circumferential surface. With this configuration, it is easy to ensure a distance from the inner circumferential surface of the valve body at the boundary between the connecting surface and the valve seat surface, and it is possible to make it difficult for the brazing material to reach the valve seat surface.

[0013] In the slide type switching valve of the present invention, the connection surface may extend along a curved surface that is concave relative to the inner circumferential surface. With this configuration, the brazing material can easily flow along the connection surface toward the recess.

[0014] In the slide-type switching valve of the present invention, the connecting surface may have regions on both sides of the recess extending along different planes or curved surfaces. This configuration improves the degree of freedom in setting the directions in which the regions on both sides of the recess extend, making it easier to ensure a distance from the inner circumferential surface of the valve body at the boundary between the connecting surface and the valve seat surface, and making it more difficult for the brazing material to reach the valve seat surface.

[0015] The refrigeration cycle system of the present invention comprises a compressor that compresses a fluid refrigerant, a first heat exchanger that functions as a condenser in cooling mode, a second heat exchanger that functions as an evaporator in cooling mode, an expansion means that expands the refrigerant between the first heat exchanger and the second heat exchanger to reduce its pressure, and a four-way switching valve, and is characterized in that the above-described slide-type switching valve is used as the four-way switching valve.

[0016] According to the present invention as described above, valve leakage can be suppressed in the same manner as described above. [Effects of the Invention]

[0017] According to the slide-type switching valve and the refrigeration cycle system of the present invention, valve leakage can be suppressed. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of a refrigeration cycle provided with a slide-type switching valve according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view showing the slide-type switching valve. [Figure 3] 2 is an enlarged cross-sectional view showing a main part of the slide-type switching valve. FIG. [Figure 4] FIG. 4 is a cross-sectional view showing an increased amount of brazing material in the slide-type switching valve. [Figure 5] FIG. 3 is an enlarged cross-sectional view showing a main part of a slide-type switching valve according to a first modified example of the present invention. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing a main part of a slide-type switching valve according to a second modification of the present invention. [Figure 7] FIG. 10 is an enlarged cross-sectional view showing a main part of a slide-type switching valve according to a third modification of the present invention. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing a main part of a slide-type switching valve according to a fourth modification of the present invention. [Figure 9] FIG. 10 is an enlarged cross-sectional view showing a main part of a slide-type switching valve according to a fifth modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described with reference to the drawings. The slide selector valve 1 of this embodiment is a four-way selector valve provided in, for example, a refrigeration cycle 100. The refrigeration cycle 100 is used in air conditioners such as room air conditioners, package air conditioners, and multi-air conditioners. It includes a compressor 102 that compresses a refrigerant fluid; an outdoor heat exchanger 103 that serves as a first heat exchanger and functions as a condenser in a cooling mode; an indoor heat exchanger 104 that serves as a second heat exchanger and functions as an evaporator in the cooling mode; an expansion valve 105 that expands and reduces the pressure of the refrigerant between the outdoor heat exchanger 103 and the indoor heat exchanger 104; the slide selector valve 1 that is a four-way selector valve; and a pilot solenoid valve 106 that controls the flow path of the slide selector valve 1. These components are connected by a refrigerant pipe. The expansion valve 105 is not limited to the expansion valve 105, and a capillary may also be used as the expansion means.

[0020] 1, the refrigeration cycle 100 constitutes a cooling cycle in which a refrigerant flows in the order of compressor 102, slide type switching valve 1, outdoor heat exchanger 103, expansion valve 105, indoor heat exchanger 104, slide type switching valve 1, and compressor 102. On the other hand, in the heating mode (heating operation) indicated by the dashed line arrow, the refrigeration cycle 100 constitutes a heating cycle in which a refrigerant flows in the order of compressor 102, slide type switching valve 1, indoor heat exchanger 104, expansion valve 105, outdoor heat exchanger 103, slide type switching valve 1, and compressor 102. Switching between the heating cycle and the cooling cycle is performed by the switching operation of slide type switching valve 1 using pilot solenoid valve 106.

[0021] As also shown in Figure 2, the slide-type switching valve 1 of this embodiment is configured to include a valve body 2 that forms a valve chamber 2R, a valve seat member 3 that is housed in the valve chamber 2R, a slide valve 4 that is slidably arranged inside the valve body 2, a high-pressure side conduit (D joint) 11 that communicates with the discharge port of the compressor 102, a low-pressure side conduit (S joint) 12 that communicates with the suction port of the compressor 102, an indoor side conduit (E joint) 13 that communicates with the indoor heat exchanger 104, and an outdoor side conduit (C joint) 14 that communicates with the outdoor heat exchanger 103.

[0022] In the following description, the sliding direction of the slide valve 4 is defined as the X direction, and two directions perpendicular to the X direction and perpendicular to each other are defined as the Y direction and the Z direction, with the top and bottom in the Z direction being based on FIG.

[0023] The valve body 2 is a metal valve housing made of, for example, stainless steel, and has a valve chamber 2R inside. The valve body 2 has a cylindrical tube portion 21 extending along the X direction (the X direction is the axial direction) and plugs 22, 23 closing both axial ends, so that it is configured as a totally sealed cylinder, and a space is formed that sandwiches a piston that moves the slide valve 4 from the X direction. A pilot solenoid valve 106 switches which of these spaces is to be made high pressure, and the slide valve 4 slides along the X direction due to the pressure difference.

[0024] On one side in the Z direction (the lower side in Figure 2) of the cylindrical portion 21 (i.e., the side portion of the valve body 2), openings 2A to 2C are formed which are aligned in a straight line along the X direction and to which each of the conduits 12 to 14 is connected, and on the other side in the Z direction (the upper side in Figure 1) an opening 21D is formed which is connected to the high-pressure side conduit 11.

[0025] The valve seat member 3 is constructed separately from the valve body 2 and is made of an appropriate metal such as stainless steel. The valve seat member 3 is fixed to the valve body 2 by brazing as described below, and its upper surface, the valve seat surface 31, is disposed within the valve chamber 2R. The valve seat member 3 has three valve ports 3A to 3C that open at the valve seat surface 31 and communicate with the openings 2A to 2C of the cylindrical portion 21, respectively. The valve seat surface 31 is a planar sliding surface that extends along the XY plane.

[0026] The slide valve 4 is made of, for example, synthetic resin and is formed in a bowl (dome) shape that opens toward the valve seat surface 31. A communication space 4R is formed inside the slide valve 4, and this communication space 4R either communicates the central valve port 3A with the valve port 3B on one side but does not communicate with the valve port 3C on the other side, or communicates the central valve port 3A with the valve port 3C on the other side but does not communicate with the valve port 3B on the one side. Note that the slide valve 4 is not shown in Figure 2.

[0027] Here, the details of the connection structure between the valve body 2 and the valve seat member 3 in the slide type switching valve 1 will be described with reference to Figure 3. Note that while Figures 2 and 3 show a cross section passing through the valve port 3A, cross sections passing through the valve ports 3B and 3C also have the same shape, and the valve seat member 3 has the same cross-sectional shape regardless of the position in the X direction. Furthermore, the valve seat member 3 has a symmetrical plane along the ZX plane, and both sides in the Y direction have the same shape, so below only the shape on one side in the Y direction will be described.

[0028] The valve seat member 3 has a joining curved surface 32 that conforms to the inner peripheral surface 21A of the tubular portion 21 of the valve body 2 and is joined to the inner peripheral surface 21A, and a connection surface 33 between the valve seat surface 31 and the joining curved surface 32, and a boundary portion 34 is formed between the valve seat surface 31 and the connection surface 33, and a boundary portion 35 is formed between the joining curved surface 32 and the connection surface 33.

[0029] The inner circumferential surface 21A and the curved joint surface 32 extend in an arc shape when viewed from the X direction (in a cross section along the YZ plane). The radii of curvature may be approximately equal, allowing them to be joined together with almost no gap. Alternatively, the inner circumferential surface 21A may have a larger or smaller radius of curvature than the curved joint surface 32, leaving a small gap between these surfaces that can be filled with brazing material. The curved joint surface 32 does not extend from the valve seat surface 31 in the Y direction to a position where it intersects with the inner circumferential surface 21A, thereby forming a connection surface 33. The valve seat surface 31 is located below the central axis of the cylindrical inner circumferential surface 21A in the Z direction. As a result, the inner circumferential surface 21A extends from the opening 2A to the intersection with the imaginary extension of the valve seat surface 31, gradually moving away from the valve port 3A as it moves upward in the Z direction.

[0030] The connecting surface 33 extends along the ZX plane, that is, along a plane perpendicular to the valve seat surface 31 (θ=90°). Therefore, the connecting surface 33 is spaced apart from the inner circumferential surface 21A across a boundary 35 with the joining curved surface 32 and a boundary 34 with the valve seat surface 31. The connecting surface 33 also extends so as to become farther away from the inner circumferential surface 21A (the distance in the Y direction becomes greater) from the boundary 35 toward the boundary 34.

[0031] In the illustrated example, a boundary 34 between the valve seat surface 31 and the connecting surface 33 is chamfered. In contrast, a boundary 35 between the joining curved surface 32 and the connecting surface 33 is not chamfered, and the connecting surface 33 has a continuous flat surface 331 that continues to the joining curved surface 32 without any intervening surface such as a chamfer. The continuous flat surface 331 is a portion that extends from the joining curved surface 32 toward the valve seat surface 31 along the ZX plane.

[0032] A V-shaped recess 36 is formed in the connecting surface 33 in a cross section along the YZ plane. The recess 36 is preferably a groove extending along the X direction, and more preferably formed over the entire length of the valve seat member 3 in the X direction. The recess 36 is composed of a first inclined surface 361 on the joining curved surface 32 side, a second inclined surface 362 on the valve seat surface 31 side, and a bottom 363 which is the side where the first inclined surface 361 and the second inclined surface 362 intersect.

[0033] The first inclined surface 361 and the second inclined surface 362 are each inclined at approximately 45° with respect to the XY plane. The first inclined surface 361 is an inner surface of the curved joint surface 32 that extends from the side of the curved joint surface 32 toward the bottom portion 363, and extends so as to move away from the inner circumferential surface 21A in the Y direction as it approaches the valve seat surface 31 in the Z direction.

[0034] The connecting surface 33 has a second flat surface 332 in addition to the continuous flat surface 331. The continuous flat surface 331 and the second flat surface 332 are located in regions on both sides of the recess 36, and both are along the ZX plane and extend along a common plane. Furthermore, the continuous flat surface 331 and the second flat surface 332 are also inclined at approximately 45° with respect to the first inclined surface 361 and the second inclined surface 362, and are clearly distinguishable from the first inclined surface 361 and the second inclined surface 362.

[0035] Next, a method for joining the valve seat member 3 to the valve body 2 by brazing will be described in detail. First, the valve seat member 3 is placed inside the valve body 2 and oriented so that the Y direction is along the vertical direction (the up and down directions in FIG. 3 coincide with the vertical direction). The valve port 3A is formed with a small diameter portion 37 on the valve seat surface 31 side and a large diameter portion 38 in which the tip of the low-pressure side conduit 12 is disposed. A gap G is formed between the small diameter portion 37 and the tip surface of the low-pressure side conduit 12 inserted to a specified depth, and an annular brazing filler metal is placed in this gap G.

[0036] When such a brazing filler metal is melted, it tends to move downward due to gravity. Specifically, the brazing filler metal passes between the low-pressure side conduit 12 and the large diameter portion 38 in the Z direction, and then passes between the joining curved surface 32 and the inner circumferential surface 21A and moves downward.

[0037] The brazing filler metal A that has reached the connecting surface 33 fills the gap between the continuous flat surface 331 and the inner circumferential surface 21A, and as the amount of brazing filler metal increases, it flows down the first inclined surface 361 and fills the recess 36. At this time, as shown in FIG. 3, the brazing filler metal A has a fillet shape and has a tip A1 that runs along the inner circumferential surface 21A.

[0038] Because the entire connecting surface 33 is separated from the inner circumferential surface 21A and the recess 36 is formed, the brazing filler metal A is less likely to reach the second plane 332. That is, even if the tip A1 reaches the intersection of the extension of the valve seat surface 31 and the inner circumferential surface 21A, the brazing filler metal A does not reach the second plane 332, and instead reaches the second plane 332 only after the recess 36 is completely filled with the brazing filler metal, as shown in FIG.

[0039] According to the present embodiment, the recess 36 is formed in the connection surface 33 of the valve seat member 3, allowing the brazing material to accumulate in the recess 36. At this time, the connection surface 33 is separated from the inner circumferential surface 21A of the valve body 2 across the boundary 35 with the joining curved surface 32 and the boundary 34 with the valve seat surface 31. This suppresses capillary action, which causes the brazing material to pass through the gap between the valve seat member 3 and the valve body 2, on the valve seat surface 31 side of the recess 36, making it difficult for the brazing material to move toward the valve seat surface 31. Therefore, the brazing material is easily accumulated in the recess 36 and is prevented from reaching the valve seat surface 31, making it difficult for the brazing material to interfere with the slide valve 4 and suppressing valve leakage.

[0040] Furthermore, since the connection surface 33 extends away from the inner surface 21A of the valve body 2 as it moves from the boundary 35 with the joining curved surface 32 toward the boundary 34 with the valve seat surface 31, it is easier to maintain a distance from the inner surface 21A of the valve body 2 at the boundary 34 between the connection surface 33 and the valve seat surface 31, making it more difficult for the brazing material to reach the valve seat surface 31.

[0041] Furthermore, the first inclined surface 361 of the recess 36 extends so as to move away from the inner peripheral surface 21A of the valve body 2 as it approaches the valve seat surface 31; in other words, when positioned during brazing, it extends upward as it approaches the valve seat surface 31. As a result, when the brazing filler metal that has flowed downward due to gravity from the joining curved surface 32 toward the valve seat surface 31 reaches the recess 36, the gravity acting on the brazing filler metal can be made relatively large relative to the surface tension that tends to move the brazing filler metal along the first inclined surface 361 toward the valve seat surface 31, and the brazing filler metal can be prevented from passing through the recess 36 toward the valve seat surface 31.

[0042] Furthermore, the continuous plane 331 and the second plane 332, which are arranged in the regions on both sides of the recess 36 of the connecting surface 33, extend along a common plane, thereby simplifying the shape of the connecting surface 33 and improving processability.

[0043] Furthermore, since the connection surface 33 extends along a plane perpendicular to the valve seat surface 31, it is easy to form a first inclined surface 361 on the connection surface 33 that extends away from the inner surface 21A of the valve body 2 as it approaches the valve seat surface 31.

[0044] The present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. That is, the shapes of the connection surface and recess formed on the valve seat member may be as shown in Modifications 1 to 5 shown in Figures 5 to 9. In the following description of Modifications 1 to 5, we will focus on the differences from the above-described embodiment, and will omit a description of the parts that are common to the above-described embodiment.

[0045] [Variation 1] Modification 1 is shown in Figure 5. In Modification 1, the planes on which the continuous flat surface 331 and the second flat surface 332 extend differ from those of the above-described embodiment. The continuous flat surface 331 and the second flat surface 332 extend along a plane that forms an acute angle (e.g., θ = 70°) with the valve seat surface 31 on the side opposite the side facing the inner circumferential surface 21A and on the lower side of the valve seat surface 31 in the Z direction (the side of the joint curved surface 32). That is, the continuous flat surface 331 and the second flat surface 332 are inclined so as to approach the valve port 3A in the Y direction as they move away from the valve seat surface 31 in the Z direction. Note that the side of the continuous flat surface 331 and the second flat surface 332 facing the inner circumferential surface 21A refers to the side of the continuous flat surface 331 and the second flat surface 332 facing the inner circumferential surface 21A (the lower side in Figure 5) (the same applies to the following modifications).

[0046] Although the first inclined surface 361 and the second inclined surface 362 of the recess 36 have the same inclination with respect to the continuous flat surface 331 and the second flat surface 332 as in the above embodiment, the inclination of the continuous flat surface 331 and the second flat surface 332 is different from that in the above embodiment, and therefore the inclination angles of the first inclined surface 361 and the second inclined surface 362 with respect to the Z direction are different from those in the above embodiment. However, the first inclined surface 361 serving as the inner surface on the joining curved surface side extends so as to move away from the inner circumferential surface 21A in the Y direction as it approaches the valve seat surface 31 in the Z direction, similar to the above embodiment.

[0047] According to the first modification, valve leakage can be suppressed in the same way as in the above embodiment.

[0048] [Variation 2] 6 shows Modification 2. In Modification 2, the planes on which the continuous flat surface 331 and the second flat surface 332 extend differ from those of the above embodiment. The continuous flat surface 331 and the second flat surface 332 extend along a plane that forms an obtuse angle (e.g., θ = 107°) with the valve seat surface 31 on the side opposite to the side facing the inner circumferential surface 21A and below the valve seat surface 31 in the Z direction (the side of the joining curved surface 32). That is, the continuous flat surface 331 and the second flat surface 332 are inclined so as to move away from the valve port 3A in the Y direction as they move away from the valve seat surface 31 in the Z direction. Note that although the continuous flat surface 311 is relatively short, it is a surface distinct from the first inclined surface 361.

[0049] Although the first inclined surface 361 and the second inclined surface 362 of the recess 36 have the same inclination with respect to the continuous flat surface 331 and the second flat surface 332 as in the above embodiment, the inclination of the continuous flat surface 331 and the second flat surface 332 is different from that in the above embodiment, and therefore the inclination angles of the first inclined surface 361 and the second inclined surface 362 with respect to the Z direction are different from those in the above embodiment. However, the first inclined surface 361 serving as the inner surface on the joining curved surface side extends so as to move away from the inner circumferential surface 21A in the Y direction as it approaches the valve seat surface 31 in the Z direction, similar to the above embodiment.

[0050] According to the second modification, valve leakage can be suppressed in the same manner as in the above embodiment.

[0051] [Variation 3] FIG. 7 shows Modification 3. Modification 3 differs from the above embodiment in that the connecting surface 33 extends along a curved surface. That is, in Modification 3, the connecting surface 33 has a continuous curved surface 333 that is continuous with the joining curved surface 32 and a second curved surface 334 on the valve seat surface 31 side. The continuous curved surface 333 and the second curved surface 334 are disposed in regions on both sides of the recess 36 and extend along a common curved surface. This common curved surface is an arc whose center is located inside the tubular portion 21 and whose diameter is smaller than that of the tubular portion 21. That is, the continuous curved surface 333 and the second curved surface 334 extend along a convex curve toward the inner circumferential surface 21A.

[0052] Also in the third modification, the connection surface 33 is spaced apart from the inner circumferential surface 21A of the valve body 2 across a boundary 35 with the curved joining surface 32 and a boundary 34 with the valve seat surface 31. Furthermore, the connection surface 33 extends away from the inner circumferential surface 21A from the boundary 35 with the curved joining surface 32 toward the boundary 34 with the valve seat surface 31.

[0053] According to this variant example 3, the connection surface 33 extends along a convex curved surface toward the inner surface 21A of the valve body 2, making it easier to maintain a distance from the inner surface 21A of the valve body 2 at the boundary 34 between the connection surface 33 and the valve seat surface 31, and making it more difficult for the brazing material to reach the valve seat surface 31.

[0054] [Variation 4] FIG. 8 shows a fourth modification. This modification differs from the previous embodiment in that the connecting surface 33 extends along a curved surface and that the recess 39 formed in the connecting surface 33 is rectangular. Specifically, in the fourth modification, the connecting surface 33 includes a continuous curved surface 335 that is continuous with the joining curved surface 32 and a second curved surface 336 on the valve seat surface 31 side. The continuous curved surface 335 and the second curved surface 336 are disposed in regions on both sides of the recess 39 and extend along a common curved surface. This common curved surface is an arc whose center is located outside the cylindrical portion 21 and whose diameter is smaller than that of the cylindrical portion 21. Specifically, the continuous curved surface 335 and the second curved surface 336 extend along a curved surface that is concave relative to the inner circumferential surface 21A.

[0055] The recess 39 in the fourth modification is configured by three surfaces: a first side surface 391 on the curved joint surface 32 side, a second side surface 392 on the valve seat surface 31 side, and a bottom surface 393 which is a plane connecting the first side surface 391 and the second side surface 392, the first side surface 391 and the bottom surface 393 being substantially perpendicular to each other, the second side surface 392 and the bottom surface 393 being substantially perpendicular to each other, and the first side surface 391 and the second side surface 392 being substantially parallel to each other. The first side surface 391, which is the inner surface on the curved joint surface side, extends so as to move away from the inner circumferential surface 21A as it approaches the valve seat surface 31.

[0056] In the fourth modification, the connecting surface 33 is also spaced from the inner circumferential surface 21A of the valve body 2 across the boundary 35 with the joining curved surface 32 and the boundary 34 with the valve seat surface 31. Furthermore, in a part of the connecting surface 33 in the fourth modification (particularly the continuous curved surface 335), the connecting surface 33 extends away from the inner circumferential surface 21A from the boundary 35 with the joining curved surface 32 toward the boundary 34 with the valve seat surface 31, but in the other part (particularly the second curved surface 336), the connecting surface 33 extends closer to the inner circumferential surface 21A from the boundary 35 with the joining curved surface 32 toward the boundary 34 with the valve seat surface 31.

[0057] According to the fourth modification, the connecting surface 33 extends along a curved surface that is concave relative to the inner circumferential surface 21A of the valve body 2, which makes it easier for the brazing material to flow along the connecting surface toward the recess.

[0058] [Variation 5] 9 shows Modification 5. Modification 5 differs from the above embodiment in that continuous plane 331 and second plane 332, which are arranged in regions on both sides of recess 30 on connecting surface 33, extend along different planes and that recess 30 is arc-shaped. In Modification 5, both continuous plane 331 and second plane 332 extend away from inner circumferential surface 21A from boundary 35 with joint curved surface 32 toward boundary 34 with valve seat surface 31, and further extend along a plane that forms an acute angle with valve seat surface 31 on the side opposite to the side facing inner circumferential surface 21A and below valve seat surface 31 in the Z direction (the side of joint curved surface 32). Furthermore, the acute angle between the second plane 332 and the valve seat surface 31 is larger than the acute angle between the continuous plane 331 and the valve seat surface 31, and the extension surface of the continuous plane 331 and the extension surface of the second plane 332 intersect in a manner that is convex toward the inner circumferential surface 21A.

[0059] The arc-shaped recess 30 has a bottom 301, a first curved surface 302 that is closer to the joining curved surface 32 than the bottom 301, and a second curved surface 303 that is closer to the valve seat surface 31 than the bottom 301. The entire first curved surface 302 as the inner surface facing the joining curved surface and a part of the second curved surface 303 extend so as to move away from the inner circumferential surface 21A as they approach the valve seat surface 31, and the other part of the second curved surface 303 extends so as to move closer to the inner circumferential surface 21A as they approach the valve seat surface 31.

[0060] According to Modification 5, the regions of the connecting surface 33 on both sides of the recess 30 extend along different planes, which increases the degree of freedom in setting the direction in which the regions on both sides of the recess 30 extend. In this case, the second plane 332 can be set at an angle such that it becomes increasingly farther away from the inner circumferential surface as it approaches the valve seat surface 31 than the continuous plane 331. This makes it easier to ensure a distance from the inner circumferential surface 21A of the valve body 2 at the boundary 34 between the connecting surface 33 and the valve seat surface 31, and makes it more difficult for the brazing material to reach the valve seat surface 31.

[0061] The shapes of the connection surfaces and grooves in the above-described embodiment and modifications 1 to 5 can be combined as appropriate.

[0062] In the above embodiment, the slide type switching valve 1 is a four-way switching valve provided in the refrigeration cycle 100, but the use and structure of the slide type switching valve are not limited to this and may be, for example, a pilot solenoid valve. Furthermore, the slide type switching valve is not limited to one in which the communication state of two ports is switched by the movement of the slide valve and may be one in which the ports simply open and close relative to the valve chest.

[0063] The embodiments of the present invention have been described above in detail with reference to the drawings, but the specific configurations are not limited to these embodiments, and the present invention also includes design changes and the like that do not deviate from the gist of the present invention. [Explanation of symbols]

[0064] 1...slide-type switching valve, 2...valve body, 21...cylindrical portion, 21A...inner peripheral surface, 2R...valve chamber, 3...valve seat member, 31...valve seat surface, 32...connecting curved surface, 33...connecting surface, 34, 35...boundary portion, 30, 36, 39...recess, 361...first inclined surface (internal surface on the connecting surface side), 391...first side surface (internal surface on the connecting surface side), 302...first curved surface (internal surface on the connecting surface side), 4...slide valve

Claims

1. A slide-type switching valve including a cylindrical valve body that defines a valve chamber, a valve seat member that has a valve seat surface within the valve chamber, and a slide valve that slides relative to the valve seat surface, the valve seat member has a curved joining surface that fits along an inner circumferential surface of a cylindrical portion of the valve body and is joined to the inner circumferential surface, and a connecting surface between the valve seat surface and the curved joining surface, and is attached to the valve body so that the valve seat surface extends along the axial direction of the cylindrical portion; a connecting surface that is spaced from the inner circumferential surface across a boundary with the joining curved surface and a boundary with the valve seat surface, and that has a portion that is continuous with the joining curved surface and extends along a predetermined plane or curved surface toward the valve seat surface, and that has a recess formed therein.

2. 2. The slide-type switching valve according to claim 1, wherein the connecting surface extends so as to become farther away from the inner circumferential surface from a boundary with the joining curved surface toward a boundary with the valve seat surface.

3. the recess has an inner surface on the curved joining surface side that extends from the curved joining surface side toward a bottom portion, 3. The slide-type switching valve according to claim 2, wherein the inner surface of the curved joint surface extends so as to move away from the inner circumferential surface as it approaches the valve seat surface, or extends parallel to the valve seat surface.

4. 4. The slide-type switching valve according to claim 2, wherein the connecting surface has regions on both sides of the recess that extend along a common plane or curved surface.

5. 5. The slide-type switching valve according to claim 4, wherein the connection surface extends along a plane perpendicular to the valve seat surface.

6. 5. The slide-type switching valve according to claim 4, wherein the connection surface extends along a plane that forms an acute angle with the valve seat surface on the side opposite to the side facing the inner circumferential surface and on the side of the joining curved surface with respect to the valve seat surface.

7. 5. The sliding switching valve according to claim 4, wherein the connection surface extends along a plane that forms an obtuse angle with the valve seat surface on the side opposite to the side facing the inner circumferential surface and on the side of the joining curved surface with respect to the valve seat surface.

8. 5. The slide-type switching valve according to claim 4, wherein the connection surface extends along a convex curved surface toward the inner circumferential surface.

9. 5. The slide-type switching valve according to claim 4, wherein the connection surface extends along a curved surface that is concave relative to the inner circumferential surface.

10. 4. The slide-type switching valve according to claim 2, wherein the connecting surface has regions on both sides of the recess that extend along different planes or curved surfaces.

11. 1. A refrigeration cycle system comprising: a compressor that compresses a fluid refrigerant; a first heat exchanger that functions as a condenser in a cooling mode; a second heat exchanger that functions as an evaporator in the cooling mode; expansion means that expands and decompresses the refrigerant between the first heat exchanger and the second heat exchanger; and a four-way switching valve, wherein the slide-type switching valve according to claim 1 is used as the four-way switching valve.

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