Steel three-way pipe fitting and pipeline connecting assembly

Abstract

The utility model provides a steel three-way pipe fitting and a pipeline connecting assembly. The steel three-way pipe fitting comprises a steel connecting piece, at least one guiding piece and three connecting pipes. The connecting piece is provided with an inner cavity with a circular or approximately circular overflowing section, at least one welding plane which is approximately parallel to the axis of the inner cavity of the connecting piece or is obliquely distributed relative to the axis of the inner cavity of the connecting piece is formed on the peripheral wall of the connecting piece, and each welding plane is provided with a pipe connecting hole communicated with the inner cavity. And at least one pipe connecting hole and at least one end part of the connecting piece form three pipe connecting ends of the connecting piece. At least one guiding piece is welded to the corresponding welding plane on the connecting piece in an attached mode, a pipe connecting hole is formed in the corresponding welding plane through the guiding piece, and the wall thickness T of the position, where the pipe connecting hole is located, of the connecting piece is larger than or equal to 0.8 mm and smaller than or equal to 5 mm so that a brazing face can be formed on the inner circumferential wall of the pipe connecting hole. The three connecting pipes are all thin-wall pipe fittings and are welded to the three connecting pipe ends of the connecting piece respectively. Wherein the connecting end of the connecting pipe connected with the connecting pipe hole is inserted into the connecting pipe hole through the guide piece, and another brazing surface is formed on the outer peripheral wall of the connecting end so as to be brazed on the brazing surface formed on the inner peripheral wall of the connecting pipe hole.

Description

Technical Field

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

[0002] In the refrigeration system, tee pipe fittings are usually required to connect the pipes to achieve the distribution of refrigerant. Existing tee pipe fittings are mostly made of copper, which is a precious metal. As its market price continues to rise, the cost of copper tee pipe fittings is also getting higher and higher. Based on the development of refrigeration system accessories, the development of tee pipe fittings that use low-cost steel materials instead of copper materials has become a research and development direction for technicians in this field.

[0003] The existing copper tee pipe fittings mainly have three structures: U-type, Y-type and fork-type, as shown in the figure below: Figure 1 (a) Figure 1 (b) and Figure 1 As shown in (c), there are two main processing methods for existing copper tee pipe fittings: one is to use the excellent physical properties of copper materials (such as high ductility and low hardness) to migrate the tube blank material to form a pipe assembly section, such as the main pipe assembly section formed by punching and flanging or the inclined branch pipe assembly section formed by internal high pressure forming; the other is to hot forge the copper material and then finely process the pipe assembly section. 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 lead to steel materials not only being much more difficult to form and migrate in internal high pressure than copper materials, but also the pipe assembly section formed by the migration of steel materials under the same conditions is also shorter than that of copper materials (the flanging height is very short, and the length of internal high pressure forming is also very short), making it difficult to meet the brazing requirements; especially when the pipe diameter of the pipe is close to the pipe diameter of the tube blank, the migration of the tube blank material will be more difficult to achieve. In addition, for U-shaped and Y-shaped tee pipe fittings, since the pipe assembly section is just located at the bend of the tube blank, the curvature of the bend will also hinder the migration of steel materials and further affect the forming of the pipe assembly section. Similarly, for hot forging, steel materials with poor ductility not only require large processing equipment and high energy consumption, but also cause the steel material to stick to the tool during subsequent finishing, resulting in excessive tool wear and low processing efficiency. In other words, the existing copper tee pipe structure will be difficult to process and form after the material is replaced with steel.

[0004] To this end, some people have proposed to use punching and welding to form stainless steel three-way pipe fittings, such as Figure 1AAs shown, the main pipe fitting 60 is provided with an intersecting line hole 601, and the end of the connecting pipe 70 is self-meltingly welded to the intersecting line hole 601. The intersecting line hole 601 is a curved structure and the weld formed by self-melting welding is a line weld. This curved surface welded line weld or butt welded line weld has safety hazards such as low connection strength and poor pressure resistance in the refrigeration pipeline with a design working pressure of 4.15MPa, and is difficult to apply; in fact, for reliability considerations, the welding of pipe fittings on the refrigeration pipeline is generally designed to be mainly brazed. In order to solve the problem of low welding strength of curved surface self-melting line welds, Chinese patent CN210566894U proposes an inclined tee stainless steel pipe fitting with a reinforcement member. The structure hopes to strengthen the strength of the curved surface weld by setting a reinforcement member at the welding point between the straight pipe and the inclined pipe. However, in this structure, the welding between the second groove at the end face of the special-shaped connection part of the inclined tube and the first groove on the special-shaped connection hole of the straight tube belongs to the form of a corner joint, and the weld formed by the two is still a line weld, which has the problems of low welding strength and poor pressure resistance. The reinforcement is only coated on the welding point of the straight tube and the inclined tube. This simple coating has little effect on the improvement of the pressure bearing capacity and sealing of the line weld; for this reason, the structure also needs to use an acrylic resin adhesive layer to further seal the reinforcement, but in the field of refrigeration, the pressure resistance of the adhesive layer is obviously difficult to meet the high working pressure of 4.15MPA. In addition, in this structure, the first reinforcement and the second reinforcement are welded and fixed on the straight tube and the inclined tube respectively. Combined with the welding of the inclined tube, the structure needs to be welded at least twice (or even three times). Not only is the welding process complicated, but also the problem of weld leakage at the welding groove caused by secondary welding must be considered. In addition, for Y-type and U-type tee pipe fittings, it is extremely difficult to open the intersecting line hole at the bend of the tube embryo; and further, since the deformation rate of the tube embryo will inevitably fluctuate within a certain range when it is bent, the fluctuation of the deformation rate will make it difficult for the arc surface on the first reinforcement member and the second reinforcement member to fit the outer peripheral wall of the bend of the tube embryo, resulting in an assembly gap, which in turn makes it difficult to weld the reinforcement members. Therefore, due to the limitations of the above-mentioned many factors, the structure of Chinese patent CN210566894U will be difficult to apply to steel tee pipe fittings for refrigeration systems. Utility Model Content

[0005] In order to overcome at least one disadvantage of the prior art, the utility model provides a steel three-way pipe fitting and a refrigeration assembly.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a steel three-way pipe fitting, which includes a steel connector, at least one guide and three pipes. The connector has an inner cavity with a flow cross-section that is circular or nearly circular, and the outer peripheral wall of the connector is formed with at least one welding plane that is roughly parallel to the axis of the inner cavity of the connector or is inclined relative to the axis of the inner cavity of the connector. Each welding plane has a pipe hole connected to the inner cavity, and at least one pipe hole and at least one end of the connector constitute three pipe ends of the connector. At least one guide is welded to the corresponding welding plane on the connector, and a pipe hole is opened on the corresponding welding plane through the guide. The wall thickness T of the connector at the location of the pipe hole satisfies 0.8mm≤T≤5mm so that the inner peripheral wall of the pipe hole forms a brazing surface. The three pipes are all thin-walled pipes and are respectively welded to the three pipe ends of the connector. Among them, the pipe connected to the pipe hole: its connecting end is inserted into the pipe hole through the guide and the outer peripheral wall of the connecting end forms another brazing surface to be brazed to the brazing surface formed by the inner peripheral wall of the pipe hole.

[0007] According to one embodiment of the utility model, the assembly end face of the guide piece is welded to the welding plane, the guide piece is any one of a tubular, columnar or plate-like structure, and has a guide channel preformed or formed together with the pipe hole, and the pipe hole is formed on the welding plane through the guide channel.

[0008] According to one embodiment of the utility model, the outer peripheral wall of the connecting end of the connecting pipe connected to the connecting pipe hole is also welded to the inner peripheral wall of the guide channel by surface brazing, and the entire or partial length of the guide channel and the hole depth of the connecting pipe hole together provide the welding depth for the connecting pipe.

[0009] According to one embodiment of the utility model, the connecting piece is in the shape of a tube with open ends, a welding plane roughly parallel to the axis of the inner cavity of the connecting piece is formed on the outer peripheral wall of the connecting piece, and a connecting pipe hole with an axis obliquely intersecting with the axis of the inner cavity of the connecting piece is formed on the welding plane, and the connecting pipe hole and the two ends of the connecting piece constitute the three connecting pipe ends of the connecting piece.

[0010] According to an embodiment of the utility model, the two connecting pipes arranged at both ends of the connecting piece are integral thin-walled pipes, which are welded inside the connecting piece and have through holes connected to the connecting pipe holes;

[0011] Alternatively, the three connecting pipes are all split pipe fittings and are respectively sleeved and connected to the three connecting pipe ends of the connecting piece.

[0012] According to one embodiment of the utility model, the connecting piece has a single-end open structure, and two welding planes located on both sides of the axis of the inner cavity of the connecting piece and roughly parallel to the axis of the inner cavity of the connecting piece are formed on the outer peripheral wall of the connecting piece. A connecting pipe hole is formed on each welding plane, and the axis intersects the axial direction of the open end of the connecting piece at an obtuse angle. The two connecting pipe holes and the open end of the connecting piece constitute the three connecting pipe ends of the connecting piece.

[0013] According to one embodiment of the utility model, the connector has a single-end open structure, and two welding planes are formed on the outer peripheral wall of the connector near the closed end, which are located on both sides of the axis of the inner cavity of the connector and are inclined relative to the axis of the inner cavity of the connector. Each welding plane is provided with a connecting pipe hole whose axis intersects with the axis of the open end of the connector at an obtuse angle, and the two connecting pipe holes and the open end of the connector constitute the three connecting pipe ends of the connector.

[0014] According to an embodiment of the present invention, a flow dividing portion which is substantially planar or protrudes toward the open end and is conical is formed on the inner wall of the closed end of the connecting piece.

[0015] According to one embodiment of the utility model, the connecting piece is an integral pipe piece with a welding plane on the outer peripheral wall;

[0016] Alternatively, the connecting piece is a split structure and includes a tubular body with a circular outer wall cross-section and a bushing arranged on the outer wall of the tubular body, one side of the bushing is arc-shaped to fit the outer wall of the tubular body and the arc length of the bushing in the circumferential direction is greater than 1 / 2 of the circumference of the outer wall of the tubular body, and the other side of the bushing forms a welding plane; when opening a connecting pipe hole, a bushing hole is opened at the welding plane through the guide and a corresponding connecting pipe hole is opened on the tubular body, and the connecting end of the connecting pipe is inserted into the connecting pipe hole on the tubular body through the guide and the bushing hole and brazed.

[0017] According to an embodiment of the utility model, each connecting pipe is any one of a straight pipe or a curved pipe; each connecting pipe is any one of a copper pipe fitting and a steel pipe fitting or a combination of the two.

[0018] On the other hand, the utility model also provides another steel three-way pipe fitting, which includes a steel connecting piece and three connecting pipes. The connecting piece has an inner cavity with a flow cross-section that is circular or nearly circular, and the outer peripheral wall of the connecting piece is formed with at least one welding plane that is roughly parallel to the axis of the inner cavity of the connecting piece or is inclined relative to the axis of the inner cavity of the connecting piece, and each welding plane has a connecting pipe hole connected to the inner cavity, and the wall thickness T of the connecting piece at the location of the connecting pipe hole satisfies 1.5mm≤T≤5mm so that the inner peripheral wall of the connecting pipe hole forms a brazing surface, and at least one connecting pipe hole and at least one end of the connecting piece constitute three connecting pipe ends of the connecting piece. The three connecting pipes are all thin-walled pipes and are respectively welded to the three connecting pipe ends of the connecting piece. Among them, the connecting pipe connected to the connecting pipe hole: its connecting end is inserted into the connecting pipe hole and the outer peripheral wall of the connecting end forms another brazing surface to be brazed to the brazing surface formed by the inner peripheral wall of the connecting pipe hole.

[0019] According to one embodiment of the utility model, the connecting piece is in the shape of a tube with open ends at both ends, a welding plane substantially parallel to the axis of the inner cavity of the connecting piece is formed on the outer peripheral wall of the connecting piece, and a pipe connecting hole with an axis obliquely intersecting the axis of the inner cavity of the connecting piece is formed on the welding plane, and the pipe connecting hole and the two ends of the connecting piece constitute three pipe connecting ends of the connecting piece;

[0020] Alternatively, the connector has a single-end open structure, and two welding planes are formed on the outer peripheral wall of the connector, which are located on both sides of the axis of the connector's inner cavity and are roughly parallel to the axis of the connector's inner cavity. Each welding plane is provided with a connecting pipe hole whose axis intersects the axial direction of the open end of the connector at an obtuse angle. The two connecting pipe holes and the open end of the connector constitute the three connecting pipe ends of the connector.

[0021] According to one embodiment of the utility model, the steel tee pipe fitting also includes a lining plate welded on the welding plane, a lining plate hole corresponding to the connecting pipe hole is formed on the lining plate, the connecting end of the connecting pipe is inserted into the connecting pipe hole through the lining plate hole and is brazed and connected to the inner circumferential wall of the lining plate hole and the inner circumferential wall of the connecting pipe hole respectively.

[0022] According to one embodiment of the utility model, the connector has a single-end open structure, and two welding planes located on both sides of the axis of the inner cavity of the connector are formed on the outer peripheral wall of the connector near the closed end. Each welding plane is inclined relative to the axis of the inner cavity of the connector and is provided with a connecting pipe hole whose axis intersects the axial direction of the open end of the connector at an obtuse angle. The two connecting pipe holes and the open end of the connector constitute the three connecting pipe ends of the connector.

[0023] On the other hand, the utility model also provides a pipeline connection assembly including the above-mentioned steel three-way pipe fitting.

[0024] In summary, a welding plane is formed on the outer peripheral wall of the connecting piece in the steel three-way pipe fitting provided by the utility model, and the welding plane provides a reference plane for the opening of the pipe hole so that the outer peripheral wall of the connecting piece can open the pipe hole to realize the connection of the pipe. The setting of the wall thickness T of the connecting piece at the pipe hole makes the inner peripheral wall of the pipe hole form a brazing surface to be brazed to the outer peripheral wall of the connecting end of the pipe. Compared with the traditional self-melting wire weld connection, the surface brazing connection of the pipe 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. Furthermore, when welding the pipe, the welding plane also carries the solder to avoid the flow welding problem caused by the solder hanging in the air, ensuring that the pipe has good connection strength everywhere in the circumferential direction after brazing. In terms of processing technology, the steel three-way pipe fitting provided by the utility model only needs to use a simple hole processing technology (such as drilling or punching) to open the pipe hole on the welding plane; and the hole processing technology does not need to involve the migration of the pipe, nor does it need to be hot forging and other treatments, so it is very suitable for the processing of steel materials.

[0025] Furthermore, a guide is provided on the welding plane, and the axis of the drilling tool can be substantially coaxial with the axis of the guide during drilling, thereby greatly improving the drilling accuracy and reducing the difficulty of drilling; at the same time, the setting of the welding plane also provides a basis for the smooth connection of the guide. In addition, the setting of the guide also allows the inner circumferential wall of the connecting end of the pipe to be brazed and connected to the inner circumferential wall of the guide channel to further improve the connection strength and pressure resistance of the pipe.

[0026] 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

[0027] Figure 1 Shown are three structural schematic diagrams of existing copper tee pipe fittings: U-type, Y-type and fork-type.

[0028] Figure 1A The figure shows a structural schematic diagram of a steel three-way pipe fitting formed by welding intersecting line holes in the prior art.

[0029] Figure 1B The figure shows the principle schematic diagram of flow welding when a connecting hole is opened on the curved peripheral wall of an existing three-way pipe fitting for brazing.

[0030] Figure 2 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in Embodiment 1 of the present utility model.

[0031] Figure 3 Shown Figure 2 Assembly diagram of the connecting parts and guide parts.

[0032] Figure 4 Shown Figure 3 Schematic diagram of the structure from another perspective.

[0033] Figure 5 Shown Figure 2 Schematic diagram of the structure of the connecting parts.

[0034] Figure 6 Shown is a schematic diagram of the processing of the guide part.

[0035] Figure 7 Shown Figure 2 Schematic diagram of the structure in which local self-fluxing welding is performed after the middle connecting part and the guide part are assembled.

[0036] Figure 8 Shown Figure 2 Schematic diagram of the structure of the annular seam self-fluxing welding after the middle connecting part and the guide part are assembled.

[0037] Fig. 9 and Fig.10 Shown is a schematic diagram of the assembly of a connecting member and a guiding member in another embodiment of the utility model.

[0038] Fig.11 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in another embodiment of the utility model.

[0039] Fig.12 Shown is a schematic structural diagram of a pipeline connection assembly provided in Embodiment 1 of the present utility model.

[0040] Fig.13 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in Embodiment 2 of the present utility model.

[0041] Fig.14 Shown Fig.13 Assembly diagram of the middle connecting piece and two guide pieces.

[0042] Fig.15 Shown Fig.14 Schematic diagram of the structure from another perspective.

[0043] Fig.16 Shown Fig.13 Schematic diagram of the structure of the connecting parts.

[0044] Fig.17 Shown Fig.16 Schematic diagram of the structure from another perspective

[0045] Fig.18 Shown is a schematic diagram of the assembly of a connecting member and two guide members in another embodiment of the utility model.

[0046] Fig.19 Shown is a schematic structural diagram of a pipeline connection assembly provided in Embodiment 2 of the present utility model.

[0047] Fig. 20 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in Embodiment 3 of the present utility model.

[0048] Fig.21 Shown Fig. 20 Assembly diagram of the middle connecting piece and two guide pieces.

[0049] Fig. 22 Shown Fig.21 Schematic diagram of the structure from another perspective.

[0050] Fig.23 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in another embodiment of the utility model.

[0051] Fig.24 Shown is a schematic structural diagram of a pipeline connection assembly provided in Embodiment 3 of the present utility model.

[0052] Fig.25 Shown is a schematic diagram of the assembly of the connecting member and the guiding member provided in the fourth embodiment of the present utility model.

[0053] Fig.26 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in Embodiment 5 of the present utility model.

[0054] Fig. 27 Shown Fig.26 Assembly diagram of the connecting parts and lining plates.

[0055] Fig.28 Shown Fig.26 Schematic diagram of the structure of the connecting parts.

[0056] Fig.29 Shown is a schematic structural diagram of a pipeline connection assembly provided in Embodiment 5 of the present utility model.

[0057] Fig.30 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in Embodiment 6 of the present utility model.

[0058] Fig.31 Shown Fig.30 Assembly diagram of the connecting parts and lining plates.

[0059] Fig.32 Shown is a schematic structural diagram of a pipeline connection assembly provided in Embodiment 5 of the present utility model.

[0060] Fig.33 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in Embodiment 7 of the present utility model.

[0061] Fig.34 Shown Fig.33 Schematic diagram of the structure of the connecting parts.

[0062] Fig.35 Shown is a schematic structural diagram of a steel three-way pipe fitting provided in another embodiment of the utility model.

[0063] Fig.36 Shown is a schematic structural diagram of a pipeline connection assembly provided in Embodiment 5 of the present utility model. DETAILED DESCRIPTION

[0064] Embodiment 1

[0065] The low ductility, high yield strength and high hardness of steel make it difficult to form a pipe assembly section that meets the brazing strength requirements through material migration when replacing copper materials to form steel tee pipe fittings. Hot forging and fine processing will lead to problems such as high energy consumption, low processing efficiency and material waste. Therefore, the existing steel tee pipe fittings can only be Figure 1A As shown, the self-fluxing wire weld is used to weld the pipe; however, due to the limitations of the strength and pressure resistance of the self-fluxing wire weld, Figure 1A This type of steel three-way pipe fitting can only be used in low-pressure water pipe systems with a pressure resistance lower than 2.5MPa, and cannot be used in refrigeration systems with a pressure as high as 4.15MPa.

[0066] In view of this, the present embodiment provides a steel three-way pipe fitting whose processing technology is almost not limited by the low ductility, high yield strength and high hardness of steel material and whose pipes are connected by surface brazing. The steel three-way pipe fitting provided in the present embodiment includes a steel connector 1, at least one guide 2 and three pipes 31, 32, 33. The connector 1 has an inner cavity with a circular or nearly circular flow cross-section, and the outer peripheral wall of the connector 1 is formed with at least one welding plane that is roughly parallel to the axis of the inner cavity of the connector 1 or is inclined relative to the axis of the inner cavity of the connector 1. Each welding plane has a pipe hole connected to the inner cavity, and at least one pipe hole and at least one end of the connector 1 constitute three pipe ends of the connector. At least one guide 2 is welded to the corresponding welding plane on the connector 1, and a pipe hole is opened on the corresponding welding plane through the guide 2. The wall thickness T of the connector at the pipe hole satisfies 0.8mm≤T≤5mm so that the inner peripheral wall of the pipe hole forms a brazing surface 100. The three connecting pipes 31, 32, 33 are thin-walled pipes and are respectively welded to the three connecting pipe ends of the connecting member 1. Among them, the connecting pipe connected to the connecting pipe hole: its connecting end is inserted into the connecting pipe hole through the guide member and the outer peripheral wall of the connecting end forms another brazing surface 200 to be brazed to the brazing surface 100 formed by the inner peripheral wall of the connecting pipe hole.

[0067] In this embodiment, thin-walled pipe fittings refer to pipe fittings with a wall thickness greater than or equal to 0.3 mm and less than or equal to 2.0 mm, such as pipe fittings with a wall thickness of 0.5 mm, 1.0 mm, 1.2 mm, 1.5 mm, and 1.8 mm. The wall thickness T of the connecting piece at the pipe hole can be any value within the range of 0.8 mm to 5 mm, such as 1.0 mm, 1.2 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, and 4.5 mm.

[0068] Specifically, Figures 2 to 5 As shown, the connector 1 is a tubular shape with open ends. A welding plane 11 roughly parallel to the axis of the inner cavity of the connector 1 is formed on the outer peripheral wall of the connector 1, and a pipe hole 12 with an axis obliquely intersecting the axis of the inner cavity of the connector 1 is opened on the welding plane 11. The pipe hole 12 and the two ends of the connector 1 constitute the three pipe ends of the connector. Three thin-walled pipes 31, 32, and 33 are welded and connected to the pipe hole 12 and the two ends of the connector 1, respectively. However, the utility model does not make any limitation to this. In other embodiments, as shown in embodiments two and three, two welding planes can also be opened on the outer peripheral wall of the connector to form two pipe holes, and the three pipe ends of the connector are formed based on the two pipe holes and the open end of the connector.

[0069] In the steel three-way pipe fitting provided in this embodiment, three thin-walled pipes are connected to the two ends of the connector 1 and the three pipe ends formed by the pipe hole 12; this structure allows the connector 1 to be processed by opening the pipe hole 12. The setting of the welding plane 11 provides a reference surface for the hole opening process, so that the pipe hole 12 can be processed and formed by a simple and mature hole processing process, such as punching or drilling, which effectively solves the problem that it is difficult to open a hole on the curved wall of a circular pipe fitting. Further, the hole processing process does not involve the migration of the pipe material, and it is less affected by the physical properties of the material such as ductility, yield strength and hardness. Therefore, the connector 1 in the steel three-way pipe fitting provided in this embodiment can be processed with low-cost steel materials. Further, by controlling the wall thickness T of the connector 1 at the pipe hole 12, the inner peripheral wall of the pipe hole is formed with a large area of ​​brazing surface 100 based on the wall thickness T to form another brazing surface 200 formed by brazing the outer peripheral wall of the pipe 33. This arrangement realizes the surface brazing connection between the connecting pipe 33 and the connecting pipe hole 12, greatly improving the connection strength and pressure resistance of the connecting pipe 33 after welding so that the steel three-way pipe fitting can be well used in refrigeration systems with high working pressure.

[0070] In addition, in the existing copper tee pipe fittings that form the pipe assembly section by material migration, the wall thickness of the copper tube blank is usually thicker so that part of the material can migrate to the pipe assembly section, and the increase in wall thickness will inevitably lead to a significant increase in copper material costs, especially when the length of the pipe is long (such as forming a branch pipe), the increase in the wall thickness of the tube blank will lead to a sharp increase in material costs. In the steel tee pipe fitting provided in this embodiment, the split structure of the connector 1 and the three pipes 31, 32, 33 allows the wall thickness of the connector 1 and the three pipes to be set independently, and the wall thickness of the connector 1 can be set thicker so that the wall thickness T at the pipe hole 12 can provide a sufficiently large brazing surface 100 for the welding of the pipe 33, while the three pipes 31, 32, 33 only need to consider the system pressure bearing capacity and use thin-walled pipe fittings to further reduce material costs.

[0071] The forming of the pipe hole 12 on the connector 1 is the basis of the steel three-way pipe fitting provided in this embodiment. The processing of the pipe hole on the curved peripheral wall is not only difficult to position the hole processing tool itself, but also difficult to align the axis of the pipe hole during processing. Figure 1B As shown, the edge of the pipe hole opened on the curved peripheral wall is also a curved structure. The height difference on the curved surface will cause the brazing material to be partially suspended (as shown in A in the figure), and the brazing material in the suspended part after melting (as shown by the dotted line) will flow along the curved outer wall of the connector under the action of gravity F, that is, it is difficult for the solder to enter the pipe hole, which will lead to the problem of cold welding and broken welding between the brazing surface 100 and the other brazing surface 200. In order to solve the problem of difficult processing of the pipe hole 12 on the curved surface and curved surface flow welding during brazing, the outer peripheral wall of the connector 1 is provided with a welding plane 11 in this embodiment, and the pipe hole 12 is located on the welding plane 11. When processing the pipe hole 12, the welding plane 11 provides a reference surface for the hole processing tool to facilitate the positioning of the tool. When opening the hole, the axis of the pipe hole 12 can be calibrated based on the welding plane 11 so that the axis of the pipe hole 12 is basically perpendicular to the welding plane 11, thereby greatly improving the accuracy of the hole opening and reducing the difficulty of the hole opening. The edge of the connecting hole 12 opened by the welding plane 11 is a planar structure. During brazing, the welding plane 11 supports the brazing material to prevent the brazing material from being suspended in the air, so that the brazing material in each circumferential part of the connecting hole 12 is only penetrated by the capillary traction of the welding gap between the two brazing surfaces, ensuring that the welding gap is filled with sufficient solder at each circumferential part, thereby effectively solving the flow soldering problem existing in curved surface brazing.

[0072] In order to further improve the opening accuracy of the pipe hole 12, the steel three-way pipe fitting provided in this embodiment also includes a guide member 2 welded to the welding plane 11. When the pipe hole 12 is opened, the operating direction of the hole processing tool is guided based on the axis of the guide member 2, and at the same time, the peripheral wall of the conducting channel 22 on the guide member 2 will also limit the hole processing tool to avoid the processing error caused by the deviation of the hole processing tool; the processing accuracy of the pipe hole 12 is further improved and the processing difficulty is further reduced from the two aspects of guidance and limitation.

[0073] In this embodiment, the assembly end face 21 of the guide member 2 is welded to the welding plane 11, and the surface-fitting connection method enables the guide member 2 to be stably fixedly connected to the welding plane 11, that is, the welding plane 11 provides support for the guide member 2 so that it can accurately guide the hole processing tool. In this embodiment, the connecting hole 12 is an inclined hole whose axis is inclined to intersect with the axis of the inner cavity of the connecting member 1; correspondingly, the assembly end face 21 of the guide member 2 is also inclined to fit the welding plane 11. However, the utility model does not impose any limitation on this. In other embodiments, when the welding plane is inclined, the assembly end face of the guide member can be roughly parallel to the welding plane to achieve fit welding.

[0074] In this embodiment, the guide member 2 is a hollow column with a preformed guide channel 22. When processing the pipe hole 12, a hole processing tool (such as a drilling tool or a punching tool) extends into the guide channel 22 and abuts against the welding plane 11 of the connector 1. Based on the axial guidance of the guide channel 22 and the limitation of its peripheral wall, the pipe hole 12 is processed on the welding plane 11. Preferably, the guide member 2 is a hollow cold-forged part formed by cold-forging, and the middle part of the cold-forged part is cut to form two guide members 2 with inclined assembly end faces 21, such as Figure 6 As shown, this arrangement greatly simplifies the forming process of the guide member 2. However, the present invention does not impose any limitation on this. In other embodiments, the guide member may also be a hollow tubular or hollow plate structure with a preformed guide channel, and the hole processing tool may also be a drilling tool or a punching tool. Alternatively, in other embodiments, the guide member may also be a solid column or solid plate, and the hole processing tool is a drilling tool. The drilling tool opens a guide channel on the solid column or solid plate guide member, and then processes the pipe hole through the guide channel.

[0075] Specifically, the assembly end face 21 of the guide member 2 is fixed to the welding plane 11 by a self-fluxing weld, and then the pipe hole 12 is processed, and then three pipes 31, 32, 33 are assembled; finally, the connector 1, the guide member 2 and the three pipes 31, 32, 33 are integrally welded by furnace brazing, and a brazing seam for sealing the guide member 2 is formed between the assembly end face 21 of the guide member 2 and the welding plane 11. The pre-fixation of the self-fluxing weld and the sealing connection of the brazing seam not only greatly improve the connection strength between the guide member 2 and the welding plane 11, but also make the guide member 2 and the connector 1 an integral sealing component, so that the entire product has better sealing. However, the utility model does not make any limitation to this. The main function of the guide member 2 is to improve the accuracy of the pipe hole 12 and reduce its difficulty in opening, so the guide member 2 and the connector 1 do not necessarily have to be sealed. In other embodiments, the assembly end surface of the guide member may be fixed to the welding plane via a local or annular self-melting weld to facilitate pipe hole processing. The local self-melting weld includes a plurality of spot welds or a plurality of line welds distributed along the circumference. Figure 7 The guide assembly end face is shown to be fixed to the welding plane 11 via a local self-melting weld 400. Figure 8 As shown, the assembly end surface of the guide member is fixed to the welding plane 11 via an annular self-melting weld 400'.

[0076] Based on the sealed brazing connection of the guide member 2 and the connector 1 in this embodiment, a connecting pipe 33 connected to the connecting pipe hole 12 is further provided, and the outer peripheral wall 331 of the connecting end is also welded to the inner peripheral wall of the guide channel 22 by surface brazing. The entire or partial length of the guide channel 22 and the hole depth of the connecting pipe hole 12 together provide the welding depth for the connecting pipe 33. That is, the outer peripheral wall 331 of the connecting end of the connecting pipe 33 is simultaneously connected to the inner peripheral wall of the connecting pipe hole 12 and the inner peripheral wall of the guide channel 22 by surface brazing. This arrangement increases the brazing area of ​​the connecting pipe 33 to further improve the connection strength and sealing of the connecting pipe 33 after brazing. However, the utility model does not make any limitation to this. In other embodiments, the outer peripheral wall of the connecting end of the connecting pipe 33 can also be only brazed to the inner peripheral wall of the connecting pipe hole 12.

[0077] In this embodiment, the connector 1 is also a hollow part with a peripheral wall formed by cold heading and having a welding plane 11. Specifically, the cross section of the peripheral wall of the connector 1 is a pentagon and one of the planes is used as the welding plane 11. In the present invention, the connector 1 only needs to be formed with a welding plane 11 for processing the pipe hole 12, and the present invention does not impose any restrictions on the structure of the connector outside the welding plane 11. In other embodiments, the cross section of the peripheral wall of the connector 1 can also be other polygonal structures, such as a square (such as Fig. 9 As shown) or hexagonal, or there is only one welding plane 11 and the other parts are still arc surfaces, such as Fig.10 Similarly, although this embodiment is described by taking the example that the welding plane extends to both ends of the connector, the present invention does not make any limitation to this. In other embodiments, the welding plane may also be located in the middle area of ​​the outer peripheral wall of the connector, while the outer peripheral walls at both ends of the connector are still circular or nearly circular.

[0078] In this embodiment, the three pipes 31, 32, 33 are split pipes that are respectively sleeved and connected to the three pipe ends of the connector 1. However, the present invention does not make any limitation to this. Fig.11 As shown, the two pipes 31 and 32 provided at both ends of the connector 1 can also be integral thin-walled pipes, which are welded in the connector 1 and have a through hole 30 formed thereon that is connected to the pipe hole 12. This arrangement only requires welding of the pipe 33, which can further reduce the welding points of the product and effectively reduce the leakage rate of the steel tee pipe.

[0079] In this embodiment, the connector 1 and the guide 2 are both steel parts. In order to ensure the corrosion resistance of the key welding connection parts (such as the welding connection of the pipe 33), 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 connecting member and the guiding member may also be made of other steel materials with a Cr content of not less than 5% according to the application environment.

[0080] In this embodiment, the three pipes 31, 32, and 33 are also steel pipes with a Cr content of not less than 5%. After the three pipes are assembled, they are brazed in a copper furnace with the connector 1 and the guide 2 to form an integral body. However, the present invention does not make any limitation to this. In other embodiments, the three pipes can also be copper pipes or a combination of copper and steel pipes. After the three pipes are assembled, they can also be brazed in a tin bronze solder furnace with the connector and the guide 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 and steel pipes.

[0081] In this embodiment, the connecting pipe 31 and the connecting pipe 32 are straight pipes, and the connecting pipe 33 is a curved pipe. However, the present invention does not make any limitation to this. In other embodiments, each connecting pipe can be any one of a straight pipe and a curved pipe.

[0082] Correspondingly, such as Fig.12 As shown, this embodiment also provides a pipeline connection assembly, which is a branch pipe, which includes the steel tee pipe fitting provided in this embodiment and three copper pipe sections, the copper pipe section 41 and the pipe section 31 together constitute the main pipe 100 of the branch pipe, the copper pipe section 42 and the pipe section 32 constitute one of the branch pipes 200, and the copper pipe section 43 and the pipe section 33 constitute another branch pipe 300 of the branch pipe. The extension length of the main pipe 100 is greater than or equal to twice the outer diameter D of the pipe section 32 at the end of the connector 1, and the extension length of at least one of the branch pipe 200 and the other branch pipe 300 is greater than four times the outer diameter D of the pipe section 32 at the end of the connector 1. The extension length L1 of the main pipe 100 refers to the vertical distance from the end of the connector 1 where the connector 31 is located to the end of the copper connector section 41; the extension length L2 of the branch pipe 200 refers to the vertical distance from the end of the connector 1 where the connector 32 is located to the end of the copper connector section 42; the extension length L3 of the other branch pipe 300 refers to the vertical distance from the end of the guide member 2 to the end of the copper connector section 43.

[0083] Although this embodiment is described by taking the pipe connection assembly as a branch pipe as an example. However, the present invention does not impose any limitation on this. The steel three-way pipe fitting provided in this embodiment can also be combined with other components in the pipe system to form other pipe connectors. In addition, although this embodiment takes the application of the steel three-way pipe fitting in 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 steel three-way pipe fitting provided by the present invention is also applicable to other pipe systems with lower working pressures, such as low-pressure water pipe systems.

[0084] Embodiment 2

[0085] This embodiment is basically the same as the first embodiment and its variations, except that: Fig.13As shown, in the steel three-way pipe fitting provided in this embodiment, the connector 1 is a single-end open structure, and two welding planes 11, 11' are formed on the outer peripheral wall of the connector 1, which are located on both sides of the inner cavity axis of the connector 1 and are roughly parallel to the inner cavity axis of the connector 1. The steel three-way pipe fitting includes two guide members 2, 2', and a pipe hole 12 whose axis intersects the axial direction of the open end of the connector 1 at an obtuse angle α1 is opened on the welding plane 11 through the guide member 2; and a pipe hole 12' whose axis intersects the axial direction of the open end of the connector 1 at an obtuse angle α2 is opened on the welding plane 11' through another guide member 2'. The two pipe holes 12, 12' and the open end of the connector 1 together constitute the three pipe ends of the connector 1, the pipe 31 is connected to the open end of the connector 1, and the pipe 32 and the pipe 33 are respectively connected to the two pipe holes 12, 12'.

[0086] In this embodiment, the axes of the two connecting holes 12, 12' are roughly symmetrically distributed on both sides of the inner cavity axial direction of the connector 1, that is, the obtuse angle α1 is close to the obtuse angle α2. However, the present invention does not make any limitation to this. In other embodiments, the two connecting holes can also be arranged to be asymmetrically distributed. Compared with the first embodiment, the steel three-way pipe fitting provided in this embodiment is a three-way pipe fitting that splits flow to both sides and has a roughly Y-shaped structure.

[0087] In this embodiment, if Fig.15 and Fig.17 As shown, the cross section of the peripheral wall of the connecting member 1 is square, and two opposite planes thereof form welding planes 11, 11'. However, the present invention does not impose any limitation on the shape of the peripheral wall of the connecting member outside the two welding planes.

[0088] Basically the same as the first embodiment, the assembly end faces 21, 21' of the two guide members are inclined to fit and weld to the corresponding welding plane, and the two guide members 2, 2' are hollow columns with preformed guide channels 22, 22'. However, the present invention does not impose any limitation on this. With respect to other possible molding methods of the guide members and the welding connection methods between the guide members and the connectors, this embodiment is basically the same as the first embodiment and its variations. Similarly, with respect to the structure of the three connecting pipes and the possible implementation methods, this embodiment is also basically the same as the first embodiment and its variations, and will not be elaborated here.

[0089] like Fig.14 and Fig.16 As shown, the opening of the two connecting holes 12, 12' enables the inner wall of the closed end of the connector 1 to form a conical flow divider 13 protruding toward the open end. The conical flow divider 13 quickly and evenly distributes the fluid input from the open end of the connector 1 to the two connecting holes 12, 12' to improve the uniformity of the flow divider. However, the present invention does not make any limitation to this. In other embodiments, such as Fig.18As shown, the inner cavity length of the connecting member 1 can also be increased so that the inner wall of the closed end of the connecting member 1 is formed with a substantially planar flow dividing portion 13 ′.

[0090] Correspondingly, such as Fig.19 As shown, this embodiment also provides a pipeline connection assembly, which is a branch pipe, which includes the steel tee pipe fitting and three copper pipe sections provided in this embodiment, the copper pipe section 41 and the pipe section 31 together constitute the main pipe 100 of the branch pipe, the copper pipe section 42 and the pipe section 32 constitute one of the branch pipes 200, and the copper pipe section 43 and the pipe section 33 constitute another branch pipe 300 of the branch pipe. Among them, the extension length of the main pipe 100 is greater than or equal to twice the outer diameter D of the pipe section 32 at the end of the connector 1, and the extension length of at least one of the branch pipe 200 and the other branch pipe 300 is greater than four times the outer diameter D of the pipe section 32 at the end of the connector 1. The extension length L1 of the main pipe 100 refers to the vertical distance from the end of the open end of the connector 1 to the end of the copper pipe section 41; the extension length L2 of the branch pipe 200 refers to the vertical distance from the end of the guide member 2 to the end of the copper pipe section 42; the extension length L3 of the other branch pipe 300 refers to the vertical distance from the end of the guide member 2' to the end of the copper pipe section 43.

[0091] However, the present invention does not impose any limitation on this. In other embodiments, other refrigeration accessories can also be connected to the three connecting pipes of the steel three-way pipe fitting; for example, components such as a muffler, a filter or a liquid distributor can be connected to the ends of the connecting pipes 32 and 33 to form other pipe connectors. Similarly, although the present embodiment takes the application of the steel 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 steel three-way pipe fitting provided in this embodiment is also applicable to other piping systems with lower working pressures, such as a low-pressure water pipe system.

[0092] Embodiment 3

[0093] This embodiment is basically the same as the second embodiment and its variations, except that: Fig. 20 As shown, the two welding planes 11 , 11 ′ are inclined welding planes that are inclined relative to the inner axis of the connecting piece 1 .

[0094] Specifically, the pipe hole 12 is formed on the inclined welding plane 11 and its axis intersects with the axis of the open end of the connector 1 at an obtuse angle α1, and the pipe hole 12' is formed on the inclined welding plane 11' and its axis intersects with the axis of the open end of the connector 1 at an obtuse angle α2. The pipe 31 is connected to the open end of the connector 1, and the pipes 32 and 33 are connected to the two pipe holes 12, 12' respectively. Fig. 20 and Fig.21As shown, in this embodiment, the pipes 32 and 33 are basically symmetrically distributed on both sides of the inner axis of the connector 1, and the steel three-way pipe fitting is a three-way pipe fitting that splits the flow to both sides and has a roughly Y-shaped structure. However, the present invention does not make any limitation to this. In other embodiments, the pipes 32 and 33 can also be asymmetrically distributed so that the steel three-way pipe fitting is eccentrically split, such as Fig.23 shown.

[0095] In this embodiment, the two guide members 2, 2' are both plate-like structures, and the assembly end faces of the two guide members are substantially parallel to the corresponding inclined welding planes so as to be welded to the corresponding inclined welding planes 11, 11'. The guide members 2, 2' are respectively formed with guide channels 22, 22' formed together with the pipe holes 12, 12'. Specifically, during processing, positioning holes can be preformed on the two plate-like guide members 2, 2', and a hole processing tool (such as a drilling tool) can process the guide channels 22, 22' on the guide members 2, 2' based on the positioning holes, and then the pipe holes 12, 12' can be respectively processed on the inclined welding planes 11, 11' based on the axial traction of the guide channels 22, 22' and their circumferential limitation. However, the utility model does not impose any limitation on this. In other embodiments, the guide channel can also be preformed; the structure of the guide member can also be a columnar structure (as shown in the first embodiment) or a tubular structure or other structures.

[0096] In this embodiment, the assembly end faces of the two guide members are fixed to the corresponding inclined welding planes 11, 11' by self-fluxing welds, and then the pipe holes 12, 12' are processed. Afterwards, three pipes are assembled and the three pipes, two guide members 2, 2' and the connector 1 are integrally welded by furnace brazing, so that a brazing seam for sealing the guide member is formed between the assembly end face of each guide member and the corresponding welding plane. The pre-fixation of the self-fluxing weld and the sealed connection of the brazing front not only greatly improve the connection strength between the guide member and the welding plane, but also make the guide member and the connector an integral seal to make the entire product have better sealing. However, the utility model does not make any limitation to this. The main function of the guide member 2 is to improve the accuracy of the pipe hole and reduce the difficulty of its opening, so the guide member and the connector do not necessarily have to be sealed. In other embodiments, the assembly end face of the guide member may be fixed to the welding plane via a local or annular self-melting weld to facilitate pipe hole processing. The local self-melting weld includes a plurality of spot welds or a plurality of line welds distributed along the circumferential direction.

[0097] Based on the sealed brazing connection of the guide and the connector in this embodiment, further, the outer peripheral wall 321 of the connecting end of the connecting pipe 32 is also welded to the inner peripheral wall of the guide channel 22 by surface brazing, and the entire or partial length of the guide channel 22 and the hole depth of the connecting pipe hole 12 jointly provide the welding depth for the connecting pipe 32; that is, the outer peripheral wall 321 of the connecting end of the connecting pipe 32 is simultaneously connected to the inner peripheral wall of the connecting pipe hole 12 and the inner peripheral wall of the guide channel 22 by surface brazing, increasing the brazing area of ​​the connecting pipe 32 to further improve its connection strength and sealing after brazing. Similarly, the outer peripheral wall 331 of the connecting end of the connecting pipe 33 is simultaneously connected to the inner peripheral wall of the connecting pipe hole 12' and the inner peripheral wall of the guide channel 22' by surface brazing to increase the welding depth of the connecting pipe 33. However, the utility model does not make any limitation to this. In other embodiments, the outer peripheral walls of the connecting ends of the two connecting pipes can also be connected to the inner peripheral walls of the corresponding connecting pipe holes by surface brazing only.

[0098] like Fig.23 As shown, the opening of the two pipe holes 12, 12' forms a taper-shaped flow divider 13 protruding toward the open end on the inner wall of the closed end of the connector 1. The taper-shaped flow divider 13 quickly and evenly distributes the fluid flowing in from the open end of the connector 1 to the two pipe holes 12, 12' to improve the uniformity of the flow divider. However, the utility model does not make any limitation to this. In other embodiments, the inner cavity length of the connector can also be increased so that the inner wall of the closed end of the connector forms a substantially planar flow divider.

[0099] Fig.24 The pipe connection assembly provided in this embodiment is shown, which is basically the same as the second embodiment: the pipe connection assembly is a branch pipe, which includes the steel three-way pipe fitting provided in this embodiment and three copper pipe sections, the copper pipe section 41 and the pipe section 31 together constitute the main pipe 100 of the branch pipe, the copper pipe section 42 and the pipe section 32 constitute one of the branch pipes 200 of the branch pipe, and the copper pipe section 43 and the pipe section 33 constitute the other branch pipe 300 of the branch pipe. However, the utility model does not make any limitation to this. The steel three-way pipe fitting provided in this embodiment can also be connected with other refrigeration accessories (such as a muffler, a filter or a liquid distributor) to form other pipe connectors. Similarly, the steel three-way pipe fitting provided in this embodiment is also suitable for other pipeline systems with lower working pressures, such as low-pressure water pipe systems.

[0100] Embodiment 4

[0101] This embodiment is basically the same as the first embodiment and its variations, except that: in this embodiment, the connecting member 1' is a split structure. Fig.25As shown, the connector 1' comprises a tubular body 101' with a circular cross-section of the outer wall and a bushing 102' arranged on the outer wall of the tubular body 101'. One side of the bushing 102' is in an arc shape to fit the outer wall of the tubular body 101' and the arc length of the bushing 102' in the circumferential direction is greater than 1 / 2 of the circumference of the outer wall of the tubular body 101'. The other side of the bushing 102' forms a welding plane 11. When opening the pipe connection hole, the bushing hole is opened at the welding plane 11 through the guide 2 and the pipe connection hole is opened on the tubular body 101' accordingly (due to the viewing angle, Fig.25 (not shown), the connecting end of the connecting pipe 33 is inserted into the connecting pipe hole on the cylindrical body 101' through the guide member 2 and the bushing hole and brazed.

[0102] Compared with the integral connector in the first embodiment, this embodiment provides another connector 1' structure in the form of a combination of a circular tubular body 101' and a bushing 102'. In this structure, the welding plane 11 is located on the bushing 102', so the circular tubular body 101' can be formed using an existing standard steel circular pipe. The bushing 102' can be an arc-shaped bushing with an arc length greater than 1 / 2 of the circumference of the outer wall of the circular tubular body 101', or a tubular bushing that completely covers the circular tubular body 101'.

[0103] Embodiment 5

[0104] like Fig.26 As shown, this embodiment provides a steel three-way pipe fitting, which includes a steel connector 1 and three pipes 31, 32, 33. The connector 1 has an inner cavity with a flow cross-section that is circular or nearly circular. The outer peripheral wall of the connector 1 is formed with at least one welding plane that is roughly parallel to the axis of the inner cavity of the connector 1 or is inclined relative to the axis of the inner cavity of the connector 1. Each welding plane has a pipe hole connected to the inner cavity. The wall thickness T of the connector 1 at the location of the pipe hole satisfies 1.5mm≤T≤5mm so that the inner peripheral wall of the pipe hole forms a brazing surface 100. At least one pipe hole and at least one end of the connector constitute three pipe ends of the connector. The three pipes 31, 32, 33 are all thin-walled pipes and are respectively welded to the three pipe ends of the connector. Among them, the pipe connected to the pipe hole: its connection end is inserted into the pipe hole and the outer peripheral wall of the connection end forms another brazing surface 200 to be brazed to the brazing surface 100 formed by the inner peripheral wall of the pipe hole.

[0105] In this embodiment, thin-walled pipe fittings refer to pipe fittings with a wall thickness greater than or equal to 0.3 mm and less than or equal to 2.0 mm, such as pipe fittings with a wall thickness of 0.5 mm, 1.0 mm, 1.2 mm, 1.5 mm, and 1.8 mm. The wall thickness T of the connecting piece at the pipe hole can be any value within the range of 1.5 mm to 5 mm, such as 1.8 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, and 4.5 mm.

[0106] Specifically, Fig. 27 and Fig.28 As shown, the connector 1 is a tubular shape with open ends. A welding plane 11 roughly parallel to the axis of the inner cavity of the connector 1 is formed on the outer peripheral wall of the connector 1, and a pipe hole 12 with an axis obliquely intersecting the axis of the inner cavity of the connector 1 is opened on the welding plane 11. The pipe hole 12 and the two ends of the connector 1 constitute the three pipe ends of the connector. Three thin-walled pipes 31, 32, and 33 are welded and connected to the pipe hole and the two ends of the connector 1, respectively. However, the utility model does not make any limitation to this. In other embodiments, two welding planes can also be opened on the outer peripheral wall of the connector to form two pipe holes, and the three pipe ends of the connector are formed based on the two pipe holes and the open end of the connector.

[0107] The steel three-way pipe fitting provided in this embodiment only needs to open a pipe hole 12 on the connector 1 to achieve the connection of the pipe 33. The setting of the welding plane 11 as described in the first embodiment provides a reference surface for the hole opening process, so that the pipe hole 12 can be processed and formed by a simple and mature hole processing process, such as punching or drilling, which effectively solves the problem that it is difficult to open a hole on the curved wall of a circular pipe fitting. Furthermore, the hole processing process does not involve the migration of the pipe material, and it is less affected by the physical properties of the material such as ductility, yield strength and hardness. Therefore, the three-way pipe fitting structure provided in this embodiment can be processed and formed using low-cost steel materials. The wall thickness T of the connector 1 at the pipe hole 12 allows the inner circumferential wall of the pipe hole to form a large area of ​​brazing surface 100 to form another brazing surface 200 formed by brazing the outer circumferential wall of the pipe. This setting realizes the surface brazing connection of the pipe 33 and the pipe hole 12, greatly improving the connection strength and pressure resistance of the pipe after welding so that the steel three-way pipe fitting can be well used in refrigeration systems with high working pressures. In addition, the split structure of the three connecting pipes and the connector 1 also allows the wall thickness at the connector 1 to be set thicker to meet the wall thickness T requirement at the connecting pipe hole, while the three connecting pipes 31, 32, and 33 only need to consider the system pressure bearing capacity and use thin-walled pipes to further reduce material costs.

[0108] Similar to the first embodiment, in order to improve the accuracy of the pipe hole 12 and reduce its processing difficulty, the outer peripheral wall of the connector 1 is provided with a welding plane 11 and the pipe hole 12 is located on the welding plane 11. When processing the pipe hole 12, the welding plane 11 provides a reference surface for the hole processing tool to facilitate the positioning of the tool. When drilling the hole, the axis of the pipe hole 12 can be calibrated based on the welding plane 11 so that the axis of the pipe hole 12 is basically perpendicular to the welding plane 11, thereby solving the problem of difficult drilling of the curved surface and low drilling accuracy. Furthermore, the edge of the pipe hole 12 opened based on the welding plane 11 is a planar structure, which can support the brazing material during brazing to avoid the brazing material hanging in the air. This setting allows the brazing material at various locations on the circumference of the pipe hole 12 to penetrate into the welding gap only by the capillary traction of the welding gap between the two brazing surfaces, ensuring that the welding gap is filled with sufficient solder at various locations on the circumference, thereby effectively solving the flow soldering problem existing in the brazing of curved surfaces.

[0109] In order to improve the welding strength of the connecting pipe 33, in this embodiment, the steel three-way pipe fitting also includes a lining plate 5 welded on the welding plane 11, and an inclined lining plate hole 51 corresponding to the connecting pipe hole 12 is formed on the lining plate 5. The connecting end of the connecting pipe 33 is inserted into the connecting pipe hole 12 through the inclined lining plate hole 51 and is brazed and connected to the inner circumferential wall of the lining plate hole 51 and the inner circumferential wall of the connecting pipe hole 12 (i.e., another brazing surface 200) respectively. This arrangement increases the brazing area of ​​the connecting end of the connecting pipe 33, thereby further enhancing its connection strength and pressure resistance after brazing. However, the utility model does not make any limitation to this. In other embodiments, when the wall thickness T of the connecting piece at the connecting pipe hole can provide sufficient welding depth for the connecting pipe so that it meets the connection strength and pressure resistance required by the system, the steel three-way pipe fitting does not need to be provided with a lining plate.

[0110] Similar to the first embodiment, the connector 1 is also a hollow part with a welding plane 11 formed by cold heading and its outer peripheral wall cross section is pentagonal. However, the utility model only needs to ensure that the outer peripheral wall of the connector where the pipe hole is located is a plane, and the shape of the outer peripheral wall in other areas is not limited. Therefore, the cross section of the outer peripheral wall of the connector can also be a square or hexagonal structure or other polygonal structures. In addition, the welding plane can also be located in the middle area of ​​the outer peripheral wall of the connector without extending to the two ends of the connector, and the outer peripheral walls at both ends of the connector are still circular or nearly circular. In terms of material, similar to the first embodiment, the connector 1 and the three pipes are all made of steel with a Cr content of not less than 5%, specifically non-300 series stainless steel with a Cr content of not less than 5%, such as SUS430 (commonly known as stainless iron, Cr% ≥ 16-18%) or SUS201 (Cr% ≥ 13%, Ni% ≥ 3.5%). However, the utility model does not make any restrictions on this. In other embodiments, the connector and the three pipes may also be made of other steel materials with a Cr content of not less than 5% according to the application environment. The three pipes may also be made of copper pipes or a combination of copper pipes and steel pipes in other embodiments.

[0111] In addition, the root pipes are all split pipe fittings that are respectively sleeved and connected to the three pipe ends of the connector. However, the present invention does not make any limitation on this. In other embodiments, the pipes 31 and 32 can be integral thin-walled pipe fittings that are integrally formed, and the integral thin-walled pipe fittings are welded inside the connector 1 and have a through hole 30 that is connected to the pipe hole 12; this structure can reduce the welding points of the steel three-way pipe fittings and effectively reduce the leakage rate of the product. In addition, each pipe is either a straight pipe or a curved pipe.

[0112] Correspondingly, such as Fig.29 As shown, this embodiment also provides a pipeline connection assembly, which is a branch pipe, which includes the steel tee pipe fitting provided in this embodiment and three copper pipe sections, the copper pipe section 41 and the pipe section 31 together constitute the main pipe 100 of the branch pipe, the copper pipe section 42 and the pipe section 32 constitute one of the branch pipes 200, and the copper pipe section 43 and the pipe section 33 constitute another branch pipe 300 of the branch pipe. Among them, the extension length of the main pipe 100 is greater than or equal to twice the outer diameter D of the pipe section 32 at the end of the connector 1, and the extension length of at least one of the branch pipe 200 and the other branch pipe 300 is greater than four times the outer diameter D of the pipe section 32 at the end of the connector 1. The extension length L1 of the main pipe 100 refers to the vertical distance from the end of the connector 1 where the pipe section 31 is located to the end of the copper pipe section 41; the extension length L2 of the branch pipe 200 refers to the vertical distance from the end of the connector 1 where the pipe section 32 is located to the end of the copper pipe section 42; the extension length L3 of the other branch pipe 300 refers to the vertical distance from the surface of the lining plate 5 to the end of the copper pipe section 43.

[0113] Although the present embodiment is described by taking the branch pipe as an example of the pipeline connection assembly, the present invention does not make any limitation to this. The steel three-way pipe provided in the present embodiment can be combined with other components in the pipeline system to form other pipeline connectors. Similarly, the steel three-way pipe provided in the present embodiment is not only suitable for refrigeration systems with high working pressure, but also suitable for water pipe systems with lower working pressure.

[0114] Embodiment 6

[0115] This embodiment is basically the same as the fifth embodiment and its variations, except that: Fig.30 As shown, in the steel three-way pipe fitting provided in this embodiment, the connector 1 is a single-end open structure, and two welding planes 11, 11' are formed on the outer peripheral wall of the connector 1, which are located on both sides of the axis of the inner cavity of the connector 1 and are roughly parallel to the axis of the inner cavity of the connector 1. A pipe hole 12 whose axis intersects the axial direction of the open end of the connector 1 at an obtuse angle α1 is formed on the welding plane 11, and a pipe hole 12' whose axis intersects the axial direction of the open end of the connector 1 at an obtuse angle α2 is formed on the welding plane 11'. The two pipe holes 12, 12' and the open end of the connector 1 constitute the three pipe ends of the connector 1, the pipe 31 is connected to the open end of the connector 1, and the pipe 32 and the pipe 33 are respectively connected to the two pipe holes 12, 12'.

[0116] In this embodiment, the axes of the two connecting holes 12, 12' are roughly symmetrically distributed on both sides of the inner cavity axial direction of the connector 1, that is, the obtuse angle α1 is close to the obtuse angle α2. However, the present invention does not make any limitation to this. In other embodiments, the two connecting holes can also be arranged to be asymmetrically distributed. Compared with the fifth embodiment, the steel three-way pipe fitting provided in this embodiment is a three-way pipe fitting that is roughly Y-shaped and diverts to both sides.

[0117] like Fig.31 As shown, the opening of the two pipe holes 12, 12' forms a taper-shaped flow divider 13 protruding toward the open end on the inner wall of the closed end of the connector 1. The taper-shaped flow divider 13 quickly and evenly distributes the fluid flowing in from the open end of the connector 1 to the two pipe holes 12, 12' to improve the uniformity of the flow divider. However, the utility model does not make any limitation to this. In other embodiments, the inner cavity length of the connector can also be increased so that the inner wall of the closed end of the connector forms a substantially planar flow divider.

[0118] Furthermore, the steel three-way pipe fitting provided in this embodiment also includes two lining plates 5, 5' which are welded to the two welding planes 11, 11'. An inclined lining plate hole 51 corresponding to the pipe hole 12 is formed on the lining plate 5, and an inclined lining plate hole 51' corresponding to the pipe hole 12' is formed on the lining plate 5'. The pipe 32 is brazed to the inner circumferential wall of the lining plate hole 51 and the inner circumferential wall of the pipe hole 12, and the pipe 33 is brazed to the inner circumferential wall of the lining plate hole 51' and the inner circumferential wall of the pipe hole 12', so as to increase the welding depth of the pipe 32 and the pipe 33 respectively (i.e., increase the brazing area). However, the present invention does not make any limitation to this. In other embodiments, it is not necessary to set a lining plate.

[0119] Correspondingly, such as Fig.32 As shown, this embodiment also provides a pipeline connection assembly, which is a branch pipe, which includes the steel tee pipe fitting provided in this embodiment and three copper pipe sections, the copper pipe section 41 and the pipe section 31 together constitute the main pipe 100 of the branch pipe, the copper pipe section 42 and the pipe section 32 constitute one of the branch pipes 200, and the copper pipe section 43 and the pipe section 33 constitute another branch pipe 300 of the branch pipe. Among them, the extension length of the main pipe 100 is greater than or equal to twice the outer diameter D of the pipe section 32 at the end of the connector 1, and the extension length of at least one of the branch pipe 200 and the other branch pipe 300 is greater than four times the outer diameter D of the pipe section 32 at the end of the connector 1. The extension length L1 of the main pipe 100 refers to the vertical distance from the end of the connector 1 where the pipe section 31 is located to the end of the copper pipe section 41; the extension length L2 of the branch pipe 200 refers to the vertical distance from the surface of the lining plate 5 to the end of the copper pipe section 42; the extension length L3 of the other branch pipe 300 refers to the vertical distance from the surface of the lining plate 5' to the end of the copper pipe section 43.

[0120] Similarly, in other embodiments, other refrigeration accessories can be connected to the three pipes of the steel three-way pipe fitting to form other pipeline connectors, such as connecting a muffler, a filter or a liquid distributor to the pipe and the end of the pipe. The steel three-way pipe fitting provided in this embodiment can be applied to refrigeration systems with high working pressures, and can also be applied to other pipeline systems with lower working pressures, such as low-pressure water pipeline systems.

[0121] Embodiment 7

[0122] This embodiment is basically the same as the sixth embodiment and its variations, except that: Fig.33 As shown, the two welding planes 11 and 11 ′ are two inclined welding planes formed on the outer peripheral wall of the connecting piece 1 close to the closed end and located on both sides of the inner cavity axis of the connecting piece 1 .

[0123] Specifically, the pipe hole 12 is located on the inclined welding plane 11 and its axis intersects with the axis of the open end of the connector 1 at an obtuse angle α1, and the pipe hole 12' is located on the inclined welding plane 11' and its axis intersects with the axis of the open end of the connector 1 at an obtuse angle α2. The pipe 31 is connected to the open end of the connector 1, and the pipes 32 and 33 are connected to the two pipe holes 12, 12' respectively. Fig.34 As shown, the connecting pipes 32 and 33 are basically symmetrically distributed on both sides of the inner axis of the connector 1, that is, the obtuse angle α1 is close to the obtuse angle α2; the steel tee pipe fitting is a roughly Y-shaped tee pipe fitting that splits the flow to both sides. However, the utility model does not make any limitation to this. In other embodiments, the connecting pipes 32 and 33 can also be asymmetrically distributed so that the steel tee pipe fitting has eccentric splitting, such as Fig.35 shown.

[0124] like Fig.34 As shown, the opening of the two pipe holes 12, 12' forms a taper-shaped flow divider 13 protruding toward the open end on the inner wall of the closed end of the connector 1. The taper-shaped flow divider 13 quickly and evenly distributes the fluid flowing in from the open end of the connector 1 to the two pipe holes 12, 12' to improve the uniformity of the flow divider. However, the utility model does not make any limitation to this. In other embodiments, the inner cavity length of the connector can be increased so that the inner wall of the closed end of the connector forms a substantially planar flow divider.

[0125] Fig.36 The pipe connection assembly provided in this embodiment is shown, which is basically the same as that in Embodiment 6: the pipe connection assembly is a branch pipe, which includes the steel three-way pipe fitting provided in this embodiment and three copper pipe sections, the copper pipe section 41 and the pipe section 31 together constitute the main pipe 100 of the branch pipe, the copper pipe section 42 and the pipe section 32 constitute one of the branch pipes 200 of the branch pipe, and the copper pipe section 43 and the pipe section 33 constitute the other branch pipe 300 of the branch pipe. However, the utility model does not impose any limitation on this. The steel three-way pipe fitting provided in this embodiment can also be connected with other refrigeration accessories (such as a muffler, a filter or a liquid distributor) to form other pipe connectors. Similarly, the steel three-way pipe fitting provided in this embodiment is also suitable for other pipeline systems with lower working pressures, such as low-pressure water pipe systems.

[0126] In summary, a welding plane is formed on the outer peripheral wall of the connecting piece in the steel three-way pipe fitting provided by the utility model, and the welding plane provides a reference plane for the opening of the pipe hole so that the outer peripheral wall of the connecting piece can open the pipe hole to realize the connection of the pipe. The setting of the wall thickness T of the connecting piece at the pipe hole makes the inner peripheral wall of the pipe hole form a brazing surface to be brazed to the outer peripheral wall of the connecting end of the pipe. Compared with the traditional self-melting wire weld connection, the surface brazing connection of the pipe 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. Furthermore, when welding the pipe, the welding plane also carries the solder to avoid the flow welding problem caused by the solder hanging in the air, ensuring that the pipe has good connection strength everywhere in the circumferential direction after brazing. In terms of processing technology, the steel three-way pipe fitting provided by the utility model only needs to use a simple hole processing technology (such as drilling or punching) to open the pipe hole on the welding plane; and the hole processing technology does not need to involve the migration of the pipe, nor does it need to be hot forging and other treatments, so it is very suitable for the processing of steel materials.

[0127] Furthermore, a guide is provided on the welding plane, and the axis of the drilling tool can be substantially coaxial with the axis of the guide during drilling, thereby greatly improving the drilling accuracy and reducing the difficulty of drilling; at the same time, the setting of the welding plane also provides a basis for the smooth connection of the guide. In addition, the setting of the guide also allows the inner circumferential wall of the connecting end of the pipe to be brazed and connected to the inner circumferential wall of the guide channel to further improve the connection strength and pressure resistance of the pipe.

[0128] 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 steel three-way pipe fitting, characterized in that: include: A steel connector having an inner cavity with a circular or nearly circular flow cross section, wherein the outer peripheral wall of the connector is formed with at least one welding plane substantially parallel to the axis of the inner cavity of the connector or inclined relative to the axis of the inner cavity of the connector, each welding plane having a pipe connection hole connected to the inner cavity, and at least one pipe connection hole and at least one end of the connector forming three pipe connection ends of the connector; At least one guide piece is welded to the corresponding welding plane on the connecting piece, and a pipe hole is opened on the corresponding welding plane through the guide piece, and the wall thickness T of the connecting piece at the location of the pipe hole satisfies 0.8mm≤T≤5mm so that the inner peripheral wall of the pipe hole forms a brazing surface; Three connecting pipes, all of which are thin-walled pipe fittings and are welded to the three connecting pipe ends of the connecting piece; Among them, the connecting pipe connected to the connecting pipe hole: its connecting end is inserted into the connecting pipe hole through the guide piece and the outer peripheral wall of the connecting end forms another brazing surface to be brazed to the brazing surface formed by the inner peripheral wall of the connecting pipe hole.

2. The steel three-way pipe fitting according to claim 1, characterized in that: The assembly end face of the guide piece is welded to the welding plane. The guide piece is any one of a tubular, columnar or plate-like structure and has a guide channel preformed or formed together with the pipe hole. The pipe hole is formed on the welding plane through the guide channel.

3. The steel three-way pipe fitting according to claim 2, characterized in that: The outer peripheral wall of the connecting end of the connecting pipe connected to the connecting pipe hole is also welded to the inner peripheral wall of the guide channel by surface brazing. The entire or partial length of the guide channel and the hole depth of the connecting pipe hole together provide the welding depth for the connecting pipe.

4. The steel three-way pipe fitting according to claim 1, characterized in that: The connecting piece is in the shape of a tube with both ends open. A welding plane roughly parallel to the axis of the inner cavity of the connecting piece is formed on the outer wall of the connecting piece, and a connecting pipe hole with an axis obliquely intersecting with the axis of the inner cavity of the connecting piece is formed on the welding plane. The connecting pipe hole and the two ends of the connecting piece constitute the three connecting pipe ends of the connecting piece.

5. The steel three-way pipe fitting according to claim 4, characterized in that: The two connecting pipes arranged at both ends of the connecting piece are integral thin-walled pipes, which are welded in the connecting piece and have through holes connected to the connecting pipe holes. Alternatively, the three connecting pipes are all split pipe fittings which are respectively sleeved and connected to the three connecting pipe ends of the connecting piece.

6. The steel three-way pipe fitting according to claim 1, characterized in that: The connector has a single-end open structure, and two welding planes are formed on the outer peripheral wall of the connector, which are located on both sides of the axis of the inner cavity of the connector and are roughly parallel to the axis of the inner cavity of the connector. Each welding plane is provided with a connecting pipe hole whose axis intersects the axial direction of the open end of the connector at an obtuse angle. The two connecting pipe holes and the open end of the connector constitute the three connecting pipe ends of the connector.

7. The steel three-way pipe fitting according to claim 1, characterized in that: The connector has a single-end open structure, and two welding planes are formed on the outer peripheral wall of the connector near the closed end, which are located on both sides of the axis of the inner cavity of the connector and are inclined relative to the axis of the inner cavity of the connector. Each welding plane is provided with a pipe connecting hole whose axis intersects with the axis of the open end of the connector at an obtuse angle. The two pipe connecting holes and the open end of the connector constitute the three pipe connecting ends of the connector.

8. The steel three-way pipe fitting according to claim 6 or 7, characterized in that: The inner wall of the closed end of the connecting piece is formed with a diversion portion which is substantially flat or protrudes toward the open end in a conical shape.

9. The steel three-way pipe fitting according to claim 1, characterized in that: The connecting piece is an integral pipe piece with a welding plane on the outer peripheral wall; Alternatively, the connecting piece is a split structure and includes a tubular body with a circular outer wall cross-section and a bushing arranged on the outer wall of the tubular body, one side of the bushing is arc-shaped to fit the outer wall of the tubular body and the arc length of the bushing in the circumferential direction is greater than 1 / 2 of the circumference of the outer wall of the tubular body, and the other side of the bushing forms a welding plane; when opening a connecting pipe hole, a bushing hole is opened at the welding plane through the guide and a corresponding connecting pipe hole is opened on the tubular body, and the connecting end of the connecting pipe is inserted into the connecting pipe hole on the tubular body through the guide and the bushing hole and brazed.

10. The steel three-way pipe fitting according to claim 1, characterized in that: Each connecting pipe is either a straight pipe or a curved pipe; each connecting pipe is either a copper pipe fitting or a steel pipe fitting or a combination of the two.

11. A steel three-way pipe fitting, characterized in that: include: A steel connector having an inner cavity with a circular or nearly circular flow cross section, wherein the outer peripheral wall of the connector is formed with at least one welding plane substantially parallel to the axis of the inner cavity of the connector or inclined relative to the axis of the inner cavity of the connector, each welding plane has a pipe hole connected to the inner cavity, the wall thickness T of the connector at the location of the pipe hole satisfies 1.5 mm ≤ T ≤ 5 mm so that the inner peripheral wall of the pipe hole forms a brazing surface, and at least one pipe hole and at least one end of the connector constitute three pipe ends of the connector; Three connecting pipes, all of which are thin-walled pipes and are respectively welded to the three connecting pipe ends of the connecting piece; Among them, the connecting pipe connected to the connecting pipe hole: its connecting end is inserted into the connecting pipe hole and the outer peripheral wall of the connecting end forms another brazing surface to be brazed to the brazing surface formed by the inner peripheral wall of the connecting pipe hole.

12. The steel three-way pipe fitting according to claim 11, characterized in that: The connecting piece is in the shape of a tube with both ends open. A welding plane substantially parallel to the axis of the inner cavity of the connecting piece is formed on the outer peripheral wall of the connecting piece, and a pipe connecting hole with an axis obliquely intersecting the axis of the inner cavity of the connecting piece is formed on the welding plane. The pipe connecting hole and the two ends of the connecting piece constitute three pipe connecting ends of the connecting piece. Alternatively, the connector has a single-end open structure, and two welding planes are formed on the outer peripheral wall of the connector, which are located on both sides of the axis of the connector's inner cavity and are roughly parallel to the axis of the connector's inner cavity. Each welding plane is provided with a connecting pipe hole whose axis intersects the axial direction of the open end of the connector at an obtuse angle. The two connecting pipe holes and the open end of the connector constitute the three connecting pipe ends of the connector.

13. The steel three-way pipe fitting according to claim 12, characterized in that: The steel three-way pipe fitting also includes a lining plate welded on the welding plane, wherein a lining plate hole corresponding to the pipe hole is formed on the lining plate, and the connecting end of the pipe is inserted into the pipe hole through the lining plate hole and brazed to the inner circumferential wall of the lining plate hole and the inner circumferential wall of the pipe hole respectively.

14. The steel three-way pipe fitting according to claim 11, characterized in that: The connector has a single-end open structure, and two welding planes located on both sides of the axis of the connector's inner cavity are formed on the outer peripheral wall of the connector near the closed end. Each welding plane is inclined relative to the axis of the connector's inner cavity and is provided with a connecting pipe hole whose axis intersects the axial direction of the open end of the connector at an obtuse angle. The two connecting pipe holes and the open end of the connector constitute the three connecting pipe ends of the connector.

15. A pipe connection assembly, characterized in that: Including the steel three-way pipe fitting according to claim 1 or 11.

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