Slide-type switching valve

Abstract

To provide a slide type selector valve capable of enhancing the accuracy of a valve position and improving operability, by suppressing the remarkable abrasion of a screw feeding mechanism and suppressing an influence of abrasion powders even in an oil-free state or a low-oil amount state.SOLUTION: A slide type selector valve is equipped with a valve body 2, a valve seat part 3, a valve body 4, and a driving part 5 in which a male screw part 55d and a female screw part 56a1 are screwed with each other, and which drives the valve body 4 to slide by a screw feeding mechanism converting rotary motion into linear motion. Either one of the male screw part 55d or the female screw part 56a1 is formed by metal and is subjected to coating with lubricity on a surface. The other is configured by a resin material. Therefore, the accuracy of a valve position can be enhanced and operability can be improved.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a slide-type switching valve equipped with a screw feed mechanism. [Background technology]

[0002] In recent years, for the purpose of improving environmental conservation and ease of maintenance, a refrigeration cycle system has been proposed that does not use refrigerating machine oil, that is, an oil-free state or a low oil amount state, as described in Patent Document 1, for example.

[0003] Furthermore, as a four-way selector valve for a general refrigeration cycle system, for example, Patent Document 2 (see, in particular, paragraphs

[0069] -

[0074] and FIG. 7) describes a slide-type selector valve (hereinafter referred to as a "conventional slide-type selector valve") in which an inlet 40 and an outlet 41 connected to the discharge port and suction port, respectively, of a compressor are selectively connected to either a first port 42 or a second port 43 via a valve element 31 slidably mounted on a valve seat 32. The valve element 31 is made of PPS (resin), and the valve stem 33 is made of stainless steel, both of which are exposed to the fluid path. A screw feed mechanism, in which a female thread formed inside the valve element 31 and a male thread 37 formed on the valve stem 33 are threadedly engaged with each other, converts the rotation of the valve stem 33 into linear motion of the valve element 31.

[0004] However, when a conventional slide-type switching valve is used in a refrigeration cycle system that is used in an oil-free state or a low oil amount state, the following two problems arise. First, significant wear of the screw feed mechanism may cause a deterioration in the operability of the four-way switching valve due to a deviation in the valve position, etc. (hereinafter referred to as "Conventional Problem 1 (significant wear of the screw feed mechanism)"). Second, the generated wear powder may become caught in the screw feed mechanism, causing the wear of the screw feed mechanism to progress at an accelerated rate (hereinafter referred to as "Conventional Problem 2 (adverse effect of wear powder on the screw feed mechanism)"). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-162213 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-179705 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention has been made in view of the above problems, and is to provide a slide-type switching valve that can increase the accuracy of the valve position and improve the operability and durability of the screw feed mechanism by suppressing significant wear of the screw feed mechanism and suppressing the effects of wear powder even in an oil-free state or a state with a low oil amount. [Means for solving the problem]

[0007] In order to solve the above problems, a slide-type switching valve is provided which includes a hollow cylindrical valve body, a valve seat portion provided in the valve body and having a valve port, a valve element provided inside the valve body so as to be able to slide freely in the axial direction, and a drive portion in which a male thread portion and a female thread portion are threadedly engaged with each other and which drives the valve element to slide by a screw feed mechanism that converts rotational motion into linear motion, wherein one of the male thread portion and the female thread portion is formed from metal and has a lubricating coating on the metal surface, and the other is made from a resin material.

[0008] In the above slide type switching valve, the coating may be any one of a fluororesin-based, molybdenum disulfide-based, and graphite-based coating having lubricity.

[0009] In the slide type switching valve, the resin material may be PPS with PTFE added.

[0010] In the slide type switching valve, the resin material may be PPS to which glass fiber or carbon fiber is further added as a reinforcing agent.

[0011] In the slide-type switching valve, a screw accommodating space that accommodates a threaded engagement region between the male thread portion and the female thread portion may be partitioned from the interior of the valve body.

[0012] In the slide type switching valve, the male thread portion and the female thread portion may be formed as multiple threads.

[0013] In the above-described slide-type switching valve, the threaded engagement regions of the male thread portion and the female thread portion at the stop positions on one axial side and the other axial side of the valve body may not overlap each other.

[0014] Further, in the above-mentioned slide-type switching valve, the drive unit may include a motor unit having a rotatable rotor, a male screw member fixed directly or indirectly to the rotor and extending in the axial direction, the male screw member having the male screw portion, a female screw member having the female screw portion and capable of moving forward and backward in the axial direction as the male screw member rotates, and a guide member that regulates the rotation of the female screw member and guides its forward and backward movement in the axial direction, and both axial ends of the threaded engagement region may always be released in the axial and radial directions.

[0015] In addition, in the above-mentioned slide-type switching valve, the female screw member may be provided with a threaded cylindrical portion having the female screw portion and a pair of enlarged diameter portions formed continuously at both ends of the female screw portion in the axial direction.

[0016] In the above slide type switching valve, the male screw member may have the male screw portion and a pair of reduced diameter portions formed continuously at both ends of the male screw portion in the axial direction.

[0017] Furthermore, in the above-mentioned slide-type switching valve, the female screw member may further have a pair of connecting arms extending axially from the threaded cylindrical portion and connected to the valve body, and the guide member may have a partition wall that separates the screw accommodating space that accommodates the threaded engagement region between the male screw portion and the female screw portion from the inside of the valve body, and a guide hole that is provided in the partition wall and through which the pair of connecting arms are inserted in the axial direction and that regulates rotation of the female screw member.

[0018] Furthermore, in the above-mentioned slide-type switching valve, the partition wall of the guide member may have a pair of air holes adjacent to the radial outside of the pair of connecting arms when the pair of connecting arms are inserted into the guide hole, which connect the screw accommodating space and the inside of the valve body.

[0019] In the slide-type switching valve, the valve element may have a bowl shape and slide over the valve seat portion having the plurality of valve ports to switch the flow path. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a slide-type switching valve that can suppress significant wear of the screw feed mechanism and suppress the effects of wear powder even in an oil-free state or a state with a low oil amount, thereby increasing the accuracy of the valve position and improving the operability and durability of the screw feed mechanism. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view of a slide-type switching valve according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along line II-II of the slide-type switching valve shown in FIG. 1. FIG. [Figure 3] 3A and 3B are detailed views of the guide member shown in FIG. 1 and FIG. 2, where (a) is an overall view of the guide member shown in FIG. 2, and (b) is a view seen from the direction of arrow IIIb shown in (a). [Figure 4]4A and 4B are detailed views of the female screw member shown in FIG. 2, in which (a) is an overall view, (b) is a view seen from the direction of arrow IVb shown in (a), (c) is a view seen from the direction of arrow IVc shown in (a), and (d) is a cross-sectional view taken along line IVd-IVd shown in (a). [Figure 5] 1A and 1B are schematic diagrams showing a refrigeration cycle system during cooling operation, where (a) is an explanatory diagram of a slide-type switching valve, and (b) is an enlarged view of the area surrounded by the dashed line Vb shown in (a) when switching from heating operation to cooling operation. [Figure 6] 1A and 1B are schematic diagrams showing a refrigeration cycle system during heating operation, where (a) is an explanatory diagram of a slide-type switching valve, and (b) is an enlarged view of the area surrounded by dashed line VIb shown in (a) when switching from cooling operation to heating operation. [Figure 7] 2A and 2B are detailed views of the screw feed mechanism shown in FIG. 1, in which (a) is an enlarged view of the area surrounded by dashed line VIIa shown in FIG. 1, (b) is a cross-sectional view (multiple-start thread) taken along line VIIb-VIIb shown in (a), (c) is a partial outline drawing of the male thread member (multiple-start thread) shown in (b) viewed from an orthogonal direction, (d) is a cross-sectional view (standard thread) of a comparative example corresponding to (b), and (e) is a partial outline drawing (standard thread) of a comparative example corresponding to (c). DETAILED DESCRIPTION OF THE INVENTION

[0022] An embodiment of the present invention will be described in detail with reference to Figures 1 to 7. However, the present invention is not limited to this embodiment.

[0023] <Terminology> In this specification and claims, the terms "left," "right," "upper," and "lower" refer to the directions shown in Figures 1, 4(a), 5, 6, 7(a), (c), and (e). In this specification and claims, the terms "one axial side" and "other axial side" refer to the "right axial side" and "left axial side," respectively, shown in Figures 1, 2, 3(a), 4(a), (d), 5, 6, 7(a), (c), and (e). In this specification and claims, the term "lead" refers to the distance the thread advances axially when the screw makes one revolution around its axis. In this specification and claims, the term "pitch" refers to the distance from one thread to the next. In this specification and claims, the term "multiple-start thread" refers to a thread whose lead is an integer multiple of the pitch. In this specification and claims, the term "normal thread" refers to a thread whose lead and pitch are the same. In this specification and claims, the term "lead angle" refers to the angle formed by the length of one turn of the screw relative to the lead. In this specification and claims, the term "helical wire" refers to a spiral in which a right triangle is wound around a cylinder.

[0024] <About slide-type switching valves> A slide type switching valve 100 of the present invention will be described using Figures 1 and 2. The slide type switching valve 100 is mainly composed of a hollow cylindrical housing 1, a hollow cylindrical valve body 2, a valve seat portion 3 provided in the valve body 2 and having a plurality of valve ports, a valve element 4 provided slidably in a valve chamber 2a inside the valve body 2, and a drive unit 5 that drives the valve element 4 to slide. Each component of the slide type switching valve 100 will be described in order below. Here, the longitudinal axis L in the figure is the central axis of the housing 1, the valve body 2, and the drive unit 5. Note that, for the sake of explanation, the slide type switching valve 100 in this embodiment is a four-way switching valve, but is not limited to this and may be, for example, a two-way valve or a three-way switching valve.

[0025] The housing 1 is made of aluminum and is formed in a cylindrical shape with a bottom. An inlet passage 1d is formed in the left side wall of the housing 1, and an opening 1a for inserting the valve body 2 is formed in the right side wall. In addition, a first passage 1e, an outlet passage 1s, and a second passage 1c are formed in the bottom wall of the housing 1 in this order along the axis L as multiple cylindrical flow paths. Here, as will be described in detail later, the inlet passage 1d and the outlet passage 1s are connected to the discharge port and the suction port of the compressor 200, respectively, and the first passage 1e and the second passage 1c are connected to either the condenser or the evaporator, respectively.

[0026] The valve body 2 is made of a resin material such as polyphenylene sulfide (PPS) and is formed in a cylindrical shape with a bottom. It contains a valve chamber 2a. An inlet port A, which communicates with the valve chamber 2a, is formed in the side wall of the valve body 2. Furthermore, a plurality of cylindrical flow paths, including a first connection flow path 21, an outlet connection flow path 22, and a second connection flow path 23, are formed in the bottom wall of the valve body 2 in this order along the axis L and communicate with the valve chamber 2a. The inlet port A and the outlet connection flow path 22 are connected to the inlet path 1d and the outlet path 1s, respectively, and the first connection flow path 21 and the second connection flow path 23 are connected to the first path 1e and the second path 1c, respectively. A cylindrical metal bottom cover 24 is fixed to the right end of the valve body 2 by insert molding. As will be described in detail later, an upper cover 25, which is fixed to a guide member 54 by insert molding, is fixed to the lower cover 24 by welding or the like. In addition, O-rings 26 are provided in a plurality of grooves G arranged at predetermined intervals along the direction of the axis L on either the outer peripheral wall of the valve body 2 or the inner peripheral wall of the housing 1. Therefore, when the valve body 2 is inserted into the housing 1 through the opening 1a of the housing 1 and fixed to the housing 1 via the upper cover 25 by a C-shaped retaining ring 27, the O-rings 26 seal between the valve body 2 and the housing 1, among the inlet path 1d, the second path 1c, the outlet path 1s, the first path 1e, and the outside of the housing 1 (the atmosphere).

[0027] In this embodiment, the valve body 2 is made of resin, but the material is not limited to this and may be metal such as brass, iron, aluminum, stainless steel, or the like.

[0028] The valve seat 3 is made of a thin metal plate and is fixed to the bottom wall of the valve body 2 by insert molding, bonding, welding, or the like. The valve seat 3 has a first port 30 communicating with the first connecting flow path 21, an outlet port 31 communicating with the outlet connecting flow path 22, and a second port 32 communicating with the second connecting flow path 23 formed at a predetermined interval in the direction of the axis L. The first port 30, the outlet port 31, and the second port 32 are formed in a cylindrical shape with an inner diameter smaller than the first connecting flow path 21, the outlet connecting flow path 22, and the second connecting flow path 23. The surface of the valve seat 3 facing the valve chamber 2a forms a sealing surface 33.

[0029] The valve body 4 is mainly made of a resin material such as polyphenylene sulfide (PPS), and includes a valve body main body 40 that has the shape of an upside-down bowl-shaped container, and a connecting part 44 that protrudes from the right end in the direction of the axis L. The valve body 4 slides with its lower surface in contact with the valve seat part 3, forming a space between it and the valve seat part 3.

[0030] The valve body 40 faces the sealing surface 33 of the valve seat 3 and has an oval opening edge 40a extending in the direction of the axis L, a bowl-shaped portion 40b protruding from the opening edge 40a toward the valve chamber 2a, and a bowl-shaped recess 40c provided inside the bowl-shaped portion 40b.

[0031] The opening edge 40a constitutes a seal portion S that can slide against the seal surface 33. A spring member 42 is sandwiched between the top of the bowl-shaped portion 40b and the inner peripheral wall of the valve body 2, and this spring member 42 urges the valve body 40 against the valve seat 3, thereby sealing between the valve chamber 2a outside the bowl-shaped portion 40b and the bowl-shaped recess 40c inside the bowl-shaped portion 40b.

[0032] The connecting portion 44 is formed in a hook shape so as to be connected to the driving portion 5. The connecting portion 44 is connected to the driving portion 5 via a shaft member 59, which will be described in detail later.

[0033] The drive unit 5 is the part that drives the valve body 4 to slide, and is equipped with a stepping motor 5a (motor unit) as an electric motor having a rotatable rotor, and a linear motion mechanism 5b that converts the rotation of the stepping motor 5a into linear motion and transmits it to the valve body 4.

[0034] The stepping motor 5a includes a can 50 having a cylindrical shape with a bottom, a magnet rotor 51 (rotor), and a stator coil 52.

[0035] The can 50 is made of a thin metal plate and is formed into a cylindrical shape with a bottom.

[0036] The magnet rotor 51 is a rotor and is disposed inside the can 50 .

[0037] The stator coil 52 is a stator, and is arranged so as to surround the outer periphery of the magnet rotor 51 around the axis L with the can 50 sandwiched therebetween.

[0038] 2, the linear motion mechanism 5b includes a bearing member 53, a guide member 54, a male screw member 55, and a female screw member 56. Details of the linear motion mechanism 5b (particularly the guide member 54, the male screw member 55, and the female screw member 56) will be described later, so only a brief description will be given here.

[0039] The bearing member 53 is made of a resin material such as polyphenylene sulfide (PPS), is arranged inside the bottom side of the can 50, and has a first bearing hole 53a that is coaxial with the axis L and supports the right end of the male thread member 55.

[0040] The guide member 54 is made of a resin material and is formed into a cylindrical shape with a bottom. A tapered upper cover 25 made of a metal material is fixed to the outer periphery of the guide member 54 by insert molding. As shown in FIG. 2, the small-diameter portion 25a of the upper cover 25 is fixed to the can 50 by welding or the like to seal the inside of the drive unit 5. The large-diameter portion 25b of the upper cover 25 is fixed to the lower cover 24 by welding or the like. As a result, the central axes of the guide member 54, the can 50, the bearing member 53, and the valve body 2 are arranged coaxially with the axis L. Furthermore, a partition wall 54d (see FIGS. 2 and 3), which is the bottom of the guide member 54, has a second bearing hole 54a that supports the left end of the male thread member 55 and a pair of guide holes 54b arranged on either side of the second bearing hole 54a, both of which are coaxial with the axis L.

[0041] The male screw member 55 is a rotor shaft having a male screw portion 55d on its outer circumferential surface, and is indirectly fixed to the center of the magnet rotor 51 via a fixing member 55a (see FIG. 2).

[0042] The female screw member 56 includes a threaded cylindrical portion 56a (see FIGS. 2 and 4) having a female screw portion 56a1 formed on its inner circumferential surface and accommodated in the guide member 54 with a radial gap therebetween, and a pair of connecting arms 56b (see FIGS. 2 and 4) that are inserted into a pair of guide holes 54b of the guide member 54 to restrict rotation of the female screw member 56 about the axis L. The pair of connecting arms 56b are connected to the valve body 4 via a shaft 59. The female screw portion 56a1 and the male screw portion 55d are threadedly engaged with each other to form a screw feed mechanism. As will be described in detail later, as shown in FIGS. 5 and 6, the threaded engagement area Sa between the female screw portion 56a1 and the male screw portion 55d is always accommodated in a screw-accommodating space Ss defined by the can 50 and the guide member 54.

[0043] In the drive unit 5, when the stepping motor 5a rotates the male screw member 55, the screw feed mechanism converts the rotation of the male screw member 55 into linear motion of the female screw member 56. This linear motion of the female screw member 56 drives the valve element 4 connected to the female screw member 56 to move back and forth so as to slide in the direction of the axis L.

[0044] In this embodiment, the drive unit 5 that drives the valve body 4 back and forth has a male screw member 55 indirectly fixed to the magnet rotor 51, but this is not limited to this, and for example, the male screw member 55 may be directly fixed to the magnet rotor 51.

[0045] <Details of the linear motion mechanism> The linear motion mechanism 5b (particularly the guide member 54, the male screw member 55, and the female screw member 56) will be described in detail in order using Figures 2 to 4. Note that Figure 2 is a cross-sectional view taken along line II-II of the slide type switching valve 100 shown in Figure 1, Figure 3 is a detailed view of the guide member 54, and Figure 4 is a detailed view of the female screw member 56.

[0046] <Guide parts> As shown in FIGS. 2 and 3, the partition wall 54d of the guide member 54 has a second bearing hole 54a that opens along the axis L. This second bearing hole 54a journals a second shaft portion 55c (FIG. 2) of the male thread member 55. The partition wall 54d of the guide member 54 also has a pair of guide holes 54b that are arranged opposite each other with the second shaft portion 55c horizontally sandwiched therebetween. The pair of guide holes 54b receive the pair of connecting arms 56b of the female thread member 56, allowing them to move forward and backward in the direction of the axis L. Here, the edges of the pair of guide holes 54b each have a shape (see FIG. 3(b)) that follows a generally crescent shape (see FIG. 4(b)) formed by curved outer surfaces 56b1 and flat inner surfaces 56b2, which are the outer wall surfaces of the pair of connecting arms 56b. The guide member 54 has a pair of connecting arms 56b of the female screw member 56 inserted into a pair of guide holes 54b, thereby preventing the female screw member 56 from rotating about the axis L and guiding the female screw member 56 to move back and forth in the direction of the axis L. Furthermore, the partition wall 54d of the guide member 54 has a pair of vent holes 54c formed continuously on the radially outer sides of the pair of guide holes 54b. When the pair of connecting arms 56b of the female screw member 56 is inserted into the pair of guide holes 54b, the pair of vent holes 54c constantly communicate between the screw accommodating space Ss (see FIG. 1) defined by the can 50 and the guide member 54 and the valve chamber 2a.

[0047] <About male threaded components> As shown in FIG. 2 , the male threaded member 55 extends along the axis L and includes a male threaded portion 55d formed on the outer circumferential surface. The male threaded member 55 includes, in order along the right side of the axis L of the male threaded portion 55d, a first reduced diameter portion 55e having a cylindrical shape whose diameter is smaller than that of the male threaded portion 55d, and a first shank portion 55b having a cylindrical shape whose diameter is smaller than that of the first reduced diameter portion 55e. The male threaded member 55 also includes, in order along the left side of the axis L of the male threaded portion 55d, a second reduced diameter portion 55f having a cylindrical shape whose diameter is smaller than that of the male threaded portion 55d, and a second shank portion 55c having a cylindrical shape whose diameter is smaller than that of the second reduced diameter portion 55f. The first shank portion 55b and the second shank portion 55c are journaled in a first bearing hole 53a and a second bearing hole 54a, respectively, which are disposed on the axis L. As a result, the male screw member 55 rotates around the axis L together with the magnet rotor 51 via the fixing member 55a.

[0048] <About female threaded components> 2 and 4, the female screw member 56 includes a cylindrical threaded tube portion 56a having a female screw portion 56a1 formed on its inner circumferential surface, and a pair of connecting arms 56b extending from the threaded tube portion 56a to the left in the direction of axis L and inserted into a pair of guide holes 54b of the guide member 54 to restrict rotation of the female screw member 56 about the axis L. The female screw portion 56a1 and the male screw portion 55d are threadedly engaged with each other to form a screw feed mechanism, and the female screw member 56 can advance and retreat in the direction of axis L as the male screw member 55 rotates. The left ends of the pair of connecting arms 56b in the direction of axis L are connected to the valve body 4.

[0049] <About the threaded barrel> The inner peripheral surface of the threaded cylindrical portion 56a is provided with a female thread portion 56a1, and a first enlarged diameter portion 56a2 and a second enlarged diameter portion 56a3, each having a cylindrical shape and enlarged in diameter from the female thread portion 56a1, on the right and left sides of the female thread portion 56a1 in the direction of the axis L. A rotation stopper 56d protruding in the direction of the axis L is provided adjacent to the first enlarged diameter portion 56a2 on the outer peripheral edge of the right end of the threaded cylindrical portion 56a in the direction of the axis L. When the rotation stopper 56d abuts against a thick portion of the rotating magnet rotor 51, the rotation of the magnet rotor 51 is stopped. As a result, the rightward movement of the female thread member 56 in the direction of the axis L is restricted, and the magnet rotor 51 stops at the right stop position (see FIG. 5(a)). Furthermore, an abutment portion 56e is provided on the connecting surface between the pair of connecting arms 56b and the left end of the threaded cylindrical portion 56a in the direction of the axis L. When this contact portion 56e comes into contact with the partition wall 54d of the guide member 54, the movement of the female screw member 56 to the left in the direction of the axis L is restricted, and the female screw member 56 stops at the left stop position (see FIG. 6(a)).

[0050] <About the pair of connecting arms> As shown in FIG. 4(b), the pair of connecting arms 56b have a generally crescent shape that is plane-symmetrical with respect to a plane P1 including the axis L. The pair of connecting arms 56b have a curved outer surface 56b1 that is arc-shaped and continuous with the outer peripheral surface of the cylindrical threaded tube portion 56a, and flat inner surfaces 56b2 that face each other in parallel between the pair of connecting arms 56b. Each connecting arm 56b has a female-thread-side locking groove 56c at its left end in the direction of the axis L for locking the shaft 59. The female-thread-side locking groove 56c has a wide-mouthed locking groove opening 56c1 at its upper opening, which allows the shaft 59 to be smoothly inserted into the female-thread-side locking groove 56c (see FIG. 2). Each connecting arm 56b has a trapezoidal recess 56b3 at its left end in the direction of the axis L.

[0051] <Connection between the pair of connecting arms and the valve body> As shown in Fig. 2, a shaft 59 is attached to the left end of the pair of connecting arms 56b in the direction of axis L. As shown in Fig. 1, this shaft 59 engages with a hook-shaped connecting portion 44 provided on the valve body 4, thereby connecting the female screw member 56, i.e., the drive unit 5, to the valve body 4. Furthermore, the connecting portions between the pair of connecting arms 56b and the connecting portion 44 are fastened with fastening bands 45 (see Fig. 1), which makes it possible to prevent the pair of connecting arms 56b from separating from each other even when a torsional moment is applied to them.

[0052] As described above, the linear motion mechanism 5b converts the rotation of the stepping motor 5a into linear motion, and this linear motion drives the valve element 4 to slide back and forth in the direction of the axis L. Note that the linear motion mechanism 5b in this embodiment is configured such that the male screw member 55 is rotatably fixed to the housing 1 and the female screw member 56 slides back and forth in the direction of the axis L, but is not limited to this. For example, the linear motion mechanism 5b may be configured such that the female screw member 56 is rotatably fixed to the housing 1 and the male screw member 55 slides back and forth in the direction of the axis L. Also, the slide type switching valve 100 in this embodiment is configured such that the longitudinal axis L is horizontal and the valve element 4 slides in the horizontal direction, but is not limited to this. For example, the linear motion mechanism 5b may be configured such that the longitudinal axis L is vertical and the valve element 4 slides in the vertical direction.

[0053] <Operation of the slide type switching valve> 5 and 6, the slide-type switching valve 100 is used in a refrigeration cycle system, and a D-type coupling pipe 1D, a C-type coupling pipe 1C, an S-type coupling pipe 1S, and an E-type coupling pipe 1E are attached to the inlet path 1d, the second path 1c, the outlet path 1s, and the first path 1e, respectively. The slide-type switching valve 100 connects the D-type coupling pipe 1D connected to the discharge port of the compressor 200 and the S-type coupling pipe 1S connected to the suction port of the compressor 200 to either the C-type coupling pipe 1C connected to the outdoor heat exchanger 300 or the E-type coupling pipe 1E connected to the indoor heat exchanger 400 by driving the valve element 4 back and forth so as to slide in the direction of the axis L using the drive unit 5. In this way, the slide-type switching valve 100 switches the fluid paths of the refrigeration cycle system.

[0054] <Operation of the refrigeration cycle system> First, during cooling operation, as shown in Fig. 5, the slide type switching valve 100 drives the drive unit 5 to slide the valve element 4 to the right position in the direction of the axis L, and the valve element main body 40 and the valve seat 3 connect the S joint pipe 1S and the E joint pipe 1E via the bowl-shaped recess 40c, and connect the D joint pipe 1D and the C joint pipe 1C via the valve chest 2a and the second port 32. As a result, high-pressure refrigerant compressed by the compressor 200 flows from the D joint pipe 1D through the valve chest 2a into the C joint pipe 1C, flows through the outdoor heat exchanger 300, the expansion device 500, and the indoor heat exchanger 400 in this order, flows from the E joint pipe 1E through the bowl-shaped recess 40c into the S joint pipe 1S, and then circulates to the compressor 200. In this case, the outdoor heat exchanger 300 functions as a condenser, and the indoor heat exchanger 400 functions as an evaporator.

[0055] Next, during heating operation, as shown in Fig. 6, the slide type switching valve 100 drives the drive unit 5 to slide the valve element 4 to the left position in the direction of the axis L, and the valve element main body 40 and the valve seat 3 connect the C joint pipe 1C and the S joint pipe 1S via the bowl-shaped recess 40c, and connect the D joint pipe 1D and the E joint pipe 1E via the valve chest 2a and the first port 30. As a result, high-pressure refrigerant compressed by the compressor 200 flows from the D joint pipe 1D through the valve chest 2a into the E joint pipe 1E, flows through the indoor heat exchanger 400, the expansion device 500, and the outdoor heat exchanger 300 in this order, flows from the C joint pipe 1C through the bowl-shaped recess 40c into the S joint pipe 1S, and then circulates to the compressor 200. At this time, during heating operation, the refrigerant is circulated in the opposite direction to that during cooling operation, and the indoor heat exchanger 400 functions as a condenser, and the outdoor heat exchanger 300 functions as an evaporator.

[0056] <Details of the screw feed mechanism> The slide-type switching valve 100 may be used in a refrigeration cycle system that operates in an oil-free state or with a low oil content. Under these conditions, in a conventional slide-type switching valve, there is no fluid lubrication film of refrigerant oil between the male and female threads, or only a relatively thin fluid lubrication film. This can lead to mechanical wear, i.e., wear due to adhesion of the mating surfaces and abrasive wear due to unevenness of the mating surfaces. As a result, conventional slide-type switching valves have problems 1 and 2 (significant wear of the screw feed mechanism and adverse effects of wear debris on the screw feed mechanism).

[0057] Furthermore, in the slide-type switching valve 100, when the refrigeration cycle system is switched from a heating operation state to a cooling operation state, the female screw member 56 moves in a movement direction M1 relative to the male screw member 55, as shown in FIG. 5(b). On the other hand, when the refrigeration cycle system is switched from a cooling operation state to a heating operation state, the female screw member 56 moves in a movement direction M2 relative to the male screw member 55, as shown in FIG. 6(b). In this way, in the slide-type switching valve 100, each time the fluid path of the refrigeration cycle system is switched, the contact surfaces C (see FIGS. 5(b) and 6(b)) of the male screw portion 55d and the female screw portion 56a1 are swapped and placed in different positions. For this reason, even if a small amount of wear powder is generated on one contact surface C of the screw feed mechanism, this wear powder may be caught in the other contact surface C, generating new wear powder, which may result in accelerated wear of the screw feed mechanism.

[0058] In contrast, the slide type switching valve 100 of this embodiment mainly takes the following two measures to solve the conventional problems 1 and 2 (significant wear of the screw feed mechanism and adverse effects of wear powder on the screw feed mechanism). In addition, although details will be described later, after taking the first measure, a third measure is taken to address the concern.

[0059] <1. Significant wear reduction in the screw feed mechanism> The first solution is to solve the conventional problems 1 and 2 by improving the materials that make up the screw feed mechanism.

[0060] <Materials that make up the screw feed mechanism> Specifically, in the slide-type switching valve 100 of this embodiment, one of the male thread portion 55d and the female thread portion 56a1 is made of metal with a lubricating coating on the metal surface, and the other is made of a resin material.

[0061] This provides good lubrication at the contact surface C of the male thread portion 55d and the female thread portion 56a1, thereby resolving the conventional problem 1 (significant wear of the screw feed mechanism), and at the same time, suppressing the generation of wear powder itself, thereby resolving the conventional problem 2 (adverse effect of wear powder on the screw feed mechanism).As a result, the accuracy of the valve position in the slide type switching valve 100 can be increased, and operability can be improved.

[0062] In the slide type switching valve 100 of this embodiment, the coating applied to the metal surface of either the male thread portion 55d or the female thread portion 56a1 is made of a lubricating fluororesin-based, molybdenum disulfide-based, or graphite-based material. These coating materials have very high heat resistance and excellent lubricity.

[0063] Here, the fluororesin-based coating contains particles of resin such as polytetrafluoroethylene (PTFE) or perfluoroethylene propene copolymer (FEP) in the binder (binding agent) of the coating material, and has a heat resistance temperature of about 230°C. The molybdenum disulfide-based coating contains crystals of molybdenum disulfide (MoS2) in the binder, and has a heat resistance temperature of about 350°C. The graphite-based coating contains crystals of graphite in the binder, and has a heat resistance temperature of about 230°C.

[0064] As a result, in addition to the effects described above, the contact surface C between the male thread portion 55d and the female thread portion 56a1 can withstand a relatively high load and has extremely good lubricity even when the ambient temperature changes.

[0065] Furthermore, in the slide type switching valve 100 of this embodiment, the resin material of the other of the male thread portion 55d and the female thread portion 56a1 is polyphenylene sulfide (PPS) to which polytetrafluoroethylene (PTFE) has been added. This PPS has very high heat resistance (for example, the heat resistance temperature of PPS is about 220°C) and good lubricity.

[0066] As a result, in addition to the effects described above, the contact surface C between the male thread portion 55d and the female thread portion 56a1 is less likely to undergo dimensional changes even when the ambient temperature changes, so that the desired meshing dimensions are well maintained and even better lubrication is obtained.

[0067] Additionally, in the slide type switching valve 100 of this embodiment, the resin material of the other of the male thread portion 55d and the female thread portion 56a1 may be PPS, which is polytetrafluoroethylene (PTFE) reinforced with glass fiber or carbon fiber. This PPS has very high tensile strength (e.g., 150 MPa) and heat resistance (e.g., heat resistance temperature of about 230°C).

[0068] As a result, in addition to the effects described above, the contact surface C between the male thread portion 55d and the female thread portion 56a1 has further improved reliability in terms of strength and heat resistance of the resin material, and the desired meshing dimensions can be maintained with high precision.

[0069] <2. Suppressing the effects of wear debris on the screw feed mechanism itself> Even if the materials that make up the screw feed mechanism are devised as part of the first measure, there is still a risk of wear powder being generated from the screw feed mechanism. Therefore, the second measure aims to resolve problem 2 (the adverse effect of wear powder on the screw feed mechanism) in particular by devising the type of screw or the screw feed mechanism itself.

[0070] <About screw types> 7(a) is an enlarged view of the area surrounded by the dashed line VIIa shown in FIG. 1. In this screw feed mechanism, the female thread portion 56a1 and the male thread portion 55d are threadedly engaged with each other. If wear powder is generated in the threaded engagement region Sa, as the male thread portion 55d rotates, the wear powder is swept out in the discharge direction E along the valleys 55g of the male thread portion 55d, and is ultimately discharged from the end of the threaded engagement region Sa on the opposite side of the moving direction M1 of the female thread member 56.

[0071] Below, the discharge of wear debris will be explained by comparing the multiple-start thread (e.g., a three-start thread) of this embodiment shown in Figures 7(b) and (c) with the standard thread (single-start thread) of a comparative example shown in Figures 7(d) and (e). Here, it is assumed that the pitch length of the multiple-start thread and the standard thread are the same. To simplify the explanation, only the male thread member 55 and the male thread member 55' are shown for the multiple-start thread and the standard thread, respectively. Note that a "multiple-start thread" means "a thread with multiple threads" and a "standard thread" means "a thread with one thread," but detailed definitions are as explained in the above section on terminology.

[0072] First, the multiple-start thread of this embodiment has a lead angle θ1 as shown in FIG. 7(c), while the conventional thread of the comparative example has a lead angle θ1' as shown in FIG. 7(e). The lead angle θ1 of this multiple-start thread is larger than the lead angle θ1' of the conventional thread. As a result, the distance between the helical windings of the multiple-start thread (see the valleys 55g of the male thread portion 55d shown by the solid and dashed lines in FIG. 7(c)) is shorter than the distance between the helical windings of the conventional thread (see the valleys 55g' of the male thread portion 55d' shown by the solid and dashed lines in FIG. 7(e)). Therefore, with a multiple-start thread, the discharge path for wear debris via the valleys 55g of the male thread portion 55d can be made relatively short, making it easier to discharge wear debris.

[0073] Furthermore, as shown in Fig. 7(b), the multiple-start thread of this embodiment has multiple-start thread terminations 55h at the end of the threaded region Sa (for example, three terminations), whereas the conventional thread of the comparative example has only one conventional thread termination 55h' as ​​shown in Fig. 7(d). Therefore, the multiple-start thread has a relatively large number of thread terminations, i.e., outlets for the wear debris discharge paths, and can simultaneously discharge wear debris in multiple discharge directions E, making it easier to discharge wear debris.

[0074] In this way, by forming the female thread portion 56a1 and the male thread portion 55d as multiple threads and actively discharging wear powder outside the threaded area, problem 2 of the conventional art (the adverse effect of wear powder on the screw feed mechanism) is particularly resolved. Also, wear powder is less likely to accumulate in the screw feed mechanism, which improves the durability of the screw feed mechanism.

[0075] <About the screw feed mechanism> During cooling operation, as shown in Fig. 5(a), the rotation stopper 56d of the female screw member 56 abuts against the thick portion of the rotating magnet rotor 51, thereby restricting the movement of the female screw member 56 to the right in the direction of axis L, and the female screw member 56 stops at the right stop position. On the other hand, during heating operation, as shown in Fig. 6(a), the abutting portion 56e of the female screw member 56 abuts against the partition wall 54d of the guide member 54, thereby restricting the movement of the female screw member 56 to the left in the direction of axis L, and the female screw member 56 stops at the left stop position. Here, in the screw feed mechanism, the screw engagement area Sa at the right stop position (see Fig. 5(a)) and the screw engagement area Sa at the left stop position (see Fig. 6(a)) are set so as not to overlap. Therefore, when switching between cooling operation and heating operation, all of the male thread portions 55d extending in the axial L direction temporarily move out of the threaded engagement area Sa and are exposed to the screw accommodating space Ss, so that wear powder is actively discharged out of the threaded engagement area Sa (see discharge direction E in the axial L direction in Figures 5(b) and 6(b)). Furthermore, after switching, the threaded engagement area Sa before switching is completely exposed to the screw accommodating space Ss, so even if wear powder adheres to the male thread portions 55d, it is easily removed by the flow of refrigerant.

[0076] In this way, by setting the screw engagement area Sa at the right stop position and the screw engagement area Sa at the left stop position so that they do not overlap, and actively discharging wear powder outside the screw engagement area, problem 2 of the conventional art (the adverse effect of wear powder on the screw feed mechanism) is particularly resolved. Also, because wear powder is less likely to accumulate in the screw feed mechanism, the durability of the screw feed mechanism can be improved.

[0077] 2, in the female thread member 56, the inner peripheral surface of the threaded cylindrical portion 56a is provided with a first enlarged diameter portion 56a2 and a second enlarged diameter portion 56a3, which are cylindrical and have a larger diameter than the female threaded portion 56a1 and are formed continuously on the right and left sides of the female threaded portion 56a1 in the direction of the axis L. Therefore, as shown in FIGS. 5(b) and 6(b), both ends in the direction of the axis L of the screw engagement region Sa, which is formed by the female threaded portion 56a1 and the male threaded portion 55d, are always released in the direction of the axis L and in the radial direction by the first enlarged diameter portion 56a2 and the second enlarged diameter portion 56a3.

[0078] In this way, both ends of the threaded engagement area Sa in the direction of the axis L are always open in the direction of the axis L and in the radial direction by the first enlarged diameter portion 56a2 and the second enlarged diameter portion 56a3, and wear powder is actively discharged outside the threaded engagement area, thereby particularly resolving conventional problem 2 (the adverse effect of wear powder on the screw feed mechanism).In addition, wear powder is less likely to accumulate in the screw feed mechanism, which improves the durability of the screw feed mechanism.

[0079] 2, the male thread member 55 includes a first reduced diameter portion 55e and a second reduced diameter portion 55f, which are cylindrical and formed continuously on the right and left sides of the male thread portion 55d in the direction of the axis L and have a smaller diameter than the male thread portion 55d. Therefore, as shown in FIG. 5(a), the right end side of the screw engagement region Sa in the direction of the axis L is released in the direction of the axis L and in the radial direction by the first reduced diameter portion 55e at the right stop position. Similarly, as shown in FIG. 6(a), the left end side of the screw engagement region Sa in the direction of the axis L is released in the direction of the axis L and in the radial direction by the second reduced diameter portion 55f at the left stop position.

[0080] Here, immediately after switching from cooling operation to heating operation, that is, when the female screw member 56 starts to move from the right stop position shown in FIG. 5(a) in the movement direction M2 (see FIG. 6(a)), which is to the left in the direction of axis L, the right end side of the threaded area Sa at the right stop position is released in the direction of axis L and in the radial direction, so that wear powder can be actively discharged outside the threaded area. Similarly, immediately after switching from heating operation to cooling operation, that is, when the female screw member 56 starts to move from the left stop position shown in FIG. 6(a) in the movement direction M1 (see FIG. 5(a)), which is to the right in the direction of axis L, the left end side of the threaded area Sa at the left stop position is released in the direction of axis L and in the radial direction, so that wear powder can be actively discharged outside the threaded area.

[0081] In this way, the right end side of the threaded engagement area Sa in the direction of axis L at the right stop position is released in the direction of axis L and radially by the first reduced diameter portion 55e, and the left end side of the threaded engagement area Sa in the direction of axis L at the left stop position is released in the direction of axis L and radially by the second reduced diameter portion 55f, thereby actively discharging wear powder outside the threaded engagement area and particularly resolving conventional problem 2 (adverse effects of wear powder on the screw feed mechanism). Also, because wear powder is less likely to accumulate in the screw feed mechanism, the durability of the screw feed mechanism can be improved.

[0082] <3. Reducing the impact of wear debris on other equipment> Here, even if the materials constituting the screw feed mechanism are improved as in the first measure, there is a risk of wear debris being generated from the screw feed mechanism. If this wear debris circulates in the fluid path, it could cause malfunctions in the devices constituting the refrigeration cycle system (hereinafter referred to as "Concern (Adverse Effects of Wear Debris on Other Devices)"). To collect the wear debris circulating in the fluid path, it is conceivable to provide a strainer or the like with a mesh that is much finer than the wear debris in the fluid path. However, this could cause pressure loss and reduce the coefficient of performance (COP) of the refrigeration cycle system. Therefore, as a third measure, the concern (adverse effects of wear debris on other devices) is resolved by improving the communication between the screw accommodation space Ss, which accommodates the screw engagement area Sa of the screw feed mechanism, and the valve chest (inside the valve body) 2a.

[0083] <Communication between the screw receiving space and the valve chest> 1 to 3, the guide member 54 has a partition wall 54d that separates the screw-accommodating space Ss, which constantly accommodates the threaded region Sa of the screw feed mechanism, from the valve chamber 2a, which is the interior of the valve body 2, and a pair of guide holes 54b formed in the partition wall 54d. Also, as shown in FIGS. 1 to 2 and 4, the female thread member 56 has a threaded cylindrical portion 56a having a female thread portion 56a1 formed on its inner circumferential surface, and a pair of connecting arms 56b extending from the threaded cylindrical portion 56a to the left in the direction of the axis L. By inserting the pair of connecting arms 56b of the female thread member 56 into the pair of guide holes 54b in the direction of the axis L, the female thread member 56 is prevented from rotating around the axis L and is guided forward and backward in the direction of the axis L.

[0084] In this way, by separating the screw accommodating space Ss and the valve chamber 2a with the partition wall 54d of the guide member 54, even if a large amount of wear powder is generated in the screw feed mechanism, the outflow of the wear powder from the screw accommodating space Ss to the valve chamber 2a is prevented, thereby eliminating the concern (adverse effects of wear powder on other equipment).

[0085] Although this is not a problem when the refrigerant is oil-free, when the refrigerant contains a low amount of refrigerant oil, it is desirable to supply even a small amount of refrigerant oil to the screw engagement area Sa of the screw feed mechanism in order to obtain the effect of reducing wear on the screw feed mechanism. However, if the partition wall 54d completely isolates the screw accommodating space Ss from the valve chest 2a, the refrigerant oil present in the valve chest 2a cannot be supplied to the screw engagement area Sa.

[0086] Furthermore, particularly during heating operation, as shown in Figure 6(a), the abutment portion 56e of the female screw member 56 is in surface contact with the partition wall 54d of the guide member 54, and therefore, refrigeration oil or the like present between the abutment portion 56e and the partition wall 54d may cause the abutment portion 56e and the partition wall 54d to stick together, which may prevent a smooth switch from heating operation to cooling operation.

[0087] 2 and 3, the partition wall 54d of the guide member 54 has, in addition to the pair of guide holes 54b, a pair of vent holes 54c formed continuously radially outward from the pair of guide holes 54b. The pair of vent holes 54c constantly communicate between the screw accommodating space Ss and the valve chamber 2a when the pair of connecting arms 56b of the female screw member 56 are inserted into the pair of guide holes 54b. Therefore, the refrigerant in the valve chamber 2a can be introduced into the screw accommodating space Ss via the pair of vent holes 54c, which allows the refrigerant oil contained in the refrigerant to be supplied to the threaded region Sa and prevents the abutment portion 56e from sticking to the partition wall 54d when switching from heating operation to cooling operation.

[0088] Here, there is a concern that wear particles present in the screw accommodating space Ss may flow out into the valve chamber 2a via the pair of vent holes 54c.

[0089] 2, when viewed from the axial direction, the threaded region Sa is located radially inward of the pair of connecting arms 56b, and the pair of vent holes 54c is located radially outward of the pair of connecting arms 56b. Therefore, the pair of connecting arms 56b are disposed in the fluid path from the threaded region Sa to the pair of vent holes 54c. This allows the pair of connecting arms 56b to function as a so-called baffle, thereby preventing wear debris from flowing out from the screw accommodating space Ss to the valve chamber 2a.

[0090] As shown in FIG. 5B, when switching from heating operation to cooling operation, wear debris is primarily discharged from the left end of the threaded region Sa in the axial direction L. Because the pair of vents 54c are located adjacent to the left end of the threaded region Sa in the axial direction L, the path for the wear debris to flow into the valve chamber 2a is relatively short. However, as the threaded cylindrical portion 56a moves in the guide member 54 in the movement direction M1, which is to the right in the axial direction L, the left space of the screw accommodating space Ss, located to the left of the threaded cylindrical portion 56a, is depressurized. This allows refrigerant to flow from the valve chamber 2a into the left space of the screw accommodating space Ss through the pair of vents 54c. This prevents the wear debris discharged from the threaded region Sa from flowing into the valve chamber 2a through the pair of vents 54c.

[0091] Furthermore, as shown in FIG. 6(b), when switching from cooling operation to heating operation, wear debris is mainly discharged from the right end of the threaded region Sa in the axial direction L. The pair of vent holes 54c are spaced apart from the right end of the threaded region Sa in the axial direction L via the threaded cylindrical portion 56a, thereby providing a relatively long path for wear debris to flow into the valve chamber 2a. Furthermore, as the threaded cylindrical portion 56a moves within the guide member 54 in the movement direction M2, i.e., to the left in the axial direction L, the right space of the screw accommodating space Ss, located to the right of the threaded cylindrical portion 56a, is depressurized. As a result, refrigerant flows from the left space to the right space of the screw accommodating space Ss through the annular gap between the outer circumferential surface of the threaded cylindrical portion 56a and the inner circumferential surface of the guide member 54. This prevents wear debris discharged from the threaded region Sa from flowing into the valve chamber 2a via the pair of vent holes 54c.

[0092] Here, in this embodiment, the wear powder discharged from the threaded region Sa is not completely prevented from flowing out into the valve chamber 2a through the pair of vent holes 54c. Specifically, the wear powder discharged from the threaded region Sa is allowed to flow in small amounts into the valve chamber 2a through the pair of vent holes 54c, but is prevented from flowing in large amounts into the valve chamber 2a.

[0093] As described above, the left and right spaces of the screw accommodating space Ss are alternately depressurized by the forward and backward movement of the threaded cylindrical portion 56a in the direction of the axis L. This depressurization prevents wear powder discharged from the threaded engagement area Sa from flowing into the valve chamber 2a through the pair of vent holes 54c, thereby eliminating the concern (the adverse effects of wear powder on other devices).

[0094] Furthermore, the slide type switching valve 100 switches flow paths by sliding the bowl-shaped valve element 4 over the valve seat 3 having multiple valve ports 30, 31, and 32. Therefore, the slide type switching valve 100 requires a relatively large driving force to move the valve element 4, which has a large pressure-receiving area, back and forth via a screw feed mechanism that has sliding resistance. In contrast, by taking the measures described above, the slide type switching valve 100 of this embodiment can reduce the sliding resistance of the screw feed mechanism and suppress the generation of wear powder, thereby realizing a reduction in the size of the entire slide type switching valve 100, including the drive unit, and improving the reliability of the slide type switching valve 100.

[0095] <Other> It goes without saying that the slide type switching valve 100 of this embodiment can be applied not only to the refrigeration cycle system illustrated, but also to any fluid device and fluid circuit. Furthermore, the present invention is not limited to the above-described aspects, embodiments, and modified examples, and can be appropriately changed or modified within the scope of the technical concept of the present invention. [Explanation of symbols]

[0096] 100 Slide type switching valve 1. Housing 1a opening 1c Pathway 2 1d Entrance route 1e 1st pathway 1s Exit Route 1C C fitting pipe 1D D joint pipe 1E E joint pipe 1S S joint pipe 2 Valve body 2a Valve chamber (inside the valve body) 21 First connecting channel 22 Outlet connection channel 23 Second connecting channel 24 Lower lid 25 Top lid 25a Small diameter section 25b Large diameter part 27 Retaining ring 3 Valve seat 30 Port 1 31 Exit Port 32 Second Port 33 Sealing surface 4 Valve body 40 Valve body 40a opening edge 40b Bowl-shaped part 40c bowl-shaped recess 42 Spring member 44 Connecting part 45 Fastening band 5 Drive unit 5a Stepping motor (motor part) 5b Linear motion mechanism 50 Can 51 Magnet rotor (rotor) 52 stator coil 53 Bearing materials 53a First bearing hole 54 Guide member 54a Second bearing hole 54b Pair of guide holes 54c Pair of vents 54d Partition wall 55 Male threaded member 55a Fixing member 55b First shaft part 55c Second shaft part 55d Male thread (screw feed mechanism) 55d' Male thread (comparison example) 55e First reduced diameter section 55f Second reduced diameter section 55g Multiple thread valley 55g' Regular thread valley 55h multi-start thread end 55h' End of normal thread 56 Female thread member 56a Threaded cylinder 56a1 Female thread part (screw feed mechanism) 56a2 First enlarged diameter part 56a3 Second enlarged diameter part 56b Pair of connecting arms 56b1 Curved outer surface 56b2 Flat inner surface 56b3 dent 56c Female thread locking groove 56c1 Locking groove opening 56d Rotation stopper 56e Contact part 59 Shaft material 200 Compressor 300 Outdoor heat exchanger 400 Indoor heat exchanger 500 aperture device A Inlet port C Contact surface E Ejection direction G groove L axis M1 movement direction M2 Moving direction P1 plane S seal part Sa threaded area Ss screw storage space θ1 Lead angle of multiple threads θ1' Normal thread lead angle

Claims

1. A hollow cylindrical valve body; a valve seat portion provided in the valve body and having a valve port; a valve element provided inside the valve body so as to be slidable in the axial direction; a drive unit that drives the valve body to slide using a screw feed mechanism that converts rotational motion into linear motion and has a male screw portion and a female screw portion that are threaded together; A slide type switching valve comprising: One of the male thread portion and the female thread portion is made of metal and has a lubricating coating on the metal surface, and the other is made of a resin material, A slide-type switching valve characterized in that, in addition to the threaded engagement area between the male threaded portion and the female threaded portion, it further comprises a partition wall that separates a screw accommodating space that always accommodates the male threaded portion and the female threaded portion from the inside of the valve body.

2. 2. The slide-type switching valve according to claim 1, wherein the coating is one of a fluororesin-based, molybdenum disulfide-based, and graphite-based coating having lubricity.

3. 2. The slide-type switching valve according to claim 1, wherein the resin material is PPS to which PTFE is added.

4. 4. The slide-type switching valve according to claim 3, wherein the resin material is PPS to which glass fiber or carbon fiber is further added as a reinforcing agent.

5. 2. The slide-type switching valve according to claim 1, wherein the male thread portion and the female thread portion are formed as multiple threads.

6. 2. The slide-type switching valve according to claim 1, wherein the threaded engagement regions of the male thread portion and the female thread portion at the stop positions on one axial side and the other axial side of the valve body do not overlap each other.

7. The drive unit includes a motor unit having a rotatable rotor, a male screw member fixed directly or indirectly to the rotor and extending in the axial direction, the male screw member having the male screw portion, a female screw member having the female screw portion and capable of advancing and retreating in the axial direction as the male screw member rotates, and a guide member that restricts rotation of the female screw member and guides its advancing and retreating in the axial direction, 7. The slide-type switching valve according to claim 6, wherein both axial ends of the threaded engagement region are always open in the axial and radial directions.

8. 8. The slide-type switching valve according to claim 7, wherein the female thread member has a threaded cylindrical portion having the female thread portion and a pair of enlarged diameter portions formed continuously at both ends of the female thread portion in the axial direction.

9. 8. The slide-type switching valve according to claim 7, wherein the male thread member has the male thread portion and a pair of reduced diameter portions formed continuously at both ends of the male thread portion in the axial direction.

10. The female screw member further includes a pair of connecting arms extending from the threaded cylindrical portion in the axial direction and connected to the valve body, 9. The slide-type switching valve according to claim 8, wherein the guide member has the partition wall and a guide hole provided in the partition wall, through which the pair of connecting arms are inserted in the axial direction and which restricts rotation of the female screw member.

11. 11. The slide-type switching valve according to claim 10, wherein the partition wall of the guide member has a pair of air holes adjacent to and radially outward from the pair of connecting arms when the pair of connecting arms are inserted into the guide holes, the air holes communicating between the screw accommodating space and the interior of the valve body.

12. 12. The slide-type switching valve according to claim 1, wherein the valve element has a bowl-like shape and slides on the valve seat portion having the plurality of valve ports to switch the flow path.

Images