Slide-type switching valve and refrigeration cycle system

Abstract

To provide a slide type changeover valve and a refrigeration cycle system that can suppress a plunger from vibrating and also enhance the stability of a changeover action.SOLUTION: A pilot valve 2 (slide type changeover valve) comprises a valve body 30, a valve seat member 40, a valve body 50, a valve body holding part 71, a first plunger 73 and a second plunger 76, and a first electromagnetic drive part 80 and a second electromagnetic drive part 90. The first electromagnetic drive part 80 has a first suction element 81 and a first electromagnetic coil 84, and the second electromagnetic drive part 90 has a second suction element 91 and a second electromagnetic coil 94. The second plunger 76 has a peripheral surface shape which is larger in area slid and guided to an inner peripheral surface of the valve body 30 than the first plunger 73, and a plunger spring 78 which energizes the first plunger 73, the second plunger 76, and the valve body holding part 71 toward the first suction element 81 or the second suction element 91 is provided in a valve chamber 31.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] A slide type switching valve (pilot valve) is known that includes a valve body (valve housing and plunger case) having a valve chamber inside, a valve seat portion (pilot valve seat) provided on the valve body and having a plurality of valve ports, a valve body (pilot valve body) slidably provided on the valve seat surface of the valve seat portion to switch the communication state of a pipe communicating with the valve chamber, a valve body holding portion (valve body holding hole) for holding the valve body, first and second plungers (plungers) provided integrally with the valve body holding portion so as to be able to move forward and backward within the valve body, and first and second electromagnetic drive portions (electromagnetic coils and attractors) for driving the valve body holding portion, the first and second plungers along the axial direction of the valve body. In this slide type switching valve, the plunger is formed with a substantially cylindrical shape as a whole and has a flat portion (D cut surface) facing the valve seat surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional slide type switching valve, since a flat portion is formed over the entire length of the plunger, the area slidably guided by the inner peripheral surface of the valve body is insufficient, and there is a possibility that the plunger may tilt or lock during forward and backward movement. Also, when not energized, the plunger may vibrate within the valve body, which may cause durability degradation due to wear of the plunger and the valve body.

[0005] The present invention aims to provide a slide-type switching valve and a refrigeration cycle system that can suppress plunger vibration and improve the stability of the switching operation. [Means for solving the problem]

[0006] To solve the aforementioned problems and achieve the objective, the sliding type switching valve of the present invention comprises a valve body having a valve chamber inside, a valve seat portion provided on the valve body and having a plurality of valve ports, a valve element slidably provided on the valve seat surface of the valve seat portion, a valve element holder portion that holds the valve element, a first plunger and a second plunger provided integrally with the valve element holder portion and movable back and forth within the valve body, and a first electromagnetic drive portion and a second electromagnetic drive portion that drive the valve element holder portion, the first plunger and the second plunger along the axial direction of the valve body. A sliding type switching valve comprising a first electromagnetic drive unit having a first suction element and a first electromagnetic coil, the second electromagnetic drive unit having a second suction element and a second electromagnetic coil, the second plunger having a circumferential shape that provides a larger area of ​​sliding guidance on the inner circumferential surface of the valve body than the first plunger, and the valve chamber provided with a plunger spring that biases the first plunger, the second plunger, and the valve body holding unit toward the first suction element or the second suction element.

[0007] According to the present invention, the second plunger has a circumferential shape that provides a larger sliding surface area to the inner surface of the valve body than the first plunger, thereby ensuring an appropriate sliding surface area for the valve body with respect to the second plunger, and improving the stability of the switching operation by the valve body. Furthermore, by providing a plunger spring, the first plunger, the second plunger, and the valve body holder can be moved towards the first suction side or the second suction side by biasing force, and the state of being pressed in the same direction can be maintained. Therefore, vibration of the first plunger and the second plunger (plunger) can be suppressed even when no power is supplied. Thus, a slide-type switching valve can be provided that suppresses plunger vibration and improves the stability of the switching operation. In addition, by providing a plunger spring, the driving force of the first electromagnetic drive unit that attracts the first plunger can be reduced by the biasing force of the plunger spring, or the driving force of the second electromagnetic drive unit that attracts the second plunger can be reduced. Therefore, it is possible to miniaturize the first or second electromagnetic drive unit, or to reduce the operating voltage of the first or second electromagnetic drive unit, which can contribute to miniaturizing or reducing the cost of the slide-type switching valve.

[0008] In this case, it is preferable that the second plunger has a cylindrical outer surface that is slidably guided by the inner surface of the valve body over almost its entire circumference. With this configuration, since the outer surface of the second plunger can be slidably guided by the inner surface of the valve body over almost its entire circumference, tilting of the first plunger, valve body holder, and second plunger can be suppressed at the second plunger portion, and locking of the first plunger, valve body holder, and second plunger can be suppressed. Therefore, the stability of the valve body switching operation can be further improved.

[0009] Furthermore, it is preferable that the first plunger has a flat portion having an opposing surface that faces the valve seat surface of the valve seat portion. With this configuration, the first plunger can be moved with the opposing surface of the flat portion facing the valve seat surface. In addition, with this configuration, a space equal to at least the height from the inner surface of the valve body to the valve seat surface is created between the first plunger and the inner surface of the valve body, and the valve seat portion can be arranged using this space. Therefore, it is not necessary to prepare a special space within the valve body for installing the valve seat portion, and the size of the valve body can be prevented from increasing accordingly.

[0010] Furthermore, it is preferable that the plunger spring biases the first plunger, the second plunger, and the valve body holder toward the first suction element. With this configuration, the driving force of the first electromagnetic drive unit that attracts the first plunger can be reduced by the biasing force of the plunger spring. As a result, the first electromagnetic drive unit can be miniaturized, the operating voltage of the first electromagnetic drive unit can be reduced, and so on, which can contribute to the miniaturization or cost reduction of the slide-type switching valve.

[0011] Furthermore, it is preferable that the area of ​​the end face of the second plunger facing the second suction element is larger than the area of ​​the end face of the first plunger facing the first suction element. With this configuration, it becomes easier to obtain the pressing force between the second plunger and the second suction element that presses the second plunger against the biasing force of the plunger spring, thereby improving the stability of the valve body switching operation.

[0012] Furthermore, it is preferable that the first plunger has a first through-hole that penetrates from the end face facing the first suction element to the outer circumferential surface. In a sliding type switching valve, the first plunger comes into contact with the first suction element when it is attracted to it. At this time, a vacuum may be created between the contact surfaces, causing the first plunger to stick to the first suction element. If this happens, a large driving force is required to detach the first plunger from the first suction element. However, with this configuration, by providing the first through-hole in the first plunger, when the first plunger comes into contact with the first suction element, the space between the contact surfaces communicates with the valve chamber via the outer circumferential surface of the first plunger. Therefore, a vacuum is prevented between the first plunger and the first suction element, and the first plunger can be prevented from sticking to the first suction element. Furthermore, by preventing the first plunger and the first suction element from sticking together, a large driving force is not required to drive the second plunger, thus preventing the second electromagnetic coil from becoming larger.

[0013] Furthermore, it is preferable that the first through-hole penetrates the flat portion from the end face facing the first suction element. With this configuration, when the first plunger contacts the first suction element, the space between the contact surfaces communicates with the valve chamber via the flat portion. Therefore, a vacuum state is prevented between the first plunger and the first suction element, and the first plunger is prevented from sticking to the first suction element. The portion where the flat portion is located is the part in the valve chamber where a space is created between the first plunger and the inner circumferential surface of the valve body, as described above. Therefore, when the first plunger contacts the first suction element, by making this space the destination of the first through-hole, it is easier to reliably connect the space between the contact surfaces with the valve chamber, and the occurrence of a vacuum state between the contact surfaces can be further suppressed.

[0014] Furthermore, the second plunger is provided with an insertion hole into which a plunger spring is inserted, and it is preferable that the insertion hole is recessed from the end face facing the second suction element. With this configuration, the plunger spring can be housed in the second plunger by inserting it into the insertion hole, thereby contributing to space saving of the valve body. This makes it possible to miniaturize the slide-type switching valve.

[0015] Furthermore, it is preferable that the second plunger has a second through-hole that penetrates from the end face facing the second suction element to the outer circumferential surface. With this configuration, by providing the second through-hole in the second plunger, when the second plunger comes into contact with the second suction element, the space between the contact surfaces communicates with the valve chamber via the outer circumferential surface of the second plunger. Therefore, a vacuum state is prevented between the second plunger and the second suction element, and the second plunger is prevented from sticking to the second suction element.

[0016] Furthermore, the first plunger has a first through-hole that penetrates from the end face facing the first suction element to the outer circumferential surface, and the second plunger has an insertion hole into which a plunger spring is inserted, preferably the insertion hole is formed recessed from the end face facing the second suction element. With this configuration, when the first plunger contacts the first suction element, the space between the contact surfaces communicates with the valve chamber via the outer circumferential surface of the first plunger, thereby preventing a vacuum from forming between the first plunger and the first suction element and preventing the first plunger from sticking to the first suction element. In addition, by inserting the plunger spring into the insertion hole, the plunger spring can be housed in the second plunger, which contributes to saving space in the valve body.

[0017] Furthermore, it is preferable that the area of ​​the second suction surface in the second plunger that contacts the second suction element is larger than the area of ​​the first suction surface in the first plunger that contacts the first suction element. For example, if the plunger spring described above biases the first plunger, valve body holder, and second plunger toward the first suction element, then in order to move the second plunger toward the second suction element and press it, it is necessary to resist the biasing force of the plunger spring, thus requiring a greater suction force than when moving the first plunger toward the first suction element and pressing it.

[0018] Specifically, for example, if P1 is the magnetic force of attraction between the first attractor and the first plunger, Q is the biasing force of the plunger spring, P2 is the magnetic force of attraction between the second attractor and the second plunger, and R is the force that moves and presses the first or second plunger, then the pressing force R = P1 + Q that presses the first plunger against the first attractor, while the pressing force R = P2 - Q that presses the second plunger against the second attractor. Therefore, since P2 - P1 = 2Q, the attractive force P2 needs to be at least twice the biasing force Q and greater than the attractive force P1. In this case, one could consider increasing the number of turns in the second electromagnetic coil or increasing the driving power, but this would increase the size of the second electromagnetic coil or increase the cost of driving it. However, with this configuration, by making the area of ​​the second suction surface larger than the area of ​​the first suction surface, a greater suction force P2 than the suction force P1 can be obtained. Therefore, it is not necessary to enlarge the second electromagnetic coil or increase the driving power to obtain this larger suction force P2.

[0019] In this configuration, for example, by adjusting the area of ​​the second suction surface to balance with the spring load of the plunger spring, the pressing force that presses the first plunger against the first suction element and the pressing force that presses the second plunger against the second suction element can be made the same. This makes it possible to use the same components for the first and second electromagnetic coils, and for the first and second suction elements. As a result, the manufacturing costs of the first and second electromagnetic drive units can be reduced. Therefore, this can contribute to miniaturization and cost reduction of the slide-type switching valve. It should be noted that using the same components for the first and second electromagnetic coils, and for the first and second suction elements, is not mandatory, and they do not necessarily have to be used in this way.

[0020] Furthermore, it is preferable that the first electromagnetic drive unit comprises a first outer casing covering the first electromagnetic coil, and the first through hole extending from the end face of the first plunger facing the first suction element to the outer circumferential surface comprises a first end hole portion opening to the end face facing the first suction element and a first outer circumferential hole portion communicating with the first end hole portion and opening to the outer circumferential surface of the first plunger, and the first suction element has a first mounting hole on its end face into which a fixing member for fixing the first outer casing is inserted, and the first end hole portion and the first mounting hole are provided coaxially, and the second electromagnetic drive unit comprises a second outer casing covering the second electromagnetic coil, the second plunger has an insertion hole into which the plunger spring is inserted, and the second suction element has a second mounting hole on its end face into which a fixing member for fixing the second outer casing is inserted, and the insertion hole portion and the second mounting hole are provided coaxially.

[0021] With this configuration, the first end hole constituting the first through-hole and the first mounting hole of the first attractor are provided coaxially, making it easier to form a continuous magnetic path in the axial direction around the first electromagnetic coil, passing through the first outer casing, the first attractor, and the first plunger without passing through spaces such as the first end hole and the first mounting hole, thereby increasing the magnetic force between the first attractor and the first plunger. Furthermore, the insertion hole for the second plunger and the second mounting hole for the second attractor are provided coaxially, making it easier to form a continuous magnetic path in the axial direction around the second electromagnetic coil, passing through the second outer casing, the second attractor, and the second plunger without passing through spaces such as the insertion hole and the second mounting hole, thereby increasing the magnetic force between the second attractor and the second plunger.

[0022] Furthermore, if the portion of the first suction surface of the first plunger that contacts the first suction element is defined as the first suction portion, excluding the portion obtained by projecting the first mounting hole in the axial direction, and the portion of the second suction surface of the second plunger that contacts the second suction element is defined as the second suction portion, excluding the portion obtained by projecting the second mounting hole in the axial direction, then it is preferable that the area of ​​the second suction portion is larger than the area of ​​the first suction portion.

[0023] With this configuration, the first adsorption section is a part where a magnetic path is formed axially continuous through the first attractor and the first plunger without passing through a space such as the first mounting hole, and is a part where the magnetic force tends to be relatively greater than in the part of the first adsorption surface where a space such as the first mounting hole is formed. Similarly, the second adsorption section is a part where a magnetic path is formed axially continuous through the second attractor and the second plunger without passing through a space such as the second mounting hole, and is a part where the magnetic force tends to be relatively greater than in the part of the second attractor where a space such as the second mounting hole is formed. Furthermore, with this configuration, since the area of ​​the second adsorption section is larger than the area of ​​the first adsorption section among the parts where the magnetic force tends to be greater than in each other, it becomes even easier to obtain an attractive force P2 that is greater than the attractive force P1. Therefore, it is not necessary to enlarge the second electromagnetic coil or increase the driving power in order to obtain the attractive force P2.

[0024] Further, the valve body may be composed of a central valve body provided with the valve seat portion, a first plunger tube connected to one side in the axial direction of the central valve body, and a second plunger tube connected to the other side in the axial direction of the central valve body.

[0025] Further, the valve body is preferably composed of an integrally formed plunger tube that is entirely circular tubular, and the valve seat portion is attached to an intermediate portion of the plunger tube. The first attractor is fixed to one end of the plunger tube in the axial direction, and the second attractor is fixed to the other end of the plunger tube in the axial direction.

[0026] According to such a configuration, the valve body can be composed of an integrally formed circular tubular plunger tube, that is, a single component. Therefore, the number of components of the valve body can be reduced, contributing to cost reduction. Also, by constructing the valve body from a single component, it is easy to prevent misalignment of the plunger tube, and sliding friction between the first plunger, the second plunger, and the valve body holding portion that move forward and backward within the plunger tube with respect to the valve body can be suppressed. According to this, even without increasing the driving force in the first electromagnetic drive unit and the second electromagnetic drive unit, the first plunger, the second plunger, and the valve body holding portion can be smoothly moved forward and backward, contributing to miniaturization of the first and second electromagnetic drive units. Also, since sliding friction between the first plunger, the second plunger, and the valve body holding portion can be suppressed, generation of abnormal noise within the valve body can be suppressed.

[0027] Further, the refrigeration cycle system of the present invention is characterized by including the slide type switching valve described above. According to the present invention like this, a refrigeration cycle system can be configured using a slide type switching valve that can suppress vibration of the plunger and enhance stability of the switching operation.

Effects of the Invention

[0028] According to the present invention, it is possible to provide a slide-type switching valve and a refrigeration cycle system that can suppress plunger vibration and improve the stability of the switching operation. [Brief explanation of the drawing]

[0029] [Figure 1] A schematic diagram showing a refrigeration cycle system equipped with a slide-type switching valve according to an embodiment of the present invention. [Figure 2] A cross-sectional view of a sliding type switching valve, cut along the axial direction of the valve body. [Figure 3] (A) is a cross-sectional view of the plunger portion of a sliding type switching valve, cut along the axial direction of the valve body; (B) is a front view of the first plunger constituting the plunger portion; and (C) is a front view of the second plunger constituting the plunger portion. [Figure 4] (A) is an enlarged cross-sectional view of the sliding type switching valve, showing the portion of the first electromagnetic drive unit, and (B) is a cross-sectional view of the first suction element, cut in a direction perpendicular to the axial direction. [Figure 5] A cross-sectional view of the slide-type switching valve in the first modified example, cut along the axial direction of the valve body. [Figure 6] (A) is a cross-sectional view of the plunger portion in the second modified example, cut along the axial direction of the valve body; (B) is a front view of the first plunger in the second modified example; and (C) is a front view of the second plunger in the second modified example. [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described below with reference to Figures 1 to 4(B). In the following description, the direction in which the axis X of the valve body 30, which will be described later, extends will be referred to as the "axis X direction." The direction intersecting the axis X direction will be referred to as the "radial direction." Furthermore, the concepts of "up and down" and "left and right" in the following description will correspond to up and down and left and right in the figures. Note that these definitions of directions are for the convenience of explanation only and do not necessarily coincide with the directions in the actual usage conditions of the present invention, nor do they 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.

[0031] The four-way valve 1 is a valve device that switches the flow path of refrigerant by switching the connection state of four pipes. The four-way valve 1 comprises a housing 10 and a slide valve body 20 that is slidably mounted inside the housing 10. The housing 10 comprises a cylindrical body 11 with both ends closed by lid members. The body 11 is formed by press working or the like from a metal material such as stainless steel. A D-joint pipe 12, which serves as a high-pressure pipe through which refrigerant flows, is fixed to the side wall of the body 11 by brazing or the like, inserted in the thickness direction of the plate, and communicates with the inside of the body 11. On the side wall of the body 11 opposite the D-joint pipe 12, an E-joint pipe 13, an S-joint pipe 14, and a C-joint pipe 15 are fixed in the same direction as shown in Figure 1, from left to right, by brazing or the like, inserted in the thickness direction of the plate, and each communicates with the inside of the body 11.

[0032] The E-connector pipe 13, S-connector pipe 14, and C-connector pipe 15 are piping through which refrigerant flows, similar to the D-connector pipe 12, and function as high-pressure or low-pressure piping. The interior of the main body 11 is divided into three spaces by a piston 23, consisting of a high-pressure chamber 16 that is always in communication with the D-connector pipe 12, and a first operating chamber 17 and a second operating chamber 18 adjacent to the high-pressure chamber 16. The slide valve body 20 is provided inside the main body 11 so as to be slidable in the direction of the central axis L of the main body 11, and switches the communication state of the D-connector pipe 12, E-connector pipe 13, S-connector pipe 14, and C-connector pipe 15 as described above. The slide valve body 20 comprises a valve body 21, a connecting plate 22 that holds the valve body 21 and extends in the direction of the central axis L of the main body 11, and a pair of pistons 23 provided at both ends of the connecting plate 22 in the direction of extension.

[0033] The valve body 21 is formed in a bowl shape so as to open toward the E joint pipe 13, S joint pipe 14, and C joint pipe 15. The opening of the valve body 21 is sized to cover two adjacent openings among the E joint pipe 13, S joint pipe 14, and C joint pipe 15. At the left end position shown in Figure 1, the valve body 21 connects the E joint pipe 13 and the S joint pipe 14 internally, and connects the D joint pipe 12 and the C joint pipe 15 externally. Then, moving from this state to the right side in Figure 1 to the right end position (not shown), it connects the C joint pipe 15 and the S joint pipe 14 internally, and connects the D joint pipe 12 and the E joint pipe 13 externally. The connecting plate 22 holds the valve body 21 at the center of the central axis L of the main body 11 and extends to one side and the other side in the direction of the central axis L. A sealing member such as a packing is attached to the piston 23, thereby dividing the inside of the main body 11 into the three spaces described above.

[0034] Specifically, the space between the pair of pistons 23 constitutes a high-pressure chamber 16, the area to the left of the high-pressure chamber 16 in Figure 1 constitutes a first working chamber 17, and the area to the right of the high-pressure chamber 16 in Figure 1 constitutes a second working chamber 18. In the refrigeration cycle system 100 shown in Figure 1, the D joint pipe 12 is connected to the discharge port of the compressor 6, and the S joint pipe 14 is connected to the suction port of the compressor 6. In addition, the C joint pipe 15 is connected to the outdoor heat exchanger 5, and the E joint 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 a throttling device 4. Thus, the refrigeration cycle system 100 is composed of a path consisting of the C joint pipe 15, the outdoor heat exchanger 5, the throttling device 4, the indoor heat exchanger 3, and the E joint pipe 13, and a path consisting of the S joint pipe 14, the compressor 6, and the D joint pipe 12.

[0035] The pilot valve 2 is a sliding type switching valve in the present invention, and it circulates a driving fluid between the pilot valve 2 and the four-way valve 1 to move the sliding valve body 20 of the four-way valve 1. As shown in Figure 2, the pilot valve 2 comprises a valve body 30, a valve seat member 40 (valve seat portion) attached to the valve body 30, a valve body 50 that slides on the valve seat member 40, and a drive unit 60 that slides the valve body 50. The valve body 30 is formed by press working or the like from a metal material such as stainless steel, and has a valve chamber 31 inside. The valve body 30 comprises a central valve body 32 extending in the axial direction X, a first plunger tube 36 connected to the left side (one side in the axial direction X) of the central valve body 32, and a second plunger tube 37 connected to the right side (the other side in the axial direction X) of the central valve body 32.

[0036] The central valve body 32 is formed in a substantially cylindrical shape extending in the axial direction X. The central part of the central valve body 32 in the axial direction X constitutes a large-diameter section 33, which has a larger diameter than other parts. The large-diameter section 33 has a thin tube mounting hole 34 that penetrates radially and a valve seat mounting hole 35 that penetrates radially opposite to the thin tube mounting hole 34. One end of the D thin tube 34a, which serves as high-pressure piping, is inserted through the thin tube mounting hole 34 and fixed by brazing or the like. The other end of the D thin tube 34a is connected to the D joint pipe 12 described above, as shown in Figure 1, thereby connecting the D thin tube 34a and the D joint pipe 12. A valve seat member 40 is fitted into the valve seat mounting hole 35. The valve seat member 40 is a member that allows the valve body 50 to slide, and is formed in a cylindrical shape extending in a direction perpendicular to the axial direction X using a metal material such as stainless steel.

[0037] As shown in Figure 2, the valve seat member 40 has an upper portion located inside the valve chamber 31 and a lower portion located outside the valve chamber 31. The end face of the valve seat member 40 on the valve chamber 31 side constitutes the valve seat surface 41 on which the valve body 50 slides. The valve seat surface 41 has a first port 42, a second port 43, and a third port 44 formed in order from left to right in the direction of the axis X. In other words, the valve seat member 40 is provided with multiple valve ports. The first port 42, the second port 43, and the third port 44 are formed in a concave shape that extends perpendicular to the direction of the axis X and opens into the valve chamber 31. On the other hand, the outer end face of the valve seat member 40 constitutes a joint surface 45. The joint surface 45 has a first joint hole 46, a second joint hole (not shown), and a third joint hole 48 formed in order from left to right in the direction of the axis X.

[0038] The first joint hole 46 has one end communicating with the first port 42 and the other end opening to the joint surface 45. The first operating tube 46a is inserted into the other end opening of the first joint hole 46 and fixed by brazing or the like. The second joint hole has one end communicating with the second port 43 and the other end opening to the joint surface 45. The S tube 47 is inserted into the other end opening of the second joint hole and fixed by brazing or the like. The third joint hole 48 has one end communicating with the third port 44 and the other end opening to the joint surface 45. The second operating tube 48a is inserted into the other end opening of the third joint hole 48 and fixed by brazing or the like. As shown in Figure 1, the first operating tube 46a communicates with the first operating chamber 17 of the four-way valve 1. The S tube 47 communicates with the S joint pipe 14 of the four-way valve 1. Furthermore, the second working tube 48a is in communication with the second working chamber 18 of the four-way valve 1.

[0039] As shown in Figure 2, the first plunger tube 36 is formed in a substantially cylindrical shape and extends in the axial direction X. The right end of the first plunger tube 36 is fixed by brazing or the like while inserted into the left end opening of the central valve body 32. The second plunger tube 37 is formed in a substantially cylindrical shape and extends in the axial direction X. The left end of the second plunger tube 37 is fixed by brazing or the like while inserted into the right end opening of the central valve body 32. The valve chamber 31 inside the valve body 30 formed in this way houses the valve element 50. As shown in Figure 2, the valve element 50 is formed in a columnar shape and extends in a direction intersecting the axial direction X.

[0040] The valve body 50 is housed and held in the valve body housing hole 72a of the valve body holding part 71, which will be described later, and is capable of moving forward and backward in the axial X direction. A recess 52 is formed on the surface of the valve body 50 facing the valve seat surface 41, opening toward the valve seat surface 41. The opening of the recess 52 is sized to cover two adjacent openings among the first port 42, second port 43, and third port 44. The recess 52 is configured to move forward and backward in the axial X direction while sliding its opening edge, the sealing surface 53, against the valve seat surface 41, and by moving forward and backward in the axial X direction, the communication state of the first port 42, second port 43, and third port 44 is switched. This switches the communication state of the D tube 34a, first working tube 46a, S tube 47, and second working tube 48a.

[0041] Specifically, at the leftmost position shown in Figure 2, the recess 52 connects the first actuating tube 46a and the S tube 47 internally, and connects the D tube 34a and the second actuating tube 48a externally. In this state, the high-pressure drive fluid that flows into the valve chamber 31 through the D tube 34a flows to the valve seat member 40 side through the pressure equalization hole 72 (described later), and flows from the third port 44, which is not covered by the recess 52, through the second actuating tube 48a into the second actuating chamber 18 of the four-way valve 1 shown in Figure 1. On the other hand, the low-pressure drive fluid that flows into the recess 52 through the S tube 47 flows from the first port 42 through the first actuating tube 46a into the first actuating chamber 17 of the four-way valve 1 shown in Figure 1.

[0042] On the other hand, when the valve body 50 moves from the left end position to the right end position (not shown), the recess 52 connects the second actuating tube 48a and the S tube 47 internally, and connects the D tube 34a and the first actuating tube 46a externally. In this state, the high-pressure drive fluid that flows into the valve chamber 31 through the D tube 34a flows through the pressure equalization hole 72 towards the valve seat member 40, and flows from the first port 42, which is not covered by the recess 52, through the first actuating tube 46a into the first actuating chamber 17 of the four-way valve 1 shown in Figure 1. On the other hand, the low-pressure drive fluid that flows into the recess 52 through the S tube 47 flows from the third port 44 through the second actuating tube 48a into the second actuating chamber 18 of the four-way valve 1.

[0043] The drive unit 60 is the part that moves the valve body 50 and the plunger unit 70 (described later) back and forth in the direction of the axis X, and comprises the plunger unit 70 extending in the direction of the axis X, a first electromagnetic drive unit 80 positioned to the left of the plunger unit 70, and a second electromagnetic drive unit 90 positioned to the right of the plunger unit 70. The plunger unit 70 is positioned within the valve chamber 31 and is provided to be movable back and forth in the direction of the axis X within the valve chamber 31, and as shown in Figure 3(A), comprises a valve body holder 71, and a first plunger 73 and a second plunger 76 provided integrally with the valve body holder 71 and having the same maximum outer diameter. A pressure equalization hole 72 is formed in the center of the valve body holder 71 in the direction of the axis X, penetrating in a direction perpendicular to the axis X. The pressure equalization hole 72 includes a valve body housing hole 72a that opens towards the valve seat member 40, a spring housing hole 72b that communicates with the valve body housing hole 72a, and a communication hole 72c that communicates with the spring housing hole 72b and opens towards the aforementioned thin tube mounting hole 34.

[0044] The valve body 50 shown in Figure 2 is housed and held in the valve body housing hole 72a. The spring housing hole 72b is formed to be smaller in diameter than the valve body housing hole 72a, and houses a biasing member 51 in a contracted state. The biasing member 51 is a spring, one end of which abuts against the stepped portion between the spring housing hole 72b and the communication hole 72c, and the other end of which abuts against the top of the valve body 50. As a result, the valve body 50 is biased toward the valve seat member 40 by the spring load of the biasing member 51. The communication hole 72c opens toward the opening of the D tube 34a, thereby enabling communication between the D tube 34a, the valve chamber 31, the first working tube 46a, the S tube 47, and the second working tube 48a.

[0045] As shown in Figure 3(A), the first plunger 73 is provided continuously with the left end of the valve body holder 71 and is formed in a substantially cylindrical shape extending to the left. As shown in Figure 4(B), the maximum outer diameter γ of the first plunger 73 is set to be the same as the maximum outer diameter σ of the second plunger 76, and most of the outer circumferential surface of the portion having the maximum outer diameter γ is slidably guided by the inner circumferential surface of the valve body 30. As shown in Figure 3(A), a flat portion 74 is formed on the lower surface of the first plunger 73, continuous with the left end face C (the end face facing the first suction element 81, which will be described later) and extending along the axis X. The flat portion 74 is formed from the left end face C of the first plunger 73 to the lower surface of the first plunger 73 and the lower surface of the valve body holder 71, and a part of it is the opposing surface 74a facing the valve seat surface 41 of the valve seat member 40. As shown in Figure 3(B), the left end face C of the first plunger 73 has a front view shape D due to the formation of the flat portion 74, which creates a space between the inner circumferential surface of the valve body 30 and the first plunger 73. Therefore, unlike the other outer circumferential surfaces that are guided by the inner circumferential surface of the valve body 30, the flat portion 74 is configured not to slide against the inner circumferential surface of the valve body 30. The flat portion 74 can also be referred to as the D-cut surface.

[0046] The first plunger 73 has a first through-hole 75 that penetrates from the left end face C to the outer circumferential surface. In this embodiment, the first through-hole 75 is formed of a first end hole portion 75a formed coaxially with axis X and a first outer circumferential hole portion 75b that communicates with the first end hole portion 75a and opens into the flat portion 74. This is merely an example, and the first end hole portion 75a does not necessarily have to be coaxial with axis X, and the first outer circumferential hole portion 75b may open into the outer circumferential surface of the first plunger 73 other than the flat portion 74. In addition, multiple first through-holes 75 may be formed. Of the left end face C of the first plunger 73, the end face excluding the portion in which the first through-hole 75 is formed and the portion in which the flat portion 74 is formed is a surface that can come into contact with the first suction element 81, which will be described later, and constitutes the first suction surface A that is attracted to the first suction element 81.

[0047] The second plunger 76 is provided continuously with the right end of the valve body holder 71 and is formed in a substantially cylindrical shape extending to the right. As shown in Figure 4(B), the maximum outer diameter σ of the second plunger 76 is set to be the same as the maximum outer diameter γ of the first plunger 73. In contrast, as shown in Figure 3(C), the second plunger 76 does not have a flat portion 74 and has an outer circumferential surface that is slidably guided by the inner circumferential surface of the valve body 30 over almost its entire circumference. That is, the second plunger 76 is formed with a circumferential surface shape that has a larger area slidably guided by the inner circumferential surface of the valve body 30 than the first plunger 73, which has a flat portion 74 that does not slide against the inner circumferential surface of the valve body 30. Furthermore, while the maximum outer diameter γ of the first plunger 73 and the maximum outer diameter σ of the second plunger 76 are the same, the second plunger 76 does not have a surface like the flat portion 74 of the first plunger 73. Therefore, the area of ​​the right end face D of the second plunger 76 (the end face facing the second suction element 91, which will be described later) is larger than the area of ​​the left end face C of the first plunger 73. Note that the larger the dimension of the second plunger 76 in the axial direction X, the more sliding surface area can be secured with respect to the valve body 30, and the more stable the forward and backward movement of the plunger portion 70 becomes. Therefore, it is desirable to set the dimension as large as possible, up to the length that does not interfere with the valve seat member 40 when it moves forward and backward.

[0048] As shown in Figure 3(A), the second plunger 76 has an insertion hole 77 that opens on the right end face D (the end face facing the second suction element 91, which will be described later) and is recessed on the left side, extending in the direction of the axis X. The plunger spring 78 shown in Figure 2 is inserted into the insertion hole 77 in a contracted state. One end of the plunger spring 78 abuts against the left end face of the second suction element 91, which will be described later, and the other end of the plunger spring 78 abuts against the stepped portion between the insertion hole 77 and the second through hole 79, which will be described later. As a result, the first plunger 73, the second plunger 76, and the valve body holder 71, i.e., the entire plunger portion 70, are biased toward the first suction element 81. The biasing force Q of the plunger spring 78 can be changed as appropriate, but in this embodiment, the biasing force Q is adjusted so that the first suction surface A of the first plunger 73 contacts the right end face of the first suction element 81 when the first electromagnetic coil 84 and the second electromagnetic coil 94, which will be described later, are not energized. As a result, even when the drive unit 60 is not energized, the plunger portion 70 moves toward the first suction element 81 and is maintained in a pressed state in the same direction, thereby suppressing vibration of the plunger portion 70.

[0049] The second plunger 76 has a second through-hole 79 that communicates with the insertion hole 77 and penetrates from the right end face D (the end face facing the second suction element 91) to the outer circumferential surface. In this embodiment, the second through-hole 79 is formed of a second end hole portion 79a formed coaxially with axis X and a second outer circumferential hole portion 79b that communicates with the second end hole portion 79a and opens to the lower surface of the second plunger 76. This is merely an example, and the second end hole portion 79a does not necessarily have to be coaxial with axis X, and the second outer circumferential hole portion 79b may open to an outer circumferential surface of the second plunger 76 other than the lower surface. In addition, multiple second through-holes 79 may be formed. Of the right end face D of the second plunger 76, the end face excluding the portion in which the insertion hole 77 is formed is a surface that can come into contact with the second suction element and constitutes the second suction surface B that is attracted to the second suction element 91. In this embodiment, the area of ​​the second adsorption surface B is set to be larger than the area of ​​the first adsorption surface A described above.

[0050] In this embodiment, the area of ​​the second suction surface B is set to be larger than the area of ​​the first suction surface A, but this relationship is not always true. For example, if the area of ​​the end face of the first suction element 81 is smaller than the area of ​​the left end face C of the first plunger 73, or if the area of ​​the end face of the second suction element 91 is smaller than the area of ​​the right end face D of the second plunger 76, the area of ​​the first suction surface A and the area of ​​the second suction surface B may be equal, or the area of ​​the first suction surface A may be larger than the area of ​​the second suction surface B. Furthermore, the relationship between the areas of the first suction surface A and the second suction surface B also changes depending on the opening area of ​​the first end hole 75a, the opening area of ​​the insertion hole 77, or the size of the width Y of the flat portion 74.

[0051] In this embodiment, regardless of the opening area of ​​the first end hole 75a or the opening area of ​​the insertion hole 77, the area of ​​the right end face D of the second plunger 76 is larger than the area of ​​the left end face C of the first plunger 73. This shape makes it easier to obtain a pressing force R that resists the biasing force Q of the plunger spring 78 between the second plunger 76 and the second suction element 91, thereby improving the stability of the switching operation of the valve body 50.

[0052] As shown in Figure 4(A), the first electromagnetic drive unit 80 includes a first suction element 81 arranged alongside the first plunger 73 in the axial direction X, a first electromagnetic coil 84 for exciting the first suction element 81, and a first outer casing 88 surrounding the first electromagnetic coil 84. The first suction element 81 is formed in a cylindrical shape extending in the axial direction X and is fixed to the left inner surface of the first plunger tube 36 in the valve body 30 by welding or the like. A first mounting hole 82 (mounting hole) opening to the left is formed on the left end face of the first suction element 81. A female thread is formed on the inner surface of the first mounting hole 82, and a first bolt 83 as a fixing member is screwed into this female thread. The first mounting hole 82 is coaxial on the axial direction X with the first end hole portion 75a of the first through hole 75 of the first plunger 73 described above.

[0053] Furthermore, as shown in Figure 4(B), the diameter α of the first mounting hole 82 is set to be larger than the diameter β of the first through hole 75 of the first plunger 73. The first electromagnetic coil 84 comprises a cylindrical first hollow bobbin 85, a first winding 86 wound around the outer circumference of the first hollow bobbin 85, and a first molded resin 87 covering the outer circumference of the first winding 86. A first insertion hole 85a is formed in the center of the first hollow bobbin 85, coaxial with the axis X and penetrating in the direction of the axis X. The first insertion hole 85a is a hole through which the first plunger tube 36 is inserted, and its inner diameter is set to be slightly larger than the outer diameter of the first plunger tube 36.

[0054] The first outer casing 88 is the part that surrounds the first electromagnetic coil 84 and constitutes the outer shell of the first electromagnetic drive unit 80. For example, it is formed in an overall rectangular tubular shape by pressing and bending a plate-shaped magnetic material. A first opening 88a is formed in the right side wall of the first outer casing 88, which is coaxial with axis X and penetrates in the direction of axis X. The first plunger tube 36 is inserted through the first opening 88a. A first fixing hole 88b is formed in the left side wall of the first outer casing 88, which is coaxial with axis X and penetrates in the direction of axis X. The first bolt 83 is inserted through the first fixing hole 88b. With the first bolt 83 inserted through the first fixing hole 88b, the first outer casing 88 is fixed to the valve body 30 by screwing the first bolt 83 into the first mounting hole 82 of the first suction element 81.

[0055] As shown in Figure 2, the second electromagnetic drive unit 90 includes a second suction element 91 positioned at a distance from the second plunger 76 in the axial direction X, a second electromagnetic coil 94 for exciting the second suction element 91, and a second outer casing 98 surrounding the second electromagnetic coil 94. The second suction element 91 has the same diameter as the first suction element 81 and is formed in a cylindrical shape extending in the axial direction X, and is fixed to the inner circumferential surface on the right side of the second plunger tube 37 in the valve body 30 by welding or the like. A second mounting hole 92 opening to the right is formed on the right end face of the second suction element 91. A female thread is formed on the inner circumferential surface of the second mounting hole 92, and a second bolt 93, which serves as a fixing member, is screwed into this female thread. The second mounting hole 92 is coaxial on the axial direction X with the second end hole portion 79a and the insertion hole 77 of the second through hole 79 of the second plunger 76 described above. The second electromagnetic coil 94 comprises a cylindrical second hollow bobbin 95, a second winding 96 wound around the outer circumference of the second hollow bobbin 95, and a second molded resin 97 covering the outer circumference of the second winding 96. A second insertion hole 95a is formed in the center of the second hollow bobbin 95, coaxial with axis X and penetrating in the direction of axis X. The right end of the second plunger tube 37 is inserted into the second insertion hole 95a.

[0056] The second outer casing 98 is the part that surrounds the second electromagnetic coil 94 and constitutes the outer shell of the second electromagnetic drive unit 90. For example, it is formed into an overall rectangular tube shape by pressing and bending a plate-shaped magnetic material. A second opening 98a is formed in the left side wall of the second outer casing 98, which is coaxial with axis X and penetrates in the direction of axis X. The second plunger tube 37 is inserted through the second opening 98a. A second fixing hole 98b is formed in the right side wall of the second outer casing 98, which is coaxial with axis X and penetrates in the direction of axis X. The second bolt 93 is inserted through the second fixing hole 98b. With the second bolt 93 inserted through the second fixing hole 98b, the second outer casing 98 is fixed to the valve body 30 by screwing the second bolt 93 into the second mounting hole 92 of the second suction element 91.

[0057] Next, the assembly of a portion of the pilot valve 2 will be described. First, the D tube 34a is inserted into the tube mounting hole 34 of the valve body 30, and the valve seat member 40 is fitted into the valve seat mounting hole 35 of the valve body 30. Also, the first plunger tube 36 is inserted into the left end of the valve body 30, and the second plunger tube 37 is inserted into the right end of the valve body 30. These components are then fixed to the valve body 30 by brazing in the furnace environment to form the first assembly. Next, the first suction element 81 is attached to the first assembly. Specifically, the first suction element 81 is press-fitted into the first plunger tube 36, and fixed to the inner circumferential surface of the left end of the first plunger tube 36 by welding. This constructs the second assembly.

[0058] Next, the plunger portion 70 is inserted into the opening of the second plunger tube 37 of the second assembly, and the third assembly is constructed in which the plunger portion 70 is housed in the valve body 30. At this time, a biasing member 51 is installed in the spring housing hole 72b of the valve body holding portion 71 of the plunger portion 70, and the valve body 50 is installed in the valve body housing hole 72a. In addition, a plunger spring 78 is installed in the insertion hole 77 of the second plunger 76 of the plunger portion 70. Finally, the second suction element 91 is attached to the third assembly. Specifically, the second suction element 91 is press-fitted into the second plunger tube 37 and fixed to the inner circumferential surface of the right end of the second plunger tube 37 by welding. This completes the assembly of the pilot valve 2.

[0059] Next, the operation of the refrigeration cycle system 100 will be described. In the refrigeration cycle system 100, the pilot valve 2 changes the flow state of the drive fluid, thereby moving the slide valve body 20 of the four-way valve 1 and switching between the cooling state shown in Figure 1 and the heating state (not shown). When switching from the heating state to the cooling state, first, a voltage is applied to the first electromagnetic drive unit 80 by turning on the power supply (not shown). This energizes the first electromagnetic coil 84, and as shown in Figure 4(A), a magnetic path M is formed around the first electromagnetic coil 84, passing through the first outer casing 88 and the first attractor 81. The formation of this magnetic path M generates a magnetic attractive force P1 between the first attractor 81 and the first plunger 73, and the first plunger 73 is guided to slide to the left by the combined pressing force R of the attractive force P1 and the biasing force Q of the plunger spring, and is pressed against the first attractor 81. Then, the first adsorption surface A of the first plunger 73 is adsorbed to the right end face of the first suction element 81.

[0060] Here, as shown in Figure 4(A), the outer peripheral portion of the first suction surface A is the part where a magnetic path M is formed that is continuous in the axial X direction through the first attractor 81 and the first plunger 73 without passing through a space such as the first mounting hole 82, and is a part where the magnetic force tends to be relatively large. In this embodiment, this part where the magnetic force tends to be large is defined as the first suction part a1. Specifically, as shown in Figure 4(B), the part of the first suction surface A excluding the projected portion a2 obtained by projecting the first mounting hole 82 in the axial X direction (i.e., the part where the magnetic path M is formed via a space such as the first mounting hole 82) becomes the first suction part a1.

[0061] As described above, in this embodiment, the first mounting hole 82 is coaxial with the first end hole 75a of the first plunger 73 on axis X. Also, the diameter α of the first mounting hole 82 is set to be larger than the diameter β of the first through hole 75 of the first plunger 73. Therefore, when the first attractor 81 and the first plunger 73 are viewed from the direction of axis X, spaces such as the first mounting hole 82 are concentrated near axis X, making it easier to secure a sufficient area for the first adsorption part a1, and increasing the magnetic force generated between the first plunger 73 and the first attractor 81.

[0062] When the first suction surface A of the first plunger 73 is attracted to the right end face of the first suction element 81, the space between the first suction surface A and the right end face of the first suction element 81 is connected to the valve chamber 31 through the first through hole 75, so that a vacuum is not created and the first plunger 73 is prevented from sticking to the first suction element 81. In this state, the valve body 50 connects the first working tube 46a and the S tube 47, and also connects the D tube 34a and the second working tube 48a.

[0063] Therefore, the high-pressure drive fluid that flows into the valve chamber 31 through the D tube 34a flows through the pressure equalization hole 72 towards the valve seat member 40, and flows from the third port 44, which is not covered by the recess 52, through the second actuating tube 48a into the second actuating chamber 18 of the four-way valve 1 shown in Figure 1. On the other hand, the low-pressure drive fluid that flows into the recess 52 through the S tube 47 flows from the first port 42 through the first actuating tube 46a into the first actuating chamber 17 of the four-way valve 1 shown in Figure 1. As a result, a pressure difference is generated between the first actuating chamber 17 and the second actuating chamber 18, and the slide valve body 20 of the four-way valve 1 moves to the left end position shown in Figure 1. In this state, the high-pressure refrigerant compressed by the compressor 6 flows into the high-pressure chamber 16 from the D joint pipe 12 and flows into the outdoor heat exchanger 5 from the C joint pipe 15.

[0064] In other words, during cooling operation, the refrigerant discharged from the compressor 6 circulates through the C-connector pipe 15, the outdoor heat exchanger 5, the throttling device 4, the indoor heat exchanger 3, and the E-connector pipe 13, with the outdoor heat exchanger 5 functioning as a condenser and the indoor heat exchanger 3 functioning as an evaporator. When switching from heating to cooling, the aforementioned (not shown) power supply may be turned ON and then OFF. This is because once the first electromagnetic coil 84 is energized, the plunger section 70 begins to move to the left, and even if the excitation is then stopped, the biasing force Q of the plunger spring 78 can bring the first plunger 73 into contact with the first suction element 81. In this case, the driving power of the sliding switching valve can be reduced compared to a configuration in which the power supply is always ON.

[0065] On the other hand, when switching from cooling to heating, first, a voltage is applied to the second electromagnetic drive unit 90 by turning on a power supply (not shown). This energizes the second electromagnetic coil 94, forming a magnetic path (not shown) through the second outer casing 98 and the second attractor 91. The formation of this magnetic path generates an attractive force P2 between the second attractor 91 and the second plunger 76. The difference between the attractive force P2 and the biasing force Q of the plunger spring 78, which is the pressing force R, guides the second plunger 76 to slide to the right and presses against the second attractor 91. Then, the second suction surface B of the second plunger 76 is attracted to the left end face of the second attractor 91.

[0066] Here, although not shown in the figures, similar to the first suction surface A, the outer peripheral portion of the second suction surface B is a portion where a magnetic path is formed that is continuous in the direction of axis X through the second attractor 91 and the second plunger 76 without passing through a space such as the second mounting hole 92, and is a portion where the magnetic force tends to be relatively large. In this embodiment, this portion where the magnetic force tends to be large is designated as the second suction portion b1 (see Figure 4(B)). Specifically, the portion of the second suction surface B excluding the unshown projected portion obtained by projecting the second mounting hole 92 in the direction of axis X becomes the second suction portion b1. As described above, in this embodiment, the second mounting hole 92 is coaxial with the insertion hole 77 of the second plunger 76 on axis X. Therefore, spaces such as the second mounting hole 92 are concentrated near axis X, making it easier to secure a sufficient area for the second suction portion b1, and the magnetic force generated between the second plunger 76 and the second attractor 91 becomes large.

[0067] When the second suction surface B of the second plunger 76 is attracted to the left end face of the second suction element 91, the space between the second suction surface B and the left end face of the second suction element 91 is connected to the valve chamber 31 through the insertion hole 77 and the second through hole 79, so that a vacuum state is not created and the second plunger 76 is prevented from sticking to the second suction element 91. In this state, the valve body 50 connects the second working tube 48a and the S tube 47, and also connects the D tube 34a and the first working tube 46a.

[0068] Therefore, the high-pressure drive fluid that flows into the valve chamber 31 through the D tube 34a flows through the pressure equalization hole 72 towards the valve seat member 40, and flows from the first port 42, which is not covered by the recess 52, through the first actuating tube 46a into the first actuating chamber 17 of the four-way valve 1 shown in Figure 1. On the other hand, the low-pressure drive fluid that flows into the recess 52 through the S tube 47 flows from the third port 44 through the second actuating tube 48a into the second actuating chamber 18 of the four-way valve 1. As a result, a pressure difference is generated between the first actuating chamber 17 and the second actuating chamber 18, and the slide valve body 20 of the four-way valve 1 moves to the rightmost position (not shown). In this state, the high-pressure refrigerant compressed by the compressor 6 flows into the indoor heat exchanger 3 from the E joint pipe 13. In other words, during heating operation, the refrigerant discharged from the compressor 6 circulates through the E fitting pipe 13, indoor heat exchanger 3, throttling device 4, outdoor heat exchanger 5, and C fitting pipe 15, with the indoor heat exchanger 3 functioning as a condenser and the outdoor heat exchanger 5 functioning as an evaporator.

[0069] In this embodiment, the pilot valve 2 comprises a first electromagnetic drive unit 80 and a second electromagnetic drive unit 90, and a plunger spring 78, as described above. Specifically, the pilot valve 2 is configured to have a W coil consisting of a first electromagnetic coil 84 and a second electromagnetic coil 94, and a plunger spring 78 on the second plunger 76 side that biases the plunger portion 70 toward the first electromagnetic drive unit 80. In such a configuration with a W coil and a one-sided plunger spring 78, the pressing force that presses the first plunger 73 against the first suction element 81 and the pressing force that presses the second plunger 76 on the side where the plunger spring 78 is provided against the second suction element 91 are both equal and can be expressed as pressing force R. In order to move and press the second plunger 76 toward the second suction element 91, it is necessary to resist the biasing force Q of the plunger spring 78, and therefore a greater suction force than the suction force P1 between the first plunger 73 and the first suction element 81 described above is required.

[0070] Specifically, for example, if we consider the magnetic force between the first attractor 81 and the first plunger 73 as P1, the biasing force of the plunger spring as Q, and the magnetic force between the second attractor 91 and the second plunger 76 as P2, then the pressing force R = P1 + Q that presses the first plunger 73 against the first attractor 81, while the pressing force R = P2 - Q that presses the second plunger 76 against the second attractor 91. Therefore, P2 - P1 = 2Q, and the attractive force P2 must be at least twice the biasing force Q, and thus greater than the attractive force P1. In this case, one could consider increasing the number of turns in the second winding 96 of the second electromagnetic coil 94 or increasing the driving power, but this would increase the size of the second electromagnetic coil 94 or increase the cost of driving it.

[0071] However, with this configuration, by making the area of ​​the second suction surface B larger than the area of ​​the first suction surface A, it is easier to make the suction force P2 generated between the second suction element 91 and the second plunger 76 larger than the suction force P2 generated between the first suction element 81 and the first plunger 73. In addition, by making the area of ​​the second suction part b1 larger than the area of ​​the first suction part a1, it is even easier to obtain a suction force P2 that is greater than the suction force P1. As a result, it is possible to increase the suction force P2 by at least twice the biasing force Q of the plunger spring 78, and it is not necessary to enlarge the second electromagnetic coil 94 or increase the driving power in order to obtain the suction force P2.

[0072] Furthermore, in this configuration, by adjusting the area of ​​the first suction surface A, the area of ​​the second suction surface B, the area of ​​the first suction part a1, or the area of ​​the second suction part b1, etc., to balance with the spring load of the plunger spring 78, the pressing force R that presses the first plunger 73 against the first suction element 81 and the pressing force R that presses the second plunger 76 against the second suction element 91 can be made the same. This makes it possible to use the same components for the first electromagnetic coil 84 and the second electromagnetic coil 94, and for the first suction element 81 and the second suction element 91. As a result, the manufacturing costs of the first electromagnetic drive unit 80 and the second electromagnetic drive unit 90 can be reduced. Note that using the same components for the first electromagnetic coil 84 and the second electromagnetic coil 94, and for the first suction element 81 and the second suction element 91 is not mandatory, and they do not necessarily need to be used together.

[0073] As described above, according to the embodiment, the second plunger 76 has a circumferential shape that provides a larger area for sliding guidance on the inner surface of the valve body 30 than the first plunger 73. This ensures that the second plunger 76 has a sliding area of ​​an appropriate size relative to the valve body 30, thereby improving the stability of the switching operation by the valve body 50. Furthermore, the provision of the plunger spring 78 allows the first plunger 73, the second plunger 76, and the valve body holding portion 71 to be moved toward the first suction element 81 by the biasing force Q, and maintain a state of being pressed in the same direction. Therefore, vibration of the plunger portion 70 can be suppressed even when no power is supplied. Thus, a pilot valve 2 (slide-type switching valve) can be provided that suppresses vibration of the plunger portion 70 (plunger) and improves the stability of the switching operation. In addition, the provision of the plunger spring 78 allows the driving force of the first electromagnetic drive unit 80 that attracts the first plunger 73 to be reduced by the biasing force Q of the plunger spring 78. Therefore, the first electromagnetic drive unit 80 can be made smaller, and the operating voltage of the first electromagnetic drive unit 80 can be reduced, which can contribute to the miniaturization or cost reduction of the pilot valve 2.

[0074] Furthermore, according to this embodiment, since the inner surface of the valve body 30 can slide-guide the almost entire outer surface of the second plunger 76, the tilting of the plunger portion 70 can be suppressed at the second plunger 76 portion, and locking of the plunger portion 70 can be suppressed. Therefore, the stability of the switching operation of the valve body 50 can be further improved.

[0075] Furthermore, according to this embodiment, the first plunger 73 can be moved with the opposing surface 74a of the flat portion 74 facing the valve seat surface 41. Also, in this configuration, a space equal to at least the height from the inner surface of the valve body 30 to the valve seat surface 41 is created between the first plunger 73 and the inner surface of the valve body 30, so the valve seat member 40 can be placed in this space. For this reason, it is not necessary to prepare a special space within the valve body 30 for installing the valve seat member 40, and the valve body 30 can be prevented from becoming larger.

[0076] Furthermore, according to this embodiment, by making the area of ​​the right end face D of the second plunger 76 (the end face facing the second suction element 91) larger than the area of ​​the left end face C of the first plunger 73 (the end face facing the first suction element 81), it becomes easier to obtain the pressing force R that presses the second plunger 76 against the second suction element 91 against the biasing force Q of the plunger spring 78 between the second plunger 76 and the second suction element 91, thereby improving the stability of the switching operation of the valve body 50.

[0077] Furthermore, according to this embodiment, by providing a first through-hole 75 in the first plunger 73, when the first plunger 73 is attracted to the first suction element 81, the space between the first suction surface A and the right end of the first suction element 81 communicates with the valve chamber 31 via the outer circumferential surface of the first plunger 73. Therefore, a vacuum state is prevented between the first plunger 73 and the first suction element 81, and the first plunger 73 is prevented from sticking to the first suction element 81. And because sticking between the first plunger 73 and the first suction element 81 is prevented, a large driving force is not required when driving the second plunger 76, thus preventing the second electromagnetic coil 94 from becoming larger.

[0078] Furthermore, according to this embodiment, since the first through-hole 75 penetrates the flat portion 74, when the first plunger 73 is attracted to the first suction element 81, the space between the first suction surface A and the right end face of the first suction element 81 communicates with the valve chamber 31 via the flat portion 74. Therefore, a vacuum state is prevented between the first plunger 73 and the first suction element 81, and the first plunger 73 is prevented from sticking to the first suction element 81. In addition, the portion where the flat portion 74 is located is the portion in the valve chamber 31 where a space is created between the first plunger 73 and the inner circumferential surface of the valve body 30, as described above. Therefore, by making this space the destination of the first through-hole 75, when the first plunger 73 comes into contact with the first suction element 81, it is easier to reliably establish communication between the space between the first suction surface A and the right end face of the first suction element 81 and the valve chamber 31, thereby further suppressing the vacuum state.

[0079] Furthermore, according to this embodiment, by inserting the plunger spring 78 into the insertion hole 77, the plunger spring 78 can be housed in the second plunger 76, thereby contributing to space saving of the valve body 30. This makes it possible to miniaturize the pilot valve 2.

[0080] Furthermore, according to this embodiment, by providing a second through-hole 79 in the second plunger 76, when the second plunger 76 comes into contact with the second suction element 91, the space between the second suction surface B and the left end face of the second suction element 91 communicates with the valve chamber 31 via the outer circumferential surface of the second plunger 76. Therefore, a vacuum state is prevented between the second plunger 76 and the second suction element 91, and the second plunger 76 is prevented from sticking to the second suction element 91.

[0081] Furthermore, according to this embodiment, when the first plunger 73 contacts the first suction element 81, the space between the first suction surface A and the right end face of the first suction element 81 communicates with the valve chamber 31 via the outer circumferential surface of the first plunger 73. This prevents a vacuum from forming between the first plunger 73 and the first suction element 81, and prevents the first plunger 73 from sticking to the first suction element 81. In addition, by inserting the plunger spring 78 into the insertion hole 77, the plunger spring 78 can be housed in the second plunger 76, thereby contributing to space saving of the valve body 30.

[0082] Furthermore, according to this embodiment, by making the area of ​​the second suction surface B larger than the area of ​​the first suction surface A, for example, the suction force P2 generated between the second suction element 91 and the second plunger 76 can be made at least twice the biasing force Q of the plunger spring 78 compared to the suction force P2 generated between the first suction element 81 and the first plunger 73. Therefore, it is not necessary to enlarge the second electromagnetic coil 94 or increase the driving power to obtain a suction force P2 greater than the suction force P1. In this configuration, by adjusting the area of ​​the second suction surface B to balance with the spring load of the plunger spring 78, the pressing force R that presses the first plunger 73 against the first suction element 81 and the pressing force R that presses the second plunger 76 against the second suction element 91 can be made the same. This makes it possible to use the same first electromagnetic coil 84 and second electromagnetic coil 94, or the same first suction element 81 and second suction element 91. Therefore, the manufacturing costs of the first electromagnetic drive unit 80 and the second electromagnetic drive unit 90 can be reduced. Consequently, this can contribute to miniaturization and cost reduction of the pilot valve 2. It should be noted that the commonality of the first electromagnetic coil 84 and the second electromagnetic coil 94, and the commonality of the first suction element 81 and the second suction element 91 are not mandatory, and they do not necessarily have to be common.

[0083] Furthermore, according to this embodiment, since the first end hole 75a constituting the first through hole 75 and the first mounting hole 82 (mounting hole) of the first attractor 81 are provided coaxially, a magnetic path M that is continuous in the axial X direction is easily formed around the first electromagnetic coil 84 without passing through spaces such as the first end hole 75a and the first mounting hole 82, passing through the first outer casing 88, the first attractor 81, and the first plunger 73, thereby increasing the attractive force between the first attractor 81 and the first plunger 73. Furthermore, because the insertion hole 77 of the second plunger 76 and the second mounting hole 92 of the second attractor 91 are provided coaxially, a magnetic path is more easily formed around the second electromagnetic coil 94 that is continuous in the axial X direction through the second outer casing 98, the second attractor 91, and the second plunger 76, without passing through spaces such as the insertion hole 77 and the second mounting hole 92, thereby increasing the magnetic force between the second attractor 91 and the second plunger 76.

[0084] Furthermore, according to this embodiment, the first adsorption part a1 is a portion where a magnetic path M is formed that is continuous in the axial direction X through the first attractor 81 and the first plunger 73 without passing through a space such as the first mounting hole 82, and is a portion where the magnetic force tends to be relatively greater than the portion where a space such as the first mounting hole 82 is formed within the first adsorption surface A. Similarly, the second adsorption part b1 is a portion where a magnetic path is formed that is continuous in the axial direction X through the second attractor 91 and the second plunger 76 without passing through a space such as the second mounting hole 92, and is a portion where the magnetic force tends to be relatively greater than the portion where a space such as the second mounting hole 92 is formed within the second adsorption surface B. With this configuration, among the portions where the magnetic force is greater than that of the other portions, the area of ​​the second adsorption part b1 is larger than the area of ​​the first adsorption part a1, making it easier to obtain an attractive force P2 that is greater than the attractive force P1. Therefore, it is not necessary to enlarge the second electromagnetic coil 94 or increase the driving power in order to obtain the attractive force P2.

[0085] Furthermore, according to this embodiment, the valve body 30 may be constructed as a single unit with a separate central valve body 32, a first plunger tube 36, and a second plunger tube 37.

[0086] Furthermore, according to this embodiment, the refrigeration cycle system 100 can be configured using a pilot valve 2 that suppresses vibration of the plunger section 70 and improves the stability of the switching operation.

[0087] Next, a first modified example of the pilot valve 2 will be described. Figure 5 is a cross-sectional view of the pilot valve 200 (slide-type switching valve) in the first modified example, cut along the axis X direction of the valve body 210. The pilot valve 200 includes a valve body 210. The valve body 210 is formed as an integral plunger tube 220, which is formed in an overall circular tubular shape by press-forming a metal material such as stainless steel. The valve body 210 corresponds to the valve body 30 in the above embodiment, but the difference is that while the valve body 30 was composed of a single component, the valve body 210 is composed of a single component, whereas the valve body 30 was composed of a single component, while the valve body 30 was composed of a single component, which consisted of a separate central valve body 32, a first plunger tube 36, and a second plunger tube 37.

[0088] In the middle section of the plunger tube 220, a tube mounting hole 34 that penetrates radially and a valve seat mounting hole 35 that penetrates radially opposite to the tube mounting hole 34 are formed by burring or the like. One end of the D tube 34a, which serves as high-pressure piping, is inserted through the tube mounting hole 34 and fixed by brazing or the like. A valve seat member 40 is fitted into the valve seat mounting hole 35. The first suction element 81 is fixed to the inner circumferential surface of the left end of the plunger tube 220 (the end on one side in the direction of the axis X) by welding or the like. The second suction element 91 is fixed to the inner circumferential surface of the right end of the plunger tube 220 (the end on the other side in the direction of the axis X) by welding or the like.

[0089] According to this first modification, the valve body 210 can be constructed as a single, integrally shaped plunger tube 220, i.e., as a single component. This reduces the number of parts in the valve body 210, contributing to cost reduction. Furthermore, constructing the valve body 210 as a single component makes it easier to prevent misalignment of the plunger tube 220, and suppresses sliding friction between the plunger portion 70, which moves back and forth within the plunger tube 220, and the valve body 210. As a result, the plunger portion 70 can move back and forth smoothly without increasing the driving force in the first electromagnetic drive unit 80 and the second electromagnetic drive unit 90, thus contributing to miniaturization of the first electromagnetic drive unit 80 and the second electromagnetic drive unit 90. In addition, suppressing sliding friction of the plunger portion 70 can suppress the generation of abnormal noise within the valve body 210.

[0090] Next, a second modified example of the pilot valve 2 will be described. Figure 6(A) is a cross-sectional view of the plunger portion 300 in the second modified example, cut along the axis X direction of the valve body 30, (B) is a front view of the first plunger 310 in the second modified example, and Figure 6(C) is a front view of the second plunger 312 in the second modified example. The plunger portion 300 includes a first plunger 310 provided continuously at the left end of the valve body holder 71, and a second plunger 312 provided continuously at the right end of the valve body holder 71. The first plunger 310 corresponds to the first plunger 73 in the above embodiment. A flat portion 74, or D-cut surface, similar to that of the first plunger 73 described above, is formed on the lower surface of the first plunger 310.

[0091] As shown in Figure 6(B), a first open groove 311 is formed on the left end face C of the first plunger 310, which is recessed in the direction of the axis X and extends in a direction intersecting the direction of the axis X. The first open groove 311 is continuous with the flat portion 74, thereby enabling communication between the first plunger 310 and the first suction element 81 and the valve chamber 31. In this modified example, the left end face C of the first plunger 310, excluding the portion where the first open groove 311 is formed and the portion where the flat portion 74 is formed, constitutes the first suction surface A. The second plunger 312 corresponds to the second plunger 76 in the above embodiment. As shown in Figure 6(C), a second open groove 313 is formed on the right end face D of the second plunger 312.

[0092] The second open groove 313 comprises a first groove 314 extending in a direction intersecting the axial X direction, and a second groove 315 that is continuous with the lower end of the first groove 314 and extends in the axial X direction along the lower surface of the second plunger 312. The formation of the second open groove 313 allows the second plunger 312 and the second suction element 91 to communicate with the valve chamber 31. In this modified example, the right end face D of the second plunger 312, excluding the portion in which the second open groove 313 is formed, constitutes the second suction surface B.

[0093] According to this second modification, by providing the first open groove 311 in the first plunger 310, when the first plunger 310 is attracted to the first suction element 81, the space between the first suction surface A and the right end of the first suction element 81 communicates with the valve chamber 31 via the first open groove 311. Therefore, a vacuum state is prevented between the first plunger 310 and the first suction element 81, and the first plunger 310 is prevented from sticking to the first suction element 81. Furthermore, by preventing the first plunger 310 and the first suction element 81 from sticking together, a large driving force is not required when driving the second plunger 312, thus preventing the second electromagnetic coil 94 from becoming larger. In addition, by forming the simple configuration of the first open groove 311, the sticking between the first plunger 310 and the first suction element 81 can be prevented, making the manufacturing of the plunger portion 300 easier compared to the configuration in which the first through hole 75 is formed.

[0094] Furthermore, by providing a second open groove 313 in the second plunger 312, when the second plunger 312 contacts the second suction element 91, the space between the second suction surface B and the left end face of the second suction element 91 communicates with the valve chamber 31 via the second open groove 313. Therefore, a vacuum state is prevented between the second plunger 312 and the second suction element 91, preventing the second plunger 312 from sticking to the second suction element 91. By preventing the second plunger 312 and the second suction element 91 from sticking together, a large driving force is not required to drive the first plunger 310, thus preventing the first electromagnetic coil 84 from becoming larger. In addition, by forming a simple configuration with a second open groove 313, the sticking between the second plunger 312 and the second suction element 91 can be prevented, making the manufacturing of the plunger portion 300 easier compared to a configuration with a second through hole 79.

[0095] Furthermore, the embodiments described above are merely representative forms of the present invention, and the present invention is not limited thereto. That is, it can be implemented with various modifications without departing from the core principles of the present invention. As long as such modifications still possess the configuration of the pilot valve 2 (slide-type switching valve) of the present invention, they are of course included within the scope of the present invention.

[0096] For example, in this embodiment and its modifications, a pilot valve 2 is provided as an example of a slide-type switching valve, which circulates a driving fluid between the four-way valve 1 and the slide valve body 20 of the four-way valve 1 that switches the communication state of four pipes. However, the present invention may also be applied directly to the four-way valve 1, for example. Furthermore, the slide-type switching valve is not limited to these four-way valves 1 and pilot valves 2. The slide-type switching valve may be a two-way valve that switches between two pipes using a valve body, or a three-way valve that switches the pipes to be connected using a valve body when, for example, connecting a pair of pipes out of three pipes. Alternatively, the number of pipes to be connected may be further increased to make it a multi-way valve. Thus, the number of pipes in the slide-type switching valve and the method of switching the communication state may be changed according to the application of the slide-type switching valve, etc.

[0097] Furthermore, in this embodiment, the maximum outer diameter γ of the first plunger 73 and the maximum outer diameter σ of the second plunger 76 are set to be the same, and a flat portion 74 is formed on the first plunger 73, so that the area of ​​the right end face D of the second plunger 76 is larger than the area of ​​the left end face C of the first plunger 73. However, these maximum outer diameters γ, σ, or diameters may differ from those in this embodiment. In addition, the present invention can be applied to configurations in which no opening such as the first end hole portion 75a or a flat portion such as the flat portion 74 is formed on the left end face C of the first plunger 73, or to configurations in which no opening such as the insertion hole 77 or the second end hole portion 79a is formed on the right end face D of the second plunger 76. In either case, as in this embodiment, by making the area of ​​the right end face D of the second plunger 76 larger than the area of ​​the left end face C of the first plunger 73, it becomes easier to obtain the pressing force R that presses the second plunger 76 against the second suction element 91 against the biasing force Q of the plunger spring 78, and the stability of the switching operation of the valve body 50 is improved.

[0098] Furthermore, in this embodiment, the area of ​​the second suction surface B on the second plunger 76 was set to be larger than the area of ​​the first suction surface A on the first plunger 73. However, as described above, the areas of the first suction surface A and the second suction surface B change depending on the opening area of ​​the first end hole 75a and the second end hole 79a, the size of the width Y of the flat portion 74, and also change in relation to the area of ​​the end faces of the first suction element 81 and the second suction element 91 that are the targets for suction. For this reason, the area of ​​the second suction surface B and the area of ​​the first suction surface A may be equal, or the area of ​​the second suction surface B may be smaller than the area of ​​the first suction surface A. However, from the viewpoint of making it easier to make the suction force P2 greater than the suction force P1, it is preferable to make the area of ​​the second suction surface B larger than the area of ​​the first suction surface A, as in the above embodiment.

[0099] In this embodiment, the plunger spring 78 is housed in the insertion hole 77, and the biasing force Q of the plunger spring 78 biases the plunger portion 70 (i.e., the first plunger 73, the valve body holder 71, and the second plunger 76) toward the first suction element 81. However, the arrangement and biasing direction of the plunger spring 78 are not limited to this. The plunger spring 78 may, for example, be installed in a portion of the second plunger 76 other than the insertion hole 77, biasing the plunger portion 70 toward the first suction element 81. Alternatively, the plunger spring 78 may be positioned on the first plunger 73 side, biasing the plunger portion 70 toward the second suction element 91.

[0100] In this case, the plunger portion 70 can be moved toward the second suction element 91 and maintained in a state of being pressed in the same direction, thereby suppressing vibration of the plunger portion 70. Furthermore, the driving force of the second electromagnetic drive unit 90 that attracts the second plunger 76 can be reduced by the biasing force Q of the plunger spring 78. As a result, the second electromagnetic drive unit 90 can be miniaturized, and the operating voltage of the second electromagnetic drive unit 90 can be reduced. Thus, unlike the embodiments and modifications described above, the plunger spring 78 may be provided to bias the first plunger 73, the second plunger 76, and the valve body holding portion 71 toward the second suction element 91. Furthermore, when the plunger portion 70 is biased toward the second suction element 91 by the plunger spring 78, in order to make it easier to obtain the pressing force between the first plunger 73 and the first suction element 81 that presses the first plunger 73 toward the first suction element 81 against the biasing force of the plunger spring 78, the area of ​​the left end face C of the first plunger 73 may be made larger than the area of ​​the right end face D of the second plunger 76, contrary to the embodiments and modifications described above. [Explanation of symbols]

[0101] X axis 2. Pilot valve (slide-type switching valve) 30 Valve body 31 valve chambers 40 Valve seat member (valve seat portion) 41 Valve seat surface 42. First port (multiple valve ports) 43. Second port (multiple valve ports) 44. Third port (multiple valve ports) 50 valve bodies 71 Valve body retaining part 73. First Plunger 76. Second Plunger 78 Plunger spring 80 First electromagnetic drive unit 81 1st suction element 84. First electromagnetic coil 90 Second electromagnetic drive unit 91 2nd suction element 94. Second electromagnetic coil

Claims

1. A sliding type switching valve comprising: a valve body having a valve chamber inside; a valve seat portion provided on the valve body and having a plurality of valve ports; a valve element slidably provided on the valve seat surface of the valve seat portion; a valve element holder portion for holding the valve element; a first plunger and a second plunger integrally provided with the valve element holder portion and movable back and forth within the valve body; and a first electromagnetic drive unit and a second electromagnetic drive unit for driving the valve element holder portion, the first plunger, and the second plunger along the axial direction of the valve body, The first electromagnetic drive unit comprises a first attractor and a first electromagnetic coil, The second electromagnetic drive unit comprises a second attractor and a second electromagnetic coil, The second plunger has a circumferential shape that provides a larger area of ​​sliding guidance on the inner circumferential surface of the valve body than the first plunger. A sliding switching valve characterized in that the valve chamber is provided with the first plunger, the second plunger, and a plunger spring that biases the valve body holder toward the first suction element or the second suction element.

2. The sliding type switching valve according to claim 1, characterized in that the second plunger has a cylindrical outer surface that is slidably guided by the inner surface of the valve body over substantially its entire circumference.

3. The sliding switching valve according to claim 2, characterized in that the first plunger has a flat portion having an opposing surface that faces the valve seat surface of the valve seat portion.

4. The slide-type switching valve according to claim 3, characterized in that the plunger spring biases the first plunger, the second plunger, and the valve body holder toward the first suction element.

5. The sliding switching valve according to claim 4, characterized in that the area of ​​the end face of the second plunger facing the second suction element is larger than the area of ​​the end face of the first plunger facing the first suction element.

6. The sliding switching valve according to claim 4, characterized in that the first plunger has a first through hole that penetrates from the end face facing the first suction element to the outer circumferential surface.

7. The sliding switching valve according to claim 6, characterized in that the first through hole penetrates from the end face facing the first suction element to the flat portion.

8. The second plunger has an insertion hole into which a plunger spring is inserted, The sliding switching valve according to claim 4, characterized in that the insertion hole is formed recessed from the end face facing the second suction element.

9. The sliding switching valve according to claim 4, characterized in that the second plunger has a second through hole that penetrates from the end face facing the second suction element to the outer circumferential surface.

10. The first plunger has a first through hole that penetrates from the end face facing the first suction element to the outer circumferential surface, The second plunger has an insertion hole into which a plunger spring is inserted, The sliding switching valve according to claim 4, characterized in that the insertion hole is formed recessed from the end face facing the second suction element.

11. A sliding switching valve according to any one of claims 4, 6 to 10, characterized in that the area of ​​the second suction surface in the second plunger that contacts the second suction element is larger than the area of ​​the first suction surface in the first plunger that contacts the first suction element.

12. The first electromagnetic drive unit comprises a first outer casing that covers the first electromagnetic coil, The first through-hole, which extends from the end face of the first plunger facing the first suction element to the outer circumferential surface, comprises a first end hole portion opening to the end face facing the first suction element, and a first outer circumferential hole portion communicating with the first end hole portion and opening to the outer circumferential surface of the first plunger. The first suction element has a first mounting hole on its end face into which a fixing member for fixing the first outer casing is inserted. The first end hole and the first mounting hole are provided coaxially. The second electromagnetic drive unit comprises a second outer casing that covers the second electromagnetic coil, The second plunger is provided with an insertion hole into which the plunger spring is inserted, The second suction element has a second mounting hole on its end face into which a fixing member for fixing the second outer casing is inserted. A sliding switching valve according to any one of claims 4, 6, 8 to 10, characterized in that the insertion hole and the second mounting hole are provided coaxially.

13. Of the first suction surface of the first plunger that contacts the first suction element, the portion excluding the portion obtained by projecting the first mounting hole in the axial direction is defined as the first suction portion. If the second suction surface of the second plunger that contacts the second suction element is defined as the portion obtained by projecting the second mounting hole in the axial direction, then, The sliding switching valve according to claim 12, characterized in that the area of ​​the second adsorption portion is larger than the area of ​​the first adsorption portion.

14. The slide-type switching valve according to claim 1, characterized in that the valve body comprises a central valve body on which the valve seat portion is provided, a first plunger tube connected to one side of the central valve body in the axial direction, and a second plunger tube connected to the other side of the central valve body in the axial direction.

15. The slide-type switching valve according to claim 1, characterized in that the valve body is composed of an overall cylindrical and integral plunger tube, the valve seat is attached to the middle part of the plunger tube, the first suction element is fixed to one end of the plunger tube in the axial direction, and the second suction element is fixed to the other end of the plunger tube in the axial direction.

16. A refrigeration cycle system characterized by comprising a slide-type switching valve as described in claim 1.

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