Stainless steel water distributing and collecting head

Abstract

The utility model provides a stainless steel water distributing and collecting head which comprises a stainless steel body assembly and a branch pipe welding assembly. The stainless steel body assembly is provided with a threaded connection end connected with an external pipeline and an open end. The branch pipe welding assembly comprises a branch pipe connecting plate and a plurality of branch pipes, the branch pipe connecting plate is made of stainless steel materials, and a plurality of branch pipe holes are formed in the branch pipe connecting plate. The branch pipe stainless steel base section on each branch pipe is inserted into the corresponding branch pipe hole, and a self-fluxing welding seam for pre-fixing the branch pipe stainless steel base section is formed between the branch pipe stainless steel base section and the inner surface of the branch pipe connecting plate near the branch pipe hole; the inner surface of the branch pipe connecting plate is the surface, close to the inserting front end, of the branch pipe connecting plate in the inserting direction of the branch pipe stainless steel base sections, and a branch pipe brazing layer is formed between the peripheral wall of each branch pipe stainless steel base section and the corresponding branch pipe hole. Wherein a branch pipe connecting plate in the branch pipe welding assembly is embedded into the open end of the stainless steel body assembly, and the branch pipe connecting plate and the stainless steel body assembly are welded and connected through a full-circumferential self-fluxing sealing welding seam.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration equipment technology, and in particular to a stainless steel manifold head. Background Technology

[0002] As a core component of the water distribution system for central air conditioning fan coil units, the manifold functions through the coordinated action of the distributor and collector. The distributor is installed at the inlet of the fan coil unit and is responsible for distributing the water flow from the main pipeline to each branch; the collector is located at the outlet and is used to collect the return water from the branch lines and guide it into the main pipeline to complete the circulation. Traditionally, manifolds are generally made of brass, but with the rise in copper prices, the industry has begun to explore cost-reduction paths such as "replacing copper with steel".

[0003] To address this trend, the inventors have proposed two innovative patents: CN118002871A discloses a manufacturing method and positioning fixture for a stainless steel water flow distributor, while CN222103992U relates to a combined stainless steel water flow distributor structure. To ensure that the positions of the numerous branch pipes on the water flow distributor accurately match the corresponding water inlet / outlet pipes on the central air conditioning fan coil unit, both patents propose pre-fixing the branch pipes before brazing in the furnace. However, this pre-fixing scheme presents practical feasibility issues. Specifically, to maintain the stability of the branch pipe ends, self-fusion welding of the stainless steel section to the branch pipe hole is required on the outer surface of the branch pipe connecting plate to achieve pre-fixation of the stainless steel section. However, due to the dense arrangement of the branch pipes (small spacing and large number) and the proximity of the bends on the branch pipes to the outer surface of the panel, the welding torch movement trajectory is severely restricted by space, making it difficult to adjust the welding angle and easily leading to quality accidents such as weld detachment, incomplete welding, and weld burn-through.

[0004] Furthermore, both of the aforementioned patents employ tin bronze brazing to weld the stainless steel body to multiple curved long branch pipes. However, this approach also suffers from the following technical bottlenecks: First, the axial / radial dimensions of the composite component formed by the columnar stainless steel body and multiple long curved branch pipes are too large, significantly occupying space during tunnel furnace brazing and resulting in a substantial reduction in the unit furnace capacity. Second, tin bronze solder itself has inherent defects such as poor fluidity and insufficient wettability on the steel surface. When welding multi-part stainless steel bodies with complex structures, it is difficult to ensure uniform solder penetration, easily leading to process defects such as incomplete welds and broken welds. Utility Model Content

[0005] In order to overcome at least one deficiency of the prior art, this utility model provides a stainless steel manifold head.

[0006] To achieve the above objectives, this utility model provides a stainless steel manifold, comprising a stainless steel body assembly and a branch pipe welding assembly. The stainless steel body assembly has a threaded connection end and an open end for connecting to external pipelines. The branch pipe welding assembly includes a branch pipe connecting plate and multiple branch pipes. The branch pipe connecting plate is made of stainless steel and has multiple branch pipe holes formed thereon. The stainless steel base segment of each branch pipe is inserted into the corresponding branch pipe hole, and a self-fusion weld for pre-fixing the stainless steel base segment is formed between the stainless steel base segment and the inner surface of the branch pipe connecting plate near the branch pipe hole. The inner surface of the branch pipe connecting plate is the surface of the branch pipe connecting plate near the insertion front end in the insertion direction of the stainless steel base segment. A branch pipe brazing layer is formed between the outer peripheral wall of each stainless steel base segment and the corresponding branch pipe hole. The branch pipe connecting plate in the branch pipe welding assembly is embedded in the open end of the stainless steel body assembly, and the two are welded together by a full-circumferential self-fusion sealing weld.

[0007] According to one embodiment of the present invention, the inner surface of the branch pipe connecting plate is generally a plane, and the insertion end face of the stainless steel base section of the branch pipe is basically flush with or extends out of the inner surface of the branch pipe connecting plate.

[0008] According to one embodiment of the present invention, the branch pipe connecting plate is partially embedded in the open end of the stainless steel body assembly, and a circumferential self-fusion sealing weld is formed between the open end of the stainless steel body assembly and the peripheral wall of the branch pipe connecting plate exposed outside the stainless steel body assembly.

[0009] According to one embodiment of the present invention, each branch pipe further includes a branch pipe copper connecting section disposed at the end of the stainless steel base section of the branch pipe. After the branch pipe welding assembly is brazed in the furnace, a branch pipe brazing layer is formed at both ends of the stainless steel base section of each branch pipe to connect the branch pipe connecting plate and the corresponding branch pipe copper connecting section respectively. The branch pipe brazing layer is formed by welding with brazing material with a liquidus greater than or equal to 750 degrees Celsius.

[0010] According to one embodiment of the present invention, in each branch pipe, the copper connecting section of the branch pipe is a straight pipe section with an axis that is basically close to a straight line, and the copper connecting section of the branch pipe is sleeved on the end of the corresponding stainless steel base section of the branch pipe.

[0011] According to one embodiment of the present invention, the stainless steel body assembly is a combined welded structure, wherein the internal components are welded together by an oxygen-free copper brazing layer.

[0012] According to one embodiment of the present invention, the self-fusion weld located on the inner surface of the branch pipe connecting plate and used for pre-fixing the stainless steel base section of the branch pipe is a partial weld or an integral circumferential weld.

[0013] On the other hand, this utility model also provides a stainless steel manifold, which includes: a stainless steel body assembly and a branch pipe assembly. The stainless steel body assembly has a threaded connection end and an open end for connecting to an external pipeline. The branch pipe assembly includes a branch pipe connecting plate and multiple branch pipes. The branch pipe connecting plate is made of stainless steel and has multiple branch pipe holes formed thereon. The stainless steel base segment of each branch pipe is inserted into the corresponding branch pipe hole, and a self-fusion weld for pre-fixing the stainless steel base segment is formed between the stainless steel base segment and the inner surface of the branch pipe connecting plate near the branch pipe hole. The inner surface of the branch pipe connecting plate is the surface of the branch pipe connecting plate near the insertion front end in the insertion direction of the stainless steel base segment. The branch pipe connecting plate in the branch pipe assembly is embedded in the open end of the stainless steel body assembly. The stainless steel body assembly, the branch pipe connecting plate, and the multiple branch pipes are integrally welded by furnace brazing. A branch pipe brazing layer is formed between the outer peripheral wall of the stainless steel base segment of each branch pipe and the corresponding branch pipe hole.

[0014] According to one embodiment of the present invention, each branch pipe further includes a branch pipe copper connecting section disposed at the end of the branch pipe stainless steel base section. The stainless steel body assembly, the branch pipe connecting plate, the multiple branch pipe stainless steel base sections and the multiple branch pipe copper connecting sections are integrally welded in a furnace. A branch pipe brazing layer is formed at both ends of each branch pipe stainless steel base section to connect the branch pipe connecting plate and the corresponding branch pipe copper connecting section respectively. The branch pipe brazing layer is formed by welding with brazing material with a liquidus greater than or equal to 750 degrees Celsius.

[0015] According to one embodiment of the present invention, the inner surface of the branch pipe connecting plate is generally a plane, and the insertion end face of the stainless steel base section of the branch pipe is basically flush with or extends out of the inner surface of the branch pipe connecting plate.

[0016] In summary, in the stainless steel manifold head provided by this utility model, the branch pipe connecting plate is embedded in the open end of the stainless steel body component in a split form. During assembly, the branch pipe connecting plate can be pre-assembled with multiple branch pipes to form an independent branch pipe welding assembly. This configuration allows a self-fusion weld to be formed on the inner surface of the branch pipe connecting plate when pre-fixing the stainless steel base section of the branch pipe. Setting the self-fusion weld on the inner surface of the branch pipe connecting plate (i.e., the front end surface in the branch pipe insertion direction) directly avoids the problem of welding torch movement interference caused by the congestion of space at the bend of the branch pipe in traditional external surface pre-fixing. This design significantly expands the welding operation space, reduces the difficulty of adjusting the welding torch trajectory, thereby reducing the quality risks such as weld detachment, incomplete welding, and weld burn-through, and improving the process stability and pre-welding qualification rate of the pre-fixing of the stainless steel base section of the branch pipe.

[0017] Furthermore, the branch pipe welding assembly is brazed as an independent module before being embedded into the stainless steel body assembly. The independent brazing of the branch pipe welding assembly significantly reduces the assembly size when brazing long branch pipes, optimizing the space utilization within the tunnel furnace to increase the unit furnace capacity. In addition, when the stainless steel body assembly is a modular welded structure, this arrangement allows for the use of different brazing materials for the stainless steel body assembly and the branch pipe welding assembly. This provides the conditions for using oxygen-free copper brazing material with excellent fluidity and wettability, high post-weld connection strength, and corrosion resistance for the stainless steel body assembly, which has many components, thereby significantly improving the overall performance of the stainless steel manifold head.

[0018] To make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 The diagram shown is a structural schematic of the stainless steel manifold provided in Embodiment 1 of this utility model.

[0020] Figure 2 As shown Figure 1 A cross-sectional schematic diagram.

[0021] Figure 3 As shown Figure 2 Enlarged diagram of point A in the middle.

[0022] Figure 4 As shown Figure 1 A schematic diagram of its breakdown.

[0023] Figure 5 As shown Figure 1 A partial schematic diagram of the welding assembly for the central branch pipe.

[0024] Figure 6 and Figure 7 The diagram shown is a partial schematic of a branch pipe welding assembly provided in another embodiment of the present invention.

[0025] Figure 8 The diagram shown is a structural schematic of a stainless steel manifold head provided in another embodiment of this utility model.

[0026] Figure 9 The figure shown is a cross-sectional schematic diagram of the stainless steel manifold provided in Embodiment 2 of this utility model.

[0027] Figure 10 As shown Figure 9 Enlarged diagram of point B in the middle. Detailed Implementation

[0028] Example 1

[0029] In existing stainless steel water flow distributors, when the branch pipes are pre-fixed by self-fusion welding on the outer surface of the branch pipe connection plate, the densely arranged multiple branch pipes with bends restrict the operating space of the self-fusion welding gun, making it difficult to adjust the welding angle and easily causing quality accidents such as weld detachment, incomplete welding, and weld burn-through.

[0030] In view of this, this embodiment provides a stainless steel manifold head that is highly feasible in terms of process, has stable welding, and high production efficiency. For example... Figures 1 to 5 As shown, the stainless steel manifold provided in this embodiment includes a stainless steel body assembly 1 and a branch pipe welding assembly 2. The stainless steel body assembly 1 has a threaded connection end 101 and an open end 102 for connecting to external pipelines. The branch pipe welding assembly 2 includes a branch pipe connecting plate 21 and multiple branch pipes 22. The branch pipe connecting plate 21 is made of stainless steel and has multiple branch pipe holes 210 formed thereon. The stainless steel base segment 221 of each branch pipe 22 is inserted into the corresponding branch pipe hole 210, and a self-fusion weld 23 for pre-fixing the stainless steel base segment 221 is formed between the stainless steel base segment 221 and the inner surface 211 of the branch pipe connecting plate near the branch pipe hole 210. The inner surface 211 of the branch pipe connecting plate is the surface of the branch pipe connecting plate 21 near the insertion front end in the insertion direction of the stainless steel base segment 221. A branch pipe brazing layer 24 is formed between the outer peripheral wall of each stainless steel base segment 221 and the corresponding branch pipe hole 210. In this component, the branch pipe connecting plate 21 in the branch pipe welding assembly 2 is embedded in the open end 102 of the stainless steel body assembly 1 and the two are welded together by a full circumferential self-fusion sealing weld 3.

[0031] In the stainless steel manifold provided in this embodiment, the stainless steel body assembly 1 has an open end 102, and the branch pipe connecting plate 21 in the branch pipe welding assembly 2 is separately embedded and welded into the open end 102. This arrangement allows the branch pipe connecting plate 21 to be pre-positioned and assembled with multiple branch pipes 22 during assembly, without being constrained by the space of the stainless steel body assembly 1. This allows the self-fusion weld 23 of the pre-fixed stainless steel base section 221 of the branch pipe to be formed on the inner surface 211 of the branch pipe connecting plate. Since the bent portion 2211 of the stainless steel base section 221 of the branch pipe is located on the outer surface 212 side of the branch pipe connecting plate, while the welding operation of the self-fusion weld 23 is located on the inner surface 211 side of the branch pipe connecting plate, this arrangement avoids the influence of the bent portion 2211 on the stainless steel base section 221 of the branch pipe on the welding torch, expands the operating space of the welding torch to facilitate the adjustment of the welding trajectory, and effectively solves the quality accidents such as weld detachment, incomplete welding, and weld burn-through caused by the inability to rotate the welding torch angle due to narrow space in the prior art.

[0032] like Figure 3 and Figure 5As shown, the inner surface 211 of the branch pipe connecting plate 21 is approximately flat, and the insertion end face of the stainless steel base section 221 of the branch pipe extends slightly beyond the inner surface 211 of the branch pipe connecting plate. This planar structure facilitates the movement of the welding torch trajectory, enabling rapid and high-precision completion of the self-fusion weld 23, thereby achieving the pre-fixation of the stainless steel base section 221 of the branch pipe. However, this invention does not impose any limitation on the specific shape of the inner surface of the branch pipe connecting plate. In other embodiments, it can also be curved. Furthermore, regarding the insertion depth of the stainless steel base section of the branch pipe, in other examples, the insertion end face of the stainless steel base section can also be set to be substantially flush with the inner surface of the branch pipe connecting plate, such as... Figure 7 and Figure 8 As shown.

[0033] In this embodiment, as Figure 5 As shown, the self-fusion weld 23 of the pre-fixed branch pipe stainless steel base section 221 is an integral circumferential weld distributed circumferentially along the branch pipe hole 210. However, this utility model does not limit this in any way. In other embodiments, the self-fusion weld 23 may also be multiple spaced local welds, such as... Figure 6 As shown. Specifically, this embodiment uses laser welding to form a self-fluxing weld. However, this invention does not limit itself to this. In other embodiments, any other welding method, such as arc welding (e.g., argon arc welding), resistance welding, or high-frequency welding, can also be used to form a self-fluxing weld.

[0034] In this embodiment, the branch pipe connecting plate 21 is composed of two superimposed sub-connecting plates 21A and 21B. Each sub-connecting plate has the same number of essentially coaxial connecting plate through holes, which together form a branch pipe hole 210. The front end of the branch pipe stainless steel base segment 221 on each branch pipe 22 is inserted into the connecting plate through hole located in the innermost sub-connecting plate 21A. The inner surface of the innermost sub-connecting plate 21A is the inner surface 211 of the branch pipe connecting plate 21. The superimposed design of multiple sub-connecting plates increases the welding depth of the branch pipe stainless steel base segment 221 while reducing the processing difficulty of the connecting pipe hole 210. However, this utility model does not impose any limitations on this. In other embodiments, the number of sub-connecting plates can be adjusted according to the welding depth requirements of the branch pipe stainless steel base segment and the thickness of the sub-connecting plates, such as three or more. Alternatively, in other embodiments, the branch pipe connecting plate 21 is set as an integral plate, such as... Figure 7 As shown.

[0035] In the stainless steel manifold provided in this embodiment, the branch pipe welding assembly 2 is pre-fixed and brazed as an independent module before being assembled into the stainless steel body assembly 1. The independent brazing of the branch pipe welding assembly 2 significantly reduces the component size required during the brazing process of long branch pipes, optimizes the space utilization within the tunnel furnace, and increases the production capacity of a single furnace. Furthermore, for the combined stainless steel body assembly 1 containing many components, the stainless steel manifold provided in this embodiment, while meeting the brazing requirements of the branch pipe welding assembly 2, can introduce brazing materials with better fluidity and wettability into the stainless steel body assembly 1 to improve the welding performance of the combined stainless steel body assembly 1.

[0036] like Figure 1 and Figure 4 As shown, in this embodiment, the stainless steel body assembly 1 is a combined welded structure, which includes a thin-walled shell 11, a threaded column 12, a flange plate 13, a drain valve connecting seat 14, and a drain nozzle 15. The threaded column 12 is separately connected to the end of the thin-walled shell 11 away from the branch pipe welding assembly 2 to form a threaded connection end 101. The flange plate 13 is separately connected to the threaded body 11 and / or the thin-walled shell 11. The drain nozzle 15 is connected to the thin-walled shell 11 via the drain valve connecting seat 14. The independent welding of the branch pipe welding assembly 2 allows the welding conditions of each component in the stainless steel body assembly 1 to be different from those of the branch pipe 22. Specifically, the main body of the drain nozzle 15 and other components in the stainless steel body assembly 1 are all made of stainless steel. During welding, oxygen-free copper brazing filler can be used for furnace brazing to form the stainless steel body assembly 1. Compared with tin bronze brazing layer, oxygen-free copper brazing filler not only has better fluidity and wettability, but also the corrosion resistance and connection strength of the brazing layer formed after welding are higher. However, this utility model does not impose any limitations on this. In other embodiments, the stainless steel body assembly may also be an integral, weld-free stainless steel casting or cold-forged part, such as... Figure 8 As shown.

[0037] In this embodiment, as Figure 1 As shown, each branch pipe 22 also includes a branch pipe copper connecting section 222 disposed at the end of the branch pipe stainless steel base section 221. When forming the branch pipe welding assembly 2, considering the melting point of the branch pipe copper connecting section 222, a brazing filler with a liquidus greater than or equal to 750 degrees Celsius and less than the melting point of the branch pipe copper connecting section 222 is used for welding. This results in branch pipe brazing layers 24 being formed at both ends of each branch pipe stainless steel base section 221 to connect the branch pipe connecting plate 21 and the corresponding branch pipe copper connecting section 222, respectively. Preferably, tin bronze brazing filler is used in this embodiment. However, this invention does not limit this. In other embodiments, the brazing filler with a liquidus greater than or equal to 750 degrees Celsius can be silver-phosphorus copper brazing filler or other brazing fillers that meet the above conditions.

[0038] In existing technologies, the copper connector section of the branch pipe is typically inserted into the flared end of the stainless steel base section of the branch pipe. However, due to the multiple bends formed on the stainless steel base section of the branch pipe, the end of the stainless steel base section usually deforms after bending. Therefore, the end of the stainless steel base section of the branch pipe needs to be precisely shaped before flaring, and a long straight section needs to be reserved for flaring. This assembly method is not only complex and requires high precision, but the length of the stainless steel base section of the branch pipe is also relatively long, making it difficult to match some situations where the installation space is narrow. In addition, the hardness of stainless steel is much greater than that of copper, but its ductility is lower than that of copper. These material characteristics make it difficult to flare the stainless steel base section of the branch pipe, and the increase in pipe diameter after flaring is relatively limited, making it difficult to accommodate changes in the diameter of the copper connector section of the branch pipe at the rear.

[0039] To address this issue, this embodiment designs the branch pipe copper connector 222 as a straight pipe section with an axis that is nearly straight, and the branch pipe copper connector 222 is sleeved over the end of the corresponding branch pipe stainless steel base section 221. This sleeve-type connection method avoids the need for flaring the end of the branch pipe stainless steel base section 221, which only requires simple shaping before insertion into the branch pipe copper connector 222. Furthermore, the straight end section does not require further flaring and can be made shorter. In addition, to match the ends of branch pipe stainless steel base sections 221 with different pipe diameters, the branch pipe copper connector 222, which has low hardness and excellent ductility, can also be flared. The simply shaped end of the branch pipe stainless steel base section 221 can be directly inserted into the flared section of the branch pipe copper connector 222. This design allows the branch pipe copper connector 222 to match branch pipe stainless steel base sections 221 with various pipe diameters, thus exhibiting excellent versatility. Furthermore, in this embodiment, the copper connecting section 222 of the branch pipe is set as a straight pipe section with an axis that is basically close to a straight line. This setting not only facilitates its assembly with the stainless steel base section 221 of the branch pipe, but also makes it more conducive to flaring processing.

[0040] For the assembly and welding of the branch pipe welding assembly 2, the copper connecting section 222 of the branch pipe can be interference-fitted onto the end of the corresponding stainless steel base section 221 of the branch pipe to complete the assembly of the branch pipe 2. Then, the front end of the stainless steel base section 221 of the branch pipe is inserted into the corresponding branch pipe hole 210 on the branch pipe connecting plate 21. Next, self-fusion welding is performed on the inner surface 211 side of the branch pipe connecting plate for each stainless steel base section 221, and pre-fixed by the self-fusion weld 23 to form the branch pipe assembly. Finally, the branch pipe assembly is placed in a tunnel furnace, and tin bronze brazing filler is used to form a brazing layer 24 at both ends of the stainless steel base section 221 to complete the welding. However, this invention does not limit this process. In other embodiments, the branch pipe connecting plate and multiple stainless steel base sections of the branch pipe can be pre-fixed; then, the corresponding copper connecting section of the branch pipe is assembled at the end of each stainless steel base section; finally, in-furnace brazing is performed to form the branch pipe welding assembly.

[0041] After forming the branch pipe welding assembly 2, the branch pipe connecting plate 21 within the branch pipe welding assembly 2 is embedded into the open end 102 of the stainless steel body assembly 1, and the two are welded together via a full-circumferential self-fusion sealing weld 3. In this embodiment, as... Figure 2 and Figure 3 As shown, a flared section 103 is formed on the open end 102 of the stainless steel body assembly 1, and the flared step limits the inner sub-connecting plate 21A of the embedded branch pipe connecting plate 21. Specifically, in this embodiment, the branch pipe connecting plate 2 is partially embedded in the open end 102 of the stainless steel body assembly 1, and a full-circumferential self-fusion sealing weld 3 is formed between the open end of the stainless steel body assembly 1 and the peripheral wall of the branch pipe connecting plate 2 exposed outside the stainless steel body assembly 1. This arrangement allows the welding torch to rotate freely during self-fusion welding without interference from the stainless steel body assembly 1 and the stainless steel base section 221 of the branch pipe, so that the welding torch can rotate freely to form a full-circumferential self-fusion sealing weld 3. However, this utility model does not impose any limitations on this. In other embodiments, the branch pipe connecting plate may be integrally embedded in the open end of the stainless steel body assembly; in this structure, the self-fusion welding torch needs to move along the inner peripheral wall of the open end of the stainless steel body assembly, thereby forming a full circumferential self-fusion sealing weld between the inner peripheral wall of the open end of the stainless steel body assembly and the outer surface of the branch pipe connecting plate.

[0042] Specifically, laser welding, arc welding (such as argon arc welding), or high-frequency welding can be used to form the circumferential self-fluxing sealing weld 3. Compared with the brazing layer formed by metallurgical diffusion and mutual dissolution, the circumferential self-fluxing sealing weld 3 is a weld structure formed by the melting of stainless steel base material and mutual dissolution of elements, followed by recrystallization in a homogeneous epitaxial manner. This weld is not only dense and has high connection strength, but also exhibits excellent performance in terms of plasticity, toughness, and corrosion resistance.

[0043] Example 2

[0044] This embodiment is basically the same as Embodiment 1 and its variations, except that: after the branch pipe connecting plate 21 and multiple branch pipes 22 are pre-fixed to form the branch pipe assembly 2' using self-fusion weld 23, they are not independently brazed. The branch pipe assembly 2' and the stainless steel body assembly 1 are integrally welded together by brazing in a furnace.

[0045] Specifically, such as Figure 9 and Figure 10As shown, the stainless steel manifold provided in this embodiment includes a stainless steel body assembly 1 and a branch pipe assembly 2'. The stainless steel body assembly 1 has a threaded connection end 101 and an open end 102 for connecting to an external pipeline. The branch pipe assembly 2' includes a branch pipe connecting plate 21 and multiple branch pipes 22. The branch pipe connecting plate 21 is made of stainless steel and has multiple branch pipe holes 210 formed thereon. The stainless steel base segment 221 of each branch pipe 22 is inserted into the corresponding branch pipe hole 210, and a self-fusion weld 23 for pre-fixing the stainless steel base segment 221 is formed between the stainless steel base segment 221 and the inner surface 211 of the branch pipe connecting plate near the branch hole 210. The inner surface 211 of the branch pipe connecting plate is the surface of the branch pipe connecting plate 21 near the insertion front end in the insertion direction of the stainless steel base segment 221. Among them, the branch pipe connecting plate 21 in the branch pipe assembly 2' is embedded in the open end 102 of the stainless steel body assembly. The stainless steel body assembly 1, the branch pipe connecting plate 21 and multiple branch pipes 22 are integrally welded in the furnace. A branch pipe brazing layer 24 is formed between the outer peripheral wall of the stainless steel base section 221 of each branch pipe and the corresponding branch pipe hole 210. The branch pipe connecting plate 2 is connected to the open end 102 of the stainless steel body assembly 1 through the connecting plate brazing layer 3'.

[0046] Similar to Embodiment 1, the open end 102 of the branch pipe connecting plate 21 and the stainless steel body assembly 1 are connected separately. This arrangement allows the self-fusion pre-fixation between the branch pipe connecting plate 21 and the stainless steel base section 221 of the branch pipe to be unrestricted by the stainless steel body assembly 1, providing conditions for the stainless steel base section 221 of the branch pipe to be pre-fixed to the inner surface 211 of the branch pipe connecting plate through the self-fusion weld 23. This arrangement ensures that the pre-fixation of the stainless steel base section 221 of the branch pipe is no longer interfered with by itself and the bending portion 2211 on the adjacent stainless steel base section of the branch pipe, increasing the welding operation space and facilitating the adjustment of the welding torch trajectory. This effectively solves the quality problems such as weld detachment, incomplete welding, and weld burn-through caused by the difficulty in adjusting the welding torch angle in the prior art.

[0047] In this embodiment, the inner surface 211 of the branch pipe connecting plate 21 is also generally planar to facilitate the adjustment of the welding torch trajectory when welding the self-fusion weld 23 with poor weldability. The insertion end face of the stainless steel base section 221 of the branch pipe extends slightly beyond the inner surface 211 of the branch pipe connecting plate. However, this utility model does not make any indication of this. In other embodiments, the insertion end face of the stainless steel base section of the branch pipe may also be substantially flush with the inner surface of the branch pipe connecting plate.

[0048] In this embodiment, each branch pipe 22 further includes a branch pipe copper connecting section 222 disposed at the end of the branch pipe stainless steel base section 221. The stainless steel body assembly 1, the branch pipe connecting plate 21, the multiple branch pipe stainless steel base sections 221, and the multiple branch pipe copper connecting sections 222 are integrally welded together by furnace brazing. Each branch pipe stainless steel base section 221 has a branch pipe brazing layer 24 formed at both ends to connect the branch pipe connecting plate 21 and the corresponding branch pipe copper connecting section 222, respectively. The branch pipe connecting plate 21 is connected to the open end 102 of the stainless steel body assembly 1 through the connecting plate brazing layer 3'.

[0049] In this embodiment, both the branch pipe brazing layer 24 and the connecting plate brazing layer 3' are tin bronze brazing layers. However, this invention does not impose any limitations on this. In other embodiments, the branch pipe brazing layer and the connecting plate brazing layer may also be formed by welding with a brazing filler metal with a liquidus greater than or equal to 750 degrees Celsius, such as silver-phosphorus copper brazing filler metal.

[0050] In summary, in the stainless steel manifold head provided by this utility model, the branch pipe connecting plate is embedded in the open end of the stainless steel body component in a split form. During assembly, the branch pipe connecting plate can be pre-assembled with multiple branch pipes to form an independent branch pipe welding assembly. This configuration allows a self-fusion weld to be formed on the inner surface of the branch pipe connecting plate when pre-fixing the stainless steel base section of the branch pipe. Setting the self-fusion weld on the inner surface of the branch pipe connecting plate (i.e., the front end surface in the branch pipe insertion direction) directly avoids the problem of welding torch movement interference caused by the congestion of space at the bend of the branch pipe in traditional external surface pre-fixing. This design significantly expands the welding operation space, reduces the difficulty of adjusting the welding torch trajectory, thereby reducing the risk of accidents such as weld detachment, incomplete welding, and weld burn-through, and improving the process stability and pre-welding qualification rate of the pre-fixing of the stainless steel base section of the branch pipe.

[0051] Furthermore, the branch pipe welding assembly is brazed as an independent module before being embedded into the stainless steel body assembly. The independent brazing of the branch pipe welding assembly significantly reduces the assembly size when brazing long branch pipes, optimizing the space utilization within the tunnel furnace to increase the unit furnace capacity. In addition, when the stainless steel body assembly is a modular welded structure, this arrangement allows for the use of different brazing materials for the stainless steel body assembly and the branch pipe welding assembly. This provides the conditions for using oxygen-free copper brazing material with excellent fluidity and wettability, high post-weld connection strength, and corrosion resistance for the stainless steel body assembly, which has many components, thereby significantly improving the overall performance of the stainless steel manifold head.

[0052] Although the present invention has been disclosed above by way of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of protection claimed in the claims.

Claims

1. A stainless steel manifold head, characterized in that, include: The stainless steel body assembly has threaded connection ends and open ends for connecting to external pipelines; A branch pipe welding assembly includes a branch pipe connecting plate and multiple branch pipes. The branch pipe connecting plate is made of stainless steel and has multiple branch pipe holes. The stainless steel base segment of each branch pipe is inserted into the corresponding branch pipe hole, and a self-fusion weld is formed between the stainless steel base segment of the branch pipe and the inner surface of the branch pipe connecting plate near the branch pipe hole to pre-fix the stainless steel base segment of the branch pipe. The inner surface of the branch pipe connecting plate is the branch pipe connecting plate surface near the insertion front end in the insertion direction of the stainless steel base segment of the branch pipe. A branch pipe brazing layer is formed between the outer peripheral wall of each stainless steel base segment of the branch pipe and the corresponding branch pipe hole. In this component, the branch pipe connecting plate within the branch pipe welding assembly is embedded in the open end of the stainless steel body assembly, and the two are welded together by a full-circumferential self-fusion sealing weld.

2. The stainless steel manifold head according to claim 1, characterized in that, The inner surface of the branch pipe connecting plate is roughly a plane, and the insertion end face of the stainless steel base section of the branch pipe is basically flush with or extends out of the inner surface of the branch pipe connecting plate.

3. The stainless steel manifold head according to claim 1, characterized in that, The branch pipe connecting plate is partially embedded in the open end of the stainless steel body assembly, and a circumferential self-fusion sealing weld is formed between the open end of the stainless steel body assembly and the peripheral wall of the branch pipe connecting plate exposed outside the stainless steel body assembly.

4. The stainless steel manifold head according to claim 1, characterized in that, Each of the branch pipes further includes a branch pipe copper connecting section disposed at the end of the stainless steel base section of the branch pipe. After the branch pipe welding assembly is brazed in the furnace, a branch pipe brazing layer is formed at both ends of each branch pipe stainless steel base section to connect the branch pipe connecting plate and the corresponding branch pipe copper connecting section respectively. The branch pipe brazing layer is formed by welding with brazing material with a liquidus greater than or equal to 750 degrees Celsius.

5. The stainless steel manifold head according to claim 4, characterized in that, Within each branch pipe, the copper connecting section is a straight pipe section with an axis that is approximately straight, and the copper connecting section is sleeved over the end of the corresponding stainless steel base section of the branch pipe.

6. The stainless steel manifold head according to claim 1, characterized in that, The stainless steel body assembly is a combined welded structure, in which each component is welded together by an oxygen-free copper brazing layer.

7. The stainless steel manifold head according to claim 1, characterized in that, The self-fusion weld located on the inner surface of the branch pipe connecting plate and used to pre-fix the stainless steel base section of the branch pipe is either a local weld or an integral circumferential weld.

8. A stainless steel manifold head, characterized in that, include: The stainless steel body assembly has threaded connection ends and open ends for connecting to external pipelines; A branch pipe assembly includes a branch pipe connecting plate and multiple branch pipes. The branch pipe connecting plate is made of stainless steel and has multiple branch pipe holes. The stainless steel base segment of each branch pipe is inserted into the corresponding branch pipe hole. A self-fusion weld for pre-fixing the stainless steel base segment of the branch pipe is formed between the stainless steel base segment of the branch pipe and the inner surface of the branch pipe connecting plate near the branch pipe hole. The inner surface of the branch pipe connecting plate is the branch pipe connecting plate surface near the insertion front end in the insertion direction of the stainless steel base segment of the branch pipe. The branch pipe connecting plate in the branch pipe assembly is embedded in the open end of the stainless steel body assembly. The stainless steel body assembly, the branch pipe connecting plate, and multiple branch pipes are integrally welded in the furnace. A branch pipe brazing layer is formed between the outer peripheral wall of the stainless steel base section of each branch pipe and the corresponding branch pipe hole.

9. The stainless steel manifold head according to claim 8, characterized in that, Each branch pipe also includes a branch pipe copper connecting section disposed at the end of the stainless steel base section of the branch pipe. The stainless steel body assembly, the branch pipe connecting plate, the multiple stainless steel base sections of the branch pipe, and the multiple branch pipe copper connecting sections are integrally welded in a furnace. Each stainless steel base section of the branch pipe has a branch pipe brazing layer formed at both ends to connect the branch pipe connecting plate and the corresponding branch pipe copper connecting section respectively. The branch pipe brazing layer is formed by welding with brazing material with a liquidus greater than or equal to 750 degrees Celsius.

10. The stainless steel manifold head according to claim 8, characterized in that, The inner surface of the branch pipe connecting plate is roughly a plane, and the insertion end face of the stainless steel base section of the branch pipe is basically flush with or extends out of the inner surface of the branch pipe connecting plate.

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