CN222597106U - Novel tee bend pipe fitting and refrigeration pipeline subassembly - Google Patents

Abstract

The utility model provides a novel three-way pipe fitting and a refrigeration pipeline assembly, wherein a main pipe body in the novel three-way pipe fitting is of a combined structure and comprises a thin-wall pipe body and an inner bushing, the cross section of the inner peripheral wall of the thin-wall pipe body is circular or nearly circular, and the inner bushing is embedded and attached in the thin-wall pipe body. The peripheral wall of the inner bushing is provided with a bushing through hole with the axis vertical or basically vertical to the axis of the thin-wall pipe body, the thin-wall pipe body is correspondingly provided with a pipe body through hole, and the bushing through hole and the pipe body through hole form a joint pipe hole together. The overlapped wall thickness of the thin-wall pipe body and the inner bushing at the connecting pipe hole is 1.5 mm-5 mm, and the inner peripheral wall of the bushing through hole and the inner peripheral wall of the pipe body through hole jointly form a brazing surface of the connecting pipe hole. The ratio of the inner diameter of the vertical connecting pipe connecting end to the inner diameter of the inner bushing at the connecting pipe hole is 0.75-1.50, the peripheral wall of the vertical connecting pipe connecting end is bonded and welded on the brazing surface in a surface contact mode, and a brazing layer is formed between the two bonding surfaces. The two end connecting pipes are respectively sleeved and welded at the two axial ends of the main pipe body.

Description

Novel tee bend pipe fitting and refrigeration pipeline subassembly

Technical Field

The utility model relates to the field of accessories of refrigeration systems, in particular to a novel tee pipe fitting and a pipeline connecting assembly.

Background

The connecting pipeline in the air conditioner refrigerating pipeline is mostly made of copper material, copper is a noble metal material, and the cost is higher and higher along with the continuous rising of the market price, so the research and application of replacing copper material with steel material is becoming the research and development direction of the technicians in the field.

The three-way pipe fitting frequently used for pipeline connection has U-shaped, Y-shaped (fork-shaped) and T-shaped structures, and in the process of replacing copper materials with steel materials, the ductility of the steel materials is only about 20 percent of that of the copper materials, but the hardness of the steel materials is 4-5 times that of the copper materials, so that the forming processing of the steel three-way pipe fitting is extremely difficult due to the physical properties, and the steel three-way pipe fitting cannot be practically produced in batch due to qualification rate and other reasons even though the steel three-way pipe fitting is barely processed. Therefore, a steel three-way pipe on a low-pressure water pipeline (with the design working pressure less than 2.5 MPa) generally adopts a self-fluxing welding structure that a punched hole is turned over and then a connecting pipe is connected, such as a T-shaped structure shown in figure 1. However, the self-fluxing type welding method has potential safety hazards such as low connection strength, poor pressure resistance and the like in a refrigeration pipeline with the design working pressure of more than 4.0MPa, and is difficult to apply. If the pipe is brazed after punching and flanging, the strength requirement after brazing is difficult to meet because the assembling section of the pipe formed by the flanging is very short (namely the flanging height is short), and particularly when the pipe diameter of the pipe is close to the pipe diameter of a main pipe, migration of pipe blank materials is more difficult to realize, and the connection of the pipe by brazing is almost impossible to realize in the structure.

To solve the above problems, the inventors have proposed adding a welding lining plate in the main pipe in the manifold pipe structure to achieve welding of the connecting pipes. It is apparent that when the branch pipe inner diameter approaches the main pipe inner diameter, and even is larger than the main pipe inner diameter, the welding lining plate can not be processed into a lining plate hole which can provide welding depth for the connecting pipe, namely, the mode of internally arranging the welding lining plate cannot be applied to the three-way pipe fitting with the inner diameter of the branch pipe close to or larger than the inner diameter of the main pipe. However, in practical application, this type of tee is used in refrigeration and air conditioning in a large number, so research on the tee made of steel with such a structure is significant in practical significance.

Disclosure of utility model

The utility model provides a novel three-way pipe fitting and a pipeline connecting assembly, which aim to overcome the defects in the prior art.

In order to achieve the above object, the present utility model provides a novel three-way pipe fitting comprising a main pipe body made of steel, a thin-walled vertical pipe fitting, and two thin-walled end pipe fittings. The main pipe body is of a combined structure and comprises a thin-wall pipe body and an inner bushing, the cross section of the inner peripheral wall of the thin-wall pipe body is circular or nearly circular, the inner bushing is embedded in the thin-wall pipe body, the outer peripheral wall of the inner bushing is attached to the inner peripheral wall of the thin-wall pipe body, bushing through holes with the axes perpendicular or basically perpendicular to the axis of the thin-wall pipe body are formed in the peripheral wall of the inner bushing, pipe body through holes are correspondingly formed in the thin-wall pipe body, the bushing through holes and the pipe body through holes form joint pipe holes together, the overlapped wall thickness of the thin-wall pipe body and the inner bushing at the joint pipe holes is 1.5 mm-5 mm, and the inner peripheral wall of the bushing through holes and the inner peripheral wall of the pipe body through holes form brazing surfaces of the joint pipe holes together. The connecting end of the vertical connecting pipe is inserted into the connecting pipe hole on the main pipe body, the ratio of the inner diameter of the connecting end of the vertical connecting pipe to the inner diameter of the inner lining at the connecting pipe hole is 0.75-1.50, the peripheral wall of the connecting end of the vertical connecting pipe is attached to the brazing surface of the connecting pipe hole in a surface contact mode, and a brazing layer is formed between the two attaching surfaces. The two end connecting pipes are respectively sleeved and welded at the two axial ends of the main pipe body. Wherein, the thin wall refers to the wall thickness of the pipe fitting is more than or equal to 0.3mm and less than 2.0mm.

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 comprises a straight hole section and an inclined section formed at the tail 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 peripheral wall of the pipe body through hole and the inner peripheral wall of the straight hole section of the bushing through hole jointly form a brazing surface of the connecting pipe hole.

According to one embodiment of the utility model, the main pipe body comprises an inner bushing embedded in the thin-wall pipe body, or a plurality of inner bushings embedded in the thin-wall pipe body, and the inner bushings are sleeved and overlapped in sequence and are provided with bushing through holes which are approximately coaxial with the pipe body through holes.

According to one embodiment of the utility model, the inner liner is hollow and tubular, or the inner liner is hollow and tubular which is formed by bending and rolling and has rolling gaps.

According to one embodiment of the utility model, the length of the inner bushing is shorter than that of the thin-wall pipe body, two limiting steps for limiting the insertion depth of the end connecting pipes are formed at the end faces of the two ends of the inner bushing, and the two end connecting pipes are respectively sleeved at the two ends of the thin-wall pipe body and are abutted against the corresponding limiting steps.

According to one embodiment of the utility model, the length of the inner bushing is close to that of the thin-wall pipe body, the two end connection pipes are sleeved in the inner bushing, and two limiting steps for limiting the insertion depth of the two end connection pipes are formed on the inner peripheral wall of the inner bushing.

According to an embodiment of the utility model, the through hole of the pipe body is a through hole with a hole depth based on the wall thickness of the thin-wall pipe body, or the through hole of the pipe body is a flanging hole with a flanging straight section.

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

According to one embodiment of the utility model, the outer peripheral wall of the thin-walled tube body is formed with a connection plane, the tube body through hole is positioned at the connection plane, and the axis of the tube body through hole is vertical or basically vertical to the connection plane;

or the cross section of the outer peripheral wall of the thin-wall pipe body is round or nearly round, and the pipe body through hole is formed in the curved outer peripheral wall of the thin-wall pipe body.

According to the embodiment of the utility model, the two end connection pipes and the vertical connection pipe are combined pipe fittings formed by combining any one or both of steel pipe fittings and copper pipe fittings, and the two end connection pipes and the vertical connection pipe are any one of straight pipes and bent pipes.

The utility model also provides another novel three-way pipe fitting, which comprises a main pipe body, a thin-wall vertical connecting pipe and two thin-wall end connecting pipes. The main pipe body is an integral steel pipe fitting with a circular or nearly circular inner peripheral wall section, a pipe connecting hole with an axis vertical or basically vertical to the axis of the main pipe body is formed in the pipe wall of the main pipe body, a connecting plane is formed in the outer peripheral wall of the main pipe body, the pipe connecting hole is formed in the curved outer peripheral wall of the main pipe body, the wall thickness of the main pipe body at the pipe connecting hole is 1.5 mm-5 mm, and a brazing surface is formed in the inner peripheral wall of the pipe connecting hole. The connecting end of the vertical connecting pipe is inserted into the connecting pipe hole on the main pipe body, 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 0.75-1.5, the peripheral wall of the connecting end of the vertical connecting pipe is attached to the brazing surface of the connecting pipe hole in a surface contact mode, and a brazing layer is formed between the two attaching surfaces. The two end connecting pipes are respectively sleeved and welded at the two axial ends of the main pipe body. Wherein, the thin wall refers to the wall thickness of the pipe fitting is more than or equal to 0.3mm and less than 2.0mm.

According to an embodiment of the present utility model, the ratio of the inner diameter of the connection end of the vertical connection pipe to the inner diameter of the main pipe body at the connection pipe hole is greater than or equal to 1.0, the connection 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 connection pipe is fitted into the straight hole section of the connection pipe hole, and the inner circumferential wall of the straight hole section of the connection pipe hole forms a brazing surface to braze-join the outer circumferential wall of the connection end of the vertical connection pipe.

On the other hand, the utility model also provides a refrigeration pipeline assembly which comprises the novel tee pipe fitting.

In summary, in the novel three-way pipe fitting provided by the utility model, the main pipe body is provided with the connecting pipe hole with the hole depth based on the wall thickness, the wall thickness of the main pipe body at the connecting pipe hole enables the inner peripheral wall of the connecting pipe hole to form a larger brazing surface, and further, the surface brazing connection of the outer peripheral wall of the vertical connecting pipe connecting end is realized. Compared with the traditional self-fluxing type wire-bonding joint, the surface-bonding joint has high joint strength, more excellent pressure resistance and sealing performance and can well bear the high working pressure of a refrigerating system. In addition, the connecting pipe hole structure Kong Shenji on the wall thickness of the main pipe body also enables the main pipe body to realize the forming of the connecting pipe hole by adopting a hole processing technology, and the hole processing technology such as drilling, punching and the like is simple and mature and has small influence on the performance such as ductility, yield strength, hardness and the like of the main pipe body material, thereby providing conditions for selecting the steel material with low cost and high strength for the main pipe body.

Further, in order to reduce the processing difficulty of the connecting pipe hole, the main pipe body is of a split structure comprising a thin-wall pipe body and an inner bushing, and the thin-wall pipe body and the inner bushing are overlapped after being respectively subjected to hole processing, so that the processing difficulty of the connecting pipe hole is greatly reduced while the hole depth requirement of the connecting pipe hole is met. Meanwhile, the independent molding of the thin-wall pipe body and the inner bushing also well solves the problems of high molding difficulty, difficult purchase and high purchase cost of the thick-wall main pipe body. The annular inner bushing has enough contact area to be stably connected to the inner peripheral wall of the thin-wall pipe body after the bushing through hole with the aperture close to or larger than the inner diameter of the bushing through hole is formed. Still further, providing the bushing through-hole includes straight hole section and inclined section, and straight hole section provides the welding depth for perpendicular connecing, and inclined section then has increased the fluid communication space between perpendicular takeover and the main pipe body and guide the fluid, and then makes the internal diameter of perpendicular takeover link accessible even be greater than the internal diameter of main pipe body.

The foregoing and other objects, features and advantages of the utility model will be apparent from the following more particular description of preferred embodiments, as illustrated in the accompanying drawings.

Drawings

Fig. 1 is a schematic structural view of a conventional T-shaped stainless steel tee pipe.

Fig. 2 is a schematic structural diagram of a novel three-way pipe according to an embodiment of the present utility model.

Fig. 3 is a schematic cross-sectional view of fig. 2 at another viewing angle.

Fig. 4 is a schematic cross-sectional view of the main body of fig. 3.

Fig. 5 is a schematic cross-sectional view of fig. 4 at another viewing angle.

Fig. 6 and 7 are schematic structural views of a novel three-way pipe according to another embodiment of the present utility model

Fig. 8 is a schematic diagram of the principle of vertical tube brazing when the outer peripheral wall of the thin-walled tube is curved.

Fig. 9 and fig. 10 are schematic structural diagrams of a novel tee pipe according to another embodiment of the present utility model.

Fig. 11 is a schematic structural diagram of a refrigeration circuit assembly according to a first embodiment of the present utility model.

Fig. 12 is a schematic structural diagram of a refrigeration circuit assembly according to another embodiment of the present utility model.

Fig. 13 is a schematic structural diagram of a novel three-way pipe fitting according to a second embodiment of the present utility model.

Fig. 13A is a schematic view of the structure of fig. 13 with the vertical nipple removed.

Fig. 14 is a schematic structural diagram of a novel three-way pipe fitting according to a third embodiment of the present utility model.

Fig. 15 is a schematic cross-sectional view of fig. 14.

Fig. 15A is a schematic cross-sectional view of the main body of fig. 15.

Fig. 16 is an assembly schematic diagram of a main pipe body and a vertical pipe in a novel tee pipe according to a fourth embodiment of the present utility model.

Fig. 17 is a schematic view of the structure of fig. 16 with the vertical nipple removed.

Fig. 18 is a schematic structural diagram of a novel three-way pipe fitting according to a fourth embodiment of the present utility model.

Fig. 19 is a schematic cross-sectional view of fig. 18 at another viewing angle.

Fig. 20 is a schematic cross-sectional view of a novel tee fitting according to another embodiment of the present utility model.

Fig. 21, 22 and 23 are schematic structural views of a novel three-way pipe according to another embodiment of the present utility model.

Fig. 24 is a schematic structural diagram of a refrigeration circuit assembly according to a fifth embodiment of the present utility model.

Detailed Description

The low ductility, high yield strength and high hardness of the steel material lead to the problem that the length of the connecting pipe assembly section is difficult to meet the brazing requirement when the steel three-way pipe fitting is formed by replacing copper materials. Particularly, when the pipe diameter of the connecting pipe is close to the pipe diameter of the main pipe body, forming the connecting pipe assembly section meeting the brazing requirement based on the migration of pipe blank materials can hardly be realized any more, and a structure that a welding lining plate is additionally arranged in the main pipe body to improve the welding depth is limited by the area of the welding lining plate, so that the connecting pipe hole with the aperture close to or larger than the inner diameter of the main pipe body is difficult to process. Therefore, the connecting pipe in the existing steel tee pipe fitting can only adopt the structure of the punching flanging in fig. 1 and then self-melting welding. The steel three-way pipe fitting of fig. 1 is difficult to be applied to a refrigerating system with high working pressure due to the limitation of the self-fluxing type weld joint connection strength and pressure resistance.

In view of this, as shown in fig. 2 to 5, the novel three-way pipe provided in the present embodiment includes a main pipe body 1 made of steel, a thin-walled vertical pipe 2, and two thin-walled end pipes 31,32. The main pipe body 1 is of a combined structure and comprises a thin-wall pipe body 11 and an inner bushing 12, the cross section of the inner peripheral wall of the thin-wall pipe body 11 is circular or nearly circular, the inner bushing 12 is embedded in the thin-wall pipe body 11, the outer peripheral wall of the inner bushing 12 is attached to the inner peripheral wall of the thin-wall pipe body 11, bushing through holes 121 with axes perpendicular or basically perpendicular to the axes of the thin-wall pipe body 11 are formed in the peripheral wall of the inner bushing 12, pipe body through holes 111 are correspondingly formed in the thin-wall pipe body 11, and the bushing through holes 121 and the pipe body through holes 111 jointly form a pipe connecting hole 10. The overlapping wall thickness T0 of the thin-walled pipe body 11 and the inner bushing 12 at the joint pipe hole 10 is 1.5 mm-5 mm, and the inner peripheral wall of the bushing through hole 121 and the inner peripheral wall of the pipe body through hole 111 jointly form the brazing surface 100 of the joint pipe hole 10. The connecting end 21 of the vertical connecting pipe 2 is inserted into the connecting pipe hole 10 on the main pipe body 1, the ratio of the inner diameter D1 of the connecting end 21 of the vertical connecting pipe to the inner diameter D2 of the inner bushing 12 at the position of the connecting pipe hole 10 is 0.75-1.50, the peripheral wall of the connecting end 21 of the vertical connecting pipe is attached to the brazing surface 100 of the connecting pipe hole in a surface contact manner, and a brazing layer 200 is formed between the two attaching surfaces. The two end connection pipes 31 and 32 are respectively sleeved and welded at the two axial ends of the main pipe body 1.

Wherein, the thin wall refers to the wall thickness of the pipe fitting is more than or equal to 0.3mm and less than 2.0mm. Specifically, the wall thickness of the thin-wall pipe fitting can be selected to be any value within 0.3 mm-2.0 mm according to the 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 tube body 11 and the inner liner 12 at the connecting tube hole 10 may be any value within 1.5mm to 5mm, such as 1.8mm,2.0mm,2.5mm,3mm,3.5mm,4.0mm, 4.5mm, etc., as required.

In the novel three-way pipe fitting provided in this embodiment, the vertical connection pipe 2 is connected to the connection pipe hole 10 on the main pipe body 1, and the two end connection pipes 31 and 32 are respectively connected to the two ends of the main pipe body 1. This structure makes it only necessary to provide the main pipe body 1 with the pipe hole 10 during processing. The hole depth is based on the structure of the connecting pipe hole 10 with the overlapping wall thickness T0 of the thin-wall pipe body 11 and the inner bushing 12, and the main pipe body 1 can be processed into the connecting pipe hole 10 by adopting a simple and mature hole processing technology (such as a drilling technology or a punching technology). The hole processing technology does not involve the migration of the pipe, and is less affected by physical properties such as ductility, yield strength and hardness of the material, so that the main pipe body 1 in the novel three-way pipe fitting provided by the embodiment can be processed by adopting a low-cost steel material. Further, the wall thickness T0 of the main pipe body 1 at the pipe connecting hole 10 (i.e. the overlapping wall thickness T0 of the thin-walled pipe body 11 and the inner liner 12 at the pipe connecting hole 10) is controlled, so that the inner peripheral wall of the pipe connecting hole 10 forms a large-area brazing surface 100, thereby realizing the surface brazing connection of the vertical pipe connecting 2 and the pipe connecting hole 10, and greatly improving the connection strength and pressure resistance of the welded vertical pipe connecting 2, so that the novel three-way pipe fitting can be well applied to a refrigerating system with high working pressure.

However, the main pipe body 1 with a thicker wall thickness is a pipe with special specifications, and the forming difficulty of the thick-wall main pipe body is limited by the wall thickness, so that the main pipe body is difficult to purchase, the purchase cost is high, and the like. In order to solve the problems of difficult forming, difficult purchasing, high purchasing difficulty, high processing difficulty of the pipe connecting hole 10 and the like of the thick-wall main pipe body, the main pipe body 1 is provided with a combined structure comprising a thin-wall pipe body 11 and an inner bushing 12. This arrangement disassembles the thick-walled main pipe body 1 into a plurality of separate and relatively thin conventional parts (i.e., the inner liner 12 and the thin-walled pipe body 11). Each component part is independently formed and then assembled and welded to form the main pipe body 1. Compared with the main pipe body 1 with a thick wall, the inner bushing 12 with a thinner wall thickness and the thin-wall pipe fitting 11 are conventional pipe fittings, and the inner bushing 12 and the thin-wall pipe fitting are easy to form, purchase and have low purchase cost, so that the cost of the main pipe body 1 is greatly reduced. Further, the combined structure also enables the thin-wall pipe body 11 and the inner bushing 12 to be respectively subjected to hole processing, and then the inner bushing 12 is embedded into the thin-wall pipe body 11, and the coaxial or approximately coaxial pipe body through hole 111 and the bushing through hole 121 jointly form the pipe connecting hole 10 so as to ensure that the inner peripheral wall of the pipe connecting hole 10 forms a brazing surface 100 meeting brazing requirements, namely, the processing difficulty of the pipe connecting hole 10 is effectively reduced while the area of the brazing surface 100 in the pipe connecting hole 10 is met. In addition, when the inner diameter D1 of the vertical pipe connecting end 21 is close to or larger 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, the inner bushing 12 still has enough connecting area so as to be firmly connected to the inner peripheral wall of the thin-walled pipe body 11, thereby well solving the problem that the welding lining plate of the existing three-way pipe fitting cannot provide a welding depth for the pipe connecting pipe with the inner diameter close to or larger than the inner diameter of the main pipe body.

In this embodiment, the main pipe body 1 comprises an inner liner 12 which is hollow and tubular. However, the present utility model is not limited in any way thereto. In other implementations, the main pipe body 1 may also include a plurality of inner bushings that are sequentially sleeved and overlapped, and each inner bushing has a bushing through hole that is substantially coaxial with the pipe body through hole. In other embodiments, the inner liner may be a hollow cylinder with a winding slit and a winding slit.

In this embodiment, as shown in fig. 3 and 5, the cross section of the outer peripheral wall of the thin-walled tube body 11 is also circular or nearly circular, and the tube through hole 111 is a through hole formed in 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 through hole 111 and the wall thickness T2 of the inner liner 12 at the liner through hole 121 are taken as the hole depth T0 of the joint tube hole 10. However, the present utility model is not limited in any way thereto. In other embodiments, the connection plane 112 may be formed on the outer peripheral wall of the thin-walled tube 11 to further reduce the difficulty of opening. As shown in fig. 6, the outer peripheral wall of the thin-walled tube body 11 has a pentagonal cross section, one of the planes of the thin-walled tube body 1 is a connection plane 112, the tube through-hole 111 is formed in the connection plane 112, and the axis of the tube through-hole 11 is perpendicular or substantially perpendicular to the connection plane 112. When the pipe body through hole 111 is processed, the connection plane 112 can provide a datum plane for a hole processing cutter so as to be convenient for cutter positioning, and the axis of the pipe body through hole 111 can be calibrated based on the connection plane 112 so that the axis of the pipe body through hole 111 is basically perpendicular to the connection plane 112, thereby greatly improving the accuracy of the hole opening and reducing the difficulty of the hole opening. Although fig. 6 exemplifies a pentagonal cross section of the outer peripheral wall of the thin-walled tube. However, the present utility model is not limited in any way thereto. In the present utility model, the outer peripheral wall of the thin-walled tube 11 is only required to be formed with a connection plane 112 for processing the tube through-hole 111, and the structure of the thin-walled tube 11 outside the connection plane 112 is not limited in any way. In other embodiments, the cross-section of the outer peripheral wall of the thin-walled tube 11 may be of other polygonal structures, such as square (as shown in fig. 7) or hexagonal, or only one connecting plane 112 may be provided while the other portions are still curved. Also, although fig. 6 and 7 illustrate an example in which the connection plane extends to both ends of the thin-walled tube body. However, the present utility model is not limited in any way thereto. In other implementations, the connection plane may also be located in a middle region of the outer peripheral wall of the thin-walled tube, and the outer peripheral walls of the two ends of the thin-walled tube are still circular or nearly circular.

In addition, when the hole diameter of the pipe body through hole 111 is larger (corresponding to the larger inner diameter D1 of the vertical connecting end of the pipe), there is a larger height difference at the edge of the pipe body through hole formed on the curved peripheral wall, and the height difference can cause the brazing material to suspend in the air in a partial area (as shown at a in fig. 8). The solder at the suspended position is pulled by gravity F after being melted to generate flow welding along the outer peripheral wall of the curved surface of the thin-wall pipe body 11, and the solder is difficult to enter the through hole 111 of the pipe body, so that the welding problems such as cold welding, broken welding and the like are easy to occur. In the structures shown in fig. 6 and 7, the edge of the pipe body through hole 111 opened on the basis of the connection plane 112 is also a plane structure, when the vertical connection pipe connecting end 21 is soldered to the connection pipe hole 10, the connection plane 112 carries solder so as to prevent the solder from suspending, so that the solder at each position in the circumferential direction of the pipe body through hole 111 is permeated only by the capillary traction of the soldering gap between the vertical connection pipe 2 and the connection pipe hole 10, and the soldering gap is ensured to be filled with enough solder at each position in the circumferential direction, thereby effectively solving the flow soldering problem existing in curved surface soldering. In addition, in other embodiments, the through hole 111 may be configured as a flanging hole with a straight-flanged section.

In this embodiment, as shown in fig. 2, the length of the inner liner 12 is shorter than that of the thin-walled tube body 11, and two limit steps 114,115 defining the insertion depths of the two end fittings 31,32 are formed at both end faces of the inner liner 12. The two end connection pipes 31 and 32 are respectively sleeved at the two ends of the thin-wall pipe body 11 and are abutted against the corresponding limiting steps 114 and 115. That is, in this embodiment, the inner liner 12 provides a weld depth for the vertical nipple 2 as well as a limit for the welded assembly of the two end nipples 31, 32. In addition, the shorter length of the inner liner 12 may further reduce the material cost of the main tubular body. However, the present utility model is not limited in any way thereto. In other embodiments, as shown in fig. 9, the length of the inner liner 12 may be close to the length of the thin-walled tube 11, two end fittings 31,32 are sleeved in the inner liner 12, and two limiting steps 114,115 for limiting the insertion depth of the two end fittings are formed on the inner peripheral wall of the inner liner 12. In addition, in other embodiments, two end nozzle jackets may be provided that are attached to the ends of the main tubular body.

In this embodiment, the thin-walled tube 11 and the inner liner 12 are steel components, and in order to ensure corrosion resistance of the critical welded connection (such as the welded connection of the vertical connection tube 2), steel with chromium (Cr) content of not less than 5% is selected to improve the service life of the product. For example, stainless steel materials which are resistant to corrosion by weak corrosive media such as air, steam, water and the like and chemical corrosive media such as acid, alkali, salt and the like are selected. Further, based on the cost, it is preferable to use a non-300 series stainless steel having a Cr content of not less than 5%, such as SUS430 (commonly called stainless iron, cr%. Gtoreq.16-18%) or SUS201 (Cr%. Gtoreq.13% and Ni%. Gtoreq.3.5%) material. The stainless steel material of SUS201 is specifically selected from steel materials with Cr percent more than or equal to 10 percent and Ni percent more than or equal to 1 percent produced by Qingshan stainless steel manufacturer and wire number of D665A or D667, and the material cost is considered on the premise of meeting the environmental corrosion resistance and rust resistance. However, the present utility model is not limited in any way thereto. In other embodiments, the thin-walled tube and the inner liner may be made of other steel materials having a Cr content of not less than 5% depending on the application environment.

In this embodiment, the two end fittings 31,32 and the vertical fitting 2 are also steel pipes having a Cr content of not less than 5%. The inner liner 12 is provided with a liner through hole 121, and then is embedded in the thin-wall pipe body 11 and fixedly connected with the thin-wall pipe body 11 through a self-fluxing welding seam, wherein the self-fluxing welding seam is a local self-fluxing welding seam (such as a plurality of self-fluxing welding spots or a plurality of intermittent self-fluxing linear welding seams) or a self-fluxing girth welding seam. Then, two end connection pipes 31 and 32 and a vertical connection pipe 2 are assembled, the three connection pipes, the inner bushing 12 and the thin-wall pipe body 11 are welded and formed integrally by brazing in a red copper furnace, and a brazing seam is formed between the thin-wall pipe body and the inner bushing. However, the present utility model is not limited in any way thereto. In the present utility model, the inner liner 12 is used for providing the welding depth for the vertical connection pipe 2 so that the inner peripheral wall of the connection pipe hole 10 forms a large area of brazing surface 100, and the inner liner 12 and the thin-walled pipe body 11 only need to be fixedly connected, but do not need to be in sealing connection. Thus, in other embodiments, a self-fluxing weld or braze joint may be provided between the thin-walled tube and the inner liner that merely secures the inner liner.

Although this embodiment is described with reference to two end fittings and a vertical fitting being steel tubing. However, the present utility model is not limited in any way thereto. In other embodiments, the two end connection pipes and the vertical connection pipe can be copper pipe pieces or a combination of the copper pipe pieces and the steel pipe pieces, and the three connection pipes, the inner bushing and the thin-wall pipe body can be integrally welded and formed together by brazing in a tin bronze solder furnace after being assembled. Or the structures of the three connecting pipes are not identical, wherein part of the connecting pipes are steel pipe fittings, and the other connecting pipes are copper pipe fittings or the combination of the copper pipe fittings and the steel pipe fittings.

In this embodiment, both the end fittings 31,32 and the vertical fitting 2 are straight tubes. However, the present utility model is not limited in any way thereto. In other embodiments, as shown in fig. 10, the end fittings 32 are straight tubes, while the end fittings 31 and the vertical fittings 2 are both curved tubes. Or the three connecting pipes can be all bent pipes, or part of the connecting pipes are straight pipes, and part of the connecting pipes are bent pipes

Correspondingly, as shown in fig. 11, the present embodiment also provides a refrigeration pipeline assembly, which includes the novel tee pipe 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 tee pipe fitting provided by the embodiment to be welded and connected in a copper pipeline of an existing refrigeration system in a flame brazing mode. Fig. 12 is a schematic view of a refrigeration circuit assembly including three copper pipe sections 41,42,43 according to another embodiment of the present utility model, in fig. 12, two end pipes 31,32 are bent pipes and are distributed approximately symmetrically, and a vertical pipe 2 is a straight pipe.

However, the present utility model is not limited in any way thereto. In other embodiments, the novel tee fitting provided in this embodiment may also be combined with components such as a muffler, a filter, or a dispenser within a piping system to form other refrigeration piping components. In addition, although the present embodiment is exemplified by the application of the novel three-way pipe fitting to a high operating pressure refrigeration system. However, the present utility model is not limited thereto. In other embodiments, the novel tee fitting provided by the utility model is also applicable to other pipeline systems with smaller working pressure, such as a low-pressure water pipeline system.

Example two

The difference between this embodiment and the first embodiment and its variation is that, as shown in fig. 13, 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 inner bushings 12,12' that are sleeved and overlapped. However, the present utility model is not limited in any way thereto. In other embodiments, the main pipe body may also include more than three inner bushings that are sequentially sleeved and overlapped.

Specifically, as shown in fig. 13A, both inner bushings 12,12 'are formed with bushing through holes 121,121' substantially coaxial with the pipe body through hole 111. The body through hole 111, the bushing through hole 121, and the bushing through hole 121' together form the joint pipe hole 10. The overlapping of the sleeves increases the depth of the nipple hole 10 and the inner peripheral wall area thereof to further improve the surface brazing strength of the perpendicular nipple 2. At the same time, the arrangement well solves the problems of difficult purchase, high purchase cost and the like of the main pipe body 1, and simultaneously further reduces the processing difficulty of the connecting pipe hole 10. In this embodiment, both inner liners 12,12' are hollow cylinders of steel sheet material bent and rolled and having a rolling slit 122. In this embodiment, high strength sealing brazing is required between the bushing through holes 121,121' and the vertical pipe connecting end 21, but only a certain connecting strength is required between the inner bushing and the thin-walled pipe body, so that a rolling gap may exist on the rolled inner bushing. However, the present utility model is not limited in any way thereto. In other embodiments, the rolled gap may be self-fused, spot-welded, or integrally brazed and then embedded in the thin-walled tube. In other embodiments, the inner liner may also be hollow and tubular, as shown in example one.

Example III

The present embodiment is basically the same as the first embodiment and its variation, except that the tube through hole 111 is a burring hole having a burring straight section 113 as shown in fig. 14, 15 and 15A.

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, the burring straight section 113 is formed in the entire circumference of the pipe body through hole 111 based on workability of the thin-walled material and the ends of the burring straight section 113 are substantially flush. The flange straight section 113 with the basically flush tail end supports brazing material during brazing, and prevents the brazing material from being welded along the curved peripheral wall of the thin-wall pipe body 11 after being melted, so that the welding and flow welding problem caused by overlarge height difference of the edge of the pipe body through hole 111 when the inner diameter D1 of the vertical connecting pipe connecting end 21 is large (namely, the pipe body through hole 111 is large) is well solved.

Although the length of the burring straight portion 113 formed on the steel thin-walled tube body 11 is limited by the material properties, it can provide a welding depth for the brazing of the vertical joint tube 2 to further increase the area of the brazing surface 100. However, the present utility model is not limited in any way thereto. In other embodiments, a local straight flange section may be formed at the lowest and lower positions of the hole edge of the through hole of the pipe body, and the tail end of the local straight flange section is approximately flush with the highest position of the hole edge. The tail end of the local flanging straight body section and the highest position of the edge of the through hole of the pipe body form a plane for supporting the brazing material, so that the flow welding problem caused by suspending the brazing material is avoided. Similarly, the partially flanged straight section also increases the area of the brazing surface 100 on the joint pipe hole to some extent to improve the welding strength and pressure resistance of the perpendicular joint pipe 2.

In addition, the structures and possible implementation manners of the thin-walled tube body 11, the inner liner 12, the vertical connection tube 2, the two end connection tubes 31,32, and the like are substantially the same as those of the first embodiment and the variations thereof, and are not described herein.

Example IV

This embodiment is substantially the same as the first embodiment and its variation in that, as shown in fig. 16 and 17, the ratio of the inner diameter D1 of the vertical nipple connecting end 21 to the inner diameter D2 of the inner sleeve 12 at the nipple hole 10 is greater than or equal to 1.0, the sleeve 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 nipple is fitted into the body through hole 111 and the straight hole section 1211 of the sleeve through hole, and the inner peripheral wall of the body through hole 111 and the inner peripheral wall of the straight hole section 1211 of the sleeve through hole together form a brazing surface of the nipple hole 10.

In the novel three-way pipe fitting provided in this embodiment, the straight hole section 1211 on the bushing through hole 121 provides a welding depth for welding the vertical connection pipe 2, and the inclined section 1212 forms the communication passage 1210. The communication passage 1210 widens the communication space between the vertical nipple connection end 21 and the bushing through-hole 121, eliminates the blocking of the fluid by the sidewall of the inner bushing 12, and further allows the inner diameter D1 of the vertical nipple connection end 21 to be close to or larger than the inner diameter D2 of the inner bushing 12 at the nipple hole 10. Specifically, D1/D2 may be 1.0,1.2,1.25,1.3,1.4 equal proportional. However, the present utility model is not limited in any way thereto. In other embodiments, D1/D2 may be any ratio between 1.0 and 1.5. Further, the angled segments 1212 may also direct fluid during diversion or confluence to better distribute fluid over the vertical nipple 2 or to collect from within the vertical nipple 2 into the main tubular body 1.

Similarly, the structures and possible implementation manners of the thin-walled tube body 11, the inner liner 12, the vertical connection tube 2, the two end connection tubes 31,32 and the like are substantially the same as those of the first embodiment and their variations, and are not described herein.

Example five

This embodiment is substantially identical to the first embodiment and its variations, except that in this embodiment the main tubular body 1 is a unitary steel tubular member.

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

In the novel three-way pipe fitting provided in this embodiment, the vertical pipe fitting 2 is connected to the pipe fitting hole 10 of the main pipe body 1, and the two end pipe fittings 31 and 32 are respectively connected to the two ends of the main pipe body 1. Therefore, the novel three-way pipe fitting provided in the embodiment only needs to process the pipe hole 10 on the main pipe body 1. The pipe connection hole 10 of Kong Shenji in the wall thickness T0 of the main pipe body 1 allows the main pipe body 1 to be processed into the pipe connection hole 10 by using a simple and mature hole processing process (such as a drilling process or a punching process). The drilling and punching processes do not involve the migration of the pipe, and are less affected by physical properties such as ductility, yield strength and hardness of the material, so that the main pipe body 1 in the novel three-way pipe fitting provided by the embodiment can be processed by adopting a low-cost steel material. Further, the wall thickness T0 of the main pipe body 1 enables the inner peripheral wall of the pipe connecting hole 10 to form a large-area brazing surface 100 to be in surface brazing connection with the vertical pipe connecting 2, so that the connection strength and pressure resistance of the welded vertical pipe connecting 2 are greatly improved, and the novel three-way pipe fitting provided by the embodiment can be well applied to a refrigerating system with high working pressure.

While the means for welding the flat surface 112 to the outer peripheral wall of the main pipe body 1 effectively reduces the difficulty in machining the pipe connection hole 10. Specifically, when the pipe connecting hole 10 is processed (such as punching or drilling), the connection plane 112 provides a reference surface for the hole processing tool to facilitate positioning of the tool, and the axis of the pipe connecting hole 10 can be calibrated based on the connection plane 112 so that the axis of the pipe connecting hole 10 is substantially perpendicular to the connection plane 112, thereby greatly improving the accuracy of the hole opening and reducing the difficulty of the hole opening. In addition, the connection plane 112 can also support the brazing material during the brazing of the vertical joint pipe 2, so that the brazing material is prevented from being melted and then flow-welded along the outer peripheral wall of the main pipe body 1.

Although the present embodiment is described taking an example in which the connection plane is formed on the outer peripheral wall of the main pipe body. However, the present utility model is not limited in any way thereto. In other embodiments, the outer peripheral wall of the main pipe body may be circular or nearly circular in cross section, and the pipe connecting hole is formed in the curved outer peripheral wall of the main pipe body, as shown in fig. 20.

In the present embodiment, two limit steps 114,115 defining the insertion depth of the two end fittings 31,32 are formed at both ends of the inner peripheral wall of the main tube body 1, however, the present utility model is not limited thereto. In other embodiments, the main pipe body 1 does not need to be provided with a limiting step, as shown in fig. 21.

Similarly, when the ratio of the inner diameter D1 of the vertical nipple connecting end 21 to the inner diameter D2' of the main tube body 1 at the nipple hole 10 is greater than or equal to 1.0, the nipple hole 10 may be provided to include a straight hole section 101 and an inclined section 102 formed at the end of the straight hole section 101. Specifically, as shown in fig. 22 and 23, the connection end 21 of the vertical nipple is fitted into the straight hole section 101 of the nipple hole, and the inner peripheral wall of the straight hole section 101 of the nipple hole forms a brazing surface to be surface-brazed to the outer peripheral wall of the connection end 21 of the vertical nipple. And the inclined section 102 of the connecting pipe hole forms a connecting pipe hole communication passage 103. The connecting pipe hole communicating channel 103 widens the communicating space between the vertical connecting pipe connecting end 21 and the connecting pipe hole 10, eliminates the blocking of the side wall of the main pipe body 1 to the fluid, and further enables the inner diameter D1 of the vertical connecting pipe connecting end 21 to be close to or larger than the inner diameter D2' of the main pipe body 1 at the connecting pipe hole 10. Specifically, D1/D2' may be 1.0,1.2,1.25,1.3,1.4 equal proportional. However, the present utility model is not limited in any way thereto. In other embodiments, D1/D2' may be any ratio between 1.0 and 1.5. Furthermore, the inclined sections 102 of the pipe bores can also guide the fluid during the diversion or collection so that the fluid can be better distributed onto the vertical pipe 2 or collected from within the vertical pipe 2 into the main pipe body 1.

In this embodiment, the two end connection pipes 31 and 32 are bent pipes and are distributed approximately symmetrically, and the vertical connection pipe 2 is a straight pipe. Fig. 24 is a schematic view showing the structure of a refrigeration circuit assembly including three copper pipe ends 41,42,43 according to the present embodiment. However, the present utility model is not limited in any way thereto. The construction and possible implementation of the vertical connection pipe 2 and the two end connection pipes 31,32 are substantially the same as those of the first embodiment and the variations thereof, and will not be described in detail herein.

In summary, in the novel three-way pipe fitting provided by the utility model, the main pipe body is provided with the connecting pipe hole with the hole depth based on the wall thickness, the wall thickness of the main pipe body at the connecting pipe hole enables the inner peripheral wall of the connecting pipe hole to form a larger brazing surface, and further, the surface brazing connection of the outer peripheral wall of the vertical connecting pipe connecting end is realized. Compared with the traditional self-fluxing type wire-bonding joint, the surface-bonding joint has high joint strength, more excellent pressure resistance and sealing performance and can well bear the high working pressure of a refrigerating system. In addition, the connecting pipe hole structure Kong Shenji on the wall thickness of the main pipe body also enables the main pipe body to realize the forming of the connecting pipe hole by adopting a hole processing technology, and the hole processing technology such as drilling, punching and the like is simple and mature and has small influence on the performance such as ductility, yield strength, hardness and the like of the main pipe body material, thereby providing conditions for selecting the steel material with low cost and high strength for the main pipe body.

Further, in order to reduce the processing difficulty of the connecting pipe hole, the main pipe body is of a split structure comprising a thin-wall pipe body and an inner bushing, and the thin-wall pipe body and the inner bushing are overlapped after being respectively subjected to hole processing, so that the processing difficulty of the connecting pipe hole is greatly reduced while the hole depth requirement of the connecting pipe hole is met. Meanwhile, the independent molding of the thin-wall pipe body and the inner bushing also well solves the problems of high molding difficulty, difficult purchase and high purchase cost of the thick-wall main pipe body. The annular inner bushing has enough contact area to be stably connected to the inner peripheral wall of the thin-wall pipe body after the bushing through hole with the aperture close to or larger than the inner diameter of the bushing through hole is formed. Still further, providing the bushing through-hole includes straight hole section and inclined section, and straight hole section provides the welding depth for perpendicular connecing, and inclined section then has increased the fluid communication space between perpendicular takeover and the main pipe body and guide the fluid, and then makes the internal diameter of perpendicular takeover link accessible even be greater than the internal diameter of main pipe body.

Although the utility model has been described with reference to the preferred embodiments, it should be understood that the utility model is not limited thereto, but rather may be modified and varied by those skilled in the art without departing from the spirit and scope of the utility model.

Claims (13)

1. A novel tee fitting, comprising:

The steel main pipe body is of a combined structure and comprises a thin-wall pipe body and an inner bushing, wherein the cross section of the inner peripheral wall of the thin-wall pipe body is circular or nearly circular, the inner bushing is embedded in the thin-wall pipe body, the outer peripheral wall of the inner bushing is attached to the inner peripheral wall of the thin-wall pipe body, a bushing through hole with the axis vertical or basically vertical to the axis of the thin-wall pipe body is formed in the peripheral wall of the inner bushing, pipe body through holes are correspondingly formed in the thin-wall pipe body, the bushing through holes and the pipe body through holes form a pipe connecting hole together, the overlapped wall thickness T of the thin-wall pipe body and the inner bushing at the pipe connecting hole is 1.5 mm-5 mm, and the inner peripheral wall of the bushing through hole and the inner peripheral wall of the pipe body through hole form a brazing surface of the pipe connecting hole together;

The connecting end of the thin-wall vertical connecting pipe is inserted into a connecting pipe hole on the main pipe body, the ratio of the inner diameter D1 of the connecting end of the vertical connecting pipe to the inner diameter D2 of the inner bushing at the connecting pipe hole is 0.75-1.50, the peripheral wall of the connecting end of the vertical connecting pipe is attached to the brazing surface of the connecting pipe hole in a surface contact manner, and a brazing layer is formed between the two attaching surfaces;

the two thin-wall end connecting pipes are respectively sleeved and welded at the two axial ends of the main pipe body;

Wherein, the thin wall refers to the wall thickness of the pipe fitting is more than or equal to 0.3mm and less than 2.0mm.

2. The novel three-way pipe fitting according to claim 1, wherein 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 comprises a straight hole section and an inclined section formed at the tail 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 peripheral wall of the pipe body through hole and the inner peripheral wall of the straight hole section of the bushing through hole jointly form a brazing surface of the connecting pipe hole.

3. The novel tee fitting of claim 1 wherein the main tubular body comprises an inner liner embedded within the thin walled tubular body or a plurality of inner liners embedded within the thin walled tubular body, the plurality of inner liners being nested one over the other and each having a liner through bore substantially coaxial with the tubular body through bore.

4. The novel three-way pipe fitting according to claim 1, wherein the inner bushing is hollow tubular or is a hollow cylinder which is formed by bending and rolling and has a rolling gap.

5. The novel three-way pipe fitting according to claim 1, wherein the length of the inner bushing is shorter than that of the thin-wall pipe body, two limiting steps for limiting the insertion depth of the end connecting pipes are formed at the end faces of the two ends of the inner bushing, and the two end connecting pipes are respectively sleeved at the two ends of the thin-wall pipe body and abut against the corresponding limiting steps.

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

7. The novel tee fitting of claim 1, wherein the body through hole is a through hole with a hole depth based on a thin wall body wall thickness, or the body through hole is a flanging hole with a flanging straight section.

8. The novel tee fitting of claim 1, wherein a self-fluxing weld and/or braze joint is formed between the thin-walled tube body and the inner liner.

9. The novel three-way pipe fitting according to claim 1, wherein the outer peripheral wall of the thin-walled pipe body is formed with a connection plane, the pipe body through hole is located at the connection plane, and the axis of the pipe body through hole is perpendicular or substantially perpendicular to the connection plane;

Or the cross section of the outer peripheral wall of the thin-wall pipe body is round or nearly round, and the pipe body through hole is formed in the curved outer peripheral wall of the thin-wall pipe body.

10. The novel three-way pipe fitting according to claim 1, wherein the two end connection pipes and the vertical connection pipe are combined pipe fittings formed by combining any one or both of steel pipe fittings and copper pipe fittings, and the two end connection pipes and the vertical connection pipe are any one of straight pipes and bent pipes.

11. A novel tee fitting, comprising:

The main pipe body is an integral steel pipe piece with a circular or nearly circular inner peripheral wall section, a pipe wall of the main pipe body is provided with a pipe connecting hole with an axis vertical or basically vertical to the axis of the main pipe body, the outer peripheral wall of the main pipe body is provided with a connecting plane, the pipe connecting hole is positioned at the connecting plane, or the outer peripheral wall section of the main pipe body is circular or nearly circular, the pipe connecting hole is formed at the curved outer peripheral wall of the main pipe body, the wall thickness of the main pipe body at the pipe connecting hole is 1.5 mm-5 mm, and the inner peripheral wall of the pipe connecting hole forms a brazing surface;

the connecting end of the thin-wall vertical connecting pipe is inserted into a connecting pipe hole on the main pipe body, 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 0.75-1.5, the peripheral wall of the connecting end of the vertical connecting pipe is attached to the brazing surface of the connecting pipe hole in a surface contact manner, and a brazing layer is formed between the two attaching surfaces;

the two thin-wall end connecting pipes are respectively sleeved and welded at the two axial ends of the main pipe body;

Wherein, the thin wall refers to the wall thickness of the pipe fitting is more than or equal to 0.3mm and less than 2.0mm.

12. The novel three-way pipe fitting according to claim 11, wherein the ratio of the inner diameter of the connecting end of the vertical nipple to the inner diameter of the main pipe body at the nipple hole is greater than or equal to 1.0, the nipple hole comprises a straight hole section and an inclined section formed at the end of the straight hole section, the connecting end of the vertical nipple is fitted into the straight hole section of the nipple hole, and the inner peripheral wall of the straight hole section of the nipple hole forms a brazing surface for brazing the connecting end peripheral wall of the vertical nipple.

13. A refrigeration circuit assembly comprising the novel tee fitting of any one of claims 1-12.