JP7761611B2 - Slide-type switching valve and refrigeration cycle system - Google Patents

Description

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

A known type of switching valve for switching refrigerant flow paths in refrigeration cycles and the like is a slide-type switching valve, which includes a cylindrical valve body, a valve element slidably mounted within the valve body, a valve seat mounted on the valve body, and a drive mechanism for axially driving the valve element (see, for example, Patent Document 1). The valve seat has multiple (e.g., three) ports opening onto the sliding surface along which the valve element slides, and coupling holes connecting each port to the opposite side of the sliding surface, with piping inserted into each coupling hole. In this slide-type switching valve, while the multiple ports are aligned axially, the coupling holes connecting the piping cannot be aligned coaxially with the ports due to their large diameters compared to the ports. Instead, they are offset from each other in the axial direction or in a direction intersecting the axial direction. In other words, when viewed perpendicular to the sliding surface, the ports and coupling holes overlap at portions of their circumferences, and are connected by this overlapping portion.

Japanese Patent Application Laid-Open No. 2017-133663

However, with conventional slide-type switching valves, when forming the port and the connecting hole in the valve seat, cutting burrs are likely to form in the overlapping area mentioned above, and these cutting burrs can become foreign matter and cause problems in the refrigeration cycle.

The present invention aims to provide a slide-type switching valve and refrigeration cycle system that can suppress the generation of cutting burrs when machining the valve seat member and make it less likely for foreign matter to cause malfunctions in the refrigeration cycle.

In order to solve the above problems and achieve the object, the slide type switching valve of the present invention is a slide type switching valve comprising: a hollow cylindrical valve body; a valve seat member provided in the valve body; a valve element provided inside the valve body so as to be slidable in an axial direction; and a drive unit that drives the valve element to slide, wherein the valve seat member has a sliding surface on which the valve element slides, a coupling surface located opposite to the sliding surface, and a plurality of through holes that penetrate from the sliding surface to the coupling surface, the through holes having a porthole that opens into the sliding surface, a coupling hole that opens into the coupling surface with an inner diameter larger than the porthole and into which a coupling member is inserted, and a communication hole that communicates the porthole and the coupling hole, and the portholes in the plurality of through holes are arranged side by side in the axial direction, and a first through hole constituting at least one of the plurality of through holes comprises a first porthole as the porthole, a first communicating hole as the communicating hole, and a first joint hole as the joint hole, the first communicating hole being arranged at an angle with respect to the direction orthogonal to the surface of the sliding surface and having an inner diameter larger than that of the first porthole, the first porthole being arranged along the direction orthogonal to the surface, the entire circumference of the continuous portion with the first communicating hole being located within the circumference of the first communicating hole, the continuous portion between the first porthole and the first communicating hole being at an angle with respect to the direction orthogonal to the surface, and the inner diameter of the first joint hole being equal to or larger than the inner diameter of the first communicating hole.

According to the present invention, the first porthole and the first coupling hole communicate with each other through a first coupling hole that is inclined relative to the direction perpendicular to the sliding surface. The inner diameter of the first porthole is smaller than that of the first coupling hole, and the entire circumference of the first porthole at the connecting portion between the first porthole and the first coupling hole is located within the circumference of the first coupling hole. The inner diameter of the first coupling hole is set to be equal to or larger than the inner diameter of the first coupling hole. This allows the first through hole to be formed without interference between the first porthole, the first coupling hole, and the first coupling hole. This eliminates the overlap between the port and the coupling hole that occurs in the conventional slide-type switching valve described above, and reduces the generation of cutting burrs when forming the through hole. This reduces the generation of cutting burrs when machining the valve seat member, resulting in a slide-type switching valve that is less susceptible to refrigeration cycle malfunctions caused by foreign matter.

Preferably, the second porthole, which is the porthole of a second through hole different from the first through hole among the plurality of through holes, extends in a direction perpendicular to the surface of the sliding surface and has a smaller inner diameter than the second communicating hole, which is the communicating hole of the second through hole; the second communicating hole extends in the direction perpendicular to the surface of the sliding surface; the entire circumference of the second porthole at the connecting portion between the second porthole and the second communicating hole is located within the circumference of the second communicating hole; and the length of the first porthole in the through-hole direction is shorter than the length of the second porthole in the through-hole direction. With this configuration, the valve seat member can be provided with communicating holes extending in different directions, namely, the first communicating hole inclined with respect to the direction perpendicular to the surface and the second communicating hole extending in the direction perpendicular to the surface, thereby preventing interference between the plurality of communicating holes and the coupling holes connected to the plurality of communicating holes. Furthermore, by making the length of the first porthole in the through-direction shorter than the length of the second porthole in the through-direction, the continuous portion between the first porthole and the first communicating hole and the continuous portion between the second porthole and the second communicating hole can be offset in the direction perpendicular to the plane. In other words, the portion where the inner diameter increases from the first porthole to the first communicating hole and the portion where the inner diameter increases from the second porthole to the second communicating hole can be offset in the direction perpendicular to the plane. Therefore, even when the first porthole and the second porthole are brought close to each other, interference between the first communicating hole and the second communicating hole can be prevented.

Preferably, the inner diameter of the first communicating hole is smaller than the inner diameter of the first coupling hole, the entire circumference of the first communicating hole is located within the circumference of the first coupling hole at the connecting portion with the first coupling hole, the inner diameter of the second communicating hole is smaller than the inner diameter of the second coupling hole, which is the coupling hole of the second through hole, the entire circumference of the second communicating hole is located within the circumference of the second coupling hole at the connecting portion with the second coupling hole, and the length of the first coupling hole in the through-hole direction is longer than the length of the second coupling hole in the through-hole direction. With this configuration, the difference between the inner diameter of the first communicating hole and the inner diameter of the first coupling hole allows the portholes and communication holes of the through-holes adjacent to the first through-hole to be closer to the first through-hole. Therefore, compared to a configuration in which the inner diameter of the first communicating hole is the same as the inner diameter of the first coupling hole, the portion of the valve seat member for forming the through-holes is smaller, contributing to a more compact valve seat member. Similarly, the difference between the inner diameter of the second communicating hole and the inner diameter of the second joint hole allows the portholes and communicating holes of the through holes adjacent to the second through hole to be closer to the second through hole. Therefore, compared to a configuration in which the inner diameter of the second communicating hole is the same as the inner diameter of the second joint hole, the portion of the valve seat member for forming the through hole can be smaller, contributing to a more compact valve seat member. Furthermore, by forming the length of the first joint hole in the through-direction to be longer than the length of the second joint hole in the through-direction, the continuous portion between the first joint hole and the first communicating hole and the continuous portion between the second joint hole and the second communicating hole can be offset in the plane-orthogonal direction. That is, the portion where the inner diameter increases from the first communicating hole to the first joint hole and the portion where the inner diameter increases from the second communicating hole to the second joint hole can be offset in the plane-orthogonal direction. Therefore, even when the first porthole and second porthole are brought close to each other, it is possible to prevent interference between the first joint hole and second joint hole.

Furthermore, it is preferable that the coupling holes of the multiple through holes are aligned in the axial direction and open to the coupling surface. With this configuration, the multiple coupling holes are aligned in the axial direction and open to the coupling surface, respectively. Therefore, compared to a configuration in which one coupling hole does not overlap with another coupling hole when viewed from the axial direction and extends to one side and the other side in the width direction perpendicular to the axial direction of the valve seat member, the width dimension of the valve seat member can be reduced, contributing to a more compact valve seat member.

Furthermore, it is preferable that the first coupling hole is provided parallel to and coaxial with the first communicating hole, and that the coupling surface is provided with a tapered surface extending in a direction intersecting the sliding surface and into which the first coupling hole opens. With this configuration, when machining the first communicating hole, which is inclined relative to the direction perpendicular to the sliding surface, the tapered surface is first cut using a machining tool to form the first coupling hole, and then the first communicating hole can be formed by cutting at the same angle. This makes it easy to form the first coupling hole and the first communicating hole. Furthermore, because the tapered surface extends in a direction intersecting the sliding surface, it can also be formed so that it extends in a direction perpendicular to the penetration direction of the first communicating hole. In this case, the machining tool can be abutted perpendicular to the tapered surface. This prevents the tool from slipping relative to the tapered surface, making it easy and accurate to form the first coupling hole and the first communicating hole.

Furthermore, a plurality of the first through holes may be provided, and the first coupling hole may extend parallel to the first porthole and open into the coupling surface, with a virtual periphery of the inclined first communication hole extending to the coupling surface located within the circumference of the opening of the first coupling hole. With this configuration, when machining the first communication hole inclined with respect to the direction perpendicular to the sliding surface, the first coupling hole is first formed by cutting the coupling surface using a machining tool, and then the first communication hole is cut at a different angle. However, because the virtual periphery of the virtual extension of the first communication hole to the coupling surface is located within the circumference of the opening of the first coupling hole, the first communication hole can be formed without the machining tool abutting the inner circumferential surface of the first coupling hole. This allows for easy formation of the first communication hole, suppresses the generation of cutting burrs during machining of the valve seat member, and provides a slide-type switching valve that is less susceptible to refrigeration cycle malfunctions caused by foreign matter.

The valve seat member may also be made of stainless steel. Stainless steel is more likely to produce cutting burrs during processing than materials such as brass, which are used to make valve seat members in conventional slide-type switching valves. However, as described above, this configuration makes it possible to suppress the generation of cutting burrs when forming the through hole. Therefore, the present invention can also be applied to valve seat members made of materials that are more likely to produce cutting burrs.

Furthermore, it is preferable that the center-to-center distance, which is the distance in the axial direction from the center of one of the portholes communicating with adjacent coupling holes to the center of the other, is smaller than the inner diameter of the adjacent coupling holes. With this configuration, the center-to-center distance of adjacent portholes can be reduced so that the distance from the center of one porthole to the center of the other porthole in the axial direction, i.e., the sliding direction of the valve disc, is within a range smaller than the inner diameter of the coupling holes, thereby reducing the sliding distance of the valve disc. Therefore, for example, if the drive unit is configured as a device equipped with a plunger and a suction element, the distance between the plunger and the suction element can be reduced, contributing to the miniaturization of the drive unit and the associated labor savings.

The refrigeration cycle system of the present invention is also characterized by including the above-mentioned slide-type switching valve. This configuration makes it possible to suppress the generation of cutting burrs during machining of the valve seat member, and to configure a refrigeration cycle system using a slide-type switching valve that makes it less likely for refrigeration cycle malfunctions caused by foreign matter to occur.

The present invention provides a slide-type switching valve and refrigeration cycle system that can suppress the generation of cutting burrs when machining the valve seat member and make it less likely for foreign matter to cause malfunctions in the refrigeration cycle.

FIG. 1 is a diagram showing an example of a refrigeration cycle system according to the present invention. 1 is a cross-sectional view taken along the axis of a slide-type switching valve according to an embodiment of the present invention; FIG. 3 is an enlarged cross-sectional view of a valve seat member that constitutes the slide-type switching valve. 4A is a plan view of the valve seat member, FIG. 4B is a cross-sectional view of the valve seat member, and FIG. 4C is a rear view of the valve seat member. FIG. 4 is an enlarged cross-sectional view showing the dimensional relationship of a valve seat member. FIG. 4 is an explanatory view of a connecting portion between a porthole and a communication hole in the valve seat member. 10A is a plan view of a modified valve seat member, FIG. 10B is a cross-sectional view of the modified valve seat member, and FIG. 10C is a rear view of the modified valve seat member. FIG. 10 is an enlarged cross-sectional view showing the dimensional relationship of a valve seat member according to a modified example.

Embodiments of the present invention will be described below with reference to Figures 1 to 6. In the following description, the direction in which the axis L of a plunger 61 (described later) extends will be referred to as the "axial L direction," and the direction perpendicular to the axial L direction will be referred to as the "perpendicular direction X." Perpendicular direction X is also the direction perpendicular to the sliding surface 41 of a valve seat member 40 (described later), and is the "plane-perpendicular direction" in the present invention. The definitions of these directions are for the convenience of explanation only, and do not necessarily coincide with the directions in the actual use state of the present invention, and are not intended to limit the directions. Figure 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 (slide-type switching valve), an indoor heat exchanger 3, a throttle device 4, an outdoor heat exchanger 5, and a compressor 6.

The four-way valve 1 is a valve device that switches the flow path of a refrigerant by switching the communication state of four pipes. The four-way valve 1 comprises a housing 10 and a slide valve element 20 slidably mounted within the housing 10. The housing 10 comprises a cylindrical main body 11, both ends of which are closed by cover members. The main body 11 is formed by pressing a stainless steel metal plate or the like. A D-type coupling pipe 12, which serves as a high-pressure pipe through which a refrigerant flows, is fixed to the side wall of the main body 11 by brazing or the like while inserted through the plate thickness and communicating with the interior of the main body 11. In the portion of the side wall of the main body 11 facing the D-type coupling pipe 12, an E-type coupling pipe 13, an S-type coupling pipe 14, and a C-type coupling pipe 15, from the left in FIG. 1 , are fixed to the side wall by brazing or the like while inserted through the plate thickness and communicating with the interior of the main body 11.

The E joint pipe 13, S joint pipe 14, and C joint pipe 15, like the D joint pipe 12, are pipes through which refrigerant flows and function as high-pressure or low-pressure pipes. The interior of the main body 11 is divided into three spaces by a piston 23 (described below), consisting of a high-pressure chamber 16 that is constantly in communication with the D joint pipe 12, and a first working chamber 17 and a second working chamber 18 adjacent to the high-pressure chamber 16. The slide valve body 20 is slidably mounted within the main body 11 in the axial direction of the main body 11 and switches the communication state of the D joint pipe 12, E joint pipe 13, S joint pipe 14, and C joint pipe 15. The slide valve body 20 includes a valve body 21, a connecting plate 22 that holds the valve body 21 and extends in the axial direction of the main body 11, and a pair of pistons 23 mounted at both ends of the connecting plate 22 in the extension direction.

The valve body 21 is bowl-shaped and opens toward the E coupling pipe 13, S coupling pipe 14, and C coupling pipe 15. The opening of the valve body 21 is large enough to cover two adjacent openings among the E coupling pipe 13, S coupling pipe 14, and C coupling pipe 15. When the valve body 21 is in the leftmost position shown in FIG. 1, it connects the E coupling pipe 13 and the S coupling pipe 14, and also connects the D coupling pipe 12 and the C coupling pipe 15. When moved to the right in FIG. 1 to the rightmost position (not shown), it connects the C coupling pipe 15 and the S coupling pipe 14, and also connects the D coupling pipe 12 and the E coupling pipe 13. The connecting plate 22 holds the valve body 21 in the axial center of the main body 11 and extends to both axial sides. A sealing member such as a packing is attached to the piston 23, which divides the interior of the main body 11 into the three spaces mentioned above.

Specifically, the space between the pair of pistons 23 forms the high-pressure chamber 16, the space to the left of the high-pressure chamber 16 in FIG. 1 forms the first working chamber 17, and the space to the right of the high-pressure chamber 16 in FIG. 1 forms the second working chamber 18. In the refrigeration cycle system 100 shown in FIG. 1, the D coupling pipe 12 is connected to the discharge port of the compressor 6, and the S coupling pipe 14 is connected to the suction port of the compressor 6. The C coupling pipe 15 is connected to the outdoor heat exchanger 5, and the E coupling pipe 13 is connected to the indoor heat exchanger 3. The outdoor heat exchanger 5 and the indoor heat exchanger 3 are connected to each other via the expansion device 4. In this way, the refrigeration cycle system 100 is composed of a path consisting of the C coupling pipe 15, outdoor heat exchanger 5, expansion device 4, indoor heat exchanger 3, and E coupling pipe 13, and a path consisting of the S coupling pipe 14 to the compressor 6 and D coupling pipe 12.

The pilot valve 2 is a slide-type switching valve according to the present invention, and is a direct-acting electromagnetic slide valve that circulates drive fluid between the four-way valve 1 and the slide valve element 20 of the four-way valve 1. As shown in FIG. 2 , the pilot valve 2 includes a valve housing 30 formed by pressing a stainless steel metal plate or the like, a valve seat member 40 attached to the valve housing 30, a valve element 50 that slides on the valve seat member 40, and an electromagnetic drive unit 60 (drive unit) that drives the valve element 50 to slide. The valve housing 30 includes a cylindrical (i.e., hollow) valve body 31 with a bottom that extends along the axis L. The interior of the valve body 31 defines a valve chamber 32 on one side of the plunger 61 (described later) along the axis L (left side in FIG. 2 ) and a plunger placement chamber 33 on the other side of the plunger 61 along the axis L (right side in FIG. 2 ). A first mounting hole 34 is formed through the side wall of the valve body 31 in the orthogonal direction X. A D-shaped thin tube 35 serving as high-pressure piping is inserted into the first mounting hole 34 and secured by brazing or the like, communicating with the interior of the valve body 31. As shown in Figure 1, the D-shaped thin tube 35 communicates with the D-type joint pipe 12 of the four-way valve 1 described above.

A second mounting hole 36 is formed in the orthogonal direction X in the side wall of the valve body 31 facing the D capillary tube 35. A valve seat member 40 is fitted into the second mounting hole 36. The valve seat member 40 is a member that allows the valve element 50 to slide. It is made of stainless steel and has a cylindrical shape extending in the orthogonal direction X. As shown in FIG. 2 , the end face of the valve seat member 40 on the inner side in the orthogonal direction X forms a sliding surface 41 along which the valve element 50 slides. The sliding surface 41 is a flat surface parallel to the axis L. Meanwhile, the portion of the valve seat member 40 on the outer side in the orthogonal direction X, i.e., the portion opposite the sliding surface 41, forms a coupling surface 42 that connects the coupling members (first actuation capillary tube 45, second actuation capillary tube 46, and S capillary tube 47) described below. As shown in Figure 3, the joint surface 42 has a flat surface 42a that extends parallel to the sliding surface 41, and a tapered surface 42b that is continuous with the flat surface 42a and extends in a direction intersecting the sliding surface 41.

The valve seat member 40 is formed with a plurality of through holes that extend from the sliding surface 41 to the coupling surface 42. For example, in this embodiment, the through holes are composed of two first through holes 43 spaced apart in the axial direction L and a second through hole 44 formed between the two first through holes 43. That is, the valve seat member 40 is provided with the first through hole 43, which constitutes at least one of the plurality of through holes, and the second through hole 44, which is different from the first through hole 43. The first through hole 43 includes a first porthole 43a (porthole) that opens to the sliding surface 41 (i.e., opens into the valve chamber 32), a first coupling hole 43b (coupling hole) that has a larger inner diameter than the first porthole 43a and opens to the coupling surface 42 (i.e., opens to the outside of the valve chamber 32), and a first communication hole 43c (communication hole) that connects the first porthole 43a and the first coupling hole 43b. As shown in Figure 3, the first porthole 43a is formed to extend in the orthogonal direction X. The first porthole 43a is formed so that the entire circumference of the portion connecting to the first communication hole 43c is located within the circumference of the first communication hole 43c.

The position of the first porthole 43a can be selected as appropriate, as long as the entire circumference of the first porthole 43a is located within the circumference of the first communicating hole 43c at the connecting portion between the first porthole 43a and the first communicating hole 43c. Specifically, as shown in FIG. 6(A), the first porthole 43a may be formed so that its central axis a is continuous with the central axis c of the first communicating hole 43c at the connecting portion with the first communicating hole 43c, and its entire circumference is located within the circumference of the first communicating hole 43c. Alternatively, as shown in FIG. 6(B), the first porthole 43a may be formed eccentrically at the connecting portion with the first communicating hole 43c, so that its central axis a is not continuous with the central axis c of the first communicating hole 43c, as long as its entire circumference is located within the circumference of the first communicating hole 43c.

In the case of the first through hole 43 shown in Figure 6(B), if the central axis a is offset from the central axis c so as to approach the adjacent porthole (in this embodiment, the second porthole 44a, described later), the first porthole 43a can be brought closer to the other portholes, making it easier to ensure the area of the sliding surface 41, which is more preferable as it contributes to a more compact valve seat member 40. On the other hand, as shown in Figure 6(C), if the entire circumference of the porthole 80a is not located within the circumference of the communicating hole 80c, as in the case of the continuous portion between the porthole 80a and the communicating hole 80c formed in a conventional member other than the valve seat member 40 of the present invention, a portion of the circumference of the porthole 80a and a portion of the circumference of the communicating hole 80c will overlap when viewed from the orthogonal direction X, as in a conventional sliding selector valve. This makes it easier for cutting burrs to occur when forming the through hole, and therefore fails to solve the problem of the present invention.

As shown in FIG. 4, the first communication hole 43c continues from the end of the first porthole 43a in the orthogonal direction X and is inclined with respect to the orthogonal direction X. The inner diameter of the first communication hole 43c is larger than the inner diameter of the first porthole 43a and smaller than the inner diameter of the first coupling hole 43b. The first communication hole 43c is formed so that the entire circumference of the connecting portion with the first coupling hole 43b is located within the circumference of the first coupling hole 43b. The first coupling hole 43b is formed parallel to and coaxial with the first communication hole 43c and opens to the tapered surface 42b of the coupling surface 42. In FIG. 3, the first actuation capillary 45, which communicates with the first actuation chamber 17 of the four-way valve 1 described above, is inserted into the left first coupling hole 43b and fixed thereto by brazing or the like. In Figure 3, a second actuation capillary tube 46 communicating with the second actuation chamber 18 of the four-way valve 1 is inserted into the first joint hole 43b on the right side and fixed in place by brazing or the like.

In this embodiment, as described above, the inner diameter of the first communicating hole 43c is larger than the inner diameter of the first porthole 43a but smaller than the inner diameter of the first coupling hole 43b. The first communicating hole 43c is formed so that the entire circumference of the connecting portion with the first coupling hole 43b is located within the circumference of the first coupling hole 43b. However, this configuration is not limited to this. For example, the first communicating hole 43c and the first coupling hole 43b may be formed coaxially and integrally with the same inner diameter, so that a portion of the first coupling hole 43b functions as the first communicating hole 43c and the first coupling hole 43b is connected to the first port 43a. Therefore, the inner diameter of the first communicating hole 43c does not necessarily have to be smaller than the inner diameter of the first coupling hole 43b and may be formed to be the same size as the inner diameter of the first coupling hole 43b. Therefore, the inner diameter of the first coupling hole 43b needs to be equal to or larger than the inner diameter of the first communication hole 43c.

The second through hole 44 includes a second porthole 44a (porthole) that opens to the sliding surface 41 (i.e., opens into the valve chamber 32), a second coupling hole 44b (coupling hole) that has a larger inner diameter than the second porthole 44a and opens to the coupling surface 42 (i.e., opens to the outside of the valve chamber 32), and a second communication hole 44c (communication hole) that connects the second porthole 44a and the second coupling hole 44b. As shown in FIG. 4 , the second porthole 44a is formed to extend in the orthogonal direction X. The second porthole 44a is formed so that the entire circumference of the second porthole 44a, at the portion where it connects with the second communication hole 44c, is located within the circumference of the second communication hole 44c. The second communication hole 44c is continuous with the orthogonal direction X end of the second porthole 44a and extends in the orthogonal direction X. That is, unlike the first communication hole 43c, the second communication hole 44c is formed without being inclined with respect to the orthogonal direction X. The inner diameter of the second communication hole 44c is larger than the inner diameter of the second porthole 44a and smaller than the inner diameter of the second joint hole 44b. The second communication hole 44c is formed so that the entire circumference of the connecting portion with the second joint hole 44b is located within the circumference of the second joint hole 44b.

The second coupling hole 44b is formed parallel to and coaxial with the second communication hole 44c and opens to the flat surface 42a of the coupling surface 42. As shown in FIG. 3, an S-shaped capillary tube 47 communicating with the S-shaped coupling pipe 14 of the four-way valve 1 is inserted into the second coupling hole 44b and fixed thereto by brazing or the like. In this embodiment, as described above, the inner diameter of the second communication hole 44c is larger than the inner diameter of the second porthole 44a but smaller than the inner diameter of the second coupling hole 44b, and the second communication hole 44c is formed so that the entire circumference of the connecting portion with the second coupling hole 44b is located within the circumference of the second coupling hole 44b. However, this configuration is not limiting. The second communication hole 44c and the second coupling hole 44b may be integrally formed with the same inner diameter and coaxially, for example, so that a portion of the second coupling hole 44b functions as the second communication hole 44c and the second coupling hole 44b is continuous with the second porthole 44a. Therefore, the inner diameter of the second communication hole 44c does not necessarily have to be smaller than the inner diameter of the second coupling hole 44b, and may be formed to be the same size as the inner diameter of the second coupling hole 44b. Therefore, the inner diameter of the second coupling hole 44b only needs to be equal to or larger than the inner diameter of the second communication hole 44c.

As shown in FIG. 4(A), in the first through hole 43 and the second through hole 44 formed in this manner, the center of the first porthole 43a and the center of the second porthole 44a are aligned in a straight line in the axial direction L. That is, the first porthole 43a and the second porthole 44a (portholes in the multiple through holes) are aligned in the axial direction L. Also, as shown in FIG. 4(B), the first communicating hole 43c and the second communicating hole 44c are aligned in the axial direction L. Also, as shown in FIG. 4(C), the first coupling hole 43b and the second coupling hole 44b (coupling holes in the multiple through holes) are aligned in the axial direction L. In this way, the first through hole 43 and the second through hole 44 are aligned in the axial direction L.

As shown in FIG. 5 , the length A of the first porthole 43a in the through-hole direction (perpendicular direction X) is shorter than the length B of the second porthole 44a in the through-hole direction (perpendicular direction X). The length C of the first coupling hole 43b in the through-hole direction (the tilt direction of the first communicating hole 43c) is longer than the length D of the second coupling hole 44b in the through-hole direction (perpendicular direction X). The center-to-center distance E, which is the distance in the axial direction L from the center of the first porthole 43a to the center of the second porthole 44a, is smaller than the inner diameter F of the coupling hole (in this embodiment, the inner diameter F of the second coupling hole 44b). In other words, the center-to-center distance E, which is the distance in the axial direction L from the center of one of the portholes (first porthole 43a and second porthole 44a) communicating with adjacent coupling holes (first coupling hole 43b and second coupling hole 44b) to the center of the other porthole, is smaller than the inner diameter F of the adjacent coupling hole.

As shown in FIG. 2, the valve element 50 is formed in a columnar shape extending in the orthogonal direction X and is slidable along the axis L. A recess 51 that opens toward the sliding surface 41 is formed on the surface of the valve element 50 facing the sliding surface 41. As shown in FIG. 3, the opening of the recess 51 is large enough to cover the openings of two adjacent portholes (the first porthole 43a and the second porthole 44a). The recess 51 is configured so that its opening edge slides along the sliding surface 41, and sliding movement along the axis L switches the communication state of the portholes (the first porthole 43a and the second porthole 44a). This switches the communication state of the D capillary tube 35, the first working capillary tube 45, the second working capillary tube 46, and the S capillary tube 47.

Specifically, in the leftmost position shown in FIG. 2 , the recess 51 connects the first working capillary tube 45 and the S-tube 47, and also connects the D-tube 35 and the second working capillary tube 46. In this state, the high-pressure driving fluid that flows into the valve chamber 32 through the D-tube 35 flows toward the valve seat member 40 through the second pressure equalizing hole 66 (described below), and then flows through the first porthole 43a (not covered by the recess 51) and the second working capillary tube 46 into the second working chamber 18 of the four-way valve 1. Meanwhile, the low-pressure driving fluid that flows into the recess 51 through the S-tube 47 flows from the first porthole 43a through the first working capillary tube 45 into the first working chamber 17 of the four-way valve 1. This creates a pressure difference between the first working chamber 17 and the second working chamber 18, causing the sliding valve element 20 of the four-way valve 1 to move to the leftmost position shown in FIG. 1.

On the other hand, when the valve element 50 moves from its leftmost position to the rightmost position (not shown), the recess 51 connects the second actuation capillary tube 46 and the S capillary tube 47, and also connects the D capillary tube 35 and the first actuation capillary tube 45. In this state, the high-pressure driving fluid that flows into the valve chamber 32 through the D capillary tube 35 flows through the second pressure equalizing hole 66 toward the valve seat member 40, and then flows through the first porthole 43a (not covered by the recess 51) and the first actuation capillary tube 45 into the first actuation chamber 17 of the four-way valve 1. On the other hand, the low-pressure driving fluid that flows into the recess 51 through the S capillary tube 47 flows from the first porthole 43a through the second actuation capillary tube 46 into the second actuation chamber 18 of the four-way valve 1. This creates a pressure difference between the first actuation chamber 17 and the second actuation chamber 18, causing the slide valve element 20 of the four-way valve 1 to move rightward from its leftmost position shown in FIG. 1.

As shown in FIG. 2, the electromagnetic drive unit 60 includes a plunger 61 disposed in the plunger placement chamber 33, an attractor 62 disposed at a distance from the plunger 61 in the axial direction L, an electromagnetic coil 63, and a case 64. The plunger 61 includes a large-diameter portion 61a that slides along the axial direction L relative to the inner surface of the valve body 31, and a small-diameter portion 61b that is continuous with the large-diameter portion 61a and extends toward the valve chamber 32. A first pressure-equalizing hole 65 is formed in the large-diameter portion 61a, penetrating it in the axial direction L. A second pressure-equalizing hole 66 is formed in the small-diameter portion 61b, penetrating it in the orthogonal direction X, intersecting the first pressure-equalizing hole 65. With this configuration, the first pressure-equalizing hole 65 and the second pressure-equalizing hole 66 are in communication. Furthermore, with this configuration, the driving fluid that flows into the valve chamber 32 from the D-shaped capillary tube 35, which serves as the high-pressure piping described above, flows through the second pressure equalizing hole 66 toward the valve seat member 40, and then flows into the first porthole 43a or second porthole 44a that opens into the valve chamber 32.

The driving fluid that flows into the valve chamber 32 flows from the second pressure equalizing hole 66 through the first pressure equalizing hole 65 to the plunger placement chamber 33. As a result, the valve chamber 32 and the plunger placement chamber 33 are connected via the first pressure equalizing hole 65 and the second pressure equalizing hole 66, and the same pressure is applied to the valve chamber 32 and the plunger placement chamber 33. A concave retaining portion 67 that opens toward the valve seat member 40 is formed in the small diameter portion 61b of the plunger 61. The retaining portion 67 houses the valve disc 50. The valve disc 50 is pressed against the sliding surface 41 of the valve seat member 40 by a biasing member 67a installed inside the retaining portion 67. The attractor 62 is disposed at a distance from the plunger 61 in the axial direction L and is fixed within the valve body 31. A plunger spring 68 is disposed between the suction element 62 and the plunger 61, which biases the plunger 61 toward the valve body 50.

The electromagnetic coil 63 is disposed on the outer periphery of the valve body 31 and surrounds the plunger 61 and attractor 62 circumferentially around the axis L. The electromagnetic coil 63 is configured to include a bobbin 69 and a winding 69a wound around the bobbin 69. With this configuration, when the electromagnetic drive unit 60 is de-energized, the force of the plunger spring 68 urges the plunger 61 to the left in FIG. 2, causing the plunger 61 and valve body 50 to move to their leftmost positions in FIG. 2. On the other hand, when energized, the attractor 62 is excited, generating an attractive force between the plunger 61 and attractor 62, causing the plunger 61 and valve body 50 to move to the right.

With the above configuration, high-pressure refrigerant compressed by the compressor 6 flows into the high-pressure chamber 16 through the D joint pipe 12. During cooling operation (cooling mode), the high-pressure refrigerant flows into the outdoor heat exchanger 5 through the C joint pipe 15. During heating operation (heating mode) with the slide valve body 20 positioned, the high-pressure refrigerant flows into the indoor heat exchanger 3 through the E joint pipe 13. During cooling operation, the refrigerant discharged from the compressor 6 circulates through the C joint pipe 15, outdoor heat exchanger 5, throttling device 4, indoor heat exchanger 3, and E joint pipe 13. The outdoor heat exchanger 5 functions as a condenser, and the indoor heat exchanger 3 functions as an evaporator, providing cooling. The throttling device 4 expands and decompresses the refrigerant between the outdoor heat exchanger 5 and the indoor heat exchanger 3. During heating operation, the refrigerant is circulated in the opposite direction, with the indoor heat exchanger 3 functioning as a condenser and the outdoor heat exchanger 5 functioning as an evaporator, providing heating.

According to the above-described embodiment, the first porthole 43a and the first coupling hole 43b communicate with each other through the first communication hole 43c, which is inclined relative to the orthogonal direction X (the direction perpendicular to the surface) of the sliding surface 41. The inner diameter of the first porthole 43a is smaller than the inner diameter of the first communication hole 43c, and the entire circumference of the first porthole 43a is located within the circumference of the first communication hole 43c at the connecting portion between the first porthole 43a and the first communication hole 43c. Furthermore, the inner diameter of the first coupling hole 43b is set to be equal to or larger than the inner diameter of the first communication hole 43c. This allows the first through hole 43 to be formed without interference between the first porthole 43a, the first communication hole 43c, and the first coupling hole 43b. Therefore, unlike the conventional slide-type switching valve described above, there is no overlap between the port and the coupling hole, and cutting burrs can be reduced when forming the through hole. This makes it possible to suppress the generation of cutting burrs when machining the valve seat member 40, resulting in a pilot valve 2 (slide-type switching valve) that is less likely to cause refrigeration cycle malfunctions due to foreign matter.

The valve seat member 40 can be provided with communication holes extending in different directions: a first communication hole 43c inclined with respect to the orthogonal direction X, and a second communication hole 44c extending in the orthogonal direction X. This prevents interference between the multiple communication holes (first communication hole 43c, second communication hole 44c) and the multiple coupling holes (first coupling hole 43b, second coupling hole 44b). Furthermore, by making the length A of the first porthole 43a in the through-direction shorter than the length B of the second porthole 44a in the through-direction, the continuous portion between the first porthole 43a and the first communication hole 43c and the continuous portion between the second porthole 44a and the second communication hole 44c can be offset in the orthogonal direction X. That is, the portion where the inner diameter increases from the first porthole 43a to the first communication hole 43c and the portion where the inner diameter increases from the second porthole 44a to the second communication hole 44c can be offset in the perpendicular direction X. Therefore, even when the first porthole 43a and the second porthole 44a are brought closer together, interference between the first communication hole 43c and the second communication hole 44c can be prevented.

In addition, in this embodiment, the inner diameter of the first communication hole 43c is smaller than the inner diameter of the first joint hole 43b, and the entire circumference of the first communication hole 43c is located within the circumference of the first joint hole 43b at the connecting portion with the first joint hole 43b. With this configuration, the porthole (e.g., second porthole 44a) and communication hole (e.g., second communication hole 44c) of a through hole (e.g., second through hole 44) adjacent to the first through hole 43 can be brought closer to the first through hole 43 by the difference between the inner diameter of the first communication hole 43c and the inner diameter of the first joint hole 43b. Therefore, compared to a configuration in which the inner diameter of the first communication hole 43c is the same as the inner diameter of the first joint hole 43b, the portion of the valve seat member 40 for forming the through holes (first through hole 43, second through hole 44) can be smaller, contributing to a more compact valve seat member 40.

Furthermore, the inner diameter of the second communication hole 44c is smaller than the inner diameter of the second joint hole 44b, and the entire circumference of the second communication hole 44c is located within the circumference of the second joint hole 44b at the connecting portion with the second joint hole 44b. With this configuration, the porthole (e.g., first porthole 43a) and communication hole (e.g., first communication hole 43c) of a through hole (e.g., first through hole 43) adjacent to the second through hole 44 can be brought closer to the second through hole 44 by the difference between the inner diameter of the second communication hole 44c and the inner diameter of the second joint hole 44b. Therefore, compared to a configuration in which the inner diameter of the second communication hole 44c is the same as the inner diameter of the second joint hole 44b, the portion of the valve seat member 40 for forming the through holes (first through hole 43, second through hole 44) can be smaller, contributing to a more compact valve seat member 40.

Furthermore, by making the length C of the first joint hole 43b in the through-direction longer than the length D of the second joint hole 44b in the through-direction, the continuous portion between the first joint hole 43b and the first communicating hole 43c and the continuous portion between the second joint hole 44b and the second communicating hole 44c can be offset in the perpendicular direction X. In other words, the portion where the inner diameter increases from the first communicating hole 43c to the first joint hole 43b and the portion where the inner diameter increases from the second communicating hole 44c to the second joint hole 44b can be offset in the perpendicular direction X. Therefore, even when the first porthole 43a and the second porthole 44a are brought close to each other, interference between the first joint hole 43b and the second joint hole 44b can be prevented.

As described above, the configuration in which the length A in the through-direction of the first porthole 43a is shorter than the length B in the through-direction of the second porthole 44a and the configuration in which the length C in the through-direction of the first coupling hole 43b is longer than the length D in the through-direction of the second coupling hole 44b can be independent of each other. However, by making the length A in the through-direction of the first porthole 43a shorter than the length B in the through-direction of the second porthole 44a and further making the length C in the through-direction of the first coupling hole 43b longer than the length D in the through-direction of the second coupling hole 44b, it is preferable to set the lengths A, B, C, and D as in this embodiment, because this prevents interference between the first communicating hole 43c and the second communicating hole 44c and between the first coupling hole 43b and the second coupling hole 44b.

In addition, because the first and second joint holes 43b and 44b (joint holes in the multiple through holes) are aligned in the axial direction L and open to the joint surface 42, the width dimension of the valve seat member 40 can be reduced, contributing to a more compact valve seat member 40, compared to a configuration in which the first and second joint holes 43b and 44b do not overlap when viewed from the axial direction L and extend to one side and the other side in the width direction perpendicular to the axial direction L of the valve seat member.

The first coupling hole 43b is parallel to and coaxial with the first communicating hole 43c, and the coupling surface 42 has a tapered surface 42b extending in a direction intersecting the sliding surface 41, through which the first coupling hole 43b opens. Therefore, when machining the first communicating hole 43c, which is inclined with respect to the orthogonal direction X of the sliding surface 41, the tapered surface 42b is first cut using a machining tool to form the first coupling hole 43b, and then the first communicating hole 43c can be formed by cutting at the same angle. This facilitates the formation of the first coupling hole 43b and the first communicating hole 43c. Furthermore, because the tapered surface 42b extends in a direction intersecting the sliding surface 41, the tapered surface 42b can also be formed to extend in a direction perpendicular to the penetration direction of the first communicating hole 43c. In this case, the machining tool can be abutted perpendicularly against the tapered surface 42b. This prevents the tool from slipping against the tapered surface 42b, making it easy and accurate to form the first joint hole 43b and the first communication hole 43c.

In addition, in this embodiment, the valve seat member 40 is made of stainless steel. Stainless steel is more likely to produce cutting burrs during processing than materials such as brass, which are used to make valve seat members in conventional slide-type switching valves. However, as described above, this configuration makes it possible to suppress the generation of cutting burrs when forming the first through hole 43 (through hole) and the second through hole 44 (through hole). Therefore, the present invention can also be applied to valve seat members 40 made of materials that are more likely to produce cutting burrs.

Furthermore, according to this embodiment, the center-to-center distance E, which is the distance in the axial direction L from the center of one of the first porthole 43a (porthole) and the second porthole 44a (porthole), which communicate with the adjacent first joint hole 43b (joint hole) and the second joint hole 44b (joint hole), respectively, to the center of the other, is smaller than the inner diameter F of the second joint hole 44b (adjacent joint hole). With this configuration, the center-to-center distance E of the first porthole 43a and the second porthole 44a (adjacent portholes) can be reduced so that the distance from the center of the first porthole 43a to the center of the second porthole 44a in the axial direction L, i.e., the sliding direction of the valve body 50, is within a range smaller than the inner diameter F of the second joint hole 44b, thereby reducing the sliding distance of the valve body 50. Therefore, for example, if the electromagnetic drive unit 60 is configured as a device equipped with a plunger 61 and an aspirator 62, the distance between the plunger 61 and the aspirator 62 can be reduced, contributing to the miniaturization of the electromagnetic drive unit 60 and the associated labor savings.

Furthermore, by reducing the center-to-center distance E as described above, it becomes easier to ensure a sufficient area for the portion of the sliding surface 41 that slides against the open edge of the valve body 50 and seals the recess 51. Therefore, compared to a configuration in which the center-to-center distance E is equal to or greater than the inner diameter of the adjacent fitting hole, the outer diameter of the sliding surface 41 can be made smaller, thereby enabling the valve seat member 40 itself to be made more compact. This miniaturization is particularly advantageous when the valve body 31 is formed into a cylindrical, bottomed shape, as in this embodiment. Specifically, when the valve body 31 is formed into a cylindrical, bottomed shape, a hole like the second mounting hole 36 described above must be formed in the valve body 31 to fit the valve seat member 40. However, because the valve body 31 is cylindrical, the larger the second mounting hole 36, the more difficult it is to process. However, with this configuration, the valve seat member 40 itself can be made smaller, eliminating the need to enlarge the second mounting hole 36, thereby facilitating the manufacture of the pilot valve 2.

In this way, the refrigeration cycle system 100 can be constructed using a slide-type switching valve that can suppress the generation of cutting burrs when machining the valve seat member 40 and make it less likely for foreign matter to cause malfunctions in the refrigeration cycle.

Although embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes that do not deviate from the gist of the present invention are also included in the present invention. Figure 7(A) is a plan view of a modified valve seat member 70, Figure 7(B) is a cross-sectional view of a modified valve seat member 70, and Figure 7(C) is a rear view of a modified valve seat member 70. Figure 8 is an enlarged cross-sectional view showing the dimensional relationship of a modified valve seat member 70.

The valve seat member 70 is made of stainless steel and is formed into a cylindrical shape extending in the orthogonal direction X. As shown in Figure 7, the end face of the valve seat member 70 on the inside in the orthogonal direction X forms a sliding surface 71 on which the valve body 50 slides, similar to the sliding surface 41 described above. On the other hand, a joint surface 72 is formed on the outside of the valve seat member 70 in the orthogonal direction X. Unlike the joint surface 42 described above, the joint surface 72 does not have a tapered surface 42b and is formed as a flat surface. Three (multiple) first through holes 73 are formed in the valve seat member 70, penetrating from the sliding surface 71 to the joint surface 72. The first through hole 73 includes a first porthole 73a (porthole) that opens to the sliding surface 71, a first coupling hole 73b (coupling hole) that has a larger inner diameter than the first porthole 73a and opens to the coupling surface 72, and a first communication hole 73c (communication hole) that connects the first porthole 73a and the first coupling hole 73b.

The first porthole 73a, first coupling hole 73b, and first communication hole 73c correspond to the first porthole 43a, first coupling hole 43b, and first communication hole 43c, but in this modified example, as shown in FIG. 7(B), the first coupling hole 73b does not extend parallel to the first communication hole 73c, but extends in the perpendicular direction X and opens to the coupling surface 72, which is different from the above-described embodiment. Furthermore, to prevent interference between adjacent first coupling holes 73b, as shown in FIG. 7(C), when the coupling surface 72 is viewed from the perpendicular direction X, the centers of the first coupling holes 73b and the other first coupling holes 73b are arranged so that they are alternately offset from each other in the width direction perpendicular to the axis L. In addition, in this modified example, as shown in Figure 7(B), an imaginary periphery 73d formed by virtually extending the inclined first communication hole 73c to the coupling surface 72 is positioned within the circumference of the opening of the first coupling hole 73b. As a result, as shown in Figure 8, the imaginary periphery 73d does not come into contact with the inner circumferential surface of the first coupling hole 73b within the range of the dimension G of the first coupling hole 73b in the orthogonal direction X (the depth dimension of the first coupling hole 73b).

With this configuration, when machining the first communication hole 73c, which is inclined relative to the orthogonal direction X of the sliding surface 71, a machining tool is first used to cut the first coupling hole 73b from the coupling surface 72, and then the first communication hole 73c is machined at a different angle. However, because the imaginary periphery 73d, which is a virtual extension of the first communication hole 73c to the coupling surface 72, is located within the circumference of the opening of the first coupling hole 73b, the first communication hole 73c can be formed without the machining tool abutting the inner surface of the first coupling hole 73b. This makes it easy to form the first communication hole 73c and reduces the generation of cutting burrs when machining the valve seat member 70, resulting in a pilot valve 2 that is less likely to cause refrigeration cycle malfunctions due to foreign matter.

In this embodiment, the valve body 31 of the pilot valve 2 is formed in a cylindrical shape with a bottom, but the present invention can also be applied to a pilot valve 2 with a valve body without a bottom. However, in such a configuration, since a hole is opened in the bottom of the valve body 31, the valve seat member 40 can be assembled through the hole in the bottom, so the second mounting hole 36 described above may not necessarily be necessary, and the problem of making it difficult to enlarge the second mounting hole 36 as described above may not arise. For this reason, the present invention is more effective when the valve body 31 is formed in a cylindrical shape with a bottom.

In addition, in this embodiment and its modified examples, as an example of a slide-type switching valve, a pilot valve 2 that circulates drive fluid between the four-way valve 1 and the slide valve element 20 of the four-way valve 1, which switches the communication state of four pipes, has been exemplified, and the description has mainly focused on the valve seat member 40 of the pilot valve 2. However, for example, the present invention may also be applied to the valve seat member on which the E joint pipe 13, S joint pipe 14, and C joint pipe 15 are disposed in the four-way valve 1. Furthermore, the slide-type switching valve is not limited to the four-way valve 1 and pilot valve 2. As long as at least one pair of pipes is connected to the valve housing, the slide-type switching valve may be a three-way valve that uses a valve element to switch the pipes to be connected when connecting one pair of pipes out of three. Alternatively, the number of pipes to be connected may be increased to form a multi-way valve. In this way, the number of pipes in the slide-type switching valve, the method of switching the communication state, and other factors may be changed depending on the application of the slide-type switching valve.

While the above embodiment has one second through hole 44 disposed between two first through holes 43, the first through holes 43 can also be adjacent to each other, as in the modified example. In this case, the first coupling holes 43b of the first through holes 43 can also extend in the perpendicular direction X, as in the modified example. In this case, as in the above configuration, the center-to-center distance E of adjacent portholes can be made smaller than the inner diameter of the coupling holes. That is, the center-to-center distance E of adjacent first portholes 43a can be made smaller than the inner diameter of the first coupling holes 43b. In this case, the size of the inner diameter of the first coupling holes 43b is equal to the sum of the radii of the respective first coupling holes 43b. The closer the distance from the center of one first porthole 43a to the center of the other first porthole 43a falls within this range, the smaller the center-to-center distance E of adjacent first portholes 43a can be.

With this configuration, for example, when one first coupling hole 43b and another first coupling hole 43b are aligned with no gap in the axial direction L, adjacent first portholes 43a can be positioned so that their center-to-center distance is smaller than the coupling-side center-to-center distance, which is the axial distance from the center of one first coupling hole 43b to the center of the other first coupling hole 43b. Even with this configuration, the inner diameter of the first coupling hole 43b is larger than the inner diameter of the first porthole 43a, so the first porthole 43a and the first coupling hole 43b are not coaxial. However, in the present invention, the first porthole 43a and the first coupling hole 43b can be connected by the inclined first communication hole 43c, preventing overlap between the port and the coupling hole as occurs in conventional slide-type switching valves. Therefore, even when adjacent first portholes 43a and adjacent first coupling holes 43b are positioned close to each other, the generation of cutting burrs during machining of the valve seat member 40 can be suppressed.

L axis X perpendicular direction (direction perpendicular to the surface)
2 Pilot valve (slide type switching valve)
31 Valve body 40 Valve seat member 41 Sliding surface 42 Joint surface 43 First through-hole (plural through-holes)
43a First porthole (porthole)
43c First communication hole (communication hole)
43b First joint hole (joint hole)
45 First working capillary (joint member)
50 Valve body 60 Electromagnetic drive unit (drive unit)

Claims (9)

A slide-type switching valve comprising: a hollow cylindrical valve body; a valve seat member provided in the valve body; a valve element provided inside the valve body so as to be slidable in an axial direction; and a drive unit that drives the valve element to slide,
the valve seat member has a sliding surface on which the valve body slides, a joint surface located on the opposite side to the sliding surface, and a plurality of through holes extending from the sliding surface to the joint surface,
the through hole has a porthole that opens into the sliding surface, a coupling hole that opens into the coupling surface with an inner diameter larger than that of the porthole and into which a coupling member is inserted, and a communication hole that communicates the porthole with the coupling hole, the portholes in the plurality of through holes being arranged side by side in the axial direction,
a first through hole constituting at least one of the plurality of through holes includes a first porthole as the porthole, a first communicating hole as the communicating hole, and a first joint hole as the joint hole;
the first communication hole is provided at an angle with respect to a direction perpendicular to the sliding surface, and the inner diameter thereof is larger than the inner diameter of the first porthole,
the first porthole is provided along the direction orthogonal to the plane, and the entire circumference of the continuous portion with the first communicating hole is located within the circumference of the first communicating hole,
a continuous portion between the first porthole and the first communication hole is inclined with respect to the direction orthogonal to the plane,
A slide-type switching valve, wherein the inner diameter of the first joint hole is set to be equal to or larger than the inner diameter of the first communication hole. a second porthole that is the porthole of a second through hole different from the first through hole among the plurality of through holes is provided to extend in a direction perpendicular to the sliding surface and has an inner diameter smaller than that of a second communicating hole that is the communicating hole of the second through hole,
The second communication hole is provided to extend in a direction perpendicular to the sliding surface,
the entire circumference of the second porthole is located within the circumference of the second communicating hole at a portion where the second porthole and the second communicating hole are continuous with each other,
2. The slide-type switching valve according to claim 1, wherein the length of the first porthole in the penetrating direction is shorter than the length of the second porthole in the penetrating direction. The inner diameter of the first communicating hole is smaller than the inner diameter of the first joint hole,
the first communicating hole has an entire periphery located within the circumference of the first joint hole at a portion connected to the first joint hole,
The inner diameter of the second communication hole is smaller than the inner diameter of the second joint hole which is the joint hole of the second through hole,
the second communicating hole has an entire periphery located within the circumference of the second joint hole at a portion connected to the second joint hole,
3. The slide-type switching valve according to claim 2, wherein the length of the first joint hole in the through direction is longer than the length of the second joint hole in the through direction. The slide-type switching valve described in claim 1, characterized in that the coupling holes in the multiple through holes are aligned in the axial direction and open to the coupling surface. The slide-type switching valve described in claim 1, characterized in that the first coupling hole is arranged parallel to and coaxial with the first communication hole, and the coupling surface is provided with a tapered surface that extends in a direction intersecting the sliding surface and into which the first coupling hole opens. a plurality of the first through holes are provided, and the first joint hole extends parallel to the first porthole and opens into the joint surface;
2. The slide-type switching valve according to claim 1, wherein an imaginary periphery of the inclined first communication hole extended to the coupling surface is located within a circumference of an opening of the first coupling hole. The slide-type switching valve described in claim 1, characterized in that the valve seat member is made of stainless steel. A slide-type switching valve as described in any one of claims 1 to 7, characterized in that the center-to-center distance, which is the distance in the axial direction from the center of one of the portholes communicating with adjacent coupling holes to the center of the other, is smaller than the inner diameter of the adjacent coupling holes. A refrigeration cycle system equipped with the slide-type switching valve described in claim 1.