Pilot valve and four-way reversing valve

Abstract

The utility model provides a pilot valve and a four-way reversing valve. The pilot valve comprises a sleeve, an end cover, a capillary tube and a cap-shaped filter screen, an accommodating part for accommodating the filter screen is formed on the inner side of one end of the capillary tube, and the filter screen is embedded in the accommodating part; the end cover is fixed to the inner side of one end of the sleeve and circumferentially sealed with the sleeve, a through hole is formed in the middle of the end cover in the axial direction, one end of the capillary tube penetrates through the through hole, and the outer wall of the capillary tube and the hole wall of the through hole are fixed and circumferentially sealed. The periphery of the through hole extends in the axial direction of the end cover to form a flange, and the outer wall of the capillary tube and the inner wall of the flange are fixed and sealed in the circumferential direction. The pilot valve further comprises a blocking piece which is fixed to one end of the capillary tube and used for blocking the filter screen so as to prevent the filter screen from being separated from the containing part. The four-way reversing valve comprises the pilot valve. According to the utility model, the fixing firmness and reliability of the capillary tube and the end cover can be improved, and the fixing firmness of the filter screen and the capillary tube can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration control, in particular to a pilot valve and a four-way reversing valve. Background Art

[0002] The four-way valve reversing valve (hereinafter referred to as the four-way valve) is mainly used in heat pump air conditioners, water heaters and other systems. It is mainly used to switch the flow direction of the refrigerant flow channel in the system, thereby realizing the cooling, heating, defrosting and other functions of the entire system; among them, the pilot valve is the core component of the four-way valve, and its working reliability is the guarantee for realizing the basic functions of the reversing valve.

[0003] At present, China Patent Publication No.: CN104075013B discloses a pilot valve and a four-way valve, the pilot valve includes a conduit, a filter, an end cover and a capillary tube; the filter includes a cap-shaped filter screen, one end of the capillary tube has a filter receiving portion, the filter is received in the filter receiving portion, the diameter of the filter receiving portion is larger than the diameter of the capillary main pipeline; the edge of the end cover is fixedly connected to one end of the conduit, the end cover has a support portion for blocking the filter, the filter receiving portion cooperates with the support portion, and the support portion is provided with a flow hole for passing the refrigerant; the pilot valve is provided with a filter receiving portion at one end of the capillary tube, the filter is clamped in the filter receiving portion, the end cover has a support portion for blocking the filter, the filter receiving portion cooperates with the support portion, the connection strength between the filter and the end cover can be improved, and the filter size is small, which can reduce the production cost.

[0004] However, in the pilot valve structure disclosed in the above-mentioned comparative document, since the diameter and wall thickness of the capillary are relatively small, and the capillary is connected only by the end portion being plugged in and fixed with the end cover, there are disadvantages of poor fixing firmness and reliability between the capillary and the end cover, that is, the capillary is easily separated from the end cover, and the filter is easily separated from the filter receiving portion located at the end of the capillary. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a pilot valve and a four-way reversing valve, which can improve the fixing firmness and reliability of the capillary tube and the end cover, that is, can effectively prevent the capillary tube from being separated from the end cover, and can improve the fixing firmness of the filter screen and the capillary tube to prevent the filter screen from being separated from the capillary tube.

[0006] The utility model provides a pilot valve, comprising a sleeve, an end cover, a capillary tube and a filter screen in the shape of a cap; a receiving portion for receiving the filter screen is formed on the inner side of one end of the capillary tube, and the filter screen is embedded in the receiving portion; the end cover is fixed on the inner side of one end of the sleeve and is circumferentially sealed with the sleeve, a through hole is provided in the middle part of the end cover in the axial direction, one end of the capillary tube is passed through the through hole, the outer wall of the capillary tube is fixed to the hole wall of the through hole and is circumferentially sealed; the periphery of the through hole extends along the axial direction of the end cover to form a flange, the outer wall of the capillary tube is fixed to the inner wall of the flange and is circumferentially sealed; the pilot valve also comprises a blocking member, which is fixed on one end of the capillary tube and is used to block the filter screen to prevent the filter screen from escaping from the receiving portion.

[0007] After the utility model adopts the above structure, since one end of the capillary is inserted into the through hole and the outer wall of the capillary is fixed to the hole wall of the through hole and circumferentially sealed, the contact area between the capillary and the fixed part of the end cover can be increased, that is, the capillary and the end cover can be reliably fixed. In addition, a flange extending along the axial direction of the end cover is provided at the periphery of the through hole, and the outer wall of the capillary is fixed to the inner wall of the flange and circumferentially sealed, so that the contact area between the capillary and the fixed part of the end cover can be further increased, that is, the capillary and the end cover can be reliably fixed, and the capillary can be effectively prevented from detaching from the end cover. In addition, through the provision of the blocking member, the blocking member is fixed on one end of the capillary and can block the filter screen to prevent the filter screen from detaching from the accommodating portion, thereby improving the fixing firmness of the filter screen and the capillary.

[0008] In a possible embodiment, the blocking member includes a retaining ring, one end of which is inserted into the receiving portion and abuts against the open end of the filter screen, an annular boss is arranged on the outer wall of the other end of the retaining ring, the annular boss abuts against one end of the capillary tube, the outer edge of the annular boss circumferentially protrudes from the outer peripheral wall of one end of the capillary tube, and the outer edge of the annular boss, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are circumferentially welded and fixed together; after adopting this structure, since one end of the retaining ring is inserted into the receiving portion and abuts against the open end of the filter screen, The retaining ring is abutted against each other, thereby achieving reliable blocking of the filter screen, and since an annular boss is provided on the outer wall of the other end of the retaining ring, the annular boss abuts against one end of the capillary tube. In addition, since the outer edge of the annular boss, the outer peripheral wall of one end of the capillary tube and the inner wall of the end cover are circumferentially welded and fixed together, the retaining ring, the capillary tube and the end cover can be reliably fixed, and then the retaining ring can be effectively prevented from separating from the capillary tube, that is, reliable blocking of the filter screen is achieved, and at the same time, the fixing firmness of the capillary tube and the end cover is further improved.

[0009] In a possible embodiment, one end of the retaining ring is inserted into the open end of the filter screen, and the open end of the filter screen is provided with an outwardly folded annular convex edge, which is embedded between the annular boss and one end of the capillary tube, and the outer edge of the annular convex edge circumferentially protrudes from the outer peripheral wall of one end of the capillary tube, and the outer edge of the annular boss, the outer edge of the annular convex edge, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are circumferentially welded and fixed together; by adopting this structure, the open end of the filter screen can be clamped between the outer wall of the retaining ring and the inner wall of the capillary tube, and the annular convex edge can be clamped between the annular boss and the end of one end of the capillary tube. In addition, since the outer edge of the annular boss, the outer edge of the annular convex edge, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are circumferentially welded and fixed together, the filter screen can be further fixed to prevent the filter screen from being separated from the capillary tube.

[0010] In a possible embodiment, the blocking member includes a blocking ring, one end of which is inserted into the accommodating portion and abuts against the open end of the filter screen, and an annular boss is provided on the outer wall of the other end of the blocking ring, an annular gap is formed between the annular boss and one end of the capillary, and the blocking ring and one end of the capillary are fixed together by circumferential welding with solder located in the annular gap; after adopting this structure, since one end of the blocking ring is inserted into the accommodating portion and abuts against the open end of the filter screen, it is possible to reliably block the filter screen, and since an annular boss is provided on the outer wall of the other end of the blocking ring, an annular gap is formed between the annular boss and one end of the capillary, the blocking ring and one end of the capillary are fixed together by circumferential welding with solder located in the annular gap, so that the blocking ring can be reliably fixed to one end of the capillary, that is, the filter screen can be effectively prevented from being separated from the capillary.

[0011] In a possible embodiment, one end of the capillary is inserted into the flange, the annular gap is located on the inner side of the through hole or the flange, and the retaining ring, one end of the capillary and the end cover are fixed together by circumferential welding through the solder located in the annular gap; after adopting this structure, since the annular gap is located on the inner side of the through hole or the flange, and since the retaining ring, one end of the capillary and the end cover are fixed together by circumferential welding through the solder located in the annular gap, the fixing firmness of the retaining ring, one end of the capillary and the end cover can be improved, that is, the capillary can be further prevented from being separated from the end cover, and the filter can be further prevented from being separated from the capillary.

[0012] In a possible embodiment, the blocking member includes a retaining ring, one side of the retaining ring abuts against one end of the capillary tube and the open end of the filter screen, the outer edge of the retaining ring circumferentially protrudes from the outer peripheral wall of one end of the capillary tube, the outer edge of the retaining ring, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover form an annular concave cavity, and the outer edge of the retaining ring, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are circumferentially welded and fixed to one body by solder located in the annular concave cavity; after adopting this structure, under the action of the retaining ring, one side of the retaining ring abuts against one end of the capillary tube and the open end of the filter screen, thereby effectively avoiding The filter screen is prevented from being separated from the capillary tube, and because the outer edge of the retaining ring, the outer peripheral wall of one end of the capillary tube and the inner wall of the end cover form an annular cavity, the outer edge of the retaining ring, the outer peripheral wall of one end of the capillary tube and the inner wall of the end cover are circumferentially welded and fixed together by the solder located in the annular cavity, thereby achieving reliable fixation of the retaining ring, the capillary tube and the end cover to avoid the end cover being separated from the capillary tube, that is, the filter screen can be prevented from being separated from the capillary tube. In addition, the fixing firmness of the capillary tube and the end cover can be improved to further avoid the capillary tube being separated from the end cover.

[0013] In a possible embodiment, the open end of the filter screen is provided with an outwardly folded annular convex edge, the annular convex edge is embedded between the retaining ring and one end of the capillary tube, the outer edge of the annular convex edge extends into the annular concave cavity, and the outer edge of the retaining ring, the outer edge of the annular convex edge, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are fixed together by circumferential welding with solder located in the annular concave cavity; by adopting this structure, the annular convex edge can be clamped between the retaining ring and the end of one end of the capillary tube, and in addition, since the outer edge of the retaining ring, the outer edge of the annular convex edge, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are fixed together by circumferential welding with solder located in the annular concave cavity, the filter screen can be further fixed to avoid the filter screen from being separated from the capillary tube.

[0014] In a possible embodiment, the blocking member includes a retaining ring, one side of which abuts against one end of the capillary tube and the open end of the filter screen, and an annular edging folded toward one side of the end cover is provided at the outer edge of the retaining ring, the annular edging is sleeved on the outside of one end of the capillary tube and abuts against the inner side wall of the end cover, and the annular edging is circumferentially welded and fixed to the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover; after adopting this structure, under the action of the retaining ring, one side of the retaining ring abuts against one end of the capillary tube and the open end of the filter screen, thereby effectively preventing the filter screen from detaching from the capillary tube. The situation, and because the outer edge of the retaining ring is provided with an annular edging folded toward one side of the end cover, the annular edging is sleeved on the outside of one end of the capillary tube and abuts against the inner side wall of the end cover, the annular edging is circumferentially welded and fixed to the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover, thereby realizing reliable fixation of the retaining ring, the capillary tube and the end cover to avoid the end cover from being separated from the capillary tube, that is, to avoid the filter screen from being separated from the capillary tube. In addition, the fixing firmness of the capillary tube and the end cover can be improved to further avoid the capillary tube from being separated from the end cover.

[0015] In a possible embodiment, the outer edge of the end cover extends along the axial direction of the end cover to form a folded edge, and the outer side wall of the folded edge is welded and fixed to the inner side wall of the sleeve and circumferentially sealed; by adopting this structure, under the action of the folded edge, the contact area between the end cover and the sleeve can be increased, so that after the outer edge of the end cover and the outer peripheral wall of the folded edge are fixed to the inner wall of the sleeve by welding, the fixing firmness of the end cover and the sleeve can be improved.

[0016] A four-way reversing valve comprises the above-mentioned pilot valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic cross-sectional view of the utility model when the technical solution of the first embodiment is adopted;

[0018] Figure 2 for Figure 1 The schematic diagram of the structure after the enlargement of A in the middle;

[0019] Figure 3 This is a schematic cross-sectional view of the utility model when the technical solution of the second embodiment is adopted;

[0020] Figure 4 for Figure 3 The schematic diagram of the structure after enlargement at B in the middle;

[0021] Figure 5 This is a schematic cross-sectional view of the utility model when the technical solution of Embodiment 3 is adopted;

[0022] Figure 6 for Figure 5 The schematic diagram of the structure after enlargement at C in the middle;

[0023] Figure 7 This is a schematic cross-sectional view of the utility model when the technical solution of the fourth embodiment is adopted;

[0024] Figure 8 for Figure 7 The schematic diagram of the structure after the enlargement of D in the middle;

[0025] Fig. 9 This is a schematic cross-sectional view of the utility model when the technical solution of Embodiment 5 is adopted;

[0026] Fig.10 for Fig. 9 The schematic diagram of the structure after enlargement at E in the middle;

[0027] Fig.11 This is a schematic cross-sectional view of the utility model when the technical solution of Embodiment 6 is adopted;

[0028] Fig.12 for Fig.11 The enlarged structural diagram at F in the middle;

[0029] Fig.13 This is a schematic cross-sectional view of the utility model when the technical solution of Embodiment 7 is adopted;

[0030] Fig.14 for Fig.13 Schematic diagram of the enlarged structure at G in the middle. DETAILED DESCRIPTION

[0031] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0032] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0033] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] The present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Embodiment 1

[0036] See also Figure 1-2 As shown, an embodiment of the present application discloses a pilot valve, comprising a sleeve 1, an end cover 2, a capillary tube 3 and a cap-shaped filter screen 4; a receiving portion 31 for receiving the filter screen 4 is formed on the inner side of one end of the capillary tube 3, and the filter screen 4 is embedded in the receiving portion 31; the end cover 2 is fixed to the inner side of one end of the sleeve 1 and is circumferentially sealed with the sleeve 1, a through hole 21 is provided in the middle part of the end cover 2 in the axial direction, one end of the capillary tube 3 is penetrated in the through hole 21, and the outer wall of the capillary tube 3 is fixed to the hole wall of the through hole 21 and is circumferentially sealed; the periphery of the through hole 21 extends along the axial direction of the end cover 2 to form a flange 22, and the outer wall of the capillary tube 3 is fixed to the inner wall of the flange 22 and is circumferentially sealed; the pilot valve also includes a blocking member, which is fixed on one end of the capillary tube 3 and is used to block the filter screen 4 to prevent the filter screen 4 from escaping from the receiving portion 31.

[0037] The blocking member includes a retaining ring 5, one end of which is inserted into the receiving portion 31 and abuts against the open end of the filter screen 4, and an annular boss 51 is arranged on the outer wall of the other end of the retaining ring 5, and the annular boss 51 abuts against one end of the capillary 3, and the outer edge of the annular boss 51 circumferentially protrudes from the outer peripheral wall of one end of the capillary 3, and the outer edge of the annular boss 51, the outer peripheral wall of one end of the capillary 3 and the inner side wall of the end cover 2 are circumferentially welded and fixed as a whole; after adopting this structure, since one end of the retaining ring is inserted into the receiving portion and abuts against the filter screen, The open ends abut against each other, thereby achieving reliable blocking of the filter screen, and since an annular boss is provided on the outer wall of the other end of the retaining ring, the annular boss abuts against one end of the capillary tube. In addition, since the outer edge of the annular boss, the outer peripheral wall of one end of the capillary tube and the inner wall of the end cover are circumferentially welded and fixed together, the retaining ring, the capillary tube and the end cover can be reliably fixed, and then the retaining ring can be effectively prevented from detaching from the capillary tube, that is, reliable blocking of the filter screen is achieved, and at the same time, the fixing firmness of the capillary tube and the end cover is further improved.

[0038] The outer edge of the end cover 2 extends along the axial direction of the end cover 2 to form a folded edge 23, and the outer side wall of the folded edge 23 is welded and fixed to the inner side wall of the sleeve 1 and sealed circumferentially; by adopting this structure, under the action of the folded edge, the contact area between the end cover and the sleeve can be increased, so that after the outer edge of the end cover and the outer peripheral wall of the folded edge are fixed to the inner wall of the sleeve by welding, the fixing firmness of the end cover and the sleeve can be improved.

[0039] Embodiment 2

[0040] See also Figure 3-4 As shown, what is different from the first embodiment is that one end of the retaining ring 5 is inserted into the open end of the filter screen 4, and the open end of the filter screen 4 is provided with an outwardly folded annular convex edge 41, which is embedded between the annular boss 51 and one end of the capillary 3, and the outer edge of the annular convex edge 41 circumferentially protrudes from the outer peripheral wall of one end of the capillary 3, and the outer edge of the annular boss 51, the outer edge of the annular convex edge 41, the outer peripheral wall of one end of the capillary 3 and the inner side wall of the end cover 2 are circumferentially welded and fixed together; by adopting this structure, the open end of the filter screen can be clamped between the outer wall of the retaining ring and the inner wall of the capillary, and the annular convex edge can be clamped between the annular boss and the end of one end of the capillary. In addition, since the outer edge of the annular boss, the outer edge of the annular convex edge, the outer peripheral wall of one end of the capillary and the inner side wall of the end cover are circumferentially welded and fixed together, the filter screen can be further fixed to prevent the filter screen from being separated from the capillary.

[0041] Embodiment 3

[0042] See also Figure 5-6 As shown, what is different from the first embodiment is that the blocking member includes a blocking ring 5, one end of which is inserted into the accommodating portion 31 and abuts against the open end of the filter screen 4, and an annular boss 51 is provided on the outer wall of the other end of the blocking ring 5, an annular gap 6 is formed between the annular boss 51 and one end of the capillary 3, and the blocking ring 5 and one end of the capillary 3 are fixed together by circumferential welding with solder located in the annular gap 6; after adopting this structure, since one end of the blocking ring is inserted into the accommodating portion and abuts against the open end of the filter screen, it is possible to achieve reliable blocking of the filter screen, and since an annular boss is provided on the outer wall of the other end of the blocking ring, an annular gap is formed between the annular boss and one end of the capillary, the blocking ring and one end of the capillary are fixed together by circumferential welding with solder located in the annular gap, so that the blocking ring can be reliably fixed to one end of the capillary, that is, the filter screen can be effectively prevented from being separated from the capillary.

[0043] Embodiment 4

[0044] See also Figure 7-8As shown, the difference from the third embodiment is that: one end of the capillary 3 is inserted into the flange 22, the annular gap 6 is located on the inner side of the through hole 21 or the flange 22, and the retaining ring 5, one end of the capillary 3 and the end cover 2 are fixed together by circumferential welding with solder located in the annular gap 6; after adopting this structure, since the annular gap is located on the inner side of the through hole or the flange, and since the retaining ring, one end of the capillary and the end cover are fixed together by circumferential welding with solder located in the annular gap, the fixing firmness of the retaining ring, one end of the capillary and the end cover can be improved, that is, the capillary can be further prevented from being separated from the end cover, and the filter can be further prevented from being separated from the capillary.

[0045] Embodiment 5

[0046] See also Figure 9-10 As shown, the difference from the first embodiment is that the blocking member includes a retaining ring 5, one side of the retaining ring 5 abuts against one end of the capillary 3 and the open end of the filter screen 4, the outer edge of the retaining ring 5 circumferentially protrudes from the outer peripheral wall of one end of the capillary 3, the outer edge of the retaining ring 5, the outer peripheral wall of one end of the capillary 3 and the inner side wall of the end cover 2 form an annular cavity 7, and the outer edge of the retaining ring 5, the outer peripheral wall of one end of the capillary 3 and the inner side wall of the end cover 2 are circumferentially welded and fixed together by the solder located in the annular cavity 7; after adopting this structure, under the action of the retaining ring, one side of the retaining ring abuts against one end of the capillary and the open end of the filter screen, Thereby, the filter screen can be effectively prevented from being separated from the capillary tube, and because the outer edge of the retaining ring, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover form an annular cavity, the outer edge of the retaining ring, the outer peripheral wall of one end of the capillary tube and the inner side wall of the end cover are fixed together by circumferential welding of solder located in the annular cavity, thereby achieving reliable fixation of the retaining ring, the capillary tube and the end cover to prevent the end cover from being separated from the capillary tube, that is, the filter screen can be prevented from being separated from the capillary tube. In addition, the fixing firmness of the capillary tube and the end cover can be improved to further prevent the capillary tube from being separated from the end cover.

[0047] Embodiment 6

[0048] See also Figure 11-12As shown, the difference from the fifth embodiment is that: the open end of the filter screen 4 is provided with an outwardly folded annular convex edge 41, the annular convex edge 41 is embedded between the retaining ring 5 and one end of the capillary 3, the outer edge of the annular convex edge 41 extends into the annular cavity 7, the outer edge of the retaining ring 5, the outer edge of the annular convex edge 41, the outer peripheral wall of one end of the capillary 3 and the inner side wall of the end cover 2 are circumferentially welded and fixed together by the solder located in the annular cavity 7; by adopting this structure, the annular convex edge can be clamped between the retaining ring and the end of one end of the capillary, in addition, because the outer edge of the retaining ring, the outer edge of the annular convex edge, the outer peripheral wall of one end of the capillary and the inner side wall of the end cover are circumferentially welded and fixed together by the solder located in the annular cavity, the filter screen can be further fixed to avoid the filter screen from being separated from the capillary.

[0049] Embodiment 7

[0050] See also Figure 13-14 As shown, what is different from the first embodiment is that the blocking member includes a retaining ring 5, one side of the retaining ring 5 abuts against one end of the capillary 3 and the open end of the filter screen 4, and an annular edging 52 folded toward one side of the end cover 2 is provided at the outer edge of the retaining ring 5, the annular edging 52 is sleeved on the outside of one end of the capillary 3 and abuts against the inner side wall of the end cover 2, and the annular edging 52 is circumferentially welded and fixed to the outer peripheral wall of one end of the capillary 3 and the inner side wall of the end cover 2; after adopting this structure, under the action of the retaining ring, one side of the retaining ring abuts against one end of the capillary and the open end of the filter screen, thereby effectively avoiding over-filtration. The filter screen tends to be separated from the capillary tube, and because an annular edging folded toward the end cover is provided at the outer edge of the retaining ring, the annular edging is sleeved on the outside of one end of the capillary tube and abuts against the inner wall of the end cover, and the annular edging is circumferentially welded and fixed to the outer peripheral wall of one end of the capillary tube and the inner wall of the end cover, thereby achieving reliable fixation of the retaining ring, the capillary tube and the end cover to avoid the end cover from being separated from the capillary tube, that is, the filter screen can be prevented from being separated from the capillary tube. In addition, the fixing firmness of the capillary tube and the end cover can be improved to further avoid the capillary tube from being separated from the end cover.

[0051] A four-way reversing valve comprises the above-mentioned pilot valve.

[0052] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A pilot valve, comprising a sleeve (1), an end cover (2), a capillary tube (3) and a cap-shaped filter screen (4); a receiving portion (31) for receiving the filter screen (4) is formed on the inner side of one end of the capillary tube (3), and the filter screen (4) is embedded in the receiving portion (31); the end cover (2) is fixed on the inner side of one end of the sleeve (1) and is circumferentially sealed with the sleeve (1); a through hole (21) is provided in the middle of the end cover (2) in the axial direction, and is characterized in that: One end of the capillary tube (3) is inserted into the through hole (21), and the outer wall of the capillary tube (3) is fixed to the hole wall of the through hole (21) and is circumferentially sealed; the periphery of the through hole (21) extends along the axial direction of the end cover (2) to form a flange (22), and the outer wall of the capillary tube (3) is fixed to the inner wall of the flange (22) and is circumferentially sealed; the pilot valve also includes a blocking member, which is fixed to one end of the capillary tube (3) and is used to block the filter screen (4) to prevent the filter screen (4) from escaping from the accommodating portion (31).

2. The pilot valve according to claim 1, characterized in that: The blocking member comprises a retaining ring (5), one end of which is inserted into the accommodating portion (31) and abuts against the open end of the filter screen (4); an annular boss (51) is provided on the outer wall of the other end of the retaining ring (5); the annular boss (51) abuts against one end of the capillary tube (3); the outer edge of the annular boss (51) protrudes circumferentially from the outer peripheral wall of one end of the capillary tube (3); the outer edge of the annular boss (51), the outer peripheral wall of one end of the capillary tube (3) and the inner side wall of the end cover (2) are circumferentially welded and fixed together.

3. The pilot valve according to claim 2, characterized in that: One end of the retaining ring (5) is inserted into the open end of the filter screen (4); the open end of the filter screen (4) is provided with an outwardly folded annular convex edge (41); the annular convex edge (41) is embedded between the annular boss (51) and one end of the capillary tube (3); the outer edge of the annular convex edge (41) circumferentially protrudes from the outer peripheral wall of one end of the capillary tube (3); the outer edge of the annular boss (51), the outer edge of the annular convex edge (41), the outer peripheral wall of one end of the capillary tube (3) and the inner side wall of the end cover (2) are circumferentially welded and fixed together.

4. The pilot valve according to claim 1, characterized in that: The blocking member comprises a retaining ring (5), one end of which is inserted into the accommodating portion (31) and abuts against the open end of the filter screen (4), an annular boss (51) is provided on the outer wall of the other end of the retaining ring (5), an annular gap (6) is formed between the annular boss (51) and one end of the capillary tube (3), and the retaining ring (5) and one end of the capillary tube (3) are fixed together by circumferential welding via solder located in the annular gap (6).

5. The pilot valve according to claim 4, characterized in that: One end of the capillary (3) is inserted into the flange (22), the annular gap (6) is located inside the through hole (21) or the flange (22), and the retaining ring (5), one end of the capillary (3) and the end cover (2) are fixed together by circumferential welding through solder located in the annular gap (6).

6. The pilot valve according to claim 1, characterized in that: The blocking member comprises a retaining ring (5), one side of which abuts against one end of the capillary tube (3) and the open end of the filter screen (4); the outer edge of the retaining ring (5) circumferentially protrudes from the outer peripheral wall of one end of the capillary tube (3); the outer edge of the retaining ring (5), the outer peripheral wall of one end of the capillary tube (3) and the inner side wall of the end cover (2) form an annular cavity (7); the outer edge of the retaining ring (5), the outer peripheral wall of one end of the capillary tube (3) and the inner side wall of the end cover (2) are fixed together by circumferential welding through solder located in the annular cavity (7).

7. The pilot valve according to claim 6, characterized in that: The open end of the filter screen (4) is provided with an outwardly folded annular convex edge (41), the annular convex edge (41) is embedded between the retaining ring (5) and one end of the capillary tube (3), the outer edge of the annular convex edge (41) extends into the annular cavity (7), and the outer edge of the retaining ring (5), the outer edge of the annular convex edge (41), the outer peripheral wall of one end of the capillary tube (3) and the inner side wall of the end cover (2) are fixed together by circumferential welding through solder located in the annular cavity (7).

8. The pilot valve according to claim 1, characterized in that: The blocking member comprises a retaining ring (5), one side of which abuts against one end of the capillary tube (3) and the open end of the filter screen (4); an annular rim (52) folded toward one side of the end cover (2) is provided at the outer edge of the retaining ring (5); the annular rim (52) is sleeved on the outside of one end of the capillary tube (3) and abuts against the inner side wall of the end cover (2); the annular rim (52) is circumferentially welded and fixed to the outer peripheral wall of one end of the capillary tube (3) and the inner side wall of the end cover (2).

9. The pilot valve according to any one of claims 1 to 8, characterized in that: The outer edge of the end cover (2) extends along the axial direction of the end cover (2) to form a folded edge (23), and the outer side wall of the folded edge (23) is welded and fixed to the inner side wall of the sleeve (1) and circumferentially sealed.

10. A four-way reversing valve, characterized in that: The four-way reversing valve comprises a pilot valve as described in any one of claims 1-9.

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