Surface anti-corrosion coating structure of PPR pipe thread insert

Abstract

The utility model provides a surface corrosion-resistant anticorrosive coating structure of a PPR (polypropylene random) pipe thread insert, which solves the problems of insufficient structural strength of a corrosion-resistant layer of a thread insert and the like, and comprises a Cr base coat, a CrN transition layer and a CrxW1-xN surface layer which are deposited on the surface of the thread insert, the thickness of the Cr base coat is 0.2-0.3 mu m, the thickness of the CrN transition layer is 0.3-0.4 mu m, and the thickness of the CrxW1-xN surface layer is 1.2-1.5 mu m. The utility model has the advantages of good structural stability, strong corrosion resistance and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of threaded inserts, and particularly relates to a surface corrosion-resistant and anti-corrosion coating structure for PPR pipe threaded inserts. Background Technique

[0002] Physical vapor deposition technology is a method for forming a protective layer on the surface of materials, mainly used to improve the wear resistance, corrosion resistance and decoration of materials. In recent years, with the development of technology, the application of PVD technology in anti-corrosion has become more and more extensive, bringing significant economic and social benefits to various industrial fields. PVD technology plays a crucial role in improving the corrosion resistance of materials. Through precise physical processes, PVD technology can form a dense and continuous protective film on the surface of materials. This protective film acts as a barrier, effectively isolating oxygen, moisture and other chemical substances that may cause corrosion in the external environment, thus significantly delaying or preventing the occurrence of the corrosion process and enabling the equipment to work normally and stably in various extreme environments. In the actual use process, the existing threaded inserts lack corresponding corrosion-resistant treatment means, and the conventional corrosion-resistant layer has problems such as excessive thickness and insufficient strength, which affect the normal assembly of the threaded parts.

[0003] In order to solve the deficiencies of the existing technology, people have carried out long-term explorations and proposed various solutions. For example, a Chinese patent document discloses a high-precision anti-corrosion quick-opening bolt [202221824681.X], which includes a bolt rod and an insertion rod. A jack is opened above the bolt rod, the outer diameter of the insertion rod is equal to the inner diameter of the jack, the insertion rod is inserted into the jack and extends into the interior of the bolt rod, and fixing rods are movably nested on both sides of the insertion rod near one end of the jack. Fixing holes are symmetrically opened on both sides of the bolt rod, an elastic limiting component is arranged between the fixing rod and the insertion rod, and the fixing rod is inserted into the fixing hole from the interior of the bolt rod.

[0004] The above solution solves the problem of corrosion-resistant treatment of threaded inserts to a certain extent, but this solution still has many deficiencies, such as the problem of insufficient strength of the corrosion-resistant layer structure. Summary of the Invention

[0005] The purpose of the utility model is to provide a surface corrosion-resistant and anti-corrosion coating structure for PPR pipe threaded inserts with high structural strength and good corrosion resistance in view of the above problems.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme: a surface corrosion-resistant and anti-corrosion coating structure for PPR pipe threaded inserts, including a Cr bottom layer, a CrN transition layer, and a Cr x W 1-x N surface layer deposited on the surface of the threaded insert. The thickness of the Cr bottom layer is 0.2 - 0.3 μm, the thickness of the CrN transition layer is 0.3 - 0.4 μm, and the Crx W 1-x The thickness of the N surface layer is 1.2 - 1.5 μm.

[0007] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, the thread insert includes a main screw sleeve, and Cr underlayers, CrN transition layers, and Cr are respectively deposited on the inner and outer thread surfaces of the main screw sleeve x W 1-x N surface layer.

[0008] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, a limiting component is arranged at the upper end of the main screw sleeve, a strengthening component is arranged at the lower end of the main screw sleeve, and an expansion component is arranged between the inner and outer threads of the main screw sleeve.

[0009] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, the limiting component includes a limiting piece connected to the upper end of the main screw sleeve and integrally formed with the main screw sleeve, and limiting ribs arranged in a spiral shape and centrosymmetrically are distributed at the lower end of the limiting piece.

[0010] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, anti-slip stripes are distributed at the upper end of the limiting piece, and Cr underlayers, CrN transition layers, and Cr are respectively deposited on the upper and lower surfaces of the limiting piece x W 1-x N surface layer.

[0011] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, the strengthening component includes a strengthening base that closes the bottom of the main screw sleeve, and the lower end of the strengthening base is conical and spiral cutting strips are distributed on the surface.

[0012] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, a locking adhesive layer opposite to the inner side of the main screw sleeve is covered on the upper end of the strengthening base.

[0013] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, the expansion component includes expansion grooves distributed along the circumferential direction of the main screw sleeve, and the expansion grooves are located between the inner and outer threads.

[0014] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, expansion sheets are slidably installed in the expansion grooves, and a guiding surface is arranged at one end of the expansion sheets opposite to the inside of the main screw sleeve.

[0015] In the surface corrosion-resistant and anti-corrosive coating structure of the above-mentioned PPR pipe thread insert, the thread insert is made of stainless steel, copper alloy or aluminum alloy.

[0016] Compared with the existing technology, the advantages of the present utility model are as follows: The surface of the thread insert is covered with Cr underlayers, CrN transition layers, and Cr by a deposition methodx W 1-x The N surface layer has good corrosion resistance and compactness to ensure the overall structural strength of the corrosion-resistant layer. The threaded insert is equipped with a limiting component and an expansion component to ensure the structural stability after assembly and ensure the tightness of the subsequent threaded connection. The locking adhesive layer is arranged in the main screw sleeve. The connection between the threaded part and the main screw sleeve can ensure that the colloid fills the gap between them, further improving the locking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the present utility model;

[0018] Figure 2 is a structural cross-sectional view of Embodiment 1 of the present utility model;

[0019] Figure 3 is a structural cross-sectional view of Embodiment 2 of the present utility model;

[0020] Figure 4 is a partial cross-sectional view of Embodiment 2 of the present utility model;

[0021] In the figure, threaded insert 1, main screw sleeve 11, internal thread 12, external thread 13, Cr underlayer 2, CrN transition layer 3, Cr x W 1- x N surface layer 4, limiting component 5, limiting piece 51, limiting rib 52, anti-slip stripe 53, strengthening component 6, strengthening base 61, cutting strip 62, locking adhesive layer 63, expansion component 7, expansion groove 71, expansion piece 72, guiding surface 73. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present utility model will be further described in detail below with reference to the drawings and specific embodiments.

[0023] Embodiment 1

[0024] As Figure 1-2 shown, a surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe threaded insert includes a Cr underlayer 2, a CrN transition layer 3, and a Cr x W 1-x N surface layer 4 deposited on the surface of the threaded insert 1. The thickness of the Cr underlayer 2 is 0.2 - 0.3 μm, the thickness of the CrN transition layer 3 is 0.3 - 0.4 μm, and the thickness of the Cr x W 1-x N surface layer 4 is 1.2 - 1.5 μm. Among them, the thickness of the Cr underlayer 2 is preferably 0.2 μm, the thickness of the CrN transition layer 3 is preferably 0.3 μm, and the Cr x W 1-xThe thickness of the N surface layer 4 is preferably 1.5 μm. The corrosion-resistant layer on the surface of the threaded insert 1 takes into account both structural strength and corrosion resistance, and is combined with the base material by physical means, usually without using chemical substances that may affect adhesion. This physical combination is generally stronger than the chemical combination during electroplating, making the PVD coating more stable in the face of chemical erosion.

[0025] Specifically, the threaded insert 1 includes a main screw sleeve 11 in a cylindrical shape. The inner thread 12 and the outer thread 13 of the main screw sleeve 11 are respectively deposited with a Cr underlayer 2, a CrN transition layer 3, and a Cr x W 1-x N surface layer 4. The outer surface of the threaded insert 1 and the internal and external threads are treated for corrosion prevention by deposition, reducing potential corrosion points and ensuring consistent performance across the entire coating surface.

[0026] Embodiment 2

[0027] As Figure 3-4 shown, the structure, principle, and specific implementation steps of this embodiment are similar to those of Embodiment 1, and the difference lies in that a limiting component 5 is provided at the upper end of the main screw sleeve 11, a strengthening component 6 is provided at the lower end of the main screw sleeve 11, and an expansion component 7 is provided between the inner thread 12 and the outer thread 13 of the main screw sleeve 11. The limiting component 5 and the expansion component 7 cooperate to achieve circumferential and axial limiting of the main screw sleeve 11, and the strengthening component 6 ensures its connection stability during the assembly of the main screw sleeve 11.

[0028] Furthermore, the limiting component 5 realizes the upper-end limiting of the main screw sleeve 11, including a limiting piece 51 connected to the upper end of the main screw sleeve 11 and integrally formed with the main screw sleeve 11. The lower end of the limiting piece 51 is distributed with limiting ribs 52 in a spiral shape and arranged in central symmetry. When the main screw sleeve 11 is completely installed in place, its limiting ribs 52 are pressed into the outer surface to achieve circumferential limiting.

[0029] Even further, the upper end of the limiting piece 51 is distributed with anti-slip stripes 53, and the upper and lower surfaces of the limiting piece 51 are respectively deposited with a Cr underlayer 2, a CrN transition layer 3, and a Cr x W 1-x N surface layer 4. The limiting piece 51 is integrally formed with the main screw sleeve 11 and undergoes anti-corrosion treatment simultaneously.

[0030] In addition, the bottom of a conventional screw sleeve usually adopts a through structure, while the bottom of the main screw sleeve 11 in this embodiment is closed. The strengthening component 6 includes a strengthening base 61 that closes the bottom of the main screw sleeve 11. The lower end of the strengthening base 61 is conical and its surface is distributed with spiral cutting strips 62. The cutting strips 62 apply a cutting torque during the rotational installation of the main screw sleeve 11 to ensure its installation lubricity.

[0031] Meanwhile, the upper end of the reinforcing base 61 is covered with a locking adhesive layer 63 opposite to the inner side of the main screw sleeve 11. The locking adhesive layer 63 uses anaerobic adhesive, which hardens when exposed to metal ions of the main screw sleeve 11 under airless conditions, thus completely filling the gap inside the main screw sleeve 11.

[0032] Visibly, in order to further improve the axial limiting effect, the expansion assembly 7 includes expansion grooves 71 circumferentially distributed along the main screw sleeve 11. The expansion grooves 71 are located between the internal thread 12 and the external thread 13. When the threaded part is screwed into the main screw sleeve 11, part of the locking adhesive is squeezed into the expansion grooves 71.

[0033] Obviously, expansion pieces 72 are slidably installed in the expansion grooves 71, and a guiding surface 73 is provided at one end of the expansion piece 72 opposite to the inside of the main screw sleeve 11. The expansion pieces 72 are pushed by the threaded part to slide radially, thereby applying a squeezing moment to the reserved assembly hole.

[0034] Preferably, the threaded insert 1 is made of stainless steel, copper alloy or aluminum alloy, and the appropriate material and specification are selected according to actual needs.

[0035] In summary, the principle of this embodiment is that a Cr underlayer 2, a CrN transition layer 3, and a Cr x W 1-x N surface layer 4 are sequentially deposited on the outer surface of the threaded insert 1. At the same time, the thickness of each layer is respectively limited, and finally a highly uniform and dense film layer is formed to ensure the overall corrosion resistance and structural strength of the threaded insert 1.

[0036] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0037] Although terms such as threaded insert 1, main screw sleeve 11, internal thread 12, external thread 13, Cr underlayer 2, CrN transition layer 3, Cr x W 1-x N surface layer 4, limiting assembly 5, limiting piece 51, limiting rib 52, anti-slip stripe 53, reinforcing assembly 6, reinforcing base 61, cutting strip 62, locking adhesive layer 63, expansion assembly 7, expansion groove 71, expansion piece 72, guiding surface 73, etc. are used more in this article, the possibility of using other terms is not excluded. Using these terms is only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. Surface corrosion-resistant and anti-corrosion coating structure for PPR pipe thread insert, including a Cr underlayer (2), a CrN transition layer (3), and a Cr x W 1-x N surface layer (4) deposited on the surface of the thread insert (1), characterized in that The thickness of the described Cr underlayer (2) is 0.2 - 0.3 μm, the thickness of the described CrN transition layer (3) is 0.3 - 0.4 μm, and the thickness of the described Cr x W 1-x N surface layer (4) is 1.2 - 1.5 μm.

2. The surface corrosion-resistant and anti-corrosive coating structure of a PPR pipe thread insert according to claim 1, characterized in that, The described threaded insert (1) includes a main screw sleeve (11), and a Cr underlayer (2), a CrN transition layer (3), and a Cr x W 1-x N surface layer (4) are respectively deposited on the inner thread (12) and the outer thread (13) surfaces of the main screw sleeve (11).

3. The surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe thread insert according to claim 2, characterized in that, A limiting component (5) is provided at the upper end of the main screw sleeve (11), a strengthening component (6) is provided at the lower end of the main screw sleeve (11), and an expansion component (7) is provided between the internal thread (12) and the external thread (13) of the main screw sleeve (11).

4. The surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe thread insert according to claim 3, characterized in that, The limiting component (5) includes a limiting piece (51) connected to the upper end of the main screw sleeve (11) and integrally formed with the main screw sleeve (11), and limiting ribs (52) distributed in a spiral and centrally symmetric arrangement are provided at the lower end of the limiting piece (51).

5. The surface corrosion-resistant and anti-corrosive coating structure of a PPR pipe thread insert according to claim 4, characterized in that, The upper end of the limiting piece (51) is distributed with anti-slip stripes (53), and a Cr underlayer (2), a CrN transition layer (3), and a Cr x W 1-x N surface layer (4) are respectively deposited on the upper and lower surfaces of the limiting piece (51).

6. The surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe thread insert according to claim 3, characterized in that, The strengthening component (6) includes a strengthening base (61) that closes the bottom of the main screw sleeve (11), and the lower end of the strengthening base (61) is conical and spiral cutting strips (62) are distributed on the surface.

7. The surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe thread insert according to claim 6, characterized in that, A locking adhesive layer (63) opposite to the inner side of the main screw sleeve (11) is covered on the upper end of the strengthening base (61).

8. The surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe thread insert according to claim 7, characterized in that, The expansion component (7) includes expansion grooves (71) distributed along the circumferential direction of the main screw sleeve (11), and the expansion grooves (71) are located between the internal thread (12) and the external thread (13).

9. The surface corrosion-resistant and anti-corrosive coating structure of a PPR pipe thread insert according to claim 8, characterized in that, An expansion piece (72) is slidably installed in the expansion groove (71), and a guiding surface (73) is provided at one end of the expansion piece (72) opposite to the inside of the main screw sleeve (11).

10. The surface corrosion-resistant and anti-corrosion coating structure of a PPR pipe thread insert according to claim 1, characterized in that, The threaded insert (1) is made of stainless steel, copper alloy or aluminum alloy.

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