Novel three-way pipe fitting and refrigeration pipeline assembly

Abstract

The utility model provides a novel three-way pipe fitting and a refrigeration pipeline assembly, a main pipe body in the novel three-way pipe fitting is of a combined structure and comprises a thin-wall pipe body and a neck bush, the section of the inner circumferential wall of the thin-wall pipe body is circular or approximately circular, and the neck bush is embedded and attached into the thin-wall pipe body. A lining through hole with the axis perpendicular to or basically perpendicular to the axis of the thin-wall pipe body is formed in the circumferential wall of the neck bush, a pipe body through hole is correspondingly formed in the thin-wall pipe body, and the lining through hole and the pipe body through hole jointly form a pipe connecting hole. The thickness of the overlapped wall of the thin-wall pipe body and the neck bush at the pipe connecting hole is 1.5 mm-5 mm, and the inner circumferential wall of the through hole of the bush and the inner circumferential wall of the through hole of the pipe body jointly form a brazing face of the pipe connecting hole. The ratio of the inner diameter of the connecting end of the vertical connecting pipe to the inner diameter of the neck bush at the connecting pipe hole is 0.75-1.50, the peripheral wall of the connecting end of the vertical connecting pipe is attached and welded to a brazing surface in a surface contact manner, and a brazing layer is formed between the two attaching surfaces. The two end connecting pipes are welded to the two axial ends of the main pipe body in a sleeved mode respectively.

Description

Technical Field

[0001] The utility model relates to the field of refrigeration system accessories, and in particular to a novel three-way pipe fitting and a pipeline connection assembly. Background Art

[0002] The connecting pipes in air-conditioning refrigeration pipelines are mostly made of copper, which is a precious metal. As its market price continues to rise, its cost is also getting higher and higher. Therefore, the research and application of replacing copper with steel is becoming a research and development direction for technicians in this field.

[0003] The three-way pipe fittings commonly used in pipeline connection have several structures, such as U-type, Y-type (fork type), and T-type. In the process of replacing copper materials with steel materials, the ductility of steel materials is only about 20% of that of copper materials, but its hardness is 4 to 5 times that of copper materials. Such physical properties make the forming and processing of steel three-way pipe fittings extremely difficult. Even if they are barely processed, they cannot be actually mass-produced due to reasons such as the pass rate. Therefore, the steel three-way pipes on low-pressure water pipelines (design working pressure less than 2.5MPa) generally adopt a self-melting welding structure after punching and flanging, such as Figure 1 The T-type structure shown. However, the self-fluxing welding method is difficult to apply in refrigeration pipelines with a design working pressure greater than 4.0MPa due to safety hazards such as low connection strength and poor pressure resistance. If the pipe is brazed after punching and flanging, it is difficult to meet the strength requirements after brazing because the pipe assembly section formed by the flanging is very short (i.e., the flanging height is short); especially when the pipe diameter of the pipe is close to the main pipe diameter, the migration of the pipe blank material will be more difficult to achieve, and it will be almost impossible to connect the pipe by brazing in this structure.

[0004] To solve the above problems, the inventor has proposed to add a welding liner inside the main pipe in a multi-branch pipe structure to realize the welding of the connecting pipe. Obviously, when the inner diameter of the branch pipe is close to the inner diameter of the main pipe, or even larger than the inner diameter of the main pipe, the welding liner will no longer be able to process a liner hole that can provide a welding depth for the connecting pipe, that is, the method of installing a welding liner inside is not suitable for three-way pipe fittings with a branch pipe inner diameter close to or larger than the inner diameter of the main pipe. However, in actual applications, this type of three-way pipe fitting is widely used in refrigeration and air conditioning, so the research on steel three-way pipe fittings of this type of structure will obviously have important practical significance. Utility Model Content

[0005] In order to overcome the deficiencies of the prior art, the utility model provides a novel three-way pipe fitting and a pipeline connecting assembly.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a new type of three-way pipe fitting, which includes a steel main body, a thin-walled vertical pipe and two thin-walled end pipes. The main body is a combined structure and includes a thin-walled pipe body and an inner sleeve. The inner peripheral wall section of the thin-walled pipe body is circular or nearly circular. The inner sleeve is embedded in the thin-walled pipe body and the outer peripheral wall of the inner sleeve is attached to the inner peripheral wall of the thin-walled pipe body. The peripheral wall of the inner sleeve is provided with a sleeve through hole whose axis is perpendicular or substantially perpendicular to the axis of the thin-walled pipe body. The thin-walled pipe body is correspondingly provided with a pipe body through hole. The sleeve through hole and the pipe body through hole together constitute a pipe pipe hole. The overlapping wall thickness of the thin-walled pipe body and the inner sleeve at the pipe pipe hole is 1.5 mm to 5 mm. The inner peripheral wall of the sleeve through hole and the inner peripheral wall of the pipe body through hole together form the brazing surface of the pipe pipe hole. The connecting end of the vertical pipe is inserted into the pipe hole on the main pipe body. The ratio of the inner diameter of the vertical pipe connecting end to the inner diameter of the inner sleeve at the pipe hole is 0.75 to 1.50. The outer peripheral wall of the vertical pipe connecting end is attached to the brazing surface of the pipe hole in a surface contact manner, and a brazing layer is formed between the two attached surfaces. The two end pipes are respectively sleeved and welded to the axial ends of the main pipe body. Among them, thin wall refers to the wall thickness of the pipe fitting is greater than or equal to 0.3mm and less than 2.0mm.

[0007] According to one embodiment of the utility model, the ratio of the inner diameter of the connecting end of the vertical connecting pipe to the inner diameter of the inner bushing at the connecting pipe hole is greater than or equal to 1.0, the bushing through hole includes a straight hole section and an inclined section formed at the end of the straight hole section, the connecting end of the vertical connecting pipe is assembled in the straight hole sections of the pipe body through hole and the bushing through hole, and the inner circumferential wall of the pipe body through hole and the inner circumferential wall of the straight hole section of the bushing through hole jointly form the brazing surface of the connecting pipe hole.

[0008] According to one embodiment of the utility model, the main pipe body includes an inner sleeve embedded in the thin-walled pipe body; or, the main pipe body includes multiple inner sleeves embedded in the thin-walled pipe body, the multiple inner sleeves are sequentially sleeved and overlapped, and each inner sleeve has a sleeve through hole that is roughly coaxial with the pipe body through hole.

[0009] According to an embodiment of the utility model, the inner sleeve is in the shape of a hollow tube; or, the inner sleeve is in the shape of a hollow cylinder formed by bending and rolling and having a rolling gap.

[0010] According to one embodiment of the utility model, the length of the inner sleeve is shorter than that of the thin-walled tube body, and two limit steps for limiting the insertion depth of the end connecting pipes are formed at the end faces of both ends of the inner sleeve. The two end connecting pipes are respectively inserted into the two ends of the thin-walled tube body and abut against the corresponding limit steps.

[0011] According to an embodiment of the utility model, the length of the inner sleeve is close to the length of the thin-walled tube body, the two end pipes are sleeved in the inner sleeve, and two limiting steps for limiting the insertion depth of the two end pipes are formed on the inner circumferential wall of the inner sleeve.

[0012] According to an embodiment of the present invention, the through hole of the tube body is a through hole whose hole depth is based on the wall thickness of the thin-walled tube body, or the through hole of the tube body is a flanging hole with a flanging straight body section.

[0013] According to an embodiment of the utility model, a self-fluxing weld and / or a brazing weld is formed between the thin-walled tube body and the inner liner.

[0014] According to an embodiment of the utility model, a connection plane is formed on the outer peripheral wall of the thin-walled tube body, the tube body through hole is located at the connection plane, and the axis of the tube body through hole is perpendicular or substantially perpendicular to the connection plane;

[0015] Alternatively, the cross section of the outer peripheral wall of the thin-walled tube body is circular or nearly circular, and the tube body through hole is formed in the curved outer peripheral wall of the thin-walled tube body.

[0016] According to an embodiment of the utility model, the two end connecting pipes and the vertical connecting pipe are combined pipes formed by any one of steel pipes and copper pipes or a combination of the two; the two end connecting pipes and the vertical connecting pipe are any one of straight pipes and curved pipes.

[0017] The utility model also provides another novel three-way pipe fitting, which includes a main pipe body, a thin-walled vertical pipe and two thin-walled end pipes. The main pipe body is an integral steel pipe fitting with a circular or nearly circular inner wall section. A pipe hole with an axis perpendicular or substantially perpendicular to the axis of the main pipe body is opened on the pipe wall of the main pipe body. A connecting plane is formed on the outer wall of the main pipe body and the pipe hole is located at the connecting plane, or the outer wall of the main pipe body has a circular or nearly circular cross section, and the pipe hole is formed on the curved outer wall of the main pipe body; the wall thickness of the main pipe body at the pipe hole is 1.5mm to 5mm, and a brazing surface is formed on the inner wall of the pipe hole. The connecting end of the vertical pipe is inserted into the pipe hole on the main pipe body, and the ratio of the inner diameter of the connecting end of the vertical pipe to the inner diameter of the main pipe body at the pipe hole is 0.75 to 1.5. The outer wall of the connecting end of the vertical pipe is fitted to the brazing surface of the pipe hole in a surface contact manner, and a brazing layer is formed between the two fitting surfaces. The two end pipes are respectively sleeved and welded to the axial ends of the main pipe body. Here, thin-walled means that the wall thickness of the pipe is greater than or equal to 0.3 mm and less than 2.0 mm.

[0018] According to one embodiment of the utility model, the ratio of the inner diameter of the connecting end of the vertical connecting pipe to the inner diameter of the main pipe body at the connecting pipe hole is greater than or equal to 1.0, the connecting pipe hole includes a straight hole section and an inclined section formed at the end of the straight hole section, the connecting end of the vertical connecting pipe is assembled in the straight hole section of the connecting pipe hole, and the inner peripheral wall of the straight hole section of the connecting pipe hole forms a brazing surface to braze the outer peripheral wall of the connecting end of the vertical connecting pipe.

[0019] On the other hand, the utility model also provides a refrigeration pipeline assembly, which includes the above-mentioned novel three-way pipe fitting.

[0020] In summary, in the new three-way pipe fitting provided by the utility model, a pipe hole with a hole depth based on its wall thickness is opened on the main pipe body, and the wall thickness of the main pipe body at the pipe hole allows the inner peripheral wall of the pipe hole to form a larger brazing surface, thereby realizing the surface brazing connection of the outer peripheral wall of the vertical pipe connection end. Compared with the traditional self-melting wire weld connection, the surface brazing connection not only has a high connection strength but also has better pressure resistance and sealing, and can well withstand the high working pressure of the refrigeration system. In addition, the pipe hole structure with a hole depth based on the wall thickness of the main pipe body also allows the main pipe body to adopt a hole processing process to realize the forming of the pipe hole, and the hole processing processes such as drilling and punching are not only simple and mature, but also less affected by the performance of the main pipe material such as ductility, yield strength and hardness, which provides conditions for the use of low-cost, high-strength steel materials for the main pipe body.

[0021] Furthermore, in order to reduce the processing difficulty of the pipe hole, the main pipe body is set to a split structure including a thin-walled pipe body and an inner sleeve. The thin-walled pipe body and the inner sleeve are processed separately and then superimposed, which greatly reduces the processing difficulty of the pipe hole while meeting the pipe hole depth requirements. At the same time, the independent molding of the thin-walled pipe body and the inner sleeve also well solves the problems of the difficulty of molding, difficult procurement and high procurement cost of the thick-walled main pipe body. The annular inner sleeve allows it to have sufficient contact area to stably connect to the inner circumferential wall of the thin-walled pipe body after opening a bushing through hole with a hole diameter close to or larger than its own inner diameter. Furthermore, the bushing through hole is set to include a straight hole section and an inclined section. The straight hole section provides a welding depth for the vertical connection, while the inclined section increases the fluid connection space between the vertical pipe and the main pipe body and guides the fluid, thereby making the inner diameter of the vertical pipe connection end close to or even larger than the inner diameter of the main pipe body.

[0022] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Shown is a structural schematic diagram of an existing T-shaped stainless steel three-way pipe fitting.

[0024] Figure 2 Shown is a schematic structural diagram of a novel three-way pipe fitting provided in Example 1 of the present utility model.

[0025] Figure 3 Shown Figure 2 A cross-sectional diagram from another viewing angle.

[0026] Figure 4 Shown Figure 3 Schematic diagram of the cross section of the middle main pipe.

[0027] Figure 5 Shown Figure 4A cross-sectional diagram from another viewing angle.

[0028] Figure 6 and Figure 7 The figure is a schematic diagram of the structure of a novel three-way pipe fitting provided by another embodiment of the utility model.

[0029] Figure 8 The figure shows the principle diagram of vertical tube brazing when the outer peripheral wall of the thin-walled tube is a curved surface.

[0030] Fig. 9 and Fig.10 Shown is a schematic structural diagram of a novel three-way pipe fitting provided in another embodiment of the utility model.

[0031] Fig.11 Shown is a schematic structural diagram of a refrigeration pipeline assembly provided in Embodiment 1 of the present utility model.

[0032] Fig.12 Shown is a schematic structural diagram of a refrigeration pipeline assembly provided in another embodiment of the utility model.

[0033] Fig.13 Shown is a schematic structural diagram of a new three-way pipe fitting provided in Example 2 of the present utility model.

[0034] Fig.13A Shown Fig.13 Schematic diagram of the structure after removing the vertical pipe.

[0035] Fig.14 Shown is a schematic structural diagram of a novel three-way pipe fitting provided in Example 3 of the present utility model.

[0036] Fig.15 Shown Fig.14 Schematic cross-section diagram of .

[0037] Fig.15A Shown Fig.15 Schematic diagram of the cross section of the middle main pipe.

[0038] Fig.16 Shown is an assembly diagram of the main pipe body and the vertical connecting pipe in the new three-way pipe fitting provided in the fourth embodiment of the present utility model.

[0039] Fig.17 Shown Fig.16 Schematic diagram of the structure after removing the vertical pipe.

[0040] Fig.18 Shown is a schematic structural diagram of a novel three-way pipe fitting provided in Example 4 of the present utility model.

[0041] Fig.19 Shown Fig.18 A cross-sectional diagram from another viewing angle.

[0042] Fig. 20 Shown is a cross-sectional schematic diagram of a novel three-way pipe fitting provided by another embodiment of the utility model.

[0043] Fig.21 , Fig. 22 as well as Fig.23 Shown is a schematic structural diagram of a novel three-way pipe fitting provided in another embodiment of the utility model.

[0044] Fig.24 Shown is a schematic structural diagram of a refrigeration pipeline assembly provided in Embodiment 5 of the present utility model. DETAILED DESCRIPTION

[0045] The low ductility, high yield strength and high hardness of steel lead to the problem that the length of the pipe assembly section is difficult to meet the brazing requirements when it replaces copper materials to form steel tee pipe fittings. Especially when the pipe diameter of the pipe is close to the pipe diameter of the main body, it is almost impossible to form a pipe assembly section that meets the brazing requirements based on the migration of the pipe blank material; and the structure of adding a welding liner in the main body to increase the welding depth is limited by the area of ​​the welding liner, making it difficult to process a pipe hole with a diameter close to or larger than the inner diameter of the main body. Therefore, the pipes in existing steel tee pipe fittings can only be made of Figure 1 This kind of punching and flanging followed by self-fluxing welding. However, due to the limitations of the connection strength and pressure resistance of the self-fluxing weld, Figure 1 This steel three-way pipe fitting is difficult to be used in refrigeration systems with high working pressure.

[0046] In view of this, if Figures 2 to 5As shown, the novel three-way pipe fitting provided in this embodiment includes a steel main pipe body 1, a thin-walled vertical pipe 2, and two thin-walled end pipes 31, 32. The main pipe body 1 is a combined structure and includes a thin-walled pipe body 11 and an inner sleeve 12. The inner peripheral wall section of the thin-walled pipe body 11 is circular or nearly circular. The inner sleeve 12 is embedded in the thin-walled pipe body 11 and the outer peripheral wall of the inner sleeve 12 is attached to the inner peripheral wall of the thin-walled pipe body 11. The peripheral wall of the inner sleeve 12 is provided with a sleeve through hole 121 whose axis is perpendicular or substantially perpendicular to the axis of the thin-walled pipe body 11. The thin-walled pipe body 11 is correspondingly provided with a pipe body through hole 111. The sleeve through hole 121 and the pipe body through hole 111 together constitute the pipe hole 10. The overlapping wall thickness T0 of the thin-walled tube body 11 and the inner bushing 12 at the pipe hole 10 is 1.5mm to 5mm, and the inner peripheral wall of the bushing through hole 121 and the inner peripheral wall of the tube body through hole 111 jointly form the brazing surface 100 of the pipe hole 10. The connecting end 21 of the vertical pipe 2 is inserted into the pipe hole 10 on the main pipe body 1, and the ratio of the inner diameter D1 of the vertical pipe connecting end 21 to the inner diameter D2 of the inner bushing 12 at the pipe hole 10 is 0.75 to 1.50. The outer peripheral wall of the vertical pipe connecting end 21 is attached to the brazing surface 100 of the pipe hole in a surface contact manner, and a brazing layer 200 is formed between the two attached surfaces. The two end pipes 31 and 32 are respectively sleeved and welded to the axial ends of the main pipe body 1.

[0047] Among them, thin-walled means that the wall thickness of the pipe is greater than or equal to 0.3mm and less than 2.0mm. Specifically, the wall thickness of the thin-walled pipe can be selected from any value within 0.3mm to 2.0mm according to its pipe diameter, such as 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm, etc. The overlapping wall thickness T0 of the thin-walled pipe body 11 and the inner liner 12 at the pipe hole 10 can also be selected from any value within 1.5mm to 5mm according to needs, such as 1.8mm, 2.0mm, 2.5mm, 3mm, 3.5mm, 4.0mm and 4.5mm, etc.

[0048] In the new three-way pipe fitting provided in this embodiment, the vertical pipe 2 is connected to the pipe hole 10 on the main pipe body 1, and the two end pipes 31 and 32 are respectively connected to the two ends of the main pipe body 1. This structure allows only the pipe hole 10 to be opened on the main pipe body 1 during processing. The pipe hole 10 structure with a hole depth based on the overlapping wall thickness T0 of the thin-walled pipe body 11 and the inner sleeve 12 allows the main pipe body 1 to be processed by a simple and mature hole processing process (such as a drilling process or a punching process, etc.). The hole processing process does not involve the migration of the pipe material, and is less affected by the physical properties of the material such as ductility, yield strength and hardness; therefore, the main pipe body 1 in the new three-way pipe fitting provided in this embodiment can be processed by low-cost steel materials. Furthermore, the wall thickness T0 of the main pipe body 1 at the connecting hole 10 (i.e., the overlapping wall thickness T0 of the thin-walled pipe body 11 and the inner sleeve 12 at the connecting hole 10) is controlled so that a large-area brazing surface 100 is formed on the inner circumferential wall of the connecting hole 10, thereby realizing the surface brazing connection between the vertical connecting pipe 2 and the connecting hole 10, greatly improving the connection strength and pressure resistance of the vertical connecting pipe 2 after welding, so that the new three-way pipe fitting can be well used in refrigeration systems with high working pressure.

[0049] However, the thick-walled main pipe body 1 is a pipe of special specifications. Due to the limitation of the wall thickness, the thick-walled main pipe body is difficult to form, so there are problems such as difficulty in procurement and high procurement cost; in addition, the difficulty of processing the connecting hole also increases with the increase of wall thickness. In order to solve the problems that the thick-walled main pipe body itself is difficult to form, difficult to purchase, and the procurement cost is high, and the connecting hole 10 is difficult to process, the main pipe body 1 in this embodiment is set to be a combined structure including a thin-walled pipe body 11 and an inner sleeve 12. This setting disassembles the thick-walled main pipe body 1 into a plurality of independent and thin conventional parts (i.e., an inner sleeve 12 and a thin-walled pipe body 11). Each component is independently processed and formed and then assembled and welded to form the main pipe body 1. Compared with the thick-walled main pipe body 1, the thin-walled inner sleeve 12 and the thin-walled pipe fitting 11 are both conventional pipe fittings. Both are not only easy to form and purchase, but also have low procurement costs, which greatly reduces the cost of the main pipe body 1. Furthermore, the combined structure also allows the thin-walled pipe body 11 and the inner bushing 12 to be processed separately; thereafter, the inner bushing 12 is embedded in the thin-walled pipe body 11, and the coaxial or substantially coaxial pipe body through hole 111 and bushing through hole 121 jointly form the pipe connection hole 10 to ensure that the inner peripheral wall of the pipe connection hole 10 forms a brazing surface 100 that meets the brazing requirements; that is, while meeting the area of ​​the brazing surface 100 in the pipe connection hole 10, the processing difficulty of the pipe connection hole 10 is effectively reduced. In addition, when the inner diameter D1 of the vertical pipe connection end 21 is close to or greater than the inner diameter D2 of the inner bushing 12, the annular inner bushing 12 also provides an opening area for the bushing through hole 121 with a large aperture, and after the bushing through hole 121 is opened, there is still enough connection area on the inner bushing 12 to enable it to be firmly connected to the inner peripheral wall of the thin-walled pipe body 11, thereby well solving the problem that the welding liner of the existing three-way pipe fitting cannot provide a welding depth for the pipe with an inner diameter close to or greater than the inner diameter of the main pipe.

[0050] In this embodiment, the main body 1 includes an inner sleeve 12 and the inner sleeve is a hollow tube. However, the present invention does not make any limitation to this. In other embodiments, the main body 1 may also include a plurality of inner sleeves that are sequentially sleeved and overlapped, and each inner sleeve has a sleeve through hole that is substantially coaxial with the tube body through hole. As for the structure of the inner sleeve, in other embodiments, it may also be a hollow cylinder formed by bending and rolling and having a rolling gap.

[0051] In this embodiment, if Figure 3 and Figure 5As shown, the cross-section of the outer peripheral wall of the thin-walled tube body 11 is also circular or nearly circular, and the tube body through hole 111 is a through hole formed on the curved outer peripheral wall of the thin-walled tube body 11 and the hole depth is based on the wall thickness of the thin-walled tube body 11; that is, the wall thickness t1 of the thin-walled tube body 11 at the tube body through hole 111 and the wall thickness t2 of the inner bushing 12 at the bushing through hole 121 serve as the hole depth T0 of the connecting hole 10. However, the present invention does not impose any limitation on this. In other embodiments, in order to further reduce the difficulty of opening the hole, the outer peripheral wall of the thin-walled tube body 11 may also be provided with a connecting plane 112. As shown in FIG. Figure 6 As shown, the cross section of the outer wall of the thin-walled tube 11 is pentagonal, one of the planes of the thin-walled tube 1 is used as the connecting plane 112, the tube through hole 111 is formed on the connecting plane 112, and the axis of the tube through hole 11 is perpendicular or substantially perpendicular to the connecting plane 112. When machining the tube through hole 111, the connecting plane 112 can provide a reference plane for the hole machining tool to facilitate tool positioning, and the axis of the tube through hole 111 can be calibrated based on the connecting plane 112 so that the axis of the tube through hole 111 is substantially perpendicular to the connecting plane 112, thereby greatly improving the hole opening accuracy and reducing the difficulty of hole opening. Figure 6 For example, the cross section of the outer peripheral wall of the thin-walled tube body 11 is a pentagonal shape. However, the present invention does not impose any limitation on this. In the present invention, the outer peripheral wall of the thin-walled tube body 11 only needs to form a connecting plane 112 for processing the tube body through hole 111, and the present invention does not impose any limitation on the structure of the thin-walled tube body 11 outside the connecting plane 112. In other embodiments, the cross section of the outer peripheral wall of the thin-walled tube body 11 can also be other polygonal structures, such as a square (such as Figure 7 As shown) or hexagonal, or only one connecting plane 112 and the other parts are still arc surfaces. Figure 6 and Figure 7 The example of the connection plane extending to both ends of the thin-walled tube body is used for explanation. However, the present invention does not impose any limitation on this. In other implementations, the connection plane may also be located in the middle area of ​​the outer peripheral wall of the thin-walled tube body, while the outer peripheral walls at both ends of the thin-walled tube body are still circular or nearly circular.

[0052] In addition, when the diameter of the tube body through hole 111 is large (equivalent to a large inner diameter D1 of the vertical pipe connection end), there is a large height difference at the edge of the tube body through hole opened on the curved peripheral wall, which may cause a part of the solder material to be suspended (e.g. Figure 8 As shown in A in the figure). After melting, the solder in the suspended part will be pulled by gravity F and flow along the curved outer peripheral wall of the thin-walled tube body 11, and it is difficult for the solder to enter the tube body through hole 111, so welding problems such as cold welding and broken welding are likely to occur. Figure 6 and Figure 7In the structure shown, the edge of the tube body through hole 111 opened based on the connection plane 112 is also a plane structure. When the vertical tube connection end 21 is brazed to the tube hole 10, the connection plane 112 supports the brazing material to prevent the brazing material from being suspended in the air, so that the brazing material at various places in the circumferential direction of the tube body through hole 111 is only infiltrated by the capillary traction of the welding gap between the vertical tube 2 and the tube hole 10, ensuring that the welding gap is filled with sufficient solder at various places in the circumferential direction, thereby effectively solving the flow soldering problem existing in the brazing of curved surfaces. In addition, for the structure of the tube body through hole 111, in other embodiments, it can also be set as a flanged hole with a flanged straight body section.

[0053] In this embodiment, if Figure 2 As shown, the length of the inner sleeve 12 is shorter than that of the thin-walled tube body 11, and two limiting steps 114, 115 for limiting the insertion depth of the two end pipes 31, 32 are formed at the end surfaces of the inner sleeve 12 at both ends. The two end pipes 31, 32 are respectively sleeved on the two ends of the thin-walled tube body 11 and abut against the corresponding limiting steps 114, 115. That is, in this embodiment, the inner sleeve 12 provides a welding depth for the vertical pipe 2 while also providing a limit for the welding assembly of the two end pipes 31, 32. In addition, the shorter inner sleeve 12 can further reduce the material cost of the main tube. However, the present invention does not impose any limitation on this. In other embodiments, such as Fig. 9 As shown, the length of the inner sleeve 12 can be set close to the length of the thin-walled tube body 11, and the two end pipes 31, 32 are sleeved in the inner sleeve 12, and two limiting steps 114, 115 for limiting the insertion depth of the two end pipes are formed on the inner peripheral wall of the inner sleeve 12. In addition, in other embodiments, two end pipes can also be provided with outer sleeves connected to the two ends of the main tube body.

[0054] In this embodiment, the thin-walled tube body 11 and the inner sleeve 12 are both steel parts. In order to ensure the corrosion resistance of the key welding connection parts (such as the welding connection of the vertical pipe 2), a steel material containing chromium (Cr) content of not less than 5% is selected to improve the service life of the product. For example, a stainless steel material resistant to corrosion by weak corrosive media such as air, steam, water and chemically corrosive media such as acids, alkalis and salts is selected. Further, based on cost considerations, non-300 series stainless steel with a Cr content of not less than 5% is preferably used, such as SUS430 (commonly known as stainless iron, Cr% ≥ 16-18%) or SUS201 (Cr% ≥ 13%, Ni% ≥ 3.5%). For the stainless steel material of SUS201, a steel material with Cr% ≥ 10% and Ni% ≥ 1% produced by the "Qingshan Stainless Steel" manufacturer and a wire grade of D665A or D667 can be selected, taking into account the material cost while meeting the requirements of environmental corrosion resistance and no rust. However, the utility model does not make any limitation to this. In other embodiments, the thin-walled tube body and the inner liner may also be made of other steel materials with a Cr content of not less than 5% according to the application environment.

[0055] In this embodiment, the two end pipes 31, 32 and the vertical pipe 2 are also steel pipes with a Cr content of not less than 5%. After the inner sleeve 12 is processed with the sleeve through hole 121, it is embedded and assembled in the thin-walled tube body 11 and the two are fixedly connected by a self-fluxing weld; the self-fluxing weld is a local self-fluxing weld (such as multiple self-fluxing welding points or multiple intermittent self-fluxing line welds) or a self-fluxing ring weld. Afterwards, the two end pipes 31, 32 and the vertical pipe 2 are assembled, and the three pipes, the inner sleeve 12 and the thin-walled tube body 11 are brazed in a copper furnace to form an integral body, and a brazing seam is also formed between the thin-walled tube body and the inner sleeve. However, the utility model does not make any limitation to this. In the present invention, the function of the inner sleeve 12 is to provide a welding depth for the vertical pipe 2 so that the inner peripheral wall of the pipe hole 10 forms a large brazing surface 100; and the inner sleeve 12 and the thin-walled pipe body 11 only need to be fixedly connected, and the two do not necessarily have to be sealed. Therefore, in other embodiments, it is also possible to set a self-fluxing weld or brazing seam that only fixes the inner sleeve between the thin-walled pipe body and the inner sleeve.

[0056] Although the present embodiment is described by taking the two end pipes and the vertical pipe as steel pipes as an example, the present invention does not impose any limitation on this. In other embodiments, the two end pipes and the vertical pipe can also be copper pipes, or a combination of copper pipes and steel pipes; after the three are assembled, they can also be brazed together with the inner sleeve and the thin-walled pipe body in a tin bronze solder furnace to form an integral body. Alternatively, the structures of the three pipes are not completely the same, and some of the pipes are steel pipes, while the other pipes are copper pipes or a combination of copper pipes and steel pipes.

[0057] In this embodiment, the two end pipes 31, 32 and the vertical pipe 2 are straight pipes. However, the present invention does not make any limitation to this. Fig.10 As shown, the end pipe 32 is a straight pipe, while the end pipe 31 and the vertical pipe 2 are all bent pipes. Alternatively, all three pipes can be bent pipes; or, some pipes are straight pipes, while some pipes are bent pipes.

[0058] Correspondingly, such as Fig.11 As shown, this embodiment also provides a refrigeration pipeline assembly, which includes the above-mentioned novel three-way pipe fitting and three copper pipe sections, the copper pipe section 41 is connected to the end of the vertical pipe 2, the copper pipe section 42 is connected to the end of the end pipe 31, and the copper pipe section 43 is connected to the end of the end pipe 32. The arrangement of the three copper pipe sections enables the novel three-way pipe fitting provided in this embodiment to be welded and connected to the copper pipeline of the existing refrigeration system in a flame brazing manner. Fig.12 FIG. 1 is a schematic diagram of the structure of a refrigeration pipeline assembly including three copper pipe sections 41, 42, and 43 provided by another embodiment of the present utility model; Fig.12 In the figure, the two end pipes 31, 32 are both bent pipes and are roughly symmetrically distributed, and the vertical pipe 2 is a straight pipe.

[0059] However, the present invention does not impose any limitation on this. In other embodiments, the new three-way pipe fitting provided in this embodiment can also be combined with components such as a muffler, a filter or a liquid distributor in the pipeline system to form other refrigeration pipeline components. In addition, although this embodiment takes the application of the new three-way pipe fitting to a refrigeration system with a high working pressure as an example. However, the present invention does not impose any limitation on this. In other embodiments, the new three-way pipe fitting provided in this utility model is also applicable to other pipeline systems with lower working pressures, such as low-pressure water pipeline systems.

[0060] Embodiment 2

[0061] This embodiment is basically the same as the first embodiment and its variations, except that: Fig.13 As shown, in the novel three-way pipe fitting provided in this embodiment, the main pipe body 1 includes a thin-walled pipe body 11 and two sleeve-connected and overlapped inner sleeves 12, 12'. However, the present invention does not make any limitation to this. In other embodiments, the main pipe body may also include more than three sleeve-connected and overlapped inner sleeves.

[0062] Specifically, Fig.13AAs shown, the two inner bushings 12, 12' are formed with bushing through holes 121, 121' which are basically coaxial with the tube body through hole 111. The tube body through hole 111, the bushing through hole 121 and the bushing through hole 121' together form the pipe hole 10. The overlapping of multiple inner bushings increases the hole depth and the inner wall area of ​​the pipe hole 10 to further improve the surface brazing strength of the vertical pipe 2. At the same time, this arrangement not only solves the problems of the main pipe 1 itself, such as difficulty in procurement and high procurement cost, but also further reduces the processing difficulty of the pipe hole 10. In this embodiment, the two inner bushings 12, 12' are both hollow cylinders formed by bending and rolling steel sheets and have a rolling gap 122. In this embodiment, high-strength sealing brazing is required between the bushing through holes 121, 121' and the vertical pipe connection end 21, but the inner bushing and the thin-walled tube body only need to meet a certain connection strength, so there may be a rolling gap on the rolled inner bushing. However, the utility model does not make any limitation to this. In other embodiments, the rolling gap can also be fixed by self-melting spot welding or integral brazing and then embedded in the thin-walled tube body. In other embodiments, the inner bushing can also be a hollow tube, as shown in the first embodiment.

[0063] Embodiment 3

[0064] This embodiment is basically the same as the first embodiment and its variations, except that: Fig.14 , Fig.15 as well as Fig.15A As shown, the tube body through hole 111 is a flanged hole having a flanged straight body section 113 .

[0065] The combined structure of the main pipe body 1 allows the wall thickness of the thin-walled pipe body 11 to be set thinner. When the pipe body through hole 111 is formed by punching, a flanged straight body section 113 is formed on the entire circumference of the pipe body through hole 111 based on the easy processing of the thin-walled material, and the ends of the flanged straight body section 113 are basically flush. The flanged straight body section 113 with basically flush ends supports the brazing material during brazing, preventing the brazing material from flowing along the curved peripheral wall of the thin-walled pipe body 11 after melting, thereby effectively improving the welding flow problem caused by the excessive height difference of the edge of the pipe body through hole 111 when the inner diameter D1 of the vertical pipe connection end 21 is large (that is, the pipe body through hole 111 is large).

[0066] Although the length of the flanged straight section 113 formed on the thin-walled steel tube body 11 is limited due to the limitations of material properties, it can still provide a welding depth for the brazing of the vertical connecting pipe 2 to further increase the area of ​​the brazing surface 100. However, the present utility model does not impose any limitation on this. In other embodiments, a local flanged straight section can also be formed at the lowest and lower part of the hole edge of the tube body through hole, and the end of the local flanged straight section is roughly flush with the highest point of the hole edge. The end of the local flanged straight section and the highest point of the hole edge of the tube body through hole form a plane supporting the brazing material, thereby avoiding the flow soldering problem caused by the brazing material hanging in the air. Similarly, the local flanged straight section will also increase the area of ​​the brazing surface 100 on the connecting pipe hole to a certain extent to improve the welding strength and pressure resistance of the vertical connecting pipe 2.

[0067] In addition, the structures and possible implementation methods of components such as the thin-walled tube body 11, the inner sleeve 12, the vertical connecting pipe 2 and the two end connecting pipes 31, 32 are basically the same as those of the first embodiment and its variations, and are not described in detail here.

[0068] Embodiment 4

[0069] This embodiment is basically the same as the first embodiment and its variations, except that: Fig.16 and Fig.17 As shown, the ratio of the inner diameter D1 of the vertical connecting pipe connection end 21 to the inner diameter D2 of the inner bushing 12 at the connecting pipe hole 10 is greater than or equal to 1.0, the bushing through hole 121 includes a straight hole section 1211 and an inclined section 1212 formed at the end of the straight hole section 1211, the connecting end 21 of the vertical connecting pipe is assembled in the straight hole section 1211 of the pipe body through hole 111 and the bushing through hole, and the inner circumferential wall of the pipe body through hole 111 and the inner circumferential wall of the straight hole section 1211 of the bushing through hole jointly form the brazing surface of the connecting pipe hole 10.

[0070] In the novel three-way pipe fitting provided in this embodiment, the straight hole section 1211 on the bushing through hole 121 provides the welding depth for the welding of the vertical pipe 2, and the connecting channel 1210 is formed at the inclined section 1212. The connecting channel 1210 widens the connecting space between the vertical pipe connection end 21 and the bushing through hole 121, eliminates the obstruction of the fluid by the side wall of the inner bushing 12, and thus enables the inner diameter D1 of the vertical pipe connection end 21 to be close to or greater than the inner diameter D2 of the inner bushing 12 at the pipe hole 10. Specifically, D1 / D2 can be a proportional relationship of 1.0, 1.2, 1.25, 1.3, 1.4, etc. However, the utility model does not make any limitation to this. In other embodiments, D1 / D2 can also be any proportional relationship within 1.0 to 1.5. Further, the inclined section 1212 can also guide the fluid when it is divided or converged, so that the fluid can be better distributed to the vertical pipe 2 or gathered from the vertical pipe 2 to the main pipe body 1.

[0071] Similarly, with regard to the structures and possible implementations of the thin-walled tube body 11, the inner sleeve 12, the vertical connecting pipe 2, and the two end connecting pipes 31, 32, this embodiment is substantially the same as the first embodiment and its variations, and will not be described in detail herein.

[0072] Embodiment 5

[0073] This embodiment is basically the same as the first embodiment and its variations, except that in this embodiment, the main pipe body 1 is an integral steel pipe fitting.

[0074] like Fig.18 and Fig.19 As shown, the novel three-way pipe fitting provided in this example includes a main pipe body 1, a thin-walled vertical pipe 2, and two thin-walled end pipes 31, 32. The main pipe body 1 is an integral steel pipe fitting with a circular or nearly circular inner wall section, and a square outer wall cross section. One of the faces of the square outer wall serves as a connecting plane 112, and a pipe hole 10 with an axis perpendicular or substantially perpendicular to the axis of the main pipe body is provided on the connecting plane 112. The wall thickness T0 of the main pipe body at the pipe hole 10 is 1.5 mm to 5 mm, and a brazing surface 100 is formed on the inner wall of the pipe hole 10. The connecting end 21 of the vertical pipe is inserted into the pipe hole 10 on the main pipe body 1, and the ratio of the inner diameter D1 of the vertical pipe connecting end 21 to the inner diameter D2' of the main pipe body 1 at the pipe hole 10 is 0.75 to 1.5, and the outer wall of the connecting end 21 of the vertical pipe is attached to the brazing surface 100 of the pipe hole in a surface contact manner, and a brazing layer 200 is formed between the two attached surfaces. The two end pipes 31, 32 are respectively sleeved and welded to the two axial ends of the main pipe body 1. The thin wall means that the wall thickness of the pipe is greater than or equal to 0.3 mm and less than 2.0 mm.

[0075] Similar to the first embodiment, in the novel three-way pipe fitting provided in this embodiment, the vertical pipe 2 is connected to the pipe hole 10 on the main pipe body 1, and the two end pipes 31, 32 are respectively connected to the two ends of the main pipe body 1. Therefore, the novel three-way pipe fitting provided in this embodiment only needs to process the pipe hole 10 on the main pipe body 1. The pipe hole 10 whose hole depth is based on the wall thickness T0 of the main pipe body 1 enables the main pipe body 1 to adopt a simple and mature hole processing process (such as drilling process or punching process, etc.) to process the pipe hole 10. The hole processing processes such as drilling and punching do not involve the migration of the pipe material, and are less affected by the physical properties of the material such as ductility, yield strength and hardness; therefore, the main pipe body 1 in the novel three-way pipe fitting provided in this embodiment can be processed with low-cost steel materials. Furthermore, the wall thickness T0 of the main pipe body 1 enables the inner wall of the pipe hole 10 to form a large brazing surface 100 for connecting the vertical pipe 2 by surface brazing, thereby greatly improving the connection strength and pressure resistance of the vertical pipe 2 after welding, thereby enabling the new three-way pipe fitting provided in this embodiment to be well applied in refrigeration systems with high working pressure.

[0076] The device of welding plane 112 on the outer peripheral wall of main pipe body 1 effectively reduces the processing difficulty of pipe hole 10. Specifically, when processing pipe hole 10 (such as punching or drilling), connecting plane 112 provides a reference surface for hole processing tool to facilitate tool positioning, and the axis of pipe hole 10 can be calibrated based on connecting plane 112 so that the axis of pipe hole 10 is basically perpendicular to connecting plane 112, thereby greatly improving the accuracy of hole opening and reducing the difficulty of hole opening. In addition, when brazing vertical pipe 2, connecting plane 112 can also support brazing material to prevent brazing material from flowing along the outer peripheral wall of main pipe body 1 after melting.

[0077] Although the present embodiment is described by taking the example of forming a connection plane on the outer peripheral wall of the main body, the present invention does not make any limitation to this. In other embodiments, the outer peripheral wall of the main body may be circular or nearly circular in cross section, and the connecting hole may be formed on the curved outer peripheral wall of the main body, such as Fig. 20 shown.

[0078] In this embodiment, two limiting steps 114, 115 are formed at both ends of the inner circumferential wall of the main body 1 to limit the insertion depth of the two end pipes 31, 32. However, the present invention does not make any limitation to this. In other embodiments, the main body 1 does not need to be provided with limiting steps, such as Fig.21 shown.

[0079] Similarly, when the ratio of the inner diameter D1 of the vertical pipe connection end 21 to the inner diameter D2' of the main pipe body 1 at the pipe hole 10 is greater than or equal to 1.0, the pipe hole 10 may also include a straight hole section 101 and an inclined section 102 formed at the end of the straight hole section 101. Specifically, Fig. 22 and Fig.23 As shown, the connecting end 21 of the vertical pipe is assembled in the straight hole section 101 of the pipe hole, and the inner peripheral wall of the straight hole section 101 of the pipe hole forms a brazing surface to connect the outer peripheral wall of the vertical pipe connecting end 21 by surface brazing. A pipe hole connecting channel 103 is formed at the inclined section 102 of the pipe hole. The pipe hole connecting channel 103 widens the connecting space between the vertical pipe connecting end 21 and the pipe hole 10, eliminates the obstruction of the side wall of the main pipe body 1 to the fluid, and thus allows the inner diameter D1 of the vertical pipe connecting end 21 to be close to or greater than the inner diameter D2' of the main pipe body 1 at the pipe hole 10. Specifically, D1 / D2' can be a proportional relationship of 1.0, 1.2, 1.25, 1.3, 1.4, etc. However, the utility model does not make any limitation to this. In other embodiments, D1 / D2' can also be any proportional relationship within 1.0 to 1.5. Furthermore, the inclined section 102 of the pipe hole can also guide the fluid during flow diversion or confluence, so that the fluid can be better distributed to the vertical pipe 2 or be collected from the vertical pipe 2 to the main pipe body 1 .

[0080] In this embodiment, the two end pipes 31 and 32 are bent pipes and are substantially symmetrically distributed, and the vertical pipe 2 is a straight pipe. Fig.24 The structure diagram of the refrigeration pipe assembly provided in this embodiment is shown as follows. However, the present invention does not make any limitation to this. As for the structure of the vertical pipe 2 and the two end pipes 31, 32 and possible implementation methods, this embodiment is basically the same as the first embodiment and its variations, and will not be described in detail here.

[0081] In summary, in the new three-way pipe fitting provided by the utility model, a pipe hole with a hole depth based on its wall thickness is opened on the main pipe body, and the wall thickness of the main pipe body at the pipe hole allows the inner circumferential wall of the pipe hole to form a larger brazing surface, thereby realizing the surface brazing connection of the outer circumferential wall of the vertical pipe connection end. Compared with the traditional self-melting wire weld connection, the surface brazing connection not only has high connection strength but also has better pressure resistance and sealing, and can well withstand the high working pressure of the refrigeration system. In addition, the pipe hole structure with a hole depth based on the wall thickness of the main pipe body also allows the main pipe body to be formed by a hole processing process, and the hole processing processes such as drilling and punching are not only simple and mature, but also less affected by the performance of the main pipe material such as ductility, yield strength and hardness, which provides conditions for the use of low-cost, high-strength steel materials for the main pipe body.

[0082] Furthermore, in order to reduce the processing difficulty of the pipe hole, the main pipe body is set to a split structure including a thin-walled pipe body and an inner sleeve. The thin-walled pipe body and the inner sleeve are processed separately and then superimposed, which greatly reduces the processing difficulty of the pipe hole while meeting the pipe hole depth requirements. At the same time, the independent molding of the thin-walled pipe body and the inner sleeve also well solves the problems of the difficulty of molding, difficult procurement and high procurement cost of the thick-walled main pipe body. The annular inner sleeve allows it to have sufficient contact area to stably connect to the inner circumferential wall of the thin-walled pipe body after opening a bushing through hole with a hole diameter close to or larger than its own inner diameter. Furthermore, the bushing through hole is set to include a straight hole section and an inclined section. The straight hole section provides a welding depth for the vertical connection, while the inclined section increases the fluid connection space between the vertical pipe and the main pipe body and guides the fluid, thereby making the inner diameter of the vertical pipe connection end close to or even larger than the inner diameter of the main pipe body.

[0083] Although the present invention has been disclosed as above by the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope required by the claims.

Claims

1. A new three-way pipe fitting, characterized in that: include: The main pipe body made of steel is a combined structure and includes a thin-walled pipe body and an inner sleeve. The inner circumferential wall section of the thin-walled pipe body is circular or nearly circular. The inner sleeve is embedded in the thin-walled pipe body and the outer circumferential wall of the inner sleeve is attached to the inner circumferential wall of the thin-walled pipe body. A sleeve through hole with an axis perpendicular or substantially perpendicular to the axis of the thin-walled pipe body is provided on the circumferential wall of the inner sleeve. A pipe body through hole is correspondingly provided on the thin-walled pipe body. The sleeve through hole and the pipe body through hole together constitute a pipe connecting hole. The overlapping wall thickness T of the thin-walled pipe body and the inner sleeve at the pipe connecting hole is 1.5 mm to 5 mm. The inner circumferential wall of the sleeve through hole and the inner circumferential wall of the pipe body through hole together form the brazing surface of the pipe connecting hole. A thin-walled vertical pipe, whose connecting end is inserted into the pipe hole on the main pipe body, the ratio of the inner diameter D1 of the vertical pipe connecting end to the inner diameter D2 of the inner bushing at the pipe hole is 0.75-1.50, and the outer peripheral wall of the vertical pipe connecting end is attached to the brazing surface of the pipe hole in a surface contact manner, and a brazing layer is formed between the two attached surfaces; Two thin-walled end pipes are respectively sleeved and welded to the axial ends of the main pipe body; Here, thin-walled means that the wall thickness of the pipe is greater than or equal to 0.3 mm and less than 2.0 mm.

2. The novel three-way pipe fitting according to claim 1 is characterized in that: The ratio of the inner diameter of the vertical connecting pipe connection end to the inner diameter of the inner bushing at the connecting pipe hole is greater than or equal to 1.

0. The bushing through hole includes a straight hole section and an inclined section formed at the end of the straight hole section. The connecting end of the vertical connecting pipe is assembled in the straight hole sections of the pipe body through hole and the bushing through hole. The inner circumferential wall of the pipe body through hole and the inner circumferential wall of the straight hole section of the bushing through hole jointly form the brazing surface of the connecting pipe hole.

3. The novel three-way pipe fitting according to claim 1 is characterized in that: The main pipe body includes an inner sleeve embedded in the thin-walled pipe body; or, the main pipe body includes multiple inner sleeves embedded in the thin-walled pipe body, the multiple inner sleeves are sequentially sleeved and overlapped, and each inner sleeve has a sleeve through hole that is substantially coaxial with the through hole of the pipe body.

4. The novel three-way pipe fitting according to claim 1 is characterized in that: The inner sleeve is in the shape of a hollow tube; or, the inner sleeve is in the shape of a hollow cylinder formed by bending and rolling and having a rolling gap.

5. The novel three-way pipe fitting according to claim 1 is characterized in that: The length of the inner sleeve is shorter than that of the thin-walled tube body. Two limit steps for limiting the insertion depth of the end pipes are formed at the end faces of the inner sleeve. The two end pipes are respectively sleeved at the two ends of the thin-walled tube body and abut against the corresponding limit steps.

6. The novel three-way pipe fitting according to claim 1 is characterized in that: The length of the inner sleeve is close to that of the thin-walled tube body. The two end pipes are sleeved in the inner sleeve, and two limiting steps for limiting the insertion depth of the two end pipes are formed on the inner peripheral wall of the inner sleeve.

7. The novel three-way pipe fitting according to claim 1 is characterized in that: The tube body through hole is a through hole whose hole depth is based on the wall thickness of the thin-walled tube body, or the tube body through hole is a flanging hole with a flanging straight body section.

8. The novel three-way pipe fitting according to claim 1 is characterized in that: A self-fluxing weld and / or a brazing weld is formed between the thin-walled tube body and the inner liner.

9. The novel three-way pipe fitting according to claim 1 is characterized in that: The outer peripheral wall of the thin-walled tube body is formed with a connection plane, the tube body through hole is located at the connection plane and the axis of the tube body through hole is perpendicular or substantially perpendicular to the connection plane; Alternatively, the cross section of the outer peripheral wall of the thin-walled tube body is circular or nearly circular, and the tube body through hole is formed on the curved outer peripheral wall of the thin-walled tube body.

10. The novel three-way pipe fitting according to claim 1, characterized in that: The two end connecting pipes and the vertical connecting pipe are combined pipe fittings formed by any one of steel pipe fittings and copper pipe fittings or a combination of the two; the two end connecting pipes and the vertical connecting pipe are any one of straight pipes and bent pipes.

11. A novel three-way pipe fitting, characterized in that: include: The main pipe body is an integral steel pipe fitting with a circular or nearly circular inner wall section, a pipe hole with an axis perpendicular or substantially perpendicular to the axis of the main pipe body is formed on the pipe wall of the main pipe body, a connecting plane is formed on the outer wall of the main pipe body and the pipe hole is located at the connecting plane, or the outer wall of the main pipe body has a circular or nearly circular cross section, and the pipe hole is formed on the curved outer wall of the main pipe body; the wall thickness of the main pipe body at the pipe hole is 1.5 mm to 5 mm, and the inner wall of the pipe hole forms a brazing surface; A thin-walled vertical pipe, the connection end of which is inserted into the pipe hole on the main pipe body, the ratio of the inner diameter of the vertical pipe connection end to the inner diameter of the main pipe body at the pipe hole is 0.75 to 1.5, the outer peripheral wall of the vertical pipe connection end is attached to the brazing surface of the pipe hole in a surface contact manner, and a brazing layer is formed between the two attached surfaces; Two thin-walled end pipes are respectively sleeved and welded to the axial ends of the main pipe body; The thin wall refers to a pipe having a wall thickness greater than or equal to 0.3 mm and less than 2.0 mm.

12. The novel three-way pipe fitting according to claim 11, characterized in that: The ratio of the inner diameter of the vertical pipe connection end to the inner diameter of the main pipe body at the pipe hole is greater than or equal to 1.

0. The pipe hole includes a straight hole section and an inclined section formed at the end of the straight hole section. The connection end of the vertical pipe is assembled in the straight hole section of the pipe hole. The inner peripheral wall of the straight hole section of the pipe hole forms a brazing surface to braze and connect the outer peripheral wall of the connection end of the vertical pipe.

13. A refrigeration pipeline assembly, characterized in that: The invention comprises the novel three-way pipe fitting according to any one of claims 1 to 12.

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