A zinc alloy shell stainless steel inner tube faucet and its manufacturing method

Abstract

This invention relates to the field of bathroom hardware faucets, and provides a zinc alloy shell faucet with a stainless steel inner tube and its manufacturing method. The faucet includes a stainless steel inner tube assembly and a zinc alloy shell. A water flow channel is formed inside the stainless steel inner tube assembly to prevent water from contacting the zinc alloy shell. A gap exists between the zinc alloy shell and the stainless steel inner tube assembly, and this gap is filled with a cured sealing layer. By placing the water flow channel inside the stainless steel inner tube assembly, this invention ensures that the water does not contact the zinc alloy shell throughout its flow, preventing the leaching of heavy metals such as lead and cadmium, meeting drinking water safety standards, and exhibiting corrosion resistance and high-temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of bathroom hardware faucets, and more particularly to a zinc alloy shell stainless steel inner tube faucet and its manufacturing method. Background Technology

[0002] Currently, faucets on the market are mainly divided into the following categories based on their materials and structures, and all of them have the following defects: 1. Zinc alloy faucet: The main body and water passage are integrally die-cast. Zinc alloy is low in cost, easy to die-cast, and has good electroplating effect, but it contains heavy metals such as lead and cadmium, which are easily leached when water flows through it. Long-term use is harmful to human health, and the pipe wall is prone to corrosion and perforation, leading to leakage.

[0003] 2. Copper faucets: Currently the mainstream product, offering good safety and durability, but the cost of high-quality brass raw materials is high. Some companies use recycled copper, which still poses a risk of excessive levels of heavy metals such as lead.

[0004] 3. Stainless steel faucets: formed by precision casting or pipe welding, they are hygienic, safe, and corrosion-resistant. However, stainless steel is difficult to process, has limited surface treatment options, restricts styles, and has relatively high production costs.

[0005] 4. Composite inner liner faucets: To reduce costs, a solution has emerged using zinc alloy or copper outer shells lined with plastic tubes. However, plastic inner tubes have drawbacks such as poor temperature resistance, susceptibility to aging and cracking, easy bacterial growth, and short service life.

[0006] In summary, there is an urgent need for a faucet structure and manufacturing process that can simultaneously achieve "low cost, safe water flow, and long lifespan". Summary of the Invention

[0007] The present invention aims to provide a zinc alloy shell stainless steel inner tube faucet and its manufacturing method to solve the problems existing in the prior art.

[0008] The present invention provides a zinc alloy shell stainless steel inner tube faucet, comprising a stainless steel water-passing inner tube assembly and a zinc alloy shell covering the periphery of the stainless steel water-passing inner tube assembly. The stainless steel water-passing inner pipe assembly forms a water flow channel inside to prevent the water flow from contacting the zinc alloy outer shell; there is a gap between the zinc alloy outer shell and the stainless steel water-passing inner pipe assembly, and the gap is filled with a cured sealing and fixing layer.

[0009] According to the present invention, a zinc alloy shell stainless steel inner tube faucet is provided, wherein the stainless steel water-passing inner tube assembly includes a stainless steel valve core seat, the stainless steel valve core seat is provided with a valve core mounting cavity, the inner bottom of the valve core mounting cavity is recessed downward to form a mixing groove; the mixing groove is connected to the inlet channel and the outlet channel, and the ends of the inlet channel and the outlet channel are respectively sealed and welded to a stainless steel inlet pipe and a stainless steel outlet pipe. After the valve core is installed into the valve core mounting cavity and tightened, the bottom of the valve core divides the mixing groove into an inlet area and an outlet area that are respectively connected to the inlet channel and the outlet channel.

[0010] According to the present invention, a zinc alloy shell stainless steel inner tube faucet is provided with an outwardly protruding boss at the end of the water outlet channel. The inner hole of the boss is inserted and fitted with the stainless steel water outlet pipe, and a sealed connection is formed on the outer periphery of the boss by laser penetration welding.

[0011] According to the present invention, a zinc alloy shell stainless steel inner tube faucet is provided with an end sealing ring at the joint between the stainless steel inlet pipe, the stainless steel outlet pipe and the zinc alloy shell. The end sealing ring is disposed in an annular groove processed after the zinc alloy shell is formed, and forms a radial compression seal with the outer wall of the stainless steel inlet pipe and the stainless steel outlet pipe.

[0012] According to the present invention, a zinc alloy shell and a stainless steel inner tube faucet are provided, wherein the gap is a micro-gap naturally formed between the zinc alloy shell and the stainless steel water-passing inner tube assembly during die casting and cooling due to the difference in material shrinkage rate.

[0013] According to the present invention, a zinc alloy shell stainless steel inner tube faucet is provided, wherein the sealing and fixing layer is epoxy resin or elastic sealant, which is injected and cured through a pre-set injection hole on the zinc alloy shell.

[0014] According to the present invention, a zinc alloy shell stainless steel inner tube faucet is provided, wherein the stainless steel valve core seat is formed into an integral component by machining a stainless steel bar.

[0015] In addition, the present invention provides a method for manufacturing a zinc alloy shell stainless steel inner tube faucet, comprising the following steps: S1. Bend the stainless steel outlet pipe according to the preset water path, and machine the stainless steel bar into a valve core seat; insert the end of the stainless steel outlet pipe into the end of the outlet flow channel of the valve core seat and weld it to seal, and insert the stainless steel inlet pipe into the end of the inlet flow channel of the valve core seat and weld it to seal, forming an integrated stainless steel water-passing inner pipe assembly with a valve core seat. S2. Fix and position the stainless steel water-passing inner pipe assembly inside the die-casting mold cavity; S3. Inject molten zinc alloy into the die-casting mold, so that the zinc alloy encapsulates the stainless steel water pipe assembly and integrally die-casts it. Cool and open the mold to obtain the blank. S4. Inject and solidify a sealing filler into the gap between the zinc alloy outer shell and the stainless steel water pipe assembly due to the difference in shrinkage rate to form a sealing and fixing layer. S5. Perform post-processing on the blank, install the valve core into the valve core mounting cavity and tighten it, then assemble the remaining accessories to obtain the finished product.

[0016] According to the manufacturing method of a zinc alloy shell stainless steel inner tube faucet provided by the present invention, in step S1, the welding is laser penetration welding, and after the welding is completed and before step S2, the stainless steel water-passing inner tube assembly is subjected to a sealing test.

[0017] According to a method for manufacturing a zinc alloy shell stainless steel inner tube faucet provided by the present invention, in step S4, the sealing filler is injected through a pre-set injection hole on the zinc alloy shell.

[0018] Compared with the prior art, the beneficial effects of this application are as follows: 1. The water flow channel is located inside the stainless steel water pipe assembly. The water does not come into contact with the zinc alloy shell throughout the entire flow process, so there is no leaching of heavy metals such as lead and cadmium. It meets drinking water safety standards and is corrosion-resistant and high-temperature resistant.

[0019] 2. The outer shell fully utilizes the advantages of zinc alloy die casting, which offers versatility in mold design and excellent electroplating mirror finish. Furthermore, the mold has a long lifespan and the material cost is far lower than that of all-copper and all-stainless steel faucets.

[0020] 3. The stainless steel inner tube assembly is pressure-resistant and corrosion-resistant, eliminating the aging and cracking problems of the plastic inner tube; the gap is naturally formed by the material shrinkage difference and then filled with glue, and the resulting sealing and fixing layer can effectively absorb water hammer vibration and external impact, preventing the inner tube from loosening.

[0021] 4. The stainless steel inner tube assembly can be independently tested for sealing before die casting, controlling quality problems in the early stages and reducing the scrap rate of finished products.

[0022] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the external structure of a zinc alloy shell stainless steel inner tube faucet provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the external structure of a zinc alloy shell stainless steel inner tube faucet provided in an embodiment of the present invention after removing the zinc alloy shell; Figure 3 This is a schematic diagram of the internal structure of the valve core seat provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the internal structure of a zinc alloy shell stainless steel inner tube faucet provided in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures: 1. Stainless steel outlet pipe; 2. Valve core seat; 21. Valve core mounting cavity; 22. Annular sealing step surface; 23. Mixing groove; 231. Cold water inlet area; 232. Hot water inlet area; 233. Mixed water outlet area; 24. Inlet channel; 25. Outlet channel; 26. Boss; 261. Limiting step; 3. Annular groove; 4. End sealing ring; 5. Zinc alloy shell; 51. Annular pressing edge; 6. Stainless steel inlet pipe. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] Example This invention provides a zinc alloy shell and stainless steel inner tube faucet; its structure is described in the following embodiment. Figures 1-4 The specific manufacturing method is as follows: Step S1: Processing of stainless steel water pipe assembly Take SUS304 food-grade stainless steel pipe and bend it into an inverted L-shaped stainless steel outlet pipe 1 using a CNC pipe bending machine; take another SUS304 stainless steel bar and process it into an integral cylindrical valve core seat 2 through turning, drilling, and milling. The valve core seat 2 has a valve core mounting cavity 21 with an open top surface to accommodate and install a standard ceramic valve core. The inner bottom surface of the valve core mounting cavity 21 adopts a stepped structure: the outer periphery is a precision-machined annular sealing stepped surface 22, and the middle part is a downwardly recessed mixing groove 23 surrounded by the annular sealing stepped surface 22; the bottom surface of the valve core seat 2 has two parallel water inlet channels 24, both of which are stepped holes. The lower end of the hole has a larger diameter for inserting and welding the stainless steel water inlet pipe 6, and the upper ends are respectively connected to the bottom surface of the mixing groove 23 to form a cold water inlet channel and a hot water inlet channel.

[0028] The side wall of the valve core seat 2 is provided with a cylindrical boss 26 that extends horizontally outward, and its axis is perpendicular to the axis of the valve core mounting cavity 21; the two ends of the water outlet channel 25 are respectively connected to the bottom surface of the mixing groove 23 and the inner hole of the boss 26; a limiting step 261 is provided at the end of the inner hole of the boss 26 to limit the insertion depth of the stainless steel water outlet pipe 1; and the edges of the step hole and the inner hole of the boss 26 are provided with welding bevels.

[0029] The horizontal end of the pre-bent stainless steel outlet pipe 1 is inserted into the inner hole of the boss 26 until it abuts against the limiting step 261, forming a precise hole-shaft fit. Then, laser penetration welding is performed from the outer circumference of the boss 26 opening to fuse the two together, forming a continuous, pore-free sealing weld. After welding, two stainless steel inlet pipes 6 are respectively inserted into the lower ends of the two inlet channels 24 at the bottom of the valve core seat 2, and then laser penetration welding is performed in the same manner to seal the connection, resulting in an integrated stainless steel water-passing inner pipe assembly.

[0030] Then, a pressure sealing test was performed on the stainless steel water inlet pipe assembly to confirm that there was no leakage.

[0031] Step S2, Pre-embedded positioning High-temperature resistant silicone rings are temporarily fitted onto the outer walls of the ends where the stainless steel outlet pipe 1 and the stainless steel inlet pipe 6 meet the zinc alloy outer shell 5, serving as temporary sealing components. These temporary sealing components can be removed or destroyed after die casting. A layer of heat-resistant fiber paper is wrapped around the outer and bottom walls of the valve core seat 2, the outer wall of the stainless steel inlet pipe 6, and the outer wall of the stainless steel outlet pipe 1, among other parts requiring protection, as a protective layer. The top surface and outer edge area of ​​the valve core seat 2, the temporary sealing components, and the pipe openings of the stainless steel outlet pipe 1 and the stainless steel inlet pipe 6 are also protected. The stainless steel welded joint area is not wrapped; then the entire stainless steel water-passing inner pipe assembly is placed into the die-casting mold, and the positioning pin on the die-casting mold is used to cooperate with the process hole reserved on the stainless steel water-passing inner pipe assembly to achieve precise positioning; the top opening of the valve core mounting cavity 21 is sealed by the mold core extending into it, and an annular gap is left between the outer contour of the core and the outer edge of the top surface of the valve core seat 2 for subsequent filling with zinc alloy; the pipe openings of the stainless steel inlet pipe 6 and the stainless steel outlet pipe 1 are also tightly sealed by the mold core to prevent zinc alloy liquid from entering the water circuit.

[0032] Step S3, Integrated die casting After mold closing, molten zinc alloy is rapidly filled into the cavity, and after pressure holding and cooling, the mold is opened to eject the faucet blank. At this time, the zinc alloy shell 5 has tightly wrapped the stainless steel water pipe assembly and formed a ring-shaped pressure edge 51 on the outer edge of the top surface of the valve core seat 2. The ring-shaped pressure edge 51 extends radially inward, covering the outer edge area of ​​the top surface of the valve core seat 2, so that the zinc alloy shell 5 and the valve core seat 2 form a double limit in the axial and radial direction at the top, effectively preventing the valve core seat 2 from loosening or sinking during subsequent processing and long-term use. During the cooling process, because the shrinkage rate of zinc alloy is greater than that of stainless steel, a micro gap is naturally formed between the two. Moreover, the heat-resistant fiber paper will be compressed or burned during the die casting process, which helps to form the micro gap. During the die casting process, the high-temperature resistant silicone rings set above can be used to temporarily seal the ends of the stainless steel water outlet pipe 1, stainless steel water inlet pipe 6 and zinc alloy shell 5 to block the molten zinc alloy.

[0033] After the die-casting cools and the mold is opened, the temporary sealing parts are removed or cleaned. An annular groove 3 is machined at the port of the zinc alloy shell 5 by machining (such as milling or drilling). Then, a standard elastic sealing ring (such as EPDM or silicone O-ring) is installed in the annular groove 3 as an end sealing ring 4. The end sealing ring 4 forms a radial compression seal with the outer wall of the stainless steel water outlet pipe 1 and the stainless steel water inlet pipe 6.

[0034] Step S4, Adhesive application and curing Two-component polyurethane sealant is injected into the pre-set injection holes on the bottom and back of the zinc alloy casing 5 using a vacuum injection machine.

[0035] Under vacuum assistance, the sealant rapidly penetrates until it fills the micro-gaps and extends to the interface between the annular pressure edge 51 and the outer edge of the top surface of the valve core seat 2. The blank is then heated and cured, causing the sealant to form a dense and elastic sealing layer, firmly bonding the stainless steel water-passing inner pipe assembly to the zinc alloy outer shell 5, while simultaneously sealing the injection hole. The end sealing ring 4 forms the first line of waterproof sealing, while the sealing layer forms the second line of sealing between the internal gaps and the interface between the top surface of the valve core seat 2. These two lines complement each other, forming a complete double-sealing protection structure.

[0036] It should be noted that before installing the end sealing ring 4, a layer of neutral silicone sealant can be applied to the inner wall of the annular groove 3 as an auxiliary seal.

[0037] Step S5, Post-processing and Final Assembly After removing and smoothing the caulking material from the injection hole, and mechanically polishing it, copper, nickel, and chromium plating are applied sequentially to obtain a mirror-like bright surface. Then, a standard ceramic valve core is installed in the valve core mounting cavity 21 and tightened with the valve core cap, so that the sealing gasket at the bottom of the valve core is tightly pressed against the annular sealing step surface 22. At the same time, the sealing gasket divides the mixing groove 23 into three non-interconnected areas: a cold water inlet area 231, a hot water inlet area 232, and a mixed water outlet area 233. One stainless steel inlet pipe 6 is connected to the cold water inlet of the valve core through the cold water inlet area 231, and the other stainless steel inlet pipe 6 is connected to the hot water inlet of the valve core through the hot water inlet area 232. The stainless steel outlet pipe 1 is connected to the mixed water outlet of the valve core through the mixed water outlet area 233. In this way, the water flow from the stainless steel inlet pipe 6 is forced into the valve core, and after being regulated by the valve core, it can flow out through the stainless steel outlet pipe 1. Finally, an aerator is installed at the inlet of the stainless steel outlet pipe 1, and a stainless steel braided inlet hose is connected to the inlet of the stainless steel inlet pipe 6, thus completing the manufacturing process.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A zinc alloy outer shell and stainless steel inner tube faucet characterized in that, It includes a stainless steel water-passing inner pipe assembly and a zinc alloy outer shell covering the periphery of the stainless steel water-passing inner pipe assembly (5). The stainless steel water-passing inner pipe assembly forms a water flow channel inside so that the water flow does not come into contact with the zinc alloy outer shell (5); there is a gap between the zinc alloy outer shell (5) and the stainless steel water-passing inner pipe assembly, and the gap is filled with a cured sealing and fixing layer.

2. A zinc alloy outer shell and stainless steel inner tube faucet according to claim 1, wherein, The stainless steel water-passing inner pipe assembly includes a stainless steel valve core seat (2), and the stainless steel valve core seat (2) is provided with a valve core mounting cavity (21). The inner bottom of the valve core mounting cavity (21) is recessed downward to form a mixing groove (23). The mixing groove (23) is connected to the inlet channel (24) and the outlet channel (25), and the ends of the inlet channel (24) and the outlet channel (25) are respectively sealed and welded to the stainless steel inlet pipe (6) and the stainless steel outlet pipe (1). When the valve core is installed into the valve core mounting cavity (21) and tightened, the bottom of the valve core divides the mixing groove (23) into an inlet area and an outlet area that are respectively connected to the inlet channel (24) and the outlet channel (25).

3. A zinc alloy outer shell and stainless steel inner tube faucet as described in claim 2, wherein, The end of the water outlet channel (25) is provided with an outwardly protruding boss (26). The inner hole of the boss (26) is inserted into the stainless steel water outlet pipe (1), and a sealed connection is formed on the outer periphery of the boss (26) by laser penetration welding.

4. A zinc alloy shell stainless steel inner tube faucet according to claim 2, characterized in that, An end sealing ring (4) is provided at the end of the stainless steel water inlet pipe (6), the stainless steel water outlet pipe (1) and the zinc alloy shell (5). The end sealing ring (4) is located in the annular groove (3) processed after the zinc alloy shell (5) is formed, and forms a radial compression seal with the outer wall of the stainless steel water inlet pipe (6) and the stainless steel water outlet pipe (1).

5. A zinc alloy shell stainless steel inner tube faucet according to claim 1, characterized in that, The gap is a micro-gap that is naturally formed between the zinc alloy outer shell (5) and the stainless steel water-passing inner pipe assembly during die casting and cooling due to the difference in material shrinkage rate.

6. A zinc alloy outer shell and stainless steel inner tube faucet according to claim 5, wherein, The sealing and fixing layer is epoxy resin or elastic sealant, which is injected and cured through the injection hole pre-set on the zinc alloy shell (5).

7. A zinc alloy shell stainless steel inner tube faucet according to claim 2, characterized in that, The stainless steel valve core seat (2) is an integral component formed by machining stainless steel bars.

8. A method for manufacturing a zinc alloy shell stainless steel inner tube faucet as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Bend the stainless steel outlet pipe (1) according to the preset water path, and machine the stainless steel bar to make the valve core seat (2); insert the end of the stainless steel outlet pipe (1) into the end of the outlet flow channel (25) of the valve core seat (2) and weld it to seal it, and insert the stainless steel inlet pipe (6) into the end of the inlet flow channel (24) of the valve core seat (2) and weld it to seal it, forming an integrated stainless steel water-passing inner pipe assembly with valve core seat (2); S2. Fix and position the stainless steel water-passing inner pipe assembly inside the die-casting mold cavity; S3. Inject molten zinc alloy into the die-casting mold, so that the zinc alloy encapsulates the stainless steel water pipe assembly and integrally die-casts it. Cool and open the mold to obtain the blank. S4. Inject and solidify a sealing filler into the gap between the zinc alloy outer shell (5) and the stainless steel water pipe assembly due to the difference in shrinkage rate to form a sealing and fixing layer. S5. Perform post-processing on the blank, install the valve core into the valve core mounting cavity (21) and tighten it, then assemble the remaining accessories to obtain the finished product.

9. A method for manufacturing a zinc alloy shell stainless steel inner tube faucet according to claim 8, characterized in that, In step S1, the welding is laser penetration welding, and after the welding is completed and before step S2, the stainless steel water-passing inner pipe assembly is subjected to a sealing test.

10. A method for manufacturing a zinc alloy shell stainless steel inner tube faucet according to claim 8, characterized in that, In step S4, the sealing filler is injected through the injection hole pre-set on the zinc alloy shell (5).

Images